4) Maintenance process and technical quality standards Before all the maintenance work, the power should be cut off to make good security work as per relevant safety regulations. a. Maintenance of parts inside the bin Rinse the inclined plate assembly with water of some pressure. Hang out half of the inclined plate assembly of bin, set up a straight ladder for direct access into the bin, rinse out the ash deposits at bottom of bin, maintain the harrow rotation device and replace worn harrow teeth. Hang out the other half of the inclined plate assembly of bin, set it on the flat floor, then maintain the inclined plate assembly and replace the damaged plate. b. Maintenance of driver and harrow lifting device Remove the dynamic and control power cord, with attention to the wire markings for easy connection. Fix the pad on the end of ash scraping harrow shaft at the bottom of bin with channel steel, and then remove the connecting bolts, step the harrow shaft out of the drive shaft. During assembly, follow the reverse sequence to disassembly, with reference to the Drawing BXKDOT.GNJTB3.0B-WT and mount each part in place. Note that all the lubricating parts should be painted with molybdenum disulfide grease and make sure the concentricity between the output shaft of reducer and worm shaft is within 0.2mm. 5) Commissioning and trial operation after Maintenance a. Check that there is no debris in the bin. b. Check that all the connection bolts are in good fastening without loose. c. Check that the electrical control device is correct. d. Check that all the lubricated parts have been filled with lubricating oil as required. e. Check that valves are good and ready to work. f. Start the harrow lifting motor, observe that the harrow lifting reducer’s lifting and lowering action are normal and control is accurate and reliable. g. Start the harrow rotation motor, and observe that the rotation reducer and gear worm reducer are running in correct direction and operating normally. Trail run with no load should not be less than 4 hours, with the bearing temperature less than 85ć and no-load noise ≤ 85db.
63
maintenance. 10) The slurry discharge port should not be blocked but should be guaranteed of continuous discharge. 11) In case of power failure that results in shutdown, it is required to timely recover the operation of concentrator. As it starts, if there is any overload protection action, it indicates that the ash and slag deposits in pool are excessive and need to be cleaned up in order to reduce the startup load; it should not be forced to start to prevent damage to the parts. 3.1.3 Maintenance 1) Maintenance period: minor maintenance period is 1 year. Overhaul period is 3 years. 2) Minor maintenance items a. Clean and check the inclined concentration plate assembly, and replace the worn PVC inclined plate. b. Check the bin bottom ash scrapping harrow rotation part and check the bottom nozzle for blockage, and remove the blockage if any. c. Check the drive and harrow lifting motor reducer as per the requirements in the “Operation & Maintenance Instructions” of Jiangsu Taixing Reducer Factory. d. Check the torque sensor instrumentation, if any abnormality, contact the manufacturer Beijing Sanjing Creation Science & Technology Group Co., Ltd. e. Check and clean up the main shaft bearing, and replace damaged bearings. f. Check the gear worm reducer housing and main shaft oil seal to eliminate leakage of oil and change lubricating oil. g. Check and fasten all the bolts on each part. 3) Safety measures provided before maintenance Prevent falling objects at height Slide and fall to get injury on work site Personal injury Scald Lifting heavy to enter the bumps Non-staff bruise in access Chain block Wire rope
The cover of lifting eye for hanging accessories must immediately reset after the use Wear non-slip shoes, and promptly clean up any oil stain on floor Properly use safety protective equipment Make good isolation measures for the equipment that had fire work. Tie up firmly, and lift up smoothly, with angular pad rubber board on the place where wire rope is hung, and prohibit using # 8 wire rope to lift up accessories Set up barrier outside of the workplace Check before use, and make sure the conformity certificate is complete and effective. Check before use, and make sure no broken strand.
High-rise operation
Make sure the conformity certificate is complete, power cord is not damaged and insulation is qualified Connect the leakage protection, and test it before use. Wear protective equipment to prevent burns and electric shock; Wear protective equipment, assign special person for safeguard as working at high rise to prevent burns, fire or explosion; Check wire rope for broken strand, whether the limit switches are complete and reliable, and the operation handle is accurate; Check seat belt before, tie it and hang tightly;
Safety regulations
Operators should comply with the work safety regulations.
Power cord, electric tools Electric welding Gas cutting Electric hoist
62
treatment and discharge of slurry or pauses operation for too long time or the content of ash and slag in incoming slurry increases suddenly which results in pressure on the ash scrapping harrow, system resistance over limit or dynamic overload, when the torque instrument makes a signal, the harrow lifting motor will start working, gear transmits to drive the screw to rise, so that the complete harrow rotation assembly will automatically lift for the purpose of unloading and reduction of load. This device is arranged on the bin roof platform, with very easy installation, repair, and maintenance. The drive harrow rotation device should run continuously, and automatic harrow lifting device runs intermittently. f. The inclined concentration plate assembly is assembled with polymer plastic panels and steel frames that have good corrosion resistance, high strength, smooth surface and long life on site according to the sample part, evenly placed in the middle part, acting as the main component for accelerating the ash slurry settling and improving the efficiency of concentration. h. The flow stabilizer is set in the center of bin and welded on the roof platform, mainly playing the function to change the direction of ash slurry water flow, stabilize the divergent flow, and enhance the effect of settling, and also support the inclined concentration plate assembly. i. The roof lifting device is set on the bin platform, composed of lifting brackets, beams, rails, electric hoist, etc. mainly for lifting of such parts as reducer for maintenance. 3.1.2 Operating maintenance and precautions 1) Reducer oil change: the oil should be replaced after running for 150 hours for the first time, the oil change should be done as the reducer is warm and cleaned, thereafter, the oil can be changed once every 3 ~ 6 months; the oil change interval may be shortened appropriately in case of much higher ambient temperature or humidity. The reducer should be stopped if the oil temperature is found significantly increased, temperature rise exceeded 60ć or oil temperature exceeded 85ć, as well as unusual noise or abnormality is found, and can only be used once again with oil changed after fault is removed. 2) The central drive harrow rotation device should have a trial run after mechanical inspection, and it can only be put into operated with load after it is normal in operation with no load. 3) It is prohibited to allow large hard materials or other rods, blocks and other debris entering the bin to block slurry discharge, jamming harrow rotation and affecting normal working of the central drive harrow rotation device, or even damage the parts. 4) The floating beads or slag on the water surface in the concentrator bin should be promptly removed to the quality of overflow water and to reduce the load on the inclined plate rack after the concentrator draining water. 5) Because of different viscosity of ash, the inclined plate surface should be rinsed regularly if any sticky ash, so as not to affect the overflow water quality and increase the load on the inclined plate and bracket. 6) Do not let the inclined plate exposed under shine for long, nor let step on it to avoid damage. The concentrator should be filled with water for long outage. 7) It is prohibited to load any person or material on the inclined plate rack. 8) In case rain or snow, the central drive unit motor should be protected with snow or rain shield on the upper part by user. 9) Concentrator should be provided with specially-assigned perform for operation, routine inspection and 61
Chapter 3 Routine Maintenance of Slag Handling System 3.1 High-efficiency concentrator Structural diagram of high-efficiency concentrator
3.1.1 YD.GNJ15TB.0 High-efficiency concentrator is mainly composed of steel support, ladder, roof platform, bin body, drive unit, ash scrapping harrow rotation device, inclined concentration plate assembly, flow stabilizer, bin roof lifting device, etc. parts, with the following structural and performance characteristics: a. Steel support is made of section steel that is welded into columns and bracing parts, etc. in manufactory and welded into the integral unit on site, acting as the support of the concentrator. b. Ladders and roof platform are welded by section steel, paved with tread plate or steel grating, according to user’s different requirements, acting as the access and maintenance platform. c. The bin body consists of upper cylindrical segment and lower cone segment. The cylindrical segment is welded on site into an integral unit by cylindrical wall board and pilaster that acts as both wall board and support, its upper part has a serrated overflow weir, for convenience in outflow of the gathered clarified water. It is welded with a prop ring plate on the middle part on which the inclined concentration plate assembly is placed and which also supports the inclined concentration plate assembly together with the flow stabilizer. The cone segment consists of two cone and several pieces of high dimensional accuracy, accurate forming cone plates that are cut by CNC flame cutter and welded into an integral unit on site. There are 3 flooding nozzles at the upconing at the slurry discharge port of lower cone row, which run intermittently, generally work once a day, and 10 minutes each time to prevent blockage of the slurry discharge port. d. Drive and automatic lifting device. The high-efficiency concentrator made by Qingdao Daneng Company uses universal motor directly connected to the cycloid reducer, torque meter connected to the worm gear to drive the harrow assembly to revolute to scrap mud. When the concentrator runs unsmooth in 60
draining water. 5) Because of different viscosity of ash, the inclined plate surface should be rinsed regularly if any sticky ash, so as not to affect the overflow water quality and increase the load on the inclined plate and bracket. 6) Do not let the inclined plate exposed under shine for long, nor let step on it to avoid damage. The concentrator should be filled with water for long outage. 7) It is prohibited to load any person or material on the inclined plate rack. 8) In case rain or snow, the central drive unit motor should be protected with snow or rain shield on the upper part by user. 9) Concentrator should be provided with specially-assigned perform for operation, routine inspection and maintenance. 10) The slurry discharge port should not be blocked but should be guaranteed of continuous discharge. 11) In case of power failure that results in shutdown, it is required to timely recover the operation of concentrator. As it starts, if there is any overload protection action, it indicates that the ash and slag deposits in pool are excessive and need to be cleaned up in order to reduce the startup load; it should not be forced to start to prevent damage to the parts.
59
slurry discharge valve at the bottom of concentrator tank, rotary harrow scraps and gathers the concentrated slurry to the slurry discharge port for discharge, then it can be put into stable operation. 8) Equipment is running in continuous mode. The slurry discharge port should continuously discharge slurry without blockage. 9) During operation of the equipment, if the lifting motor starts to run and ash scraping harrow rises up, it indicates the ash content in slurry is too high, it should increase the discharge flow of the bottom slurry discharge port to exhaust the thick slurry at bottom and restore normal operating conditions of equipment. At the same time, it also should check the ash content of the incoming slurry, and take measures to prevent too much ash into the high-efficiency concentrator. 10) Before shutdown, the slurry inlet valve should be closed, and the concentrator should be shut down after the discharge of settled and concentrated slurry particles. 11) Before startup of equipment after long outage for some reason, it should first check for debris or muds stuck on harrow, and clean up if any to reduce the starting load. The equipment should not be forced to start with load. 2.1.3Concentrator put-in 1) Close the valve of slurry discharge port at the bottom of concentrator tank, start the harrow rotating motor and open the valve of slurry inlet pipe to fill the concentrator bin with water or slurry. 2) When the water level in bin is close to the weir overflow, open the slurry discharge valve at the bottom of concentrator tank, rotary harrow scraps and gathers the concentrated slurry to the slurry discharge port for discharge, then it can be put into stable operation. 3) The slurry discharge port should continuously discharge slurry without blockage. The flooding nozzle at the slurry discharge port should be opened regularly, generally once per shift, about 10 minutes. The high-efficiency concentrator must use continuous operation mode. Before shutdown of high-efficiency concentrator, the ash and slag stuck on the settling board at the bottom of tank must be cleaned up in order to ensure the normal operation of high-efficiency concentrator. 2.1.4 Operating maintenance and precautions 1) Reducer oil change: the oil should be replaced after running for 150 hours for the first time, the oil change should be done as the reducer is warm and cleaned, thereafter, the oil can be changed once every 3 ~ 6 months; the oil change interval may be shortened appropriately in case of much higher ambient temperature or humidity. The reducer should be stopped if the oil temperature is found significantly increased, temperature rise exceeded 60ć or oil temperature exceeded 85ć, as well as unusual noise or abnormality is found, and can only be used once again with oil changed after fault is removed. 2) The central drive harrow rotation device should have a trial run after mechanical inspection, and it can only be put into operated with load after it is normal in operation with no load. 3) It is prohibited to allow large hard materials or other rods, blocks and other debris entering the bin to block slurry discharge, jamming harrow rotation and affecting normal working of the central drive harrow rotation device, or even damage the parts. 4) The floating beads or slag on the water surface in the concentrator bin should be promptly removed to the quality of overflow water and to reduce the load on the inclined plate rack after the concentrator 58
Chapter 2 Running of Slag Handling System 2.1 Operating principle of high-efficiency concentrator 2.1.1 The high-efficiency concentrator makes use of the deposition characteristics of ash and slag particles in the liquid to separate solids from liquid, and also makes use inclined concentration plate to accelerate the sedimentation, significantly improving settling efficiency; solid particles settled to the bottom of tank are gathered by the bottom rotary ash scraping harrow to the central slurry discharge port at the bottom of tank. Precipitated slurry of the discharge of high-concentration slurry and the recycling of clarified water. Then the high-concentration slurry is re-conveyed to the dewatering bin, etc. superior equipment for further dehydration. The concentration process is: slurry flows into the concentration tank via inlet pipe, quickly dispersed throughout the cross-section by means of the flow stabilizer under conditions of minimizing disturbance; coarse ash particles directly sank to the bottom, smaller particles spread around, settling and diffusing at the same time; and also flow through inclined concentration plate with improved settlement efficiency. Installation of inclined concentration plate is use of the fluid shouldow theory, the principle is: (1) increasing the settling area; (2) the settling zone of inclined concentration plate is divided into many small portions, so the flow is relatively stable, unease to produce vortex, and conducive to particle sedimentation; (3) the particle sedimentation distance is shorter, which is equivalent to the distance between two adjacent inclined plates, and therefore the time required of settlement is shorter, settling slurry particles decline along the inclined plate, i.e. increase settling velocity, improve the settling efficiency. In this way, the solids in slurry by own gravity sink in a fairly steady medium, the upper water separates from solid phase, the solid phase slurry particles concentrated in the lower layer and gradually concentrated to the bottom, they accumulate and being close to each other at the bottom of tank, in the meanwhile, under the action of the scraper on the rotating harrow frame, the settled solid phase slurry particles further accumulate and ion of concentrate, and then the precipitated slurry particles are slowly scrapped to the center of tank by the scrapper on harrow frame to be discharged via the slurry discharge port; there formed a upper layer of clarified water that flows out along the overflow groove to complete the whole process of concentration. 2.1.2 Running operation requirements 1) Before running, check that all the bolts have good and tight connections, and whether all the piping and valves are in starting state. 2) Before running, check whether the reducer has been filled with lubricating oil as required. 3) Before running, check that the motor reducer’s electrical control is normal. 4) Before running, check that the motor reducer is normal in empty running test, and check and verify that the motor wiring is correct, you must make the rotating direction of reducer output shaft consistent with the that of the ash scrapping harrow as shown on the general drawing of equipment. 5) Check that there should be no rod, block and other debris in bin, and prevent jamming the harrow rotation and blocking the slurry discharge pipeline. 6) Close the slurry outlet valve at the bottom of concentrator bin, start the motor reducer, open the valve of slurry inlet pipe to fill the concentrator bin with water or slurry. 7) When the water level in bin is close to the weir overflow (open swirl nozzle water supply valve) open the 57
1.2.23 Vibrating feeder Manufacture Type Quantity Output Motor power Service life Weight
3 80~100 11 10000 ~400
set/bin t/h kW H Kg
1.2.24 Biaxial agitating device Manufacture Type Quantity Output Motor power Required Water flow: Required water pressure: Material of wearing parts Service life Weight
STATE GRID FUTONG JSL-100 1 100 22 ~15 0.3~0.6 Iron-based wear-resistant alloy 10000 4.5
set/bin m3/ h Kw m3/h Mpa H T
1.2.25 Bag dust collector No. 1 2 3 4 5 6
Item Type Quantity Air treatment capacity Filtration air speed Filtration area Filter bag quantity and size
7
Filter bag withstand temperature
8 9 10 11 12 13 14
Bag life Filter bag resistance Concentration of dust emission Dusting fan flow Dusting fan pressure head Dusting fan life Manufacturer
Parameter Pulse jet 1 set 16m3/min 0.8m/min 20m2 24 pcs/ Ø 130×2100mm Normal temperature 150ć Impact temperature 200ć 18000h 1200Pa ≤50mg/m3 20m3/min 2500Pa 18000h STATE GRID FUTONG
56
Remarks Each boiler
Type of sealing Crushed particle size Gear form Teeth roll material Cutting board material Operating temperature of the slag crusher Motor power Motor supply voltage IP Service life Overall weight
Labyrinth 30×30 Involute High manganese alloy High manganese alloy 300 2×37 415 IP54 24000 7.5
mm
ć kW V h t
1.2.20 Bucket elevator Manufacture Quantity Model Design output Motor model Motor power Reducer model Max operating temperature of bucket elevator Running speed of the chain bucket Chain bucket specifications (chord length X width) Lifting height Overall weight
STATE GRID FUTONG 2 FLNE50 60 Y160-4 15 ZLYNZ160-46 250 30 320×400 ~26 ~13
set/boiler t/h kW ć m/min mm m t
1.2.21 Bag dust collector Manufacture Quantity Model Separation efficiency Bag service life Operating pressure range Bag dust collector flow rate Bag dust collector area Bag material/operating temperature Filter bag specifications/quantity Pulse cleaning air consumption Pulse cleaning air pressure Pulse controller Dusting fan Solenoid valve model Solenoid valve quantity
STATE GRID FUTONG 1 DMC-170 99.9 10000 1800 0.8 ≥140 NOMEX/300 Ø130X2000/168 0.53 0.5~0.7 DMK-21-3CS 9-19A ASCO 21 Shanghai Instrument Factory No.3 YZ-60
Differential pressure transmitter Vacuum gauge
set/bin % H Pa m/min m2 m3/min Mpa
1.2.22 Slag bin and its equipment Effective volume of slag bin Quantity of slag bin Slag bin diameter Slag bin manufacturer Slag bin design temperature
800 1 Ø10000 STATE GRID FUTONG 200 Tuning fork /E+H radar wave/Milltronics 3 10000 3
Type, model and manufacture of slag level meter Quantity of slag level meter Service life of slag level meter Quantity of slag bin shaker 55
m3 set/2 boilers Mm ć
H
1.2.17 Bottom slag discharge device Manufacture Quantity (each boiler) Model Drive mode Type Unit Quantity Cylinder stroke Cylinder thrust Oil pressure Motor model Motor power (2 sets) Motor Supply Voltage IP Dimensions Proper material Proper thickness Max temperature Structural features
STATE GRID FUTONG 1 GPZP14 Hydraulic Back to back 12 720 80 11 Y112M4 2×5.5 415 IP55 5000×3100×3200 Heat-resistant stainless steel 300 800 Gear form
mm kN Mpa kW V mm
1.2.18 Dry slag conveyor Manufacture Quantity Model Drive mode Rated output Max output Rated output slag discharge temperature Max output slag discharge temperature Rated output cooling air flow Max output cooling air flow Conveyor belt type Belt speed (normal/max) Service life of the chain and chain wheel Service life of mesh belt Slag storage capacity Max amount of slag storage allowing start with load Chain tensioning mode Speed regulation mode Signal that can be monitored and obtained in the control room Conveyor chain motor model Conveyor chains motor power Conveyor chain reducer model Cleaning chain motor model Cleaning chain motor power Motor supply voltage IP Fire service installations Angle of inclined segment Overall weight
STATE GRID FUTONG 1 GPZS14 Friction drive 15~34.4 51.4 100 100 14070 17980 Bidirectional spiral 70/140 30000 50000 12 12 Hydraulic automatic variable frequency speed control Slip, overload, chain rupture QABP-160 18.5 SC6004 DM100 2.2 415 IP55 Available 27 ~130
set/boiler
t/h t/h 0C 0C Nm3/h Nm3/h mm/s h h m3 m3
kW
kW V
t
1.2.19 Slag crusher Manufacture Quantity Model Rated output
STATE GRID FUTONG 1 2PG800×1000 52 54
set/boiler
1.2.16 Main technical parameters of slag conveying system No. Parameter name
Unit
Design value
1
Effective volume of boiler slag pit
m3
320
2 3
Operating temperature of boiler slag pit ć Closing time of slag discharge device h Normal output of Dry slag conveyor t/h (continuous) Maximum output of dry slag conveyor t/h (continuous) Dry slag conveyor belt speed under m/min normal output conditions Dry slag conveyor belt speed under max m/min output conditions Dry slag conveyor cleaning chain speed m/min under normal output conditions Dry slag conveyor outlet slag temperature ć under normal output conditions Dry slag conveyor outlet slag temperature ć under max output conditions Dry slag conveyor cooling air flow under 3 m /h normal output conditions Dry slag conveyor cooling air flow under 3 m /h max output conditions Surface temperature of dry slag conveyor equipment under normal output ć conditions Effective width of dry slag conveyor belt mm
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
Upper metal plate material of dry slag conveyor belt Upper metal plate thickness of dry slag mm conveyor belt Dry slag conveyor tank width mm Angle of inclination of dry slag conveyor Temperature of air flow into the furnace ć Particle size at the outlet of large slag mm crushing equipment Slag crusher output t/h Size of particle at outlet of slag crusher mm Bucket elevator output t/h Effective volume of slag storage bin m3 Filtration efficiency bag dust collector ˁ Dust concentration of bag dust collector mg/m3 emission Biaxial agitating device output t/h Vibrating feeder output t/h
System performance Normal conditions
operating
Max conditions
operating
Design output Cooled slag temperature Cooling air flow Design output Cooled slag temperature Cooling air flow 53
1000 6
Guaranteed Remarks value Actual volume 320 360 m3 1000 6
15~34.4
15~34.4
51.4
51.4
0.8~8
0.8~8
8
8
0.2~2
0.2~2
100
100
100
100
14070
14070
17980
17980
50
50
1400 1400 Heat-resista Heat-resista nt stainless nt stainless steel steel 4
4
1800 27 350
1800 27 350
200
200
52 30×30 60 900 99.9
52 30×30 60 900 99.5
50
50
100 100
100 100
Value 15~34.4 70 14070 51.4 70 17980
Unit t/h ć Nm3/h t/h ć Nm3/h
5
6 7 8 9
10
Normal speed: Maximum speed: Cooling capacity and pressure Normal conditions: Maximum operating conditions: Sealing form Angle of inclination of the rising segment: Tank volume Motor Model: Power: Voltage: Speed: Driver:
m/s m/s
0.04 0.06
m3/h, MPa m3/h, MPa ° m3
8, normal pressure 20, normal pressure Anhydrous seal 30 50
kW V r/min
7.5 415 1450
KNm rpm
Changzhou Nanjiang Reducer Co., Ltd. 11767 11
Manufacturer:
11
Max torque generated: Output speed range: Tensioning device:
Qingdao Jinhuahai Hydraulic Manufacturing Co., Ltd. CBN-E314 300 102 16 Q235-A, 10 Basalt cast board, 40mm in thickness, and service life of 8 years
Manufacturer:
12 13
14
15
Tensioner oil pump model: Tensioning cylinder stroke: Cylinder diameter: Max set pressure of the system: Material and thickness of the tank body Wear-resistant material, thickness and service life of the tank body Chain Chain specifications: Chain diameter: Pitch: Conveyor chain material and service life Manufacturer Scraper Material and thickness of scraper Scraper width Scraper material life Total weight:
mm mm MPa
φ26×92 26 92 14CrNiMo5 Tianjin Jinxin
mm mm
mm mm hour ton
Q235-Aˇ65Mn 182 25000 38
1.2.15 High-concentration pump LV motor Item Model Rated power Rated voltage Synchronous speed Rated current Frequency
Main characteristics
Insulation class Weight Cooling method Direction of rotation
Unit kW kV r/min A Hz %
Efficiency Power factor Stall torque Stall current Maximum torque Effi i
(Times) (Times) (Times) kg Bidirectional 52
Data 1PQ83554PB90-Z 355 415 1500 690 50 96.4 0.86 2.3 7.2 2.9 IP55 2100 IC416
Size of connector with the coal mill (pipe dia./height/horizontal sextant angle): DN250/2.0m/35°; Hopper wall thickness: 10 mm; Hoppe wall material: Q235A; Liner thickness: 16 mm; Liner material: QT700-2; Level meter model: EP-LA2600 1.2.11 Hydraulic jet pump of mill rejects Quantity per boiler: 7sets; Manufacture and design size: Feed port: φ270mm; Water inlet: φ75 mm; Boosting nozzle: φ29 mm; Discharge port: DN125 mm; Solids carried per hour: 18000 kg/h (net output); Velocity of mixture flow: 2.2 m/s; Solids weight percentage: 20 %; Water flow of nozzle: Jet pump nozzle: 90 m3/h; Booster nozzle: 90 m3/h; Required water jet pressure: 0.9 MPa; Main structure material: Nozzle: MTCuMo-175; Pump body: QT700-2; Jet tube: QT700-2; 1.2.12 Conveying pipe Pipe diameter: 159 mm; Minimum wall thickness: 14 mm; Medium velocity: 2.0 m/s; Outer diameter × inner diameter: 159×131 mm; Material: mixture of mill rejects and water; 1.2.13 High-pressure pump Flow rate: 120 m3/h; Head: 0.9 MPa; 1.2.14 Scrapper conveyor of mill rejects No. 1
Item Manufacturer
2
Type:
3
Conveying capacity Normal conveying capacity: Max conveying capacity: Chain pulling speed
4
Unit
Parameter Upper back chain water-immersed scrapper type
m3/h m3/h 51
18.0 33.0
Quantity
1 set
Tank diameter
Ø12m
Tank wall thickness
≥10mm
Sewage treatment capacity
>350m3/h
Effective volume
≥500m3
Sewage medium
Overflow water of mill rejects conveyor, and sewage collected from bottom of tank
Sewage quality at inlet
300~2000mg/l (estimated)
Required drain water quality
≤300mg/l
Sewage suspended solids content at inlet:
≤2000mg/l (estimated)
Required suspended solids content in overflow water:
≤350 mg/l
Circulation nozzle quantity/diameter: 6pcs/φ8 mm Flooding nozzle quantity/diameter:
3pcs/φ8 mm
Total water consumption of nozzle: 84m3/h (circulation nozzle: 54m3/h; flooding nozzle: 30m3/h) Water supply required by nozzle:
0.4 MPa
Tank material:
Q235-B
Total weight:
52 t
1.2.9 Surge tank Quantity
1 set
Tank diameter
Ø12m
Tank wall thickness
≥10mm
Sewage treatment capacity/set >350m3/h Effective volume
≥500 m3
Sewage medium
Drain water from clarified water tank, make-up water from hydraulic division
Sewage quality at inlet
350mg/l
Required drain water quality
≤120mg/l
Circulation nozzle quantity/ diameter: 6pcs/φ8 mm Flooding nozzle quantity/diameter: 3 pcs/φ8 mm Total water consumption of nozzle: 84 m3/h (circulation nozzle: 54m3/h; flooding nozzle: 30m3/h) Water supply required by nozzle: 0.4 MPa Tank wall thickness:
10 mm
Tank material:
Q235-B
Total weight:
48 t
1.2.10 Mill rejects hopper Quantity per boiler: Effective volume:
7 pcs; 1.0 m3;
Mill rejects hopper dimensions: (L×W×H): 1340×1430×1440 mm; Empty weight of each mill rejects hopper: 1.5 t; All-up weight of each mill rejects hopper: 2.5 t; Access door diameter: φ460 mm; Water seal available or not: none; 50
1.2.2 Surge tank Quantity
1 set
Hopper diameter
Ø 15m
Wall thickness of hopper
≥10mm
Effective volume
≥750 m3
Sewage medium
Overflow water of concentrator, and make-up water from hydraulic division
Sewage quality at inlet
350mg/l
Required drainage water quality ≤10 ppm 1.2.3 Distribution box Quantity
1 set
Box size
6000X1500X1500 (L×W×H)
Effective volume
≥10 m3
Outlet (2 pieces)
Ø630X11
Overflow port (2 pieces)
Ø325X8
1.2.4 Agitating device Quantity
4 sets
Diameter
Ø750mm
1.2.5 Bottom slag hopper overflow water tank (each boiler) Quantity
1 set
Tank diameter
Ø 4m
Tank height
4.5m
Tank wall thickness
≥6mm
Effective volume
≥50 m3
Water inlet flange
PN1.0, DN300
Water outlet flange
PN1.0, DN250
1.2.6 Vacuum pump house water storage tank (each boiler) Quantity
1 set
Tank size
2500X1500X1500 (L×W×H)
Effective volume
≥5 m3
Water inlet floating valve PN1.6, DN65 Water outlet flange
PN1.0, DN100 (2 pieces)
1.2.7 Mill rejects amount Capacity Item Coal consumption Mill rejects
Design coal (t/h) Check coal (t/h) Design coal (t/h) Check coal (t/h)
1×600MW
6×600MW
346 386.5 3.46 3.865
2076 2319 20.76 23.19
1.2.8 Clarified water tank 49
c) air preheater ash 5%; d) ESP ash 90%. The ash bulk density: bottom ash and fly ash is 650kg/Cum as calculated by volume, bottom ash and fly ash is 1350 kg/Cum as calculated by strength, ESP/air preheater/economizer ash hopper is 650kg/Cum as calculated by volume. 1.2 Equipment specifications of slag handling system 1.2.1 Concentrator No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
Name Model Quantity Hopper diameter Sewage treatment capacity/set Effective volume/set Effective settling area/set Sewage suspended solids content at inlet Required suspended solids content in overflow water Harrow body diameter Rotary harrow diameter Rotary harrow speed Lifting harrow height Allowable max particle size of slurry Material of inclined plate Thickness of the inclined plate Quantity of inclined plate Vertical distance between inclined plates Angle between inclined plate and horizontal plane Wall thickness of hopper Drive motor model Main harrow motor power Main harrow motor voltage Main harrow motor IP Drive mode of main harrow motor Reducer model Reduction ratio Lifting motor power Lifting motor voltage Total weight of the whole unit/set
Unit Set m m3/h m3 m2 ppm ppm m m r/min m mm mm Piece mm mm kW V
kW V t
Parameter GNJ15.0TB 2 15 900 900 1600 ζ2000 ≤10 0.219 9 0.148 350 50 PVC 3 1200 90 65° 10 Y100L2-4 3.0 415 IP56 Direct connection XWED3-84-1/187 1:187 2.2 415 100
Technical data of drive motor Items Model Rated power Rated voltage Synchronous speed Start-up current Rated current Frequency Efficiency Power factor Main Stall torque Characteristics Stall current Maximum torque Insulation class Weight Cooling method Direction of rotation
Unit
Data Y100L2-4 kW 3 kV 0.415 r/min 1500 A 56 A 6.8 Hz 50 % 82.5 0.81 (Times) 2.2 (Times) 7.0 (Times) 2.2 F kg 55 Air cooled Clockwise (viewed from drive end to non drive end ) 48
Remarks
PART 3 Ash & Slag System Chapter 1 System Overview 1.1 Overview of slag handling system In this project, the boiler slag is handled by hydraulic conveying mode, i.e. the boiler slag is discharged into the water sealing slag hopper for cooling, cooled bottom ash and slag are sent through the slag discharge valve outlet to crusher for crushing, and then conveyed to the ash slurry pond by hydraulic jet pump. The fly ash in economizer ash hopper is conveyed to the ash slurry pond by hydraulic jet pump. The ash and slag discharged into the ash slurry pond are conveyed to the ash year through pipeline by the ash slurry pump. Overflow water from the water sealing slag hopper is conveyed to the concentrator by overflow water pump, and the clarified water overflows to the surge tank. This project of 3X600MW coal-fired unit is set with one concentrator and one surge tank. The 6X600MW coal-fired units of the whole plant are set with 2 concentrators and 2 surge tanks. The concentrator and surge tank in common use by boilers # 1, #2 and #3 are arranged in between #1 and #2; the concentrator and surge tank in common used by boilers # 4, #5 and #6 are arranged in between #5 and #6. Each boiler is individually set with mill rejects conveying system which uses mill rejects hopper (provided by coal mill manufacturer) and hydraulic jet pump to convey the mill rejects discharged from the mill to the mill rejects scrapper’s upper hopper through pipeline, and then transported out by dumping truck. The conveying water of mill rejects is overflow water of mill rejects conveyor that is treated in clarified water tank and surge tank and provided by high pressure pump. Conveying sequence: mill rejects discharge outlet → mill rejects hopper feed valve → mill rejects hopper → mill rejects hopper discharge valve → hydraulic jet pump→ mill rejects scraper’s upper hopper → truck. Each boiler is set with one mill rejects conveying system which design conveying output could guarantee that the mill rejects generated in 4 hours of running under MCR condition can be conveyed to the mill rejects scrapper’s hopper within 1 hour, and is not less than 16t/h. Mill rejects conveying system is hydraulic conveying, which forms one unit for each boiler that runs intermittently. The mill rejects are conveyed by hydraulic jet pump through pipeline to the mill rejects scraper’s upper hopper, and then transported out by dumping truck. The overflow water of mill rejects scrapper is treated in the clarified water tank and surge tank and then provided by high-pressure pump to the mill rejects conveying system. There is one clarified water tank and surge tank in common use by 3X600MW unit. 6X600MW unit is set with totally two sets of clarified water tank and surge tank. Slag handling system is included in the PLC control system for monitoring, the whole system uses automatic programmable control, with control point set in the ash handling control room, and the state of which can be monitored in the centralized control room of unit plant. For ease of loading, slag bin unloading uses local control mode, by which the loading is monitored directly locally. Except the slag handling and conveying equipment that are designed for boiler BMCR condition with poorest coal quality, all the other equipment from bottom slag hopper to the slag bin are designed by 150%. For each boiler, the total ash content is designed at least the following percentages: a) bottom ash, 20%; b) economizer ash 5%; 47
No.
Fault
Cause
7
The system does not continue running after the solenoid seal valve is opened
8
After rotation of discharge valve, system does intake air conveying
9
System plugging
the the not for
Solution 1. Replace the seal ring; Seal ring is damaged; 2. Check whether the air source pressure Sealing pressure is lower than is greater than 0.50Mpa; the sealing pressure switch Check whether the sealing pressure settings; switch setting is higher; The discharge valve opens in place but the limit switch makes no signal, there are the 1.Adjust the position of limit switch; following reasons: Position of limit switch is 2. Replace the limit switch; wrong The limit switch has been damaged; 1.Adjust the feeding time; 2. Adjust the regulated value of pressure Feeding time is too long; Conveying pressure is lower; relief valve on the air intake valve block; Conveying air flow is too increase the conveying pressure; 3. Adjust the air intake orifice plate, and small; Air supply amount is too increase the air supply amount; small; 4. Adjust the orifice of flow orifice plate, and increase the air supply amount.
46
DN 200 dome valve maintenance guidance: DN200 dome valve is mounted on the transmitter for feeding. Before maintenance for security considerations, please pay attention to the following matters: 1) Ensure the system is local control; 2) Close the maintenance valve (flapper valve); 3) Change the conveying cycle switch to the “Start” position, and runs conveyor for 2 cycles; 4) The dome valve is in the closed position; 5) Close the air intake valve; close the manual ball valve on the inlet valve block; 6) Carefully open the pressure relief valve to ensure no residual pressure in the system; 7) Turn off the manual air intake valve on the local control box; 8) Demount compressed air piping on the dome valve; 3.4 Fault diagnosis of ash conveying system No.
Fault
Cause
Solution
Valve is opened beyond limit
Loosen the bolts between connecting plate and valve flange, draw out the valve plate 100mm, and insert it at 15° tip back into place.
1
Manual access door cannot be tightly closed after it is opened
2
Feed valve does not after air rotate supply
3
The feed valve sealing pressure switch signal is unavailable.
4
Discharge valve does not operated after air supply
5
Conveying air pressure switch signal is active during the transmitter feeding
Intake valve does not close in 1. Maintain the air intake valve; place; 2. Adjust the conveying air pressure Conveying air pressure switch switch value; value is lower
The feed valve seal ring is replaced frequently
Feed valve is closed not in place, the air intake is sealed; Air intake misaligns with collar hole; Sealing pressure switch setting is low, less than 0.40Mpa; Sealing pressure switch setting is higher, more than 0.55Mpa
6
1. Low pressure air source. 2. Pneumatic device air inlet 1. Adjust the pressure of air source 2. Maintain pneumatic device and blow-by 3. Valve spindle lubrication is bearing, and increase lubrication not good 1. Replace the seal ring; Feed valve seal ring is 2. Adjust the pneumatic device to the damaged; extent that the pneumatic device is in the Ball position misalignment; closed position when ball position is in the middle; Seal ring does not inflate; Air source pressure falls 3. Check the air line, and check the below the seal switch setting; solenoid valve for damage; Pressure switch setting is over 4. Adjust the pressure of air source; 5. Adjust the sealing pressure switch high setting Low pressure gas source; The pneumatic device intake 1. Adjust the pressure of air source; and exhaust ports blow-by; 2. Maintain the pneumatic device; Gap between the valve body 3. Adjust the gap between the valve body and the valve core is too and valve core; small, with jamming
45
1. Adjust the feed valve closing time; 2. Adjust the position of air intake and collar hole, make them aligned; 3. Adjust the sealing pressure switch setting; 4. Adjust the setting of pressure relief valve of air source triplet
equipped with a double-contact pressure in order to ensure the seal charging and relief pressure of seal ring reaches the set pressure. The domed surface is smooth and hard, so that it can be brought into close contact with rubber seal ring. The rubber seal rings are made of specially-formulated rubber, which are corrosion resistant, wear resistant, and anti-aging. The actuator of the valve is fully sealed bidirectional straight cylinder, which directly drives the feed valve to rotate, effectively preventing dust from entering wherein and causing wear, leakage and other problems. The dome valve is provided with a mechanical control valve at the output of rotating shaft, which connect through the sealing air passage when the dome valve operates in place. Structural diagram:
Working principle: before the dome opening and closing, the seal ring first release pressure, when the pressure reaches the low value set for pressure switch, it indicates the seal ring is completely separated from the dome, with a gap between about 2 ~ 3mm, when the valve is closed in place, the seal ring starts to inflate until the pressure reaches the high value set, seal ring clings to the dome, forming a very reliable seal valve ring band. In the switching process, the dome does not contact with the seal, and thus the opening and closing moment is small, while the sealing surface of the dome and the seal ring of valve body are not easily damaged. Main technical parameters Nominal Diameter Air bag design pressure Feed valve design pressure Control air source
Pressure Air consumption
Cylinder Actuator output torque Operating Temperature Design temperature Suitable medium 44
DN200 0.6 MPa ≤0.5MPa 0.55~0.6 MPa 1L/time Cylinder DN125 650N·m ≤170ć 200ć Fly ash, limestone powder, etc.
Low exhaust pressure
7. Temperature sensor failure 1. Air demand exceeds supply 2. 2. Air filter is blocked 3. Intake valve can not be fully opened 4. Oil-gas separator element is blocked
1. Air intake valve failure 2. Pressure sensor failure 1. Piping leaks Frequent loading 2. Differential pressure between loading and unloading and unloading is set too small 3. Unstable air consumption
Unloading failure
1. The amount of oil is too high The oil content in air is too high, oil 2. Return pipe orifice blockage consumption is too 3. Oil-gas separator element or gasket is high damaged 4. Exhaust pressure is too low. Ultra-high Actual pressure is ultra-high, and sensor pressure is not accurate Power phase failure, contactor contact is Lack of phase bad, etc. Too low voltage, pipe blockage, bearing Overload wear, other mechanical failure, set data error Power imbalance, bad contactor contacts, Unbalance inside of motor has open loop, etc. Low voltage, pipe blockage, bearing wear, other mechanical failure, sett data Stall error Short circuit Wiring error, set data error, etc. Phase sequence Phase sequence is reversed, phase failure error Fan failure, contactor failure, no control Fan is not running output Main unit overload, stall, etc. The main unit startup time is set to be less electrical fault in than the star-delta delay time the starting process Regular action of Emergency stop button becomes loose the main contactor
Check and replace the temperature sensor Detect pipeline for leakage Clean or replace the filter element Check the air intake Check the pressure gauges and display values before and after the oil-gas separator element, if necessary, replace the oil separator element. Check the air intake valve Repair, if necessary, replace Check piping Reset Increase the air storage tank volume Check the oil level, and discharge oil to its normal position Clean the oil return pipe orifice and replace it if necessary Check the filter element and gasket, replace if damaged Increase the exhaust pressure Check machine pressure and the pressure sensor Check the power and contactor Check the setting data, check the voltage, bearings, piping and other mechanical failure Check the power supply, contactor and motor Check the set data, check the voltage, bearings, piping and other mechanical failure Check the line, setting data Check the line Check the line
Reset the start time of main unit to be more than star-delta delay + load delay Check the wiring
3.3 Other equipment structure and maintenance 3.3.1 Dome valve Pneumatic dome valve is special valve for conveying powder material, the feed valve as transmitter in the present system and the discharge valve in each electric field. The dome valve body is constituted by ductile iron. The valve core is dome-shaped and made of stainless steel, with surface hardening treatment. Valve core rotates 90°by the rotating shaft on both sides, to open and close the valve. Valve is equipped with a pneumatic seal ring on the upper portion close to the dome top, the pneumatic piping of seal ring is 43
E. too large running current of compressor result in the thermal overload fault indicator lights up
1. Thermal load is too large and the intake air temperature is too high 2. The ambient temperature is too high. 3. Insufficient refrigerant results in too high degree of its superheat 4. Compression overload 5. Compressor lacks of oil or oil level is too low 6. Compressor bearing is worn or cylinder is jammed
1. Reduce the thermal load and the intake air temperature 2. Improve ventilation conditions to reduce the ambient temperature. 3. Add refrigerant 4. Reduce the number of compressor start 5 Check compressor oil level, and add oil 6. Replace compressor
F. Evaporator internal icing, appearing as the drainer failure to drain water, and ice particles blowing out after opening the blowdown valve
1. Air flow is too small or the load is too light 2. Hot gas bypass valve is not open or poor and expansion valve opens too large 3. Evaporator drain outlet is blocked, too much water deposit creates ice block
1. Increase the compressed air flow or load 2. Adjust or replace the hot gas bypass valve and expansion valve 3. Dredge drain port to discharge the evaporator condensate
G. Equipment is operating normally, but the pressure drops significantly
1. Low air intake pressure. 2. Pipeline valve is not fully opened 3. Pipe diameter is too small, the elbow too many or piping is too long 4. Evaporator ice blockage 5. Compressor suction filter is blocked 6. Equipment has too much water deposit 7. Selected equipment has a lower treatment capacity 8. The air system is blocked by dust
H. Equipment operation noise is too high
1. Fan blades are bent 2. Fan motor bearing is worn 3. Refrigerant liquid return 4. Compressor is damaged (cylinder jamming, bearing wear) 5. Compressor lacks of oil
1. Increase the intake air pressure 2. Open all air line valves 3. Improve air piping system 4. Refer to F1-3 5. Clean or replace the filter 6. Check repair or replace the drainage system 7. Increase equipment or replace the equipment of greater treatment capacity 8. Reversely clean with cleaning agent 1. Make correction or replace 2. Replace fan 3. Check adjust or replace expansion valve 4. Replace compressor 5. Check the oil level, add oil and check whether the oil heater is working properly
I. Liquid piping frosting J. Suction pipe frosting
1. Valves on high-pressure side are blocked 2. Dry filter is blocked 1. Expansion valve is abnormal 2. Hot gas bypass valve is not opened or poor
1. Open the valve to remove blockage 2. Replace 1. Replace the expansion valve 2. Adjust or replace the hot gas bypass valve
3.2 Fault analysis and solution of air compressor Fault
Possible Cause 1. Fuse blew out 2. Protection relay operates Start failure 3. Poor contact of start button 4. Voltage is too low 5. Motor failure 1. The ambient temperature is too high. 2. Thermostatic valve failure Exhaust 3. Insufficient amount of lubricating oil. temperature is too 4. Oil cooler fins are too dirty high 5. Oil filter is blocked 6. Cooling fan failure 42
Solution Please contact with the electrical maintenance or personnel for replacement Improve ventilation around Check and replace the thermostatic valve Check and adjust oil level Clean cooler fins Replace the oil filter Replace the cooling fan
Chapter 3 Routine Maintenance & Treatment 3.1 Typical fault analysis and treatment of refrigeration dryer The main fault of refrigeration dryer comes from the circuit and cooling systems, and the final result will inevitably lead to failure to start of the compressor, cooling capacity reduction or equipment damage. Making correctly judgement of the causes of various faults and taking reasonable solutions not only involve the theoretical knowledge of electrical and refrigeration technology, but what is more importantly is having practical skills, some faults may be caused by several reasons, you must first of all make comprehensive analysis of the fault phenomenon to find an effective solution. In addition, some faults are often caused by improper use and maintenance by the user, and that is so-called “pseudo-fault”, so the location of fault can only be determined through actual operation so as to find the right solution. The refrigeration dryer’s some common faults and solutions are highlighted as follows: Fault phenomenon
Cause Analysis
Solution
A. Refrigeration dryer does not work
1. No power supply 2. blown fuse 3. Circuit is open or loose
B. Compressor does not run
1. Power phase failure or voltage is outside the allowable range 2. Incorrect wiring 3. Relay or contactor does not pick up 4. If the compressor is capacitor start, then the start capacitor may be damaged 5. HV and LV protection switches are poor 6. Compressor mechanical failure, such as cylinder jamming
C. Too high pressure of refrigerant results in the high refrigerant pressure fault indicator lights up
1. Thermal load is too large and the intake air temperature is too high 2. Ambient temperature is too high. 3. Condenser is dirty and blocked or cooling water is insufficient and cooling water temperature is too high 4. Air mixed in the cooling system 5. Fan rotation direction is incorrect or fan motor failure 6. Expansion valve is abnormal 7. Dry filter is blocked. 8. Refrigerant charge amount is too large
D. Too low pressure of refrigerant results in the refrigerant pressure fault indicator lights up
1. Refrigerant shortage or leakage 2. Air flow is too small or load is too light 3. Hot gas bypass valve is not open or poor 4. The ambient temperature is too low.
41
1. Check the power supply system 2. Replace the fuse 3. Check the line according to the circuit diagram 1. Check the power supply to make supply voltage be within the nominal range 2. Check line according to the circuit diagram 3. Check the reason, replace or repair 4. Replace start capacitor 5. Adjust the pressure switch setting, or replace the pressure protection switch 6. Replace compressor 1. Reduce the thermal load and the air intake temperature 2. Improve ventilation conditions, and reduce the ambient temperature. 3. Clean condenser or increase the amount of cooling water and reduce the temperature of cooling water inlet 4. Find out the reasons and maintain. 5. Exchange any two of the three phase lines or replace fan 6. Replace the expansion valve 7. Replace 8. Discharge refrigerant (the above reasons must be excluded before this operation) 1. Make leak detection, extract vacuum once again and charge refrigerant 2. Increase the compressed air flow or load 3. Adjust or replace the hot gas bypass valve 4. Reduce the cooling water flow, or turn off the cooling water
When the system runs under automatic control of PLC control system, each boiler creates a conveying unit. Its basic operating steps are as follows: System feed. The exhaust valve is opened, then the seal ring of feed valve is released from pressure, and feed valve is opened, when any a vessel transporter in the conveying system reaches the set material level (or reaches the clock setting), the system is triggered. Conveying. Close the core of feed dome valve is closed, pressurize the seal ring for sealing, and confirm normal closing by the pressure switch, and close the exhaust valve, open the discharge valve, and in the meanwhile open the air intake valve block and gulp valve, opens the boost air intake valve block, then the compressed air will convey the ash to silo ash from all the conveyors. System reset. There is pressure switch on the air intake line, as reaching the set low limit, close the compressed air inlet valve block and boost air intake valve block, and then close the discharge valve, system resets, and waits for the next cycle. 2.10.3 Programmed logic 2.10.3.1 Starting point Feed valve (dome valve) is closed. The conveying pressure is zero. Discharge valve closed. The sealing pressure is zero. 2.10.3.2 Feed Open the exhaust Wait 3 seconds, and then close the feed valve for sealing. Wait 5 seconds, and then open the feed valve for feeding. 2.10.3.2 Feed valve is closed Level meter operates or feed time out, close the feed valve and exhaust valve 5 seconds later, open the inlet valve seal. When the sealing pressure reaches 5.5 bar, the feed valve is opened. 2.10.3.3 Conveying When the discharge valve is fully open, the air intake discharge is opened. Once pressure is set up in the transmitter, and the fly ash moves in the pipeline. The conveying process continues until the conveying pressure is reduced to the set value, and lasts the shortest conveying time. The conveying compressed air is discharged from the bag dust collector. 2.10.3.4 Conveying process end The conveying pressure is zero. Air intake and discharge valve are closed. Discharge valve is closed. Transmitter waits for a new start signal from the material level meter.
40
2.8.2 For the water-cooled type, the cooling water inlet and outlet valves should be opened; 2.8.3 Press the green start button, contactor picks up until the start indicator (green) lights up, 5 minutes later when the start indicator (green) goes out, the compressor starts running, with running indicator (green) lit up; 2.8.4 Check whether the compressor is functioning properly, with or without abnormal noise, whether the pointer of refrigerant LP gauge dropped to within the normal range of 0.3 ~ 0.5MPa (R22 refrigerant). 2.8.5 If everything is normal, turn on the air compressor and the air inlet and outlet shutoff valves to supply air to the refrigeration dryer, and close the air bypass valve, at this point, the air pressure gauge will indicate the pressure of the air outlet; 2.8.6 After 5 ~ 10min of observation, the air temperature treated by the refrigeration dryer can reach up to the design pressure dew point 2~ 10ć, at this point, the refrigerant HP and LP gauge indicate normal range as follows: Refrigerant low voltage: R22 R407C 0.3 ~ 0.5MPa
R134A 0.1 ~ 0.3Mpa
Refrigerant pressure: R22 and R407C 1.2 ~ 1.8MPa
R134A 0.7 ~ 1.1Mpa
2.8.7 Slowly open the copper ball valve of automatic drainer, so that the condensate in the air flows into the drainer to be discharged thereby. 2.9 Shutdown process of refrigeration dryer: 2.9.1 Open the bypass valve to allow compressed air to continue to flow into the downstream pipeline, and then close the outlet valve of refrigeration dryer; 2.9.2 Close the inlet stop valve of refrigeration dryer, and release the pressure of refrigeration dryer; 2.9.3 Press the red stop button to stop the refrigeration dryer, and cut off the power, open the hand-operated blowdown valve to discharge all the residual condensate. Operation of the refrigeration dryer should pay attention to that: 1. Try to avoid the refrigeration dryer operating with no load for long; 2. Prohibit the refrigeration dryer to start and stop within a short time, the interval should be at least 10 minutes so as to avoid damage to the refrigeration compressor. 2.10 Operation and control of pneumatic ash conveying system 2.10.1 Control mode The control system uses three control modes: full automatic control, remote hand operation and local control. Under normal circumstances, the system uses full automatic control mode. In the full automatic control mode, the operator sends starting or stopping commands to the ash conveying system via the computer keyboard installed in the control room, the whole ash conveying system will run based on the process professional requirements in order. If the system is running conditions are not met, or the selected device has fault, the cause of fault will be displayed on the CRT. In remote hand operation mode, the operator sends commands to equipment of ash conveying system via the computer keyboard installed in the control room, the interlock mode between equipment is the same with that in the full automatic control mode. Local control mode: in maintenance of equipment or commissioning, the equipment operation is controlled manually with the local control box. 2.10.2 Operation mode 39
The tip “*” on upper right corner indicates entering the user parameters setting status. Press the Shift key “
”, there will be a flicker bit, then press the key “
” and “
” to change the
flicker bit, after that, press the Shift key to move the flicker bit to the next one, press the key “
” and
” to change the flicker bit, after editing all the bits in this way, press the confirm key “S” to save data.
“
It may edit other user parameters in the same way. 2.6 Routine inspection of air compressor Period Every day ″ 3 months ″
″
Operation Check the oil level. Check the reading of display screen. Check the cooler, and clean up if necessary Remove the air filter element, clean up with compressed air and check. If the compressor is running in a dusty environment, clean up more frequently. If the air filter element is damaged or contaminated seriously, please replace the air filter element. Check whether all electrical components are operating normally, and tighten the terminals of the main power supply.
The condensate in air may accumulate in the tank, particularly in wet weather, when the exhaust temperature is below the pressure dew point of gas or shutdown for cooling, there will be more condensate precipitated. Oil containing too much water will cause oil emulsification, affecting the safe operation of machine; therefore, condensate should be discharged depending on humidity on a regular basis. The condensate should be discharged after the machine shut down and cooled sufficiently, and the condensate is precipitated sufficiently, such as before startup in the morning. 2.7 Inspection before startup of series refrigeration dryer 2.7.1 Check the cooling system: observe the readings of HP and LP gauge on the instrument panel of equipment, which should reach a balance under a certain pressure, while this equilibrium pressure fluctuates with the ambient temperature, generally around (0.5MPa~1.2MPa). 2.7.2
Check
whether
the
power
supply
voltage
is
normal,
(AC220V/50HZ
±
5%
for
SLAD-0.5NF~SLAD-8.5NF; 3-phase AC380/220V/50HZ ± 5% for above SLAD-10NF). 2.7.3 Check whether the air line is normal, the air inlet pressure must not exceed the working pressure in selection, and the intake air temperature should not exceed that determined in selection as much as possible. 2.7.4. Refrigeration dryers with handling capacity of 30 cubic meters and above are equipped with a compressor oil heater that must be warmed up for more than 8 hours before the equipment is started for the first time (with power on, the heater automatically heats), to ensure that the oil temperature in compressor oil chamber is at least higher than the ambient temperature by 10 ć, otherwise, the compressor will be seriously damaged. 2.7.5 If water cooling mode is selected, you should also check whether the cooling water has been connected to the condenser, cooling water is normal, water pressure is 0.2Mpa~0.4Mpa and water temperature is ≤ 32ć. 2.8 Starting process of refrigeration dryer: 2.8.1 Power on, close the air switch, and the power indicator (red) on the equipment instrument lights up. 38
2.5.2.2.1 Viewing operating parameters Press “
”to view the operating parameters directly: first pressing it to view the total operating time Total operating time: ****hour****minute
Press “
” in order to view the status of the following parameters:
Load running time, main motor current, fan current, current running time, current load time, load/unload pressure, historical fault 1, historical fault 2, historical fault 3, historical fault 4, historical fault 5, date of manufacture, factory ID, user parameters, manufacturer’s parameters, etc. 2.5.2.2.2 Viewing and editing user parameters 1) Parameter editing method
User parameters and manufacturer’s parameters can not be edited in the running state
and
shutdown delay process. It can view and edit the user parameters by aforementioned means of viewing operating parameters, such as edit the upper pressure limit, the operating method of which is as follows: Press the Move upward key “
” or Move downward key “
” to move the black scroll bar to the
display the following screen User Parameter Mfr. Parameter
Then press the Enter key, the following screen will pop out: Low pressure limit 00.50MPa
Again press the “
” key to pop out the following screen on which it is required to input password: Input password: ****
Note: the password can be edited in the User parameters After this screen pops out, there will a flicker bit, at this point the keys “
” and “
Increase and Decrease key, used for editing the data on current flicker bit, the key “
” become
” becomes Shift
key to move the flicker bit, at last, press the confirm key “S” to confirm input. After the system validates correct password, the following screen will pop out: Low pressure limit 00.50MPa 37
ON - Start button: press this button to start the motor running. OFF - Stop button: press this button to stop the motor running S - Confirm key/Load & Unload key: confirm the input after editing data; acts as the load and unload key when the air compressor is running. - Move upward/Increase key: press this key to increase the current position data; to move the the last menu as selecting menu. - Move downward/Decrease key: press this key to decrease the current position data; to move to the next menu as selecting menu. - Shift/Enter key: press this key to shift position as editing data; acts as the enter key as selecting menu. - Return/Reset key: press this key to return to the last stage of menu in menu operation; press this key to reset as shutdown for fault. 2.5.2 2 Status display and operation The unit displays the following screen after powered on: Welcome to use Screw Compressor The following main screen is displayed 5 seconds later Tep.: 10ć Pressure: 00.00 Status: OFF Press the Move Leftward key “
” to view the exhaust temperature:
Tep.: 10ć Pressure: 00.00 Status: OFF
36
Chapter 2 Pneumatic Ash Conveying Operation 2.1 Preparations before air compressor starting 2.1.1 Check whether all the mechanical components and piping of air compressor are in reliable connection, if any loosening, give treatment timely. 2.1.2 Check the compressor oil level, when the oil level is higher than the lowest position on the fuel gauge, the unit can be started for normal operation, and even if the oil level at once cannot be seen after the unit starts running, it will not affect the normal use of the unit. 2.1.3 Turn the coupling manually following the required direction for several rounds to ensure that the unit rotates flexibly. 2.1.4 Check whether the electrical part is in compliance with the requirements of safety regulations, and switch on the power after confirming it. 2.2 Air compressor start 2.2.1 The following procedures should be followed when the air compressor is started initially or restarted after the air compressor and its system equipment maintenance: a. Check whether all the valves are in the right position and the right open or close state; b. Remove all the maintenance attachments for security maintenance (such as the blind plate), and signs for maintenance; c. Check the system and remove the foreign matters inside; d. Open and then close the drain valve again; e. Turn gear for at least a round to ensure that no mechanical interference; 2.2.2 If there is no phase sequence error displayed on the unit control screen after power on, then it can press the “Start” button for normal starting, please verify the correct direction of rotation of the drive motor and rotating equipment after startup, and make sure all the safety devices are in proper operating status. 2.2.3 After unit startup process is completed, the air compressor enters the state of automatic control. 2.3 Air compressor running 2.3.1 After the operation of unit becomes normal, check throughout the unit for oil or air leakage, if any shut down for treatment immediately. 2.3.2 Check whether the exhaust pressure, exhaust temperature and other operating parameters are normal. 2.3.3 Make good job of running records, compare whether various operating parameters are always normal, if there is an abnormal phenomenon, it should promptly shut down and make analysis to find the cause. 2.4 Air compressor shutdown 2.4.1 If it is necessary to stop the running unit, then it only needs press the stop button, the unit will shut down 20-30s after compressor automatically unloads. Do not use the emergency stop button to stop the unit if there is no particular reason. 2.4.2 Cut off power of the unit. 2.5 Air compressor computer controller 2.5.1 Description of keys
35
No. 1 2 3 4 5 6 7
Name Model Type Overall dimension Cooling area Compressed air inlet & outlet temperature Copper tube material Weight
34
Unit
mm m2 ć kg
Hangzhou Shanli SLAD-70NW-ZF Fin type Φ466X1644 85 30/5 T2 180
Working pressure: 0.6-1.0MPa; Working temperature: 0-50ć; Filter element material: Fiberglass; Filter precision: 1μm; DOP efficiency: >99.96%; Service life of filter element: >8760h; Filter differential pressure: 7kPa; Weight: 115kg. 22.3 Main technical data of gas-liquid separator No. 1 2 3 4 5 6 7 8 9 10 11 12 13
Name Model Treatment medium Rated air capacity processed Separation principle Working pressure Pressure loss Dehydration efficiency Model of automatic blowdown valve Discharge interval Discharge time each Case material Capacity Weight
Unit Nm3/min MPa MPa % min s L Kg
Hangzhou Shanli SLAD-70NW-GF Air 69 Stainless steel screen 0.85 0.001 99 RPT-16 0.5 5 Q235B 130 80
22.4 Main technical data of pre-cooler No. 1 2 3 4 5 6 7 8 9 10
Name Model Type Overall dimension Cooling area Velocity of pipe side medium Velocity of case side medium Exhaust port temperature Suction inlet temperature Case material Weight
Unit
mm m2 m/s m/s ć ć kg
Hangzhou Shanli SLAD-70NW-YL Light pipe type Φ412X2074 15 8 7 30 45 Q235B 320
22.5 Main technical data of condenser No. 1 2 3 4 5 6 7 8
Name Model Type Overall dimension Cooling area Velocity of pipe side medium Velocity of case side medium Copper tube material Weight
Unit
Hangzhou Shanli FS15S6 Shell-tube type Φ168X1354 7.8 1.5 0.5 T2 68
mm m2 m/s m/s kg
22.6 Main technical data of evaporator No.
Name
Unit 33
Hangzhou Shanli
No. 1 2 3 4 5
Name Air capacity Intake pressure Ambient temperature Discharge pressure Cooling water amount (water pressure) Cooling water amount (water volume) 6 Discharge temperature 7 Shaft power 8 Specific power 9 Positive and negative rotor shaped wire 10 Oil content of gas outlet 11 Main motor model 12 Nominal power of main motor 13 Service factor 14 Power supply 15 Insulation class of main motor 16 Protection class of main motor 17 Unit noise 18 Unit vibration 19 Unit overall dimension (length × width × height) 20 Unit weight 22. Refrigerated compressed air drier
Unit Nm3/min MPa ć MPa MPa m3/h ć kW Nm3/kW PPm kW
dB(A) μm mm kg
Quantity: 24sets; Air capacity processed: 70Nm3/min; Intake pressure: 0.6-1.0 MPa; Intake temperature: ≤45ć; Pressure dew point: ≤ 3ć; Refrigerant: R22; Pressure loss: <0.02MPa; Cooling mode: Water cooled. 22.1 Pre filter Model: SLAF-70HC; Rated air capacity processed: 70Nm3/min; Working pressure: 0.8Mpa (G); Working temperature: 0-80ć; Filter element material: stainless steel netting and fiberglass; Water diversion efficiency: 99.9%; Filter precision: 3μm; Filter differential pressure: 7KPa; Service life of filter element: ≥ 8760hr; Weight: 115kg. 22.2 Dust removal filter Model: SLAD-70HT; Rated air capacity processed: 70Nm3/min; 32
Technical parameter Remarks 69 0.1013 -5~50 0.8 0.2~0.6 18~51 <40 391 5.7 SAP shaped wire <3 Y2-HV450-4 355 1.2 11KV/50HZ IP54 F 82±2 7.1 4250×1900×2200 7390
e) Chloride (Clˉ): <150 mg/L. 21.3 Technical data of air compressor motor Item Model Rated power Rated voltage Synchronous speed Startup current Rated current Frequency
Primary properties
Unit
Efficiency Power factor Stall torque Stall current Max. torque
Insulation class Weight Cooling mode Rotating direction
Data Y2-HV450-4 kW 355 kV 11 r/min 1500 A 180.6 A 25.8 Hz 50 93.4 0.85 0.8 7.0 2.0 IP54 kg 3700 IC411 Clockwise (viewed from drive end to non drive end)
No.
Name
1
Insulation class/Insulation treatment
2 3 4 5 6 7
Operation factor Temperature rise during operation at full load (resistivity method) (ć) Case/ Ventilation type Case protection degree Type of driving shaft Model of built-in bearing
8
Rotating direction
9 10 11 12 13
Size of junction box (mm) Voltage/Power/Quantity of heater (V/W) Full load current/ Full load current multiple Startup torque under rated voltage/min. startup voltage (multiple) At full load At 3/4 load At 1/2 load Model and specification of recommended lubrication Rotor material Type and model of stator RTD Type and model of bearing RTD Sound pressure level (1 meter away from motor case) dB(A) Model/Code of manufactory base Overall dimension/Chart no. (mm) Weight (kg) Manufactory name
14 15 16 17 18 19 20 21 22
21.4 Summary statement of air compressor performance parameters No. Name Unit 31
Motor F/VPI (Vacuum Pressure Impregnation) S1 80K IC411 IP54 Clutch driving 6328C3/6328C3 Clockwise (can be bidirectional) 535×770 240/2×250 25.8/7.0 11/0.512 93.4/0.85 94.0/0.82 93.0/0.78 Caltex SRI-2 Cu (copper cage) PT100 PT100 94 H450 2169×1416×1084/OG45001969 3700 Huada
Technical parameter Remarks
Item Model Rated power Rated voltage Synchronous speed Startup current Rated current Frequency
Primary properties
Unit
Data Y2 315L1-4 kW 160 kV 0.415 r/min 1500 A 1531.5 A 263.2 Hz 50 % 94.9 0.89 (Times) 2.2 (Times) 5.81 (Times) 205% of the max load F kg ~1150 Air cooling Clockwise (viewed from drive end to motor)
Efficiency Power factor Stall torque Stall current Max. torque
Insulation class Weight Cooling mode Rotating direction 21. Air compressor 21.1 Main technical specifications of the equipment Model: BLT475W.
Type: screw type, low noise, and micro-oil type air compressor. Installation quantity: 24sets. Rated output of air compressor: 69 Nm3/min (101.3KPa (absolute), 20ć air as the standard air). Rated working pressure: 0.8MPa. Cooling mode: Water cooling. Max. ambient temperature: 50ć. Outdoor air suction: Oil content of air compressor outlet air: <3mg/m3. 21.2 Technical parameters for compressor Product model
Overall Equipment Dia. of equipment Dia. of cable dimensions weight exhaust port inlet L×W×H (mm) kg G/DN mm
BLT-475W 4250×1900×2200 (Water-cooled)
7390
DN125
D120/D80
Cable Cooling water Vent. dia. amount volume 2 3 mm m /h m3/h -
25–35
15000
Requirements of cooling water for water-cooling air compressor Cooling water pressure is usually controlled within the range of 0.3-0.4MPa, and inlet & outlet water pressure should be above 0.15MPa. Cooling water temperature should be controlled below 35ć and inlet & outlet water temperature should be around 10ć. Water quality requirement on cooling water: a) PH value: 6.8
Vacuum relief value (Normal value/Max. value): 0.83x10-3MPa; Weight: 512kg; 19. Primary technical data for fly ash handling system (Below is the data for single boiler) System output: No less than200 (with negative pressure˅/No less than 240(with positive pressure)t/h; Ash/Air ratio: Negative pressure conveying: 15.17Kg/kg (average); Positive pressure conveying: 19.24Kg/Kg (average); Air consumption: Average air consumption for unit conveying: 120m3/min; Max. air consumption for unit conveying: 208m3/min (per boiler with positive pressure conveying); Air consumption for unit instrument: 3m3/min; Air consumption for each filter/separator bag cleaning: 1.5m3/min; Power for system operation: Average power: 704kW; Peak power: 1232kW; Power consumption for ash conveying of each ton: 6.16kWh/t; Speed: Negative pressure conveying part: Initial velocity of fly ash conveying pipe: 24.13m/s; End velocity of fly ash conveying pipe: 27.19m/s; Positive pressure conveying part: Initial velocity of fly ash conveying pipe: 6m/s; End velocity of fly ash conveying pipe: 15m/s; 20. Vacuum pump This project is Subcritical Coal-fired Power Plant Unit 6X600MW. And each unit is equipped with one vacuum pump house for ash handling in each of which eight vacuum pumps are set. And there are totally 48 vacuum pumps in unit 6X600 with continuous and intermittent operation mode respectively. Type of vacuum pump: liquid ring vacuum pump; Model of vacuum pump: 2BE4 400-2BY3; Inlet water temperature of cooling water: 33ć (Normal), 36ć(Max.). Inlet water pressure of cooling water: 0.2~0.6Mpa. Pumping capacity: 62.53kg/ min; Suction pressure: -45.06 kPa; Rotating speed: 495 r/min; Efficiency: 47.75%; Shaft power (Design point): 125.4KW; Cooling mode (Air/Water): Air IC411; Water consumption: 7.5m3/h; Technical data of motor 29
Design pressure: 1.0MPa; Design temperature: 180 ć; Nominal diameter: 200mm; Service life of vulnerable part: 8760h; Fittings: Pneumatic triplet/Electromagnetic valve; Weight: 260kg; 15. Exhaust valve of Fly ash conveying device Manufactory: United Energy Group Limited; Model: DN150; Type: Double gate valve; Quantity: 48sets; Design pressure: 1.0MPa; Design temperature: 180ć; Nominal diameter: 150mm; Service life of vulnerable part: 8760h; Fittings: Pneumatic triplet/Solenoid valve; Weight: 180kg; 16. Vacuum breaker Type: ZKF; Quantity: 24sets; Property parameters: -75KPa/-100 KPa; Overall dimension: φ275x308; Interface size: DN150; Air consumption of cylinder: 0.1 m3/min; Weight: 16 kg; 17. Pressure vacuum relief valve (for ash silo) Manufactory: Shanghai Zhongfen Electrics; Model: SFF508; Type: Bob-weight; Quantity: 4sets; Pressure relief value (Normal value/Max. value): 2.58x10-3MPa; Vacuum relief value (Normal value/Max. value): 0.86x10-3MPa; Weight: 126kg; 18. Pressure vacuum relief valve (for surge bunker) Manufactory: UCC India; Model: Type: Bob-weight; Quantity: 24sets; Pressure relief value (Normal value/Max. value): 2.5x10-3MPa; 28
11. Screw conveyor No. Name 1 Equipment model 2 Lifting capacity 3 Blade 4 Distance between center of inlet & outlet 5 Motor parameter Motor model Motor power Motor rotating speed Power voltage Motor insulation class Motor protection degree Motor connection mode
Parameter LCS type 210 16Mn 11 Y180L-4 22 1470 415 F IP55 ‘’Y’’
12. Filter/separator Type & Model: 126W72; Quantity: 24sets; Manufacturer: UCC India; Air filtering volume: 117.8m3/min; Filtering area: 101m2; Filter efficiency: > 99% (by weight); Pulse blowing air amount: 1.5m3/min; Pulse blowing air pressure: 0.55 - 0.7MPa; Filter overall dimension: Φ2.8 X10.4m; Filter weight: 8074kg (without load)/18396kg (at full load); Number & size of bag: 126bags/φ143X1835mm; Air/cloth ratio of bag: <1.21m3/min/m2; Filtering resistance: 1.69Kpa; Filtering speed: 1.17 m/min; Working temperature: 170ć (MAX); Service life: 8760h; Total weight: 8074kg (without load)/18396kg (at full load); 13. Fluidizing slide of pneumatic conveying device Manufactory: Shanghai Zhongfen Electrics. Model: QHPZ150; Type: Nozzle gasifying/fluidizing plate; Quantity: 48sets; Weight: 5kg; 14. Inlet valve of pneumatic conveying device (inlet & outlet valve) Manufactory: United Energy Group Limited; Model: DN200/DN300; Type: Dome valve/Double gate valve; Quantity: 48/48 sets; 27
Unit t/h m
kW rpm V
Remarks
9. Electrical feeder No. 1
2
3 4
Name Equipment model Equipment output Specifications of inlet & outlet flange Motor parameters Motor model Motor shaft output Motor power Motor rotating speed Power voltage Motor insulation class Motor protection degree Motor connection mode Noise Weight
Parameter DS200 200 600X600 Y132S-4 4.78 5.5 1440 415 F IP55 ‘’Y’’ 85 638
Unit
Remarks
t/h
kW kW rpm V
dB(A) kg
10. Twin shaft mixer of ash unloading system for ash silo No. 1 2 3 4 5 6 7 8 9 10 11 12 13
14
15 16 17 18
Name Equipment model Equipment quantity Equipment output Max. output of equipment Min. output of equipment Equipment length Moisture content of wet ash Water supply Water supply pressure Flange of water supply pipe Lubrication type for bearing Rotating speed of main bearing Motor parameters Motor model Shaft power of motor Motor power Motor rotating speed Power voltage Motor insulation class Motor protection degree Motor connection mode Parameters of speed reducer Reducer type Reducer model Transmission ratio Output rotating speed Motor insulation class Motor protection degree Driving mode Case material Case thickness Noise Weight
Parameter SZ200D 2 200 200 200 4.49 20~25 50~67 0.2~0.6 PN1.0, DN100 Grease 42 Y225M-6 26 30 980 415 F IP55 Y cycloidal-pin wheel BWY45-23-30 1:23 42 F IP55 Chain 16Mn 10 85 6800
26
Unit
Remarks set t/h t/h t/h m % m3/h MPa
r.p.m
kW kW rpm V
rpm
mm dB(A) kg
7.2 Fluidizing blower Item Model Rated power Rated voltage Synchronous speed Startup current Rated current Frequency Efficiency Power factor Primary Stall torque properties Stall current Max. torque Insulation class Weight Cooling mode Rotating direction
Unit
Data Y280S-4 kW 75 kV 415 r/min 1480 A 70.4 A 70.4 Hz 60 % 91.8 0.87 (Times) 1.9 (Times) 7 (Times) 2.2 F kg 303 Air cooling Clockwise (viewed from drive end)
8. Dry ash unloader No. Name 1 Model 2 Handling capacity 3 Diameter of discharge pipe 4 Specification of flange at ash entrance 5 Specification of flange at ash discharge interface 6 Travel of unloading head 7 Lifting speed of unloading head 8 Parameters of lifting motor Motor model Motor shaft output Motor power Motor rotating speed Power voltage Motor insulation class Motor protection degree Motor connection mode 9 Parameters of dusting blower Flow rate Air pressure Specification of dust outlet flange Motor model Motor shaft output Motor power Motor rotating speed Power voltage Motor insulation class Motor protection degree 10 11 12
Data Y160M-4 11 415 1460 22.6 22.6 60 88 0.84 2.2 7 2.2 F 130 Air cooling
Parameter ZSJ200D 200 Φ350 PN 0.6, DN300 PN 0.6, DN125 2000 0.1 YEJ90S-6 0.5 0.75 940 415 F IP55 ‘’Y’’ 824 3660 PN0.6,DN125 Y100L-2 2.6 3 2880 415 F IP55
Motor connection mode
‘’Y’’
Type of bin level indicator Model of bin level indicator Noise Weight
Solid tuning fork type FTN50 85 550
25
Data Y250M-4 55 415 1480 102.5 102.5 60 92.6 0.88 2 7 2.2 F 425 Air cooling
Unit t/h mm
mm m/s
kW kW rpm V
m3/h Pa
kW kW rpm V
dB(A) kg
5. Bag dust collector on silo top Type and model: MDQ200; Quantity: 8 sets; Manufactory: Shanghai Zhongfen Electrics Co., Ltd. Air filtering volume: 320m3/min; Filtration area: 200m2 /set; Filtration efficiency: >99.9%; Air volume blown by pulse: 3.5 m3/min; Air-blowing pressure of pulse: 0.5 -0.7MPa; Overall dimension of filter: 8060x3860x4500mm; Filter weight: 15371Kg; Number and dimension of bags: 260bags/ φ120X2050mm; Bag air/cloth ratio: 1.21m3/min/m2; Filtration resistance: 1200 Pa; Filtration velocity: 0.8 m/min; Working temperature: 180ć (MAX); Time required for replacing a bag: 40hours; Service life: 30000h; Total weight: 15371Kg. 6. Surge tank (equipped with fluidizer) Type: Steel structure; Quantity: 24; Volume: 100 m3; Design pressure: constant pressure; Overall dimension: φ6000X15000mm; Weight: 20 T. 7. Motor data 7.1 Ash silo unloading system Item Model Rated power Rated voltage Synchronous speed Starting current Rated current Frequency
Primary properties
Insulation class Weight Cooling mode Rotating direction
Unit
Efficiency Power factor Stall torque Stall current Max. torque
Data Y225M-6 kW 30 kV 415 r/min 980 A 59.5 A 59.5 Hz 60 % 92.4 0.84 (Times) 2.18 (Times) 5.8 (Times) 2.17 F kg 272 Air cooling Bi-directional, viewed from drive end 24
Data YEJ90S-6 0.75 415 920 4 4 60 76.8 0.764 2.41 4.22 2.2 F 32 Air cooling
4.2 Air preheated fluidizing air heater for ash hopper No. Name Parameter Zhenjiang Power Station 1 Manufactory Auxiliary Equipment Plant 2 Type Horizontal type 3 Model DYK15(II) 4 Quantity 12 5 Power 15 6 Voltage 415 7 Heating air flow 3.5 8 Max. allowable air temperature 150 9 Specification for outlet and inlet flange DN100 10 Temperature control precision 0.5 11 Temperature control range 0~400 12 Type of temperature measurement Double 13 Measurement range of temperature measurement 0~400 14 Power of each heating element 2.5 15 Design pressure of the case 0.8 16 Insulation class F 17 Weight of each heater 175 4.3 Fluidizing air heater for ash silo No. Name 1
Manufactory
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Type Model Quantity Power Voltage Heating air flow Max. allowable air temperature Specification for outlet and inlet flange Temperature control precision Temperature control range Type of temperature measurement Measurement range of temperature measurement Power of each heating element Design pressure of the case Insulation class Weight of each heater
4.4 Fluidizing device at silo bottom No. Name 1
Manufactory
2 3 4 5 6 7 8 9
Type Model Quantity Size of fluidizing device (width × thickness) Air penetrability of fluidizing plate Max. allowable temperature of fluidizing device Resistance of fluidizing device Weight of fluidizing device
Unit
Set kW V Nm3/min ć Grade ć ć kW MPa kg
Parameter Zhenjiang Power Station Auxiliary Equipment Plant Horizontal type DYK80(II) 4 80 415 21.16 150 DN150 0.5 0~400 Double 0~400 4.44 0.8 F 220
Unit
Parameter Zhenjiang Power Station Auxiliary Equipment Plant Side air intake KXC150 720 150X25 0.6~0.8 300 4 16.5
Unit
23
Remarks
Remarks
Set kW V m3/min ć Grade ć ć kW MPa kg
m mmumm m3/m2×min ć KPa kg/m
Remarks
3.3 Fluidizing blower for ash silo No. 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 3 3.1 3.2 3.3 4
Name Fluidizing blower Model Quantity Flow rate Outlet pressure Outlet temperature Driving mode Fan series Cooling mode Noise (noise one meter away from equipment case and ground should not exceed) Motor Model Bearing power Electric power Number of rotates Power voltage Motor insulation class Motor Protection degree Motor connection mode Blimp cooling fan Electric power Motor Protection degree Motor insulation class Total weight of equipment
Parameter SNH811 6 21.16 90 111 Driving belt Single-stage Air cooling 85 Y250M-4 47.8 55 1480 415 F IP54 ‘’Y’’ 0.18 IP54 F 1450
Unit
Remarks
Set Nm3/min KPa ć % dB(A)
kW kW r.p.m V
kW
kg
4. Fluidizing air heater In the project, each boiler is equipped with 2 fluidizing air heaters for dust collector ash hopper, 12 of which, located in fluidizing blower chamber, are set for unit 6X600MW. Each boiler is allotted with 2 air preheated fluidizing air heater for ash hopper, 12 of which are set for unit 6X600MW. Fluidizing air heater are set indoor close to boiler and 6 fluidizing air heaters for ash silo are set for 4 ash silos. It uses continuous operation mode. 4.1 Fluidizing air heater for dust collector ash hopper No. Name 1
Manufactory
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Type Model Quantity Power Voltage Heating air flow Outlet air temperature Specification for outlet and inlet flange Temperature control precision Temperature control range Type of temperature measurement Measurement range of temperature measurement Power of each heating element Design pressure of the case Insulation class Weight of each heater
Parameter Zhenjiang Power Station Auxiliary Equipment Plant Horizontal type DYK90(II) 12 90 415 33 150 DN150 0.5 0~400 Double 0~400 4.67 0.8 F 220 22
Unit
Set kW V Nm3/min ć Grade ć ć kW MPa kg
Remarks
3.1 Fluidizing blower for dust collector ash hopper No. 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 3 3.1 3.2 3.3 4
Name Fluidizing blower Model Quantity Design flow rate Outlet pressure Outlet temperature
Parameter
Fan series Cooling mode Noise (noise one meter away from equipment case and ground should not exceed) Motor Model Bearing power Electric power Number of rotates Power voltage Motor insulation class Motor Protection degree Motor connection mode Blimp fan Electric power Motor Protection degree Motor insulation class Total weight of equipment
SNH817 12 33 70 130 Driving belt Single-stage Air cooling 80 Y280S-4 65.2 75 1480 415 F 54 “Y’’
Unit
Remarks
Set Nm3/min KPa ć
dB(A)
kW kW r.p.m V
0.18kW IP54 F 1450
kW
Parameter
Unit
kg
3.2 Air preheated fluidizing blower for ash hopper No. 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 3
Name Fluidizing blower Model Quantity Flow rate Outlet pressure Outlet temperature Driving mode Fan series Cooling mode Noise (noise one meter away from equipment case and ground should not exceed) Motor Model Bearing power Electric power Number of rotates Power voltage Motor insulation class Motor Protection degree Motor connection type Total weight of equipment
21
SNH803 12 3.5 70 92 Driving belt Single-stage Air cooling 85 Y160M-4 9.6 11 1460 415 F IP54 ‘’Y’’ 560
set Nm3/min KPa ć
dB(A)
kW kW r.p.m V
kg
Remarks
ash silos. The air source for conveying is supplied by air compressor of dust collector. The largest conveying distance is approximately 1000meters (excluding lifting height). 2. Design parameters of system No.
Item
:
Secondary ash handling system
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Ash volume of design coal Ash volume of checked coal System output Conveying distance Number of ash hoppers per electric field Ash deposit proportion Gas velocity at pipe terminal Initial temperature Selected conveying pressure Fr(min) Ash distribution conditions Normal Volume after resting Pump diameter Pump quantity Number of units for each pipe
: : : : : : : : : : : : : : : :
114.0 142 240 1000 8 0.75 30.8 110 2.35 6.5 8 vessel transporters 240 10 300 2 4
17 19 20 21 22 23 24 25 26 L7 28 29 30 31 32 34
Time for single cycle Max. system output System gas consumption(T) Average gas consumption(T) Ash air ratio
: : : : :
225.0 240.0 120.0 208.0 11.9 Segment 1 0.3 3.0 0.0 340.0 11.1 15.1 0.9 3.4 2.5 2.35
Diameter for each segment Bend quantity Vertical climb Length of each segment Velocity at fore-end Velocity at terminal Resistance P2 P1
: : : : : : : : :
t/h t/h t/h m Piece t/m3 m/s ć Bar
t/h m mm
s t/h m3/min m3/min Segment 2 Segment 3 0.4 0.4 3.0 4.0 0.0 30.0 340.0 320.0 11.1 11.1 14.5 15.0 0.6 0.9 2.5 1.9 1.9 1.0 Bar
m m m m/s m/s Bar Bar Bar
3. Fluidizing blower In this project, each boiler is equipped with 2 fluidizing blowers for dust collector ash hopper and there are totally 12 fluidizing blowers for dust collector ash hopper in unit 6X600MW. Fluidizing blowers are located in chamber of fluidizing blower. There are two air preheated fluidizing blowers for ash hopper for each boiler and totally 12 sets of air preheated fluidizing blowers for ash hopper for unit 6X600MW.Fluidizing blowers are arranged outdoor close to boiler and there are 6 ash silo fluidizing blowers for 4 ash silos. The fluidizing blower uses continuous operation mode.
20
PART 2 Pneumatic Ash Handling Chapter 1 Equipment Overview 1. Pressure concentrated phase pneumatic ash handling system is applied to secondary ash discharge under intermediate bin of coal-fired unit 6X 600 MW of this project. One boiler is a conveying unit and there are 6 conveying units in total. Conveying system employs LPT type vessel transporter to send ash to terminal ash silo. There are two terminal ash silos for three boilers, each of which has 4 intermediate bins. And each bin is equipped with 2 ash hoppers and there is one LPT transmitter under each ash hopper. Each primary ash conveying system has two ash conveying pipes and each pipe has one silo top changeover valve and one discharge box at terminal located at ash silo, on which two bag dust collectors are arranged. Every conveying pipe is equipped with 4 transmitters LPT10000 in four units, each of which includes one transmitter and one discharge valve while the pipe diameter is DN300-DN350-DN400. Transmitter of each unit has one set of air inlet valve block on initial end. Another set of air inlet valve block is arranged after discharge valve on each ash conveying pipe. Each boiler is a control unit and each transmitter has one local control box which is also arranged at blowing valve block and changeover valve over ash silo. Each ash silo has three bin level indicators (high, low and continuous bin lever indicator). Each transmitter is installed with one bin level indicator. In this project, each boiler air preheated has 8 ash hoppers in total; hence unit 6×600MW totally has 48 ash hoppers. Coal-fired unit 6X600MW of this project is equipped with 4 ash silos with reinforced concrete structure (Ash silo no. is 1, 2, 3, 4 respectively). The diameter of each ash silo is 15m and the effective volume is 3970m3. Two ash silos can store fly ash produced from worst coal fired no less than 12 hours in three boilers under BMCR working conditions. Ash silo ash unloading system is a system guaranteeing the normal ash unloading of the ash silo. All equipments of this system are located over the ash silo operating layer; when discharging ash, equipments in system should apply continuous operation mode. Diameter of each ash silo is Ø15 m and the silo height is 38.5m while the stored ash height is 24m. Ash handling system of this project applies vacuum conveying system first to collect fly ash from ash hopper of dust collector, air preheater and economizer into the surge tank and then into ash silo through pressure pneumatic conveying system. Output of pressure and vacuum pneumatic conveying system should be no less than 200t/h according to the requirement in contracts and technical documents. Vacuum pneumatic conveying system means that ash hoppers in one electric field of electrostatic dust collector are connected in series with ash hoppers in three bins of bag dust collector through one pipe and there are 8 pipes in two electric-bag dust collectors. Two adjacent pipes will be combined into one pipe, hence there would be four pipes in total, which will be connected to four surge tanks respectively, supplied with air source by vacuum pump and the fly ash in ash hopper will be conveyed into surge tanks. Output of each pipe is 50t/h. Pressure pneumatic conveying system means: two pneumatic conveying devices under each surge tank are connected respectively to two conveying pipes. Each boiler has two pipes and output of each conveying pipe is 120t/h. There boilers form a unit equipped with two ash silos. Three boilers with six conveying pipes are connected to two ash silos and each pipe can convey fly ash in surge tank respectively into two 19
bag and bag cage is applied. 6)
Check the sealing property of manhole door, access door and flange to ensure its air tightness.
7)
Check whether there is rain leakage in the insulation layer or rainproof facilities.
8)
Check differential pressure and if the pressure pipeline is smooth.
9)
Check and timely replace the gasket of bypass valve in bypass flue if there is damage.
10) Maintenance should be applied to electric apparatus and other general-purpose equipments according to its corresponding instructions and general provisions. 3.4.3 Maintenance Only after three-year operation, the overhaul will be implemented and it lasts 5 to 15 days. The content of overhaul is a thorough maintenance and adjustment based on the equipment conditions according to the faults checked but not resolved timely in medium and minor overhaul, damaged and rusted parts and wearing and normally aging parts need to be replaced. Preparation before overhaul should be performed as the below table: Repair items
Work out maintenance plan
Make material preparation and site layout
Prepare relevant tables for technical records Take safety measures
Techniques and Precautions Check operation parameters of electric field before electric-bag compound dust collector stops running(secondary voltage, current, operation rate, operation hours and so on), operation parameter of ash removal system and spray cooling system, equipment defects, the last summary of overhaul and maintenance records since the last overhaul(such as the technical measures for improvement, replacement with spare parts or repair pieces), and work out overhaul plan through in-depth analysis of various materials: Work out maintenance control schedule, technique process, labor organization plan and the matching condition; Draw up detailed regulations of technique and safety for major special projects.
Material preparation work includes the preparation of materials, spare parts and repair pieces, safety tools, construction equipments, instruments and meters, lighting appliances. Maintenance site layout work includes site cleaning, dividing of working area and material stacking area, management measures of field spare parts and so on.
There should be tables for electrodes spacing test record , record card for test of electrified unload electric field with voltage rising and recording tables required in air distribution test, rapping acceleration measuring, air leakage rate measuring (if necessary). Process various work sheets and take safety measures strictly according to relevant security operation regulations.
18
Quality standard
The plan is to be approved by technology department; and to be checked by safety supervision department if major safety measures are involved.
Safety tools should be checked by full-time or part-time safety officer; the lighting appliances inside electric field should be torches or 12v portable lighter. If 220V lighting or power maintenance is needed, electric shock protector should be installed and knife switch should be mounted in conspicuous place outside of manhole door which is to be protected by specially-assigned person.
Checked and accepted by work approver jointly with maintenance head on site.
3.3 Regular maintenance 3.3.1 Check regularly if rapping device is working normally. 3.3.2 Each heater should keep working when dust collector is disabled temporarily. 3.3.3 During temporary shutdown period, each rapping device should keep rapping for more than 10 hours before it stops. 3.3.4 Each shift should open ball valve once at air bag bottom of bag ash removal system to release the condensed water produced by compressed air in air bag. 3.3.5 Regularly check the acting situation of each pulse valve in bag ash removal system and handle it timely when it doesn’t act. 3.3.6 Regularly clean the filter of lifting valve air passage triplet and regularly fill clean engine oil into oil sprayer. 3.3.7 Regularly check acting situation of lifting valve. 3.3.8 Regular maintenance should be applied by electrical personnel to the below devices: 3.3.8.1 Regularly test and check high voltage silicon rectifier transformer and test its insulation resistance, which should be close to zero when high voltage forward against the ground and should exceeds 1000MΩ when it reverse against the ground. That of primary sides should exceed 300MΩ. 3.3.8.2 Perform a withstand voltage test per year for transformer oil and average of puncture voltage should be more than 35kV/2.5mm. 3.3.8.3 Grounding resistance should be tested per year and it should be less than 2Ω. 3.3.8.4 Fault trip circuit action test should be performed each year. 3.4 Repair/Maintenance 3.4.1 Minor repair Minor repair should be performed every six-month operation of electric-bag compound dust collector, which mainly includes: handle inner equipment faults, clean ash deposit inside electric field, check and adjust anode rapping system operation condition, check and adjust the deformation of space between electric field electrodes, wipe up insulation porcelain pieces, check whether ash discharging system is smooth, rectify indicating instrument, check the accurate situation of temperature measurement, check the sealing situation of ash removal air passage and the fastening of blow tube, check the changes after filter bag and bag cage is applied. 3.4.2 Medium repair After about one-year operation, a medium repair should be performed which will last 2 to 5 days with the content as follows: 1)
Clean ash deposit inside electric field and check space between electric field electrodes to make sure
deviation doesn’t exceed the specified value. 2)
Check the internal parts and just simply cut off the discharge electrodes if it is broken or unsoldering
and replace with new one if time allows. 3)
Check whether the anode rapping hammer is at the valid position of center area of rapping anvil, and
adjust it properly if there is deviation. Check the wear situation of rapping bearing and hammer and replace with new ones if the wear is serious. 4)
Check, replace and clean the insulated bushing and porcelain shaft if there is damage or wear to
guarantee its insulation performance. 5)
Check the sealing of ash removal air passage and fastening of blow tube. Check the changes after filter 17
No.
Fault
3
Dust collection efficiency of the former-stage dust collector Resistance of latter-stage declines, and dust bag rises rapidly concentration in latter-stage bag dust collector increases.
4
(1) New filter bag is applied There is obvious visible and dust collection is not flue gas in chimney stable yet. (2) Particular filter bags are outlet. damaged.
5
6
Causes analysis
Differential pressure of certain chamber deviates Particular filter bags are the normal value damaged in the chamber. obviously (1) Air passages released Pulse valve solenoid coil pressure in pulse valve outer has been turned on but chamber are blocked. pulse valve fails to act. (2) Electromagnet fault.
7
Air bag pressure alarm
8
Lifting valve fails to act.
9
Obvious sound of air leakage in air bag can be heard.
10
Air escapes from blowhole of cylinder reverse flow valve.
11
Bag pastes.
Solutions (1) Operation condition of former-stage electric dust collector is poor or has fault. Adjust the secondary voltage and current of electric field and shorten rapping period. (2) Former-stage electric dust collector fault cannot be eliminated temporarily/ Shorten ash removal pulse interval properly. (1) Dust collection will go steady after the new filter bags are in operation for several weeks. (2) As to the compartment with checked differential pressure less than outlier, close the lifting valve of this compartment to get blocked off or replace the damaged filter bags. See the treatment process in 4(2)
(1) Check or clear air passages released pressure in pulse valve outer chamber. (2) Replace solenoid coil.
(1) Air source pressure or output of compressed air is insufficient. (2) Seal the leakage point as there is Pressure beyond limit is not relatively big leakage in air passage. within range of 0.2~0.3Mpa. (3) Clear out the foreign body as piston of pressure reducing valve is blocked with foreign body. (1) Cylinder solenoid valve (1) Replace the solenoid valve. doesn’t conduct. (2) Air pressure supplied is (2) Check air passage. insufficient. (1) Close ball valve at air bag bottom. (1) Ball valve at air bag (2) Lock tight connecting pieces of air bottom is closed incomplete. bags. (2) Connecting pieces of air (3) Conduct the pulse valve manually bags are not sealed. and clear impurities in diaphragm (3) There are impurities in outlet. Cut off the air source for air diaphragm outlet of pulse bags when necessary and dismount pulse valve to clear impurities when valve. pressure declines. Open the end-cap of reverse flow valve Inner piston of reverse flow with Allen wrench and pull out the valve is stuck by foreign body. piston to remove foreign body and get piston installed. High moisture and low After the dew condensing phenomenon temperature of flue gas causes is removed, filter bag pressure will dew condensing, high restore naturally. viscidity between dust and filter bag. And the ash removal becomes invalid.
16
No.
Fault
Cause analysis
Solution (1) To check whether the rapping device of air distribution plate works. (2) Check the baffle plate for proper treatment. (1) Air distribution plat holes (3) Strengthen the sealing of ash are jammed and the air isn’t discharge device and handle the reasons distributed evenly. for air leakage. (2) Baffle plate of ash hopper (4) a. Adjust the rapping force, time and Primary and secondary and the case has dropped off period; current and voltage is and the air flow has short b. Improve air distribution normal but the dust circuit. 11 c. Enhance the sealing and adjust switch collection efficiency is (3) Ash discharge device near board and the whole system for less air not satisfactory. outlet has serious air leakage leakage. problem and inlet air volume is d. Apply wet ash removal out of limit. e. Reduce the air speed of electric field (4) Secondary dust flying. f. Provide ash collection device at outlet (5) Flue gas condition has of electric dust collector. changed. g. Prevent back corona from happening h. Adjust spark frequency control i. Improve dust resistance ratio (5) Improve flue gas condition (1) Except electric field, other parts like isolation switches, (1) Handle the discharge parts. high voltage cable and damping (2) Adjust spark frequency resistor discharge. potentiometer and set it to automatic (2) Spark frequency of electric state. control cabinet is not properly (3) Adjust rapping period. Flashover is too frequent (4) After boiler is disabled, enter the adjusted. 12 and ash collection (3) Rapping periodic time of electric field for inspection and efficiency declines. front electric field is not up to eliminate the abnormal discharge parts. (5) Notify shift supervisor for adjusting standard. (4) As the working condition technological condition and improving changes, flue gas condition flue gas condition. fluctuates a lot. (6) Adjust the tap position. (5) Tap is not adjusted properly.
3.2 Fault causes and solutions of bag system No.
Fault
Causes analysis
Solutions
1
Preheater outlet temperature keeps Boiler may constant rapid rising and combustion control system gives overtemperature alarm
2
Preheater outlet temperature suddenly drops sharply and the Boiler may has tube explosion control system gives fault temperature ultra-low alarm/
has
15
Contact boiler center console. Stop the tail boiler resolutely when temperature keeps rising up above 190ć in case the filter bags are burnt. Contact boiler center console and stop boiler resolutely when it drops below dew point temperature in case dew condensing causes bag paste and wall wetting.
No.
Fault
Cause analysis Solution Discharge electrode break causes the short circuit between dust plate and corona electrode. (2) Dew condensation of (1) Clear short circuit sundries or cut insulator out broken corona wire. pressure-bearing inner wall causes the high (2) Wipe inner wall of pressure-bearing voltage short circuit to ground. insulator or raise temperature of (3) Corundum magnetic axis insulation box. of cathode rapping device is (3) Replace corundum magnetic axis damaged or short circuit to the (4) Replace the damaged cable or cable joints. Secondary current is ground is caused. large, but secondary (4) High voltage cable or cable (5) Remove the ash deposit in lower 6 voltage rise is poor or terminal joint has breakdown ash hopper. short circuit. even close to zero. (6) Clean the pressure-bearing (5) There is too much ash insulator, supporting insulator and deposit in ash hopper and the corundum magnetic axis. dust has piled up to corona (7) Change the flue gas conditions. Moisten the flue gas with steam. polar framework. (6) Pressure-bearing insulator, Chemical quenching and tempering supporting insulator and should be implemented on flue gas and corundum magnetic axis are power should be supplied with pulse. damp and covered with ash deposit and that causes creepage. (7) Back corona. (1) Partial distance between Secondary working electrodes becomes small. (1) Adjust distance between electrodes. current is normal or too (2) Sundries are hanging on (2) Clear sundries 7 large, secondary voltage dust plate or cathode electrode. (3) Replace the cable is low with flashover. (3) Cable breakdown or has power leakage. (1) Rapping device on dust electrode or corona electrode (1) Check and repair rapping device. is not started or doesn’t work. (2) Analyze the reason of loose wire Secondary voltage is too (2) Corona wires are wide and and take necessary measures. 8 high and secondary loose or power discharge is (3) Improve the technological current is strikingly low poor. processing to reduce dust density in (3) Dust density in flue gas is flue gas. too large. (1) Capacitor parallel connected with milliammeter is damaged and that causes short Secondary voltage and circuit. primary current is normal. Figure out the causes and eliminate 9 (2) Connection lead from Secondary current doesn’t faults transformer to milliammeter is read. grounded at a certain place. (3) Milliammeter pointers are stuck. (1) Corona wire is broken and its remaining segment swings Secondary current is not caused by flow influence. Cutoff the remaining segment. stable and the (2) Humidity of flue gas is too Notify the technologist for proper 10 milliamphere pointer is large and the dust resistance treatment. Deal with the discharge part. ratio declines as a result. swinging sharply. (3) Cathode insulators discharge to ground surface. 14
Chapter 3 Routine Maintenance and Treatment 3.1 Fault causes and solutions of former-stage electric filed: No.
1
2
3
4
5
Fault Primary and secondary voltage is low; secondary current is small. Primary current is too large and it rises rapidly out of proportion with secondary current. Voltage rises without current emerging. When the voltage is in normal operation, voltage starts declining and current emerges and rises rapidly. Primary and secondary voltage is low and secondary current is small. The primary current is very large and when it is rising, primary and secondary current is out of proportion. The primary current will rise rapidly and mutates until nearly come to detonation fuse. There is obvious abnormal sound in transformer. When primary and secondary current reaches the rated value, the primary voltage will be within 280~330V and secondary voltage within 40~50kV without flashover. Primary and secondary current, primary voltage keeps normal without change. The secondary voltage indicator is swinging or it will indicate higher after power cutoff.
Cause analysis There is interturn short circuit in rectifier transformer or open circuit or breakdown short circuit in silicon stack.
(1) Dust resistance ratio is too high and it causes back corona; (2) Coal quality and processing operation is poor.
Solution Perform open circuit test. If there is current in primary sides, it means there is certain part damaged inside transformer, partial excitation or short circuit. Pendant-core repair is necessary and damaged part should be replaced. (1) Usually the power plant will improve the coal quality and processing operation to get coal fully combusted for enhancing rapping force. (2) Intermittent pulse power supply is applied.
(1)Rectifier transformer low pressure short circuit fault; (2)Iron core (including core (1) Replace the low pressure package; perforating bolts) insulation of (2) Redo the iron core insulation. rectifier transformer is damaged and vortexing is serious.
(1) Dust density is low and the electric field is without load; (1) Decline the rapping force; (2) High voltage cable and (2) Redo the high voltage cable and terminal head has serious terminal head. leakage.
(1) Secondary voltmeter has loose moving coil screws; (1) Recalibrate. (2) Affected by charged dust of front electric field.
13
field and its subordinate equipments should be disabled. Make sure the power supply and flue gas is isolated and dust collector temperature drops below 40ć and the working site has reliable grounding connection and reliable safety measures are made. If there is toxic or explosive gas, don’t enter the electric field immediately in case accidents happen. 4)
Before entering dust collector, high voltage isolation knife switch should be put to position
“grounding” and the electric discharge part of high voltage silicon rectifier transformer output end should be discharged with ground rod and be grounded reliably to prevent remnants of static electricity from hurting people. 5)
It is prohibited to contact discharge electrodes if there is no reliable grounding connection in advance
though the power supply is cut off in all electric fields. 6)
Before entering dust collector, stored ash in ash hopper should be discharged and get it fully ventilated
and checked. Only when there is no toxic gas inside, can the work start. 7)
None of the grounding devices of each parts of electric precipitation area should not be dismounted
casually. 8)
Platform inside electric precipitation area maybe of corrosion as has been immersed in flue gas for
long. Special attention should be paid to the corrosion of platform at entering in case the platform damage causes personal injury accident. 9)
Confirm that there is nothing left inside dust collector before leaving the precipitation area.
10) Operating area should be well lighted and the passages should be clear and all manholes should be closed tightly.
12
shorten properly the rapping periodic time and vice versa. 13) Control operation strictly according to electric-bag compound dust collector parameters: A. Differential pressure of filter bag: 400~800Pa; B. Differential pressure of dust collector inlet & outlet: 900~1200Pa 14) Strictly select ash removal type in order of priority as below: A. Online ash removal: favored type; B. Offline ash removal: deprecated type. Only applied when flue gas and dust is abnormally fine and sticky and filter resistance exceeds the normal range. C. Timing ash removal: favored type D. Timing constant pressure ash removal. 15) Set ash removal system parameters strictly according to the below ranges: A. Pulse pressure: 0.2~0.3Mpa, from low to high when adjusting; B. Pulse width: 0.15S (unadjustable); C. Working pressure of lifting valve cylinder: 0.35Mpa; D. Pulse interval: 5~1000s; 16) Set working temperature points of bypass flue strictly according to below motioned tips: A. It is normal when flue gas temperature≤160ć, the bypass flue should be closed and protection air passage should be open. B. When flue temperature>160ć, there is high temperature alarm; when flue temperature>180ć, bypass valve of control system should be open and lifting valve will be closed. And that time, the flue gas will be discharged directly to dust collector outlet. C. When flue gas temperature restores to and under 160ć, lifting valve in bag area of control system will be open and bypass valve will be closed. And then flue gas will enter dust collector as normal. 17) During temporary shutdown, each rapping device should keep rapping for more than 10 hours before it stops. 18) When dust collector is disabled temporarily, heating devices should be kept going on working. 19) Each shift should conduct a comprehensive inspection for electric-bag compound dust collector and do cleaning work within the scope of responsibilities. Make detailed records of abnormalities and equipment defectors during this operation and do the shift hand over working well. 2.9 Safety precautions As high voltage power is applied in dust collector operation, relevant regulations in Working Regulation of Power Safety should be strictly implemented and special attention should be paid on personal and equipment safety during operation. 1)
It is forbidden to open the high voltage isolation switch cabinet and the cabinet door should be closed
tight. 2)
When the dust collector is in operation, it is forbidden to open seal-capping of all doors or manholes.
If it needs to open insulation manhole door, get permission from attendant on duty and make effective safety measures. 3)
As to working inside dust collector, work sheet system should be implemented strictly and the electric 11
5) Shut down the equipment when the above mentioned points are distinguished as the ambient factors threatening equipment. 6) There is slight creepage phenomenon in starting system and it disappears after a while. 7) There is ash block in ash hoppers but it can be removed timely. 2.8 Check and adjustment during operation 1) Operation parameters can be properly lowered (usually through adjusting current limit value for current-limiting) to keep electric field in operation when electric equipments are overheated caused by poor operating conditions, for example, highly arranged rectifier transformer and damping resistor is overheated during operation under moon hot weather, components is overheated resulted from thyristor cooling fan fault. If the former-stage electric field has a declined capacity of ash discharge, the ash can be properly transferred to the latter stage by lowering the operation parameters of the electric field. 2) Adjustment of rapping control mode: Rapping frequency can be increased properly and rapping interval will be shortened consequently when ash accumulates heavily on electrodes; and rapping interval can be properly prolonged conversely. 3) When the differential pressure of filter bags in bag area rise up to 1500Pa for long, shorten the ash removal periodic time till the differential pressure declines down to normal value. 4) The ash discharge mode is automatic ash discharge based on the high ash level. During ash discharging, if ash level signal doesn’t work, it can be switched ion successive ash discharging. It can also be operated in the way of simulated automatic ash discharging by programmable controller according to electric field conditions to keep certain ash seal to ash hopper. 5) Closely supervise primary voltage and current, secondary voltage and current, flashover frequency of power supply equipment. Records should be made per 2 hours. Each shift should check the temperature-measuring thermometer works normally. 6) Strictly monitor temperature of preheater outlet and dust collector inlet and outlet and usually, make records per 2 hours 7) Strictly monitor the differential pressure of filter bag, pressure of dust collector inlet and outlet, ash removal pressure, working pressure of lifting valve, pulse interval and ash removal period. And the records should be made per 2 hours usually. 8) Monitor the temperature rise of high voltage silicon rectifier transformer and it should not exceeds above 80ć without abnormal sound. Abnormal discharge phenomenon should not happen to high voltage output network. 9) Check each insulation box and ash hopper heater should be working normally. 10) In case of fault or misoperation for dust collector and auxiliary equipment during operation, operators should go to site to confirm fault point immediately after receiving alarm notice, analyze the cause and contact for treatment. 11) Each shift should check twice all motors, speed reducers, bearings and outer operating parts. Check the lubrication of lubrication points regularly and add lubricating oil or grease when necessary. 12) Adjust periodic time of anode and cathode rapping according to dust collector inlet & outlet flue gas condition. When the inlet flue gas density is large, secondary voltage high and secondary current small, 10
rectifier transformer and control cabinet for the sake of anti-interference; 3) Neither high voltage isolation room nor dust collector body should be entered during operation of high voltage equipment. 4) It is forbidden to run ash removal system of bag dust collector during ash pre-coating and ignition of boiler oil spray for combustion-supporting till the boiler burns coal at normal furnace temperature, to prevent ash-coated layer from falling off and losing the protective effect of anti-dewing resulted from low temperature. 5) Continuous ash pre-coating of a small quantity should be implemented when time spent on the process of boiler ignition of oil spraying for combustion-supporting exceeds 2 hours. 6) Try to prolong the ash removing period on the condition that differential pressure of filter bag is within the allowable range. 7) Temperature-measuring thermometer after the preheating should be timely replaced if there is a fault (or wear) to ensure a normal operation of system. 2.6 Conditions for immediate shutdown of equipment 2.6.1 Electrical part: 1) Rectifier transformer and reactor are in high heat, temperature rise of reactor exceeds 65ć, temperature rise of rectifier transformer exceeds 40ć or there are obvious flashover, arc discharge and vibration, etc. inside equipment. 2) Damping resistance catches on fire. 3) Severe flashover occurs in high voltage insulation parts, and flashover discharge in high-voltage pothead. 4) Power supply unit is out of control, and high current impact occurs. 5) Electric equipment catches on fire. 6) Other conditions that seriously threaten personal and equipment safety. 2.6.2 Proper part: 1) Space between opposite electrodes in electric field reduces materially, and arc discharge continuously occurs in electric field. And there is dewfall and severe creepage of insulator. 2) Temperature of boiler flue gas rise steeply up to above 190ć. There is an emergency alarm in control system and the open temperature of bypass valves still doesn’t decline. 3) Gas temperature sharply falls below dew point temperature and there is bag paste phenomenon of the filter bag. 4) When there is ash blockage in ash handling system and ash level keeps on rising after it reaches high bin level, urgently stop the boiler to discharge ashes for protecting the filter bag from being damaged. 2.7 Conditions for appropriate shutdown of equipment 1) Rectifier transformer and reactor are in high heat and have already exceeded the normal allowable value. 2) Damping resistance belches fire, and power supply unit has partial excitation problem. 3) Cooling fan for thyristor is in high heat due to faults. 4) All sorts of cable heads, especially the main loop cable head and incoming line joints of rectifier transformer and reactor are in high heat. 9
15) Check whether the air supply operating pressure of the outlet damper cylinder and bypass damper cylinder is above 0.5Mpa. 16) Put it into insulating box for heating 12~24 hours before boiler ignition or system start-up to prevent insulators from creepage as a result of dewing. 17) Put it into the ash hopper for heating 12~24 hours before boiler ignition or system start-up to prevent ash hopper from cross-linking or ash clogging resulting from dewing or damp ash. 18) Ash pre-coating protection for filter bags should be conducted before the filter bag is put into operation for the first time or after the boiler stops and cools before another start. Ash pre-coating should be done on the day when the host is certain to ignite the boiler. When the host cannot ignite temporarily after the filter bag ash pre-coating, ash cleaning system should be started to clean the ash layers of filter bag and to pre-coat ash before the next start-up by host. In that way, the surface of filter bag can be protected from being damp or pasted. 2.3 Startup of electric-bag compound dust collector 1) 12~24hours before the boiler ignites, put it into insulator heating device and temperature detecting device in insulation box. Observe the heating situations should be normal and electric heating has insulator room temperature rise above dew point temperature 20~30ć. 2) Put it into ash hopper heating system 12~24 hours before boiler ignites. As to steam heating system, it should be fully drained before heating system is put into operation. 3) Bypass valve should be opened and lifting valve should be all at “close” position. 4) Put the ash discharging device and rapping device into operation at time of boiler ignition or start-up of system to start corresponding ash handling system. 5) Stop supplying oil to the boiler for combustion-supporting and start the ash removal system after the boiler has started burning coal and running normally. 6) After it runs stably, adjust and set the secondary voltage ad current based on working conditions. It can be switched into automatic operation after the setting. 7) Adjust the periodic time of anode and cathode rapping according to flue gas and running secondary voltage and current conditions. 8) Set the pulse ash removal of bag dust collector according to differential pressure conditions. 2.4 Shutdown of electric-bag compound dust collector 1) After the host stop, cut off the electric field high voltage supply according to the shutdown process for electric dust collector. 2) Keep running the anode and cathode rapping and latter-stage ash removal system of the electric dust collector and conduct ash removing continuously for 10 ~20 periods. 3) Shut down low voltage control system after ash discharging and conveying of ash hopper is done. 4) Shut down the system blower. 2.5 Precautions for equipment operation: 1) To prevent the switches from being burnt down, do not switch the high voltage switch or directly pull down the switches under the equipment operation status; 2) Metal-shielded wires should be applied as the feedback connection lines of current and voltage between 8
rise up to 800Pa → Ash coating; If flue gas pass through bypass flue, Clean the ash → Times of ash coating can be less, as below: Automatic ash cleaning for a period (manual ash cleaning is also allowed) → Open the butterfly valve of ash coating pipe → Ash car delivers the ash → Close the butterfly valve; Notice: If flue gas passes through the bypass flue, and if it is the control cabinet controlling the bypass valve, the ash cleaning can only be conducted manually. If the local operating box controls the bypass valve, it will clean the ash automatically when the ash cleaning period should be shortened. 2)
Precautions:
a)
Ash coating volume has to do with air volume of inlet flue. The larger of the baffle opening of induced
draught fan, the larger of the air volume and the higher of spraying efficiency; b)
When cleaning → coating ash in midway, the shorter of the time, the better. It is in the order of
cleaning first and coating afterwards. c)
After a long time oil burning and boiler stop, ash cleaning should be immediately conducted followed
by ash coating which should be kept on the boiler till next ignition and operation. d)
After coal is put in and the oil is stopped to supply for combustion-supporting, if the differential
pressure of filter bag rises up above 800Pa, ash cleaning can be conducted while the ash coating can be canceled. 2.2 Check before starting the electro-bag compound dust collector: 1) Check whether there is foreign matter in the casing and insulator box of electrostatic dust collector, if all the manhole doors are closed tightly. 2) Check whether the platforms, stairs and handrails of each part of the electrostatic dust collector are firm and complete, the passage is clear and the lighting is sufficient. 3) Check whether each transmission mechanism is in good condition and if each lubrication point has sufficient lubricating oil. 4) Check whether dry ash handling system is in good condition and if each ash discharging valve is in proper position. 5) Check that grounding device in each part should be in good condition. 6) Check whether each heating unit is in good condition and reliable. 7) Check and measure if the insulation of relevant equipment is qualified. 8) Check to make sure both the high-voltage cable head and high-voltage silicon rectifier transformer not have oil leakage phenomenon. 9) Check to make sure each connection of the power supply unit is in good condition and reliable, no component is loose, and operating mechanism of the high-voltage disconnector is flexible and in proper position. 10) Check to make sure all the maintenance personnel has left the electrostatic dust collector body. 11) Check to make sure the functions of all the instruments, power switches, adjusters, monitor and alarm signals and protection devices is in good condition. 12) Check whether the test rapping device runs normally and if the rapping device head raps on central position of the rapping bar. 13) Check whether the pulse valves act normally. 14) check whether all the cylinders of each damper work smoothly 7
2)
The state of lifting valve and bypass valve during fluorescent powder leakage detection: Lifting valve
is in open state while the bypass valve in close state and all manholes should be closed. 3)
Put the fluorescent powder into the opening of inlet flue (usually pour it through pressure test hole and
details depend on the specific circumstances) on the condition that the main air blower runs at half of the design airflow while the air removal system stops running; 4)
After the fluorescent powder is put into the dust collector, the air blower should keep going on running
for at least above 20minutes to make sure the powder is distributed evenly on the filter bags in each compartment of electric-bag compound dust collector. 5)
After main air blower is closed, open the manhole door of the cleaning chamber of electric-bag
compound dust collector for inspection personnel to enter with fluorescent lamps (UV lamp) to inspect in each cleaning chamber. There should be no fluorescent powder in clothes, hats, shoes and other parts of the body of the inspection personnel. And the one with fluorescent powder should not be allowed to enter for inspection. To seriously check the seam crossing of card, joints between filter bag and card in cleaning chamber with fluorescent lamp. The dimmer it is in ambient environment, the more it will help the leakage detection work. 6)
If there is fluorescent powder (fluorescent powder displays as red under the rays of fluorescent lamp)
discovered during inspection, analyze the reason carefully and take notes. When dealing with the fluorescent power leakage problem, if welding is needed, take measures protecting the filter bag; 7)
Check the quantity of fluorescent powder around bypass flue valve plate and open the bypass valve to
check the fluorescent powder quantity at the positions of silicon rubber gasket before and after the valve plated is pressed tight. To check whether the leakage of bypass flue is too serious and if it is, the reason analysis must be implemented and corresponding treatment should be conducted (Usually, the reason is that the space of valve plated press-in silicon rubber is too small. And the valve plate can be screwed slightly down). 2.1.3 Ash pre-coating When igniting the boiler, certain lampblack with incompletely combusted tars will enter dust collector and get the surface of filter bags binding and pasted. If the phenomenon is temporary or intermittent, it can be settled by “ash pre-coating” measures. 1)
Operation method of ash pre-coating:
a)
Principle of ash pre-coating: Filter bags should be pre-coated with ash before the boiler’s ignition and
oil burning; b)
Usually, the operation sequence of ash pre-coating when start and stop the boiler is: Make sure the
lifting valve is in open state while the bypass valve is in close state → ash tank car is in place and taken over → Start the induced draught fan (baffle opening is above 60%) → Open the butterfly valve of ash pre-coating pipe → Ash car delivers the ash → the filter bag differential pressure is ranged within 300-400pa→Stop ash coating and close the butterfly valve of ash pre-coating pipe; c)
Operation sequence of ash coating during long time oil burning process: System long time oil burning
requires intermittent ash coating → Ash cleaning → Ash coating. Hence there should be two ash tank cars ready to feed and coat the filter bags during long time oil burning. If the flue gas pass by bag area, ash coating frequency should be higher and ash cleaning is necessary when differential pressure of filter bag 6
Chapter 2 Operation & Maintenance of Electric-bag Compound Dust Collector 2.1 Work before operation 2.1.1 Cleaning of air passage pipeline After the installation of compressed air system, put through the main air supply. When the main air supply get all the conditions to supply compressed air, the cleaning of compressed air system pipelines should be performed timely and welding slag and other impurities should be eliminated from the pipelines. The cleaning must be done before the installation of filter bag cage to make sure filter bag cage is conditioned to be installed. Specific cleaning solution is as below: 1) Close all stop valves and ball valves, and dismount one end of PU tube (copper tube) leading to cylinders and pressure transmitters. 2) Dismount the air supply triplets in the air passage of lift valve and bypass valve. 3) Open the water drain valve at gasholder bottom and the stop valve (ball valve) in main air supply to gasholder following, then after a period of time for ventilation, close the water drain valve at gasholder bottom. 4) Open the stop valve mounted ahead of air supply triplet in air passage of lift valve and bypass valve to blow the welding slag. And after a while, close the stop valve and mount the air supply triplet. 5) Open the air discharge ball valve at the medium and end of lift valve and bypass valve air passage to blow and clean. And after it is closed, open the ball valves leading to cylinders and pressure transmitter to be blown and cleaned. 6) Open water drain valve at filter bottom in air passage of air bag and stop valve (ball valve) in front of it for ventilation. After a while, close the water drain valve at filter bottom. 7) Dismount the last pulse valve near inlet of the air bag in the air flow direction for compressed air entering and turn up the air pressure of pressure relief valve. And mount the pulse valve after blowing for a while until no obvious particles discovered. 8) Blow the air bags in the direction of outlet-to-inlet respectively according to step 7; 9) After blowing air bags is finished, open water drain valves at air bag bottom respectively for a period of ventilation; 10) If the electrics have got all the conditions, adjust the pressure in air bag to 0.2~0.25Mpa and operate the field end box of pulse valve to have each pulse valve work at least twice. 11) Finally, check whether there is air leakage on two joints of pulse valve and air bag. And if there is between pulse valve and air bag pulse valve pedestal, check whether the bolts and nuts are screwed tightly. If it is air leakage between pulse valve and air bag connecting short tube, the pulse valve should be dismounted to check whether the gasket is broken and if it is , replace it with a ne w one to be mounted. 2.1.2 Fluorescent powder leakage detection Leakage detection for filter bag of electric-bag compound dust collector is the “fluorescent powder leakage detection” after the installation of filter bags for dust collector. 1)
Essential conditions for fluorescent powder leakage detection: Induced draught fan works normally
and its opening fits and the air compressor is capable of supplying gas; 5
7) Required NO2 content of the flue gas: <260ppm (~450mg/Nm3). 8) Required SO2 content of the flue gas: <1600ppm (~4200mg/Nm3). 9) Ash cleaning control mode: PLC control, give priority to on-line ash removal and can switch to off-line ash removal at any time; 8) Design pressure of case: positive pressure (+9.8 kPa), negative pressure (-9.8 kPa); 9) Pulse valve specification: 4 inches. 10) Consumption of compressed air: 35 Nm3/min (when pulse period is of adjustable minutes). 1.5 Control panel (console) 1) Number and type of control panels (consoles) for rectifier transformer per filter: 4 sets; cabinet. 2) Number and type of control panels for discharge electrode rapping, collecting electrode rapping and channel plate rapping: 1 set, cabinet type 3) Quantity and type of control panels (set) of insulator and porcelain bushing electric heater per dust collector: 1 set; cabinet type. 4) Quantity and type of local terminal boxes: refer to the actual quantity (sets); vertical 1.6 Ash hopper 1) Number/material of ash hoppers on dust collector: 40/Q235. 2) Capacity per ash hopper: ~127 m3. 3) Size of ash outlet flange of hopper (internal opening): 300 mm×300 mm. 4) Elevation of ash outlet flange of hopper: 3.5m. 5) Type, number of layers and material of the inlet & outlet gas distribution device: There is three-layer resistance flow diversion type distribution board/Q235 1.7 High voltage supply system: 1) Number of rectifier transformers equipped for each dust collector: 4 sets 2) Type and weight of rectifier transformer: oil-immersed /~1.73t. 3) Mode and requirements of installing rectifier transformer: outdoor fitness type 4) Applicable altitude and ambient temperature of rectifier transformer: 1,000 m; -25-50ć.
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20m tentatively while size of outlet & inlet is 5m (width) X4m (height) tentatively. 1.2 Anode system 1) Number of flue gas passes per dust collector: 80. 2) Space between the same electrodes: 400 mm. 3) Rapping device of anode plate: a. Type: top electromagnetic hammer rapping b. Number of rapping device per ESP: 128 sets. c. Rapping mode and operation mode: Top/Automatic. d. Min. rapping acceleration: >150g. e. Mode and location of control system: SCM (single chip microcomputer) control, control room. f. Type of rapping device for control system: g. Material of rapping bar: Q235, lubrication is not required. h. If one set of transformer gets fault, the area of polar plate loses 12.5%. 4) Supporting and guiding way: rigid connection on the top, directional anti-pendulum on the lower part and free expansion on the upper part. 1.3 Cathode system 1) Material and type of discharge electrodes: acupuncture line, stainless steel, carbon steel. 2) Discharge electrode rapping device: a. Type of rapping device: Rapping of top electromagnetic hammer b. Total number of rapping devices: 64 sets. c. Rapping position: Top. d. Operation mode of rapping device: automatic control. e. Min. rapping acceleration: >80g. f. Material and specification of rapping device: Q235 (carburizing treatment) g. Control mode of rapping system device: SCM automatic control 3) Total length and number of discharge electrodes per electrostatic dust collector: ~38125m /~2560. 4) Discharge electrodes spacing in the direction of airflow: 203 mm. 5) Space between discharge electrodes perpendicular to airflow direction: 400mm. 6) Design height of discharge electrode: 15 m. Supporting and guiding way of discharge electrode frame: Top suspension, lower directional anti-pendulum and free expansion. 7) Number of heaters for thermo tank per dust collector: 64 sets. 1.4 Bag dust collector 1) Total compartments of bag dust collector: 2 x 4 x 3. 2) Total filtration area: 61586 m2. 3) Filter bag specification: Ø168mm×8.25m. 4) Wind velocity of filtration: 1 m/min. 5) Design resistance of bag dust collector: ≤ 950Pa. 6) Required O2 content of the flue gas: <8% while temperature≤160ć, <5% while temperature ≤170ć; 3
PART 1 Electric-Bag Compound Dust Collector Chapter 1 Overview Technical specifications for main parameters: 1.1 Structural parameters 1) Model: 2FE480/4-2E4×3-G. 2) Type: Dry type, horizontal type, plate type and half pulse type. 3) Number of sets equipped for each boiler: 2 sets. 4) Dust collector inlet flue gas flow (per boiler): Design coal: 3709139.3 m3/h Worst coal: 3735890.2 m3/h 5) Dust collector inlet dust content: Design coal: 51 g/Nm3 Worst coal: 63 g/ Nm3. 6) When the worst coal is fired, the max outlet dust content of dust collector is guaranteed within 50mg/Nm3 when one bag chamber or one electric field bypass or one bypass is disabled. Total electricity consumption of two electric dust collectors per boiler is guaranteed at 651.7 kVA while that of two bag dust collectors per boiler is guaranteed at 117.4kVA. 7) Dust collector inlet flue gas temperature (BMCR): 137ć (design coal), 137ć (worst coal). 8) Dust collection efficiency: ≥99.94%. 9) Dust collector proper resistance: ≤250Pa (electrostatic dust collector); ≤ 950Pa (bag dust collector); <800 Pa (overall initial); ≤1200 Pa (end o bag f service life) 10) Proper air leakage rate: ≤2%. 11) Service life: 30 years, over 8,000 hours/year; service life of the bag is required to be longer than 35,000 hours at the operating temperature of 160ć. 12) Number of electric fields per dust collector: 2. 13) Number of inlets and outlets per boiler dust collector: 4 at inlet, 4 at outlet. Air intake and discharge directions: horizontally intake, horizontally discharge. 14) Bag dust collector requires considering adding 100% gas bypass when adopting fuel oil for boiler startup or part load combustion-supporting. And detection and protection measures of explosion temperature are taken. 15) Filtration velocity of bag filtration is 1.0m/min, and bag dust collector has three chambers and four passes. 16) Length height ratio of dust collector: 1.13. 17) Noise :< 80dB. 18) Number of electric fields/single electric field length of electrostatic dust collector: 2/3.8 m. 19) Flue gas treatment time: 7.03s. 20) Effective cross sectional area of electrostatic dust collector: 480×2 m2 21) Total width of dust collector (including staircases of both sides) doesn’t exceed 75cm and total length of column space before and after should not exceed 32.12m. Elevation of central inlet of flue air passage is 2
CONTENTS PART 1 Electric-Bag Compound Dust Collector ................................... ..................2 Chapter 1 Overview……………………………………………………………………2 Chapter 2 Operation & Maintenance of Electric-bag Compound Dust Collector…….5 Chapter 3 Routine Maintenance and Treatment…………………………………..13 PART 2 Pneumatic Ash Handling ............................................................................ 19 Chapter 1 Equipment Overview……………………………………………………19 Chapter 2 Pneumatic Ash Conveying Operation………………………………….35 Chapter 3 Routine Maintenance & Treatment……………………………………41 PART 3 Ash & Slag System ...................................................................................... 47 Chapter 1 System Overview………………………………………………………..47 Chapter 2 Running of Slag Handling System……………………………………..57 Chapter 3 Routine Maintenance of Slag Handling System………………………60
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KMPCL 6 x 600 MW Subcritical Coal-fired Power Plant Project KSK Mahanadi Power Company Limited 6 x 600 MW Thermal Power Project Nariyara, Chhattisgarh, India
SEPCO ELECTRIC POWER CONSTRUCTION CORP. No.
AH-002
Boiler Ash Handling Operation & Maintenance Manual
Total 64 Pages
Boiler Ash Handling Operation & Maintenance Manual
Drafted by:
Xu Yuguo
Reviewed by:
Li Xinli
Approved by:
Li Mingda
