Oxidation Air

Tanjung Jati B Training OXIDATION AIR

OPERATIONS OXID OX IDA A TI TION ON AIR A IR

Tanjung Jati B Training

OPERATIONS OXID OX IDA A TI TION ON AIR A IR


PT Cen t r al J av a Po w er Tanju njung ng Ja J ati B Units 1 & 2 Flu lue e Ga Gas De Desu sulf lfur uriza izati tion on (F (FG GD) Sys ystem tem

Absorber Area

Dewatering Area

Reagent Preparation Area

Limestone Jetty And Conveyor


FGD Operations Oxidation Air There are three (3) 100% capacity Oxidation Air Blowers, one dedicated to each Absorber and one as a spare or standby blower. Oxidation Air functions to minimize the buildup of solids within the Absorber Module by converting Calcium Sulfite (CaSO3) to Calcium Sulfate (CaSO4).


FGD Operations Oxidation Air ●

Gas to Sorbent (Limestone Slurry) Reaction

CaCO3 + SO2 + H2O → CaSO3 • 1/2H2O + CO2 Calcium Carbonate (In Limestone)

●

Flue Gas

Calcium Sulfite

Forced Oxidation Reaction

CaSO3 • 1/2H2O + O2 + H2O → CaSO4 • 2H2O Calcium Sulfate

(There are many other intermediate reactions)


FGD Operations Oxidation Air

Flue Gas

Reaction Tank Oxidation Air Headers



Dewatering Building

PLANT NORTH

Filter Feed Tank

Oxidation Air Blowers

Process Water Tank

Mist Eliminator Wash Water Tank


PLANT NORTH

FGD Operations Oxidation Air 1

1 2 3 4 5 6 7 8 9 10 11 12 13 14

UNIT-1 ABSORBER UNIT-1 RECIRCULATION PUMPS UNIT-2 ABSORBER UNIT-2 RECIRCULATION PUMPS FILTER FEED TANK ME WASH WATER TANK PROCESS WATER TANK VACUUM FILTERS OXIDATION AIR BLOWERS LIMESTONE SLURRY TANK LIMESTONE SILO “A” LIMESTONE SILO “B” LS BUCKET ELEVATOR & RAMP STACK

2

PIPE RACK “A”

5 6

8

14 7

9

3

4

PIPE RACK “B”

BURIED SEAWATER TERMINAL POINT 11 YARD PIPING 10

13 12



OXIDATION AIR BLOWERS Tanjung Jati B Training

FGD Operations Oxidation Air For the proper operation of an Absorber Module, one (1) Oxidation Air Blower is required. Therefore, when two Absorber Modules are in service two blowers will be running and the third blower is used for standby if one blower were to trip.



Each Oxidation Air Blower has its own dedicated Lube Oil Unit which provides the necessary lubrication for the Gear Increaser . A single Programmable Logic Controller (PLC) provides control and protection for all three Blowers. The DCS, which interfaces with the PLC, has the capability to start and stop a given Blower.


FGD Operations Oxidation Air To Unit-1 Absorber

A

Lube Oil Skid

To Unit-2 Absorber

B

Lube Oil Skid

C

Lube Oil Skid

PLC OXIDATION AIR BLOWERS Tanjung Jati B Training

FGD Operations FGD Start-Up Each Absorber has a dedicated Blower. Here is the arrangement… Blower A: Blower B: Blower C:

Unit-1 Absorber only Unit-1 or Unit-2 Absorber (or standby) Unit-2 Absorber only



We have already discussed the start-up of an Oxidation Blower, so let’s have a short review regarding start-up then shutdown. You will recall that an Oxidation Air Blower can be started and stopped from the DCS or the local PLC.


FGD Operations Oxidation Air You will recall there are two different start-up scenarios… • Reaction Tank Level below the OA Headers • Reaction Tank Level above the OA Headers



OA HEADER ELEVATION -PIPE SIZING

TEMPERATURE ELEMENT

3.5 METERS

1/2”

HUMIDIFICATION (SERVICE WATER)

12”

FROM OXIDATION AIR BLOWER

6” ABSORBER MODULE

FLUSH WATER (PROCESS WATER)

= Manual Valve


FGD Operations Oxidation Air Reaction Tank Level is below OA Headers… • OA Blower can & should be started prior to increasing the Reaction Tank Level above the OA Header elevation. • This assumes that the OA Blower was shutdown after the Reaction Tank Level went below the OA Header elevation (during an extended shutdown of the Absorber). • Remember, an OA Blower cannot be started unless the Absorber Vent or Absorber Outlet Damper is open. Tanjung Jati B Training

FGD Operations Oxidation Air Reaction Tank Level is above OA Headers… • The OA Headers and piping must be flushed prior to starting a Blower. • The Air Isolation Valve must be closed prior to opening the Flush Water Isolation Valve. • Both the Flush Valve & Air Isolation Valve are located near the Absorber Module. • Remember, these valves are manually operated and have no position limit switches. Tanjung Jati B Training

FGD Operations Oxidation Air FLUSHING OA PIPING & HEADER

TEMPERATURE ELEMENT

MANUAL FLUSH VALVE

3.5 METERS

MANUAL CONTROL VALVE

MANUAL ISOL.VALVE

HUMIDIFICATION (SERVICE WATER) FROM OXIDATION AIR BLOWER FLUSH WATER (PROCESS WATER)

ABSORBER MODULE



Prior to starting any Oxidation Air Blower be sure to walk down and inspect the entire system. Be sure there is cooling water available for the Blower Bearings and Lube Oil Unit.


FGD Operations Oxidation Air ATM

INLET SILENCER

BLOWOFF SILENCER

CROSSOVER TIE VALVE

TO ABSORBER-1

BLOWOFF VALVE

DISCHARGE VALVE

OUTLET SILENCER

INLET FILTER ATM

INLET VALVE

CLOSED CIRCUIT COOLING WATER

A OXIDATION AIR BLOWER

LUBE OIL SKID

STARTING BLOWER “A” FOR UNIT-1 ABSORBER


FGD Operations Oxidation Air After an Oxidation Air Blower is started, water is introduced to the downstream piping to humidify the air to its saturation point. Why do we introduce water to humidify the air… It eliminates the wet-dry interface between the Gypsum Slurry and Air Header Piping, thus minimizing the potential for deposits forming within the Air Headers and at the Header Nozzles.


FGD Operations Oxidation Air HUMIDIFICATION WATER

TEMPERATURE ELEMENT

MANUAL FLUSH VALVE

3.5 METERS


MANUAL ISOL.VALVE


ABSORBER MODULE



Let’s go through the basic steps for starting and stopping an Oxidation Air Blower from the DCS and local PLC Panel… Once the “ start” command from the DCS is generated the PLC will automatically start Lube Oil Unit, set the Blower Dampers to their proper position and start the Blower.


FGD Operations Oxidation Air When starting an OA Blower from the DCS, the PLC will automatically perform the following… • • • • • • • •

Start Lube Oil Unit Opens Blower Inlet Valve to predetermined position Opens Blowoff Valve to full open Opens Discharge Valve to full open Closes/Opens Crosstie Valve as required Blower Starts Blowoff Valve closes slowly Inlet Valve to automatic control

• Operator to open manual Humidification Valve to full open position… Tanjung Jati B Training

FGD Operations Oxidation Air ATM

INLET SILENCER

BLOWOFF SILENCER

CROSSOVER TIE VALVE

TO ABSORBER-1

BLOWOFF VALVE

DISCHARGE VALVE

OUTLET SILENCER

INLET FILTER ATM

INLET VALVE

CLOSED CIRCUIT COOLING WATER

A OXIDATION AIR BLOWER

LUBE OIL SKID

STARTING BLOWER “A” FOR UNIT-1 ABSORBER


FGD Operations Oxidation Air Starting an OA Blower from the local PLC… • • • • • •

Blower Selector Switch to “ON” Position Select Blower “B” as Standby Open Blower Inlet Valve to predetermined position Open Discharge Valve to full open Start Blower Verify Blower Motor Amps and adjust Blower Inlet Valve if required..

• Operator to open manual Humidification Valve to full open position…



A

PLC

BREAKER

B

C

OXIDATION AIR BLOWER PANEL Tanjung Jati B Training

FGD Operations Oxidation Air INLET VALVE

OPEN

BLOWER “A” OR “C”

OPEN CLOSED

MIDPOINT CLOSED

BLOWOFF VALVE

RUNNING

FAULT

SWITCH ON OFF

PUSHBUTTONS START

STOP

JOG SWITCHES O I C

INLET VALVE

O

I C

BLOWOFF VALVE


FGD Operations Oxidation Air INLET VALVE

OPEN

BLOWER “B”

OPEN

MIDPOINT

CLOSED

CLOSED

BLOWOFF VALVE

RUNNING

FAULT

SELECTOR SWITCH OFF U1

PUSHBUTTONS START

JOG SWITCHES

STOP

U2

AUTO

INLET VALVE

BLOWOFF VALVE



OXIDATION AIR PANEL

POWER ON

INLET VALVES M A

GENERAL FAULT



The optimum position of the Blower Inlet Valve before the Blower is started is based upon the Blower Motor Amps during normal operation and this position will be determined during Commissioning. These positions should be recorded and used for future reference.


FGD Operations Oxidation Air Stopping an OA Blower from the DCS… Once a stop command is generated, the local PLC panel will automatically stop the Blower, stop the Lube Oil Unit and close the Blower Inlet and Outlet Valves. • The Operator will need to close the OA Isolation Valve located near the Absorber Module & the Humidification Water Valve. • It is good practice to keep cooling water flowing to the Blower Bearings until temperatures sufficiently low. Tanjung Jati B Training


OPERATING LEVEL & OA HEADER ELEVATION

TEMPERATURE ELEMENT

MANUAL FLUSH VALVE

3.5 METERS


MANUAL ISOL.VALVE


ABSORBER MODULE


FGD Operations Oxidation Air Stopping an OA Blower from the local PLC… • Stop Blower • Close Inlet Damper • Close Outlet Damper • Keep cooling water circulating to the Blower Bearing to cool the bearings sufficiently (20-30 minutes) • Operator to close the OA Isolation Valve located near the Absorber Module and close the Humidification Water Valve


FGD Operations Oxidation Air If the Absorber Module is to be shutdown and the slurry level of the Reaction Tank will be lowered below the OA Headers, the following should be performed… • Close OA Isolation Valve located near the Module • Open the Flush Valve and flush for approximately 5-10 minutes.



FLUSHING THE AIR PIPING AND HEADERS

TEMPERATURE ELEMENT

C

MANUAL FLUSH VALVE


C O

FROM OXIDATION AIR BLOWER

MANUAL ISOL.VALVE

FLUSH WATER (PROCESS WATER)

3.5 METERS

ABSORBER MODULE

HUMIDIFICATION (SERVICE WATER)

C = CLOSED O = OPEN Tanjung Jati B Training

Oxidation Air

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