Lab 4(Flowmeter Demonstration)

UNIVERSITI TEKNOLOGI MARA FAKULTI KEJURUTERAAN KIMIA PROCESS ENGINEERING LABORATORY 1 (CPE465) NAME

: MUHAMAD BAIHAKHI BIN SHAMSUDIN STUDENT ID : 2014442906 GROUP : EH2202A GROUP EXPERIMENT : 3 EXPERIMENT : FLOWMETER DEMONSTRATION DATE DATE PERFORMED : 28 APRIL 2015 SEMESTER : 2 PROGRAMME  !ODE : EH220  !PE465

No. 1   4 5 6   7 10 11 1

Tit! A't%#"t*S+,,#%I/t%o$+"tio/ Ai,' T2!o%A33#%#t+' M!t2o$oo-*P%o"!$+%! R!'+t' C#"+#tio/' 8i'"+''io/ Co/"+'io/ R!"o,,!/$#tio/' R!9!%!/"! * A33!/$i: TOTAL TOTAL MARKS

R!,#%&'; C2!"&!$ -;

<<<<<<<<<<<<<<<<<<<<<<<<<<< 8#t!;

Ao"#t!$ M#%&' () 5 10 5 10 5 10 10 10 0 5 5 5 100

M#%&'

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ABSTRACT

This experime experiment nt has been done to investiga investigate te and demonstra demonstrate te the operation operation and characteristics of three flow meter with different types including it accuracy and energy losses. The Flow Meter Demonstration Unit was used as the apparatus in this experiment. We need to identified three different types of flow meter contain or found in the unit at the beginning of the experiment. Orifice meter !enturi meter and !ariable "otameter were the flow meters that placed in this unit. The !enturi !enturi and and Orifice meter only can measured the output which not linear with the flow rate #. The !ariable !ariable rotameter was in the other hand. The output which is directly proportional to the flow rate can measured by the variable rotameter and no need to measure the pressure difference. The average timed flow rate # t was calculated to be $%.&' l(min the average venturi meter flow rate # v was calculated to be )%.$* l(min t2! #=!%#! =#%i#! %ot#,!t!% >o? %#t!@ % ?#' "#"+#t!$ to was estab establis lished hed to be ! 1.50 1.50 *,i/ *,i/ and the average orifice plate flow rate # o was approximately )+.)+ l(min. Thus the average velocity had calculated was %.,- m(s and the average velocity head was ).'* mm.











Introduction

n various various industrial plants process of measuring measuring the flow flow of li/uids is critical critical needed in the pipeline. n some operation or process accuracy can ma0e the difference between ma0ing a profit or having a loss to the plant or company. 1ecause of that accuracy of the flow measurements is very important. 2 inaccurate inaccurate measurement of the li/uids flow can also cause a serious result and can cause a death. 3owadays there are a lot of li/uid flow measurements instruments and the flow rate can be determined inferentially by measuring the change in 0inetic energy or li/uid4s velocity with this instruments. The pressure differential that is forcing the li/uid through a pipe or conduit will affect the li/uid velocity. The pipe4s cross5sectional area is 0nown and it is remains constant and because of this the average velocity is an indication of the flow rate. The relationship of the li/uid4s flow rate in such cases is6 Q=V × A

7O8T9#: Flowmeter Measurement 2pparatus ;Model6 FM$%$< apparatus is designed to operate together with a basic hydraulic bench or any water supply. t is to familiari=e the students with typical methods of flow measurement measurement of an incompressible fluid. The flow measurement measurement comparison is able to demonstrate by the apparatus by using a orifice device venture device and rotameter. 1ased on the flow comparison we can compare against the flow measurement of the hydraulics bench which can be either by !olumetric or >ravimeteric Method. The two methods is chosen depending on the type of hydraulics bench in use. 2 *% degree elbow with pressure tappings before and after this elbow is another features of the flow apparatus. These features purpose is to provide an added function to this apparatus to allow students to calculate the total head loss and loss coefficient coefficient when fluid flows through these devices. n short the following range of experiment to be carried out is allowed by the apparatus. a< Direct comparison of flow measurement using venturi orifice rotameter and bench.











Aims

$. To obtain the flow rate measurement by utili=ing three basic types of flow measuring techni/ues@ rotameter venturi meter and orifice meter. A. To investigate the loss coefficient of fluid through *% degree elbow.

THEORY

Three most common devices used to measure the flow rate in pipes or internal flow. The three meters are orifice meter !enturi meter and rotameter. They operates with the same principle which is the decrease in flow area in a pipe will causes an increase in velocity that will cause decreasing in pressure. 2 correlation of the velocity with the pressure difference provides provides a means of measuring the flow rate. 1y negligible the viscous effects and under the assumption of a hori=ontal pipe and with the application of the 1ernoulli e/uation between point ;$< and ;A< it gave6

Qideal = A 2 V 2 = A 2

Where B C D / D 2

Q= A1 V 1= A2 V 2

( p − p ) ρ ( 1− β )

2

1

2

4

1

. There is a head loss between ;$< and ;A< so the e/uation becomes6











The rotameter rotameter is is a flow meter meter in which a rotating free float float is the indicating indicating element. element. Usually Usually a rotameter consists of a transparent tapered vertical tube through which fluid flow upward. Within the tube is placed a freely suspended floatE of pump5bob shape. The float rests on a stop at the bottom end when there is no flow.The float rises until upward as it commences and buoyancy buoyancy forces on it are balanced by its weight. f the rate of flow is small the float rises only a short distance and vice versa. The points of e/uilibrium can be noted as a function of flow rate. With a well5calibrated well5calibrated mar0ed glass tube the level of the float f loat becomes a direct measure of flow rate.

Orifice meter

Orifice meter is constructed by inserting a flat plate with a hole between two flanges of a pipe. The geometry of the orifice meter is simple low in cost and easy to install or











ressure taps for orifices may be placed in several locations as shown in Figure -.$.

Figure 4.1: Tyic!" Orifice #eter

$enturi meter

>enerally the venture meter are made from castings and machined. This is to close tolerances to duplicate the performance of the standard design. The !enturi meter are expensive heavy and bul0y. 9xcellent pressure recovery is form as the conical diffuser section downstream from the throat. The diagram of !enturi meter is shown in the Figure -.A below.

Figure 4.%: &i!gr!m of $enturi meter

2pplications of the 1ernoulli e/uation yield the following result which applies for both the













$ G !$A G H$ C A G ! AA G HA Ig

Ag

Ig

Ag

H$CHA $ G !$A C A G !AA Ig

Ag

Ig

Ag

A A $5A C !A 5! $ 555555555555;$<

Ig

Ag

from6 #$C#A 2$!$C2A!A !$C2A!A 555555555555;A< 2$ ;A< in ;$< 6 A A 5A C !A 5;2 A!A(2$<

Ig

Ag

so@ A A !A J$5;2 A(2$< K C L

Ag

Ig !AC

$ J$5;2A(2$<K

. ; AL< 555555555555555;,< 555555555555555;,< I











where ;ANp< C ;AgNh< p

where@ Nh 6 head difference in meter ;m< from the t he manometer readings for the appropriate meter g 6 acceleration due to gravity ;m(s A< ?d6 discharge coefficient for meter 2$ 6 area of the test pipe upstream of the meter ;m A< 2A 6 throat area of the meter ;mA<

t is nece necess ssar aryy to use use of disc discha harg rge e coef coeffifici cien ent t ? d becau because se of the simpli simplifyi fying ng assumptions made when applying the 1ernoulli e/uations. From this experiment values of this coefficient are determined. The assumed values used in the soft ware are6 !enturi meter ? d C %.*& Orifice plate ?d C%.+,

The energy loss that occurs in a pipe fitting ;so5called secondary loss< is commonly expressed in term of e head loss ;h meters< and can be determined from the manometer readings. For this experiment head losses will be compared against the s/uare of the flow f low











A''ARAT(S





















7taddle valve

Manometer tube

Discharge valve *%o elbow

Orifice

Water outlet

Water su l

!enturi













)ener!" St!rt*u 'rocedures

The Flowmeter Measurement 2pparatus ;Model6 FM $%$< is supplied ready for use and only re/uires connection to the Pydraulic 1ench ;Model6 FM $$%< as follows6 a< The apparatus was placed on top of a suitable hydraulic bench. b< The apparatus was level on the bench top. c< The hydraulic coupling was connected to the outlet supply of the hydraulic bench. d< The discharge connect of the flow apparatus hose was connected to the collection tan0 of the hydraulic bench. e< The apparatus was ready to be started.

7tarting up the 2pparatus6











reduce the flow to the the maximum maximum measurable measurable flow rate. '. The water level in the manometer board can be seen began to display different level of water water heights. heights. ;f the the water water level in the manometer board is too high where where it is is out of visible point adQust adQust the water water level by using using the staddle staddle valve. With the the maximum maximum measurable flow rate retain retain maximum readings on manometer<. +. 2t this point the flow was slowly reduced by controlling the flow discharge valve of apparatus and this discharge valve might closed totally. totally. ). The water level in the manometer board can be seen began to level level into into a straight level. This level maybe at the lower or maybe maybe at the higher end of the manometer board range. ;Ta0e ;Ta0e note that the pump from the hydraulic bench is at this time time still supplying water at at a certain pressure in the system<. &. The glass tube or plastic transfer tube has been watched out for Trapped 1ubblesE. f bubbles present it will remove remove from the system for better accuracy. To do this either slowly press the plastic tube to push the bubbles bubbles u

lightly tabE the glass tube tube to release the bubbles bubbles











A. With the bench valve fully closed and the discharge valve fully opened the pump supply was started up from hydraulic bench. ,. The bench valve was opened slowly until it is fully opened. -. When the flow in the pipe is steady and there is no trapped bubble the bench valve was started to close to reduce the flow f low to the maximum measurable flow rate. '. 1y using the air bleed screw water level in the manometer board was adQusted. The maximum maximum readings was retained retained on on manometers manometers with with the maximum measurable flow rate. +. The readings on manometers ;2 5 R< rotameter was noted and flow rate was measured.. ). 7tep + was repeated for different flow rates. The flow rates can be adQusted by utili=ing both bench valve and discharge valve. &. To demonstrate similar flow rates at different system static pressures bench and flow control valve was adQusted together. Manometer levels was adQusting as re/uired.











The maximum maximum readings was retained retained on on manometers manometers with with the maximum measurable flow rate. +. "eadings on manometers ; and R< was noted and flow rate was measured. ). 7tep + was repeated for different flow rates. The flow rates can be adQusted by utili=ing both bench valve and discharge valve. &. The tables was completed.

*. >raph

∆h

of losses.

against !sA(Ag for *% degree elbow was plotted to determine the coefficient











/ C A*.-- l(min

For rotameter flowrate C $% l(min !enturi !enturi flow rate ×

/ C ?d

2t 2t

/ C %.*&;A.%$$

− ;$5;2t(2$ ¿ ¿ 2

×

−4 10

× /

1 2

%.A,-< ¿

;%.A)+5

/

1 2

/

1 2

JAg;ha5hc< ¿

×

−4

10

<(; '.,%*

S$%%% l( $(+% min

/ C +%.,A l(min For rotameter flowrate C $' l(min !enturi !enturi flow rate / C ?d

×

2t 2t

×

− ;$5;2t(2$ ¿ ¿ 2

/

1 2

/

1 2

JAg;ha5hc< ¿

−4

× 10

− / << ¿ J A;*.&$< 1 2













For orifice flowrate C ' l(min / C ?d

×

2t 2t

/ C %.*&;A.%$$ ;%.A-%5

− ;$5;2t(2) ¿ ¿ 2

×

−4 10

×

/ C ,A.A- l(min

/

1 2

%.AA&< ¿

/

1 2

/

1 2

JAg;hg5hh< ¿

×

S$%%% l( $(+% min

−4

10

− − / <(; '.,%* × 10 << ¿ J A;*.&$< 4

1 2











/ C )'.$& l(min For orifice flowrate C A% l(min / C ?d

×

2t 2t

/ C %.*&;A.%$$ ;%.,%'5

− ;$5;2t(2) ¿ ¿ 2

×

−4 10

×

/ C $,+.-* l(min

/

1 2

%.%*%< ¿

/

1 2

/

1 2

JAg;hg5hh< ¿

×

S$%%% l( $(+% min

−4

10

− − / <(; '.,%* × 10 << ¿ J A;*.&$< 4

1 2











The minimum flowrate# C '.$) l(min C &.+AS

−5 10

m

3

!elocity !elocity of flow in i n pipe ;diameterC A+ mm<

!C &.+AS

−5 10

'.,$S

m

3

(s

−4 10

C %.$+ m(s ! C $.,% mm Ag 4

3

(s











C %.,- m(s ! C '.&* mm Ag

The minimum flowrate# C A%.%% l(min C ,.,,S !elocity !elocity of flow in i n pipe ;diameterC A+ mm<

!C ,.,,S

−4

10

'.,$S

−4 10

m

3

(s

−4 10

m

3

(s











14 1 10 

pie=ometer head ;mm<

6 4  0 1





velocity velocity head ;mm< ;mm <

4













&ISC(SSIO0S

Flow meter demonstration is to demonstrate three different types of flow meter which are variable rotameter venturi meter orifice plate meter. From the reading ta0en we can calculate variable rotameter flow rate orifice plate flow rate venture meter flow rate and the head velocity. 1ased on these experiments we can see the characteristic characteristic of three different types of











Conc"usion

2s a conclusion we can say that the most accurate flow meter is a venturi venturi meter. 1ased

on theory the venturi meter is the precise device in measuring the flow rate of any fluid as it has the diverged portion that increases the velocity and r educes the friction loss. 1y utili=ing three basic types t ypes of flow measuring techni/ues@ rotameter venturi











References

$. 1ruce ". Munson Donald F. oung Theodore P. O0iishi Fundamental of Fluid Mechanics Pipe Flow Rate Measurement  'th 9dition ;A%%+< Rohn Wiley V 7ons nc. A. .8. umar 9ngineering Fluid MechanicsE $ st 9dition ;$*)+< 7. ?hand V ?ompany 8td. TheVenturi and Orifice Meters ,. "obert 2. >ranger 9xperiments in Fluid MechanicsE TheVenturi st $ 9dition ;$*&&< Polt "inehart and Winston nc.

Lab 4(Flowmeter Demonstration)

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