Experiment 4 Uploaded

Fluid Mechanics (CLD 10603) Experiment 4: Multi Pump Test Rig

Experiment 4 Multi Pump Test Rig

Objectives -

-

Determine the operating characteristic of different pumps in a contained unit. Understand the types of pumps in principle and design, and the selection of the appropriate pump for a particular application for optimal operation.

Overview Pumps are of a major concern to most engineers and technicians. The types of pump vary considerably in principle and design, and the selection of the appropriate pump for a particular application is essential for satisfactory operation. This experiment allows students to measure the operating characteristic of different pumps in a contained unit. This training unit incorporates appropriate pipe work and tanks to make the operation selfcontained. The manually operated valves and pipe work are arranged for rapid and safe selection of any one-test pump. All necessary instrumentation for measurement of flow, pump head, speed and power are included. In the experiments, students are able to operate three types of pump namely a Horizontal Single Stage Centrifugal Pump, a Positive Displacement Plunger Pump and a Positive Displacement Gear Pump.

1


General Start - Up Procedures Before conducting any experiment, it is necessary to do the following checking to avoid any misuse and malfunction of equipment. 1.

Make sure that the water tank is filled with water up to at least 50%.

2.

Make sure that the oil tank is filled with oil up to at least 50%.

3.

Make sure that the RS 232 data cable is connected to the computer.

4.

Switch on the main power supply located on the control panel. The instruments should light up.

5.

Select the appropriate pump and flow meter according to the following combination.

6.

Switch on the computer and monitor if you are using them to collect data and generate the characteristic curve. Pump

Indication

P1/P2

0 -100%

Flow Meter FT 1

Types of Pump

Pump Selection Switch

Process Selection Switch

Hand Valve OPEN

Hand Valve CLOSE

P1

Water

HV2, HV3, HV4

P2

Water

HV2, HV5, HV6

HV1, HV5, HV6, HV7, HV8 HV1, HV3, HV4, HV7, HV8

Horizontal Single Stage Pump Plunger Pump

Flow rate 0 – 113.56 L/min

2

Diff. Pressure DPT 1

Pump Head 0 – 3 bar


Important: i. ii.

Never operate the pumps when there is no liquid in the pipeline. It will cause serious damage to the pumps. Always watch out for the direction of the motor impeller, it should follow the direction of the arrow on the pump.

Data Acquisition System 1.

Power the pump Test Rig first.

2.

Ensure that the cable between the computer and the Pump Test Rig is correctly connected.

3.

Switch on the power to the computer.

4.

Under Windows click on the Pump Test Rig icon. The program wills startup automatically.

5.

The table consists of fifteen entries and a final entry at the bottom labeled 'live'- this is the live reading at that moment in time (online data).

6.

During an experiment, if you wish capture these data, click on the 'Record' button.

7.

The recording mechanism will capture at maximum 15 entries. After which it will try to replace the closest old entry found.

8.

These captured data could be saved in the form of a file. It could also be loaded later for review or to add a new entry.

9.

It is important that the user selects the correct pump before recording the data, as live data will be represented differently for each pump.

3


Experimental Procedures Experi ment 1

: Rot at i onal Speed Vs Vol umet ri c Fl ow rat e. Perfor mance Curv e for a Cent ri fugal Pump

Experimental Procedures 1 for P1 Please refer to the general start - up procedures before conducting this experiment. 1.

Press the START push button to start the pump.

2.

Set the motor speed to about 2800rpm using the speed control beside the speed indicator.

3.

Open HV2 fully so that the flow rate is at its maximum.

4.

Record the flow rate once the readings are stable. (Refer Table 1)

5.

Repeat steps 2 and 4 for the following speed readings of 2600, 2400, 2200, 2000, 1800, 1600, 1400, 1200, 1000, 800 and 600rpm.

6.

The data collected using above procedure will enable you to plot the following characteristic curve: i. Rotational speed (N) Vs. Volume Flow (Q)

Note: i. ii.

Please switch off the pump by pressing the stop push button at the end of experiment. Adjust the potentiometer to its minimum setting (fully anti clockwise).

4


Experi ment 2

: O t her Perfor mance Curv e for a Cent ri fugal Pump

Experimental Procedures 2 for P1 Please refer to the general start - up procedures before conducting this experiment. 1.


2.

Set the motor speed to maximum (2800rpm) using the speed control beside the speed indicator.

3.

Set HV2 at full opening so that the output flow rate is maximum and record the readings for the flow rate, the differential pressure, the power and speed once the readings are stable. (Refer Table 2)

4.

Repeat step 3 with the following flow rate of output 70%, 60%, 50%, 40%, 30%, 20%, 10%. You can try any other intermediate reading.

5.

The data you have collected will enable you to analyze the following characteristic curve: i. ii. iii. iv. v. vi.

Note: i. ii.

Motor Input Power (PMi) Pump Total Head (H) Pump Power Output (P o) Pump Power Input (Pi) Pump Efficiency (ETA) Overall Efficiency (ETAgr)

Vs Vs Vs Vs Vs Vs

Volume Flow rate (Q) Volume Flow rate (Q) Volume Flow rate (Q) Volume Flow rate (Q) Volume Flow rate (Q) Volume Flow rate (Q)

Please turn off the pump by pressing the stop push button at the end of experiment. Adjust the potentiometer to its minimum setting (fully anti clockwise).

5


Experi ment 3

: Rot at i onal Speed Vs O ut put Pr essure Perfor mance Curv e for a Posit i ve Di spl acement Pump

Experimental Procedures 1 for P2 Please refer to the general start-up procedures before conducting this experiment. 1.


2.

Adjust the potentiometer beside the speed indicator, set the motor speed to its maximum (i.e. About 950 rpm)

3.

Slowly adjust the HV2 so that the pump head (pressure) is at 90%.

4.

Record the flow rate once the readings are stable.(Refer Table 3)

5.

Repeat steps 2 and 4 for the following motor speed readings of P2 = 950, 900, 850, 800, 750, 700, 650, 600, 550 rpm.

6.

The data you have collected will enable you to plot the following characteristic curve. i.

Rotational Speed (N)

Vs.

Volume Flow Rate (Q)

Note: i. ii.


Warning: Do not close the HV2 completely when P2 is running. This may cause serious damage to the instrument.

6


Experi ment 4

: O t her Perfor mance Curv e for a Posi t i ve D i spl acement Pump

Experimental Procedures 2 for P2 Please refer to the general start-up procedures before conducting this experiment. 1.


2.

Adjust the potentiometer beside the speed indicator, set the motor speed to its maximum (i.e. About 950 rpm).

3.

Slowly adjust the HV2 or HV 11 so that the pump head (pressure) is at 90%, record the flow rate, differential pressure, power and speed once the readings are stable (Refer Table 4).

4.

Repeat step 3 with the following pump head readings of P2 = 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%. You can try any other intermediate reading but never try to close the HV2 or HV 11 fully. This is to ensure that the existing pressure develop in the pipeline doesn’t exceed the limit.

5.

The data you have collected will enable you to plot the following characteristic curve; i. Motor Input Power (PMi) ii. Volume Flow (Q) iii. Pump Power Output (P o) iv. Pump Power Input (Pi) v. Pump Efficiency (ETA) vi. Overall Efficiency (ETA gr) vii. Volumetric Efficiency (ETA v)

Vs Vs Vs Vs Vs Vs Vs

Output Pressure (Pr) Output Pressure (Pr) Output Pressure (Pr) Output Pressure (Pr) Output Pressure (Pr) Output Pressure (Pr) Output Pressure (Pr)

Note: i. ii.


7


Warning: Do not close the HV2 completely when P2 is running. This may cause serious damage to the instrument.

Results Record the data collected for experiment 1 in the table below. Tabl e 1: Rotat i onal Speed and Flow rat e for P1

Speed (RPM)

Flow rate (%)

Record the data collected for experiment 2 in the table below. Tabl e 2: Fl ow rat e, Speed, Di ff erent i al Pressure and P ow er f or P 1

Flow rate %

Speed RPM

Diff.Pressure %

8

Power kW


Record the data collected for experiment 3 in the table below . Tabl e 3: Rota t i onal Speed and D i fferent i al Pressure for P2

Speed (RPM) 950 900 850 800 750 700 650 600 550

Flow Rate (%)

Record the data collected for experiment 4 in the table below . Tab l e 4: Pr essur e, Fl ow ra t e, Speed and P ow er fo r P2

Pressure % 90 80 70 60 50 40 30 20 10

Flow rate %

Speed RPM

9

Power kW


Li st of Abbrevi ati on

Symbol

Description

N PMI H Q Pi Po Pm Zc1 Zc2 ETA ETAgr ETAv

Rotational Speed Motor Input Power Pump Total Head Volume Flowrate Pump Power Input Pump Power Output Pump Mechanical Power Inlet Distance From Datum (water) Outlet Distance From Datum (water) Pump Efficiency Overall Efficiency Volumetric Efficiency Density of Water Density of Oil Differential Pressure Pressure Gravity Pump 1 Power at No Load (50 Hz) Pump 2 Power at No Load (50 Hz) Pump 3 Power at No Load (50 Hz) Volume Displacement for Gear Pump Volume Displacement for Plunger Pump Inlet Distance From Datum (oil) Outlet Distance From Datum (oil)

w oil DP Pr g Pp1min Pp2min Pp3min Vigar Vipiston ZG1 ZG2

Constant Value

10

180 mm 860 mm

1000 910

9.81 70 60 50 6.309 x 10 -6 2.09 x 10 -5 64 mm 380 mm

Unit RPM W m m3/hr W W W m m % % % kg/m3 kg/m3 % % m/s2 W W W m3/rev m3/rev m m


Formul a for Cal culat i on of Vari ables

Horizontal Single Stage Centrifugal Pump/ Plunger Pump Volumetric flow rate, m3/hr

 113.56 x 60    1000 

Q = (q/100) x 

Pump Power Output, W

3 x 10.2 x 10  DP  x  H = (Zc 2- Zc 1) +     w g  100   Po = (wg HQ) / 3600

Pump Power Input, W

Pi = (PMI – P1min ) or (PMI – P2min)

Pump Efficiency, %

ETA =

Overall Efficiency, %

ETA gr=

Pump Total Head, m

Po Pi

4

  

x 100

Po P MI

x 100

* For Plunger Pump Only Volumetric Efficiency, %

Note: 1 GPM

1 bar

ETAv =

Q V i x N x 60

x 100

= 3.7854 LPM = 10.2 mH2O

Discussion Plot all the characteristic curves which have been stated in all the experiment conducted. Comments the plotted graphs in terms of their relationships between the y – axis and the x – axis

11


Tutorial

1.

Define pump.

2.

What is the difference between dynamic pump and positive displacement pump?

3.

List down three factors which influence the choice of pump for a particular operation.

12


Conclusion

References 1. White, F.M. Fluid Mechanics 4th Ed. McGraw Hill 2. McCabe, W.L., Smith, J.C and Harriot Unit Operations of Chemical Engineering 5th Ed. McGraw Hill 3. Anthony Esposito. Fluid Mechanics with Applications. Prentice Hall International Inc. 4. Debler, W.R. Fluid Mechanics Fundamentals. Prentice Hall International Inc. 13

Experiment 4 Uploaded

Recommend Documents