series & parallel pump

8/12/2019 series & parallel pump

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ECE3421 CHEMICAL ENGINEERING LAB II

EXPERIMENT 5 : SERIES AND PARALLEL PUMP

Candidates Name : Divaan Raj Karunakaran

Student ID : SCM 026024

Group Members Name : Yuga Raaj A/P J.Balar

Viveta Priyaa A/P Selvarajan

Thivya A/P P.Maran

Alaa adnan

Mohammed Salleh

Lecturer/ Supervisor : Dr. Yap Pow Seng

Date of Submission : 24 / 02 / `2014


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ABSTRACT

The purpose behind conducting this experiment on the two different pump system , the single

pump system and the identical pump system ( series and parallel pump ) is to observe how

will such a pump system operate and the characteristics behind its way of operation. But as of

the main objective to experiment on the different pump systems is to differentiate the flow

rate and pressure head of a single pump and of two other identical pumps which was run in

series and parallel. In our experiment, we have used the centrifugal pump to determine the

flow rates and the pressure head of the pumps. A very common system used to transfer

liquids will be a centrifugal pump, as it is very quiet while operating in a way that in

produces less friction and the noise production is lower. Also it takes up very little operating

and maintenance costs, while it takes up very little floor space and create a uniform, non-

pulsating flow. As we are experimenting manually on the different pump systems, this is to

actually measure the performance of a centrifugal pump and to compare the results with the

theoretical predictions. Besides all these, this experimental results will be helpful to even

investigate the affinity laws for pumps.


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INTRODUCTION

Almost in every industry and engineering fields, right from feeds to reactors or distillation

columns to pumping storm water uses the aspects of pumps. Pumps are used to transfer fluid

in a system, either at the same elevation or to a new height. The height to which the fluid will

be pumped is responsible for the flow rate needed. Every pump has its head discharge

relationship that is inversely proportional for instance if a higher flow rate is needed, then

lesser pressure head will be produced by the pump, and vice versa. Usually the pump

manufacturers will provide this head - discharge relationship, also known to be the pump

characteristic curve. A centrifugal pump converts the input energy to kinetic energy in the

liquid by accelerating the liquid by a revolving device as an impeller. Fluids enter the pump

via eye of the impeller which rotates at high speed. The fluid is accelerated radically outward

from pump chasing. A vacuum is created at the impellers of the eye that continuously draws

more liquid into the pump. The energy created by the pump is a kinetic energy according to

the Bernoulli equation. The energy transferred to the liquid corresponds to the velocity of the

impeller. The faster the impeller revolves, the higher the velocity of the liquid energy

transferred to the liquid. The basic operation of centrifugal pumps is to explore the flow rates

and pressure head of a single pump and of two identical pumps that operate in series or in

parallel. When pumps are arranged in series their resulting pump performance curve is

obtained by adding their heads at the same flow rate. When pumps are arranged in parallel

their resulting performance curve is obtained by adding their flow rates at the same head.

Schematic Diagram: Series pump


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Schematic Diagram: Parallel pump

3.1 Overall Dimensions

Height: 700mm

Width : 650mm

Depth: 1100mm

3.1 General requirements

Electrical: 240VAC, 1-phase, 50Hz

Water: clean tap water

3.2 Installation

Installation procedures:

1. The unit was unpacked and placed on a table close to the single phase electrical supply.

2. The equipment was placed on top of a table and the equipment was level with the

adjustable feet.

3. All the parts inspected and instruments on the unit and make sure that it is in proper

condition.

4. The equipment was connected to the nearest power supply.


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3.3 Commissioning procedures:

1. The equipment was installed according to the section 3.1.

2. All the valves are initially closed.

3. The sump tank was filled up with clean water until the water level is sufficient to cover the

return flow pipe.

4. The test pump was tested according to section 5.1.

5. The pumps were checked like the flow meter and the gauges. Then, any leakage on the

pipe line was identified. If there is any leakage it was fixed.

6. The pumps was turn off after the commissioning.

4.0 Experimental Procedures

4.1 General Start-up Procedures:

1. The circulation tank is filled with water up to at least the end of the pipe output issubmerge with water.

2. The V5is in partial open position.3. The main power supply is switched on.4. The appropriate pump was selected and checked for following valve position.

Pump operation Running pump Open valve Close valve

Single Pump1,P1 1,4 2,3

Serial Both Pump,P1&P2 1,3 2,4

Parallel Both Pump, ,P1&P2 1,2,4 3

5. Turned on pump and slowly open V5 until maximum flowrate is achieved.

Orientation Minimum flowrate(LPM) Maximum flowrate(LPM)

Single 20 90

Series 20 90

Parallel 40 180


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EXPERIMENT 2 : Series Pump Operation

Equipment Set Up:

Fully close valve Fully open valve Variable parameter Pump ON

2&4 1&3 Valve 5 Both Pump

Procedures:

1. The basic procedure as written is followed.2. Ensured that all setting follows the equipment set up.3. Slowly opened valve V5 until the flowrate reaches 20 LPM.4. The pressure reading on the pressure indicator was observed. The flowrate and

pressure value was recorded when stable condition is achieved.

5. The observation was repeated by increasing the flowrate with increment by 10LPMuntil the flowrate reaches 90 LPM.

EXPERIMENT 3 : Parallel Pump Operation

Equipment Set Up:

Fully close valve Fully open valve Variable parameter Pump ON

3 1&2&4 Valve 5 Both Pump

Procedures:

1. The basic procedure as written is followed.2. Ensured that all setting follows the equipment set up.3. Slowly opened valve V5 until the flowrate reaches 40 LPM.4. The pressure reading on the pressure indicator was observed. The flowrate and

pressure value was recorded when stable condition is achieved.

5. The observation was repeated by increasing the flowrate with increment by 20LPMuntil the flowrate reaches 180 LPM.


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RESULTS

Rotameter (FI1)

LPM

Pressure Gauge 1

(PI1) kgf/cm2

Pressure Gauge 2

(PI2) kgf/cm2

Analogue (PI1)

kgf/cm2

Digital (PI1)

kgf/cm2

Analogue (PI2)

kgf/cm2

Digital (PI2)

kgf/cm2

20 0.00 1.07 2.10 3.14

30 0.00 1.07 2.10 3.08

40 0.00 1.07 2.00 3.03

50 0.00 1.06 2.00 2.97

60 0.00 1.05 1.80 2.89

70 0.00 1.05 1.80 2.79

80 0.00 1.04 1.70 2.70

90 0.00 1.04 1.60 2.59

Table 6: Result of Experiment 1

PI2PI1

ANALOGUE DIGITAL

2.10 2.07

2.10 2.01

2.00 1.96

2.00 1.91

1.80 1.841.80 1.74

1.70 1.66

1.60 1.55

Table 6.1: Result of Experiment 1


Rotameter

(FI1) LPM

Pressure Gauge 1

(HI) kgf/cm2

Pressure Gauge 3

(PI3) kgf/cm2

Pressure Gauge 4

(PI4) kgf/cm2

Analogue

(HI)kgf/cm2

Digital

(HI)kgf/cm2

Analogue

(PI3)kgf/cm2

Digital(PI3)

kgf/cm2

Analogue

(PI4)kgf/cm2

Digital

(PI4)kgf/cm2

20 0.00 1.06 2.10 5.16 4.20 5.09

30 0.00 1.06 2.10 3.07 4.20 5.00

40 0.00 1.05 2.00 3.00 4.00 4.86

50 0.00 1.04 1.90 2.92 3.90 4.72

60 0.00 1.04 1.85 2.84 3.70 4.57

70 0.00 1.03 1.80 2.76 3.60 4.44

80 0.00 1.02 1.70 2.66 3.40 4.24

90 0.00 1.00 1.60 2.53 3.20 4.08


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PI3HI PI4- H1

ANALOGUE DIGITAL ANALOGUE DIGITAL

2.10 4.10 4.20 4.03

2.10 2.01 4.20 3.94

2.00 1.95 4.00 3.81

1.90 1.88 3.90 3.681.85 1.80 3.70 3.53

1.80 1.73 3.60 3.41

1.70 1.64 3.40 3.22

1.60 1.53 3.20 3.08



PI2PI1 PI4- PI1

ANALOGUE DIGITAL ANALOGUE DIGITAL2.10 2.02 2.10 1.97

2.00 1.97 2.10 1.93

2.00 1.92 2.00 1.88

1.90 1.86 2.00 1.83

1.80 1.80 1.90 1.74

1.80 1.72 1.80 1.68

1.70 1.64 1.70 1.60

1.60 1.55 1.60 1.51


Rotamete

r (FI1)

LPM

Pressure Gauge 1

(PI1) kgf/cm2

Pressure Gauge 2

(PI2) kgf/cm2

Pressure Gauge 4

(PI4) kgf/cm2

Analogu

e (PI1)

kgf/cm2

Digital(PI1

) kgf/cm2

Analogue(PI2

) kgf/cm2

Digital(PI2

) kgf/cm2

Analogu

e (PI4)

kgf/cm2

Digital(PI4

) kgf/cm2

40 0.00 1.06 2.10 3.08 2.10 3.03

60 0.00 1.05 2.00 3.02 2.10 2.98

80 0.00 1.05 2.00 2.97 2.00 2.93

100 0.00 1.04 1.90 2.90 2.00 2.87

120 0.00 1.03 1.80 2.83 1.90 2.77

140 0.00 1.03 1.80 2.75 1.80 2.71

160 0.00 1.02 1.70 2.66 1.70 2.62

180 0.00 1.00 1.60 2.55 1.60 2.51


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DISCUSSION

From the results obtained in this experiment, it is noticeable that the efficiency would depend

on the species of the pump. As shown in the graph, we can conclude that as flow rate

increases the pressure in each pump decrease either it is single, series or parallel pump.

Efficiency of the pumps in series is higher than in parallel. The efficiency of the pumps in

series is better in lower flow rate and higher head delivered and pumps in parallel is better for

high flow rates and low head delivered

The first experiment done for the single pump system, the results of it clearly shows that as

the flow rate of water increases, the pressure at gage 1 and pressure at gage 2 decreases.

Somehow, theres a slight difference inthe magnitude of the pressure difference between the

reading shown in the analogue and the digital meter. The pressure difference is graphed

below :

Graph 1.0 Pressure difference versus water flow rate for single pump

0

0.5

1

1.5

2

2.5

20 30 40 50 60 70 80 90

PI2- PI1

(kgf/cm2)

Rotameter (FI1) LPM

Pressure difference vs Flow rate

ANALOGUE

DIGITAL


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The second experiment was conducted for the two identical pumps in a series system. In this

experiment quite a similar results was seen as that to the single pump system. As the flow rate is being

increased, the pressure in gage 1 decreases also the pressure at gage 3 and 4 decreased with the

increase in the water flow rate. The pressure difference between gage 3 and gage 1 and the pressure

difference between gage 4 and gage 1 are shown in the graphs below :

Graph 2.0 Pressure difference ( PI3 - HI) versus water flow rate for series pump

Graph 2.1Pressure difference (PI4HI) versus water flow rate for series pump

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

20 30 40 50 60 70 80 90

(PI3 - HI)

(kgf/cm2)

Rotameter (FI1) LPM


ANALOGUE

DIGITAL

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

20 30 40 50 60 70 80 90

(PI4 - HI)

(kgf/cm2)

Rotameter (FI1) LPM


ANALOGUE

DIGITAL


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While the third experiment we did was on an identical pump too which was run in a parallel system.

The results of this experiment shows not much of a difference to the previous single and series pump

system experiments we did. At gage 1, pressure decreased almost significantly same as the single and

series pump. At gage 2 and gage 4, pressure again decreased as the water flow rate increases.

Pressure Gage 4 in series pump has a higher pressure than the pressure gage 4 in a parallel pump.

The difference in pressure between pressure gage 2 and 1 and the difference in pressure between

pressure gage 4 and 1 are shown below :

Graph 3.0: Pressure difference (PI2PI1) versus water flow rate for parallel pump

Graph 3.1: Pressure difference (PI4PI1) versus water flow rate for parallel pum

0

0.5

1

1.5

2

2.5

40 60 80 100 120 140 160 180

(PI2 - PI1)

(kgf/cm2)

Rotameter (FI1) LPM

Pressure diffeence vs Flow rate

ANALOGUE

DIGITAL

0

0.5

1

1.5

2

2.5

40 60 80 100 120 140 160 180

(PI4 - PI1)

(kgf/cm2)

Rotameter (FI1) LPM

Pressure diffeence vs Flow rate

ANALOGUE

DIGITAL


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CONCLUSION

The pressure gradually decreases as the flow rate increases. A higher flow rate can be

obtained when pumps are connected in series. Therefore, pumps in parallel mainly used

because the flow is large. Pumps in series are not generally used because the maximum shut

head of pump is additive and results in high design pressure.As an overall conclusion, from

the results obtained in this experiment, it is noticeable that the efficiency would depend on

the species of the pump. As shown in the graph, we can conclude that as flow rate increases

the pressure in each pump decrease either it is single, series or parallel pump. Efficiency of

the pumps in series is higher than in parallel. The efficiency of the pumps in series is better

in lower flow rate and higher head delivered and pumps in parallel is better for high flow

rates and low head delivered


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REFERRENCE

Berham, P.P., Crawford, R.J., Armstrong, C.G. 1996, Mechanism of EngineeringMaterials, 2ndEdition, Pearson Education Limited, china.

Hibbeler, R.C. 2005, Mechanics of Materials, 6thEdition, Prentice Hall, Singapore. Rama Durgaiah, 2002, Fluid Mechanics and Machinery, 1stEdition, New Age

International (P) Ltd, India.

Hassan Sadiq. 18 March 2013. Centrifugal Pump Characteristic. [online] Availablefrom:

http://share.pdfonline.com/c901652df76f4bbaae22401aff9bb080/Sadiq%20report.htm

[Accessed 18TH February 2014].

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series & parallel pump