Experiment Instructions

HM 150.04 Centrifugal Pump

 HM 150.04 CENTRIFUGAL PUMP
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Experiment Instructions

Last modification by: Dipl.-Ing. (FH) Peter Mittasch

This manual must be kept by the unit.

Before operating the unit:

- Read this manual.
- All participants must be instructed on
handling of the unit and, where appropriate,
on the necessary safety precautions.

Version 0.7 Subject to technical alterations

i
 HM 150.04 CENTRIFUGAL PUMP

Table of Contents

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1 Intended Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Structure of the Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.3 Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.4 Ambient Conditions for Operating and Storage Location . . . . . . . . . . 4
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3 Unit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2 Setting Up, Connection and Commissioning . . . . . . . . . . . . . . . . . . . . 7

4 Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.1 Effect of the Rotational Speed on the Pump Efficiency . . . . . . . . . . . 10
4.1.1 Motor Input-Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.1.2 Hydraulic Pump Output Power . . . . . . . . . . . . . . . . . . . . . . . 10
4.1.3 Volume Flow-Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1.4 Delivery Head of the Pump. . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1.5 Pump Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.2 Pump Characteristic-Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2.1 Preparation of the Experiment . . . . . . . . . . . . . . . . . . . . . . . 13
4.2.2 Measurement Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2.3 Presentation of the Measured Values. . . . . . . . . . . . . . . . . . 15

5 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1 Technical Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2 List of Formula Symbols and Units Used . . . . . . . . . . . . . . . . . . . . . 17
5.3 Pump characteristic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.4 Worksheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

ii
 HM 150.04 CENTRIFUGAL PUMP

1 Introduction

The attachment set HM 150.04 Centrifugal Pump

is used in conjunction with HM 150 Base Module
for Experiments in Fluid Mechanics.
The connection with HM 150 is made by using a
hose with quick fit. The centrifugal pump supplies
water through the submerge pump of HM 150.
The centrifugal pump is experimented without the
pump of HM 150.
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Learning Objectives
Familiarisation with operating behaviour and
characteristics of a centrifugal pump through
experiments.
• recording the pump characteristic curve at a
constant pump speed
– measuring the intake and delivery pressure
– determining the flow rate
• recording the pump characteristic curves for
different speeds
• power and efficiency curves
– measuring the electrical drive power
– determining the hydraulic power
– calculating the efficiency

1 Introduction 1
 HM 150.04 CENTRIFUGAL PUMP

2 Safety

2.1 Intended Use

The unit is to be used only for teaching purposes.

2.2 Structure of the Safety Instructions

The signal words DANGER, WARNING or

CAUTION indicate the probability and potential
severity of injury.
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An additional symbol indicates the nature of the

hazard or a required action.

Signal word Explanation

Indicates a situation which, if not avoided, will result in

DANGER death or serious injury.

Indicates a situation which, if not avoided, may result in

WARNING death or serious injury.

Indicates a situation which, if not avoided, may result in

CAUTION minor or moderately serious injury.

Indicates a situation which may result in damage to

NOTICE equipment, or provides instructions on operation of
the equipment.

2 Safety 2
 HM 150.04 CENTRIFUGAL PUMP

Symbol Explanation

Electrical voltage

Notice

2.3 Safety Instructions

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Note also the instruction manual for HM 150 and

the safety instructions specified therein.

WARNING
Electrical connections are exposed when the
switch box is open.
Risk of electric shock.
• Disconnect the mains plug before opening the
switch box.
• Work should only be performed by qualified
electricians.
• Protect the switch box against humidity.

NOTICE
The centrifugal pump is destroyed if operated
without water.
• Make sure that the centrifugal pump is filled
with water before operation.

2 Safety 3
 HM 150.04 CENTRIFUGAL PUMP

NOTICE
Fault current protective devices
In the event of an earth fault, the fault current may
contain a DC component.
• Only all current sensitive residual current pro-
tective devices (RCD, type B) are to be used
(EN 50178, IEC 755).
• Identification on the all current sensitive resid-
ual current protective device (RCD, type B).
• When using residual current circuit breakers,
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compliance with the applicable local regula-

tions must be ensured. The circuit breaker
used must be approved for protection of
devices with three-phase rectifier bridge (type
B) and for a transient pulse current in the when
switching on.

2.4 Ambient Conditions for Operating and Storage Location

• Enclosed room.
• Free of dirt and moisture.
• Level and secure base.
• Frost free.

2 Safety 4
 HM 150.04 CENTRIFUGAL PUMP

3 Unit Description

3.1 Layout

6 5 4 3

2
7

1
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10 11 12 13

Pos. Designation Pos. Designation

1 Asynchronous motor 8 On-off switch for the Centrifugal pump
2 Rear panel 9 Potentiometer for speed
3 Ball valve 10 Master switch
4 Manometer, delivery side 11 Emergency-off switch
5 Manometer, intake side 12 Centrifugal pump
6 Digital display for n 13 Frame
7 Digital display for Pel

Fig. 3.1 Layout HM 150.04

The overall structure is made of anti-corrosion

materials. The piping and the stop valves are
made of plastic material. The centrifugal
pump (12) is driven by an asynchronous
motor (1).

3 Unit Description 5
 HM 150.04 CENTRIFUGAL PUMP

The pump speed is controlled by an asynchro-

nous motor with a frequency converter. The
speed and the power consumption can be read on
the digital displays (6, 7).
The suction pressure and delivery pressure are
measured by 2 manometers (4, 5).
The volume (mass) flow-rate is measured using
the volumetric tank of HM 150.
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3 Unit Description 6
 HM 150.04 CENTRIFUGAL PUMP

3.2 Setting Up, Connection and Commissioning

17
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18 19

16

20

21
15

Pos. Designation Pos. Designation

15 Storage tank 19 Quick fit
16 Drain 20 Ball valve
17 Hose connection 21 Water supply connection with cap
18 Diverting cap

Fig. 3.2 Setting up and connection onto the Base Module HM 150

3 Unit Description 7
 HM 150.04 CENTRIFUGAL PUMP

1. Place the experimental unit HM 150.04 onto

the base module HM 150. Make sure that the
return pipe conducts the water into the channel
(see Fig. 3.3).

2. Open the drain (16) of HM 150.

3. Open the ball valve (20).

4. Open the ball valve (3).

5. Fill the storage tank (15) of HM 150 with water.

Return pipe
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HM 150
NOTICE
Connection for hose
Danger of damage to the unit.
• Before connecting to the electrical supply:
Fig. 3.3 Rear HM 150.04 Make sure that the power supply in the labora-
tory corresponds to the specifications on the
unit's rating plate.

6. Connect the electrical supply.

NOTICE
Remove the transport lock at the rubber blow-out
disc of the manometers (at the top of the case)
before operation.

7. Vent the pump.

• Connect HM 150 and HM 150.04 using the

hose (17).
To do so, unsrew the diverting cap (18) from
the connecting piece of the HM 150 and
replace it by the quick fit (19).

3 Unit Description 8
 HM 150.04 CENTRIFUGAL PUMP

• Turn on the submersible pump of the

HM 150 until water flows out of the return
pipe.
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3 Unit Description 9
 HM 150.04 CENTRIFUGAL PUMP

4 Experiments

The selection of experiments makes no claims of

completeness but is intended to be used as a
stimulus for your own experiments.
The results shown are intended as a guide only.
Depending on the construction of the individual
components, experimental skills and environmen-
tal conditions, deviations may occur in the experi-
ments. Nevertheless, the laws can be clearly
demonstrated.
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4.1 Effect of the Rotational Speed on the Pump Efficiency

To determine the pump efficiency, the electrical

input power of the drive motor and the hydraulic
output power of the pump are needed.

4.1.1 Motor Input-Power

The asynchronous motor input-power is given

from the frequency converter and shown on the
digital display:
Pel

4.1.2 Hydraulic Pump Output Power

The output power of the hydraulic pump is calcu-

lated from:
·
P hyd = V  H    g

4 Experiments 10
 HM 150.04 CENTRIFUGAL PUMP

·
To measure the volume flow-rate V , you need to
measure the time t needed to fill the volumetric
tank of HM 150 from 20L to 30L

4.1.3 Volume Flow-Rate

The volume flow-rate is calculated as:

V· = V
--------
t
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The density of water is considerd as:

kg
 = 998 ------3-
m

The gravity acceleration:

m
g = 9,81 ----2-
s

4.1.4 Delivery Head of the Pump

The delivery head is calculated as follows:

2 2
p ds – p is c ds – c is
H = --------------------
- + y + -------------------------
-
g 2g

The influences of the flow speeds cds and cis can-

cel each other due to equal cross-sections in suc-
tion and pressure connections.
y is the height difference of the two manometer,
where y = 0,18m.

4 Experiments 11
 HM 150.04 CENTRIFUGAL PUMP

4.1.5 Pump Efficiency

The pump efficiency is calculated from the

hydraulic pump power and the asynchronous
motor power. With a motor effeciency of
 m = 0,92 the pump efficiency is
P
 P = -------------------
hyd
-
P el   m
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4 Experiments 12
 HM 150.04 CENTRIFUGAL PUMP

4.2 Pump Characteristic-Curves

4.2.1 Preparation of the Experiment

– Delivery pressure is adjusted by the ball valve

(3) (see Fig. 3.1, Page 5).
– The speed is adjusted via the potentiometer on
the switch box.

4.2.2 Measurement Results

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Speed n = 900min-1
pis in bar pds in bar V in L t in s V· in L/h H in m Pel in W Phyd in W  P in %
-0,18 0,00 10 31 1161,29 2,02 75 6,37 9,2
-0,12 0,05 10 53 679,25 1,92 75 3,54 5,1
-0,11 0,10 10 69 521,74 2,32 75 3,30 4,8
-0,11 0,15 10 90 400,00 2,84 75 3,08 4,5
-0,11 0,20 5 73 246,58 3,35 75 2,24 3,3
-0,11 0,27 0 0 0,00 4,06 75 0,00 0,0
Tab. 4.1 Measurement results at speed n = 900min-1

Speed n = 1800min-1
pis in bar pds in bar V in L t in s V· in L/h H in m Pel in W Phyd in W  P in %
-0,39 0,0 20 27 2666,67 4,16 190 30,19 17,3
-0,39 0,2 20 35 2057,14 6,21 190 34,72 19,9
-0,20 0,5 20 54 1333,33 7,33 185 26,58 15,6
-0,14 0,8 20 105 757,89 9,78 185 20,16 11,8
-0,12 1,0 10 78 461,54 11,62 185 14,58 8,6
-0,11 1,2 8 102 282,35 13,56 185 10,41 6,1
Tab. 4.2 Measurement results at speed n = 1800min-1

4 Experiments 13
 HM 150.04 CENTRIFUGAL PUMP

Speed n = 2700min-1

pis in bar pds in bar V in L t in s V· in L/h H in m Pel in W Phyd in W  P in %

-0,40 0,0 20 26 2769,23 4,27 410 32,12 8,5

-0,38 0,5 20 29 2482,76 9,17 440 61,91 15,3

-0,32 1,0 20 31 2322,58 13,66 450 86,30 20,8

-0,23 1,5 20 48 1500,00 17,85 445 72,82 17,8

-0,17 2,0 20 77 935,06 22,34 440 56,82 14,0

-0,12 2,5 20 136 529,41 26,94 440 38,79 9,6

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-0,11 3,0 20 263 273,76 31,95 440 23,78 5,9

-0,11 3,4 0 0 0 36,03 440 0,00 0,0

Tab. 4.3 Measurement results at speed n = 2700min-1

4 Experiments 14
 HM 150.04 CENTRIFUGAL PUMP

4.2.3 Presentation of the Measured Values

The measurement results give the following char-

acteristic curves.

40

-1
900 1/min
900min
0% 1800 1/min-1
1800min

35 2700 1/min
2700min -1

5,9%
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30

9,6%
Delivery head H in m

25

14,0%

20

17,8%
0%

15
6,1% 20,8%

8,6%

10 11,8%
15,3%
15,6%
19,9%
6,6%
5 0%
3,3%
17,3%
4,8%
4,5%  p = 9,2%
5,1%
0
0 500 1000 1500 2000 2500 3000
·
Flow rate V in L/h

Fig. 4.1 Diagram

4 Experiments 15
 HM 150.04 CENTRIFUGAL PUMP

5 Appendix

5.1 Technical Data

Dimensions
Length x width x height 1.100mm x 640mm x 600 mm
Weight approx. 46 kg

Power supply
Voltage 230 V
Frequency 50 Hz
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Phases 1

Nominal consumption (power) 1 kW

Optional alternatives, see rating plate

Pump
Type Centrifugal pump
Delivery head, maximum 36 m
Flow rate, maximum 45 L/min
Nominal speed 2.820 min-1
Optional alternatives, see rating plate

Asynchronous Motor
Type Asynchronous motor
Nominal consumption (power) 0,44 kW
Optional alternatives, see rating plate

Manometer, delivery side

Type Bourdon tube RKG 63
Measuring range -1...5 bar
Accuracy (EN 837-1) Grade 1,6
Nominal size 63 mm
Connection G 1/4“

5 Appendix 16
 HM 150.04 CENTRIFUGAL PUMP

Manometer, intake side

Type Bourdon tube RKG 63
Measuring range -1...1,5 bar
Accuracy (EN 837-1) Grade 1,6
Nominal size 63 mm
Connection G 1/4 “

5.2 List of Formula Symbols and Units Used

Symbol Mathematical/physical quantity Unit

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g Gravity acceleration m/s2

H Delivery head m

n Speed min-1

p Pressure bar

P Power W

t Time s

V Volume L

y Height difference of the manometers m

 Density kg/m3

 Efficiency

V· Flow rate L/h

Suffix Explanation

ds Delivery side

el Electrical

hyd Hydraulic

is Intake side

m Motor

p Pump

5 Appendix 17
 HM 150.04 CENTRIFUGAL PUMP

5.3 Pump characteristic

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Fig. 5.1 Ebara JESX 6; 0,44 kW

5 Appendix 18
 HM 150.04 CENTRIFUGAL PUMP

5.4 Worksheet

Name

Date

Speed n = ______min-1

pis in bar pds in bar V in L t in s V· in L/h H in m Pel in W Phyd in W  P in %

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5 Appendix 19