SERIES AND PARALLELPUMP TEST SET Introduction Transport Transport of water from low sources sources to elevated tanks or from low sources to direct directly ly consum consumers ers is accom accompli plish shed ed by the help help of pumps. pumps. Pu Pumps mps are are used used to transfer uid in a system, either at the same level or to a new height. The ow rate depends on the height to which the uid is pumped, and the relationship between characteristic”. This has to be “hea “h ead d” and and ow ow rate rate is calle alled d the the “pump characteristic” deter determin mined ed exper experime imenta ntally lly for a pump pump and the TecQuipment H! Series and Para""e" Pump Test set provides a low cost and eective way of demonstrating how this is achieved, and enabling more detailed experiments to be done. The !"# uses domestic central heating pumps, more correctly correctly known as “circulators”, which provide relatively low outputs compared with pumps designed for high performance. This enables the !$ !ydraulic %ench to be used as both the source of water and to measure the ow rate. &ften in civil engineering applications a single pump cannot deliver the ow rate or head necessary for a particular need, and two 'or more in practice( can be combin combined ed in series series to incre increas ase e the the ow rate. The !"# demons demonstra trates tes how the combined pump characteristic compares compares with that of the single pump. )ore sophisticated sophisticated pump test sets, such as the !"* +omputeried +entrifugal +entrifugal Pump Test -ig, may be found in the Tecuipment range. These are suitable for more advanced studies in the uid dynamic performance of pumps.
Desi#n o$ the Apparatus
The H! Series and Para""e" Pump Test Set
The Tecuipment !"# /eries and Parallel Pump Test /et, shown in 0igure above, is one of a range of small e1uipment intended for use with the Tecuipment !$ 2ravimetric !ydraulic %ench or !$d 3olumetric !ydraulic %ench. Two similar single phase multi4speed pump units are connected by a pipe system so that each pump can be run on its own, combined in series, or combined in parallel. 0igures $a, $b, $c, and d show the position of the three valves 5, % and + re1uired to set up each ow condition. 6ach pump has a control panel which enables it to be switched on or o, together with a three speed control.
Figure 1a: Setting the three control valves: Pump 2 only.
Figure 1b: Setting the three control valves: Pump 1 only. Figure 1c: Setting the three control
valves: Pumps in parallel.
Figure 1d: Setting the three control valves: Pumps in series.
5 single %ourdon gauge is 7tted to the top panel which can be switched to measure the delivery pressure of either pump. The pump inlet pressure can be determined from %ernoulli8s 61uation. The water ow rate is ad9usted using a gate valve 7tted in the return pipe between the pump test set and the hydraulic bench. This valve must not be 7tted in the water pipe leading to the pump test set, as to do so would mean that an unknown and variable pressure drop would be introduced so that the pump inlet pressure could not be determined. :f a valve is 7tted before the pump, it must be fully open when measurements are taken. 0or experiments to determine the pump overall e;ciency, it is necessary to measure the input electrical power with a wattmeter. !owever, the input powers 1uoted by the pump manufacturer will be su;cient to demonstrate how the e;ciency is calculated. Table $ gives typical input powers and pump speeds.
Ta%"e &' T(pica" pump input po)ers and speeds Speed & !
Input po)er* )atts <= >= $=?
Re+s,min >?= $$?= $@?=
Parts and -unction
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3. PARTS 4 ILLUSTRATI5N &. 5ut"et
6.
-UN7TI5N
&8. :t is the exit point of the pumped uid. &&.
#. Pump S)itch &3.
&. They switch on if&6. the pressure reading on pump $ !8. or pump # is necessary. !&. $#. !!. PARTS 4 ILLUSTRATI5N 3 .De l i ver yPr essur e 0. Pumps :7entri$u#a" Pump;
1 4 .
/. Po)er 9utton !/. 1.
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-UN7TI5N
!0. is used to &0. :t reads:tthe delivered transport by the pressure by uids the pump conversion of rotational during the operation. kinetic energy to the hydrodynamic energy of the uid ow. !2. :t regulates, &2. :t powers on and directs o the or controls the ow of a device. uid by opening, closing, or partially obstructing various passageways.
2. In"et !3.
8. :t is the entry point of uid into the pump area.
!6. &. !.
5peratin# 7onditions'
&perating environmentG Baboratory environment /torage temperature rangeG H#?I+ to J??I+ 'when packed for transport( &perating temperature rangeG J?I+ to J<=I+ &perating relative humidity rangeG @=K at temperatures L "$I+ decreasing linearly to ?=K at <=I+
.
Speci=cations'
Fet dimensionsG ?#= mm x <*= mm x >== mm Packed dimensions and weightG =."< m" and #? kg /. 0. 1.
2.
Essentia" 9ase Unit'
3olumetric !ydraulic %ench '!$D( 3.
6.
Essentia" Ser+ices'
6lectrical /upplyG #"= 35+, ?=M*= !, #5, single4phase or two4phase Cater /upplyG 0rom the !ydraulic %ench '!$D( 0loor space neededG $m x $m 'plus space for the hydraulic bench( /8.
