Classification of centrifugal pump pwi

CLASSIFICATION OF CENTRIFUGAL PUMP

1. CLASSIFICATION
of Centrifugal Pump
Prof. P.W.Ingle
SanjivaniCollege Of Engineering
Kopargaon

2. CLASSIFICATION
Based on mechanical construction
Closed:Shroudsorsidewallenclosingthe
vanes.
Open:Noshroudsorwalltoenclosethe
vanes.
Semi-openorvortextype.

3. Closed Impeller
•The vanes are provided with metal cover
plates or shrouds ( to hide) on both the
sides.
•It provides better guidence for the liquid
and has a high efficiency.
•It is employed when the liquid to be
pumped is pure and relatively free from
debris.

4. Closed Impeller

5. Closed Impeller

6. •Vanes are open on both sides.
•Open face impellers are popular because
the cost less money to manufacture so the
pump cost less.
•Such impellers are employed for pumping
liquids which contains suspended solid
matter like sewage, paper pulp, water
containing sand or grit i.e. small particles
of stone and sand.
Open impeller

7. Open and Semi Open Impeller

8. Open impeller

9. Open impeller

10. Close and Open Impeller

11. Semi-open Impeller
•The semi open impeller, due to its lack of
a front shroud, also tends to create greater
unbalanced axial force than does the
closed impeller.
•This impellers can be used even if the
liquid contains some debris .

12. Semi-open Impeller

14. Centrifugal Pumps Groups
•Centrifugal pumps can be classified in
three major groups depending on their
design and application:
1. Volute pumps
2. Diffuser pumps OR casing with guide
blades
3. vortex pumps

15. Volute pumps

16. •Inthistypeofcasingorpumptheareaofflow
graduallyincreasefromtheimpelleroutletto
deliverypipesoastoreducethevelocityofflow.
•Thustheincreaseinpressureoccursinvolute
casinginotherwordsthekineticenergyis
convertedintothepressureenergy.
•Thevolutepumpisthemostcommontypeof
radial-flowcentrifugalpump.Ithasanimpeller
housedinaprogressivelywideningspiralcasing
asshown

18. •Waterenterstheeyeoftheimpellerandis
thrownradialoutward.
•Volute pumps can be single-suction or
double-suction pumps.
•in a single-suction pump impeller water is
admitted on one side of impeller.
•In a double-suction pump, water is fed from
both sides of the impeller, significantly
improving its hydraulic balance. As a result,
double-suction volute pumps can produce
higher pressures than single-suction pump

19. •Volutepumpsarecommerciallyavailableas
single-stage(singleimpeller)ormultistage
(multipleimpellers)pumps.
•Themostcommonreasonforthemulti-stage
configurationistoincreasetheheadproducedby
thepump.
•Ifamulti-stagepumphassinglesuctionimpellers,
theimpellersareusuallyarrangedwithequal
numbersdischarginginoppositedirectionsto
counteractthehydraulicimbalanceoneachofthe
impellers.
•Volutepumpsareusedwhereirrigationwateris
obtainedfromdepthsgenerallylessthan20feet,
Theexactvalueofpossibleliftisdeterminedby
thenetpositivesuctionheadrequiredbythe
pump.

20. Diffuser pumps or casing with
diffuser(guide) ring

21. •Inadiffuser-typecentrifugalpump,theimpelleris
surroundedbyaringoffixeddiffuservanesthat
provideenlargingpassagesinwhichthevelocity
ofthewaterleavingtheimpellerisreducedand
asaresultpressureisincreased.
•Thediffuservanesprovideamorecontrolledflow
andallowforamoreefficientconversionof
velocityintopressurethanvolutepumpssince
thechangefromvelocitytopressuretakesplace
gradually.
•Diffuserpumps,especiallylargeones,oftenhave
efficienciesover90percent.
•Diffuserpumpshavetheadditionaladvantageof
abalancedradialloadingontheimpeller,which
reducesthechanceofshaftfailureduetofatigue.

22. Centrifugal pump diffuser

23. VORTEX CASING
•If a circular chamber is provided between the
impeller and the volute chamber, the casing is
known as vortex casing.
•The circular chamber is known as vortex or
whirlpool chamber and such a pump is known as
volute pump with vortex chamber
•The vortex chamber converts some of the kinetic
energy into the pressure energy.
•Volute chamber further increases the pressure
energy thus more efficient than volute pump.