PPT ON MULTISTAGE OF PUMP.pptx

Multistage of centrifugal pump

1. KALI CHARAN NIGAM INSTITUTE OF TECHNOLOGY, BANDA LECTURE ON CENTRIFUGAL PUMP TOPICS – MULTISTAGE CENTRIFUGAL PUMPS -- MODEL TESTING OF CENTRIFUGAL PUMPS FLUID MECHANICS AND FLUID MACHINE (KME302) BY : DEEPAK KUMAR YADAV ME DEPARTMENT

2. MULTISTAGE CENTRIFUGAL PUMPS If a centrifugal pump consists of two or more impellers, the pump is called a multistage centrifugal pump. The impellers may be mounted on the same shaft or on different shafts. A multistage pump is having the following two important functions : To produce a high head (Impeller are connected in series) To discharge a large quantity of liquid(Impeller are connected in parallel)

3. MULTISTAGE CENTRIFUGAL PUMPS FOR HIGH HEADS For developing a high head, a number of impellers are mounted in series or on the same shaft as shown in fig. The water from suction pipe enter 1 st impeller at inlet and is discharge at outlet with increased pressure. The water with increased pressure from the outlet of the 1 st impeller is taken to the inlet of the 2 nd Impeller with the help of connecting rod.

4. MULTISTAGE CENTRIFUGAL PUMPS FOR HIGH HEADS At the outlet of the 2 nd impeller, the pressure of water will be more than the pressure of water at the outlet of the 1 st impeller. If more impeller are mounted on the same shaft, the pressure at the outlet will be increased. Let n = Number of identical impellers mounted on the same shaft. H m = Head developed by each impeller Then T otal head developed = n. H m The discharge passing through each impeller is same.

5. MULTISTAGE CENTRIFUGAL PUMPS FOR HIGH DISCHARGE For obtaining high discharge, the pump should be connected in parallel as shown in fig. Each of the pumps lifts the water from a common pump and discharge water to a common pipe to which the delivery pipes of each pump is connected . Each of the pump is working against the same head.

6. MULTISTAGE CENTRIFUGAL PUMPS FOR HIGH DISCHARGE Let n = Number of identical pumps arranged in parallel. Q= Discharge from one pump. Total discharge = n. Q

7. MODEL TESTING OF CENTRIFUGAL PUMPS Before manufacturing the large sized pumps, their models which are in complete similarity with the actual pumps are made. Tests are conducted on the models and performance of the prototype are predicted. The complete similarity between the model and actual pump will exist if the following conditions are satisfied: 1. Specific speed of model = Specific speed of prototype

8. MODEL TESTING OF CENTRIFUGAL PUMPS 2.Tangential velocity (u) is given by 3. Discharge is given by

9. MODEL TESTING OF CENTRIFUGAL PUMPS Then Power of the pump,

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