Pumps

Pumps

1 Classification Of Pumps

2 Reciprocating Pumps

3 Working Of Single Acting Reciprocating Pump

4 Double Acting Reciprocating Pump

Air Vessels

1 purpose Of Using An Air Vessel

PUMPS

•         A pump is a machine which is used to raise or transfer the fluids.

•         It is also used to maintain the constant flow rate or constant pressure.

•         It is normally driven by a engine or a motor.

•         Pumps are rated by the horse power.

1 CLASSIFICATION OF PUMPS:

It is classified into positive displacement pumps and roto dynamic pumps.

•         In positive displacement pumps, fluid is drawn or forced into a finite space and it is sealed.

•           It is then forced out and the cycle is repeated.

In roto dynamic pumps, centrifugal force is used to move the fluid into a pipe.

2 RECIPROCATING PUMPS:

•         It is a positive displacement pump

•         It uses a piston and cylinder arrangement with suction and delivery valves integrated with the pump.

•           It can be single acting and double acting

•           There may be single or multi cylinders also.

•         It is a positive displacement pump

•         It sucks and raises the liquid by actually displacing it with a piston/plunger that executes a reciprocating motion in a closely fitting cylinder.

3 WORKING OF SINGLE ACTING RECIPROCATING PUMP:

^·         During suction stroke the piston moves to the left, causing the inlet valve to open.

^·         Water is admitted into the cylinder through the inlet valve.

^·         During the discharge stroke the piston moves to the right closes the suction valve and opens the out let valve.

^·         Through the outlet valve the volume of liquid moved out of the cylinder.

4 DOUBLE ACTING RECIPROCATING PUMP –WORKING:

•         Each cycle consists of two strokes.

•           Both the strokes are effective, hence it is known as double acting pump

•           Liquid is filled at one end and discharged at other end during forward stroke.

•           During the return stroke, end of cylinder just emptied is filled and the end just filled is emptied.

AIR VESSELS

Air vessel is a closed chamber containing compressed air in the upper part and liquid being pumped in the lower part.

1PURPOSE OF USING AN AIR VESSEL:

^·         To get continuous supply of liquid at a uniform rate.

^·         To save the power required to drive the pump (By using an air vessel the acceleration and friction heads are considerably reduced)

^·         To run the pump at much higher speed without any danger of separation.

Advantages of reciprocating pump:

•         Relatively compact design

•           High viscosity performance

•           Ability to handle high differential pressure.