Pump World

CENTRIFUGAL PUMPS:-
         
              The centrifugal pump is the most used pump type in the world. The principle

is simple, well-described and thoroughly tested, and the pump is robust,effective and relatively inexpensive to produce. There is a wide range of variations based on the principle of the centrifugal pump and consisting of the same basic hydraulic parts. 
     The centrifugal pump creates an increase in pressure by transferring mechanical energy from the motor to the fluid through the rotating impeller.The fluid flows from the inlet to the impeller center and out along its blades.The centrifugal force hereby increases the fluid velocity and consequently also the kinetic energy is transformed to pressure.
 

                                                                                                                                                                                                                                                                                                                                       

A centrifugal pump converts input power to kinetic energy by accelerating liquid in a revolving device - an impeller.

The most common is the volute pump - where fluid enters the pump through the eye of the impeller which rotates at high speed. The fluid accelerates radially outward from the pump chasing and a vacuum is created at the impellers eye that continuously draws more fluid into the pump.

Pressur &Head:-

The kinetic energy of a liquid coming out of an impeller is obstructed by creating a resistance in the flow. The first resistance is created by the pump casing which catches the liquid and slows it down. When the liquid slows down the kinetic energy is converted to pressure energy.  It is the resistance to the pump's flow that is read on a pressure gauge attached to the discharge line
A pump does not create pressure, it only creates flow. The gauge pressure is a measurement of the resistance to flow.

             In fluids the term head is used to measure the kinetic energy which a pump creates. Head is a measurement of the height of the liquid column the pump could create from the kinetic energy the pump gives to the liquid.

              The main reason for using head instead of pressure to measure a centrifugal pump's energy is that the pressure from a pump will change if the specific gravity (weight) of the liquid changes, but the head will not.

 Types of Pump Head:-

1. Total Static Head - Total head when the pump is not running

2. Total Dynamic Head (Total System Head) - Total head when the pump is running

3. Static Suction Head - Head on the suction side, with pump off, if the head is higher than the pump impeller

4. Static Suction Lift - Head on the suction side, with pump off, if the head is lower than the pump impeller

5. Static Discharge Head - Head on discharge side of pump with the pump off

6. Dynamic Suction Head/Lift - Head on suction side of pump with pump on

7. Dynamic Discharge Head - Head on discharge side of pump with pump on

                 

• Tweet
• Share
• Share
• Share
• Share

Sign up here with your email