Definitions of Efficiencies Centrifugal pump
Definitions of Heads also Efficiencies Centrifugal Pump
- Suction Head (hs): This is the vertical height of the centre line of the centrifugal pump over the water surface in the tank or pump from which water is to be lifted. This height is also called suction lift also is denoted by ‘hs’.
- Delivery Head (HD): Some vertical distance within the centre line from this pump also the water surface into the tank to which water exists delivered is known as the delivery head. Here is denoted by ‘HD’.
- Static Head (Hs): The sum of the suction head and the delivery head is known as a static head. That is represented by ‘Hs’ also written as
Efficiencies Centrifugal Pump H=hs+hd
- Manometric Head (Hm): Every manometric head is defined as a unique head against which a centrifugal pump has to work. This is denoted by Hm.
Efficiencies of a Centrifugal Pump
- In the case of a centrifugal pump, some power is transmitted from the shaft of the electric motor so the shaft of the pump also then to the impeller. Of the impeller, a special power is given to the water. Therefore power is decreasing from every shaft of the pump to the impeller and also then to the water.
The following are the important efficiencies of a centrifugal pump
- Manometric Efficiency (ηman) That ratio of that manometric head toward some head imparted by the impeller toward the water is known as manometric efficiency. Mathematically, here is written as
Ƞman=Manometric head / Head imparted on the impeller so the water
- Mechanical Efficiency (ηm): This power at the shaft of the centrifugal pump is higher than the power available through the impeller of the pump. Some ratio of the power available at the impeller to this power at the shaft of the centrifugal pump remains known as mechanical efficiency. It is written as
ηm=Power to the impeller / Power to the shaft
- Overall Efficiency (ηo): This is defined as the ratio of the power output of the pump to the power input into the pump.
ηo=Power output from the pump/ Power output from the pump
ηo = ηman x ηm