How can you increase the flow rate of a centrifugal pump?

The workable way to improve pump performance is to redesign or modify the impellers of centrifugal pump. The purpose of impeller pump modification is to improve pump efficiency, reduce cross flow, reduce secondary incidence flows, and decrease backflow areas at impeller outlets.

How do you control the flow rate of a pump?

Therefore, to control the flow of a centrifugal pump, simply set the output pressure to the point on the P-V diagram that allows the pump to deliver the desired flow rate. The output pressure of the pump is set using a back pressure regulator. Once the pressure is set, the flow rate to the process is established.

What is operating point of a centrifugal pump?

The operating point of a centrifugal pump is the intersection of the pump characteristic curve (H/Q curve) and the system characteristic curve Hsys /Q. H/Q is the pump-based variable, Hsys/Q the the system-based variable.

How long can a centrifugal pump run dry?

Safe Options for Dry Pumping If the pump is run dry for less than 45-60 seconds, the pump should not suffer damage.

How do you increase the discharge of a centrifugal pump?

Throttle the valve by reducing the flow thus increasing the head. Reducing the flow also helps to reduce the frictional losses along the discharge line, so it will see an increase in pressure. Reducing the discharge pipe size will have adverse effect as it will increase the frictional losses across a smaller pipe.

How is discharge pressure reduced in a centrifugal pump?

Variable speed drives are increasingly applied in many applications to reduce energy consumption. Reducing the speed of a centrifugal pump reduces the pump discharge pressure by the square of its speed.

Which are the method normally followed if the flow from centrifugal pump is to be reduced?

Throttling. Throttle control is the most commonly used method. The flow caused by the constant speed pump is reduced by increasing the losses in the system by closing the valve. In the example in Figure 2 the operating point is moved from (Q = 10, H = 10) to (Q = 7, H = 12.7).

How do you choose the operating point of a pump?

When flow data are not available, operators can use the following five ways to try and determine a pump operating point.

1. Measure total dynamic head.
2. Measure motor/driver load BHP.
3. Process instrumentation and process mass balance calculations.
4. Tank volume changes.
5. Other operating data.

What happens if the discharge end of centrifugal pump is closed?

If the discharge valve is closed and there is no other flow path available to the pump, the impeller will churn the same volume of water as it rotates in the pump casing. The vapor can interrupt the cooling flow to the pump’s packing and bearings, causing excessive wear and heat.