How does density affect pump performance?

Specific Gravity affects a pump curve as flow rate is a volumetric flow rate and will thus be directly affected by the density of a liquid. Pump curves are calculated based on water which has an SG of 1. However slurries or sludges can have a density 2 or 3 times higher, affecting the motor power accordingly.

How does density affect pump head?

Considering the volume flow rate, head and efficiency remain unchanged an increase in density increases the absorbed power and a decrease in density decreases the absorbed power for the pump. This principle is important when a motor rating is to be provided for a pumped liquid which has a cold start-up.

How does viscosity affect centrifugal pumps?

Mainly because viscosity has such an extraordinary and often negative effect on centrifugal pump performance. An increase in viscosity will dramatically reduce a pump’s efficiency in conjunction with marked reductions in head and flow. The net result is an increase in the brake horsepower required for the driver.

What affects pump efficiency?

Pump efficiency is determined by principally two parameters, head and flow rate, in addition to other factors such as properties of the fluid, impeller design and motor speed selected.

Why does the head not depend on the density of fluid in a centrifugal pump?

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 change.

Why does pump power increase with flow rate?

When work (or head in foot-pounds per pound) is combined with the flow rate (measured in gallons per minute (GPM)), the result is the conversion for horsepower. This is because at any fixed GPM point, more mass (more pounds per minute of fluid) is being pumped at the higher fluid density.

How does centrifugal pump control flow rate?

Centrifugal pumps can be used to transfer large volumes of liquid between vessels in an industrial process. When a constant speed motor is used to drive the pump then the pump flow rate may be controlled by adjusting a throttling valve that is installed after the pump discharge, as illustrated below.

Are centrifugal pumps good for high viscosity?

For high viscosity fluids, centrifugal pumps are not ideal because of the close critical tolerances and lack of ability to mix thixotropic materials to provide a shear thinning effect.

For which pump the efficiency decreases with increase in viscosity of the fluid?

Mainly because viscosity has such an extraordinary and often negative effect on centrifugal pump performance. An increase in viscosity will dramatically reduce a pump’s efficiency in conjunction with marked reductions in head and flow.