Describe with diagrams a typical characteristic pump curve f

Describe (with diagrams) a typical characteristic pump curve for a centrifugal pump, highlighting any important points. Also, outline the process for determining the characteristic pump curve. Describe (including a line diagram) the pump system located in the thermal lab. A filter is proposed to be added to this system, where should this device be placed within the system? Why?

Solution

Pumps are generally grouped into two broad categories—positive displacement pumps and dynamic (centrifugal) pumps. Positive displacement pumps use a mechanical means to vary the size of (or move) the fluid chamber to cause the fluid to flow. On the other hand, centrifugal pumps impart momentum to the fluid by rotating impellers that are immersed in the fluid. The momentum produces an increase in pressure or flow at the pump outlet.

Positive displacement pumps have a constant torque characteristic, whereas centrifugal pumpsdemonstrate variable torque characteristics. This article will discuss only centrifugal pumps.

A centrifugal pump converts driver energy to kinetic energy in a liquid by accelerating the fluid to the outer rim of an impeller. The amount of energy given to the liquid corresponds to the velocity at the edge or vane tip of the impeller. The faster the impeller revolves or the bigger the impeller, then the higher the velocity of the liquid at the vane tip and the greater the energy imparted to the liquid.