Question

Identify five of the systems that are necessary for pump optimisation

Answer 1

Five Basic system necessary for pump optimisations are as follows:

1.centrifugal pumps should be selected and operated at or near the manufacturer's design rated conditions of head and flow. This is typically at the best efficiency point (BEP).

2. pump impeller vane angles and the size and shape of the internal liquid flow passages are fixed and can only be designed for one point of optimum operation. For any other flow conditions, these angles and liquid channels are either too large or too small.

3. Any pump operated at excess capacity, (i.e., at a flow significantly greater than BEP and at a lower head), will surge and vibrate, creating potential bearing and shaft seal problems as well as requiring excessive power forcing the driver (induction motor) into an over amp condition.

4. When operation is at reduced capacity, (i.e., at a flow significantly less than BEP and at a higher head), fixed vane angles will now cause eddy flows within the impeller and casing, and between wear rings. The radial thrust on the rotor will increase, causing higher shaft stresses, increased shaft deflection, and potential bearing and mechanical seal problems, while radial vibration and shaft axial movement also will increase. The induction motor will be operating at a reduced load and efficiency. Continued operation in this mode will result in accelerated deterioration of mechanical and hydraulic performance and may ultimately result in pump failure.

5 .typical system issues include:

• 1. Systems controlled by throttle valves/dampers
  2. Recirculation line normally open
  3. Cavitation noise at valve or pump
  4. Systems with multiple parallel pumps with the same number of pumps always operating
  5. Constant pump operation in a batch environment or frequent cycle batch operation in a continuous process
  6. Systems that have undergone a change in function.
  7. High system maintenance
  8. Motor tripping out