Abstract
The burden of production is in the difficulties of installation, maintenance, and operations. Centrifugal pumps contain two main parts: an impeller (rotor) that rotates at the motor speed and imparts centrifugal forces to the production fluid and diffuser (stator) which is the fixed part that guides the flow to the discharge. The study is required due to the failures of centrifugal pumps at Zuikerbourch Rand Water Pumping Station. The shape of the impeller influences the performance of the pump. Thus the area of significance to the pump design is the impeller geometry parameters to achieve pump performance. The consumption of energy by the pump is caused by the failure to choose the right pump size for the system, improper installation and pump operation. Poor pump performance may affect the plant operation such as maintenance cost, downtime, loss of production, increase in operating cost. Over the years the hydraulic efficiency of the pump has dropped to a point at which it consumes more energy to deliver the required head and flow rate. The loss of the hydraulic performance of the centrifugal pump is as a result of the detachment of the impeller neck rings on the impellers. A design modification to the casing wear rings or impeller neck rings is recommended to smooth the entry of water into the eye of the impeller by reducing the gap between the casing wear ring and the impeller neck ring. Various tests are performed on the Rand Water centrifugal pump installed at Zuikerbourch Rand Water Pumping Station. These tests show that design parameters such as the diameter of the impeller, blade angles, number of blades, suction diameter and discharge diameter can have considerable influence on the performance of the centrifugal pumps. On this basis, the design of a suitable impeller is carried out. A model and simulation to predict the efficiency losses of these pumps is developed and proposed. The Computation Fluid Dynamic (CFD) simulations was carried for different parameters. The simulation results indicate that an increase of the diameter of the impeller, blade angles, number of blades reduces the performance of the centrifugal pump leading to more power consumption due to increased weight and reduced spacing in the volute. It was discovered in the research that to improve the efficiency of the centrifugal pump performance the focus should be on these parameters.
M.Tech. (Mechanical Engineering Technology)