In centrifugal pump usages, there is an increase in the fluid pressure from the inlet to the outlet which drives the centrifugal pump fluids through the system or plant. As a result, the mechanical energy is transferred from the centrifugal pump motor to the rotating impeller while the fluids flow from the inlet to the blades due to the centrifugal forces increased by the velocity and the kinetic energy transformed to pressure.
In other words, the design of the centrifugal pump inlets is mainly determined by the centrifugal pump usages and is aimed at creating a uniform profile that leads to an outstanding performance of the pump in spite of the fact that the velocity distribution at a variety of cross sections may vary. What is more, the centrifugal pump blades of the rotating impeller is capable of transferring energy so as to increase pressure and velocity once the fluid has moved into the impeller via the channels formed by the blades. As a matter of fact, apart from centrifugal pump usages, the design of the impeller also depends on the specific requirements for pressure and flow rate and is of great importance to the overall performance of the centrifugal pump as a primary component. At the same time, a number of centrifugal pump variants are often created by modification of the impeller and its ability to increase the flow rate either radically or axially.
In fact, not only the centrifugal pump impeller design is influenced by centrifugal pump usages, but the same is true with the centrifugal pump volute. Generally speaking, the function of the volute is to collect the fluids that come out of the impeller and at the same time, to deliver them to a number of discharge chambers and there are many geometrical parameters that have an impact on its performance. Designed for different centrifugal pump usages, there are many volute alternatives with different efficiencies and pressure ratios that may influence the flow rate inside the impeller and the centrifugal pump performance. In addition, radial forces will be created on the impeller shaft under different flow rate conditions at the volute inlet that is linked to the impeller.
Therefore, the operating range of the centrifugal pump will become wider with its adaptability to more kinds of pressure distribution. As a matter of fact, the impacts of the centrifugal pump volute’s geometrical parameters such as the shape, the variation of the cross section areas, and the radial position can be evaluated in a global centrifugal pump performance even though we have known that internal volute that is smaller than the exit radius has less energy loss in comparison with other types and circular volute often has minimum losses.