Balance of Axial Forces in Centrifugal Pumps With Opposite Impellers

During pump operation, processes occur that significantly affect performance and energy efficiency. Some of them can lead to pump malfunctions and even failure. One of the main phenomena that occur is axial force. In back-to-back pumps, its impact on operation increases significantly. These problems encourage engineers to new design solutions, such as new configurations of central bushings. This paper investigates the processes occurring in the throttling gap and side sinuses of the impeller for two designs of central bushings with and without relief holes. Analysis of the performed numerical study showed the feasibility of using a central bushing with relief holes.