Determination of Vortex and Critical Submergence of Submersible Pumps

In this study, submergence vortex and critical submergence of submersible pumps were investigated at different pump nominal diameters and water inlet crosssections. Experiments were conducted with submersible pumps with three different outside diameters. For each pump, outlet pressure and inlet pressure measurements were performed at three different water inlet cross-sections, five different flow rates and different submergence. Present findings revealed that for all three nominal diameters and cross-sections, critical submergence increased with increasing flow rates. The greatest critical submergence depth (1000 mm) was obtained from 3" pumps and the smallest critical submergence depth (10 mm) was obtained from 5" pump. Critical submergence increased with decreasing cross-sections. It was determined that there was an inverse relationship between the pump nominal diameter and the critical immersion depth. The critical dipping decreased with the increase of the pump nominal diameter. Critical submergence obtained at original cross-sections of submersible pumps were compared with the aid of a developed momentum equilibrium equation. The experiments were determined the submergence of vortex and vortex types. The vortex that occurred in all pump tests formed generally below the critical submergence.