Influence of dynamic seals on silt abrasion of the impeller ring in a centrifugal pump

Abstract

The water flow and movement of silt in a prototype double suction centrifugal pump was simulated using an Euler–Lagrange multiphase flow model. Back-blade and J-groove configurations were adopted to protect the impeller ring from silt abrasion. Four back-blades and four J-grooves were considered. The results show that the relative velocity of water around the impeller ring is too low to move silt out of the spacing between the impeller and the casing, which results in a high silt concentration around the impeller ring. The high silt concentration around the impeller ring is the major contributor to silt abrasion of the ring. Back-blade and J-groove configurations are effective in reducing the silt concentration around the ring but extra friction loss is also introduced and the pump efficiency is decreased. Optimization of the length, position and number of back-blades, and the shape and number of J-grooves, decreases losses in pump efficiency and effectively protects the impeller ring. Case 4 for the back-blade and Case 8 for the J-groove were the most effective configurations in this study.