ANALYTICAL SOLUTION FOR THE RADIAL SLIP OF SEDIMENT PARTICLES IN A ROTATING IMPELLER CHANNEL OF A LARGE CENTRIFUGAL PUMP

Centrifugal pumps of irrigation pumping stations on the Amu Darya transport water with suspended sediment. The mean turbidity of the river varies from 2.5 to 3.8 kg/m³ with peaks up to 7 kg/m³ [1]. Sediment particles moving through the impeller strike the blade surfaces and cause hydro-abrasive wear. The direction and the velocity with which a particle leaves the fluid streamline depend on the forces acting on it in the rotating frame. Full Euler-Lagrange computations [2] describe this in detail, but a simple analytical estimate is useful both for understanding the physics and for checking numerical codes. This work gives such a solution for the large vertical centrifugal pump of pumping station No. 7 (rated flow 25 m³/s, rated head 25 m, speed 187.5 rpm) [3].