| 摘要 |
PURPOSE:To prevent sand from being jammed in both stationary and rotating parts of a pump, by causing a setup between the inner wall of a casing and the inner surface of a shroud in front of an impeller of the pump to be interconnected with a little vertical step difference H. CONSTITUTION:When stopping operation of a multistage submersible pump, water being once pushed upward flows backward and sand contained in pumped water is put back in the suction port side. An inner wall 3b of a casing 3 and an inner surface 2d of a shroud 2c in front of an impeller 2 are interconnected with each other via a small clearance S but since there is a step difference H between them, sand being dropped along the inner wall 3b of the casing 3 will surely drops on the inner surface 2d of the shroud 2c in front of the impeller 2 across the clearance S. Therefore, sand jamming trouble can be prevented more certainly. |
