Patent ID: 6059535
Filing Date: 2000-05-09
Classification: F04D

Abstract:
A liquid collection system including a tank for receiving a liquid, and a pump installation including a pump motor having an output shaft extending vertically down from a top of said tank, an impeller drive means drivingly connected to said motor shaft, a fixed support sleeve extending down over said impeller drive means, a pump housing supported at a bottom end of said sleeve, an impeller mounted in said pump housing and drivingly connected to said impeller drive means to be rotatable about a vertical axis, said impeller including an impeller disc, and a series of radially outwardly extending vanes projecting axially downward from one side of said disc, a cover plate overlying said pump housing and having a bore therein receiving a segment of said impeller drive means with a substantial annular clearance between, at least one opening extending axially through said impeller disc in a radially inward location to allow air trapped beneath said impeller disc to flow upwardly through said opening, and through said annular clearance, whereby said pump is able to rapidly eliminate air beneath said impeller disc to quickly re-achieve prime after losing prime by pumping down liquid in said tank.