| 摘要 |
A pump (10) comprising a pump casing (20) having front and rear sides (23, 24) with a pumping chamber (38), a chamber inlet (26) and a discharge outlet (27). An impeller (40) within the chamber rotates about an axis. The chamber includes an inner region at or near the axis and an outer region remote from the axis within which is the discharge outlet. The impeller includes a shroud (42) having front and rear faces (43, 44) with a plurality of pumping vanes (46). A collection chamber (60) is provided at the rear side of the pump casing in fluid communication with the pumping chamber. The impeller includes one or more passageways (52) through the shroud, one end opening into the collection chamber and the other opening into the pumping chamber through the impeller front face. A flow inducer (70, 72) is within the collection chamber, which includes a venting outlet (62) and a transfer outlet zone in fluid communication with the outer region of the pumping chamber. |
