AIR-LOCK PREVENTION STRUCTURE OF UNDERWATER PUMP

摘要

PROBLEM TO BE SOLVED: To provide an air-lock prevention structure of an underwater pump which prevents air lock without decreasing a pump discharge amount of an operating pump and does not undermine the function even when used in sewage. SOLUTION: A ceiling 7c of a discharge port 7 is set higher than a slat lower edge 9e of an impeller 4 and lower than a shroud lower face 10u, and a boundary line 2L formed between an inner circumferential lower edge of an impeller chamber 5 and an upper edge inner circumference of a scroll chamber 8 is at almost the same height as the slat lower edge 9e at the beginning of a scroll of the scroll chamber 8 and formed in the rising gradient state to the position of the ceiling 7c of the discharge port 7 at the end of the scroll so that it is kept in the soaked state up to almost the lower half of the slat 9 when the pump is stopped.