Self-priming pump

Abstract

The present invention relates to a self-priming pump capable of preventing a swirl flow from developing during the self-priming operation and assuring the smooth flow of a stream of water during the pumping operation. The self-priming pump has a main line ( 12 ) formed with a swirl flow forming space ( 15 ) allowing self-primed water accumulated in a casing ( 1 ) to be discharged together with air from a small scroll casing 11 through an auxiliary line ( 14 ) to the main line ( 12 ) during the self-priming operation to produce a swirl flow in the main line so as to allow air-water separation. The self-priming pump is provided with a plate member ( 16 ) for eliminating the swirl flow in the main line below the swirl flow forming space extendedly in the extension direction of the main line.

1 . A self-priming pump comprising a casing in which a large scroll casing and a small scroll casing are formed around an impeller, a main line extends from said large scroll casing, and a spout is formed on an upper end of said main line, an auxiliary line extends from said small scroll casing, and an upper end of said auxiliary line is spirally brought into communication with said main line along a wall surface of said main line from a tangent direction thereof, a swirl flow forming space being formed in said main line, and in said swirl flow forming space, self-primed water accumulated in said casing being discharged into said main line together with air from said small scroll casing through said auxiliary line during self-priming operation, thereby generating swirl flow in said main line, and air-water separation being carried out, wherein 
 a plate member for eliminating the swirl flow extends in an extension direction of said main line in said main line below said swirl flow forming space.    
     
     
         2 . A self-priming pump wherein a water tank for self-primed water is provided between said suction opening and a suction pipe, said water tank comprises a reserving portion swelling in the lateral direction and having a cross-sectional area greater than an opening area of said suction opening, a water outlet which laterally opens into a bottom end of said reserving portion and which is in communication with said suction opening substantially horizontally, and a water inlet which laterally opens into an upper end of said reserving portion and which is in communication with said suction pipe, and a lower end level of said water inlet is formed higher than an upper end level of said water outlet.