GB1201721A - A single-stage or multistage self-priming pump - Google Patents

Abstract

1,201,721. Priming centrifugal pumps. MUANYAGIPARI KUTATO INTEZET. June 28, 1968 [July 7, 1967], No.30910/68. Heading F1C. A self-priming pump comprises a guide duct of annular cross-section connecting the outflow area of the impeller to a swirl reduction element, a jet pump being arranged between the swirl reduction element and the inflow area of the impeller and connected to the suction space of the pump, and a second swirl reduction element leading from the guide duct into a pressure space. In the two-stage pump shown in Fig. 3 the liquid remaining in the pump after the previous operation is recirculated by the fist-stage impeller 5 during priming, the liquid passing via a rotary vaneless annular guide duct 6a forming an extension of the impeller to a stationary bladed swirl reduction element 7 contained in a stationary annular guide duct 6 and there via the nozzles 8 and diffuses 4 of a jet pump to the eye of the impeller 5. Air in the suction branch 1 is entrained by the jet pump and mixes with the recirculated liquid. The air is separated centrifugally from the recirculated liquid in the guide duct 6a and passes via slots 18, a second bladed swirl reduction element 9, a pressure space 10 and a duct 17 to the second stage of the pump. Transverse passages 12, 13 formed in the swirl reduction element 7 provides communication between the suction branch 1 and the suction space 2 surrounding the jet pump and between the pressure space 10 and the duct 17. In a single-stage embodiment Figs. 1 and 2 (not shown), the rotary guide duct 6a and the front shroud of the impeller (5) are omitted. Suction openings (14) may be provided in the diffuser(4). Several concentric jet pumps may be provided.