VERTICAL CENTRIFUGAL SCREW PUMP

FIELD: mechanical engineering. ^ SUBSTANCE: proposed pump has housing 1 with centrifugal impeller 3 and screw 4 placed inside lower part of elongated pipe 6. Pipe 6 is cantilever mounted on central suction part of housing 1. Centrifugal impeller 3 and screw 4 are interconnected by elongated transmission 7. Made on suction section of pipe 6 are one or more check valves 10 in form of ports 8 arranged higher than screw 4 which are furnished with normally closed leaf elastic elements 9. With screw 4 being rotated, liquid is taken into pipe 6 through valve 10 and is delivered along pipe 6 to centrifugal impeller 3. Valve 10 is open, and elastic elements 9 close ports 8. After filling of centrifugal impeller 3 with liquid, pump starts operating at nominal duty. Rarefaction is built in suction section of pipe 6, and elastic elements 9 recede from ports 8. Liquid passes into pipe 6 through ports 8 at lower hydrostatic resistance. At subsequent switching on of pump, the latter turns for operation at nominal duty owing to holding of liquid in centrifugal impeller by valves 9, 10. ^ EFFECT: provision of pump with lower power consumption and increased service life. ^ 2 cl, 2 dwg