MULTISTEP CENTRIFUGAL PUMP Russian patent published in 2000 - IPC

FIELD: pump manufacture, mainly multistep centrifugal well pumps. SUBSTANCE: multistep centrifugal pump includes successively mounted on shaft working steps. Guiding apparatuses of steps are in the form of cylindrical shell with annular return ducts. Impellers are mounted on shaft in such a way that flow-through cavity of each impeller is joined with flow-through cavity of return ducts of guiding apparatus by means of annular duct. Inner flow-through portion of duct is restricted by outlet member of impeller and blade disc of guiding apparatus; its outer surface is formed by inner surface of shell. Communication duct between impeller and guiding apparatus is in the form of annular axially symmetrical diffuser with angle in cross section equal to 2-10 degrees. EFFECT: enhanced efficiency, improved head parameters, increased reliability and useful life of pump due to small hydraulic losses. 4 cl, 1 dwg