SEMI-SUBMERSIBLE CENTRIFUGAL PUMP WITH SEALED SHAFT LINE ON BEARINGS (VARIANTS) Russian patent published in 2022 - IPC F04D13/08 

FIELD: pumps.

SUBSTANCE: invention relates to pumping equipment and can be used in creation of sets for pumping explosive and flammable media, such an oil-water mixture containing abrasive mechanical impurities, from tanks. The stated technical result is achieved by the fact that in a known semi-submersible centrifugal pump with a shaft line on bearings, including a pump body, one or multiple impellers with blades, a discharge pipe, a pressure branch pipe, a base plate, a shaft line constituting a solid shaft or a series connection of shafts installed on bearings in sealed suspensions; wherein the bearings of the shaft are separated from the pumped liquid by a double end seal consisting of two single end seals, a separation chamber filled with a barrier liquid; according to the invention, a shaft line section that is non-tight with respect to the pump inlet (i.e., hydraulically connected to the pump inlet, leading to the pressure of the pumped liquid therein being equal to the pressure of said liquid before the pump inlet minus the difference between the hydrostatic pressures before the pump inlet and in the non-tight section) is made between the pump body and the end seal closest thereto.

EFFECT: prevented effects of the pressure of the pumped liquid, created in the pump body during operation, on the primary seal; resulting increase in the operating life of end seals, especially when pumping contaminated liquid; and prevented possibility of outflow of the pumped liquid through the shaft line from the container wherein the pump is installed due to the pressure in the pump body, which increases the overall safety, reliability, and operating life of the pump.

7 cl, 2 dwg