Multi-stage low-temperature centrifugal pump provided with built-in motor

Abstract

The invention provides a multi-stage low-temperature centrifugal pump provided with a built-in motor. The multi-stage low-temperature centrifugal pump comprises a front shell, a motor shell and a backshell; a forward impeller and a forward guide vane are arranged in the front shell; the motor is arranged in the motor shell; a reverse impeller and a reverse guide vane are arranged in the back shell; the motor shell is located between the front shell and the back shell; an inlet horn pipe is arranged at the end of the front shell; an outlet volute is arranged between the back shell and the motor shell; the forward impeller, a motor rotor and the reverse impeller are connected in series through a rotating shaft assembly; the motor rotor is directly connected with the rotating shaft assemblyfrom the middle to drive the rotating shaft assembly to rotate so as to drive the forward impeller, the reverse impeller and an inducer to rotate. A low-temperature liquid enters a pump body from theinlet horn pipe, is pressurized by the forward impeller and the reverse impeller and is sprayed out of the outlet volute. According to the pump, the motor is arranged internally and is cooled throughthe low-temperature liquid, the overall sealing performance is good, the size is small, the weight is light, the structure is compact, and the pump is particularly applicable to conveying of low-temperature volatile liquids.

Description

technical field [0001] The invention belongs to the field of centrifugal pumps, in particular to a multistage low-temperature centrifugal pump with a built-in motor. Background technique [0002] In the transportation of cryogenic liquids, such as the mining and transportation of LNG (liquefied natural gas), cryogenic pumps are required. The pump body of the existing cryogenic pump is separated from the motor, and the rotating shaft of the pump body protrudes from the pump casing to connect with the motor. The requirements for sealing materials are very high; at present, the core loss of the pump motor is high, and the heat generation is large. The higher the motor speed, the more heat is generated. Usually, the air cooling device is used for cooling, which not only increases the volume of the pump, but also has poor heat dissipation performance. With the development of cryogenic liquid-related industries, the application range and performance requirements of cryopumps have...

AI Technical Summary

Problems solved by technology

The pump body of the existing cryogenic pump is separated from the motor, and the rotating shaft of the pump body protrudes from the pump casing to connect with the motor. The rotating shaft and the casing are sealed by a dynamic sealing device. The requirements for sealing materials are very high; at present, the core loss of the pump motor is high and the heat generation is large. The higher the motor speed, the greater the heat generation. Usually, the air cooling device is used for cooling, which not only increases the volume of the pump, but also has poor heat dissipation performance.

Images