Hermetically sealed pump with non-wetted motor

Abstract

A process pump is provided including pressurized dry motor and integrated adapter cavities. The pump also includes a hermetically sealed motor housing and a specially arranged seal assembly. In accordance with one embodiment of the present invention, a hermetically sealed pump is provided including a motor, a motor housing, a gas supply port, a drive shaft, first and second rotational supports, an integrated adapter, a pump housing, a seal assembly, and an impeller. The motor is arranged to impart rotational movement to the drive shaft. The first and second rotational supports are arranged to support the drive shaft. The second rotational support is accommodated by the integrated adapter. The drive shaft is coupled to the impeller such that rotation of the drive shaft causes rotation of the impeller. The motor housing is disposed about the motor and defines a front end, a rear end, and a motor cavity. The pump housing is disposed about the impeller and defines a process fluid cavity. The integrated adapter is arranged to define an adapter cavity and to couple mechanically the rear end of the motor housing to the pump housing. The motor cavity and the adapter cavity are in fluid communication with one another and collectively define a hermetically sealed pressurized gas cavity having a motor cavity portion and an adapter cavity portion. The gas supply port is arranged to introduce pressurized gas into the pressurized gas cavity. The seal assembly is arranged to inhibit the passage of fluid from the process fluid cavity to the adapter cavity and to permit the passage of pressurized gas contained in the adapter cavity portion of the pressurized gas cavity to the process fluid cavity.