Pumps – Motor driven – Electric or magnetic motor
Reexamination Certificate
1999-11-03
2001-03-20
Walberg, Teresa (Department: 3742)
Pumps
Motor driven
Electric or magnetic motor
C417S366000, C417S423300
Reexamination Certificate
active
06203294
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to process pumps and, more particularly, to a process pump arranged to optimize pumping efficiency, minimize component wear, and improve reliability.
Process pumps, for example, chemical process pumps, petroleum pumps, and pumps utilized in the power generation industries, face common design challenges efficiency, durability, and emissions control. Pump efficiency relates directly to the arrangement of the motor, the motor housing, the drive shaft, and the associated bearings. Preferably, the arrangement selected for the specific pumping application optimizes pumping efficiency. However, additional design considerations related to durability and emission control often require that efficiency be compromised.
Emissions control is a primary concern where process fluid leakage cannot be tolerated. For example, pumps are often used to move gases or liquids such as acids, oils, and toxins, that can cause serious damage if they escape from the line through which they are pumped. Specialized mechanical seal designs, barrier fluid seals, canned motor pumps, and magnetic pumps have all been introduced to address the challenges associated with emissions control. Despite the past advances in process pump design, there is continuing drive to maximize pump efficiency, minimize component wear, and reduce the risk of process fluid leakage.
BRIEF SUMMARY OF THE INVENTION
This need is met by the present invention wherein a process pump is provided comprising 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 comprising 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.
The hermetically sealed pump may further comprise a motor liner arranged to define a hermetically sealed barrier between an inner motor cavity and an outer motor cavity. The inner motor cavity and the adapter cavity are in fluid communication with one another and define the pressurized gas cavity. The outer motor cavity may be hermetically sealed from the ambient. The motor comprises a rotor and a stator and the stator may be arranged in the outer motor cavity and the rotor may be arranged in the inner motor cavity. The adapter cavity, the motor liner, and the motor housing are preferably arranged to contain pressurized gas.
The seal assembly, the integrated adapter, the motor liner, and the motor housing preferably define three levels of process fluid containment such that a first level of process fluid containment is defined by the seal assembly, a second level of process fluid containment is defined by the integrated adapter and the motor liner, and a third level of process fluid containment is defined by the motor housing.
The seal assembly may comprise a gas barrier seal arranged to provide for inside diameter entry or outside diameter entry of a barrier gas between two opposing seal faces of the gas barrier seal. For inside diameter entry, the gas barrier seal preferably includes a patterned seal face having spaced grooves formed therein. The width of the spaced grooves preferably decreases in the direction of an outside diameter of the seal face.
The first and second rotational supports are preferably positioned within the pressurized gas cavity. The second rotational support is preferably positioned within the adapter cavity. The gas supply port may be provided in the integrated adapter. The integrated adapter is preferably arranged to secure the second rotational support about an axis of rotation of the drive shaft.
In accordance with another embodiment of the present invention, a hermetically sealed pump is provided comprising 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 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 gas supply port is arranged to introduce pressurized gas into the adapter 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.
In accordance with yet another embodiment of the present invention, a hermetically sealed pump is provided comprising a motor, a motor housing, a motor liner, 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, couple mechanically the rear end of the motor housing to the pump housing, and secure the second rotational support about an axis of rotation of the drive shaft. The motor liner is arranged to define a hermetically sealed barrier between an inner motor cavity and an outer motor cavity. The motor comprises a rotor and a stator. The motor liner is arranged between the rotor and the stator such that the stator is arranged in the outer motor cavity and the rotor is arranged in the inner motor cavity. The inner motor cavity and the adapter cavity are in fluid communication with one another and define a pressurized gas cavity. The gas supply port is provided in the integrated adapter and is arranged to introduce pressurized gas into the pressurized gas cavity. The outer motor cavity is hermetically sealed from the ambient. The seal assembly comprises a gas barrier seal arranged to inhibit the passage of fluid from the process fluid cavity to t
Hery Frederick Dague
Stauble Frank Edward
Turley Roger Scott
Flowserve Management Company
Killworth, Gottman Hagan & Schaeff LLP
Pwu Jeffrey C
Walberg Teresa
LandOfFree
Hermetically sealed pump with non-wetted motor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hermetically sealed pump with non-wetted motor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hermetically sealed pump with non-wetted motor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2464166