Centrifugal pumps and canned pumps
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This post was last edited by zhangqi1234 on 2015-12-3 21:15. What are the differences between centrifugal pumps and shielded pumps? Please, experts, offer your guidance
There is a big difference; take a look at this: http://bbs.hcbbs.com/thread-822951-1-1.html The biggest difference lies in the sealing
A shielded pump is a leak-free, fully enclosed centrifugal pump; this answer isn’t necessary
A canned pump is composed of a centrifugal pump and a three-phase asynchronous canned motor mounted coaxially. It requires no mechanical seal and thus experiences no leakage; it is suitable for transporting various toxic, hazardous, and valuable liquids, and is widely used in facilities in the chemical and pharmaceutical industries, the nuclear industry, aerospace, and other fields.
A shielded pump can be considered an improved version of a centrifugal pump, featuring a fully sealed design without mechanical seals, with the motor enclosed within the overall pump chamber.
Broadly speaking, a screen pump is also a type of centrifugal pump. A canned pump is a liquid-cooled motor, while a centrifugal pump is an air-cooled motor. Canned pumps are more expensive, whereas centrifugal pumps are cheaper; canned pumps have a higher cost but also offer greater safety. The impeller pump motor has a designed pressure, while the centrifugal pump motor does not
In a conventional centrifugal pump, the drive mechanism connects the impeller shaft of the pump to the motor shaft through a coupling, allowing the impeller to rotate together with the motor in order to function. In contrast, a shielded pump is a type of seal-less pump; both the pump and the drive motor are enclosed within a pressure vessel filled with the medium to be pumped. This pressure vessel has only static seals, and an electrical winding set is used to generate a rotating magnetic field that drives the rotor. This design eliminates the rotating shaft sealing mechanism found in traditional centrifugal pumps, thereby achieving complete leaklessness.
Shielded pumps have excellent sealing properties, and they are commonly used for liquid ammonia pumps. Shielded pumps are expensive
A shielded pump is actually also a centrifugal pump; it is called a shielded pump specifically due to its sealing mechanism. Even the area where the seal of a regular centrifugal pump is exposed is covered by the pump body as well.