A kind of asynchronous transmission multistage centrifugal pump

Abstract

The invention discloses an asynchronous transmission multistage centrifugal pump, belongs to the technical field of centrifugal pumps, and particularly relates to asynchronous transmission multistage centrifugal pumps. The asynchronous transmission multistage centrifugal pump comprises a primary pump body. A double-sided impeller is arranged in the primary pump body via a primary shaft. The asynchronous transmission multistage centrifugal pump is characterized in that a water outlet end of the primary pump body is connected with a water inlet end of a multistage pump body; a multistage impeller is arranged in the multistage pump body via a multistage shaft; the multistage shaft is connected with the primary shaft by a gearbox. The asynchronous transmission multistage centrifugal pump has the advantages that the net positive suction head can be greatly reduced without changing the number of stages of the centrifugal pump, and the lift of the horizontal asynchronous transmission multistage centrifugal pump can be guaranteed.

Description

technical field [0001] The invention belongs to the technical field of centrifugal pumps, in particular to an asynchronous transmission multistage centrifugal pump. Background technique [0002] In order to achieve high head output, most of them are realized by multistage centrifugal pumps. Traditional multi-stage centrifugal pumps are installed on a shaft with multi-stage impellers step by step, and the lifts are accumulated to obtain high lifts. In some installations in the petrochemical industry, the requirements for pumps are strict, not only high head, but also extremely low NPSH, high efficiency and energy saving, no leakage and so on. In order to achieve low NPSH, the traditional method is: 1. Select the first-stage double-suction impeller. [0003] 2. Add an inducer at the suction end of the first stage impeller. [0004] 3. Adopt a vertical multi-stage pump, and set the first-stage impeller of the pump in a low pump pit. [0005] 4. Reduce the speed of the multi...

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Problems solved by technology

[0005] 4. Reduce the speed of the multi-stage pump

[0006] Traditional pumps only use the first-stage double-suction impeller or inducer to reduce the NPSH of the pump, and the reduction range is limited.

At the same time, in some actual engineering installations, it is not allowed to use vertical pumps due to the limitations of the installation location and civil foundation.

Reduce the NPSH by reducing the speed of the multi-stage pump, by the formula It is known that when the speed decreases, the head will drop greatly by the power of 2, resulting in too many stages of the pump, wasting costs, and when the speed decreases, the efficiency will also decrease.

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