Vertical type multilevel barrel bag pump

Abstract

The invention discloses a vertical multi-level barrel pump which is characterized in that a first level absorption section of the barrel pump adopts a dual absorption impeller and a first level pump body matched with the dual absorption impeller and provided with a dual channel and a radial volute shell; the rotating shafts above and under the dual absorption impeller are respectively provided with a preposed inducer and an absorption guide pipe matched with the preposed inducer so as to realize the dual absorption of pumped fluid. Under the condition that the flow is limited, the value r of net positive suction head (NPSH) can be reduced by more than 1.5m, namely the cavitation corrosion performance is remarkably improved, thereby not only reducing the height and volume of the barrel and the manufacturing cost, but also improving the efficiency and the operation reliability of the pump and bringing convenience for the installation and the maintenance of the pump.

Description

technical field [0001] The invention relates to a vertical multi-stage barrel pump used for pumping condensed water of a steam turbine or a liquid in a high-vacuum airtight container, especially a vertical multi-stage barrel pump with a bidirectional suction function at the first stage. Background technique [0002] At present, most of the first-stage suction sections of vertical multi-stage barrel pumps produced at home and abroad use single-suction impellers. In order to improve the cavitation performance of the pump (that is, reduce the NPSHr value), there are also examples of using double-suction impellers in the first-stage suction section, such as the LN25-110 condensate pump produced by Shenyang Industrial Pump Manufacturing Co., Ltd. The suction impeller and the matching symmetrical single-channel volute are composed. Although the vertical multi-stage barrel pump with this structure improves the cavitation performance of the pump to a certain extent, there are still ...

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Problems solved by technology

In order to improve the cavitation performance of the pump (that is, reduce the NPSHr value), there are also examples of using double-suction impellers in the first-stage suction section, such as the LN25-110 condensate pump produced by Shenyang Industrial Pump Manufacturing Co., Ltd. The suction impeller and the matching symmetrical single-channel volute are composed. Although the vertical multi-stage barrel pump with this structure improves the cavitation performance of the pump to a certain extent, there are still shortcomings: one is Because there is no front inducer, the inlet pressure of the fluid in the double-suction impeller is not increased, which affects the cavitation performance of the pump; secondly, because the double-suction impeller does not form a partition on the outer edge of the junction of the upper and lower impellers, the upper and lower suction The fluid is easy to form mixed flow at the outlet of the impeller, which reduces the cavitation performance of the pump; third, the symmetrical single-channel volute has a large volume, complex structure, large fluid energy loss, and poor performance when introduced into the next stage, which affects the pump efficiency. further improvement of

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