Single-section structure of sectional-type multi-stage pump for sewage

Abstract

The invention relates to a sectional-type multi-stage centrifugal pump, in particular to a single-section structure of a sectional-type multi-stage pump for sewage. The single-section structure of the sectional-type multi-stage pump for the sewage is composed of impellers, impeller back vanes, impeller inlet seal rings, spatial guide vanes, guide vane flow guide pads, bearings, shaft sleeves, middle sections, spindles and flat keys. The single-section structure is characterized in that the spindles, the impellers, the shaft sleeves and the flat keys form the rotor part of the single-section structure of the sectional-type multi-stage centrifugal pump for the sewage; the middle sections, the spatial guide vanes, the guide vane flow guide pads, the impeller inlet seal rings and the bearings form the stator part of the single-section structure of the sectional-type multi-stage centrifugal pump for the sewage. The single-section structure has the axial force balancing function of the pump and the independent supporting function; moreover, the spatial guide vanes are adopted, the radial size of the single-section structure is smaller than that of a structure with radial-type guide vanes adopted by more than 5%, liquid flowing out from the impellers is collected separately through single flow channels and is independently conveyed to next-stage impeller inlets respectively and the fluid hydraulic loss is less than that of an existing structure by about three percent.

Description

technical field [0001] The invention relates to a segmented multistage pump, in particular to a single segment structure of a segmented multistage pump for sewage. Background technique [0002] The segmented multi-stage pump is composed of multiple single-stage centrifugal pumps connected in series. The single-stage structure design of the segmented multi-stage pump mainly needs to be considered: 1. To ensure the minimum loss during the process of collecting, pressurizing and transporting liquid as much as possible, and to make the liquid enter the next single-stage structure evenly; 2. It is possible to reduce the outer diameter and axial size of the impeller, guide vane and middle section, so as to reduce the space volume and material consumption of the pump, reduce the manufacturing cost of the product, and improve the market competitiveness of the product. The single-stage structure of the existing segmented multi-stage pump is divided into two types: the single-port ri...

AI Technical Summary

Problems solved by technology

[0005] The defect of the impeller structure of the single port ring is: the axial force of the pump is balanced by the balance drum or the balance disc. safe operation of

[0008] The defects of the double-port ring impeller structure are: 1. The setting of the sealing ring of the impeller rear cover plate and the rear chamber space of the impeller balance hole needs to occupy a certain axial dimension, which will increase the axial dimension of the impeller, guide vane and middle section of the pump. Increase the space volume and material consumption of the pump, increase the manufacturing cost of the product, and reduce the market competitiveness of the product; 2. The sealing ring of the impeller rear cover plate is set on the guide vane, and the superposition of multiple shape and position tolerances may cause The friction between the ring and the sealing ring of the back cover of the impeller occurs when the pump is running, which not only increases the mechanical loss of the pump, but also increases the volume loss of the pump; impeller low

[0009] The structure of the radial guide vane is simple, and the diameter and axial dimensions are smaller than that of the flow channel guide vane, but the size and shape of the curved part of the guide vane change greatly, and the liquid flow flowing out of a single guide vane produces irregular movement and collision here. After converging with the flow guide vane, the hydraulic loss of the fluid is greater than that of the channel guide vane, which is not conducive to improving the efficiency of the pump; the liquid flow from the impeller with the channel guide vane passes through the spiral collection section, diffusion section, and curved section And the centripetal drainage section enters the inlet of the next-stage impeller, the liquid flow is regular, there is no collision and confluence, so the hydraulic loss of the fluid is smaller than that of the radial guide vane, which is conducive to improving the efficiency of the pump, but the casting shape is more difficult, and the guide vane The outer diameter and axial dimension are 10% to 15% larger than the radial guide vane, which increases the space volume and material consumption of the pump, and increases the manufacturing cost of the pump

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