Multi-stage pump structure description and related knowledge

A, multi-stage pump structure description

The multistage pump is mainly composed of four parts: stator, rotor, bearing and shaft seal.

1, The stator part of multistage pump is mainly composed of inlet section, middle section, spitting section and guide lobe, etc. There are tensioning bolts to clamp each section to form the workshop. d-type pump generally inhales horizontally and spits vertically upwards; when used for oilfield water injection, the pump inlet and outlet are vertically upwards. dg-type multistage pump outlet and inlet are vertically upwards.

2, The rotor part of multi-stage pump is mainly composed of shaft, impeller, balancing disk and sleeve. The axial force is balanced by the balancing disk.

3, The bearing of multi-stage pump is mainly composed of bearing body, bearing and bearing gland, etc. The bearing is lubricated by grease or thin oil.

4, Shaft seal of multi-stage pump adopts soft packing seal, which is mainly composed of sealing body, packing and water retaining ring on water inlet section and tail cover. D-type pump water seal water comes from the pressure water inside the pump. DG type pump water seal water comes from external water supply.

5, Multi-stage pump rotating pump is directly driven by the prime mover through flexible coupling. The pump rotates in a clockwise direction when viewed from the prime mover's end D, DG type pumps are horizontal single suction multi-stage sectional centrifugal pumps. It is suitable for conveying clear water (containing less than 1% of impurities and less than 0.1mm granularity) or other liquids with physical and chemical properties similar to water, and is suitable for mine drainage, oilfield water injection, factory and urban water supply and drainage. DG type pumps are suitable for boiler water supply of all kinds.

What is the difference between multi-stage pumps and single-stage pumps?

1, Single-stage pump is a pump with only one impeller and the maximum head is only 125m.

2, multi-stage pump refers to the pump with two or more impellers, the maximum head can be more than 125 meters; multi-stage pump in the single-stage pump head need to be equipped with two-stage motor, you can increase the number of impellers to match the four-stage motor, which can improve the pump life and reduce the noise of the unit, but multi-stage pump maintenance is a little more difficult compared to single-stage pump.

3, in the actual need for pump head less than 125 meters, according to the pump room area, pump price (multi-stage pump is generally higher than the price of single-stage pump), and other factors to consider the choice of single-stage pump or multi-stage pump.

With the progress of technology, single-stage impeller pump can be improved by increasing the pump speed to improve the pump head, instead of multi-stage pump, but the price is a little more expensive.

Second, the management and maintenance of multi-stage pumps and operational considerations

The pump should be divided into two aspects of electricity and machine, for the machine, mainly the previous maintenance records out of the comparison will know. The second is the electrical aspect, to understand the power of each pump motor, to have a certain understanding of his control system.