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Working principle and characteristics of sewage pump
- Sep 28, 2018 -

Working principle and characteristics of sewage pump

Sewage pump, such as pump impeller, pressurized water room, sewage pump is the two core elements. The advantages and disadvantages of its performance, but also on behalf of the pump performance is superior, sewage pump's resistance to plug performance, efficiency and cavitation performance, by the vane pump and pressure water Chamber two major components to ensure.

The working principle of sewage discharge pump and the characteristics of sewage sewage pump belong to a kind of plug pump, there are many forms: such as diving type and dry type, the most common submersible sewage pump WQ type, most commonly dry sewage pumps such as w-type horizontal sewage pump and WL vertical sewage pump two kinds. Mainly used for transporting municipal sewage, feces or liquid containing fiber. The medium of a solid particle is usually not more than 80 ℃. Because the transported medium contains fibers that are easily wound or bunched. Therefore, it is easy to plug the pump flow, the pump once blocked will make the pump can not work properly, or even burn the motor, resulting in poor sewage. To urban life and environmental pollution caused serious impact. Therefore, an important factor of blocking resistance and reliability is the quality of sewage pump.

In terms of performance, the sewage pump has a steep drop in the head curve, the power curve is relatively flat.

Sewage pump used in the most common water pressure chamber is the volute, in the inner-mounted submersible pump selection of the path guide vane or runner type Guide. There are three kinds of spiral case, ring type and intermediary type. Spiral casing is basically not in the sewage pump. The Annular pressurized water chamber is easy to be used in the small sewage pump because of its simple structure. However, the application range of annular pressure chamber in the medium (half helix) water pressure chamber is gradually smaller. Because of the high efficiency of the medium pressure water chamber and the annular pressure chamber. Has increasingly been the concern of manufacturers.

The following is a description of the impeller type of sewage pump:

1. Impeller Structure Type:

The structure of the impeller is divided into four types: vane (open, closed), swirl type, runner type, (including single road and dual-stream road) spiral centrifugal type, open-type semi-automatic impeller manufacturing convenience, when the impeller caused by blockage, it can be very easy to clean and repair, but in the long run, under the abrasive of the particles will make the blade and pressure in the interior of the wall of the gap between the increase, so that the efficiency of the reduction. And the increase of clearance will destroy the distribution of pressure difference on the blade. Not only produces a large number of vortex losses, but also increases the axial force of the pump, at the same time, due to increased clearance, the flow of liquid flow in the stability of the state is destroyed, so that the pump vibration, the type of impeller is not easy to transport the medium containing large particles and long fiber, from the performance, the type of impeller efficiency is low, the maximum efficiency is about 92% of the ordinary closed-impeller, the head curve is relatively flat.

2, Rotating impeller:

The pump of the impeller is used, because the impeller is partially or wholly retracted from the pressurized water chamber flow path. So there is no blockage performance, particles and long fiber through the ability of strong. Particles in the water pressure indoor flow by the impeller rotation of the vortex generated by the movement, the suspended particles movement itself does not generate energy, flow channel and liquid exchange energy. In the flow process, suspended particles or long fibers do not contact with wear blades, blade wear more light, there is no gap due to abrasion and increase the situation, in the long run will not cause the problem of serious decline in efficiency, the use of the impeller pump is suitable for pumping containing large particles and long fiber medium. From the performance, the impeller efficiency is low, only equivalent to the ordinary closed impeller of about 70%, the head curve is relatively flat.

3, Spiral centrifugal impeller:
The blades of the impeller are twisted helical blades that extend along the axial direction of the cone-shaped hub body from the suction inlet. The pump of this type impeller has the function of volume pump and centrifugal pump, the suspended particles flow through the blade, do not impact any part of the pump, so the Non-destructive property is good. The damage to the conveyor is small. As a result of the spiral propulsion, suspended particles through the strong, so the use of this type of impeller pump is suitable for pumping containing large particles and long fiber medium, as well as high concentration of medium. It has obvious characteristics in the case of strict requirements for the destruction of the conveying medium.

4. Runner Impeller:This impeller belongs to a vane-free impeller, and the leaf rotation path is a curved runner from the inlet to the exit. Therefore, it is suitable for pumping medium containing large particles and long fiber. Good blocking resistance. In terms of performance, the efficiency of the impeller and the ordinary closed-type impeller is not very large, but the type of impeller pump head curve is steeper. The power curve is relatively stable, it is not easy to produce super power problem, but the cavitation performance of the impeller is inferior to the ordinary closed impeller, especially suitable for the pump with pressure inlet.

5, Closed impeller:This type of impeller has a normal high efficiency. In the long-term operation of stable, using the type of impeller pump axial Force is small, you can set up on the front and rear cover plate on the pair of blades. The auxiliary blades on the front cover plate can reduce the vortex loss of Impeller Inlet and the wear of the particles to the sealing ring. The auxiliary vane on the rear cover plate not only balances the axial force, but also prevents the suspended particles from entering the mechanical seal cavity to protect the mechanical seal. However, the impeller without blocking, easy winding, not suitable for the extraction of a large number of particles (long fiber) at the end of treated sewage medium.
To sum up, no matter any series of sewage pump impeller, just different types of impeller and different type of water pressure chamber according to the transport medium and installation requirements of a combination, as long as the impeller and the pressure water room can be optimized configuration. The performance of the pump will be guaranteed.

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