What is the structure of the sewage pump?

Impeller

The sewage pump is the same as other pumps, the impeller, the pressurized water chamber, and the two core components of the sewage pump. The performance of the pump is representative of the performance of the pump, the anti-blocking performance of the sewage pump, the efficiency of the high and low, as well as the cavitation performance, anti-abrasion performance is mainly guaranteed by the two major components of the leaf pump and the pressurized water chamber. Here's a separate introduction:

Impeller structure type:

The structure of the impeller is divided into four categories: vane type (open type, closed type), swirl type, flow path type, (including single flow path and double flow path), and four types of spiral centrifugal type.

The open semi-open impeller is easy to manufacture. When the impeller is clogged, it can be easily cleaned and repaired. However, in the long-term operation, the gap between the vane and the sidewall of the pressurized water chamber will increase when the particles are abraded. Reduce efficiency. And the addition of the gap destroys the pressure difference distribution on the blade. Not only does it generate a large amount of vortex loss, but it also increases the axial force of the pump. At the same time, due to the increased clearance, the stability of the liquid flow state in the flow channel is destroyed, causing the pump to vibrate. This type of impeller is not easy to transport. The medium of large particles and long fibers, in terms of performance, the impeller of this type has low efficiency, and the highest efficiency is about 92% of that of the ordinary closed impeller, and the head curve is relatively flat.

Swirling impeller

A pump using this type of impeller is partially or completely retracted from the flow passage of the pressurized water chamber. Therefore, the non-clogging performance is good, and the ability to pass the particles and the passage ability of the long fibers are strong. The particles move in the pressurized water chamber by the vortex generated by the rotation of the impeller, and the suspended particles themselves do not generate energy, but exchange energy with the liquid in the flow channel. During the flow process, the suspended particles or long fibers are not in contact with the blades, and the blades are less worn, and there is no case where the gaps are increased due to abrasion, and the problem of serious decline in efficiency is not caused in long-term operation. The pump of the type impeller is suitable for pumping media containing large particles and long fibers.

In terms of performance, the impeller has low efficiency, which is only about 70% of the ordinary closed impeller, and the head curve is relatively flat.

Closed impeller

This type of impeller has a higher normal efficiency. Moreover, the condition is relatively stable in long-term operation, and the axial force of the pump using the type impeller is small, and the auxiliary blades can be disposed on the front and rear covers. The secondary vanes on the front cover reduce vortex losses at the impeller inlet and wear of the particles against the seal ring. The auxiliary vanes on the rear cover not only balance the axial force, but also prevent the suspended particles from entering the mechanical seal chamber to protect the mechanical seal. However, the impeller of the type has poor non-blocking property and is easy to be entangled, and is not suitable for pumping a sewage medium containing large particles (long fibers).

Runner impeller

The impeller is a bladeless impeller, and the impeller flow path is a curved flow path from the inlet to the outlet. Therefore, it is suitable for pumping a medium containing large particles and long fibers. Good resistance to blocking.

In terms of performance, the efficiency of the impeller of this type is not much different from that of the ordinary closed impeller, but the head curve of the impeller pump is steeply lowered. The power curve is relatively stable and it is not easy to produce super power. However, the impeller performance of this type of impeller is not as good as that of the ordinary closed impeller, especially suitable for pumps with pressurized inlets.

Spiral centrifugal impeller

The blades of this type of impeller are twisted helical blades that extend axially from the suction port on the tapered hub body. The pump of the impeller has the functions of a positive displacement pump and a centrifugal pump. When the suspended particles flow through the blade, they do not hit any part of the pump, so the damage is good. It is less destructive to the transported material. The pump with this type of impeller is suitable for pumping media containing large particles and long fibers, as well as high concentration media, due to the propulsion of the spiral and the high permeability of the suspended particles. It has obvious features in the case where the damage of the transport medium is strictly required.

In terms of performance, the pump has a steep drop head curve and a flat power curve.

Pressurized water chamber

The most common type of pressurized water chamber used in sewage pumps is the volute. Radial vanes or runner vanes are often used in internal submersible pumps. The volute has three types: spiral type, ring type and intermediate type. The spiral volute is basically not used in the sewage pump. The annular pressure water chamber is more convenient to use on a small sewage pump because of its simple structure. However, due to the appearance of the intermediate type (semi-spiral) pressurized water chamber, the application range of the annular pressurized water chamber is gradually reduced. The intermediate type pressurized water chamber has both the high efficiency of the spiral and the high permeability of the annular pressurized water chamber. It has received increasing attention from manufacturers.

In summary, any series of sewage pumps are only a combination of different types of impellers and different types of pressurized water chambers according to the requirements of conveying medium and installation, as long as the impeller and the pressurized water chamber can be optimally configured. The various properties of the pump are guaranteed. (Of course, we cannot ignore the design and manufacture of other parts and structures)