How To Prevent Blockage Of Submersible Pumps

Apr 17, 2025

Submersible sewage pumps are widely used in municipal engineering, factories, commercial areas, hospitals, hotels, residential areas, etc. for sewage discharge due to their advantages of simple installation, small footprint, easy maintenance, and no noise.

The sewage pumps sold in the market are mostly vertically arranged, with the pump coaxial with the motor, so that the weight of the rotating parts is in the same direction as the water pressure borne by the impeller; Secondly, submersible sewage pumps are used underwater and transport sewage media containing impurities, sludge, and other substances; Thirdly, submersible sewage pumps belong to a type of centrifugal pump.

During their operation, the power always increases with the increase of flow rate. When the flow rate exceeds the design flow rate and reaches a certain value, the motor will burn out due to overload. The reliability of sewage pumps needs to be strengthened. Therefore, improving the technical content of their products is the main direction for manufacturers' future development.
Improving the technological content of products and strengthening their market competitiveness can drive the development of the industry. The market prospects for sewage pumps in our country are very broad.
But everything is divided into two parts, and the most critical issue for a sewage pump is reliability, as the pump is used underwater; The medium being transported is a mixture of liquids containing solid materials; The pump is very close to the motor; The pump is arranged vertically, and the weight of the rotating components is in the same direction as the water pressure borne by the impeller.
These issues make the requirements for sealing, motor bearing capacity, bearing arrangement, and selection of sewage pumps higher than those of general sewage pumps.

In order to improve the service life of sewage pumps, many manufacturers in China have found ways to implement pump protection systems that can automatically alarm and shut down for maintenance in the event of pump leakage, overload, overheating, and other faults.
But we believe that it is necessary to install a protection system in the sewage pump, which can effectively protect the safe operation of the electric pump. But this is not the key issue, the protection system is just a remedial measure after a pump failure, which is a relatively passive approach.
The key to the problem should be to start from the root and thoroughly solve the problems of pump sealing, overload, etc. This is a more proactive approach. To this end, we have applied the hydrodynamic sealing technology of the secondary impeller and the overload free design technology of the pump to the submersible sewage pump, greatly improving the reliability and load-bearing capacity of the pump seal and extending the service life of the pump.

The selection of sewage pumps (submersible cutter pumps) and precautions: Currently, all visible sewage pumps on the market are called unobstructed sewage pumps. So, are they truly unobstructed?
not always!
Often, users' sewage pumps are blocked by debris in the sewage tank, causing the motor to burn out and causing a lot of headaches for many users. So, what is the principle of an unobstructed sewage pump?
Firstly, we analyze several situations where the sewage pump is blocked:
(1) Fiber materials such as sanitary napkins in septic tanks;
(2) Convenience bags in hotels, guesthouses, and kitchens;
(3) Hair and convenience bags at the bathing center;
(4) Woven bags, woven ropes, and plastic bags in the water accumulation pit.
From the above situations, it can be seen that the blockage of the sewage pump is caused by some soft fiber materials. A typical sewage pump can only discharge a mixture of mud and water containing sediment or particles, so only a sewage pump that can crush the soft fibers mentioned above can be called an unobstructed sewage pump.
At present, the general structures of sewage pumps on the market are S-shaped channel flat plate impellers and closed channel impellers, which have better sewage discharge effects.
In terms of selection, the following points should still be noted:
(1) The diameter of the sewage pump should be selected as DN65 or DN80 or above as much as possible.
(2) It is best to use materials with higher strength for the impeller. But the truly unobstructed submersible sewage pump is the submersible cutter pump, and the provided sewage pump can solve the problem of sewage pump blockage.