Essential basic knowledge for water pump maintenance, after reading this article, you will become a

1. Insufficient traffic

Cause: Insufficient water pump flow is often caused by leakage in the suction pipe and bottom valve;

 

Blocked water inlet; Insufficient water inlet depth of the bottom valve;

 

The water pump speed is too low; Excessive wear of sealing rings or impellers; Excessive water absorption height, etc.

 

Solution: Check the suction pipe and bottom valve, and block the source of gas leakage;

 

Clean the silt or blockages at the water inlet;

 

The inlet depth of the bottom valve must be greater than 1.5 times the diameter of the inlet pipe, and the inlet depth of the bottom valve should be increased;

 

Check the power supply voltage, increase the water pump speed, and replace the sealing ring or impeller; Lower the installation position of the water pump or replace the high head water pump.

 

2. Power consumption

Cause: The water pump speed is too high;

 

The water pump spindle is bent or the water pump spindle is not concentric or parallel to the motor spindle;

 

Inappropriate selection of water pump head;

 

The water pump sucks in sediment or has blockages;

 

Damaged motor ball bearings, etc.

 

Solution: Check the circuit voltage and reduce the water pump speed;

 

Correct the main shaft of the water pump or adjust the relative position between the water pump and the motor;

 

Select a water pump with an appropriate head;

 

Clean up sediment or blockages; Replace the ball bearings of the motor.

 

3. Severe vibration or noise generated by the pump body

Cause: The water pump is not securely installed or installed too high;

 

Damaged motor ball bearings;

 

The water pump spindle is bent or not concentric or parallel to the motor spindle.

 

Solution: Install the water pump steadily or lower the installation height of the water pump;

 

Replace the motor ball bearings;

 

Correct the bent water pump spindle or adjust the relative position between the water pump and the motor.

 

4. Overheating of drive shaft or motor bearings

Cause: Lack of lubricating oil or bearing rupture, etc.

 

Solution: Add lubricating oil or replace bearings.

 

5. The water pump does not discharge water

Cause: The pump body and suction pipe are not fully filled with water;

 

The dynamic water level is lower than the water pump filter pipe; Rupture of suction pipe, etc.

 

Solution: Eliminate the malfunction of the bottom valve and fill it with water;

 

Lower the installation position of the water pump so that the filter pipe is below the dynamic water level, or wait for the dynamic water level to rise before pumping again;

 

Repair or replace the suction pipe.

 

Introduction to Basic Knowledge and Impeller Classification of Sewage Pump Use

Sewage pump belongs to a type of non clogging pump, which has various forms:

 

There are two types of submersible and dry sewage pumps. Currently, the most common submersible is the WQ submersible sewage pump, and the most common dry sewage pumps are the W-type horizontal sewage pump and the WL type vertical sewage pump.

 

Mainly used for transporting urban sewage, feces or liquids containing fibers.

 

The medium for solid particles such as paper scraps is usually transported at a temperature not exceeding 80 ℃.

 

Due to the presence of fibers that are prone to entanglement or bunching in the medium being transported. Therefore, the flow channel of this type of pump is prone to blockage. Once the pump is blocked, it will not work properly, and even burn out the motor, resulting in poor drainage.

 

It has a serious impact on urban life and environmental protection. Therefore, anti clogging and reliability are important factors for the quality of sewage pumps.

 

Like other pumps, the impeller and pressure chamber are the two core components of the sewage pump.

 

The quality of its performance represents the quality of the pump's performance. The anti clogging performance, efficiency, cavitation performance, and anti wear performance of the sewage pump are mainly ensured by the two components of the vane pump and the pressure chamber.

 

Below is an introduction:

 

1. Impeller structure type: The impeller structure is divided into four categories: blade type (open, closed), swirl type, channel type, (including single channel and double channel) spiral centrifugal type.

 

The manufacturing of open and semi open impellers is convenient. When blockage occurs inside the impeller, it can be easily cleaned and repaired. However, in long-term operation, the wear and tear of particles can increase the gap between the blades and the sidewall of the pressurized water chamber, thereby reducing efficiency. And increasing the gap will damage the pressure difference distribution on the blade.

 

Not only does it generate a large amount of vortex losses, but it also increases the axial force of the pump.

 

At the same time, due to the increased gap, the stability of the liquid flow state in the channel is disrupted, causing the pump to vibrate. This type of impeller is not easy to transport media containing large particles and long fibers.

 

In terms of performance, this type of impeller has low efficiency, with the highest efficiency equivalent to about 92% of a regular closed impeller, and the head curve is relatively flat.

 

2. Swirl impeller: A pump that uses this type of impeller, as the impeller partially or completely shrinks away from the flow path of the pressurized water chamber.

 

So it has good non blocking performance, strong ability to pass through particles and long fibers.

 

The particles flow in the pressurized water chamber and are propelled by the eddy currents generated by the rotation of the impeller. Suspended particles themselves do not generate energy, but only exchange energy with the liquid in the flow channel.

 

During the flow process, suspended particles or long fibers do not come into contact with the blades, and the wear of the blades is relatively light. There is no situation where the gap increases due to erosion, and it will not cause a serious decrease in efficiency during long-term operation. The pump using this type of impeller is suitable for pumping media containing large particles and long fibers.

 

In terms of performance, the efficiency of this impeller is relatively low, only about 70% of that of a regular closed impeller, and the head curve is relatively flat.

 

3. Closed impeller: This type of impeller has a higher normal efficiency.

 

And in long-term operation, the situation is relatively stable. The axial force of the pump using this type of impeller is relatively small, and auxiliary blades can be set on the front and rear cover plates.

 

The auxiliary blades on the front cover plate can reduce the vortex loss at the impeller inlet and the wear of particles on the sealing ring.

 

The auxiliary blades on the rear cover plate not only balance the axial force, but also prevent suspended particles from entering the mechanical seal chamber and provide protection for the mechanical seal.

 

However, this type of impeller has poor blockage free performance, is easy to entangle, and is not suitable for pumping untreated sewage media containing large particles (long fibers).

 

4. Channel type impeller: This type of impeller is a bladeless impeller, and the impeller flow passage is a curved flow passage from the inlet to the outlet. So it is suitable for pumping media containing large particles and long fibers. Good resistance to blockage.

 

In terms of performance, this type of impeller has high efficiency and is not much different from a regular closed impeller, but the head curve of the impeller pump with this type is relatively steep.

 

The power curve is relatively stable and not prone to generating excessive power, but the cavitation performance of this type of impeller is not as good as that of ordinary closed impellers, especially suitable for pumps with pressure inlet.

 

5. Spiral centrifugal impeller: The blades of this type of impeller are twisted spiral blades that extend axially from the inlet on the conical hub body.

 

This type of impeller pump combines the functions of a positive displacement pump and a centrifugal pump. When suspended particles flow through the blades, they do not collide with any part of the pump, so it has good non-destructive performance. Less destructive to the conveyed material.

 

Due to the propelling effect of the spiral, the passing ability of suspended particles is strong, so pumps using this type of impeller are suitable for pumping media containing large particles and long fibers, as well as high concentration media. It has obvious characteristics in situations where there are strict requirements for the destruction of the conveying medium.