Diaphragm Booster Pump Common Failures

Understanding the Challenges: Diaphragm Booster Pump Issues

Diaphragm booster pumps are vital components in various industries, contributing to efficient processes and reliable fluid transfer. However, like any mechanical system, these pumps are susceptible to common failures that can impact their performance. Let's explore some of these issues and their possible causes.

Bearing Damage in Diaphragm Booster Pump

One frequent issue encountered is bearing damage in diaphragm booster pumps, particularly when the pump experiences water interruptions or contains impurities. The bearings in CQB diaphragm booster pumps use high-density carbon, and any disruptions, such as pump water interruption or impurities in the pump, can lead to bearing damage. Additionally, if the coaxiality between the inner and outer magnetic rotors in the cylindrical coupling is not ensured, it can directly affect the bearing's lifespan.

Insufficient Head (Head is too low)

Insufficient head or head that is too low is another common problem in diaphragm booster pumps. Several factors contribute to this issue, including the presence of air in the conveyed medium, damaged impellers, inadequate speed, excessive density of the conveyed liquid, and high flow rates.

Diaphragm Booster Pump Shaft Breakage

The pump shaft in CQB-type diaphragm booster pumps, made from 99% aluminum oxide ceramic, may experience breakage. This breakage is mainly attributed to dry grinding of the bearings due to pump idling, leading to shaft twisting. To prevent pump breakage, it is crucial to avoid the pump running without liquid.

Inadequate Flow Rate

Insufficient flow rates can arise due to various reasons, such as damaged impellers, inadequate speed, excessively high head, and blockages in the pipe containing foreign particles.

Inability to Pump Liquid

A common and critical issue is the inability of the diaphragm booster pump to pump liquid. This problem has various potential causes. Firstly, check for air leaks in the pump's suction pipeline, ensure the removal of air from the suction pipe, verify an adequate volume of liquid in the pump, inspect for blockages in the suction pipe, and check if the pump is not running in reverse (especially after motor replacement or power line maintenance). Additionally, consider the pump's suction height, ensuring it is not too high. If issues persist, disassemble the pump for a detailed examination, checking for shaft breakage and the integrity of dynamic and static rings. Ensure the rotor can move slightly axially. If axial movement is difficult, inspect if the carbon bearing is excessively tight with the pump shaft.

Additional Considerations for Diaphragm Booster Pump Reliability

Sometimes, despite multiple attempts at repairs, issues persist. In such cases, it's crucial to examine the proper functioning of the magnetic coupling. Bearings, inner magnetic rotors, and isolation sleeves generate heat during operation, leading to elevated temperatures. The rise in temperature can cause a decrease in power transmission, posing challenges for diaphragm booster pumps handling easily vaporizable liquids. The power transmission of magnetic steel decreases continuously with increasing temperature. Generally, the decrease in transmission capacity is reversible below the magnetic steel's working limit temperature, but it becomes irreversible above this limit. In situations where slippage (loss of synchronization) occurs in the magnetic coupling, the eddy current heat in the isolation sleeve increases sharply, causing a rapid temperature rise. Without timely intervention, this can lead to demagnetization of the magnetic steel, resulting in the failure of the magnetic coupling. Therefore, diaphragm booster pumps should be designed with reliable cooling systems.

For less vaporizable media, the cooling cycle system typically directs liquid flow from the impeller or pump outlet through the bearing and magnetic drive sections back to the suction port. For easily vaporizable media, consider adding a heat exchanger or diverting liquid flow to an external tank to avoid heat returning to the suction port. For media with solid or ferromagnetic impurities, filtration should be considered, while high-temperature media requires cooling to ensure the magnetic coupling does not exceed its working limit temperature.

In conclusion, understanding and addressing common failures in diaphragm booster pumps are crucial for maintaining their optimal performance and reliability. Regular inspection, preventive measures, and adherence to proper operating conditions play a pivotal role in extending the lifespan of these essential components in industrial applications.