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Solutions to Three Common Problems of Slurry Pumps

Mar. 16, 2021


Slurry pump is a common machine that uses centrifugal force to increase the energy of solid-liquid mixed media. It is mainly used in mining, metallurgy, construction and other fields. As a common and practical auxiliary tool, slurry pumps have three common problems during use, that is, flow instability, cavitation, and seal failure, which will lead to the leakage of slurry pumps. Then how do you solve such problems? What? The following Slurry Pump Suppliers come to give everyone a popular science!


Slurry Pump

Slurry Pump

How to solve the unstable flow of slurry pump?


1. The suction pipe or bottom valve is leaking, or the water inlet is blocked, which is a common cause of insufficient flow. It is necessary to check the air leakage source of the suction pipe and the bottom valve and block it in time, or clean the sludge or blockage at the water inlet.


2. If the voltage is too low, the speed of the slurry pump will decrease, resulting in insufficient flow of the slurry pump. At this time, the power supply voltage should be checked and adjusted in time.


3. If there is air leakage in the pipeline or there is air in the pump body, the air in the pipeline can be discharged in time.


4. Severe wear of the seal ring or impeller will also cause the slurry pump flow to be unstable, and the severely worn seal ring and impeller should be checked and replaced in time.


5. The depth of the bottom valve is insufficient, which causes air to enter when pumping. The depth of the bottom valve should be adjusted according to the suction stroke of the slurry pump.


6. If the slurry pump works normally within a period of time after starting, but the current gradually drops and the flow is obviously insufficient, this problem still occurs after restarting the normal operation for a period of time, mostly due to the accumulation of slurry or other debris in the suction pipe. Cavitation occurs in the slurry pump. When it is more serious, there will be loud noises in the slurry pump and obvious vibration of the pump head. At this time, the front pool and suction pipe should be thoroughly cleaned, and the length below the elbow should be reduced, or a stirring device should be added to reduce The slurry settles.


How to solve the cavitation phenomenon of the slurry pump?


At a certain temperature, when the liquid pressure drops below the saturated pressure, boiling vaporization occurs. This is the characteristic of the liquid itself. At a certain temperature, the saturated pressure is constant, and it increases with the increase in temperature.


For Centrifugal Pumps such as slurry pumps, the suction port pressure can be reduced to make the liquid suck into the pump. When the suction port pressure is lower than the saturated air pressure corresponding to the water temperature, the sucked liquid will undergo a vaporization reaction. The bubbles formed by gasification converge at the lowest pressure position in the slurry pump, that is, the back of the blade above the impeller inlet. As the surrounding liquid flows outward, the impact of the liquid will cause noise and vibration. If this happens, the impeller will be eroded. damage.


Generally speaking, the measures to solve the cavitation phenomenon are:


1. Control the suction liquid surface pressure to prevent the liquid surface pressure from being too low.


2. Control the flow rate of the suction port to make the slurry pump work under the specified beat volume.


3. Appropriately reduce the installation height of the slurry pump.


4. The suction valve is fully open, and the filter screen should be cleaned frequently.


How to solve the failure of the slurry pump seal?


In different stages of operation, the reasons for the failure of the slurry pump seal are different, and then we will analyze them one by one.



1. The slurry pump leaked during the assembly process



Slurry pumps are prone to problems during installation. It is generally necessary to observe whether the slurry pump is leaking through static pressure test. When the leakage is small, there are problems with the moving ring or static ring sealing ring in small shifts. If the leakage is large, it is There are problems with the dynamic and static ring friction pairs. The leaking medium is sprayed along the axial direction, and it is mostly the problem of the moving ring seal. If the leaking medium is sprayed around or leaks from the water cooling port, most of the static ring seal has a problem. At this time, you should carefully observe to determine the problem and proceed in time Adjustment.



2. Leakage during the test operation of the slurry pump



After the static pressure test, the cause of the leakage of the slurry pump is generally caused by the damage of the dynamic and static ring friction pairs. There are many reasons for this phenomenon, generally: axial force caused by abnormal phenomena such as cavitation, evacuation, and holding pressure, excessive compression when installing the seal, too tight or too loose moving or static ring seals, There are reasons such as particles in the working medium entering the friction pair. The main solution is to re-disassemble and replace the seal.



3. Sudden leakage during normal operation of slurry pump



In this case, a few are caused by normal wear or the service life of the slurry pump, but most of them are caused by changes in working conditions or improper operation or maintenance. The main reasons are: evacuating cavitation or holding the pressure for a long time, the actual output is too small, the sealing cooling water is interrupted, the operation is stopped for a long time and the car is restarted, the corrosive, polymerizable or gelling substances in the medium increase, and the slurry The temperature of the working environment of the pump changes drastically, and the working conditions are frequently adjusted. In the process of using the slurry pump, please pay attention to the use specifications. The shaft seal water must be connected before use, and the pump can be turned off after five minutes of stopping. If the pump is out of operation for a long time, clean water and clean the pump cavity and mechanical seal before shutting down. , Manual cranking when restarting, prolong the service life of the slurry pump.


Above we have summarized some common problems in the use of slurry pumps. In order to avoid problems during use, the use process of slurry pumps should be standardized, and regular inspections should be conducted to find out the cause and make timely decisions when abnormal conditions occur. Only adjustments can ensure the normal use of equipment and the normal operation of the concentrator. In addition, the company also provides Flue Gas Desulfurization Pumps and dredging pumps, please feel free to contact us if necessary