How to carry out daily maintenance and repair of vacuum pumps through "observation, smell, consultation, and diagnosis" ("Maintenance Manual for Vacuum Pumps and Oil Mist Separators") provides a detailed explanation of the four steps of observation, smell, consultation, and diagnosis to achieve "miraculous rejuvenation" of equipment and extend the service life of vacuum pumps and oil mist separators. Below, we will share with you how to use "listening" to determine equipment malfunctions.
The sound of a pump comes from a wide range of sources, but mainly from the rotation of the motor. The motor noise is also divided into three parts: electromagnetic vibration of the motor itself, rotational noise of the tail fan, and physical mechanical noise. When a pump malfunctions, it will produce some abnormal noise, such as cavitation, pumping, and significant changes in pump capacity. The oil mist separator is a filtering device at the exhaust port, which filters the oil mist and cleans the discharge, making the vacuum pump more stable. For the pump, it is an icing on the cake effect and does not produce additional noise.
1. Increased pump noise
When cavitation occurs, continuous and enormous impact forces will damage the surface of the impeller, and this process will develop from pitting corrosion to large-scale erosion, resulting in noise and abnormal vibration. When cavitation is severe, the flow rate, pressure head, and efficiency of the pump significantly decrease due to the occupation of bubbles in the liquid flow channel. To avoid this phenomenon, it is necessary to maintain the minimum pressure at the impeller inlet above a stable critical point, so that this value should be higher than the saturated vapor pressure of the liquid. When cavitation occurs, timely exhaust treatment should be carried out, and attention should be paid to the maintenance and observation of the oil mist separator. If the oil mist separator is blocked, it will delay the exhaust time. Therefore, it is also important to observe the state of the oil.
2. When the pump makes a trembling sound
When the centrifugal pump emits a trembling sound, it indicates that the pump is evacuating, and the pump's evacuation usually occurs on the centrifugal pump. The reason for this situation is that the suction pressure is too low, the liquid vaporizes, a large number of bubbles deform and burst, making a trembling sound. If not handled in time, the pump shaft seal and other workpieces will be affected. The method to prevent pump emptying is to reduce the flow rate at the pump outlet and directly stop the pump.
3. When the pump equipment emits a deep sound
This situation is generally due to the pump capacity being too large. If the capacity is reduced, it will cause the pump to produce abnormal low noise, due to differences in internal circulation of the impeller. Long term damage to the impeller can occur, and the solution is to increase the inlet flow rate. Vacuum equipment not only requires the installation of oil mist separators, but also the installation of air filters, which can ensure that the pump oil is not contaminated, and also prevent large particle impurities from causing impact wear on the surface of the pump workpiece.
Different sounds have different fault points. The above is used as a reference for listening to sound to determine the fault, and the specific situation depends on the actual situation. The manufacturer of the vacuum pump oil mist separator, Brother Filter, suggests paying attention to regular maintenance and pre inspection and repair, which can greatly reduce the frequency of equipment failures.
