Analysis Of The Five Major Reasons For Vibration Of Slurry Pumps

Slurry pumps are common mechanical equipment used in many chemical and metallurgy industries. In fact, when working, there will be vibration problems due to the reasons and working conditions of the equipment. So what is the reason for the vibration of the slurry pump?The manufacturer CNSME has drawn the following conclusions through analysis. Let’s take a look! Analysis of the causes of vibration of the slurry pump: 1. Mass imbalance fault of the impeller The centrifugal force generated by the mass imbalance of the impeller always acts on the slurry pump. When the equipment leaves the factory, the corresponding inspection and adjustment of each spare parts are carried out, especially the impeller part has been static/dynamic balance detection and drilling/milling correcting treatment. The position of the mass imbalance will be processed. At this time, the impeller is in a relatively good mass balance state, so the operating state of the slurry pump is also stable, and the vibration of the equipment is also slight.However, after a long-term operation in the later stage, due to wear of the impeller and scars caused by the adhesion of the ore slurry, the overall mass balance of the impeller will be broken and the impeller \"partial load\" will be correspondingly present. At this time, the centrifugal force on the heavier side of the slag impeller will increase, especially when the sludge pump rotates at a high speed, the heavy impeller will cause serious unbalanced rotational force. At this time, the measurement will find that the vibration amplitude gradually increases from the motor end to the pump body end.　　2. Vibration failure caused by coupling　　Vibration caused by coupling is more common in slurry pumps, especially in rigidly connected couplings. The vibration between the motor and the pump resonates in the transmission of the coupling, causing the vibration to intensify. Even the column pin coupling, which is more common in slurry pumps, will produce violent and short-term vibrations because the column pin/glue ring and other components cannot meet the axial movement. Although the failure of the coupling will also cause the pump to vibrate, it is far less than the vibration caused by impeller failure.　　After the production is completed, the coupling leveling will also be carried out in the later stage. The coupling leveling and impeller leveling are also to reduce the unbalanced forces generated during rotation. However, in addition to the self-rightening of the mass, the coupling must also consider the balance of the installation and coordination of the two couplings. In addition to the balance of its own mass, the balance of a pair of couplings must meet the following two conditions: (1) Make the intermediate points of the two pairs of wheels overlap, that is, make the outer circles of the two pairs of wheels overlap; (2) Make the joint surfaces (end surfaces) of the two pairs of wheels parallel (two intermediate points and lines are parallel).Only when these two conditions are met can the stable operation of the equipment be better ensured and the wear of the coupling spare parts.　　3. Vibration caused by loosening of tightening bolts　　Even equipment operating in good condition, there is a \"micro-shaking\" phenomenon. After the equipment is running for a period of time, the bolts in the pump body, bearing bracket, foot and other parts will be more or less loose. After the bolt is loose, the pump body will increase vibration due to loss of constraints. Sometimes the tightened bolts cannot be tightened in time after they are loosened, and the vibration will further increase. The increase in vibration will lead to further loosening and wear of the bolts, which will cause vicious cycles and lead to greater failures in the slurry pump.　　4. Faults caused by bearing wear or insufficient lubrication　　The service life of the bearing is directly related to the use environment and lubrication, and lubricating oil leakage is a common problem. Due to the poor sealing of the shaft ends of the bearing bracket, the lubricating oil of the bearing is in a state of oil leakage for a long time, or due to the large amount of impurities in the lubricating oil, the oil conduction groove is blocked and affected by the lubricating oil on both sides of the bracket.When the bearing is insufficient lubrication, abnormal noise and vibration will occur regardless of whether the bearing is worn or not. This is because when the bearing is insufficient lubrication, the bearing balls cause direct contact between metal and metal due to the absence of lubricating oil film, and lose their shock absorption ability. Although the vibration at this time is mild, it is harmful to the equipment. At the same time, the bearing brackets of a large number of slurry pumps use \"maze\" seals. This seal can ensure that the lubricating oil does not leak, but it cannot ensure that the impurities in the outside world do not enter the bearing, which is easy to cause the bearing to be contaminated outside and wear.　　5. Equipment failure caused by unstable feed The working conditions of the slurry pump are generally relatively harsh. Most slurry pumps are divided into large flow pumps. During the conveying of slurry, large pieces of impurities in the slurry will inevitably affect the feed and even block the blade. When the feed is unstable or the feed is insufficient, severe cavitation will occur inside the pump chamber, and the balance of the impeller in the pump chamber will be seriously affected, which not only produces vibration, but also seriously harms the equipment.The above are the five major reasons for the vibration of the slurry pump compiled by CNSME. Of course, there may be some other factors. So users are welcome to communicate and improve!