Why the Slurry Pump Vibration And How To Prevent It
Slurry pump is the core equipment for pipeline transportation of liquid or solid-liquid mixed slurry, which is widely used in many industrial processes. It has the advantages of good wear resistance, long service life, high work efficiency and good work stability. In the process of use, due to the working conditions of the slurry pump and the characteristics of the slurry pump itself, vibration often occurs due to various reasons. We analyzed the reasons for the vibration of the slurry pump, learned its and carried out further preventive treatment.
About Slurry Pump
The slurry pump has become an important equipment for the slurry pipeline transportation system due to its advantages of large particle size, wide flow range, simple structure, low cost, light weight, easy installation and easy operation.
Slurry pump belongs to centrifugal pump in terms of working principle. Conceptually, it refers to a machine that increases the energy of solid and liquid mixed medium by means of centrifugal force (the rotation of the impeller of the pump), and converts electrical energy into A device for the kinetic and potential energy of a medium. Mainly used in: mining, power plant, dredging, metallurgy, chemical industry, building materials and petroleum and other industries.
Why the slurry pump vibration
The abnormal vibration of the slurry pump is the main reason for other failures. At the same time, the failure of the equipment directly aggravates the vibration of the equipment, which seriously affects the safe operation of the equipment. And the corresponding increase in maintenance costs, as well as production losses due to equipment failures.
1. The quality of the impeller is unbalanced: the centrifugal force generated by the mass unbalance of the impeller always acts on the slurry pump. The equipment has been inspected and adjusted accordingly for each spare part of the slurry pump when it leaves the factory. In particular, the impeller part has undergone static/dynamic balance detection and drilling/milling alignment treatment, and the balanced position of the mass part will be processed. At this time, the impeller is in a relatively good mass balance state. At this time, the operating state of the slurry pump is also the most stable state, and the vibration of the equipment is also slight. After a long period of operation in the later period, due to the wear of the impeller and the scarring caused by the attachment of the pulp, the overall mass balance of the impeller will be broken and the impeller will be “eccentrically loaded” accordingly. At this time, the centrifugal force on the heavier side of the impeller “eccentrically loaded” of the impeller of the slurry pump will increase. Especially when the slurry pump rotates at 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 the coupling: the vibration caused by the coupling is more common in the slurry pump, especially the coupling with rigid connection. The vibration of the motor and the pump produces resonance in the transmission of the coupling, which leads to vibration. intensification. Although the failure of the coupling can also cause the vibration of the pump, it is nowhere near as much as the vibration caused by the failure of the impeller. The coupling will also be leveled in the later stage after the production is completed. The leveling of the coupling and the leveling of the impeller are also aimed at minimizing the unbalanced force generated during rotation. However, in addition to the quality alignment of the coupling itself, the balance of the installation and coordination of the two couplings must also be considered. The following two conditions must also be met:
- Make the centers of the two pairs of wheels coincide, that is, to coincide the outer circles of the two pairs of wheels;
- Make the joint surfaces (end surfaces) of the two pairs of wheels parallel (the two center lines are parallel).
Only when these two conditions are met can the stable operation of the equipment and the minimum wear of the coupling spare parts be better guaranteed.
3. Vibration caused by loosening of fastening bolts: Even equipment running in good condition has the phenomenon of “micro-vibration”. In this micro-seismic state, after the equipment runs for a period of time, the bolts of the pump body, bearing bracket, foundation and other parts will be loose more or less. After the bolts are loosened, the vibration of the pump body will increase due to the loss of restraint. Sometimes the tightened bolts cannot be tightened in time after loosening, and the vibration will further increase. The increase in vibration will lead to further loosening and wear of the bolts, which will create a vicious circle, which will eventually lead to greater failure of the slurry pump.
How to prevent the slurry pump vabration
The vibration phenomenon of the pump will not disappear, but will only be slowed down by effective treatment measures. For the slurry pump, it is necessary to select a more reasonable model and operate more standardly to enable the pump to run stably for a long time. Vibration is also a double-edged sword, which can not only cause more serious failures, but also detect problems in time according to the changes in the vibration of the pump to prevent them.
1. Model selection: The working conditions and working environment of the slurry pump are generally poor, so the failure rate of the slurry pump is often relatively high, which requires the selection of higher specifications as much as possible on the premise of meeting the production technical requirements. At the same time, it is necessary to ensure a good working environment in the feeding.
2. Operation: When the pump is running, some cavitation will occur. Especially in the case of insufficient feed, the cavitation of the centrifugal pump will be aggravated, and the vibration of the pump will also be aggravated. The vibration caused by short-term cavitation is caused by the uneven distribution of the liquid in the pump chamber. The vibration of the pump can be effectively eliminated by stabilizing the feed of the centrifugal pump or adjusting the speed of the pump at the outlet valve.
3. Tightening: The bolts will be loose in the “micro-vibration” state. After repairing, you can apply some thread locking agent on the bolts, which can not only prevent the bolts from loosening, but also prevent the bolts from being damaged. When disassembling, only The loosening agent can be melted by heating. Although the investment is small, it is necessary for the equipment reassembly.
Abnormal vibration is not only a kind of failure, but also an important reason for the aggravation of failure. Analysis of abnormal vibration is a method of diagnosing faults. It is most important to deal with the vibration of equipment in a timely manner and strengthen prevention. Our Walker slurry pump has a relatively long service life and requires little maintenance, which can effectively save production costs.