Common problems and solutions in the operation of circular vibrating screen

The vibrating screen is a very important auxiliary equipment in mining production, and once it malfunctions, it will directly affect the normal operation of the production line. As a common type of vibrating screen, what are the common problems with circular vibrating screens in daily operation? How should we solve these problems when we encounter them? This article analyzes the causes of five common problems with circular vibrating screens and proposes countermeasures.
1、 Circular vibrating screen shaft fracture
Generally, circular vibrating screens generate vibration by driving a vibrator with eccentric mass through an electric motor. During the vibration process, the shaft is the key component that drives the circular vibrating screen to vibrate, while also experiencing significant forces. Therefore, in practical use, shaft fracture is a common fault. Once a shaft fracture occurs, the circular vibrating screen will immediately stop working, and its maintenance is complex and requires high attention.
Reasons and countermeasures:
1. Long term metal fatigue or poor shaft material
The shaft of a circular vibrating screen is a metal material that is subjected to a combined torque of torque and repeated impact forces for a long time during use. Under the long-term impact torque, the materials inside the shaft will gradually experience fatigue, and when the fatigue limit is reached, fracture will occur. In addition, there are significant differences in the torsional strength of different materials. If the material is poor, it will inevitably lead to low bending strength and fatigue limit, and it is easy to cause damage.
It is recommended to choose a reputable manufacturer when purchasing a circular vibrating screen to ensure that the material selection for each component is reasonable. At the same time, it is strictly prohibited to start the circular vibrating screen with materials, ensuring that the circular vibrating screen is only started without materials; Strengthen daily maintenance and inspection, regularly inspect the shaft, and if any bending, deformation, or other phenomena are found, they must be replaced in a timely manner to avoid damage during the transmission process.
2. Excessive tension in the V-belt
If the tension of the triangular belt of the circular vibrating screen is too high, it will cause an additional bending moment on the shaft, increase the composite moment, and significantly increase the stress during the material feeding process, even exceeding the allowable stress of the shaft, directly leading to the failure of the shaft. Therefore, it is necessary to adjust the tension of the V-belt in a timely manner, and it is recommended to minimize the V-belt tension as much as possible while ensuring normal transmission. Of course, replacing it with a flexible connection can prevent this phenomenon from occurring.
2、 Circular vibrating screen experiences transmission failure
The vibrating screen is mainly composed of a vibrator, a screen box, a support or suspension device, a transmission device, and other components. Once a transmission failure occurs, the circular vibrating screen will be unusable, seriously affecting normal production. At the same time, the transmission failure of the vibrating screen is relatively complex and difficult to repair.
Reasons and countermeasures:
Common transmission failures of circular vibrating screens include coupling wear, broken connecting bolts, cracked protective tubes, damaged pulley bearings, and torn belts.
For this reason, operators of the circular vibrating screen need to regularly conduct preventive inspections on the transmission part. During the inspection process, special attention should be paid to the longitudinal and transverse clearances of the bearings to ensure that the spacing meets the requirements. Lubricating oil should also be added in a timely manner to avoid serious wear and tear; Check the bearing support every week and add lubricating oil in a timely manner; Observe the operation of the circular vibrating screen. If there are any abnormal situations, it is necessary to stop the operation and conduct a system check to avoid larger accidents.
3、 The temperature of the circular vibrating screen bearing is too high
High bearing temperature is also a common fault in the use of circular vibrating screens. Although high bearing temperature does not immediately have a direct impact on production, if it persists for a long time, it will inevitably have a significant impact on the service life of the bearings. Therefore, technicians must also attach great importance to this issue.
Reasons and countermeasures:
1. The working time of the circular vibrating screen is too long
Long term work will inevitably generate a certain amount of heat, which will promote the evaporation of lubricating oil, and the evaporation of lubricating oil will further lead to an increase in friction, causing the temperature to rise. Therefore, it is necessary to arrange the operation time of the circular vibrating screen reasonably, improve the efficiency of equipment operation, avoid long-term continuous work, and timely shut down when the circular vibrating screen is not needed.
2. Insufficient lubricating oil
Insufficient lubricating oil will inevitably lead to a continuous increase in temperature. It is necessary to regularly inspect the bearings and add lubricating oil to avoid excessive temperature caused by insufficient lubricating oil.
4、 Continuously shaking oil during use
Due to the fact that the lubrication method for most circular vibrating screens is eccentric shaft oil splash lubrication, this lubrication method is difficult to fundamentally eliminate the phenomenon of oil splashing.
Reasons and countermeasures:
1. The rotation centerline of the vibration source generates motion
When the center line of the vibration source of the circular vibrating screen moves, the sealing of the vibrator is severely damaged. Under the action of centrifugal force, the circular vibrating screen will inevitably experience oil spillage during operation.
2. Internal and external pressure difference
During the rotation of the circular vibrating screen, a large amount of heat is generated, which causes the pressure inside the vibrator to continuously increase. Once the ventilation hole is blocked, the internal pressure will continue to increase. When the internal pressure reaches a certain level, it will cause damage to the vibrator, thereby destroying its airtightness and producing oil splashing phenomenon.
3. Loose sealing gland
The bearings of the circular vibrating screen are installed inside the bearing seat, and the sealing ring is installed on the sealing cover. If the height difference between the end face of the bearing seat and the end face of the bearing is too small, the positioning protrusion on the sealing cover will lose its fixed positioning function, causing the sealing cover and the bearing to be not concentric, resulting in the failure of the sealing effect of the sealing cover and the occurrence of oil leakage.
Regularly inspect the vibrator to prevent it from sliding; Choose lubricating oil with higher viscosity to reduce oil spillage.
5、 The service life of the circular vibrating screen surface is short
The main factors affecting the aging of the screen surface are the structure, material, and degree of tension of the screen surface. Currently, many circular vibrating screens use polyurethane screen surfaces.
Reasons and countermeasures:
On the one hand, the aging resistance of polyurethane itself is not high. On the other hand, if the staff does not tighten the screen surface during installation, that is, only fixing the two sides of the screen surface without fixing the middle, the screen surface and the bracket will constantly collide and rub up and down during operation. Due to the direct contact between the screen surface and the material during the operation of the circular vibrating screen, when the screen surface is not tightened and is in a loose state, the screen surface will undergo secondary vibration, resulting in increased wear and accelerating the aging phenomenon of the screen surface of the circular vibrating screen.
It is recommended to choose high-quality screening surfaces and regularly check for looseness or damage. If there is looseness, the screening surface should be tightened in a timely manner; If there is any damage, the screen surface should be replaced in a timely manner. When replacing the screen surface, the tension plates on both sides should have the same and uniform tension, and the screen surface must be tightened. For screens that have aged and cannot be used, they need to be replaced in a timely manner to avoid causing more serious problems.
The above are the five common problems, causes, and countermeasures of circular vibrating screens. To ensure stable and efficient operation of equipment, in addition to selecting equipment types that comply with the beneficiation process, daily maintenance and upkeep are particularly important. Therefore, it is recommended that all mine owners consult professional equipment manufacturers when selecting circular vibrating screens, choose equipment suitable for their own process flow, and fundamentally ensure the normal operation and economic benefits of the entire beneficiation plant.