In the use of centrifugal fans, you should have encountered abnormal bearing vibration. There are many reasons for this problem, so we need to solve it in a targeted manner.
1)The main reason for abnormal vibration of high-efficiency centrifugal fans
1. The leaves are dusty
If the blades of the centrifugal fan are full of dust, it will be easier to vibrate, which is often manifested as a sudden rise in vibration. This is because there will be a certain angle between the gas entering the impeller and the rotating blades during operation. According to the principle of fluid mechanics, the non-working surface of the gas blade will begin to generate vortices, and the dust particles in the gas will accumulate on the non-working surface. With the increase of dust, the centrifugal fan will cause uneven dispersion of dust particles during operation, and the fan The weight of the blade is also different, which will increase the vibration frequency.
2. The equipment connection is not firm
The fixing parts of the high-efficiency centrifugal fan mainly include the base, the base, the foot bolts, the volute and the connecting pipe. If the connection is not tight, or loose after a period of use, the vertical vibration of the bearing will increase, and abnormal vibration will occur.
3. Vibration of smoke and air duct system
The vibration of the smoke and air duct system will cause the forced vibration of the centrifugal fan. With the increase of the load of the fan outlet diffuser, the air volume in and out increases, and the vibration will change. Usually there are four fulcrums below the diffuser, and the other side is a soft joint, then 60% of the weight of the entire diffuser is the suspension force, so the greater the load, the greater the vibration generated by the bearing.
4. The bearing clearance is too large or too small
The size of the bearing clearance needs to be determined according to the size of the inner diameter of the bearing. The bearing clearance with an inner diameter of 50-100mm is 0.2mm, and the bearing clearance with an inner diameter greater than 100mm is 0.3mm. If it exceeds the above range, it cannot be used. It will cause the fan to vibrate abnormally.
2)Solutions to abnormal vibration of high-efficiency centrifugal fans
1. Remove dust in time
In daily use, it is necessary to check frequently. If it is found that there is a lot of dust on the blades, it should be cleaned up in time. The specific method is: first stop the operation of the centrifugal fan, open the entrance door of the casing, and remove the dust.
2. The connection is firm
When installing the centrifugal fan, pay attention to installing each connecting part firmly, and check whether there is any looseness in each connection during use. If found, it needs to be tightened in time. If it cannot be tightened, it is necessary to check whether Parts need to be replaced.
3. Increase the living fulcrum
A live fulcrum is added below the outlet end of the diffuser, which can be raised, lowered and moved. When the unit load changes, the vibration can be eliminated by only fine-tuning this fulcrum, which generally only occurs when the air duct is short.
4. Control the size of the clearance
The size of the clearance is determined according to the inner diameter of different bearings. For unsuitable bearings, they should be returned to the factory in time, and do not be used forcibly.
After the above introduction, it can be seen that the reasons for the abnormal vibration of the high-efficiency centrifugal fan bearings mainly include dust on the blades, weak equipment connection, smoke, vibration of the air duct system, and excessive or small bearing clearance. , increase the live fulcrum, control the size of the clearance and other methods to solve.