What is the reason for the large vibration of the screw air compressor

Air compressor in the normal operation, vibration is inevitable, but in the operation of vibration is too large, will cause serious harm to the air compressor, the following air compressor vibration reasons are analyzed as follows:

vibration after 1. start-up:

when the unit starts, due to the large starting current of the unit and the large instantaneous torque, the motor has a sense of displacement, and during the starting process, it is an unstable process to cross the surge zone, and the vibration is obviously fluctuating.

Example: Because the start-up is not standardized, the position of the inlet guide vane and the scale are often inconsistent during the start-up, resulting in a large starting current during the start-up, and even an obvious feeling of surge, resulting in a large vibration after the start-up. Therefore, multiple start-up affects The service life of the compressor requires frequent shutdown for maintenance.

Frequent start and stop also have an impact on the vibration of the unit. Due to considerable conditions or mechanical failure.

The impact of the barrier, forced to start and stop many times a year, so that the rotor balance is destroyed. When parking, the dust or other oxides accumulated on the rotor will fall off unevenly, breaking the balance of the rotor.

Due to the large torque at the moment of starting and stopping, the gear shaft and the seal are greatly abraded. Although the seal and the shaft are matched within the qualified range, it will produce a large axial displacement, which will always cause a certain point of the seal and the shaft. Wear damage reduces the surface smoothness of the seal or the shaft, which increases the vibration and even damages the equipment.

2. bearing impact:

in the past, air compressors often used two sliding bearing tiles. After 2003, the industry generally reformed the sliding bearing of air compressors. The bearing tiles were upgraded on the basis of the original air compressor body. Five tilting tiles were adopted. The oil volume between the tiles and between the tiles and the shaft increased. Although the lubrication and cooling performance were improved, the sealing performance was not as good as that of the original sliding bearing. However, the vibration is reduced and the mechanical efficiency is greatly improved, it is now recognized by the industry. The defect is that the bearing temperature and vibration detection equipment often drifts and jumps. When readjust, it only depends on experience and lacks standards, which makes the daily monitoring fail and brings misjudgment to the operator.

the impact of 3. condensate:

condensed water with corrosive gases in the air causes serious corrosion of the rotor, gas seal, diffuser and carbon steel air pipes, resulting in vibration of air vortex. The erosion of the pipeline oxide caused the rotor balance damage and the vibration was intense, so it was forced to stop. Such accidents have occurred twice. The influence of condensed water, especially in humid weather, does not discharge the condensed water in time, or the trap fails, causing the condensed water to be discharged, so that the water is brought into the impeller. Increase the vibration and damage the equipment.

4. to poor alignment, the axial displacement causes the vibration value to increase:

the motion and torque are transmitted by coupling between the cylinders. Due to the installation error of the unit, thermal expansion under working condition, deformation after bearing and uneven settlement of the unit foundation, it is possible to cause misalignment between the axes of the cylinders when the unit is working. The misalignment will result in alternating forces in the axial and radial directions, causing axial vibration and radial vibration, which will increase with the increase of the severity of the misalignment.

The failure of the coupling will be caused by the installation error of the coupling, the manufacturing imbalance of the coupling, the excessive deviation of the end face of the coupling, the insufficient manufacturing precision of the elastic coupling and the unequal cancellation. The main causes of bearing defects caused by large bearing clearance and oil whirl.