Causes of large vibration of screw compressor

The vibration of screw compressor is inevitable in operation, but excessive vibration in operation will cause serious harm to screw compressor. When the permanent magnet air compressor is started by star-triangle, the starting current is still relatively large. When the capacity of the factory power grid is limited, the upstream air switch will trip. The use of high-efficiency and energy-saving controllers can save the cost of expansion of the factory power grid.

When the variable frequency permanent magnet air compressor starts, the current is about 3-6 times of the rated working current. If it starts frequently, a large amount of electric energy will be wasted. However, the variable frequency type does not start and stop frequently, and when it starts, it is a soft start. The maximum current does not exceed the rated working current and there is no energy waste.

At the same time, it also greatly reduces the impact on the power grid equipment, and will not cause damage to the electrical equipment. Air compressor brand A device used to compress gas.

Air compressors are similar in construction to water pumps. Most air compressors are reciprocating piston type, rotating blade or rotating screw.

The reasons for the excessive vibration of the screw air compressor in most of the following screw air compressor networks are analyzed as follows:

vibration after startup:

when the device is started, due to the large starting current of the device and the large instantaneous torque, the motor has a sense of displacement. During the starting process, passing through the surge zone is an unstable process., The vibration fluctuates obviously.

Taking a screw air compressor of a company as an example, due to the irregular start-up, the inlet guide vane and the scale position are often inconsistent during start-up, resulting in large start-up current, even obvious surge feeling, and large vibration after start-up. It's ready. Therefore, multiple starts will affect the service life of the compressor, requiring frequent shutdown and maintenance.

Frequent opening and parking will also have an impact on the vibration of the unit. Due to the considerable conditions do not allow, or the impact of mechanical failure, forced to open and stop many times a year, resulting in the rotor balance is destroyed. When parking, 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 time of start-stop, the impact wear of the gear shaft and the seal is very large. Although the seal and the shaft fit within an acceptable range, it will produce a large axial displacement, which will always cause wear of the seal and the shaft. Damage can reduce the smoothness of the seal or shaft surface, thereby increasing vibration and even damaging the equipment.

2. bearing impact:

in the past, two plain bearings were often used in screw compressors. Later, the screw air compressor sliding bearing was modified. On the basis of the original screw air compressor, the bearing bush was upgraded. Five tilt bushings were used. The amount of oil between the bushing, bushing and shaft increases. Although the lubrication and cooling performance has improved, the sealing performance does not exist. The original sliding bearing has good performance, but the vibration is small, and the mechanical efficiency is greatly improved, which has been recognized by the industry. The defect is that the bearing temperature and vibration detection equipment often drifts and bounces, and the readjustment only depends on experience and lacks standards, so that the daily monitoring fails and brings misjudgment to the operator.

the impact of 3. condensate:

condensed water with corrosive gases in the air causes severe corrosion of the rotor, air seal, diffuser and carbon steel air pipes, causing air vortex vibration. The erosion of the pipeline oxide causes the rotor balance to be destroyed and the vibration is so severe that it is forced to stop. This kind of accident has happened twice. The influence of condensed water, especially in humid weather, does not discharge the condensed water in time, or the water trap fails, resulting in the condensed water can not be discharged, so that the water is brought into the impeller. More vibration and damage to equipment.

Fourth, the difference in the alignment, the axial displacement causes the vibration value to rise:

the coupling between the cylinders transmits motion and torque. Due to the installation error of the device, thermal expansion under working conditions, deformation after loading and uneven settlement of the device foundation, the cylinder shaft may work between the devices. misplaced. Misalignment will result in axial and radial alternating forces, causing axial and radial vibrations, and will increase as the severity of the misalignment increases.