How To Troubleshoot Your Air Compressor on Frequent Loading and Unloading (Ⅱ)

In last news, Elang compressor analysed the main reasons of frequent loading and unloading on  your screw air compresosr system, below are the main solutions for solving this problem:

1. Handling methods for frequent loading and unloading caused by control reasons:

This kind of reason can be directly seen through the pressure display when the compressor is loaded and unloaded. If there is any change, it can be solved by online calibration or by removing the pressure sensor, checking in detail and reinstalling the pressure sensor to solve it. Of course, it is also common for the pressure sensor measurement pipeline to be blocked and cause measurement errors. The usual practice is to use compressed air to purge the sampling pipeline.

2. How to deal with frequent loading and unloading caused by system reasons:

The treatment of the system reason is more complicated, which can be judged by the difference between the compressor outlet pressure and the refrigerating dryer outlet pressure. If there is a difference or the difference is too large (generally the filter is less than or equal to 0.6bar, and the dryer is more than or equal to 0.2bar), it can be judged that the pipeline or equipment is blocked. Since there are many equipment in this pipeline, after long-term maintenance and observation, it is found that the equipment that are often blocked are:

1) Oil removal and water removal filters (the dust removal filter is located behind the air dryer, and the probability of blockage is generally small): including the filter element; the filter drain solenoid valve; the filter screen in front of the drain solenoid valve. Among them, the filter screen in front of the drain solenoid valve is most likely to be blocked, which can be solved by cleaning or replacement. The blowdown solenoid valve generally has the phenomenon of valve body jamming, coil burning, timer failure, etc., which can be solved by replacing it. In a factory, the ash removal compressor once occurred because the filter screen in front of the drain solenoid valve of the water removal filter was blocked, and the water drain could not be discharged in time. The sewage filled the filter and caused the compressor to be frequently loaded and unloaded. After the maintenance personnel cleaned the filter screen, it became normal;

2) The inlet switching valve of tower A and B of adsorption dryer. At present, many companies use adsorption dryers for post-processing of compressed air, and generally need to switch between A and B towers. If the switching valve is not switched in place, it can also cause the air flow to be blocked. If the inlet switching valves of the drying towers A and B of the suction dryer are of the pneumatic switch type, the failure of the pneumatic switch type valve generally occurs in the control air source and the valve body. Maintenance personnel can judge whether the control air source is normal by checking whether there is water in the filter pressure reducing valve or whether the air source pipeline is falling off; they can also manually operate the pneumatic valve to judge whether the valve body is flexible and whether the cylinder is tight. good. If the control air source with water blocks the filter pressure reducing valve, the compressor will be frequently loaded and unloaded due to the inability to control the switching valve. In view of this situation, the sampling point of the control air source can be changed to the outlet pipe of the suction dryer to solve the problem of water in the control air source;

3. The unstable air consumption leads to frequent loading and unloading processing:

In this case, the method of adding a air tank is generally adopted, or the volume of the original air tank is increased. If the installation of the air tank cannot meet the production needs, it is recommended to use the VSD compressor to replace the original power frequency compressor. In addition to solving the harm caused by frequent loading and unloading, the VSD compressor has other advantages:

(1) The air pressure is stable

Because the variable frequency screw compressor generally utilizes the stepless speed regulation feature of the frequency converter, it can start smoothly through the controller or the PID regulator inside the frequency converter; it can quickly adjust the response when the air consumption fluctuates greatly.

Compared with the upper and lower limit switch control of power frequency operation, the air pressure stability is exponentially improved.

(2) Start without impact

Since the frequency inverter itself contains the function of a soft starter, the maximum starting current is within 1.2 times of the rated current. Compared with the power frequency starting, which is generally 4 to 7 times the rated current, the starting impact is very small. This kind of impact is not only on the power grid, but also on the entire mechanical system, which is also greatly reduced.

(3) Variable air flow control

The power frequency air compressor can only work in one air delivery, and the VSD compressor can work in a relatively wide range of air delivery. The frequency inverter adjusts the motor speed in real time according to the actual air consumption to control the discharge air delivery.

When the air consumption is low, the compressor can be automatically sleep, which greatly reduces the loss of energy.

(4) The voltage adaptability of the AC power supply is better

The frequency inverter using overmodulation technology can still output enough torque to drive the motor when the AC power supply voltage is slightly lower; when the voltage is slightly higher, it will not cause the output voltage to the motor to be too high. For the occasion of self-generating, the variable frequency drive can better show its advantages.

(5) Low noise

Most of the working conditions of the frequency conversion system work below the rated speed, the mechanical noise and wear of the main motor are reduced, and the maintenance and service life are prolonged. If the fan is also driven by variable frequency, the noise of the compressor can be significantly reduced.

in conclusion, the maintenance of the air compressor is an objective requirement for the movement of the air compressor itself, and it is especially important for the air compressor. Only by insisting on regular inspection and timely replacement of relevant parts, can the normality of mechanical work be ensured, thereby ensuring the continuity and stability of enterprise production, and bringing higher benefits to the enterprise. Elang screw air compressors focus on the high quality products and continuous cooperation with our loyal agents and clients for win-win business, we can provide the turnkey projects, helping the local tender and projects and provide supporting for our loyal agents. Welcome to discuss cooperation with Elang compressor.