Common troubleshooting methods for screw air compressors

1. Analysis of the working principle of the screw air compressor

Before the air enters the screw air compressor, the dust and impurities in the atmosphere are filtered by the filter. Clean air reaches the compressor main unit through the intake control valve, and is fully mixed with cooling lubricating oil for compression. The oil-containing gas is compressed and discharged, and after a series of treatments, the compressed air with less oil content is obtained through the oil-gas fine separator. When the air is compressed to the specified pressure value, the compressed air is discharged to the cooler by the minimum pressure valve, and the cooled compressed air can be used.

During the suction process, the suction port on the intake side of the screw air compressor can ensure that the compression chamber has sufficient air intake. The air intake process mainly relies on the control of the regulating valve. When the rotor rotates, the amount of air absorbed is the largest. When the exhaust is completed, the tooth groove is in a vacuum state. During gas sealing and transportation, the teeth peaks of the main and auxiliary rotors form a sealed space with the casing to ensure that the air is sealed in the tooth grooves and cannot communicate with the outside world. Immediately afterwards, the two rotors continue to rotate, and the tooth grooves and tooth peaks match at the suction end, so that the gas is introduced into the exhaust end. In the process of compression and fuel injection, the distance between the tooth groove of the exhaust port and the tooth engagement surface becomes smaller and smaller, so that the pressure in the entire enclosed space is continuously reduced to ensure that the gas in the tooth groove is in a compressed state.

2. Causes and countermeasures of common failures of screw air compressors

2.1 The screw air compressor is difficult to start

When the screw air compressor has an electrical fault light on and cannot start, it is first necessary to check the fuse, motor, thermal relay and other equipment to ensure that these equipment are in a normal operating state. If there are problems or hidden dangers, it is necessary to take timely measures Relevant measures to replace these devices. Then check the pressure temperature sensor and the start button. If there is a disconnection or poor contact, it needs to be further repaired. In addition, to detect the controller program, if it is a program error, it is necessary to change the phase sequence of the power supply. Finally, check the body. If the body still cannot rotate with external force, you need to ask the manufacturer to deal with it directly.

2.2 The operating current value exceeds the normal range

When the operating current exceeds the normal range, the compressor will automatically trip. Therefore, it is necessary to check the transmission belt first. If the belt is too loose, it may cause idling, and the current sound is high. Tighten the belt to solve the problem. It is also possible to check the oil-gas separator to make sure that the lubricating oil used complies with the relevant regulations. Once the unqualified lubricating oil is used, it is easy to cause the oil-gas separator to malfunction and need to be replaced with a suitable lubricating oil. In addition, if the exhaust pressure value is high, you should also check the pressure setting of the controller, and adjust the pressure setting to make the interior within the normal pressure range. Finally, the failure of the compressor itself will also cause the current value to exceed the normal range, so it is necessary to check whether the compressor can operate normally.

2.3 The running current is low

The reasons for the low operating current fault are as follows: First, the air filter is clogged. This is due to the relatively poor air quality in the working environment of the air compressor, which makes the filter clogged. This phenomenon often occurs in the central and western regions where the pollution is serious and the air quality is relatively poor. Once clogging occurs, the filter should be cleaned in time. If the filter is used for a long time and it is difficult to clean it thoroughly, the filter needs to be replaced. The second is that the intake valve is not operating normally. This is because the operating environment of the intake valve interferes with its normal use. You can try to add lubricating oil to help the intake valve operate smoothly. In addition, improper adjustment of the capacity regulating valve will also cause the phenomenon of low operating current. This fault can be eliminated by adjusting or resetting the setting value of the capacity regulating valve. Fourth, the air consumption is too large, and it is necessary to coordinate the relationship between the intake and use of air to ensure that the air consumption is maintained within a stable range.

2.4 Exhaust temperature is too low

The normal exhaust temperature should be above 75°C, if it is lower than this temperature, it is likely to cause poor use of subsequent gas. This is because the external environment where the air compressor operates is likely to be in an environment with a large external temperature difference, and it cannot be guaranteed that the external ambient temperature is within a stable range. Therefore, when the exhaust gas temperature is low, it is necessary to reduce the cooling area of the cooler. If the heat dissipation area of the cooler is reduced but the temperature still does not rise to the normal range, it is necessary to check the exhaust temperature gauge to ensure its normal use. Finally, the thermal control valve can also be checked and replaced in time if there is a fault.

2.5 Exhaust temperature is too high

Due to changes in the external environment, there may be an excessively high ambient temperature, and it is easy to cause a failure of the exhaust gas temperature being too high. First of all, you need to check the cooling fan of the cooling system of the body itself to see if it can operate normally. In addition, it is also necessary to ensure that the air duct of the cooler is not blocked by foreign objects, and if there is a problem, it must be dredged in time. In addition, it is necessary to check the oil quantity and specifications of the lubricating oil. If the oil level of the lubricating oil is lower than the red line, it is necessary to refuel, and at the same time, it is necessary to ensure that the oil product is suitable. Excessive impurities in the air filter will also affect the temperature control of the exhaust. Generally speaking, the air filter is not clean and the oil filter is clogged more frequently. Finally, the thermal control valve should also be inspected.

2.6 High oil content in the air

When the oil content in the air is high, the cycle of lubricating oil addition becomes shorter, and the filter will emit smoke when there is no load. When such a failure occurs, the oil level of the lubricating oil should be checked first to ensure that the oil level is within a reasonable range. Secondly, it is necessary to ensure that the flow restriction hole of the oil return pipe is not blocked. If there is a blockage, the oil return pipe needs to be disassembled for cleaning. The failure of the oil-fine separator will also lead to a high oil content in the air, which requires the replacement of the oil-fine separator. Finally, it is necessary to check the exhaust pressure to ensure that it is within the specified range.

2.7 The screw air compressor cannot run at full load

First of all, the control pipeline should be checked, focusing on whether there is any leakage. Once there is a leak, the leak position needs to be locked to ensure that there are no gaps in the control pipeline. It is also necessary to check the volume control valve and replace it in time if there is a problem. When the pressure sensor does not work normally, it needs to be replaced. It is also necessary to check the intake valve. It can be said that lubricating grease is added to the intake valve to ensure its smooth operation. Finally, check the pressure maintenance valve. If there is a failure, you can first disassemble the valve seat, and confirm whether the check valve is worn. If it is worn, replace it in time.

Sollant Group-Professional Compressed Gas Solutions Provider