Twin-screw compressorsare widely used in various industrial applications due to their high efficiency and reliability. However, to ensure their stable operation and prolong their service life, regular maintenance and proper repair are essential. This article will elaborate on the specific steps and methods for the maintenance and repair oftwin-screw compressorsin detail.
1. Adjustment of the Pressure Regulator of the Air Compressor
The unloading pressure of the air compressor can be adjusted using the upper regulating bolt. When the bolt is rotated clockwise, the unloading pressure increases, and when rotated counterclockwise, the unloading pressure decreases. It is crucial to adjust the unloading pressure accurately according to the actual working requirements of the compressor. An inappropriate unloading pressure can lead to inefficient operation, increased energy consumption, and potential damage to the compressor components.
Before making any adjustments, it is necessary to understand the normal operating pressure range of the compressor and the specific requirements of the production process. During the adjustment process, monitor the pressure gauge carefully to ensure that the pressure is adjusted to the desired value. After the adjustment, test the compressor to confirm that it operates stably under the new pressure setting.
2. Maintenance of the Air Filter
The air filter plays a vital role in preventing dust and other contaminants in the inhaled air from entering the compressor. This helps to avoid premature wear of the compressor and blockage of the oil separator. Generally, the filter element should be replaced after the compressor has been in operation for 1000 hours or once a year. In areas with a high dust concentration, the replacement interval should be shortened accordingly.
When maintaining the air filter, the compressor must be shut down to ensure the safety of the maintenance personnel. To reduce the downtime, it is recommended to replace the filter element with a new or cleaned spare one.
Cleaning Steps of the Filter Element
Knocking: Lightly tap the two end faces of the filter element alternately against a flat surface to remove most of the heavy and dry dust and sand. This step helps to loosen the larger particles of dust attached to the filter element.
Blowing with Compressed Air: Use dry air with a pressure of less than 0.28 MPa to blow in the direction opposite to the inhaled air. Keep the nozzle at a distance of at least 25 millimeters from the folded paper and blow up and down along its length. This process can effectively remove the remaining dust particles that are difficult to remove by knocking.
Washing (if there is grease): If there is grease on the filter element, it should be washed in warm water with a foam-free detergent. Immerse the filter element in the warm water for at least 15 minutes and then rinse it with clean water from a hose. Do not use heating methods to accelerate drying, as this may damage the filter element. A filter element can be washed up to 5 times, after which it should be discarded and replaced with a new one.
Inspection: Place a light inside the filter element for inspection. If the filter element is found to be thinned, have pinholes, or other damages, it should be discarded immediately, as a damaged filter element will not be able to effectively filter the air.
3. Maintenance of the Cooler
Both the inner and outer surfaces of the cooler tubes need to be kept absolutely clean. Otherwise, the cooling effect of the cooler will be reduced, which can lead to an increase in the operating temperature of the compressor and affect its performance and service life. According to the working conditions, the cooler should be cleaned regularly.
The cleaning method of the cooler may vary depending on the type of dirt and the structure of the cooler. For example, if the dirt is mainly dust and debris, it can be cleaned with compressed air or a brush. If there is scale or other stubborn dirt, a special cleaning agent may be required. When using a cleaning agent, follow the instructions carefully to ensure that it does not damage the cooler tubes.
After cleaning, it is necessary to check the cooler for any damage or leakage. If any problems are found, they should be repaired or replaced immediately to ensure the normal operation of the cooler.
4. Maintenance of the Air Receiver/Tank and Oil-Gas Separator
The air receiver/tank and oil-gas separator are manufactured and accepted according to the standards of pressure vessels and should not be modified arbitrarily. These components are crucial for the safe and stable operation of the compressor system.
Regular inspections should be carried out on the air receiver/tank and oil-gas separator to check for any signs of corrosion, leakage, or damage. Pay attention to the pressure gauge, safety valve, and other accessories on the air receiver/tank to ensure that they are in good working condition. If any problems are found, they should be dealt with in a timely manner to avoid potential safety hazards.
5. Maintenance and Inspection of the Safety Valve
The safety valve installed on the air receiver/tank or oil-gas separator should be inspected at least once a year. The adjustment of the safety valve should be carried out by professional personnel. At least once every three months, pull the lever of the safety valve to open and close it once to ensure that the safety valve can work properly.
Inspection Steps of the Safety Valve
Close the Gas Supply Valve: This step cuts off the gas supply to the system to ensure safety during the inspection process.
Connect the Water Source: In some cases, water may be required for the inspection or testing of the safety valve.
Start the Unit: Start the compressor unit to build up pressure in the system.
Observe the Working Pressure: Slowly rotate the pressure regulator adjustment bolt clockwise. When the pressure reaches the specified value, check whether the safety valve opens. If the safety valve does not open when the pressure reaches the specified value or opens before reaching the specified value, it is necessary to adjust it.
Adjustment Steps of the Safety Valve
Remove the Cap and Lead Seal: These components need to be removed to access the adjustment parts of the safety valve.
Adjust the Valve Opening Time: If the valve opens too early, loosen the lock nut and tighten the positioning bolt by half a turn. If the valve opens too late, loosen the lock nut by about one turn and loosen the positioning bolt by half a turn. This adjustment is aimed at making the safety valve open at the correct pressure value.
Repeat the Detection Steps: After the adjustment, repeat the inspection steps to ensure that the safety valve can open at the specified pressure value. If it still cannot open at the specified pressure, further adjustment is required.
6. Test of the Digital Thermometer
The test method for the digital thermometer is to place its thermocouple together with a reliable thermometer in an oil bath. If the temperature deviation is greater than or equal to ±5%, the thermometer should be replaced. A reliable thermometer is crucial for accurately monitoring the operating temperature of the compressor, which helps to prevent overheating and potential damage to the compressor components.
When conducting the test, ensure that the oil bath is at a stable temperature and that the thermometers are properly placed in the oil bath. After the test, record the test results and replace the thermometer if necessary.
7. Maintenance of the Motor Overload Relay
Under normal circumstances, the contacts of the motor overload relay should be closed. When the current exceeds the rated value, the contacts will open and cut off the power supply to the motor. This is an important protective device for the motor, which can prevent the motor from being damaged due to overloading.
Regularly inspect the motor overload relay to check the condition of the contacts. If the contacts are found to be damaged or have poor contact, they should be replaced or repaired immediately. In addition, check the setting value of the overload relay to ensure that it is consistent with the rated current of the motor.
8. Lubrication System Maintenance
The lubrication system of the twin-screw compressor is essential for reducing friction and wear between the moving parts. Regularly check the oil level in the lubrication system to ensure that it is within the normal range. If the oil level is too low, add the appropriate lubricating oil in a timely manner.
Also, pay attention to the quality of the lubricating oil. Over time, the lubricating oil may deteriorate due to factors such as heat, oxidation, and contamination. Regularly replace the lubricating oil according to the manufacturer’s recommendations to ensure its lubricating performance.
When replacing the lubricating oil, it is necessary to clean the lubrication system thoroughly to remove any impurities or sludge. This can help to improve the efficiency of the lubrication system and prolong the service life of the compressor.
9. Belt and Coupling Maintenance
If the twin-screw compressor is equipped with a belt drive system, regularly check the tension of the belt. A loose belt can cause slippage, resulting in reduced efficiency and potential damage to the belt. Adjust the belt tension according to the manufacturer’s instructions.
For the coupling, check for any signs of wear, looseness, or misalignment. A misaligned coupling can cause vibration and noise, which can affect the normal operation of the compressor and may even lead to damage to the compressor and the driven equipment. If any problems are found with the coupling, they should be repaired or replaced immediately.
10. Electrical System Maintenance
The electrical system of the twin-screw compressor includes components such as motors, control panels, and wiring. Regularly inspect the electrical system to check for any loose connections, damaged wires, or abnormal electrical components.
Tighten any loose connections to ensure a reliable electrical connection. Replace any damaged wires or electrical components to prevent electrical failures or safety hazards. In addition, check the insulation resistance of the electrical system to ensure that it meets the safety requirements.
In conclusion, proper maintenance and repair oftwin-screw compressorsrequire attention to various aspects, from the adjustment of the pressure regulator to the maintenance of the electrical system. By following the above steps and methods and carrying out regular inspections and maintenance, the stable operation and long service life of the twin-screw compressor can be ensured, reducing the occurrence of failures and minimizing production losses. If you are not familiar with the maintenance and repair operations, it is recommended to consult professional technicians or refer to the manufacturer’s instructions.
