1. Running status monitoring
Pressure monitoring:
Install reliable pressure sensors to monitor intake and exhaust pressures in real-time. Ensure that the intake pressure is within the allowable range of the compressor design, and avoid affecting the normal operation of the compressor due to excessively high or low intake pressure. To prevent the exhaust pressure from exceeding the rated pressure of the compressor, a pressure alarm value is usually set, and an alarm is issued when the exhaust pressure approaches or exceeds 90% of the rated pressure.
Regularly check the accuracy of the pressure sensor, such as calibrating it once a month and comparing it with a standard pressure gauge. The error range should be controlled within ± 1%. At the same time, record pressure data and analyze the trend of pressure changes to determine whether there are potential problems with the compressor, such as a gradual increase in pressure, which may be a sign of pipeline blockage or valve failure.
Temperature monitoring:
Monitor the temperature of key parts of the compressor, such as the cylinder, crankcase, cooling system, etc. During operation, the cylinder temperature should generally not exceed 160 180 ℃ (depending on the type and operating conditions of the compressor), and the crankcase temperature should be below 70 80 ℃.
Using a combination of temperature sensors and thermometers for monitoring, check the temperature display value at least once a day. If an abnormal increase in temperature is detected, immediately stop the machine for inspection, as high temperatures may cause serious consequences such as lubricant failure, increased component wear, and even fire. At the same time, pay attention to checking the operating status of the cooling system to ensure good cooling effect.
Traffic monitoring:
Monitor the flow rate of nitrogen to ensure it meets the needs of industrial production. Set a reasonable flow range based on the nameplate parameters and actual application scenarios of the compressor. For variable flow compressors, check if the flow control device is working properly.
Flow meters can be used for flow monitoring, and they should be calibrated regularly (quarterly) to ensure the accuracy of flow measurement. Abnormal changes in flow rate may be a signal of internal faults in the compressor (such as leaks, valve damage) or external pipeline problems, and need to be promptly investigated.
Vibration and noise monitoring:
Pay attention to the vibration and noise of the compressor. During normal operation, the compressor should have a stable vibration level and low noise. If vibration intensifies or abnormal noise is detected, such as metal impact sound, friction sound, etc., it may be caused by loose, worn or unbalanced components.
Vibration sensors and noise meters can be used for monitoring, with a simple inspection conducted once a week. Compare the monitored vibration amplitude and noise decibel values with the normal operating standards of the equipment. If they exceed the standard range, stop the machine for maintenance in a timely manner to avoid further damage to the equipment.
2. Maintenance of lubrication system
Lubricating oil inspection and replacement:
Regularly check the oil level of the lubricating oil to ensure that it is within the specified range. Low oil level can lead to insufficient lubrication and accelerate component wear; High oil level may cause oil temperature rise, foam increase and other problems. Check the oil level before starting the compressor every day and observe whether the oil level meets the requirements through the oil level gauge.
Regularly replace lubricating oil according to the operating time and working environment of the compressor. Generally, the lubricating oil should be replaced after 2000 to 3000 hours of operation. But if the working environment is harsh (such as high temperature, high humidity, high dust), the replacement cycle should be appropriately shortened. When replacing lubricating oil, thoroughly drain the old oil, clean the oil chamber and oil filter, and then add new lubricating oil that meets the specifications of the compressor.
Oil quality inspection:
Regularly (every 3 to 6 months) inspect the quality of lubricating oil, including viscosity, acid value, moisture, impurity content, and other indicators. Viscosity that does not meet the requirements will affect the lubrication effect. An increase in acid value may lead to increased corrosiveness of the lubricating oil to the components. Excessive moisture and impurities will accelerate the deterioration of the lubricating oil and wear of the components.
Use professional oil quality testing equipment or send samples to a professional laboratory for testing. If the oil quality index exceeds the specified range, replace the lubricating oil in a timely manner and inspect the compressor to find the cause of the deterioration of the oil quality, such as whether there are leaks, cooling system failures, etc.
3. Maintenance of cooling system
Maintenance of air cooling system:
For air-cooled compressors, regularly clean the dust, debris, etc. on the surface of the radiator to ensure good ventilation and heat dissipation. Compressed air can be used to blow off or a soft bristled brush can be used to clean the surface of the radiator, at least once a month.
Check the operation of the fan, including the fan speed, whether the blades are loose or damaged, etc. Abnormal fan speed can affect cooling efficiency, and blade damage may cause vibration and noise. If any problems are found with the fan, repair or replace it promptly.
Water cooling system maintenance:
Water cooled compressors should regularly check the water level, quality, and flow rate of the cooling water. Low water level will affect the cooling effect, and cooling water should be replenished in a timely manner; Poor water quality can lead to scaling and corrosion of cooling water pipelines. Generally, water quality indicators such as hardness and acidity should be checked once a week, and softening or purification treatment should be carried out if necessary.
Check the operating status of the cooling water pump, including pump pressure, flow rate, sealing condition, etc. Check the operation of the water pump once a month to ensure that it is functioning properly and providing sufficient cooling water flow. At the same time, regularly (annually) clean and maintain the cooling water pipeline to prevent blockages and leaks.
4. Component inspection and fastening
Valve inspection:
Regularly check the working status of the intake and exhaust valves, including whether the opening and closing actions of the valves are flexible, and whether the sealing is good. It is possible to preliminarily determine whether the valve is normal by listening to sound, touching temperature, and other methods. For example, a normally functioning exhaust valve should be quiet when closed, and the exhaust port temperature should be relatively stable.
Disassemble the valve every 3 to 6 months for detailed inspection, clean the carbon deposits, impurities, etc. inside the valve, check the wear of the valve sealing surface, and if necessary, grind or replace the seals. At the same time, check whether the spring, valve core and other components of the valve are damaged or deformed.
Tightening of connecting components:
Check if the connecting flanges, bolts, and other components between the compressor and the pipeline are loose. Use a wrench to perform a simple inspection and tightening of the connecting bolts every week to ensure a tight connection and prevent leakage.
Check the connection of internal components of the compressor, such as the connection between the piston and connecting rod, and the connection between the connecting rod and crankshaft, for firmness. Conduct a comprehensive internal inspection every six months, tighten loose components, and replace worn connectors.
5. Maintenance of intake and exhaust systems
Air intake filtration:
Regularly clean or replace the intake filter to ensure that the nitrogen entering the compressor is clean. Blockage of the intake filter can lead to a decrease in intake volume and pressure, affecting the performance of the compressor. According to the degree of pollution in the work environment, clean the filter once a week or a month, and replace the filter element every 36 months.
Check the intake duct for leaks, deformations, and other issues. If any problems are found in the intake pipe, repair or replace it in a timely manner, as the failure of the intake pipe will affect the quality of nitrogen supply and the intake efficiency of the compressor.
Exhaust system inspection:
Check the pressure, temperature, and sealing of the exhaust pipe. Ensure that the exhaust pipe can withstand the exhaust pressure without any leakage. If the exhaust pipe temperature is too high, it may be caused by excessive internal resistance or cooling system failure.
For equipment such as gas storage tanks in the exhaust system, regular drainage and cleaning should be carried out. The accumulation of moisture in the gas storage tank can cause corrosion and affect the quality of nitrogen gas. Drainage should be carried out at least once a month, and internal inspection and cleaning should be conducted once a year.
1. Comprehensive cleaning
External cleaning:
Regularly (every 3 to 6 months) clean the exterior of the compressor to remove dust, oil stains, and debris from the surface. Use a clean soft cloth or brush to wipe the compressor housing. For stubborn oil stains, appropriate cleaning agents can be used, but avoid the cleaning agents from entering the interior of the compressor.
Clean the radiator (for air-cooled compressors) to ensure that there is no blockage between its fins caused by dust, cotton, or other debris. Compressed air can be used to blow the heat sink in the opposite direction to remove dust and other impurities from the radiator.
Internal cleaning:
Clean the interior of the compressor under the guidance of professional personnel every 12 years. This includes cleaning carbon deposits, oil sludge, and metal debris inside components such as cylinders, pistons, and crankcases. For example, using specialized cleaning solvents and tools, after removing the piston from the cylinder, clean the carbon deposits on the surface of the piston and the inner wall of the cylinder.
Clean the interior of the intake and exhaust valves, remove dirt and carbon deposits on the valves to ensure their normal opening and closing actions. During the cleaning process, pay attention to checking whether the sealing surface of the valve is damaged.
2. Inspection and replacement of key components
Inspection and replacement of pistons and piston rings:
Check the wear of the piston every 3000 to 5000 hours of operation, including the wear of the piston skirt and piston head. If the wear of the piston exceeds the specified limit (usually the wear of the piston diameter does not exceed 0.30.5mm), the piston should be replaced.
Check the wear, elasticity, and opening clearance of the piston ring. An increase in the clearance between the piston ring openings, a decrease in elasticity, or severe surface wear can all lead to air leakage. Usually, when the opening clearance of the piston ring exceeds 50% or 80% of the initial clearance, it is necessary to replace the piston ring.
Packing box inspection and replacement:
For compressors with packing boxes (such as piston rod seals), check the packing rings inside the packing boxes every 2000 to 3000 hours. Check the wear condition of the packing ring, whether there is eccentric wear, and the sealing effect.
If the packing ring is severely worn, aged, or has decreased sealing performance, it should be replaced. When replacing, pay attention to the correct installation sequence and adjustment of pre tightening force to ensure good sealing effect.
Valve inspection and replacement:
The intake valve and exhaust valve are critical components that require a comprehensive inspection every 2000 to 3000 hours of operation. Check for scratches, wear, or corrosion on the sealing surface of the valve, deformation or reduced elasticity of the valve spring, and proper movement of the valve core.
If the valve sealing surface is severely damaged, the spring fails, or the valve core movement is obstructed, the valve should be replaced. After replacement, a sealing test should be conducted to ensure that the valve can effectively prevent gas leakage when closed.
Bearing inspection and replacement:
Check the bearings of the compressor (including the main bearings and connecting rod bearings) every 4000 to 6000 hours of operation. Check the wear condition of the bearings, whether the clearance is within the specified range, and the lubrication condition.
If the bearing shows wear, discoloration due to overheating (such as blue or black on the surface of the bearing ball or raceway), excessive clearance, etc., the bearing should be replaced. When replacing bearings, ensure that the model and accuracy of the new bearings meet the requirements, and pay attention to cleanliness and correct installation methods during the installation process.
3. Electrical system inspection
Motor inspection:
Regularly (every 3 to 6 months) inspect the appearance of the motor for signs of dust accumulation, damage, or corrosion. Clean the dust on the surface of the motor, especially the heat sink part of the motor, to ensure good heat dissipation.
Check the insulation resistance of the motor and measure it every 12 years using an insulation resistance meter. The insulation resistance value should meet the requirements of the motor nameplate, generally not less than 0.5 1 megaohms. If the insulation resistance is too low, check the insulation condition of the motor, identify the cause of insulation damage, and repair it.
Check if the wiring terminals of the motor are loose or oxidized. If loose or oxidized wiring terminals are found, they should be tightened and cleaned in a timely manner to ensure good electrical connection of the motor.
Control circuit inspection:
Check the control circuit of the compressor, including start, stop, pressure control, temperature control, and other circuits. Check if there is any damage, aging, short circuit or open circuit in the circuit.
Perform insulation testing on the control circuit every 12 years to ensure good insulation performance of the circuit. At the same time, check the working status of electrical components such as relays, contactors, and sensors in the control circuit, and replace them in a timely manner if there are any faults.
4. Inspection and maintenance of pipeline system
Pipeline appearance inspection:
Regularly (every 3 to 6 months) inspect the appearance of the compressor inlet and outlet pipelines, as well as the connecting pipelines. Check for signs of corrosion, deformation, cracking, or leakage in the pipeline. For pipelines with insulation layers, check if the insulation layer is intact and repair it promptly if it is damaged.
Pay special attention to the welds, flange connections, and bends of the pipeline, as these areas are more prone to problems. For minor corrosion, anti-corrosion treatment can be carried out, such as applying anti-corrosion paint; For pipelines with cracks or severe deformation, they should be replaced in a timely manner.
Internal inspection of pipelines (depending on the situation):
Inspect the interior of the pipeline every 3 to 5 years based on its service life and working environment. An endoscope or disassembly of the pipeline can be used for inspection to see if there is scale, corrosion, or foreign object blockage inside the pipeline.
If scale is found inside the pipeline, chemical cleaning or mechanical cleaning methods can be used for cleaning; For severely blocked pipelines, new pipelines need to be replaced.
Stress testing:
Conduct a pressure test on the pipeline system every 12 years to check its pressure resistance performance. The test pressure is generally 1.1 to 1.25 times the design pressure of the pipeline, and the holding time is not less than 30 minutes. During the pressure testing process, carefully inspect the pipeline for any leaks. If any leaks are found, promptly locate the leak point and repair it.
5. Maintenance and upgrade of cooling system (if necessary)
Water cooling system upgrade:
For water-cooled compressors, the cooling system should be upgraded every 35 years based on the water quality and scaling degree of the cooling water. For example, replacing high-performance water softening equipment or installing more efficient cooling water pumps.
Check if the material of the cooling water pipeline needs to be replaced, such as replacing it from ordinary steel pipe to stainless steel pipe, to improve its corrosion resistance. At the same time, optimize the pipeline connection method of the cooling system to reduce the possibility of leakage.
Air cooling system upgrade:
If the heat dissipation effect of the air-cooled compressor is poor, upgrading the radiator can be considered. For example, replacing the radiator with a larger heat dissipation area and higher heat dissipation efficiency. At the same time, check the performance of the fan, such as replacing the ordinary fan with a variable speed fan, automatically adjusting the fan speed according to the operating temperature of the compressor, and improving the cooling effect.
