How to deal with the water in the air compressor

Water accumulation inside the air compressor is a common problem, which is mainly formed by the condensation of water vapor in the air during the compression process. If it is not handled in time, it will cause equipment corrosion, lubricating oil emulsification, pneumatic component damage and other problems. The following is a systematic solution, covering cause analysis, treatment steps and preventive measures:

causes of 1. ponding

1. high air humidity when the ambient air humidity exceeds 70%, the water vapor content increases significantly, and it is easier to condense after compression.
2. Temperature rise during compression: The temperature rises when the air is compressed, but the water vapor reaches the dew point temperature and condenses during subsequent cooling.
3. Low cooling system efficiency: The cooler is blocked or the heat dissipation is poor, resulting in the compressed air temperature not falling below the dew point.
4. Failure of drainage device: Automatic drain valve is blocked, solenoid valve fails or manual drain is not performed on a scheduled basis.
5. Insufficient post-treatment equipment: No dryer is configured or the filter accuracy is insufficient to effectively remove moisture.

2. accumulated water treatment steps

1. Emergency drainage (immediate operation)

• manual drainage:
  • close the air compressor and release the pressure to the safe pressure (usually ≤ 0.1MPa).
  • Open the drain valve at the bottom of the gas storage tank, oil and gas separation tank, and cooler to drain the accumulated water (it is recommended to use a container for collection to avoid environmental pollution).
  • Check whether the drain valve is blocked. If it is blocked, remove and clean it (use wire to dredge or replace the valve core).
• Automatic Drain Valve Inspection:
  • confirm whether the solenoid valve is energized (listen to the action sound or observe the indicator light).
  • Check whether the drainage pipeline is bent or blocked to ensure smooth drainage.
  • If the automatic drain valve fails, temporarily change to manual drain, and replace the new valve as soon as possible.

2. System inspection and repair

• cooler cleaning:
  • remove the cooler end cover and reverse purge the fin gap with high-pressure air (≥ 0.6MPa) to remove dust and oil.
  • If the fins are deformed, special tools shall be used to correct or replace the cooler.
  • Check whether the cooling fan operates normally and whether the air volume is sufficient.
• Lubricating oil replacement:
  • accumulation of water can cause oil to emulsify (turn white or turbid) and require immediate replacement with new oil.
  • When replacing, clean the oil system (such as oil filter and oil separation core) to prevent the residual moisture from continuing to corrode.
• Pneumatic element inspection:
  • check the cylinder, solenoid valve, air pipe, etc. for corrosion or seizure.
  • Slightly rusted parts shall be sanded with sandpaper and then applied with anti-rust oil; seriously damaged parts shall be replaced.

3. Optimization of post-processing equipment

• dryer Configuration:
  • freeze dryer: Ensure that the refrigeration compressor works normally and the refrigerant pressure is within the specified range (usually R22 pressure is 0.4-0.6MPa).
  • adsorption dryer: Check whether the molecular sieve is invalid (if the outlet dew point is higher than -40 ℃, the molecular sieve needs to be replaced), and confirm that the regeneration gas circuit is unblocked.
  • Combined dryer: "Freezing + adsorption" two-stage drying is preferred to ensure the outlet air dew point ≤-70 ℃.
• Filter Upgrade:
  • A precision filter (such as 0.01μm accuracy) is installed after the dryer to further remove residual moisture and particulate matter.
  • Replace the filter element regularly (it is recommended to replace it every 2000 hours or when the pressure difference is ≥ 0.05MPa).

3. precautions (long-term maintenance)

1. Environmental control

• reduce intake humidity:
  • install an air filter (such as a paper filter or a degreasing filter) at the air inlet of the air compressor to filter large particles of impurities and some moisture.
  • If the ambient humidity is> 80% for a long time, an air inlet precooler (such as air-cooled or water-cooled) can be installed to reduce the inlet air temperature to 25-35 ℃.
• Room ventilation improvement:
  • ensure that the machine room is well ventilated and avoid high temperature and high humidity environment (recommended temperature ≤ 40 ℃ and humidity ≤ 70%).
  • If possible, install a dehumidifier or air conditioner to directly control the humidity in the room.

2. Regular maintenance plan

• drainage cycle setting:
  • manual drainage: at least once per shift (8 hours) and once every 2 hours in humid environment.
  • Automatic drain valve: check the action reliability once a week and clean the valve body once a month.
• Cooling system maintenance:
  • clean the cooler fins every 500 hours and change the coolant (if water-cooled) every 2000 hours.
  • Check the cooling fan belt tension to ensure that there is no slippage.
• Lubricant management:
  • regular inspection of oil quality (such as acid value, moisture content), every 4000-8000 hours to replace the new oil (specific according to the requirements of the manufacturer).
  • Avoid mixing different brands of lubricants to prevent performance degradation caused by chemical reactions.

3. Monitoring and alarm system

• dew point monitoring:
  • A dew point meter is installed at the outlet of the dryer to monitor the moisture content of the compressed air in real time.
  • Set the dew point alarm threshold (such as -40 ℃), and automatically stop or switch the standby dryer when it exceeds the limit.
• Differential pressure monitoring:
  • install a differential pressure gauge before and after the filter, and prompt to replace the filter element when the differential pressure is greater than or equal to 0.05MPa.
  • Record the trend of differential pressure and predict the risk of filter clogging in advance.

4. Case Reference

case 1: A food processing plant air compressor water problem

• question: The ambient humidity is 90%, and the processing capacity of the original refrigeration dryer is insufficient, resulting in serious water accumulation in the gas storage tank and affecting the cylinder operation of the packaging equipment.
• Solution:
  1. the inlet air precooler is installed to reduce the inlet air temperature from 45 ℃ to 30 ℃.
  2. Replace it with a combined dryer (freezing and adsorption), and the dew point of the outlet is reduced to -60°C.
  3. Increase the number of automatic drain valves (from 1 to 3) and connect to the centralized control system.
• Effect: The problem of water accumulation was completely solved, and the equipment failure rate was reduced by 80%.

Case 2: the problem of emulsified oil in screw air compressor of an automobile factory

• question: If the dryer is not configured, the lubricating oil is emulsified and the main engine bearing is damaged.
• Solution:
  1. add a freeze dryer, outlet dew point ≤-20 ℃.
  2. Replace all lubricating oil and clean the oil system.
  3. Drainage system for each class shall be formulated, and the responsibility shall be transferred to people.
• Effect: The life of the lubricating oil is extended to 6000 hours, and the bearing has not failed again.