Techniques for unclogging the air pump outlet blockage

The unblocking of the air pump outlet blockage should be carried out in combination with the type of blockage, equipment structure and safety regulations. It should be treated layer by layer through physical cleaning, pressure backflushing, chemical decomposition and other methods. At the same time, violent operation should be avoided to prevent secondary damage. The following are the systematic unblocking techniques and key implementation points:

First, rapid diagnosis of the cause of blockage

Foreign object blockage

Characteristics: There is no airflow at the air outlet at all, accompanied by abnormal vibration of the air pump or violent swinging of the pressure gauge pointer.

Common foreign substances: metal debris (in processing workshops), fiber fabrics (in textile factories), plastic particles (in injection molding conditions).

Example: In a certain auto repair shop, the air pump sucked in dust from the brake pads, causing the outlet filter screen to be completely clogged. The pressure dropped from 0.7MPa to 0.2MPa within 3 seconds.

Carbon deposits/sludge deposits

Characteristics: After long-term operation, the exhaust gas volume gradually decreases and the exhaust temperature rises (20 to 30 degrees Celsius higher than normal).

Formation mechanism: High-temperature cracking of lubricating oil + mixing of dust, forming a viscous deposit layer at the muffler or pipe elbow.

Data reference: After 800 hours of operation of a certain mine air pump, the outlet pipe diameter decreased by 40% due to the accumulation of oil sludge, resulting in a threeves increase in exhaust resistance.

Ice crystal blockage (low-temperature working conditions)

Characteristics: Sudden blockage occurs when the ambient temperature is ≤5℃, frost layer can be seen at the exhaust port, and the pressure fluctuates sharply after restart.

Formation conditions: Excessive moisture content in compressed air (dew point temperature > ambient temperature)+ lack of pipeline insulation.

Case: Due to a malfunction of the drain valve of the air pump in a certain cold storage at -15℃, a 3-cm-thick ice layer formed on the outlet pipe of the compressed air.

Second, the stratified unblocking technical solution

1. Physical cleaning method (applicable to foreign object blockage)

Tool selection:

Soft tools: Silicone gel cleaning rod (diameter ≤ 80% of the pipe diameter), nylon brush (to avoid scratching the inner wall).

Hard tools: Stainless steel spring unclogging tool (with barbs design), magnetic picker (for metal foreign objects).

Operation steps:

Power off and release the system pressure (key!) Avoid being injured by the backflow of high-pressure gas.

Disassemble the quick plug of the air outlet and use an endoscope to confirm the blockage location (if the pipeline is ≥5m, a guide pipe needs to be installed).

Slowly rotate and insert the unblocking tool. When encountering resistance, adopt the "forward - backward - rotate" cycle operation to avoid violent stabbing.

After cleaning, blow back with dry nitrogen at 0.3MPa for 30 seconds to remove the residual debris.

2. Pressure backflushing method (applicable to carbon deposits/sludge)

Equipment requirements:

Backflush pressure: 1.2 to 1.5 times the rated pressure of the air pump (if the rated pressure is 0.8MPa, the backflush pressure is set at 0.96 to 1.2MPa).

Backwash medium: Dry compressed air (dew point ≤-40℃) or nitrogen (purity ≥99.9%).

Implementation process:

Install a pressure relief valve downstream of the air outlet (with a set pressure of 110% of the backflush pressure).

Close the intake valve of the air pump and inflate it in the opposite direction from the exhaust end. Each time, continue for 5 to 8 seconds, with an interval of 2 minutes (to prevent the motor from overheating).

Accelerate the sediment stripping by combining mechanical vibration (gently tapping the pipeline with a rubber hammer), and repeat the operation 3 to 5 times.

Disassemble the muffler, rinse the filter screen with a high-pressure water gun (water pressure ≤10MPa), dry it with hot air at 40℃, and then reinstall it.

3. Chemical decomposition method (applicable to stubborn oil sludge)

Drug selection:

Alkaline cleaning agent: pH 12-13(such as sodium hydroxide solution, concentration ≤5%), suitable for mineral oil-based sludge.

Solvent-based cleaning agents: dichloromethane/trichloroethylene (operation required in a fume hood), suitable for residues of synthetic ester-based lubricating oils.

Operating Specifications:

Make the soaking fixture: Seal the blocked section of the pipe with PVC pipes and blind plates, and inject the cleaning solution until the liquid level is higher than the blocked position.

Soaking parameters: Soak in alkaline cleaning agent at 60℃ for 2 hours, and in solvent-based cleaning agent at room temperature for 4 hours.

Rinsing process: First, rinse with clean water until pH neutral, then neutralize the residual alkaline solution with 5% citric acid solution, and finally dry.

Safety Warning: Wear a gas mask and rubber gloves during operation. Open flames and static electricity are strictly prohibited.

Third, emergency response and preventive measures

1. Temporary unblocking techniques (Quick on-site recovery)

High-pressure airflow pulse method

The gas storage tank (with a pressure of ≥1.0MPa) is used to spray the blockage point through the pulse valve (with an opening time of 0.1 second per time), and the sediment is removed by the impact of pressure waves.

Case: When the air pump outlet of a certain cement plant was blocked, the exhaust volume was restored to 75% of the normal value through 10 pulse impacts.

Thermal expansion and contraction method

Locally heat the blocked section of the metal pipe (with a 200℃ hot air gun for 3 minutes), and suddenly introduce cold nitrogen at -20℃. Utilize the thermal stress to cause the oil sludge to crack and fall off.

Restrictions: Only applicable to seamless steel pipes. Prohibited for use in plastic/rubber pipes.

2. Long-term prevention plan

Intelligent monitoring

Install a differential pressure sensor (with a range of 0 to 0.5MPa) at the air outlet. When the differential pressure is ≥0.1MPa, trigger a three-level alarm (light/buzzer/shutdown).

Configure an automatic drain valve (with a drainage interval of ≤15 minutes) to reduce the moisture content of the compressed air to below 3g/m³.

Fourth, Risk Avoidance and Precautions

Safety red line

It is prohibited to disassemble the pipeline under pressure (operation is prohibited when the pressure is greater than 0.05MPa).

After chemical cleaning, the concentration of flammable gas should be detected with an explosion detector (LEL<10% before power is applied).

At least two people should work together during the unblocking operation, with one person operating and the other supervising.

Equipment protection

Avoid using steel tools to scratch aluminum alloy pipes (which can easily cause electrochemical corrosion).

The backwash pressure must not exceed 80% of the pipeline design pressure (parameters can be obtained by checking the equipment nameplate).

After unblocking, the safety valve needs to be recalibrated (with the lifting pressure error ≤±3%).

Through the above combination of technologies, rapid handling of over 90% of clogged scenarios can be achieved, reducing the average maintenance time from 8 hours to less than 2 hours. It is recommended to conduct an endoscopic inspection of the exhaust port once a month and establish a database of blockage components to provide data support for optimizing the maintenance strategy.