How to maintain the liquid tank air supply outlet daily?

The liquid tank supply air outlet is an important component of the cleanroom ventilation system. Daily maintenance is crucial for ensuring the supply air efficiency, cleanliness, and service life of the equipment. The following are the daily maintenance points and operation suggestions for the liquid tank supply air outlet:
I. Daily Cleaning and maintenance
1. Surface cleaning
Frequency: At least once a week (frequency should be increased in severely polluted areas).
Operation method:
Wipe the dust on the surface of the air supply outlet frame and the diffuser plate with a dry or slightly damp lint-free cloth to prevent dust accumulation from affecting the appearance or entering the liquid tank.
If there are stubborn stains, you can wipe them with a neutral cleaner (such as an alcohol solution), and then wipe them clean with a damp cloth to ensure no cleaner remains.
Note: Avoid using rough tools such as steel wool balls and sandpaper to prevent scratching the surface coating.
2. Check the sealing performance of the liquid tank
Frequency: Once a month (or adjusted according to the usage frequency of the cleanroom).
Operation method:
Observe whether there are any cracks, bubbles, hardening, or peeling of the sealant in the liquid tank (usually silicone sealant or liquid tank sealant).
Check whether there is any air leakage at the joints between the liquid tank, the frame, and the filter (which can be detected by a smoke test or anemometer).
Handling measures: If the sealant is found to be ineffective, the old sealant should be removed in time and reapplied to ensure a tight seal.
Ii. Filter Maintenance
The liquid tank supply air outlet is usually used in conjunction with high-efficiency filters (HEPA/ULPA), and special attention should be paid to the condition of the filters:
1. Filter replacement cycle
Regular cycle: The primary filter should be replaced every 1 to 3 months, the medium filter every 3 to 6 months, and the high-efficiency filter should be replaced based on the pressure difference alarm or usage conditions (usually every 1 to 3 years).
The basis for judgment:
Monitor the pressure difference before and after the filter through a differential pressure gauge. When it exceeds the designed final resistance (for example, the final resistance of a high-efficiency filter is approximately twice the initial resistance), it needs to be replaced.
Observe the dust condition on the surface of the filter. If it is blackened or clogged, it needs to be replaced in advance.
2. Replace the key points of operation
Turn off the supply fan and ensure that the system stops and the power is cut off.
Disassemble the air supply outlet panel and the old filter in sequence. Be careful when handling them to avoid dust from spilling.
Before installing the new filter, clean the liquid tank and the frame to ensure there is no debris or residual sealant.
When installing the new filter, it should be closely attached to the liquid tank. Use a sealant to evenly fill the gaps and fix them firmly with pressure strips.
After the installation is completed, conduct a leak detection test (such as the PAO test) to ensure that there is no leakage at the connection between the filter and the liquid tank.
Iii. Inspection of Transmission Components and Fans
If the supply air outlet is equipped with an adjustable air valve, electric actuator, or fan (such as an FFU fan filter unit), regular maintenance is required:
1. Air valves and actuators
Check whether the blades of the air valve are flexible, without any jamming or deformation, and whether the screws at the connection points are loose.
The electric actuator needs to be tested to ensure its opening and closing functions are normal. Regularly lubricate the transmission components (such as gears and pins) to prevent rust and jamming.
2. Fan maintenance
For supply air outlets such as FFU that come with their fans, it is necessary to check whether there are any abnormal noises, vibrations, or overheating phenomena when the fans are in operation.
Regularly clean the dust at the air inlet of the fan to prevent the filter screen from clogging and affecting the air volume.
The fan bearings should be lubricated with oil once every six months (according to the recommended model by the manufacturer) to extend their service life.
Iv. Other Precautions
1. Environmental control
The clean room needs to maintain a constant temperature and humidity (such as a temperature of 20-24℃ and a humidity of 45%-65%) to prevent the accelerated aging of the liquid tank sealant due to drastic environmental changes.
Reduce frequent personnel entry and exit or severe airflow disturbance to prevent a large amount of dust from entering the supply air outlet.
2. Records and ledgers
Establish a maintenance record table, detailing the time, content, and consumable model of each cleaning, inspection, and replacement of parts, to facilitate the traceability and analysis of the equipment status.
Regularly (such as every quarter) summarize maintenance data, assess the performance trend of supply air outlets, and detect potential problems in advance (such as an abnormal increase in filter replacement frequency, which may indicate system leakage).
3. Operated by professionals
When it comes to the replacement of high-efficiency filters, the application of sealant, or the maintenance of fan circuits, it is recommended that they be carried out by trained professionals to avoid affecting the cleanroom grade due to improper operation.
V. Common Faults and Their Handling
Possible causes and handling methods for fault phenomena
Insufficient air supply, filter blockage, air valve not fully open. Replace the filter and check the air valve actuator
The air leakage sealant at the liquid tank has aged, and the filter is not installed tightly. Reapply the sealant and adjust the filter installation
Abnormal noise or shutdown of the fan, worn bearings, power failure. Lubricate the bearings or replace components, and check the circuit
Rust or corrosion on the surface is not cleaned in time. In a humid environment, enhance cleaning and improve ventilation and dehumidification
Through standardized daily maintenance, the stability of the liquid tank supply air outlet and the air quality of the clean room can be effectively improved, reducing the risk of production suspension caused by equipment failure. If the equipment is used frequently or in a highly polluted environment, it is recommended to shorten the maintenance cycle and increase the frequency of inspections.