The replacement steps of the high-efficiency filter for the air shower transfer window

The replacement of the high-efficiency filter of the air shower transfer window must follow strict operating procedures to ensure that the clean environment is not contaminated. The following are the detailed replacement steps and precautions, applicable to most conventional models of air shower transfer Windows (it is recommended to consult the equipment manual or contact the manufacturer to confirm the details before operation) :
I. Preparations before Replacement
Personnel and environmental requirements
Personnel protection: When changing personnel, clean suits, masks, and gloves must be worn. If operating in a high-level clean area, air showers should be blown in advance to ensure personal cleanliness.
Environmental control
Close the air conditioning system (or purification unit) in the area where the transfer window is located to avoid pollution caused by airflow disturbance.
Lay clean plastic sheeting or dust-proof cloth in the replacement area to prevent dust from falling when the old filter is disassembled.
2. Preparation of tools and materials
Tools: Screwdriver, wrench (prepare according to the type of screws on the equipment), tape measure (for measuring the size of the old filter), flashlight (for lighting).
Materials:
High-efficiency filters of the same model (the size and filtration efficiency level need to be confirmed, such as H13 or H14 grade).
Sealant (such as silicone sealant), sealant strips (if the original strips age, they need to be replaced), alcohol cotton balls, and lint-free cloths.
Others: Garbage bags (for storing old filters), and differential pressure gauges (to test resistance after replacement).
3. Shutdown and power failure
Turn off the power supply of the transfer window, unplug the plug turn off the circuit breaker of the control box, and hang the "Under Maintenance" warning sign to prevent misoperation.
Second, disassemble the old high-efficiency filter.
Open the inspection opening of the equipment.
Locate the high-efficiency filter (usually under the maintenance cover plate at the top or side of the transfer window), remove the fixing screws with a screwdriver, and then take off the maintenance cover plate.
If there is sealant between the cover plate and the box body, it should be carefully cut open with a blade to avoid damaging the box body.
2. Remove the old filter-fixing device
Unfasten the fixing clips, bolts, or pressure strips of the old filter (different devices have different structures and may require the assistance of a wrench).
Pay close attention to the sealing method between the filter and the frame (such as liquid tank sealing or rubber strip sealing), and record the position and installation direction (high-efficiency filters usually have airflow direction markings, such as "→" pointing to the air outlet).
3. Remove the old filter
Hold both sides of the filter with both hands and take it out vertically and slowly to avoid tilting and colliding with the surrounding components (to prevent dust from falling).
If the filter has been in use for many years, there may be a risk of damage. Extra care should be taken during the operation. After taking it out, immediately put it in a garbage bag and seal it to prevent dust from spreading.
Check whether the filter frame is rusted or deformed, clean the old sealant or rubber strip residue on the surface of the frame, and wipe it clean with an alcoholic cotton ball.
Iii. Install new high-efficiency filters
Check the new filter.
Before opening the new filter packaging, make sure the outer packaging is intact and undamaged, and the label information (model, efficiency level, production date) is consistent with the equipment requirements.
After removing the packaging, check that the appearance of the filter is not damaged or deformed, the sealing rubber layer is not cracked, and the airflow direction is marked.
2. Install the filter
Gently place the new filter into the installation frame, ensuring that the airflow direction is consistent with the equipment marking (usually "→" points to the air supply direction inside the transfer window).
Adjust the position of the filter to ensure it fits tightly with the frame without any skew or gap.
3. Fixation and Sealing
Liquid tank sealing type:
If it is a liquid tank type high-efficiency filter, it is necessary to ensure that the edge of the filter is completely immersed in the sealed liquid tank of the frame (the liquid tank is pre-injected with sealant or inert liquid), and the liquid level height meets the manufacturer's requirements.
Rubber strip sealed type
Stick new sealing strips (or apply sealant) around the frame, ensuring that the strips are continuous without any breaks. Then, press the filter tightly with fixed clips or bolts, applying even force to avoid local pressure damage.
Note: During operation, avoid touching the surface of the filter material directly with your hands. If you need to adjust the position, hold the frame.
Iv. Restoration of Equipment and Inspection
1. Install the maintenance cover plate
Clean the edge of the inspection opening, stick new sealing strips (if the original strips are aged), then reset the inspection cover plate and tighten the fixing screws to ensure a good seal.
2. Check before starting up
Check that all components are installed properly and there are no tools or debris left in the equipment.
Restore the power connection and confirm that the control panel displays normally.
3. Run tests and inspections
Wind speed detection
Turn on the fan and operate the air shower mode. Use an anemometer to measure the air velocity at the air outlet (10-15cm away from the surface of the filter). The air velocity at each point should be uniform and meet the design requirements (usually ≥20m/s).
If the wind speed is too low, it might be that the filter is not sealed properly or the model does not match. A recheck is required.
Differential pressure detection
Check the differential pressure gauge built into the equipment and record the initial resistance value of the high-efficiency filter (refer to the standard value provided by the manufacturer). If the resistance exceeds the rated value (such as more than twice the initial resistance), reconfirm the installation or replace the filter.
Leakage detection (optional) :
If it is a high-grade clean area (such as ISO level 5 and above), a particle counter or aerosol photometer should be used for scanning and detection to ensure that there is no leakage at the edge of the filter and in the installation frame.
V. Finishing Work
Clean up the site
Remove the dust-proof cloth, put the old filter and waste into a special garbage bag, and dispose of them according to the contaminated waste treatment process.
Wipe the surface of the equipment with an alcoholic cotton ball to keep it clean.
Record and archive:
Record the replacement date, filter model, resistance value, test results, and other information in the "Maintenance Ledger", and sign to confirm.
Keep the certificates of conformity, test reports, and other documents of the new filter for inspection.
Restore the environment
Turn on the air conditioning system. Only after the air in the clean area has self-purified can the transfer window be used normally.
Vi. Precautions
Prohibited behavior:
It is strictly prohibited to operate without stopping the machine or cutting off the power to avoid electric shock or mechanical injury.
High-efficiency filters are precision components. They must not be subjected to heavy pressure, impact, or unauthorized modification.
Professional operation
If the equipment has a complex structure (such as laminar flow transfer Windows) or is being replaced for the first time, it is recommended to contact the manufacturer's technical personnel for on-site guidance to ensure the installation quality.
If leakage or abnormal wind speed is detected after replacement, the machine must be stopped immediately for inspection. Do not force its use.
Replacement cycle:
The replacement cycle of high-efficiency filters is usually 3 to 5 years (specifically determined based on the usage frequency, the amount of dust in the environment, and the data from the differential pressure gauge). If the resistance limit is frequently reached, the inspection frequency should be shortened.
Through standardized replacement procedures and inspections, the purification performance of the air shower transfer window can be ensured to be stable, maintaining the reliability of a clean environment. During the operation process, the principles of "dust prevention, sealing, and correct direction" must always be followed to avoid the introduction of contamination by humans.