The embedded transfer window, as a key device for controlling cross-contamination in clean environments, directly affects the purification effect and service life through its daily maintenance. Maintenance should revolve around the four core aspects of “cleaning, inspection, calibration, and replacement of consumables”, and formulate standardized procedures in combination with the equipment structure (interlock devices, purification systems, sealing components, etc.). The specific methods are as follows:
1. Daily basic cleaning: Keep the interior clean
Surface wiping
Use a lint-free cloth dipped in 75% medical alcohol or neutral detergent (such as a diluted solution of dishwashing liquid) to wipe the inner walls of transfer Windows, the inner sides of doors, shelves, and other surfaces to remove any remaining dust, stains, or liquid marks.
Pay special attention to cleaning the areas prone to dust accumulation, such as the ultraviolet lamp and the air outlet of the filter, to avoid obstruction and affect the function.
After cleaning, wipe it a second time with a lint-free cloth moistened with pure water or sterile water to remove any residue of cleaning agents (especially in the pharmaceutical and food industries).
Cleaning of the sealing rubber strip
Use a soft-bristled brush or lint-free cloth to clean the dust in the gaps of the rubber strips to prevent poor sealing. If there are stains on the surface of the rubber strip, you can gently wipe it with alcohol (avoid using corrosive solvents to prevent the rubber strip from aging).
Ii. Core Component Inspection: Ensure normal functionality
Interlock device inspection (Daily)
Test the interlocking function of the two side doors: Open one side door and observe whether the other side door is fully locked (cannot be pulled). After closing this side door, try to open the other side door and make sure it can be opened normally.
If the interlock fails (such as both doors can be opened simultaneously), it should be immediately stopped and repaired (possibly due to loose mechanical locks, electronic sensor malfunctions, etc.) to prevent cross-contamination of the air.
Ultraviolet lamp inspection (Weekly)
Observe whether the lamp tube is glowing normally (whether it lights up after startup). If the lamp tube turns black, flickers, or does not light up, it indicates that it has aged or been damaged and needs to be replaced in time. (The service life of ultraviolet lamps is usually 800 to 1000 hours. It is recommended to record the usage time.)
Check the interlock protection of the ultraviolet lamp: Open either side door and confirm whether the ultraviolet lamp goes out immediately to prevent personnel from being exposed to ultraviolet radiation.
High-efficiency filter (HEPA/ULPA) inspection (Monthly)
Observe whether there is obvious dust accumulation, damage, or deformation on the surface of the filter.
For the transfer window with a fan, check whether the fan is operating normally (whether there is any abnormal noise, whether the air volume has weakened). If the air volume drops significantly, it may be that the filter is clogged, and the resistance needs to be tested (through the differential pressure gauge). If it exceeds 1.5 times the initial resistance, it needs to be replaced.
Inspection of ozone generator (if available) (monthly)
Confirm whether the ozone concentration meets the standard (an ozone detector can be used). If the concentration is insufficient, it may be due to the aging of the generator or pipeline leakage, and maintenance or replacement is required.
Check whether the ozone degradation device (such as the activated carbon filter) is effective in preventing the leakage of residual ozone.
Iii. Consumable Replacement: Regularly update vulnerable parts
Ultraviolet lamp tube
Replace according to the usage time or luminous efficiency (it is recommended to replace every 6 to 12 months. Even if it can still emit light, the sterilization efficiency may have declined. When replacing, cut off the power supply and wear gloves (to avoid handprints contaminating the lamp tube and affecting the light transmission).
High-efficiency filter
Replace it based on the resistance monitoring results or the service life (usually 6 to 12 months, depending on the cleanliness of the environment). During replacement, the operation should be carried out in a clean environment to avoid the filter being exposed to contaminants. When installing, ensure that the sealing gasket is a good fit and there is no air leakage.
Sealing rubber strip
If the rubber strip is found to be aged (hardened, cracked, lost in elasticity), damaged or not sealed tightly (there is a gap after closing the door), it should be replaced in time with a rubber strip of the same specification (it is recommended to use silicone rubber material that is resistant to high and low temperatures and aging).
Ozone generator accessories
Ozone tubes, activated carbon filters, etc., should be replaced at the intervals recommended by the manufacturer to ensure disinfection effectiveness and safety.
Iv. Regular Calibration and Functional Testing (quarterly)
Timer calibration
Calibrate the timing devices for ultraviolet disinfection, fan operation, etc., to ensure that the set time is consistent with the actual operating time (for example, if 30 minutes of disinfection is set, the actual operating error should be ≤±1 minute).
Electrical safety inspection
Check if the power cord and plug are damaged and if the grounding is good (to prevent leakage). Use a multimeter to check the continuity of each electrical component (such as contactors and relays) to avoid short circuits or open circuits.
Cleanliness testing (High-demand scenarios)
For transferring Windows in industries such as pharmaceuticals and electronics, it is necessary to regularly (such as every quarter) entrust a third-party testing agency to use a particle counter to test the cleanliness inside the box (such as whether it meets ISO level 5) and verify the effect of the filter.
V. Handling of Special Circumstances
Sudden contamination: If the interior of the transfer window is contaminated by contaminants (such as liquid leakage or blood contamination), it should be thoroughly wiped immediately with a chlorine-containing disinfectant (such as 500mg/L chlorine-containing disinfectant solution). After 30 minutes of action, it should be cleaned with sterile water to prevent residue from corroding the equipment.
Long-term disuse: When the equipment is not in use for more than one week, the power supply should be turned off, the interior thoroughly cleaned, and kept dry. Before reactivating, a comprehensive check of the interlock and purification functions is required, and an empty disinfection program should be run once before use.
Summary
The core of maintaining the embedded transfer window is “prevention first”: reduce the accumulation of pollution through daily cleaning, ensure the normal function of key components through regular inspection, replace consumables in time to maintain purification efficiency, and at the same time, formulate personalized maintenance plans based on scene requirements (such as cleanliness level, disinfection method) (for example, hospitals focus on ultraviolet lamp and seal inspection, and the electronics industry focuses on filter resistance monitoring). Standardized maintenance not only extends the lifespan of equipment but also ensures the stability of a clean environment, avoiding the risk of cross-contamination caused by equipment failure.