How to choose the appropriate cleaning tools for the stainless steel surface of transfer Windows?

The daily maintenance of transfer Windows is the key to ensuring their clean performance and the service life of the equipment. Especially in scenarios with high environmental requirements such as medicine, food, and electronics, systematic maintenance should be carried out from multiple dimensions including structural inspection, functional testing, cleaning and disinfection, and component maintenance. The following are the specific maintenance points and operation norms:
I. Inspection of structural sealing performance
Maintenance of the door body and sealing strips
Inspection frequency: Visual inspection before daily use.
Key points of operation:
Observe whether the door body is flat when closed and whether the sealing strip is deformed or aged (such as hardened or cracked). The gap between the sealing surfaces should be ≤0.5mm.
If the sealing strip is worn and causes air leakage, it should be replaced in time (the preferred material is silicone rubber or ethylene propylene diene monomer rubber, which is resistant to aging and antibacterial).
Test method: Use a smoke tester to test at the door gap. If there is no smoke leakage, it is considered qualified.
2. Maintenance of box integrity
Check whether there is rust or cracking at the connection points of the box body plates (such as welding seams and bolt holes). If rust spots appear on the stainless steel surface (304/316L material is recommended), they need to be ground with special stainless steel polishing paste (particle size ≤1200 mesh) and then passivated.
Ii. Maintenance of Purification Function
Air filter maintenance
Primary filter
Take it out every week and blow it in the opposite direction from the clean side with compressed air (pressure ≤0.4MPa) to remove surface dust. Replace it when the cumulative use is 3 months or the resistance increases by 50%.
High-efficiency Filter (HEPA)
The particle concentration on the air surface should be detected by a dust particle counter every quarter (for particles ≥0.5μm, it should be ≤3520 per m³, that is, by ISO level 8 standard). If the resistance exceeds 150% of the initial value or after 2 years of use, it must be replaced.
Replacement precautions: After replacement, a scan for leakage detection is required (scanning speed ≤5cm/s), and the leakage rate should be less than 0.01%.
2. Fans and wind speed management
Use an anemometer to measure the air velocity at the air outlet (it is recommended to be 0.3-0.5m/s). If the air velocity drops by more than 10%, check whether the fan impeller is dusty or the belt is loose (for belt-driven types). If necessary, clean the impeller or adjust the tension.
Iii. Maintenance of Electrical and Control Systems
Interlock function test
Daily test the interlocking logic of the left and right doors: When one side door is opened, the other side door should not be able to be opened, and the control panel should display the "Door not Closed" alarm. If the interlock fails, check whether the limit switch (accuracy ±0.5mm) or the PLC program is abnormal.
2. Ultraviolet lamps and disinfection systems
The irradiation intensity of the ultraviolet lamp (with a wavelength of 254nm) is tested monthly with a radiometer. The intensity at a distance of 1m from the lamp tube should be ≥70μW/cm². When it is lower than this value, it should be replaced (the typical lifespan is 8000-10,000 hours).
Ozone disinfection-type transfer Windows need to have the efficiency of the ozone generator checked regularly (the concentration should be ≥20ppm). If the odor is obvious after disinfection, the ozone tube or activated carbon filter (to adsorb residual ozone) should be replaced.
Iv. Cleaning and Disinfection Standards
1. Daily cleaning process
Frequency: Clean immediately after each use and thoroughly disinfect once a day.
Cleaning agent selection:
General scenario: Wipe the surface with 75% ethanol or neutral detergent (pH 7-8), and avoid using chlorine-containing disinfectants (which are prone to corrode stainless steel).
In the medical field, a 0.1% benzalkonium chloride solution should be prepared with purified water for disinfection, and the action time should be ≥10 minutes.
Operation details: When wiping, clean in one direction along the stainless steel grain (brushed direction) to avoid scratches caused by back-and-forth friction. Use a dust-free cotton swab (made of lint-free cotton) to deeply clean the corners.
2. Deep disinfection plan
It should be disinfected with formaldehyde fumigation (concentration 3g/m³) or hydrogen peroxide dry mist (concentration 800ppm) every month. After disinfection, it needs to be ventilated for more than 2 hours. The residual concentration (formaldehyde ≤ 0.5 ppm) should be tested before use.
V. Maintenance of Key Components
Bearings and transmission components
For moving parts such as door shafts and pulleys, apply food-grade silicon-based grease (such as Dow Corning DC111) once every quarter. Avoid using mineral oil (which is prone to dust adsorption). After lubrication, wipe off the excess grease to prevent contamination.
2. Sensor maintenance
The infrared sensor (used for automatic door sensing) should have its surface wiped with a lint-free cloth every week to prevent dust from blocking it. Test the sensing distance (standard 0.5-1m). If it malfunctions, adjust the emission Angle or replace the sensor.
Vi. Maintenance Records and Anomaly Handling
1. Standardized record forms
Measures for handling abnormal measured values of the standard values of the maintenance project cycle
Clean the fan or replace the filter at a wind speed of 0.3-0.5m/s per month
The ultraviolet lamp intensity should be ≥70μW/cm² every month. Replace the lamp tube and record the usage time
The pressure difference of the box should be 5 to 10Pa every quarter (the side height of the clean area). Check the sealing strips or the air leakage points
2. Emergency fault handling
If problems such as the door being unable to close, abnormal noise from the fan, or malfunction of the disinfection system occur, immediately hang a "Fault Prohibited" sign and notify professional personnel for repair. After the repair, the cleanliness performance (such as dust particle detection and air tightness test) needs to be re-verified.
Vii. Enhanced Maintenance in Special Scenarios
High humidity environment
During the rainy season in the south, dehumidifiers should be added (with humidity control ≤ 50%RH), and moisture-proof heating strips should be installed at the bottom of the box (with a temperature setting of 40-50℃) to prevent stainless steel from rusting due to condensation water.
2. Flammable and explosive scenarios
The transfer Windows used in the chemical workshop need to have their explosion-proof certification marks (such as Ex d IIB T4) inspected regularly. The electrical components must meet the explosion-proof requirements. It is prohibited to use tools that produce sparks (such as ordinary wrenches) for maintenance.
Viii. Key Points for Operator Training
Sharp objects (such as tweezers and scissors, which need to be covered with protective sleeves) are prohibited from being placed inside the transfer window to avoid scratching the inner wall.
When transferring materials, the outer packaging should be cleaned first to prevent dust from being brought in. In the biomedicine scenario, materials need to be disinfected by ultraviolet light through the transfer window for more than 30 minutes.
Maintenance personnel need to wear clean suits (sterile suits are required in scenarios above Class 1000), and gloves need to be disinfected with 75% ethanol before operation.
Through the above systematic maintenance, the cleanliness efficiency retention rate of the transfer window can be increased to over 95%, the equipment life can be extended to 5-8 years, and at the same time, the risk of microbial contamination (such as floating bacteria ≤10CFU/m³ in the medical field) can be reduced.