How to install an automatic double-door air shower correctly?

When installing the automatic double-door air shower, it is necessary to strictly follow the procedures to ensure that the site is well-matched, the installation accurate, and the functions meet the standards, so as to avoid contamination of the clean area or equipment failure due to improper operation. The following are the detailed installation steps and key points:
I. Preparations before installation
1. Confirmation of venue conditions
Space requirements:
At least 50cm of maintenance space should be reserved around the goods shower room, and 20-30cm should be reserved at the top for filter replacement. If it is a ceiling installation, it is necessary to ensure that the ceiling load-bearing capacity is ≥200kg (the weight of the equipment and the filter).
The ground flatness error is ≤2mm/m. It is recommended to measure it with a level. For uneven areas, metal gaskets or cement should be used to level them (the thickness of the gasket should be ≤5mm).
Power supply and gas source:
Connect to a 380V three-phase five-wire power supply (independent circuit). The distance between the distribution box and the equipment should be no more than 3m. The live wire (L1/L2/L3), neutral wire (N), and ground wire (PE) should be marked.
If the equipment includes a pneumatic door (optional configuration), it needs to be connected to compressed air at 0.4-0.6MPa, with a pipe diameter of φ8mm. The interface must be leak-proof.
Environmental adaptation
In damp environments, drainage channels (with a slope of ≥5°) should be pre-buried on the ground, and the bottom of the equipment should be at least 10cm above the ground to prevent water accumulation and corrosion.
The explosion-proof area needs to inform the supplier in advance to install explosion-proof fans and electrical control boxes (explosion-proof grade Ex d IIC T6).
2. Unbox inspection of the equipment
Appearance acceptance:
Check whether there are any scratches or deformations on the surface of the box and whether the coating of the stainless steel plate (304/316L) is uniform. The weld seams should be smooth without burrs (check by touch).
Check the list of accessories: whether the high-efficiency filter, fan, control box, nozzle, sealing strip, expansion bolt, etc. are complete (with the accessory list provided by the supplier attached).
Performance test
Power on to test the functions of the control box panel (such as the setting of air shower time and the response of the emergency stop button). When the fan is idling, the noise should be ≤75dB (A) (measured with a noise meter).
Ii. Core Installation Steps
1. Position and fix the base
Layout and positioning
Mark the outline of the material shower room on the ground according to the drawing, ensuring that the centerlines of the front and rear doors are perpendicular to the clean area passage (with an error of ≤1°). A laser marking instrument can be used for assistance.
Base installation:
Place the base frame (usually a stainless steel square tube) within the positioning line, adjust the levelness with a level (with the bubble centered), and fix it to the ground with expansion bolts (M10×100mm), with the bolt spacing ≤50cm.
The gap between the base and the ground is filled with food-grade sealant (such as silicone sealant) to prevent dust from seeping in.
2. Box assembly and sealing
Modular assembly
Assemble in the order of "base → side plate → top plate → rear plate → front plate". Each plate should be fixed with M6 stainless steel bolts (spacing ≤30cm), and the bolt holes need to be pre-coated with sealant (thickness ≥1mm).
Case: A certain pharmaceutical factory had an air leakage rate of 3% due to uneven application of sealant at the side panel splicing area, and the number of dust particles in the clean area exceeded the standard, increasing the rework cost by 20,000 yuan.
Door gap treatment:
When installing the double door frame, ensure that the door gap is uniform (with an error of no more than 1mm in the up, down, left, and right directions). Add EPDM sealing strips (with compression of no less than 30%) between the door frame and the box body. When closing the door, the strips must be fully adhered to.
3. Installation of fans and filters
Fan hoisting
Fix the centrifugal fan (with a shock-absorbing pad) to the top plate bracket. The interface between the fan outlet and the air duct should be connected with a sealing canvas (to prevent air leakage). The gap between the fan impeller and the casing should be ≥5mm (to avoid abnormal friction noise).
Installation of high-efficiency filters
Before opening the filter, the installation frame should be wiped with alcohol. The filter and the frame should be sealed with a liquid tank or a knife frame (the liquid tank seal needs to be injected with silicone sealant, with a height of ≥20mm).
When installing, hold the filter frame by hand to avoid touching the filter material. At the interface between the filter and the air duct, use an air volume regulating valve to adjust the air velocity (target 25-30m/s).
4. Wiring of electrical and control systems
Line layout:
Power lines and signal lines should be threaded through metal corrugated pipes (explosion-proof pipes should be used in explosion-proof areas) and introduced into the control box through the bottom wire entry holes of the equipment. Cables of different voltages (such as 220V and 24V) should be laid separately, with a spacing of ≥5cm.
Control logic debugging
Set up a double-door interlock program: Front door opens → Rear door locks → Goods enter → Door closes → Air shower starts → air shower is completed → Rear door opens. The test response time is ≤1 second.
Install infrared sensors (2 sets each for the front and rear doors) to ensure that the air shower system automatically starts when the goods are blocked, leaving no blind spots (the sensing range can be tested by simulating the goods with cardboard).
Iii. Sealing and Cleaning Treatment
1. Overall sealing test
Smoke test
Light the smoke generator inside the goods shower chamber and observe whether there is any smoke leakage at the door gaps and the joints of the boards. The leakage points should be marked and then reapplied with sealant (it is recommended to use fluorescent sealant for easy detection by ultraviolet lamps).
Air volume test
Measure the total air volume at the air outlet with an air volume hood. The standard value should be ≥ 95% of the design value (for example, the designed air volume is 2000m³/h, and the measured value should be ≥1900m³/h). Otherwise, the air velocity may be insufficient due to air leakage.
2. Protection in clean areas
Internal cleaning
After installation, wipe the inner walls, floor, and door body with deionized water and a lint-free cloth. Do not use ordinary clothes (which are prone to shedding fibers). Finally, spray and disinfect with 75% alcohol.
Dust-proof treatment:
Dust-proof floor MATS should be laid within a 2-meter radius around the equipment. Non-construction personnel are prohibited from entering within 24 hours after installation to avoid secondary pollution.
Iv. Commissioning and Acceptance Standards
1. Functional test checklist
The test item standards require testing tools
Spray air velocity: 25-30m/s (deviation of each nozzle ≤±10%) Anemometer (accuracy ±0.5m/s)
The error between the set value of the air shower time control and the actual operating time is ≤±2 seconds on the stopwatch
The dual-door interlock response: The time from the front door opening to the rear door locking is ≤1 second for the oscilloscope
The noise value of the equipment at 1 meter is ≤75dB (A) noise meter
Filter leakage rate scanning test: Leakage point ≤0.01% (@0.3μm particles) particle counter
2. Operation and debugging steps
No-load trial operation
Operate continuously for 8 hours, monitor the temperature rise of the fan (≤40℃) and the temperature of the control box (≤50℃), and record the operation data (such as the fluctuation range of current and voltage ≤±5%).
Load simulation test
Place standard palletized goods (1.2m×1.0m×1.8m) and test the dust removal rate on the surface of the goods during the air shower (it should be ≥99% and a white cotton cloth can be used for wiping and testing).
V. Installation Precautions and Risk Avoidance
Safe operation
When hoisting equipment, a hoist with a load capacity of no less than 2 tons must be used. Personnel should wear safety belts and are strictly prohibited from standing under the equipment.
When wiring electrical systems, the power supply must be cut off and the insulation resistance of the circuit (≥2MΩ) should be tested with a multimeter to prevent leakage.
Environmental adaptation adjustment
In high-temperature environments (≥40℃), cooling fans need to be installed. The fan motor should be of a high-temperature resistant type (insulation class F).
In high-altitude areas (> 1000m), the fan speed needs to be adjusted (for every 1000m increase, the speed increases by 5%) to avoid a decline in air volume.
Supplier on-site support
It is required that the supplier send technicians to the site to guide the installation, with a focus on supervising key steps such as filter sealing and electrical wiring, to avoid warranty invalidation due to non-professional operation.
Six. Archiving of installation acceptance documents
Save documents such as the "Installation and Commissioning Report" (including all test data), "Equipment Qualification Certificate", and "Filter Inspection Report" (issued by a third party) for easy maintenance and traceability in the future.
Prepare the "Equipment Operation Manual", marking key parameters (such as air shower time and wind speed setting values) and emergency fault handling procedures (such as manual door opening methods in case of power failure).
The above steps can ensure that the installation accuracy and functions of the air shower meet the standards. It is recommended to operate continuously for 3 days after installation and test the number of dust particles in the clean area every day. Only after confirming that there are no abnormalities can it be officially put into use. If it involves certification scenarios such as GMP and FDA, it is necessary to invite a third-party testing institution to conduct compliance verification.