Design of sterile air filtration and cooling system for edible fungus sterilizer that meets Class 100 cleanliness

For the air filtration and cooling system of the edible fungus sterilizer, and the filtration system that meets Class 100 cleanliness (ISO Class 5) under the flow demand of 100 m³/min, what equipment should be equipped and what kind of air filter should be selected? Here are some sharing:
First of all, the system composition can be divided into the following 5 aspects
1. Air pretreatment unit:
Equipped with primary filter (G4 grade) and pressure difference alarm prompt replacement, filter particles ≥5m, filter large particles for the main filter in the back, protect subsequent equipment, reduce the burden of the main filter, and relatively extend the service life of the main filter.
2. Air dehumidification and temperature control module:
Cool the sterilized high-temperature culture material (above 100℃) to room temperature (25-30℃). Set up a surface cooler and an electric heating compensator: precool the outside air to 15-20℃ to avoid high temperature damage to the high-efficiency filter. The temperature control module sets the air supply temperature and the culture medium temperature difference ≤30℃.
3. High-efficiency filtration unit
Use HEPA high-efficiency filter (H14 level and above), the filtration efficiency of 0.3um particles is ≥99.99%, and the pressure loss is ≤250Pa. Here, glass fiber filter materials with relatively stable performance should be selected so that the subsequent filtration efficiency will not be excessively attenuated. Under the condition that the resistance is allowed, the activated carbon layer can also be added to adsorb V0Cs and odors. Note that activated carbon will have the hidden danger of desorption at high temperature, so high-temperature use environment should be avoided.
4. Air delivery system:
The selected centrifugal fan air volume should be around 7000 m³/min (redundant design), and the frequency conversion speed control flow. Static pressure overcomes the filter resistance. Use 316L stainless steel pipes, the inner wall is electrolytically polished (Ra≤0.5um), and the slope design needs to prevent water accumulation.
5. Laminar flow distribution module
Uniform flow membrane diffuser: wind speed uniformity ≤±15%, covering the cross section of the fire bacteria cabinet.
Secondly, based on the above basic settings, according to the actual use environment and filtration requirements, the following modules can be added as appropriate:
1. Configure the ozone in-situ system, which will start automatically when shut down. You can also add a UV catalytic module (254nm, 100uW/cm²) downstream of the filter.
2. Intelligent monitoring system: wind speed test, real-time monitoring of pressure difference, temperature and humidity, online particle counter (0.5/5um), floating bacteria sampler. Continuing to use after the pressure difference reaches the final resistance may cause the air quality in the environment to fail to meet the requirements.
3. Pay attention to the sealing work at all possible leaks. The sealing material is medical silicone rubber (temperature resistance -70~250℃). The frame can be made of 304 stainless steel + anodized aluminum structure, with IP65 protection level
In addition, during the operation and maintenance process, we need to pay attention to:
1. Replacement cycle of air filter: 3 months for initial effect, 1 year for HEPA filter (PAO leak detection every year)
2. Perform moist heat sterilization and VHP sterilization according to actual needs
This solution can achieve cooling through three-stage filtration + dynamic sterilization + laminar flow control, and the air filtration particle efficiency is ≥99.99%. It is recommended to match dual system redundancy to ensure continuous production needs.
The above solution is a suggestion. If there is anything wrong, please call or correct it online. Thank you!