Maintaining clean and dust-free air is critical in cleanrooms, especially in industries that demand the highest air quality, such as semiconductor manufacturing, biopharmaceuticals, and food processing. Air showers clean the surfaces of people and objects through highly efficient filtered air flow, thereby reducing the possibility of external contaminants being brought into the cleanroom.
Working Principle of Air Shower Room
Setting the blowing time
The operating time of an air shower is usually set between 15-30 seconds, which is sufficient time to clean the surface of contaminants. Of course, the blowing time can be adjusted according to the requirements of the cleanroom, wind speed and air flow rate to ensure sufficient blowing time to clean the surface as much as possible.
Entering an Air Shower
Air showers usually have two doors, with the inner and outer doors forming an airtight isolation area between them to prevent people or items from entering with contaminants that could contaminate the air in the clean room. These two doors cannot be opened at the same time; the inner door can only be opened after the outer door is closed. When personnel or goods enter the air shower room, the outer door will be automatically closed, and the inner door will be opened only after the air shower room has been blown.
High-speed Airflow Blowing
The core function of the air shower room is the high-speed airflow blowing. There are several high-efficiency fans and nozzles inside the air shower room, and they blow the air through the nozzles or air outlets at a high speed of 20-25 meters per second to the people or goods inside the air shower room, so that it can quickly remove the dust, particles, or other pollutants that are carried on the surface of the people or goods. The nozzles in the air shower room are generally set in the direction of the upper, lower, side, and can make the airflow all-round coverage to all areas, leaving no dead ends, and cleaning more comprehensive.
Filtration and Air Purification
Air showers are equipped with a high efficiency filtration system, the air inside the air shower room can be filtered through a high efficiency filtration system (HEPA high efficiency filters or ULPA ultra high efficiency filters) to ensure that no large particles of dust enter the air shower room. HEPA filters can filter particles with a diameter of more than 0.3 micrometers, the ULPA filters have a higher efficiency than HEPA and can filter smaller particles as well. The filtered air can be blown out by a fan to ensure that the air inside the air shower room is not contaminated.
The air inside the air shower room can also be circulated after filtration to ensure that the airflow remains efficient and clean. Air that has been filtered and circulated several times continues to provide effective blowdown.
Entering the cleanroom
After the blowing is completed, the inner door of the cleanroom can be opened manually or automatically. By this time, most of the contaminants on the surface of people or objects are blown off, reducing the risk of contaminating the clean area after entering the cleanroom.
Conclusion
Air showers remove contaminants from the surfaces of entrants or objects through the dual action of high-speed airflow and high-efficiency filters, thereby effectively preventing the air in the cleanroom from being contaminated by external sources, which is essential to maintaining a high standard of air quality in the cleanroom.
