Working Principle Of The Air Shower
Air showers operate similarly to automated car wash pressure washer systems. Here is a brief introduction How The Air Shower Works And Air Shower Preparation Procedures.
How The Air Shower Works
In an air shower, a worker passes through the entry door and a sensor activates interlock magnets, which lock the air shower and cleanroom doors. Numerous adjustable nozzles blow high-velocity streams of Class 100 filtered air onto workers. The high-velocity air creates a flapping effect on clothing which produces a scrubbing action, removing particulates from cleanroom garments. To ensure all particulates are removed, workers raise their arms and rotate in place.
Indicator lights signal the end of the cleaning cycle, and the cleanroom door opens. It takes four to eight seconds of cleaning time and another two to four seconds for the air shower to purge contaminated air prior to the worker exiting. Microprocessors control the cleaning and wait times.
Air Shower Preparation Procedures
Because people are the main source of cleanroom contamination, workers follow a series of procedures before entering a cleanroom. Air showers are the final cleaning step before entering a cleanroom. Prior to entering the air shower, workers put on appropriate cleanroom clothing in a gowning room—either a suit (which covers nearly the entire body) or a gown and cap or hood (which covers street clothes)
This “gowning” process disturbs and releases contaminants from street clothes that can settle onto cleanroom garments. Air showers remove the contaminants. This procedure helps to maintain cleanroom standards and also helps to lower operating costs. The decontamination procedure in the air shower means cleaner air enters the cleanroom, reducing product defects and increasing production yields. Cleanroom HEPA filters last longer because contaminant loads are lower. The cleanroom will require less maintenance and consume less energy. Also, a gown room air shower lowers costs by allowing garments to be used multiple times before thorough cleaning is needed.
Important factors to consider when specifying an air shower include effectiveness (power and capacity) and air filtration.