Filtration of gases

Sterile Filtration of Gases. Primary appHcations for sterile gas filtration are the sterilization of fermentor inlet air, fermentor vent gas, vents on water for injection tanks, and vacuum break filters during lyophilization. Operational and process considerations apply. Typically, the membrane in gas... 

Chemically Resistant Fibers. Fibers with exceUent chemical resistance to corrosive and/or chemical warfare agents or extreme pH conditions (eg, very acidic or very alkaline) were initially used for protective clothing. However, appHcations for filtration of gases and Hquids in numerous industrial faciHties are now the more important. For example, PPS is suitable for use in filter fabrics for coal-fired boilers because of its outstanding chemical and heat resistance to acidic flue gases and its exceUent durabUity under these end use conditions. Many high tenacity fibers are also chemically inert or relatively unaffected under a variety of conditions. Aramids, gel spun polyethylene, polypropylene, fluorocarbon, and carbon fibers meet these criteria and have been used or are being considered for appHcations where chemical resistance is important. 

TR 36 Current Practices in the validation of Aseptic Processing, 2002 TR 40 Sterilizing Filtration of Gases, 2005... 

Aguiar, M. L. Coury, JR. (1996) Cake formation in fabric filtration of gases. 

Although the method has been used to characterize MF membranes for the filtration of gases, the retention of a liquid aerosol does not correlate well with the retention of particles suspended in a liquid. 

Sterile filtration of gases has three main applications first, when sterile air is required as an ingredient gas in fermentation processes second, when gases are used for service purposes in sterile manufacture, for instance to actuate valves and to stabilize head space contents and third, to protect the venting of sterile enclosures such as storage tanks. 

For the final filtration of gases, the best type of filter is a membrane filter, which exhibits the characteristic of being able to retain particles that are actually smaller than the rated pore size of the filter. 

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