Sterilizing filtration of gases being in critical contact with the product (ventilation gases - sterile "breathing" of tanks, fermenters, bioreactors, nitrogen atmosphere for pressure and drying) is an important production process in pharmaceutical industries.
Membrane filters are widely used to remove microorganisms and viruses from compressed air and gases. Filter cartridges with pleated membrane and filter housing intended for operation under pressure, allow to remove particles up to 0.01 μm in size.
Process requirements
Air sterilizing filters must
- provide gas sterilization, low pressure drops and high flow rates at sterilization by steam-in-line
- control pathogens, prevent bacterial germination and passage of viruses with aerosol and maintain integrity after numerous cycles of sterilization
Recommendations for filter cartridges
For sterilizing filtration of gases, we recommend hydrophobic sterilizing filter cartridfges EPM.F4-020 (PTFE). The basis of the filter elements is a polytetrafluoroethylene membrane with a pore size of 0.2 μm, obtained by stretching. The filter cartridges EPM.F4 fully comply with the requirements for filters of this class. The undoubted advantage of EPM.F4 is the high flow rate, the ability to repeatedly sterilize steam in the line at 134 ºC, 100% integrity control during production guarantees sterility of gas media.
For small gas flows, with sterile breathing of tanks, we recommend the one-piece capsule filters KMF.F4-020, made from the same membrane.
To extend the life of sterilizing filters, prefilters from various materials are used to retain aerosol impurities, solid particulates, oil mist particles.
Prefilters are made from stainless steel, metal fiber (EPNS, EPNS.P) or thermally bonded polypropylene (EPV.P).
To remove smells and vapors of oil from carbon dioxide, sorption-filtering cartridge filters with activated carbon of EPS.F grade are used.
Filtration of steam for equipment sterilization
Steam is used for sterilization of tanks, pipelines or filtration systems, for heating washing water on washing facilities, etc.
In the process of production and passing of steam through pipelines, particles of rust and scale from the pipelines accumulate in the steam. These particles can damage sterilizing filters, significantly shorten the life of the valves and equipment.
For fine filtration of the steam, we recommend filter cartridges EPNS.P made from metal multilayer fiber in the all-metal version with a rating of 1-3 microns. The advantage of these filters is the ability for multiple regenerations by steam-in-line, high thermomechanical strength, chemical resistance, high efficiency of microparticle retention.
To organize the filtration process, we offer equipment made from stainless steel. Filter housings for the process of cleaning compressed air and steam are equipped with a steam trap and a valve for draining condensate from the system in the lower part of the housing. The size of the filter housing is selected on the base of the capacity and pressure in the system.