The AstroCel HT filter is a High Efficiency Particulate Air (HEPA) filter that is specifically designed to remove airborne contaminants in critical areas where high efficiency filtration is required and hot air is used during the production process. These filters are used in a broad range of industries, from photography and video to food processing.
Components used for the assembly of this filter are either specifically selected for their heat resistance, or because they are not severely affected by higher temperatures. To have the prototype tested under hot dynamic conditions, the AstroCel HT filter was presented to the independent U.K. Research Laboratory of Atomic Energy Authority Technology. The conclusion after testing was that the filters performed very satisfactorily and well within the criteria specified.
This filter’s cell sides are made of hot dipped aluminized steel. This material has excellent characteristics at high temperatures and easily regains its original dimensions after sudden temperature variations. The cell sides are mechanically put together with stainless steel pop rivets to ensure a permanent close fit.
Heat resistant corrugated aluminum separators keep the pleats of the filter media apart. Uniform spacing between the pleats allows optimal air flow throughout the filter.
High temperatures have an influence on the filter media, sealant, and cell sides, since they do not expand equally due to their different coefficients. By designing a filter with a unique expansion layer, which is mounted with special glue to the cell sides, the difference in expansion is absorbed, thus preventing tears in the filter media and cracks in the sealant. In addition, the use of an expansion layer ensures that during the cooling down process, the filter cell sides and media will regain their original dimensions.
The media pack is thoroughly sealed to an expansion layer with a special, heat resistant sealant. This bond totally encapsulates the media edges and separators, preventing bypass leakages. The sealant consists of ceramic based components.