Abstract
A new generation of gas filter media is becoming available, based on rigidly bonded ceramic granules or fibres, and suitable for high-temperature duty. This paper outlines the main considerations in selecting and applying such a medium. Pressure drop through a 'virgin' medium is readily predictable from simple tests at ambient conditions. Behaviour on 'conditioning' over many cycles of filtration and cleaning can be determined by a simple 'coupon test', which shows the range of filter velocities which can be used and the cleaning action needed. Low-density media have some advantages, and this paper concentrates on one such medium which has been found to have good performance: Cerafil 12H10, formed as a bonded mat of synthetic ceramic fibres. It is currently supplied as cylindrical candles, but other geometries are under development. Experience in using Cerafil to filter gases generated by a pyrolytic incinerator treating contaminated soil is outlined.