Adsorption filter for air purification or off-gases - contains adsorber granules, e.g. active carbon, fixed on a support which can be heated, e.g. electrically, to regenerate the filter

摘要

Adsorption filters (I) comprise a 2- or 3-dimensional supporting structure (A) with adsorber granules (B) fixed thereon. Support (A) is capable of being heated. (A) is of electrically conductive material which is heated by passing a current, or (A) can be heated by means of a circulating hot medium; (A) can be heated up to 250 deg.C. (B) are spherical granules of dia. 0.2-1.5 mm, pref. active carbon, "porous polymers" based on styrene and di- or tri-vinylbenzene, or mol. sieves (zeolites). USE/ADVANTAGE - Filters are used for the filtration and purification of industrial off-gas and fresh air. Filter (I) can be regenerated by direct heating (see below), using only very small amts. of gas to remove the desorbed material. W.r.t. prior-art filters which are regenerated with hot gas (air or nitrogen) or steam, this requires less energy and gives more conc. prods. which are more economically recovered and do not require drying, and also does not produce an aq. effluent.