Abstract: A filter medium has a woven fabric (1) made from mineral yarns that is in turn covered with polymeric staple fibres (2) by needling. Optionally, a diaphragm (3) made from porous polytetrafluoroethylene is applied at least on one side of the filter medium, in particular on its inflow side.

Abstract: A filter medium has a woven fabric (1) made from mineral yarns that is in turn covered with polymeric staple fibres (2) by needling. Optionally, a diaphragm (3) made from porous polytetrafluoroethylene is applied at least on one side of the filter medium, in particular on its inflow side.

Abstract: A method and a device are provided for the adsorption and chemisorption, respectively, of gaseous components out of a gas stream. The dust return is achieved within a fabric filter. A combination comprising a nozzle and a trap shaft are disposed in the lower part of the fabric filter. Thereby both a changeable gas return as well as a dust return changeable and variable over wide ranges can be effected. This method is performed in a total filter plant with several filter chambers. One of the filter chambers is alternatingly cleaned for the discharge of the reaction products and simultaneously at least one filter chamber is operated in on-line operation.