Abstract: The wet cleaning of filter cartridges (4) in fluidised-bed apparatuses and similar process units, without their being dismantled, is carried out by means of cleaning fluid sprayed out of nozzle orifices (10) arranged in the form of a ring, the nozzle orifices (10) being installed in the filtered exhaust-gas space (7) and the filter cartridge (4) being moved through this ring of nozzle orifices (10) by a lifting device (17). In a preceding flushing cycle, the filter cartridge (4) is filled with cleaning fluid and is then subjected to an ultrasonic transmitter (26) and with pressure pulses. The nozzle orifices (10) are designed and arranged in such a way that the issuing cleaning jets strike the filter casing (5) tangentially at an angle of inclination .alpha. and thus set the filter cartridge (4) in rotation. The best possible cleaning effect is achieved by the rotation and lift of the filter cartridge (4).

Abstract: A bed plate (13) for a fluidized bed apparatus is made from a plate (23) from sheet metal and comprises openings (22) for fluidizing air or gas of the so-called "gill-type". In order to reduce or prevent fall-through of product, at least one of the edge portions (24,34) defining the opening (22) has been deformed so as to increase the extension thereof along the plane of the bed plate, and so as to thereby reduce or eliminate the orthographic projection on said plane of the opening (22). Such deformation may comprise compression and/or stretching. The edge portion or portions (24,34) are preferably deformed to such an extent that a partial overlap is obtained.