Abstract: Apparatus for catalytic cleaning of the exhaust gases of furnace systems. For selectively eliminating nitrogen oxides in the exhaust gases of furnace systems, chemical compounds, such as ammonia in vapor form, are introduced into the exhaust gases emerging from the furnace systems. The exhaust gases are then passed through a catalytic converter, which initiates and/or accelerates the reaction of the oxides of nitrogen with the admixed chemical compounds. In different zones in the catalytic converter, the exhaust gases that are to be treated catalytically and of at least one current of cleaning gas are passed in a countercurrent. The location of the catalyst zones through which the exhaust gases and the cleaning gas, respectively, flow is varied continuously or intermittently. The catalytic converter has catalyst elements disposed in a carrier, and the carrier and the gas connections relative to one another.

Abstract: Hot gas filter for separating solid particles carried along in high temperature or waste gases having a filter casing made of heat-resistant brickwork, in which there is provided at least one oblong filter cell one end of which ends in a hot gas supply duct whereas the other end is tightly closed by a removable cover. The walls of the filter cell are at least partly made of perforated bricks, through which the hot gas entering the filter cell may overflow to a treated gas discharge duct. The filter cell is lined over the whole length thereof with a replaceable filter hose of heat resistant fabric or tissue, preferably non-woven ceramic fiber fabric or a fabric of ytrium-oxide stabilized zircon-oxide fibers.