Abstract: The electrostatic dust separator (10) has integrated filter tubing (12) whereby it is also known as a hybrid filter. The invention comprises plate-type collecting electrodes (14) which are arranged in a substantially parallel manner, filter tubing (12) extending in the channels thus formed (72) parallel to the collecting electrodes, and emission electrodes (16) disposed between the collecting electrodes (14) and the filter tubing (12). The electrodes (14,16) are connected to systems producing high voltage. A filter leading to the electrodes (14,16), a gas outlet (30) and a dust collector funnel (32). The collecting electrodes (14) are electrically insulated in relation to the filter housing (18) and connected to the positive pole of the system for producing high voltage. The negative pole of the system for producing high voltage is connected to the filter housing (24) which forms an earth (24).

Abstract: The installation (10) proposed in intended for the cleaning of flue gases from an oven (12), particularly a revolving cylindrical cement kiln. It includes at least one reduction catalyst (14) for gaseous pollutants and a dust collector. The reduction catalyst (14), together with a reagent-injection point on the input side of the catalyst, is located immediately after the oven (12), i.e. before the dust collector. In preferred embodiments, the reduction catalyst (14) has a basic honeycomb structure with wide gas-circulation channels (66) and/or the honeycombs are screened off upstream by at least one screen. Gaseous pollutants removed by the system are, in particular, NO.sub.x, CO and hydrocarbons.