Device for contacting a fluid medium with a reaction-inducing material

In the catalytic conversion of nitrogen oxides contained in flue gas, usually, a plurality of planes of DeNOx catalysts are installed one above the other in a DeNOx reactor in which the flow passes through the catalysts essentially parallel to the direction of gravity. Such reactors have a large overall height. In particular in the retrofitting of existing power stations, problems result, because this space requirement can often only be provided by complex reconstruction, for example of the steam generator built into the plant. For this purpose, in the device according to the invention for contacting a fluid medium with a reaction-inducing material, the device including reaction modules which are connected in series, arranged in a flow duct and contain the reaction-inducing material, it is proposed to arrange the reaction modules adjacently and to set the flow direction of the fluid medium in opposite direction in immediately adjacent reaction modules. Such a device is characterised by a particularly low overall height as a result of the adjacent arrangement and by a high operational reliability with respect to blockage of the gas ducts in the reaction modules owing to setting the direction of flow in opposite senses in adjacent reaction modules. Such devices are suitable in principle for decreasing nitrogen oxide, for decomposing halogenated hydrocarbons, for ... Original abstract incomplete.