Catalytic reaction for reduction of nitrogen oxide

Claim 1

A catalytic reactor for reducing nitrogen oxide (NO X ) contained in exhaust gas, wherein a plurality of individual tubular catalyst units each being a ring shape in cross-section are disposed in the cross-section of the flow path of the exhaust gas in a manner that tubular axes thereof are in parallel with the direction of the gas flow within a reaction vessel through which the exhaust gas containing nitrogen oxide (NO X ) flows, constructed such that: said catalyst units are disposed in spaced apart relationship from one another so that the respective equivalent diameters of the cross-sectional areas of the flow paths of gas formed inside and outside said tubular catalyst units per pitch of said tubular catalyst units are equal; said catalyst units are disposed in a triangular pitch arrangement in the reaction vessel by wire stretching across a support frame in manner to form a rhombic mesh; and said support frame having supported thereon a plurality of wire nets of said rhombic mesh, wherein said plurality of wire nets are spaced in the direction of the gas flow in the reaction vessel in a manner to support at least the opposite end portions of the tubular catalyst units and wherein the size of the rhombic mesh is smaller than the outer diameter of the catalyst units whereby said tubular catalyst units are grasped thereby.