Rensning af spildegasser fra forbrændingsanlæg

摘要

In a process for purifying combustion gases, an aqueous urea solution prepared in a reactant tank (20) is introduced into the hot exhaust gas stream (30) of varying concentration and finely sprayed in the direction of the exhaust gas stream. After decomposition of the urea in a pyrolysis channel (14), the exhaust gas stream (30) is homogeneously mixed in-line by a mixer (34) arranged in a mixing channel (16). In a subsequent in-line reaction channel (18), the reducible exhaust gas components are substantially completely reacted with the aqueous urea solution in at least one selective non-zeolite-containing reduction catalyst (36), then, depending on the plant, the oxidisable exhaust gas components are also substantially completely reacted without reactant in at least one oxidation catalyst (38) to form non-toxic gases. A two-component nozzle apparatus (26) opening out into the pyrolysis channel (14) includes a changeover valve (88) for the working position and the blow-out position, a jacketed pipe (24) for the compressed air, arranged in the region of the exhaust gas stream (30), a urea line conducted at a distance in the jacketed pipe (24) and a nozzle for fine spraying of the aqueous urea solution.