Cleaning exhaust gases from combustion installations

Abstract

In a process for cleaning the exhaust gases from combustion installations, a dilute urea solution prepared in a reagent tank (20) is introduced into the hot exhaust gas flow (30) of differing concentrations and is finely sprayed in the direction of the exhaust gas flow. After decomposition of the urea in a pyrolysation channel (14), the exhaust gas flow (30) is homogeneously mixed in-line by a mixer located in a mixing channel (16). In a subsequent in-line reaction channel (18), the reducible exhaust gas constituents are converted into non-toxic gases in at least one selective reduction catalyst which does not contain zeolite (36), then, dependent on the installation, the oxidizable exhaust gas components are converted into non-toxic gases without reagent in at least one oxidation catalyst (38) to produce a virtually complete reaction. A dual substance nozzle appliance (26) opening into the pyrolysation channel (14) comprises a reversing valve (88) for the working and blowing out position, a casing tube (24) for the compressed air, located in the area of the exhaust gas flow ( 30), a urea conductor carried at a distance in the casing tube (24) and a nozzle for fine spraying of the dilute urea solution.

Dependencies are inferred from the claim text.