摘要 |
A method and apparatus for adding a reactant to an exhaust gas from an internal combustion engine is based on the principle of dividing the exhaust gas stream into an inner exhaust gas flow and an outer exhaust gas flow, which radially surrounds the inner exhaust gas flow. A swirl is imparted to the outer exhaust gas flow and then the reactant is added to the inner exhaust gas flow. The method and apparatus advantageously enable the reactant, in particular a reducing agent precursor and/or a reducing agent, preferably urea, in particular in aqueous solution, to be introduced into the exhaust system of the internal combustion engine without the formation of undesirable by-products, such as for example biuret, as a result of contact between the reactant and the usually relatively cool outer tubular casing of the apparatus. |