Arrangement for treatment of exhaust gases for a compression-ignition internal combustion engine

An arrangement for treating exhaust gases of a compression-ignition internal combustion engine comprising an exhaust-gas collecting system (9) including a reduction catalyst (11) for the reduction of NO.sub.x components of the exhaust gas from the internal combustion engine, an electrically controlled valve (23) as a metering device for a metered introduction of a reducing agent into a stream of the exhaust gas supplied to the catalyst (11) as a function of operating values, stored in a control device, for the NO.sub.x content of the exhaust gas given various operating parameters of the internal combustion engine and of the catalyst, and with an evaporator device (26), said evaporator device communicates with said controlled valve (23) via a connecting line (35) for vaporizing the reducing agent introduced in vapor form into the exhaust-gas stream, said evaporating device includes a hollow body (30) which projects into the exhaust-gas stream, the hollow body includes a heating device (32) in an interior space (31) which is separated from the exhaust-gas stream by a porous wall, a reducing agent is introduced into the interior space, the reducing agent is heated to an evaporation temperature and then introduced into the exhaust gas.