Patent ID: 7775036

Claim:
A method for the aftertreatment of exhaust gases of an internal combustion engine using a reagent which is to be introduced into the exhaust gases, in which method the reagent is pumped by means of a feed device ( 4 ) from a reagent tank ( 1 ) to a metering device, such that the reagent can be introduced in a metered fashion into an exhaust line of the internal combustion engine according to the opening of the metering device, with it being possible for reagent to be returned from the feed device ( 4 ) to the reagent tank ( 1 ) via a return line ( 12 , 75 ), characterized in that the feed device is contained within a feed module and the reagent can circulate between the feed device ( 4 ) and the reagent tank ( 1 ) in such a way that freezing of the reagent is prevented, particularly when the metering device is closed, with the circulation taking place between the reagent tank and the feed module, with the feed module being connected by means of a supply line ( 76 ), which is not involved in said circulation, to the metering device, and wherein the circulation takes place only if the temperature of the external air or of the reagent situated in the reagent tank falls below a threshold value.