Exhaust gas subsequent treatment method and method therefor
First Claim
1. 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.
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Abstract
A method and device for treating exhaust gases of an internal combustion engine with a reducing agent introduced into the exhaust gases. The reducing agent is pumped out of a reactant reservoir and to a dosing valve so that after the dosing valve is opened, the reducing agent can be introduced into the engine'"'"'s exhaust gas line in a dosed manner. Reducing agent can be conveyed back from the delivery device to the reservoir via a return line. The reducing agent can circulate between the delivery device and the reactant reservoir thereby, particularly when the dosing valve is closed, preventing the reactant from freezing.
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Citations
13 Claims
- 1. 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.
Specification