Ventilation element for a storage tank

Abstract

The invention relates to a storage tank (10) for receiving a medium (12) that can be frozen, in particular a reducing agent, comprising a ventilation unit (34, 36; 72) and a crucible-shaped container (22) introduced in the storage tank (10). An air chamber (50) in the crucible-shaped container (22) is connected via a ventilation line (60) or an overflow opening (40) to an air chamber (48) of the storage tank (10), which is ventilated via a ventilation unit (34, 36; 72).

Description

BACKGROUND OF THE INVENTION[0001]In motor vehicles with internal combustion engines, because of the more stringent exhaust gas legislation due in the coming years, amongst other things the pollutant in NOx must be reduced. One method of reducing this pollutant, which is already being used, is the SCR method (selective catalytic reaction), according to which the pollutant NOx is reduced to N2 and H2O with the aid of liquid reducing agent. The reducing agent is conveyed in a line from the storage tank storing the reducing agent to the metering module. The reducing agents normally used nowadays freeze between −11° C. and −40° C., depending on the antifreeze added.[0002]In order to ensure rapid thawing of the frozen medium, an electric heater is installed in the storage tank, inside a cup open at the bottom. Thus, the heat output by the heater is used first to thaw the content of the cup. Via a suction lance, likewise of heated design, the liquid thawed around the heater is extracted vi...

AI Technical Summary

Benefits of technology

[0007]The solution proposed according to the invention offers simplification of the design and therefore greater robustness with low manufacturing costs because of the omission of a number of parts. Furthermore, in the storage tank proposed by the invention, considerable simplification of the installation can be achieved because of the reduced number of components, and thus a considerable reduction in the manufacturing costs. In relation to fording-capable systems, only one hose connection is required, which likewise results in considerable simplification.

[0008]In a further advantageous embodiment of the solution on which the invention is based, an air space which above the frozen content of a tank and an air space which above the frozen content of a cup which is introduced into the tank is aerated or ventilated into the surroundings via a separate ventilating means in each case. In this design variant of the solution proposed by the invention, in each case ventilation elements formed in the manner of tablets can be introduced into the connectors of a lid which closes the cup and into a connector for an aeration / ventilation line of the tank above an air space. By means of the two separate ventilating means provided in this design variant, ventilation of the tank and also ventilation of the cup are possible.

Problems solved by technology

In relation to fording-capable systems, only one hose connection is required, which likewise results in considerable simplification.

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