Tank for storing a reducing agent

Abstract

The invention relates to a tank for storing a reducing agent, in particular a liquid reducing agent for reducing nitrogen oxides from the waste gas of an internal combustion engine to nitrogen and water. The tank includes an external container in which an internal container is accommodated. The internal container is held in the external container in a mounting that can be axially displaced in relation to an axis of the external container. The internal container is held such that the volume in the external container is modified by displacing the internal container in the mounting.

Description

PRIOR ART[0001]The invention relates to a tank for storing a liquid reducing agent according to the preamble to claim 1.[0002]In internal combustion engines, particularly in diesel-operated internal combustion engines, due to stricter exhaust legislation going into effect in the next few years, it will be necessary among other things to reduce the percentage of nitrogen oxides in exhaust. In order to reduce the percentage of nitrogen oxides, a selective catalytic reduction, for example, is carried out in which the nitrogen oxides are reduced to nitrogen and water with the aid of reducing agents. For example, an aqueous urea solution is used as a reducing agent.[0003]The reducing agent is normally stored in a tank and supplied via a line from the tank to a metering module that injects the reducing agent into the exhaust pipe, for example.[0004]Depending on the antifreeze used, the conventional liquid reducing agents currently in use freeze at a temperature in the range from −11° C. t...

AI Technical Summary

Benefits of technology

The invention is a tank for storing a reducing agent to reduce nitrogen oxides in the exhaust of an internal combustion engine. The tank has an inner container for storing the reducing agent and an outer container that slides in relation to the inner container. The inner container is supported so that a sliding of the inner container changes the volume of the outer container without damaging the inner container. The tank also has a spring element that allows the inner container to slide in an axial direction in the outer container. The inner container is connected to a supply module that prevents relative movement between the two. The tank is designed to prevent damage to the reducing agent during freezing and to allow for easy replacement of the supply module without disassembling the entire tank.

Problems solved by technology

As a result, the reducing agent causes a dome to form as it freezes.

A disadvantage of the air cushion in the tank, however, is that if the tank is overfilled, an expansion of the reducing agent can cause damage to the tank.

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