Exhaust gas post treatment device

Abstract

An exhaust gas post-treatment system for purifying exhaust gas from an internal combustion engine, and to a corresponding method. The system includes a particle filter, a device having catalytic oxidation function, and at least one mixing chamber which are combined to form a constructive unit.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an exhaust gas including a particle filter having a catalytic oxidation function and at least one mixing chamber, combined to form a constructive unit, and to a corresponding method for exhaust gas post-treatment.BACKGROUND INFORMATION[0002]Internal combustion engines, in particular diesel-operated motor vehicles, emit a complex mixture of air pollutants including particles, or fine materials, and gaseous compounds, inter alia nitrogen oxides (NOx), carbon monoxide (CO), and uncombusted hydrocarbons (HC). Due to stricter pollutant emission standards that are now in effect, attempts are being made to regulate the quantity of air pollutants emitted by an internal combustion engine.[0003]In exhaust gas post-treatment systems, in addition to an oxidation catalytic converter and a soot particle filter, a selective catalytic reduction (SCR) is used to meet the strict exhaust gas regulations with regard to the NOx portion in the ...

AI Technical Summary

Benefits of technology

The present invention provides an exhaust gas post-treatment system that has a reduced installation space and mass, resulting in lower costs. The system achieves improved low-temperature response behavior and requires less supporting structures. By placing the system close to the engine, heat losses are minimized. The high temperatures in the system enable additional dosing of reducing agent and protect the downstream catalytic converters. The integration of additional catalytically active elements enhances conversion of pollutants in the exhaust gas. The sensors provided in the system enable improved controlling of the pollutant conversion. The cylindrical container of the system allows for easy access to the individual elements for cleaning or replacement.

Problems solved by technology

Disadvantageous are the large space requirement of the components of the exhaust gas post-treatment system, and in particular the situation of the individual components upstream from the SCR catalytic converter.

In addition, the voluminous and long configuration of the installation results in a greater distance from the internal combustion engine and, finally, a lower temperature at the SCR catalytic converter.

Accordingly, a configuration of oxidation catalytic converter, fine material filter, and SCR catalytic converter represents a large thermic mass that causes heat losses and, due to the large number of components, a significant cost outlay.

However, in such a combination a high loading of the filter substrate with an SCR catalyst compound is required, which can cause an unacceptably high pressure loss.

In such a system, the required installation space, in particular installation length, has turned out to be a problem.

The associated heat losses are high.

In addition, such a system does not support the passive regeneration of the filter substrate.

Images