EXHAUST GAS AFTERTREATMENT DEVICE

Abstract

A device for the aftertreatment of exhaust gases from an exhaust-gas source, having a spatially delimited flow path through which flow may pass proceeding from the exhaust-gas source, having a heating catalytic converter which is arranged in the flow path and which, as viewed in a flow direction, firstly has a catalytically active catalytic converter through which flow may pass and, following this in the flow direction, has an electrically heatable heating disk, wherein at least one outlet of a secondary air supply is arranged in the region of the heating catalytic converter such that a gas flow referred to as secondary air is fed into the flow path in the region of the heating catalytic converter.

Claims

1. A device for the aftertreatment of exhaust gases from an exhaust-gas source, comprising: a spatially delimited flow path through which flow can pass proceeding from the exhaust-gas source; a heating catalytic converter which is arranged in the flow path, the heating catalytic converter further comprising: a catalytically active catalytic converter through which flow may pass; an electrically heatable heating disk arranged downstream in a flow direction from the catalytically active catalytic converter; a secondary air supply, at least one outlet of the secondary air supply arranged in the region of the heating catalytic converter such that a gas flow referred to as secondary air is fed into the flow path in the region of the heating catalytic converter.

2. The device of claim 1, the catalytic converter further comprising a metallic honeycomb body.

3. The device of claim 1, the catalytic converter further comprising a supporting catalytic converter, wherein the heating disk is mechanically connected to the supporting catalytic converter.

4. The device of claim 1, wherein the secondary air is fed into the flow path between the catalytic converter and the heating disk.

5. The device of claim 1, the secondary air supply further comprising multiple feed points.

6. The device of claim 1, further comprising a heating conductor arranged in the heating disk such that the heating conductor generates one or more local temperature maxima, and the positions of the temperature maxima on the heating disk correlate with the positions of flow maxima of the secondary air that is generated as a result of the feed of the secondary air.

7. The device of claim 1, wherein the secondary air supply is at least partially arranged in at least one cavity formed in the honeycomb body of the catalytic converter.

8. The device of claim 7, the honeycomb body of the catalytic converter further comprising: an adsorbent coating, the honeycomb body of the catalytic converter is coated with the adsorbent coating from an inflow side to the at least one cavity in the flow direction; and an oxidizing coating, the honeycomb body is coated with the oxidizing coating from the at least one cavity to an outflow side.

9. The device of claim 7, wherein the cavity is arranged in a region between the center and the outflow side of the catalytic converter in the flow direction.

10. The device of claim 7, catalytic converter further comprising corrugated layers and smooth layers downstream of the at least one cavity in the flow direction, wherein the corrugated layers and smooth layers are of perforated form.

11. The device of claim 10, the corrugated layers and smooth layers further comprising expanded metal downstream of the at least one cavity in the flow direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention will be discussed in more detail below on the basis of exemplary embodiments with reference to the drawings. In the drawings:

[0032] FIG. 1 shows a schematic view of a device having a heating catalytic converter, having a secondary air supply and having a main catalytic converter;

[0033] FIG. 2 shows a schematic view of a device having a heating catalytic converter, having a secondary air supply that allows secondary air to be supplied at multiple points along the circumference of the flow path, and having a main catalytic converter;

[0034] FIG. 3 shows a schematic view of a device having a heating catalytic converter, having a secondary air supply into a cavity of the catalytic converter, and having a main catalytic converter; and

[0035] FIG. 4 shows a schematic view of a device having a heating catalytic converter, having a secondary air supply into a cavity of the catalytic converter, wherein the metal layers that form the supporting catalytic converter are perforated, and having a main catalytic converter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0037] FIG. 1, and also FIGS. 2 to 4, show(s) in each case a schematic view of a device according to the invention for treating exhaust gases. Corresponding components are therefore denoted by the same reference designations.

[0038] The Figures show a heating catalytic converter 1 which is formed from a catalytic converter 2 and a heating disk 3 located downstream in a flow direction 8 of the exhaust gas. A gap 6 is formed between the heating disk 3 and the catalytic converter 2. The heating disk 3 is connected via an indicated electrical contact 4 to a voltage source, such that the heating disk may be electrically heated.

[0039] Located downstream of the heating catalytic converter 1 in the flow direction 8 is a catalytic converter referred to as main catalytic converter 7, which is representative of one or more further catalytic converters for exhaust-gas aftertreatment. These may for example be oxidation catalytic converters, SCR catalytic converters, NH3 slip catalytic converters or even filter elements.

[0040] Secondary air, that is to say air from the surroundings, may be supplied into the gap 6 via the secondary air supply 5. FIG. 1 illustrates a supply at only one location directly into the gap 6.

[0041] By contrast to FIG. 1, FIG. 2 shows a supply of the secondary air at multiple locations into the gap 6. For this purpose, an annular structure 9 is arranged around the region of the gap 6, through which annular structure secondary air may flow, wherein the secondary air flows around the heating catalytic converter 1 and flow into the gap 6 through openings 10. This supply of the secondary air at multiple locations simultaneously is an example.

[0042] FIG. 3 shows an alternative form of the supply of the secondary air. The catalytic converter 2 has a cavity 12 which may be formed for example by cutouts in the metal layers that form the honeycomb body. Into this cavity 12, secondary air is fed directly into the cavity 12 via the secondary air supply 11. The secondary air is distributed from there via the flow channels, which are intersected by the cavity 12, of the catalytic converter 2.

[0043] FIG. 4 shows a construction according to FIG. 3. In addition, the metal layers that form the catalytic converter 2 have perforations 13, which allow a transfer flow of the exhaust gas-secondary air mixture between the flow channels of the catalytic converter 2 and thus allow a more homogeneous distribution.

[0044] The different features of the individual exemplary embodiments may also be combined with one another. The exemplary embodiments in FIGS. 1 to 4 are not of a limiting nature and serve for illustrating the concept of the invention.

[0045] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.