SCR exhaust gas aftertreatment device
View Patent ↗An SCR exhaust gas aftertreatment device in which a urea-water solution is injected into an exhaust gas line is provided. At least one component of the device (e.g., a filter element) lies in an area of an internal space, and is bounded by an elastomer membrane that is embedded in a frost equalization foam. This prevents freezing damage even over a very long period of time and a large number of freezing cycles.
1. An SCR exhaust gas aftertreatment device for injecting a urea-water solution into an exhaust gas line, comprising:
at least one filter element arranged in an area of an internal space of the device and in contact with the urea-water solution, and
an elastomer membrane embedded in a frost equalization foam bounding the at least one filter element, wherein the elastomer membrane and the frost equalization foam surround at least a portion of the filter element when the filter element is received in the internal space of the device.
2. The SCR exhaust gas aftertreatment device according to claim 1 , wherein the elastomer membrane together with the frost equalization foam is designed to be sufficiently rigid so as to prevent a volume decrease greater than 10% at a pressure of 10 bars.
3. The SCR exhaust gas aftertreatment device according to claim 1 , further comprising a ventilation element which allows a pressure equalization upon changes in volume of the frost equalization foam.
4. The SCR exhaust gas aftertreatment device according to claim 3 , wherein the ventilating element comprises a gas-permeable and water-impermeable separating element.
5. The SCR exhaust gas aftertreatment device according to claim 1 , further comprising a plug arranged inside the filter element.
6. The SCR exhaust gas aftertreatment device according to claim 1 , further wherein the filter element is installed in a rigid receiving part, in which the elastomer membrane is tightly installed.
7. The SCR exhaust gas aftertreatment device according to claim 6 , further comprising a filter housing fastened on the receiving part, which presses a sealing bulge of the elastomer membrane against the receiving part.
8. The SCR exhaust gas aftertreatment device according to claim 6 , wherein the receiving part is sealed off against the filter housing by means of a sealing element.
9. An SCR exhaust gas aftertreatment device for injecting a urea-water solution into an exhaust gas line, comprising:
a filter element for cleaning of the urea-water solution arranged in an area of an internal space of the device and in contact with the urea-water solution, and
an elastomer membrane including a first portion surrounding at least a portion of the filter element, the first portion of the elastomer membrane being embedded in a frost equalization foam surrounding the filter element;
wherein the filter element is installed in a rigid receiving part, in which the elastomer membrane is tightly installed.
10. The SCR exhaust gas aftertreatment device according to claim 9 , further comprising a filter housing fastened on the receiving part, which presses a sealing bulge of the elastomer membrane against the receiving part.
11. The SCR exhaust gas aftertreatment device according to claim 9 , wherein the receiving part is sealed against the filter housing by means of a sealing element.
12. A filter assembly for an SCR exhaust gas aftertreatment system configured for injecting a urea-water solution into an exhaust gas line, the assembly comprising:
a filter housing including an internal cavity configured to receive a filter element,
a frost equalization foam lining at least a portion of the internal cavity of the filter housing; and
an elastomer membrane embedded in the frost equalization foam;
wherein the elastomer membrane and the frost equalization foam surround at least a portion of the filter element when the filter element is received in the internal cavity.
13. The filter assembly of claim 12 wherein the elastomer membrane together with the frost equalization foam is designed to be sufficiently rigid so as to prevent a volume decrease greater than 10% at a pressure of 10 bars.
14. The filter assembly of claim 12 further comprising a ventilation element which allows a pressure equalization upon changes in volume of the frost equalization foam.
15. The filter assembly of claim 14 wherein the ventilating element comprises a gas-permeable and water-impermeable separating element.
16. The filter assembly of claim 12 wherein the receiving part is sealed off against the filter housing by means of a sealing element.