Exhaust gas purification device and corresponding control process

Patent metadata

Field	Value
Publication number	US-10309279-B2
Application number	US-201815944977-A
Country	US
Kind code	B2
Filing date	Apr 4, 2018
Priority date	Apr 7, 2017
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A device includes a power source, at least one exhaust gas purification member having an upstream face and a downstream face, and a heating member placed in front of and at a distance from the upstream or downstream face. The heating member comprises a frame and a plurality of elongate heating elements surrounded by a peripheral part of the frame. Each heating element has first and second ends, with at least one of the first and second ends being electrically connected to the power source with the other end being connected to the frame. Each heating element is, between the first and second ends, connected only to at least one other of the heating elements. The heating elements are in contact with one another by respective points of contact, two points of contact of two different heating elements in contact with one another being at the same electric potential.

First claim

The invention claimed is:

1. A device for purifying exhaust gases from a vehicle, the device comprising:
at least one exhaust gas purification member having an upstream face by which the exhaust gases penetrate the purification member and a downstream face by which the exhaust gases leave the purification member;
a power source;
a heating member placed in front of and at a distance from the upstream face or the downstream face, the heating member comprising a frame and a plurality of elongate heating elements forming at least one heating layer permeable to the exhaust gases, the frame comprising a peripheral part surrounding the elongate heating elements and having a geometric center, each elongate heating element having first and second ends opposite one another, at least one of the first and second ends being electrically connected to a terminal of the power source;
at least one of the first and second ends being connected to the frame, and each elongate heating element being, between the first and second ends, connected only to at least one other of the elongate heating elements; and
wherein the elongate heating elements are in contact with one another by respective points of contact, two points of contact of two different elongate heating elements in contact with one another being at the same electric potential, and the elongate heating elements having no electrically insulating coating.

2. The device according to claim 1 , wherein the elongate heating elements are arranged in a pattern that repeats circumferentially around the geometric center and all of the points of contact are arranged on a plurality of isopotential lines, with a closed contour, substantially centered on the geometric center, all of the points of contact at the same electrical potential being placed on a same isopotential line.

3. The device according to claim 1 , wherein each elongate heating element is arranged in a zigzag and alternately forms first and second segments connected by elbows, the first segments extending radially from the peripheral part toward the geometric center and circumferentially around geometric center along a first direction, the second segments extending radially from the peripheral part toward the geometric center and circumferentially around the geometric center along a second direction opposite the first direction.

4. The device according to claim 1 , wherein the elongate heating elements are wires or strips assembled to one another by any appropriate method, or strips integral with one another.

5. The device according to claim 1 , wherein the elongate heating elements are heated to a temperature comprised between 150 and 1300° C. and are made from a material chosen from among FeCrAl and its alloys, NiCr and its alloys, stainless steel, inconel or silicon carbide.

6. The device according to claim 1 , comprising at least first and second layers of elongate heating elements, each elongate heating element being rigidly fastened by the first end to the peripheral part, the elongate heating elements of the first layer and the elongate heating elements of the second layer being electrically connected to one another by respective second ends, second ends being situated in a central zone of the frame, and wherein the peripheral part of the frame comprises a first electric distributor extending around the elongate heating elements, and a second electric distributor extending around the elongate heating elements, the elongate heating elements of the first layer being electrically connected by respective first ends to the first electric distributor, the elongate heating elements of the second layer being electrically connected by respective first ends to the second electric distributor.

7. The device according to claim 6 , wherein the first and second electric distributors are positioned side by side along a central axis of the frame, or concentrically, and are electrically isolated from one another.

8. The device according to claim 1 , wherein the device comprises an enclosure inside which the exhaust gas purification member is placed, the enclosure constituting an electric distributor to which the first or second ends of the elongate heating elements are electrically connected.

9. The device according to claim 1 , wherein each elongate heating element is, between the first and second ends, directly connected only to at least one other of the elongate heating elements.

10. A device for purifying exhaust gases from a vehicle, the device comprising:
at least one exhaust gas purification member having an upstream face by which the exhaust gases penetrate the purification member and a downstream face by which the exhaust gases leave the purification member;
a power source;
a heating member placed in front of and at a distance from the upstream face or the downstream face, the heating member comprising a frame and a plurality of elongate heating elements forming at least one heating layer permeable to the exhaust gases, the frame comprising a peripheral part surrounding the elongate heating elements and having a geometric center, each elongate heating element having first and second ends opposite one another, at least one of the first and second ends being electrically connected to a terminal of the power source;
at least one of the first and second ends being connected to the frame, and each elongate heating element being, between the first and second ends, connected only to at least one other of the elongate heating elements; and

wherein the elongate heating elements are in contact with one another by respective points of contact, two points of contact of two different elongate heating elements in contact with one another being at the same electric potential; and
wherein the frame further includes a central support placed at the center of the frame and mechanically connected to the peripheral part, each elongate heating element being mechanically connected by the first end to the peripheral part and by the second end to the central support, the peripheral part including a first electric distributor and the central support includes a second electric distributor, each elongate heating element being electrically connected by the first end to the first electric distributor and by the second end to the second electric distributor.

11. The device according to the claim 10 , wherein the central support and/or the electric distributor is/are integral with the elongate heating elements.

12. A device for purifying exhaust gases from a vehicle, the device comprising:
at least one exhaust gas purification member having an upstream face by which the exhaust gases penetrate the purification member and a downstream face by which the exhaust gases leave the purification member;
a power source;
a heating member placed in front of and at a distance from the upstream face or the downstream face, the heating member comprising a frame and a plurality of elongate heating elements forming at least one heating layer permeable to the exhaust gases, the frame comprising a peripheral part surrounding the elongate heating elements and having a geometric center, each elongate heating element having first and second ends opposite one another, at least one of the first and second ends being electrically connected to a terminal of the power source;
at least one of the first and second ends being connected to the frame, and each elongate heating element being, between the first and second ends, connected only to at least one other of the elongate heating elements; and
wherein the elongate heating elements are in contact with one another by respective points of contact, two points of contact of two different elon

Assignees

• Faurecia Systemes Dechappement

Inventors

• Bartolo Xavier

Classifications

• B01D53/9418

  for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas · CPC title

• F01N3/2882

  Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices (combined with absorbents or adsorbents only F01N3/0814; combined with particulate filters F01N3/035) · CPC title

• F01N3/0842

  Nitrogen oxides · CPC title

• F01N2530/06

  Aluminium or alloys thereof · CPC title

• F01N3/101

  Three-way catalysts · CPC title