Carbon particle reducing apparatus

• US 20030185722A1
• Filed: 03/28/2003
• Published: 10/02/2003
• Est. Priority Date: 04/02/2002
• Status: Active Grant

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Toyoda, Tetsuro
• Granted Patent: US 7,470,407 B2
• Time in Patent Office: Days
• US Class Current: 422/177
• CPC Class Codes: B01D 2258/012 Diesel engines and lean burn gasoline engines
• CPC Class Codes: B01D 53/944 Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts three-way-catalysts [TWC] B01D53/9445
• CPC Class Codes: B01D 53/9454 characterised by a specific device
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 2240/20 a flow director or deflector
• CPC Class Codes: F01N 3/0222 the structure being monolithic, e.g. honeycombs
• CPC Class Codes: F01N 3/0231 using special exhaust apparatus upstream of the filter for producing nitrogen dioxide, e.g. for continuous filter regeneration systems [CRT]
• CPC Class Codes: F01N 3/035 with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/2892 Exhaust flow directors or the like, e.g. upstream of catalytic device
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A reducing apparatus 16 for carbon particles PM is provided with one or more filters 19 of a wire mesh structure. The filter 19 is formed in a substantially short column-shape and is provided with a central through-hole 21 and a pair of exhaust ducts 26. The filter 19 is situated within an outer cylindrical casing 4 on an axis perpendicular to the axis of the outer cylindrical casing 4. Exhaust gas 1 discharged from a diesel engine flows from an outer periphery 22 side of the filter 19 to the central through-hole 21 side, wherein the carbon particles PM contained in the exhaust gas 1 are captured, burned and reduced. A plurality of filters 19, each formed in a hollow cylinder-shape, can also be provided side by side in the same direction as the axis of the outer cylindrical casing 4.

Claims

1. A reducing apparatus for carbon particles having one or more filters of a wire mesh structure which capture, accumulate, oxidize, burn, and reduce the carbon particles contained in the exhaust gas of a diesel engine, characterized in that the filter is formed in a substantially short column-shape and is provided with one or more central through-holes, wherein the exhaust gas flows from an outer peripheral side of the filter to the central through-hole side thereof.

2. The reducing apparatus for carbon particles according to claim 1, wherein the filter is composed of a wire mesh structure of which the wire, made of metal, is formed in a mesh-shape and is housed in an outer cylindrical casing set between an upstream portion and a downstream portion of an exhaust pipe for the exhaust gas, and the filter is disposed on the axis perpendicular to an axis of the outer cylindrical casing.

3. The reducing apparatus for carbon particles according to claim 2 comprising the filter, a pair of holding plates for blocking and holding the two ends of the filter, a shielding plate for partitioning the inside of the outer cylindrical casing in the lateral direction on the downstream side of the filter, and a pair of exhaust ducts for communicating between the central through-hole of the filter and the downstream side of the shielding plate via the two holding plates and the shielding plate.

4. The reducing apparatus for carbon particles according to claim 3, wherein the outer cylindrical casing is formed in a substantially cylindrical shape, one or more filters are formed in a substantially short column-shape, one or more central through-holes are formed in a circular shape, the two holding plates are formed in a circular flange shape, the shielding plate is formed in a disc-shape, and the two exhaust ducts are formed in a curved cylindrical shape.

5. The reducing apparatus for carbon particles according to claim 3, wherein the shielding plate is provided with one or more pressure-relief holes for releasing the raised pressure onto the downstream side.

6. The reducing apparatus for carbon particles according to claim 3, wherein the filter is provided with one or more pressure-relief holes for releasing the raised pressure between the periphery and the central through-hole.

7. The reducing apparatus for carbon particles according to claim 3, wherein the wire of the filter is coated by adhesion of an oxidation catalyst such as platinum.

8. The reducing apparatus for carbon particles according to claim 3, wherein the mesh density of the filter is set between 10% and 35%, and the wire diameter of the filter is between 0.2 mm and 0.8 mm.

9. The reducing apparatus for carbon particles according to claim 3, wherein the reducing apparatus for carbon particles is used along with one or more rectifying plates and one or more purifiers disposed in order on the upstream side within the outer cylindrical casing, the rectifying plate is entirely provided with a plurality of wall openings throughout the rectifying plate to uniformly disperse, rectify, and accelerate the exhaust gas, thereby raising the temperature, and the purifier is provided with a honeycomb core made of metal of which each cell wall is coated by adhesion of oxidation catalyst such as platinum, and the purifier is adapted to oxidize, burn, and reduce carbon monoxide and hydrocarbon contained in the exhaust gas and to oxidize nitrogen oxide into nitrogen dioxide which is supplied to the downstream side.

10. The reducing apparatus for carbon particles according to claim 3, wherein the capture rate and the reduction rate of the carbon particles are set between 5% and 80%.

11. A reducing apparatus for carbon particles, having a plurality of filters of a wire mesh structure, which captures, accumulates, oxidizes and burns the carbon particles contained in the exhaust gas of a diesel engine, thereby reducing these, characterized in that each filter is formed in a hollow cylinder-shape and the exhaust gas flows through each filter.

12. The reducing apparatus for carbon particles according to claim 11, wherein the filter is composed of a wire mesh structure of which the wire, made of metal, is formed in a mesh-shape and is housed in an outer cylindrical casing set between an upstream portion and a downstream portion of an exhaust pipe for the exhaust gas, and a plurality of filters is disposed in parallel side by side in the same direction as the axis of the outer cylindrical casing.

13. The reducing apparatus for carbon particles according to claim 12, wherein a pair of front and rear perforated plates is provided along with the filters, and the two perforated plates are disposed before and after each filter to partition the inside of the outer cylindrical casing in the lateral direction, wherein one perforated plate is provided to block one end of the inner space of each filter and is provided with a plurality of passing holes for the exhaust gas, while the other perforated plate is provided with a plurality of passing holes for the exhaust gas in a corresponding position on the other end of the inner space of the filter.

14. The reducing apparatus for carbon particles according to claim 13, wherein the outer cylindrical casing is formed in a substantially cylindrical shape, each filter is formed in a cylinder-shape, the two peforated plates are formed in a disc-shape, and each passing hole is formed in a circular shape.

15. The reducing apparatus for carbon particles according to claim 13, wherein the wire of each filter is coated by adhesion of an oxidation catalyst such as platinum.

16. The reducing apparatus for carbon particles according to claim 13, wherein the mesh density of each filter is set between 10% and 35%, and the wire diameter of each filter is between 0.2 mm and 0.8 mm.

17. The reducing apparatus for carbon particles according to claim 13, wherein each filter is formed in a multi-layered structure and the mesh density between the adjacent layers differs.

18. The reducing apparatus for carbon particles according to claim 17, wherein each filter is constructed by rolling up a belt-shaped material of each layer which is extended in a sheet, and the belt-shaped material of the outermost peripheral layer is branched off from the middle of a belt-shaped material of the inner layer to provide the filter with a structure which has no step on the outer periphery.

19. The reducing apparatus for carbon particles according to claim 13, wherein the reducing apparatus for carbon particles is used along with one or more rectifying plates and one or more purifiers provided, in order, on the upstream side within the outer cylindrical casing, and the rectifying plate is provided with a plurality of wall openings throughout the rectifying plate to uniformly disperse, rectify, and accelerate the exhaust gas and to cause the temperature to rise, wherein the purifier is provided with a honeycomb core made of metal of which each cell wall is coated by adhesion of an oxidation catalyst such as platinum, and the purifier is provided to oxidize, burn, and reduce carbon monoxide and hydrocarbon contained in the exhaust gas and to oxidize nitrogen oxide into nitrogen dioxide which is supplied to the downstream side.

20. The reducing apparatus for carbon particles according to claim 13, wherein the capture rate and the reduction rate of the carbon particles are set between 5% and 30%.