Exhaust gas filter, method of manufacturing the exhaust gas filter, and exhaust gas processing device using the exhaust gas filter

• US 20050207946A1
• Filed: 03/15/2005
• Published: 09/22/2005
• Est. Priority Date: 03/17/2004
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Asano, Akihiko, Hayashi, Hidemitsu, Tani, Takao, Kurazono, Koichi, Tanaka, Toshiaki, Kubo, Shuichi
• Application Number:
  US11/079,428
• Publication Number:
  US 20050207946A1
• Time in Patent Office: Days
• US Class Current: 422/177
• CPC Class Codes: B01D 2275/30 Porosity of filtering material
• CPC Class Codes: B01D 46/0001 Making filtering elements
• CPC Class Codes: B01D 46/2429 of the honeycomb walls or cells
• CPC Class Codes: B01D 46/24491 Porosity
• CPC Class Codes: B01D 46/24492 Pore diameter
• CPC Class Codes: B01D 46/2482 Thickness, height, width, length or diameter
• CPC Class Codes: B01D 53/9431 Processes characterised by a specific device
• CPC Class Codes: B01D 53/9454 characterised by a specific device
• CPC Class Codes: F01N 3/0222 the structure being monolithic, e.g. honeycombs
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An exhaust gas filter including a filter base body which has many pores and has a flow-in surface, in which exhaust gas containing particulate matter flows, and an exhaust surface, from which purified gas is exhausted, the exhaust gas filter having at least a function of removing the particulate matter from the exhaust gas by passing the exhaust gas through the filter base body from the flow-in surface toward the exhaust surface, wherein a micropore structure, in which agglomerates of particulates having fine gaps are connectedly provided and which is air-permeable and which collects the particulate matter contained in the exhaust gas, is provided at the filter base body at a surface and/or within the pores which open and communicate the flow-in surface and the exhaust surface to and with one another.

Claims

1. An exhaust gas filter including a filter base body which has many pores and has a flow-in surface, in which exhaust gas containing particulate matter flows, and an exhaust surface, from which purified gas is exhausted,

the exhaust gas filter having at least a function of removing the particulate matter from the exhaust gas by passing the exhaust gas through the filter base body from the flow-in surface toward the exhaust surface,

wherein a micropore structure, in which agglomerates of particulates having fine gaps are connectedly provided and which is air-permeable and which collects the particulate matter contained in the exhaust gas, is provided at the filter base body at a surface and/or within the pores which open and communicate the flow-in surface and the exhaust surface to and with one another.

2. The exhaust gas filter of claim 1, wherein a porosity of the micropore structure is within a range of 60 to 90%.

3. The exhaust gas filter of claim 1, wherein the micropore structure is fibrous.

4. The exhaust gas filter of claim 1, wherein the micropore structure contains a material which has heat-resistance and/or a function of oxidizing the particulate matter, and which can be made into particulates of a particle diameter of about 10 nm to 200 nm.

5. The exhaust gas filter of claim 1, wherein the micropore structure is provided in a vicinity of the exhaust surface.

6. The exhaust gas filter of claim 1, wherein a mean pore diameter of the filter base body is within a range of 5 μ

m to 50 μ

m.

7. The exhaust gas filter of claim 1, wherein a catalyst, which has a function of oxidizing the particulate matter, is carried on surfaces of walls of the pores of the filter base body.

8. An exhaust gas filter including a filter base body which has many pores and has a flow-in surface, in which exhaust gas containing particulate matter flows, and an exhaust surface, from which purified gas is exhausted,

the exhaust gas filter having at least a function of removing the particulate matter from the exhaust gas by passing the exhaust gas through the filter base body from the flow-in surface toward the exhaust surface,

wherein a micropore structure, whose thickness is 3.5 μ

m or less and whose mean pore diameter is within a range of 20 nm to 200 nm, is provided within and/or at a surface of the filter base body so as to intersect a direction of passage of the exhaust gas.

9. The exhaust gas filter of claim 8, wherein a porosity of the micropore structure is within a range of 60 to 90%.

10. The exhaust gas filter of claim 8, wherein the micropore structure is fibrous.

11. The exhaust gas filter of claim 8, wherein the micropore structure contains a material which has heat-resistance and/or a function of oxidizing the particulate matter, and which can be made into particulates of a particle diameter of about 10 nm to 200 nm.

12. The exhaust gas filter of claim 8, wherein the micropore structure is provided in a vicinity of the exhaust surface.

13. The exhaust gas filter of claim 8, wherein a mean pore diameter of the filter base body is within a range of 5 μ

m to 50 μ

m.

14. The exhaust gas filter of claim 8, wherein a catalyst, which has a function of oxidizing the particulate matter, is carried on surfaces of walls of the pores of the filter base body.

15. A method of manufacturing an exhaust gas filter including a filter base body which has many pores and has a flow-in surface, in which exhaust gas containing particulate matter flows, and an exhaust surface, from which purified gas is exhausted,

the exhaust gas filter having at least a function of removing the particulate matter from the exhaust gas by passing the exhaust gas through the filter base body from the flow-in surface toward the exhaust surface, and

a micropore structure, in which agglomerates of particulates having fine gaps are connectedly provided and which is air-permeable and which collects the particulate matter contained in the exhaust gas, being provided at the filter base body at a surface and/or within the pores which open and communicate the flow-in surface and the exhaust surface to and with one another,

the method comprising:

a micropore structure precursor forming step of forming a micropore structure precursor by adhering/accumulating heat-resistant particulates in a vicinity of the exhaust surface by sucking-in a gas, in which the heat-resistant particulates are dispersed, from the exhaust surface and exhausting the gas toward the flow-in surface; and

a sintering step of forming the micropore structure by sintering the micropore structure precursor by heating the micropore structure precursor.

16. A method of manufacturing an exhaust gas filter including a filter base body which has many pores and has a flow-in surface, in which exhaust gas containing particulate matter flows, and an exhaust surface, from which purified gas is exhausted,

the exhaust gas filter having at least a function of removing the particulate matter from the exhaust gas by passing the exhaust gas through the filter base body from the flow-in surface toward the exhaust surface, and

a micropore structure, whose thickness is 3.5 μ

m or less and whose mean pore diameter is within a range of 20 nm to 200 nm, being provided within and/or at a surface of the filter base body so as to intersect a direction of passage of the exhaust gas,

the method comprising;

a micropore structure precursor forming step of forming a micropore structure precursor by adhering/accumulating heat-resistant particulates in a vicinity of the exhaust surface by sucking-in a gas, in which the heat-resistant particulates are dispersed, from the exhaust surface and exhausting the gas toward the flow-in surface; and

a sintering step of forming the micropore structure by sintering the micropore structure precursor by heating the micropore structure precursor.

17. An exhaust gas processing device having at least a flow-in port, an exhaust port, a gas flow path connecting the flow-in port and the exhaust port, and a partitioning wall which divides the gas flow path into a flow-in port side and an exhaust port side,

wherein the partitioning wall includes an exhaust gas filter including a filter base body which has many pores and has a flow-in surface, in which exhaust gas containing particulate matter flows, and an exhaust surface, from which purified gas is exhausted,

the exhaust gas filter has at least a function of removing the particulate matter from the exhaust gas by passing the exhaust gas through the filter base body from the flow-in surface toward the exhaust surface,

a micropore structure, in which agglomerates of particulates having fine gaps are connectedly provided and which is air-permeable and which collects the particulate matter contained in the exhaust gas, is provided at the filter base body at a surface and/or within the pores which open and communicate the flow-in surface and the exhaust surface to and with one another, and

the flow-in surface of the exhaust gas filter is provided at the flow-in port side, and the exhaust surface of the exhaust gas filter is provided at the exhaust port side.

18. An exhaust gas processing device having at least a flow-in port, an exhaust port, a gas flow path connecting the flow-in port and the exhaust port, and a partitioning wall which divides the gas flow path into a flow-in port side and an exhaust port side,

wherein the partitioning wall includes an exhaust gas filter including a filter base body which has many pores and has a flow-in surface, in which exhaust gas containing particulate matter flows, and an exhaust surface, from which purified gas is exhausted,

the exhaust gas filter has at least a function of removing the particulate matter from the exhaust gas by passing the exhaust gas through the filter base body from the flow-in surface toward the exhaust surface,

a micropore structure, whose thickness is 3.5 μ

m or less and whose mean pore diameter is within a range of 20 nm to 200 nm, is provided within and/or at a surface of the filter base body so as to intersect a direction of passage of the exhaust gas, and

the flow-in surface of the exhaust gas filter is provided at the flow-in port side, and the exhaust surface of the exhaust gas filter is provided at the exhaust port side.