Diesel particulate trap

• US 4,329,162 A
• Filed: 07/03/1980
• Issued: 05/11/1982
• Est. Priority Date: 07/03/1980
• Status: Expired due to Term

• Current Assignee: Corning Glass Works Inc. (Corning Incorporated)
• Original Assignee: Corning Glass Works (Corning Incorporated)
• Inventors: Pitcher, Wayne H. Jr.
• Primary Examiner(s): Lacey, David L.
• Application Number:
  US06/165,391
• Time in Patent Office: 677 Days
• Field of Search: 55/523, 55/DIG. 30, 210/510, 60/295, 60/299, 60/311, 252/477 R, 106/40 R, 106/40 V, 106/41, 106/62, 428/73, 428/116-118, 428/411, 422/180, 75/20 F, 75/68 R, 75/69, 75/93 R, 165/8
• US Class Current: 55/523
• CPC Class Codes: B01D 39/2075 sintered or bonded by inorganic agents
• CPC Class Codes: B01D 46/2407 Filter candles
• CPC Class Codes: C04B 38/0006 Honeycomb structures from one or more corrugated sheets by winding or stacking C04B38/0083
• CPC Class Codes: F01N 2330/06 Ceramic, e.g. monoliths
• CPC Class Codes: F01N 2350/02 Fitting ceramic monoliths in a metallic housing
• CPC Class Codes: F01N 3/0211 Arrangements for mounting filtering elements in housing, e.g. with means for compensating thermal expansion or vibration
• CPC Class Codes: F01N 3/0222 the structure being monolithic, e.g. honeycombs
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y10S 55/30 Exhaust treatment
• CPC Class Codes: Y10T 428/24157 Filled honeycomb cells [e.g., solid substance in cavities, etc.]
• CPC Class Codes: Y10T 428/24744 Longitudinal or transverse tubular cavity or cell

Abstract

Apparatus for filtering solid particulates from suspension in fluid streams (especially carbon particulates from exhaust gas of diesel engines) comprising a honeycomb filter with thin porous walls defining cells extending therethrough, with the transverse cross-sectional shapes of the cells forming a repeating pattern of geometric shapes without interior corner angles of less than 30° and with alternate cells forming an inlet group and an outlet group. The inlet group is open at the inlet face and closed adjacent the outlet face. The outlet group is closed adjacent the inlet face and open at the outlet face. Each cell of each group shares cell walls only with cells of the other group. The walls have a volume of substantially uniform interconnected open porosity and a mean pore diameter of the pores forming the open porosity lying within the area defined by the boundary lines connecting points 1-2-3-4 in FIG. 4.

Claims

1. Apparatus for filtering solid particulates from suspension in fluid streams such as exhaust gas from diesel engines, which comprises a filter of honeycomb structure having

a matrix of thin porous walls defining a plurality of cells extending longitudinally and mutually parallel therethrough between inlet and outlet end faces of the structure,

the walls containing substantially uniform interconnected open porosity of a volume and size sufficient to enable the fluid to flow completely through the walls and to restrain most or all of the particulates from passing completely through the walls,

the transverse cross-sectional shapes of the cells forming a substantially uniformly repeating pattern of geometric shapes without interior corner angles of less than 30°

,

an inlet group of the cells open at the inlet end face and closed adjacent to the outlet end face,

an outlet group of the cells closed adjacent to the inlet end face and open at the outlet end face,

each cell of the inlet group sharing cell walls only with cells of the outlet group and

each cell of the outlet group sharing cell walls only with cells of the inlet group,

wherein the improvement comprises

the volume of interconnected open porosity and the mean pore diameter of the pores forming the open porosity lying within the area defined by the boundary lines connecting points 1-2-3-4 in FIG. 4.

2. Apparatus of claim 1 wherein the walls within each transverse sector of the structure have substantially uniform thickness.

3. Apparatus of claim 1 wherein the walls throughout the structure have a substantially uniform thickness.

4. Apparatus of claim 1 wherein the transverse cross-sectional geometric shapes of the cells are quadrilaterals.

5. Apparatus of claim 4 wherein the geometric shapes are squares.

6. Apparatus of claim 1 wherein

the walls are not greater than about 1.5 mm thick,

the volume of interconnected open porosity and the mean pore diameter of the pores forming the open porosity lie within the area defined by the boundary lines connecting points 1-5-6-4 in FIG. 4, and

the structure has a transverse cross-sectional cell density of at least about 1.5 cells/cm².

7. Apparatus of claim 6 wherein the walls have a thickness in the range of about 0.05-1.27 mm. and the cell density is in the range of about 2-93 cells/cm².

8. Apparatus of claim 7 wherein the walls are not less than about 0.3 mm. thick.

9. Apparatus of claim 8 wherein the walls are not greater than about 0.635 mm thick.

10. Apparatus of claim 9 wherein the cell density is at least about 7.75 cells/cm².

11. Apparatus of claim 10 wherein the geometric shapes of the cells are squares.

12. Apparatus of claim 10 wherein the geometric shapes of the cells are triangles.

13. Apparatus of claim 1 including

a diesel engine exhaust gas conduit, and

a portion of the conduit comprising a housing containing the filter interposed across the exhaust gas path through the housing with the inlet end face of the filter facing upstream of the gas path.

14. Apparatus of claim 13 wherein

the walls throughout the structure having a substantially uniform thickness of not greater than about 1.5 mm,

the transverse cross-sectional geometric shapes of the cells are squares,

the volume of interconnected open porosity and the mean pore diameter of the pores forming the open porosity lie within the area defined by the boundary lines connecting points 1-5-6-4 in FIG. 4, and

the structure has a transverse cross-sectional cell density of at least about 1.5 cells/cm².

15. Apparatus of claim 14 wherein the walls have a thickness in the range of about 0.05-1.27 mm. and the cell density is in the range of about 2-93 cells/cm².

16. Apparatus of claim 15 wherein the walls have a thickness in the range of about 0.3-0.635 mm. and the cell density is at least about 7.75 cells/cm².

17. Apparatus of claim 1 or 13 wherein the filter is fabricated of ceramic material.

18. Apparatus of claim 1 wherein the transverse cross-sectional geometric shapes of the cells are triangles.

19. Apparatus of claim 13 wherein

the walls throughout the structure have a substantially uniform thickness of not greater than about 1.5 mm,

the transverse cross-sectional geometric shapes of the cells are triangles,

the volume of interconnected open porosity and the mean pore diameter of the pores forming the open porosity lie within the area defined by the boundary lines connecting points 1-5-6-4 in FIG. 4, and

the structure has a transverse cross-sectional cell density of at least about 1.5 cells/cm².