Trap apparatus with tubular filter element

• US 5,293,742 A
• Filed: 04/14/1993
• Issued: 03/15/1994
• Est. Priority Date: 06/27/1991
• Status: Expired due to Fees

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: Betts, Peter, Gillingham, Gary R., Barris, Marty A., Wagner, Wayne M., Rothman, James C., Robertson, Kelly C.
• Primary Examiner(s): Hart, Douglas
• Application Number:
  US08/047,772
• Time in Patent Office: 335 Days
• Field of Search: 60/274, 60/288, 60/303, 60/311, 55/DIG. 30, 55/466, 55/523
• US Class Current: 60/288
• CPC Class Codes: F01N 2230/02 Exhaust filters
• CPC Class Codes: F01N 2330/10 Fibrous material, e.g. mineral or metallic wool
• CPC Class Codes: F01N 2430/04 by adding non-fuel substances to combustion air or fuel, e.g. additives
• CPC Class Codes: F01N 3/0212 with one or more perforated tubes surrounded by filtering material, e.g. filter candles
• CPC Class Codes: F01N 3/0226 the structure being fibrous
• CPC Class Codes: F01N 3/023 using means for regenerating the filters, e.g. by burning trapped particles by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F01N 3/0235 using exhaust gas throttling means
• CPC Class Codes: F01N 3/027 using electric or magnetic heating means
• CPC Class Codes: F01N 3/032 during filter regeneration only
• CPC Class Codes: F01N 3/0335 with exhaust silencers in a single housing
• CPC Class Codes: Y10S 55/30 Exhaust treatment

Abstract

A muffler-filter apparatus having a particulate trap using filter tubes with high temperature filter materials, like fiber in the form of yarn, woven yarn mat, or a non-woven, random array fiber mat, or various foams. Filter tubes have various structural configurations and are regenerated by axial propagation using ring heaters or stub rod heaters, by heating the entire length of the filter tube with a rod heater or some other full-length heater configuration. For regeneration, exhaust flow is bypassed using various valve configurations including a poppet valve, a shutter valve, or a tubular valve. Filter tube filters may also be self-regenerated by the heat from the exhaust gases as controlled by a throttle valve or on inclusion of fuel additives which lower particulate ignition temperature.

Claims

1. Apparatus for processing exhaust gases from an engine, said apparatus comprising:

a housing receiving said exhaust gases at an upstream end and exhausting said exhaust gases from a common space through an outlet downstream;

a plurality of flow paths for said exhaust gases in a region between said inlet and said common space;

an arrangement of filter modules operably placed in said flow paths;

means with said exhaust gases flowing for selectively regenerating at any time at least one and less than all of said filter modules; and

means for separating said exhaust gases upstream of said filter modules away from said one and less than all of said filter modules being regenerated and maintaining said exhaust gases separation from said one and less than all of said filter modules being regenerated until said exhaust gases flow to said common space.

2. Apparatus in accordance with claim 1 wherein each if said filtering means has a longitudinal axis and a filter material volume solidity sufficient to create more surface loading of particulates than depth loading, said regenerating means for each of said filtering means including means for igniting the particulates and propagating combustion axially.

3. Apparatus in accordance with claim 1 wherein each of said filtering means has a filter material volume solidity sufficient to create more depth loading of particulates than surface loading, said regenerating means for each of said filtering means including means for igniting said depth loading and combusting the particulates.

4. Apparatus in accordance with claim 1 wherein each of said filtering means has a longitudinal length and said regenerating means for each of said filtering means includes means spaced from said wall with filter material along substantially the entire longitudinal length for radiating heat toward said filter material to ignite and combust the particulates.

5. Apparatus in accordance with claim 1 wherein said regenerating means includes an exhaust gas throttle valve.

6. Apparatus in accordance with claim 1 wherein said filter module includes filter material to filter said particulates and tubular means for supporting said filter material;

an electrical heater having electrodes adapted to be energized to heat said particulates to combustion thereby regenerating said filter material, sad heater having an axis, said heater being spaced from and surrounded along said axis by said filter module; and

means for controlling said heater.

7. Apparatus in accordance with claim 6 wherein said filter material includes a ceramic fiber yarn wound about said tubular supporting means.

8. Apparatus in accordance with claim 6 wherein said filter material includes a woven mat of fibers.

9. Apparatus in accordance with claim 6 wherein said filter material includes a mat formed from a non-woven, random array of fibers.

10. Apparatus in accordance with claim 8 wherein said mat includes a plurality of layers having a plurality of volume solidity values.

11. Apparatus in accordance with claim 9 wherein said mat includes a plurality of layers having a plurality of volume solidity values.

12. Apparatus in accordance with claim 6 wherein said filter material has opposite ends relative to said axis, said heater being in the form of a ring near one of said ends.

13. Apparatus in accordance with claim 6 wherein said filter material has opposite ends relative to said axis, said heater being in the form of a rod extending from near one of said ends toward the other.

14. Apparatus in accordance with claim 13 wherein said rod is in the form of a helix.

15. Apparatus in accordance with claim 13 wherein said rod is in the form of a perforated tube.

16. Apparatus in accordance with claim 13 wherein said supporting means includes said rod.

17. Apparatus in accordance with claim 16 wherein said supporting means includes a mesh surrounding said rod along said axis.

18. Apparatus in accordance with claim 17 wherein said rod is in the form of a helix.

19. Apparatus in accordance with claim 6 wherein said filter material has opposite ends relative to said axis, said heater being in the form of a wire mesh extending between said ends.

20. Apparatus in accordance with claim 6 wherein said supporting means includes a perforated tube surrounding said filter material.

21. Apparatus for processing exhaust gases from an engine, said apparatus comprising:

an enclosure having inlet means and outlet means for passing the exhaust gases;

means in the enclosure for segmenting flow of said exhaust gases into a plurality of fluid flow paths, said segmenting means including a valve which variously directs the flow among the paths, said segmenting means including an assembly with a plurality of openings, each of said openings leading to one of said flow paths, said valve including a shutter and means for directing said shutter to variously close one of said openings;

means for filtering said exhaust gases flowing along each of said paths, each of said filtering means being a module, each of said modules having an open interior for flow of exhaust gases and a wall with filter material;

means for supporting said modules relative to said housing so that each said wall with filter material has open space thereabout for flow of exhaust gases;

means for heating said filtering means in said one of said fluid flow paths closed by said shutter directing means to cause particulates accumulated thereon to combust thereby regenerating said filtering means in said one path; and

means for controlling said valve and said heating means.

22. Apparatus in accordance with claim 21 wherein said enclosure includes a plurality of canisters, each of said canisters having an inlet tube leading from common manifold means.

23. Apparatus in accordance with claim 27 wherein said valve is tubular with first means for flow restriction upstream from said filtering means and second means for flow restriction downstream from said filtering means.

24. Apparatus in accordance with claim 21 wherein said controlling means includes a first electrical contact on said shutter and a second electrical contact on said assembly whereby said shutter variously opens and closes electrical continuity between said first and second contacts as said shutter opens and closes said openings thereby energizing said heater when said shutter closes one of said openings and likewise closes continuity between said first and second contacts.

25. Apparatus in accordance with claim 21 wherein said valve includes a member which is movable between closed and open positions, said member including electrical contacts which make and break electrical continuity energizing said heating means, respectively.

26. Apparatus in accordance with claim 25 wherein said member includes a heating element extending into the open interior of one of said modules.

27. Apparatus in accordance with claim 21 including means in said enclosure for bypassing said filtering means.

28. Apparatus in accordance with claim 27 wherein said bypassing means includes a pressure relief valve between said inlet means and said outlet means.

29. Apparatus in accordance with claim 21 wherein said supporting means includes a tube, one of said filtering means modules fitting within said tube.

30. A filter module for trap apparatus used to process exhaust gases from an engine, comprising:

tubular means for filtering particulates from said exhaust gases;

means, connected with said trap apparatus, for supporting said tubular filtering means, said supporting means including a tubular structural support closely adjacent said tubular filtering means; and

electrical resistance means arranged in separation from said tubular filtering means for periodically radiating heat energy to said tubular filtering means and particulates accumulated therein to cause said particulates to combust;

thereby periodically regenerating said tubular filtering means without said radiating means deteriorating due to high temperature contact with said filtering means during particulates combustion.

31. The module in accordance with claim 30 including means for insulating one end of said tubular filtering means thereby closing said end to flow of exhaust gases and retaining that heat energy within said tubular filtering means.