US5571298A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Regeneratable filter for combustible particles, particularly soot filter
Assignee: Individual
•
Filing: 1995-08-09
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Granted: 1996-11-05
•
Expires: 2015-08-09
Abstract
Abstract To prevent damage to an electrical resistance heater (13-16) which, when energized by electrical energy, for example in the order of 100 A at 12-24 V, a heat reservoir substance is included in the filter, positioned in heat transfer relation to the electrical resistance heater (13-16) and located, with respect to the flow direction of the gas stream through the filter, upstream of the filter material (15). Preferably, the electrical resistance heater is a perforated, tubular sheet-metal structure, axial ends of which are electrically connectable by connecting bolts (21, 25) to an electrical energy supply. The heat reservoir substance (14) is either wrapped at the outside over the tubular resistance heater (13-16), applied as a layer (14a) at the inside of the tubular resistance heater, or filled into the hollow interior thereof in form of a wire wool (14b). This substantially increases the heat transfer or heat exchange surface between the resistance heater and gases flowing therethrough, thus decreasing required electrical heating energy and protecting the resistance heater (13-16) against overheating upon variations in gas flow when the heater is energized. A typical heater temperature is 1300° C., and it is, for example, made of sheet metal of 22% chromium, 4.8% aluminum, the remainder iron; the filter material preferably includes mineral fibers and metal wire; the heat reservoir substance (14) can be Inconel (Reg. TM) wire, preferably knitted.
Inventors
- 👤 Alfred Buck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:54
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/24; B01D46/2403; B01D46/2411; B01D39/00; B01D39/10; B01D39/12; B01D46/66; B01D46/80; B01D46/84; F; F01; F01N; F01N3/00; F01N3/02; F01N3/021; F01N3/0211; F01N3/0212; F01N3/022; F01N3/0226; F01N3/023; F01N3/027; B01D2279/00; B01D2279/30; F01N2330/00; F01N2330/10; Y; Y10; Y10S; Y10S55/00; Y10S55/10; Y10S55/30
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
217 words
Regeneratable filter for combustible solid particles within a gas stream, having a housing (2) having a gas stream inlet (7) and a gas stream outlet (8); a filter medium support (13) located in the housing (2); gas pervious, high temperature resistant filter material (15) supported on said filter medium support (13); an electrical resistance heater (13-16) located in the housing and positioned, with respect to the flow direction of the gas stream through the filter, upstream of said filter material (15), and comprising, in accordance with the invention, a heat transfer material (14) located in the housing, and having, inherently, limited thermal inertia, said heat transfer material being located in physical heat transfer contact with the electrical resistance heater (13-16), to increase the effective heat transfer surface of the electrical resistance heater to the gas stream and affect heat transfer from said heater to the gas stream without essentially inhibiting gas flow; said heat transfer material having a surface in contact with the gas which is substantially larger than the surface of the electrical resistance heater; and said heat transfer material (14) being positioned, with respect to the flow direction of the gas stream through the filter, upstream of said filter material (15), and thermally exposed to said gas stream for heat exchange with the gas stream.
Claim 2
Dependent Claim
217 words
Regeneratable filter for combustible solid particles within a gas stream, having a housing (2) having a gas stream inlet (7) and a gas stream outlet (8); a filter medium support (13) located in the housing (2); gas pervious, high temperature resistant filter material (15) supported on said filter medium support (13); an electrical resistance heater (13-16) located in the housing and positioned, with respect to the flow direction of the gas stream through the filter, upstream of said filter material (15), and comprising, in accordance with the invention, a heat transfer material (14) located in the housing, and having, inherently, limited thermal inertia, said heat transfer material being located in physical heat transfer contact with the electrical resistance heater (13-16), to increase the effective heat transfer surface of the electrical resistance heater to the gas stream and affect heat transfer from said heater to the gas stream without essentially inhibiting gas flow; said heat transfer material having a surface in contact with the gas which is substantially larger than the surface of the electrical resistance heater; and said heat transfer material (14) being positioned, with respect to the flow direction of the gas stream through the filter, upstream of said filter material (15), and thermally exposed to said gas stream for heat exchange with the gas stream.
Claim 3
Dependent Claim
18 words
The filter of claim 1, wherein said filter medium support (13), simultaneously, forms said electrical resistance heater (13-16).
Claim 4
Dependent Claim
20 words
The filter of claim 1, wherein said electrical resistance heater (13-16) is electrically insulated from said heat transfer material (14).
Claim 5
Dependent Claim
49 words
The filter of claim 1, wherein said electrical resistance heater (13-16) comprises a tubular sheet-metal structure, thermally coupled to the heat transfer material (14), and a plurality of holes (16) formed in said structure to reduce the cross-sectional area of said tubular structure and increase the electrical resistance thereof.
Claim 6
Dependent Claim
26 words
The filter of claim 4, wherein the tubular sheet-metal structure forming the resistance heater (13-16) has axial end portions (13a) which are insulated from each other.
Claim 7
Dependent Claim
18 words
The filter of claim 5, wherein said end portions (13a) are spaced from each other by a gap.
Claim 8
Dependent Claim
23 words
The filter of claim 1, wherein said heat transfer material is located between the electrical resistance heater (13-16) and said filter material (15).
Claim 9
Dependent Claim
34 words
The filter of claim 1, wherein, with respect to the flow direction of the gas stream through the filter, said heat transfer material (14) is located in advance of said electrical resistance heater (13-16).
Claim 10
Dependent Claim
25 words
The filter of claim 1, wherein said heat transfer material (14) comprises a fibrous or filamentary body which is formed of essentially flat textile material.
Claim 11
Dependent Claim
30 words
The filter of claim 9, wherein said electrical resistance heater (13-16) is a hollow tubular structure, and said heat transfer material (14) loosely fills the interior of said hollow structure.
Claim 12
Dependent Claim
26 words
The filter of claim 1, wherein said transfer material substance (14) comprises a textile body of good heat conductive and high heat resistant filaments or fibers.
Claim 13
Dependent Claim
15 words
The filter of claim 11, wherein said filaments or fibers are wire filaments or fibers.
Claim 14
Dependent Claim
14 words
The filter of claim 11, wherein said textile material body comprises a woven structure.
Claim 15
Dependent Claim
14 words
The filter of claim 11, wherein said textile material body comprises a knitted structure.
Claim 16
Dependent Claim
14 words
The filter of claim 1, wherein said heat transfer material (14) comprises wire wool.
Claim 17
Dependent Claim
18 words
The filter of claim 15, wherein said wire wool is a substantially flat body formed as felted material.
Claim 18
Dependent Claim
37 words
The filter of claim 1, wherein said electrical resistance heater (13-16) is a hollow tubular structure and said heat transfer material (14a) is formed as a layer, lining the interior, in circumferential direction, of said tubular structure.
Claim 19
Dependent Claim
34 words
The filter of claim 1, wherein the electrical resistance heater (13-16) is a hollow tubular structure and said heat transfer material (14) is wound about the tubular structure in form of a wound layer.
Claim 20
Dependent Claim
26 words
The filter of claim 1, wherein said filter material (15) comprises a plurality of portions (32) of filter material structure in the form of textile material.
Claim 21
Dependent Claim
39 words
The filter of claim 19, wherein said portions of textile material structure are rolled in ring form (32); and wherein a plurality of such ring-formed rolls are located, axially next to each other, about the electrical resistance heater (13-16).
Claim 22
Dependent Claim
29 words
The filter of claim 1, further including a filter holder (33) located within the housing (2), said filter holder surrounding the filter material (15), and having a gas-pervious wall.
Claim 23
Dependent Claim
38 words
The filter of claim 21, further including end walls (37) engaging end portions of the filter material (15), and forming, with the filter holder (33), the resistance heater (13-16) and the heat transfer material (14), a filter cartridge.
Claim 24
Dependent Claim
29 words
The filter of claim 1, wherein said filter material (15) comprises, at least in part, at least one of fibers, or filaments of good heat conductive material, or wire.
Claim 25
Dependent Claim
38 words
The filter of claim 1, wherein said filter comprises a soot filter for exhaust gases from a Diesel engine, and said gas stream inlet (7) includes means for coupling the filter to the exhaust from a Diesel engine.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-11-05 | 2000-05-06 | 2000-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-05 | 2004-05-06 | 2004-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-05 | 2008-05-06 | 2008-11-05 | $7700.00 | Window Closed / Lapsed |