US4093816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Furnace heating apparatus
Assignee: Surface Combustion Corp
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Filing: 1977-02-11
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Granted: 1978-06-06
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Expires: 1997-02-11
Abstract
Abstract A radiantly heated furnace is provided with a heating arrangement capable of generating heat from two different sources of energy. The arrangement includes a thin-walled tube extending within the furnace which operates as a resistor when connected to a high current source of electrical energy to generate and radiate heat within the furnace. The thin-walled tube also acts to radiate heat into the furnace from hot burner gases injected therein by a fuel fired burner. The arrangement is so constructed that switching from the electric to the gas fire mode or vice versa can be swiftly effected without removal of electrical connections or burners.
Inventors
- 👤 Thomas L. Case
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:28
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/62; H05B3/64
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
115 words
Heating apparatus for a furnace enclosure comprising: a thin-walled, open-ended tube extending into and out of said enclosure; electrical power means attached to said ends of said tube for heating said enclosure by initially passing a high amperage current of about 3800 amperes but not less than about 3000 amperes through said tube; combustion means attached to an end of said tube for heating said enclosure by passing hot gases through said tube; and switching means for actuating said electrical power means while deactivating said combustion means without removing said combustion means from said tube and actuating said combustion means while deactivating said electrical power means without removing said electrical power means from said tube.
Claim 2
Dependent Claim
115 words
Heating apparatus for a furnace enclosure comprising: a thin-walled, open-ended tube extending into and out of said enclosure; electrical power means attached to said ends of said tube for heating said enclosure by initially passing a high amperage current of about 3800 amperes but not less than about 3000 amperes through said tube; combustion means attached to an end of said tube for heating said enclosure by passing hot gases through said tube; and switching means for actuating said electrical power means while deactivating said combustion means without removing said combustion means from said tube and actuating said combustion means while deactivating said electrical power means without removing said electrical power means from said tube.
Claim 3
Dependent Claim
32 words
Apparatus of claim 1 wherein said thin-walled tube has a typical wall thickness of about 0.120 inch and no greater than 0.125 inch and a diameter between 4 inches and 8 inches.
Claim 4
Dependent Claim
16 words
Apparatus of claim 2 wherein the cross-section through said tube is constant throughout said tube's length.
Claim 5
Dependent Claim
75 words
Apparatus of claim 4 wherein: said furnace enclosure is defined by a roof, a floor, and a plurality of walls, said tube having at least an entrance end and an exit end with both ends extending through and supported by the same furnace wall, a straight line tube portion adjacent each tube end and a curved tube portion adjacent each straight line tube portion, and at least two supports for each straight line tube portion.
Claim 6
Dependent Claim
24 words
Apparatus of claim 4 wherein a plurality of tubes are provided in said wall, said electrical power means connecting said tubes in series relationship.
Claim 7
Dependent Claim
112 words
Heating apparatus of claim 4 wherein said electrical power means includes: a source of alternating current, a step down transformer connected to said source and in close proximity to said tube, a bus connector comprising substantially straight line segments extending from a first terminal of said transformer to one end of said tube and extending from the opposite end of said tube to a second terminal of said transformer, temperature sensing means in said enclosure for sensing the temperature thereof, transformer actuating means for actuating said temperature sensing means for controlling the output of said transformer, and controller means for actuating said transformer actuating means in accordance with said temperature sensing means.
Claim 8
Dependent Claim
94 words
Heating apparatus of claim 6 wherein said combustion means includes a burner mounted in an isolated manner in one end of said tube, a flue in fluid communication with the opposite end of said tube, a fuel line and an air line to said burner, and pressure regulator means between said air line and said fuel line for controlling fuel flow in accordance with air pressure flow, burner valve means controlling the air flow in said air line, second controller means for controlling said burner valve means in accordance with said temperature sensing means.
Claim 9
Dependent Claim
24 words
Heating apparatus of claim 7 wherein said switching means includes an interlock means for actuating either said electrical power means or said combustion means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |