US3675905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for infrared heating
Assignee: Van Dorn Co
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Filing: 1970-09-17
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Granted: 1972-07-11
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Expires: 1990-09-17
Abstract
Abstract The present invention pertains to a novel and improved method of rapidly heating metals and other materials by means of gas-fired infrared generators, and to apparatus therefor. Infrared generators are positioned in close proximity to a workpiece, preferably so that the infrared radiation source is not more than about five inches nor less than about 3/4 inch distant from the surface of the workpiece to be heated. Combustion gas from the generator is directed in turbulent flow onto the workpiece surface facing the generator so as to supplement infrared radiant heating (1) by convection/conduction heat transfer to the workpiece and (2) by secondary radiation from the combustion gas. By use of the method and apparatus of the invention, heating of workpieces is obtained with efficiency and speed far in excess of that possible with prior heating methods.
Inventors
- 👤 Eugene W Placek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:51
CPC Classifications
F; F23; F23C; F23C99/00; C; C21; C21D; C21D1/00; C21D1/34; F23C2700/00; F23C2700/04; F23C2700/043
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
147 words
Apparatus for heating comprising: one or more gas-fired infrared generators, each generator including emitter means and a plenum chamber from which gas is supplied to said emitter means, said emitter means being adapted to direct infrared radiation upon a material to be heated, whereby a portion at least of such radiation is absorbed by and converted to heat within said material, openings in said generator through which hot combustion gases are expulsed from said generator, means for spacing said emitter means a distance from the surface of said material, said distance being such that at least about 10 percent of the total heat imparted to said material is imparted by convention/conduction heating from said hot combustion gases and such that ignition back-flash into said plenum chamber is precluded, means to distribute a combustion gas mixtire to each generator, and ignition means to ignite said combustion gas mixture.
Claim 2
Dependent Claim
147 words
Apparatus for heating comprising: one or more gas-fired infrared generators, each generator including emitter means and a plenum chamber from which gas is supplied to said emitter means, said emitter means being adapted to direct infrared radiation upon a material to be heated, whereby a portion at least of such radiation is absorbed by and converted to heat within said material, openings in said generator through which hot combustion gases are expulsed from said generator, means for spacing said emitter means a distance from the surface of said material, said distance being such that at least about 10 percent of the total heat imparted to said material is imparted by convention/conduction heating from said hot combustion gases and such that ignition back-flash into said plenum chamber is precluded, means to distribute a combustion gas mixtire to each generator, and ignition means to ignite said combustion gas mixture.
Claim 3
Dependent Claim
16 words
The apparatus of claim 1 including ignition switch controller means to cyclically extinguish and re-ignite combustion.
Claim 4
Dependent Claim
20 words
The apparatus of claim 1 including flat locking link means adapted to hold said one or more generators in place.
Claim 5
Dependent Claim
20 words
The apparatus of claim 1 including contour locking link means adapted to hold said one or more generators in place.
Claim 6
Dependent Claim
22 words
The apparatus of claim 1 wherein said distance is not less than about three-quarters inch and not more than about 5 inches.
Claim 7
Dependent Claim
14 words
The apparatus of claim 1 wherein said emitter means comprises a woven metallic screen.
Claim 8
Dependent Claim
20 words
The apparatus of claim 1 wherein said emitter means comprises a plurality of woven metallic screens positioned in overlying relationship.
Claim 9
Dependent Claim
33 words
The apparatus of claim 1 wherein said emitter means comprises three screens of woven Inconel wire positioned in overlying relationship with the weave at a 45* angle to the sides of said generator.
Claim 10
Dependent Claim
85 words
Apparatus for heating comprising: a plurality of gas-fired infrared generators, each generator including infrared radiation emitters; contour locking link means adapted to hold said generators substantially parallel one to the other and in substantially cylindrical configuration in encircling relationship about the periphery of a material to be heated so that said emitters face inwardly towards said material; and stand-off means to space said emitters a distance of not less than about three-quarters inch nor more than about 5 inches from the surface of said material.
Claim 11
Dependent Claim
85 words
Apparatus for heating comprising: a plurality of gas-fired infrared generators, each generator including infrared radiation emitters; contour locking link means adapted to hold said generators substantially parallel one to the other and in substantially cylindrical configuration in encircling relationship about the periphery of a material to be heated so that said emitters face inwardly towards said material; and stand-off means to space said emitters a distance of not less than about three-quarters inch nor more than about 5 inches from the surface of said material.
Claim 12
Dependent Claim
72 words
Apparatus for heating comprising: a plurality of gas-fired infrared generators, each generator including infrared radiation emitters, flat locking link means adapted to hold said generators in predetermined relationship over the surface of a material to be heated with said emitters facing said material, and stand-off means adapted to space said emitters a distance of not less than about three-quarters inch nor more than about 5 inches from the surface of said material.
Claim 13
Dependent Claim
72 words
Apparatus for heating comprising: a plurality of gas-fired infrared generators, each generator including infrared radiation emitters, flat locking link means adapted to hold said generators in predetermined relationship over the surface of a material to be heated with said emitters facing said material, and stand-off means adapted to space said emitters a distance of not less than about three-quarters inch nor more than about 5 inches from the surface of said material.
Claim 14
Dependent Claim
81 words
Apparatus for heating comprising: a plurality of fired infrared generators, each generator including infrared radiation emitters, a frame adapted to hold said plurality of generators in side-by-side relationship with said emitters facing in the same general direction, means to adjustably position said frame in proximity to the surface of a material to be heated so that said emitters are positioned at a distance not less than about three-quarters inch nor more than about 5 inches from said surface of said material.
Claim 15
Dependent Claim
81 words
Apparatus for heating comprising: a plurality of fired infrared generators, each generator including infrared radiation emitters, a frame adapted to hold said plurality of generators in side-by-side relationship with said emitters facing in the same general direction, means to adjustably position said frame in proximity to the surface of a material to be heated so that said emitters are positioned at a distance not less than about three-quarters inch nor more than about 5 inches from said surface of said material.
Claim 16
Dependent Claim
24 words
The apparatus of claim 11 including stand-off means to hold said frame in a position such that said emitters are spaced at said distance.
Claim 17
Dependent Claim
24 words
The apparatus of claim 11 including locking means to hold said frame in a position such that said emitters are spaced at said distance.
Claim 18
Dependent Claim
32 words
The apparatus of claim 11 including means to adjustably recess said plurality of generators within said frame so that said frame serves as stand-off means to space said emitters at said distance.
Claim 19
Dependent Claim
23 words
The apparatus of claim 11 wherein said generators are held in position such that said emitters are substantially aligned with a contoured surface.
Claim 20
Dependent Claim
24 words
The apparatus of claim 11 wherein said frame is adapted to be adjustably raised or lowered over a slab of material to be heated.
Claim 21
Dependent Claim
95 words
Apparatus for heating comprising: one or more infrared generators, each generator including infrared radiation emitters and each generator being mounted within a modular table, stand-off means mounted within said table adjacent said emitters and adapted to space workpieces to be heated at a distance of not less than about three-quarters inch nor more than about 5 inches from said emitters, and hood means adapted to direct combustion gases emerging from said generators in sweeping flow relationship around said workpieces and further adapted to reflect infrared radiation from said emitters back thereto and onto said workpieces.
Claim 22
Dependent Claim
95 words
Apparatus for heating comprising: one or more infrared generators, each generator including infrared radiation emitters and each generator being mounted within a modular table, stand-off means mounted within said table adjacent said emitters and adapted to space workpieces to be heated at a distance of not less than about three-quarters inch nor more than about 5 inches from said emitters, and hood means adapted to direct combustion gases emerging from said generators in sweeping flow relationship around said workpieces and further adapted to reflect infrared radiation from said emitters back thereto and onto said workpieces.
Claim 23
Dependent Claim
49 words
The apparatus of claim 17 wherein said stand-off means comprise stand-off bars, said modular table comprises an outer frame which cooperates with said stand-off bars to space said workpieces at said distance from said emitters, anD said hood has an inner surface which is highly reflective to infrared radiation.
Claim 24
Independent Claim
122 words
A method of heating a material comprising: heating emitters of one or more gas-fired infrared generators to infrared radiation temperature by combusting a gas supplied from a plenum chamber to the emitters of said one or more generators, expulsing hot combustion gases obtained thereby from said one or more generators at a velocity great enough to preclude ignition back-flash into said plenum chambers, impinging infrared radiation from said emitter upon said material whereby a portion at least of said radiation is absorbed by said material and converted to heat therein, and directing said hot gases over said material so that at least about 10 percent of the total heat imparted to said material is imparted by convection/conduction heating by said hot gases.
Claim 25
Independent Claim
122 words
A method of heating a material comprising: heating emitters of one or more gas-fired infrared generators to infrared radiation temperature by combusting a gas supplied from a plenum chamber to the emitters of said one or more generators, expulsing hot combustion gases obtained thereby from said one or more generators at a velocity great enough to preclude ignition back-flash into said plenum chambers, impinging infrared radiation from said emitter upon said material whereby a portion at least of said radiation is absorbed by said material and converted to heat therein, and directing said hot gases over said material so that at least about 10 percent of the total heat imparted to said material is imparted by convection/conduction heating by said hot gases.
Claim 26
Dependent Claim
29 words
The method of claim 19 including cyclic extinguishment and re-ignition of the combusting of said gas within said one or more generators whereby the rate of heating is controlled.
Claim 27
Dependent Claim
19 words
The method of claim 19 including maintaining said one or more generators in position by means of locking links.
Claim 28
Dependent Claim
33 words
The method of claim 19 including positioning said one or more emitters not more than about 5 inches nor less than about three-quarters inch from the surface of said material to be heated.
Claim 29
Dependent Claim
25 words
The method of claim 22 wherein said emitters are positioned not more than about 2 inches nor less than about 1 inch from said surface.
Claim 30
Dependent Claim
11 words
The method of claim 23 wherein said material is a metal.
Claim 31
Dependent Claim
16 words
The method of claim 10 including passing said combustion product gases through openings in said emitter.
Claim 32
Dependent Claim
20 words
The method of claim 25 including increasing the velocity of said combustion product gases as they pass through said openings.
Claim 33
Dependent Claim
20 words
The method of claim 19 including blowing a gas-air mixture into the plenum chamber of said one or more generators.
Claim 34
Dependent Claim
18 words
The method of claim 27 wherein said material is heated to a temperature not less than about 1,600*F.
Claim 35
Dependent Claim
19 words
The method of claim 19 wherein said material is heated to a temperature of not less than about 1,350*F.
Claim 36
Dependent Claim
35 words
The method of claim 19 including introducing a gas-air mixture to be combusted into a plenum chamber contained within said generator and maintaining said plenum chamber at a temperature of not more than about 800*F.
Claim 37
Independent Claim
92 words
A method of heating a material comprising: placing the emitter of one or more gas-fired infrared generators not more than about 5 inches and not less than about three-quarters inch from the surface of the material to be heated, passing hot combustion gases from said one or more generators in turbulent flow over the surface of said material to be heated, and impinging infrared radiation from said emitter upon said material to be heated whereby a part at least of said radiation is absorbed by said material and converted to heat therein.
Claim 38
Independent Claim
92 words
A method of heating a material comprising: placing the emitter of one or more gas-fired infrared generators not more than about 5 inches and not less than about three-quarters inch from the surface of the material to be heated, passing hot combustion gases from said one or more generators in turbulent flow over the surface of said material to be heated, and impinging infrared radiation from said emitter upon said material to be heated whereby a part at least of said radiation is absorbed by said material and converted to heat therein.
Claim 39
Dependent Claim
19 words
The method of claim 31 including holding said one or more generators in placed by means of locking links.
Claim 40
Dependent Claim
29 words
The method of claim 32 wherein a part at least of the surface of the material to be heated is flat and said locking links are flat locking links.
Claim 41
Dependent Claim
29 words
The method of claim 32 wherein a part at least of the surface of the material to be heated is contoured and said locking links are contour locking links.
Claim 42
Dependent Claim
32 words
The method of claim 31 including holding said one or more generators in place by means of a frame adapted to be angularly adjusted in relation to the material to be heated.
Claim 43
Independent Claim
72 words
A method of heating slab-shaped materials comprising positioning a bank of gas-fired infrared generators so that the emitters thereof are not less than about three-quarters inch and not more than about 5 inches from the surface of the slab to be heated, passing combustion gases from said infrared generators in sweeping flow relationship over the surface of said slab and impinging infrared radiation from said emitteRs onto the surface of said slab.
Claim 44
Independent Claim
72 words
A method of heating slab-shaped materials comprising positioning a bank of gas-fired infrared generators so that the emitters thereof are not less than about three-quarters inch and not more than about 5 inches from the surface of the slab to be heated, passing combustion gases from said infrared generators in sweeping flow relationship over the surface of said slab and impinging infrared radiation from said emitteRs onto the surface of said slab.
Claim 45
Independent Claim
110 words
A method of heating one or more workpieces comprising positioning said one or more workpieces on a modular table comprising emitters of one or more gas-fired infrared generators, spacing said one or more workpieces not less than about three-quarters inch and not more than about 5 inches from said emitters by means of spacer bars disposed between and among said emitters, directing hot combustion gases from said one or more generators over and around said one or more workpieces by means of one or more hoods emplaced over said one or more workpieces and over said emitters, and impinging infrared radiation from said emitters onto said one or more workpieces.
Claim 46
Independent Claim
110 words
A method of heating one or more workpieces comprising positioning said one or more workpieces on a modular table comprising emitters of one or more gas-fired infrared generators, spacing said one or more workpieces not less than about three-quarters inch and not more than about 5 inches from said emitters by means of spacer bars disposed between and among said emitters, directing hot combustion gases from said one or more generators over and around said one or more workpieces by means of one or more hoods emplaced over said one or more workpieces and over said emitters, and impinging infrared radiation from said emitters onto said one or more workpieces.
Claim 47
Dependent Claim
26 words
The method of claim 37 wherein said workpieces are spaced not less than about 1 inch and not more than about 2 inches from said emitters.
Claim 48
Dependent Claim
17 words
The method of claim 37 including using two or more modular tables to heat an oversize workpiece.
Claim 49
Independent Claim
161 words
A method of heating a material comprising: combusting a gas within one or more infrared generators containing emitter means to heat said emitter means to infrared radiation temperature, passing hot combustion gases so obtained in turbulent flow relationship over the surface of said material and between said emitter means and said surface, impinging infrared radiation from said emitter means onto said material whereby a part at least of said radiation is absorbed by said material and converted to heat therein, stimulating molecules contained in said hot gases into secondary radiation emissions by radiation bombardment, whereby a part at least of said secondary radiation impinges onto said material and is absorbed and converted to heat therein, absorbing infrared radiation emanating from said material into molecules of said hot gases, and heating said material by means of convection/conduction heating by said gases so that at least about 10 percent of the total heat imparted to said material is imparted by said convection/conduction heating.
Claim 50
Independent Claim
161 words
A method of heating a material comprising: combusting a gas within one or more infrared generators containing emitter means to heat said emitter means to infrared radiation temperature, passing hot combustion gases so obtained in turbulent flow relationship over the surface of said material and between said emitter means and said surface, impinging infrared radiation from said emitter means onto said material whereby a part at least of said radiation is absorbed by said material and converted to heat therein, stimulating molecules contained in said hot gases into secondary radiation emissions by radiation bombardment, whereby a part at least of said secondary radiation impinges onto said material and is absorbed and converted to heat therein, absorbing infrared radiation emanating from said material into molecules of said hot gases, and heating said material by means of convection/conduction heating by said gases so that at least about 10 percent of the total heat imparted to said material is imparted by said convection/conduction heating.
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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |