US3786165A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preheating method for furnaces
Assignee: Bpifrance Financement SA
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Filing: 1972-11-30
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Granted: 1974-01-15
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Expires: 1992-11-30
Abstract
Abstract The furnace has n superposed rows of m heating elements suspended on supports, the assembly bounding a heating cavity in the form of a tunnel. The elements are U-shaped and suspended at the ends of their arms. At least some of these elements are heated to 2000* to 2200*C by a movable preheating element, supplemented by radiation from the initially preheated elements to the others progressively.
Inventors
- 👤 Nee Barbier A Anthony
- 👤 K Dembinski
- 👤 Nee Dupre M Faucher
- 👤 L Dupont
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:20
CPC Classifications
F; F27; F27D; F27D11/00; F27D11/02; H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/141
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
195 words
A method of preheating a furnace of the type comprising an assembly of a plurality of heating elements, each heating element being a resistor heating element of oxidation-resistant refractory material having two arms connected at one end by a common part, said arms being in the form of elongated parallel strips having narrow facing sides along their longest dimension, the other ends of said arms being free and adapted so that they can be suspended and adapted to be supplied with electric current, the thickness of said arms as well as the distance which separates them decreasing from the free ends in thE direction of the common part; each said element of the furnace resting by its two arms on separate neighbouring supports constructed of a material compatible with that of the heating elements at the temperature of operation of the latter, heat-insulating means being provided to protect the said elements and supports: said method comprising the steps of heating to 2,000* - 2,200*C at least some of said heating elements by a movable preheating element, preheating of the other elements then occurring from one to the next by radiation from the initially preheated elements.
Claim 2
Independent Claim
195 words
A method of preheating a furnace of the type comprising an assembly of a plurality of heating elements, each heating element being a resistor heating element of oxidation-resistant refractory material having two arms connected at one end by a common part, said arms being in the form of elongated parallel strips having narrow facing sides along their longest dimension, the other ends of said arms being free and adapted so that they can be suspended and adapted to be supplied with electric current, the thickness of said arms as well as the distance which separates them decreasing from the free ends in thE direction of the common part; each said element of the furnace resting by its two arms on separate neighbouring supports constructed of a material compatible with that of the heating elements at the temperature of operation of the latter, heat-insulating means being provided to protect the said elements and supports: said method comprising the steps of heating to 2,000* - 2,200*C at least some of said heating elements by a movable preheating element, preheating of the other elements then occurring from one to the next by radiation from the initially preheated elements.
Claim 3
Dependent Claim
70 words
Method of preheating according to claim 1, comprising heating only some opposite heating elements by said preheating element, heat insulating means being provided on both sides of the preheating element, gradually moving said insulating means and said preheating elements outwardly from the time when the heating elements directly preheated have reached the temperature at which they become conductive, and cutting off the supply of the preheating elements from said time.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |