Patent US4273949A successfully refreshed from Google Patents.
US4273949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arc furnace roof
Assignee: Fried Krupp Huettenwerke AG
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Filing: 1979-07-24
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Granted: 1981-06-16
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Expires: 1999-07-24
Abstract
Abstract An arc furnace roof has a central portion formed by a circular group of individually suspended segments having sides which cooperatively form openings for the passage of arcing electrodes. Each segment is formed by a metal shell having cooling water inlets and outlets and internal baffles causing cooling water to be guided through the shell so that cooling is adequate to avoid the need for lining the bottoms of the segments with thick refractory linings, the bottoms being only coated with a thin layer of refractory electrical insulation. The electrode openings have refractory electrical insulation to isolate the segments from electrode currents.
Inventors
- 👤 Otto Fischer
- 👤 Wilfried Pulvermacher
- 👤 Bernd Koch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:31
CPC Classifications
F; F27; F27D; F27D1/00; F27D1/18; F27D1/1808; F27D1/1816
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
155 words
An arc furnace roof formed by an annular outer group of metal segments and an inner circular group of metal segments and overhead means for individually suspending the segments to form a roof structure, the segments not being otherwise held to each other, the segments of the inner group being shaped as circular sectors and having interfacing radial side walls of which at least two have semicircular side wall portions cooperatively forming at least one arcing electrode passage and having a refractory electrically insulating bushing in said passage, each of the segments of the inner group being hollow and having at least one cooling fluid inlet and outlet and internally containing a series of baffles for guiding cooling fluid as alternately reversing flows extending from the inlet to the outlet, and each having a bottom wall exposed to the interior of an arc furnace using the roof and which is free from refractory thermal insulation.
Claim 2
Dependent Claim
155 words
An arc furnace roof formed by an annular outer group of metal segments and an inner circular group of metal segments and overhead means for individually suspending the segments to form a roof structure, the segments not being otherwise held to each other, the segments of the inner group being shaped as circular sectors and having interfacing radial side walls of which at least two have semicircular side wall portions cooperatively forming at least one arcing electrode passage and having a refractory electrically insulating bushing in said passage, each of the segments of the inner group being hollow and having at least one cooling fluid inlet and outlet and internally containing a series of baffles for guiding cooling fluid as alternately reversing flows extending from the inlet to the outlet, and each having a bottom wall exposed to the interior of an arc furnace using the roof and which is free from refractory thermal insulation.
Claim 3
Dependent Claim
64 words
The roof of claim 1 in which each segment of said inner circular group internally has a cental radial wall extending from its apex formed by its circular sector shape radially to the middle of its outer peripheral wall so as to divide its interior into two compartments, each compartment having said inlets and outlets individually and containing one of said series of baffles.
Claim 4
Dependent Claim
64 words
A roof according to claim 1 and in which said series of baffles is formed by arcuate baffles forming arcuate flow passages each opening to the other alternately at opposite ends, said inlet opening into the one of said passages adjacent to said semicircular side wall portions, at least the innermost ones of said baffles being substantially concentric with said semicircular side wall portion.
Claim 5
Dependent Claim
26 words
The roof of claim 1 and in which strips of elastic refractory electrical insulating material is positioned between said interfacing radial side walls of the segments.
Claim 6
Dependent Claim
111 words
The roof of claim 1 in which said annular outer group of metal segments are shaped as annulus sectors with inner ends conforming to the circular shape of said inner group of segments, the segments of said outer group being hollow and each having at least one cooling fluid inlet and outlet and internally containing a series of baffles which are curved about the axis of the roof and form arcuate flow passages each opening to the other alternately at opposite ends and into which the just-named inlet and outlet open at radially opposite positions, strips of said insulating material being positioned between the sides of all segments of the roof.
Claim 7
Dependent Claim
33 words
The roof of claims 1, 2, 3, 4, or 5 in which the bottoms of said segments are covered by a layer of electrical insulation too thin to function alone as thermal insulation.
References Cited (Backward Citations)
US4107449A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-15 | 1984-12-15 | 1985-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-15 | 1988-12-15 | 1989-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-15 | 1992-12-15 | 1993-06-16 | $7700.00 | Window Closed / Lapsed |