US4086050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for gas circulation in a heat treating furnace
Assignee: Ipsen International GmbH
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Filing: 1976-01-05
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Granted: 1978-04-25
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Expires: 1996-01-05
Abstract
Abstract The method for gas circulation in a furnace, such as a vacuum furnace, for the heat treatment of work pieces wherein the gas is caused to circulate with turbulence while avoiding a set or stable flow pattern and the vacuum furnace adapted to carry out this method by means of fans so located and operated as to circulate the gas with turbulence and vorticity.
Inventors
- 👤 Cornelis Hendricus Luiten
- 👤 Ferdinand Limque
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:29
CPC Classifications
F; F27; F27D; F27D7/00; F27D7/04; C; C21; C21D; C21D1/00; C21D1/74; C21D1/767; C21D1/773
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
64 words
Method for thermo-chemical treatment of work pieces in a furnace operated at pressure, in particular vacuum, characterized by the steps of treating the charge, introducing the treating gas into the vacuum chamber containing the charge, causing the gas to become turbulent while avoiding a stable gas circulation, and varying the flow pattern and intensity of the gas circulation during the treatment of the charge.
Claim 2
Dependent Claim
64 words
Method for thermo-chemical treatment of work pieces in a furnace operated at pressure, in particular vacuum, characterized by the steps of treating the charge, introducing the treating gas into the vacuum chamber containing the charge, causing the gas to become turbulent while avoiding a stable gas circulation, and varying the flow pattern and intensity of the gas circulation during the treatment of the charge.
Claim 3
Dependent Claim
19 words
Method according to claim 1, characterized in that heating is effected by direct heat transfer through radiation in vacuum.
Claim 4
Dependent Claim
62 words
A vacuum furnace for the heat treatment of work pieces comprising a heating chamber, means for supporting work pieces in said chamber, means for evacuating said chamber, means for heating said work pieces, means for supplying a gas to said chamber, a plurality of closely spaced fans in said chamber and means coordinating said fans to circulate said gas with increased vorticity.
Claim 5
Dependent Claim
62 words
A vacuum furnace for the heat treatment of work pieces comprising a heating chamber, means for supporting work pieces in said chamber, means for evacuating said chamber, means for heating said work pieces, means for supplying a gas to said chamber, a plurality of closely spaced fans in said chamber and means coordinating said fans to circulate said gas with increased vorticity.
Claim 6
Dependent Claim
27 words
A vacuum furnace according to claim 3 in which includes means for controlling and the varying the speed of rotation of at least one of said fans.
Claim 7
Dependent Claim
29 words
A vacuum furnace according to claim 3 in which the coordinating means includes means for controlling and varying the direction of rotation of at least one of said fans.
Claim 8
Dependent Claim
31 words
A vacuum furnace according to claim 3 in which the coordinating means includes means for controlling and varying the speed and direction of rotation of at least one of said fans.
Claim 9
Dependent Claim
23 words
A vacuum furnace according to claim 3 in which the coordinating means includes means for controlling independently the operation of the respective fans.
Claim 10
Dependent Claim
39 words
A vacuum furnace according to claim 3 wherein each fan is provided with two blades disposed crosswise to each other, and the fans are mounted with the radii of rotation of their blades spaced by only a short distance.
Claim 11
Dependent Claim
21 words
A vacuum furnace according to claim 3 wherein the fans are mounted adjacent to the upper wall of the heatiing chamber.
Claim 12
Dependent Claim
14 words
A vacuum furnace according to claim 3 wherein more than two fans are provided.
Claim 13
Dependent Claim
19 words
A vacuum furnace according to claim 3 wherein the heating means comprises radiation heating elements in the heating chamber.
References Cited (Backward Citations)
US1949716A
Cited
US2091172A
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US2589811A
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US2800317A
Cited
US2839285A
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US3399875A
Cited
US3517916A
Cited
US3850574A
Cited
US3837794A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-24 | 1981-10-24 | 1982-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-24 | 1985-10-24 | 1986-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-24 | 1989-10-24 | 1990-04-25 | $7700.00 | Window Closed / Lapsed |