Patent US3575398A successfully refreshed from Google Patents.
US3575398A
Expired / Lapsed
US
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Apparatus for minimizing atmosphere upset in a furnace for heat treating articles
Assignee: Grimes Aerospace Co
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Filing: 1968-11-13
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Granted: 1971-04-20
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Expires: 1988-11-13
Abstract
Abstract This invention relates to the prevention of atmosphere upset and to the rapid recovery from such an upset which is caused by contaminating gases entering through the workpiece discharge opening of a controlled atmosphere furnace or hot chamber. The discharge opening is protected by a flame screen directed across its outer face and by a jet stream curtain of gases directed outwardly across the opening. Atmosphere is constantly supplied to the furnace and, additionally, a restoring gas is supplied intermittently to the furnace.
Inventors
- 👤 Joseph A Lincoln
- 👤 Orville E Cullen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:27
CPC Classifications
F; F27; F27D; F27D99/00; F27D99/0073; F27D99/0075; C; C21; C21D; C21D1/00; C21D1/74
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
117 words
A controlled atmosphere furnace comprising: walls defining a heat processing chamber having a discharge opening associated therewith, a jet stream curtain barrier means directed across said opening for producing an unbalanced outward component of force in said opening, said barrier including two jet stream curtains directed at an angle towards each other with at least one of said curtains being directed outwardly with respect to said opening, means for continuously supplying atmosphere to said chamber means for automatically supplying a surge of enriching gas to said chamber in response to a predetermined event and when said chamber is open to ambient atmosphere, said surge supply means having an inlet which is separate from said jet stream curtains.
Claim 2
Dependent Claim
117 words
A controlled atmosphere furnace comprising: walls defining a heat processing chamber having a discharge opening associated therewith, a jet stream curtain barrier means directed across said opening for producing an unbalanced outward component of force in said opening, said barrier including two jet stream curtains directed at an angle towards each other with at least one of said curtains being directed outwardly with respect to said opening, means for continuously supplying atmosphere to said chamber means for automatically supplying a surge of enriching gas to said chamber in response to a predetermined event and when said chamber is open to ambient atmosphere, said surge supply means having an inlet which is separate from said jet stream curtains.
Claim 3
Dependent Claim
35 words
A furnace according to claim 1 wherein at least one jet stream curtain emanates from a side of said opening and is directed so as to impinge upon an opposite side surface of said opening.
Claim 4
Dependent Claim
36 words
A furnace according to claim 1 wherein said jet stream includes two jet stream curtains directed at an angle with respect to each other and one of said jet stream curtains is a curtain of flame.
Claim 5
Dependent Claim
19 words
A furnace accordinG to claim 1 wherein one of said jet stream curtains is a curtain of nonoxidizing gas.
Claim 6
Dependent Claim
109 words
A controlled atmosphere furnace comprising: a heat processing chamber, a hot vestibule adjacent said processing chamber, an entry door means between said chamber and said hot vestibule for the admission of heat treated workpieces into said hot vestibule from said processing chamber, a discharge opening in said vestibule having a door for the removal of said workpieces from said hot vestibule, jet stream means for directing a barrier curtain of gases outwardly across the discharge door opening from within said hot vestibule and a flame curtain directed across the outside face of said opening whereby contaminating gases are prevented from entering said hot vestibule through said discharge door opening.
Claim 7
Dependent Claim
109 words
A controlled atmosphere furnace comprising: a heat processing chamber, a hot vestibule adjacent said processing chamber, an entry door means between said chamber and said hot vestibule for the admission of heat treated workpieces into said hot vestibule from said processing chamber, a discharge opening in said vestibule having a door for the removal of said workpieces from said hot vestibule, jet stream means for directing a barrier curtain of gases outwardly across the discharge door opening from within said hot vestibule and a flame curtain directed across the outside face of said opening whereby contaminating gases are prevented from entering said hot vestibule through said discharge door opening.
Claim 8
Dependent Claim
42 words
A furnace according to claim 5 wherein said discharge door means has a threshold and said curtain is directed from the top of said discharge door opening downwardly towards said threshold and impinges thereon at an angle of incidence of about 60*.
Claim 9
Dependent Claim
22 words
A furnace according to claim 5 further including means for actuating said barrier in response to the opening of said discharge door.
Claim 10
Dependent Claim
28 words
A furnace according to claim 5 further including means for supplying a quantity of atmosphere restoring gas to said hot vestibule intermittently in response to an atmosphere upset.
Claim 11
Dependent Claim
39 words
A furnace according to claim 8 further including means for initiating the flow of said atmosphere restoring gas in response to the opening of said discharge door and discontinuing said flow when the atmosphere in the vestibule is restored.
Claim 12
Dependent Claim
39 words
A furnace according to claim 9 further including means for constantly supplying an atmosphere carrier gas to said hot vestibule at a rate at least 5 times the rate at which the restoring gas is supplied to said vestibule.
Claim 13
Dependent Claim
36 words
A furnace according to claim 9 further including means for constantly supplying an atmosphere carrier gas to said hot vestibule at the rate of approximately 5 to 10 times the volume of the chamber per hour.
Claim 14
Dependent Claim
125 words
A controlled atmosphere furnace comprising: a heat processing chamber, a subsequent chamber adjacent said processing chamber, an entry door means between said chambers for the admission of heat treated workpieces into said subsequent chamber from said processing chamber, a discharge door means in said subsequent chamber for removing workpieces therefrom, jet stream means for directing a high velocity curtain barrier outwardly across the discharge door opening from within said subsequent chamber, means for intermittently supplying a restoring gas to said subsequent chamber in response to an atmosphere upset, means for directing a curtain of flame across the outside face of said opening whereby the upset of the furnace atmosphere caused by opening of the discharge door is minimized and the desired atmosphere is rapidly restored.
Claim 15
Dependent Claim
125 words
A controlled atmosphere furnace comprising: a heat processing chamber, a subsequent chamber adjacent said processing chamber, an entry door means between said chambers for the admission of heat treated workpieces into said subsequent chamber from said processing chamber, a discharge door means in said subsequent chamber for removing workpieces therefrom, jet stream means for directing a high velocity curtain barrier outwardly across the discharge door opening from within said subsequent chamber, means for intermittently supplying a restoring gas to said subsequent chamber in response to an atmosphere upset, means for directing a curtain of flame across the outside face of said opening whereby the upset of the furnace atmosphere caused by opening of the discharge door is minimized and the desired atmosphere is rapidly restored.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |