Patent US3620518A successfully refreshed from Google Patents.
US3620518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and device for the treatment of surfaces of workpieces in an annealing furnace
Assignee: Evonik Operations GmbH
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Filing: 1970-02-25
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Granted: 1971-11-16
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Expires: 1990-02-25
Abstract
Abstract Protective and carrier gases which are to be used in various processes in annealing furnaces are produced in situ with the aid of catalysts applied to the inner surfaces of the furnaces. Preferably the oxygen containing gas is preheated before being mixed with fuel to form the protective or carrier gas.
Inventors
- 👤 Karl-Heinz Winter
- 👤 Ottwin Krach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:44
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/20; C23C8/22; C21; C21D; C21D1/00; C21D1/74; C21D1/76; C21D1/763; C23C8/28; C23C8/30; C23C8/32
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
13 words
An apparatus according to claim 1 wherein said mixing means comprises a nozzle.
Claim 2
Dependent Claim
64 words
In a process for treating a workpiece in an annealing furnace in an atmosphere of a protective or carrier gas, the improvement comprising forming the gas for said treatment in said furnace by preheating oxygen mixing the preheated oxygen with fuel and combusting the mixture of fuel and oxygen while contacting the mixture with a catalyst adapted to catalyze the formation of said gas.
Claim 3
Dependent Claim
31 words
A process according to claim 3 in which said catalyst is present at least in part as a coating on an inner surface of said furnace and said fuel includes hydrocarbon.
Claim 4
Dependent Claim
18 words
A process according to claim 4 wherein the preheating is to a temperature of 600* to 1,600* C.
Claim 5
Dependent Claim
16 words
A process according to claim 5 wherein the preheating is to a temperature of 800* C.
Claim 6
Dependent Claim
22 words
A process according to claim 4 wherein the catalyst is selected from the group consisting of nickel, nickel oxide, platinum and palladium.
Claim 7
Dependent Claim
27 words
A process according to claim 7 wherein the gas is selected from the group consisting of a carburizing gas, a carbonitriding gas and a bright hardening gas.
Claim 8
Dependent Claim
22 words
A process according to claim 8 wherein the fuel and preheated oxygen are partially combusted before contacting the catalyst in the furnace.
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) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |