US3795478A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of operation of a chamber furnace
Assignee: Koppers Wistra Ofenbau GmbH
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Filing: 1973-02-23
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Granted: 1974-03-05
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Expires: 1993-02-23
Abstract
Abstract A method of operating a chamber furnace for heat treatment of material located in the furnace spaced from the wall thereof by a plurality of high-speed burners arranged so that half of the burners produce a helix of combustion gases extending in one direction about the material to be treated and the other half a helix in the opposite direction and in which during operation of the furnace at full load, all burners are simultaneously operated, during operation of the furnace at 99-50% of its full load all burners are operated for a first time interval and then for a second time interval only half of the burners which produce a helix in the same direction, and during operation of the furnace at less than 50 percent of the full load, only burners which produce a helix in the same direction are operated, whereby during operation of the furnace at less than full loads the burners which produce a helix in the one and in the opposite direction are cyclically changed.
Inventors
- 👤 R Knaak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:29
CPC Classifications
F; F27; F27B; F27B9/00; F27B9/30; F27B9/36; C; C21; C21D; C21D1/00; C21D1/34; C21D1/52; C21D1/74; C21D1/767; F27B9/3005; F27B9/3011; F27D; F27D7/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
251 words
A method of operating an elongated chamber furnace for heat treatment of material located in the furnace spaced from the wall thereof by high-speed burners arranged in n groups in such a manner that the impulses of the flames and combustion gases emanating from the burners of n/2 burner groups produce a helix of combustion gases rotating in one direction about the material to be heated and those from the remaining n/2 burner groups a helix rotating in the opposite direction about the material, said method comprising the steps of operating, during full-load operation of the furnace, the burners of all burner groups simultaneously; operating, during operation of the furnace at 50-99 percent of its full load, only the burners of n/2 burner groups which produce a helix in one direction for a first time interval, then operating the burners of all burner groups simultaneously for a second time interval, then operating the burners of n/2 burner groups which produce a helix in the opposite direction for a first time interval, then operating the burners of all burner groups simultaneously for a second time interval, the operating the burners of n/2 burner groups which produce a helix in the opposite direction for said first time interval, and then again operating the burners of all burner groups for said second time interval; and during operation of the furnace at less than 50 percent of its full-load capacity, alternatingly operating the burners of said n/2 burner groups, each for a predetermined time interval.
Claim 2
Independent Claim
251 words
A method of operating an elongated chamber furnace for heat treatment of material located in the furnace spaced from the wall thereof by high-speed burners arranged in n groups in such a manner that the impulses of the flames and combustion gases emanating from the burners of n/2 burner groups produce a helix of combustion gases rotating in one direction about the material to be heated and those from the remaining n/2 burner groups a helix rotating in the opposite direction about the material, said method comprising the steps of operating, during full-load operation of the furnace, the burners of all burner groups simultaneously; operating, during operation of the furnace at 50-99 percent of its full load, only the burners of n/2 burner groups which produce a helix in one direction for a first time interval, then operating the burners of all burner groups simultaneously for a second time interval, then operating the burners of n/2 burner groups which produce a helix in the opposite direction for a first time interval, then operating the burners of all burner groups simultaneously for a second time interval, the operating the burners of n/2 burner groups which produce a helix in the opposite direction for said first time interval, and then again operating the burners of all burner groups for said second time interval; and during operation of the furnace at less than 50 percent of its full-load capacity, alternatingly operating the burners of said n/2 burner groups, each for a predetermined time interval.
Claim 3
Dependent Claim
84 words
A method as defined in claim 1, wherein during operation of said furnace at 50-99 percent of its full-load capacity, said first time interval is increased and said second time interval is correspondingly increased when the load at which the furnace is to be operated approaches 100 percent of the full-load capacity, whereas when the load at which the furnace is to be operated approaches 50 percent of its full-load capacity, said first time interval is increased and said second time iNterval correspondingly decreased.
Claim 4
Dependent Claim
261 words
A method as defined in claim 1, wherein n is an even number greater than 2, and wherein the load range of operation of the furnace at less than 50 percent of its full-load capacity is divided into a plurality of load ranges increasing stepwise from a minimum to a maximum load range, and wherein during operation within the smallest load range only the burners of one group are intermittently operated, and said one group is cyclically changed within the n/2 burner groups so as to alternatingly produce a helix in the one and in the opposite direction, wherein in the next load range the burners of one group are intermittently operated while at the same time the burners of another group which produce a helix in the same direction as the burners of the one group which are intermittently operated, are continuously operated, and wherein said one and said another group are cyclically changed within the n/2 burner groups, and so on, until in the highest load range (n/2 ) - 1 groups are continuously operated and only one group which produces a helix in the same direction as the (n/2) - 1 burner groups is intermittently operated, and wherein said n/2 - 1 groups and said one group are cyclically changed within the n/2 burner groups, and wherein the time T during which the burner groups are operated which produce a helix in the same direction is subdivided into n/2 time intervals and wherein the cyclical change within the n/2 burner groups is performed in time intervals equalling 2T/n.
Claim 5
Dependent Claim
85 words
A method as defined in claim 3, wherein in the load range between 50-100 percent of the full load the burners of the n/2 burner groups which produce a helix in one direction are operated as base load and the burners of the remaining n/2 burner groups which produce a helix in the opposite direction are operated as regulating load and wherein a change of operation of the burner groups as base load or as regulating load is carried out in the time interval T.
References Cited (Backward Citations)
US3726515A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |