US3884667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tunnel furnace, and a method of operating same
Assignee: Smit Nijmegan BV
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Filing: 1973-09-17
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Granted: 1975-05-20
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Expires: 1993-09-17
Abstract
Abstract A method and apparatus for the heat treatment of articles in a tunnel furnace comprises means for transporting the articles in longitudinal direction through a tunnel furnace having separate successive sections each with variable temperature controls, means for controlling the temperature of the air in each of the sections and for circuiting the air transversely across the articles traveling longitudinally therein to obtain a more uniform temperature about the articles in each section, and means for controlling and for inducing a longitudinal flow of air between sections by controlling air inlet and exhaust damper means to vary the quantity of cooling air admitted relative to the quantity of exhaust air expelled. The method and apparatus provide a better adjustment of the temperature curve for the articles passing through the furnace.
Inventors
- 👤 Willem Schraven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:32
CPC Classifications
F; F27; F27B; F27B9/00; F27B9/30; F27B9/3005; F27B9/3011; C; C03; C03B; C03B25/00; C03B25/04; C03B25/06; F27B9/02; F27B9/029; F27B9/14; F27B9/20; F27B9/24; F27B9/243
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
176 words
A method for the heat treatment of articles comprising transporting said articles in a longitudinal direction through a horizontal tunnel furnace having separate successive sections each with variable temperature controls, controlling the temperature of the air in each of said sections by operating said variable temperature controls, circulating air transversely to the articles traveling in the longitudinal direction to obtain a more uniform air temperature about the articles in each section, drawing air into each section by a selectively controlled air damper and fan means in each section, exhausting air from each section through selectively controlled outlet damper means in each section, sensing the temperature in said sections, inducing a longitudinal flow of air between adjacent sections by varying the pressure between sections, and controlling in accordance with the temperature values in said sections the selective drawing in and exhausting of air from the respective sections to change the pressure between the sections and to induce the longitudinal flow and to provide a uNiform and predictable cooling cycle for the articles passing longitudinally through the furnace.
Claim 2
Independent Claim
176 words
A method for the heat treatment of articles comprising transporting said articles in a longitudinal direction through a horizontal tunnel furnace having separate successive sections each with variable temperature controls, controlling the temperature of the air in each of said sections by operating said variable temperature controls, circulating air transversely to the articles traveling in the longitudinal direction to obtain a more uniform air temperature about the articles in each section, drawing air into each section by a selectively controlled air damper and fan means in each section, exhausting air from each section through selectively controlled outlet damper means in each section, sensing the temperature in said sections, inducing a longitudinal flow of air between adjacent sections by varying the pressure between sections, and controlling in accordance with the temperature values in said sections the selective drawing in and exhausting of air from the respective sections to change the pressure between the sections and to induce the longitudinal flow and to provide a uNiform and predictable cooling cycle for the articles passing longitudinally through the furnace.
Claim 3
Dependent Claim
41 words
The method in accordance with claim 1 in which the step of inducing longitudinal flow includes a greater quantity air from said second section than is drawn in at said second section to create a longitudinal flow in said tunnel furnace.
Claim 4
Dependent Claim
182 words
A tunnel furnace for cooling articles with a controlled temperature as the articles pass longitudinally through the furnace, said furnace comprising a plurality of successive sections through which articles are transported, conveyor means for transporting the articles in the longitudinal direction through said sections, variable temperature control means in each of said sections for controlling the temperature of air therein, circulating means in each section for circulating the air therein transversely to the articles traveling in the longitudinal direction to obtain a more uniform air temperature about the articles in each section, temperature sensing means for sensing the air temperature within said sections, air inlet and exhaust damper means in each of said sections movable to positions to vary the quantity of cooling air drawn in relative to the quantity of exhaust air expelled, and a control means for positioning said air inlet and exhaust damper means in accordance with temperature values in said sections to induce a longitudinal flow of air between adjacent sections to provide a more uniform and predictable cooling cycle as the articles pass longitudinally through the furnace.
Claim 5
Dependent Claim
182 words
A tunnel furnace for cooling articles with a controlled temperature as the articles pass longitudinally through the furnace, said furnace comprising a plurality of successive sections through which articles are transported, conveyor means for transporting the articles in the longitudinal direction through said sections, variable temperature control means in each of said sections for controlling the temperature of air therein, circulating means in each section for circulating the air therein transversely to the articles traveling in the longitudinal direction to obtain a more uniform air temperature about the articles in each section, temperature sensing means for sensing the air temperature within said sections, air inlet and exhaust damper means in each of said sections movable to positions to vary the quantity of cooling air drawn in relative to the quantity of exhaust air expelled, and a control means for positioning said air inlet and exhaust damper means in accordance with temperature values in said sections to induce a longitudinal flow of air between adjacent sections to provide a more uniform and predictable cooling cycle as the articles pass longitudinally through the furnace.
References Cited (Backward Citations)
US2544947A
Cited
US2822645A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |