US4070542A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of beta-alumina ceramic articles and furnace therefor
Assignee: Electricity Council
•
Filing: 1975-09-22
•
Granted: 1978-01-24
•
Expires: 1995-09-22
Abstract
Abstract In making β-alumina ceramic articles by a fast firing technique in which the green shapes of compressed powder material are sintered by passing them continuously through a tubular furnace, the furnace is sloped upwardly to give convective air flow forwardly through the furnace at a speed not less than the speed of movement of the article or other means are provided for causing such an air flow or flow of other oxygen-containing gas. An induction furnace is described having a rotating tube and automatic temperature control means.
Inventors
- 👤 Lyndon James Miles
- 👤 Ivor Wynn Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:28
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; H05B6/105; H05B6/108; C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/113; H05B6/06; H05B2213/00; H05B2213/07
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
54 words
A furnace for the production of β-alumina ceramic articles comprising an open-ended tube with heating means for heating the tube and means for moving the articles continuously through the tube at a uniform rate and having means for inducing oxygen-containing gas to flow through the tube in the direction of movement of the articles.
Claim 2
Dependent Claim
54 words
A furnace for the production of β-alumina ceramic articles comprising an open-ended tube with heating means for heating the tube and means for moving the articles continuously through the tube at a uniform rate and having means for inducing oxygen-containing gas to flow through the tube in the direction of movement of the articles.
Claim 3
Dependent Claim
34 words
A furnace as claimed in claim 1 wherein the tube is sloped upwardly with respect to the horizontal in the direction of movement of the articles to induce convective air flow through the tube.
Claim 4
Dependent Claim
23 words
A furnace as claimed in claim 2 wherein the tube is sloped upwardly at an angle of 4 to 10° to the horizontal.
Claim 5
Dependent Claim
18 words
A furnace as claimed in claim 1 wherein said heating means comprise an induction coil around the tube.
Claim 6
Dependent Claim
20 words
A furnace as claimed in claim 4 wherein a susceptor block is arranged around said tube within the induction coil.
Claim 7
Dependent Claim
16 words
A furnace as claimed in claim 5 wherein said susceptor block is a block of graphite.
Claim 8
Dependent Claim
86 words
A furnace for the production of β-alumina ceramic articles comprising an open-ended tube, a susceptor block having a bore through which said open-ended tube passes, an induction coil around said susceptor block, a second tube through said susceptor block, means for moving the ceramic articles continuously through said open-ended tube at a uniform rate, means for inducing oxygen-containing gas to flow through said open-ended tube in the direction of movement of the articles, and a radiation pyrometer for observing a test element within said second tube.
Claim 9
Dependent Claim
86 words
A furnace for the production of β-alumina ceramic articles comprising an open-ended tube, a susceptor block having a bore through which said open-ended tube passes, an induction coil around said susceptor block, a second tube through said susceptor block, means for moving the ceramic articles continuously through said open-ended tube at a uniform rate, means for inducing oxygen-containing gas to flow through said open-ended tube in the direction of movement of the articles, and a radiation pyrometer for observing a test element within said second tube.
Claim 10
Dependent Claim
28 words
A furnace as claimed in claim 7 wherein automatic control means are provided responsive to said radiation pyrometer and arranged to control the power supply to said furnace.
Claim 11
Dependent Claim
38 words
A furnace as claimed in claim 7 wherein the tube through which the β-alumina articles are traversed and the tube containing the test element are symmetrically disposed on opposite sides of the axis of the induction heating coil.
Claim 12
Dependent Claim
18 words
A furnace as claimed in claim 7 wherein said second tube through said susceptor block has open ends.
Claim 13
Dependent Claim
93 words
A furnace for the production of β-alumina ceramic articles comprising a susceptor block, an open-ended tube extending through said susceptor block, an induction coil around said susceptor block, means for rotating said open-ended tube about its axis, means for moving the ceramic articles continuously through said open-ended tube at a uniform rate, means for inducing oxygen-containing gas to flow through said open-ended tube in the direction of movement of the articles, a second tube extending into said susceptor block, and means responsive to the temperature of a test element in said second tube.
Claim 14
Dependent Claim
93 words
A furnace for the production of β-alumina ceramic articles comprising a susceptor block, an open-ended tube extending through said susceptor block, an induction coil around said susceptor block, means for rotating said open-ended tube about its axis, means for moving the ceramic articles continuously through said open-ended tube at a uniform rate, means for inducing oxygen-containing gas to flow through said open-ended tube in the direction of movement of the articles, a second tube extending into said susceptor block, and means responsive to the temperature of a test element in said second tube.
Claim 15
Dependent Claim
37 words
A furnace as claimed in claim 11 wherein the tube containing the β-alumina ceramic articles is continuously rotated and is arranged within a second stationary tube of slightly greater diameter extending through the susceptor block and furnace.
Claim 16
Dependent Claim
26 words
A furnace as claimed in claim 11 wherein said means responsive to the temperature of a test element in said second tube is a radiation pyrometer.
Claim 17
Dependent Claim
55 words
A furnace for the production of β-alumina ceramic articles comprising an open-ended tube with heating means for heating the tube and means for moving the articles continuously through the tube at a uniform rate and having means for forcing an oxygen-containing gas to flow through the tube in the direction of movement of the articles.
Claim 18
Dependent Claim
55 words
A furnace for the production of β-alumina ceramic articles comprising an open-ended tube with heating means for heating the tube and means for moving the articles continuously through the tube at a uniform rate and having means for forcing an oxygen-containing gas to flow through the tube in the direction of movement of the articles.
Claim 19
Dependent Claim
18 words
A furnace as claimed in claim 14 and further comprising means for rotating said tube about its axis.
References Cited (Backward Citations)
US3226465A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |