US4391585A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of operating a continuous ceramic kiln
Assignee: Air Products and Chemicals Inc
•
Filing: 1981-03-20
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Granted: 1983-07-05
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Expires: 2001-03-20
Abstract
Abstract A method of operating a continuous ceramic kiln having a decarbonization zone characterized in that oxygen or oxygen enriched air is added to the decarbonization zone to maintain the average oxygen concentration in the decarbonization zone at or about a predetermined level. The predetermined level need only be adjusted for different throughputs and need not be adjusted for moderate changes in the amount of organic matter in the clay.
Inventors
- 👤 Eric K. Riley
- 👤 Colin D. Smith
- 👤 Garry J. Yates
- 👤 Norris W. Shepherd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:33
CPC Classifications
F; F27; F27B; F27B9/00; F27B9/30; F27B9/36; C; C04; C04B; C04B33/00; C04B33/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
214 words
A method of decarbonizing shaped ceramic articles in an intermittent push continuous ceramic kiln having a heating and decarbonizing zone, a firing zone and a cooling zone fitted with means to sense the concentration of oxygen in the decarbonizing zone, said means associated with a control fitted to oxygen or oxygen enriched air injection means associated with said decarbonizing zone comprising the steps of: progressively heating said shaped ceramic articles to about 900° C. in the decarbonizing zone to oxidize organic matter contained in the articles; maintaining the oxygen concentration of the decarbonization zone at a minimum level of 7.5% by volume between pushes as determined by the equation: ##EQU3## where C is the predetermined level at a point in the decarbonization zone; R 1 is the throughput of clayware articles during satisfactory operation of the kiln without oxygen addition; A is the average oxygen concentration at said point during satisfactory operation of the kiln without oxygen addition at throughput rate R 1 ; R 2 is the new throughput of clayware articles; and X is between the limits of ≧0 and ≦0.5, by adding oxygen or oxygen enriched air to the decarbonization zone; continuing heating of said shaped ceramic articles until firing is completed; and cooling said shaped ceramic articles to ambient temperature.
Claim 2
Independent Claim
214 words
A method of decarbonizing shaped ceramic articles in an intermittent push continuous ceramic kiln having a heating and decarbonizing zone, a firing zone and a cooling zone fitted with means to sense the concentration of oxygen in the decarbonizing zone, said means associated with a control fitted to oxygen or oxygen enriched air injection means associated with said decarbonizing zone comprising the steps of: progressively heating said shaped ceramic articles to about 900° C. in the decarbonizing zone to oxidize organic matter contained in the articles; maintaining the oxygen concentration of the decarbonization zone at a minimum level of 7.5% by volume between pushes as determined by the equation: ##EQU3## where C is the predetermined level at a point in the decarbonization zone; R 1 is the throughput of clayware articles during satisfactory operation of the kiln without oxygen addition; A is the average oxygen concentration at said point during satisfactory operation of the kiln without oxygen addition at throughput rate R 1 ; R 2 is the new throughput of clayware articles; and X is between the limits of ≧0 and ≦0.5, by adding oxygen or oxygen enriched air to the decarbonization zone; continuing heating of said shaped ceramic articles until firing is completed; and cooling said shaped ceramic articles to ambient temperature.
Claim 3
Dependent Claim
36 words
A method according to claim 1, characterized in that the concentration of oxygen in the decarbonization zone is measured at a point in the decarbonization zone where the temperature is nominally between 700° and 875° C.
Claim 4
Dependent Claim
18 words
A method according to claim 2, characterized in that said temperature is nominally between 750° and 850° C.
Claim 5
Dependent Claim
45 words
A method according to claim 1, characterized in that the oxygen or oxygen enriched air is injected into the kiln at a position where the nominal kiln temperature is between 800° and 950° C. and where the injected oxygen will flow through the decarbonization zone.
Claim 6
Dependent Claim
20 words
A method according to claim 1, characterized in that said predetermined level is between 7.5 and 11% oxygen (by volume).
Claim 7
Dependent Claim
20 words
A method according to claim 5, characterized in that said predetermined level is between 8 and 8.5% oxygen (by volume).
References Cited (Backward Citations)
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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) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |