US3887326A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Kilns and furnaces
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1973-09-21
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Granted: 1975-06-03
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Expires: 1993-09-21
Abstract
Abstract This invention relates to kilns and furnaces in which granular material is heat treated and to a method of operating such kilns and furnaces.
Inventors
- 👤 Harry Townley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:53
CPC Classifications
F; F27; F27B; F27B1/00; F27B1/08; C; C04; C04B; C04B2/00; C04B2/10; C04B2/12; F27B1/005
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
159 words
In a process for operating a vertical shaft kiln which has a plurality of burners disposed around the shaft and through which solid granular material passes downwardly through the shaft and is contacted while in the shaft with hot gaseous fluid, the improved method of obtaining substantially uniform heat treatment of the material leaving the shaft which comprises controlling the flow pattern of said hot gaseous fluid in a manner to obtain a temperature distribution of the hot gaseous fluid in the shaft which is asymmetrical in a horizontal plane at a given level in the shaft so that heating of the downwardly moving material passing through said plane is non-uniform across the shaft and varying the flow pattern of said hot gaseous fluid in a manner to change the asymmetrical temperature distribution at said given level in accordance with a predetermined sequence, all the granular material passing downwardly through the kiln receiving substantially the same overall heat treatment.
Claim 2
Dependent Claim
159 words
In a process for operating a vertical shaft kiln which has a plurality of burners disposed around the shaft and through which solid granular material passes downwardly through the shaft and is contacted while in the shaft with hot gaseous fluid, the improved method of obtaining substantially uniform heat treatment of the material leaving the shaft which comprises controlling the flow pattern of said hot gaseous fluid in a manner to obtain a temperature distribution of the hot gaseous fluid in the shaft which is asymmetrical in a horizontal plane at a given level in the shaft so that heating of the downwardly moving material passing through said plane is non-uniform across the shaft and varying the flow pattern of said hot gaseous fluid in a manner to change the asymmetrical temperature distribution at said given level in accordance with a predetermined sequence, all the granular material passing downwardly through the kiln receiving substantially the same overall heat treatment.
Claim 3
Dependent Claim
159 words
In a process for operating a vertical shaft kiln which has a plurality of burners disposed around the shaft and through which solid granular material passes downwardly through the shaft and is contacted while in the shaft with hot gaseous fluid, the improved method of obtaining substantially uniform heat treatment of the material leaving the shaft which comprises controlling the flow pattern of said hot gaseous fluid in a manner to obtain a temperature distribution of the hot gaseous fluid in the shaft which is asymmetrical in a horizontal plane at a given level in the shaft so that heating of the downwardly moving material passing through said plane is non-uniform across the shaft and varying the flow pattern of said hot gaseous fluid in a manner to change the asymmetrical temperature distribution at said given level in accordance with a predetermined sequence, all the granular material passing downwardly through the kiln receiving substantially the same overall heat treatment.
Claim 4
Dependent Claim
159 words
In a process for operating a vertical shaft kiln which has a plurality of burners disposed around the shaft and through which solid granular material passes downwardly through the shaft and is contacted while in the shaft with hot gaseous fluid, the improved method of obtaining substantially uniform heat treatment of the material leaving the shaft which comprises controlling the flow pattern of said hot gaseous fluid in a manner to obtain a temperature distribution of the hot gaseous fluid in the shaft which is asymmetrical in a horizontal plane at a given level in the shaft so that heating of the downwardly moving material passing through said plane is non-uniform across the shaft and varying the flow pattern of said hot gaseous fluid in a manner to change the asymmetrical temperature distribution at said given level in accordance with a predetermined sequence, all the granular material passing downwardly through the kiln receiving substantially the same overall heat treatment.
Claim 5
Dependent Claim
22 words
A method as in claim 1 wherein the kiln is fired by hot gases produced by combustion of fuel outside the shaft.
Claim 6
Dependent Claim
16 words
A method as in claim 1 wherein the kiln is fired by a normally gaseous fuel.
Claim 7
Dependent Claim
23 words
A method as in claim 1 wherein the kiln is fired by a normally liquid fuel supplied to the shaft in gaseous form.
Claim 8
Dependent Claim
27 words
A method as in claim 1 wherein the configuration of at least one flame front associated with at least one burner is varied in a predetermined sequence.
Claim 9
Dependent Claim
17 words
A method as in claim 1 wherein the pattern of flow is varied in a cyclic sequence.
Claim 10
Dependent Claim
30 words
A method as in claim 1 wherein burners are provided at at least two levels in the shaft, and burners at the said two levels are operated out of phase.
Claim 11
Dependent Claim
29 words
A method as in claim 1 wherein hot gaseous fluid is withdrawn from the shaft and at least a portion of the same is variably returned to the shaft.
Claim 12
Dependent Claim
30 words
A method as in claim 1 wherein the pattern of flow is varied by variation of the location at which exit gases are removed from the top of the shaft.
Claim 13
Dependent Claim
28 words
A method as in claim 1 wherein the pattern of flow is varied in a cyclic sequence having a period in the range 5 minutes to two hours.
Claim 14
Dependent Claim
26 words
A method as in claim 10 wherein the duration of operation in any standing mode in the cycle is in the range 1 to 10 minutes.
Claim 15
Dependent Claim
31 words
A method as in claim 1 wherein the step of varying the flow pattern of said hot gaseous fluid includes supplying fuel at a variable rate to at least one burner.
Claim 16
Dependent Claim
32 words
A method as in claim 1 wherein the step of varying the flow pattern of said hot gaseous fluid includes supplying hot gas at a variable rate to at least one burner.
Claim 17
Dependent Claim
28 words
A method as in claim 1 wherein the step of varying the flow pattern of said hot gaseous fluid includes supplying air to the shaft in varying quantities.
Claim 18
Dependent Claim
28 words
A method as in claim 1 wherein the step of varying the flow pattern of said hot gaseous fluid includes supplying oxygen to the shaft in varying quantities.
Claim 19
Dependent Claim
156 words
In a vertical shaft kiln including a shaft through which solid granular material passes downwardly during operation of the kiln and a plurality of burners disposed symmetrically around the shaft at at least one level for introducing hot gaseous fluid into the shaft, the improvement which comprises means for controlling the flow pattern of the hot gaseous fluid in the shaft in a manner to obtain a temperature distribution of the hot gaseous fluid in the shaft which is asymmetrical in a horizontal plane at a given level in the shaft so that heating of downwardly-moving material passing through said plane is Non-uniform across the shaft, and programming means for varying the flow pattern of the hot gaseous fluid in a manner to change the asymmetrical temperature distribution at said given level in accordance with a predetermined sequence so that all the granular material passing downwardly through the kiln receives substantially the same overall heat treatment.
Claim 20
Dependent Claim
156 words
In a vertical shaft kiln including a shaft through which solid granular material passes downwardly during operation of the kiln and a plurality of burners disposed symmetrically around the shaft at at least one level for introducing hot gaseous fluid into the shaft, the improvement which comprises means for controlling the flow pattern of the hot gaseous fluid in the shaft in a manner to obtain a temperature distribution of the hot gaseous fluid in the shaft which is asymmetrical in a horizontal plane at a given level in the shaft so that heating of downwardly-moving material passing through said plane is Non-uniform across the shaft, and programming means for varying the flow pattern of the hot gaseous fluid in a manner to change the asymmetrical temperature distribution at said given level in accordance with a predetermined sequence so that all the granular material passing downwardly through the kiln receives substantially the same overall heat treatment.
Claim 21
Dependent Claim
20 words
A vertical shaft kiln as in claim 16 wherein burners are disposed at at least two levels in the shaft.
Claim 22
Dependent Claim
32 words
A vertical shaft kiln as in claim 16 wherein said programming means is arranged to provide a variation in the flow pattern of hot gaseous fluid in accordance with a cyclic sequence.
Claim 23
Dependent Claim
47 words
A vertical shaft kiln as in claim 16 wherein the means to vary the pattern of flow of hot gaseous fluid in the shaft includes means to withdraw gaseous fluid from the shaft and variably return at least a proportion of the withdrawn gases to the shaft.
Claim 24
Dependent Claim
38 words
A vertical shaft kiln as in claim 16 wherein the means for varying the flow pattern of the hot gaseous fluid in the shaft includes means for admitting air in variable amounts at the base of the shaft.
Claim 25
Dependent Claim
38 words
A vertical shaft kiln as in claim 16 wherein the means for varying the flow pattern of the hot gaseous fluid in the shaft includes means for admitting oxygen in variable amounts at the base of the shaft.
Claim 26
Dependent Claim
146 words
A vertical shaft kiln comprising: a shaft through which solid granular material passes downwardly during operation of the kiln; a plurality of burners disposed symmetrically around the shaft at a plurality of levels in the shaft for introducing hot gaseous fluid into the shaft; means for controlling the flow pattern of the hot gaseous fluid in the shaft in a manner to obtain at each of a plurality of levels a temperature distribution of the hot gaseous fluid which is asymmetrical in a horizontal plane so that heating of downwardly-moving material passing through each of said planes is non-uniform across the shaft; and programming means for varying the control means in a manner to change the asymmetrical temperature distribution at said levels in accordance with a predetermined sequence so that all the granular material passing downwardly through the kiln receives substantially the same overall heat treatment.
Claim 27
Dependent Claim
146 words
A vertical shaft kiln comprising: a shaft through which solid granular material passes downwardly during operation of the kiln; a plurality of burners disposed symmetrically around the shaft at a plurality of levels in the shaft for introducing hot gaseous fluid into the shaft; means for controlling the flow pattern of the hot gaseous fluid in the shaft in a manner to obtain at each of a plurality of levels a temperature distribution of the hot gaseous fluid which is asymmetrical in a horizontal plane so that heating of downwardly-moving material passing through each of said planes is non-uniform across the shaft; and programming means for varying the control means in a manner to change the asymmetrical temperature distribution at said levels in accordance with a predetermined sequence so that all the granular material passing downwardly through the kiln receives substantially the same overall heat treatment.
Claim 28
Dependent Claim
146 words
A vertical shaft kiln comprising: a shaft through which solid granular material passes downwardly during operation of the kiln; a plurality of burners disposed symmetrically around the shaft at a plurality of levels in the shaft for introducing hot gaseous fluid into the shaft; means for controlling the flow pattern of the hot gaseous fluid in the shaft in a manner to obtain at each of a plurality of levels a temperature distribution of the hot gaseous fluid which is asymmetrical in a horizontal plane so that heating of downwardly-moving material passing through each of said planes is non-uniform across the shaft; and programming means for varying the control means in a manner to change the asymmetrical temperature distribution at said levels in accordance with a predetermined sequence so that all the granular material passing downwardly through the kiln receives substantially the same overall heat treatment.
Claim 29
Dependent Claim
146 words
A vertical shaft kiln comprising: a shaft through which solid granular material passes downwardly during operation of the kiln; a plurality of burners disposed symmetrically around the shaft at a plurality of levels in the shaft for introducing hot gaseous fluid into the shaft; means for controlling the flow pattern of the hot gaseous fluid in the shaft in a manner to obtain at each of a plurality of levels a temperature distribution of the hot gaseous fluid which is asymmetrical in a horizontal plane so that heating of downwardly-moving material passing through each of said planes is non-uniform across the shaft; and programming means for varying the control means in a manner to change the asymmetrical temperature distribution at said levels in accordance with a predetermined sequence so that all the granular material passing downwardly through the kiln receives substantially the same overall heat treatment.
Claim 30
Dependent Claim
48 words
Apparatus as in claim 22 wherein said means for controlling the flow pattern of hot gaseous fluid in the shaft includes means for controlling said burners so as to control the position of the flame front produced by those burners which are disposed at at least one level.
Claim 31
Dependent Claim
63 words
Apparatus as in claim 22 wherein said means for controlling the flow pattern of hot gaseous fluid in the shaft includes means for withdrawing gaseous fluid from the shaft from at least two points at substantially the same level and for varying the rate of withdrawal at one of said points relative to the rate of withdrawal at the other of said points.
Claim 32
Dependent Claim
64 words
Apparatus as in claim 22 wherein said means for controlling the flow pattern of hot gaseous fluid in the shaft includes means for supplying air to at least two points at substantially the same level in the shaft and for varying the rate of supply at one of said points relative to the rate of supply to at least one other of said points.
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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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |