US4060375A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods and apparatus for the heat treatment of fine-grained materials
Assignee: ThyssenKrupp Industrial Solutions AG
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Filing: 1976-01-12
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Granted: 1977-11-29
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Expires: 1996-01-12
Abstract
Abstract Fine-grained material such as raw ground cement adapted to be fired in a rotary tube furnace is introduced to a vertical preheater and falls through a heating zone located at a level below the level at which the material enters the preheater. A stream of air enters the preheater at a level below the heating zone and passes upwardly at sufficient velocity to entrain the material that has passed through the heating zone, thereby causing such material to pass again through the heating zone. From the preheater the material is delivered to the furnace for final firing.
Inventors
- 👤 Paul Weber
- 👤 Hans Mollenkopf
- 👤 Kurt Henning
- 👤 Otto Heinemann
- 👤 Heinz-Herbert Schmits
- 👤 Wolfgang Rother
- 👤 Horst Ritzmann
- 👤 Jurgen Wurr
- 👤 Karl Krutzner, Jr.
- 👤 Werner Schossler
- 👤 Wolf Goldmann
- 👤 Georg Schepers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:17
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/36; C04B7/43; C04B7/434; F; F27; F27B; F27B7/00; F27B7/20; F27B7/2016; F27B7/2025; F27B7/2033
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
184 words
A method for the heat treatment of fine-grained material prior to firing said material in a furnace having a walled, vertical waste gas conduit, said method comprising conducting a waste gas stream from said furnace upwardly through said conduit at a predetermined velocity; supplying fine-grained material having a grain size so related to the velocity of said gas stream that no substantial portion of said material is entrained by said gas stream; introducing said material into said conduit at a first level between its upper and lower ends so that said material will fall downwardly in opposition to said gas stream toward the lower end of said conduit; combusting fuel in said conduit at a second level below said first level to provide a heating zone below the level at which said material is introduced to said conduit; and deflecting downwardly moving material inwardly of said conduit toward the center thereof and at a level above that of said heating zone to assure that said downwardly moving material passes through said heating zone as said material falls toward said lower end of said conduit.
Claim 2
Independent Claim
184 words
A method for the heat treatment of fine-grained material prior to firing said material in a furnace having a walled, vertical waste gas conduit, said method comprising conducting a waste gas stream from said furnace upwardly through said conduit at a predetermined velocity; supplying fine-grained material having a grain size so related to the velocity of said gas stream that no substantial portion of said material is entrained by said gas stream; introducing said material into said conduit at a first level between its upper and lower ends so that said material will fall downwardly in opposition to said gas stream toward the lower end of said conduit; combusting fuel in said conduit at a second level below said first level to provide a heating zone below the level at which said material is introduced to said conduit; and deflecting downwardly moving material inwardly of said conduit toward the center thereof and at a level above that of said heating zone to assure that said downwardly moving material passes through said heating zone as said material falls toward said lower end of said conduit.
Claim 3
Dependent Claim
34 words
A method according to claim 1 including generating heat at said zone by the combustion of fuel in an atmosphere containing oxygen at a concentration of between 5 and 14 percent of said atmosphere.
Claim 4
Dependent Claim
17 words
A method according to claim 2 wherein the concentration of oxygen is between 8 and 12 percent.
Claim 5
Dependent Claim
18 words
A method according to claim 1 including heating said gas stream prior to its introduction to said conduit.
Claim 6
Dependent Claim
16 words
A method according to claim 1 wherein said gas stream contains at least 2.5 percent oxygen.
Claim 7
Dependent Claim
20 words
A method according to claim 1 wherein said gas stream has a velocity of at least 7 meters per second.
Claim 8
Dependent Claim
17 words
A method according to claim 1 including delivering material from said conduit to a rotary tube furnace.
Claim 9
Dependent Claim
19 words
A method according to claim 7 wherein said gas stream is introduced to said conduit directly from said furnace.
Claim 10
Dependent Claim
19 words
A method according to claim 1 wherein said gas stream passes upwardly through said conduit with a whirling movement.
Claim 11
Dependent Claim
29 words
A method according to claim 1 wherein said gas stream is accelerated following its passage through said heating zone and at the level at which said material is deflected.
Claim 12
Dependent Claim
35 words
A method according to claim 1 wherein said material is deflected toward the center of said conduit at a plurality of vertically spaced levels all of which are above the level of said heating zone.
Claim 13
Dependent Claim
195 words
Apparatus for the heat treatment of fine-grained material prior to firing said material in a furnace, said apparatus comprising a walled conduit having a substantially vertical portion; inlet means for introducing material at a first level to said conduit such that said material may fall downwardly through said vertical portion; means defining a constriction of said conduit at least at one level below said first level, said conduit having on opposite sides of said constriction a cross-sectional area greater than that of said conduit at said constriction, said constriction sloping downwardly and inwardly toward the center of said conduit; means for combusting fuel at a level below said constriction to provide a heating zone through which said material passing said constriction may fall; and means for delivering a stream of waste furnace gas to said conduit at a level below said heating zone and at such velocity with respect to the grain size of said material that no substantial portion of said material is entrained in said stream, the velocity of said gas stream being sufficient to decelerate a substantial portion of the material which passes downwardly past said constriction and into said heating zone.
Claim 14
Dependent Claim
195 words
Apparatus for the heat treatment of fine-grained material prior to firing said material in a furnace, said apparatus comprising a walled conduit having a substantially vertical portion; inlet means for introducing material at a first level to said conduit such that said material may fall downwardly through said vertical portion; means defining a constriction of said conduit at least at one level below said first level, said conduit having on opposite sides of said constriction a cross-sectional area greater than that of said conduit at said constriction, said constriction sloping downwardly and inwardly toward the center of said conduit; means for combusting fuel at a level below said constriction to provide a heating zone through which said material passing said constriction may fall; and means for delivering a stream of waste furnace gas to said conduit at a level below said heating zone and at such velocity with respect to the grain size of said material that no substantial portion of said material is entrained in said stream, the velocity of said gas stream being sufficient to decelerate a substantial portion of the material which passes downwardly past said constriction and into said heating zone.
Claim 15
Dependent Claim
18 words
Apparatus according to claim 12 wherein there are a plurality of said constrictions vertically spaced from one another.
Claim 16
Dependent Claim
21 words
Apparatus according to claim 13 wherein said fuel combusting means is located at a level below the lowermost of said constrictions.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-28 | 1981-05-30 | 1981-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-28 | 1985-05-30 | 1985-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-28 | 1989-05-30 | 1989-11-29 | $7700.00 | Window Closed / Lapsed |