US3690628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and a rotary kiln for producing a bloated clay product
Assignee: Saint Gobain Denmark AS
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Filing: 1970-08-06
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Granted: 1972-09-12
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Expires: 1990-08-06
Abstract
Abstract A bloated granular clay product is manufactured by heating clay in a first step from atmospheric temperature to 300*-600* C. during a long period of time whereafter the clay now forming granules in a second step is heated to 1,150*-1,175* C. in a relatively short period of time i.e., about 15 - 30 minutes. The heating is effected in a rotary kiln having a drying section and a burning section. The first heating step is provided in the drying section and the second heating step takes place in a transition zone between the two sections. To ensure the quick heating in said second step there is provided heat transfer means in the transition zone.
Inventors
- 👤 Harry Kamstrup-Larsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:47
CPC Classifications
C; C04; C04B; C04B20/00; C04B20/02; C04B20/04; C04B20/06; C04B20/061; F; F27; F27B; F27B7/00; F27B7/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
37 words
A method as claimed in claim 1 characterized in that the heating of the clay product from a temperature in the interval 300*-600* C. to a temperature in the interval 1,150-1,175* C. is made during 20-30 minutes.
Claim 2
Dependent Claim
141 words
A rotary kiln for use in producing an expanded clay product comprising a rotary drying portion, a rotary burning portion and a rotary transition portion located intermediate said drying and burning portions, said transition portion being in flow communication with said drying and burning portions, said transition portion comprising a body having an axis of rotation and a generally cylindrically shaped interior surface spaced radially from said axis, a plurality of heat transfer members disposed generally concentrically about said axis in said body and supported to extend closely adjacent said interior surface thereof, said members having a heat capacity and thermal conductivity that is high relative to that of the other portions of said kiln, said members being arranged in close proximity to one another so as to present a large surface area to material being treated in said transition portion.
Claim 3
Dependent Claim
27 words
The rotary kiln as claimed in claim 3 wherein said heat transfer members are rings having diameters smaller than that of the interior surface of said body.
Claim 4
Dependent Claim
70 words
The rotary kiln as claimed in claim 3 wherein said heat transfer members are a plurality of tapered trays, each tray having an open tapered end, said trays being attached in end to end relation to form annular rings, said rings being positioned along said axis of said interior surface, said tapered end of each of said trays being disposed to merge into an adjacent tray of a said ring.
Claim 5
Dependent Claim
28 words
The rotary kiln as claimed in claim 5 wherein each of said trays hAs side edge portions which extend in the direction of said axis of said body.
Claim 6
Dependent Claim
21 words
The rotary kiln as claimed in claim 5 wherein said rings of trays are mounted to be contiguous to one another.
Claim 7
Dependent Claim
30 words
The rotary kiln as claimed in claim 6 wherein said trays have bottom surfaces and said side edges of said trays are connected to said bottom surfaces with sloping surfaces.
Claim 8
Dependent Claim
50 words
The rotary kiln as claimed in claim 4 wherein said rings are attached to said interior surface by holding means such that the centers of said rings will define a sine curve in a plane passing through a diameter of said interior surface and through said axis of said body.
Claim 9
Dependent Claim
28 words
The rotary kiln as claimed in claim 3 wherein said heat transfer members comprise a plurality of bars which are arranged to extend generally parallel to said axis.
Claim 10
Dependent Claim
38 words
The rotary kiln as claimed in claim 10 wherein two radially spaced layers of bars are provided, the bars of one layer being arranged so as to register with the spaces between the bars in the other layer.
Claim 11
Dependent Claim
25 words
The rotary kiln as claimed in claim 10 wherein the distance between adjacent bars is between one to five times the diameter of one bar.
Claim 12
Dependent Claim
17 words
The rotary kiln as claimed in claim 3 wherein said heat transfer members are made of steel.
Claim 13
Dependent Claim
30 words
The rotary kiln as claimed in claim 3 wherein said heat transfer members comprise a plurality of flat bands, each band having an outer surface constructed from a wear-resistant material.
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) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |