Patent US3646689A successfully refreshed from Google Patents.
US3646689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continually operating fluidized bed dryer for drying loose material
Assignee: Werner and Pfleiderer GmbH
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Filing: 1970-09-11
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Granted: 1972-03-07
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Expires: 1990-09-11
Abstract
Abstract A continuously operating fluidized bed dryer for loose material such as granulated material comprises a housing in which the fluidized bed is generated by feeding the material into the housing and fluidizing the same by a flow of pressurized air directed upon the material in the housing. Two or more meshing conveyor screws are rotatably mounted in the housing substantially occupying the space therein within which the fluidized bed is generated. The meshing turns or windings of the screws define a plurality of individual fluidizing chambers by which the material fed into the housing at the intake end thereof is conveyed to the discharge end of the housing.
Inventors
- 👤 Gunther Kuchenthal
- 👤 Wolfgang Hentzschel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:34
CPC Classifications
F; F26; F26B; F26B17/00; F26B17/18; F26B17/20; F26B3/00; F26B3/02; F26B3/06; F26B3/08; F26B3/092; F26B3/0923
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
41 words
The dryer according to claim 1 and comprising a second conduit communicating with space within the housing above said conveyor screws for discharging spent air from the housing and particles of material escaping from said chambers and entrained in the air.
Claim 2
Dependent Claim
25 words
The dryer according to claim 2 wherein said housing includes above the conveyor screws an air-stilling space, said second conduit communicating with said air-stilling space.
Claim 3
Dependent Claim
23 words
The dryer according to claim 2 wherein said second conduit includes a cyclone separator for liberating the spend air from particles entrained therein.
Claim 4
Dependent Claim
22 words
The dryer according to claim 1 wherein said conduit communicates with the housing through apertures in the bottom wall of the housing.
Claim 5
Dependent Claim
21 words
The dryer according to claim 1 wherein a drive means with gradually variable speed is drivingly coupled to said conveyor screws.
Claim 6
Dependent Claim
30 words
The dryer according to claim 1 wherein each of said conveyor screws comprises a shaft having mounted thereon a helically wound strip, said strips defining the windings of the screws.
Claim 7
Dependent Claim
29 words
The dryer according to claim 7 wherein the windings of adjacent conveyor screws mesh tightly one with another and have outer diameters extending closely adjacent to the respective shafts.
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) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |