US3909958A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiple pass drying apparatus
Assignee: Individual
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Filing: 1974-09-27
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Granted: 1975-10-07
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Expires: 1994-09-27
Abstract
Abstract Apparatus for treating a material by indirect heat exchange comprising a plurality of conveyor passes arranged in series, each pass having a centrally disposed hollow conveyor screw, means for passing a heating medium through the conveyor screw and through a hollow screw flight of the conveyor screw, a heating jacket disposed around the conveyor screw and the material to be treated, means for exhausting vapor emanating from the material under a vacuum, and the material passing in series from one pass to another. Preferably the conveyor screws are driven in unison and the heat exchange medium from one pass flows to the next concurrently with the material. Breaker means are provided adjacent the inlet to the apparatus to prevent caking of the wet material. The breaker means are disposed around the conveyor shaft and are actuated by a planetary gear arrangement connected to the drive for the conveyor shaft. The apparatus has particular utility for the drying of wet coal since the coal is maintained out of direct contact with the heating fluid and thus coal dust does not exhaust to the atmosphere.
Inventors
- 👤 Alder F Castanoli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:18
CPC Classifications
F; F26; F26B; F26B17/00; F26B17/18; F26B17/20; F26B17/205; F26B23/00; F26B23/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
218 words
Apparatus for subjecting a material to indirect heat exchange comprising a casing, a plurality of passes arranged in series within said casing, each pass including an annular jacket and a conveyor screw disposed in said heating jacket, said conveyor screw having a hollow shaft and having a hollow screw flight, means for introducing a material to be treated into an annulus provided between the jacket and conveyor screw of a first pass, conduit means for discharging the material from the end of one pass to the beginning of the next pass, means for discharging treated material from said casing, means for introducing a heat exchange medium into the jacket and into the conveyor shaft and screw flight of one of said passes, connecting means for passing the heat exchange medium from one pass to the next, said jackets being provided with aperture means for the passage of vapor which may emanate from the material being treated radially outwardly through said jackets into said casing, said aperture means being defined by a plurality of small passageways spaced along the lengths of said jackets and being of a size to allow moisture passage with substantially no passage of particles of the material being dried, and means for maintaining a vacuum in said casing to exhaust said vapor from said casing.
Claim 2
Dependent Claim
218 words
Apparatus for subjecting a material to indirect heat exchange comprising a casing, a plurality of passes arranged in series within said casing, each pass including an annular jacket and a conveyor screw disposed in said heating jacket, said conveyor screw having a hollow shaft and having a hollow screw flight, means for introducing a material to be treated into an annulus provided between the jacket and conveyor screw of a first pass, conduit means for discharging the material from the end of one pass to the beginning of the next pass, means for discharging treated material from said casing, means for introducing a heat exchange medium into the jacket and into the conveyor shaft and screw flight of one of said passes, connecting means for passing the heat exchange medium from one pass to the next, said jackets being provided with aperture means for the passage of vapor which may emanate from the material being treated radially outwardly through said jackets into said casing, said aperture means being defined by a plurality of small passageways spaced along the lengths of said jackets and being of a size to allow moisture passage with substantially no passage of particles of the material being dried, and means for maintaining a vacuum in said casing to exhaust said vapor from said casing.
Claim 3
Dependent Claim
53 words
Apparatus according to claim 1, further comprising breaker means provided adjacent the inlet end of the first pass, said breaker means including a plurality of longitudinally extending rotatable rods disposed in the annulus between the conveyor shaft and the inner periphery of said heating jacket, and planetary gear means for rotating said rods.
Claim 4
Dependent Claim
45 words
Apparatus according to claim 2, further comprising a plurality of paddle members attached to said rods, and said planetary gear means including a stationary sun gear, and a plurality of planetary gears rotating about said sun gear and connected to the ends of said rods.
Claim 5
Dependent Claim
31 words
Apparatus according to claim 1, wherein at least some of said passes are disposed one above the other to enable material to flow from one pass to the next by gravity.
Claim 6
Dependent Claim
18 words
Apparatus according to claim 1, further comprising means to drive each of said conveyor screw shafts in unison.
Claim 7
Dependent Claim
64 words
Apparatus according to claim 1, wherein the connecting means for passing heat exchange medium from one pass to another including conduit means interconnecting the discharge end of the jacket of one pass with the adjacent end of the jacket of an adjacent pass, headers disposed about adjacent ends of the conveyor shafts of adjacent passes, and conduit means interconnecting adjacent ones of said headers.
Claim 8
Dependent Claim
125 words
A process for drying wet coal comprising the steps of introducing wet coal into an annulus between a hollow conveyor screw and a heating jacket forming a first pass of a multi-pass drying apparatus, subjecting the weT coal to indirect heat exchange by introducing a heated heat exchange medium into the hollow screw and into the heating jacket, transporting coal discharged from the first pass to at least one subsequent pass for further indirect heat exchange, flowing heating exchange medium from one pass to the next pass, and removing vapors emanating from the wet coal through small longitudinally spaced transverse passageways extending through said heating jackets under vacuum, said passageways being of a size to allow moisture passage with substantially no passage of coal particles.
Claim 9
Dependent Claim
125 words
A process for drying wet coal comprising the steps of introducing wet coal into an annulus between a hollow conveyor screw and a heating jacket forming a first pass of a multi-pass drying apparatus, subjecting the weT coal to indirect heat exchange by introducing a heated heat exchange medium into the hollow screw and into the heating jacket, transporting coal discharged from the first pass to at least one subsequent pass for further indirect heat exchange, flowing heating exchange medium from one pass to the next pass, and removing vapors emanating from the wet coal through small longitudinally spaced transverse passageways extending through said heating jackets under vacuum, said passageways being of a size to allow moisture passage with substantially no passage of coal particles.
Claim 10
Dependent Claim
28 words
A process according to claim 7, further comprising rotating the conveyor screws of each pass in unison, and discharging coal from one pass to the next by gravity.
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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |