Patent US4828541A successfully refreshed from Google Patents.
US4828541A
Expired / Lapsed
US
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Decanter centrifuge
Assignee: Alfa Laval Copenhagen AS
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Filing: 1987-05-05
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Granted: 1989-05-09
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Expires: 2007-05-05
Abstract
Abstract The decanter centrifuge (1) comprises a conveyor screw (5) constructed as a hollow body with a lower average density than the lighter liquid phase of the surrounding slurry. The conveyor (5) thus flows in said liquid phase which is utilized in that the one traditional radial bearing of the conveyor is replaced by a radial support bearing (22) which only during starting and stopping of the centrifuge cooperates with the conveyor (5) in order to prevent it from contacting the bowl (2). In operation, the conveyor is thus only supported in the radial direction at the one end, entailing that the flexural rigidity of the conveyor becomes less important to the maximum allowable number of revolutions of the centrifuge which may then be increased for a given centrifuge, thereby obtaining an improved separating effect.
Inventors
- 👤 Niels F. Madsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:09
CPC Classifications
B; B04; B04B; B04B1/00; B04B1/20; B04B2001/2066
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
74 words
A decanter centrifuge for separating a slurry into a heavier phase and a lighter phase, which comprises: an axially symmetrical bowl; and a screw conveyor, rotatably located in the bowl, having a body with at least one flight, wherein a specific density of the screw conveyor is lower than a specific density of the lighter liquid phase of the slurry and, in operation, at least one end of the screw conveyor is radially unsupported.
Claim 2
Dependent Claim
74 words
A decanter centrifuge for separating a slurry into a heavier phase and a lighter phase, which comprises: an axially symmetrical bowl; and a screw conveyor, rotatably located in the bowl, having a body with at least one flight, wherein a specific density of the screw conveyor is lower than a specific density of the lighter liquid phase of the slurry and, in operation, at least one end of the screw conveyor is radially unsupported.
Claim 3
Dependent Claim
23 words
A decanter centrifuge as in claim 1, further comprising means, disposed on the centrifuge, for radially supporting one end of the screw conveyor.
Claim 4
Dependent Claim
45 words
A decanter centrifuge as in claim 1, further comprising means, arranged at the at least one unsupported end of the screw conveyor, for preventing contact between the at least one flight of the screw conveyor and the bowl during starting and stopping of the centrifuge.
Claim 5
Dependent Claim
101 words
A decanter centrifuge for separating a slurry into a heavier phase and a lighter phase, which comprises: an axially symmetrical bowl; and a screw conveyor, rotatably located in the bowl, having a body with flights, wherein a specific density of the screw conveyor is lower than a specific density of the lighter liquid phase of the slurry, and, in operation, at least one end of the screw conveyor is radially unsupported, and whereby, when in operation, the at least one unsupported end of the screw conveyor is centered in relation to the bowl by buoyancy forces acting on the screw conveyor.
Claim 6
Dependent Claim
101 words
A decanter centrifuge for separating a slurry into a heavier phase and a lighter phase, which comprises: an axially symmetrical bowl; and a screw conveyor, rotatably located in the bowl, having a body with flights, wherein a specific density of the screw conveyor is lower than a specific density of the lighter liquid phase of the slurry, and, in operation, at least one end of the screw conveyor is radially unsupported, and whereby, when in operation, the at least one unsupported end of the screw conveyor is centered in relation to the bowl by buoyancy forces acting on the screw conveyor.
Claim 7
Dependent Claim
24 words
A decanter centrifuge as in claim 4, further comprising a bearing, disposed on the centrifuge, for radially supporting one end of the screen conveyor.
Claim 8
Dependent Claim
44 words
A decanter centrifuge as in claim 4, further comprising a limiting device, arranged at the at least one unsupported end of the screw conveyor, for preventing contact between the flights of the screw conveyor and the bowl during starting and stopping of the centrifuge.
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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) | 1992-05-08 | 1992-11-07 | 1993-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-08 | 1996-11-07 | 1997-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-08 | 2000-11-07 | 2001-05-09 | $7700.00 | Window Closed / Lapsed |