Patent US3785548A successfully refreshed from Google Patents.
US3785548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifuge with intermittent sludge discharge
Assignee: Alfa Laval AB
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Filing: 1972-07-07
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Granted: 1974-01-15
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Expires: 1992-07-07
Abstract
Abstract Sludge is discharged intermittently from the centrifugal rotor under control of a hydraulically actuated piston valve movable axially of the rotor. The piston valve has a radially inner area facing the rotor''s separating chamber and partly defining a space within the rotor, and means are provided for maintaining this space free of liquid and thereby reducing the hydraulic pressure tending to shift the piston valve to its sludge-discharging position.
Inventors
- 👤 K Stroucken
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:27
CPC Classifications
B; B04; B04B; B04B1/00; B04B1/10; B04B1/14; B04B1/16; B04B1/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
136 words
In a sludge centrifuge, the combination of a centrifugal rotor mounted for rotation about an axis and having a separating chamber And an inlet for supplying a sludge-containing liquid to said chamber, the rotor also having a separated liquid outlet and a peripheral outlet for separated sludge, an hydraulically operated piston valve movable in the rotor axially thereof to open and close said sludge outlet, said piston valve having one side facing said separating chamber and including a first area on which the contents of said chamber act to urge said valve in the direction to open the sludge outlet, said one side also including a second area located radially inward from said first area and partly defining a space separated from said chamber, and means in the rotor for maintaining said space free of liquid.
Claim 2
Dependent Claim
136 words
In a sludge centrifuge, the combination of a centrifugal rotor mounted for rotation about an axis and having a separating chamber And an inlet for supplying a sludge-containing liquid to said chamber, the rotor also having a separated liquid outlet and a peripheral outlet for separated sludge, an hydraulically operated piston valve movable in the rotor axially thereof to open and close said sludge outlet, said piston valve having one side facing said separating chamber and including a first area on which the contents of said chamber act to urge said valve in the direction to open the sludge outlet, said one side also including a second area located radially inward from said first area and partly defining a space separated from said chamber, and means in the rotor for maintaining said space free of liquid.
Claim 3
Dependent Claim
54 words
The combination according to claim 1, in which the rotor has a second chamber for receiving an operating liquid and located on the side of the piston valve opposite said one side facing the separating chamber, said means including a seal and being operable to separate said space liquid-tight from both of said chambers.
Claim 4
Dependent Claim
68 words
The combination according to claim 1, comprising also a conical disc fixed in the rotor and having first and second sides partly defining said inlet and said space, respectively, said one side of the piston valve having a cylindrical surface concentric to the rotor axis, said means including a sealing ring mounted on said second side of the conical disc and on which said cylindrical surface is slidable.
References Cited (Backward Citations)
US3237854A
Cited
US3460750A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |