Patent US3701469A successfully refreshed from Google Patents.
US3701469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifuge sludge control and method of operating same
Assignee: Alfa Laval AB
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Filing: 1970-11-02
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Granted: 1972-10-31
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Expires: 1990-11-02
Abstract
Abstract When the rotor of a sludge centrifuge is to be emptied of its contents during operation, its peripheral sludge outlets are opened to discharge at least part of the settled sludge; and while liquid is still retained in the rotor, its balance condition is determined by a sensing means. If the latter senses a predetermined degree of unbalance at the prevailing speed of the rotor, as when sludge adheres to the rotor wall and thus fails to discharge, a suitable control is signalled to prevent complete emptying of the rotor at the prevailing speed, thereby avoiding possible damage to the rotor.
Inventors
- 👤 Vilgot Raymond Nilsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:49
CPC Classifications
B; B04; B04B; B04B1/00; B04B1/10; B04B1/14; B04B1/16; B04B1/18
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
110 words
In the operation of a sludge centrifuge including a centrifugal rotor to which a sludge-liquid mixture is fed and having peripheral sludge outlets adapted to be opened and closed during operation of the centrifuge, the method for use when emptying the rotor of its contents, which comprises the steps of opening said outlets to discharge at least part of the settled sludge therethrough while rotating the rotor, then sensing the balance of the rotating rotor while maintaining liquid therein, and, in response to said sensing of a predetermined degree of unbalance of the rotor, preventing emptying of the rotor at the speed at which it is rotating during said sensing.
Claim 2
Dependent Claim
110 words
In the operation of a sludge centrifuge including a centrifugal rotor to which a sludge-liquid mixture is fed and having peripheral sludge outlets adapted to be opened and closed during operation of the centrifuge, the method for use when emptying the rotor of its contents, which comprises the steps of opening said outlets to discharge at least part of the settled sludge therethrough while rotating the rotor, then sensing the balance of the rotating rotor while maintaining liquid therein, and, in response to said sensing of a predetermined degree of unbalance of the rotor, preventing emptying of the rotor at the speed at which it is rotating during said sensing.
Claim 3
Dependent Claim
22 words
The method of claim 1, comprising also gradually emptying the rotor of sludge and liquid while sensing the balance of the rotor.
Claim 4
Dependent Claim
18 words
The method of claim 2, in which the rotor is emptied of sludge and liquid step by step.
Claim 5
Dependent Claim
28 words
The method of claim 3, in which said sensing of the rotor balance is effected only between the points of time represented by said step by step emptying.
Claim 6
Dependent Claim
19 words
The method of claim 1, comprising also discharging some of said liquid through said outlets prior to said sensing.
Claim 7
Dependent Claim
21 words
The method of claim 1, comprising also stopping the feed of said mixture to the rotor before effecting said discharge therefrom.
Claim 8
Dependent Claim
30 words
The method of claim 1, comprising also stopping the feed of said mixture to the rotor when at least said part of the sludge has been discharged through said outlets.
Claim 9
Dependent Claim
99 words
A sludge centrifuge comprising a rotor provided with an inlet for a sludge-liquid mixture and also provided with peripheral sludge outlets adapted to be opened and closed during operation of the centrifuge, discharge means for opening said outlets to commence emptying the rotor of its contents, means for sensing the balance of the rotor while liquid is still maintained therein and while the rotor is at an operating speed, and means operatively connected to the sensing means and responsive to said sensing of a predetermined degree of rotor unbalance for preventing emptying of the rotor at said operating speed.
Claim 10
Dependent Claim
99 words
A sludge centrifuge comprising a rotor provided with an inlet for a sludge-liquid mixture and also provided with peripheral sludge outlets adapted to be opened and closed during operation of the centrifuge, discharge means for opening said outlets to commence emptying the rotor of its contents, means for sensing the balance of the rotor while liquid is still maintained therein and while the rotor is at an operating speed, and means operatively connected to the sensing means and responsive to said sensing of a predetermined degree of rotor unbalance for preventing emptying of the rotor at said operating speed.
Claim 11
Dependent Claim
51 words
A sludge centrifuge according to claim 8, in which said discharge means are operable to open said outlets intermittently to empty the rotor in a plurality of steps, said sensing and responsive means being operable to prevent said emptying in response to said unbalance arising from any of said emptying steps.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |