Centrifugal separator having energy consumption reducing devices

Patent metadata

Field	Value
Publication number	US-10357787-B2
Application number	US-201013254297-A
Country	US
Kind code	B2
Filing date	Mar 5, 2010
Priority date	Mar 6, 2009
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

The invention relates to a centrifugal separator comprising a casing which delimits and seals off a space in which a rotor is arranged. The rotor forms a separation space which is sealed or isolated from the space, and in which separation space centrifugal separation of a higher density and a lower density component from a fluid takes place. An inlet extends into the rotor for introducing fluid to the separation space, and a first outlet extends from the rotor for discharge of a component separated from the fluid. The space is connected to a pump device which is arranged to remove gas, thereby maintaining negative pressure in said space. The rotor comprises at least one second outlet extending from the separation space to the space for discharge of at least one higher density component separated from the fluid. The invention also relates to a method in such a centrifugal separator.

First claim

The invention claimed is:

1. A centrifugal separator comprising a casing which delimits a space which is sealed relative to the surroundings of the casing and in which a rotor is arranged for rotation, which rotor forms within itself a separation space, and in which separation space centrifugal separation of at least one higher density component and at least one lower density component from a fluid takes place during operation, into which rotor at least one inlet extends for introducing said fluid to the separation space, and from which rotor at least one first outlet extends for discharge of at least one component separated from the fluid during operation, where a pump device is in fluid communication with all of said space, the pump device being arranged to remove gas from the space during operation, thereby maintaining negative pressure in said space, and wherein the rotor comprises at least one second outlet extending from a portion of the separation space to the space for discharge of at least one higher density component separated from the fluid during operation;
the at least one second outlet being configured to at least partially seal the separation space from the space or selectively isolate the separation space from the spacer; and
a discharge device in the form of a sludge pump being arranged to remove the at least one higher density component separated from the fluid from the space during operation.

2. A centrifugal separator according to claim 1 , wherein second outlet is arranged for intermittent discharge of at least one higher density component separated from the fluid during operation.

3. A centrifugal separator according to claim 1 , wherein second outlet is arranged for continuous discharge of at least one higher density component separated from the fluid during operation.

4. A centrifugal separator according to claim 1 , further comprising an inlet line for supplying a medium to the space, which medium is brought into heat-transferring contact with the rotor in order to regulate the temperature of the rotor.

5. A centrifugal separator according to claim 4 , wherein said medium comprises a liquid which in said heat-transferring contact is at least partly caused to evaporate and form a gas medium in the space.

6. A centrifugal separator according to claim 4 , wherein said medium comprises a gas medium.

7. A centrifugal separator according to claim 5 , wherein said gas medium has a density lower than the density of air and/or a viscosity lower than the viscosity of air.

8. A centrifugal separator according to claim 4 , wherein said medium is sprayed towards the rotor.

9. A centrifugal separator according to claim 4 , wherein said medium is finely divided in the space.

10. A centrifugal separator according to claim 4 , wherein a flow of medium into the space is driven by pressure difference between a container for medium and the space and is controlled by a valve.

11. A centrifugal separator according to claim 5 , further comprising a cold surface in the space for condensation of said gas medium to a condensate.

12. A centrifugal separator according to claim 11 , wherein the condensate is brought into heat-transferring contact with the rotor in order to regulate the temperature of the rotor.

13. A centrifugal separator according to claim 1 , wherein the casing comprises thermally insulating and/or sound-insulating material.

14. A centrifugal separator according to claim 1 , wherein the space is sealed or isolated from an inlet chamber in the rotor or an outlet chamber in the rotor or both the inlet chamber and outlet chamber.

15. A centrifugal separator according to claim 1 , wherein the space is sealed relative to a drive device which is arranged to provide torque to the rotor.

16. A centrifugal separator according to claim 1 , wherein a discharge device is arranged to remove at least one component separated from the fluid during operation from the space.

17. A centrifugal separator according to claim 16 , further comprising a vessel between the space and the discharge device for gathering at least one component separated from the fluid.

18. A method for operating a centrifugal separator, the method comprising:
providing a centrifugal separator comprising a casing which delimits a space which is sealed relative to the surroundings of the casing and in which a rotor is arranged for rotation, said rotor forming within itself a separation space, at least one inlet extending into said rotor, and at least one first outlet extending from said rotor, a pump device is in fluid communication with all of said space, the rotor comprises at least one second outlet extending from a portion of the separation space to the space, the at least one second outlet being configured to at least partially seal the separation space from the space or selectively isolate the separation space from the space;
removing gas from the space round the rotor, thereby maintaining negative pressure in said space;
discharging from a portion of the separation space to the space via said second outlet at least one higher density component separated from the fluid during operation; and

removing the at least one higher density component separated from the fluid from the space during separation via a discharge device in the form of a sludge pump.

19. A method according to claim 18 , which further comprises the steps of:
supplying a medium to said space, which medium is brought into heat-transferring contact with the rotor in order to regulate the temperature of the rotor.

20. A method according to claim 19 , in which said medium comprises a liquid which in said heat-transferring contact with the rotor is at least partly caused to evaporate and form a gas medium in the space, and in which at least part of said gas medium is removed from the space.

Assignees

• Thorwid Peter
• Isaksson Roland
• Hagqvist Peter
• Haeggmark Carl
• Hillstroem Lars
• Alfa Laval Corp Ab

Inventors

• Thorwid Peter
• Isaksson Roland
• Hagqvist Peter
• Häggmark Carl
• Hillström Lars

Classifications

• B04B7/02 Primary

  Casings; Lids (shock absorbers, vibration dampers F16F) · CPC title

• B04B11/02 Primary

  Continuous feeding or discharging; Control arrangements therefor · CPC title

• B04B15/08 Primary

  for ventilating or producing a vacuum in the centrifuge · CPC title

• B04B15/02

  for cooling, heating, or heat insulating · CPC title

• B04B11/00

  Feeding, charging, or discharging bowls (B04B1/00, B04B3/00, B04B7/04 take precedence) · CPC title