Refiner with Spiral Inlet and Dual Tangential Discharge Outlet

• US 20080272216A1
• Filed: 03/25/2008
• Published: 11/06/2008
• Est. Priority Date: 05/03/2007
• Status: Active Grant

• Current Assignee: Andritz Incorporated
• Original Assignee: Andritz Incorporated
• Inventors: Kraft, Michael, Ruch, Julie
• Granted Patent: US 7,726,596 B2
• Time in Patent Office: Days
• US Class Current: 241/28
• CPC Class Codes: B02C 7/02 with coaxial discs
• CPC Class Codes: D21D 1/303 Double disc mills

Abstract

A fibrous slurry refiner includes a casing, a rotor secured to a rotor shaft, and first and second pluralities of grinding surfaces. The rotor is disposed within the casing and is rotatable via the rotor shaft. The first plurality of grinding surfaces is secured to the rotor, and the second plurality of grinding surfaces is disposed facing the first plurality of grinding surfaces and fixed in the casing. An inlet plate for each of the plurality of grinding surfaces directs the fibrous slurry toward a set of facing first and second grinding surfaces and imparts a rotary flow to the fibrous slurry.

Claims

1. A fibrous slurry refiner comprising:

a casing;

a rotor secured to a rotor shaft, the rotor being disposed within the casing and rotatable via the rotor shaft;

a first plurality of grinding surfaces secured to the rotor;

a second plurality of grinding surfaces disposed facing the first plurality of grinding surfaces and being fixed in the casing; and

an inlet housing made up of an inlet plate, an axial cylinder and a spiral inlet opening for each of the plurality of grinding surfaces, each inlet plate directing the fibrous slurry toward a set of facing first and second grinding surfaces and imparting a rotary flow to the fibrous slurry.

2. A fibrous slurry refiner according to claim 1, wherein the axial cylinder is substantially circular, and wherein the spiral inlet opening is positioned tangentially relative to a center of inlet plate.

3. A fibrous slurry refiner according to claim 2, wherein the inlet housing comprises a spiral channel extending from the inlet opening to the center of the inlet plate.

4. A fibrous slurry refiner according to claim 3, wherein the center of the inlet plate defines an axial channel that directs the fibrous slurry toward the grinding surfaces.

5. A fibrous slurry refiner according to claim 1, comprising a first set of first and second grinding surfaces on one side of the casing and a second set of first and second grinding surfaces on an opposite side of the casing, wherein the refiner includes a pair of inlet plates, one on each side of the casing.

6. A fibrous slurry refiner according to claim 5, wherein the casing comprises a pair of outlet channels, one on each side of the casing, the outlet channels being positioned to receive flow from the grinding surfaces.

7. A fibrous slurry refiner according to claim 6, wherein the outlet channels are configured to minimize a disturbance on the casing caused by discharge of the flow.

8. A fibrous slurry refiner according to claim 7, wherein the pair of outlet channels are substantially volumetrically equal.

9. A fibrous slurry refiner according to claim 8, wherein the casing comprises a substantially circular housing disposed surrounding the grinding surfaces, and wherein the outlet channels are defined along an outer circumference of the substantially circular housing.

10. A fibrous slurry refiner according to claim 6, wherein the casing comprises a substantially circular housing disposed surrounding the grinding surfaces, and wherein the outlet channels are defined along an outer circumference of the substantially circular housing.

11. An inlet plate for a fibrous slurry refiner, the inlet plate comprising an inlet opening that imparts a rotary flow to the fibrous slurry.

12. An inlet plate according to claim 11, wherein the inlet plate is substantially circular, and wherein the inlet opening is positioned tangentially relative to a center of inlet plate.

13. An inlet plate according to claim 12, comprising a spiral channel extending from the inlet opening to the center of the inlet plate.

14. An inlet plate according to claim 13, wherein the center of the inlet defines an axial channel.

15. A casing for a fibrous slurry refiner, the casing comprising a pair of outlet channels, one on each side of the casing, wherein the outlet channels are configured to minimize a disturbance on the casing caused by discharge of a refined slurry.

16. A casing according to claim 15, wherein the pair of outlet channels are substantially volumetrically equal.

17. A casing according to claim 16, comprising a substantially circular housing, wherein the outlet channels are defined along an outer circumference of the substantially circular housing.

18. A method of refining a fibrous slurry in a refiner, the method comprising:

flowing the fibrous slurry through a pair of inlet plate openings in an inlet housing;

accelerating and imparting rotary flow to the fibrous slurry via the inlet housing;

directing the accelerated and rotary flow fibrous slurry to a plurality of grinding surfaces; and

refining the fibrous slurry with the grinding surfaces.

19. A method according to claim 18, further comprising discharging the refined slurry through a pair of outlet channels, the outlet channels being configured to minimize a disturbance on the refiner.