REFINER PLATES HAVING STEAM CHANNELS AND METHOD FOR EXTRACTING BACKFLOW STEAM FROM A DISK REFINER

• US 20080296419A1
• Filed: 05/05/2008
• Published: 12/04/2008
• Est. Priority Date: 05/31/2007
• Status: Active Grant

• Current Assignee: Andritz Incorporated
• Original Assignee: Andritz Incorporated
• Inventors: Gingras, Luc
• Granted Patent: US 8,028,945 B2
• Time in Patent Office: Days
• US Class Current: 241/28
• CPC Class Codes: D21D 1/30 Disc mills
• CPC Class Codes: D21D 1/306 Discs

Abstract

A refining plate for refining lignocellulosic material including: a radially outer peripheral edge and a substrate surface; a refining zone having a plurality of substantially radially disposed bars and grooves between the bars, wherein the bars protrude upward from the substrate surface and the grooves each have a groove width, and a steam channel traversing the bars and grooves of the refining zone, wherein the steam channel has a radially outer end radially inward of the outer peripheral edge of the plate and the steam channel has a width substantially greater than the groove width.

Claims

1. A refining plate for refining lignocellulosic material, the plate comprising:

a radially outer peripheral edge and a substrate surface;

a refining zone including a plurality of substantially radially disposed bars and grooves between the bars, wherein the bars protrude upward from the substrate surface and the grooves each have a groove width, and

a steam channel traversing the bars and grooves of the refining zone, wherein the steam channel has a radially outer end inward of the outer peripheral edge of the plate and has a width substantially greater than the groove width.

2. A refining plate as in claim 1 wherein the plate is a directional plate and the bars and grooves are at an acute angle with respect to a radius of the plate.

3. A refining plate as in claim 1 further comprising an inlet zone and the steam channel has a radially inner end adjacent the inlet zone.

4. A refining plate as in claim 1 wherein the plate is a stator plate.

5. A refining plate as in claim 1 wherein the plate comprises an annular array of plate segments and each segment includes the refining zone, and a plurality of the plate segments each includes one of the steam channels.

6. A refining plate as in claim 5 wherein at least one of the plate segments is devoid of the steam channel.

7. A refining plate as in claim 1 wherein the width of the steam channel is at least three-quarters (¾

) of an inch.

8. A refining plate as in claim 1 wherein the steam channel discharges to an inlet zone of bars separated by at least one-half of an inch.

9. A refining plate as in claim 1 wherein the plate is adapted to refine fibers for medium density fiberboard (MDF).

10. A method to extract high pressure steam from a refining system comprising:

introducing a cellulose fibrous feed material to an inlet of a disk refiner;

feeding the cellulose fibrous feed material between opposing disks of the refiner, wherein one disk rotates relative to the other;

refining the cellulose fibrous feed material between opposing refiner plates each mounted on a respective one of the opposing disks, wherein each refiner plate has a zone of refining bars and grooves;

back flowing steam generated during the refining of the feed material through steam channels in at least one of the plates, wherein the steam channels have a width substantially greater than a width of the grooves, and

extracting the back flow steam from the disk refiner from a steam outlet radially inward of an outlet of the channels.

11. A method as in claim 10 wherein back flow steam is extracted at a pressure of at least 6 bar.

12. A method as in claims 10 wherein the plates with the steam channel comprise stator plates.

13. A method as in claims 10 wherein the back flow steam is forced to flow radially inward through the channels by forming a radially outer end of the channel substantially radially inward of the outer circumference of the disks.

14. A method as in claim 10 wherein the back flow steam flows through a discontinuous steam path including at least one of the channels.

15. A method as in claim 10 wherein the back flow steam discharges from the steam channel to an inlet zone of the refining plate, wherein bars of the inlet zone are substantially wider than bars of the refining zone.

16. A refining plate for refining lignocellulosic material, the plate comprising:

a radially outer peripheral edge and a substrate surface;

a refining zone including a plurality of substantially radially disposed bars and grooves between the bars, wherein the bars protrude upward from the substrate surface and the grooves each have a groove width, and

a steam channel traversing the refining zone, wherein the steam channel has a radially outer end radially inward of the outer peripheral edge of the plate and the steam channel has a width substantially greater than the groove width.

17. A refining plate as in claim 16 wherein the steam channel is parallel to the bars and grooves in the refining zone.

18. A refining plate as in claim 16 the steam channel forms an angle with respect to a radius of the plate opposite to an angle formed by the bars with respect to the radius.

19. A refining plate as in claim 16 wherein the steam channel is straight.

20. A refining plate as in claim 16 wherein the steam channel is at least as deep as the grooves.

21. A refining plate as in claim 20 wherein the steam channel is deeper than the grooves.

22. A refining plate as in claim 16 wherein the steam channel is curved.

23. A refining plate as in claim 16 further comprising an inlet zone and the steam channel has a radially inner end adjacent the inlet zone.

24. A refining plate as in claim 16 wherein the plate is a stator plate.

25. A refining plate as in claim 16 wherein the plate comprises an annular array of plate segments and each segment includes the refining zone, and a plurality of the plate segments includes the steam channel.

26. A refining plate as in claim 25 wherein at least one of the plate segments is devoid of the steam channel.

27. A refining plate as in any of claim 16 wherein the width of the steam channel is at least three-quarters (¾

) of an inch.

28. A refining plate as in claims 16 wherein the steam channel discharges into an inlet zone of bars separated by at least one-half of an inch.

29. A refining plate as in any of claim 16 wherein the plate is adapted to refine fibers for medium density fiberboard (MDF).