Stator refiner plate element having curved bars and serrated leading edges

Patent metadata

Field	Value
Publication number	US-9604221-B2
Application number	US-201314056348-A
Country	US
Kind code	B2
Filing date	Oct 17, 2013
Priority date	Nov 9, 2012
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A refining system and process using a specially designed stator refiner plate that includes a major refining surface having a series of bars and grooves, the bars include a leading surface having an irregular surface hosting a series of protrusions extending along the bar, and a trailing surface that is relatively smooth compared to the leading surface that lacks an irregular surface.

First claim

What is claimed is:

1. A stator refiner plate for a mechanical refiner of lignocellulosic material comprising:
a stator refining surface affixed to a substrate;
multiple bars and grooves situated on the stator refining surface, wherein a bar of the multiple bars comprises a leading sidewall and a trailing sidewall opposite the leading sidewall, and wherein the bar of the multiple bars has a feeding angle;
an irregular surface on the leading sidewall; and
multiple protrusions extending from the irregular surface of the leading sidewall of the bar of the multiple bars toward a trailing sidewall on an adjacent bar;
wherein the irregular surface and multiple protrusions comprise at least 25% a length of the leading sidewall;
wherein the bar of the multiple bars is curved with respect to a radial line extending through the stator refiner plate to define the feeding angle, and wherein the feeding angle increases continuously and gradually along a radially outward section of the stator refining surface, and
wherein the feeding angle of the bar of the multiple bars disposed in the radially outward section increases 10 degrees to 15 degrees in the radially outward section.

2. The stator refiner plate in claim 1 , wherein the stator refiner plate has a plate segment, the plate segment including a stator refining surface.

3. The stator refiner plate in claim 2 further comprising a first refining zone and a second refining zone, wherein the multiple bars disposed in the first refining zone comprises wide bars and wide grooves and the multiple bars disposed in the second refining zone comprises narrow bars and narrow grooves.

4. The stator refiner plate in claim 3 , wherein the second refining zone is disposed at the radially outward section on the plate segment and wherein the first refining zone is disposed at a radially inward section on the plate segment.

5. The stator refiner plate in claim 1 , wherein each of the multiple bars include a trailing sidewall, wherein the trailing sidewall has a smooth surface and, wherein the trailing sidewall lacks an irregular surface.

6. The stator refiner plate in claim 1 , wherein the multiple bars at a radially inward section of the stator refining surface each have a feeding angle, and wherein the feeding angle of each of the multiple bars is within 20 degrees of the radial line of the stator refiner plate.

7. The stator refiner plate in claim 1 , wherein the multiple protrusions extending from the irregular surface have a shape, wherein the shape is selected from the group consisting of a seven shape, a saw tooth shape, a concave shape, and a teeth shape.

8. The stator refiner plate in claim 1 , wherein the irregular surface extends at or near an outer periphery of the stator refining surface, and wherein the irregular surface is not disposed at a radially inward section of the stator refining surface.

9. The stator refiner plate in claim 8 , wherein a distance between the multiple protrusions on the irregular surface is in a range of 3 millimeters to 18 millimeters.

10. The stator refiner plate in claim 1 further comprising a series of ramps on the irregular surface on the leading sidewall, each ramp in the series of ramps comprises a lower edge at the substrate, wherein each ramp extends from the lower edge at least partially up the leading sidewall.

11. The stator refiner plate of claim 1 , wherein the stator refining surface includes an outer stator refining surface, wherein the multiple bars disposed on the outer stator refining surface have a higher density than a density of the multiple bars disposed on an inner stator refining surface.

12. The stator refiner plate of claim 1 , wherein the irregular surface includes at least one protrusion of the multiple protrusions comprising:
a first sidewall, a second sidewall, and a curved sidewall between the first sidewall and the second sidewall;
a sloped ramp extending up from a bottom of an adjacent groove to a bottom edge of the second sidewall; and
a top edge of the second sidewall, wherein an interior corner formed by the curved sidewall and the first sidewall are disposed at a ridge at a top of the bar of the multiple bars.

13. The stator refiner plate of claim 12 , wherein the first sidewall and the second sidewall are substantially perpendicular.

14. The stator refiner plate of claim 12 , wherein the first sidewall and the second sidewall form an angle in a range of 45 degrees to 120 degrees.

15. A method of mechanically refining lignocellulosic material comprising:
introducing lignocellulosic material to an inlet of opposing refiner plates, the opposing refiner plates comprising a rotor refiner plate and a stator refiner plate;
rotating the rotor refiner plate and maintaining the stator refiner plate stationary such that the lignocellulosic material moves radially outwardly through a gap between the opposing refiner plates due to centrifugal forces created by the rotor refiner plate rotation;
passing the lignocellulosic material over multiple bars disposed on a stator refining surface and through grooves between the multiple bars, wherein each of the multiple bars comprises a leading sidewall and a trailing sidewall opposite of the leading sidewall, wherein each bar of the multiple bars has a feeding angle;
inhibiting the movement of the lignocellulosic material through the grooves by interaction of the lignocellulosic material and an irregular surface on the leading sidewall of a bar of the multiple bars adjacent the groove, wherein the irregular surface comprises at least 25% of a length of the leading sidewall; and
discharging the lignocellulosic material from the gap at an outer periphery of the opposing refiner plates,
wherein the multiple bars are disposed on a radially outward section of the stator refining surface, wherein each bar of the multiple bars is curved with respect to a radial line extending through the stator refiner plate to define the feeding angle for each bar of the multiple bars, wherein the feeding angle increases continuously and gradually along the radially outward section, and wherein the feeding angle increases 10 degrees to 15 degrees in the radially outward section.

16. The method in claim 15 , wherein the passing of lignocellulosic material over the multiple bars occurs in the radially outward section of the stator refining plate.

17. The method in claim 15 , wherein the irregular surface includes multiple protrusions extending from the leading sidewall toward the trailing sidewall of an adjacent bar.

18. The method in claim 15 , further comprising feeding the lignocellulosic material into the gap with a series of ramps, wherein a ramp of the series of ramps comprises a lower edge at a substrate of the stator refiner plate, wherein the ramp extends from the lower edge at least partially up the leading sidewall.

Assignees

• Andritz Inc
• Andrtiz Inc

Inventors

• Gingras Luc

Classifications

• D21D1/303 Primary

  Double disc mills · CPC title

• B02C7/12 Primary

  Shape or construction of discs · CPC title

• D21D1/306 Primary

  Discs · CPC title

• D21D1/30 Primary

  Disc mills · CPC title