Rotor refiner plate element for counter-rotating refiner having curved bars and serrated leading edges

Patent metadata

Field	Value
Publication number	US-10487450-B2
Application number	US-201715620114-A
Country	US
Kind code	B2
Filing date	Jun 12, 2017
Priority date	Jul 13, 2011
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A refining plate segment for a mechanical refiner of lignocellulosic material including: a refining surface on a substrate, wherein the refining surface faces a refining surface of an opposing refiner plate, the refining surface including bars and grooves between the bars, wherein an angle of each bar with respect to a radial line corresponding to the bar increases at least 15 degrees along a radially outward direction, and the angle is a holdback angle in a range of 10 to 45 degrees at the periphery of the refining surface, and wherein the bars each include a leading sidewall having an irregular surface, wherein the irregular surface includes protrusions extending outwardly from the sidewall towards a sidewall on an adjacent bar and the irregular surface extends from at or near the outer periphery of the refining surface extends radially inwardly along the bars without reaching an inlet of the refining surface.

First claim

What is claimed is:

1. A counter-rotating mechanical refiner system comprising:
a first rotor refiner plate segment having a first refining surface on a first substrate, wherein the first refining surface is configured to face a second refining surface on a second substrate of an opposing rotor refiner plate segment, the first refining surface further comprises a first set of multiple bars and a groove disposed between each of the multiple bars in the first set of multiple bars, and the second refining surface further comprises a second set of multiple bars and a groove disposed between each of the multiple bars in the second set of multiple bars,
wherein a holdback angle of a bar of the first set of multiple bars increases at least 10 degrees along the first refining surface in a radially outward direction, wherein the holdback angle is defined by a line extending tangentially from the bar and a radial line extending radially outward along the first rotor refiner plate segment from a center of rotor rotation of the first rotor refiner plate segment on a mechanical refiner, and wherein the holdback angle has a value in a range of 5 degrees to 60 degrees at a periphery of the first refining surface,
wherein the bar on the first rotor refiner plate segment includes a trailing sidewall extending from an upper surface of the bar to the first substrate, wherein the trailing sidewall has a smooth surface;
wherein the bar of the first set of multiple bars includes a leading sidewall comprising:
an irregular surface, wherein the irregular surface includes:
teeth extending outwardly from the bar into the groove toward an adjacent trailing sidewall on an adjacent bar of the first set of multiple bars, wherein the irregular surface extends toward an inlet of the first rotor refiner plate segment,
wherein a tooth of the teeth includes a sloped ramp extending from the first substrate toward a top of the bar having the teeth and a second sidewall extending from the sloped ramp to the top of the bar having the teeth,

wherein a slope of the sloped ramp with respect to the first substrate is smaller than a slope of the second sidewall with respect to the first substrate,
wherein the tooth includes a corner formed at an interface of the sloped ramp, the first substrate, and a first sidewall, and
wherein the first sidewall forms an oblique angle with respect to the trailing sidewall of the bar such that the first sidewall and the corner project obliquely into the groove.

2. The refiner system of claim 1 , wherein the holdback angle increases in an involute arc along the radially outward direction.

3. The refiner system of claim 1 , wherein the holdback angle increases in an exponential arc along the radially outward direction.

4. The refiner system of claim 1 , wherein the holdback angle increases in steps along the radially outward direction.

5. The refiner system of claim 1 , wherein at a radially inward inlet to the first refining surface, the bars of the first set of bars are each arranged at an angle within 10 degrees to 20 degrees of a radial line passing through the inlet of the first rotor refiner plate segment and the periphery of the first refining surface.

6. The refiner system of claim 1 , wherein the first refining surface includes multiple refining zones, wherein a first refining zone of the multiple refining zones has relatively wide bars and wide grooves, and a second refining zone has narrow bars and narrow grooves compared to the wide bars and wide grooves of the first refining zone, and wherein the second refining zone is disposed radially outward on first refining surface from the first refining zone.

7. The refiner system of claim 6 , wherein the holdback angle is measured from a bar of the first set of multiple bars in the second refining zone.

8. The refiner system of claim 1 , wherein the bar of the first set of multiple bars has a holdback angle of zero degrees at a radially inward inlet to the first refining surface.

Assignees

• Andritz Inc

Inventors

• Gingras Luc

Classifications

• D21D1/303

  Double disc mills · CPC title

• D21D1/30

  Disc mills · CPC title

• D21D1/306 Primary

  Discs · CPC title