US 2007/0164143 A1 · Disc refiner with increased gap between fiberizing and fibrillating bands

Abstract

Plate elements, a plate configuration, and associated system for thermomechanical refining of wood chips wherein destructured and partially defibrated chips are fed to a rotating disc primary refiner, where opposed discs each have an inner band pattern of bars and grooves and outer band pattern of bars and grooves, such that substantially complete fiberization (defibration) of the chips is achieved in the inner band and the resulting fibers are fibrillated in the outer band. One embodiment is directed to a pair of opposed co-operating refining plate elements for a flat disc refiner wherein the bars and grooves on each of the inner bands form an inner feed region followed by an outer working region, the bars and groove on each of the outer bands form an inner feed region followed by an outer working region, and the gap and/or material flow area formed when the plates are placed in front of each other increases between the inner working region and the outer feed region.

Claims23

Dependent claims

In a primary wood chip refiner having flat, relatively rotating discs, each having a working plate thereon, the working plates being arranged in confronting coaxial relation thereby defining a refiner gap which extends substantially radially outward from the inner diameter of the discs to the outer diameter of the discs and defines a flow area for the chip material to be refined, the improvement comprising:

each plate having a radially inner fiberizing band and a radially outer fibrillating band, each band having an inner feeding region and an outer working region, wherein the working region of the inner band is defined by a first pattern of alternating bars and grooves, and the feeding region of the outer band is defined by a second pattern of alternating bars and grooves, and said flow area increases immediately after the inner working region into the outer feed region.

In a disc refiner for lignocellulosic material, a pair of confronting relatively rotatable discs having flat refiner plates, comprising:

a first plate having inner and outer radii and a working face including a pattern of raised and relief structure which as viewed transversely to the rotation axis has a radially varying profile;
a second plate having inner and outer radii and a working face including a pattern of raised and relief structure which as viewed transversely to the rotation axis has a radially varying profile, said second plate axially confronting but spaced from the first plate whereby a radially extending refiner gap is formed, said gap as view transversely to the rotation axis having a varying profile from the inner to the outer radius of the plates such that:
a radially inner feeding portion converges radially outwardly to an inner working portion;
the inner working portion extends radially with a minimum gap in the range of about 1.5-3.0 mm to a transition portion;
the transition portion has an abrupt increase in the gap of more than about 4.0 mm leading to an outer working portion;
and
the outer working portion radially converges to an outer minimum gap in the range of about 0.5-1.0 mm.

4 more elements

Dependencies are inferred from the claim text.

Disc refiner with increased gap between fiberizing and fibrillating bands

Life of this patent

Disc refiner with increased gap between fiberizing and fibrillating bands

Life of this patent

Abstract

Claims23