Debarking drum, method and system for debarking of wood

Patent metadata

Field	Value
Publication number	US-12576552-B2
Application number	US-202218285482-A
Country	US
Kind code	B2
Filing date	Apr 1, 2022
Priority date	Apr 7, 2021
Publication date	Mar 17, 2026
Grant date	Mar 17, 2026

Abstract

A debarking drum ( 1 ) for the debarking of wood ( 2 ) has an essentially horizontal cylindrical drum ( 10 ) supported to revolve around its longitudinal axis. The drum has a first end ( 12 ) and a second end ( 14 ) with an inner surface with inwardly projecting longitudinally extending debarking iron sections ( 16 ). Bark openings or slots ( 20 ) extend through the drum inner surface ( 18 ) and multiple rigid studs ( 22 ) protrude inwardly from the inner surface ( 18 ) and are positioned between the debarking iron sections ( 16 ). The studs operate to break the bark ( 3 ) of the wood ( 2 ) for debarking. The studs ( 22 ) are positioned along a partial length (L) of the drum ( 10 ) between the first end ( 12 ) and the second end ( 14 ). The invention also relates to a method and system for the debarking of wood by the debarking drum.

First claim

The invention claimed is:

1 . A drum for the debarking of wood, including an essentially horizontal cylindrical drum, which is supported to revolve around its longitudinal axis, the drum comprising:
a first end for the feeding of wood into the drum; a second end for the removing of wood from the drum, the drum having an interior for the passage of the wood therethrough, the interior having a drum total length in the direction of the longitudinal axis between the first end and the second end; debarking iron sections fixed to an inner surface of the drum which extend in the longitudinal direction of the drum, wherein the debarking iron sections are positioned on an internal circumference of the drum and are spaced circumferentially from each other to define gaps therebetween, the debarking iron sections disposed to lift input wood upwards on the circumference of the drum when the drum is revolving and to release the bark of the wood when the wood drops; bark openings formed to extend through the drum and extending from the inner surface of the drum to an exterior of the drum, the bark openings providing pathways for the removal of the bark which comes off from the wood to pass out of the drum; and rigid studs fixed to the inner surface of the drum and positioned in the gaps between the debarking iron sections, the studs disposed to project into the interior of the drum to break the bark of the wood for the debarking of the wood, wherein the studs are positioned at the first end of the drum along a partial length of the drum total length.

2 . The drum of claim 1 wherein the partial length is 10-40% of the drum total length between the first end and the second end.

3 . The drum of claim 1 wherein the studs on the inner surface of the drum are disposed on at least every second gap between the debarking iron sections on the circumference of the drum.

4 . The drum of claim 1 wherein the studs are formed directly on the drum or on protective plates that form the inner surface of the drum and that are fastened to the drum in a detachable manner.

5 . The drum of claim 1 wherein the studs extend inwardly into the interior of the drum a height, and wherein the height of each stud is 10-25 mm.

6 . The drum of claim 5 wherein the height of each stud is 13-19 mm.

7 . The drum of claim 1 wherein the studs are spaced from one another in a circumferential direction in each gap a distance of 10-60 mm.

8 . The drum of claim 7 wherein the studs are spaced from one another in the circumferential direction in each gap a distance of 25-40 mm.

9 . The drum of claim 1 wherein the distance of each debarking iron section from the closest studs is 10-60 mm.

10 . The drum of claim 9 wherein the distance of each debarking iron section from the closest studs is 25-40 mm.

11 . The drum of claim 1 wherein the studs between two adjacent debarking iron sections are placed in rows, and wherein consecutive rows are placed in an overlapping manner with respect to each other in the longitudinal direction of the drum.

12 . The drum of claim 11 wherein the studs are arranged in an overlapping manner to form a spiral to speed up or slow down the progress of the wood in the drum in accordance with the selected direction of the spiral.

13 . The drum of claim 1 wherein each stud extends into the interior of the drum about a first axis, and wherein each stud is comprised of a surface material and a core material positioned radially inwardly of the surface material, wherein the core material is harder than the surface material, enabling that the stud becomes sharper as the stud wears down.

14 . The drum of claim 13 wherein the surface material of the stud is of steel, and the core material is of a material the hardness of which is more than 800 HV.

15 . The drum of claim 14 wherein the core material is tungsten carbide.

16 . A system for the debarking of wood, which system comprises a debarking drum apparatus, which includes an essentially horizontal cylindrical drum which is supported to revolve around its longitudinal axis, wherein the drum comprises:
a first end for the feeding of wood into the drum; a second end for the removing of wood from the drum, wherein an inner surface extends between the first end and the second end; debarking iron sections extending inwardly from and fixed to the inner surface, the debarking sections extending in the longitudinal direction of the drum on an interior circumference of the drum, wherein the debarking iron sections are spaced in the circumferential direction to define gaps therebetween, the debarking iron sections positioned to lift input wood upwards on the circumference of the drum when the drum is revolving and to release the bark of the wood; bark openings which extend through the drum from the inner surface to an exterior of the drum, the bark openings allowing the passage of bark which comes off from the wood, out of the drum; rigid structure for the breaking of the bark of the wood for the debarking of the wood, which structure comprises studs for the breaking of the bark of the wood for the debarking of the wood, which studs are positioned either: fixed on the inner surface of the drum between said debarking iron sections, and the studs are at the first end of the drum on a partial length of a total length of the drum between the first end and the second end; or on rotating elements that precede the drum.

17 . A method for the debarking of wood using a debarking drum apparatus having an essentially horizontal cylindrical drum, which is supported to revolve around a longitudinal axis, the method comprising:
feeding wood into the drum from a first end while the drum is rotated; lifting the wood which has been fed into the drum upwards by engaging debarking iron sections fixed to an interior of the drum with said wood in order to debark the wood as the wood drops on the wood in the drum, the debarking iron sections being spaced circumferentially to define gaps therebetween; removing bark released from the wood through bark openings in the drum; and removing debarked wood from the rotating drum from a second end of the drum which is downstream of the first end; and breaking the bark of the wood fed into the drum by engaging a plurality of inwardly protruding rigid studs fixed to the interior of the drum and positioned to facilitate debarking, wherein the studs are fixed in the drum in the gaps between the debarking iron sections at the first end of the drum or are positioned ahead of the first end of the drum as part of a separate structure rotating for the breaking of bark, the separate structure being positioned ahead of the first end of the drum and feeding into the drum.

Assignees

• Valmet Technologies Oy

Inventors

• Honkanen Tommi

Classifications

• B27L1/025 Primary

  Debarking in rotating drums · CPC title

• B27L1/05 Primary

  Drums therefor · CPC title

• B27L1/00 Primary

  Debarking or removing vestiges of branches from trees or logs (debarking by chemical treatment B27L3/00 {; peeling osier rods B27J3/00}); Machines therefor · CPC title