WO2023046989A2

WO2023046989A2 - Apparatus and method for processing waste wood, in particular for manufacturing material boards

Info

Publication number: WO2023046989A2
Application number: PCT/EP2022/076837
Authority: WO
Inventors: Jan Kasten; Jochen KAMM; Felix Hofmann
Original assignee: Dieffenbacher GmbH Maschinen- und Anlagenbau
Priority date: 2021-09-27
Filing date: 2022-09-27
Publication date: 2023-03-30
Also published as: WO2023046989A3; DE102021004877A1

Abstract

The invention relates to an apparatus and to a method for processing waste wood, in particular during the manufacture of material boards, said apparatus comprising a storage facility (2) for a feedstock (1) such as waste wood and a classifying device, the classifying device being at least suitable for classifying the feedstock (1) or other input material (4) into fine material (6) and a usable fraction. The object of the present invention is to provide an apparatus and a method in which collected and recyclable waste wood can be processed and supplied for proper recycling. According to the invention, in the apparatus the classifying device (5) is operatively connected to at least one purification device (10) for separating foreign materials (13) from the usable fraction, and a sorting device (12) for dividing the purified fraction into solid wood (18) and wood materials (16) is connected downstream of the at least one purification device (10).

Description

DEVICE AND PROCESS FOR THE TREATMENT OF WASTE WOOD, IN PARTICULAR FOR THE MANUFACTURE OF COMPOSITE PANELS

The invention relates to a device for processing waste wood, in particular in the course of the production of material panels, according to the preamble of patent claim 1.

The invention also relates to a method for processing waste wood, in particular in the course of the production of material panels, according to patent claim 14.

Waste wood, which is classified into different waste classes, is usually collected centrally, but in particular pre-sorted by non-professionals. As a rule, these are instructed to the extent that they can roughly differentiate between the waste classes; further sorting is not planned. In a large number of countries with a recycling structure that has not yet developed, such pre-sorting does not even take place. As a rule, impregnated or tarred wood is disposed of directly and all other wood (solid wood mixed with wood-based materials) is sent for recycling in containers.

For recycling, the collected and non-uniform starting material is subjected to an initial crushing, as is usual in recycling. Foreign matter is then removed from the shredded starting material until reusable waste wood can be recycled with the highest possible degree of purity.

The invention distinguishes between two different types within the waste wood: - once the natural wood, which was machined into a suitable form ready for use, possibly coated or painted (window frames, beams, timber, solid wood furniture) and

- on the other hand "man-made materials" which are based on crushed and glued natural wood. This was glued in the course of production and pressed into specified shapes (usually boards) and the binder cured accordingly, for example MDF, HDF, chipboard, OSB, LVL and the like.

The main difference between these two types is that after crushing, the natural wood (solid wood) can provide good quality and larger chips/shavings of wood, whereas the already artificially produced wood materials, already consisting of relatively small chipped wood particles, only produce smaller ones , Partially containing binder particles can be obtained.

Waste wood suppliers can indeed comply with certain specifications, but purely usable waste wood of the natural variety is usually not offered or is very expensive. The device and the method are therefore preferably used for an A1/A2 mixed fraction.

The main difference between these two types is that after crushing, the natural wood (solid wood) can provide good quality and larger chips/shavings of wood, whereas the already artificially produced wood materials, already consisting of relatively small chipped wood particles, only produce smaller ones Particles, usually with adhering binder, can be obtained. However, the smaller particles in particular are not desired or reusable in every product.

The production of material panels from crushed vegetable particles has been known for decades. Here, as a rule, woody plants such as trees and shrubs, but also annual plants (such as straw), are crushed into fibers or particles, dried, glued and pressed in a press to form a material board. In the course of climate change, however, these raw materials are also considered climate-neutral Fuels used, so that it is desirable to significantly increase the proportion of recycling in the production of material panels.

In particular, it would be desirable if waste wood could also be used to produce chipboard (OSB) or MDF, since this branch of industry in particular is very dependent on fresh wood. But the waste wood can also be processed and then used in chipboard production or MDF production.

In addition to the production of material panels, a large number of uses for the material obtained are of course conceivable, for example the production of molded wood or HWS (wooden materials), WPG or the like.

The object of the present invention is to create a device and a method in which collected and reusable waste wood can be processed and recycled, in particular in the course of the production of material panels.

In an extension of the task, it should be possible that part of the waste wood can be used for the production of chipboard (OSB) or MDF.

A generic device for the processing of waste wood, in particular in the course of the production of material panels, comprises a store for a starting material such as waste wood and a classification device, the classification device being suitable at least for classifying the starting material or other input material into fines and a usable fraction.

The solution of the invention for a device is that the classification device is operatively connected to at least one cleaning device for separating foreign materials from the usable fraction and a sorting device for dividing the cleaned fraction into solid wood and wood-based materials is connected downstream of the at least one cleaning device. Wood-based materials are understood to mean wood-like or natural material that has already gone through a manufacturing process and is possibly connected with binding agents or other substances.

Means for creating at least three fractions, preferably fines, oversizes and a usable fraction, can preferably be arranged in the classification device.

Alternatively or cumulatively, further means for dividing the usable fraction into a micro-fraction and a macro-fraction can be arranged in the classifying device. Preferably, these means would be screens.

Alternatively or cumulatively, a comminution device can be arranged, the comminution device being suitable for producing input material for the classifying device. By suitable is meant that the input material is suitable to be screened by the classifier

Alternatively or cumulatively, means for detecting and ejecting foreign substances, preferably an X-ray device, can be arranged in the cleaning device.

Alternatively or cumulatively, means for differentiating between solid wood and wood-based material, as well as correspondingly controllable separating means, preferably an NIR device, can be arranged in the sorting device. NIR means near-infrared spectroscopy. Equivalent devices that seem suitable for the task at hand can also be arranged. Separating means are to be understood as meaning dividing devices or sorting devices. In addition to an NIR device, camera systems can also be used.

Alternatively or cumulatively, storage bins can be arranged for the various classified and/or cleaned material flows. possibly storage conveyor belts or devices are also to be understood as storage bunkers. Alternatively or cumulatively, the device can be operatively connected to a plant for the production of material boards, to a plant for the production of WPC (Wood Plastic Compound), to a plant for the production of wood-based materials or the like.

Alternatively or cumulatively, means for comminuting the starting material to a size of less than 100 mm, preferably less than 90 mm, particularly preferably less than 80 mm and very particularly preferably less than 70 mm can be arranged in the comminution device, with a drum chopper being arranged in particular as the comminution device.

Alternatively or cumulatively, means for separating oversizes with a size of greater than 100 mm, preferably greater than 90 mm, particularly preferably greater than 80 mm and very particularly preferably greater than 70 mm can be arranged in the classifying device.

Alternatively or cumulatively, means for separating fines with a size of less than 5 mm, preferably less than 3 mm, particularly preferably less than 2 mm and very particularly preferably less than 1 mm can be arranged in the classifying device.

Alternatively or cumulatively, means for separating a macrofraction larger than 10 mm, preferably larger than 12 mm, particularly preferably larger than 15 mm and very particularly preferably from coarse wood chips up to an oversize size can be arranged in the classifying device.

Alternatively or cumulatively, means for separating a micro-fraction with a size of more than 1 mm, preferably more than 3 mm, particularly preferably more than 5 mm and possibly up to the size of the macro-fraction can be arranged in the classifying device.

A method according to the invention for the processing of waste wood, in particular in the course of the production of material panels, comprises the following method steps:

- stockpiling of starting material in a warehouse, - optional crushing of the starting material by means of a crushing device into input material for processing,

- Classification of the starting material or the input material by means of a classification device into fines and at least one fraction that can be used further,

- Cleaning the usable fraction from foreign materials and

- Sorting of the usable fraction by means of a sorting device into solid wood and wood-based materials.

The input material in the classification device is preferably divided into fines, oversizes, at least one usable fraction. It would be particularly advantageous if the usable fraction comprised a microfraction and a macrofraction.

Alternatively or cumulatively, an X-ray device can be used for cleaning or an NIR device can be used for sorting. Equivalent devices that seem suitable for the task at hand can also be arranged. Sorting devices are preferably operatively connected to the means for detecting the material. In addition to an NIR device, camera systems can also be used for detection.

Alternatively or cumulatively, the cleaned and/or sorted material flows or fractions can be stored in storage bunkers.

Alternatively or cumulatively, the sorted solid wood and/or the sorted wooden materials can be processed in a plant for the production of material boards and preferably pressed with other streams of material to form material boards.

Alternatively or cumulatively, the starting material can be comminuted in the comminution device to a size of less than 100 mm, preferably less than 90 mm, particularly preferably less than 80 mm and very particularly preferably less than 70 mm. A drum chopper or a shredder is preferably used as the comminution device. Alternatively or cumulatively, oversizes with a size greater than 100 mm, preferably greater than 90 mm, particularly preferably greater than 80 mm and very particularly preferably greater than 70 mm can be separated off in the classification device and, in particular, fed to further comminution.

Alternatively or cumulatively, fines with a size of less than 5 mm, preferably less than 3 mm, particularly preferably less than 2 mm and very particularly preferably less than 1 mm can be separated in the classifying device.

Alternatively or cumulatively, a macro-fraction with a size of greater than 10 mm, preferably greater than 12 mm, particularly preferably greater than 15 mm and very particularly preferably from coarse wood chips up to an oversize size can be separated in the classifying device.

Alternatively or cumulatively, a micro-fraction with a size of more than 1 mm, preferably more than 3 mm, particularly preferably more than 5 mm and up to a size of the macro-fraction can be separated in the classifying device.

Advantageously, the invention enables waste wood to be processed and used, among other things, in the production of material panels (including MDF, chipboard, chipboard - OSB). For this purpose, the material, preferably prepared and particularly preferably in predetermined mixing ratios with other materials or fresh wood, can be scattered and pressed to form a material panel. In addition to a single-layer material panel, such as MDF; multi-layer material panels, such as chipboard, can also be produced. Steam presses, cycle presses, block presses or a continuous press are suitable as presses.

As already explained above, when carrying out waste wood recycling, there is a more or less high proportion of (high-quality) solid wood. It is therefore primarily proposed to separate the solid wood from the old wood before or after the comminution and then to comminute the old wood. In order to reliably meet the highest demands, foreign substances such as metals, non-metals, plastics, sand and stones are first separated from the wood. through careful By sorting, you can ensure that only uncontaminated waste wood is recycled.

The invention has found, among other things, that after a first pre-crushing and a cleaning process, there are roughly two different types of materials, namely solid wood and “manufactured” wood-based materials with binders. After pre-shredding, these usually differ in their length/width ratio, since the solid wood is longer than wide from pre-shredding, while artificial wood materials (crushed material with binding agent) are more square, i.e. more the same in length and width.

This goes hand in hand with the realization that it is possible to sort out solid wood from mixed waste wood (solid wood and manufactured wood materials) after appropriate cleaning in order to obtain high-quality material for the production of material panels. In particular, it should be possible with the method and the device to process waste wood in such a way that a portion of it can be used as an equivalent substitute for MDF, OSB or chipboard production. With MDF, the material will probably need to be further defibrated.

In an extension, the proportion of cleaned from sorted solid wood from the old wood, depending on the quality and quantity of the fresh wood delivery, can be fed either to the chipper for the production of chips for the middle layer or to a knife ring chipper for the production of top layer material

The invention makes it possible to obtain large-volume (chip) chips from recycled solid wood or glued laminated wood when recycling waste wood, which chips can be regarded as equivalent to fresh wood (logs).

In terms of process technology, a solution for the individual areas in a particular exemplary embodiment can appear as follows. The individual areas are independently divided into areas A, B, C and D and can be combined as desired:

A) Material entry a1) Mixed starting material (waste wood with solid wood parts) is shredded in order to obtain a size of 60, 70, 80, 90 or 100 mm and smaller that is as uniform as possible. => as input material (a1) for processing b) a2) Fresh wood is crushed and fed to the needs-based production of particles c).

B) Processing (chip cleaning) b) Based on the findings, the input material (a1) is now subjected to screening and preferably divided into four fractions b1) fines for thermal recycling (b11) and/or for top layers of material boards after optional cleaning (b12) (less than 5, preferably less than 3 mm, in particular less than 1 mm). Alternatively, there is the possibility of using this group as fillers in other areas, for example in WPG (Wood Plastic Compounds), after appropriate classification. b2) micro-fraction (larger than 1, 3, 5 mm down to smaller than 10 mm, 12, 15 mm) b3) macro-fraction (10, 12, 15 mm or larger, coarse wood chips) b4) oversizes back to shredding (to a1 )

C) cleaning

In a cleaning process, the microfraction (b2) and the macrofraction (b3) are cleaned, preferably with a non-contact X-ray sorting device, unusable materials (preferably all non-wood) are sorted out. What remains in the cleaned micro-fraction (c2) is directly usable material of small size and in the cleaned macro-fraction (c3) usable material of larger size.

D) sorting:

It is precisely this larger usable material that is suitable for further sorting, since it is either solid wood or artificial wood-based materials. This flow of matter from greater usable material is thus subjected to a sorting that distinguishes between these two types

In summary, the waste wood should be sorted into solid wood and artificial wood after an initial cleaning of foreign matter (metals, non-metals, plastics).

The separated solid wood, provided it is in chip size, can be used in the production of high-quality panels due to its properties being the same as wood chips from fresh wood. It should be noted that the proportions are variable. Buffer options should be provided so that the ratios between solid wood (from recycling), wood materials (from recycling) and fresh wood remain approximately the same for the production of a batch of material boards in order to avoid quality differences in a batch. For this purpose, the system must be designed accordingly and appropriate regulation or control devices must also be created.

The treatment facility mentioned can be spatially separated from facilities for further processing of the materials from the storage bunkers. The fractions from the storage bunkers can therefore be delivered to the later intended use or location by truck or other transport options.

Alternatively, the solid wood can also be processed for use in top layers of material panels.

Alternatively, the solid wood can be incorporated into the middle layer to produce an MDF board if this is produced as a three-layer board.

In principle, it is preferable for a proportion of solid wood to be supplied from the device to a fresh wood process.

The system is suitable for carrying out the process, but can also be operated independently. In the single FIGURE, the process sequence and a corresponding device are explained schematically using a schematic plant structure according to an exemplary embodiment.

Waste wood is collected as starting material 1 and fed to at least one warehouse 2 . Starting material 1 is preferably fed from storage 2 to a comminution, which preferably comminutes starting material 1 to a maximum size of 100 mm, preferably 80 mm, and subjects it to further processing as input material 4 . For this purpose, the input material 4 is fed to a classification device 5, which preferably divides the input material 4 into four classifications (oversize, macro, micro, fine). The smallest fraction as fines 6 is fed to thermal utilization in an energy plant 28 .

Before that, however, the fines can be classified again in order to obtain panels from the fines 6 or top layer material 29 for material. Alternatively, the fines can be used proportionately in other technical areas as fillers, for example in WPG (Wood Plastic Compounds). As a rule, a fraction of oversizes 9 is also returned by the classifying device 5 . The oversizes 9 have not been optimally comminuted and are fed back to the comminuting device 3 for further comminution. The useful fraction lying within these two extreme fractions is divided here according to the preferred embodiment into a micro fraction 7 and a macro fraction 8 .

The micro-fraction 7 preferably has particle sizes larger than 1, 3, 5 mm down to less than 10 mm, 12, 15 mm, whereas in the macro-fraction 8 there are preferably particle sizes of larger than 10, 12, 15 mm down to coarse wood chips. The upper limit results from the extracted oversizes 9.

The preferred division into two different useful fractions has the advantage that these two fractions can be given to cleaning devices 10 that are specially calibrated and adjusted for these sizes. An X-ray measurement is preferably carried out in the cleaning device, on the basis of which foreign material 13 (non-metals, metals, ....) is recognized and removed from the material flow can be eliminated. This results in two material flows, on the one hand a cleaned micro-fraction 14 and a cleaned macro-fraction 11.

The cleaned macro-fraction 11 is now preferably subjected to sorting in a sorting device 12, in which solid wood 18 on the one hand and wood-based materials 16 on the other (glue/binder present) are separated from the macro-fraction 11.

The microfraction 14 can also be subjected to an equivalent sorting (not shown).

As shown, the cleaned micro-fraction 14 can be stored in a storage bunker 15, the solid wood 18 in a storage bunker 19 and the wood-based materials 16 in a storage bunker 17 until they can be used appropriately. Until recycling can mean that the above-mentioned plant is spatially separated from plants for further processing of the materials from the storage bunkers 15, 17 and 19 and is therefore delivered by truck or other transport options to the later intended use.

In the exemplary embodiment, the material flows of solid wood 18, wood-based material 16 and microfraction 14 are fed to a plant for the production of material panels and material panels 27 are produced from them again. As a rule, this is carried out in such a way that a proportion of fresh wood 29 is substituted. To this end, the material streams are fed to a preparation stage or, as shown, to two different preparation stages 20 and 21 . In the preparations 20, 21, the various material flows are re-shredded according to the intended use, optionally dried and glued. According to the embodiment, the preparation 21 is suitable from the solid wood material 18 scatterable material for the middle layer of a material plate, preferably an OSB, to produce and a scattering device 23, for example for middle layers, to feed. The preparation 20 would accordingly be suitable for drying the cleaned microfraction 14 and/or the sorted wooden materials 16, for gluing them and for feeding them to a scattering device 22 for top layers. The technological difference is that solid wood 18 in the middle layer of a material board, in particular OSB, is suitable for raising the quality of the material board to the necessary level for A boards. Of course, other presses can also be used, in contrast to the exemplary representation of a continuously operating press 25, for which the material is scattered in one or more layers by means of a spreading device 22, 23 onto a forming belt 24 with a feed direction 26 and transported to the press 25.

In addition, the material obtained from the waste wood or recycling wood can now also be used in MDF production, preferably by breaking down the solid wood in a refiner as usual.

The material can also be used sensibly in the production of chipboard 1629, especially if it has gone through the steps that may be necessary, such as drying, crushing, screening, and gluing.

List of references 1629:

1 starting material (waste wood)

2 bearings

3 crushing device

4 input material

5 classification device

6 fines

7 microfraction

8 macro fraction

9 plus sizes

10 cleaning device

11 macro fraction (purified)

12 sorting device

13 Foreign Material

14 microfraction (purified)

15 storage bunkers for 14

16 wood-based materials (from 11 )

17 storage bunkers for 16

18 solid wood (from 11 )

19 storage bunkers for 18

20 Preparation (top layer)

21 processing (middle class)

22 spreading device (top layer)

23 spreader (middle layer)

24 shape band

25 press

26 feed direction of 24

27 material plate

28 energy plant

29 fresh wood

Claims

Device for the processing of waste wood, in particular in the course of the production of material panels, comprising a store (2) for a starting material (1) such as waste wood and a classification device (5), the classification device at least for classifying the starting material (1) or other input material (4) into fines (6) and a usable fraction, characterized in that the classification device (5) is operatively connected to at least one cleaning device (10) for separating foreign materials (13) from the usable fraction and the at least one cleaning device ( 10) a sorting device (12) for dividing the cleaned fraction into solid wood (18) and wood-based materials (16) is connected downstream. Device according to claim 1, characterized in that in the classification device (5) means for creating at least three fractions, preferably fines (6), oversize (9) and a usable fraction are arranged. Device according to Claim 1 or 2, characterized in that further means for dividing the usable fraction into a micro-fraction (7) and a macro-fraction (8) are arranged in the classifying device (5), and sieves are preferably arranged as these means. Device according to one or more of the preceding claims, characterized in that a comminuting device (3) is arranged, the comminuting device (3) being suitable for producing input material (4) for the classifying device (5). Device according to one or more of the preceding claims, characterized in that means for detecting and removing foreign substances, preferably an X-ray device, are arranged in the cleaning device (10). Device according to one or more of the preceding claims, characterized in that in the sorting device (12) there are means for distinguishing between solid wood (18) and wood material (16) and correspondingly controllable separating means, preferably an NIR device or camera systems. Device according to one or more of the preceding claims, characterized in that storage bins (15, 17, 19) are arranged for the various classified and/or cleaned material flows. Device according to one or more of the preceding claims, characterized in that the device is operatively connected to a plant for the production of material panels. Device according to one or more of the preceding claims, characterized in that in the crushing device (3) means for crushing the starting material (1) to a size of less than 100 mm, preferably less than 90 mm, particularly preferably less than 80 mm and very particularly preferably are arranged less than 70 mm and 17 in particular as a crushing device (3) a drum chipper is arranged. Device according to one or more of the preceding claims, characterized in that in the classification device (5) means for separating oversizes (9) with a size of greater than 100 mm, preferably greater than 90 mm, particularly preferably greater than 80 mm and very particularly preferably from greater than 70 mm are arranged. Device according to one or more of the preceding claims, characterized in that in the classification device (5) means for separating fines (9) with a size of less than 5 mm, preferably less than 3 mm, particularly preferably less than 2 mm and very particularly preferably from are arranged less than 1 mm. Device according to one or more of the preceding claims, characterized in that in the classification device (5) means for separating a macro fraction (8) with a size of greater than 10 mm, preferably greater than 12 mm, particularly preferably greater than 15 mm and very particularly preferably from coarse wood chips are arranged up to a size of oversize (9). Device according to one or more of the preceding claims, characterized in that in the classification device (5) means for separating a microfraction (7) with a size of greater than 1 mm, preferably greater than 3 mm, particularly preferably greater than 5 mm and up to a size the macro fraction (8) are arranged. Process for the processing of waste wood, in particular in the course of the production of material panels, comprising the following process steps: 18

- Stockpiling of starting material (1) in a warehouse,

- optional crushing of the starting material (1) by means of a crushing device (3) into an input material (4) for the processing,

- Classifying the starting material (1) or the input material (4) by means of a classifying device (5) into fines (6) and at least one further usable fraction,

- cleaning the usable fraction from foreign materials (13) and

- Sorting the usable fraction by means of a sorting device (12) in solid wood (18) and wood materials (16). Method according to Claim 14, characterized in that the input material (2) in the classification device (5) is divided into fines (6), oversizes (9) at least one usable fraction, preferably into a micro-fraction (7) and a macro-fraction (8). . Method according to Claim 14 or 15, characterized in that an X-ray device is used for cleaning or an NIR device for sorting or camera systems are used for detection. Method according to one or more of the preceding method claims, characterized in that the cleaned and/or sorted material flows or fractions are stored in storage bunkers (15, 17, 19). Method according to one or more of the preceding method claims, characterized in that the sorted solid wood (16) and/or the sorted wooden materials (16) are processed in a plant for the production of material boards and are preferably pressed with other streams of material to form material boards (27). 19 Method according to one or more of the preceding method claims, characterized in that in the comminution device (3) the starting material (1) is reduced to a size of less than 100 mm, preferably less than 90 mm, particularly preferably less than 80 mm and very particularly preferably less than 70 mm is crushed and in particular as a crushing device (3) a drum chipper or a shredder is used. Method according to one or more of the preceding method claims, characterized in that oversizes (9) with a size of greater than 100 mm, preferably greater than 90 mm, particularly preferably greater than 80 mm and very particularly preferably greater than 70 mm are separated in the classification device (5). and in particular fed to further comminution. Method according to one or more of the preceding method claims, characterized in that fines (9) with a size of less than 5 mm, preferably less than 3 mm, particularly preferably less than 2 mm and very particularly preferably less than 1 mm are separated in the classification device (5). becomes. Method according to one or more of the preceding method claims, characterized in that in the classification device (5) a macro fraction (8) with a size of greater than 10 mm, preferably greater than 12 mm, particularly preferably greater than 15 mm and very particularly preferably from coarse wood chips to is severed to an oversize size (9). Method according to one or more of the preceding method claims, characterized in that in the classification device (5) a microfraction (7) with a size of greater than 1 - 20 - mm, preferably greater than 3 mm, particularly preferably greater than 5 mm and up to a size of the macro fraction (8) is separated.