Machine and method for separating wood material from other materials

Abstract

A machine (10) for separating wood materials from other materials, comprising: feeding means (24) conveying the material (A) on a conveyor belt (11) associated with a detection unit (14) configured to detect the presence of an organic source material and / or a metallic material; a plurality of compressed air nozzles (12a) disposed downstream of an outlet end (13) of such a conveyor belt (11) and configured to selectively push the material downward; and a blowing device (25) for blowing the wood material from the outlet end (13) so as to push the wood material beyond a separating element (18) arranged downstream of the blowing device (25).

Description

Technical Field

[0001] The present invention relates to the separation of wood materials such as wood pieces, shavings or wood chips (also called "wood chips") from other non-wood materials such as plastic materials, rubber, metallic materials or inert materials (e.g. glass, stone, rock or brick) as a preliminary operation to the production of wood-based panels. Background Art

[0002] In the field of wood-based panels such as particleboard (PB), medium-density fiberboard (MDF), oriented strand board (OSB), etc., the processing of the wood stream in the so-called "green" area of ​​the factory is an important step in the next stage of the actual production of the boards, including drying, gluing, forming and pressing.

[0003] In particular, in the aforementioned “green” area, recycled wood requires more cleaning steps to primarily remove metal contaminants and inert materials.

[0004] In patent application WO-A-2018211545, a separation machine for separating wood material from other materials is disclosed, wherein the wood material to be cleaned enters an entry section, is placed on a conveyor belt and is accelerated by the conveyor belt to obtain a substantially single layer of material, without overlapping objects, to allow recognition by an optical system.

[0005] The machine also includes a sensor configured to identify any metallic objects in the stream by transmitting a signal to a processing system to activate at least one or more air nozzles included at the location of the object detected on the conveyor. The compressed air stream delivered by the nozzles deflects the foreign objects downward by causing them to fall into a collection section immediately adjacent to the exit end of the objects from the conveyor.

[0006] The optical system allows the same nozzle to be activated when materials of organic origin such as plastics and rubber are detected, which are always dispersed and discharged in this section.

[0007] Then, after a first selection and cleaning by the nozzles, the material continues its trajectory through the air, due to the high speed of the conveyor, maintaining a height close to the conveyor surface for a sufficiently long horizontal stretch to allow selection by the blower blowing air. In this way, similar to the method used in a powered air separator with a belt feed, the lighter residual material (i.e. wood) is pushed forward, bypassing the separation element, allowing the heavier residual material (such as rocks and glass) to fall into the collection section.

[0008] The blower can be adjusted in airflow, inclination, height and position along the axis of the machine to allow the selection of wood flows adapted to different densities and humidity as well as different conveyor belt speeds, which require different output flow trajectories. The speed of the conveyor belt is related to the flow rate of the material processed by the machine, always constrained by the singularity of the block to allow the optical system to read it.

[0009] One of the limitations of this type of machine is that the compressed air delivery nozzle is located at a certain distance from the blowing device, which can be related to the size of the machine and can also increase the efficiency of material selection.

[0010] Such a machine, besides being relatively cumbersome, therefore does not allow the selection with greater precision and efficiency of the objects or materials affected in particular by the compressed air flow supplied by said nozzle.

[0011] Therefore, there is a need to improve a machine for separating wood materials from other materials and a separation method to overcome at least one disadvantage of the prior art.

[0012] In particular, it is an object of the present invention to provide a separation machine for separating wood materials from other materials, which is able to select various types of materials simultaneously and efficiently, effectively and reliably.

[0013] Another object of the invention is to provide a compact separating machine which allows the selection of more material fractions than known separating machines.

[0014] Another object of the present invention is to provide an efficient and simple method for separating wood material from other materials.

[0015] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages. Summary of the invention

[0016] The invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the invention or variants to the main inventive idea.

[0017] In accordance with the above-mentioned purpose, a separation machine for separating wood material from other materials according to the present invention comprises: a feeding device for conveying material on a conveyor belt, the conveyor belt being associated with a detection unit configured to detect the presence of organic-origin material and / or metal material; a plurality of compressed air nozzles arranged downstream of the outlet end of the conveyor belt and configured to selectively push the material downward; and a blowing device for blowing air to the wood material from the outlet end, thereby pushing the wood material beyond a separation element arranged downstream of the blowing device.

[0018] According to one aspect of the invention, the separation machine comprises a collecting area positioned between the separation element and the blowing device, which is used for the material selected by the nozzle, the nozzle being positioned near the blowing device and being configured to provide the selected material with sufficient inertia to avoid being pushed by the blowing device.

[0019] In the separating machine of the invention, a collecting zone is advantageously provided between the separating element and the blowing device, and the plurality of nozzles are positioned near the blowing device, making the machine extremely compact, efficient and capable of selecting more material portions than in the case of known machines.

[0020] According to another aspect of the invention, the nozzle is positioned along a collector above the blowing device and is aligned with the collector in a substantially vertical direction.

[0021] According to another aspect of the present invention, the collector includes a support, and the nozzles are aligned along the support.

[0022] According to another aspect of the invention, the shape of the support is suitable for enabling the nozzle to deliver compressed air according to a direction inclined relative to the longitudinal plane of the collector.

[0023] According to another aspect of the invention, each of the nozzles is supplied with air by its own valve, the operating pressure of which is higher than the pressure of the air blown by the blowing device.

[0024] According to another aspect of the invention, the separation machine comprises an additional plurality of nozzles configured to deliver selected material to an additional collection zone and located downstream of the outlet end and upstream of the nozzles positioned adjacent the blowing device.

[0025] According to another aspect of the invention, the additional nozzles are positioned along the collector.

[0026] According to another aspect of the invention, the collector delivers compressed air in a diverging direction through the corresponding nozzles.

[0027] According to another aspect of the invention, the collector is specularly positioned relative to a substantially vertical plane.

[0028] Another object of the present invention is a method for separating wood material from other materials, comprising: a step of loading all the materials to be separated onto a conveyor belt through a feeding device; a step of detecting the presence of organic-origin materials and / or metal materials in the materials to be separated through a detection unit associated with the conveyor belt; a step of selecting materials through at least one set of compressed air nozzles and through a blowing unit, wherein the nozzle is arranged downstream of the outlet end of the conveyor belt and is configured to selectively push down the organic-origin materials and / or the metal materials detected by the detection unit through compressed air under the control of an electronic control unit, the electronic control unit processes the signal from the detection unit, and wherein the blowing device is configured to blow air at the wood material from the outlet end that passes over the blowing device due to inertia and pushes the wood material over a separation element arranged downstream of the blowing device; and a step of collecting the material selected by the nozzle in a collection area located between the separation element and the blowing device, wherein the nozzle is positioned near the blowing device and is configured to provide sufficient inertia for the selected material to avoid the thrust of the blowing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] These and other aspects, features and advantages of the invention will become apparent from the following description of some embodiments given as non-limiting examples with reference to the accompanying drawings, in which:

[0030] - Figure 1 is a schematic side view of a separation machine according to the invention;

[0031] - Figure 2 is an axonometric view of a compressed air nozzle collector;

[0032] - Figure 2a yes Figure 2 a larger scale view of a portion of the collector;

[0033] - Figure 3 yes Figure 1 A larger scale view of a portion of a separation machine.

[0034] We must clarify that the words and terms used in this description as well as the figures in the accompanying drawings have the sole function of better illustrating and explaining the invention as described, their function being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0035] To facilitate understanding, the same reference numerals are used, where possible, to identify the same common elements in the drawings. It should be understood that the elements and features of one embodiment may be conveniently combined or incorporated into other embodiments without further explanation. DETAILED DESCRIPTION

[0036] Reference will now be made in detail to possible embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings by way of non-limiting example. The phraseology and terminology used herein are also for non-limiting exemplary purposes.

[0037] With reference to the drawings, in particular to Figure 1 A separation machine 10 for separating wood material from other materials comprises: a conveyor belt 11 and a feeding device 24, which are configured to collect and transport all materials A to be separated on the conveyor belt 11; a detection unit 14, which is associated with the conveyor belt 11 and is configured to detect the presence of organic-derived materials and / or metal materials from the material A to be separated; a plurality of compressed air nozzles 12a, which are arranged downstream of an outlet end 13 of the conveyor belt 11 and are configured to selectively push downward the organic-derived materials and / or the metal materials detected by the detection unit 14 by compressed air under the control of an electronic control unit 15 that processes signals from the detection unit 14; and a blowing device 25, which is configured to blow air toward the wood material from the outlet end 13, over which the wood material passes due to inertia, and pushes the wood material over a separation element 18 arranged downstream of the blowing device 25.

[0038] The material to be separated is then loaded onto the supporting surface 27 of the conveyor belt 11 by means of the feed device 24 and translated in the direction A1 towards the outlet end 13 .

[0039] The separation machine 10 comprises a collection zone C of the material selected from the nozzle 12a (i.e. at least part F2) between the blowing device 25 and the separation element 18. The nozzle 12a is positioned near the blowing device 25 and is configured to provide the selected material with sufficient inertia to avoid the thrust of the blowing device 25, in particular from below and forwards.

[0040] The nozzles 12a are positioned along the collector 19a, see also Figure 2 , Figure 2a , the collector 19a is located above the blowing device 25 and is aligned therewith in a substantially vertical direction.

[0041] The collector 19a comprises a box 20 provided at one end with an inlet opening 21 for compressed air from a suitable feed source.

[0042] The collector 19a comprises a support 22, in particular positioned on the box 20, along which the nozzles 12a are aligned. The shape of the support 22 is suitable for enabling the nozzles 12a to deliver compressed air in a direction D2, see also Figure 3, which is inclined at an angle α2 relative to the longitudinal plane P2 of the collector 19a. Such an angle α2 may be any angle between 0° and 90°, such as about 45°.

[0043] Each of the nozzles 12a is supplied with air by its own valve 23, for example a pneumatic valve. Each valve 23 is connected to the electronic control unit 15 which controls its opening and closing based on a signal from the detection unit 14.

[0044] Said valve 23 operates at a pressure comprised between about 6 bar and about 10 bar, preferably between 6 bar and 8 bar, and at an air flow rate comprised between about 90 Nl / min and about 400 Nl / min.

[0045] The detection unit 14 may be of an optical type and include a near-infrared camera, a light source, and the like.

[0046] The detection unit 14 is capable of detecting the passage of materials of organic origin, such as plastic materials, rubber, wood derivatives, such as MDF boards, high pressure laminate (HPL) boards, plastic or melamine coated particle boards. The detection unit 14 is also capable of detecting inert materials such as glass, rocks, etc.

[0047] The detection unit 14 may also include a plurality of inductive sensors 26 of a type known per se, arranged just below the support surface 27 of the conveyor belt 11 and configured to detect the passage of metallic materials (ferrous and non-ferrous). Additionally or alternatively to the inductive sensors 26, an X-ray scanner for metals and inert materials may be arranged below the support surface 27 of the conveyor belt 11, with the source being arranged above and aligned with the scanner.

[0048] For example, when the detection unit 14 detects the presence of organic source materials through the camera or detects the presence of metal through the inductive sensor 26, the detection unit 14 sends a corresponding signal to the electronic control unit 15, and the electronic control unit 15 activates the corresponding valve 23 connected to the multiple nozzles 12b, and the multiple nozzles 12b use compressed air to push the detected material (i.e., part F1) downward into the first collection area D below.

[0049] The nozzle 12 b is located downstream of the outlet end 13 and upstream of the nozzle 12 a , and the nozzle 12 a is located near the blowing device 25 .

[0050] Downstream of the nozzle 12b and substantially below the nozzle 12a, an outlet of the blowing device 25 is arranged, and the blowing device 25 comprises a blower 16 connected to a fan 17. The blowing device 25 is configured to blow continuously or selectively at a certain pressure (e.g., from about 0.005 bar to about 0.02 bar).

[0051] Therefore, the pressure (such as can be included between about 6 bar and about 10 bar) when the valve 23 of each nozzle 12a works is significantly higher than the blowing pressure of the wind from the blowing device 25. Therefore, the thrust of the compressed air downward from the nozzle 12a can overcome the air blown to another direction by the blowing device 25.

[0052] The blowing device 25 is configured to achieve, by blowing, separation of wood materials having a relatively low specific gravity from inert materials having a higher specific gravity, such as stones, rocks and glass, which have not yet been detected by the detection unit 14. In practice, the selected wood elements (i.e., the portion F3) leaving the conveyor belt 11 will be blown beyond the separation element 18 and will be thrown relatively further than the inert materials and will fall into the collection area B after passing through the separation element 18.

[0053] Advantageously, in the present separation machine 10, the collection zone C is also provided between the separation element 18 and the blowing device 25, so that the material that does not exceed the separation element 18 can be further divided into two collection zones, namely the collection zone C and the collection zone D.

[0054] The nozzle 12b is positioned along another collector 19b, see Figure 3 , the collector 19b is preferably identical to the collector 19a.

[0055] The shape of the support 22 of the collector 19b is suitable for the nozzle 12b to deliver compressed air in a direction D1, which is inclined at an angle α1 relative to the longitudinal plane P1 of the collector 19b. The angle α1 can be any angle between 0° and 90°, such as about 45° or other angles.

[0056] Said collectors 19 a and 19 b are specularly positioned relative to a substantially vertical plane V. In particular, said collectors 19 a and 19 b may be suitably fixed to a frame 28 of the separating machine 10 .

[0057] Said collectors 19a and 19b deliver compressed air in said divergent directions D2 and D1 , preferably specular directions D2 and D1 , relative to said plane V, through respective nozzles 12a and 12b.

[0058] The direction D2 may be inclined at an angle comprised between about 0° and about 40° relative to the plane V. The direction D1 may also be inclined at an angle comprised between about 0° and about 40° relative to the plane V.

[0059] The supply of compressed air from top to bottom in the directions D2 and D1 allows further separation of the material relative to known machines, but in the case of part F2 the material must overcome the thrust of the blowing device 25; this is because the thrust from above of the compressed air flowing out of the nozzle 12a provides the object with sufficient inertia to avoid the thrust from below and forwards of the blowing device 25, which blows at a low pressure via the fan 17; this applies both to heavy objects such as metals and to light objects such as plastics, rubber or MDF and PB boards.

[0060] The operation of the nozzles 12a and / or the nozzles 12b is defined at the software level and controlled by the electronic control unit 15 by associating certain classes of material with the nozzles 12a and other classes of material with the nozzles 12b. For example, if the detection unit 14 identifies a class of objects associated with the nozzles 12a, one or more of the nozzles 12a will be activated to push the object (i.e., the portion F2) into the collection area C when the nozzles 12a pass under the nozzles.

[0061] By way of example, by means of the separation machine 10, the following fractions F1, F2 and F3 of selected material can be obtained:

[0062] Part F1 : plastic, rubber, MDF associated with said nozzle 12 b and therefore with the collector 19 b ;

[0063] Part F2: inert material (glass, stone), metal (stainless steel, aluminium, wood with metal nails, copper) associated with said nozzle 12a and therefore with the collector 19a;

[0064] Part F3 : Wood associated with said blowing device 25 .

[0065] Other examples of the fractions F1 , F2 and F3 obtainable by the present separation machine 10 include a first fraction F1 with material based on an MDF board, a second fraction F2 with material based on a PB board, and a third fraction F3 of solid wood.

[0066] The present separation machine 10 with said three collecting zones B, C, D therefore allows a more precise and fine separation of the various materials compared to known machines.

[0067] A separation method for separating wood materials from other materials comprises, for example, a step of loading the material to be separated into the feed device 24 so that the material to be separated falls on the support plane below the conveyor belt 11. The conveyor belt 11 can move the material to be separated in the direction A1 at a relatively high conveying speed (for example, about 5 to 8 m / s) so that the material to be separated is arranged substantially in a single layer without overlapping different pieces, thereby obtaining a so-called singularization of the pieces themselves to allow optimal recognition of these pieces by the detection unit 14. A detection step is then performed, in which the detection unit 14 detects the possible presence of materials of organic origin and metal materials. In a subsequent separation step, the actual separation is carried out by selectively activating the nozzle 12a and possibly the nozzle 12b and by the wind blown out from the blower device 25, the selective activation of the nozzle 12a and possibly the nozzle 12b causing the separation of the aforementioned organic origin material and the metal material, the aforementioned organic origin material and the metal material being pushed downward into the collection area C and possibly into the collection area D, the air blown out from the blower device 25 only pushing the wood material that exceeds the separation element 18 into the collection area B, while the inert material falls into the collection area C below and possibly into the collection area D.

[0068] It is obvious that modifications and / or additions of parts or stages may be made to the separation machine and separation method described above without departing from the scope of the invention as defined in the claims. It is also obvious that, although the invention has been described with reference to some specific examples, a person skilled in the art will be able to realize other equivalent forms of the machine and method for separating wood material from other materials, which have the characteristics described in the claims and therefore all belong to the scope of protection defined thereby.

[0069] In the following claims, the sole purpose of reference signs between parentheses is to facilitate reading thereof and shall not be construed as limiting factors with respect to the protective scope defined in the claims.

Claims

1. A machine (10) for separating wood material from other materials, comprising: a feeding device (24) conveying said material (A) on a conveyor belt (11), said conveyor belt (11) being associated with a detection unit (14) configured to detect the presence of material of organic origin and / or metallic material; a plurality of compressed air nozzles (12a) arranged downstream of the outlet end (13) of said conveyor belt (11) and configured to selectively push said material downwards; and a device (25) for blowing air at the wood material coming from the outlet end (13) so as to push the wood material beyond a separating element (18) arranged downstream of the blowing device (25), characterized in that the machine (10) comprises a collecting area (C) located between the separating element (18) and the blowing device (25), the collecting area (C) being used to collect the material selected by the nozzle (12a), the nozzle (12a) being positioned near the blowing device (25) and being configured to provide the selected material with sufficient inertia to avoid the thrust of the blowing device (25).

2. The separation machine (10) according to claim 1, characterized in that The nozzle (12a) is positioned along a collector (19a) above the blowing device (25) and is aligned with the collector (19a) in a substantially vertical direction.

3. The separation machine (10) according to claim 2, characterized in that The collector (19a) comprises a support (22) along which the nozzles (12a) are aligned.

4. The separation machine (10) according to claim 3, characterized in that The support (22) is shaped so that the nozzle (12a) delivers compressed air in a direction (D2) that is inclined relative to the longitudinal plane (P2) of the collector (19a).

5. A separation machine (10) according to any one of the preceding claims, characterised in that Each of the nozzles (12a) is supplied with air by its own valve (23), the working pressure of the valve (23) being higher than the pressure of the air blown by the blowing device (25).

6. A separation machine (10) according to any one of the preceding claims, characterised in that The separation machine (10) comprises an additional plurality of nozzles (12b) configured to deliver the selected material to an additional collection zone (D), and the plurality of nozzles (12b) are located downstream of the outlet end (13) and upstream of the nozzle (12a) positioned near the blowing device (25).

7. A separation machine (10) according to any one of the preceding claims, characterised in that The additional nozzles (12b) are positioned along the collector (19b).

8. A separation machine (10) according to claims 2 and 7, characterised in that The collectors (19a, 19b) deliver compressed air in diverging directions (D2, D1) through the corresponding nozzles (12a, 12b).

9. A separation machine (10) according to claim 7 or 8, characterised in that The collectors (19a, 19b) are specularly positioned relative to a substantially vertical plane (V).

10. A method for separating wood material from other materials, comprising: The steps of loading all the materials (A) onto the conveyor belt (11) by means of a feeding device (24); detecting the presence of the organic origin material and / or the metal material to be separated by means of a detection unit (14); selecting the material by means of at least one set of compressed air nozzles (12a) and by means of a blowing unit (25), wherein the nozzles (12a) are arranged downstream of the outlet end (13) of the conveyor belt (11) and are configured to selectively push downwards the organic origin material and / or the metal material detected by the detection unit (14) by means of compressed air under the control of an electronic control unit (15); the blowing device (12a) 25) is configured to blow air toward the wood material from the outlet end (13) passing over the blowing device (25) due to inertia, and push the wood material over the separation element (18) arranged downstream of the blowing device (25); a step of collecting the material selected by the nozzle (12a) in a collecting area (C) located between the separation element (18) and the blowing device (25), the nozzle (12a) being positioned near the blowing device (25), and the nozzle (12a) being configured to provide sufficient inertia for the selected material to avoid the thrust of the blowing device (25).

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