GB2528979A - A method and system for recycling wood - Google Patents
A method and system for recycling wood Download PDFInfo
- Publication number
- GB2528979A GB2528979A GB1414090.9A GB201414090A GB2528979A GB 2528979 A GB2528979 A GB 2528979A GB 201414090 A GB201414090 A GB 201414090A GB 2528979 A GB2528979 A GB 2528979A
- Authority
- GB
- United Kingdom
- Prior art keywords
- wood
- shredded wood
- shredded
- sized
- metalized
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
- B07C5/00—Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or measure such characteristic or feature; Sorting by manually actuated devices, e.g. switches
- B07C5/34—Sorting according to other particular properties
- B07C5/342—Sorting according to other particular properties according to optical properties, e.g. colour
Landscapes
- Processing Of Solid Wastes (AREA)
Abstract
A method for automatically recycling wood into a plurality of disparate grades of wood comprises the steps of shredding the wood in a shredder 5, preferably into a size of the order of less than 60mm in diameter, removing metal from the shredded wood at a first metal removal station 9, screening the shredded wood in a first sorting station 15 to remove fines and oversized shredded wood, removing any residual metal from the shredded wood at a second metal removal station 25, delivering the de-metalized sized shredded wood in an even manner to a second sorting station 39, 41 where the de-metalized sized shredded wood is processed using an optical sorting unit 43 having an optical sensor unit 44 and an actuator unit 45 to separate the shredded wood into a plurality of disparate grades which are then stored in separate, dedicated storage areas 59, 61, 63. The optical sensor unit 44 may comprise a near infra red light unit, a detector for detecting reflected light and a processor and the actuator unit 45 may comprise a plurality of pressurised air nozzles. The oversized wood may be returned to the shredder 5 and the fines may be led off to a storage area 19.
Description
"A method and system for recycling wood"
Introduction
This invention relates to a method and system for recycling wood. More specificaUy, the present invention relates to a method and system for automatically recycling wood into a plurality of disparate grades of wood.
It is estimated that approximately 4.5 million tons of waste wood are generated in the UK each year. Up until quite recently, a significant portion of this waste wood was sent directly to landfill each year rather than being recycled. However, with the introduction of landfill taxes on waste wood, waste wood processors have been looking at alternative methods of disposal of their waste wood. Recycled waste wood can be used in a plethora of different areas including animal bedding, Ieedstock for new panel boards, landscaping, play areas, filter areas as well as feedstock for boilers and as a biomass fuel.
Grade A" waste wood can be used in several areas including pellet manufacture, animal bedding and Non-WID compliant boilers. Grade B wood can be used in a number of areas including panel board manufacture. Grade C wood can only be used in WID compliant boilers. Therefore, there is a need to effectively separate the different grades of wood for subsequent processing.
However, there are problems with the existing methods of recycling waste wood. First of all, in order to use the recycled waste wood as a feedstock for certain types of boiler or as a biomass fuel in certain types of boilers, it is necessary to ensure that the waste wood is free from any contaminants such as paint, wood preservatives, plastic and metal, Failure to ensure that the waste wood is free from these contaminants prior to use as a fuel can result in environmental pollution that is hazardous to human health.
However, the separation of the waste wood into grade "A" waste wood which is suitable for use as a fuel in certain types of boilers and into the other grades of waste wood suitable for other purposes is a time consuming and labour intensive process. This leads to increased costs of recycling the waste wood and the production of a recycled biomass fuel that is relatively expensive when compared with competing offerings.
Therefore, it is an object of the present invention to provide a method and system for recycling waste wood that overcomes at east some of the problems with the known methods and systems. It is a further object to provide a method and system that is relatively inexpensive to operate and that is efficient in operation.
Statements of Invention
According to the invention there is provided a method of automatically recycling wood into a plurality of disparate grades of wood comprising the steps of: receiving a consignment of recycled wood; delivering the consignment of recycled wood to a shredder; shredding the consignment of recycled wood; passing the shredded wood from the shredder through a first metal removal station and removing metal from the shredded wood; delivering the de-metalized shredded wood to a first sorting station comprising a screen unit; removing the fines and oversized wood from the sized shredded wood; storing the fines in a dedicated storage area; returning the oversized wood back to the shredder; and passing the sized shredded wood onwards for further processing; passing the sized shredded wood through a second metal removal station and removing residual metal from the sized shredded wood; deliver ing the de-metalized sized shredded wood to a vibration feeder; delivering the demetalized sized shredded wood from the vibration feeder to a conveyor of a second sorting station, the second sorting station further comprising an optical sorting unit having an optical sensor unit and an actuator unit, the optical sensor unit detecting a plurafity of disparate grades of wood in the de-metalized sized shredded wood and the actuator unit separating the plurality of disparate grades of de-metalized sized shredded wood in response to the optical sensor unit; and delivering the disparate grades of de-metalized sized shredded wood to dedicated storage areas.
By having such a method, the waste wood will be automatically sorted into a plurality of different grades of waste wood with the minimum of difficulty and expense. The method requires minimal human interaction and therefore the cost of the method is significantly reduced and the speed of the recycling is increased. This allows for an economically viable recycled waste wood product to be produced.
In one embodiment of the invention there is provided a method in which the optical sensor unit comprises a near infra-red unit and a detector, the optical sensor unit: shining near infra-red light onto the de-metalized sized shredded wood passing on the conveyor underneath; detecting the reflected light from the de-metalized sized shredded wood; plotting the reflected light data thereby determining the grades of wood present and their location in the de-metalized sized shredded wood; and selecting the de-metalized sized shredded wood for separation from the remainder of the de-metalized sized shredded wood.
This is seen as a particularly effective way of detecting the different types of waste wood contained in the recycled waste wood that will allow them to be separated reliably, quickly and at minimal cost. Again, this method will obviate the need for other known labour-intensive methodologies of recycling waste wood. -4.-
In one embodiment of the invention there is provided a method in which the actuator unit comprises a pressurized air supply and a plurality of pressurized air nozzles; and in which the step of the actuator unit separating the plurality of disparate grades of de-nietalized sized shredded wood in response to the optical sensor unit comprises the actuator unit delivering a jet of air through one or more of the pressurized air nozzles onto pre-selected pieces of de-metalized sized shredded wood as they pass by the nozzle. This is seen as a simple and effective way of separating the desired grade waste wood from the recycled waste wood. The air nozzles will be effective and inexpensive in operation.
In one embodiment of the invention there is provided a method in which the de-metalized sized shredded wood is delivered to one of a pair of vibration feeders, the vibration feeders each deliver de-metalized sized shredded wood from the vibration feeder to one of a pair of conveyors of one of a pair of second sorting stations.
In one embodiment of the invention there is provided a method in which the first metal removal station comprises a ferrous metal removal unit and a non-ferrous conductive metal removal unit so that both ferrous and non-ferrous conductive metal is removed from the shredded wood as it passes through the first metal removal station.
In one embodiment of the invention there is provided a method in which the second metal removal station comprises an overband magnet that draws any residual metal upwardly and out from the sized shredded wood on a conveyor passing below.
In one embodiment of the invention there is provided a method in which the shredder shreds the consignment of recycled wood to a target size of less than 60mm diameter.
In one embodiment of the invention there is provided a method in which the consignment of recycled wood passes through at least a three step shredding process in the shredder. A three step shredding process will help provide a thoroughly shredded waste wood product for subsequent sorting and will reduce the amount of returned oversized shredded wood that will have to be returned from the shredder leading to a more efficient method.
In one embodiment of the invention there is provided a method in which the oversized wood is returned back to the shredder on a conveyor from the screen unit.
In one embodiment of the invention there is provided a method in which the shredder is a horizontal shredder fed by a substantially horizontal conveyor.
In one embodiment of the invention there is provided a method in which the second sorting station separates the plurality of disparate grades of de-metalized sized shredded wood into three grades of de-metalized sized shredded wood.
In one embodiment of the invention there is provided a system for automaticafly recycling wood into a plurality of disparate grades of wood comprising: a feed conveyor for delivery of a consignment of recycled wood to a shredder; a shredder for shredding the consignment of recycled wood; a metal removal station; a first delivery conveyor for transporting the shredded wood from the shredder to the first metal removal station; a first sorting station comprising a screen unit for removing fines and oversized a second delivery conveyor for transporting the shredded wood to the first sorting station from the metal removal station; a second metal removal station for removal of metal from the sized shrodded wood; a vibration feeder; a third defivery conveyor for transporting the sized shredded wood from the first sorting station, through the second metal removal station to the vibration feeder; a second sorting station comprising a second sorting station conveyor for receipt of sized shredded wood from the vibration feeder; and an optical sorting unit having an optical sensor unit and an actuator unit; the optical sensor unit being operable to detect a plurality of disparate grades of wood in the de-metalized sized shredded wood and the actuator unit being operable to separate the plurality of disparate grades of de-metafized sized wood in response to the optical sensor unit; a plurality of dedicated storage areas including a first storage area for the fines, a second storage area for a first grade of de-metalized sized shredded wood and a third storage area for a second grade of de-metaUzed sized shredded wood; and a fourth delivery conveyor for transporting the fines from the first sorting station to the first storage area, a fiflh delivery conveyor for transporting the first grade of dernetalized sized shredded wood to the second storage area; and a sixth delivery conveyor for transporting the second grade of de-metalized sized shredded wood to the third storage area.
Such a system is efficient in use and will be relatively inexpensive to run. The system will reduce the labour costs considerably and will speed up the recycling process.
In one embodiment of the invention there is provided a system in which the optical sensor unit comprises a near infra-red unit and a detector.
In one embodiment of the invention there is provided a system in which the optical sensor unit comprises a camera.
In one embodiment of the invention there is provided a system in which the actuator unit comprises a pressurized air supply and a plurality of pressurized air nozzles. -7..-
In one embodiment of the invention there is provided a system in which there is provided a pair of vibration feeders and a pair of sorting stations.
In one embodiment of the invention there is provided a system in which in which the first metal removal station comprises a ferrous metal removal unit and a non-ferrous conductive metal removal unit.
In one embodiment of the invention there is provided a system in which the second metal removal station comprises an overband magnet.
In one embodiment of the invention there is provided a system in which the shredder is configured to shred the consignment of recycled wood to a target size of less than 60mm diameter.
In one embodiment of the invention there is provided a system in which there is provided a return conveyor for returning the oversized wood from the first sorting station back to the feed conveyor.
In one embodiment of the invention there is provided a system in which the shredder is a horizontal shredder fed by a substantially horizontal conveyor.
In one embodiment of the invention there is provided a system in which there is provided a fourth storage area for a third grade of de-metalized sized shredded wood and a seventh delivery conveyor for transporting the third grade of de-metalized sized shredded wood to the fourth storage area.
Detailed Description of the Invention
The invention wiU now be more dearly understood from the following description of some embodiments thereof given by way of example only with reference to the accompanying drawings, in which:-Figure 1 is a plane view of the system according to the invention; Figure 2 is a cross-sectional view of part of the system along the lines A-A of Figure 1; Figure 3 is a cross-sectional view of part of the system along the lines B-B of Figure 1; Figure 4 is a cross-sectional view of part of the system along the Dines C-C of Figure 1; Figure 5 is a cross-sectional view of part of the system along the lines D-D of Figure 1; Figure 6 is a cross-sectional view of part of the system along the lines E-E of Figure 1; Figure 7 is a perspective view of a second sorting station used in the system according to the invention.
Referring to Figures 1 to 6, there is shown a system for automatically recycling wood into a plurality of disparate grades of wood, indicated generally by the reference numeral 1 comprising a feed conveyor 3 for receiving a consignment of recycled wood and delivering the consignment to a shredder 5. The shredded wood exiting the shredder is passed along a conveyor 7 to a first metal removal station 9. The first metal removal station 9 comprises a ferrous metal removal unit 11 and a non-ferrous conductive metal removal unit 13 for removal of both ferrous and non-ferrous conductive metal from the shredded wood.
Once the metal has been removed from the shredded wood, the de-metalized shredded wood is then passed along a delivery conveyor 14 to a first sorting station 15. The first sorting station comprises a screen system which separates the shredded wood into sized shredded wood, fines and oversized shredded wood. The fines are led off along a delivery conveyor 17 to a first storage area 19 and the oversized shredded wood is led along a return conveyor 21 back to the feed conveyor for reintroduction to the shredder 5. The sized shredded wood is passed along another conveyor 23 for further processing which will be described in more detail below.
First of all, the sized shredded wood is passed along the conveyor 23 under an overband magnet 25 which removes any residual metal from the sized shredded wood.
The demetalized sized shredded wood is then fed along one of a pair ci transport conveyors 27, 29 to one of a pair of vibrating feeders 31, 33. Each of the vibrating feeders deliver the de-metalized sized shredded wood evenly onto one of a pair of conveyors 35, 37 of a pair of second sorting stations 39, 41. The second sorting stations 39, 41 each comprise an optical sorting unit 43.
The second sorting stations 39, 41 sort the de-metalized sized shredded wood into a plurality of disparate grades in a manner that will be described in more detail with reference to Figure 7 below. Once sorted into a plurality of disparate grades of de-metalized sized shredded wood, the grades are led off to dedicated storage areas 47, 49, 51 along conveyors 53, 55, 57 respectively.
Referring to Figure 7, there is shown a perspective view of a second sorting station 39 used in the system 1 and method according to the invention. The second sorting station 39 comprises a conveyor 35 which is fed from a vibrating feeder (not shown). The conveyor advances de-rnetahzed sized shredded wood along the conveyor to an optical sorting unit 43. The optical sorting unit 43 comprises an optical sensor unit 44 and an actuator unit 45. The optical sensor unit 44 in turn comprises a near infra-red (NIR) unit, a detector and a processor (not shown) whereas the actuator unit 45 comprises a pressurized air supply and a plurality of pressurized air nozzles (not shown). -10-
In use, as the de-nietalized sized shredded wood approaches the optical sensor unit 44, the NIR light from the NIR unit is incident on the de-metalized sized shredded wood and depending on the characteristics of the shredded wood, certain light frequencies wifi be absorbed whereas other kght frequencies will be reflected back. The reflected hght is picked up by the detector and the processor thereafter creates a plot of the reflected light. This plot of reflected light is indicative of the type or grade of shredded wood on the conveyor and the location of that grade of shredded wood along the conveyor As the de-metalized sized shredded wood continues along the conveyor, the processor sends control instructions to the actuator unit to either operate the pressurized air supply through one or more the pressurized air nozzles or not as the case may be. Whether the pressurized air supply is operated will depend on the grade of de-metalized sized shredded wood on the conveyor adjacent the nozzle at that moment in time and whether or not the de-metalized sized shredded wood is to be ejected into a certain stream of graded de-rnetalized sized shredded wood. If the pressurized air supply is not operated, the de-metalized sized shredded wood will fall down chute 59 and onto the conveyor 53.
It the pressurized air supply is operated through a first bank of pressurized air nozzles, the de-rnetalized sized shredded wood will fall down chute 61 onto conveyor 55 and if the pressurized air supply is operated through a second bank of pressurized air nozzles angled with respect to the first bank of pressurized air nozzles, the de-rnetalized sized shredded wood will fall down chute 63 onto conveyor 57.
In the present embodiment, the second bank of air nozzles is located below the first bank of air nozzles. The second bank of air nozzles are directed at a different angle to the first bank of air nozzles so that each bank of air nozzles is used to deliver wood to one of the chutes 61, 63 different from the other bank of air nozzles. In this way, depending on the grade of wood, either the first or the second bank of air nozzles is used to deliver the wood to the appropriate chute 61, 63.
It will be understood from the foregoing that more or less than three grades of waste wood and fines can be provided if desired. By implementing the method according to the present invention, it will be possible to reclaim Grade A recycled waste wood which can be sold at a premium in a far more efficient and effective manner, resulting in a far more cost effective process.
In thIs specification the terms comprise, comprises, comprised and comprising" and the terms "include, includes, included and including' are all deemed totally interchangeable and should be afforded the widest possible interpretation.
The Invention Is in no way limited to the embodiments hereinbefore described but may be varied in both constniotion and detail within the scope of the appended claims.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1414090.9A GB2528979A (en) | 2014-08-08 | 2014-08-08 | A method and system for recycling wood |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1414090.9A GB2528979A (en) | 2014-08-08 | 2014-08-08 | A method and system for recycling wood |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201414090D0 GB201414090D0 (en) | 2014-09-24 |
| GB2528979A true GB2528979A (en) | 2016-02-10 |
Family
ID=51629518
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1414090.9A Withdrawn GB2528979A (en) | 2014-08-08 | 2014-08-08 | A method and system for recycling wood |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2528979A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3817459A (en) * | 1973-01-02 | 1974-06-18 | D Keller | Device and process for reclaiming used wood |
| CA1186654A (en) * | 1981-03-30 | 1985-05-07 | Vesa Tamminen | Procedure and apparatus for separating incompletely barked pieces |
| DE4339960A1 (en) * | 1993-11-24 | 1995-06-29 | Alfred Kerber | Environmentally friendly utilisation of waste wood |
| WO2001001113A1 (en) * | 1999-06-28 | 2001-01-04 | New Zealand Forest Research Institute Ltd. | Method for identifying properties of wood by infra-red or visible light |
| US20030056306A1 (en) * | 2001-09-21 | 2003-03-27 | B. Maier Zerkleinerungstechnik Gmbh | Installation for cleaning wood-containing material |
| EP1533045A1 (en) * | 2003-11-18 | 2005-05-25 | Binder & Co. Aktiengesellschaft | Process and device for improved sorting of waste based on wood or wood fibre products |
| WO2007112591A1 (en) * | 2006-04-04 | 2007-10-11 | 6511660 Canada Inc. | System and method for identifying and sorting material |
-
2014
- 2014-08-08 GB GB1414090.9A patent/GB2528979A/en not_active Withdrawn
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3817459A (en) * | 1973-01-02 | 1974-06-18 | D Keller | Device and process for reclaiming used wood |
| CA1186654A (en) * | 1981-03-30 | 1985-05-07 | Vesa Tamminen | Procedure and apparatus for separating incompletely barked pieces |
| DE4339960A1 (en) * | 1993-11-24 | 1995-06-29 | Alfred Kerber | Environmentally friendly utilisation of waste wood |
| WO2001001113A1 (en) * | 1999-06-28 | 2001-01-04 | New Zealand Forest Research Institute Ltd. | Method for identifying properties of wood by infra-red or visible light |
| US20030056306A1 (en) * | 2001-09-21 | 2003-03-27 | B. Maier Zerkleinerungstechnik Gmbh | Installation for cleaning wood-containing material |
| EP1533045A1 (en) * | 2003-11-18 | 2005-05-25 | Binder & Co. Aktiengesellschaft | Process and device for improved sorting of waste based on wood or wood fibre products |
| WO2007112591A1 (en) * | 2006-04-04 | 2007-10-11 | 6511660 Canada Inc. | System and method for identifying and sorting material |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201414090D0 (en) | 2014-09-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103476515B (en) | Method for reclaiming recycling material from hybrid solid waste stream | |
| US11097283B2 (en) | Systems and methods for municipal solid waste recycling facility | |
| US8322639B2 (en) | Mechanized separation of mixed solid waste and recovery of recyclable products | |
| US10835927B2 (en) | System and process for sorting and recovery of recyclable materials from mixed waste | |
| Mastellone et al. | Evaluation of performance indicators applied to a material recovery facility fed by mixed packaging waste | |
| US20100282646A1 (en) | Method and unit for the separation of non-ferrous metals and stainless steel in bulk material handling | |
| IE42268B1 (en) | Refuse fractionation | |
| US10328464B2 (en) | Method and apparatus for sorting heterogeneous material | |
| KR101965425B1 (en) | Apparatus for sorting of scrap plastics | |
| CN110202716A (en) | Waste product plastic bottle sorting system and its method for sorting | |
| Verheyen et al. | Vision-based sorting of medium density fibreboard and grade A wood waste | |
| WO2012119739A3 (en) | Processing of waste incineration ashes | |
| KR900000617B1 (en) | Recovery method of useful material from refuse and plant therefrom | |
| CN113784805A (en) | Waste screening machine and screening method | |
| GB2528979A (en) | A method and system for recycling wood | |
| DE102004041494A1 (en) | Pre-processed and partial demounted material compound e.g. electro and electronic unit, disintegrating and separating method, involves crushing material into one or two staged processes and freeing material from damages and anionic trashes | |
| Dias et al. | Recovery of glass contained in the heavy residual fraction of Portuguese mechanical Biological Treatment Plants | |
| WO2017116550A1 (en) | Objection detection apparatus | |
| CN106426642A (en) | Near-infrared sorting device for waste household appliance dismantled and broken plastic | |
| WO1999034927A1 (en) | Method and device for processing packaging wastes | |
| CN205284974U (en) | Online smoked sheet automatic separation device of air -sweeping type | |
| US5887806A (en) | Safety device for preventing a fire in a shredder machine | |
| GB2527544A (en) | A method of processing waste material to produce various wood products | |
| CA1053530A (en) | Tobacco/paper sorter method and apparatus | |
| CN205413617U (en) | Weight material air current sorter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |