SELECTION MACHINE FOR WASTE PRODUCTS AND SELECTION METHOD

Abstract

Selection machine for wood-type waste products to produce panels which comprises a delivery hopper and a conveyor belt on which a flow of wood material to be selected advances.

Claims

1. A selection machine for wood-type waste products to produce panels, comprising: a delivery hopper and a conveyor belt on which a flow of wood material to be selected advances, wherein at the exit of the conveyor belt there are at least two identification stations, of which at least one located below the conveyor belt, having at least one light source and at least one camera each cooperating with a respective contrast element, said identification stations being opposite and located astride the transit of the material to be selected, said camera being associated to a respective lighting system equipped with a protective glass and being governed by a control and command unit which, by means of recognition programs, conditions the drive of point nozzles operating on the flow of material exiting from the conveyor belt to remove contaminating materials from said flow characterized in that at least the identification station located below the conveyor belt comprises a protection system comprising at least a pneumatic system for cleaning said glass.

2. The selection machine as in claim 1, characterized in that said pneumatic system comprises an element that emits an air barrier, continuous or periodic, substantially for the entire length of the glass, such as to determine the removal of particles, dust or other contaminant that could fall from the conveyor belt onto the glass itself.

3. The selection machine as in claim 1, characterized in that it comprises a compressed air nozzle mounted on a pneumatic cylinder provided with alternate motion for the removal of particles and pieces of a certain size from the glass.

4. The selection machine as in claim 3, characterized in that said alternate motion of the pneumatic cylinder is governed by the detection, by suitable sensors, of the presence of particles or pieces larger than a certain size.

5. The selection machine as in claim 1, characterized in that said light source is associated with an air or water cooling system.

6. The selection machine for waste products as in claim 1, characterized in that the contrast element is white.

7. The selection machine for waste products as in claim 1, characterized in that the light source emits at least one light radiation in the near infrared.

8. The selection machine for waste products as in claim 7, characterized in that the cameras read in the region in the near infrared.

9. The selection machine for waste products as in claim 1, characterized in that at least one bar of inductive sensors is present along the conveyor belt, governed by a control and command unit and that commands nozzles that operate from the top downward.

10. The selection machine for waste products as in claim 1, characterized in that the nozzles are fed by pressurized fluids by means of an electro valve governed by a control and command unit.

11. The selection machine for waste products as in claim 1, characterized in that said conveyor belt is configured to advance at a speed in the range of 8-10 m/s.

12. The selection machine for waste products as in claim 1, characterized in that the hopper has means to control the flow rate of the material discharged onto the conveyor belt.

13. The selection machine for waste products as in claim 1, characterized in that the adjustment of the flow rate is defined by acting on the speed of the conveyor belt.

14. The selection machine for waste products as in claim 1, characterized in that at least one identification station cooperates with position adjustment means.

15. The selection machine for waste products as in claim 1, characterized in that two different selective reception zones are present downstream of the conveyor belt.

16. The selection machine for waste products as in claim 15, characterized in that it comprises means to adjust the longitudinal amplitude of said selective reception zone.

17. A method to select wood-type waste products to produce panels, the method comprising: Feeding, by means of a conveyor belt, a mass of wood material wherein, at the exit of the conveyor belt two opposite identification stations, comprising at least one light source, a camera and a respective contrast element, identify the presence of contaminating materials in the mass of wood material, and by means of recognition programs, activate nozzles to deliver compressed air operating on the flow of plastics and suchlike exiting from the conveyor belt to remove said contaminants from the mass of wood material and cause their separation, characterized in that it provides an operation of cleaning the glass at least of the identification station located below the conveyor belt by means of a pneumatic system for cleaning said glass.

18. The method as in claim 17, characterized in that it provides that said operation of cleaning the glass is carried out by emitting a flow of air through an air barrier, continuous or periodic, substantially for the entire length of the glass, such as to determine the removal of particles, dust or other contaminant that could fall from the conveyor belt onto the glass itself.

19. The method as in claim 17, characterized in that it provides that said cleaning operation is carried out by means of a compressed air nozzle mounted on a pneumatic cylinder provided with alternate motion for the removal of particles and pieces of a certain size from the glass.

20. The method as in claim 13, characterized in that the flow of compressed air, in order to remove the contaminating elements of the mass of wood material, operates from the top downward.

21. The method as in claim 13, characterized in that the cameras are operating in the field in the near infrared.

Description

ILLUSTRATION OF THE DRAWINGS

[0064] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0065] FIG. 1 is a schematic lateral view of a selection machine for wood material provided with an apparatus for selecting wood material according to embodiments described here;

[0066] FIG. 2 is a schematic view of the apparatus for selecting wood material of FIG. 1;

[0067] FIGS. 3 and 4 show two views of a viewing unit able to be used in the selection machine for wood material of FIG. 1.

[0068] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DESCRIPTION OF EMBODIMENTS

[0069] We will now refer in detail to the various embodiments of the invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.

[0070] A selection machine according to the present invention is indicated as a whole with reference number 100 in FIGS. 1 and 2.

[0071] The selection machine 100 comprises a hopper 14, which according to the chosen solution has means 114 for regulating, on each occasion, the flow rate of the material, that is, acting on the speed of a conveyor belt 10. In this way, the desired quantity (see FIG. 2) of loose and incoherent material to be selected is unloaded onto the conveyor belt 10, which travels at the desired and set speeds 26 by means of a motor member 23. The speed 26 can be adjusted in relation at least to the type of material to be selected, and/or to the presence of accumulations, piles or lumps detected by suitable detectors, not shown.

[0072] A control and command unit 25, which possibly has control and regulation means 24, governs and controls the various devices.

[0073] The devices, in a synthesis sufficient to explain, by way of example, the invention, consist of various components.

[0074] The conveyor belt 10 cooperates with tail rollers 12 and head rollers 13, and can have means for regulating its tension. The conveyor belt 10 can cooperate directly at least with bars of sensors 15 which are, advantageously but not exclusively, inductive, in order to detect at least the presence and/or position of metal contaminants in the mass of wood material advancing on the conveyor belt 10.

[0075] In cooperation or correspondence with the exit of the conveyor belt 10, there are two stations 27 for identifying plastic materials or wood-plastic compounds to be discarded, respectively above and below the trajectory of the materials to be selected.

[0076] At least one bar of nozzles 19 that deliver, on command, jets of compressed air cooperates with the stations 27. The nozzles 19 are fed, on each occasion and each one in a point manner, by electro valves 28 selectively driven by the control and command unit 25.

[0077] A conduit 29 of pressurized air feeds, on each occasion, the nozzles 19. The nozzles 19 are of the concentrated jet type.

[0078] The nozzles 19 are fed on the basis of the point signal which cameras 16 send to the control and command unit 25; the cameras 16, at least an upper one and a lower one, being part of the identification stations 27.

[0079] Even if only one control and command unit 25 has been mentioned, in practice there can be modules that together make up the control and command unit 25.

[0080] The control and command unit 25, or the respective modules, are able to be programmed in a fixed manner on each occasion by means of the control and adjustment means 24, possibly even located at a distance.

[0081] The two cameras 16, advantageously of the color and/or hyperspectral type, are managed, advantageously although not necessarily, in an independent manner but in relation to respective light sources 17.

[0082] The light sources 17 can emit a single luminous spectrum, or can be adjusted on each occasion in order to emit, even simultaneously, different light spectra in relation to the type of contaminants and/or wood to be cleaned.

[0083] The cameras 16 operate respectively from below and from above the flow of material to be selected, and are coordinated with the respective light source 17.

[0084] The cameras 16 operate advantageously in cooperation with a contrast 18 which advantageously has a white background, so that the material to be selected transits between the white background and the camera 16 which is assisted by the light source 17.

[0085] Advantageously, there is a camera 16 which covers the width of the transiting material.

[0086] According to one variant, for each side of the transit of the material to be selected, there can be two or more cameras 16 operating in parallel, where the width of the belt requires it, with respective light sources 17.

[0087] Associated with the light sources 17 there is at least one covering and protective glass 34. Instead, the cameras 16 cooperate with a mirror 35 thanks to which the images of the material thrown by the conveyor belt 10 can be filmed at the desired angle.

[0088] According to one aspect of the present invention, associated with the glass 34 there is an air barrier 36 which emits a jet of air, continuous or suitably timed, so as to keep the glass 34 itself constantly clean, and reduce the danger of combustion due to the contact between particles or small pieces of loose material and the glass 34 made incandescent by the temperature of the lamps 17. The air barrier 36 serves to prevent the glass 34 from being dirtied both due to the deposit of wet dust through the air barrier 36 and the controlled temperature cooling of the glass 34, and also due to the deposit of pieces of a certain size and weight, for example metals, inert materials, wood chips, etc.

[0089] Furthermore, it serves to prevent the dangers of combustion due to the contact between flammable material such as wood, both in the form of dust and chips, and the glass 34, which is in fact at a high temperature caused by the heating due to the use of high power halogen lamps 17, which are necessary for the NIR (Near Infrared) viewing system.

[0090] In turn, according to the invention, the lamps 17 are equipped with a thermostatically controlled water cooling system, by means of a cooler and water circulation in the lamp holder 117.

[0091] The combined use of the air barrier 36 and the water cooling of the lamps 17 allows to keep the temperature of the glass 34 very low, typically in the range of ambient temperature at 20° C., so as to prevent risks of combustion, or even a partial burning of the glass which would lead to a loss of efficiency in the reading.

[0092] Furthermore, the viewing system also comprises a nozzle 38 for the delivery of compressed air, mounted on a pneumatic cylinder provided with alternate motion. The delivery nozzle 38 is advantageously timed to emit a jet of air able to remove heavy bodies, for example pieces of wood, plastic or metal, which could fall from the conveyor belt 10 and remain on the glass 34. In one variant, the drive of the delivery nozzle 38 and/or of the pneumatic cylinder can also be governed by the detection by suitable sensors (not shown), for example optical, of the presence of heavy bodies on the glass 34.

[0093] A conduit 39 allows the entry of the ventilation air to be fed to the air barrier 36, while the compressed air nozzle is fed by an independent line of compressed air.

[0094] As indicated, in the proximity of the exit of the conveyor belt 10 there are inductive sensors 15 that detect the presence of metal contaminants.

[0095] The signals that come from the cameras 16 and from the inductive sensors 15 are processed by the control and command unit 25.

[0096] The control and command unit 25 is able to define, with an accuracy of about 3-8 mm, the position/size of each material in transit to be selected.

[0097] The signals, which are detected on each occasion by the control and command unit 25, are sent in a point manner to actuators of the electro valves 28 of individual nozzles 19 suitable to emit specific and point jets of compressed air, downstream of the conveyor belt 10.

[0098] Thanks to the specific jet of compressed air which acts on the specific contaminant, this is displaced from its natural trajectory 32, indicated with dashed lines in FIG. 2, and moves to another trajectory 132, then falling into an area 20 designated to receive the contaminants.

[0099] The longitudinal definition of this area 20 is able to be adjusted by means of adjustment means 30 according to the speed 26 of the conveyor belt 10 and the pre-eminent type of contaminant.

[0100] Where there are contaminants that roll, or bounce, on the conveyor belt 10, these fall into the area 20 designated to receive the contaminants since they have a lower speed than that of the conveyor belt.

[0101] Similarly, the products deemed non-contaminating by the system fall into an area 21 possibly served by evacuation means 22.

[0102] Means 31 for adjusting the position of the identification stations 27 are advantageously provided.

[0103] It is clear that modifications and/or additions of parts or steps may be made to the selection machine as described heretofore, without departing from the field the present invention as defined by the claims.

[0104] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of machine or method for selecting contaminants from a mass of wood material, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.