WO2025160073A1

WO2025160073A1 - Scrap sorting system

Info

Publication number: WO2025160073A1
Application number: PCT/US2025/012430
Authority: WO
Inventors: Kerry Francis LANG; Benjamin Aubuchon; Paul Volkening TOREK; Aishwary Sharad PATIL; Walter Timothy PITTMAN; Richard WOLANSKI
Original assignee: Huron Valley Steel Corp
Current assignee: Huron Valley Steel Corp
Priority date: 2024-01-24
Filing date: 2025-01-21
Publication date: 2025-07-31
Anticipated expiration: 2026-07-24

Abstract

A system and method for sorting scrap material particles is provided. The system has a conveyor assembly with first and second conveyor portions spaced apart via at least one gap, a laser system providing a laser beam and a sensor positioned to detect light emitted from a particle within the target location in the gap. At least one controller is configured to classify the particle into a classification of material using spectral data indicative of one or more selected frequency bands of light emitted from the particle in response to the laser beam interacting with the particle. A system may be provided with a separator assembly having at least one separator device adjacent to a first side of the conveyor, and an associated bin positioned transversely across the conveyor from the separator device. An optical window with a nozzle region defined by a housing may also be provided.

Description

SCRAP SORTING SYSTEM

CROSS-REFERENCE TO RELATED APPLICATIONS

[00011 This application claims the benefit of U.S. provisional application Serial No. 63/624,401 filed January 24, 2024, the disclosure of which is hereby incorporated in its entirety by reference herein.

TECHNICAL FIELD

[0002] Various embodiments relate to a method and system for sorting scrap particles in a line operation based on the analysis of laser induced plasma, and an associated separator system.

BACKGROUND

|'00031 Scrap metals are currently sorted at high speed or high volume using a conveyor belt or other line operations using a variety of techniques including: hand sorting by a line operator, air sorting, vibratory sorting, color based sorting, magnetic sorting, spectroscopic sorting, and the like. The scrap materials are typically shredded before sorting and require sorting to facilitate separation and reuse of materials in the scrap, for example, by sorting based on classification or type of material. By sorting, the scrap materials may be reused instead of going to a landfill or incinerator. Additionally, use of sorted scrap material leads to reduced pollution and emissions in comparison to refining virgin feedstock from ore or plastic from oil. Sorted scrap materials may be used in place of virgin feedstock by manufacturers if the quality of the sorted material meets a specified standard. The scrap materials may be classified as metals, plastics, and the like, and may also be further classified into types of metals, types of plastics, etc. For example, it may be desirable to classify and sort the scrap material into types of ferrous and non-ferrous metals, heavy metals, high value metals such as nickel or titanium, cast or wrought metals. Furthermore, it may be desirable to classify and sort the scrap material into various types of alloys. Prior sorting systems using Laser Induced Breakdown Spectroscopy (LIBS) include U.S. Pat. No. 5,042,947, U.S. Pat. No. 6,545,240, and U.S. Pat. No. 9,785,851. SUMMARY

[0004] According to an example, a system for sorting scrap material particles is provided. The system has a conveyor assembly having a first conveyor portion and a second conveyor portion each moving in a longitudinal direction, with the first and second conveyor portions spaced apart from one another via at least one gap. A laser system is provided with at least one laser to provide a laser beam to a target location in the gap between the first and second conveyor portions. A sensor is positioned to detect light emitted from a particle within the target location. At least one controller is configured to (i) receive a signal from the sensor indicative of spectral data for the particle, the spectral data indicative of one or more selected frequency bands of light emitted from the particle in response to the laser beam interacting with the particle, and (ii) classify the particle into a classification of material using the spectral data.

|0005] According to another example, a method of sorting scrap particles is provided. A scrap particle is moved in a longitudinal direction on a conveyor assembly with a first conveyor portion and a second conveyor portion spaced apart from one another via a gap. A light beam is generated and directed to the conveyor assembly to a target location associated with the gap such that the light beam interacts with the particle when passing through the target location. At least one emitted band of light from the particle in the target location is isolated and measured at a selected frequency band using a detector to provide a signal indicative of spectral data for the particle to a controller. The particle, via the controller, is classified into one of at least two classifications of a material as a function of the spectral data.

[0006] According to yet another example, a system for sorting scrap material particles is provided. The system includes a conveyor assembly having a conveyor moving in a longitudinal direction, a laser system comprising at least one laser to provide a laser beam to a target location adjacent to the conveyor, and a sensor positioned to detect light emitted from a particle within the target location. A separator assembly is positioned downstream of the target location, with the separator assembly having at least one separator device adjacent to a first side of the conveyor, and an associated bin positioned transversely across the conveyor from the separator device and adjacent to a second side of the conveyor. The separator device is selectively operable to move the particle transversely across the conveyor assembly and into the associated bin. At least one controller is configured to (i) receive a signal from the sensor indicative of spectral data for the particle, the spectral data indicative of one or more selected frequency bands of light emitted from the particle in response to the laser beam interacting with the particle, (ii) classify the particle into a classification of material using the spectral data, and (iii) control the separator assembly based on the classification of material to sort the particle.

[0007] According to another example, an optical window assembly is provided with an optical window for a laser beam, and a housing surrounding and supporting the optical window, with the housing extending away from the optical window to form a nozzle region with an open distal end. At least one air inlet is connected to the housing. The housing defines a plurality of air outlets positioned within the nozzle region to surround the optical window and direct air flow away from the optical window, through the nozzle region, and through the open distal end to the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIGURE 1 illustrates a perspective view of a system according to an embodiment;

[0009] FIGURE 2 illustrates a side view of the system of Figure 1;

[0010] FIGURE 3 illustrates a schematic of a laser system according to an embodiment and for use with the system of Figure 1;

|00l 11 FIGURE 4 illustrates a perspective view of an optical window assembly according to an embodiment and for use with the laser system of Figure 3;

[0012] FIGURE 5 illustrates a side schematic view of the optical window assembly of Figure 4;

[0013] FIGURE 6 illustrates a side view of a separator device according to an embodiment, and for use with the system of Figure 1;

[0014] FIGURE 7 illustrates a top view of the separator device of Figure 6;

[0015] FIGURE 8 illustrates a perspective view of a system according to another embodiment; [0016] FIGURE 9 illustrates a side view of the system of Figure 8;

[0017] FIGURE 10 illustrates a flow chart of a method for sorting scrap material particles according to an embodiment; and

[0018] FIGURE 11 illustrates a top schematic view of the system of Figure 1 or Figure 8 installed in a larger sorting facility.

DETAILED DESCRIPTION

|0019| As required, detailed embodiments of the present disclosure are provided herein; however, it is to be understood that the disclosed embodiments are examples and may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure.

10020| It is recognized that any controller, circuit or other electrical device disclosed herein may include any number of microprocessors, integrated circuits, memory devices (e.g., FLASH, random access memory (RAM), read only memory (ROM), electrically programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), or other suitable variants thereof) and software which co-act with one another to perform operation(s) disclosed herein. In addition, any one or more of the electrical devices as disclosed herein may be configured to execute a computer-program that is embodied in a non-transitory computer readable medium that is programmed to perform any number of the functions as disclosed herein. A controller may include any number of controllers, and may be integrated into a single controller, or have various modules. Some or all of the controllers may be connected by a controller area network (CAN) or other system. The controller(s) 110 may additionally be located at various locations in the system 100.

[0021 ] The term “substantially,” “generally,” or “about” may be used herein to describe disclosed or claimed embodiments. The term “substantially” may modify a value or relative characteristic disclosed or claimed in the present disclosure. In such instances, “substantially” may signify that the value or relative characteristic it modifies is within ± 0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or 10% of the value or relative characteristic. Figures 1 and 8 illustrate systems 100 or apparatus for classifying scrap materials into two or more classifications of materials, and then sorting the materials into their assigned classification according to various embodiments. In the example shown, the system 100 is a laser induced breakdown spectroscopy (LIBS) sorting system for categorizing and sorting scrap materials, e.g. scrap material particles, such as different metals or alloys of metal. The scrap materials may be provided from a vehicle, airplane, a recycling center; or other solid scrap materials as are known in the art. The materials are typically broken up into smaller pieces or particles 101 on the order of centimeters or millimeters by a shredding process, or the like, before going through the sorting system 100 or a larger sorting facility. The particles may have random and widely varying shapes, and have varying properties, such as a wide range of reflectivity.

100221 In the example shown, the particles 101 are sized to be 30+ mm (or 20+ mm), with a maximum dimension of approximately 150 mm. In other examples, other sized particles may be provided for use with the system 100. In one non-limiting example, the particles 101 may be provided as mixed aluminum alloys and sorted in a seven-way sort as shown, or into another number of classifications greater or fewer than seven, including as few as two classifications. In various examples, different scrap materials may be sorted, e.g. types of mixed metals, cast versus wrought, alloys, etc.

[0023] Referring first to Figures 1-2, the system 100 receives a single particle stream of sized particles 101 at a first end, or the right-hand side of Figures 1-2. The single particle stream is moved through the system 100 on a conveyor assembly 102. The conveyor assembly 102 may extend from the first end 104 of the system to the second end 106 of the system, and furthermore, the conveyor assembly 102 may provide a continuous surface in the longitudinal direction, or from the first end 104 to the second end 106. In the example shown, the conveyor assembly 102 is positioned to be horizontal or flat, and move in a longitudinal direction, or from right to left in Figures 1-2. [0024] The conveyor assembly 102 may be moved via one or more motors and support rollers. A controller 110 for the system 100 controls the motor(s) to control the movement and speed of the conveyor assembly 102. The controller 110 may include one or more position sensors to determine a location and timing of the conveyor assembly 102 for use locating and tracking particles as they move through the system. In one example, the conveyor assembly 102 is linearly moved at a speed on the order of 1-3 meters per second, although other speeds are contemplated.

[0025] The conveyor assembly 102 may be provided with a first conveyor portion 120 and a second conveyor portion 122. The first and second conveyor portions 120, 122 each move in the longitudinal direction L, and are transversely spaced apart from one another via at least one gap 124. In the example shown, the gap has a width in the range of 10-15 mm, although other widths for the gap 124 are also contemplated, for example, for use with other particle size ranges. As used herein, the transverse direction T is orthogonal or perpendicular to the longitudinal direction L as well as the vertical direction.

[0026] In the example shown, the first conveyor portion 120 is provided as a first conveyor belt, and the second conveyor portion 122 is provided as a second conveyor belt. The first conveyor belt is separate and distinct from the second conveyor belt, and may be synchronized for movement with the second conveyor belt. The first and second conveyor belts are separated by the gap 124, which extends continuously from the first end to the second end of the system. The system 100 may be provided with one or more platforms 126 that are positioned beneath the first and second portions 120, 122 to support them from their lower surface. In one example, and as shown in Figures 6 and 7, the platform 126 extends transversely to support both the first and second conveyor portions 120, 122, and furthermore, may be provided with a protrusion 127 that extends longitudinally to fill the gap 124 between the portions 120, 122 and provide a flush upper surface for the conveyor assembly 102. A sectional view of the conveyor assembly 102 may be seen in Figure 6, which illustrates the belts 120, 122 on the platform 126, as well as the belts 120, 122 in the return portion of the conveyor loop.

[0027] In another example, the conveyor assembly 102 has the first and second conveyor portions 120, 122 connected to one another, with a series of apertures extending longitudinally along the conveyor assembly 102 to transversely space the conveyor portions 120, 122 apart from and provide the at least one gap. In one example, a mesh panel may be provided to connect the conveyor portions 120, 122 and form the gaps.

[0028] The particles 101 are directed to a conveyor assembly 102 via another belt, such as a feeder conveyor 130, positioned at the first end of the system 100. The feeder conveyor 130 has an upstream end region 130a and a downstream end region 130b, with the downstream end region 130b being directly adjacent to the conveyor assembly 102. The upstream end region 130a and/or the intermediate region 130c of the feeder conveyor 130 may be formed with a concave shape or concave cross-sectional shape, e.g. such that particles 101 on the conveyor 130 that are not along the centerline fall down towards and are oriented along the centerline of the feeder conveyor 130 when it transitions to the concave shape. In one non-limiting example, the intermediate region 130c may have a semi-circular cross-sectional shape. The feeder conveyor 130 then flattens towards the downstream end region 130b. In one example, the downstream end region 130b may provide a flat (or substantially flat) cross-sectional shape to correspond to the flat upper profde of the conveyor assembly 102. In one example, the feeder conveyor 130 is positioned with the upstream and downstream end regions 130a, 130b level with one another such that the feeder conveyor 130 is horizontal as shown. In another example, the feeder conveyor may be inclined such that the conveyor descends towards the downstream end region 130b and the conveyor assembly 102. The feeder conveyor 130 may have a head pulley at the downstream end region 130b with a smaller diameter than a tail pulley at the first end region 104 of the conveyor assembly 102, and in one example may be on the order of one fourth the diameter or smaller. This allows the head pulley and downstream end region 130b of the feeder conveyor 130 to be positioned very close to the tail pulley and associated conveyor portions of the conveyor assembly 102, e.g. the space between the feeder conveyor and conveyor assembly 102 may be on the order of 3mm for a feeder conveyor head pulley diameter of 25mm and a conveyor assembly tail pulley diameter of 130mm. Additionally, the feeder conveyor may provide an upper surface at the downstream end region 130b that is slightly elevated compared to the upper surface of the conveyor assembly 102, e.g. with the upper surface of the feeder conveyor positioned on the order of 20 mm or less above the upper surface of the conveyor assembly 102 where they come together. By positioning the feeder conveyer 130 to be close to and slightly elevated relative to the conveyor assembly 102, the gap between the two is reduced, and the particle 101 may be passed from the feeder conveyor 130 to the conveyor assembly 102 with little to no movement in the transverse direction.

(0029] In other examples, the particles 101 may be directed to the conveyor assembly 102 via a chute 130 or other device positioned at the first end of the system 100.

10030] Downstream of the feeder conveyor 130, the system 100 additionally may be provided with first and second guides 132, 134 to move the particles transversely inward if needed to overlap the gap 124, and generally position the particles into a single line on the conveyor assembly. The first and second guides 132, 134 are angled towards one another in the longitudinal downstream direction as shown. The first and second guides 132, 134 may be longitudinally offset from one another. In one example, the first and second guides may be formed from a flexible material, such as a rubber, such that the guide moves in the event that a particle catches on it. In a further example, the first and second guides 132, 134 may further be connected to the system 100 via associated springs, e.g. to further provide relief and movement away from the centerline of the conveyor assembly 102 in response to a particle 101 catching on it, and also allowing the associated guide to return to the normal use position. The angle of the guides 132, 134 may be adjusted in order to allow for use of the system with different size ranges of particles, or to fine tune the positioning of the particles on the conveyor assembly 102. The first and second guides 132, 134 therefore align and position the particles 101 to overlap the at least one gap 124 on the conveyor assembly 102.

[0031] The system 100 has a laser spectroscopic system 140 and associated sensor 150 that are positioned downstream of the guides 132, 134. The laser system 140 has one or more lasers 142 that provide a light beam or laser beam 144, e.g. as a series of laser pulses, to a target location 146 in the system 100. The laser beam or pulse interacts with the particle to form a plasma. The sensor 150 collects and measures light emitted by the plasma, for example, in one or more specified frequency bands, to provide a signal indicative of spectral data to a controller 110.

[0032] The laser system 140 provides the laser beam 144 to a target location 146 for the system 100. The target location 146 is adjacent to the conveyor assembly 102, and in the example shown, is positioned to overlay the gap 124 of the conveyor assembly 102. The laser beam 144 therefore interacts with a particle as it passes through the target location 146 on the conveyor assembly 102.

Likewise, light emitted from the particle 101 passes through the gap 124 and to the detector 150.

(0033] The controller 110 may be provided by a networked computer system employing a plurality of processors to achieve a high-speed, multi-tasking environment in which processing takes place continuously and simultaneously on a number of different processors. In the controller 110, each processor in turn is capable of providing a multi-tasking environment where a number of functionally different programs could be simultaneously active, sharing the processor on a priority and need basis. The choice of implementation of hardware to support the functions identified in the process groups may also depend upon the size and speed of the system, as well as upon the categories being sorted. The controller 110 may be contained within a compartment as shown for the system 100, or at least some of the processors for the controller 110 may be provided within the housing for the laser system 140 or in another location in the system 100.

(0034] The controller 110 uses the spectral data for each particle 101 and conducts a multivariate analysis for the particle to classify the particle into one of two or more preselected classifications. In one non-limiting example, the controller 110 may conduct a multi-discriminant analysis for the particle 101 to classify the particle. Based on the classification outcome, the controller 110 controls the separator assembly as described below to sort the particles based on their associated classifications. The controller 110 may also include one or more display screens and a human machine interface, for use in controlling the system 100 during operation and also for use in calibration or system setup.

[0035] The laser system 140 may operate as a Laser-Induced Breakdown Spectroscopy (LIBS), Laser Spark Spectroscopy (LSS), or Laser-Induced Optical Emission Spectroscopy (LIOES) system, and uses a focused laser beam to vaporize and subsequently produce spectral line emissions from a sample material, such as a particle, to analyze the chemical composition of the particle. The laser system 140 provides optical emission data of the laser-induced plasmas of the particles after a LIBS interrogation to the controller 110 for use in classifying and sorting the particles. An example of a laser-induced spectroscopy sorting system is provided in U.S. Patent No. 6,545,240 B2, issued April 8, 2003, the disclosure of which is incorporated in its entirety by reference herein.

(0036] Referring to Figures 1-3, the laser system 140 is provided with at least one laser 142 generating a laser beam 144 including at least one laser pulse, and in some examples a stream of a plurality of laser pulses, within a selected time interval. In other example, the laser system 140 may have two or more lasers 142 with pulses that are interlaced. In the example shown, the laser 142 is a fiber laser that is tuned to 1064 nm, with a 2mJ pulse continuously firing at 150 kHz for a total power of 300 W. In another example, the laser 142 is a fiber laser that is tuned to 532 nm, with a 500uJ pulse continuously firing at 100 kHz for a total power of 50 W. The laser pulses interact with particles to form a plasma. Based on the speed of the conveyor assembly 102, the translational movement of a particle 101 during this time period is negligible such that multiple pulses may be directed to the same particle. In further examples, the system 100 includes more than one laser 142 or more than one laser system 140.

[0037] The system 100 further includes at least one sensor 150, which may include a light collector 152 and a detector 154, for collecting and measuring light 156 emitted by plasma produced from the particles 101 as they are irradiated by the laser pulses in the target location 146. The sensor 150 may include optical fibers 152 distributed to collect light from the generated plasma, and is connected to a detector 154 such as a spectrometer or other light distribution and spectral analyzer unit to isolate and measure selected spectral components of the collected light.

[0038] In one example, the sensor 150 is provided with one or more polychromator detectors 154, such as a CMOS polychromator detector. The polychromator detector 154 may detect light within a spectral band, and in one non-limiting example, the detector 154 detects light within a 200 nm band, e.g. from 250 nm to 450 nm, although other bands are also contemplated based on the particles 101 and associated classifications. The detector 150 provides a signal to the controller 110 that is indicative of the wavelengths and the intensities of the emission from the polychromator.

[0039] In another example, the light distribution and spectral analysis unit 154 may include an integrating chamber to provide a uniform distribution of the collected light to the one or more spectral filters. In one example, the spectral filters are provided by monochromator systems that transmit a narrow band of light (approximately 0.05 to 0.1 nanometers wavelength) centered around a selected frequency to a detector such as a photomultiplier tube (PMT), a photodiode, an intensified diode array, a CCD detector, or the like. In another example, the spectral filters are provided by a polychromator. The detector 150 provides a signal to a spectral processor in the controller 110 that is indicative of the intensity of the emission from the associated monochromator.

[0040] In one example, the controller 110 controls the laser system 140 and laser 142 to generate the laser beam (or pulses) only while the sensor 154 in the detector 150 is detecting light, and not when the detector 150 is busy reading out its circuits and transferring data to the controller 110. In one example, the laser 142 and detector 150 share a trigger, such that the controller 110 to synchronize their operation and shut off the laser 142 during data transfer from the detector 150. By controlling when the laser 142 is operated such that a laser beam 144 is generated only when the detector 154 is detecting, thermal stress (or heating) on the optical window 204 as described below and other optical components 160 is reduced as laser pulses are no longer generated when the detector 154 is not detecting light. By reducing thermal stress on the optical window 204 and optical components 160, the focal position of the laser beam 144 may be better maintained and predicted, resulting in improved targeting of the particle 101.

10041] The controller 110 uses the spectral data as described below to classify each particle into one of a plurality of classifications, e.g. to determine the type or classification of the material.

[0042] The controller 110 then controls the separator assembly as described below, using the classification for each particle, the location of the particles, and the conveyor assembly 102 position to sort and separate the particles.

[0043] As shown in Figure 3, one or more optical components 160 may be provided for use with the laser system 140 and the detector 150. In the example shown, the laser system 140 and detector 150 share at least some of the optical components 160. In other examples, the laser system 140 and detector 150 may each be provided with their own separate, dedicated optical components, or with greater or fewer optical components 160 that as described herein. [0044] According to one example, the optical components 160 include elements to focus the laser beam 144 and/or direct the laser beam to the target location, as well as collect, focus, and direct the emitted light 156 from a particle. In the example shown, the optical components 160 include first and second turning mirrors 182, 184, a first focusing lens 186, a mirror 188 having a central aperture, a second focusing lens 190, a third turning mirror 192, and an optical window 204 as described below. The laser beam is directed from the laser to the first and second turning mirrors 182, 184, through the first lens 186, through the central aperture in the mirror 188, through the optical window 204, and to the target location. The light emitted from a particle passes through the optical window 204, is reflected by the mirror 188 surrounding the aperture, and is directed to the second focusing lens 190, the third turning mirror 192, and to the sensor, for example, via fiber 152 to the detector 154. Additionally, the optical components 160 may include various additional mirrors, e.g. to direct the laser beam.

|0045] In another example, the laser beam is directed from the laser through the central aperture in the mirror 188, through the optical window 204 also acting as a lens, and to the target location. The light emitted from a particle passes through the optical window 204 where the window also provides a lens, is reflected by the mirror 188 surrounding the aperture, and is directed to the second focusing lens 190, the third turning mirror 192, and to the sensor, for example, via fiber 152 to the detector 154.

|0046| In other examples, other optical components and/or arrangements are also contemplated for use with the system 100, including greater or fewer optical components 160 than those shown. For example, in alternative embodiments, mirror 188 having a central aperture may be replaced by a dichroic mirror allowing the laser beam 144 to pass through the dichroic mirror while reflecting the light emitted 156 from a particle 101. In other examples, the dichroic mirror might reflect the laser beam 144 while transmitting the light emitted 156 from a particle 101. In another example the focusing lens 186 may be moved in-line with the laser beam 144 so that the resulting focus at the target location 146 can be adjusted. This focal adjustment may be done prior to operating the system 100 and/or while the system 100 is running. [0047] Referring to Figures 1-3, and in one example, the laser system 140 and the detector 150 are provided on the same side of the conveyor assembly 102, e.g. beneath the conveyor assembly as shown. In other examples, the laser system 140 and detector 150 are each provided above the conveyor assembly 102, or alternatively may be otherwise positioned relative to the conveyor assembly 102. The optical components 160 may likewise be provided with the laser system 140 and detector 150 on the same side of the conveyor assembly 102. In one example, the laser system 140, and the detector 150 are longitudinally offset from the target location. In a further example, the laser 142 and of the detector 150 may be remote from the conveyor assembly 102, and optically connected, e.g. via a fiber optic line. Furthermore, the laser system 140 and detector 150 may be positioned between the upper portion of the conveyor assembly 102 and the lower return portion (e.g. with the laser system 140 and/or detector 150 in the middle of the conveyor loop) such that the laser pulses may pass through only one gap between conveyor portions 120, 122. Alternatively, the laser system 140 and detector 150 may be positioned beneath both the upper portion of the conveyor assembly 102 and the lower return portion (e.g. below the conveyor loop entirely) such that the laser pulses and the emitted light pass through two gaps, which may further attenuate the signal for the emitted light.

[0048] The laser system 140, detector 150, and optical components 160 may be surrounded by an optical enclosure 180, or housing for the laser system 140, as well as components of the detector 150 and optical components 160. The enclosure 180 may contain laser light other than the beam directed to the target location, and may additionally provide protection against dust, moisture, or debris reaching the laser system 140, optical components 160, or detector 150 components. The enclosure 180 may be provided with an optical window assembly 200 as shown. In other examples, other optical window assembly arrangements may be used, for example, the optical window assembly may be provided with an air nozzle to provide laminar flow across the outer face of the optical window, or the like.

[0049] Referring to Figures 4-5, the optical window assembly 200 is shown with a housing 202 adjacent to and surrounding an optical window 204 for the laser beam 144. The optical window 204 may be supported by the enclosure 180, and the housing 202 may be connected and mounted to the enclosure 180. The optical window 204 may be formed from a flat plate with the desired optical quality, to allow transmission of light in the wavelengths for both the laser beam 144 and the emitted light 156. In one example, and as shown, the optical window 204 is oriented at an angle relative to the laser beam 144, e.g. as a Brewster window. In other examples, the optical window 204 may additionally be provided as an optical component 160, such as a lens. The optical window assembly 200 both provides an optical window for the laser beam 144 and emitted light 156, and also provides for an air system to prevent or reduce dust and debris from collecting on the optical window 204, which may affect system 100 operation. The housing 202 defines an internal wall 206 that extends away from the optical window 204 and towards the conveyor assembly 102 to form a nozzle region 208 with an open distal end, with a diverging and converging shape from the optical window outwardly according to various non-limiting examples. In one example, and as shown, the nozzle region 208 has, sequentially outwardly from the optical window, a first diverging section 208a, a converging section 208b, a second diverging section 208c, and the open distal end. In the example shown, the converging section 208b has a longer length than the first diverging section 208a, which in turn is longer in length than the second diverging section 208c. In other examples, the nozzle region 208 may be provided without the second diverging section 208c, or with other nozzle geometries. The nozzle region 208 may be generally shaped to provide laminar air flow out of the distal end of the nozzle region. The housing 202 may be formed from a tube with an insert to form the nozzle region 208 and nozzle shape.

[0050] The housing 202 defines at least one inlet port 210 to receive pressurized air or another gas, and four inlet ports 210 radially arranged on the housing are shown for the present example. The housing 202 defines internal passages that connect the inlet ports 210 to a series of air outlets 212. The series of air outlets 212 are defined by the housing 202, and are positioned on the internal wall 206. The series of air outlets 212 are radially positioned about the internal wall, and additionally are spaced apart in rows at varying distances from the optical window 204, and may be formed to direct air at different angles into the nozzle region 208. The series of air outlets 212 may further be positioned on the diverging section of the internal wall 206 as shown. The series of air outlets 212 surround the optical window 204 and direct air flow away from the optical window, through the nozzle, and towards the conveyor assembly to prevent or reduce the amount of dust and debris from reaching the optical window. The series of air outlets 212, along with the nozzle region 208shape, also prevent eddy current formation, which, if present, would recirculate any dust within the nozzle region back towards the optical window.

[0051] To the extent that a platform 126 is provided, the platform 126 defines an aperture adjacent to and overlapping the target location to allow the laser beam to pass through the platform 126 and the gap 124 to reach a particle on the conveyor assembly, and to allow the emitted light to pass through the platform 126 and the gap 124 to reach the sensor.

[0052] Additional shielding 220, as shown, may be provided around the target location 146 to prevent laser light 144 or emitted light 156 from entering the surrounding environment, and also to limit dust and debris from entering the target location.

[0053] Referring back to Figures 1-2, the controller 110 has at least one processor configured to (i) receive a signal from the sensor 150 indicative of spectral data for the particle 101, the spectral data indicative of one or more selected frequency bands of light emitted from the particle in response to the laser beam 144 interacting with the particle, and (ii) classify the particle into a classification of material using the spectral data.

[0054] The spectral analysis may be conducted similarly to that described in U.S. Pat. 6,545,240 issued to Huron Valley Steel, and, in one example, five to eight spectral peaks (or narrow spectral bands) may be identified for use in classification of the particle, as well as other analyses performed based on the background, noise, and the like. The controller 110 may use multiple spectra from a particle to analyze and classify the particle. The controller 110 may use the intensities relating to one or more selected narrow bands of spectral emission recognized by the spectrometer for each laser pulse for a particle. The specific spectral lines that are observed, the delay time (gate delay) from the firing of the pulse when observations begin, and the time duration (gate width) during which data is collected, all depend on the elements that are required to be identified in the scrap particles. The selection of these parameters has been researched, and is described in at least the following publications: “The Analysis of Metals at a Distance Using Laser- Induced Breakdown Spectroscopy” David A. Cremers, Applied Spectroscopy, Vol. 41, No. 4, May/June, 1987; and “Quantitative Analysis of Aluminum Alloys by Laser-Induced Breakdown Spectroscopy and Plasma Characterization,” Mohamad Sabsabi and Paolo Cielo, Applied Spectroscopy, Vol. 49, No. 4, 1995.

[0055] The controller 110 classifies the particle 101 into one of at least two classifications of a material by inputting the data into a machine learning algorithm. The controller 110 may use a Support Vector Machine (SVM), a Partial Least Squares Discriminant Analysis (PLSDA), a neural network, a random forest of decision trees, gradient boosting, or another machine learning and classification technique to evaluate the spectral data and classify the particle . In one example, a neural network is used to classify each of the scrap particles as one of a preselected list of alloy families or other preselected list of materials based on elemental or chemical composition based on the analysis of spectral data and color input data.

]0056| The spectral data may be analyzed at for the multiple pulses for each particle 101. For example, the spectral data for two categories of particles may be distinguished and sorted by isolating one or two spectral bands and utilizing simple ratioing techniques by comparing the intensities of one or more analyte spectral lines to the intensity of a reference line, and then comparing these ratios to different ranges of values corresponding to different alloys to categorize the particle in conjunction with the color input in the data vector.

[0057] In an example, when sorting several categories of particles that have similar constituents, such as several different aluminum alloys, the method may use a complex classification regime, such as a neural network, which uses the data vector which includes a plurality of selected spectral lines, and may include other particle characteristics if available such as shape, texture, and the like to categorize the particles. The spectral data may also include other data for use in classifying the particle such as inputs from the sensor 150 or spectrometer including a value corresponding to the amount of scattered radiation at the operating wavelength of the laser, laser energy produced, and/or particle location on the conveyor assembly 102.

[0058] For a controller 110 implementing a machine learning algorithm as described herein for classifying the particle using the spectral data, the machine learning algorithm program may be “trained” to “learn” relationships between groups of input and output data by running the machine learning algorithm through a “supervised learning” process. The learned relationships may then be used to predict outputs and categorize a scrap particle using data containing spectral data such as emission intensities and scatter produced from representative samples of scrap having known chemistry, a color input, and other particle characteristic data. For example, a neural network as the machine learning algorithm may be configured to provide a known generalized functional relationship between sets of input and output data. Algorithmic techniques such as gradient descent and back propagation may be used to estimate the various parameters or weights for a given class of input and output data.

[0059] The controller 110 may arbitrate multiple classifications for a particle 101 if the particle is interrogated by more than one laser shot, as each laser shot may result in an associated classification. The controller 110 combines the classification verdicts for all laser shots on each particle to reach a final classification decision for the particle using one of a number of arbitration techniques, including a weighted average of scores, or voting, or other methods known in the art of machine learning.

[0060] Once the spectral data is acquired, the system 100 and controller 110 then analyze the data for the multiple pulses for each particle 101. Again, the type and scope of data analysis can vary, utilizing in each case known regimes, depending upon the different types of particles that are being sorted. For example, two categories of scrap particles may be distinguished and sorted by isolating one or two spectral bands and utilizing simple ratioing techniques. In contrast, sorting several categories of particles that have similar constituents, such as several different aluminum alloys, may require the utilization of a more complex classification regime, such as a neural network, which receives inputs relating to a plurality of selected spectral lines such as five to eight lines.

[0061] In one example, the multiple data inputs corresponding to the spectral data for a selected particle 101 may include a series of data inputs corresponding to intensity readings from the detector for a selected spectral band (L) over a selected period of time (t) following the first pulse (P) (LiPiti, LiPitz. . . LiPitn), data corresponding to detector readings for the same selected band following the second pulse (LiP2ti, LiP2t2 . . . LiP2t_n), and similar data inputs for that selected spectral band for each additional pulse directed to the particle (LiPnti, LiP_nt2. . . LiP2tn), as well as additional of these sets for each of the selected bands (L2Piti. . . L2Pntn, LnPiti . . . LnPntn), and so on. The neural network may also be provided with a variety of other desired inputs, including data relating to laser energy scattered, and data related to laser energy produced for each particle.

[0062] As a result of the analysis, the particle 101 is then categorized, and the controller 110 controls the separator assembly 240. The controller 110 may determine the location of the particle 101 relative to the conveyor assembly 102, in addition to the classification of the particle 101. The controller 110 may use the conveyor assembly 102 location, e.g. using the speed of the conveyor assembly 102 and data from the position sensor, as well as information from the sensor 150 as to when light was emitted from a particle, to determine a location of the particle on and relative to the conveyor assembly 102. Additionally or alternatively, the system 100 may be provided with a camera or other detector to determine the presence and the location of particle on the conveyor assembly 102, the spacing between the particles, and to aid in control of the separator. In further examples, images or data from a camera or other detector may be used to determine color, size, texture, or other information regarding a particle 101 that may be used by the controller 110 in classifying the particle in conjunction with the spectral data from the detector 150.

[0063| The controller 110 operates or controls the separator assembly 240 to selectively move each particle 101 into a bin associated with its classification. In the example shown, the separator assembly 240 is positioned downstream of the target location 146, and has a series of separator devices 242 and associated bins 244 positioned and spaced apart from one another along the conveyor assembly 102 in the longitudinal direction, and an additional bin 246 at the end of the conveyor assembly 102. Each separator device 242 is positioned transversely across the conveyor assembly 102 from its associated bin 244. In other examples, other separator arrangements are also contemplated. The controller 110 provides a signal to the separator assembly 240 to control each separator device 242 based on the classification and location of the particle to sort the particles on the conveyor assembly 102.

[0064| In the example shown, the separator assembly 240 has six separator devices 242 and six associated bins 244 and an additional bin 246 for a seven-way sort. In other examples, the separator assembly 240 may have a single separator device 242, e.g. for a binary sort, or may have two, three, four, five, or seven or more separator devices 242 and associated bins 244. Each separator assembly 240 may be configured to sort the particles into n+1 classifications based on having n separator devices 242, and n associated bins 244.

[0065] In the example shown, the separator assembly 240 has each separator device 242 adj acent to a first side of the conveyor assembly 102 (e.g. the first conveyor portion 120 in Figures 1-2, or a first side of the second conveyor portion 122a in Figures 8-9), and its associated bin 244 positioned transversely across the conveyor assembly 102 from the separator device 242 and adjacent to a second side of the conveyor assembly 102 (e.g. the second conveyor portion 122 in Figures 1-2, or a second side of the second conveyor portion 122a in Figures 8-9). Bin shielding 248 may additionally be provided to help direct particles into the associated bin, and retain particles 101 within the bin, e.g. without bounceback. In one example, the bin shielding 248 may include multiple panels that are angled relative to one another and/or one or more curved panels. Each separator device 242 is selectively operable by the controller 1 10 to move the particle 101 transversely across the conveyor assembly 102 and into its associated bin 244. Any particles that are not sorted by a separator device 242 are directed to a bin 246 at the end of the conveyor assembly 102. In other examples, any particles 101 that are not sorted by a separator device 242 may be directed in a recycle loop to be returned to the chute 130 to be sent through the system 100 again, and/or may be directed to a different sorting system in a sorting facility.

[0066] In the example shown, each separator device 242 has at least one nozzle 250 and an associated valve 252 in fluid communication with an air source, with the controller 110 controlling the valve 252 between open and closed positions. When the controller 110 opens the valve 252, air flows through the nozzle 250 and causes a particle 101 on the conveyor assembly 102 in the air flow path 254 from the nozzle 250 to be moved into the associated bin 244 transversely across from the separator device 242.

[0067] In the example shown, the separator device 240 has four nozzles 250 that are spaced apart from one another in the longitudinal direction L. In the example shown, the nozzles 250 in the separator device 242 are mounted to collectively provide converging air flow paths 254 towards the conveyor assembly 102. The central two nozzles 250 direct air generally transversely across the belt, or in the transverse direction T, and the outer two nozzles 250 direct air at an acute angle relative to the transverse direction. The outer two nozzles 250 direct air in converging air flow paths. All of the nozzles 250 in the separator device 242 may be fluidly coupled to the same valve 252, or may be connected to separate valves 252 for independent control. The separator device 242 may be further provided on an adjustable mounting plate 260 to control the angle of the nozzles 250 and air flow paths 254 relative to the conveyor assembly 102, e.g. in the L-T plane, to allow for adjustment and fine tune of the separator assembly 240. In other examples, the nozzles 250, including the central and/or outer nozzles, may be positioned such that there is an upstream longitudinal component to their airflow directional vector (e.g. in opposite to the movement of the conveyor) in addition to the transverse component, which may assist in countering forward motion effects imparted on the particle by the conveyor. In still further examples, one or more of the nozzles 250 may be positioned such that there is an upward or downward vertical component to their airflow directional vector, e.g. to assist in getting airflow underneath the particle on the conveyor or to lift the particle from the conveyor. In other examples, the separator device 242 may have one, two, three, or more than four nozzles, and varying numbers of valves.

(0068] In a further example for use with the system 100 of Figures 1-2, and as shown in Figure 7, each separator device 242 may additionally have a secondary nozzle 256 positioned to provide air flow upwardly, or in an upward direction through the gap 124 between the first and second conveyor portions 120, 122. The secondary air nozzle 256 may have an associated valve, and be controlled by the controller 110 to provide air flow in conjunction with the nozzles 250 of the associated separator device 242. The secondary air nozzle 256 may be positioned between the nozzles 250 of the separator device and the associated bin 244. The secondary air nozzle 256 may assist in lifting the particle 101 off the conveyor assembly 102 or exerting an upward force on the particle 101 when it is being sorted by the transverse air flow from the nozzles 250 into the associated bin 244. In other examples, the secondary nozzle 256 may be provided by a plate with a plurality of small holes therethrough, with air flowing through a valve and through the small holes when the nozzles 250 are operated to provide a thin cushion of air to lift the particle 101 and aid in its movement to the bin 244. [0069] In one non-limiting example, the conveyor assembly 102 comprises metal, such as steel. The second conveyor portion 122 or both conveyor portions 120, 122 may each contain metal, e g. as threads or layers within each belt. In some examples, the conveyor assembly 102 additionally comprises a plastic or rubber material. The platform 126 may be provided with magnets 260 that are supported by or embedded within the platform 126. The magnets 260 may be provided as permanent magnets such as rare earth magnets according to one example. The magnets 260 may be positioned to be underneath the second conveyor portion 122 according to one example, and furthermore, may be positioned to be adjacent to the gap 124. One or more magnets 260 may be positioned between the nozzles 250 of each separator device 242 and the associated bin 244. One, two, three, or more magnets 260 may be associated with each separator device 242, and may be arranged in the longitudinal direction relative to one another and adjacent to the gap 124. The magnets 260 exert a magnetic force on overlaying conveyor portion, e.g. the second conveyor portion 122, to limit movement of the associated conveyor portion away from the platform 124, e g. to limit or prevent the conveyor portion from lifting away from the platform 126 in response to air flow from the nozzles 250 in the associated separator device 242 trying to go beneath the conveyor portion. In other examples, additional magnets 260 may be provided at other locations on the platform 124, and magnets with varying strengths are also contemplated. In alternative examples, the conveyor assembly 102 may be formed wholly from a plastic, rubber, or other material, and the platform 126 may be provided without magnets.

[0070] As described above, a protrusion 127 may be provided lengthwise along the conveyor assembly 120 to generally fill the gap 124 other than as required for optical access or the like, and provide a substantially flush upper surface with the conveyor portions 120, 122, which may further limit particles from catching on edges of the conveyor assembly 120 and prevent air from traveling along the gap 124 to a location upstream or downstream of the separator device 242. Additionally or alternatively, an air shield 262 may be provided adjacent to the separator device 242 and first conveyor portion 120 to limit air flow from the nozzles 250 from flowing beneath the adjacent edge of the first conveyor portion 120 and lifting the first conveyor portion 120 away from the platform 126. [0071 ] In another example, the first conveyor portion 120 and/or the second conveyor portion 122 define a series of transverse grooves 270 in an upper surface thereof. The transverse grooves 270 in each conveyor portion 120, 122 provide a channel for air flow, such that air from the nozzles 250 in a separator device 242 may flow through the grooves 270 and at least partially under a particle 101 to aid in lifting the particle from the conveyor assembly and sorting it into the associated bin 244. Alternatively, the first and/or second conveyor portions 120, 122 may be provided with a smooth upper surface, or with another texture or pattern.

[0072] Referring to Figures 8-9, a system is shown according to another embodiment, and as a further example of the system 100 in Figure 1. Elements that are the same as or similar to those described above with respect to Figures 1-7 are given the same reference numbers for simplicity, and reference may be made to the description above for further details of these elements.

[0073] The system 100 receives a single particle stream of sized particles 101 at a first end, or the right-hand side of Figures 8-9. The single particle stream is moved through the system 100 on a conveyor assembly 102a. The conveyor assembly 102a may extend from the first end 104 of the system to the second end 106 of the system.

|0074| In the example shown, the conveyor assembly 102a is positioned to be horizontal or flat, and move in a longitudinal direction, or from right to left in Figures 8-9.

[0075] The conveyor assembly 102a may be provided with a first conveyor portion 120a and a second conveyor portion 122a. The first and second conveyor portions 120a, 122a each move in the longitudinal direction L, and are longitudinally spaced apart from one another via at least one gap 124a. Note that the first and second portions 120a, 122a may be longitudinally offset from one another to provide the gap 124a, and that the gap 124a may be provided with the first and second portions 120a 122a partially overlapping with one another as further described below. In the example shown, the gap 124a has a width in the range of 10-30 mm, although other widths for the gap 124 are also contemplated, for example, for use with other particle size ranges. As used herein, the longitudinal direction L is aligned with the movement for the first and second conveyor portions 120a, 122a, and is orthogonal or perpendicular to the transverse direction T as well as the vertical direction. [0076] In the example shown, the first conveyor portion 120a is provided as a first conveyor belt, and the second conveyor portion 122a is provided as a second conveyor belt. The first conveyor belt is separate and distinct from the second conveyor belt, and may be synchronized for movement with the second conveyor belt. The first and second conveyor belts are separated by the gap 124a. The gap 124a extends transversely to separate the two conveyor portions or belts 120a, 122a.

[0077] In some examples, particles 101 may be directed to the conveyor assembly 102a via another belt, such as a feeder conveyor 130 or feed chute (not shown) as described above, positioned at the first end of the system 100 and upstream of the conveyor assembly 102a.

[0078] The first conveyor portion 120a may be positioned with the upstream and downstream end regions level with one another such that the first conveyor portion 120a is horizontal as shown, or substantially horizontal. The second conveyor portion 122a may be positioned with the upstream and downstream end regions level with one another such that the second conveyor portion 122a is horizontal as shown, or substantially horizontal. In other examples, the first and/or second conveyor portions 120a, 122a may be inclined such that that conveyor portion descends towards its downstream end region. In one example, the first conveyor portion 120a may have a head pulley at its downstream end region adjacent to the gap 124a with a smaller diameter than a tail pulley at the upstream end region of the second conveyor portion 122a adjacent to the gap; and in a further example may be on the order of one fourth the diameter or smaller. This allows the head pulley and downstream end region of the first conveyor portion 120a to be positioned very close to the tail pulley and associated upstream end region of the second conveyor portion 122a to reduce or minimize the gap 124a that the particle traverses, while also providing sufficient space in the gap 124a to allow sufficient emitted light to return to the detector 150. In one non-limiting example, the gap 124a between the conveyor portions may as small as on the order of 3mm for a feeder conveyor head pulley diameter of 25-40mm and a conveyor assembly tail pulley diameter of 130- 160mm. Furthermore, and according to various examples, the head pulley at the downstream end region of the first conveyor portion 120a adjacent to the gap 124a may have a diameter that is on the same order of magnitude as the minimum particle size, e.g. 20-30 mm based on the screening. In other embodiments or examples, the gap 124a may be larger (as described above), and tail pulleys and head pulleys with other diameters may be used. In other examples, the head pulley and tail pulley may have diameters that are substantially the same, or the tail pulley may have a larger diameter than the head pulley.

(0079] Additionally, the first, upstream conveyor portion 120a may provide an upper surface at its downstream end region that is slightly elevated compared to the upper surface of the upstream end region of the second, downstream conveyor portion 122a, e.g. with the upper surface of the first conveyor portion 120a positioned on the order of 20 mm or less above the upper surface of the first conveyor portion 122a adjacent the gap 124a. By positioning the first conveyor portion 120a to be close to and slightly elevated relative to the conveyor assembly 102, the gap 124a between the two is reduced while maintaining the target location, and the particle 101 may be passed from the first conveyor portion 120a to the second conveyor portion 122a with little to no movement in the transverse direction as it flows over or jumps the gap 124a. With this positioning, the first conveyor portion 120a may be partially overlapped with the second conveyor portion 122a, e.g. with overlap occurring when viewed along a transverse vertical plane taken through the gap 124a.

]0080| The system 100 additionally may be provided with first and second guides 132a, 134a to move the particles transversely inward to generally position the particles into a single line on the conveyor assembly 102a (e.g. along a centerline of the conveyor assembly 102a, or along another line or pathway parallel to the longitudinal direction L), and such that the particles pass through the target location when crossing the gap 124a between the first and second conveyor portions 120a, 122a. The first and second guides 132a, 134a may each be provided above the upper surface of the first conveyor portion 120a, and upstream of the target location 126 as shown. The first and second guides 132a, 134a are angled towards one another in the longitudinal downstream direction as shown, and may be longitudinally offset from one another. The longitudinal guides 132a, 134a may be formed and provided as generally described above with respect to Figures 1-2.

|0081| The system 100 has a laser spectroscopic system 140, associated sensor 150, optical components 160, and an optical window assembly 200 that are positioned downstream of the guides 132, 134, and as described above with respect to Figures 1-4. The laser system 140 has one or more lasers 142 that provide a light beam or laser beam 144, e.g. as a series of laser pulses, to a target location 146 in the system 100. The target location 146 is adjacent to the conveyor assembly 102, and in the example shown, is positioned to overlay the gap 124a of the conveyor assembly 102. The laser beam 144 therefore interacts with a particle as it passes through the target location 146 on the conveyor assembly 102. Likewise, light emitted from the particle 101 passes through the gap 124a and to the detector 150.

[0082] The system 100 as shown in Figures 8-9 uses a controller 110 as described above to analyze the spectral data to classify the particle 101, and also to control a separator assembly 240 to sort particles 101 from the conveyor assembly, e.g. transversely across the conveyor assembly 102a from one side of the conveyor assembly 102a to the other side of the conveyor assembly 102a, or across the second conveyor portion 122a that passes through the separator assembly 240.

[0083] Note that the second conveyor portion 122a may present a continuous upper surface for transverse sorting (e.g. without the gap 124 as shown in Figure 7), as the first conveyor portion 120a is located upstream of the laser system 150 and second conveyor portion 122a. In this case, the conveyor assembly 102a of Figures 8-9 may be provided without a protrusion 127 as described above, and/or without an air shield 262. When used with the system as shown in Figures 8-9, the separator assembly 240 may be provided without a secondary air nozzle 256. Furthermore, and in some examples, the conveyor assembly 102a may comprise metal or non-metal materials, and to the extent that the conveyor assembly 102a comprises non-metal materials, the system 100 may be provided without magnets 260 as described above with reference to Figure 7. Furthermore, the first and/or second portions of the conveyor assembly 102a, may be provided with grooves, or with a smooth or other textured surface as describe above with reference to Figure 7.

[0084] Referring to Figure 10, a method 300 is shown for classifying and sorting particles. In various examples, the method 300 is implemented using the controller 110 and the system 100 as shown in Figures 1-2 and as shown in Figures 8-9. In other embodiments, various steps in the method may be combined, rearranged, or omitted.

|0085[ At step 302, a scrap particle 101 is moved in a longitudinal direction L on a conveyor assembly 102. In one example, and with reference to the system 100 shown in Figure 1, the conveyor assembly 102 may be provided with a first conveyor portion 120 and a second conveyor portion 122 transversely spaced apart from one another via a gap 124, and with the scrap particle overlapping the gap. The movement of the first conveyor portion 120 may be synchronized with the movement of the second conveyor portion 122, e.g. such that they both move together and at the same speed. Additionally, and in conjunction with step 302, the particle 101 may be positioned onto the conveyor assembly 102 to overlap the gap 124 via a first guide 132 angled towards the gap and a second guide 134 angled towards the gap. In another example, and with reference to the system 100 shown in Figure 8, the conveyor assembly 102a may be provided with a first conveyor portion 120a and a second conveyor portion 122a longitudinally spaced apart from one another via a gap 124a, and with the scrap particle passing through the gap and target location. The movement of the first conveyor portion 120 may be synchronized with the movement of the second conveyor portion 122, e.g. such that they both move together and at the same speed. Additionally, and in conjunction with step 302, the particle 101 may be positioned onto the conveyor assembly 102a to be generally aligned with a centerline or other location on the conveyor assembly 102a via a first guide 132a and a second guide 134a angled towards one another.

[0086] At step 304, a light beam 144 is generated and directed to the conveyor assembly 102 to a target location 146 associated with the gap. The light beam may be generated by a laser 142 in the laser system 140, and directed via one or more optical components 160. The light beam 144 may be directed to the target location 146 by, sequentially, focusing the light beam via a first lens 186, and passing the light beam through an aperture in a mirror 188 to the target location.

[0087] At step 306, at least one emitted band of light 156 from the particle is isolated and measured in the target location 146 at a selected frequency band using a detector, such as sensor 150 and spectrometer 154 to provide a signal indicative of spectral data for the particle to a controller 110. The emitted light 156 is generally in the gap associated with the conveyor assembly 102. The emitted light 156 may be directed to the sensor 150 via one or more optical components 160. In one example, the emitted light 156 is directed by, sequentially, reflecting the at least one emitted band of light via the mirror 188, and focusing the at least one emitted band of light via a second focusing lens 190 to the detector 150. [0088] In conjunction with step 304 and/or step 306, air flow may be directed through a plurality of outlets 212 defined by a nozzle housing 202 and surrounding an optical window 204 associated with the light beam 144 and/or the emitted light 156 to direct air away from the optical window 204.

[0089] At step 308, the particle 101 is classified, via the controller 110, into one of at least two classifications of a material as a function of the spectral data. In further examples, the particle 101 may be classified into six, eight, or more classifications based on the spectral data.

[0090] At step 310, the particle 101 is sorted by controlling a separator device 242 in a separator assembly 240 based on the classification for the particle. The particle 101 may be sorted by selectively moving the particle 101 transversely, or in a transverse direction T, across the conveyor assembly 102 and into a bin 244.

[0091] Figure 9 illustrates a system 400 running multiple systems 100. The systems 100 may be arranged as sub-systems into the larger system 400, and run parallel and simultaneously, for example, to classify and sort multiple streams of particles simultaneously and increase overall throughput. While the controller 110 for each system 100 may operate independently, the system 400 may additionally have a control unit 402 in communication with the various controllers 110, or the controllers 110 may be integrated into the control unit 402.

[0092] The particles are fed into the system 400 via a material feed 403 and a shaker table 404. The shaker table 404 distributes the particles 101 into multiple streams in conjunction with a lane sorter 405, with each stream being directed to an associated system 100. One or more belts 406 may be provided between the shaker table 404 and lane sorter 405 and each system 100 to increase spacing or separation between the particles 101 in each stream.

[0093] Each system 100 operates as described above, and classifies and sorts the particles 101 in its associated stream. The particles 101 in each system that reach the end of the conveyor assembly 102 may be directed into an end bin 246, or may be directed to a recycle loop 408 as shown. The recycle loop 408 may return particles that are not otherwise in a sorted bin 244 to the material feed 403 to re-run these particles through the system 400. Alternatively, the recycle loop 408 may be directed to another type of sorting system in the sorting facility, and not used to cycle these particles back through systems 100.

(0094] Various embodiments according to the present disclosure have associated, non-limiting advantages. For example, the sorting system as described herein provides for sorting of materials that are traditionally challenging to sort - such as multiple alloys of aluminum, titanium, or other metals. By providing the scrap particles in a linear manner on the conveyor, line speeds may be increased and/or processing speeds may be reduced as the laser beam does not need to be scanned or targeted. As the laser beam is directed to the particle while the particle is supported by the conveyor assembly (and the light emission for the particle is likewise while the particle is supported by the conveyor assembly), the location of the interrogation surface of the particle is well-defined and known providing for increased accuracy in measurement and classification, particularly when directing the laser to the lower surface of the particle supported by the conveyor, which lies along a known plane. The separator assembly as described herein also provides for increased efficiency and flexibility for sorting into multiple bins based on multiple classifications in comparison to other sorting methods such as a blow bar providing various trajectories to direct a particle into a splitter box and associated bins based on its classification.

[0095] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the disclosure. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the disclosure.

Claims

WHAT IS CLAIMED IS:

1. A system for sorting scrap material particles, the system comprising: a conveyor assembly having a first conveyor portion and a second conveyor portion each moving in a longitudinal direction, the first and second conveyor portions spaced apart from one another via at least one gap; a laser system comprising at least one laser to provide a laser beam to a target location in the gap between the first and second conveyor portions; a sensor positioned to detect light emitted from a particle within the target location; and at least one controller configured to (i) receive a signal from the sensor indicative of spectral data for the particle, the spectral data indicative of one or more selected frequency bands of light emitted from the particle in response to the laser beam interacting with the particle, and (ii) classify the particle into a classification of material using the spectral data.

2. The system of claim 1 wherein the laser system further comprises at least one optical component to focus the laser beam and/or direct the laser beam to the target location.

3. The system of claim 2 wherein the at least one optical component comprises a first focusing lens, a mirror having a central aperture, and a second focusing lens, wherein the laser beam is directed from the laser to the first focusing lens and through the central aperture to the target location, and wherein the light emitted from a particle is directed by the mirror to the second focusing lens and to the sensor.

4. The system of claim 2 wherein the at least one optical component comprises a dichroic mirror, wherein the laser beam is directed from the laser to the dichroic mirror to the target location, and wherein the light emitted from a particle is directed by the dichroic mirror to the sensor, wherein one of the laser beam and the light emitted from the particle is transmitted through the dichroic mirror, and the other of the laser beam and the light emitted from the particle is reflected by the dichroic mirror.

5. The system of claim 1 further comprising an enclosure surrounding the laser system; and an optical window assembly supported by the enclosure, the optical window assembly comprising a housing surrounding and supporting an optical window for the laser beam.

6. The system of claim 5 wherein the housing for the optical window assembly extends away from the optical window and towards the conveyor assembly to form a nozzle region, wherein the optical window assembly has at least one air inlet connected to the housing and a plurality of air outlets defined by the housing, the plurality of air outlets positioned within the nozzle region to surround the optical window and direct air flow away from the optical window, through the nozzle region, and towards the conveyor assembly.

7. The system of claim 1 wherein the at least one controller is further configured to (iii) trigger the laser to generate the laser beam only while the sensor is detecting light.

8. The system of claim 1 further comprising a separator assembly positioned downstream of the target location; wherein the at least one controller is further configured to control the separator assembly based on the classification of material to sort the particle.

9. The system of claim 8 wherein the separator assembly comprises at least three separator devices selectively operable to sort the particle into one of four classifications, wherein the three separator devices are spaced apart from one another along the conveyor assembly in the longitudinal direction.

10. The system of claim 8 wherein the separator assembly comprises at least one separator device adjacent to a first side of the conveyor assembly, and an associated bin positioned transversely across the conveyor assembly from the separator device and adjacent to a second side of the conveyor assembly, the separator device selectively operable to move the particle transversely across the conveyor assembly and into the associated bin.

11. The system of claim 10 wherein the separator device comprises at least one nozzle and an associated valve in fluid communication with an air source.

12. The system of claim 11 further comprising a secondary air nozzle positioned to direct air flow upwardly through the gap between the first and second conveyor portions, the secondary air nozzle positioned between the separator device and the associated bin.

13. The system of claim 10 wherein the separator device comprises three nozzles and at least one associated valve operable to control air flow through the three nozzles, the three nozzles spaced apart from one another in the longitudinal direction, and mounted to collectively provide converging air flow.

14. The system of claim 10 wherein the conveyor assembly comprises metal; and wherein the system further comprises a platform to support at least one of the first and second conveyor portions, and at least one magnet supported by the platform, the at least one magnet position between the separator device and the associated bin, the at least one magnet adjacent to the conveyor assembly to exert a magnetic force on the conveyor assembly and limit movement away from the platform.

15. The system of claim 10 wherein the first conveyor portion and/or the second conveyor portion define a series of transverse grooves in an upper surface thereof.

16. The system of claim 1 wherein the first and second conveyor portions are transversely spaced apart from one another.

17. The system of claim 1 wherein the first and second conveyor portions are longitudinally spaced apart from one another.

18. The system of claim 1 further comprising first and second guides angled towards one another in a downstream direction and positioned upstream of the target location, the first and second guides to align and position the particle on the conveyor assembly.

19. The system of claim 18 further comprising a feeder conveyor positioned upstream of the conveyor assembly, the feeder conveyor comprising an upstream end region and a downstream end region adjacent to the conveyor assembly, wherein the feeder conveyor defines a concave cross-sectional shape that flattens towards the downstream end region.

20. The system of claim 1 further comprising a chute positioned upstream of the conveyor assembly to direct scrap particles to the conveyor assembly, and first and second guides angled towards one another in a downstream direction, the first and second guides to align and position the particle on the conveyor assembly.

21. The system of claim 1 wherein the laser system and the sensor are positioned on a first side of the conveyor assembly.

22. The system of claim 21 wherein the laser system is longitudinally offset from the target location.

23. The system of claim 1 wherein the sensor is a spectrometer.

24. The system of claim 1 wherein the first and second conveyor portions comprise a first conveyor belt and a second conveyor belt separate from the first conveyor belt, respectively, and wherein the first conveyor belt is synchronized for movement with the second conveyor belt.

25. The system of claim 24 wherein the conveyor assembly further comprises a platform to support the first and second conveyor belts, wherein the platform defines an aperture overlapping the target location.

26. The system of claim 1 wherein the conveyor assembly further comprises a conveyor belt comprising the first and second conveyor portions, wherein the conveyor belt defines a series of apertures therethrough such that the first and second conveyor portions are transversely spaced apart from one another via the series of apertures.

27. The system of claim 1 wherein an upper surface of the first conveyor portion is offset from an upper surface of the second conveyor portion.

28. The system of claim 27 wherein a downstream end of the first conveyor portion partially overlaps an upstream end of the second conveyor portion.

29. The system of claim 27 wherein the first conveyor portion is positioned upstream of the second conveyor portion; and wherein a first diameter of a first pulley associated with a downstream end of the first conveyor portion is on the same order of magnitude as a size of the particle.

30. A method of sorting scrap particles comprising: moving a scrap particle in a longitudinal direction on a conveyor assembly with a first conveyor portion and a second conveyor portion spaced apart from one another via a gap; generating and directing a light beam to the conveyor assembly to a target location associated with the gap such that the light beam interacts with the particle when passing through the target location; isolating and measuring at least one emitted band of light from the particle in the target location at a selected frequency band using a detector to provide a signal indicative of spectral data for the particle to a controller; and classifying the particle, via the controller, into one of at least two classifications of a material as a function of the spectral data.

31. The method of claim 30 further comprising, sequentially, focusing the light beam via a first focusing lens, and passing the light beam through an aperture in a mirror to the target location; and sequentially, reflecting the at least one emitted band of light via the mirror, and focusing the at least one emitted band of light via a second focusing lens to the detector.

32. The method of claim 30 further comprising directing air flow through a plurality of outlets defined by a nozzle housing and surrounding an optical window associated with the light beam to direct air away from the optical window.

33. The method of claim 30 further comprising sorting the particle by controlling a separator device based on the classification for the particle.

34. The method of claim 33 further comprising sorting the particle by selectively moving the particle transversely across the conveyor assembly and into a bin.

35. The method of claim 30 further comprising positioning the particle onto the conveyor assembly via a first guide and a second guide, the first and second guides angled towards one another.

36. The method of claim 30 further comprising substantially synchronizing movement of the first conveyor portion and the second conveyor portion.

37. The method of claim 30 wherein the light beam is a laser beam generated by a laser; and wherein the method further comprises triggering the laser to generate the laser beam only while the detector is detecting light.

38. A system for sorting scrap material particles, the system comprising: a conveyor assembly having a conveyor moving in a longitudinal direction; a laser system comprising at least one laser to provide a laser beam to a target location adjacent to the conveyor; a sensor positioned to detect light emitted from a particle within the target location; a separator assembly positioned downstream of the target location, the separator assembly having at least one separator device adjacent to a first side of the conveyor, and an associated bin positioned transversely across the conveyor from the separator device and adjacent to a second side of the conveyor, the separator device selectively operable to move the particle transversely across the conveyor assembly and into the associated bin; and at least one controller configured to (i) receive a signal from the sensor indicative of spectral data for the particle, the spectral data indicative of one or more selected frequency bands of light emitted from the particle in response to the laser beam interacting with the particle, (ii) classify the particle into a classification of material using the spectral data, and (iii) control the separator assembly based on the classification of material to sort the particle.

39. The system of claim 38 wherein each separator device comprises three nozzles and at least one associated valve operable to control air flow through the three nozzles, the three nozzles spaced apart from one another in the longitudinal direction, and mounted to collectively provide converging air flow towards the particle.

40. The system of claim 38 wherein each separator device comprises at least one nozzle and an associated valve operable to control air flow through the nozzle.

41. An optical window assembly comprising: an optical window for a laser beam; and a housing surrounding and supporting the optical window, the housing extending away from the optical window to form a nozzle region with an open distal end; and at least one air inlet connected to the housing; wherein the housing defines a plurality of air outlets positioned within the nozzle region to surround the optical window and direct air flow away from the optical window, through the nozzle region, and through the open distal end to the environment.

42. A system for sorting scrap material particles, the system comprising: a conveyor assembly having a conveyor moving in a longitudinal direction; a laser system comprising at least one laser to provide a laser beam to a target location adjacent to the conveyor; a sensor positioned to detect light emitted from a particle within the target location; an enclosure surrounding the laser system; the optical window assembly according to claim 41 supported by the enclosure, wherein the housing extends towards the conveyor assembly; and at least one controller configured to (i) receive a signal from the sensor indicative of spectral data for the particle, the spectral data indicative of one or more selected frequency bands of light emitted from the particle in response to the laser beam interacting with the particle, and (ii) classify the particle into a classification of material using the spectral data.

43. The system of claim 42 wherein the at least one controller is further configured to (iii) trigger the laser to generate the laser beam only while the sensor is detecting light.