FIELD OF THE INVENTION

The present invention relates broadly to a sorting apparatus and relates particularly, though not exclusively, to an apparatus for sorting refuse for recycling purposes. The invention further relates to a method of sorting items, in particular refuse.

BACKGROUND TO THE INVENTION

The majoring of sorting for recycling purposes occurs at the place at which the refuse is generated. Thus, sorting takes place at domestic residences and commercial premises to separate recyclable items from each other, such as paper and cardboard from glass and plastic. The effort to sort different forms of recyclable items often results in sorting not taking place, or poor sorting. In particular, public rubbish bins and dumping facilities are not always set up for recyclable items to be separated. Also, the sorting that occurs at domestic residences and commercial premises often is only general, such as separating paper and cardboard from plastic and glass and more specific sorting is required later. It is therefore desirable for refuse to be sorted automatically to avoid variations in the amount and quality of refuse sorting.

Automatic refuse sorters exist but in general, these are only effective to sort very different items of refuse from each other. Thus, such sorters can employ magnetic forces to remove ferrous metals, and liquid baths can be employed to separate light materials, such as plastic bottles, from heavier materials, such as ceramics. This, however, is very basic sorting and far more sophisticated equipment is necessary for sorting similar items, such as different types of plastic bottles. Thus, automatic sorting equipment can be large and expensive, both to purchase and operate, and it can be prone to breakdown, given that the apparatus presently available has many moving parts.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided a sorting apparatus for sorting items, said apparatus comprising:

detection means being adapted to detect at least one of a plurality of distinguishing characteristics of said items; and

deflection means operatively coupled to the detection means and configured to facilitate deflection of said items dependent on the detected characteristic whereby said items are sorted according to at least the detected of the distinguishing characteristics.

Preferably the deflection means includes one or more fluid nozzles or ejectors being designed to discharge jets of high pressure fluid to effect deflection of said items. More preferably the fluid nozzles are each operatively coupled to solenoid actuated valves.

Preferably the deflection means includes one or more of the following being deployed either solitarily and independently, or in combination and co-operatively: fluid nozzles, water jets, deflector plates or arms, robotic arms, fans or vacuum means.

Preferably the sorting apparatus further comprises delivery means for delivering items to be sorted to the deflection means.

Preferably the sorting apparatus further comprises a detection chamber disposed at or adjacent the detection means and arranged to receive the items to be sorted. More preferably the detection chamber is at least in part defined by one or more chamber walls configured to have minimal contact with the items as they fall through the chamber. Alternatively preferably the detection chamber is at least in part defined by an inclined surface on which the items to be sorted are received, said items being in contact with said inclined surface as they flow through the chamber.

Preferably the chamber walls or inclined surface has a colour which assists the detection means to detect a distinguishing characteristic of said items. More preferably the colour is one of a plurality of colours spaced apart from upper to lower portions of said chamber wall or inclined surface to assist the detection of different distinguishing characteristics of said items.

Preferably the chamber wall or inclined surface is at an angle of between 75° to 90° to horizontal.

Preferably the detection means has capacity to detect one or more of the following distinguishing characteristics:

(a) size;

(b) shape;

(C) colour;

(d) transparency;

(e) molecular structure;

(f) conductivity;

(g) velocity;

(h) magnetism; and

(i) fluorescence.

bly the detection means is selected i

G ⁾ camera;

(k) spectrometer;

(1) metal detector;

(m) light sensor;

(n) motion detector;

(o) sonic detector; and

(P) x-ray fluorescence detector.

Preferably the detection means include a plurality of detectors selected from:

(q) cameras;

(r) spectrometers;

(s) metal detectors;

(t) light sensors (u) motion detectors;

(v) sonic detectors; and

(w) x-ray fluorescence detectors.

Preferably the spectrometer is selected from a visible, near infra-red, ultra violet, and/or x-ray.

Preferably the sorting apparatus further comprises processing means in communication with the detection and the deflection means to analyse detection information detected by said

detection means, and to actuate said deflection means to cause deflection of said items according to the detected characteristics.

Preferably the sorting apparatus further comprises a collection means operatively coupled to the deflection means for collection of the sorted items into separate compartments depending on their detected characteristics. More preferably the collection means includes a plurality of chutes or bins.

Preferably the sorting apparatus further comprises a fan or vacuum for removal of lightweight of the items to be sorted. More preferably the fan or vacuum is located upstream of or adjacent said detection means.

According to another aspect of the present invention there is provided a method of sorting items, said method comprising the steps of: exposing said items to detection means which is adapted to detect at least one of a plurality of distinguishing characteristics of said items; and sorting said items according to at least the detected of the distinguishing characteristics by utilising deflection means operatively coupled to the detection means and configured to facilitate deflection of said items dependent on the detected characteristic.

BRIEF DESCRIPTION OF THE FIGURES

For a better understanding of the invention and to show how it may be performed, embodiments thereof will now be described, by way of non-limiting example only, with reference to the accompanying drawings.

Figure 1 is a side elevation which schematically illustrates one embodiment of a sorting apparatus of the invention.

Figure 2 is a front elevation of the sorting apparatus of figure 1.

Figure 3 is a side elevation which schematically illustrates another embodiment of a sorting apparatus of the invention.

Figure 4 is a front elevation of the sorting apparatus of Figure 3.

DETAILED DESCRIPTION OF THE INVENTION

As shown in figure 1, there is a sorting apparatus 10 for in this embodiment sorting refuse. The refuse often includes items 13 having different characteristics, forms and shapes. The sorting apparatus 10 comprises detection means each of which is adapted to detect at least one of a plurality of distinguishing characteristics of the items 13. The detection means in this embodiment includes a camera detector 14, a spectrometer 15, metal detectors 16 and illuminating lights 17 and 18. The lights 17 and 18 are disposed on both sides (front and rear) of the chute 12, while the spectrometer 15 is disposed centrally of the sorting apparatus 10. The sorting apparatus 10 also comprises deflection means 22 which are operatively coupled to the detection means 15 and 16. The deflection means 22 are configured to facilitate deflection of the items 13 dependent on the detected characteristic of the items 13. The items 13 are sorted according to at least the detected of the distinguishing characteristics.

It can be seen from figure 1 that the deflection means 22 of the present embodiment are disposed at various locations on the lower or downward side of the detection means 15 and 16. The deflection means 22 may be angled differently so as to achieve a high level of precision in deflecting the items 13. In a preferred embodiment, the deflection means 22 include one or more fluid nozzles or ejectors 28 which are designed to discharge jets of high pressure fluid to effect deflection of the items 13. In this preferred embodiment the deflection means 22 are air ejectors and nozzles which discharge jets of high pressure air. The fluid nozzles 28 are each operatively coupled to solenoid actuated valves (details not shown) which control the operation of the nozzles 28 individually and independently. Optionally, the deflection means 22 may include fluid nozzles, water jets, deflector plates or arms, robotic arms, fans or vacuum means. These deflection means, in addition to or in place of the fluid nozzles or ejectors 28 may be deployed either solitarily and independently, or in combination and co-operatively at the discretion of the user for the purposes of enhancing deflection accuracy and saving power.

The sorting apparatus 10 further comprises delivery means 11 preferably in the form of elongate conveyors for delivering items 13 to be sorted to the deflection means 15 and 16. Referring to figure 1, by way of example, the delivery means 11 is located so as to ensure smooth delivery or feeding of the items 11 so that they are exposed to the detection means 15

and 16. The delivery means 11 is designed to deliver the items 11 in a steady manner so as to avoid superposition of the items 13. This is advantageous as any congestion or overloading of the items 13 may result in malfunctioning of or false results from the detection means 15 and 16.

The sorting apparatus 10 also includes a detection chamber 12 disposed at or adjacent the detection means 15 and 16. The detection chamber 12 is arranged to receive a flow of the items 13 to be sorted from the delivery means 11. The detection chamber 12 is at least in part defined by one or more chamber walls 30 configured to have minimal contact with the items 11 as they fall through the detection chamber 12. Alternatively, it is envisaged that the detection chamber 12 is at least in part defined by an inclined surface (refer to figure 3) on which the items 13 to be sorted are received. In the embodiment with the inclined surface, the items 13 are in contact with said inclined surface as they flow through the chamber 12. The embodiment with the inclined surface has the advantage that the items 13 are supported and guided throughout their course within the chamber 12. As such, the likelihood of the items 13 superimposing on each other is minimised. In both embodiments, the items 13 are adapted to free fall or slide under gravitational force. This is advantageous in that the items 13 are set to accelerate through the detection chamber 12 under gravity providing relatively quick throughput of items 13 to be sorted.

Referring to figure 1, the chamber walls 30 of the present embodiment (or the inclined surface with the other embodiment) have a colour which assists the detection means 15 and 16 to detect a distinguishing characteristic of the items 13. The colour is one of a plurality of colours spaced apart from upper to lower portions of said chamber walls 30 (or inclined surface) to assist the detection of different distinguishing characteristics of the items. In order to ensure a steady and orderly flow of the items 13 past the detection means, the chamber walls 30 (or inclined surface) are at an angle of between 75° to 90° to horizontal. As can be seen in figure 1, when the chamber walls 30 are perpendicular to the horizontal, the items 13 are unlikely to be in contact with the chamber walls 30 as they fall under gravity. This is beneficial in that the chamber walls 30 do not wear over time.

The detection means 15 and 16 include a plurality of detectors selected from one or more of the following: a camera, a spectrometer, a metal detector, a light sensor, a motion detector; a

sonic detector, or an x-ray fluorescence detector. The detection means 15 and 16 have capacity to detect one or more of the following distinguishing characteristics: size, shape, colour, transparency, molecular structure, conductivity, velocity, magnetism and fluorescence. The detection means 15 and 16 as shown in figure 1 are for exemplary purposes. It is contemplated that more (or less) than two detection means may be incorporated in the proximity of the chamber 12 such that more specific and delicate sorting of the items 13 may be achieved. For instance, the spectrometer mentioned above may be selected from a visible, near infra-red, ultra violet, and/or x-ray.

The sorting apparatus 10 further comprises one or more processing means (not shown) which are in communication with the detection and deflection means 15, 16 and 22 to analyse detection information detected by the detection means 15 and 16. The processing means also function to actuate the deflection means 22 to cause deflection of the items 13 according to the detected characteristics.

The sorting apparatus 10 further comprises collection means operatively coupled to the deflection means 15 and 16 for collection of the sorted items 13 into separate compartments depending on the detected characteristics. The collection means include a plurality of chutes or bins 23 to 27. In addition to the deflection means 22, the sorting apparatus 10 comprises a fan or vacuum (not shown) for removal of lightweight of the items to be sorted. In a preferred embodiment, the fan or vacuum is located upstream of or adjacent the detection means 15 and 16. As such, lightweight of the items such as paper may be removed or sorted before reaching the chamber 12. This is advantageous as items such as paper, particular when it is wet, is likely to adhere to other items such as glasses or bottles. This blanketing effect often affects the quality of sorting.

Turning to figure 2, the operation of the sorting apparatus is now described. The items 13 may be delivered to be sorted to the deflection means 22 by way of the delivery means 11. The items 13 then fall into a detection chamber disposed at or adjacent the detection means 15 and 16. The detection chamber 12 is configured and arranged to receive a flow of the items 13 to be sorted. The detection chamber 12 is at least in part defined by one or more chamber walls 30 configured to have minimal contact with the items 13 as they fall through the chamber 12. Alternatively, the items 13 are received by the chamber walls (or inclined surface) 30. As

such, the items 13 are in contact with the chamber walls or inclined surface 30 as they flow through the chamber 12. Being guided by the chamber walls (or inclined surface) 30, the items 30 run past the detection means 15 and 16 which are adapted to detect different distinguishing characteristics of the items 13. The detection means 15 and 16 have horizontal and vertical fields of view covering the full width W of the detection chamber 12. The deflection means 22 are operatively coupled to the detection means 15 and 16 and configured to facilitate deflection of the items 13 dependent on the detected characteristic(s). The items 13 are then sorted according to at least the detected of the distinguishing characteristics. The detection and deflection means are in communication with each other by way of one (or more) processing means which analyses detection information detected by the detection means 15 and 16. The processing means functions to actuate the deflection means 22 which spans the width W of the chamber 12 and causes deflection of the items 13 according to the detected characteristic(s). The deflection means 22 include one or more fluid nozzles or ejectors which are designed to discharge jets of high pressure fluid to effect deflection of the items 13. The fluid nozzles are each operatively coupled to solenoid actuated valves which are controlled by the processing means,

After travelling past the detection chamber 12, the items 13 are deflected from their normal paths of travelling into the collection means by the deflection means 22. The collection means include the chutes or bins 23 to 27. The collection means are operatively coupled to the deflection means 15 and 16 for collection of the sorted items 13 into separate compartments depending on the detected characteristics.

Figure 3 illustrates a sorting apparatus 100 according to another embodiment of the invention. The sorting apparatus 100 includes a delivery conveyor 110 which is operable to deliver refuse items to be sorted to a chute 120. For the purposes of illustration, only a single item 130 is shown in Figure 3 and that item 130 has been delivered from the delivery conveyor 110 and is shown positioned at the upper end of the chute 120. The item 130 is shown in the form of a bottle, and it will be appreciated that the effect of gravity will cause the item 130 to fall from its position shown in Figure 3 in the direction of arrow A. The item 130 is shown slightly spaced from the upwardly facing surface 190 of the chute 120, although it will be appreciated that the item 130 is intended to fall generally in contact with chute 120.

The chute 120 directs the item 130 through a detection facility and in Figure 3, that facility comprises various detectors that are positioned suitably for detecting characteristics of the item 130. Thus, the detection facility includes a camera detector 140, a spectrometer 150, metal detectors 160 and illuminating lights 170 and 180. As shown in Figure 4, the light 170 and 180 are disposed on both sides (front and rear) of the chute 120, while the spectrometer 150 is disposed centrally of the chute 120 and the array of metal detectors 160 extent fully across the width W of the chute 120.

Each of the camera 140 and the spectrometer 150 has vertical and horizontal fields of view. For each of these components of the detection facility, the horizontal field of view should be sufficient to cover the full width W of the chute 120, and to have a vertical field of view sufficient to detect certain qualities in items which pass through the detection facility in the time it takes the items to pass through the facility. The vertical field of view of each of the camera 140 and the spectrometer 150 are show in Figure 3 in broken outline. The camera 140 also has a horizontal field of view equal to the width W and while the spectrometer 150 provides coverage over the width W, it does this by scanning across the width W. Thus, the spectrometer 150 has a circular field of view of about 150 mm diameter, that rapidly scans across the width W.

The lights 170 and 180 are disposed to illuminate different areas of the detection facility. The lights 170 illuminate across the front surface 190 of the chute 120 to assist detection of items by the camera 140. The lights 180 illuminate the rear surface 200 of an opaque screen 210 to assist detection of items by the spectrometer 150. The screen 210 provides a background against which items pass and which promotes proper detection by the spectrometer 150. It also provides a background for the camera 140 for the detection of transparency.

As the item 130 moves through the detection facility, the camera 140 is operable to detect the size of the item, its shape, colour, position and velocity. A camera which has been successfully Mailed at this stage is a Logitech WebCam, 120 x 160 resolution, 20-30 frames/sec, colour.

The item 130 also passes over the linear array of metal detectors which in trials have been included as 30 mm inductive coils. The spectrometer 15 is a Near Infra-re (NIR),

spectrometer. The combination of the spectrometer 150 and the metal detectors 160 identify the material of the item 130.

It follows that as the item 130 moves through the path of the detection facility, various characteristics of the item are detected and that information is analysed by one or more computers or programmable logic controllers ("PLC") and the analysis is employed for the next stage of the sorting apparatus. The analysis that takes place is one which can be programmed by a person skilled in the art and therefore the detail of the analysis programming is not necessary to recite here.

The item 130 passes from the detection facility to deflection means which in the embodiment illustrated in figures 3 and 4, comprises a plurality of air ejection solenoids 220. Such solenoids can have high speed switching and high air flow rates to provide sufficient accuracy when fired.

The ejection solenoids 220 are controlled by the computer or computers, or the PLC and thus once the item 130 have been fully detected by the various detector components 140 to 160 and the results of that detection has been analysed, the ejectors are fired appropriately to deflect the path of the item from the path identified by arrow A. Thus Figure 3 illustrates that the item 130 can be ^' deflected in either one of four directions, or it can be allowed to continue undeflected. Thus in Figure 3, there are five chutes numbered 230 to 270 into which the item 130 can be collected, with four of those chutes, namely chute number 230, 240, 260 and 270, requiring deflection of the path of the item 130 from that identified by the arrow A. Where no deflection takes place, the item 130 will be collected in the chute 250. In one arrangement, chutes 230 and 270 are for the collection of plastic items, and chutes 240 and 260 are for the collection of glass items. As plastic items are generally of less weight than glass items, for items that have a similar size and shape, it is easier to shift plastic items a greater distance than glass items.

The item 130 is collected in one of the chutes 230 to 270 according to the above arrangement and is then processed further as required. Further processing may involve directly recycling the item 130, or the item 130 may be collected in a chute which requires further sorting. Further sorting may be through a further apparatus 100, in which the detection facility detects different characteristics to those detected in the embodiment described above. For example, a

first pass through a first sorting apparatus 100 may generally separate plastic items from glass items, while a second passage through that apparatus might separate different types of plastic and different types of glass from each other. It is possible for example, for the computer control of the sorting apparatus 100 to have various programmes so that a suitable programme is selected to suit the particular refuse being sorted. For example, where domestic or commercial sorting has produced refuse which comprises only plastic and glass bottles, then a programme could be selected for the separation of the different types of bottles. Alternatively, where general refuse has been collected, and includes recyclable and non- recyclable refuse, then a different programme would be employed.

In one form of the sorting apparatus 100, loose paper and plastic bags can be separated from other refuse either on the delivery conveyor 110 prior to discharge of refuse onto the chute 120 or between the delivery conveyor 110 and the chute 120, by the use of a fan or vacuum. This example is to show that other components may be included in the sorting apparatus 100 in particular to remove items that may foul the sorting process through the detection facility. A magnet may actually form the first component to remove ferrous metals.

An example of the operation of the present invention is set out below.

Four items of refuse, comprising a clear plastic bottle, a piece of green glass, an aluminium can and a piece of paper are feed onto the chute 120 from the delivery conveyor 110, in a steady flow. The delivery is most preferably one item deep, ie with no items sitting on top of another. To facilitate this, a fan may be provided to blow air over the conveyor 110, so that all light, large surface area items can be separated into a bin before the items reach the chute 120. By this mechanism, all loose paper and plastic bags can be removed. Likewise, the material being fed on the conveyor 110 can be subjected to a magnetic force to remove ferrous metals.

The four items listed above now fall onto the chute 120, and those items are first subjected to detection by the camera 140. The camera records for each item, its size, shape, colour and position. The camera takes images at a rate sufficient to take at least three images of each item. From those images, the velocity and acceleration of each item can be calculated. The colour of the front surface 190 of the chute 110 is chosen to assist the camera to detect the transparency of each item and to track the path of items of any colour, including black. The

front surface 190 of the chute 110 can have a selection of different colours to assist the camera in detecting different characteristics.

As the items pass through the camera viewing area, they pass over the array of metal detectors 106 which can identify any metallic material. Thus, the metal detectors 160 provide information as to the type of materials of the items and in the selection of items used for this example, the metal detectors 160 will identify that one of the items, the aluminium can, is metallic and that the other items are not.

The items then pass the screen 210 which is an opaque glass with lighting behind it. At this point, the camera 140 can best determine the transparency of each item. It is also the region where the NIR spectrometer 150 scans the items. The NIR spectrometer 150 can identify the molecular structure of the items by analysing the NIR spectrum to calculate the percentage of spectrum from each of the plastics (PET, HDPE, PBC, PP, PS etc), paper, cardboard, and organics. The computer which analyses the results of the detection facility can correlate the information retrieved from each of the detectors to identify each item as to its size, shape, colour, material, position and velocity. The computer will send information to the deflection means for appropriate actuation of the deflectors 220. The deflectors 220 will be switched on for the duration of the path of the items past the deflectors and for example, if the item is plastic, the deflectors 220 will fire and the item will be sent at an almost horizontal trajectory to either of the bins 230 or 270. Alternatively, if the item is glass, the deflection will result in change in trajectory of only a slight deviation from the path A, so that the item will pass to one of the bins 240 or 260.

Specifically, the plastic bottle of this example will pass through the view of the camera 140 where the camera 140 will determine its size, shape and position. The plastic bottle then passes the metal detectors 160 which records a non-metal result. The camera 140 then records another image additional to the first image, but with the bottle having passed further down the chute 120. The computer calculates its velocity using the two separate images and the computer also notes that the image has changed colours as the front surface 190 of the chute 110 changes colour and the computer then determines that the plastic bottle is transparent. Finally, the plastic bottle passes in front of the screen 210 where it is scanned by

the NIR spectrometer which detects it as being PET plastic material. Thus the deflectors 220 are fired to deflect the plastic bottle to the appropriate PET bin.

The glass and aluminium are also detected by the camera in the same manner and likewise, the camera records their size, shape and position and from a second image calculates the velocity of each item. As the items pass the metal detectors 160, the aluminium is detected and the computer assigns the aluminium can as being of a metal material. In contrast, the metal detectors do not record a metallic material in respect of the glass item, but the glass item does change colour as it travels over the front surface 190 of the chute 120 although it maintains a continual green base colour. When the glass item passes over the screen 210, the camera detects the transparency of the glass and the non-transparency of the aluminium can. The NIR spectrometer detects a slopped spectrum indicating glass, so that the ejectors will be operated to eject the glass into an alternative chute to that of the plastic bottle and the aluminium can. Likewise, the aluminium can will be ejected into a suitable aluminium bin.

Finally, the paper item might be removed as a sheet by the initial fans which are applied to the delivery conveyor 110. Alternatively, if the paper is wet, or if it has a sufficient weight, such as a book, it will fall in a similar manner past the chute 120 as the other items and once more, it will be detected by the camera, the metal detectors and the spectrometer.

Thus, the invention has enabled four items of different material to be analysed and sorted following that analysis into four different chutes.

The invention is envisaged to provide a high speed, cost effective apparatus for sorting recyclable and non- recyclable items which is almost entirely automatic and which has high rates of efficiency.

Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. For example, the

number and selection of the detection means may vary for coarse or fine sorting of the items. A different selection of detection means would have different capacity to detect different distinguishing characteristics. Also, the detection and deflection means may be placed in different locations to effect different orders of sorting or placement of the sorted items. Furthermore, the construction of the detection chamber 12 may vary such that the angle at which the chamber walls (or inclined surface) are disposed may be automatically or manually altered. As such, the flow rate of the items being sorted may be altered before or during operation of the sorting apparatus. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.