SE1451571A1 - Sorting system with multiple sorting devices - Google Patents

Description

SORTING SYSTEM WITH MULTIPLE SORTING DEVICES Technical field The present document relates to a sorting system and a sorting method forsorting waste objects. More specifically the present document relates tosorting units comprising multiple sorting devices.

Backgroundln recent years an automated sorting of domestic waste, sorted at source, into different fractions has become more and more important in orderto increase the efficiency of the waste handling facilities and in order to beable to take care of the ever growing amounts of waste produced by thehouseholds.There are a number ofdifferent methods and systems available today to perform this type of sorting.

WO95/32062 discloses an arrangement for sorting differently colouredwaste sacks which occur in random distributions and contain different types ofwaste sorted at source. This arrangement comprises sorting stations, whichby means of a colour analysis as disclosed in WO9622512 identify and thenseparate waste sacks of a predetermined colour, which are conveyed on aconveyor belt. ln EP 1 583 618 the refuse sacks are provided with a means ofidentification, in this case the entire bag is provided with a specific colour, andthe sorting is performed at least one sorting station, which is able to identify atleast two means of identification, this method and arrangement thus furtherenhances the accuracy of the sorting. ln WO90/11142 an apparatus and method for sorting waste isdisclosed. The waste is provided in coloured bags and sorted by sortingmeans after being detected by a detection device. ln EP1854555B1 waste bags are transported in screw conveyors inorder to separate the waste bags. The bags are identified based on e.g.colour and separated from the others by opening a bottom plate. ln recent years environmental concerns have also moved the wastesorting to include more fractions to be sorted at source, i.e. food waste,paper, plastics etc. is to be sorted in the homes of the users.

As both the amounts of domestic waste and the fractions ofwaste to be sorted continues to increase, there is a need to not only providefor a more efficient sorting, in terms of speed and accuracy, in the sortingfacilities, but also a need to keep the size of the facilities at a minimum toreduce the costs of buildings, equipment etc..

Summarylt is an object of the present disclosure, to provide an improved sorting system, which eliminates or alleviates at least some of thedisadvantages of the prior art sorting systems and facilities.

More specific objects include providing a sorting system and amethod for sorting waste objects which allows for more compact and efficientwaste sorting facilities.

The object is wholly or partially achieved by a sorting system and amethod for sorting waste objects according to the appended independentclaims. Embodiments are set forth in the appended dependent claims, and inthe following description and drawings.

According to a first aspect, there is provided a system for sorting wasteobjects, wherein the waste object is provided with means for identificationthereof, wherein the system comprises, at least one sorting unit, wherein thesorting unit is connected to at least one sensor system for identifying saidwaste object or said means for identification, said sensor system beingarranged to detect one or more means for identification and arranged toprovide a control system with a signal when a waste object of a desired typeis detected. The sorting system comprises at least one sorting conveyor forconveying said waste objects to said sorting unit. The said sorting unit isprovided with two or more sorting devices for sorting the waste objects,wherein said sorting devices are arranged to receive at least one signal fromsaid control system in response to a waste object of a desired type beingdetected by the sensor system and wherein said multiple sorting devices arearranged to push the waste objects from the sorting conveyor.

By “sorting the waste objects” is meant that the sorting devices arearranged to move the waste objects from the sorting conveyor and either intoa sorting container or e.g. onto another conveyor.

By “being connected to” means that a sensor system in some waycontrols one or more sorting units. 3 This innovative system, with one sensor system controlling multiplesorting devices for sorting waste objects, provides for a way of providing ashorter and more compact sorting facility and for a higher throughput of wasteobjects and material.

According to one embodiment said sorting devices may be arranged tobe individually controllable.

This allows for the sensor system being more flexible, sincedifferent types of waste objects may have different types of demands for thesubsequent treatment in the sorting process. This means that when a wasteobject of a desired type has been detected by the sensor system and this hasgenerated a signal to the control system, the control system may provide thesorting devices with the same or different signals, e.g. it may provide only oneof the sorting devices with a signal to remove the waste object or both. Thisalso means that if a first sorting devices is activated, i.e. has received a signalfrom the control system to remove an object from the conveyor, and a newobject of the desired type passes the sensor system, the control system mayprovide a signal to a second sorting device to become activated, i.e. toremove waste from the conveyor. This type of control function may thereforefurther enhance the sorting capacity of the sorting facility. This may alsomean that the sorting devices are physically remote from the sensor system,such that one sensor system may be arranged to control the function ofseveral sorting units having multiple sorting devices. lt is further possible thatdifferent waste objects may be treated differently in that they may be removedby different types of sorting devices.

According to one embodiment the sorting unit may be provided withtwo sorting devices.

The waste object may be a container or bag, and wherein saidcontainer or bag is provided with means for identification.

This provides for a way of the user, or households to sort the waste atsource and place the waste in a container or bag, which can subsequently besorted at a sorting facility.

The means for identification may comprise any one of colour,pattern or RFID-identification, or a combination thereof.

This provides for a system which can detect and sort manydifferent types of waste material, which may have been sorted at source bythe user. Such means for identification and containers are for instancedescribed in EP1855964 and EP2694223.

According to one embodiment the sensor system may comprisesensors arranged to be able to detect at least one of said means foridentification or a combination thereof.

This means that the sensor system may comprises colourdetection sensors, such as cameras, and also sensors for identifying patternarranged on the containers. Such sensors for detecting pattern may becameras, but may also be other types of sensors. The sensor system mayalso comprise sensors for detecting RFID signals. ln an alternative the sensorsystem may comprise a combination of one or more of these types ofsensors, which may also allow for a more accurate sorting to take place.

According to one embodiment the sorting device may comprise ablade.

According to a second aspect there is provided a method for sortingwaste objects in a sorting system according to the first aspect, wherein thewaste objects are provided with means for identification, and wherein themethod comprises the steps of: providing said waste objects on at least onesorting conveyor, detecting said waste object or means for identificationthrough at least one sensor system, arranged in connection with at least onesorting unit, providing a control system with a signal when a desired object orobject provided with desired means for identification is detected by saidsensor system. The method further comprises the step of providing two ormore sorting devices with an activation signal by said control system, inresponse to said desired object or object provided with desired means foridentification being detected, wherein said multiple sorting devices arearranged to push the waste objects from the sorting conveyor.

The sorting system may comprise several sorting conveyors, forinstance in parallel or in series. The sorting system according to the methodmay comprise one sensor system controlling multiple sorting units and/orsorting devices. The sorting system may comprise multiple sorting units, e.g.one for each means of identification. The sorting units may be arranged inparallel or in series.

By “activation signal” is meant that the sorting device is provided with asignal or some other type of input to react or act on a specific waste object,i.e. to remove the waste object from the sorting conveyor.

According to one embodiment the sorting device may comprise ablade. 5 According to one alternative embodiment the sorting devices may beindividually controllable by said control system.

Brief Description of the DrawinqsEmbodiments of the present solution will now be described, by way of example, with reference to the accompanying schematic drawings.

Fig. 1a is a schematic top view of a prior art sorting system Fig. 1b is a schematic top view of a sorting system according to thepresent disclosure.

Fig. 2a is a schematic top view of a prior art sorting system.

Fig. 2b is a schematic top view of a sorting system according to thepresent disclosure.

Fig. 3 is a schematic top view of a sorting unit.

Fig. 4 is a schematic top view of a sorting unit.

Description of Embodiments ln a central waste sorting facility, waste objects, such as containers orbags comprising different types of waste fractions, are collected to be sortedin an automated process in different material fractions.

The waste objects may be provided with means for identificationcorresponding to the waste fraction contained therein. ln the alternative the waste object may be sorted based on materialrecognition sensors, i.e. recognition of the waste object itself rather than onmeans of identification provided thereon. Such sorting is disclosed in forinstance EP2064004 B1.

The means for identification may be a specific colour of the bag, aspecific pattern arranged on the bag or an RFID-tag arranged on the bag, orany other means for identification suitable for waste sorting. Different meansmay also be combined.

Usually the waste objects are delivered to the waste sorting facility by arefuse collection vehicle or pneumatic transport system, where a mixture ofdifferent types of waste objects are is placed in a receiving bunker. The bagsor containers are moved from the receiving bunker into the sorting facility bemeans of conveyors.

The conveyors may be e.g. conventional belt conveyors or rotatingshaft (screw) conveyors. Often the bags are transported through a series ofconveyors in order to separate the bags from each other to make the detection and sorting of each individual object or bag easier. The speed of theconveyors is often increased gradually.

The objects 2 may be transported to a sorting conveyor 5 which isillustrated in Figs 1a and 1b. Fig. 1a illustrates a conventional system forsorting two different fractions, G and R. The waste objects 2 are transportedinto a first sorting unit 3, and each sorting unit 3 is provided with only onesorting device 27. ln Fig. 1b each sorting unit 4, 4' is provided with two (ormore) sorting devices 27. ln the sorting system of Fig. 1a the waste objects orbags provided with identification means R are sorted in the two firstconsecutive sorting units 3 and 3', and the bags with identification means Gare sorted in the second two consecutive sorting units 3" and 3"' and movedonto a second conveyor 6. ln the sorting system 1' illustrated in Fig. 1b theobjects provided with identification means R are sorted in the first sorting unit4 and the objects provided with identification means G are sorted in thesecond sorting unit 4'. lt is possible to sort the same amount of objects in thesorting system as disclosed in Fig. 1b as compared to the system in Fig. 1a,but the system takes up far less space and is also more efficient as will bedescribed below.

Figs 2a and 2b illustrate a sorting system 10 and 10' for sorting objectshaving different identifications means RBOP in a first sorting unit. This meansthat more than one fraction is sorted in the first sorting unit 13 and 14.

Fig 2a each illustrates a conventional sorting unit 10 which is providedwith one sorting device and also in a second sorting unit 13' objects havingdifferent identification means are RBOP sorted. These objects RBOP areconveyed onto a transport conveyor 16 onto a second sorting conveyor 17,for a new sorting in the consecutively arranged sorting units 18, 18', 19, 19',20, 20', 21, 21' for sorting of the R, B, O and P fractions in respective two (ormore) sorting units. The object G not being sorted in the first two sorting units13, 13' is sorted in the two (or more) consecutive second sorting units 13",13"'. ln Fig. 2b each sorting unit 14, 14', 22, 23, 24, 25 is provided with twosorting devices 27. ln the first sorting unit 14 objects having differentidentifications means RBOP are sorted onto a transport conveyor 16 andfurther onto a second sorting conveyor 17 along which a series of third sortingunits 22, 23, 24 ,25 are arranged. ln each of these third sorting units it ispossible to sort one fraction R, B, O, P respectively. The fraction G not beingsorted in the first sorting unit 14 is sorted in the second sorting unit 14' downstream the first sorting conveyor 15. Fig. 2b illustrate that a sortingfacility can be more compact, and which will be described below moreefficient in sorting waste objects.

Fig. 3 illustrates a sorting unit 10' having a sensor system 35 and twosorting devices 40. ln each of the sorting units described above the sorting unit is providedwith a sensor system 35. The sensor system is arranged to detectidentification means provided on the waste objects or as described above thematerial of the waste object itself. Different types of sensors have beendescribed in the prior art, such as cameras for colour and pattern recognitionor RFID-readers for RFID-tags. The sensor system is arranged to provide asignal to a control system, which, in turn, controls the sorting devices.

When a waste object 2 with a desired identification means is detectedby the sensor system, e.g. as in Fig. 1b when a waste bag with identificationmeans R passes through sorting unit 4, a signal is sent to a control system(not shown). The control system then provides the sorting device with a signalfor sorting the waste object R. By ““sorting” may be meant that the object iseither transferred to another conveyor for a second sorting, or into a sortingcontainer specific for that waste fraction. Fractions not sorted in the sortingunits may either be transferred to a sorting container or transported back intothe sorting facility or system for a renewed sorting, which is illustrated in Figs1a and 1b and Figs 2a and 2b where a waste object 2 is transporteddownstream 30 of either one of the sorting units.

As a waste object of a specific waste fraction passes by the sensorsystem the present parameters or identification means (i.e. colour, pattern,RFID etc.) are detected or identified and compared to predeterminedrequirements set in a control system. The parameters are then compared,individually orjointly to these predetermined requirements. lf the sensorsystem detects a waste fraction which fulfils the predetermined requirementsfor that sorting unit, i.e. is approved or desired for that sorting unit, the sensorsystem sends a signal to the control system. The waste objects may havedifferent predetermined requirements depending on the fraction theyrepresent and may be treated differently in the subsequent steps of thesorting unit.

The control system provides the control devices with a signaldepending on the requirements of the present fraction. lf the sensor systemdetects a desired object the control system may provide a signal to the sorting devices to activate the device or devices, i.e. an activation signal. By “activateor activation” is meant that the sorting device is made to act upon the signal,e.g. to remove the object from the conveyor.

According to one embodiment the control system may be arranged tocontrol each of the sorting devices individually. This means that the controlsystem may provide only one of the two (or more) sorting devices with anactivation signal, depending on the predetermined requirements of the wastefraction or e.g. on the position of the waste object on the conveyor. Thisallows for a greater flexibility and an improved sorting accuracy of the system.This also means that while one sorting device is activated, the second (orfurther) sorting device(s) may be activated independently as a response to adesired waste fraction being detected by the sensor system. The controlsystem may also send an activation signal to both (or more) sorting devicessimultaneously.

According to one alternative embodiment the control system may alsosend a signal to a sorting device of another sorting unit further downstream30 the sorting system or sorting line. For instance, in Fig. 1b if a wastefraction G which is approved for sorting unit 4' is detected in sorting unit 4 thecontrol system may send an activation signal to the sorting devices of sortingunit 4”.

According to one embodiment, as illustrated by Fig. 3 the sortingsystem may even comprise only one sensor system 28, e.g. arranged at thebeginning 40 of a sorting conveyor 5, or in the proximity of the sortingdevices, and the subsequent sorting unit 31, may then comprise two or moresorting devices 27, 27', 27", 27"', which are then controlled by that onesensor system 28, according to the same definitions and principles as set outabove. ln Fig. 3 the waste fractions 2 are sorted by the sorting devices ontoconveyors 51, 52, 53, 54, or directly into sorting containers. Fig. 3 thusillustrates that one sensor system 28 is arranged to control multiple sortingdevices 27 within one sorting unit 31. ln the sorting unit as illustrated by Fig. 3 the respective sorting devicesmay also be arranged to remove more than one fraction 2, B, O, P, R. Forinstance it could be possible to have sorting device 27 remove two fractions Rand P, sorting device 27' two fractions B and O etc. in any possiblecombination or number of fractions. 9 This may be a way to reduce the cost of the facility even further. Thecontrol system then regulates which of the sorting devices in the respectivesorting units that should be activated. ln Fig. 4 yet another embodiment is illustrated in which one sensorsystem 28 detects and controls two or more separate sorting units 32, 33, 34.The respective sorting units may comprise one or more sorting devices 27.The waste fractions 2, B, O, P, R may for instance be removed ontoconveyors 56, 57, 58 or directly into sorting containers. ln all of the above described sorting operations it is possible to allowthe sorted waste fractions to move on to a new identification and sorting,either by bringing them back into the inlet, or by moving them to anothersorting unit.

According to one embodiment the sorting device 27 may be a pushertype, i.e. comprise a blade, scraper or paddle which moves over the conveyorbelt to push or scrape the waste object from the conveyor. According toanother embodiment the sorting device 27 may comprise a compressed airdevice, where air is used to push the waste object off of the conveyor.According to yet an alternative the sorting device may be a robot device,which may either push or lift the waste object off of the conveyor. Accordingto another alternative the sorting device may comprise a suction device.According to yet another alternative the sorting device may comprise e.g. anopenable hatch or some type of opening at the bottom of the conveyor. Othertypes of sorting devices known to the skilled person may also be used in thepresent invention.

According to one embodiment the sensor system may detect where onthe conveyor surface the waste object is located. This means that if the wasteobject, or bag is located to the left and the sorting device is arranged to theright, it is possible to provide the sorting device with a signal such that itbegins the sorting movement over the conveyor earlier than it would if thewaste object was located at the right or middle of the conveyor.

According to an alternative system further may comprise a heightdetector to detect that it in fact is a bag or container that is conveyed on theconveyor. The height detector may be a photo sensor or laser or even acamera. This provides for a way of not providing the sorting device with asignal if there is no waste object to remove, i.e. that the sensor system hasdetected something other than a bag or container being conveyed on thecontainer.

Claims (11)

1. System (1 ”, 10') för sortering av avfallsföremàl (2), varvidavfallsföremälet är tillhandahället med medel för identifiering (RGBOP) därav,varvid systemet innefattar: minst en sorteringsenhet (4, 14, 22, 31, 32), varvid sorteringsenhetenär förbunden med minst ett sensorsystem (28) för identifiering av nämndaavfallsföremàl eller nämnda medel för identifiering, varvid nämndasensorsystem är anordnat att detektera ett eller flera medel för identifieringoch anordnat att tillhandahålla ett styrsystem med en signal när ettavfallsföremàl av en önskad typ är detekterat, minst en sorteringstransportör (5, 15, 17) för transport av nämndaavfallsföremàl till nämnda sorteringsenhet,kännetecknatavatt nämnda sorteringsenhet är tillhandahàllet med tvà eller flerasorteringsanordningar (27, 27') för sortering av avfallsföremàlen, varvidnämnda sorteringsanordningar är anordnade att ta emot minst en signal frànnämnda styrsystem som svar pà att ett avfallsföremàl av en önskad typ ärdetekterat av sensorsystemet, varvid nämnda flera sorteringsanordningar (27,27”) är anordnade att skjuta pà, lyfta eller suga avfallsföremàlen (2) frànsorteringstransportören (5, 15, 17), eller varvid nämnda flerasorteringsanordningar (27, 27”) är anordnade som minst en öppningsbarlucka.

2. System enligt krav 1, varvid nämnda sorteringsanordningar äranordnade att styras individuellt.

3. System enligt krav 1 eller 2, varvid sorteringsenheten ärtillhandahàllen med tvà sorteringsanordningar.

4. System enligt något av föregående krav, varvid avfallsföremåletär en behållare eller påse, och varvid nämnda behållare eller påse ärtillhandahållet med medel för identifiering.

5. System enligt krav 4, varvid nämnda medel för identifieringinnefattar något av färg, mönster, RFID-identifiering, eller en kombinationdärav.

6. System enligt krav 5, varvid sensorsystemet innefattar sensoreranordnade att kunna detektera minst ett av nämnda medel för identifiering eller en kombination därav.

7. System enligt något av föregående krav, varvidsorteringsanordningen innefattar ett blad.

8. Förfarande för sortering av avfallsföremål (2) i ettsorteringssystem (1 ”, 10”) enligt något av krav 1 till 6, varvid avfallsföremålenär tillhandahållna med medel för identifiering (RGBOP), och varvid förfarandetinnefattar följande steg att: tillhandahålla nämnda avfallsföremål (2) på minst ensorteringstransportör (5, 15, 17), detektera nämnda avfallsföremål (2) eller medel för identifiering(RGBOP) genom minst ett sensorsystem (28), anordnat i förbindelse medminst en sorteringsenhet (4, 14, 22, 23, 24, 25), tillhandahålla minst ett styrsystem med en signal när ett önskat föremåleller föremål tillhandahållet med önskade medel för identifiering detekteras avnämnda sensorsystem, k ä n n e t e c k n a t av att förfarandet vidare innefattarföljande steg att: tillhandahålla två eller flera sorteringsanordningar (27, 27”, 27", 27””)med en aktiveringssignal av nämnda styrsystem, som svar på att nämndaönskade föremål eller föremål tillhandahållet med önskade medel föridentifiering är detekterat, varvid nämnda flera sorteringsanordningar (27, 27”) är anordnade att skjuta pà, lyfta eller suga avfallsföremàlen (2) frànsorteringstransportören (5, 15, 17), eller varvid nämnda flerasorteringsanordningar (27, 27”) är anordnade som minst en öppningsbarlucka.

9. Förfarande enligt krav 8, varvid nämnda sorteringsanordningarär individuellt styrbara med nämnda styrsystem.

10. Förfarande enligt nàgot av krav 8 eller 9, varvidsorteringsanordningen innefattar ett blad.

11. Förfarande enligt nàgot av krav 8 till 10, varvid sensorsystemetinnefattar sensorer anordnande att kunna detektera minst ett av nämndamedel för identifiering eller en kombination därav.