METHOD AND ARRANGEMENT FOR THE SORTING OF REFUSE SACKS

Description

[0001] The present invention relates to a method and an arrangement for the sorting of refuse sacks according to the pre-characterising clause of claim 1 and claim 4 respectively.

[0002] A number of different types of refuse occur in present-day communities. Economic and environmental handling of this refuse requires that it be sorted at source and thereafter transported to a sorting plant, for example, where the various fractions of the refuse sorted at source are sorted out for further processing according to the content of each fraction. It is important that each separated fraction containing refuse sorted at source be unadulterated. It is therefore essential that the refuse be correctly sorted at source and that the refuse sorted at source be sorted with as few errors as possible. Furthermore the investment and operating costs, for example, of arrangements for the separation of refuse sorted at source must be minimised. For example, the total energy consumption expended in refuse handling should not exceed that recovered from the sorted material or saved in a recycling system.

[0003] SE 507 257 (corresponding to WO-A-96/22512), for example, discloses a method of the aforementioned type. According to the method each refuse sack is assigned a predetermined means of identification, such as colour coding, for each refuse fraction, by means of which sacks are sorted. The refuse sacks are transported along a conveyor and are sorted by successively identifying and separating each refuse sack having a predetermined means of identification. SE 517 667 (corresponding to WO-A-03/039773) discloses a method of sorting for identifying sacks having a means of identification, but in contrast to the aforementioned method it is refuse sacks not having a predetermined means of identification that are separated out. In the sorting of refuse sacks provided with means of identification, there is a general desire to achieve a greater number of unadulterated fractions of refuse sacks, low energy consumption and low costs.

[0004] The object of the present invention is to provide a method that is improved in the aforementioned respects.

[0005] This object is achieved by the features specified in the characterising part of claim 1.

[0006] A further object of the invention is to provide an arrangement for performing the method according to the invention. This is achieved by an arrangement having the characteristics specified in claim 4.

[0007] The invention affords lower sorting-related costs and lower energy consumption. Furthermore, the sorting can be performed with few errors, which is important in obtaining unadulterated fractions, which is in turn important for processable fractions, as in the manufacture of biogas, composts and in other material recycling.

[0008] The invention will be explained in more detail here with reference to the following examples and the drawing attached, in which Fig. 1 in a schematic plan view from above shows an example of an arrangement for carrying out the sorting of two selected fractions of refuse sacks according to a known method and Fig. 2 similarly shows an example of an arrangement for carrying out sortings of two selected fractions of refuse sacks according to the present invention with the same degree of adulteration of the residual fraction and essentially the same capacity. Like Figs. 1 and 2, Figs. 3 and 4 show two comparative examples of the sorting of five selected fractions of refuse sacks according to a known method and according to the present invention, it being possible here also to carry out the sorting with the same degree of adulteration of the residual fraction and essentially the same capacity.

[0009] In an example of the sorting of two different colour-coded, randomly distributed fractions of refuse sacks shown in Fig. 1, these are placed at respective feed inputs 2a, 2b, 2c in a sorting plant, generally denoted by 1, with three sorting channels working in parallel in order to achieve the required sorting capacity, before then being transported on conveyors 3a, 3b, 3c arranged in series one after the other with a certain interval between individual sacks along each conveyor, to be identified at successively arranged sorting stations 4a-9a, 4b-9b and 4c-9c in order to separate red (R) and green (G) colour-coded sacks. The sacks provided with red (R) colour coding are identified and separated at the first three sorting stations 4a-6a, 4b-6b, 4c-6c and thereafter the sacks provided with green (G) colour coding are identified and separated at the three succeeding sorting stations 7a-9a, 7b-9b, 7c-9c. Separating sacks identifiable by the same colour at multiple succeeding sorting stations in this way naturally increases the capacity but primarily improves the unadulterated nature of the unseparated residual fraction, that is to say the sacks which have not been identified at any earlier sorting station. As stated, it is also possible to use multiple parallel sorting conveyors.

[0010] In the sorting performed according to the invention of two differently colour-coded, randomly distributed fractions of refuse sacks illustrated in Fig. 2, these are placed and transported in a similar way to that in the example above. The sacks provided with red (R) colour coding are identified and separated at the first two sorting stations 4a, 5a, 5b, 4b, 5b, 4c, 5c and thereafter the sacks provided with green (G) colour coding are identified and separated at the two succeeding sorting stations 7a, 8a, 7b, 8b, 7c, 8c. At a final sorting station both sacks with red (R) and green (G) colour coding are identified and separated in order to finally transport the separated sacks back to the feed input for renewed sorting as indicated by the conveyor belt 11. By sorting in this way a considerable improvement in the degree of adulteration of the residual fraction is achieved using fewer sorting stations than in the comparative example described above.

[0011] In order to further explain the advantages of the invention, the sorting of five differently colour-coded, randomly distributed refuse sacks containing different refuse fractions according to a known method and according to the method of the invention will be demonstrated with reference to Figs. 3 and 4. As has been explained in connection with Fig. 1, the refuse sacks are placed and transported on three parallel sorting conveyors 3a, 3b, 3c each having the sorting stations 4a-4c, 5a-5c, 7a-7c, 8a-8c, 11a-11c, 12a-12c, 13a-13c. Here the sacks provided with red (R), green (G), blue (B) orange (O) and grey (GR) colour coding are identified and separated in such a way that on each sorting conveyor 3a-3c the sacks provided with red (R) colour coding are separated from the other sacks at the first two sorting stations 4a-4c, 5a-5c, and sacks provided with green (G) colour coding are then separated at the two succeeding sorting stations 7a-7c, 8a-8c. Refuse sacks with blue (B), orange (O) or grey (GR) colour coding are identified and separated at the three succeeding sorting stations 11a-11-c, 12a-12c, 13a-13c. In this example, therefore, 21 sorting stations are needed.

[0012] In a sorting according to the invention of five differently colour-coded, randomly distributed refuse sacks the refuse sacks are placed and transported as illustrated in Fig. 4. The first four sorting stations 4a-4c, 5a-5c, 7a-7c, 8a-8c produce a separation of sacks provided with red (R) and green (G) colour coding. In a final sorting station (14a-14c) for each conveyor 3a-3c sacks provided with blue (B), orange (O) or grey (GR) colour coding are simultaneously identified and separated onto yet another sorting conveyor 15. Along this are three successively arranged sorting stations 16, 17, 18 in which sacks provided with blue (B), orange (O) or grey (GR) colour coding are identified and separated. The residual fraction from this conveyor is transported back to the inlet feed (2a, 2b, 2c) for renewed sorting. With this method according to the invention for sorting the five different fractions, the degree of adulteration achieved corresponds to that obtained in the example of the prior art, but is achieved with a smaller number of sorting stations, that is, in this example, 18 stations.

[0013] It will also be appreciated that the person skilled in the art is capable of selecting variants of sorting stations and combinations thereof, and of selecting the number and location of sorting conveyors with suitable sorting stations according to requirements.

Claims

1. Method of sorting randomly distributed refuse sacks containing different types of refuse sorted at source, each refuse sack having a means of identification (R, G, B; O, GR) for each type of refuse sorted at source and the sorting involving transport of the refuse sacks for them to be identified in successive sorting stations and separated so that refuse sacks having a predetermined means of identification for each sorting station are sorted out at the sorting station intended for this purpose, characterised in that in at least one sorting station (10a, 10b,10c; 14a, 14b, 14c) at least two means of identification (R, G; B, O, GR) predetermined for the sorting station are selectively identified and the corresponding refuse sacks separated, each of these having any of the selectively identified means of identification.

2. Method according to Claim 1, characterised in that refuse sacks which have been transported and undergone a successive sorting without being separated, are transported back for renewed sorting.

3. Method according to Claim 1 or 2, characterised in that a predetermined colour is used as means of identification for each type of refuse.

4. Arrangement for the sorting of refuse sacks comprising a transporting arrangement designed to transport randomly distributed refuse sacks containing different types of refuse sorted at source, each refuse sack having a means of identification (R, G; B, O, GR) for the type of refuse in the sack, a number of successively arranged sorting stations each comprising a sensor selectively sensitive to the respective means of identification and designed to emit a signal when a refuse sack passes which has a means of identification predetermined for the sensor and to which the sensor is sensitive, and separating elements designed, in response to a signal from the sensor, to undertake separation of the refuse sack in question from the transporting arrangement, characterised in that the sensing arrangement in at least one sorting station is sensitive to at least one further predetermined means of identification (R, G, B, O, GR) on refuse sacks containing another type of refuse.

Ansprüche

1. Verfahren zum Sortieren zufällig angeordneter Müllsäcke, die unterschiedliche Arten von am Ursprung sortierten Mülls enthalten,
wobei jeder Müllsack ein Identifikationsmittel (R, G, B, O, GR) für jede Art von am Ursprung sortierten Mülls hat und das Sortieren den Transport der Müllsäcke einbezieht, damit diese in nacheinander angeordneten Sortierstationen erkannt und abgesondert werden, so dass Müllsäcke mit einem für jede Sortierstation vorgegebenen Identifikationsmittel an der für diesen Zweck vorgesehenen Sortierstation aussortiert werden,
dadurch gekennzeichnet, dass in mindestens einer Sortierstation (10a, 10b, 10c; 14a, 14b, 14c) mindestens zwei für die Sortierstation vorgegebene Identifikationsmittel (R, G, B, O, GR) wahlweise erkannt und die entsprechenden Müllsäcke abgesondert werden,
wobei jeder von diesen irgendeines der wahlweise erkannten Identifikationsmittel hat.

2. Verfahren nach Anspruch 1,
dadurch gekennzeichnet, dass Müllsäcke, die transportiert wurden und eine nacheinander erfolgende Sortierung durchliefen, ohne abgesondert worden zu sein, für ein erneutes Sortieren zurück transportiert werden.

3. Verfahren nach Anspruch 1 oder 2,
dadurch gekennzeichnet, dass eine vorgegebene Farbe als Identifikationsmittel für jede Art von Müll genutzt wird.

4. Vorrichtung für das Sortieren von Müllsäcken, umfassend:

eine Transportvorrichtung , welche so gestaltet ist, dass zufällig angeordnete Müllsäcke, die verschiedene Arten von am Ursprung sortierten Mülls enthalten, transportiert werden,

wobei jeder Müllsack über ein Identifikationsmittel (R, G, B, O, GR) für die Art des Mülls im Sack verfügt,

eine Anzahl von nacheinander angeordneten Sortierstationen, von denen jede einen Sensor enthält, welcher wahlweise auf das zugehörige Identifikationsmittel reagiert und so gestaltet ist, dass ein Signal abgegeben wird, wenn ein Müllsack den Sensor passiert, welcher ein Identifikationsmittel hat, das dem Sensor zugeordnet ist und auf welches der Sensor reagiert, und

Trennelemente, die so gestaltet sind, dass sie in Erwiderung des Sensorsignals eine Absonderung des besagten Müllsacks von der Transportvorrichtung vornehmen,

dadurch gekennzeichnet, dass die Sensorvorrichtung in mindestens einer Sortierstation auf mindestens ein weiteres vorgegebenes Identifikationsmittel (R, G, B, O, GR) von Müllsäcken, die eine andere Art von Müll enthalten, reagiert.

Revendications

1. Procédé de tri de sacs de déchets distribués aléatoirement contenant différents types de déchets triés à la source, chaque sac de déchets ayant un moyen d'identification (R, G, B, O, GR) pour chaque type de déchets triés à la source et le tri impliquant le transport des sacs de déchets pour qu'ils soient identifiés dans des postes de tri successifs et séparés de sorte que les sacs de déchets ayant un moyen prédéterminé d'identification pour chaque poste de tri soient triés au poste de tri destiné à cet effet, caractérisé en ce que dans au moins un poste de tri (10a, 10b, 10c ; 14a, 14b, 14c) au moins deux moyens d'identification (R, G, B, O, GR) prédéterminés pour le poste de tri sont sélectivement identifiés et les sacs de déchets correspondants sont séparés, chacun d'eux ayant l'un quelconque des moyens sélectivement identifiés d'identification.

2. Procédé selon la revendication 1, caractérisé en ce que les sacs de déchets qui ont été transportés et qui ont subi un tri successif sans être séparés, sont retournés pour un nouveau tri.

3. Procédé selon la revendication 1 ou 2, caractérisé en ce qu'une couleur prédéterminée est utilisée comme moyen d'identification pour chaque type de déchets.

4. Dispositif de tri de sacs de déchets comprenant un dispositif de transport conçu pour transporter des sacs de déchets distribués aléatoirement contenant différents types de déchets triés à la source, chaque sac de déchets ayant un moyen d'identification (R, G, B, O, GR) pour le type de déchets dans le sac, un certain nombre de postes de tri agencés successivement, chacun comprenant un capteur sensible sélectivement au moyen d'identification respectif et conçu pour émettre un signal lorsque passe un sac de déchets ayant un moyen d'identification prédéterminé pour le capteur et auquel le capteur est sensible, et des éléments de séparation conçus, en réponse à un signal du capteur, pour entreprendre la séparation du sac de déchets en question du dispositif de transport, caractérisé en ce que le dispositif de détection dans au moins un poste de tri est sensible à au moins un autre moyen prédéterminé d'identification (R, G, B, O, GR) sur des sacs de déchets contenant un autre type de déchets.

Drawing