DEVICE AND METHOD FOR WASTE SEPARATION

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of sorting, and in particular to the automation of sorting using a rotary machine, in particular to carry out the sorting of waste, with a view to its treatment, in particular its recycling or its recovery.

[0002] The invention relates more specifically to a rotary sorting machine for a mixture of waste, the latter being of heterogeneous sizes, shapes and consistencies, the mixture of waste comprising at least biodegradable waste and non-biodegradable recyclable waste.

[0003] The invention also relates to a method for sorting a mixture of waste of heterogeneous sizes, shapes and consistencies, comprising at least biodegradable waste and non-biodegradable recyclable waste, a non-negligible portion of the mass of the waste mixture being formed by biodegradable waste, for example at least 10% of the mass, and a non-negligible portion of the mass of the mixture being formed by non-biodegradable recyclable waste, for example at least 10% of the mass. PRIOR TECHNIQUE

[0004] To sort a mixture of dirty, sticky, or clogging-prone objects, or a mixture of heavy objects such as rubble, a rotary trommel can be used. Known rotary trommels are generally formed by a rotating screening chamber around its longitudinal axis, which is slightly inclined relative to the horizontal, the wall of the screening chamber being provided with calibrated through-separation orifices. Thanks to these orifices, the wall of the chamber allows for segregation of objects by size, making it possible to separate, on the one hand, passing objects, whose size is smaller than the size of the separation orifices, and, on the other hand, rejected objects, whose size is larger than the mesh size of the separation orifices.Thus, when objects to be sorted are introduced into the enclosure, for example at one end, a flow of objects passes through the separating wall, and a flow of rejected objects is formed, which are generally destined to exit through the other end of the enclosure. The objects to be sorted generally move through the enclosure under the influence of gravity, with the first end being positioned higher than the second end.

[0005] While this type of known rotating trommel is generally satisfactory for certain types of objects, it appears that it could be improved to allow better separation of objects, in particular for waste-type objects, the segregation of which by type (biodegradable waste, non-biodegradable recyclable waste, non-recyclable waste) is often made difficult due to their great heterogeneity in size, shape, consistency, and density, as well as their generally sticky or greasy nature.

[0006] GB-127,783 A describes a round drum, with four decks dividing the interior of the drum into four parts and with auger blades for continuous movement of materials, for screening materials such as coke, coke dust sand and gravel, whinstone clinker slag coal ballast, etc.

[0007] Document FR-2 977 813 A1 describes a process, and corresponding device, for adjustable granulometric sorting of waste in operation comprising the steps of separating according to an adjustable cut of products according to their granulometry a set of unit wastes, collecting a fraction produced on a mobile conveyor, ensuring the sealing between the fractions produced in the whole range of variation, making the adjustments without interrupting production, adapting the sealing partition in the whole range of variation, and controlling the position of the shuttle conveyor to physical quantities observed on the downstream flows. STATEMENT OF THE INVENTION

[0008] The objects assigned to the present invention therefore aim to remedy the various drawbacks listed above and to propose a new sorting machine and a new sorting method making it possible to effectively sort a particularly heterogeneous mixture of waste.

[0009] Another object of the invention is to propose a new sorting machine and a new sorting method making it possible to sort household waste, from economic or industrial activities, in an efficient manner.

[0010] Another object of the invention aims to propose a new sorting machine and a new sorting process to ensure good quality sorting.

[0011] Another object of the invention is to propose a new sorting machine and a new sorting process that are particularly versatile and universal.

[0012] Another object of the invention is to propose a new sorting machine and a new sorting method which is inexpensive and easy to implement.

[0013] Another object of the invention is to propose a new sorting machine which is particularly easy to maintain.

[0014] Another object of the invention is to propose a new sorting machine and a new sorting method for which the risk of clogging is particularly low.

[0015] The objects assigned to the invention are achieved using a rotary sorting machine according to claim 1 of a mixture of waste, the latter being of heterogeneous sizes, shapes and consistencies, the mixture of waste comprising at least biodegradable waste and non-biodegradable recyclable waste, said sorting machine being characterized in that it comprises at least: a first trommel section, provided with a first separating wall extending over a first axial length and being provided with a first series of through separating orifices for separating the waste mixture into a first fraction of waste passing through said first separating wall via the first series of separating orifices and into a second residual fraction of waste, the waste mixture being intended to circulate along said first wall to be thus separated, and a second trommel section, provided with a second separating wall extending over a second axial length less than the first length,said second separation wall being provided with a second series of through separation orifices allowing the second residual waste fraction to be separated into a sub-fraction of small waste passing through said second separation wall via said second series of separation orifices and into a residual large waste sub-fraction, the large waste sub-fraction being formed by waste whose size is greater than the small waste sub-fraction, the second residual waste fraction being intended to flow along said second wall to be separated in this way, said second series of separation orifices comprising at least tertiary orifices allowing at least to contribute to separating the second residual waste fraction according to the small waste sub-fraction and according to the large waste sub-fraction by passage of the small waste sub-fraction through said tertiary orifices,said tertiary orifices being of oblong section, and said oblong section having a small diameter, and a large diameter, the tertiary orifices being distributed in successive rows along the second length, alternating at least: o a longitudinal row of tertiary orifices, in which the large diameter of the tertiary orifices of the straight row is aligned in the direction of the second length, and o a transverse row of tertiary orifices, in which the small diameter of the tertiary orifices of the transverse row is aligned in the direction of the second length.

[0016] The objects of the invention are also achieved using a sorting process according to claim 10 for sorting a mixture of waste of heterogeneous sizes, shapes and consistencies, comprising at least biodegradable waste and non-biodegradable recyclable waste, a non-negligible portion of the mass of the waste mixture being formed by biodegradable waste, for example at least 10% of the mass, and a non-negligible portion of the mass of the mixture being formed by non-biodegradable recyclable waste, for example at least 10% of the mass, said sorting process being characterized in that, successively: the waste mixture is introduced into a first trommel section, provided with a first separating wall extending over a first axial length and being provided with a first series of through separating orifices, the waste mixture is separated into a first waste fraction passing through said first separating wall via the first series of separating orifices and into a second residual waste fraction, the waste mixture flowing along said first wall to be thus separated, the second residual waste fraction is passed from the first trommel section to a second trommel section, provided with a second separating wall extending over a second axial length less than the first length, said second separating wall being provided with a second series of through separating orifices,The second residual waste fraction is separated into a sub-fraction of small waste passing through said second separation wall via said second series of separation orifices and into a residual large waste sub-fraction, the large waste sub-fraction being formed by waste whose size is greater than the small waste sub-fraction, the second residual waste fraction being intended to flow along said second wall to be thus separated, said second series of separation orifices comprising at least tertiary orifices enabling at least to contribute to separating the second residual waste fraction according to the small waste sub-fraction and according to the large waste sub-fraction by passage of the small waste sub-fraction through said tertiary orifices, said tertiary orifices being of oblong cross-section, and said oblong cross-section having a small diameter,and a large diameter, the tertiary orifices being distributed in successive rows along the second length, alternating at least: o a longitudinal row of tertiary orifices, in which the large diameter of the tertiary orifices of the straight row is aligned in the direction of the second length, and o a transverse row of tertiary orifices, in which the small diameter of the tertiary orifices of the transverse row is aligned in the direction of the second length. SUMMARY DESCRIPTION OF THE DRAWINGS

[0017] Other features and advantages of the invention will appear and emerge in more detail on reading the description given below, with reference to the appended drawings, given solely by way of illustrative and non-limiting example, in which: There figure 1represents, according to a schematic perspective view, a longitudinal section of the sorting machine according to the invention, showing in particular the interior of a first and a second trommel section of said sorting machine, comprising respectively a first separating wall and a second separating wall. figure 2 represents, according to a schematic front view, a detail of the construction of the first dividing wall of the figure 1 . There figure 3 illustrates, according to a schematic front view, a detail of the construction of the second dividing wall of the figure 1 There figure 4 illustrates a waste treatment process in which the waste sorting machine figures 1 to 3 can be used advantageously. BEST WAY TO CARRY OUT THE INVENTION

[0018] The invention relates, as such, to a rotary sorting machine 1 for sorting a waste mixture 2. The purpose of this sorting machine 1 of the invention is to organize the waste from said waste mixture 2, by classifying and separating the waste it contains into categories according to their nature or specific characteristics. The waste thus sorted by the sorting machine 1 can in this way advantageously be subject to subsequent treatments, for example treatments which could not be carried out when said waste is in the initial waste mixture 2 state, such as recycling, composting, or conversion into solid recovered fuel.

[0019] A non-exhaustive and non-limiting example of a sorting machine 1 according to the invention is illustrated in figure 1 . Such a sorting machine 1 is advantageously implemented in an industrial waste treatment process.

[0020] The waste mixture 2 is preferably formed by household waste, but may also be formed by waste from economic or industrial activities, or both, said waste not having undergone any prior sorting or grinding. This waste mixture 2 is thus advantageously formed from waste generated by households, during their consumption and daily life.

[0021] Preferably, the waste mixture 2 has not undergone any treatment and constitutes a raw waste mixture 2. In particular, no grinding of the raw waste mixture has been carried out, nor has any prior sorting been performed to segregate one type of waste from another, and especially to separate biodegradable waste from non-biodegradable recyclable waste. Preferably, the waste mixture 2 has been collected, for example, using garbage trucks, from households and / or economic activities without said households and / or economic activities having carried out any prior sorting or selection of the collected waste. In particular, the collection of the waste mixture 2 has not been selective. Thus, according to a particularly advantageous embodiment of the invention, the process of the invention is a process for treating a raw, unground waste mixture.

[0022] Of course, without departing from the scope of the invention, the waste mixture 2 may on the contrary have been stripped of a portion of the recyclable waste that it contains, for example by households during pre-sorting, or have itself been the subject of pre-sorting, for example by households.

[0023] The waste from waste mixture 2 is advantageously collected in a raw and undifferentiated form, mixed together in bags, such as plastic garbage bags closed by households. The process includes a preliminary step of opening said bags to release the waste they contain individually, thus forming waste mixture 2 according to the invention, which is a grouping of the waste initially contained in said bags. The opening of the waste bags can be carried out, for example, using a bag opening device, to allow the release of the waste from said bags, preferably without damaging or altering said waste.

[0024] In particular, due to the lack of prior sorting before the waste mixture 2 enters the treatment process of the invention, the waste is of heterogeneous sizes, shapes, and consistencies, preferably of varied nature and origin. The waste mixture 2 thus considered may include, in particular, soft, hard, sharp, liquid, powdery, solid, flat, hollow, solid, sticky, slippery, greasy, brittle, flexible, compressible, incompressible, combustible, incombustible waste, or waste combining several of these characteristics. The waste mixture 2 contains primarily used and unwanted elements, for example, food waste, newspapers, paper, cardboard, glass, plastic, metal, textiles, various combustibles and non-combustibles, complex materials, household hazardous waste, inert waste, and bulky waste.

[0025] According to the invention, the waste mixture 2 comprises at least biodegradable waste and non-biodegradable waste, the biodegradable waste advantageously forming a significant portion of the waste mixture 2, for example at least 10% of the mass of the latter.

[0026] Advantageously, at least 10%, preferably at least 20%, of the mass of the waste mixture 2 is formed by biodegradable waste, and at least 10%, preferably at least 20%, of the mass of the mixture is formed by non-biodegradable recyclable waste.

[0027] For the purposes of the invention, the term “ wastebiodegradable » means waste which, under the action of a natural environment, including for example living organisms and / or air and / or water, can naturally and spontaneously decompose into various elements likely to damage the natural environment (high oxygen demand, emission of leachates) if it has not been stabilized, for example by composting. Living organisms can in particular be formed by micro-organisms such as bacteria, fungi or algae, which are likely to degrade biodegradable waste using biochemical reactions. The term "biodegradable" is preferably understood to mean: biodegradable waste » waste which can be degraded in this way on the time scale of a human life, a decade, or more preferably a year or a few months, preferably a few weeks. The term " biodegradable waste» waste likely to be used in the manufacture and formation of compost by composting the latter.

[0028] Waste non-biodegradable ", within the meaning of the invention, forms other waste, which does not spontaneously and naturally undergo such degradation, or which undergoes it too slowly. The waste " non-biodegradable ", are particularly unsuitable for entering into the formation of compost by composting the latter.

[0029] A piece of waste recyclable", within the meaning of the invention, forms a waste that can be easily transformed, for example chemically or mechanically, to form a recycled material similar to a raw material, which can be used, for example, in the manufacture of an object. The term "recyclable waste" preferably excludes biodegradable waste, even if its transformation into compost gives it, in practice, a recyclable character. Within the meaning of the invention, recyclable waste may include, for example: non-metallic waste, in particular polymers, glass, paper, cardboard, newspapers, rubble, wood, textiles, electronics, etc. metallic waste, formed by all types of metals.

[0030] For the purposes of the invention, the term “ non-recyclable waste " refers to any waste not falling into the categories described above of the " recyclable waste » and « biodegradable wasteIn particular, non-recyclable waste includes waste with a calorific value that makes it suitable for conversion into solid recovered fuels, and other unusable ultimate waste (complex waste, etc.) intended for landfill or incineration, for example.

[0031] According to the invention, the sorting machine 1 comprises at least a first trommel section 3, provided with a first separation wall 5 extending over a first axial length L1 and being provided with a first series of separation orifices 7, 8 passing through it making it possible to separate the waste mixture 2 into a first waste fraction 13 passing through said first separation wall 5 via the first series of separation orifices 7, 8 and into a second residual waste fraction 14, the waste mixture 2 being intended to circulate along said first wall to be thus separated.

[0032] The first trommel section 3 is designed to receive the waste mixture 2 within it to carry out a first sorting thereof. Said first trommel section 3 of the invention is designed to bring the waste mixture 2 into contact with the first separation wall 5. Upon contact with the latter, the waste mixture 2 is sieved and / or filtered, said first separation wall 5 being porous, so as to allow the passage through it of the first waste fraction 13, and to prevent the passage through it of the second residual waste fraction 14. Preferably, the first waste fraction 13 is formed by waste whose size is smaller, on average, than that of the second residual waste fraction 14.

[0033] The separation orifices 7, 8 of the first series of separation orifices 7, 8 are arranged through the first separation wall 5, so as to make it porous, and are calibrated to allow exclusively the first fraction of waste 13 to pass through them, the elements of which are finer than those of the second residual fraction of waste 14, in the manner of a sieve.

[0034] The waste mixture 2 is intended to progress, for example by gravity, along the first separation wall 5 over the entire first length L1. The latter advantageously represents the porous length of the first separation wall 5, that is to say the useful length pierced by the first series of separation orifices 7, 8.

[0035] The first fraction of waste 13 is evacuated from the first trommel section 3 using gravity, for example, into a first hopper 12 placed below the first trommel section 3. The second residual fraction of waste 14 advantageously remains channeled within the first trommel section 3, and is brought to pass into the second trommel section 4.

[0036] Since the waste mixture 2 first passes into the first trommel section 3, the latter preferably makes it possible to separate therefrom the waste with the highest density, with the greatest dynamic inertia, the most sticky, greasy, dirty and humid waste from the waste mixture 2. The first waste fraction 13 is thus advantageously mainly formed by waste having such properties. In this case, the first waste fraction 13 thus mainly concentrates organic and / or biodegradable waste, which most of the time has the aforementioned properties. Thus, preferably, a significant portion of the mass of the first waste fraction 13 is formed by biodegradable waste, for example at least 50% of the mass of the first waste fraction 13, or even at least 60%, or even preferably at least 80%.Also, a significant portion of the mass of the second residual fraction of waste 14 is advantageously formed by non-biodegradable recyclable waste, for example at least 10% of the mass, which may eventually be separated and recovered later.

[0037] The first fraction of waste 13 may advantageously be subject to a composting process comprising in particular the following successive stages: Step A: the first fraction of waste 13 is subjected to a first composting cycle so as to at least partially compost the biodegradable waste of said first fraction of waste 13, and to obtain a mixture of pre-composted waste, Step B: the mixture of pre-composted waste is subjected to drying to obtain a mixture of dried waste, Step C: the mixture of dried waste is separated into at least one portion of heavy waste and one portion of light waste, the portion of heavy waste being formed by waste with a higher density than the waste of the portion of light waste, the heavy waste being able to be recycled, Step D: the portion of light waste is subjected to a second composting cycle so as to at least partially compost the biodegradable waste it contains, and to obtain a mixture of refined waste.The mixture of refined waste advantageously forms compost, preferably satisfying the NF U 44-051 standard. The NF U 44-051 standard of 2006, called “. Organic amendments - Designations, specifications and marking ", is a French standard.

[0038] Of course, without departing from the scope of the invention, the first fraction of waste 13 may be treated differently.

[0039] Preferably, as illustrated in figures 1 and 2, the first series of separation orifices 7, 8 comprises at least primary orifices 7 making it possible at least to contribute to separating the waste mixture 2 according to the first waste fraction 13 and according to the second residual waste fraction 14 by passage of the first waste fraction 13 through said primary orifices 7, the latter being of a size adapted to prevent the passage of waste of a size greater than 80 mm. Thus, only waste sufficiently small to form the first waste fraction 13 is allowed to pass through the primary orifices 7, in this preferred case. The size of the primary orifices 7 thus chosen preferably makes it possible to carry out a good quality selection of the biodegradable waste, that is to say it makes it possible to obtain a high concentration of biodegradable waste in the first waste fraction 13.For this purpose, the primary orifices 7 are preferably of circular section, and of a diameter between 85 mm and 95 mm, preferably approximately 90 mm. It should be considered that, in particular to adapt to the composition of the waste mixture 2, other sizes and shapes of primary orifices 7 may be envisaged without departing from the scope of the invention, for example polygonal, oblong, smaller size, or larger size.

[0040] The primary orifices 7 are advantageously distributed regularly, so as to form a mesh, over the majority of the surface of the first separation wall 5.

[0041] Advantageously, and as illustrated in the figure 1, the first series of separation orifices 7, 8 also comprises secondary orifices 8 making it possible to contribute to separating the waste mixture 2 according to the first waste fraction 13 and according to the second residual waste fraction 14 by passage of the first waste fraction 13 through said secondary orifices 8, the latter being of a size adapted to allow the passage of waste whose size is between 1 and 1.5 times the size of the waste whose passage is allowed by the primary orifices 7, the secondary orifices 8 being arranged upstream of the primary orifices 7, in consideration of the direction of circulation of the waste mixture 2.

[0042] Unlike conventional trommels, the first separating wall 5 advantageously has a decreasing porosity along its first length L1, so that the waste mixture 2 is first brought into contact with the secondary orifices 8, then with the primary orifices 7, the size of the secondary orifices 8 being greater than the size of the primary orifices 7. The secondary orifices 8 are preferably of circular section, and of a diameter between 105 mm and 115 mm, preferably approximately 110 mm. It should be considered that, in particular to adapt to the composition of the waste mixture 2, other sizes and shapes of secondary orifices 8 may be envisaged without departing from the scope of the invention, for example polygonal, oblong, smaller size, or larger size.

[0043] The secondary orifices 8 are preferably distributed regularly, so as to form a mesh, over a minor portion of the surface of the first separation wall 5 which is unoccupied by the primary orifices 7. The secondary orifices 8 are advantageously distributed over approximately one eighth of the first length L1, the primary orifices 7 occupying substantially the entire remaining length.

[0044] Distributed over such a short length, the secondary orifices 8 allow the first waste fraction 13 to include only a portion of waste larger than that permitted by the primary orifices 7 and contained in the waste mixture 2. Particularly advantageously, such a design makes it possible to ensure that the second residual waste fraction 14 contains a smaller, or even substantially zero, proportion of biodegradable waste, even if a larger proportion of non-biodegradable waste is likely to be introduced into the first waste fraction 13.

[0045] Therefore, preferably, a significant portion of the mass of the second residual waste fraction 14 is formed by recyclable waste, for example at least 50% of the mass of the second residual waste fraction 14, or even at least 60%, or even preferably at least 80%. Also, a significant portion, but as small as possible, of the mass of the first waste fraction 13 is advantageously formed by biodegradable waste, which may possibly be separated and recovered later. Preferably, less than 40% of the mass of the second residual waste fraction 14 is formed at this stage of biodegradable waste, preferably less than 25%, or even less than 10%.

[0046] According to the invention, the sorting machine 1 also comprises a second trommel section 4, provided with a second separation wall 6 extending over a second axial length L2, said second separation wall 6 being provided with a second series of separation orifices 9 passing through it making it possible to separate the second residual fraction of waste 14 into a small waste sub-fraction 15 passing through said second separation wall 6 via said second series of separation orifices 9 and into a residual large waste sub-fraction 16, the large waste sub-fraction 16 being formed by waste whose size is greater than the small waste sub-fraction 15, the second residual fraction of waste 14 being intended to circulate along said second wall to be thus separated.

[0047] The second trommel section 4 is designed to receive the second residual waste fraction 14, coming from the first trommel section 3, to perform a second sorting of said second residual waste fraction 14. The second trommel section 4 of the invention is provided to bring the second residual waste fraction 14 into contact with the second separation wall 6. Upon contact with the latter, the second residual waste fraction 14 is sieved and / or filtered, said second separation wall 6 being porous, so as to allow the passage through itself of the small waste subfraction 15, and to prevent the passage through itself of the large waste subfraction 16.

[0048] The separation orifices 9 of the second series of separation orifices 9 are arranged through the second separation wall 6, so as to make it porous, and are calibrated to allow exclusively the small waste sub-fraction 15 to pass through them, the elements of which are finer than those of the large waste sub-fraction 16, in the manner of a sieve.

[0049] The second residual waste fraction 14 is intended to progress, for example by gravity, along the second separation wall 6 over the entire second length L2. The latter advantageously represents the porous length of the second separation wall 6, that is to say the useful length pierced by the second series of separation orifices 9.

[0050] As illustrated in the figure 1The small waste subfraction 15 is discharged from the second trommel section 4, for example by gravity, into a second hopper 17 located below the second trommel section 4. The large waste subfraction 16 preferably remains channeled within the second trommel section 4 and is discharged from it. Preferably, the second trommel section 4 has a reject outlet through which the large waste subfraction 16 is discharged from said second trommel section 4. The reject outlet 21 advantageously leads to a discharge hopper 18 connected to the end of the second trommel section 4, into which the large waste subfraction 16 falls by gravity.

[0051] To the extent that the second residual waste fraction 14 is preferably substantially free of biodegradable, dirty, sticky and / or high density waste, which has been removed by the first trommel section 3, the second trommel section 4 preferably allows sorting of the waste, including in particular recyclable waste, present in the second residual waste fraction 14. In particular, it preferably allows isolation of relatively large waste contained in the large waste subsection 16, which may, for example, be subject to manual sorting of biodegradable waste, recyclable waste and non-recyclable waste. The smaller waste advantageously contained in the small waste subsection 15 may, for example, be subject to automated sorting aimed at separating biodegradable waste, recyclable waste and non-recyclable waste.In any event, the subsequent sorting carried out on the small waste subsection 15 and on the large waste subsection 16 is advantageously facilitated, insofar as the waste is, at this stage, substantially cleaned of organic and / or biodegradable, sticky, dirty and nauseating waste.

[0052] According to the invention, the second series of separation orifices 9 comprises at least tertiary orifices 9 making it possible at least to contribute to separating the second residual fraction of waste 14 according to the small waste sub-fraction 15 and according to the large waste sub-fraction 16 by passage of the small waste sub-fraction 15 through said tertiary orifices 9, the latter being of a size adapted to prevent the passage of waste of a size greater than at least 200 mm, or even 300 mm. Only waste that is small enough to form the small waste sub-fraction 15 is thus allowed to pass through the tertiary orifices 9, in this preferred case. The size of the tertiary orifices 9 thus chosen preferably makes it possible to select a predetermined type of recyclable waste, i.e. it makes it possible to obtain a high concentration of this particular type of recyclable waste, the small waste sub-fraction 15.To do this, the tertiary orifices 9 are of oblong section, and said oblong section has a small diameter Dp, and a large diameter Dg, as illustrated in particular in . figure 3 . The expression "section oblong» preferably includes a cross-sectional shape, for example rectangular or elliptical, or a shape combining the characteristics of the latter. Advantageously, the large diameter Dg and the small diameter Dp are chosen so that they correspond to types of waste that it is desired to include in particular in the small waste sub-fraction 15. For example, since the waste mixture 2 is likely to contain plastic or glass bottles, the standard size of which is generally around thirty centimeters, it will be possible to choose a large diameter Dg of a size slightly larger than the size of said bottles, i.e. slightly larger than around thirty centimeters.Similarly, for example, since waste mixture 2 may contain used newspapers, the standard size of which is generally around twenty centimetres, a small diameter Dp may be chosen which is slightly larger than the size of said newspapers, i.e. slightly larger than around twenty centimetres.

[0053] Therefore, preferably, for each tertiary orifice, the small diameter Dp is between 200 and 240 mm, preferably about 220 mm, the large diameter Dg being between 300 and 400 mm, preferably about 330 mm, the small diameter Dp being substantially perpendicular to the large diameter Dg, as illustrated in particular in figure 3. Of course, in particular to adapt to the composition of the initial waste mixture 2, other sizes and shapes of tertiary orifices 9 may be envisaged without departing from the scope of the invention, for example polygonal, circular, smaller size, or larger size.

[0054] According to the invention and as illustrated in the figure 3 The tertiary orifices 9 are distributed in successive rows along the second length L2, alternating at least: a longitudinal row 19 of tertiary orifices 9, in which the large diameter Dg of the tertiary orifices 9 of the right row is aligned in the direction of the second length L2, and a transverse row 20 of tertiary orifices 9, in which the small diameter Dp of the tertiary orifices 9 of the transverse row 20 is aligned in the direction of the second length L2.

[0055] Preferably, the major diameter Dg of the tertiary orifices 9 is parallel to a second longitudinal axis YY' of the second trommel 4, as described below. Preferably, on the contrary, the major diameter Dg of the tertiary orifices 9 is perpendicular to the second longitudinal axis Y-Y'.

[0056] From one row to the next, the tertiary orifices 9 are thus preferably substantially perpendicular to each other, so as to anticipate the orientation of the waste to be included in the small waste sub-fraction 15, and to improve the sorting efficiency of the second trommel section 4.

[0057] Preferably, the second series of separation orifices 9 will be formed of an alternation of longitudinal rows 19 and transverse rows 20 of tertiary orifices 9.

[0058] Of course, other arrangements of the tertiary orifices may be considered without departing from the scope of the invention.

[0059] Advantageously, the first series of separation orifices 7, 8 is distributed substantially over the entire first length L1 of the first trommel section 3, the second series of separation orifices 9 is distributed substantially over the entire second length L2 of the second trommel section 4, so as to be distributed over at least the majority of, or even over the entire, surface formed by the first separation wall 5 and by the second separation wall 6. Such a design makes it possible to increase the useful proportion of said separation walls, and thus to improve the compactness of the sorting machine 1 in general.

[0060] According to a particularly important characteristic of the invention, the second length L2 is less than the first length L1. Thus, the first trommel section 3, and in particular the first separating wall 5, is of a length greater than that of the second trommel section 4, and in particular the second separating wall 6. Such a design allows the first trommel section 3 to effectively ensure the separation of a majority, or even all, of the biodegradable waste initially contained in the waste mixture 2. Indeed, the first length L1 is advantageously chosen to be sufficiently long so that all the waste in the waste mixture 2 likely to pass through the first separating wall 5 is effectively included in the first fraction of waste 13.

[0061] Preferably, the first length L1 is at least 1.05 times the second length L2, preferably at least 1.10 times, even more preferably at least 1.12 times. The sum of the first length L1 and the second length L2 is advantageously between 10 and 20 m. The sorting machine 1 is preferably designed to sort between 10 and 50 T / h of waste mixture (2).

[0062] Advantageously: the first waste fraction 13 represents between 35 and 60% of the mass of the initial waste mixture 2, preferably approximately 42%, the small waste sub-fraction 15 represents between 20 and 40% of the mass of the initial waste mixture 2, preferably approximately 28%, the large waste sub-fraction 16 represents between 20 and 40% of the mass of the initial waste mixture 2, preferably approximately 30%.

[0063] Preferably, as represented for example in the figure 1, the first separating wall 5 has a general shape of a prism, cylinder or truncated cone, the height of which forms a first longitudinal axis XX' of the first separating wall 5, the latter being rotated around the first longitudinal axis X-X'.

[0064] Advantageously, the second separating wall 6 has a general shape of a prism, cylinder or truncated cone, the height of which forms a second longitudinal axis YY' of the second separating wall 6, the latter being rotated around the second longitudinal axis Y-Y'.

[0065] The first longitudinal axis XX' and / or the second longitudinal axis YY' are preferably slightly inclined with respect to the horizontal, so as to allow, by gravity, a progression of waste in the trommel sections according to a predetermined direction of circulation, advantageously from the inlet 10, towards the second trommel section 4, up to the discharge hopper 18 at the outlet of the refusal of the second trommel section 4.

[0066] Rotating the first trommel section 3 and / or the second trommel section 4 allows the waste to be stirred and turned over, so that at least a majority of it, if not all of it, has the opportunity to come into contact with the first separation wall 5 and / or the second separation wall 6 to be sorted.

[0067] To enable better mixing of the waste and improve the sorting efficiency of the sorting machine 1, the first trommel section 3 and / or the second trommel section 4 are each designed to be rotated independently or not of each other, the independent rotation of the first trommel section 3 and / or the independent rotation of the second trommel section 4 and / or the dependent rotation of both preferably taking place alternately in one direction and the other at a desired frequency, around their respective longitudinal axes.

[0068] It is advantageous to choose a cylindrical shape, which allows the waste, when the trommel sections rotate, to rub against each other so as to clean each other of sticky waste. Alternatively, for example, a prismatic shape with an octagonal base could be chosen to cause the waste to bounce off the walls, in order to allow better separation of the waste from each other.

[0069] The diameter of the first trommel section 3 and the second trommel section 4 is advantageously between 2 and 3 m.

[0070] Therefore, as illustrated in the figure 1 , the first series of separation orifices 7, 8 is preferably distributed over the entire circumference of the first separation wall 5, the second series of separation orifices 9 being distributed over the entire circumference of the second separation wall 6.

[0071] Preferably, and as illustrated in the figures, the separation orifices 7, 8 of the first set of separation orifices 7, 8 are distributed on the first separation wall 5 in a first staggered pattern, while the separation orifices 9 of the second set of separation orifices 9 are distributed on the second separation wall 6 in a second staggered pattern. In this way, the separation orifices 7, 8, 9 are arranged in both a first helix and a second crossed helix, which improves the sorting efficiency during the flow of waste through the first trommel section 3 and the second trommel section 4, regardless of the direction of rotation of said trommel sections 3, 4.

[0072] Preferably, the first partition wall 5 and / or the second partition wall 6 is provided with lifting fins 22 for the waste circulating in the first trommel section 3 and / or in the second trommel section 4, respectively. The lifting fins 22 are preferably each arranged in the longitudinal direction of the trommel sections 3, 4, so as to drive, lift and stir the waste during the rotation of said trommel sections 3, 4. The lifting fins 22 are advantageously arranged in a staggered manner.

[0073] As illustrated in the figure 1, the first trommel section 3 and the second trommel section 4 form a single trommel 3, 4 rotating in a single piece around a single longitudinal axis X-X'-Y-Y', the output end of the first trommel section 3 being directly connected to the input end of the second trommel section 4. In this preferred case, the trommel sections 3, 4 are integral, and form a single drum.

[0074] In this preferential case represented in the figure 1, the sorting machine 1 comprises three force take-ups 23 for supporting and / or rotating the single trommel, two of the force take-ups 23 being placed at the ends of the single trommel, the last being placed substantially centrally to the other two. The force take-ups 23 correspond for example to bearings, and / or to drive means of the toothed wheel or drive pulley type. The central force take-up 23 advantageously makes it possible to avoid any risk of bending of the single trommel 3, 4, in particular in the case where its total length is significant and where the quantity of waste within it is particularly massive.

[0075] Alternatively, according to another preferred embodiment of the invention not shown in the figures, it is possible to envisage that the first trommel section 3 and the second trommel section 4 form two independent trommels, the sorting machine 1 including means for transferring the second residual waste fraction 14 from the first trommel section 3 to the second trommel section 4.

[0076] The first trommel section 3 preferably comprises a transfer outlet for the second residual waste fraction 14, the second trommel section 4 comprising a secondary inlet for the second residual waste fraction 14. The secondary inlet is advantageously connected to the transfer outlet, so that the waste can circulate from the first trommel section 3 to the second trommel section 4. Preferably, the sorting machine 1 is designed so that the second residual waste fraction 14 falls by gravity from the first trommel section 3 into the second trommel section 4.

[0077] For purely illustrative purposes, the variant of the invention shown in the figures can operate in the manner described below.

[0078] The single trommel 3, 4 being in rotation alternately in one direction and in the other around its longitudinal axis, the mixture of waste 2 to be sorted is introduced through the intake inlet 10.

[0079] The waste mixture 2 first circulates in the first section of trommel 3 so as to be separated: on the one hand into a first fraction of waste 13, which passes through the first separation wall 5 to fall into the first hopper 12, and on the other hand a second residual fraction of waste 14 which remains inside the single trommel 3, 4 and progresses towards the second trommel section 4.

[0080] Upon reaching the second trommel section 4, the second residual fraction of waste 14 is again sorted, and in this case separated: on the one hand into a sub-fraction of small waste 15, which passes through the second separation wall 6 to fall into the second hopper 17, and on the other hand into a sub-fraction of large waste 16, which is evacuated from the second trommel section 4 via the reject outlet 21, so as to fall into the discharge hopper 18.

[0081] The waste fractions and sub-fractions 13, 15, 18 recovered separately in the hoppers 12, 17, 18 can thus be treated separately, despite the very great heterogeneity of the initial waste mixture 2.

[0082] Preferably, the sorting machine 1 described above may be integrated into a more global waste treatment process, in particular to carry out a step E1 of the latter, as illustrated in figure 2 .

[0083] The treatment method preferably comprises step E1 during which the waste mixture 2 is separated into a first waste fraction 13 whose size is less than approximately 180 mm, preferably less than 140 mm, and a second residual waste fraction 14.

[0084] Step E1 is advantageously carried out using a sorting machine 1 described above.

[0085] By "we mean size ", generally speaking, a dimension of the waste space according to its greatest length, or a characteristic dimension. We mean by " size » of waste, a geometric dimension characteristic of the individual waste, which allows it for example to pass through a mesh of corresponding size if the size of the waste is less than the size of the mesh, or on the contrary not to pass if the size of said waste is greater than the size of said mesh.

[0086] By "we meansecond residual portion of waste "the remaining portion of waste, which did not meet the separation criteria of the first portion of waste 13, in this case the size criterion. However, nothing prevents, within the meaning of the invention, waste that could have met the separation criterion, in this case size, of the first portion of waste 13 from also existing in the second residual portion of waste 14. For example, the second residual portion of waste 14 may contain waste with a size of less than 50 mm."

[0087] In this way, the first fraction of waste 13 is advantageously formed by waste having on average a higher density than the waste of the second residual fraction of waste 14, insofar as, in practice, the waste with the highest density is preferentially smaller than 180 mm.

[0088] According to the invention, the sorting method for sorting a waste mixture 2 is characterized in that the waste mixture 2 is introduced into a first trommel section 3 provided with a first separating wall 5 whose first length L1 is at least 1.05 times, preferably at least 1.10 times, even more preferably at least 1.12 times the second length L2 of the second trommel section 4 into which the second residual waste fraction 14 is passed.

[0089] Preferably, step E1 of the process thus includes the separation of waste materials that are sufficiently small, have the highest density, the highest density, the greatest dynamic inertia, and are the stickiest, greasy, dirty, and wettest from the waste mixture 2 to form the first waste fraction. This first fraction is thus advantageously composed of at least a majority of waste materials exhibiting such properties. Preferably, in this case, the first waste fraction 13 consists mainly of organic and / or biodegradable waste, which generally exhibits the aforementioned properties.

[0090] Following this first separation carried out during step E1, the first waste fraction 13 and the second residual waste fraction 14 can be treated more easily in the following steps of the process, in particular insofar as the waste of the second residual waste fraction 14 is, at this stage, cleaned of most of the organic and / or biodegradable, sticky, dirty and foul-smelling waste.

[0091] Preferably, the waste of the first waste fraction 13 has a size less than approximately 110 mm, and is separated using the sorting machine 1 previously described.

[0092] Advantageously, the method comprises, at the end of step E1 or simultaneously with the latter, a step E4 of separating the second residual fraction of waste 14 into a sub-fraction of large waste and a sub-fraction of small waste 15, the sub-fraction of large waste being formed by waste whose size is greater than the sub-fraction of small waste 15. The sub-fraction of large waste is preferably formed by waste whose size is greater than approximately 330 mm, the sub-fraction of small waste 15 being formed by waste whose size is less than approximately 330 mm. Step E4 may also be carried out using the sorting machine 1 described above.

[0093] The treatment method preferably comprises a step E5 of manual sorting of the large waste sub-fraction 16, making it possible to separate, on the one hand, the recyclable waste 26 that it contains, and on the other hand, the non-recyclable waste 27 that it contains. Manual sorting is advantageously made possible at this stage, insofar as the waste is of a sufficiently large size, free of small waste and most of the fines. In addition, the waste is advantageously free of most of the sticky and nauseating material formed by the biodegradable material, which makes manual sorting possible. Manual sorting makes it possible in particular to separate from the large waste sub-fraction 16 metal waste 26A, plastic waste, large electronic waste, cardboard packaging, etc.

[0094] Waste recognized as recyclable waste during manual sorting will advantageously be sent to a recycling step W, as described below. Residual waste that is not separated for recycling will advantageously be sent to a solid recovered fuel manufacturing step X, whether it is actually recyclable or not.

[0095] Preferably, the treatment method comprises a step E6 of automated sorting of the small waste sub-fraction 15, making it possible to separate on the one hand the recyclable waste 26 that it contains, and on the other hand the non-recyclable waste 27 that it contains. The small waste sub-fraction 15 is preferably suitable for automatic sorting, the small waste 15 being lighter to be handled for example by sorting devices.

[0096] Step E6 preferably comprises a first sub-step E61 of separating metal waste 26A contained in the small waste sub-fraction 15, for example using an electromagnetic separator and / or an eddy current separator, so as to separate at least the majority of the metal waste 26A contained in said small waste sub-fraction 15, the metal waste 26A forming at least the majority of recyclable waste 26. The metal waste 26A can thus advantageously be extracted from the small waste sub-fraction 15, insofar as said small waste sub-fraction 15 is preferably substantially free of sticky biodegradable waste.

[0097] Preferably, step E6 comprises a second sub-step E62, of separating the small waste sub-fraction 15 into a stream of substantially flat waste and a stream of substantially voluminous waste. In this way, the two waste streams can be directed to sorting machines adapted to the morphology of the waste they contain.

[0098] By "we mean waste, roughly flat ", the waste being mostly spread over a surface area, such as newspapers, paper, and sheets of various plastic materials. The term " waste, roughly flat » also advantageously includes sufficiently soft bulk waste, or of sufficiently low mechanical resistance to be able to be flattened or compacted easily, for example certain cardboard boxes.

[0099] By "we mean substantial volume waste"Waste that extends in three dimensions, can be hollow, and resists compaction more than relatively flat waste, being more rigid or solid. For example, significantly bulky waste might include plastic or glass bottles, plastic boxes, and various containers and flasks."

[0100] This sub-step E62 is preferably carried out using a ballistic belt separator (not shown). The ballistic belt preferably has an inclination relative to the horizontal so as to form a slope, the tread being designed to provide a forward movement in the direction of the rise of the slope. Advantageously, the substantially voluminous waste is intended to roll and bounce on the ballistic belt by gravity so as to roll down the slope towards a low recovery means of the bin or conveyor type, optionally incorporating a glass trap. The substantially flat waste is, for its part, preferably driven up the slope by the forward movement of the belt, towards a high recovery means, for example another conveyor, so that the substantially flat waste and the substantially voluminous waste are separated.

[0101] The fine particles likely to be contained in the small waste subfraction 15 adhere advantageously to the ballistic belt (which can optionally be moistened to enhance this effect), and can advantageously be scraped and recovered using, for example, a tungsten belt scraper mounted on said belt. The tread of the ballistic belt can advantageously have elastic properties that allow the rebound of the substantially bulky waste.

[0102] The ballistic belt is preferably combined with an accelerator belt mounted upstream, making it possible to accelerate the sub-fraction of small waste 15 so that the latter reaches the ballistic belt of the ballistic belt separator with a predetermined speed.

[0103] Preferably, step E6 comprises a third sub-step E63 of robotic sorting of the stream of substantially flat waste and the stream of substantially voluminous waste, to separate recyclable waste 26 and non-recyclable waste from each of said streams, the third sub-step E63 being carried out at the end of the second sub-step E62. Advantageously, separate sorting robots will be chosen, adapted respectively to the sorting of substantially flat waste and substantially voluminous waste. The sorting robots are preferably designed to separate recyclable waste from substantially flat waste and substantially voluminous waste by recognizing the latter, in particular by optical signature recognition, allowing in particular the sorting robot to detect the material of the waste to be sorted. The recyclable waste recognized by the sorting robots will advantageously be sent to a recycling step W.Unrecognized waste, preferably including a small proportion of recyclable waste and a majority of non-recyclable waste, will be advantageously sent to a stage X of solid recovered fuel manufacturing.

[0104] After sorting by sorting robots, before recycling step W, the recyclable waste can advantageously be subject to a step T of the treatment process, during which non-ferrous metal waste is separated from recyclable waste, for example using an eddy current separator. At this stage of the process, the non-ferrous metal waste is, for example, formed by aluminum waste, or flexible food packaging containing aluminum foil.

[0105] Advantageously, the separate streams of substantially bulky waste and substantially flat waste are conveyed using a set of belt conveyors to the sorting robots, the set of belt conveyors being designed to spread and distribute the waste in such a way that substantially no waste is superimposed on another when said waste arrives at the sorting robots. The efficiency of sorting by the robots is thus advantageously improved.

[0106] Sub-steps E61, E62 and E63 are preferably carried out successively in this order.

[0107] The treatment method preferably also comprises a step E2, carried out successively to step E1, during which the first fraction of waste 13 is subjected to a composting process so as to compost at least in part the biodegradable waste that it contains.

[0108] Step E2 thus preferably aims to recover the first fraction of waste 13, and in particular to convert the biodegradable waste that it contains into a mixture of refined waste 28, so that, preferably, the mixture of refined waste 28 forms compost satisfying the NF U 44-051 standard. The NF U 44-051 standard of 2006, called " Organic amendments - Designations, specifications and marking ", is a French standard.

[0109] The composting process of stage E2 advantageously includes the following successive stages: Step A: the first fraction of waste 13 is subjected to a first composting cycle so as to at least partially compost the biodegradable waste of said first fraction of waste 13, and to obtain a mixture of pre-composted waste 2, Step B: the mixture of pre-composted waste 2 is subjected to drying to obtain a mixture of dried waste 2, Step C: the mixture of dried waste 2 is separated into at least one portion of heavy waste 25 and one portion of light waste, the portion of heavy waste 25 being formed by waste of higher density than the waste of the portion of light waste, Step D: the portion of light waste is subjected to a second composting cycle so as to at least partially compost the biodegradable waste it contains, and to obtain a mixture of refined waste 28, in particular compost.

[0110] Step E2 advantageously includes the treatment of the first fraction of waste 13 by two successive composting cycles separated by a drying step of the first fraction of waste 13 at the end of the first composting cycle to facilitate the separation and easier refining of the first fraction of waste 13. Thus, even if the first fraction of waste 13 is particularly heterogeneous and has many undesirable items that cannot be treated by composting, it is possible to refine the latter using step E2 to obtain refined waste 28 whose value is higher than that of the initial waste mixture.

[0111] For the purposes of the invention, the term “ composting"a biological process of conversion and valorization of organic waste, and in particular of biodegradable waste contained in the first waste fraction 13, by promoting and / or accelerating the natural biodegradation process. The composting cycles of stage E2 preferentially allow the conversion of at least a portion of the first waste fraction 13 into a stabilized, hygienic product, rich in humic compounds, preferably compost. By " composting"a traditional or industrial composting process, for example, implementing in particular the action of microorganisms to degrade and putrefy waste from the first waste fraction 13, these microorganisms being naturally present in the first waste fraction 13 and / or added to the first waste fraction 13, and / or made to multiply in the first waste fraction 13. The present composting process implements in particular an aeration of the first waste fraction 13, and / or a regulation of the humidity of the first waste fraction 13 (for example by adding water, and / or reintroducing into the first waste fraction 13 composting juice 11 emitted by the latter), and / or an addition of microorganisms to the first waste fraction 13 and / or an addition of structuring agents to stimulate the composting process, and / or an input of light, for example solar.

[0112] Preferably, step A corresponds to, or comprises, a phase of degradation of the waste, in particular biodegradable waste, while step C corresponds to, or comprises, a phase of maturation of the waste, in particular biodegradable waste, to obtain the mixture of refined waste 28, the latter advantageously forming compost. The degradation phase advantageously results in a proliferation of microorganisms in the first fraction of waste 13, while the maturation phase preferentially results in the progressive reduction of the quantity of microorganisms having proliferated during the degradation phase, and the conservation of microorganisms beneficial for the soil. The degradation and maturation phases may overlap or even be combined.

[0113] The invention also relates as such to a sorting method for sorting a mixture of waste 2 of heterogeneous sizes, shapes and consistencies, comprising at least biodegradable waste and non-biodegradable recyclable waste, a non-negligible portion of the mass of the mixture of waste being formed by biodegradable waste, for example at least 10% of the mass, and a non-negligible portion of the mass of the mixture being formed by non-biodegradable recyclable waste, for example at least 10% of the mass, said sorting method being characterized in that, successively: the waste mixture 2 is introduced into a first trommel section 3, provided with a first separation wall 5 extending over a first axial length L1 and being provided with a first series of separation orifices 7, 8 passing therethrough, the waste mixture 2 is separated into a first waste fraction 13 passing through said first separation wall 5 via the first series of separation orifices 7, 8 and into a second residual waste fraction 14, the waste mixture 2 flowing along said first wall to be thus separated, the second residual waste fraction 14 is passed from the first trommel section 3 to a second trommel section 4, provided with a second separation wall 6 extending over a second axial length L2 less than the first length L1, said second separation wall 6 being provided with a second series of separation orifices 9 passing therethrough,the second residual fraction of waste 14 is separated into a small waste sub-fraction 15 passing through said second separation wall 6 via said second series of separation orifices 9 and into a residual large waste sub-fraction 16, the large waste sub-fraction 16 being formed by waste whose size is greater than the small waste sub-fraction 15, the second residual fraction of waste 14 being intended to circulate along said second wall to be thus separated, said second series of separation orifices 9 comprising at least tertiary orifices 9 making it possible at least to contribute to separating the second residual fraction of waste 14 according to the small waste sub-fraction 15 and according to the large waste sub-fraction 16 by passage of the small waste sub-fraction 15 through said tertiary orifices 9, said tertiary orifices 9 being of oblong section,and said oblong section having a small diameter Dp, and a large diameter Dg, the tertiary orifices 9 being distributed in successive rows along the second length L2, alternating at least: ∘ a longitudinal row 19 of tertiary orifices 9, in which the large diameter Dg of the tertiary orifices 9 of the straight row is aligned in the direction of the second length L2, and ∘ a transverse row 20 of tertiary orifices 9, in which the small diameter Dp of the tertiary orifices 9 of the transverse row 20 is aligned in the direction of the second length L2.

[0114] The method of the invention can advantageously be carried out using the sorting machine 1 described above. POSSIBILITY OF INDUSTRIAL APPLICATION

[0115] The invention finds its industrial application in the design, production and implementation of means for sorting a mixture of waste of various sizes, shapes and consistencies, a mixture comprising biodegradable waste and non-biodegradable recyclable waste.

Claims

1. A rotary machine (1) for sorting a mixture of wastes (2), the latter being of heterogeneous sizes, shapes and consistencies, the mixture of wastes (2) comprising at least biodegradable wastes and non-biodegradable recyclable wastes, said sorting machine (1) being characterized in that it comprises at least: - one first trommel section (3), provided with a first separation wall (5) extending over a first axial length (L1) and being provided with a first series of separation through orifices (7, 8) allowing separating the mixture of wastes (2) into a first fraction of wastes (13) getting through said first separation wall (5) via the first series of separation orifices (7, 8) and into a residual second fraction of wastes (14), the mixture of wastes (2) being intended to circulate along said first wall so as to be separated, and - one second trommel section (4), provided with a second separation wall (6) extending over a second axial length (L2) smaller than the first length (L1), said second separation wall (6) being provided with a second series of separation through orifices allowing separating the residual second fraction of wastes (14) into a subfraction of small-sized wastes (15) getting through said second separation wall (6) via said second series of separation orifices and into a residual subfraction of large-sized wastes (16), the subfraction of large-sized wastes (16) being formed by wastes the size of which is larger than the subfraction of small-sized wastes (15), the residual second fraction of wastes (14) being intended to circulate along said second wall so as to be separated, characterized in that said second series of separation orifices comprises at least tertiary orifices (9) at least contributing to the separation of the residual second fraction of wastes (14) into the subfraction of small-sized wastes (15) and into the subfraction of large-sized wastes (16) by passage of the subfraction of small-sized wastes (15) throughout said tertiary orifices (9), the section of said tertiary orifices (9) being oblong-shaped, and said oblong section having a small diameter (Dp), and a large diameter (Dg), the tertiary orifices (9) being distributed in successive rows along the second length (L2), by alternating at least: ∘ a longitudinal row (19) of tertiary orifices (9), in which the large diameter (Dg) of the tertiary orifices (9) of the straight row is aligned in the direction of the second length (L2), and ∘ a transverse row (20) of tertiary orifices (9), in which the small diameter (Dp) of the tertiary orifices (9) of the transverse row (20) is aligned in the direction of the second length (L2).

2. The sorting machine (1) according to claim 1, characterized in that the first length (L1) is at least equal to 1.05 times the second length (L2), preferably at least 1.10 times, still more preferably at least 1.12 times.

3. The machine (1) for sorting a mixture of wastes (2) according to any one of the preceding claims, characterized in that the first series of separation orifices (7, 8) comprises at least primary orifices (7) enabling at least contributing to the separation of the mixture of wastes (2) into the first fraction of wastes (13) and into the residual second fraction of wastes (14) by passage of the first fraction of wastes (13) throughout said primary orifices (7), the latter having a size adapted to prevent the passage of wastes with a size larger than 80 mm.

4. The machine (1) for sorting a mixture of wastes (2) according to the preceding claim, characterized in that the section of the primary orifices (7) is circular, with a diameter comprised between 85 mm and 95 mm, preferably about 90 mm.

5. The machine (1) for sorting a mixture of wastes (2) according to any one of claims 4 or 5, characterized in that the first series of separation orifices (7, 8) also comprises secondary orifices (8) enabling contributing to the separation of the mixture of wastes (2) into the first fraction of wastes (13) and into the residual second fraction of wastes (14) by passage of the first fraction of wastes (13) throughout said secondary orifices (8), the latter having a size adapted to allow the passage of wastes the size of which is comprised between 1 and 1.5 times the size of the wastes the passage of which is allowed by the primary orifices (7), the secondary orifices (8) being disposed upstream of the primary orifices (7), with regards to the flow direction of the mixture of wastes (2).

6. The machine (1) for sorting a mixture of wastes (2) according to the preceding claim, characterized in that the section of the secondary orifices (8) is circular, with a diameter comprised between 105 mm and 115 mm, preferably about 110 mm.

7. The sorting machine (1) according to any one of the preceding claims, characterized in that, for each tertiary orifice (9), the small diameter (Dp) is comprised between 200 and 240 mm, preferably about 220 mm, the large diameter (Dg) being comprised between 300 and 400 mm, preferably about 330 mm, the small diameter (Dp) being substantially perpendicular to the large diameter (Dg).

8. The sorting machine (1) according to any one of the preceding claims, characterized in that the separation orifices (7, 8) of the first series of separation orifices (7, 8) are distributed over the first separation wall (5) according to a first staggered meshing, the separation orifices (9) of the second series of separation orifices (9) being distributed over the second separation wall (6) according to a second staggered meshing.

9. The sorting machine (1) according to any one of the preceding claims, characterized in that each of the first trommel section (3) and the second trommel section (4) is designed to be rotated, the rotation is performed in an alternating manner in one direction and in the other according to a desired frequency.

10. A sorting method for sorting a mixture of wastes (2) with heterogeneous sizes, shapes and consistencies, comprising at least biodegradable wastes and non-biodegradable recyclable wastes, a non-negligible portion of the mass of the mixture of wastes being formed by biodegradable wastes, for example at least 10% of the mass, and a non-negligible portion of the mass of the mixture being formed by non-biodegradable recyclable wastes, for example at least 10% of the mass, said sorting method being characterized in that it includes the following successive steps: - introducing the mixture of wastes (2) in a first trommel section (3), provided with a first separation wall (5) extending over a first axial length (L1) and being provided with a first series of separation through orifices (7, 8), - separating the mixture of wastes (2) into a first fraction of wastes (13) getting through said first separation wall (5) via the first series of separation orifices (7, 8) and into a residual second fraction of wastes (14), the mixture of wastes (2) circulating along said first wall so as to be separated, - making the residual second fraction of wastes (14) pass from the first trommel section (3) to a second trommel section (4), provided with a second separation wall (6) extending over a second axial length (L2) smaller than the first length (L1), said second separation wall (6) being provided with a second series of separation through orifices, - separating the residual second fraction of wastes (14) into a subfraction of small-sized wastes (15) getting through said second separation wall (6) via said second series of separation orifices (9) and into a residual subfraction of large-sized wastes (16), the subfraction of large-sized wastes (16) being formed by wastes the size of which is larger than the subfraction of small-sized wastes (15), the residual second fraction of wastes (14) being intended to circulate along said second wall so as to be separated, said second series of separation orifices comprises at least tertiary orifices (9) at least contributing to the separation of the residual second fraction of wastes (14) into the subfraction of small-sized wastes (15) and into the subfraction of large-sized wastes (16) by passage of the subfraction of small-sized wastes (15) throughout said tertiary orifices (9), the section of said tertiary orifices (9) being oblong-shaped, and said oblong section having a small diameter (Dp), and a large diameter (Dg), the tertiary orifices (9) being distributed in successive rows along the second length (L2), by alternating at least: ∘ a longitudinal row (19) of tertiary orifices (9), in which the large diameter (Dg) of the tertiary orifices (9) of the straight row is aligned in the direction of the second length (L2), and ∘ a transverse row (20) of tertiary orifices (9), in which the small diameter (Dp) of the tertiary orifices (9) of the transverse row (20) is aligned in the direction of the second length (L2).

11. The method for sorting a mixture of wastes (2) according to claim 10 characterized in that the mixture of wastes (2) is introduced into a first trommel section (3) provided with a first separation wall (5) the first length (L1) of which is at least equal to 1.05 times, preferably at least 1.10 times, still more preferably at least 1.12 times the second length (L2) of the second trommel section (4) in which the residual second fraction of wastes (14) is passed.