Method for separating the components of a mixture of fibres and granules, the method comprising a step of disentangling the mixture by brushing over a screen

Abstract

The present invention relates to a separation method which, starting from a mixture (1) of components (2, 3) comprising a first family of components (2) formed by fibres (2) and a second family of components (3) formed by granules (3), makes it possible to separate the fibres (2) from the granules (3), the method comprising a brushing step, during which the mixture (1) is subjected to the combined action of a brush (4) and a crumbling screen (5) in order to generate a rain of dissociated fibres (2) and granules (3), followed by a fibre reagglomeration step, during which the rain of fibres (2) and granules (3) is collected on a reagglomeration screen (6) which is vibrated, such that, on the surface of the reagglomeration screen (6), at least some of the fibres (2) are reagglomerated into fibre pellets (7).

Description

METHOD FOR SEPARATING THE COMPONENTS OF A MIXTURE OF FIBERS AND GRANULES COMPRISING A STEP OF DISENTANGLING THE MIXTURE BY BRUSHING ON A SIEVE

[0001] The present invention relates to the general field of separation installations and methods intended to separate the different components of a mixture containing fibers and granules, in particular with a view to recycling the materials which respectively constitute these different components.

[0002] The invention finds more particular application in the treatment of mixtures which are obtained from the grinding of pneumatic tires and which contain textile fibers, in particular polyethylene terephthalate, and granules of rubber-based material.

[0003] The present invention is particularly applicable to the treatment of mixtures whose components are of millimetric and sub-millimetric size, that is to say in particular to the treatment of mixtures which contain fibers whose diameter is between 10 μm and 1 mm for a length of between 1 mm and 10 mm, and granules whose equivalent diameter is between 125 μm and 5 mm.

[0004] Various separation methods are known, in particular electrostatic separation methods according to which the components of the mixture are given, for example by tribocharging, electrostatic charges whose polarity is different depending on whether it is a fibre or a granule, then the fibres are separated from the granules by passing the mixture thus charged through an electric field formed between two electrodes, each of which selectively attracts a type of component depending on the polarity of the charge of said component.

[0005] However, the efficiency of known processes remains improvable, particularly with regard to their yield in terms of the quantity of mixture treated per unit of time, and therefore the quantity of material harvested with a degree of purity deemed satisfactory per unit of time.

[0006] The objects assigned to the invention therefore aim to remedy the aforementioned drawbacks and to propose a new separation process which presents improved efficiency, and allows for efficient processing of large quantities of fiber and granule mixtures.

[0007] The objects assigned to the invention are achieved by means of a separation process making it possible, from a mixture of components comprising a first family of components formed by fibers and a second family of components formed by granules, to separate the fibers from the granules, said process being characterized in that it comprises: - a brushing step, during which the mixture is subjected to the combined action of a brush and a first sieve, called a "crumbling sieve", said brush and said crumbling sieve being in relative movement called a "brushing movement" with respect to each other, so that the brush rubs the mixture against the crumbling sieve to disentangle the fibers and dissociate the components of the mixture from each other, and thus generate, through the crumbling sieve, a shower of dissociated fibers and granules, - then a fiber re-agglomeration step, during which the rain of fibers and granules from the crumbling sieve is collected on a second sieve, called a "re-agglomeration sieve", which is driven by a vibrating movement, so that at least a portion of the fibers are re-agglomerated on the surface of said re-agglomeration sieve in the form of fiber balls which are retained by said re-agglomeration sieve while the granules pass through said re-agglomeration sieve.

[0008] Advantageously, the brushing step makes it possible to diffuse, in a way to spray, the mixture in the form of a fine but fairly dense rain, and over a fairly large surface, and therefore to effectively and simultaneously treat a large flow of mixture.

[0009] The mechanical sorting carried out by the sieves, and in particular according to the principle of reagglomeration of the fibers into pellets on a vibrating sieve, after separation of the components of the mixture in rain, advantageously makes it possible to collect in a simple, rapid and efficient manner relatively pure fiber pellets, almost or even entirely free of residual granules, while avoiding clogging the reagglomeration sieve.

[0010] The fiber pellets can also be easily evacuated, for example by providing a slight slope on the re-agglomeration screen which allows the pellets to roll, under the vibrations of the screen towards a collector.

[0011] This allows a large and continuous flow of mixture to be processed, with a high sorting yield.

[0012] Other objects, characteristics and advantages of the invention will appear in more detail on reading the description which follows, as well as with the aid of the appended drawings, provided for purely illustrative and non-limiting purposes, among which:

[0013] Figure 1A and Figure 1B illustrate, in perspective overall views, respectively whole and in section in a vertical plane, an example of an installation allowing the implementation of the method according to the invention, said installation forming a tower which comprises in the upper part a brushing stage, provided here with a brush with a horizontal axis cooperating with a curved crumbling screen, and under which there follow, vertically perpendicular to each other, a plurality of re-agglomeration stages, each formed by a re-agglomeration tank whose bottom is provided with a re-agglomeration screen.When the mixture, crumbled by the brushing stage, falls as rain, by gravity, through the tower, it passes through the re-agglomeration stages which allow the fibres to be collected, and the mixture to be progressively refined and sorted in order to obtain on the one hand a first product enriched in fibres, that is to say having a fibre content higher than that of the initial mixture, said first product corresponding to the fibre balls generated by the re-agglomeration sieves and collected at each re-agglomeration stage, and on the other hand, at the bottom of the tower, a second product enriched in granules, that is to say having a granule content higher than that of the initial mixture.

[0014] Figure 2A, Figure 2B, and Figure 2C represent, in exploded perspective views respectively, in front section in a vertical plane, and in side section in a vertical plane, a first possible arrangement of a brushing stage, with a horizontal axis brush, as used within the installation of Figure 1A and Figure 1B.

[0015] Figure 3A and Figure 3B illustrate, in perspective overall views, respectively whole and in section in a vertical plane, another example of an installation allowing the implementation of the method according to the invention, the brushing stage of which this time comprises a brush with a vertical axis cooperating with a horizontal crumbling screen.

[0016] Figure 4A and Figure 4B represent, in exploded perspective and front section views respectively in a vertical plane, a second possible arrangement. brush stage, with vertical axis brush, as used in the installation of Figure 3A and Figure 3B.

[0017] Figure 5 illustrates, in a schematic sectional front view, the operation of the brushing stage and the first re-agglomeration stage of the installation of Figure 3A and Figure 3B, in accordance with the method according to the invention.

[0018] Figure 6A, Figure 6B and Figure 6C illustrate, in schematic perspective, side, and top views respectively, a third possible brushing stage arrangement, comprising a crumbling screen which forms an inclined plane as well as a brush which comprises, along the slope, several rows of brushes arranged to form V-shaped receptacles, so that the brush can regulate the flow of the mixture along the slope of the inclined plane while performing an alternating brushing movement, transverse to the slope of the inclined plane.

[0019] Figure 7 illustrates, in a sectional view in a vertical plane, a rotary grinder ensuring grinding of the mixture prior to the brushing step.

[0020] The present invention relates to a separation method making it possible, from a mixture 1 of components 2, 3 comprising a first family of components 2 formed by fibers 2 and a second family of components 3 formed by granules 3, to separate the fibers 2 from the granules 3.

[0021] The fibers 2 will have a thin and elongated shape, preferably substantially cylindrical.

[0022] At least a portion, preferably the majority of said fibers 2 present in the mixture 1 (i.e. more than 50% of the total number of fibers present), and more preferably all (100% of the total number of fibers present) of said fibers 2 which are present in the mixture 1 will have a length of between 1 mm and 10 mm, while the largest of their transverse dimensions, i.e. the largest of the dimensions considered perpendicular to their length, i.e. typically the diameter in the case of a cylindrical fiber, will be between 10 μm and 1 mm.

[0023] The method according to the invention, and the corresponding installation 100, will preferably be designed to be able to separate and recover (at least) fibers of such dimensions.

[0024] More preferably, the fibers 2 will have a dimension, called length, which is clearly greater than the other two dimensions, called transverse dimensions, and more particularly will have a length at least 5 times, preferably at least 10 times, at least 20 times, or even at least 50 times or even 100 times greater than the largest of these two transverse dimensions, that is to say, typically, in the case of a fiber 2 of cylindrical shape, a length at least 5 times, preferably at least 10 times, at least 20 times, or even at least 50 times or even 100 times greater than the diameter of the fiber 2 concerned.

[0025] The fibers 2 may be made from a natural or synthetic textile material, and more preferably from a polymer or a combination of polymers from (non-exhaustive list): polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and nylon or polyamide (PA).

[0026] Furthermore, at least a portion of the granules 3 present in the mixture 1, preferably the majority of the granules 3 present in the mixture 1 (more than 50% of the total number of granules present), and more preferably all (100% of the total number of granules present) of said granules 3 present in the mixture 1 will preferably have an equivalent diameter of between 125 μm and 5 mm, and a form factor of between 1 and 2.

[0027] By "equivalent diameter" we mean the diameter that a fictitious sphere would have which occupied the same volume as the volume occupied by the granule 3 considered.

[0028] By "shape factor" is meant the ratio between on the one hand the maximum Feret diameter, that is to say the maximum distance, observable for the granule 3 considered, between two straight lines which are parallel to each other and tangent respectively to opposite sides of said granule 3 considered, and on the other hand the minimum Feret diameter, that is to say the minimum distance, observable for the granule 3 considered, between two straight lines which are parallel to each other and tangent respectively to opposite sides of said granule considered. This shape factor makes it possible to give a good indication of the slenderness of the granules 3. For information, it is recalled that a sphere has a form factor equal to 1 corresponds to a sphere, and that a cube has a form factor equal to the square root of 2.

[0029] The invention will of course also relate to an installation 100 making it possible to implement the method.

[0030] According to the invention, the method comprises a brushing step (SI), during which the mixture 1 is subjected to the combined action of a brush 4 and a first sieve 5, called a “crumbling sieve” 5, said brush 4 and said crumbling sieve 5 being in relative movement called a “brushing movement” M4 with respect to each other, so that the brush 4 rubs the mixture 1 against the crumbling sieve 5 to disentangle the fibers 2 and dissociate the components 2, 3 of the mixture from each other, and thus generate, through the crumbling sieve 5, as can be seen in FIG. 5, a shower of dissociated fibers 2 and granules 3.

[0031] Advantageously, the brush 4, by pressing and scraping the mixture 1 against the sieve 5, breaks up the mixture 1, and in particular disintegrates the agglomerates of fibers 2 and granules 3 which, within the initial mixture 1, keep granules 3 trapped in masses of tangled fibers 2.

[0032] The mechanical brushing action thus makes it possible to dissociate all or part of the fibers 2 from each other, and to dissociate all or part of the granules 3 from the surrounding fibers 2, and thus, by crumbling the mixture 1, to generate a rain which contains fibers 2 which are dissociated from each other, and granules 3 which are dissociated from each other and dissociated from the fibers 2.

[0033] The mixture 1 and the brushing action are advantageously distributed over a large surface area of sieve 5, and thus make it possible to generate a high flow rate of rain of fibers 2 and granules 3.

[0034] This rain is advantageously both dense, that is to say comprising a high number of components 2, 3 per volume of air, and fine, that is to say composed of fibers 2 and granules 3 which are finely dissociated from each other, and more preferably individualized.

[0035] The said rain falls preferably by simple gravity, after having passed through the crumbling sieve 4.

[0036] The method then comprises a step (S2) of re-agglomeration of fibers, during which the rain of fibers 2 and granules 3 from the crumbling sieve 4 is collected on a second sieve, called the "re-agglomeration sieve" 6, which is driven by a vibrating movement, so that at least a portion of the fibers 2 is caused to re-agglomerate on the surface of said re-agglomeration sieve 6 in the form of fiber balls 7 which are retained by said re-agglomeration sieve 6 while the granules 3 pass through said re-agglomeration sieve 6, as illustrated in FIG. 5.

[0037] The inventors have in fact discovered that by subjecting the fibers 2 previously finely dissociated by the brushing operation to the vibrations of a sieve 6, said fibers, free of granules 3, spontaneously reaggregate to form balls of tangled fibers 2, of substantially spherical shape, called "balls" 7.

[0038] The fiber balls 7 having dimensions, here diameters, greater than the mesh size of the re-agglomeration sieve 6, this makes it possible to retain the fibers 2 on said re-agglomeration sieve 6, while the latter allows the free granules 3 to escape, in particular the granules 3 which have been extracted and dissociated from the initial fiber agglomerates during the brushing step (SI).

[0039] The inventors also found that, in order to obtain a satisfactory result during the re-agglomeration stage, it is important to have produced, by a brushing operation, a shower of fibers 2 and granules 3 of good quality.

[0040] Advantageously, the substantially spherical shape of the fiber balls 7 simplifies the recovery of said fibers 2.

[0041] For example, it may be possible to slightly tilt the re-agglomeration sieve 6 relative to the horizontal, so that the fiber balls 7 roll spontaneously, under the effect of vibrations, towards a peripheral collector.

[0042] It will also be noted that, if the mixture contains large granules, with a diameter greater than the mesh of the crumbling sieve 5, these granules may, after having been dissociated from the fibers 2 by the brushing action, be recovered at the level of said sieve. of crumbling 5. This recovery of large granules can be done punctually on the crumbling sieve, or continuously. Preferably, an evacuation of the large granules from the crumbling sieve 5 is provided, for example by an inclination of the crumbling sieve 5 or any other arrangement allowing the granules to be moved. The large granules recovered at the crumbling sieve 5 can return to a screening and / or grinding type circuit in order to eliminate, for example by crushing, the large granules that are too solid and possibly to be able to reintroduce their components into the mixture 1.

[0043] Advantageously, the method according to the invention is a dry method, which uses neither liquid nor solvent. Said method is also simple to implement and requires very little energy, in particular electrical energy, and is safe for the equipment and operators located in the vicinity of the installation 100.

[0044] Preferably, the crumbling sieve 5 will have asperities on its surface receiving the mixture 1, here its upper surface, so that said crumbling sieve 5 forms a grater against the brush 4 during the brushing movement M4.

[0045] For example, if the crumbling screen 5 is formed by a wire mesh, preferably a metal wire mesh, the roughness may be formed by projecting portions of said mesh, for example projecting bends formed in the wires of the mesh. If the crumbling screen 5 is formed by a sheet, metal or rigid polymer, pierced by cracks, the roughness may correspond to the projecting edges of said cracks.

[0046] Advantageously, the roughness imparted by the asperities, and the alternation of projections and hollows which results therefrom on the surface of the crumbling sieve 5, will promote the disintegration of the mixture 1, and in particular of the agglomerates of fibers 2 and granules 3, under the action of the brush 4, the disentanglement of the fibers 2, the separation of the fibers 2 and the granules 3, and the expulsion in rain, through the crumbling sieve 5, of the components 2, 3 thus dissociated.

[0047] It is not excluded that the brush may include, in particular in addition to stirring elements such as bristles, scraping elements, such as rubber blades, or metal blades.

[0048] Preferably, the brush 4 has flexible bristles, preferably made of polymer material, the free ends of which are pressed against the surface of the crumbling sieve 5 in order to cause, during the brushing movement M4, a jerky alternation of bending and straightening of said bristles, which causes a beating of the mixture 1 present on the surface of the crumbling sieve 5.

[0049] The inventors have in fact noted that the multiplicity of bristles, and therefore the multiplicity of elastic deformation movements in flexion of each of the bristles, makes it possible to multiply the beating and scraping actions of the mixture 1 against the crumbling sieve 5, and in particular against the roughness of its surface, which ensures effective crumbling of the mixture 1 then effective ejection through the crumbling sieve 5 of the mixture 1 thus crumbled.

[0050] Of course, the brush 4 may include several rows of bristles, which follow one another in the direction of the brushing movement M4, so as to further accentuate these actions of beating and scraping the mixture 1.

[0051] According to a possible first arrangement, illustrated in figures 1A, 1B, 2A, 2B and 2C, the brush 4 extends on the lateral face 10A of a cylindrical rotor 10 with horizontal axis Y10.

[0052] In this respect, the bristles of the brush 4 may preferably extend radially, or substantially radially, on the lateral face 10A of the rotor 10, continuously along the length and / or around the circumference of the rotor 10, or else in tufts forming brushes spaced apart from each other, for example arranged in a staggered pattern relative to each other.

[0053] By "horizontal", we indicate that the element considered, here the axis Y10 of the rotor 10, around which said rotor 10 turns on itself to carry out the brushing movement M4 relative to the fixed crumbling screen 5, forms an angle relative to the horizontal which is, in absolute value, less than 20 degrees, preferably less than 10 degrees, 5 degrees, or even 3 degrees, and more preferably zero.

[0054] The crumbling sieve 5 then preferably forms a basket 11 which is delimited by a first side wall 12 which extends along the horizontal axis Y10 of the rotor 10, on a first side of the horizontal axis Y10 of the rotor, and by a second side wall 13 which extends along the horizontal axis Y10 of the rotor, on a second side of the axis of the rotor opposite the first side, the first and second side walls 12, 13 being inclined relative to each other so as to converge towards a bottom 14 in an arc of a circle, with which the brush 4 cooperates.

[0055] The crumbling sieve 5 thus has a curved, hollow shape.

[0056] Advantageously, the converging section of the basket, here for example V-shaped or U-shaped, creates a sort of funnel, and more particularly a hopper, between the brush 4 and a corresponding side wall 12, 13, a funnel which will comprise a movable face, formed by the free surface of the brush 4, and a fixed face, formed by the side wall 12, 13 located opposite the brush 4, and which will therefore tend to pinch, advance, and therefore in other words to “swallow”, in the direction of the rotary brushing movement M4, the mixture 1 poured into the basket 11.

[0057] The first and second side walls 12, 13 will preferably be planar and parallel to the central axis Y10 of the rotor 10.

[0058] The bottom 14 will preferably have a shape matching that of the lateral face of the rotor 10, and therefore of the brush 4.

[0059] Preferably, the brush 4 will thus be applied in a substantially tangent manner to the bottom 14 of the basket 11.

[0060] Said base 14, as well as all or part of the side walls 12, 13, will be pierced by the orifices of the crumbling sieve 5.

[0061] A feed spillway 15 intended to feed the basket 11 with mixture 1 will open into the upper part of the basket 11, preferably vertically above the part of the basket 11 which is located on the side of the axis of rotation Y10 where the direction of rotation of the rotor, and therefore the direction of the brushing movement M4, causes the brush 4 to converge towards the side wall 13.

[0062] The feed spillway 15 may operate by pouring the mixture 1 into the basket 11 in successive batches, or continuously.

[0063] According to a possible second arrangement, illustrated in figures 3 A, 3B, 4A and 4B, the brush 4 extends on a lower front face 20F of a rotor 20 with vertical axis Z20.

[0064] The front face 20F may be in the form, for example, of a disc, normal to the vertical axis Z20 of the rotor 20, or of a set of arms 21, for example four arms 21, intersecting the vertical axis Z20, preferably perpendicular to the vertical axis Z20, and which extend in a star shape around said vertical axis Z20, as illustrated in FIG. 3B.

[0065] The bristles of the brush 4 will preferably extend parallel to the vertical axis Z20, in the axial extension of the rotor 20, and more particularly of the plate or arms 21 forming the front face 20F.

[0066] The bristles of the brush 4 can be distributed evenly and continuously on the front face 20F, or in tufts spaced apart from each other.

[0067] According to a preferred possibility, the bristles will form brushes 22, preferably arranged in a star shape, substantially or even exactly radially to the vertical axis Z20, for example at the rate of one brush 22 fixed to each arm 21, and more particularly four brushes each fixed to one of four radial arms equally distributed in azimuth around the vertical axis Z20, as is partially visible in FIG. 3B.

[0068] By "vertical", we indicate that the element considered, here the axis Z20 of the rotor 20, around which said rotor 20 rotates on itself to carry out the brushing movement M4 relative to the crumbling sieve 5, fixed, forms an angle relative to the vertical which is, in absolute value, less than 20 degrees, preferably less than 10 degrees, 5 degrees, or even 3 degrees, and more preferably zero.

[0069] In this second arrangement, the surface of the crumbling screen 5 with which the brush 4 cooperates preferably extends substantially in a horizontal plane, normal to the vertical axis Z20 of the rotor 20.

[0070] It will be noted in this respect that the surface of the crumbling sieve 5 may possibly have a bulge to facilitate the evacuation towards the periphery of the crumbling sieve 5 of the large granules 3, too large to pass through the mesh of said crumbling sieve 5.

[0071] Likewise, the brushes 22 may possibly have a chosen yaw angle, relative to the radial directions perpendicular to the vertical axis Z20 of the rotor, in order to distribute and / or convey the large granules 3 and / or the mixture 1 to be treated according to a radial movement, which will be centrifugal or centripetal depending on the chosen yaw angle and the direction of rotation of the rotor 20 around the vertical axis Z20.

[0072] It will be noted that the brush 4 may be driven by a brushing movement M4 forming a simple rotation, the position of the vertical axis Z20 being fixed relative to the crumbling sieve 5, or else orbital, the vertical axis Z20 being carried by an eccentric system so as to move itself in rotation around another secondary vertical axis, while the rotor 20 rotates in rotation around said vertical axis Z20.

[0073] According to a possible third arrangement, illustrated in Figures 6A, 6B and 6C, the crumbling screen 5 forms an inclined plane 30 relative to the horizontal, on which the brush 4 moves according to a brushing movement M4 which comprises at least one component of alternating movement transverse to the direction of the slope of the inclined plane 30.

[0074] The inclination of the inclined plane could, for example, be between 5 degrees and 45 degrees.

[0075] According to this third arrangement, the brush 4 preferably comprises one or more brushes 31 which delimit, projecting from the inclined plane, one or more retention reservoirs 32, preferably U-shaped or V-shaped, which are open towards the upstream of the slope of the inclined plane 30, so as to be able to receive the mixture 1 to be brushed, and closed towards the downstream, so as to be able to regulate the flow of the mixture 1 along the slope of the inclined plane 30 during the execution of the alternating brushing movement M4.

[0076] The bristles of the brush 4, and more particularly of the brooms 31, preferably extend in a direction substantially normal to the inclined plane 30, for example at + / - 20 degrees, + / - 10 degrees, + / - 3 degrees, or even zero degrees relative to the normal to the inclined plane 30.

[0077] It may be provided, as is visible in Figures 6A and 6C, to form at least one row 33 of several holding tanks 32 juxtaposed over a portion, preferably at least 50% or even at least 65%, of the horizontal width W30 of the inclined plane 30.

[0078] Preferably, several rows 33 may be provided distributed along the slope of the inclined plane 30.

[0079] Advantageously, this third arrangement, in particular when several rows 33 of holding tanks 32 are used, makes it possible to maximize the useful surface area of the crumbling screen 5, over which the mixture extends and is subjected to the action of the brush 4, relative to the footprint of the crumbling screen, that is to say relative to the extent of the surface area of the crumbling screen considered in vertical projection in a horizontal plane.

[0080] Furthermore, such an arrangement makes it possible to distribute the mixture 1 initially received and contained in the retention tanks 32 of a first row 33, under the combined action of gravity and the brushes 31 of said first row 33, in a second row located under the first row, a part of the mixture 1 thus being recovered in the retention tanks 32 of the second row 33 and is therefore again exposed to a brushing action, by the brushes 31 of said second row 33.

[0081] Here again, we maximize the useful brushing surface, while maintaining a relatively compact 100 installation.

[0082] Furthermore, with reference to Figure 7, the method may comprise, before the brushing step (S1), a grinding step (S0) during which the mixture is passed through a grinder 40 which comprises a rotor 41 with a horizontal axis Y41 provided with a first set of knives 42, which thus form movable knives 42, which rotor 41 cooperates with a stator 43 provided with a second set of knives 44, which form fixed knives 44, said stator 43 being provided, following the fixed knives 44, in the direction of rotation, with a grid 45 which allows the mixture 1, once it has been ground sufficiently finely by the knives 42, 44, to leave the grinder 40 through the grid 45, to reach a brushing stage 101 comprising the brush 4 and the crumbling sieve 5.

[0083] Grinding will advantageously make it possible to have a mixture 1 with a certainty of size of fibers 2 and granules 3 adapted to the meshes of the crumbling sieves 5 and re-agglomeration sieves 6.

[0084] According to one possible implementation, the grinding step (S0) and the brushing step (SI) are carried out within the same apparatus which comprises a rotor 41 with a horizontal axis Y41 which comprises on the one hand at least a first set of knives 42 which are arranged in one or more angular sectors of the rotor 41 extending in azimuth around the axis of the rotor, and which are arranged to cooperate with a second set of knives 44, fixed on the stator 43 of the apparatus, in order to carry out grinding of the mixture, and on the other hand, in one or more angular sectors of the rotor 41 distinct from the angular sectors carrying the first set of knives 42, one or more brushes 46 intended to ensure brushing of the mixture against the grid 45 of the stator which forms the first sieve. It is possible to implement a mechanism allowing the brushes 46 to retract when passing in front of a knife 44, for example by a cam system or equivalent.

[0085] The 100 installation will thus be able to become more compact.

[0086] According to a preferred embodiment, the method comprises a second step (S2_2) of re-agglomeration of fibers, during which the fibers 2 which have passed through the re-agglomeration sieve 6 during the step (S2) of re-agglomeration of fibers are collected in a third vibrating sieve, forming a second re-agglomeration sieve 6 2, so as to cause, on the surface of said second re-agglomeration sieve 6 2, a re-agglomeration of at least a portion of said fibers 2 in the form of fiber balls which are retained by said second re-agglomeration sieve 6 2 while the granules pass through said second re-agglomeration sieve 6 2.

[0087] In order to perfect the refining of the flow of granules 3, it will thus be possible to provide a third or even a fourth stage of re-agglomeration of fibers 2, on a third, respectively a fourth re-agglomeration sieve 6 3, 6 4.

[0088] The re-agglomeration sieves will preferably be arranged vertically perpendicular to each other, so as to allow circulation of the mixture by gravity through the different stages.

[0089] More generally, the installation 1 may advantageously take the form of a tower, as can be seen in figures 1 A, 1B, 3 A and 3B, which comprises, from top to bottom, a brushing stage 101, comprising the brush 4 and the crumbling screen 5, possibly preceded by, or associated with, a grinding stage, and under which there will be at least one re-agglomeration stage 102, preferably several successive re-agglomeration stages 102, each comprising a re-agglomeration tank whose bottom is formed by a re-agglomeration sieve 6, 6 2, 6 3, 6 4.

[0090] Preferably, the crumbling sieve 5 has a mesh size of between 0.25 mm and 10 mm, and the re-agglomeration sieve 6 has a mesh size greater than or equal to the mesh size of the crumbling sieve 5 to ensure that the granules 3 which pass through the crumbling sieve 5 can pass through the re-agglomeration sieve 6 and not become trapped in the pellets 7. For example, the mesh size of the re-agglomeration sieve 6 may be between 0.25 mm and 10 mm. Similarly, all the re-agglomeration sieves 6 may have a mesh size greater than or equal to the mesh size of the crumbling sieve 5. Preferably, at least two re-agglomeration sieves 6, and preferably all, have the same mesh size.

[0091] Of course, the invention is in no way limited to the sole exemplary embodiments described above, the person skilled in the art being able in particular to isolate or freely combine one or other of the aforementioned characteristics, or to substitute equivalents for them.

Claims

CLAIMS 1. Separation method allowing, from a mixture (1) of components (2, 3) comprising a first family of components (2) formed by fibers (2) and a second family of components (3) formed by granules (3), to separate the fibers (2) from the granules (3), said method being characterized in that it comprises: - a brushing step, during which the mixture (1) is subjected to the combined action of a brush (4) and a first sieve (5), called a "crumbling sieve" (5), said brush (4) and said crumbling sieve (5) being in relative movement called a "brushing movement" with respect to each other, so that the brush rubs the mixture against the crumbling sieve to disentangle the fibers and dissociate the components (2, 3) of the mixture from each other, and thus generate, through the crumbling sieve, a shower of dissociated fibers (2) and granules (3), - then a fiber re-agglomeration step, during which the rain of fibers (2) and granules (3) from the crumbling sieve (5) is collected on a second sieve (6), called the "re-agglomeration sieve" (6), which is driven by a vibrating movement, so that at least a portion of the fibers (2) is caused to re-agglomerate on the surface of said re-agglomeration sieve (6) in the form of fiber balls (7) which are retained by said re-agglomeration sieve (6) while the granules (3) pass through said re-agglomeration sieve (6).

2. Method according to claim 1 characterized in that the crumbling sieve (5) has asperities on its surface receiving the mixture (1), so that said crumbling sieve (5) forms a grater against the brush (4) during the brushing movement (M4).

3. Method according to claim 1 or 2, characterized in that the brush (4) has flexible bristles, preferably made of polymer material, the free ends of which are pressed against the surface of the crumbling sieve (5) in order to cause, during the brushing movement (4), a jerky alternation of bending and straightening of said bristles, which causes a beating of the mixture (1) present on the surface of the crumbling sieve (5).

4. Method according to one of the preceding claims, characterized in that the brush (4) extends on the lateral face (10A) of a cylindrical rotor (10) with a horizontal axis (Y10), and in that the crumbling sieve (5) forms a basket (11) which is delimited by a first lateral wall (12) which extends along the horizontal axis (Y10) of the rotor, on a first side of the horizontal axis (Y10) of the rotor, and by a second lateral wall (13) which extends along the axis of the rotor, on a second side of the axis of the rotor (Y10) opposite the first side, the first and second lateral walls (12, 13) being inclined relative to each other so as to converge towards a base (14) in the form of an arc of a circle, with which the brush (4) cooperates.

5. Method according to one of claims 1 to 3, characterized in that the brush (4) extends over a lower front face (20F) of a rotor (20) with a vertical axis (Z20), and in that the surface of the crumbling sieve (5) with which the brush (4) cooperates extends substantially horizontally.

6. Method according to one of claims 1 to 3, characterized in that the crumbling screen (5) forms an inclined plane (30) relative to the horizontal, on which the brush (4) moves according to a brushing movement (M4) which comprises at least one component of alternating movement transverse to the direction of the slope of the inclined plane (30), and in that the brush (4) comprises one or more brushes (31) which delimit, projecting from the inclined plane (30), one or more retention tanks (32), preferably U-shaped or V-shaped, which are open towards the upstream of the slope of the inclined plane (30), so as to be able to receive the mixture (1) to be brushed, and closed towards the downstream, so as to be able to regulate the flow of the mixture (1) along the slope of the inclined plane (30) during the execution of the alternating brushing movement.

7. Method according to one of the preceding claims, characterized in that it comprises, before the brushing step, a grinding step during which the mixture (1) is passed through a knife mill (40) which comprises a rotor (41) with a horizontal axis (Y41) provided with a first set of knives (42), which thus form movable knives, which rotor cooperates with a stator (43) provided with a second set of knives (44), forming fixed knives, said stator (43) being provided, following the fixed knives (44), in the direction of rotation, of a grid (45) which allows the mixture (1), once it has been ground sufficiently finely by the knives (42, 44), to leave the grinder (40) through the grid (45), to reach a brushing stage (101) comprising the brush (4) and the crumbling sieve (5).

8. Method according to claims 4 and 7 characterized in that the grinding step and the brushing step are carried out within the same apparatus which comprises a rotor (41) with a horizontal axis (Y41) which comprises on the one hand at least a first set of knives (42) which are arranged in one or more angular sectors of the rotor extending in azimuth around the axis of the rotor, and which are arranged to cooperate with a second set of knives (44), fixed on the stator (43) of the apparatus, in order to carry out grinding of the mixture (1), and on the other hand, in one or more angular sectors of the rotor (41) distinct from the angular sectors carrying the first set of knives (42), one or more brushes intended to ensure brushing of the mixture against the grid (45) of the stator which forms the crumbling sieve (5).

9. Method according to one of the preceding claims, characterized in that it comprises a second step of re-agglomeration of fibers, during which the fibers (2) passed through the crumbling sieve (6) during the step of re-agglomeration of fibers are collected in a third, vibrating sieve, forming a second re-agglomeration sieve (6 2), so as to cause, on the surface of said second re-agglomeration sieve (6 2), a re-agglomeration of at least a portion of said fibers (2) in the form of fiber balls which are retained by said second re-agglomeration sieve (6 2) while the granules (3) pass through said second re-agglomeration sieve (6 2).

10. Method according to one of the preceding claims, characterized in that the crumbling sieve (5) has a mesh size of between 0.25 mm and 10 mm, and the reagglomeration sieve (6) has a mesh size greater than or equal to the mesh size of the crumbling sieve (5).

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