METHOD FOR SEPARING THE COMPONENTS OF A MIXTURE OF FIBERS AND GRANULES COMPRISING A STEP OF UNTANGLING THE MIXTURE BY BRUSHING THROUGH A SIEVE

Abstract

The present invention relates to a separation process for separating the fibers (2) from the granules (3) of 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). The process comprises a brushing step, during which the mixture (1) is subjected to the combined action of a brush (4) and a crumbling sieve (5) to generate a shower of dissociated fibers (2) and granules (3), followed by a fiber re-agglomeration step, during which the shower of fibers (2) and granules (3) is collected on a re-agglomeration sieve (6), which is vibrated, causing at least a portion of the fibers (2) to re-agglomerate on the surface of said re-agglomeration sieve (6) in the form of fiber pellets (7). Figure 5

Description

Title of the invention: METHOD FOR SEPARING THE COMPONENTS OF A MIXTURE OF FIBERS AND GRANULES COMPRISING A CLOTHING-DRYING STEP OF THE MIXTURE BY BRUSHING THROUGH A SIEVE

[0001] The present invention relates to the general field of separation installations and processes intended to separate the different components of a mixture containing fibers and granules, in particular for the purpose of recycling the materials which are respectively constitutive of these different components.

[0002] The invention finds more particularly 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 processing of mixtures whose components are millimeter and sub-millimeter in size, that is to say in particular to the processing of mixtures which contain fibers whose diameter is between 10 pm and 1 mm for a length between 1 mm and 10 mm, and granules whose equivalent diameter is between 125 pm and 5 mm.

[0004] Various separation processes are known, including electrostatic separation processes in which the components of the mixture are given, for example by tribocharging, electrostatic charges whose polarity differs depending on whether it is a fiber or a granule, then the fibers 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 according to the polarity of the charge of said component.

[0005] However, the efficiency of known processes can still be improved, particularly with regard to their yield in terms of quantity of mixture treated per unit of time, and therefore 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 has an improved yield, and allows to efficiently process large quantities of mixture of fibers and granules.

[0007] The objects assigned to the invention are achieved by means of a separation process enabling, 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 stage, during which the mixture is subjected to the combined action of a brush and a first sieve, called the "crumbling sieve," said brush and said crumbling sieve being in relative motion, called the "brushing motion," with respect to each other, so that the brush rubs the mixture against the crumbling sieve to disentangle the fibers and separate the components of the mixture from one another, and thus generate, through the crumbling sieve, a shower of dissociated fibers and granules, - then a fiber re-agglomeration stage, during which the shower of fibers and granules from the crumbling sieve is collected on a second sieve, called the "re-agglomeration sieve," which is animated by a vibrating motion, so that, on the surface of said re-agglomeration sieve,a re-agglomeration of at least a portion of the fibers in the form of fiber pellets which are retained by said re-agglomeration sieve while the granules pass through said re-agglomeration sieve.

[0008] Advantageously, the brushing step allows the mixture to be diffused, in a way to be sprayed, in the form of a fine but fairly dense rain, and over a fairly wide area, and thus to treat a large flow of mixture efficiently and simultaneously.

[0009] The mechanical sorting carried out by the sieves, and in particular according to the principle of re-agglomerating the fibers into pellets on a vibrating sieve, after separation of the components of the mixture by rain, advantageously allows to collect in a simple, fast and efficient way relatively pure fiber pellets, almost or entirely free of residual granules, while avoiding clogging the re-agglomeration sieve.

[0010] The fiber pellets can also be easily removed, 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] A large and continuous flow of mixture can thus be processed, with a high sorting efficiency.

[0012] Other objects, features and advantages of the invention will become apparent in more detail from the following description and with the aid of the accompanying drawings, which are provided by way of illustration only and are not intended to be limiting, among which:

[0013] Figures [Fig. 1A] and [Fig. 1B] illustrate, in perspective views, respectively full and cross-sectional in a vertical plane, an example of an installation for implementing the process according to the invention, said installation forming a tower which includes in its upper part a brushing stage, provided here with a horizontally oriented brush cooperating with a curved crumbling sieve, and below which Following one another vertically, a plurality of re-agglomeration stages are formed, each consisting of a re-agglomeration tank whose bottom is equipped with a re-agglomeration screen. When the mixture, broken up by the brushing stage, falls by gravity through the tower, it passes through the re-agglomeration stages which allow the fibers 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 fibers, that is to say having a higher fiber content than the initial mixture, this first product corresponding to the fiber pellets generated by the re-agglomeration screens 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 higher granule content than the initial mixture.

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

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

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

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

[0018] Fig. 6A, Fig. 6B and Fig. 6C illustrate, according to schematic views respectively in perspective, side and top, a third possible arrangement of brushing stage, comprising a crumbling sieve which forms an inclined plane and a brush which includes, 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 motion, transverse to the slope of the inclined plane.

[0019] Fig. 7 illustrates, according to a cross-sectional view in a vertical plane, a rotary mill ensuring grinding of the mixture prior to the brushing stage.

[0020] The present invention relates to a separation process 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.

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

[0022] At least a part, 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 shall have a length 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, shall be between 10 pm and 1 mm.

[0023] The process 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 significantly 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 cylindrical fiber 2, 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 of a natural or synthetic textile material, and more preferably of a polymer or a combination of polymers from among (non-exhaustive list): polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and nylon or polyamide (PA).

[0026] Furthermore, at least part 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 between 125 pm and 5 mm, and a shape factor between 1 and 2.

[0027] By "equivalent diameter" is meant the diameter that a fictitious sphere would have which would occupy 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 diameter of Féret The maximum diameter is the maximum observable distance for the given granule 3 between two parallel lines tangent to opposite sides of that granule 3. The minimum diameter is the minimum observable distance for the given granule 3 between two parallel lines tangent to opposite sides of that granule. This shape factor provides a good indication of the slenderness of the granules. For reference, a sphere has a shape factor of 1, and a cube has a shape factor equal to the square root of 2.

[0029] The invention will of course also relate to an installation 100 enabling the process to be implemented.

[0030] According to the invention, the process includes 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 motion said "brushing motion" 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 prisoners of masses of entangled 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 ​​the sieve 5, and thus allow to generate a high flow rate of rain of fibers 2 and granule 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 preferentially individualized.

[0035] Said rain falls preferably by simple gravity, after passing through the crumbling sieve 4.

[0036] The process then comprises a step (S2) of fiber re-agglomeration, during from 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 animated by a vibrating movement, so that at least a part of the fibers 2 are re-agglomerated 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 indeed discovered that by subjecting the fibers 2 previously finely separated by the brushing operation to the vibrations of a sieve 6, the said fibers, free of granules 3, spontaneously re-aggregate to form balls of tangled fibers 2, of substantially spherical shape, called "balls" 7.

[0038] The fiber pellets 7 having dimensions, here diameters, greater than the mesh size of the re-agglomeration sieve 6, this allows the fibers 2 to be retained on said re-agglomeration sieve 6, while the latter lets the free granules 3 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 pellets 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 pellets 7 roll spontaneously, under the effect of vibrations, towards a peripheral collector.

[0042] It should also be noted that, if the mixture contains large granules with a diameter greater than the mesh size of the crumbling sieve 5, these granules, after being separated from the fibers 2 by brushing, can be recovered at the level of said crumbling sieve 5. This recovery of large granules can be carried out intermittently on the crumbling sieve, or continuously. Preferably, a means of removing the large granules from the crumbling sieve 5 is provided, for example by tilting the crumbling sieve 5 or any other arrangement allowing the granules to move. The large granules recovered at the level of the crumbling sieve 5 can be returned to a sieving and / or grinding circuit in order to eliminate, for example by crushing, the large, overly solid granules and possibly to reintroduce their components into the mixture 1.

[0043] Advantageously, the process according to the invention is a dry process, which uses neither liquid nor solvent. The process is also simple to implement and very low energy consumption, particularly in terms of electrical energy, and no danger to 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 rasp against the brush 4 during the brushing movement M4.

[0045] By way of example, if the crumbling sieve 5 is formed by a wire mesh, preferably a metal wire mesh, the asperities may be formed by protruding portions of said mesh, for example, protruding bends formed in the wires of the mesh. If the crumbling sieve 5 is formed by a sheet, metallic or rigid polymer, perforated by slits, the asperities may correspond to the protruding edges of said slits.

[0046] Advantageously, the roughness conferred by the asperities, and the resulting alternation of protrusions and hollows 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 granules 3, and the expulsion in a 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 brushing 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 the mixture 1 present on the surface of the crumbling sieve 5 to be beaten.

[0049] The inventors have indeed observed that the multiplicity of hairs, and therefore the multiplicity of elastic deformation movements in bending of each of the hairs, makes it possible to multiply the beating and scraping actions of the mixture 1 against the crumbling sieve 5, and in particular against the asperities of its surface, which ensures an effective crumbling of the mixture 1 and then an 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 IA, IB, 2A, 2B and 2C, the brush 4 extends over 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 circumference of the rotor 10, or in tufts forming brushes spaced apart from each other, for example arranged in a staggered pattern with respect to each other.

[0053] By "horizontal", it is indicated that the element considered, here the axis Y10 of the rotor 10, around which said rotor 10 rotates on itself to perform the brushing movement M4 relative to the fixed crumbling sieve 5, forms an angle with respect 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 lateral 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 lateral wall 13 which extends along the horizontal axis Y10 of the rotor, on a second side of the axis of the rotor opposite to the first side, the first and second lateral 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 in V or U, creates a kind of funnel, and more particularly a hopper, between the brush 4 and a corresponding lateral wall 12, 13, a funnel which will include a movable face, formed by the free surface of the brush 4, and a fixed face, formed by the lateral wall 12, 13 located opposite the brush 4, and which will therefore tend to pinch, advance, and thus 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 lateral walls 12, 13 will preferably be flat and parallel to the central axis Y10 of the rotor 10.

[0058] The base 14 will preferably have a shape conjugate to 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, shall be pierced by the orifices of the crumbling sieve 5.

[0061] A feed weir 15 intended to supply 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, makes the brush 4 converge towards the lateral wall 13.

[0062] The feed weir 15 can 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 3A, 3B, 4A and 4B, the brush 4 extends over a lower front face 20F of a rotor 20 with a vertical axis Z20.

[0064] The front face 20F can be in the form of a disk, 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 extending 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 the arms 21 forming the front face 20F.

[0066] The bristles of the brush 4 may 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 with one brush 22 attached to each arm 21, and more particularly with four brushes each attached to one of four radial arms equally distributed in azimuth around the vertical axis Z20, as can be partially seen in [Fig.3B].

[0068] By "vertical", it is indicated that the element considered, here the axis Z20 of the rotor 20, around which said rotor 20 rotates on itself to perform the brushing movement M4 relative to the fixed crumbling sieve 5, forms an angle with respect 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 sieve 5 with which the brush 4 cooperates extends preferably substantially in a horizontal plane, normal to the vertical axis Z20 of the rotor 20.

[0070] It should be noted in this regard that the surface of the crumbling sieve 5 may possibly have a convex shape to promote the evacuation towards the periphery of the crumbling sieve 5 of large granules 3, which are too large to pass through the mesh of said crumbling sieve 5.

[0071] Similarly, the brushes 22 may optionally have a yaw angle chosen, with respect 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 yaw angle chosen and the direction of rotation of the rotor 20 around the vertical axis Z20.

[0072] It should be noted that the brush 4 can be animated 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 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 sieve 5 forms an inclined plane 30 with respect to the horizontal, on which the brush 4 moves according to a brushing motion M4 which includes at least one alternating displacement component transverse to the direction of the slope of the inclined plane 30.

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

[0075] According to this third arrangement, the brush 4 preferably includes one or more brushes 31 which delimit, projecting on the inclined plane, one or more retention reservoirs 32, preferably in the shape of U or V, which are open upstream of the slope of the inclined plane 30, so as to be able to receive the mixture 1 to be brushed, and closed 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 brushes 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] As can be seen in Figures 6A and 6C, at least one row 33 of several retention tanks 32 can be formed side by side 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 can be provided distributed along the slope of the inclined plane 30.

[0079] Advantageously, this third arrangement, in particular when implementing several rows 33 of retention tanks 32, makes it possible to maximize the effective surface of the crumbling sieve 5, on which the mixture spreads and is subjected to the action of the brush 4, in relation to the ground footprint of the crumbling sieve, that is to say in relation to the extent of the surface of the crumbling sieve considered in vertical projection in a horizontal plane.

[0080] In addition, such an arrangement allows the mixture 1 initially received and contained in the retention tanks 32 of a first row 33 to be distributed, under the combined action of gravity and the brushes 31 of said first row 33, into a second row located below the first row, a part of the mixture 1 being thus 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, the useful brushing surface is maximized, while maintaining a relatively compact installation.

[0082] Furthermore, with reference to [Fig.7], the process may include, before the brushing step (SI), a grinding step (S0) during which the mixture is passed through a grinder 40 which includes a horizontal axis rotor 41 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 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 provide a mixture 1 whose size of fibers 2 and granules 3 is adapted to the mesh of the crumbling 5 and re-agglomeration 6 sieves.

[0084] According to one possible embodiment, the grinding step (S0) and the brushing step (SI) are carried out within the same apparatus which includes a horizontal axis rotor 41 Y41 which includes, 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 grind 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 over a knife 44, for example by a cam system or equivalent.

[0085] Installation 100 will thus be able to gain in compactness.

[0086] According to a preferred embodiment, the process includes a second step (S2_2) of fiber re-agglomeration, in which the fibers 2 that passed through the re-agglomeration sieve 6 during the step (S2) of fiber re-agglomeration 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 part of said fibers 2 in the form of fiber pellets which are retained by said second re-agglomeration sieve 6_2 while the granules pass through said second re-agglomeration sieve 6_2.

[0087] It will thus be possible to provide, in order to perfect the refining of the granule stream 3, a third or even a fourth fiber re-agglomeration stage 2, on a third, respectively a fourth re-agglomeration screen 6_3, 6_4.

[0088] The re-agglomeration sieves will preferably be arranged vertically above each other, so as to allow the mixture to circulate by gravity through the different levels.

[0089] More generally, the installation 1 may advantageously take the form of a tower, as can be seen in Figures IA, IB, 3A and 3B, which includes, from top to bottom, a brushing stage 101, comprising the brush 4 and the crumbling sieve 5, possibly preceded by, or associated with, a grinding stage, and below which there will be at least one re-agglomeration stage 102, preferably several successive re-agglomeration stages 102, each comprising a re-agglomeration tray 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 between 0.25 mm and 10 mm, and the re-agglomeration sieve 6 has a mesh size greater than or equal to that of the crumbling sieve 5 to ensure that the granules 3 passing through the crumbling sieve 5 can also 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 that of the crumbling sieve 5. Preferably, at least two, and preferably all, of the re-agglomeration sieves 6 have the same mesh size.

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

Claims

Demands

1. A separation process for separating the fibers (2) from the granules (3) of a mixture (1) of components (2, 3) comprising a first set of components (2) formed by fibers (2) and a second set of components (3) formed by granules (3), said process 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 motion, called a "brushing motion," with respect to each other, such that the brush rubs the mixture against the crumbling sieve to disentangle the fibers and separate the components (2, 3) of the mixture from one another, and thus generate, through the crumbling sieve, a shower of fibers (2) and dissociated granules (3), - followed by 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 animated by a vibrating motion, so that a re-agglomeration of at least a part of the fibers (2) is caused 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. The 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 rasp against the brush (4) during the brushing movement (M4).

3. A 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 the mixture (1) present on the surface of the crumbling sieve (5) to be beaten.

4. A method according to any one of the preceding claims, characterized in that the brush (4) extends over the lateral face (10A) of a cylindrical rotor (10) with a horizontal axis (Y 10), 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 (Y 10) of the rotor, on a first side of the horizontal axis (Y 10) 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 (Y 10) opposite to the first side, the first and second lateral walls (12, 13) being inclined relative to each other so as to converge towards a bottom (14) in the shape of an arc of a circle, with which the brush (4) cooperates.

5. A method according to any 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. A method according to any one of claims 1 to 3 characterized in that the crumbling sieve (5) forms an inclined plane (30) with respect to the horizontal, on which the brush (4) moves according to a brushing motion (M4) which includes at least one alternating displacement component transverse to the direction of the slope of the inclined plane (30), and in that the brush (4) has one or more brushes (31) which delimit, projecting from the inclined plane (30), one or more retention reservoirs (32), preferably in the shape of a U or a V, which are open upstream of the slope of the inclined plane (30), so as to be able to receive the mixture (1) to be brushed, and closed 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 motion.

7. A method according to any one of the preceding claims characterized in that it comprises, before the brushing step, a grinding step in which the mixture (1) is passed through a knife mill (40) comprising a horizontally oriented rotor (41) (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, with a grid (45) which allows the mixture (1), once ground sufficiently finely by the knives (42, 44), to leave the mill (40) through the grid (45), to reach a brushing stage (101) comprising the brush (4) and the crumbling sieve (5).

8. A 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 includes a horizontal axis rotor (41) (Y41) which includes, 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 achieve a 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 a brushing of the mixture against the grid (45) of the stator which forms the crumbling sieve (5).

9. A method according to any one of the preceding claims characterized in that it comprises a second fiber re-agglomeration step, during which the fibers (2) that passed through the crumbling sieve (6) during the fiber re-agglomeration step 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 part of said fibers (2) in the form of fiber pellets 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. A method according to any one of the preceding claims characterized in that the crumbling sieve (5) has a mesh size 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).

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