WO2024218460A1 - Waste crusher - Google Patents

Abstract

The crusher (100) for crushing items of waste comprises: a chassis (101); a single drive shaft (102) movable in rotation with respect to the chassis (101) about an axis (Al); knives (103) mounted on the drive shaft (102) so as to rotate as one with the drive shaft (102) about said axis (Al) in at least one crushing direction (F1). The knives (103) are arranged so as to completely or partially define at least one receiving region (104a, 104b) capable of receiving, during the rotation of the shaft (102) in the crushing direction (F1), at least one part of a waste item that is to be crushed. The knives (103) are arranged such that at least one of the knives (103a) makes it possible to grip said waste item to be crushed, said at least one part of which waste item is positioned in said receiving region (104a, 104b).

Description

Waste crusher

Technical field of the invention

[0001] The technical field of the invention relates to the grinding of waste, in particular bottles, for example with a view to enabling their recycling. More particularly, the invention relates to a grinder for grinding waste.

State of the prior art

[0002] In the field of recycling plastic bottles, for example PET corresponding to the acronym “polyethylene terephthalate”, it is known to crush the bottles to obtain a source of material to be recycled.

[0003] A recurring problem in grinding is the capture of waste to be ground by the grinder blades. To enable this, it is for example possible to exert a force on waste to be ground to urge it towards the blades so that the latter can engage with said waste which is then ground as the blades rotate. This solution is not suitable because it requires providing a grinder comprising an energy-consuming stress element which complicates the grinder.

[0004] According to an example of a known crusher, the latter comprises two sets of knives each associated with a movable shaft rotating along an axis of rotation. The rotation of the two shafts then substantially parallel allows the knives of the two sets of knives to cooperate together to crush waste. Such an example of crusher is bulky and energy-consuming.

Subject of the invention

[0005] The invention aims to limit the size of the crusher.

[0006] For this purpose, the invention relates to a crusher for crushing waste, said crusher comprising: a chassis; a single drive shaft movable in rotation relative to the chassis about an axis; knives mounted on the drive shaft so as to be integral in rotation with the drive shaft about said axis in at least one crushing direction. The knives are staggered along the drive shaft according to the axis. The knives are arranged so as to delimit in whole or in part at least one receiving region capable of receiving, during the rotation of the shaft in the crushing direction, at least a portion of waste to be crushed. The knives are arranged so that at least one of the knives makes it possible, during the rotation of the shaft in the crushing direction, to grip said waste to be crushed, said at least a portion of which is positioned in said receiving region.

[0007] Such a crusher has the advantage that its size is limited because only one shaft is mobile. In addition, the presence of the reception region has the advantage of providing a reservation where the seizure of the waste is favored. In other words, the region reception allows the insertion of the waste to be crushed directly into a volume, for example cylindrical, depending on the dimensions of the knives in order to facilitate its grip.

[0008] The grinder may further comprise one or more of the following features.

[0009] According to a characteristic of the grinder, each knife comprises teeth offset from each other angularly around the axis, each tooth comprising a gripping tip.

[0010] Thus, the use of several teeth per knife makes grinding easier.

[0011] According to a characteristic of the crusher, for any pair of adjacent knives, the teeth of one of the knives of said pair are at a distance from the teeth of the other of the knives of said pair along the axis.

[0012] This thus allows the knives of each pair of knives to define a cutting width in order to obtain calibrated ground material.

[0013] According to a characteristic of the grinder, at least one of the knives comprises two teeth whose gripping points are diametrically opposed relative to the axis, for example the two teeth are axially symmetrical along the axis.

[0014] This makes it possible to optimize the setting time of the waste to be ground in the sense that said waste to be ground will have an opportunity to be gripped by the grinder at each half-turn made by the two-toothed knife whose gripping points are diametrically opposed relative to the axis.

[0015] According to a characteristic of the crusher, it comprises a sieve secured to the chassis, the sieve being configured to allow the passage of crushed material from the crushing through the crusher. [0016] This makes it possible to calibrate the crushed material at the outlet of the crusher in an appropriate manner.

[0017] According to a characteristic of the grinder, at least one of the knives is configured so as to have at least one end passing, at each turn made by said knife, close to the sieve at a distance of between 1 mm and 4 mm, and preferably equal to 2.5 mm.

[0018] Such a configuration of the knife allows it to stir the crushed material retained by the sieve in order to facilitate the passage of the crushed material through the sieve or for elements of the crushed material whose dimensions do not allow their passage through the sieve to be driven to be cut by the crusher in order to reduce their size.

[0019] According to a characteristic of the grinder, at least one of the knives comprises at least three teeth.

[0020] The presence of three teeth improves the grip of the waste.

[0021] According to a characteristic of the crusher, among said at least three teeth, two teeth of these three teeth have different sizes.

[0022] This difference in size makes it possible to improve the capture of the waste to be ground in the sense that it makes it possible to adapt to the morphology of the waste to be ground and/or to the way in which the waste to be ground appears upon arrival in the grinder.

[0023] According to a characteristic of the crusher, said receiving region is arranged laterally to a first tooth formed by one of the teeth of a first of the knives, and a second tooth formed by one of the teeth of a second of the knives is arranged in an angularly offset manner around the axis and behind the first tooth according to the grinding direction.

[0024] Thus, the second tooth makes it possible to grip the corresponding waste when the latter is present in the receiving region. In addition, such a configuration makes it possible to guarantee rapid and systematic gripping while limiting the efforts of the crusher, and in particular by limiting the number of knives engaged with the waste.

[0025] According to a characteristic of the crusher, each tooth comprises a curved cutting blade ending in the gripping tip of said tooth.

[0026] The curvature of the cutting blade associated with the gripping tip makes it possible to form a “claw” facilitating the gripping of waste to be crushed or during crushing.

[0027] According to a feature of the grinder, the curved cutting blade is serrated.

[0028] This makes it possible to break the material to be ground just before cutting it, thus limiting the forces on the drive shaft.

[0029] According to a characteristic of the grinder, the knives delimit in whole or in part several reception regions and the grinder comprises:

• a first grinding chamber housing a first part of the knives;

• a separator;

• a second grinding chamber, separated from the first grinding chamber by the separator crossed by the drive shaft, the second grinding chamber housing a second part of the knives; the knives of the first part of the knives being arranged so as to form, in the first grinding chamber, at least one of the receiving regions and the knives of the second part of the knives being arranged so as to form, in the second grinding chamber, at least one of the receiving regions.

[0030] The use of first and second grinding chambers makes it possible to grind waste separately, for example according to a predetermined characteristic such as its color, to obtain two separate deposits of material, for example in the form of flakes ready for recycling.

[0031] According to a characteristic of the crusher, it comprises a block of counter-knives arranged to cooperate with the knives, the block of counter-knives being for example fixed to the chassis, in particular on a single internal face of the chassis.

[0032] The counter-knives make it possible to provide a temporary stop for material from waste or scrap before cutting this material by cooperation between one or more knives with one or more counter-knives. The fixed counter-knives make it possible to limit the size, unlike two sets of moving knives facing each other.

[0033] According to a characteristic of the crusher, it comprises an additional block of counter-knives angularly offset along the axis relative to the block of counter-knives.

[0034] This makes it possible to integrate an additional cutting function into the grinder to reduce the time required to grind waste.

[0035] According to a characteristic of the crusher, it comprises a comb configured for cooperate with the knives to disentangle material caught in the knives, said cooperation being enabled by rotating the drive shaft in a direction opposite to the grinding direction.

[0036] The comb allows, due to the disentangling that it allows, to limit the power of the grinder since this will de facto limit the efforts of the knives by avoiding having to cut tangled material from the waste(s).

[0037] According to a characteristic of the crusher, the comb and the additional block of counter-knives form the same part.

[0038] Thus, the same part has two different functions depending on the direction of rotation of the shaft around the axis, thereby reducing the number of parts and, where appropriate, the overall size of the crusher.

[0039] According to a feature of the crusher, the comb is fixed to the frame opposite the counter-knife block.

[0040] Thus, a simple change in the direction of rotation by imposing a half-turn may be sufficient to unblock an entanglement situation.

[0041] The invention also relates to a device for crushing waste comprising a crusher as described and a guide duct comprising an inlet for introducing waste into the guide duct, the guide duct being configured to guide the waste previously introduced into the guide duct towards the crusher.

[0042] Such a device for crushing waste has advantages in relation to the crusher it comprises. In particular, it makes it possible to ensure efficient crushing while having a limited footprint.

[0043] Other advantages and characteristics may emerge from the detailed description which follows.

Brief description of the drawings

[0044] The invention will be better understood upon reading the detailed description which follows, given solely as a non-limiting example and made with reference to the appended drawings listed below.

[0045] Figure 1 illustrates a perspective view of a crusher according to a particular embodiment of the invention.

[0046] Figure 2 illustrates the grinder of Figure 1 in a view looking towards the top of the grinder to visualize an arrangement of grinder knives mounted on a drive shaft belonging to the grinder.

[0047] Figure 3 illustrates the grinder of Figure 2 with the knives removed to view other parts of the grinder.

[0048] Figure 4 illustrates the grinder of Figure 1 but in another perspective view to visualize the underside of the grinder.

[0049] Figure 5 illustrates in a perspective view the drive shaft, extracted from the crusher of figure 1, on which the knives are mounted.

[0050] Figure 6 illustrates in a side view the drive shaft, extracted from the crusher of Figure 1, on which the knives are mounted.

[0051] Figure 7 illustrates a first type of knife that can equip the grinder according to the invention.

[0052] Figure 8 illustrates a second type of knife that can be fitted to the grinder according to the invention.

[0053] Figure 9 illustrates a sectional view of the crusher taken perpendicular to the axis A1 of Figure 3 and along the section plane B-B.

[0054] Figure 10 illustrates a sectional and perspective view of one half of the crusher of Figure 3 for which the drive shaft and the knives have been removed to clearly visualize other parts of the crusher, the section being made along the cutting plane C-C visible in Figure 3 and passing through the axis Al.

[0055] Figure 11 is a supplementary view to Figure 10 in that it shows the other half of the grinder and in which the drive shaft and knives have also been removed to clearly view other parts of the grinder.

[0056] Figure 12 is a schematic side view of a device for crushing waste, this device comprising the crusher.

[0057] Figure 13 is a sectional view of the waste crushing device of Figure 12 taken along a section plane parallel to the plane of Figure 12 and schematically showing a first configuration of the waste crushing device.

[0058] Figure 14 is a sectional view of the waste crushing device of Figure 12 taken along a sectional plane parallel to the plane of Figure 12 and schematically showing a second configuration of the waste crushing device.

[0059] Figure 15 illustrates a particular embodiment of a grinder knife.

[0060] In these figures, the same numerical references are used to designate the same elements. The elements represented in the different figures are not necessarily made to scale in order to facilitate the understanding of the figures.

Detailed description

[0061] By “substantially parallel” is meant parallel or parallel to plus or minus 10 degrees.

[0062] By between two values, it is understood that the corresponding range of values includes said two values.

[0063] The crushing of waste 10 makes it possible to reduce logistics costs in the sense that the volume of waste 10, for example to be transported from a collection point to a treatment point in a process of recycling this waste, is thus reduced.

[0064] The waste 10 may be of elongated shape. For example, the waste 10 may be bottles as schematically represented in FIGS. 13 and 14. The bottles may be made of PET (acronym for “polyethylene terephthalate”).

[0065] The crushed material is considered to be the result of the crushing of waste(s) 10, the crushed material is therefore formed by elements, called crushed elements, resulting from the crushing of the waste(s) 10, in particular by cutting or dicing.

[0066] In the field of crushing bottles as waste 10, the crushed material is also called chips or flakes.

[0067] Where appropriate, the ground material may be used to manufacture granules which form an intermediate product usable as a raw material for manufacturing new objects of any type capable of being formed using granules, such as for example new bottles when the granules (then obtained using flakes) are made of light-coloured PET. Where appropriate, the ground material is cleaned, i.e. decontaminated, before forming the granules, for example by extrusion, which will be used to manufacture new objects.

[0068] The invention relates to a crusher 100 for crushing waste 10, a particular embodiment of this crusher 100 is illustrated in particular in FIGS. 1 to 4. The crusher 100 comprises a frame 101 and a single drive shaft 102 movable in rotation relative to the frame 101 about an axis Al. The axis Al therefore corresponds to the rotation axis of the drive shaft 102. Knives 103 are mounted on the drive shaft 102 so as to be integral in rotation with the drive shaft 102 about said axis Al in at least one grinding direction El. The knives 103 are staggered along the drive shaft 102 along axis A1 (i.e. the knives 103 are offset from each other in the direction of axis A1) as shown in particular in FIGS. 1, 2, 5 and 6; Figures 5 and 6 showing the drive shaft 102 and the knives 103 disengaged from the rest of the crusher 100. The knives 103 are arranged so as to delimit in whole or in part at least one receiving region 104a, 104b (in Figures 1, 2 and 5 two receiving regions 104a, 104b are shown diagrammatically using quadrilaterals shown in dotted lines) capable of receiving, during the rotation of the drive shaft 102 in the crushing direction E1, at least a portion of a waste 10 to be crushed, the knives 103 being arranged so that at least one of the knives 103b (Figure 1) makes it possible, during the rotation of the drive shaft 102 in the crushing direction E1, to grip said waste 10 to be crushed, said at least one of which a portion is positioned in said receiving region 104a, 104b. Therefore, the or each receiving region 104a, 104b belongs to the crusher 100 and forms a housing for receiving said at least one portion of the corresponding waste 10 to be crushed.

[0069] The person skilled in the art will then understand that the knives 103 are preferably configured and arranged in a certain manner to reserve at least one clearance capable of being positioned during the rotation of the knives to be accessible between an inlet 105a (FIGS. 1 and 2) of the grinder 100 and the drive shaft 102. This makes it possible to present, during the rotation of the drive shaft 102 in the grinding direction E1 (in particular periodically), the receiving region 104 opposite the inlet 105a in order to insert said at least one portion of the waste 10 into the receiving region 104 and in order to allow it to be gripped by at least one of the knives 103 in order to allow the grinding of said waste 10. [0070] The notions of “above” and “below” are notably given in relation to each other in the frame of reference of the crusher 100 and more particularly in the terrestrial frame of reference in a configuration of use of the crusher 100.

[0071] The inlet 105a mentioned above is for example arranged on the top of the grinder 100.

[0072] The drive shaft 102 may have, over all or part of its length, a hexagonal section which in particular makes it possible to mount the knives 103 on said drive shaft 102 effectively to set these knives 103 in rotation concomitantly with said drive shaft 102. Consequently, the knives 103 may each have a through opening 128 of hexagonal shape complementary to the hexagonal section of the drive shaft 102 as shown for example in FIGS. 7 and 8.

[0073] The drive shaft 102 may be made of steel, in particular the composition of which is adapted to the function of the drive shaft 102 within the crusher 100.4.

[0074] The knives 103 may each be made of steel, in particular, the composition of which is adapted to the function of said knife 103 within the grinder 100.

[0075] The knives 103 can each be a single piece and therefore formed from a single material.

[0076] Said at least one part of the waste 10 mentioned above may be a longitudinal end of this waste 10. When the waste 10 is a bottle, said at least one part of the waste may be the bottom (or base) of the bottle or its neck which respectively form the two opposite ends of the bottle. Where appropriate, depending on the dimensions of the waste 10, all of the waste 10 may be introduced into the corresponding receiving region 104a, 104b.

[0077] To crush plastic bottles, the knives 103 can each have a width (also called thickness) measured parallel to the axis Al of between 8 mm and 12 mm, and in particular equal to 10 mm.

[0078] The grinder 100 may be such that the knives 103 delimit in whole or in part several reception regions 104, 104a (figures 1 and 2) and the grinder 100 comprises:

• a first grinding chamber 106 housing a first part of the knives 103;

• a separator 107;

• a second grinding chamber 108, separated from the first grinding chamber 106 by the separator 107 crossed by the drive shaft 102 (also visible in figure 3 for which the knives 103 have been removed to visualize certain parts of the grinder 100), the second grinding chamber 108 housing a second part of the knives 103.

In this case, the knives 103 of the first part of the knives 103 are arranged so as to form, in the first grinding chamber 106, at least one 104a of the receiving regions 104a, 104b and the knives 103 of the second part of the knives 103 are arranged so as to form, in the second grinding chamber 108, at least one (i.e. at least one other) 104b of the receiving regions 104a, 104b. This makes it possible to grind different wastes 10 separately.

[0079] For example, when recycling bottles as waste 10, the crushed material from light-colored bottles can be used to form new light-colored bottles and the crushed material from dark-colored bottles is not reused to form new dark-colored or light-colored bottles; it is then redirected to other recycling channels to, for example, form textiles or insulation, hence the need for good sorting of the waste 10. Thus, in order to limit the collection points for crushed waste, the presence of the first and second crushing chambers 106, 108 makes it possible to obtain crushed material at the outlet of the crusher 100 formed by different deposits of waste, in particular depending on their color, thus facilitating recycling.

[0080] Generally speaking, in addition to allowing the separation of two deposits of crushed waste, the use of a single drive shaft 102 (the rotation of which allows the rotation of the knives 103 of the first and second grinding chambers 106, 108 mounted on this drive shaft 102) makes it possible to considerably reduce the volume occupied by the crusher and in particular its motor 127, for example mechanically coupled to a toothed end 109 of the drive shaft 102 extending outside the chassis 101. The motor 127 may be part of the crusher 100, or be external to the crusher 100 and mechanically coupled to the drive shaft 102 by any type of suitable means such as, for example, splines on the side of one of the motor 127 and the drive shaft 102 and a gear coupled to the splines on the side of the other of the motor. 127 and drive shaft 102.

[0081] In particular, the separator 107 can participate, with the chassis 101, in delimiting the inlet 105a which then corresponds to the inlet 105a of the first grinding chamber 106 and an inlet 105b of the second grinding chamber 108; these inlets 105a, 105b then being for example both arranged at the level of the top of the grinder 100.

[0082] Each knife 103 may comprise teeth 110a, 110b, 110c offset from each other angularly around the axis A1, each tooth 110a, 110b, 110c then comprising a gripping tip 111a, 111b, 111c. For example, FIGS. 7 and 8 respectively illustrate two types of knives 103 that can be distributed along the drive shaft 102. FIG. 7 shows a knife 103 with two teeth 110a, 110b and FIG. 8 shows a knife 103 with three teeth 110a, 110b, 110c. The multiplication of knives 103 with several teeth 110a, 110b, 110c, and in particular mixed according to the types respectively illustrated in figures 7 and 8 makes it easier to take the waste 10 and therefore to crush it by helping to form the receiving region(s) 104a, 104b.

[0083] According to a particular embodiment, for any pair of adjacent knives 103, the teeth 110a, 110b, 110c of one of the knives 103 of said pair may be at a distance from the teeth 110a, 110b, 110c of the other of the knives 103 of said pair along the axis Al; i.e. there is a spacing of the knives two by two adjacent which are then at a distance from each other. This makes it possible to participate in defining the size/calibration of the elements of the ground material resulting from the grinding at the outlet of the grinder 100 which ultimately may have elements (for example example where applicable these elements are the flakes mentioned above) whose dimensions are such that these elements are each included in a sphere with a diameter of between 10 mm and 14 mm which can more or less correspond to the width of the knives measured in the direction of the axis plus, for example, 10 mm spacing between the adjacent knives which corresponds to the distance mentioned above so as to form strips which will then be cut until obtaining the elements of the ground material which can then exit the grinder 100, and in particular the first and second grinding chambers 106, 108.

[0084] In particular, to ensure that the distance is maintained (between the teeth of two adjacent knives 103 and therefore between the two adjacent knives), the knives 103 are separated two by two, where appropriate in each of the first and second grinding chambers 106, 108, by a spacer 112 mounted on the drive shaft 102 through which this spacer 112 passes, for example visible in FIGS. 1, 2, 6 and 7. Consequently, the grinder 100 may comprise a plurality of spacers 112 distributed along the drive shaft 102.

[0085] For example, at least one of the knives 103 comprises two teeth 110a, 110b whose gripping tips 111a, 111b are diametrically opposed relative to the axis A1, for example the two teeth 110a, 110b are axially symmetrical along the axis A1. This is in particular what is illustrated in FIG. 7. The aim is in particular to optimize the setting time of the waste 10 to be ground. In particular, to promote gripping, at least two knives 103, each comprising two teeth 110a, 110b whose gripping tips 111a, 111b are diametrically opposed relative to the axis A1, are arranged in each of the first and second grinding chambers 106, 108, from which it may result, depending on the arrangement of the knives 103, the presence of at least two opposite reception regions 104a, 104b per grinding chamber (i.e. two reception regions in the first grinding chamber 106 and two reception regions in the second grinding chamber 108).

[0086] The crusher 100 may comprise a sieve 113 secured to the frame 101 (for example visible in FIGS. 3, 4, 9, 10, 11, 13, 14), the sieve 113 being configured to allow the passage of crushed material resulting from the crushing through the crusher 100 (for example the passage of flakes resulting from the crushing of bottles through the crusher 100). Thus, the dimensions of the elements of the crushed material at the outlet of the crusher 100 can be adapted according to the waste recycling channel 10 using the sieve 113. The sieve 113 can be a curved grid or a perforated curved plate, i.e. the curved grid or the curved plate has orifices 114 calibrated in the desired manner for the passage of the elements of the crushed material expected at the outlet of the crusher 100. The sieve 113 serves in particular to retain the lamellae mentioned above so that they are cut until the elements of the crushed material are obtained which can then exit the crusher 100 via the sieve 113.

[0087] Of course, the orifices 114 can be in number, density, shape, diameter adapted to comply with the criteria of requirement of industrial recycling sector of waste 10 crushed by the crusher 100 in order to be part of a process industrial recycling, in particular in the industrial process of recycling plastic bottles, in particular PET. Thus, in the remainder of the description, a plastic bottle may preferably be PET.

[0088] In the example of crushing plastic bottles as waste 10, the diameter of the orifices 114 of the sieve 113 is not equal to the size of the flakes expected at the outlet of the crusher 100. That is to say that to obtain flakes of a size between 10 mm and 12 mm, the orifices 114 will have a diameter strictly greater than this size and for example between 10 mm and 17 mm, and in particular equal to 15 mm. The optimization of the dimensions of the orifices 114 can be carried out by tests carried out empirically on different dimensions of these orifices 114.

[0089] For example, the orifices 114 with a diameter equal to 15 mm can be arranged along lines of orifices 114 extending substantially parallel to the axis A1 and whose pitch between the centers of two adjacent orifices 114 is adapted to maximize the number of orifices 114 while making it possible to maintain a fairly solid screen 113, for example formed in a sheet metal 1.5 mm thick.

[0090] The orifices 114 may be arranged so as to prevent the passage of strips from the waste 10 when it comes to plastic bottles. For this purpose, the orifices

114 may be arranged so as not to be completely opposite the knives 103. For this, an offset of the orifices 114 with the knives of more than half the diameter of the orifices 114 may be provided in order to prevent the lamellae from passing directly through the orifices 114 when the bottle is taken by the crusher 100. [0091] In particular, when the crusher 100 comprises the first and second crushing chambers 106, 108, the separator 107 may comprise a first part

115 and a second part 116 (figures 1 and 4). The first part 115 extends from the inlets 105a and 105b which it helps to delimit until it comes into contact with the sieve 113 to oppose the mixing of what is ground in first and second grinding chambers 106, 108 before the passage of what is ground by the sieve 113. The second part 116 makes it possible to extend the first part 115 with the interposition of a portion of the sieve 113 so as to delimit with the frame 101 outlets 117a, 117b of the grinder 100 respectively forming the outlet 117a of the first grinding chamber 106 and the outlet 117b of the second grinding chamber 108. This makes it possible to avoid mixing of what is ground in the first and second grinding chambers 106, 108 after what is ground has passed through the sieve 113. In other words, the sieve 113 can be formed from a single part/component which makes it possible to locally sieve what is ground in the first grinding chamber 106 and to locally sieve what is ground in the second grinding chamber 108. In particular, the first part 115 and the second part 116 enclose the sieve 113, this being able to give the sieve 113 its shape, in particular when the latter is formed by an openwork sheet. The first part 115 and the second part 116 can be fixed to each other using screws whose body, in particular threaded, passes through the sieve 113.

[0092] To avoid mixing of what is ground in the first and second chambers 106, 108 grinding, the drive shaft 2 can pass through the separator 107 through an opening in the separator 107, this opening being shaped to have dimensions adapted to oppose the passage of ground material between the first and second grinding chambers 106, 108.

[0093] It follows from what has been described above that when a waste 10 is crushed it may be in the form of elements (if applicable in flakes) cut (i.e. crushed) but whose dimensions do not allow the passage of all or part of the elements through the sieve 113 or whose positions result in overlapping of elements opposing their passage through the sieve 113. Therefore, there is a need to find a solution for mixing the elements to promote their passage through the sieve 113 and/or to allow the crusher 100 to cut them again in order to obtain smaller elements. For this purpose, at least one of the knives 103 is configured so as to have at least one end passing, at each turn made by said knife 103, near the sieve 113 at a distance of between 1 mm and 4 mm, and preferably equal to 2.5 mm. Thus, one or more or all of the knives 103 can come along the sieve 113 at a distance of between 1 mm and 4 mm, and preferably equal to 2.5 mm, to mix the elements retained by the sieve 113 (where applicable the elements retained in the first grinding chamber 106 and other elements retained in the second grinding chamber 108). This end of said at least one of the knives 103 is in particular that of one of the teeth of said knife 103. Of course, several knives 103, or even all of the knives 103, may each have at least one such end passing close to the sieve 113 in the manner described to promote the mixing of the elements resulting from the grinding of waste(s) 10 between the drive shaft 102 and the sieve 113. In particular, the fact that said distance is greater than or equal to 1 mm makes it possible to produce the knife(s) 103 running along the sieve 113 with reasonable machining precision and therefore economically viable. In particular, the fact that said distance is less than or equal to 4 mm makes it possible to ensure effective mixing of what is ground, in particular flakes from bottles.

[0094] Preferably, all the knives 103 are arranged so that at least one of the teeth of each of the knives 103 describes a circle coaxial with the axis A1, the circles then make it possible to define a cylindrical volume of diameter equal to that of the circles and the sieve 113 is shaped so as to run along a portion of the cylindrical volume at a distance from this portion of between 1 mm and 4 mm, and preferably equal to 2.5 mm. This portion of the cylindrical volume having a profile delimited by a circular sector of the profile of the cylindrical volume and the sieve 113 therefore running along the portion of the cylindrical volume coaxially with this cylindrical volume and along the arc of the circular sector. The mixing of the ground material retained by the sieve 113, where appropriate in the first grinding chamber 106 and in the second grinding chamber 108, is then improved here.

[0095] The range given above from 1 mm to 4 mm is particularly suitable for the field of crushing plastic bottles, the flakes of which at the outlet of the crusher 100 must preferably each be included in the sphere mentioned above. Before.

[0096] Depending on the waste 10, it is more generally possible to provide a positioning of the sieve 113 so that it is bordered by one or more of the knives 103 at each turn of the latter at a distance between a mounting clearance of the crusher 100 avoiding any direct contact of the knives 103 during their rotation with the sieve 113 and between a value allowing the knives 103 to stir the crushed material. [0097] At least one of the knives 103 may comprise at least three teeth 110a, 110b, 110c, as shown for example in FIG. 8, to improve the gripping of the waste 10 in particular on the side of the inlet(s) 105a, 105b. Although FIG. 8 shows a knife 103 with three teeth 110a, 110b, 110c, it is possible to provide a knife 103 with more than three teeth 110a, 110b, 110c.

[0098] According to one embodiment, among said at least three teeth 110a, 110b, 110c, two 110c, 110a of these three teeth may have different sizes to adapt to different morphologies of waste 10, for example this makes it possible to adapt to the arrival configuration of the waste 10 to be crushed to facilitate its gripping, in particular when it is waste 10 of elongated shape such as a bottle. This is in particular what is visible in FIG. 8 where the tooth 110c is larger than the teeth 110a and 110b. In particular, the tooth 110c is the one which forms the end of the knife 103 which comes along the sieve 113 at each turn of the knife 103 in the grinding direction F1.

[0099] The presence of one or more receiving regions 104a, 104b has been mentioned above. The or each receiving region 104a, 104b may be arranged laterally to a first tooth 118 formed by one of the teeth of a first 103a of the knives, and a second tooth 119 formed by one of the teeth of a second 103b of the knives is arranged in an angularly offset manner around the axis A1 and behind the first tooth 103a in the grinding direction F1. Thus, the first tooth 118 can participate in locally delimiting the volume of the reception region 104a, 104b and the second tooth 119 is arranged to allow the gripping of the waste 10, the portion of which is present in the reception region 104a, 104b during the rotation of the drive shaft 102 in the grinding direction Fl.

[0100] Each tooth 110a, 110b, 110c may comprise a curved cutting blade 120a, 120b, 120c ending in the gripping tip 111a, 111b, 111c of said tooth 110a, 110b, 110c; this being particularly visible in FIGS. 7 and 8. This curvature makes it possible to form claws facilitating crushing by promoting the gripping of waste 10, for example by perforating the latter.

[0101] Advantageously, the crusher 100 may comprise a block 121 of counter-knives 129 (notably visible in FIG. 3, 9 and 11) arranged to cooperate with the knives 103 in order to cut the waste 10 (i.e. grind it), the block 121 of counter-knives being for example fixed to the chassis 101, in particular on an internal face 122 of the chassis 101. Thus, the size of the crusher 100 may be limited. This fixing of the block 121 of counter-knives may be ensured by any suitable means, for example using screws. The block 121 of counter-knives 129 may be formed in a single piece of steel, in particular whose composition is adapted to the function of the block 121 of counter-knives 129. The counter-knives 129 of the block 121 of counter-knives 129 are arranged to delimit between them spaces for the passage of the knives 103.

[0102] To crush plastic bottles, the counter-knives 129 of the block 121 of counter-knives 129 may each have a width measured parallel to the axis A1 (also called thickness) of between 8 mm and 12 mm, and in particular equal to 10 mm. The width of the knives 103 may be equal to the width of the counter-knives.

[0103] According to a measurement direction parallel to the axis A1, the clearance between any pair of adjacent knives and counter-knives cooperating with each other to cut material from one or more wastes 10 can be between 0.1 mm and 1.5 mm. 1.5 mm allows a good cut, going below 0.1 mm would be possible but would increase the production costs because this would require suitable machining and precise assembly of the crusher 100.

[0104] The crusher 100 may comprise an additional block 123 of counter-knives 130 (notably visible in FIGS. 3, 9 and 10) angularly offset along the axis A1 relative to the block 121 of counter-knives 129. For example, the additional block 123 of counter-knives 103 may be fixed to the frame 101, in particular on an internal face 124 of the frame 101 opposite the internal face 122 on which the block 121 of counter-knives 129 is fixed. In addition to integrating into the crusher 100 an additional cutting function making it possible to reduce the time required to crush a waste 100, this makes it possible, where appropriate, to facilitate a new cutting of flakes arranged between the drive shaft 102 and the sieve 113. The additional block 123 of counter-knives 130 may be formed in a single piece in steel, in particular the composition of which is adapted to the function of the additional block 123 of counter-knives 130. The counter-knives 130 of the additional block 123 of counter-knives 129 are arranged to delimit between them spaces for the passage of the knives 103.

[0105] To crush plastic bottles, the counter-knives 130 of the additional block 123 of counter-knives 129 may each have a width measured parallel to the axis A1 equal to that of each of the knives 103 in the context of a cutting and, where appropriate, disentangling function, or strictly less than that of each of the knives 103 if the only function of the additional block 123 of counter-knives 129 is disentangling.

[0106] The crusher 100 may comprise a comb 125 (notably visible in FIGS. 3, 9 and 10) configured to cooperate with the knives 103 to disentangle material caught in the knives 103, said cooperation being enabled by rotating the drive shaft 102 in a direction F2 opposite to the crushing direction F1 (FIG. 1). The presence of this comb 125 makes it possible to avoid jamming of the crusher 100 which would require significant efforts of the motor 127 to resolve the jamming problem: it is then sufficient to reverse the direction of rotation of the drive shaft 102 to resolve the jamming problem. Typically, the comb 125 may comprise fingers 131 which delimit interdigital spaces for the passage of the knives 103. [0107] The comb 125 can be fixed to the frame 101 opposite the block 121 of counter-knives 130. Thus, a simple half-turn of the knives 103 in the direction F2 can be sufficient to disentangle before putting the knives 103 back into rotation in the grinding direction F1, reducing the time needed to resolve the problem.

[0108] The comb 125 may be made of steel, in particular the composition of which is adapted to the function of the comb 125. The fingers 131 of the comb 125 may each have a width measured parallel to the axis A1 identical to that of each of the counter-knives 130, in this case the fingers 131 of the comb 125 participate in the cutting which results in the application of forces on the drive shaft 2.

[0109] The comb 125 and the additional block 123 of counter-knives 130 can form the same part as can be seen in FIG. 11. This makes it possible to reduce, if necessary, the number of parts constituting the grinder 100. If the additional block 123 is not present in the grinder 100, the grinder 100 can include the comb 125 which then simply has a disentangling function and does not participate in cutting the waste(s) 10 with the knives 103.

[0110] The crusher 100 may comprise bearings 126a, 126b for guiding the rotation of the drive shaft 102, the rotation of which may be ensured/controlled by the motor 127. The bearings 126a, 126b are notably visible in FIGS. 10, 11, 12, 13 and 14. The bearings 126a, 126b are integral with the chassis 101.

[yes] The invention also relates to a device 1000 for grinding waste 10 comprising the grinder 100 as described and a guide duct 1001 comprising an inlet 1003 for introducing waste 10 into the guide duct 1001. The guide duct 1001 is configured to guide the waste 10 previously introduced into the guide duct 1001 towards the grinder 100. In other words, the guide duct 1001 can be mounted on the grinder 100 so as to guide the waste 10 towards the grinder 100 as shown for example in FIGS. 12 to 14. Such a device 1000 for grinding waste 10 is in particular compact and makes it possible to grind waste 10 efficiently. In the case where the crusher 100 comprises the first and second crushing chambers 106, 108, the guide duct 1001 may comprise the means necessary to ensure suitable guidance of the waste 10 previously introduced into the guide duct 1001 within the guide duct 1001 such as a movable guide member 1002 (also called a movable flap) controlled according to the type of waste 10 to be crushed so as to direct the waste 10 previously introduced into the guide duct 1001 either towards the first crushing chamber 106 in a first configuration of the device 1000 (FIG. 13), or towards the second crushing chamber 108 in a second configuration of the device 1000 (FIG. 14). Alternatively, two separate conduits can also be provided with two separate openings for waste which can be sorted at these two openings, for example by a person wishing to recycle their waste 10.

[0112] As shown in FIG. 12, the guide duct 1001 may include the inlet 1003 through which the waste 10 can be introduced. The member 1002 of guide 1002 can then orient the introduced waste 10, according to the position of said guide member 1002, either towards a first outlet 1004 of the guide conduit 1001 in communication with the first grinding chamber 106 (figure 13) - i.e. with the inlet

105 a of the first grinding chamber 106 - or towards a second outlet 1005 of the guide conduit 1001 in communication with the second grinding chamber 108 (figure 14) - i.e. with the inlet 105b of the second grinding chamber 108.

[0113] The guide conduit 1001 can be directly mounted on the grinder 100 so that the first and second outlets 1004, 1005 are respectively in junction with the inlet 105a of the first grinding chamber 106 and with the inlet 105b of the second grinding chamber 108 as can be deduced in particular from FIGS. 13 and 14.

[0114] The device 1000 for grinding waste 10 may further comprise at least one bin 1006, 1007 for receiving ground material at the outlet of the grinder 100. In particular, the device 1000 for grinding waste 10 may comprise first and second bins 1006, 1007 for receiving ground material arranged respectively at the outlet 117a of the first grinding chamber 106 and at the outlet 117b of the second grinding chamber 108 in order to recover separately what is ground in the first chamber.

106 grinding and what is ground in the second grinding chamber 108 from which results the formation of two deposits 1008a, 1008b, respectively in the first tank 1006 and in the second tank 1007 which can be recycled in different ways.

[0115] In Figures 13 and 14, the knives 103 are schematized by a set 132 of knives.

[0116] A particular exemplary embodiment is now described in which the crusher 100 comprises the first crushing chamber 106 for receiving waste, preferably plastic bottles, in particular dark-colored PET, and the second crushing chamber 108 for receiving waste, preferably plastic bottles, in particular light-colored PET.

[0117] In this particular embodiment, the knives 103 are mounted on the hexagonal drive shaft 102 which is mechanically coupled to the motor 127 with a reduction to adapt the rotation speed of a motor shaft of the motor to that desired of the drive shaft 102 for a suitable cut of waste(s) 10. The grinding of the waste 10 is then made possible by the association of the knives 103 and the block 121 of counter-knives 129. Of course, the reduction may not be necessary if the rotation speed of the motor shaft is equal to the desired rotation speed of the drive shaft 102.

[0118] In the particular embodiment, the knives are according to the types of figures 7 and 8, they then each comprise gripping tips 111a, 111b, 111c whose role is to guarantee the gripping of the waste 10 by perforation of this waste 10 and curved cutting blades 120a, 120b, 120c which will participate in the cutting of the waste 10.

[0119] In the particular embodiment, the counter-knife block 121 is fixed to the frame 101 opposite the knives 103 and makes it possible to present cutting stops intended to cooperate with the knives 103 to cut the waste 10 into strips which will then be cut again in order to form the desired flakes at the outlet of the grinder 100.

[0120] In order to reduce the cycle time for crushing a bottle, for example to a maximum of 3 seconds, the crusher 100 comprises in the particular embodiment the comb 125 for disentangling the knives 103, if necessary, in the direction F2 of rotation of the drive shaft 102. The trio of knives 103, block 121 of counter-knives and comb 125 makes it possible to limit the power required for crushing plastic bottles, and thus guarantee, for example, the installation of the device 1000 for crushing on the basis of a conventional single-phase electrical supply of less than 16 amps.

[0121] Still within the framework of the particular exemplary embodiment, once the waste or wastes 10 have been crushed, the flakes resulting from the crushing flow through the orifices 114 of the sieve 113 to be stored in the bins 1006, 1007 allowing the storage of the crushed material resulting from the crusher 100 according to two different deposits (for example respectively dark-colored PET flakes and light-colored PET flakes).

[0122] A clearance of 2 mm between the knives and the sieve 113, for example defined as the distance separating the maximum external radius described by the knives 103 when passing along the sieve 113 and the internal radius of the sieve 113, allows the PET flakes not having the required size to pass through the sieve 113 (in particular to pass through the orifices 114) to be cut again in order to reach the required size.

[0123] As mentioned above, the grinder 100 according to the particular embodiment is compartmentalized using the separator 107 so as to have the first and second grinding chambers 106, 108. Preferably, in each of the first and second grinding chambers 106, 108, the typology and number of knives 103 are identical: as illustrated in FIG. 5, the grinder 100 can then comprise, in each of the first grinding chamber 106 and the second grinding chamber 108, nine knives.

[0124] The knives of the first grinding chamber 106 and the knives of the second grinding chamber 108 are in particular arranged identically along the drive shaft 102, for example according to the following sequence from the serrated end 109 of the drive shaft 102: five three-tooth knives, followed by two two-tooth knives, followed by two three-tooth knives. Of course, in each of the first and second grinding chambers 106, 108, the knives 103 are separated two by two by one of the spacers 112.

[0125] In particular, in the context of the particular example embodiment:

• the knives 103 with two teeth 110a, 110b may be such that the gripping points 111a, 111b of the teeth 110a, 110b of said knives 103 describe, during the rotation of said knives 103 around the axis Al, each a circle with a radius equal to 9 cm (these circles then being coaxial for the different knives 103 and concentric for the same knife 103);

• the knives 103 with three teeth 110a, 110b, 110c may be such that, for each of these knives 103, the gripping tip 111c of the largest of the teeth 110a, 110b, 110c of said knife 103 describes, during the rotation of said knife 103 around the axis A1, a circle with a radius equal to 9 cm and the tips 111a, 111b of the other teeth 110a, 110b of said knife 103 each describe a circle with a radius equal to 7.5 cm (for the same knife 103 the circles described by the different teeth are concentric and for two separate knives the circles of the largest of the teeth are coaxial and the circles of the other teeth are coaxial).

[0126] In order to determine the shape, arrangement and orientation of the knives 103 per grinding chamber, it is interesting to note how the bottles fall into the grinder 100 between the lying position and the vertical position. When the bottle enters the grinder 100 in the lying position, it is the outer radius of the teeth 110a, 110b, 110c which comes into play, on the contrary when the bottles enter the grinder 100 in the vertical position it is the orientation and arrangement of the knives 103 which predominate.

[0127] In the particular example, and this can be applied more generally to all the described embodiments of the crusher 100, in order to determine the radius of the circle described by the knives 103, it is interesting to take into account the dimensions and the typologies of the waste 10 to be crushed. By experiments carried out within the framework of the present invention, for a bottle to be taken optimally by the teeth 110a, 110b, 110c, the tip of the knife must reach between 73% and 80% of the diameter of the bottle. Typically, bottle diameters can be 4.8 cm for a 25 cl bottle, 6.5 cm for a 50 cl bottle, 7.8 cm for a 1 L bottle and 9.8 cm for a 2 L bottle. Thus, at the level of the circle mentioned above, the knife 103, the tip of which defines this circle, is preferably shaped so that said tip can penetrate the 1 L bottle at 73% of its diameter and the 25 cl bottle at 80% of its diameter. Of course, the knives 103 of the grinder 100 will be adapted in shape according to the type of waste to be ground.

[0128] For example, the “large teeth” whose tips 111a, 111b, 111c move in a circular manner with a radius of 9 cm are designed to grip and perforate bottles according to the above diameters which would be presented lying down and for example whose longitudinal axis would be substantially parallel to the axis A1.

[0129] For example, the “small teeth” whose tips 111a, 111b move in a circular manner with a radius of 7.5 cm are designed to grip and perforate bottles with the above diameters which would appear via their neck (diameter at the level of the cap of a bottle for example equal to 2.7 cm).

[0130] Generally, the height of each of the teeth 110a, 110b, 110c can be defined by a person skilled in the art depending on the type of waste 10 to be ground. For example, the height of a tooth can be defined to have a cutting angle (measurable at the gripping tip 111a, 111b, 111c of the tooth 110a, 110b, 110c when the tooth 110a, 110b, 110c comes into cooperation with a counter-knife) as small as possible between the tooth and the counter-knife 130 with which it will cooperate in the manner of the scissors cutting phenomenon. The cutting length of the tooth, in particular defined by the curvature of the tooth 110a, 110b, 110c can be maximized to smooth or evenly distribute the forces during cutting without causing “load peaks” during rotation of the shaft of the crusher 100. Overall, the choices as to the height of the teeth 110a, 110b, 110c and their cutting length make it possible to limit the cutting forces necessary for crushing waste 10.

[0131] Generally, each knife 103 may comprise a hub 133 (FIGS. 7, 8 and 15) shaped to ensure the mounting of said knife 103 on the drive shaft 102. Each tooth 110a, 110b, 110c then extends from the hub 133 of the knife 103 which comprises said tooth 110a, 110b, 110c. For example, at least one of the teeth 110a, 110b, 110c, and in particular each tooth, may have at its base, i.e. at the level of the zone where it extends from the hub 133, a fillet 134. This fillet 134 makes it possible to form a recess so that the crushed material can be crushed as close as possible to the drive shaft 102 where the transmissible torque is greatest. This also helps to limit the cutting forces required for grinding.

[0132] Generally, at least one of the teeth 110a, 110b, 110c, and in particular each tooth 110a, 110b, 110c, may be such that its cutting blade 120a, 120b, 120c is serrated. This makes it possible to limit the cutting forces required for grinding. FIG. 15 represents an example of this with a knife 103 with two teeth 110a, 110b whose cutting blades 120a, 120b are serrated. In the case illustrated in figure 15, each of the two teeth 110a, 110b is then provided with three projections 135 between the gripping tip 111a, 111b of the tooth 110a, 110b and the base of the tooth 110a, 110b at the fillet 134. Each projection 135 then locally forms a tooth of the cutting blade 120a, 120b. The number of teeth of the blade 120a, 120b of the cutting blade is not limited to three and can be adapted to any number depending on the type of waste 10. Thus, the serrated cutting blade 120a, 120b can act as a chip breaker, and facilitates cutting because the material, previously locally broken, will offer less resistance when it is cut, thus relieving the motor of the grinder 100.

[0133] Generally speaking, regarding the choice of the orientation and the angles of the knives 103, the dimensioning criterion may be the cycle time (i.e. the time required to grind the waste 10). In order to guarantee rapid gripping of the waste 10, in this case preferably the plastic bottle, the arrangement of the knives 103 may be adapted by a person skilled in the art.

[0134] Thus, generally speaking, the crusher 100 can be configured to crush waste 10 from a range of waste, the range being defined by the fact that each waste 10 of the range has:

• an elongated shape along a longitudinal dimension of said waste 10;

• a first longitudinal end; • a second longitudinal end opposite the first end along the longitudinal dimension, the second end having dimensions, taken in a plane orthogonal to the direction of the longitudinal dimension, greater than dimensions of the first end taken in a plane orthogonal to the direction of the longitudinal dimension; therefore, the receiving region(s) are configured/sized to receive the second end, and therefore not consequently also the first end.

[0135] In particular, the most restrictive case is that of crushing large bottles. For example, for a 1.5 L bottle 32 cm high and with a diameter equal to 8.8 cm, it is preferable for the receiving region 104a, 104b to be shaped to allow the lower part of the bottle which includes its bottom to be inserted therein. For this purpose, the knives 103 can be arranged so as to delimit within each of the first and second crushing chambers 106, 108, in particular with the frame 101, a free zone (i.e. the corresponding receiving region 104a, 104b) so that the bottle can be deposited therein. This free zone may have a dimension counted along the axis Al of 117 mm. Therefore, if each of the first and second grinding chambers 106, 108 comprises within it two reception regions 104a, 104b diametrically opposed relative to the axis A1 of the drive shaft 102, in less than half a turn of the drive shaft 102 in the grinding direction F1 the bottle can be perforated and therefore gripped to then be ground by the grinder 100.

[0136] The present invention finds an industrial application in the grinding of waste 10, for example with a view to recycling it. The present invention can therefore be integrated into a waste recycling process.

Claims

Claims 1. Grinder (100) for grinding waste (10), said grinder (100) comprising: • a chassis (101); • a single drive shaft (102) movable in rotation relative to the chassis (101) around an axis (Al); • knives (103) mounted on the drive shaft (102) so as to be integral in rotation with the drive shaft (102) around said axis (Al) in at least one grinding direction (Fl); the knives (103) being staggered along the drive shaft (102) along the axis (A1), the knives (103) being arranged so as to delimit in whole or in part at least one receiving region (104a, 104b) capable of receiving, during the rotation of the shaft (102) in the grinding direction (Fl), at least a portion of a waste (10) to be ground, the knives (103) being arranged so that at least one of the knives (103a) makes it possible, during the rotation of the drive shaft (102) in the grinding direction (Fl), to grip said waste (10) to be ground, said at least one portion of which is positioned in said receiving region (104a, 104b). 2. Crusher (100) according to claim 1, characterized in that each knife (103) comprises teeth (110a, 110b, 110c) offset from each other angularly around the axis (Al), each tooth (110a, 110b, 110c) comprising a gripping tip (111a, 111b, 111c). 3. Grinder (100) according to claim 2, characterized in that for any pair of adjacent knives (103), the teeth (110a, 110b, 110c) of one of the knives (103) of said pair are at a distance from the teeth (110a, 110b, 110c) of the other of the knives (103) of said pair along the axis (Al). 4. Crusher (100) according to any one of claims 2 to 3, characterized in that at least one of the knives (103) comprises two teeth (110a, 110b) whose gripping tips (111a, 111b) are diametrically opposed relative to the axis (Al), for example the two teeth (110a, 110b) are axially symmetrical along the axis (Al). 5. Grinder (100) according to any one of claims 1 to 4, characterized in that it comprises a sieve (113) secured to the chassis (101), the sieve (113) being configured to allow the passage of crushed material resulting from the grinding through the grinder (100). 6. Grinder (100) according to claim 5, characterized in that at least one of the knives (103) is configured so as to have at least one end (111a, 111b, 111c) passing, at each turn made by said knife (103), close to the sieve (113) at a distance of between 1 mm and 4 mm, and preferably equal to 2.5 mm. 7. Grinder (100) according to any one of claims 1 to 6, characterized in that at least one of the knives (103) comprises at least three teeth (110a, 110b, 110c). 8. Crusher (100) according to claim 7, characterized in that among said at least three teeth (110a, 110b, 110c), two teeth (110a, 110c) of these three teeth have different sizes. 9. Grinder (100) according to claim 2 or according to claim 2 and any one of claims 3 to 8, characterized in that said receiving region (104a, 104b) is arranged laterally to a first tooth (118) formed by one of the teeth of a first (103a) of the knives (103) and in that a second tooth (119) formed by one of the teeth of a second (103b) of the knives (103) is arranged in an angularly offset manner around the axis (A1) and behind the first tooth (103a) in the grinding direction (Fl). 10. Crusher (100) according to claim 2 or according to claim 2 and any one of claims 3 to 9, characterized in that each tooth (110a, 110b, 110c) comprises a curved cutting blade (120a, 120b, 120c) ending in the gripping tip (111a, 111b, 111c) of said tooth (110a, 110b, 110c). 11. Grinder (100) according to claim 10, characterized in that the curved cutting blade (120a, 120b, 120c) is serrated. 12. Grinder (100) according to any one of claims 1 to 11, characterized in that the knives (103) delimit in whole or in part several receiving regions (104a, 104b) and in that the grinder (100) comprises: • a first grinding chamber (106) housing a first part of the knives (103); • a separator (107); • a second grinding chamber (108), separated from the first grinding chamber (106) by the separator (107) crossed by the drive shaft (102), the second grinding chamber (108) housing a second part of the knives (103); the knives (103) of the first part of the knives (103) being arranged so as to form, in the first grinding chamber (106), at least one (104a) of the receiving regions (104a, 104b) and the knives (103) of the second part of the knives (103) being arranged so as to form, in the second grinding chamber (108), at least one (104b) of the receiving regions (104a, 104b). 13. Crusher (100) according to any one of claims 1 to 12, characterized in that it comprises a block (121) of counter-knives (129) arranged to cooperate with the knives (103), the block (121) of counter-knives (129) being for example fixed to the chassis (101), in particular on a single internal face (122) of the chassis (101). 14. Crusher (100) according to claim 13, characterized in that it comprises an additional block (123) of counter-knives (130) angularly offset along the axis (Al) relative to the block (121) of counter-knives (129). 15. Grinder (100) according to any one of claims 1 to 14, characterized in that it comprises a comb (125) configured to cooperate with the knives (103) to disentangle material caught in the knives (103), said cooperation being enabled by rotating the drive shaft (102) in a direction (F2) opposite to the grinding direction (F1). 16. Crusher (100) according to claim 14 and claim 15, characterized in that the comb (125) and the additional block (123) of counter-knives form the same part. 17. Crusher (100) according to any one of claims 15 to 16, characterized in that the comb (125) is fixed to the frame (101) opposite the block (121) of counter-knives (130). 18. Device (1000) for crushing waste (10) comprising a crusher (100) according to any one of claims 1 to 17 and a guide duct (1001) comprising an inlet (1003) for introducing waste (10) into the guide duct (1001), the guide duct (1001) being configured to guide the waste (10) previously introduced into the guide duct (1001) towards the crusher (100).