Waste shredder
A single-shaft waste crusher with staggered knives and separate grinding chambers addresses the bulkiness and energy inefficiency of existing crushers, enhancing gripping and sorting capabilities for efficient waste processing and recycling.
Patent Information
- Application Number
- FR2023004016
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-04-21
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2043-04-21
AI Technical Summary
Existing waste crushers, particularly those used for plastic bottles, are bulky and energy-intensive due to the need for multiple shafts and energy-consuming drives to grip and crush waste, and they lack efficient mechanisms for handling and sorting crushed materials.
A waste crusher with a single drive shaft and staggered knives that facilitate gripping and crushing, featuring receiving areas, multiple teeth for improved gripping, and separate grinding chambers for sorting by characteristics like color, along with a comb for disentanglement and counter-knives for additional cutting, all designed for compactness and efficient material handling.
The solution results in a compact, energy-efficient crusher that effectively grips and crushes waste, reduces material volume, and facilitates sorting, thereby optimizing logistics and recycling efficiency.
Smart Images
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Abstract
Description
Title of the invention: 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 to enable their recycling. More particularly, the invention relates to a grinder for grinding waste. 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 deposit of material to be recycled.
[0003] A recurring problem in crushing is the gripping of waste to be crushed by the crusher's knives. To overcome this, it is possible, for example, to apply force to the waste to be crushed to move it towards the knives so that the latter can engage with the waste, which is then crushed as the knives rotate. This solution is not suitable because it requires a crusher with an energy-consuming drive element, which complicates the crusher's design.
[0004] According to a known example of a crusher, the latter comprises two sets of knives, each associated with a shaft rotating about an axis of rotation. The rotation of the two shafts, which are substantially parallel, allows the knives of the two sets of knives to cooperate in crushing waste. Such a crusher is bulky and energy-intensive. Object of the invention
[0005] The invention aims to limit the size of the crusher.
[0006] To this end, the invention relates to a waste crusher, said crusher comprising: a frame; a single drive shaft that rotates about an axis relative to the frame; and knives mounted on the drive shaft so as to be rotationally fixed to the drive shaft about said axis in at least one direction of crushing. The knives are staggered along the drive shaft along the axis. The knives are arranged so as to define, in whole or in part, at least one receiving area capable of receiving, during the rotation of the shaft in the crushing direction, at least a portion of the waste to be crushed. The knives are arranged so that at least one of the knives allows, during the rotation of the shaft in the crushing direction, the gripping of said waste to be crushed, at least a portion of which is positioned in said receiving area.
[0007] Such a shredder has the advantage of a compact design, as only one shaft is mobile. Furthermore, the presence of the receiving area provides a designated space where waste intake is facilitated. In other words, the receiving area allows the waste to be inserted directly into a volume, for example a cylindrical one, the size of which depends on the dimensions of the blades, in order to facilitate its handling.
[0008] The crusher may further comprise one or more of the following features.
[0009] According to one feature of the crusher, each knife comprises teeth offset from each other angularly around the axis, each tooth comprising a gripping point.
[0010] Thus, the use of several teeth per knife makes it easier to grind.
[0011] According to a feature 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] Thus, this allows the knives of each pair of knives to define a cutting width in order to obtain a calibrated shred.
[0013] According to a feature of the crusher, at least one of the knives comprises two teeth whose gripping points are diametrically opposed with respect to the axis, for example the two teeth are axially symmetrical along the axis.
[0014] This optimizes the time it takes to grip the waste to be ground, in the sense that the 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 with respect to the axis.
[0015] According to a feature of the crusher, it includes a sieve attached to the frame, the sieve being configured to allow the passage of crushed material from the crushing by the crusher.
[0016] This allows the ground material to be calibrated appropriately at the outlet of the crusher.
[0017] According to a feature of the crusher, at least one of the knives is configured so as to have at least one end passing, at each turn made by said knife, near 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 ground material retained by the sieve in order to facilitate the passage of the ground material through the sieve or for elements of the ground material whose dimensions do not allow their passage through the sieve to be carried along to be cut by the crusher in order to reduce their size.
[0019] According to a feature of the crusher, at least one of the knives comprises at least three teeth.
[0020] The presence of three teeth improves the gripping of the waste(s).
[0021] According to a feature of the crusher, among said at least three teeth, two of these three teeth have different sizes.
[0022] This size difference makes it possible to improve the gripping 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 is presented upon its arrival in the grinder.
[0023] According to a feature 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 in the direction of crushing.
[0024] Thus, the second tooth grips the corresponding waste material when it is present in the receiving area. Furthermore, this configuration ensures rapid and systematic gripping while minimizing the effort required by the crusher, particularly by reducing the number of knives in contact with the waste.
[0025] According to a feature of the crusher, each tooth comprises a curved cutting blade ending in the gripping point of said tooth.
[0026] The curvature of the cutting blade combined with the gripping point makes it possible to form a "claw" facilitating the gripping of waste to be ground or in the process of being ground.
[0027] According to a feature of the crusher, the curved cutting blade is serrated.
[0028] This allows the material to be broken up just before cutting, thus limiting the stress on the drive shaft.
[0029] According to a feature of the crusher, the knives delimit, in whole or in part, several reception areas and the crusher 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 through which the drive shaft passes, 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 reception 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 reception 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 their color, to obtain two separate deposits of material which are presented for example in the form of flakes ready for recycling.
[0031] According to a feature of the crusher, it includes a counter-knife block arranged to cooperate with the knives, the counter-knife block being for example fixed to the frame, in particular on a single internal face of the frame.
[0032] Counter-knives provide a temporary stop to waste material before cutting that material through cooperation between one or more knives and one or more counter-knives. Fixed counter-knives reduce the overall size compared to two sets of facing, moving knives.
[0033] According to a feature of the crusher, it includes an additional block of counter-knives offset angularly along the axis relative to the block of counter-knives.
[0034] This allows an additional cutting function to be integrated into the crusher, reducing the time required to crush waste.
[0035] According to a feature of the crusher, it includes a comb configured to 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 direction of crushing.
[0036] The comb, by virtue of the disentanglement it allows, makes it possible to limit the power of the crusher since this will de facto limit the efforts of the knives by avoiding having to cut tangled material from the waste or waste.
[0037] According to a feature of the crusher, the comb and the additional block of counter-knives form a single piece.
[0038] Thus, the same part has two different functions depending on the direction of rotation of the shaft around the axis, thereby effectively reducing the number of parts and, where applicable, 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 of direction of rotation by imposing a half turn may be enough to unblock an entanglement situation.
[0041] The invention also relates to a device for grinding waste comprising a grinder as described and a guide conduit comprising an inlet for introducing waste into the guide conduit, the guide conduit being configured to guide the waste previously introduced into the guide conduit towards the grinder.
[0042] Such a device for shredding waste offers advantages related to the shredder it comprises. In particular, it ensures efficient shredding while maintaining a compact size.
[0043] Other advantages and features may become apparent from the detailed description that follows. Brief description of the drawings
[0044] The invention will be better understood upon reading the detailed description that follows, given solely by way of non-limiting example and made with reference to the drawings attached and listed below.
[0045] [Fig-1] Fig. 1 illustrates a perspective view of a crusher according to a mode of a particular implementation of the invention.
[0046] [Fig.2] [Fig.2] illustrates the crusher of [Fig.1] from a view oriented towards the top of the crusher in order to visualize an arrangement of crusher knives mounted on a drive shaft belonging to the crusher.
[0047] [Fig.3] Figure [Fig.3] illustrates the crusher of Figure [Fig.2] from which the knives have been removed in order to view other parts of the crusher.
[0048] [Fig.4] [Fig.4] The [Fig.4] illustrates the crusher of the [Fig.1] but from another view in perspective to view the underside of the crusher.
[0049] [Fig. 5] [Fig. 5] illustrates, in perspective view, the drive shaft, extracted of the crusher in [Fig.1], on which the knives are mounted.
[0050] [Fig. 6] Fig. 6 illustrates, in a side view, the drive shaft, extracted from the crusher of the [Fig.1], on which the knives are mounted.
[0051] [Fig.7] Fig.7 illustrates a first type of knife that can be fitted to the crusher according to the invention.
[0052] [Fig.8] Fig.8 illustrates a second type of knife that can be fitted to the crusher according to the invention.
[0053] [Fig.9] Fig.9 illustrates a cross-sectional view of the crusher taken in a perpendicular to the axis Al of [Fig.3] and along the cutting plane BB.
[0054] [Fig. 10] [Fig. 10] illustrates a cross-sectional and perspective view of one half of the crusher of [Fig. 3] from which the drive shaft and knives have been removed to clearly visualize other parts of the crusher, the section being made along the cutting plane CC visible in [Fig. 3] and passing through the axis AL
[0055] [Fig. 11] [Fig. 11] is a complementary view to [Fig. 10] in that it shows the other half of the crusher and for which the drive shaft and knives have also been removed to clearly visualize other parts of the crusher.
[0056] [Fig. 12] The [Fig. 12] is a schematic side view of a device for grinding waste, this device comprising the grinder.
[0057] [Fig. 13] The [Fig. 13] is a cross-sectional view of the device for grinding waste of the [Fig. 12] taken along a cutting plane parallel to the plane of the [Fig. 12] and schematically showing a first configuration of the device for grinding waste.
[0058] [Fig. 14] The [Fig. 14] is a cross-sectional view of the device for grinding waste of the [Fig. 12] taken along a cutting plane parallel to the plane of the [Fig. 12] and schematically showing a second configuration of the device for grinding waste.
[0059] [Fig. 15] The [Fig. 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 shown in the different figures are not necessarily drawn to scale in order to facilitate understanding of the figures. Detailed description
[0061] By "substantially parallel", it is understood to be 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 shredding 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 recycling process of this waste, is thus reduced.
[0064] The waste 10 may be elongated in shape. For example, the waste 10 may be bottles as schematically represented in Figures 13 and 14. The bottles may be made of PET (acronym for "polyethylene terephthalate").
[0065] The ground material is considered to be the result of grinding waste(s) 10, the ground material is therefore formed by elements, called ground elements, resulting from the grinding of the waste(s) 10 in particular by cutting or trimming.
[0066] In the field of bottle crushing as waste 10, the crushed material is also called chips or flakes.
[0067] Where appropriate, the ground material can be used to manufacture granules that form an intermediate product usable as a raw material for manufacturing new articles of any type suitable for being formed using granules, such as, for example, new bottles when the granules (obtained using flakes) are made of light-colored 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 articles.
[0068] The invention relates to a crusher 100 for crushing waste 10. A particular embodiment of this crusher 100 is illustrated in Figures 1 to 4. The crusher 100 comprises a frame 101 and a single drive shaft 102 that rotates relative to the frame 101 about an axis AL. The axis AL therefore corresponds to the axis of rotation of the drive shaft 102. Knives 103 are mounted on the drive shaft 102 so as to be rotationally fixed with the drive shaft 102 about said axis AL in at least one direction FL of crushing. The knives 103 are staggered along the drive shaft 102 along the axis AL (i.e., the knives 103 are offset from each other in the direction of the Al axis) as shown in particular in figures 1, 2, 5 and 6; Figures 5 and 6 show the drive shaft 102 and the knives 103 separated 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 schematically represented by quadrilaterals shown in dashed lines) capable of receiving, during the rotation of the drive shaft 102 in the grinding direction Fl, at least a portion of a waste product 10 to be crushed, the knives 103 being arranged so that at least one of the knives 103b ([Fig. 1]) allows, during the rotation of the drive shaft 102 in the grinding direction Fl, the gripping of said waste product 10 to be crushed, of which said at least one part is positioned in said host region 104a, 104b.Therefore, each receiving region 104a, 104b belongs to the crusher 100 and forms a housing to receive said at least a part of the waste 10 corresponding to be crushed.
[0069] A person skilled in the art will understand that the knives 103 are preferably configured and arranged in such a way as to provide at least one clearance suitable for positioning itself during the rotation of the knives so as to be accessible between an inlet 105a (Figures 1 and 2) of the crusher 100 and the drive shaft 102. This allows the receiving region 104 to be presented, during the rotation of the drive shaft 102 in the crushing direction (particularly periodically), opposite the inlet 105a in order to insert at least a portion of the waste 10 into the receiving region 104 and to allow it to be gripped by at least one of the knives 103 in order to allow the crushing of said waste 10.
[0070] The notions of "above" and "below" are given in particular in relation to each other in the reference frame of the crusher 100 and more particularly in the terrestrial reference frame in a configuration of use of the crusher 100.
[0071] The inlet 105a mentioned above is for example arranged on top of the crusher 100.
[0072] The drive shaft 102 may have a hexagonal cross-section along all or part of its length, which allows the knives 103 to be mounted efficiently on said drive shaft 102 so as to rotate these knives 103 concurrently with said drive shaft 102. Therefore, each knife 103 may have a hexagonal opening 128 complementary to the hexagonal cross-section of the drive shaft 102, as shown, for example, in Figures 7 and 8.
[0073] The drive shaft 102 can be made of steel, in particular whose composition is adapted to the function of the drive shaft 102 within the crusher 100.4.
[0074] The knives 103 can each be made of steel, in particular, whose composition is adapted to the function of said knife 103 within the crusher 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 referred to above may be a longitudinal end of said waste 10. When the waste 10 is a bottle, said at least one part of the waste may be the bottom 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, the entire waste 10 may be introduced into the corresponding reception area 104a, 104b.
[0077] For crushing 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 crusher 100 can be such that the knives 103 delimit in whole or in part several reception regions 104, 104a (figures 1 and 2) and the crusher 100 comprises: • a first crushing 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 through which the drive shaft 102 passes (also visible in [Fig.3] for which the knives 103 have been removed to visualize some 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 allows for the separate grinding of different wastes 10.
[0079] For example, when recycling bottles as waste 10, the crushed light-colored bottles can be used to form new light-colored bottles, and the crushed dark-colored bottles are not reused to form new dark- or light-colored bottles; they are instead redirected to other recycling streams to, for example, form textiles or insulation, hence the need for proper sorting of 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 a crushed material at the output of the crusher 100 formed from different waste streams, particularly according to their color, thus facilitating recycling.
[0080] In general, besides allowing the separation of two deposits of shredded waste, the use of a single drive shaft 102 (whose rotation allows the knives 103 of the first and second grinding chambers 106, 108 mounted on this drive shaft 102 to rotate) allows considerably reducing 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 out of the frame 101. The motor 127 can 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 one side of the motor 127 and the drive shaft 102 and a gear coupled to the splines on the other side of the motor 127 and the drive shaft 102.
[0081] In particular, the separator 107 can participate, with the frame 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 being then for example both arranged at the level of the top of the grinder 100.
[0082] Each knife 103 may comprise teeth 110a, 110b, 110c angularly offset from each other about the axis Al, each tooth 110a, 110b, 110c then comprising a gripping point 111a, 111b, 11. For example, Figures 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 the knives 103 with several teeth 110a, 110b, 110c, and in particular mixed according to the types respectively illustrated in [Fig.7] and 8 makes it easier to take the waste 10 and therefore to grind it up by allowing it to participate in forming the reception 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 can 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 bracing of the knives two by two adjacent which are then at a distance from each other.This allows us to participate in defining the size / calibration of the elements of the ground material resulting from the grinding at the output of the mill 100 which ultimately may present elements (for example, where applicable, these elements are the flakes mentioned above) whose dimensions are such that each of these elements is included in a sphere with a diameter between 10 mm and 14 mm, which may more or less correspond to the width of the knives measured along the direction of the axis plus, for example, 10 mm of spacing between adjacent knives which corresponds to the distance mentioned previously, so as to form slivers which will then be cut until the elements of the ground material are obtained which can then exit the mill 100, and in particular the first and second grinding chambers 106, 108.
[0084] In particular, to ensure the maintenance of the distance (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 figures 1, 2, 6 and 7. Therefore, the crusher 100 can include 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 points 111a, 111b are diametrically opposed with respect to the axis Al; for example, the two teeth 110a, 110b are axially symmetrical along the axis Al. This is notably illustrated in [Fig. 7]. The aim is, in particular, to optimize the holding 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 points 111a, 111b are diametrically opposed with respect to the axis Al, 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, in the presence of at least two opposing receiving regions 104a, 104b per grinding chamber (i.e. two receiving regions in the first grinding chamber 106 and two receiving regions in the second grinding chamber 108).
[0086] The crusher 100 may include a sieve 113 attached to the frame 101 (for example visible in figures 3, 4, 9, 10, 11, 13, 14), the sieve 113 being configured to allow the passage of crushed material from the crushing by the crusher 100 (for example the passage of flakes from the crushing of bottles by the crusher 100). Thus, the dimensions of the shredded material exiting the crusher 100 can be adapted according to the waste recycling process 10 using the sieve 113. The sieve 113 can be a curved grid or a perforated curved plate, i.e., the curved grid or plate has orifices 114 calibrated as desired for the passage of the expected shredded material exiting the crusher 100. The sieve 113 serves in particular to retain the aforementioned slivers so that they are cut until the shredded material is obtained, which can then exit the crusher 100 via the sieve 113.
[0087] Of course, the number, density, shape, and diameter of the orifices 114 can be adapted to meet the requirements of the industrial recycling process for the waste 10 crushed by the crusher 100, in order to be part of an industrial recycling process, particularly the industrial recycling process for plastic bottles, especially PET bottles. Thus, in the following description, a plastic bottle may preferably be made of PET.
[0088] In the example of shredding 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 shredder 100. That is to say, to obtain flakes with a size between 10 mm and 12 mm, the orifices 114 will have a diameter strictly greater than this size, 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 empirical tests on different dimensions of these orifices 114.
[0089] For example, the orifices 114 with a diameter of 15 mm can be arranged in rows of orifices 114 extending substantially parallel to the axis Al and whose pitch between the centers of two adjacent orifices 114 is adapted to maximize the number of orifices 114 while allowing a sieve 113 to be kept sufficiently strong, for example formed in a sheet of 1.5 mm thick.
[0090] The orifices 114 can be arranged to prevent the passage of strips from the waste 10 when dealing with plastic bottles. To this end, the orifices 114 can be positioned so as not to be directly opposite the knives 103. For this purpose, an offset of the orifices 114 from the knives of more than half the diameter of the orifices 114 can be provided to prevent the strips from passing directly through the orifices 114 when the bottle is picked up by the crusher 100.
[0091] In particular, when the crusher 100 includes the first and second crushing chambers 106, 108, the separator 107 can include 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 prevent the mixing of what is ground in the first and second grinding chambers 106, 108 before the ground material passes through the sieve 113. The second part 116 allows the first part 115 to be extended with the interposition of a portion of the sieve 113 so as to delimit with the frame 101 the outlets 117a, 117b of the crusher 100 forming respectively the outlet 117a of the first grinding chamber 106 and the outlet 117b of the second grinding chamber 108. This prevents the mixture of what is ground in the first and second grinding chambers 106, 108 after the ground material has passed through the sieve 113.In other words, the sieve 113 can be formed from a single piece / component that allows for local sieving of the material ground in the first grinding chamber 106 and local sieving of the material ground in the second grinding chamber 108. Specifically, the first part 115 and the second part 116 enclose the sieve 113, thereby shaping the sieve 113, particularly when it is made of perforated sheet metal. The first part 115 and the second part 116 can be fastened to each other using screws whose body, especially threaded screws, passes through the sieve 113.
[0092] To avoid mixing what is ground in the first and second grinding chambers 106, 108, 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 the foregoing that when waste 10 is ground, it may end up in the form of cut (i.e., ground) elements (possibly flakes) whose dimensions do not allow all or part of the elements to pass through the sieve 113, or whose positioning results in overlapping elements that prevent their passage through the sieve 113. Therefore, there is a need to find a solution for mixing the elements to facilitate their passage through the sieve 113 and / or to allow the grinder 100 to cut them again to obtain smaller elements. To this end, at least one of the knives 103 is configured so that at least one end passes, with each rotation of said knife 103, close to the sieve 113 at a distance of between 1 mm and 4 mm, and preferably 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 stir 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 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 manufacture the knife(s) 103 along the sieve 113 with reasonable machining accuracy and therefore economically viable.In particular, the fact that said distance is less than or equal to 4 mm ensures efficient mixing of what is ground, especially flakes from bottles.
[0094] Preferably, all the knives 103 are arranged so that at least one of the teeth of each knife 103 describes a circle coaxial with the axis Al. The circles then define a cylindrical volume with a diameter equal to that of the circles, and the sieve 113 is shaped 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 has a profile delimited by a circular sector of the profile of the cylindrical volume, and the sieve 113 therefore runs along the portion of the cylindrical volume coaxially with this cylindrical volume and along the arc of the circular sector. The mixing of the crushed material retained by the sieve 113, where applicable 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 at the output of the crusher 100 of which should preferably each be included in the sphere mentioned above.
[0096] Depending on the waste 10, it is more generally possible to provide a positioning of the sieve 113 so that it is alongside one or more of the knives 103 at each turn of this or these 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 include at least three teeth 110a, 110b, 110c, as shown for example in [Fig. 8], to improve the gripping of waste 10, particularly 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 configuration of the waste 10 to be ground to facilitate its handling, particularly when it is an elongated piece of waste 10 such as a bottle. This is notably visible in [Fig. 8] where tooth 110c is larger than teeth 110a and 110b. In particular, tooth 110c is the one that forms the end of the knife 103 which runs along the sieve 113 with each rotation of the knife 103 in the grinding direction Fl.
[0099] The presence of one or more reception regions 104a, 104b has been mentioned above. The reception region or regions 104a, 104b can 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 direction of grinding. Thus, the first tooth 118 can participate in locally delimiting the volume of the reception area 104a, 104b and the second tooth 119 is arranged to allow the gripping of the waste 10 whose portion is present in the reception area 104a, 104b during the rotation of the drive shaft 102 in the direction Fl of grinding.
[0100] Each tooth 110a, 110b, 110c may include a curved cutting blade 120a, 120b, 120c ending in the gripping point 111a, 111b, 11 of said tooth 110a, 110b, 110c; this being particularly visible in figures 7 and 8. This curvature allows the formation of claws facilitating grinding by promoting the gripping of waste 10 for example by perforation of the latter.
[0101] Advantageously, the crusher 100 can include a block 121 of counter-knives 129 (particularly visible in [Fig. 3], 9 and 11) arranged to cooperate with the knives 103 in order to cut the waste 10 (i.e., crush it), the block 121 of counter-knives being, for example, fixed to the frame 101, in particular on an internal face 122 of the frame 101. Thus, the overall size of the crusher 100 can be reduced. This fixing of the block 121 of counter-knives can be achieved by any suitable means, for example, by means of screws. The counter-knives block 121 can be formed in a single piece of steel, in particular whose composition is adapted to the function of the counter-knives block 121. The counter-knives 129 of the counter-knives block 121 are arranged to delimit spaces between them for the passage of the knives 103.
[0102] For crushing plastic bottles, the counter-knives 129 of the counter-knive block 121 may each have a width measured parallel to the axis Al (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] With respect to a measurement direction parallel to the axis Al, the clearance between any pair of adjacent knife and counter-knife cooperating to cut material from one or more waste materials 10 can be between 0.1 mm and 1.5 mm. 1.5 mm provides a good cut; going below 0.1 mm would be possible but would increase production costs because it would require specific machining and precise assembly of the crusher 100.
[0104] The crusher 100 may include an additional block 123 of counter-knives 130 (particularly visible in [Fig. 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 allowing the reduction of the time required to crush waste 100, this also allows, where appropriate, for further cutting of the flakes arranged between the drive shaft 102 and the screen 113. The additional block 123 of counter-knives 130 may be formed in a single piece in steel, in particular whose composition 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 spaces between them for the passage of the knives 103.
[0105] For crushing plastic bottles, the counter-knives 130 of the additional block 123 of counter-knives 129 can each have a measured width parallel to the axis Al equal to that of each of the knives 103 in the context of a cutting function and, where applicable, disentanglement, 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 disentanglement.
[0106] The crusher 100 may include a comb 125 (notably visible in [Fig. 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 direction Fl of crushing ([Fig. 1]). The presence of this comb 125 prevents jamming of the crusher 100, which would require significant effort from the motor 127 to clear the jam: it is sufficient to reverse the direction of rotation of the drive shaft 102 to resolve the jam. Typically, the comb 125 may include fingers 131 that define inter-finger spaces for the passage of the knives 103.
[0107] The comb 125 can be fixed to the frame 101 opposite the counter-knife block 121 130. Thus, a simple half-turn of the knives 103 in the direction F2 can suffice to disentangle before putting the knives 103 back into rotation in the direction Fl of grinding, reducing the time required to solve the problem.
[0108] The comb 125 can be made of steel, in particular of a composition adapted to the function of the comb 125. The fingers 131 of the comb 125 can each have a width measured parallel to the axis Al identical to that of each of the counter-knives 130, in this case the fingers 131 of the comb 125 participate in the cutting from which results the application of forces on the drive shaft 2.
[0109] The comb 125 and the additional block 123 of counter-knives 130 can form a single part, as shown in [Fig. 11]. This allows, if necessary, for a reduction in the number of parts constituting the crusher 100. If the additional block 123 is not present in the crusher 100, the crusher 100 can include the comb 125, which then simply has a disentanglement function and does not participate in cutting the waste 10 with the knives 103.
[0110] The crusher 100 may include bearings 126a, 126b for guiding the drive shaft 102 in rotation, the rotation of which may be ensured / controlled by the motor 127. The bearings 126a, 126b are particularly visible in figures 10, 11, 12, 13 and 14. The bearings 126a, 126b are integral with the frame 101.
[0111] The invention also relates to a device 1000 for grinding waste 10, comprising the grinder 100 as described and a guide conduit 1001 including an inlet 1003 for introducing waste 10 into the guide conduit 1001. The guide conduit 1001 is configured to guide the waste 10 previously introduced into the guide conduit 1001 towards the grinder 100. In other words, the The guide conduit 1001 can be mounted on the crusher 100 so as to guide the waste 10 towards the crusher 100 as shown for example in figures 12 to 14. Such a device 1000 for crushing waste 10 is particularly compact and allows waste 10 to be crushed efficiently. In the case where the crusher 100 includes the first and second crushing chambers 106, 108, the guide conduit 1001 may include the means necessary to ensure suitable guidance of the waste 10 previously introduced into the guide conduit 1001 within the guide conduit 1001 such as a movable guide element 1002 (also called a movable flap) controlled according to the type of waste 10 to be crushed so as to orient the waste 10 previously introduced into the guide conduit 1001 either towards the first crushing chamber 106 in a first configuration of the device 1000 ([Fig.13]), or towards the second grinding 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, for example, be sorted at these two openings by a person wishing to recycle their waste 10.
[0112] As shown in [Fig. 12], the guide conduit 1001 may include the inlet 1003 through which the waste 10 can be introduced. The guide member 1002 can then direct 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 ([Fig. 13]) - i.e. with the inlet 105a 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 ([Fig. 14]) - i.e. with the inlet 105b of the second grinding chamber 108.
[0113] The guide conduit 1001 can be mounted directly on the crusher 100 so that the first and second outlets 1004, 1005 are respectively in junction with the inlet 105a of the first crushing chamber 106 and with the inlet 105b of the second crushing chamber 108 as can be deduced in particular from figures 13 and 14.
[0114] The device 1000 for grinding waste 10 may further include at least one receiving bin 1006, 1007 for the ground material at the outlet of the grinder 100. In particular, the device 1000 for grinding waste 10 may include first and second receiving bins 1006, 1007 for the 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 separately recover what is ground in the first grinding chamber 106 and what is ground in the second grinding chamber 108, resulting in the formation of two deposits 1008a, 1008b, respectively in the first bin 1006 and in the second bin 1007 which can be recycled in different ways.
[0115] In figures 13 and 14, the knives 103 are schematically represented by a set 132 of knives.
[0116] A particular embodiment is now described in which the crusher 100 includes 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 gear to adapt the rotational speed of a motor shaft to the desired speed of the drive shaft 102 for proper cutting of the waste 10. The shredding of the waste 10 is then made possible by the combination of the knives 103 and the counter-knife block 121. Of course, the reduction gear may not be necessary if the rotational speed of the motor shaft is equal to the desired rotational speed of the drive shaft 102.
[0118] In the particular embodiment, the knives are of the types shown in Figures 7 and 8, they each include gripping points 111a, 111b, 11 whose role is to ensure the gripping of the waste 10 by perforation of this waste 10 and curved cutting blades 120a, 120b, 120c which will participate in cutting the waste 10.
[0119] In the particular embodiment, the counter-knife block 121 is fixed to the frame 101 opposite the knives 103 and provides cutting stops intended to cooperate with the knives 103 to cut the waste 10 into strips which will then be cut again to form the desired flakes at the output of the crusher 100.
[0120] In order to reduce the bottle crushing cycle time, for example to a maximum of 3 seconds, the crusher 100 includes, in this particular embodiment, the comb 125 for disentangling the knives 103, if necessary, according to the direction F2 of rotation of the drive shaft 102. The trio of knives 103, counter-knives 121, and comb 125 makes it possible to limit the power required to crush plastic bottles, and thus ensure, for example, that the crushing device 1000 can be installed using a conventional single-phase power supply of less than 16 amps.
[0121] Still within the framework of the particular embodiment example, once the waste 10 has been ground, the resulting flakes flow through the orifices 114 of the sieve 113 to be stored in the bins 1006, 1007 allowing the storage of the granulate from the 100 crusher according to two different deposits (for example respectively dark-colored PET flakes and light-colored PET flakes).
[0122] A 2 mm gap between the knives and the sieve 113, for example defined as the distance separating the maximum outer radius described by the knives 103 as they pass along the sieve 113 and the inner radius of the sieve 113, allows PET flakes that are not 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 crusher 100 according to the particular embodiment is compartmentalized by means of the separator 107 so as to present the first and second crushing chambers 106, 108. Preferably, in each of the first and second crushing chambers 106, 108, the type and number of knives 103 are identical: as illustrated in [Fig. 5], the crusher 100 can then comprise nine knives in each of the first crushing chamber 106 and the second crushing chamber 108.
[0124] The knives of the first grinding chamber 106 and the knives of the second grinding chamber 108 are arranged identically along the drive shaft 102, for example, in the following sequence from the toothed end 109 of the drive shaft 102: five three-toothed knives, followed by two two-toothed knives, followed by two three-toothed knives. Naturally, in each of the first and second grinding chambers 106 and 108, the knives 103 are separated in pairs by one of the spacers 112.
[0125] In particular, within the context of the specific embodiment example: • the knives 103 with two teeth 110a, 110b can 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 of radius equal to 9 cm (these circles being then coaxial for the different knives 103 and concentric for the same knife 103); • the knives 103 with three teeth 110a, 110b, 110c can be such that, for each of these knives 103, the gripping point 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 Al, a circle of radius equal to 9 cm and the points 111a, 111b of the other teeth 110a, 110b of said knife 103 each describe a circle of radius equal to 7.5 cm (for the same knife 103 the circles described by the different teeth are concentric and for two distinct knives the circles of the largest teeth are coaxial and the circles of other teeth are coaxial).
[0126] In order to determine the shape, arrangement, and orientation of the knives 103 in each crushing chamber, it is useful to note how the bottles fall into the crusher 100 between a horizontal and a vertical position. When the bottle enters the crusher 100 in a horizontal position, the outer radius of the teeth 110a, 110b, 110c is the determining factor; conversely, when the bottles enter the crusher 100 in a vertical position, the orientation and arrangement of the knives 103 are predominant.
[0127] In this 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 useful to consider the dimensions and types of waste 10 to be crushed. Experiments carried out within the framework of the present invention have shown that for a bottle to be optimally gripped by the teeth 110a, 110b, 110c, the tip of the knife must reach between 73% and 80% of the bottle's diameter. Typically, bottle diameters are 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, whose tip defines this circle, is preferentially shaped so that said tip can penetrate the 1 L bottle to 73% of its diameter and the 25 cl bottle to 80% of its diameter. Of course, the knives 103 of the crusher 100 will be adapted in shape according to the type of waste to be crushed.
[0128] For example, the "large teeth" whose points 111a, 111b, 11 evolve in a circular manner around a radius of 9 cm are designed to grip and pierce bottles of the diameters above which would be lying down and for example whose longitudinal axis would be substantially parallel to the axis Al.
[0129] For example, the "small teeth" whose tips 111a, 111b evolve in a circular manner around a radius of 7.5 cm are designed to grip and pierce bottles of the diameters above which would be presented 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 according to the type of waste 10 to be ground. For example, the height of a tooth can be defined to present the smallest possible cutting angle (measurable at the tip 111a, 111b, 11 the gripping angle of the tooth 110a, 110b, 110c when the tooth 110a, 110b, 110c comes into cooperation with a counter-knife) between the tooth and the counter-knife 130 with which it will cooperate in the manner of the cutting phenomenon of scissors. The cutting length of the tooth, notably defined by the curvature of tooth 110a, 110b, 110c, can be maximized to smooth or evenly distribute the forces during cutting without causing "load peaks" during the rotation of the crusher shaft 100. Overall, the choices regarding the height of the teeth 110a, 110b, 110c and their cutting length allow limiting the cutting forces required for crushing waste 10.
[0131] Generally, each knife 103 may include a hub 133 (Figures 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 that includes 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 area where it extends from the hub 133, a fillet 134. This fillet 134 creates 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 effort required for grinding.
[0132] Generally, at least one of the teeth 110a, 110b, 110c, and in particular each tooth 110a, 110b, 110c, can be such that its cutting edge 120a, 120b, 120c is serrated. This makes it possible to limit the cutting forces required for grinding. Figure 15 illustrates this with a knife 103 having two teeth 110a, 110b whose cutting edges 120a, 120b are serrated. In the case illustrated in [Fig. 15], each of the two teeth 110a, 110b is provided with three projections 135 between the gripping point 111a, 111b of the tooth 110a, 110b and the base of the tooth 110a, 110b at the chamfer 134. Each projection 135 then locally forms a tooth of the cutting blade 120a, 120b. The number of teeth of the cutting blade 120a, 120b is not limited to three and can be adapted to any number depending on the type of waste 10.Thus, the 120a, 120b serrated cutting blade acts as a chip breaker, and facilitates cutting because the material, previously broken locally, will offer less resistance during cutting, thus relieving the motor of the 100 crusher.
[0133] Generally, regarding the choice of orientation and angles of the knives 103, the determining criterion can be the cycle time (i.e., the time required to shred the waste 10). In order to ensure rapid intake of the waste 10, in this case preferably the plastic bottle, the arrangement of the knives 103 can be adapted by a person skilled in the art.
[0134] Thus, in general, the crusher 100 can be configured to crush waste 10 from a range of waste, the range being defined by the fact that each piece of waste 10 in 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 the dimensions of the first end taken in a plane orthogonal to the direction of the longitudinal dimension; Therefore, the host region(s) are configured / sized to receive the second end, and consequently also the first end.
[0135] In particular, the most demanding case is that of crushing large bottles. For example, for a 1.5 L bottle 32 cm high and with a diameter of 8.8 cm, it is preferable that the receiving area 104a, 104b be shaped to allow the lower part of the bottle, including its base, to be inserted into it. To this end, the knives 103 can be arranged so as to delimit, within each of the first and second crushing chambers 106, 108, particularly with the frame 101, a free zone (i.e., the corresponding receiving area 104a, 104b) into which the bottle can be placed. This free zone can have a dimension of 117 mm, measured along the A1 axis.Therefore, if each of the first and second crushing chambers 106, 108 includes within it two reception regions 104a, 104b diametrically opposed with respect to the axis Al of the drive shaft 102, in less than half a turn of the drive shaft 102 in the direction Fl of crushing the bottle can be perforated and thus gripped to then be crushed by the crusher 100.
[0136] The present invention finds an industrial application in the grinding of waste 10, for example for the purpose of recycling. The present invention can therefore be integrated into a waste recycling process.
Claims
1. Demands Crusher (100) for crushing waste (10), said crusher (100) comprising: • a chassis (101); • a single mobile drive shaft (102) rotating relative to the chassis (101) around an axis (Al); • knives (103) mounted on the drive shaft (102) so as to be rotationally fixed with the drive shaft (102) around said axis (Al) in at least one direction (Fl) of grinding; 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 (F1), 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) allows, during the rotation of the drive shaft (102) in the grinding direction (F1), the gripping of said waste (10) to be ground, at least a portion of which is positioned in said receiving region (104a, 104b), characterized in that the knives (103) delimit, in whole or in part, several regions (104a, 104b) reception and in that the crusher (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) through which the drive shaft (102) passes, 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).
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 point (111a, 111b, 111e).
3. Crusher (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 points (111a, 111b) are diametrically opposed with respect to the axis (Al), for example the two teeth (110a, 110b) are axially symmetrical about the axis (Al).
5. Crusher (100) according to any one of claims 1 to 4, characterized in that it comprises a screen (113) integral with the frame (101), the screen (113) being configured to allow the passage of crushed material from the crushing by the crusher (100).
6. Crusher (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, 111e) passing, at each turn made by said knife (103), near the screen (113) at a distance of between 1 mm and 4 mm, and preferably equal to 2.5 mm.
7. Crusher (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. A crusher (100) according to claim 2 or according to claim 2 and any one of claims 3 to 8, characterized in that said at least one 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 of the axis (Al) and behind the first tooth (103a) according to the direction (Fl) of grinding.
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 point (111a, 111b, 111e) of said tooth (110a, 110b, 110c).
11. Crusher (100) according to claim 10, characterized in that the curved cutting blade (120a, 120b, 120c) is serrated.
12. Crusher (100) according to any one of claims 1 to 11, 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 frame (101), in particular on a single internal face (122) of the frame (101).
13. Crusher (100) according to claim 12, 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).
14. Crusher (100) according to any one of claims 1 to 13, 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 direction (Fl) of crushing.
15. Crusher (100) according to claim 13 and claim 14, characterized in that the comb (125) and the additional block (123) of counter-knives form a single piece.
16. Crusher (100) according to any one of claims 14 to 15, characterized in that the comb (125) is fixed to the frame (101) opposite the block (121) of counter-knives (130).
17. Device (1000) for grinding waste (10) comprising a grinder (100) according to any one of claims 1 to 16 and a guide conduit (1001) comprising an inlet (1003) for introducing waste (10) into the guide conduit (1001), the guide conduit (1001) being configured to guide the waste (10) previously introduced into the guide conduit (1001) towards the grinder (100).