Device for producing defibrated hay or straw flakes

Abstract

Title: Device for producing defibrated hay or straw straw. The invention relates to a device for transforming fibrous plant stems into defibrated straw, the device comprising: - a hopper (1) for receiving fibrous plant stems; - a grinding system (2) located below the hopper (1), and comprising a rotor (20) carrying grinding hammers (21), and having an outlet; - a conduit (3) located in line with the outlet of the grinding system (2), the conduit (3) extending along a longitudinal axis (30); - a cutting system (4) into which the conduit (3) opens, the cutting system (4) comprising a rotor (40) carrying cutting hammers (41). Figure for the abstract: Fig. 1

Description

Title of the invention: Device for producing defibrated hay or straw straw. Technical field

[0001] The field of the invention is that of the design and manufacture of equipment for processing straw or hay.

[0002] The invention relates more particularly to a device for transforming straw or hay into defibrated straw. State of the art

[0003] Defibrated straw, or defibrated hay, can be used as bedding, mainly for poultry, but also as a dietary supplement in ruminant rations to promote their ingestion.

[0004] Existing shredding systems allow the defibration of straw, or hay, but have various disadvantages.

[0005] For example, a first system includes a rotor carrying small crushing hammers and / or knives forcing the straw through a cylindrical calibration grid.

[0006] This type of system has several disadvantages.

[0007] For example, in the case where stones are present in the straw bale to be defibrated, which is frequent, these stones must be reduced into smaller fragments by the friction of the hammers which risks breaking them, and causing a fire to start.

[0008] Moreover, in this type of system the flow rate of chopped straw is low.

[0009] Another crushing system, conventionally towed and powered by an agricultural tractor, The system comprises a rotor carrying a plurality of rectangular hammers designed to strike the straw to be chopped, located above the rotor, through a grid formed of bars. The system also includes a semi-cylinder forming a cradle in which the rotor rotates; the semi-cylinder is formed from a grid and constitutes a screening means through which the straw must pass.

[0010] Such a system also presents a risk of fire starting when crushing the stones contained in the straw, of breakage of the hammers, but also a risk of clogging when the straw does not exit directly through the grid forming the screening means and makes several turns in the rotor, and this in particular with wet straw. Technical problem

[0011] The invention aims in particular to overcome these drawbacks of the prior art.

[0012] More specifically, the invention aims to provide a device for efficiently transforming straw or hay into defibrated straw.

[0013] The invention also aims to provide such a device which can transform straw with a high flow rate, minimizing the risk of clogging.

[0014] The invention also aims to provide such a device which avoids the inconveniences classically found in the prior art due to the presence of stones in straw or hay bales. Summary of the invention

[0015] These objectives, as well as others that will appear subsequently, are achieved thanks to the invention, which relates to a device for transforming fibrous plant stems into defibrated flakes, the device comprising: - a receiving hopper for fibrous plant stems; - a grinding system located below the hopper, comprising a rotor carrying grinding hammers, and having an outlet; characterized in that the device comprises: - a conduit located in the extension of the outlet of the grinding system, the conduit extending along a longitudinal axis; - a cutting system into which the conduit opens, the cutting system comprising a rotor carrying cutting hammers, the cutting hammers having a cutting edge extending transversely to the longitudinal axis of the conduit.

[0016] The device described above makes it possible to efficiently transform straw, or hay, into defibrated straw, or hay flakes.

[0017] The efficiency of the device is achieved by distributing the defibration and cutting operations between two separate components. Defibration is carried out using the grinding system, which tends to break the cereal straw stems lengthwise. The grinding system then pushes the defibrated stems into the conduit, where they tend to be oriented parallel to its longitudinal axis. Upon exiting the conduit, the cutting system makes a cut transverse to the orientation of the defibrated stems, thus producing defibrated flakes.

[0018] According to a preferred feature, the grinding system includes a counter-iron having at least two blades extending in an arc around the rotor, and parallel to each other, the blades having teeth extending in the direction of the rotor, the teeth of two blades juxtaposed to each other, providing between them a space for the passage of grinding hammers.

[0019] The combined action of the counter-iron and the hammers of the grinding system promotes the defibration of the straw or hay strands.

[0020] Advantageously, the rotor of the grinding system has, distributed along the axis of rotation of its rotor, a plurality of sets of grinding hammers, the grinding hammers of each set being radially distributed around a point along the axis of rotation, the counter-iron having more than two blades.

[0021] The plurality of crushing hammers, in combination with the counter-iron, promotes the defibration of straw or hay strands. Furthermore, the combined action of the hammers and blades tends to "comb" the defibrated strands and promote their orientation in the chute parallel to the longitudinal axis of the chute.

[0022] According to an advantageous design, the counter-iron is mounted movable relative to the rotor of the grinding system, and in that the device includes means for adjusting the position of the counter-iron relative to the rotor of the grinding system.

[0023] This allows adjustment of how the straw or hay strands caught by the shredding hammers are ground along the counter-iron. For example, the part of the counter-iron located upstream of the flow of straw caught by the shredding hammers can be further away from the rotor compared to the part of the counter-iron located downstream of said flow of straw, in order to strengthen the shredding at the distal end.

[0024] According to an advantageous embodiment, at least one grinding hammer extends longitudinally between a first end and a second end, said grinding hammer being rotationally mounted on the rotor by its first end and having at its second end a distal edge of the first end, the distal edge having a convex profile.

[0025] The convex profile of the distal edge of the hammer helps to maintain a consistent distance between the grinding hammer and the chipbreaker throughout the device's use, despite predictable hammer wear. Indeed, prior art hammers have a rectangular shape, which causes the distance between the grinding hammer and the chipbreaker to vary as the hammer wears, this distance being measured between an angle of the distal edge of the hammer and the chipbreaker.

[0026] Preferably, at least one crushing hammer extends longitudinally between a first end and a second end, and has a front slice extending between the first end and the second end, the front slice having a concave profile intended to grab fibrous stems of plants located in the receiving hopper.

[0027] In this way, despite wear on the grinding hammer, the latter tends to maintain a shape which remains aggressive to grab the fibrous stems of plants.

[0028] Advantageously, the hopper comprises a grid on a hopper bottom, the grid having longitudinal openings, the grinding hammers of the system shredders being designed to catch the fibrous stems of plants through the longitudinal openings of the grid.

[0029] According to a preferred embodiment, a bottom of the hopper carries an anti-jamming plate, the plate being movablely mounted on the bottom by means of an actuator, and extending along the side of a volume overhanging a passage communicating between the hopper and the grinding system.

[0030] Such a plate makes it possible to raise a mass of straw from the bottom of the hopper in order to limit, or avoid, a blockage at the level of the grinding system.

[0031] According to a preferred feature, the bottom of the hopper has a stone collector located under the anti-jamming plate, and which is juxtaposed at the interface between the hopper and the grinding system, the collector having a stone discharge hole communicating with the outside of the device.

[0032] Thanks to this feature, the stones located in the mass of hay or straw to be processed and which are struck by the crushing hammers tend to escape by rebound under the anti-clogging plate, into the collector.

[0033] Advantageously, the cutting system includes a cage inside which the rotor is mobile to rotation, the rotor of the cutting system and its cage forming means for aspiration of a ground material located in the conduit.

[0034] The cutting of the crushed material and its ejection are optimized thanks to this configuration.

[0035] According to a preferred design, the cage has an air intake opening juxtaposed to an opening of the duct leading into the cage.

[0036] This increases the Venturi effect phenomenon occurring at the cutting system, resulting in improved ejection of the defibrated flakes. Brief description of the drawings

[0037] Other features and advantages of the invention will become more apparent upon reading the following description of various preferred embodiments of the invention, given by way of illustrative and non-limiting examples, and the accompanying drawings, among which: • [Fig.1] [Fig.1] is a schematic perspective representation of a transformation device according to the invention, along a median longitudinal section; • [Fig.2] [Fig.2] is a simplified schematic representation, seen from the side and according to the median longitudinal section, of the transformation device; • [Fig.3] [Fig.3] is a schematic representation viewed from above of the transformation device; • [Fig.4] [Fig.4] is a partial schematic representation, side view, of grinding means of the transformation device; • [Fig. 5] [Fig. 5] is a schematic, perspective representation of a part of the grinding means of the transformation device; • [Fig.6] [Fig.6] is a partial schematic representation, seen from the front, of part of the grinding means of the transformation device; • [Fig.7] [Fig.7] is a partial schematic representation, in perspective, means of cutting the transformation device; • [Fig.8] [Fig.8] is a partial schematic representation, in perspective, from the bottom of a hopper of the transformation device; • [Fig.9] [Fig.9] is a schematic representation from another angle view, from the bottom of the hopper of the transformation device, according to a longitudinal section passing through a stone discharge hole of a stone collector of the transformation device; • [Fig. 10] [Fig. 10] is a schematic side view representation of a grinding hammer. Detailed description

[0038] With reference to figures 1 to 3, a device for transforming fibrous rods, according to the invention, is shown.

[0039] This transformation device is designed to transform fibrous plant stems into defibrated flakes.

[0040] According to the present embodiment, the device comprises a frame 91 on which its components are assembled.

[0041] The device includes, for example, a platform 92 allowing an operator to move around the different systems accessible from the platform 92, and at least one ladder 93 allowing access to the platform 92.

[0042] The device includes a hopper 1 for receiving fibrous plant stems.

[0043] This receiving hopper 1 comprises a bottom 11, and a peripheral wall 12 extending vertically from the bottom 11 to an upper collar 13 defining an opening for the introduction of straw or hay to be processed.

[0044] The upper collar 13 is flared.

[0045] According to the present embodiment, the hopper 1 adopts an essentially cylindrical shape of revolution, and the upper collar 13 takes a frustoconical shape.

[0046] The peripheral wall 12 is separated from the bottom 11 of the hopper 1 and is mounted to rotate freely relative to the bottom 11, around an axis of rotation extending perpendicularly to the bottom 11.

[0047] The peripheral wall 12 is also decoupled from the collar which can thus be fixed relative to the bottom 11.

[0048] The peripheral wall 12 is provided with internal deflectors 14 extending towards the interior of the hopper 1.

[0049] Straw or hay inserted into the receiving hopper 1 is thus likely to be carried along by the peripheral wall 12.

[0050] Of course, the device includes a motor to rotate the peripheral wall 12.

[0051] The receiving hopper 1 is dimensioned so as to be able to receive a mass 10 of straw or hay in the form of bales, or a ball.

[0052] With reference to figures 1 to 6, the device includes a grinding system 2 which includes a rotor 20 carrying grinding hammers 21.

[0053] This grinding system 2 is located below the hopper 1.

[0054] More specifically, the hopper 1 comprises a grid 15 on its base 11. This grid 15 is formed by bars coupled at their ends to the base 11, and having a central section substantially curved upwards. These bars extend parallel to each other. The grid 15 thus has longitudinal openings.

[0055] As shown in [Fig.2], the grinding hammers 21 of the grinding system 2 are designed to grab the fibrous stems of plants through the longitudinal openings of the grid 15.

[0056] The rotor 20 is movable around an axis of rotation.

[0057] This rotor 20 is for example driven in rotation by an electric motor.

[0058] This rotor 20 of the grinding system 2 has a plurality of hammer assemblies grinding 21.

[0059] These grinding hammer assemblies 21 are distributed along its rotor rotation axis.

[0060] Each rotor assembly 20 comprises a central star-shaped part 22 having a plurality of branches 23 regularly distributed around the axis of rotation. In this case, each central part 22 has six branches 23.

[0061] A grinding hammer 21 is freely coupled in rotation on each distal end of the branches 23 of the central part 22. The grinding hammers 21 of each assembly are thus distributed radially around a point along the axis of rotation.

[0062] The grinding hammers 21 extend longitudinally between a first end 211 and a second end 512.

[0063] The grinding hammers 21 are mounted for rotation on the rotor 20 by their first ends 211, and more specifically on the distal ends of the axis of rotation of the branches of the central parts.

[0064] More specifically, the grinding hammers 21 are mounted to rotate freely. The hammer positions illustrated in [Fig. 4] are reached when the rotor 20 is set in rotation and centrifugal forces are applied.

[0065] Each grinding hammer 21 has: - a rear edge 213 at its first end 211; - a distal edge 214 of the first end 211, at the level of its second end 212; - a front slice 215 extending between the first end and the second end, and intended to catch fibrous stems of plants located in the receiving hopper 1; - a rear slice 216 opposite the front slice 215.

[0066] At least one grinding hammer 21 has a distal edge 214 having a convex profile.

[0067] The convex profile has a single radius of curvature. As shown in [Fig.4], the radius of curvature of the convex profile of the distal edge 214 is equal to the radius of curvature of a circle Cl centered on the axis of rotation of the rotor 20 and passing through the distal edges 214 of the hammers in the position illustrated in [Fig.4], or is substantially equal to the radius of curvature of said circle while being less than this radius of curvature.

[0068] This mitigates the negative impacts of wear on the grinding hammer 21.

[0069] According to the present embodiment, each grinding hammer 21 has a distal edge 214 with the previously described shape.

[0070] In addition, at least one grinding hammer 21 has a front edge 215 having a concave profile.

[0071] This makes it possible to tend to maintain the ability of the crushing hammer 21 to grab straw strands despite wear of the crushing hammer 21.

[0072] According to the present embodiment, each grinding hammer 21 has a front slice with the shape described above.

[0073] The combination of the shape of the distal edge 214 and the front slice 215 makes it possible to create a beak 217 intended to grasp plant strands.

[0074] A discontinuous line U on [Fig.10] illustrates wear of the grinding hammer 21. As has been observed experimentally, the wear does not tend to significantly alter the ability of the grinding hammer to grasp plant material, nor does it affect the distance separating the distal edge 214 from the counter-iron 25 described below.

[0075] The grinding system 2 includes a counter-iron 25 complementary to the grinding hammers 21.

[0076] This counter-iron 25 has a plurality of blades 26 extending in an arc around the rotor 20, and parallel to each other.

[0077] In this case, the counter-iron 25 has three blades 26, and the blades 26 extend over an arc of approximately 120° around the rotor 20 of the grinding system 2.

[0078] The blades 26 having teeth 27 extending in the direction of the rotor 20.

[0079] These teeth 27 have a triangular section whose tip is oriented towards the rotor 20.

[0080] The teeth 27 of two blades 26 juxtaposed to each other provide between them a space for the passage of grinding hammers 21, and in particular of grinding hammers 21 of a set of grinding hammers 21.

[0081] The counter-iron 25 is mounted movable relative to the rotor of the grinding system 2.

[0082] With reference to [Fig.4], the counter-iron 25 is mounted to rotate freely on a pivot axis which extends parallel to the axis of rotation of the rotor 20 of the grinding system 2.

[0083] The device further includes means for adjusting the position of the counter-iron 25 relative to the rotor of the grinding system 2.

[0084] More specifically, a pivot axis 291 is located at the lower end 251 of the counter-iron 25, and the adjustment means 29, for example formed by a cylinder and a connecting rod, allow the upper end 252 of the counter-iron 25 to be moved closer to or further away from the rotor of the grinding system 2 (displacement illustrated by the arrow DI on [Fig.4]).

[0085] Preferably, the upper end 252 is positioned at a greater distance from the rotor 20 of the grinding system 2 than that of the lower end 521.

[0086] This upper end 252 is located directly below the grid 15 through which the plant fibers are caught.

[0087] This allows the crushing to be intensified as the straw progresses along the direction of rotation (direction illustrated by arrow RI in figures 2 and 4) of the rotor 20, towards the lower end of the counter-iron 25.

[0088] As can be seen in figures 4 and 5, the counter iron 25 has L-shaped spacers 28 with the wedge oriented towards the rotor, between each blade 26 at the level of each tooth 27.

[0089] This intensifies the grinding.

[0090] With reference to figures 5 and 6, the grinding hammers 21 and the blades 26 have rectangular sections when viewed from the front.

[0091] With reference to figures 1, 2, and 7, the device includes an outlet of the grinding system 2, as well as a conduit 3 located in the extension of this outlet.

[0092] This outlet of the grinding system 2 is positioned in the lower part of the grinding system 2, in continuity with a tangent to the circle described by the grinding hammers 21, directly at the level of, or directly after, the lower end of the counter-iron 25.

[0093] The conduit 3 extends along an axis, the conduit 3 extending along a longitudinal axis 30. The longitudinal axis 30 is in particular orthogonal to the axis of rotation of the rotor of the grinding system 2.

[0094] The design of the grinding system 2 and the conduit 3 described above makes it possible to defibrate fibrous plant stems by splitting them along their length, while by producing a combing effect tending to orient the defibrated plant stems parallel, or substantially parallel to the longitudinal axis 30 of the conduit 3. The defibrated plant stems are projected into the conduit 3 in the direction of the cutting system 4 described below, as illustrated by the arrow Fl on [Fig.2].

[0095] The device also includes a cutting system 4.

[0096] The conduit 3 extends longitudinally from the grinding system 2 to the cutting system 4, in order to supply the cutting system 4 with defibrated plant stems, which must cut the stems into flakes.

[0097] The conduit 3 has a rectangular cross-section. This cross-section narrows towards the cutting system 4.

[0098] The conduit 3 is formed by an upper wall, two lateral cheeks, and a lower wall 31.

[0099] According to the present embodiment, the lower wall 31 of the conduit 3 is mounted movable so that the end of this lower wall 31 close to the cutting system 4 can be lowered or raised.

[0100] More specifically, the lower wall 31 is formed by a U-shaped bent sheet metal plate, the web of which forms the lower wall 31 and the two arms of which form part of the side panels. A connecting rod system 32 is coupled under the end of the lower wall 31 and causes the end of the bent sheet metal to be lowered or raised, and thus the lower wall 31 to be lowered or raised.

[0101] With further reference to Figures 1, 2, and 7, the cutting system 4 comprises: - a rotor 40 carrying cutting hammers 41; - a cage 42 inside which the rotor 40 is mobile in rotation.

[0102] Conduit 3 opens into cutting system 4. More specifically, conduit 3 opens into cage 42.

[0103] The rotor 40 of the cutting system 4 has an axis of rotation parallel to the axis of rotation of the rotor of the grinding system 2.

[0104] The rotor of the cutting system 4 is designed to rotate in the same direction as the rotor 20 of the grinding system 2 as illustrated by arrow R2 on [Fig.2].

[0105] The cutting hammers 41 have a cutting edge 411 extending transversely to the longitudinal axis 30 of the conduit 3. More precisely, the cutting edge 411 extends orthogonally to the longitudinal axis 30 of the conduit 3.

[0106] The edge of the lower wall 31 of the conduit 3 forms a counter-knife 311 to the cutting edges 411 of the cutting hammers 4L

[0107] These cutting hammers 41 allow the defibrated plant stems to be transformed into flakes.

[0108] According to the present embodiment, the rotor 40 carries a plurality of cutting hammers 41 regularly distributed angularly around its axis of rotation. In addition, the rotor 40 has a plurality of sets of cutting hammers 41 along its axis of rotation.

[0109] The cutting hammers 41 of the different assemblies are aligned in rows relative to each other, around the rotor 40.

[0110] According to the present embodiment, the cutting hammers 41 have a T-shaped form with a shaft 412 and a head 413 having a cutting edge 411 at each of its two ends.

[0111] Although the cutting hammer rods 412 directly adjacent in a row are spaced apart from each other, the rotation of the rotor 40 in the cage 42 produces a suction.

[0112] Indeed, the rotor of the cutting system 4 and its cage form means for aspiration of a ground material located in the conduit 3.

[0113] According to one conceivable embodiment, the rods 412 of cutting hammers 41 directly adjacent in a row could be connected by a plate which would form a fin to enhance suction.

[0114] With reference to [Fig.7] more specifically, the cage has an air intake opening 43 juxtaposed to the opening of the duct 3 leading into the cage.

[0115] Adjusting the position of the end of the lower wall 31 near the cutting system 4 allows the suction capacity of the suction means to be varied, in particular by increasing or decreasing a Venturi effect produced by the presence of this air suction opening and its cross-section.

[0116] The device also includes a glitter ejection chute 5 extending from the cutting system 4. The glitter ejection is represented by arrow F2 in [Fig.2]

[0117] With reference to figures 1, 3, 8, and 9, the bottom 11 of the hopper 1 carries an anti-jamming plate 6.

[0118] This anti-jamming plate 6 extends along the side of a volume overhanging a passage communicating between the hopper 1 and the grinding system 2.

[0119] More specifically, the anti-jamming plate 6 extends longitudinally parallel to the grid 15 overhanging the rotor of the grinding system 2.

[0120] This anti-jamming plate 6 is mounted movably on the bottom 11 of the hopper 1 by means of an actuator 61, in particular formed in part by a cylinder.

[0121] For this purpose, the anti-clogging plate 6 is rotatably mounted at one of its ends, referred to as the rotating coupling end 62, which is juxtaposed to the part, referred to as the front part 151, of the grid 15 from which the crushing hammers 21 protrude. Consequently, the end of the anti-clogging plate 6 located at the level of the part, referred to as the rear part 152, of the grid 15 where the crushing hammers 21 re-enter, having caught the straw or the hay, called the liftable end 63, presents the greatest movement when raising or lowering the anti-blocking plate 6.

[0122] Lifting the anti-jamming plate 6 makes it possible to limit, or even eliminate, a jamming phenomenon that may occur in the presence of too much straw, or in the case where the nature of the straw is likely to cause a jam (wet straw).

[0123] According to the same figures, the bottom 11 of the hopper 1 has a stone collector 7.

[0124] This stone collector 7 is located under the anti-jamming plate 6.

[0125] This stone collector 7 is juxtaposed at the interface between the hopper 1 and the system of grinding 2, that is to say at the grid 15 above the rotor of the grinding system 2 and through which the stems of the plants are caught by the grinding hammers 21.

[0126] The collector 7 has a stone drainage hole 71 communicating with the outside of the device.

[0127] With more specific reference to figures 8 and 9, the collector 7 includes an opening provided in the bottom 11 of the hopper 1.

[0128] This opening is located directly under the anti-jamming plate 6 and directly adjacent to the grid of the hopper 1.

[0129] Stones struck by the crushing hammers 21 can be sent directly towards the opening, but can in particular rebound against an underside of the anti-jamming plate 6 to be redirected towards the opening.

[0130] The collector 7 also includes at least one inclined plate 72 forming a slide which gravitationally redirects stones passing through the aforementioned opening, in particular towards the drainage hole 71.

[0131] In this case, the collector 7 comprises two inclined plates 72.

[0132] The collector defines a passage through which the stones can fall. This passage is separated laterally from the volume in which the rotor 20 of the crushing system 2 rotates by a lateral plate 73.

[0133] The drainage hole 71 is located in continuity with the passage, at least at the lowest level of the slide(s).

[0134] This stone collector 7, thanks to the fluidic communication it forms between the volume underlying the anti-jamming plate 6 and the outside of the device, forms means of supplying air to the level of the grid 15 above the rotor of the grinding system 2, from the outside of the device.

[0135] This additional airflow is particularly beneficial for grinding, as well as for ejecting the defibrated straw or hay shavings.

[0136] The anti-jamming plate 6 may be provided with a side plate extending downwards from the side of the anti-jamming plate 6 opposite the grid 15 overhanging the crushing system 2, in order to avoid or limit the entry of straw or hay at this level, and to tend to optimize the redirection of stones towards the collector 7.

[0137] With reference to figures 3 and 9, the bottom 11 of the receiving hopper 1 also includes a dome section 8 juxtaposed to the grid 15, opposite the anti-jamming plate 6 with respect to the grid 15.

[0138] This dome section 8 is formed by folded sheets extending from a peripheral portion 81 having segments distributed in an arc of a circle, from the bottom 11 of the hopper 1, to a raised central portion 82, bordering the grid 15.

[0139] This dome section 8 promotes the action of the grinding hammers 21 and prevents clogging of the device.

Claims

Demands

1. Device for transforming fibrous plant stems into defibrated flakes, the device comprising: - a hopper (1) for receiving fibrous plant stems; - a grinding system (2) located below the hopper (1), and comprising a rotor (20) carrying grinding hammers (21), and having an outlet; characterized in that the device comprises: - a conduit (3) located in the extension of the outlet of the grinding system (2), the conduit (3) extending along a longitudinal axis (30); - a cutting system (4) into which the conduit (3) opens, the cutting system (4) comprising a rotor (40) carrying cutting hammers (41), the cutting hammers (41) having a cutting edge (411) extending transversely to the longitudinal axis (30) of the conduit (3).

2. Device according to the preceding claim, characterized in that the grinding system (2) comprises a counter-iron (25) having at least two blades (26) extending in an arc around the rotor (20), and parallel to each other, the blades (26) having teeth (27) extending in the direction of the rotor (20), the teeth (27) of two blades (26) juxtaposed to each other, providing between them a space for the passage of grinding hammers (21).

3. Device according to the preceding claim, characterized in that the rotor (20) of the grinding system (2) has, distributed along the axis of rotation of its rotor (20), a plurality of sets of grinding hammers (21), the grinding hammers (21) of each set being radially distributed around a point along the axis of rotation, the counter-iron (25) having more than two blades (26).

4. Device according to claims 2 and 3, characterized in that the counter-iron (25) is mounted movable relative to the rotor (20) of the grinding system (2), and in that the device includes means for adjusting (29) the position of the counter-iron (25) relative to the rotor (20) of the grinding system (2).

5. A device according to any one of the preceding claims, characterized in that at least one grinding hammer (21) extends longitudinally between a first end (211) and a second end (212), said grinding hammer (21) being mounted for rotation on the rotor (20) by its first end (211) and having at its second end (212) a distal edge (214) of the first end (211), the distal edge (214) having a convex profile.

6. Device according to any one of the preceding claims, characterized in that at least one crushing hammer (21) extends longitudinally between a first end (211) and a second end (212), and has a front slice (215) extending between the first end (211) and the second end (212), the front slice (215) having a concave profile intended to catch fibrous stems of plants located in the receiving hopper (1).

7. Device according to any one of the preceding claims, characterized in that the hopper (1) comprises a grid (15) on a bottom (11) of the hopper (1), the grid (15) having longitudinal openings, the grinding hammers (21) of the grinding system (2) being designed to grab the fibrous stems of plants through the longitudinal openings of the grid (15).

8. Device according to any one of the preceding claims, characterized in that a bottom (11) of the hopper (1) carries an anti-jamming plate (6), the anti-jamming plate (6) being movably mounted on the bottom (11) by means of an actuator (61), and extending laterally over a volume overhanging a passage communicating between the hopper (1) and the grinding system.

9. Device according to any one of the preceding claims, characterized in that the cutting system (4) comprises a cage (42) inside which the rotor (41) is rotationally movable, the rotor (41) of the cutting system (4) and its cage (42) forming means for sucking up a ground material located in the conduit (3).

10. Device according to the preceding claim, characterized in that the cage (42) has an air intake opening (43) juxtaposed to an opening in the conduit (3) leading into the cage (42).

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