Die for the extrusion of a material rich in protein and water, as well as a system for the continuous preparation of an extruded food product, comprising such a die

Abstract

Die for the extrusion of a material rich in protein and water, as well as a system for the continuous preparation of an extruded food product, comprising such a die. This die (200) comprises a tubular casing (210), centered on an axis (XX), and a coaxial core (220), rotatably mounted around the axis. An upstream part (220.1) of the core extends into the casing so that a material flow channel (230) is delimited between them, with an annular cross-section and centered on the axis. A downstream part (220.2) of the core extends outside the casing and is coupled to a rotation drive motor (250). A male divergent (260) is fixedly secured to the casing and received coaxially in the casing so that a passage (270) is delimited between them, connecting a central inlet (211) of the casing and an upstream end (230A) of the channel.The passage is shaped so that the material progresses through it, forming a flow (6) which diverges from the axis downstream and is distributed around the axis. The male divergent is axially abutted to the upstream part of the core, supporting it and guiding it in rotation. Figure for the abstract: 2.

Description

Title of the invention: Die for the extrusion of a material rich in proteins and water, as well as a system for the continuous preparation of an extruded food product, comprising such a die

[0001] The present invention relates to a die for the extrusion of a material rich in protein and water. It also relates to a system for the continuous preparation of an extruded food product, comprising such an extrusion die.

[0002] The invention relates to extrusion equipment for forcing a material, driven into an extruder barrel by one or more screws, in particular two screws, driven in rotation on themselves, to flow through an extrusion die, provided at the downstream end of the extruder barrel. The screws and the extruder barrel typically belong to an extruder which makes it possible to apply a thermomechanical treatment to the material, in the sense that this material undergoes both an essentially mechanical transformation, by pressurization and shearing by the screws, and an essentially thermal transformation, by regulating the temperature along the extruder barrel. The extrusion die makes it possible to shape, texture and / or fiberize the extruded material.

[0003] The invention relates more specifically to the extrusion of materials rich in protein and water, as well as to the associated systems which make it possible to continuously prepare an extruded food product from a raw material rich in protein and water. The proteins of the raw material may be of animal origin and / or of vegetable origin and / or of another origin. In all cases, the proteins are mixed with a significant proportion of water, as well as, possibly, fats and additives, and the corresponding mixture is subjected to the thermomechanical treatment applied by the extruder in order to be heated and then gelled before being shaped in the die. The texturizing, otherwise known as fibration, of the food product occurs essentially in the die through which the material leaving the extruder barrel passes, being pushed by the extruder screws.This process for preparing food products based on fibrous proteins is known as "CEMH" which is the acronym for the expression Cuisson-Extrusion en Milieu Humide, as well as "HME" which is the acronym for the English expression "High Moisture Extrusion".

[0004] WO 03 / 007729 discloses a CEMH process and associated extrusion equipment, in which a die is provided for cooling in a controlled manner the material passing through it, by causing this material to flow in a channel which has both a great length, typically several meters, and a rectangular section, a temperature profile being applied along this channel so as to decrease the temperature of the material progressively between the inlet and the outlet of the channel. The material in contact with the cooled wall of the channel tends to adhere to this wall, which allows shearing of the laminar flow of material in the channel. This shearing contributes to developing streamlines within the material paste and tends to align denatured macromolecules in the direction of flow. In practice, the shear rate and the flow regime result from the fixed geometry of the channel, so that the control of the fibration requires that the channel and, therefore, the processing time of the die be long.

[0005] On the same principle, WO 2019 / 158605 discloses a tubular extrusion die, in which the material flows in the form of an annular flow which, in its peripheral direction, is interrupted in a lower portion by a support part of the die. This die is arranged at the downstream end of an extruder at the outlet of which a cylindrical material flow is annularized by the die to form the aforementioned annular flow. For this purpose, the die comprises, at the inlet, a cone-shaped divergent whose tip is centered and turned on the outlet of the extruder. The shear applied to the annular material flow in the die is similar to that described in WO 03 / 007729. The corresponding annular channel of the die is therefore also long.

[0006] WO 2022 / 018084 and WO 2023 / 006713 propose an alternative approach, by providing that their die comprises a core mounted to rotate on itself in a coaxial tubular casing, while delimiting, between this rotating core and the fixed casing, an annular channel through which the material flows to pass through the die. These dies allow very efficient fibration in the sense that the material flowing in the annular channel of the die is subjected to two combined movements, namely that this material is pushed along the axis of the die by the screws of an extruder at the outlet of which the die is arranged, and that the material is sheared at the periphery by the rotation of the rotating core. The fibration rate of the material is adjustable in particular by adjusting the speed with which the rotating core is driven.

[0007] The dies proposed in WO 2022 / 018084 and WO 2023 / 006713 are therefore particularly interesting, but induce mechanical constraints for some of their components. Indeed, at the inlet of the die, the cylindrical flow of material pushed by the extruder is annularized by a cone integrated at the upstream end of the rotating core: the axial hydrostatic thrust forces applied to this cone by the material leaving the extruder are therefore substantial and are transmitted directly to the rest of the rotating core which must therefore be axially blocked accordingly, typically by ball bearings. These axial forces are taken up by a support structure of the die, which risks deforming locally, unless it is sized accordingly, or even fixed to the ground, and then with the disadvantage of making this support structure diffi mobile and therefore impractical. Furthermore, although the downstream part of the rotating core, arranged outside the fixed casing, is supported and guided in rotation, the rotating core tends, due to its own weight and length, to bend at its upstream part, in other words at the level of the aforementioned cone and the annular channel between the casing and this upstream part of the rotating core, which can induce a lack of co-axiality between the latter and, thereby, a degradation of the adjustment of the fiberization of the material passing through the die.

[0008] The aim of the present invention is to provide a rotating core extrusion die which is more practical and more efficient.

[0009] To this end, the invention relates to a die for the extrusion of a material rich in proteins and water, comprising: - a casing, which is tubular, being centered on an axis, and which is provided with a central inlet through which the material enters the interior of the casing to be pushed through the die, and - a core, which is coaxial with the casing and mounted to rotate around the axis relative to the casing,

[0010] wherein the core includes an upstream portion, extending at least partially inside the casing such that, between an inner surface of the casing and an outer surface of the core, there is defined a channel having a cross-section which is annular and centered on the axis, which channel includes an upstream end and a downstream end, which are opposite each other along the axis and between which the material pushed through the die flows in the channel progressing from the upstream end to the downstream end of the channel, and

[0011] in which the core also includes a downstream portion, extending outside the casing and coupled to a motorization of the die, adapted to drive the core in rotation around the axis,

[0012] characterized in that the die further comprises a male divergent which is:

[0013] - fixedly secured to the casing and received coaxially inside the casing so that, between the male divergent and the casing, a passage is delimited, by which the central inlet of the casing and the upstream end of the channel are connected and which is shaped in such a way that the material pushed through the die progresses in the passage, from the central inlet of the casing towards the upstream end of the channel, forming a flow of material which diverges from the axis towards the downstream and is distributed around the axis, and

[0014] - axially abutted to the upstream part of the core, supporting and guiding in rotation of the core.

[0015] Thanks to the invention, a flow of cylindrical material, entering the die, is annularized by the male divergent, by applying hydro thrust forces to the latter. static forces which are not taken up by the rotating core, but by the casing of the die. The dimensioning of the fixed connection between the male divergent and the casing is easy, by means of a simple static mechanics calculation, and all the mechanical stresses resulting from the hydrostatic thrust remain localized in a well-circumscribed region of the die. Any deformations induced by these mechanical stresses also remain local, in particular without significant impact on a supporting structure of the die, this supporting structure being thus easily adapted to be mobile on the ground, for example by means of casters. In particular, no hydrostatic thrust force is transmitted to the supporting structure via the rotating core, which avoids having to stiffen the part of the supporting structure, which axially retains the rotating core, typically at the downstream part of the latter.At the same time, the male divergent integrates a support and rotational guidance function for the rotating core, cooperating for this purpose with the upstream part of the rotating core, and this outside the flow of the material through the die. This results in excellent control of the coaxiality between the rotating core and the casing and, thereby, excellent control of the fibration conditions of the material passing through the die according to the invention. The performance and practicality of the die according to the invention are thus remarkable.

[0016] According to additional advantageous characteristics of the die according to the invention, taken in isolation or in all technically possible combinations:

[0017] - The male divergent delimits an internal housing, which is separated from the passage and in in which the upstream part of the core is received by being supported and guided in rotation.

[0018] - The die further comprises a bearing, which is centered on the axis and which is radially interposed between the upstream part of the core and a wall of the male divergent, delimiting the internal housing.

[0019] - The passage is delimited by an outer surface of the male divergent, which is conical being centered on the axis and diverging downstream.

[0020] - The casing comprises a die sleeve, which delimits said inner surface of the casing, and wherein the casing also includes a female divergent (i) which is fixedly secured to the die sleeve, (ii) which is provided with the central inlet of the casing, and (iii) inside which the male divergent is arranged coaxially so as to delimit the passage between the female divergent and the male divergent.

[0021] - The male divergent is fixedly secured to the casing by respective parts of the male divergent and of the envelope, one and / or the other of which are perforated to be crossed by said flow of material.

[0022] - The male divergent includes a peripheral flange (i) by which the male divergent is fixedly secured to the envelope, (ii) which extends, transversely to the axis, in through said material flow, and (iii) which is crossed by the passage via lights in the peripheral flange, which are distributed around the axis and through which said material flow crosses the peripheral flange.

[0023] - The peripheral flange is axially pinched between the die sleeve and the female divergent from the envelope.

[0024] - The die also includes a sealing member which is designed to seal a mechanical rotary decoupling interface between the male divergent and the core.

[0025] - The sealing member is (i) received in a peripheral groove of the upstream part of the core, and (ii) applied radially against a ring of the male divergent, this ring having an outer surface which is flush with said outer surface of the upstream part of the core.

[0026] The invention also relates to a system for the continuous preparation of an extruded food product, comprising:

[0027] - a raw material which is rich in protein and water,

[0028] - an extruder comprising at least one screw and an extruder barrel inside of which said at least one screw is rotatable so as to apply a thermomechanical treatment to the raw material, and

[0029] - a die, which is as defined above and whose casing is secured fixed to the extruder barrel such that, upon exiting the extruder barrel, the material is pushed by said at least one screw through the die via the central inlet of the casing.

[0030] The invention will be better understood on reading the following description, given solely by way of example and with reference to the drawings in which: - [Fig.l] [Fig.l] is a perspective and partially schematic view of a system in accordance with the invention; - [Fig.2] [Fig.2] is a section, partially schematic, of a part of the system of [Fig.l] according to plan II of [Fig.l]; - [Fig.3] [Fig.3] is a larger scale view of an area boxed III on [Fig.2]; - [Fig.4][Fig.5] Figures 4 and 5 are perspective views, from angles of different respective observation, of a male divergent belonging to the system of [Fig.l]; and - [Fig.6] [Fig.6] is a larger scale view of an area boxed VI on [Fig.3].

[0031] Figures 1 and 2 schematically show a system for continuously preparing, by extrusion, a food product 1 intended for human and / or animal consumption. This system mainly comprises a raw material 3 and an extrusion machine 10, which will be detailed a little further down.

[0032] The raw material 3 is rich in proteins and water. More precisely, the raw material 3, that is to say all of the ingredients which are processed by the extrusion machine 10 to form the food product 1, contains mainly, in other words more than 50% by weight, water and proteins, as well as, to a minor extent or even marginally, dietary fibers and / or starch, as well as possibly fats and additives.

[0033] The food product 1, as obtained at the outlet of the extrusion machine 10, is textured, in other words fibrous. The food product 1 comprises between 25 and 90% by weight, preferably between 50 and 85% by weight, of water and also comprises, by weight of the total dry matter, between 20 and 90% of proteins.

[0034] The proteins of the raw material 3 and therefore of the food product 1 are of plant origin and / or of animal origin and / or of at least one other origin. The proteins of plant origin come for example from legumes, cereals and / or protein crops (soy, wheat, peas, corn, chickpeas, lentils, etc.). The proteins of animal origin come for example from fish, meat, milk and / or eggs. The other origin(s) of proteins are for example fungi, algae, insects, cellular meat, etc.

[0035] The food product 1 also comprises, by weight of the total dry matter, between 0 and 50% of dietary fibers and between 0 and 50% of starch, the sum of the dietary fibers and / or starch being preferably greater than 0.01%. The dietary fibers are, for example, fibers of plant origin and the starch is, for example, of plant origin, in the native, pregelatinized or modified state.

[0036] The food product 1 may also comprise, by weight of the total dry matter, between 0 and 20% of fats, in particular of vegetable and / or animal origin, and / or functional ingredients, such as lecithins, caseinates or other ingredients.

[0037] As clearly visible in Figures 1 and 2, the extrusion machine 10 mainly comprises an extruder 100 and a die 200 which will be detailed later.

[0038] As shown schematically in [Fig.l], the extruder 100 comprises a sheath 110 of elongated shape, which extends along a geometric axis XX and which is centered on this axis. Inside the sheath 110, two screws 120 extend parallel to the axis XX, being received in a central longitudinal bore of the sheath, centered on the axis XX. In practice, in a manner known per se, each screw 120 includes for example a central screw shaft on which a set of screw elements is mounted. In all cases, the two screws 120 extend here on either side of the axis XX, while being interpenetrating, the bore of the sheath 110 thus having a bilobed transverse profile.

[0039] The screws 120 are designed to be driven in rotation on themselves, around their central axis, by a motor unit, not shown in the figures, engaged with the upstream end of the screws 120, namely the one on the right in [Fig.l], emerging outside the sheath 110.

[0040] The screws 120 are designed, by their threaded profile, to drive the raw material 3 inside the sleeve 110 along the axis XX, from an upstream part of the sleeve 110, in which the ingredients of the raw material 3 are introduced inside the central longitudinal bore of the sleeve 110, to the downstream end of the sleeve 110, the terms “upstream” and “downstream” being oriented in the direction of progression of the material in the extrusion machine 10 under the action of the screws 120, this direction of progression being from right to left in Figures 1 to 3 and 6.

[0041] In practice, the sheath 110 here comprises several modular elements 111 which, as shown schematically in [Fig. 1], follow one another along the axis XX. Each of the modular elements 111 internally delimits a corresponding part of the central longitudinal bore of the sheath 110, these bore parts being in the extension of each other along the axis XX in the assembled state of the modular elements 111, as in [Fig. 1]. In [Fig. 1], the modular element which is furthest downstream among the modular elements 111 is only partially shown, which allows the corresponding bore part to be observed, it being noted that, for reasons of visibility, the screws 120 are also not shown in this bore part.

[0042] In the embodiment considered in the figures, the modular element of the sheath 110, the most upstream among the modular elements 111, makes it possible to introduce, inside its bore part, the ingredients of the raw material 3. For this purpose, in a manner known per se and not detailed here, this most upstream modular element is provided with an orifice 112 which, transversely to the axis XX, opens to the outside, here upwards, the bore part of this most upstream modular element. More generally, it is understood that, among the different modular elements 111 of the sheath 110, one or more of them make it possible to introduce, inside the central longitudinal bore of the sheath 110, the ingredients, solid and / or liquid, of the raw material 3 for the purposes of their treatment by the extrusion machine 10.

[0043] As mentioned in the introductory part of this document, the screws 120 are designed to, in addition to driving the material to be extruded, shear and pressurize the raw material 3, so as to transform it in an essentially mechanical manner. This aspect of the extruder 100 being well known in the field, it will not be described here further. Similarly, also as mentioned in the introductory part, the sheath 110 is advantageously designed to regulate the temperature of the material to be extruded along the sheath 110 so as to transform this material in an essentially thermal manner. Indeed, all or part of the modular elements 111 of the sheath 110 are thermoregulated and / or allow steam to be injected into the sheath 110 and / or allow the material being extruded into the sheath 110 to be degassed. Again, this aspect of the extruder 100 being well known in the field, it will not be described further here. More generally, the sheath 110 and the screws 120 are provided to apply a thermomechanical treatment to the raw material 3 as this material progresses from the upstream end of the sheath 110 to the downstream end of the sheath 110. The material resulting from this thermomechanical treatment and leaving the sheath 110 is referenced 5 in Figures 2 and 3.

[0044] At its downstream end, the sheath 110 advantageously comprises an end element 113, commonly called a “front plate” in the field. The end element 113 is fixedly attached to the rest of the sheath 110, here to the downstream end of the most downstream modular element, among the modular elements 111, of the sheath 110. As clearly visible in FIGS. 2 and 3, the end element 113 internally delimits a through bore 114, which is centered on the axis XX and which forms a downstream end portion of the central longitudinal bore of the sheath 110, receiving, where appropriate, the downstream end of the screws 120. Here, the bore 114 of the end element 113 extends in the axial extension of the bore portion of the most downstream modular element among the modular elements 111.This bore 114 is adapted to channel the material 5 pushed downstream by the screws 120, so as to ensure appropriate pressurization and filling rate for the central longitudinal bore of the sheath 110. For this purpose, the bore 114 is, for example, at least partially throttled downstream, here in a plane perpendicular to the plane of Figures 2 and 3, and / or provided with a transverse grid, here not shown in the figures. This aspect of the extruder 100 not being limiting of the invention, it will not be described here further.

[0045] Now focusing more specifically on the die 200, this die 200 is designed to be traversed by the material 5 for the purposes of extruding the latter. In the assembled state of the extrusion machine 10, the die 200 is arranged at the downstream end of the barrel 110 of the extruder 100 so that the material 5 leaving the barrel 110 is forced, under the action of the screws 120 of the extruder 100, to flow through the die 200.

[0046] As clearly visible in Figures 1 to 3, the die 200 comprises a casing 210 which is tubular, being centered on a geometric axis which, in the assembled state of the extrusion machine 10, is coincident with the axis XX and which will therefore be considered as being the axis XX hereinafter. The casing 210 thus has two opposite ends along the axis XX, namely an upstream end 210A and a downstream end 210B. The casing 210 delimits an internal volume which, due to the tubular shape of the casing 210, is essentially closed all around the axis XX by the casing 210, while opening axially onto the outside of the casing 210 at the ends upstream 21 OA and downstream 210B of the latter.

[0047] In the assembled state of the extrusion machine 10, the sheath 110 of the extruder 100 and the casing 210 of FIG. 200 are fixedly secured to each other. In practice, the casing 210, in particular its upstream end 210A, is for this purpose fixedly secured, directly or indirectly, to a downstream part of the sheath 110, in particular, as here, to the terminal element 113 of this sheath.

[0048] At its upstream end 210A, the casing 210 is provided with a central inlet 211, which is centered on the axis XX and through which the axis XX passes. This central inlet 211 connects the internal volume of the casing 210 with the exterior of the casing 210. In the assembled state of the extrusion machine 10, the material 5 pushed by the screws 120 of the extruder 100 enters the internal volume of the casing 210 via the central inlet 211 to be pushed through the die 200: in the embodiment considered here, the central inlet 211 is abutted against the bore 114 of the terminal element 113 of the sheath 110, more precisely at the downstream end of this bore 114, in order to allow the flow of the material 5 between the bore 114 and the central inlet 211.In practice, the cross-section of the central inlet 211, that is to say the section of the latter in a plane perpendicular to the axis XX, is advantageously adjusted to that of the downstream end of the central longitudinal bore of the sheath 110, here to that of the downstream end of the bore 114, in particular to limit pressure losses and disturbances in the flow of the material. Preferably, the cross-section of the central inlet 211 has a circular contour, centered on the axis XX.

[0049] In the embodiment considered in the figures, the casing 210 comprises a female divergent 212 and a sheath 213, which follow one another along the axis XX, the sheath 213 being arranged downstream of the female divergent 212, as clearly visible in Figures 1 to 3. The female divergent 212 and the sheath 213 each have a tubular shape, in the sense that they delimit respective internal volumes corresponding respectively to sub-volumes of the internal volume of the casing 210. The female divergent 212 and the sheath 213 are fixedly secured to each other, here by a fixing collar 214.

[0050] The female divergent 212 has the upstream end 210A of the casing 210, being provided with the central inlet 211. Here, in the assembled state of the extrusion machine 10, the terminal element 113 of the sheath 110 of the extruder 100 is secured to the casing 210 of the die 200 by means of the female divergent 212, the terminal element 113 being for example bolted onto the female divergent 212.

[0051] In all cases, the female divergent 212 delimits an interior surface 212A, which closes the internal volume of the female divergent 212 all around the axis XX and by which the central inlet 211 is connected along the axis XX with the internal volume of the sheath 213: as clearly visible in figures 2 and 3, this inner surface 212A of the female divergent 212 is centered on the axis XX while widening downstream. According to a practical embodiment, implemented in the figures, this inner surface 212A is frustoconical, being centered on the axis XX and diverging downstream. Here, this inner surface 212A is completely smooth.

[0052] The sheath 213 of the casing 210 delimits an inner surface 213A, which closes the internal volume of the sheath 213 all around the axis XX and by which the internal volume of the female divergent 212 is connected along the axis XX with the exterior of the casing 210: in the embodiment considered in the figures, this inner surface 213A of the sheath 213 is cylindrical with a circular base, centered on the axis XX. Here, the inner surface 213A extends over the entire axial extent of the sheath 213 and opens onto the downstream end 210B of the casing 210, this downstream end 210B thus being presented by the sheath 213.

[0053] In the embodiment considered here, and as clearly visible in Figures 1 and 2, the sheath 213 comprises modular elements 215 which follow one another along the axis XX. In the example illustrated, these modular elements 215 are three in number. Each of the modular elements 215 internally delimits a corresponding part of the internal volume of the sheath 213 and therefore delimits a corresponding part of the internal surface 213A. In practice, these modular elements 215 are assembled two by two, for example by fixing collars 216.

[0054] Furthermore, it will be noted that the specific features of the outer face of the envelope 210 are not limiting.

[0055] In addition to the casing 210, the die 200 comprises a core 220. As clearly visible in FIGS. 1 and 2, the core 220 has an elongated shape, centered on a geometric axis which, in the assembled state of the extrusion machine 10, is coincident with the axis XX and which will therefore be considered as being the axis XX hereinafter. Within the die 200, the core 220 is coaxial with the casing 210, being partially arranged inside the latter, in other words in the internal volume of the casing 210. The core 220 thus includes two parts succeeding one another along the axis XX, namely an upstream part 220.1, which extends at least partially inside the casing 210, in other words in the internal volume of the latter, and a downstream part 220.2, which extends entirely outside the casing 210. In the embodiment considered in the figures, the upstream part 220.1 of the core 220 extends essentially inside the casing 210, while emerging, downstream, from the downstream end 210B of the casing 210. .

[0056] In all cases, the upstream part 220.1 of the core 220 is provided with an outer surface 220A, that is to say a surface facing radially away from the axis XX, which extends over the entire axial extent of the upstream part 220.1 of the core 220 and which is arranged both opposite, radially to the axis XX, and coaxially with the inner surface 213A of the sheath 213 of the casing 210: here, this outer surface 220A of the core 220 is cylindrical with a circular base, centered on the axis XX.

[0057] In all cases, the inner surface 213A of the casing 210 and the outer surface 220A of the core 220 radially delimit between them a channel 230 having a cross-section, that is to say a section in cross-section perpendicular to the axis XX, which is annular and centered on the axis XX. This channel 230 thus extends along the axis XX from an upstream end 230A of the channel to a downstream end 230B of the channel, this upstream end 230A being axially turned towards the extruder 100 in the assembled state of the extrusion machine 10. The inner surface 213A of the casing 210 delimits the channel 230 by forming the outer periphery of this channel, and this from the upstream end 230A to the downstream end 230B of this channel 230. The outer surface 220A of the core 220 delimits the channel 230 by forming the inner periphery of this channel, and this from the upstream end 230A to the downstream end 230B of the channel.The channel 230 extends continuously around the axis XX, i.e. over 360°. In operation, the material 5 leaving the sheath 110 flows into the channel 230 to pass through the die 200, progressing in the channel 230 from the upstream end 230A to the downstream end 230B of the channel 230. The flow of material flowing in the channel 230, which is referenced 7 in FIGS. 2 and 3, thus has an annular shape, centered on the axis XX.

[0058] In the embodiment considered in the figures, in which the inner surface 213A of the casing 210 and the outer surface 220A of the core 220 are each cylindrical with a circular base. It is understood that the annular cross-section of the channel 230 is constant from its upstream end 230A to its downstream end 230B.

[0059] In practice, as shown in [Fig.l], the die 200 comprises a supporting structure 240, on which the casing 210 rests fixedly and which is supported on the ground. This supporting structure 240 is advantageously provided with rollers 241 by which the supporting structure 240 rests on the ground, these rollers 241 making it possible, when the die 200 is not in use, to move this die relative to the ground, for example for reasons of cleaning, maintenance or successive use with respect to several extruders. Of course, the form of the embodiment of the supporting structure 240 is not limiting.

[0060] Whatever its embodiment, the core 220 is not, unlike the casing 210, provided fixed relative to the supporting structure 240 and relative to the sheath 110 of the extruder 100 in the assembled state of the extrusion machine 10, but is provided rotatable about the axis XX. Thus, within the die 200, the core 220 is mounted rotatable about the axis XX relative to the casing 210. The outer surface 220A of the core 220 is thus rotating on itself around the axis XX.

[0061] For the purpose of driving the core 220 in rotation about the axis XX, the die 200 comprises a motorization 250 which is coupled to the downstream part 220.2 of the core 220. In practice, the technical specifications of the motorization 250 are not limiting. For example, this motorization 250 is electric and its drive output is, outside the casing 210, engaged, directly or indirectly, with the downstream part 220.2 of the core 220. According to a practical arrangement, which does not appear in the figures, the motorization 250 advantageously rests on the supporting structure 240, the fixed components of this motorization being fixedly connected to this supporting structure 240.

[0062] As an example of a possible embodiment of the core 220, which is implemented in the figures, the core 220 comprises a central shaft 221 and a staging member 222, fixedly secured to each other. The central shaft 221 is centered on the axis XX and an upstream portion of this central shaft 221, which belongs to the upstream portion 220.1 of the core 220, is arranged inside the casing 210, while a downstream portion of the central shaft 221, belonging to the downstream portion 220.2 of the core 220, is located outside the casing 210 where this downstream portion of the central shaft is coupled with the motorization 250. The staging member 222 belongs to the upstream portion 220.1 of the core 220 and is arranged essentially inside the casing 210, being fixedly secured to the upstream portion of the central shaft 221. The staging member 222 delimits the outer surface 220A.

[0063] As clearly visible in Figures 2 and 3, the die 200 further comprises a male divergent 260 which is shown alone in Figures 4 and 5. Within the die 200, this male divergent 260 is arranged coaxially inside the casing 210, more precisely essentially in the internal volume of this casing 210, and is located both immediately upstream of the core 220 and downstream of the central inlet 211.

[0064] As clearly visible in Figures 4 and 5, the male divergent 260 is in the form of a Chinese hat, centered on the axis XX. Thus, as clearly visible in [Fig. 4], on its upstream side, that is to say its axial side facing the central inlet 211, the male divergent 260 gradually widens downstream, from a pointed upstream end of the male divergent 260, centered on the axis XX: in the embodiment considered here, the male divergent 260 delimits, on its upstream side, an outer surface 260A which is conical while being centered on the axis XX and diverging downstream. In the example envisaged in the figures, this outer surface 260A is entirely smooth, as clearly visible in [Fig. 4]. As clearly visible in [Fig.5], on its downstream side, that is to say its axial side facing away from the central inlet 211, the male divergent 260 is hollow and delimits an internal housing 261, which is centered on the axis XX and which opens axially onto the downstream side of the male divergent 260. The . internal housing 261 does not open onto the external surface 260A which is completely separated from the internal housing 261 by a solid wall 262 of the male divergent 260, which is generally conical and which delimits the internal housing 261. In the embodiment considered here, the internal housing 261 is advantageously stepped relative to the axis XX.

[0065] According to an advantageous aspect, the interest of which will appear later, the male divergent 260 is provided with a peripheral flange 263, which is centered on the axis XX and which runs all around this axis XX. As clearly visible in Figures 4 and 5, the peripheral flange 263 extends from the solid wall 262, being radially projecting from the outer surface 260A. Here, the peripheral flange 263 is axially located at the downstream end of the male divergent 260, in other words at the axial level where the solid wall 262 has its largest outer diameter. In all cases, as clearly visible in Figures 4 and 5, the peripheral flange 263 is provided with slots 264 which each pass axially right through the peripheral flange 263, more precisely an inner part 263.1 of the latter, that is to say a part facing the axis XX. The slots 264 are distributed around the axis XX, advantageously in a regular manner.Here, the lights 264 each have an arcuate profile, centered on the axis XX. Between the two lights 264 of each pair of lights adjacent to each other around the axis XX, the peripheral flange 263 includes a tab 265 which, around the axis XX, separates from each other the two lights of the pair of lights considered and which, radially to the axis XX, connects to the wall 262 an external part 263.2 of the peripheral flange 263, externally surrounding the lights 264.

[0066] According to another advantageous aspect, the interest of which will also appear later, the male divergent 260 comprises, at its downstream end, a ring 266, or cylindrical protrusion, which is centered on the axis XX and which extends axially in projection downstream from the solid wall 262, more precisely from the downstream axial edge of this solid wall. As clearly visible in Figures 5 and 6, the ring 266 is inscribed inside the interior contour of the peripheral flange 263 and is provided with an exterior surface 266A which is here both cylindrical with a circular base, centered on the axis XX, and flush with the respective edges of the slots 264, radially turned towards the axis XX.

[0067] As clearly visible in Figures 2, 3 and 6, the male divergent 260 is, within the die 200, fixedly secured to the casing 210, being received in the internal volume of the casing 210, so that, between the male divergent 260 and the casing 210, a passage 270 is delimited by which the central inlet 211 of the casing 210 and the upstream end 230A of the channel 230 are connected to each other. In the embodiment considered here, the male divergent 260 is thus essentially housed inside the female divergent 212 of the casing 210 and the passage 270 is essentially delimited between the inner surface 212A of the female divergent 212 and the outer surface 230A of the channel 230. inner 260A of the male divergent 260: the material pushed through the die 200 progresses in this passage 270, from the central inlet 211 towards the upstream end 230A of the channel 230, forming a material flow 6 of generally frustoconical shape, centered on the axis XX and diverging downstream. More generally, the passage 270 delimited between the male divergent 260 and the casing 210 is shaped so that the material flow 6, formed by the material progressing in this passage 270 from the central inlet 211 of the casing 210 to the upstream end 230A of the channel 230, diverges from the axis XX towards the downstream and is distributed around the axis XX. The passage 270 thus makes it possible to annularize the cylindrical flow of material 5 entering the die 200.

[0068] In the embodiment considered here, the fixed connection between the male divergent 260 and the casing 210 is advantageously achieved by the peripheral flange 263 of the male divergent 260. The fixing of the peripheral flange 263 to the casing 210 is preferably achieved by axial pinching of the peripheral flange 263, in particular the outer part 263.2 of the latter, between the female divergent 212 and the sheath 213 of the casing 210, advantageously with axial interposition of a sealing gasket 280, as clearly visible in [Fig. 6]. For this purpose, one and / or the other of the female divergent 212 and the sheath 213 are provided with a peripheral groove in which the peripheral flange 263 is assembled by recessing, as clearly visible in [Fig. 6].The fixing between the peripheral flange 263 and the casing 210 is advantageously reinforced by one or more pins 281, which are attached axially through the peripheral flange 263, in particular its outer part 263.2, and which make it possible to improve both the positioning transversely to the axis XX and the locking in rotation around this axis XX between the peripheral flange 263 and the casing 210.

[0069] It is understood that, in the embodiment considered in the figures, the peripheral flange 263, in particular its inner part 263.1, is found on the passage 270, extending, transversely to the axis XX, across the flow of material 6 flowing in the passage 270. This being the case, the openings 264 allow the peripheral flange 263 to be crossed by the passage 270, in the sense that the peripheral flange 263 can be crossed by the flow of material 6 via these openings 264, as indicated in dotted lines in [Fig. 6]. It is therefore understood that the flow section of the openings 264 is preferably as large as possible.

[0070] More generally, in continuation of the considerations immediately above, it is understood that the passage 270 is designed to pass through one and / or the other of the parts, which belong respectively to the male divergent 260 and to the casing 210 and by which the male divergent 260 is fixedly secured to the casing 210. For this purpose, one and / or the other of the two aforementioned parts belonging respectively to the divergent male 260 and to the casing 210 are perforated right through by one or more slots functionally analogous to the slots 264 which, in the example illustrated in the figures, each pass axially right through the peripheral flange 263: this or these slots allow the flow of material 6 flowing in the passage 270 to pass through the two aforementioned parts belonging respectively to the divergent male 260 and to the casing 210.

[0071] In all cases, as the male divergent 260 is fixedly secured to the casing 210, the core 220 is rotatable about the axis XX relative to the male divergent 260. As clearly visible in FIGS. 2 and 3, with respect to the core 220, the male divergent 260 is axially abutted to the upstream part 220.1 of the core 220, supporting and guiding in rotation the core 220, and this outside the passage 270. For this purpose, in the embodiment considered here, the upstream part 220.1 of the core 220, in particular an upstream end of the central shaft 221, is partially received in the internal housing 261 of the male divergent 260, being supported there and guided in rotation by the solid wall 262 which separates the internal housing 261 opposite the passage 270. The internal housing 261 being here stepped, a bearing 290, in particular a smooth bearing, is advantageously interposed radially between the upstream part 220.1 of the core 220, in particular the aforementioned upstream end of the central shaft 221, and the solid wall 262 of the male divergent 260.

[0072] In practice, as clearly visible in [Fig.6], a sliding washer 292 is advantageously interposed axially between the male divergent 260 and the upstream part 220.1 of the core 220: this washer 292 makes it possible to decouple in rotation the male divergent 260 and the core 220 from each other. Here, this sliding washer 292 is interposed axially between an upstream end shoulder 222A of the staging member 222 of the core 220, extending radially back from the outer surface 220A of the upstream part 220.1 of the core 220, and the ring 266 of the male divergent 260, while providing that the outer surface 266A of the ring 266 and an outer surface 292A of the sliding washer 292 are flush with the outer surface 220A of the upstream part 220.1 of the core 220: in this way, the rotary decoupling between the male divergent 260 and the core 220 is effective, without inducing pressure losses, nor disturbances in the flow of the material in the upstream end 230A of the channel 230.

[0073] Furthermore, to seal the rotary decoupling between the male divergent 260 and the core 220 and thus avoid any substantial leakage of the material passing through the die 200, the latter advantageously comprises a sealing member 294 which is more particularly visible in [Fig. 6]. In practice, the embodiment of this sealing member is not limiting, the sealing member 294 can thus comprise a single O-ring, as illustrated in the figures, or comprise several seals O-rings and / or a quad-lobe seal and / or a mechanical seal and / or etc. In all cases, as clearly visible in [Fig. 6], this sealing member 294 is received in a peripheral groove 223 of the upstream part 220.1 of the core 220, this peripheral groove 223 being here delimited at an upstream end of the staging member 222. In addition, the sealing member 294 is applied radially against the ring 266 of the male divergent 260, more precisely against an inner surface 266B of this ring 266. To facilitate the cleaning of the peripheral groove 223 and / or the maintenance of the sealing member 294, the groove 223 is delimited axially by a dedicated member 296 which is advantageously attached in a removable manner to the upstream part 220.1 of the core 220: here, as clearly visible in [Fig.6], this dedicated member 296 comprises a stop ring 297, retained axially on the staging member 222 of the core 220, and a sliding washer 298, axially interposed between the stop ring 297 and the sealing member 294.

[0074] Of course, the embodiment of the sealing member 294, detailed above, is specific to the example illustrated in the figures. It is understood that, more generally, the die 200 advantageously comprises a sealing member, such as the sealing member 294, designed to seal the mechanical interface of rotary decoupling between the male divergent 260 and the core 220.

[0075] The operation of the extrusion machine 10 will now be described.

[0076] The ingredients of the raw material 3 are introduced inside the sheath 110 and are then driven downstream by the screws 120, while being transformed under the effect of the thermomechanical treatment applied by the sheath and the screws. The material 5 leaving the sheath 110 is pushed, by the screws 120, through the die 200, entering the latter through the central inlet 211 and flowing into the die 200 successively in the passage 270 and in the channel 230.

[0077] In the passage 270, the material forming the material flow 6 is distributed all around the axis XX, while moving away from the axis XX downstream, to reach the upstream end 230A of the channel 230. The hydrostatic thrust of the material flow 6 generates axial stresses on the male divergent 260, which are fully transmitted to the casing 210 and, thereby, to the supporting structure 240, without passing through the core 220.

[0078] In the channel 230, the material forms the material flow 7 and flows from the upstream end 230A to the downstream end 230B of the channel 230, where the material exits outside the casing 210 to form the food product 1. As it flows in the channel 230, the material of the material flow 7 is sheared due to the rotational drive around the axis XX of the core 220 by the motor 250, the material flow 7 thus winding in a helix around the axis XX towards the downstream. The technical considerations relating to this shearing are explained in detail in WO 2022 / 018084 and WO 2023 / 006713 to which the reader may usefully refer. In in all cases, the fibration of the material of the material flow 7, resulting from this shearing, is controlled due, in particular, to the positioning and rotational guidance of the core 220 relative to the casing 210 thanks to the male divergent 260.

[0079] It will be noted that, at the level of the ports 264 through which the flow of material 6 crosses the peripheral flange 263 during its flow in the passage 270, the flow of material 6 is locally interrupted, around the axis XX, by the tabs 265. In other words, the legs 265 form point obstacles for the material flow 6, which are located here immediately upstream of the end 230A of the channel 230. It is understood that the material flow 6, which is subdivided by cutting by crossing the peripheral flange 263 to bypass the legs 265, tends to rejoin all around the axis XX downstream of the legs 265. Therefore, the die 200 makes it possible, to a certain extent, to take advantage of this situation. Indeed, to the extent that the material flow 7 is controllable to wind in a helix around the axis XX towards the downstream, by means of the control of the motorization 250, the rejoining of the material flow downstream of the legs 265 is easy to control in the material flow 7, by acting on the rotational drive speed of the core 220.It is thus possible, within the rheological limits of the material actually extruded and depending, on the one hand, on the operating parameters of the die 200, in particular the rotational drive speed of the core 220 and, on the other hand, on the dimensioning of the tabs 265, to obtain at the outlet of the channel 230 both a flow of material which is completely homogeneous around the axis, that is to say without any perceptible trace of the crossing of the peripheral flange 263, and a flow of material incorporating cutting lines, more or less marked, resulting from the presence of the tabs 265.

[0080] In the immediate extension of the foregoing, it will be noted that the shape of the legs 265 is not limited to that of the example illustrated in the figures. On the contrary, it is understood that multiple geometries are conceivable for the legs 265. Such geometries make it possible in particular to mark the aforementioned cutting lines to a greater or lesser extent. Such geometries also make it possible, where appropriate, to participate in hygiene considerations, depending on their influence on the ease of cleaning the legs 265 and / or on the accumulation / evacuation of material at the level of the legs 265. By way of non-limiting examples, rather than, as in the example illustrated in the figures, each of the legs 265 having, on its upstream side, a flat facet inscribed in a geometric plane perpendicular to the axis XX, each of the legs 265 can be shaped in a pointed or curved manner towards the upstream side, gradually widening towards the downstream side, in particular in the manner of a boat bow.The invention encompasses these various geometries for the legs 265. .

[0081] Finally, various arrangements and variants to the extrusion machine 10 described so far are also conceivable. By way of examples, various aspects are listed below respondents, which can be considered in isolation with the above, or in combination with each other:

[0082] - Rather than being completely smooth as in the example illustrated in the figures, the outer surface 260A of the male divergent 260 and / or the inner surface 212A of the female divergent 212 may have a non-smooth surface condition, in particular to act on the flow of the material flow 6 as the latter progresses in the passage 270, diverging from the axis XX downstream and being distributed around the axis XX. Thus, the outer surface 260A and / or the inner surface 212A may in particular be provided, for one and / or the other, with projecting ribs which each extend in length parallel to the axis XX or else inclined relative to the axis XX or else wound around the axis XX. Such ribs may, if necessary, join the tabs 265 and thus participate in a pre-orientation of the material with respect to the aforementioned cutting lines.

[0083] - As mentioned above, rather than by the peripheral flange 263, the joining fixed between the male divergent 260 and the casing 210 can be achieved by various arrangements, such as bolting the male divergent 260 onto the female divergent 212.

[0084] - Unlike what is schematically illustrated in figures 1 and 2, the surface The inner end 220A of the core 220 may slightly emerge, downstream, from the downstream end 210B of the casing 210 and / or extend downstream by an outlet deflector so as to exert counter-pressure with respect to the flow of material leaving the channel 230. In this regard, the reader may usefully refer to WO 2022 / 018084 and WO 2023 / 006713.

[0085] - The core 220 can be equipped with a tool for breaking up the material exiting at the outside of the casing 210, this fragmentation tool taking advantage of the rotational drive of the core 220 to act on the food product 1 as it leaves the channel 230.

[0086] - The core 220 may include several successive modules along the axis XX, such as taught in WO 2022 / 018084 and WO 2023 / 006173 to which the reader can refer in this regard.

[0087] - Rather than being cylindrical with a circular base, one and / or the other of the surface in The inner surface 213A of the casing 210 and the outer surface 220A of the core 220 may be frustoconical, being centered on the axis XX and diverging downstream, as explained in detail in WO 2023 / 006173 to which the reader can refer for more details.

[0088] - Whatever the embodiment of the envelope 210 and the core 220, one and / or the other of the envelope 210 and the upstream part 220.1 of the core 120 can be thermoregulated, that is to say each designed to control their temperature so as to, at least locally, maintain it at a value determined advantageously adjustable, despite the heat exchanges with their immediate environment. In this way, the casing 210 and / or the upstream part 220.1 of the core 220 are capable of acting on the temperature in the channel 230, more precisely on the temperature of the material flow 7, by means of a heat exchange with the material through, respectively, the inner surface 213A and the outer surface 220A. Practical details relating to such thermoregulation are given in WO 2022 / 018084 and WO 2023 / 006713 to which the reader may usefully refer. Of course, the thermoregulation of the casing 210 includes the potential thermoregulation of the female divergent 212. As for the male divergent 260, its thermoregulation is optionally possible, either from the casing 210 via arrangements dedicated to the interface between the upstream part 220.1 of the core 220 and the male divergent 260, such as rotating joints.

Claims

1. Claims Die (200) for the extrusion of a material rich in proteins and water, comprising: - a casing (210), which is tubular, being centered on an axis (XX), and which is provided with a central inlet (211) through which the material enters the interior of the casing to be pushed through the die, and - a core (220), which is coaxial with the casing and rotatably mounted around the axis relative to the casing, wherein the core (220) includes an upstream portion (220.1), extending at least partially inside the casing (210) such that, between an inner surface (213A) of the casing and an outer surface (220A) of the core, there is defined a channel (230) having a cross-section which is annular and centered on the axis (XX), which channel includes an upstream end (230A) and a downstream end (230B), which are opposite each other along the axis and between which the material pushed through the die flows in the channel progressing from the upstream end to the downstream end of the channel, and in which the core (220) also includes a downstream part (220.2), extending outside the casing (210) and coupled to a motorization (250) of the die, adapted to drive the core in rotation around the axis (XX), characterized in that the die (200) further comprises a male divergent (260) which is: - fixedly secured to the casing (210) and received coaxially inside the casing so that, between the male divergent and the casing, a passage (270) is delimited, by which the central inlet (211) of the casing and the upstream end (230A) of the channel (230) are connected and which is shaped so that the material pushed through the die progresses in the passage, from the central inlet of the casing towards the upstream end of the channel, forming a flow of material (6) which diverges from the axis (XX) towards the downstream and is distributed around the axis, and - axially abutted to the upstream part (220.1) of the core (220), supporting and guiding the core in rotation.

2. A die according to claim 1 wherein the male divergent (260) defines an internal housing (261), which is separated from the passage (270) and in which the upstream portion (220.1) of the core (220) is received by being supported and guided in rotation.

3. Die according to claim 2, in which the die (200) further comprises a bearing (290), which is centered on the axis (XX) and which is radially interposed between the upstream part (220.1) of the core (220) and a wall (262) of the male divergent (260), delimiting the internal housing (261).

4. A die according to any preceding claim, wherein the passage (270) is delimited by an outer surface (260A) of the male divergent (260), which is conical being centered on the axis (XX) and divergent downstream.

5. A die according to any preceding claim, wherein the casing (210) comprises a die sleeve (213), which delimits said inner surface (213A) of the casing, and wherein the casing (210) also includes a female divergent (212): - which is fixedly secured to the die sleeve (213), - which is provided with the central inlet (211) of the casing, and - inside which the male divergent (260) is arranged coaxially so as to delimit the passage (270) between the female divergent and the male divergent.

6. Die according to any one of the preceding claims, in which the male divergent (260) is fixedly secured to the casing (210) by respective parts of the male divergent and of the casing, one and / or the other of which are perforated to be crossed by said flow of material (6).

7. Die according to any one of the preceding claims, in which the male divergent (260) includes a peripheral flange (263): - by which the male divergent is fixedly secured to the casing (210), - which extends, transversely to the axis (XX), across said material flow (6), and - which is crossed by the passage (270) via openings (264) of the peripheral flange (263), which are distributed around the axis (XX) and by which said material flow (6) crosses the peripheral flange.

8. A die according to claims 6 and 7 taken together, wherein the peripheral flange (263) is axially pinched between the sheath of die (213) and the female divergent (212) of the casing (210).

9. A die according to any preceding claim, wherein the die (200) also comprises a sealing member (294) which is adapted to seal a rotary decoupling mechanical interface between the male divergent (260) and the core (220).

10. Die according to claim 9, in which the sealing member (294) is: - received in a peripheral groove (223) of the upstream part (220.1) of the core (220), and - applied radially against a ring (266) of the male divergent (260), this ring having an outer surface (266A) which is flush with said outer surface (220A) of the upstream part (220.1) of the core (220).

11. System for the continuous preparation of an extruded food product (1), comprising: - a raw material (3) which is rich in proteins and water, - an extruder (100) comprising at least one screw (120) and an extruder barrel (110) inside which said at least one screw is rotatable so as to apply a thermomechanical treatment to the raw material, and - a die (200), which is in accordance with any one of the preceding claims and the casing (210) of which is fixedly secured to the extruder barrel (110) so that, at the outlet of the extruder barrel, the material is pushed by said at least one screw through the die via the central inlet (211) of the casing.

Images