Device for grinding a pasty or powdered and suspended product

Abstract

The invention relates to a device for grinding a pasty or powdered and suspended product, suitable for conching chocolate, characterised in that it comprises: a hollow outer cylinder (14) having a first axis (A14) and an inner diameter (D14); an inner cylinder (16) having a second axis (A16) and an outer diameter (D16); a supply system (18) for supplying the product to be ground, positioned between the hollow outer cylinder (14) and the inner cylinder (16); and a collection system (20) for collecting the ground product; the inner cylinder (16) being positioned inside the hollow outer cylinder (14), the first and second axes (A14, A16) being parallel, the outer diameter (D16) of the inner cylinder (16) being more than 0.5 times the inner diameter (D14) of the hollow outer cylinder (14), and the first and second axes (A14, A16) being offset.

Description

[0001] Device for grinding a pasty or powdery product and in suspension

[0002] This application relates to a device for grinding a pasty or powdery and suspended product, such as chocolate for example.

[0003] The term grinding more broadly covers all techniques of pressing between cylinders, such as refining or conching in the case of chocolate.

[0004] According to an embodiment illustrated in Figure 1, a chocolate refining device comprises a series of five horizontal and tangent cylinders W1 to W5 in pairs so as to create four grinding zones Z1 to Z4. According to one operating mode, the chocolate is poured at the grinding zone Z1, between the cylinders W1 and W2, remains stuck on the cylinder W2 until the second grinding zone Z2, passes between the cylinders W2 and W3, remains stuck on the cylinder W3 until the third grinding zone Z3, passes between the cylinders W3 and W4, remains stuck on the cylinder W4 until the fourth grinding zone Z4, passes between the cylinders W4 and W5 and then remains stuck on the cylinder W5 before being detached from the cylinder W5 using a scraper R.

[0005] At each grinding zone Z1 to Z4, the chocolate is ground or refined over a short length depending on its direction of travel.

[0006] Therefore, it is necessary to provide a succession of four grinding zones Z1 to Z4, and therefore five cylinders W1 to W5, to obtain the desired refining.

[0007] This type of device is relatively bulky and expensive.

[0008] Document CH40047 describes a device for conching chocolate which comprises a drum rotating on itself along a horizontal axis, an inlet and an outlet for the chocolate provided at the ends of the drum, partitions positioned in the drum and delimiting four compartments distributed between the inlet and the outlet as well as three grinding wheels positioned in three of the compartments. These grinding wheels are free and are not pivoting. In operation, the drum pivots on itself and the chocolate is introduced into the drum via the inlet and flows successively into the different compartments until the outlet. At each compartment provided with a grinding wheel, the chocolate is compressed between the wall of the drum and the grinding wheel which pivots freely on itself (due to friction) in a random manner. This device does not allow fine control of the grinding parameters.Furthermore, it is relatively long and bulky along the drum's pivot axis.

[0009] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0010] For this purpose, the invention relates to a device for grinding a pasty or powdery product and in suspension, characterized in that it comprises a hollow outer cylinder having a first axis, an internal diameter and a first side wall, an inner cylinder having a second axis, an external diameter and a second side surface, a system for supplying the product to be ground positioned between the hollow outer cylinder and the inner cylinder and a system for collecting the ground product. According to other characteristics: the inner cylinder is positioned inside the hollow outer cylinder, the first and second axes are parallel, the first and second side faces face each other, the external diameter of the inner cylinder is greater than 0.5 times the internal diameter of the hollow outer cylinder,the first and second axes are offset so that the hollow outer cylinder comprises a first generatrix closest to the inner cylinder and the inner cylinder comprises a second generatrix closest to the hollow outer cylinder, the grinding device comprising a grinding zone between the hollow outer cylinder and the inner cylinder at the first and second generatrices, at least one cylinder among the hollow outer cylinder and the inner cylinder is movable between a first position in which the hollow outer cylinder and the inner cylinder are close together and / or in contact with each other and a second position in which the hollow outer cylinder and the inner cylinder are further apart than in the first position the grinding device comprises at least one return element which exerts a pressure force tending to bring the two cylinders closer together.,

[0011] According to the invention, a cylindrical convex surface coincides with a concave cylinder surface at the grinding zone, which makes it possible to increase the length of the grinding zone according to the direction of travel of the product to be ground. Thus, from two cylinders positioned one inside the other, it is possible to obtain a length for the grinding zone equivalent to the sum of the lengths of four grinding zones formed between five cylinders arranged according to the prior art. Furthermore, the fact that the outer and inner cylinders are movable relative to each other and that at least one return element exerts a pressure force tending to bring the two cylinders closer together makes it possible to adjust the grinding forces.

[0012] Other characteristics and advantages will emerge from the description of the invention which follows, a description given by way of example only, with reference to the appended drawings, among which:

[0013] Figure 1 is a diagram of a grinding device illustrating an embodiment of the prior art,

[0014] Figure 2 is a schematic representation of a grinding device illustrating one embodiment of the invention,

[0015] Figure 3 is a front view of a grinding device illustrating one embodiment of the invention,

[0016] Figure 4 is a perspective view from a first viewing angle of the grinding device visible in Figure 3,

[0017] Figure 5 is a perspective view from a second viewing angle of the grinding device visible in Figure 3,

[0018] Figure 6 is a top view of a hollow outer cylinder in which an inner cylinder of the grinding device visible in Figure 3 is positioned,

[0019] Figure 7 is a front view of an inner cylinder, a feed system and a scraper of the grinding device seen in Figure 3, and

[0020] Figure 8 is a sectional view of a feed system of the grinding device seen in Figure 8.

[0021] According to an embodiment illustrated by Figures 2 to 5, a grinding device 10 comprises a frame 12, a hollow outer cylinder 14, having a first axis A14 and a first side wall 14.1, supported by the frame 12, an inner cylinder 16, having a second axis A16 and a second side surface 16.1, positioned inside the hollow outer cylinder 14 and supported by the frame 12, a system 18 for supplying the product to be ground positioned between the hollow outer cylinder 14 and the inner cylinder 16 and a system 20 for collecting the ground product. According to one application, the product to be ground is chocolate. Of course, the invention is not limited to this product. More broadly, the grinding device according to the invention can be used to grind other pasty or powdery products and in suspension in a liquid or a mixture of liquids whose viscosity for pasty products is between approximately 0.1 and 10 Pa.s. Although the grinding device 10 is more particularly suitable for chocolate, its use is not limited to food products. In addition, the grinding device can be used at different stages of the chocolate production process, such as refining or conching, for example.

[0022] The first and second axes A14 and A16 are parallel and the first and second side faces 14.1, 16.1 face each other. By parallel is meant that the first and second axes A14 and A16 are strictly parallel or approximately parallel and form an angle of less than 1°.

[0023] The hollow outer cylinder has an inner diameter D14 corresponding to the diameter of the first side wall 14.1. The inner cylinder 16 has an outer diameter D16 corresponding to the diameter of the second side wall 16.1, smaller than the inner diameter D14 of the hollow outer cylinder 14.

[0024] The hollow outer cylinder 14 has a first end 14E1 positioned in a first transverse plane perpendicular to the first axis A14 and a second end 14E2 positioned in a second transverse plane perpendicular to the first axis A14. The inner cylinder 16 has a first end 16E1 positioned in a third transverse plane perpendicular to the second axis A16, close to or coincident with the first transverse plane, and a second end 16E2 positioned in a fourth transverse plane perpendicular to the second axis A16, close to or coincident with the second transverse plane. Thus, when the inner cylinder 16 is positioned inside the hollow outer cylinder 14, the first ends 14E1, 16E1 of the two cylinders 14, 16 are positioned approximately in the same transverse plane and the second ends 14E2, 16E2 of the two cylinders 14, 16 are positioned approximately in the same transverse plane.

[0025] The hollow outer cylinder 14 pivots about the first axis of rotation A14 in a first direction SI. The inner cylinder 16 pivots about the second axis of rotation A16 in a second direction S2 identical to the first direction SI. Thus, the hollow outer cylinder 14 and the inner cylinder 16 rotate in the same direction. Alternatively, the hollow outer cylinder 14 and inner cylinder 16 could rotate in opposite directions. The first and second axes A14, A16 are offset. Thus, the hollow outer cylinder 14 comprises a first generator Gl closest to the inner cylinder 16 and the inner cylinder 16 comprises a second generator G2 closest to the hollow outer cylinder 14.

[0026] The grinding device comprises a grinding zone 22 provided between the hollow outer cylinder 14 and the inner cylinder 16, positioned at the level of the first and second generators G1, G2, extending on either side of said first and second generators G1, G2.

[0027] According to one mode of operation, the rotation speeds of the two cylinders 14, 16 are coordinated so as to obtain substantially identical linear speeds in the grinding zone 22 for the two cylinders 14, 16.

[0028] According to another mode of operation, the rotation speeds of the two cylinders 14, 16 are coordinated so as to obtain different linear speeds in the grinding zone 22 for the two cylinders 14, 16. This mode of operation makes it possible to obtain shearing effects at the level of the grinding zone 22. According to one configuration, the inner cylinder 16 has a linear speed at the level of the grinding zone 22 greater than that of the outer cylinder 14.

[0029] According to one feature, the outer and inner cylinders 14, 16 each have a controlled rotation speed and are driven in rotation by motors. According to other embodiments, only one of the two cylinders 14, 16 is driven in rotation by a motor, the other cylinder being driven in rotation by friction.

[0030] At least one cylinder among the hollow outer cylinder 14 and the inner cylinder 16 is movable between a first position in which the hollow outer cylinder 14 and the inner cylinder 16 are close together and / or in contact with each other at the first and second generatrices G1, G2 and a second position in which the hollow outer cylinder 14 and the inner cylinder 16 are further apart than in the first position at the first and second generatrices G1, G2 and spaced apart by a few millimeters. As an indication and not a limitation, the maximum distance between the two cylinders is of the order of 20 mm. According to one configuration, the hollow outer cylinder 16 is movable relative to the inner cylinder 14. Alternatively, the inner cylinder 14 or both cylinders could be movable. Whatever the configuration, there is a relative movement between the inner cylinder 14 and the hollow outer cylinder 16.In addition, the grinding device 10 comprises at least one return element 24 which exerts a pressure force tending to bring the two cylinders 14, 16 together against the product to be ground.

[0031] According to one embodiment, the return element 24 is a compression spring. Of course, the invention is not limited to this embodiment for the return element 24.

[0032] According to one configuration, the grinding device 10 comprises an adjustment system 25 making it possible to vary the pressure force exerted by the return element 24.

[0033] According to one mode of operation, the grinding device is configured so that the outer and inner cylinders 14, 16 exert a constant pressure force on the material. According to another mode of operation, the grinding device is configured so that the outer and inner cylinders 14, 16 exert a pressure force on the material that varies progressively over time.

[0034] The outer diameter D16 of the inner cylinder 16 is greater than 0.5 times the inner diameter D14 of the hollow outer cylinder 14. This configuration makes it possible to increase the length (distance along the circumference of the inner cylinder 16) of the grinding zone 22. Consequently, it is not necessary to provide a succession of five or more cylinders to obtain satisfactory grinding. Two cylinders are sufficient, one being positioned in the other. Thus, the invention makes it possible to obtain a compact and less expensive grinding device.

[0035] To allow the installation of the feed system 18, the outer diameter D16 of the inner cylinder 16 is less than 0.95 times the inner diameter D14 of the hollow outer cylinder 14.

[0036] According to one configuration, the outer diameter D16 of the inner cylinder 16 is between 0.7 and 0.75 times the inner diameter D14 of the hollow outer cylinder 14.

[0037] According to one arrangement, the first and second axes A14, A16 are vertical, the first ends 14E1, 16E1 being positioned above the second ends 14E2, 16E2 so that the product to be ground flows by gravity between the hollow outer cylinder 14 and the inner cylinder 16 from the first ends 14E1, 16E1 to the second ends 14E2, 16E2.

[0038] According to this arrangement, the system 18 for supplying the product to be ground is positioned close to the first ends 14E1, 16E1 called upper ends, the collection system 20 being positioned under the hollow outer cylinder 14 and the inner cylinder 16. Of course, the invention is not limited to this position for the supply system 18, the latter being able to be positioned centered relative to the first and second ends. Whatever the arrangement, the supply system 18 is positioned so as to promote the distribution of the product to be ground between the cylinders 14 and 16.

[0039] The feed system 18 is located upstream of the grinding zone 22 according to the direction of rotation of the two cylinders 14, 16.

[0040] The grinding device 10 comprises at least one scraper 26 positioned downstream of the grinding zone 22 (depending on the direction of rotation of the two cylinders 14, 16) so as to detach the ground product from the hollow outer cylinder 14 and / or from the inner cylinder 16.

[0041] According to one embodiment, the grinding device 10 comprises a recirculation circuit 28 for the ground product to convey the ground product from the collection system 20 to the feed system 18. According to one configuration, the recirculation circuit 28 comprises at least one recirculation pump 30 configured to raise the ground product from the collection system 20 to the feed system 18. Of course, the invention is not limited to this configuration. Thus, a worm screw or any other similar element could be used to raise the ground product from the collection system 20 to the feed system 18.

[0042] According to one configuration, the supply system 18, the adjustment system 24, the scraper 26, the recirculation pump 30 and at least part of the recirculation circuit 28 are connected to the chassis 12. The collection system 20 is mobile and independent of the chassis 12 or can be detached from the latter. In addition, the recirculation circuit 28 comprises a connection system 32 to be able to detach the collection system 20.

[0043] According to one embodiment, the chassis 12 comprises an upper frame 34, an intermediate frame 36, a lower frame 38 as well as uprights 40 connecting the upper, intermediate and lower frames 34, 36, 38.

[0044] The upper frame 34 comprises two side members 34.1 and several cross members 34.2 connecting the two side members 34.1.

[0045] The intermediate frame 36 also includes two side members 36.1 and several cross members 36.2 connecting the two side members 36.1.

[0046] The lower frame 38 comprises first and second side members 38.1, 38.2 and three cross members 38.4, 38.5, 38.6, the first side member 38.1 extending between the two end cross members 38.4, 38.6, the second side member 38.2 connecting a first end cross member 38.4 and the intermediate cross member 38.5. Thus, the area between the second end cross member 38.6 and the intermediate cross member 38.5 forms a housing 42 in which the collection system 20 can be positioned.

[0047] According to one configuration, the chassis 12 is movable and comprises casters 44 under the lower frame 38. The chassis 12 can be equipped with handles 46 and a fairing (not shown). Of course, the invention is not limited to this embodiment for the chassis 12.

[0048] According to one embodiment, the collection system 20 comprises a tank 48 with a cylindrical upper portion and a lower portion in the shape of a hemisphere. The cylindrical upper portion is open and has a diameter greater than the inner diameter D14 of the hollow outer cylinder 14.

[0049] According to one configuration, the tank 48 is mobile and mounted on casters 50. It comprises, in the lower part, a tapping 48.1 connected to the recirculation circuit 28.

[0050] This tank 48 can be thermoregulated and include a mixing system.

[0051] According to one arrangement, the recirculation pump 30 is positioned at the level of the lower frame 38 and connected thereto.

[0052] According to one embodiment, the inner cylinder 16 has shaft sections 52 which extend on either side of the first and second ends 16E1, 16E2. Depending on the case, the two shaft sections 52 are independent, or originate from the same shaft passing through the inner cylinder 16. The inner cylinder 16 is supported by two guide bearings 52.1, connected to the frame 12 and positioned on either side of the inner cylinder 16, cooperating with the two shaft sections 52. These two guide bearings 52.1 make it possible to obtain a pivot connection between the frame 12 and the inner cylinder 16. Thus, the inner cylinder 16 is positioned between two guide bearings 52.1 secured to the frame 12, said guide bearings 52.1 being configured to ensure holding and rotational guidance of the inner cylinder 16.

[0053] The grinding device comprises a first motor 54, supported by the chassis 12 and more particularly by the upper frame 34, configured to drive the inner cylinder 16 in rotation. According to one configuration, the first motor 54 is coupled to an angle transmission itself coupled to the upper shaft section 52. Of course, the invention is not limited to this embodiment for driving the inner cylinder 16 in rotation. The latter could be driven in rotation by friction by the hollow outer cylinder 14. According to one embodiment, the hollow outer cylinder 14 comprises a tubular shape as well as a collar 56 positioned at mid-height. The grinding device comprises a second motor 58, supported by the chassis 12 and more particularly by the intermediate frame 36, configured to drive the hollow outer cylinder 16 in rotation.According to one configuration, the second motorization 58 is coupled to an angle transmission itself coupled to a pinion 60 which has a vertical axis. The hollow outer cylinder 14 has a toothed crown 62, integral with the collar 56, which cooperates with the pinion 60. Of course, the invention is not limited to this embodiment for the rotational drive of the hollow outer cylinder 14. The latter could be driven in rotation by friction by the inner cylinder 16.

[0054] Other solutions are possible for driving the hollow outer cylinder 14 and the inner cylinder 16 in rotation.

[0055] According to one embodiment, to make the hollow outer cylinder 14 movable relative to the inner cylinder 16, the grinding device 10 comprises a support plate 64, on which the hollow outer cylinder 14 is pivotally mounted, as well as a guide 66 connecting the support plate 64 to the chassis 12 and more particularly to the intermediate frame 36.

[0056] This guide 66 is configured to allow the support plate 64 to move in a horizontal plane, perpendicular to the first and second axes A14, A16, in a direction parallel to a straight line perpendicular to the first and second axes A14, A16 and passing through the first and second axes A14, A16. Thus, the movement of the support plate 64 allows the two cylinders 14, 16 to move apart or come closer together.

[0057] According to one configuration, the guide 66 comprises two slides secured to the side members 36.1 of the intermediate frame 36. According to one arrangement, an orientation ring 56.1 connects the collar 56 and the support plate 64. According to one embodiment, the second motorization 58 can be connected to this support plate 64. Thus, the crushing device comprises an orientation ring 56.1 configured to guide the hollow outer cylinder 14 in rotation relative to the chassis 12 or relative to a support plate 64 guided in translation relative to the chassis 12.

[0058] According to one configuration, the adjustment system 25 comprises a spring 68.1 arranged so as to push the support plate 64 in a direction which tends to bring the first and second axes A14, A16 closer together as well as a crank 68.2 which tends to compress the spring 68.1 more or less in order to adjust the pressure force exerted by the two cylinders 14 and 16 on the product to be ground. Of course, the invention is not limited to this embodiment for the guide 66, the return element 24 and the adjustment system 25.

[0059] According to an embodiment visible in Figure 6, the grinding device comprises a support 70, which extends from one end to the other of the cylinders 14, 16 connected to the frame 12, on which are fixed two scrapers 26, 26', a first scraper 26 in contact with the hollow outer cylinder 14 as well as a second scraper 26' in contact with the inner cylinder 16. According to one arrangement, the two scrapers 26, 26' form a V in contact with the two cylinders 14, 16, the tip of the V being further away from the grinding zone 22 than the contact zones between the scrapers 26, 26' and the cylinders 14, 16.

[0060] According to one embodiment, the recirculation circuit 28 comprises different tubes and valves for channeling the product to be ground from the collection system 20 to the supply system 18.

[0061] According to an embodiment visible in Figures 7 and 8, the feed system 18 comprises a feed tube 72 closed at its upper end and opening at its lower end as well as a feed conduit 74 opening into the feed tube 72 and connected to the recirculation circuit 28. The feed tube 72 has an axis A72 oriented in a first direction, approximately vertical. The feed system 18 comprises a rotating disk 76 configured to pivot about a pivot axis forming an angle of less than 20° with the first and second axes A14, A16 on which the product to be ground falls. The pivot axis of the rotating disk is parallel to the first and second axes A14, A16. Of course, the invention is not limited to these angles for the pivot axis.

[0062] According to one configuration, the rotating disc 76 pivots about an axis coaxial with the axis A72 of the feed tube 72. It is positioned under the feed tube 72 and has a diameter greater than the inner diameter of the feed tube 72. This rotating disc 76 is fixed to one end of a shaft 78 passing through the feed tube 72 and coupled to a third motorization 80. According to this embodiment, the product to be ground flows by gravity at the lower end of the feed tube 72 and falls onto the rotating disc 76 which projects it radially onto the side walls 14.1, 16.1 of the hollow outer cylinder 14 and the inner cylinder 16. By gravity, the product to be ground flows along said side walls 14.1 and 16.1. According to one arrangement, the rotating disc 78 is positioned in a plane located in the upper third of the cylinders 14, 16.

[0063] Of course, the invention is not limited to this embodiment for the power supply system.

Claims

CLAIMS 1. Device for grinding a pasty or powdery and suspended product, characterized in that it comprises a hollow outer cylinder (14) having a first axis (A14), an inner diameter (D14) and a first side wall (14.1), an inner cylinder (16) having a second axis (A16), an outer diameter (D16) and a second side surface (16.1), a system (18) for feeding the product to be ground positioned between the hollow outer cylinder (14) and the inner cylinder (16) and a system (20) for collecting the ground product, the inner cylinder (16) being positioned inside the hollow outer cylinder (14), the first and second axes (A14, A16) being parallel, the first and second side faces (14.1, 16.1) facing each other, the outer diameter (D16) of the inner cylinder (16) being greater than 0.5 times the inner diameter (D14) of the hollow outer cylinder (14), the first and second axes (A14,A16) being offset so that the hollow outer cylinder (14) comprises a first generatrix (G1) closest to the inner cylinder (16) and the inner cylinder (16) comprises a second generatrix (G2) closest to the hollow outer cylinder (14), the grinding device comprising a grinding zone (22) between the hollow outer cylinder (14) and the inner cylinder (16) at the first and second generatrices (G1,G2); in that at least one cylinder among the hollow outer cylinder (14) and the inner cylinder (16) is movable between a first position in which the hollow outer cylinder (14) and the inner cylinder (16) are close together and / or in contact with each other and a second position in which the hollow outer cylinder (14) and the inner cylinder (16) are further apart than in the first position and in that the grinding device comprises at least one return element (24) which exerts a pressure force tending to bring the two cylinders (14, 16) closer together., 2. Grinding device according to the preceding claim, characterized in that the outer diameter (D16) of the inner cylinder (16) is between 0.7 and 0.75 times the inner diameter (D14) of the hollow outer cylinder (14).

3. Grinding device according to one of the preceding claims, characterized in that the hollow outer cylinder (14) and the inner cylinder (16) rotate in the same direction.

4. Grinding device according to one of the preceding claims, characterized in that it comprises an adjustment system (25) making it possible to vary the pressure force exerted by the return element (24).

5. Grinding device according to one of the preceding claims, characterized in that it comprises a support plate (64) on which the hollow outer cylinder (14) is pivotally mounted as well as a guide (66) configured to move the support plate (64) in a direction parallel to a straight line perpendicular to the first and second axes (A14, A16) and passing through the first and second axes (A14, A16).

6. Grinding device according to one of the preceding claims, characterized in that the first and second axes (A14, A16) are vertical, the feed system (18) being positioned close to the upper ends (14E1, 16E1) of the hollow outer cylinder (14) and the inner cylinder (16), the collection system (20) being positioned under the hollow outer cylinder (14) and the inner cylinder (16).

7. Grinding device according to the preceding claim, characterized in that the feed system (18) is located upstream of the grinding zone (22) and in that the grinding device comprises at least one scraper (26) positioned downstream of the grinding zone (22).

8. Grinding device according to the preceding claim, characterized in that the feed system (18) comprises a rotating disc (76), configured to pivot about a pivot axis forming an angle of less than 20° with the first and second axes (A14, A16), onto which the product to be ground falls.

9. Grinding device according to one of the preceding claims, characterized in that it comprises a recirculation circuit (28) configured to convey the ground product from the collection system (20) to the supply system (18).

10. Grinding device according to one of the preceding claims, characterized in that it comprises a frame (12) supporting the hollow outer cylinder (14), the inner cylinder (36) as well as the feed system (18), the collection system (20) being mobile and independent of the frame (12).

11. Grinding device according to the preceding claim, characterized in that the inner cylinder (16) is positioned between two guide bearings (52.1) secured to the frame (12), said guide bearings (52.1) being configured to ensure maintenance and rotational guidance of the inner cylinder (16).

12. Grinding device according to claim 10 or 11, characterized in that the grinding device comprises an orientation ring (56.1) configured to guide in rotation the hollow outer cylinder (14) relative to the frame (12) or relative to a support plate (64) guided in translation relative to the chassis (12).

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