Device for processing a product

Abstract

The invention relates to a device for processing a product comprising: an enclosure (2), means for conveying the product which comprise a screw (13), means for heating the screw by Joule effect, the device being characterized in that the screw and the enclosure are mounted in the device to rotate jointly around a geometric axis of rotation (X), the device thus comprising means for driving in rotation an assembly formed by the enclosure and the screw along said axis. FIGURE OF THE ABSTRACT: Fig. 1

Description

Title of the invention: Device for processing a product

[0001] The present invention relates to a device for treating (drying, debacterization, cooking, roasting, pyrolysis, toasting, decarbonization, activation, etc.) a product.

[0002] BACKGROUND OF THE INVENTION

[0003] A heat treatment device is known comprising an enclosure and means for conveying the product between the inlet of the enclosure and the outlet of the enclosure which comprise a screw and means for driving the screw in rotation in the enclosure. The device further comprises means for heating the screw by the Joule effect.

[0004] The product to be treated is usually introduced at the inlet of the enclosure in the form of divided solids. The screw continuously pushes the product particles towards the outlet of the enclosure. Due to the temperature of the screw, the product is heated as it progresses, which allows its heat treatment.

[0005] Due to electrical standards, the voltage that can be supplied to the screw remains limited. Consequently, if one wishes to increase the processing capacity of the device and therefore the electrical power dissipated by the screw, it is appropriate, with the voltage maintained at a relatively low level, to increase the intensity, which involves seeking a minimum electrical resistance of the coil.

[0006] Constructively this translates into turns having to have large diameters and current passage sections.

[0007] SUBJECT OF THE INVENTION

[0008] An aim of the invention is to propose a treatment device which makes it possible to overcome the aforementioned problem. Summary of the invention

[0009] With a view to achieving this aim, a device for processing a product is proposed comprising:

[0010] - an enclosure, - means of conveying the product which include a screw, - means of heating the screw by Joule effect.

[0011] According to the invention, the screw and the enclosure are mounted in the device to rotate jointly around an axis of rotation, the device thus comprising means for driving in rotation an assembly formed by the enclosure and the screw along said axis.

[0012] Thus, whereas in the prior art the screw rotated inside the enclosure, in the invention, the screw and the enclosure are integral in rotation.

[0013] The inventors were able to observe that this made it possible to greatly increase the exchange surface between the product and the device, thus making it possible to achieve a very good treatment of the product while maintaining dimensions compatible with the means of implementation of this type of device.

[0014] Optionally, the enclosure comprises several layers, at least one of which is thermally insulating.

[0015] Optionally, the enclosure comprises a layer of refractory material.

[0016] Optionally, the device further comprises an inlet chamber and an outlet chamber framing the enclosure, the inlet chamber, the enclosure being rotatably mounted with respect to these two chambers.

[0017] Optionally, the drive means are connected only to the enclosure.

[0018] Optionally, the drive means comprise two members coupled to each other, one of the members being connected to the enclosure and the other of the members being connected to the frame.

[0019] Optionally, the screw extends into the enclosure so as to be in contact with walls of the enclosure at least when the screw is heated.

[0020] Optionally, the device comprises at least one rotation guide for the enclosure.

[0021] Optionally, the rotating guide comprises two members cooperating together, one of the members being connected to the enclosure and the other of the members being connected to a frame of the device.

[0022] Optionally, the device comprises a frame made of at least two parts which are movable relative to each other, the enclosure being fixed to one of the parts.

[0023] Optionally one of the parts is tiltable with respect to the other of the parts.

[0024] Optionally one of the parts is tiltable with respect to the other of the parts in an angular interval between 0 and 10 degrees.

[0025] Of course, for the present application, the terms "low", "high", "vertical", "horizontal"... must be understood according to the operating position of the device, that is to say when the device rests on a floor or a support and is ready to heat treat a product. The terms "upstream" and "downstream" must be understood according to the direction of advancement of the product in the device.

[0026] Other characteristics and advantages of the invention will emerge from reading the following description of a particular non-limiting embodiment of the invention. Brief description of the drawings

[0027] The invention will be better understood in light of the description which follows with reference to the appended figures among which:

[0028] [fig. 1] [fig.l] is a schematic perspective view of a device according to a particular embodiment of the invention,

[0029] [fig.2] [fig.2] is a schematic longitudinal sectional view of the illustrated device to [fig.l]. DETAILED DESCRIPTION OF THE INVENTION

[0030] Figures 1 to 2 show the device according to a particular embodiment of the invention.

[0031] The device is applicable to any type of product treatment (drying, debacterization, cooking, roasting, pyrolysis, toasting, activation, decarbonization, etc.).

[0032] The device comprises a structure 1 which is kept at a distance from the ground by means of a frame 3 which will be detailed below.

[0033] The structure comprises an enclosure 2 which extends longitudinally in a general direction.

[0034] The enclosure 2 here has an external envelope 4.

[0035] The outer casing 4 is for example made of metallic material. Typically the outer casing 4 is made of steel, such as stainless steel, and for example non-magnetic.

[0036] Furthermore, the enclosure 2 comprises an internal casing 6 made of refractory material which is arranged in the external casing 4.

[0037] According to a preferred embodiment, the outer casing 4 and the inner casing 6 are not in contact with each other.

[0038] Thus, the enclosure 2 comprises at least one intermediate cover 5 made of thermally insulating material extending between the internal envelope 6 and the external envelope 4. The cover 5 is for example made of rock wool or a more technical material which is more resistant to very high temperatures.

[0039] The different layers forming the enclosure 1 (namely here the internal envelope 6, the cover 5 and the external envelope 4) each have a general direction which is the same as or parallel to the general direction of the enclosure 2.

[0040] The different layers have a circular section. The different layers are preferably coaxial with each other.

[0041] More precisely, the different layers all have the same length here (length considered in the general direction of the enclosure).

[0042] Furthermore, the structure comprises at least one inlet chamber 7 arranged in the extension of the enclosure 2 at a first longitudinal end of the enclosure 2, inlet chamber 7 through which at least one product is introduced. The inlet chamber 7 and the enclosure 2 also communicate with each other to allow the passage of the at least one product between the inlet chamber 7 and the enclosure 2.

[0043] In the present case, a single product is introduced. Said product is introduced into the device preferably in the form of divided solids. The divided solids can be in the form of powders, granules, pieces, fibers, sheets, etc. and be of a vegetable, mineral, chemical nature, etc. The product can thus be of any type (wood, plastic, mud, waste, biomass, coal, calcium oxide, calcium carbonate, calcium hydroxide, etc.).

[0044] According to a particular embodiment, the device 1 comprises an inlet chimney 8 (not visible in [fig.2]) which is connected in a sealed manner to the inlet chamber 7. The inlet chimney 8 is for example connected to a device for grinding, compacting, extruding, melting, dosing or granulating the product in question into divided solids.

[0045] The structure further comprises at least one outlet chamber 9 arranged here in the extension of the enclosure 2 substantially at the level of the second of the two longitudinal ends of the enclosure 2, outlet chamber 9 through which at least one by-product resulting from the treatment of the product is recovered. The outlet chamber 9 and the enclosure 2 also communicate with each other to allow the passage of the at least one product between the enclosure 2 and the outlet chamber 9.

[0046] According to a particular embodiment, the device comprises a first outlet chimney 10 which is connected in a sealed manner to the outlet chamber 9. At least one solid by-product resulting from the treatment of the product introduced via the inlet chamber 7 is extracted through this first outlet chimney 10. The first outlet chimney 10 is for example connected to a device for cooling a by-product or to a device for post-treatment of the by-product.

[0047] Furthermore, the device 1 comprises a second outlet chimney 11 which is connected in a sealed manner to the outlet chamber 9. At least one gaseous by-product resulting from the treatment of the product introduced via the inlet chamber 7 is extracted via this second outlet chimney 11. The nature of the gaseous by-product concerned will depend on the type of reaction targeted: it may thus be gas, smoke, water vapor, heavy metal, carbon dioxide, carbon monoxide, di-hydrogen or any other gaseous product. The second outlet chimney 11 is for example connected to a device for cooling a by-product or to a device for post-treatment of the by-product.

[0048] The inlet chamber 7, the enclosure 2 and the outlet chamber 9 preferably extend coaxially with each other and in the general direction of the enclosure 2. The enclosure 2 is also framed by the inlet chamber 7 upstream and by the outlet chamber 9 downstream.

[0049] Boxes 12 are fixed to each of the longitudinal ends of the structure 1. In the present case, one of the boxes 12 is arranged in the extension of the inlet chamber 7, upstream of the inlet chamber 7, and the other of the boxes 12 in the extension of the outlet chamber 9, downstream of the outlet chamber 9. Each box 12 extends longitudinally in the general direction of the enclosure 2.

[0050] The device 1 comprises a screw 13 having a longitudinal axis X, the longitudinal axis X here being parallel to the general direction of the enclosure 2 and therefore of the structure 1.

[0051] In this case, the screw 13 has a helical serpentine shape which is fixed at its two ex ends at the end of a shaft section 14, but this is naturally only an example, and any other helical type geometry can be used.

[0052] The screw 13 is thus itself devoid of a shaft strictly speaking.

[0053] Each shaft section 14 is connected at its other end to a coaxial shaft which passes through the associated box 12.

[0054] In the present case, the screw 13 is entirely arranged in the enclosure 2. On the other hand, one of the shaft sections 14 extends from one of the boxes 12 into the enclosure 2 by crossing the inlet chamber 7 and the other of the shaft sections 14 extends from one of the boxes 12 into the enclosure 2 by crossing the outlet chamber 9.

[0055] At least one of the two boxes 12 is equipped with means for supplying electrical energy to the screw 13 so that the latter forms a heating means by the Joule effect. Preferably, said means comprise means for regulating the intensity of the electric current passing through the screw 13. The regulation means thus make it possible to adapt the electrical intensity passing through the screw 13 to the product conveyed and therefore the temperature of the screw 13.

[0056] The screw 13 therefore constitutes a heating means.

[0057] For this purpose, the screw 13 is formed in its mass from an electrically conductive material.

[0058] Because the screw 13 extends directly inside the internal casing of the enclosure, the screw 13 forms, in addition to its functions of direct heating of the product coming into contact with it, a heating of the internal casing 6 which thus itself constitutes a means of indirect heating of the product.

[0059] Because the screw 13 is formed in its mass from an electrically conductive material, and is connected to at least one source of electrical power supply, it is preferable for the internal casing 6 to be made from a material that is both refractory and electrically insulating. It could, for example, be a refractory concrete or a refractory ceramic material such as those commonly used to make furnace walls. Such materials have a very high melting point, in particular greater than 2000 degrees Celsius. The internal casing 6 is, for example, based on alumina (A12O3).

[0060] In the present case, the inlet chamber 7, the outlet chamber 9 and the chimneys 8, 10, 11 are preferably also made of refractory material of the same nature as that of the internal casing 6.

[0061] Furthermore, the screw 13 and the enclosure 2 are mounted in the device to rotate jointly around at least one axis, which is here the X axis.

[0062] In the present case, the screw 13 and the internal casing 6 are shaped so that the internal casing 6 follows the external contour of the screw 13. Thus the internal diameter of the internal casing 6 is substantially the same as that of the screw 13 so that in service screw 13 is in contact with the walls of the internal casing 6.

[0063] Consequently, the screw 13 is integral in rotation around the axis X with the internal casing 6 (and therefore with the entire enclosure 2) due to the fact that the turns of the screw 13 are in contact with the internal casing 6. Of course, when dimensioning the device, the thermal expansion of the screw 13 during its operation is taken into account in order to dimension the internal casing 6 accordingly.

[0064] The device thus comprises means for driving in rotation an assembly formed by the enclosure 2 and the screw 13 along the axis X.

[0065] Said means comprise for example two members coupled to each other, one of the members being connected to the enclosure 2 and the other of the members being connected to the frame 3, the assembly further comprising an element for driving one of the members into movement.

[0066] For example, one of the members comprises one or more pinions and the other of the members one or more racks each coupled to one or more pinions. In the present case, one of the members comprises a rack 14 and the other of the members a pinion 15 cooperating with said rack 14. The element for rotating the pinion 15 is a motor assembly 16.

[0067] In the present case, the rack 14 is fixed to the enclosure 2. The rack 14 is here arranged so as to externally surround the enclosure 2. For example, the rack 14 extends 360 degrees around the enclosure 2. The rack 14 extends coaxially to the enclosure 2 and therefore in the general direction of the enclosure 2.

[0068] Preferably, the enclosure 2 is provided with a plurality of spacers 17 (only one of which is referenced here) which make it possible to keep the rack 14 at a distance from the external casing 4, thus facilitating the rotation of the enclosure 2 relative to the frame 3.

[0069] The pinion 15 and the motor assembly 16 are fixed to the frame 3.

[0070] Preferably, the rotational drive means are arranged in the device on the inlet chamber side 7, downstream of the inlet chamber 7.

[0071] The rotation drive means here comprise means for controlling the rotation speed of the output shaft of the motor which comprise for example a speed variator. The control means thus make it possible to adapt the rotation speed of the enclosure 2 (and therefore of the screw 13 because the enclosure 2 and the screw 13 are linked in rotation) to the conveyed product, that is to say to adapt the residence time of the product in the enclosure 1.

[0072] The product then moves in the enclosure 1 by the joint rotation of the screw 13 and the enclosure 2.

[0073] On the other hand, the inlet 7 and outlet 9 chambers as well as the boxes 12 remain fixed with respect to the frame 3. For this purpose, bearings (or any other element such as, for example, rotating joints) allow, for example, the rotation of the two shaft sections 14 through them (to allow rotation of screw 13 relative to them) and bearings (or any other element such as for example rotating joints) allow rotation of enclosure 2 relative to the inlet 7 and outlet 9 chambers.

[0074] It is therefore noted that the screw 13 has a dual role of moving the product and heating the product by Joule effect. The screw 13 therefore constitutes a heating transfer means.

[0075] As indicated previously, the device comprises a frame 3 by means of which the structure 1 but also the boxes 12 rest on the ground.

[0076] Legs 18 (only a part of which is referenced here) extend between the frame 3 and at least one of the fixed parts of the device (box(es) 12 and / or inlet chamber 7 and / or outlet chamber 9). In the present case, legs 18 extend between each box 12 and the frame 3 and legs 18 extend between the inlet chamber 7 and the frame 3 and legs 18 extend between the outlet chamber 9 and the frame 3.

[0077] Preferably, the device comprises at least one rotation guide for the enclosure 2 (and therefore for the screw 13) relative to the frame 3.

[0078] The rotating guide comprises, for example, two members cooperating together, one of the members being connected to the enclosure 2 and the other of the members being connected to the frame 3.

[0079] For example, one of the members comprises one or more rollers and the other of the members comprises one or more tread-type crowns.

[0080] In the present case, one of the members comprises two rollers and the other of the members a crown.

[0081] In the present case, the crown 19 is fixed to the enclosure 2. The crown 19 is here arranged so as to externally surround the enclosure 2. For example, the crown 19 extends 360 degrees around the enclosure 2. The crown 19 extends coaxially to the enclosure 2 and therefore in the general direction of the enclosure 2.

[0082] Preferably, the enclosure 2 is provided with a plurality of spacers 20 (only one of which is referenced here) which make it possible to keep the crown 19 at a distance from the external casing 4, thus facilitating the rotation of the enclosure 2 relative to the frame 3.

[0083] The rollers 21 are fixed to the frame 3.

[0084] Preferably, the device comprises two rotating guides.

[0085] The device here comprises a first roller / crown assembly and a second roller / crown assembly which are preferably identical to each other and to what has been described previously.

[0086] The first assembly is arranged on the inlet chamber 7 side, downstream of the inlet chamber 7, and the second assembly on the outlet chamber 9 side, upstream of the outlet chamber 9.

[0087] The rack and pinion assembly is here framed by the two rotating guides.

[0088] According to a preferred embodiment, the frame 3 is in two parts which can be moved relative to each other.

[0089] The first part 22 is intended to rest on the ground to be immobile with respect to the ground when using the device.

[0090] On the other hand, the second part 23 is mounted to move on the first part 22 in a rotational movement.

[0091] The structure 1, the boxes 12, the rotation guides and the rotation drive means are carried by this second part 23.

[0092] The legs 18 are thus fixed at a first end to the second part 23 and at a second end to one of the boxes 12 or the inlet chamber 7 or the outlet chamber 9.

[0093] Typically the second part 23 is mounted to move relative to the first part 22 according to a rotation of transverse axis Y which is here substantially orthogonal to the axis X when the second part 22 extends parallel to the first part 23.

[0094] The first part 22 here extends horizontally so that the Y axis belongs to the horizontal plane when the second part 23 extends parallel to the first part 22.

[0095] Thanks to this movement between the two parts of the frame 3, it is thus possible to tilt the second part 22 with respect to the first part 21 and therefore to tilt the enclosure 2 with respect to the first part 21 (and therefore the ground).

[0096] Typically the two parts of the frame 21, 22 are arranged so as to allow a movement of the second part 22 with respect to the first part 21 of between [0; 10] degrees and for example of between [0; 5] degrees.

[0097] This makes it possible to control the residence time of the product in enclosure 2 by promoting more or less the flow by gravity in enclosure 2.

[0098] Thus, the second part 22 is pivotally mounted on the first part 21 at one of the longitudinal ends of the structure 1 and preferably at the downstream longitudinal end of the structure 1 (i.e. outlet chamber 9 side).

[0099] Preferably, the device comprises motorized means for moving the second part 23 relative to the first part 21. Said moving means comprise, for example, one or more jacks 24 for lifting the upstream end of the second part 23 relative to the upstream end of the first part 22 and thus tilting the structure 1 towards the downstream end of the device.

[0100] In operation, the screw 13 is powered allowing the heating of the product. Typically the screw 13 is heated so that the temperature in the internal casing is between 150 and 1600 degrees and preferably between 200 and 1500 degrees and for example between 500 and 1500 degrees Celsius. Of course the target temperature will depend on the desired treatment (for example if the desired treatment is debacterization and / or a toasting the temperature will be between 150 and 500 degrees Celsius and preferably between 200 and 300 degrees Celsius; if the device is used as an oven (for cooking or pyrolysis of the product for example) the temperature will be between 500 and 1600 degrees Celsius and preferably between 500 and 1500 degrees Celsius).

[0101] In fact, the Joule effect released by the screw 13 is adjustable (by modifying the intensity of the electric current passing through the screw), which makes it possible to very finely control the heating temperature of the screw 13 and therefore of the internal casing 6.

[0102] Furthermore, the screw 13 and the enclosure 2 are driven in rotation. It is noted that the rotation speed of the screw 13, like that of the enclosure 2, is adjustable (by modifying the rotation speed of the motor assembly 16), which makes it possible to precisely control the time taken for the product to pass through the enclosure 2.

[0103] Furthermore, the enclosure 2 is tiltable with respect to the ground, which again makes it possible to precisely control the time taken for the product to pass through the enclosure 2.

[0104] This ensures a good treatment in the device 1 thus described in a simple, relatively energy-efficient and efficient manner, a reaction which is moreover continuous.

[0105] The invention is not limited to the embodiment which has just been described, but on the contrary encompasses any variant incorporating, with equivalent means, the essential characteristics set out above.

[0106] Thus the screw may be different from what has been indicated. In particular the screw may have a resistance which varies along the geometric axis of the screw as proposed in patent FR 2 995 986 of the present applicant. The screw may be provided with a central shaft.

[0107] Furthermore, although here the internal envelope is in one piece, the internal envelope may be formed of at least two sections and / or a succession of sections which can optionally be fitted into each other.

[0108] The internal envelope may have a shape other than that described and, for example, have a section such that the internal part of the envelope is rectangular or square.

[0109] The device may also comprise one or more heating elements of the internal casing as proposed in application PCT / EP2020 / 067397 of the present applicant and / or may comprise one or more heating elements external to the internal casing and / or one or more heating elements incorporated in the screw and / or one or more heating elements extending parallel to the screw. At least one of the elements may be, for example, a radiant tube.

[0110] The cover may not be a single piece but may be composed of several elements fixed together and / or fixed to the envelope and / or fixed to the enclosure. It will be possible to do without a cover.

[0111] The device may not be arranged horizontally but may be arranged for example horizontally vertical and / or oblique.

[0112] Furthermore, although here the product is introduced in the form of divided solids into the enclosure, the product may be introduced in another form, for example liquid or gaseous. Several products may be introduced simultaneously through the same inlet, for example a gas / product mixture.

[0113] In the same way, it will also be possible to inject a first product into at least one inlet and a second product into at least one other inlet independently of the first. The second product may thus be a gas (such as water vapor or other) interacting with the first product to treat it (for example to debacterize or activate it). For example, the inlet(s) associated with the gas may be shaped to inject the gas axially into the enclosure (i.e. parallel to the axis of the screw).

[0114] In the same way, one or more by-products in the form of gas, liquid, oil, solid, etc. can be recovered at the outlet. The number of inlets and outlets of the structure will vary accordingly. It will thus be possible to have several inlets (independent or not in pairs) and / or several outlets (independent or not in pairs; moreover, an inlet and an outlet may be independent or not from each other). The frame may be a single fixed part. The enclosure may thus not be tiltable and / or not movable relative to the ground.

[0115] The screw and the enclosure may be fixed to each other (for example by expansion joint type fasteners or elastic fixing in order to take into account any possible expansion of the screw during operation) or not be fixed to each other but only integral with each other in rotation as has been described (by tightening the screw in the internal enclosure).

[0116] The device may include rotational drive means directly driving the screw and / or directly driving the enclosure (and not only the enclosure as has been described). For example, the rotational drive means may rotate the shaft sections connected to the screw (the drive means being arranged in the boxes).

[0117] The rotation drive means may be different from what has been described. For example, the enclosure may be driven in rotation by a pulley-belt (toothed or not) or by a worm screw-rack assembly or directly by the motor shaft or via an additional shaft section.

[0118] The rotating guide may be different from what has been indicated and may comprise, for example, a guide rail in which a corresponding guide circulates. Preferably, the crown and / or the guide will be rigid and not flexible.

Claims

Claims

1. Device for processing a product comprising: - an enclosure (2), - means for conveying the product which comprise a screw (13), - means for heating the screw by Joule effect, the device being characterized in that the screw and the enclosure are mounted in the device to rotate jointly around a geometric axis of rotation (X), the device thus comprising means for driving in rotation an assembly formed by the enclosure and the screw along said axis.

2. Device according to claim 1, in which the enclosure (2) comprises several layers, at least one of which is thermally insulating.

3. Device according to claim 1 or claim 2, in which the enclosure (2) comprises a layer of refractory material.

4. Device according to one of claims 1 to 3, further comprising an inlet chamber (7) and an outlet chamber (9) framing the enclosure, the inlet chamber, the enclosure being rotatably mounted with respect to these two chambers.

5. Device according to one of the preceding claims, in which the drive means are connected only to the enclosure (2).

6. Device according to claim 5, in which the drive means comprise two members coupled to each other, one of the members being connected to the enclosure (2) and the other of the members being connected to the frame (3).

7. Device according to one of the preceding claims, in which the screw (13) extends into the enclosure so as to be in contact with walls of the enclosure at least when the screw is heated.

8. Device according to one of the preceding claims, in which the device comprises at least one rotation guide for the enclosure (2).

9. Device according to claim 8, in which the rotating guide comprises two members cooperating together, one of the members being connected to the enclosure (2) and the other of the members being connected to a frame (3) of the device.

10. Device according to one of the preceding claims, comprising a

11.

12. frame (3) in at least two parts movable relative to each other, the enclosure being fixed to one of the parts. A device according to claim 10, wherein one of the parts is tiltable relative to the other of the parts. Device according to claim 11, wherein one of the parts is tiltable relative to the other of the parts within an angular range of between 0 and 10 degrees.

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