MICROWAVE RADIATION HEAT TREATMENT SYSTEM INCLUDING A SWITCHING UNIT

Abstract

MICROWAVE RADIATION HEAT TREATMENT SYSTEM INCLUDING A SWITCHING UNIT The present invention relates to a treatment system including first and second reaction chambers (1, 1'), a generator (2), and a switching unit (4) movable between first and second extreme positions such that: in the first extreme position, the first chamber (1) is connected to the generator (2) via the switching unit (4), and the second chamber (1') is disconnected from the generator (2); and in the second extreme position, the second chamber (1') is connected to the generator (2) via the switching unit (4), and the first chamber (1) is disconnected from the generator (2). Abstract figure: Figure 2

Description

Title of the invention: MICROWAVE RADIATION HEAT TREATMENT SYSTEM INCLUDING A UNIT SWITCHING FIELD OF INVENTION

[0001] The present invention relates to the general technical field of systems for processing plant biomass of any plant species known to those skilled in the art, for example parts of a vine.

[0002] The biomass to be treated may be dry or wet, and its treatment may be carried out in the presence (or not) of an aqueous solvent.

[0003] Such a processing device allows the extraction of metabolites from plant biomass, said metabolites being polyphenols or any other type of secondary metabolites known to those skilled in the art.

[0004] The metabolites thus extracted can be used in various fields of application, such as biocontrol applications or cosmetic applications.

[0005] In the following, the device according to the invention will be described with reference to the treatment of dry plant biomass rich in polyphenols (such as parts of a vine) in the presence of an aqueous solvent, it being understood for those skilled in the art that the device according to the invention can be used for the treatment of any type of plant biomass - dry or wet - in the presence or not of one (or more) aqueous solvent(s). STATE OF THE ART 1. Introduction

[0006] Extracts of plant biomass rich in polyphenols are known to those skilled in the art.

[0007] Numerous studies have focused on the extraction of biomass to obtain a polyphenol-rich extract, all of which have presented several drawbacks regarding the economic viability of the processes, such as low yields or very long extraction times, or limiting their post-extraction use, and in particular the use of toxic organic solvents.

[0008] Document WO 2018 / 115296 describes a process for preparing a dry plant biomass extract, rich in polyphenols, comprising: - a step of extracting dry biomass by bringing it into contact with an aqueous solvent, and - a step of recovering the aqueous phase enriched in polyphenols.

[0009] During the extraction step, the plant biomass / aqueous solvent mixture is treated, at a pressure between 50 and 950 mbar (5,000 to 95,000 Pa), by applying, at

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[0016] blend : - electromagnetic waves with frequencies between 10 MHz and 100 GHz, preferably between 433 MHz and 30 GHz, and even more preferably between 915 MHz and 28 GHz, and - by stirring the mixture. The present invention aims to provide a heat treatment system for implementing the process according to WO 2018 / 115296. In particular, the present invention relates to a product treatment system for the extraction of a substance of interest, the treatment system being configured to: - stir the product, and - apply to the product electromagnetic waves of frequency between 10 MHz and 100 GHz, preferably between 433 MHz and 30 GHz, and even more preferably between 915 MHz and 28 GHz. - 2. Issues associated with the use of electromagnetic waves 2.1 Minimizing electromagnetic leakage levels The use of electromagnetic waves for industrial, scientific and medical applications is subject to compliance with several standards for the protection of people and the protection of communication networks: - the EN 50413 standard for the exposure of people, - the EN 50499 standard for worker exposure, - the EN 55011 standard for the protection of telecommunications networks. The industrial use of electromagnetic waves with a frequency of 915 MHz requires compliance with standard NE 55011. This standard stipulates that the electromagnetic radiation emitted outwards by a system generating electromagnetic waves with a frequency of 915 MHz must be less than a threshold value of -40 dB microvolts per meter, at 30 m from said system. This helps to avoid disruptions to telecommunications networks. Any exceedance of this threshold value may be sanctioned, without prior notice, by the immediate shutdown of the system deemed to be faulty. One aim of the present invention is to propose a heat treatment system using electromagnetic waves that does not exceed the electromagnetic leakage levels imposed by the EN 55011 standard. 2.2 Productivity Improvement Given the restrictions related to the NE 55011 standard (leakage radiation at 30 m less than 40 dB mV / s), the industrial use of electromagnetic wave processing devices with a frequency of 915 MHz is generally limited to batch processing (or "batch" processing, according to the terminology used in industrial processes), provided that all protective measures have been implemented. implemented to avoid exceeding the imposed electromagnetic leakage levels.

[0017] As illustrated in [Fig. 1], such a device is composed of: - of an enclosure 1 containing the product 2 to be treated, - a mixing unit housed within the enclosure, and - a waveguide 3, connected between enclosure 1 and an electromagnetic wave generator 4, to transmit the electromagnetic waves generated by the generator 4 to enclosure 1.

[0018] A common drawback of various batch product processing devices is their limited productivity due to the relatively long batch processing time. Indeed, for each new use, it is necessary to: • load the reaction chamber 1, • the generation of a depression in chamber 1, • heating by electromagnetic waves of the product placed in enclosure 1, • the cooling and atmospheric pressure adjustment of enclosure 1 for the recovery of treated product 2 and cleaning of enclosure 1.

[0019] One object of the present invention is to provide a batch product processing system in which productivity is improved. SUMMARY

[0020] To this end, the invention proposes a system for processing plant biomass, the processing system comprising: - A first and a second enclosure, each intended to contain the plant biomass to be treated, each of the first and second enclosures comprising a lower partition, an upper partition and at least one lateral partition extending between the upper and lower partitions, the upper partition including a pass-through inlet, - a generator for the production of electromagnetic waves, the generator comprising a protective casing, at least one source of electromagnetic waves housed in the protective casing, and an outlet opening provided in an upper plate of the protective casing, - the first and second mixing units contained respectively in the first and second enclosures, characterized in that the processing system further comprises a switching unit including: - a tubular waveguide for the circulation of electromagnetic waves between the generator and the first and second enclosures, and - the first and second connection cells arranged at one end of the waveguide respectively, said switching unit being movable between: - a first extreme position in which the first connecting cell is connected to the inlet of the first enclosure and the second connecting cell is connected to the outlet of the generator so that the electromagnetic waves produced by the generator are transmitted to the first enclosure via the switching unit, and - a second extreme position in which the first cell is connected to the output opening of the generator and the second connecting cell is connected to the inlet mouth of the second enclosure so that the electromagnetic waves produced by the generator are transmitted to the second enclosure via the switching unit.

[0021] In the context of the present invention, "connected to" means a first element connected directly to a second element, or connected indirectly to the second element, in particular via a third element disposed between the first and second elements.

[0022] Preferred, but not limiting, aspects of the present invention are as follows: - the processing system may further comprise a metal plate including first, second and third aligned through-lights of identical dimensions, the distance between the centers of the first and second through-lights being equal to the distance between the centers of the second and third through-lights: • the first light being connected to the entrance of the first enclosure, • the second light being connected to the generator's output opening, and • the third light being connected to the entrance of the second enclosure, the switching unit being in contact with the metal plate in the first and second extreme positions; - each of the first and second connection cells may include a curved, loop-shaped rectangular metal frame, said frame including an electromagnetic wave inlet / outlet slot, the dimensions of said frame being determined so that electromagnetic waves entering the metal frame at the inlet / outlet slot emerge from said metal frame in opposite phase at the inlet / outlet slot; - The frame may include: • an external face extending perpendicularly to the metal plate, • an inner pane parallel to the outer pane, the distance between the metal plate and the edge of the inner pane closest to the metal plate being non-zero when the switching unit is in the first or second extreme position, • an upper plate between the outer and inner plates, the edges of the upper plate being connected to the edges of the outer and inner plates furthest from the metal plate, and • a lower panel parallel to the upper panel, the lower panel extending between the outer and inner panels and including: • a connecting edge linked to the edge of the inner panel closest to the metal plate, • a free edge opposite the connecting edge, so that the lower pane extends in relation to the metal plate, at a non-zero distance from said metal plate when the switching unit is in the first or second extreme position, said lower pane not being in contact with either the metal plate or the external pane; Each panel is generally rectangular in shape; the sum of the widths is: • of the outer panel, • of the upper panel, • of the inner pane, and • of the lower panel being equal to a multiple of the wavelength of the electromagnetic waves plus a quarter of the wavelength of said electromagnetic waves; the thickness of the panels can be approximately equal to the thickness of the waveguide walls; Each of the first and second connecting cells may include a central channel whose dimensions are identical to the dimensions of the first, second, and third through lights, the center distance between the first and second connecting cells being equal to the distance separating the centers of the first and second through lights; The processing system may further include means for moving the switching unit between the first and second extreme positions, said means for moving the unit being configured to perform the following operations successively when the switching unit is in the first extreme position: • Move the switching unit vertically so that: • Disconnect the first connection cell from the inlet of the first enclosure, and • Disconnect the second connection cell from the generator's output opening, • Move the switching unit horizontally so that: • Position the first connection cell directly above the generator's output opening, and • Position the second connection cell directly opposite the entrance of the second speaker, • Move the switching unit vertically so that: • Connect the first connection cell to the generator's output opening, and • connect the second connection cell to the inlet of the first speaker; - the switching unit may further include at least one sensor to detect whether the switching unit is in the first extreme position or the second extreme position, the generator being able to be activated for the production of electromagnetic waves only if said and at least one sensor has detected that the switching unit is in the first extreme position or the second extreme position. DETAILED DESCRIPTION OF THE INVENTION

[0023] We will now describe an example of a processing system with reference to the figures. In these different figures, the equivalent elements are designated by the same numerical reference. 1. General Information

[0024] The processing device described below allows the preparation of an extract rich in metabolites (polyphenols and / or other secondary metabolite(s)) by extraction from a dry (or wet) biomass with (or without) an aqueous solvent.

[0025] By "aqueous solvent", according to the invention, means water or an aliphatic alcohol / water mixture, in particular ethanol / water.

[0026] Plant biomass can, for example, be biomass containing polyphenols, in particular trans-resveratrol, trans-e-viniferin, trans-piceatannol, and trans-vitisin. Those skilled in the art are familiar with this biomass from plants known to contain these polyphenols, used alone or in mixtures, generally dicotyledonous plants such as grapevines, tea plants, or Japanese knotweed, more particularly- ligingly the vine.

[0027] When the biomass is dry, that is, obtained by drying the aforementioned plants, it may consist of dry parts of plants of the genus Vitis, in particular Vitis vinifera, Vitis labrusca, Vitis riparia, Vitis rupestris, Vitis berlandieri, Vitis amurensis, Vitis coignetiae, Vitis vulpina, Vitis acerifolia, Vitis aestivalis, Vitis ro-tundifolia, and more particularly Vitis vinifera. According to an advantageous embodiment of the invention, the dry biomass comprises or is made up of vine shoots.

[0028] Alternatively, the biomass may be wet. In this case, the water molecules contained in the biomass may eliminate the need for the use of aqueous solvents.

[0029] This device allows the implementation of a process for extracting metabolites such as polyphenols.

[0030] This process is characterized by the combination of at least two constraints applied to plant biomass (dry or wet) in the presence (or absence) of an aqueous solvent: i. electromagnetic waves with a frequency between 10 MHz and 100 GHz, preferably between 433 MHz and 30 GHz, and even more preferably between 915 MHz and 28 GHz, and ii. stirring, and / or iii. a pressure of 50 to 950 mbar.

[0031] In the following, the device according to the invention will be described with reference to the treatment of a mixture composed of dry biomass and an aqueous solvent, it being understood for those skilled in the art that this device can be used with other types of products. 2. Processing System

[0032] With reference to [Fig. 2], an example of a processing system according to the invention is illustrated. The system comprises: - of the first and second speakers 1.1', - a generator 2, - the first and second mixing units 3, 3' contained respectively in the first and second enclosures 1, 1', and - a switching unit 4 to connect the first and second speakers 1, 1' to the generator 2.

[0033] As will become apparent later in the description, the presence of a switching unit 4 allows electromagnetic waves to be sequentially supplied to two separate chambers 1, 1' from a single generator 2. This makes it possible to limit the production costs associated with processing the biomass / solvent mixture: - firstly, by reducing the number of generators required for powering the in electromagnetic waves from the processing system, and on the other hand by allowing an operator to carry out, on enclosure 1, operations related to production (cleaning, loading of the enclosure with biomass / solvent mixture to be treated, etc.) or maintenance) while a biomass / solvent mixture is being treated in the other enclosure 1'.

[0034] This switching unit was also designed to limit the risks of arcing and leakage of electromagnetic waves to the outside of the processing system. 2.1 Speakers

[0035] The enclosure 1 allows us to define an enclosed space in which it is possible to generate a depression (or an overpressure), that is to say a space in which it is possible to decrease (or increase) the pressure to a value lower (or higher) than atmospheric pressure, in particular to a pressure between 50 and 950 mbar.

[0036] Each enclosure 1, 1' is configured to withstand pressures above or below atmospheric pressure. Furthermore, each enclosure 1, 1' is configured to resist corrosion. Finally, each enclosure 1, 1' is configured to withstand temperatures of 200 °C or higher.

[0037] Such enclosures 1,1' can have different shapes and be made from different conductive materials to perform this function. In the embodiment illustrated in [Fig. 2], each enclosure 1,1' has a cylindrical shape and is essentially made of stainless steel plates.

[0038] Each 1.1" sealed enclosure comprises: a lower partition 11, 11' forming a bottom of the enclosure 1,1', a curved upper partition 12, 12' forming a ceiling of the enclosure 1,1', and one (or more) lateral partition(s) 13, 13' vertical(s) extending between the upper and lower partitions 11,11' and 12, 12'.

[0039] The lower partition 11, 11' may be flat or concave towards the inside of the enclosure 1, 1'. It includes an opening 111, 111' to allow an operator to access the inside of the enclosure 1, 1'. In operation, this opening 111, 111' is closed by a hatch (or door) 112, 112' normally locked hermetically by any technique known to those skilled in the art, for example by bolting the hatch 112, 112' to the lower partition 11, 11', a sealing gasket (for example made of rubber) being fitted between the opening 111, 111' and the opposite hatch 112, 112' (i.e. between the edges of the opening and the opposite edges of the hatch). Of course, the lower partition 11, 11' can include more than one opening 111, 111' which can be closed by a hatch 112, 112'.Furthermore, the reader will appreciate that this (or these) opening(s) 111, 111' which can be closed by a (or) hatch(es) 112, 112' can (can) be arranged in a different partition 12, 12' and 13, 13' than the lower partition 11, 11'. .

[0040] The upper partition 12, 12' includes a through-port 121, 121' to which the switching unit can be connected. Thus, the incident waves (electromagnetic waves produced by the generator 2) circulating in the switching unit 4 exit into the enclosure 1, 1' through the through-port 121, 121'. Of course, this through-port 121, 121' can be provided in the side partition 13, 13' rather than the upper partition 12, 12'. The upper partition 12, 12' can include one (or more) other through-port(s), for example, for the passage of a shaft from the mixing unit 3, 3'.

[0041] Each enclosure 1,1' may include a hole to which a pump (not shown) is connected for generating a vacuum in the enclosure 1,1'.

[0042] Such an enclosure 1,1' being known to a person skilled in the art, it will not be described in further detail hereafter. 2.2 Generator

[0043] The generator 2 is configured for the emission of electromagnetic waves with a frequency between 10 MHz and 100 GHz, preferably between 433 MHz and 30 GHz, and even more preferably between 915 MHz and 28 GHz, corresponding to waves in the microwave range.

[0044] A person skilled in the art will be able to choose the most suitable frequency for implementing the process, particularly depending on the biomass, to optimize the extraction process. Advantageously, the frequency of the electromagnetic waves ranges from 915 MHz to 2.45 GHz. Advantageously, the frequency of the electromagnetic waves will be chosen based on known industrial devices for generating electromagnetic waves on an industrial scale, in particular electromagnetic wave generators with frequencies below 1500 MHz, more advantageously around 915 MHz.

[0045] A person skilled in the art will also be able to choose the electromagnetic wave power best suited to the biomass and the extracts obtained. The electromagnetic wave power advantageously ranges from 300 W to 100 kW, and more advantageously from 1 to 75 kW. This power will be chosen in particular according to the volume to be processed and the time required for extraction. For example, the electromagnetic wave power can be chosen according to the following ratio: for 1 kg of material to be extracted, the electromagnetic wave power is 1 to 10 kW, ideally 2 to 6 kW.

[0046] In a conventional manner, the generator 2 comprises one (or more) electromagnetic wave source(s) (not shown) of the solid state or transistor type housed in a protective casing 21, and an output opening 22 — provided in an upper plate of the protective casing 21 — for the emission of electromagnetic waves to the outside of the generator 2. 2.3 Brewing Unit

[0047] Each mixing unit 3, 3' mixes the biomass / solvent mixture to be treated in order to homogenize the treatment of this mixture. As previously stated, each mixing unit 3, 3' is associated with a respective chamber 1, 1'.

[0048] Each mixing unit 3, 3' may include a propeller including a shaft and two (or four) blades at one end of the shaft, the other end of the shaft being connected to a motor to induce the rotation of the shaft and the propeller blades.

[0049] Alternatively, each mixing unit 3, 3' may include ejection nozzles mounted in the lower partition 11, 11', these nozzles allowing the injection of a gas — inert such as air — into the mixture to induce its mixing.

[0050] Of course, a person skilled in the art may consider other types of mixing unit 3, 3' of the biomass / solvent mixture to be treated.

[0051] Preferably, the mixing is carried out by rotating the blades at a rotation speed ranging from 3 to 20 revolutions per minute. 2.4 Switching Unit

[0052] The switching unit 4 allows the first and second speakers 1, 1' to be connected sequentially to the generator 2. More specifically, the switching unit 4 is configured to be moved between: - a first extreme position in which the generator 2 is connected to the first enclosure 1 via the switching unit 4, as illustrated in [Fig. 3a], and - a second extreme position in which the generator 2 is connected to the second enclosure 1' via the switching unit 4, as illustrated in figure 3b.

[0053] The movement of the switching unit 4 between the first and second extreme positions can be achieved by one (or more) motor(s), by one (or more) cylinder(s), or by any other means known to those skilled in the art. Advantageously, the switching unit 4 may include one (or more) sensor(s) to detect whether the switching unit 4 is in the first extreme position or the second extreme position, the generator being able to be activated for the production of electromagnetic waves only if the sensor(s) has detected that the switching unit 4 is in the first extreme position or the second extreme position.

[0054] When the switching unit 4 is in the first extreme position, the first enclosure 1 is coupled to the generator 2 via the switching unit 4, while the second enclosure 1' is decoupled from the generator 2. Thus, the electromagnetic waves produced by the generator 2 travel to the first enclosure 1 at Through the switching unit 4, the second enclosure 1' receives no electromagnetic waves. This allows an operator to perform loading or maintenance operations on the second enclosure 1' without risk of electromagnetic radiation.

[0055] When the switching unit 4 is in the second extreme position, the second enclosure 1' is coupled to the generator 2 via the switching unit 4, while the first enclosure 1 is decoupled from the generator 2. Thus, the electromagnetic waves produced by the generator 2 travel to the second enclosure 1' through the switching unit 4, the first enclosure 1 receiving no electromagnetic waves. This allows an operator to perform loading or maintenance operations on the first enclosure 1 without risk of electromagnetic radiation.

[0056] This maximizes the usage time of generator 2 for batch production of polyphenol-rich extract, and therefore the productivity of the processing system.

[0057] The switching unit 4 comprises: - a tubular waveguide 41, and - the first and second connection cells 42, 43 arranged at a respective end of the waveguide 4L

[0058] The waveguide 41 allows the electromagnetic waves produced by the generator 2 to circulate towards one or the other of the first and second enclosures 1, 1'. It can consist of a parallelepiped tube with a rectangular cross-section (waveguide standardized to the frequency used), for example in the shape of a U as illustrated in [Fig. 2]. Such a waveguide 41 is made of a material that is impermeable to electromagnetic waves, for example of an electrically conductive and magnetic material (metal) such as stainless steel or aluminum.

[0059] The first and second connection cells 42, 43 are configured to be connected with the outlet opening 22 on the one hand, and with the through inlet openings 121, 121' on the other hand.

[0060] Each connection cell 42, 43 is configured to trap electromagnetic waves that might escape outside the processing system at the interface between the generator 2 and the switching unit 4 on the one hand, and at the interface between the first and second enclosures 1, 1' and the switching unit 4 on the other. This makes it possible to move the switching unit 4 without using screws, and thus reduces operating time.

[0061] Thus, the first and second connection cells 42, 43 limit the risk of high-power electromagnetic wave leakage outside the processing system. Furthermore, the first and second connection cells 42, 43 reduce the risk of electric arc formation (in case of false contact between two metal parts) in the first enclosure 1 and the second enclosure 1'.

[0062] Each connection cell 42, 43 has the form of a metal frame designed to be positioned around the outlet opening 22 or the inlet opening 121, 121' to which said connection cell 42, 43 is associated. This curved, loop-shaped metal frame with a rectangular cross-section includes an inlet / outlet slot 425 for electromagnetic waves. The dimensions of the frame are determined so that electromagnetic waves entering the metal frame at the inlet / outlet slot 425 exit said metal frame in opposite phase and cancel each other out. This principle makes it possible to achieve a virtual metal-to-metal contact that is equivalent to a "real" metal-to-metal contact.

[0063] These connecting cells 42, 43 allow the capture of reflected waves originating: - from the first enclosure 1 at the inlet 121, - from the second enclosure 1' at the inlet 121', and - from generator 2 at the level of the output opening 22.

[0064] With reference to [Fig.4], a cross-sectional example of a connection cell 42 in the first extreme position (connection cell 42 positioned on the through mouth 121 of the first enclosure 1) has been shown.

[0065] The connection cell 42 comprises: - a central channel 426 whose dimensions are identical to the dimensions of the inlet openings 121, 121' and the outlet opening 22 of generator 2, and - an inner chamber C, the central channel 426 and chamber C being delimited by a curved loop plate, here rectangular in shape, with a free panel 421 configured to extend opposite the partition 12 in which the through mouth 121 is provided.

[0066] More specifically, the connection cell 42 comprises: - an external vertical panel 422 extending perpendicularly to the partition 12, the external vertical panel 422 having a lower edge 422a in contact with the partition 12, and an upper edge 422b opposite the lower edge 422a, - an upper panel 423 extending parallel to the partition 12, the upper panel 423 having an external lateral edge 423a connected to the upper edge 422b of the external vertical panel 422, and an internal lateral edge 423b extending to the right of the entrance opening 121, - an internal vertical panel 424 extending parallel to the external vertical panel 422, the internal vertical panel 424 having an upper edge 424a connected to the internal lateral edge 423b of the upper panel 423, and an opposing lower edge 424b, the lower edge 424b being closer to the inlet opening 121 that the upper edge 424a, - the free panel 421 extending parallel to the partition 12, the free panel 421 having a connecting edge 421a connected to the lower edge 424 b of the internal vertical panel 424, and an opposite free edge 421 b, the free edge being closer to the external vertical panel 422 than the connecting edge 421a.

[0067] The free panel 421 extends in relation to the partition 12, at a non-zero distance d from it so that the free panel 421 is not in physical contact with the partition 12. Thus, the free panel 421 defines with the partition 12 a passage forming the inlet / outlet slot 425 of the wave trap constituted by the connection cell 42.

[0068] Advantageously, the dimensions of the various panels 421-424 (and in particular the widths L1, L2, L3 and L4 of the various panels) are determined (experimentally or by modeling) to be equal to a multiple of the wavelength of the reflected waves plus one-quarter thereof, so that the reflected waves exiting the connecting cell 42 (hereinafter referred to as "outgoing reflected waves") are phase-shifted by half a wavelength with the reflected waves entering the connecting cell 42 (hereinafter referred to as "incoming reflected waves"). The incoming and outgoing reflected waves are thus in opposite phase and cancel each other out.

[0069] Indeed, the operating principle of the connection cell 42 (forming a wave trap) is based on the combination of two waves (incoming wave and outgoing wave) which cross in opposite phase at the level of the inlet / outlet slot 425.

[0070] In the case of the system according to the invention, the waves reflected by the enclosure 1 propagate to the mouth 121 and enter the connection cell 42 at the inlet / outlet slot 425. These reflected waves propagate in the connection cell 42 along the various faces 421-424 constituting it, to exit the connection cell 42 through the inlet / outlet slot 425. The waves exiting the connection cell 42 interfere with the waves entering the connection cell 42.

[0071] The phase of the outgoing waves depends on the distance traveled (Dp) in the connection cell 42, and in particular on the widths of the different panels 421-424 constituting the connection cell 42 (DP=L2 + L3 + L4 + 2xLi).

[0072] Under conditions of phase opposition, these incoming and outgoing waves OE, Os cancel each other out.

[0073] The determination of the dimensions of the connection cell 42 forming a wave trap can be carried out experimentally, or on the basis of modeling results.

[0074] Such connection cells 42, 43 make it possible to limit the risks of leakage to the outside of reflected waves as well as the risks of generating an electric arc at level of the entrance openings 121, 121'. 2.5 Metal plate

[0075] To facilitate the connection of the switching unit 4 to the inlet ports 121, 121' of the first and second speakers 1, 1', and to the outlet opening 22 of the generator 2, the system may include a metal plate on which the first and second speakers 1, 1' and the generator 2 are connected.

[0076] This substantially flat metal plate includes first, second and third aligned through-holes of identical dimensions.

[0077] The first light is connected to the inlet 121 of the first enclosure 1, the second light is connected to the outlet 22 of the generator 2 (the second light being positioned between the first and third lights), and the third light is connected to the inlet 121' of the second enclosure 1'.

[0078] The dimensions of the first, second, and third lights are identical to the dimensions of the central channels 426 of the first and second connecting cells 42, 43. Furthermore, the distance separating the centers of the first and second lights is equal to the distance separating the centers of the second and third lights. This distance is also equal to the center-to-center distance E (see [Fig. 5]) between the first and second connecting cells 42, 43.

[0079] Thus, when the switching unit 4 is: - in the first extreme position ([Fig.3a]), the central channel of the first connecting cell 42 is aligned with the first light, while the central channel of the second connecting cell 43 is aligned with the second light, - in the second extreme position (figure 3 b), the central channel of the first connecting cell 42 is aligned with the second light, while the central channel of the second connecting cell 43 is aligned with the third light. 3. Operating Principle

[0080] In conventional prior art processing devices, the activation time of generator 4 for the production of electromagnetic waves is very limited.

[0081] Indeed, a large part of the processing time is occupied by loading, unloading and cleaning times, to which must be added the time related to reaction kinetics (depressurization, heating, cooling of the enclosure).

[0082] Given the high cost of generator 2, it is preferable to maximize its activation time in order to reduce the costs associated with processing the mixture. However, it is not feasible to imagine a manual switching operation involving disassembling and reassembling the various components (waveguide 3, unit) impedance matching unit 5, wave trapping unit 6, coupling unit 8) of the device positioned between the generator and the enclosure 1.

[0083] As previously stated, the switching unit 4 of the system according to the invention allows the first and second enclosures 1, 1' to be connected alternately to the generator 2 according to the following operating principle.

[0084] In a first step, the first and second reaction chambers 1,1' are loaded with product to be treated.

[0085] The switching unit 4 is then moved by appropriate means (motor(s), cylinder(s), etc.) into the first extreme position: - the first connection cell 42 is connected to the inlet 121 of the first enclosure 1, and - the second connection cell 43 is connected to the output opening 22 of generator 2.

[0086] Advantageously, the switching unit 4 may include safety contactors to detect whether the first and second connection cells 42, 43 are correctly connected to the inlet 121 and the outlet opening 22, the activation of the generator 2 being permitted only when a correct connection is detected.

[0087] When the switching unit 4 is in the first extreme position, the generator 2 is activated to produce electromagnetic waves. These electromagnetic waves propagate towards the outlet of the generator 2 at the outlet opening 22, enter the second connecting cell 43, pass through the waveguide 41, enter the first connecting cell 42, and exit into the first reaction chamber 1 at the inlet 121. The first mixing unit 3 mixes the product during the application of the electromagnetic waves for the treatment of said product.

[0088] When the product has been processed, generator 2 is deactivated.

[0089] The switching unit 4 is then moved from the first extreme position to the second extreme position. In particular, the switching unit 4 is moved in translation along a direction parallel to a longitudinal axis A-A' (and in the opposite direction to the first enclosure 1) to dissociate: - the first connection cell 42 of the upper partition 12 of the first enclosure 1, and - the second connection cell 43 of the upper plate of the protective housing 21.

[0090] Once the first and second connection cells 42, 43 are dissociated from the first enclosure 1 and the generator 2, the switching unit 4 is moved in translation along a direction perpendicular to the longitudinal axis A-A' such that: - the first connection cell 42 is positioned directly above the output opening 22 of generator 2, and - the second connection cell 43 comes to the right of the entrance mouth 121' of the second enclosure 1'.

[0091] When the first and second cells are correctly positioned above the outlet opening 22 and the inlet mouth 121' respectively, the displacement means induce translational displacement along a direction parallel to the longitudinal axis A-A' (towards the second enclosure 1') so that: - the first connection cell 42 is connected to the output opening 22 of generator 2, and that - the second connection cell 43 is connected to the inlet mouth 121' of the second enclosure 1'.

[0092] When the switching unit 4 is in the second extreme position, the generator 2 is activated to produce electromagnetic waves. These electromagnetic waves propagate towards the outlet of the generator 2 at the outlet opening 22, enter the first connecting cell 42, pass through the waveguide 41, enter the second connecting cell 43, and exit into the second reaction chamber 1' at the inlet 121'. The second mixing unit 3' mixes the product during the application of electromagnetic waves for the treatment of said product.

[0093] During the application of electromagnetic waves to the product contained in the second enclosure 1', an operator can carry out maintenance operations in the first enclosure 1 (extraction of the treated product, cleaning of the first enclosure 1, reloading of the first enclosure 1 with a new product to be treated, etc.) without risk of being irradiated by the electromagnetic waves generated by the generator 2.

[0094] Once the product contained in the second enclosure 1' has been processed, the generator 2 is deactivated, the switching unit 4 is moved to the first extreme position, and the generator 2 is reactivated to process the product contained in the first enclosure 1. The operator can then carry out the necessary maintenance operations in the second enclosure 1' without risk to his safety.

[0095] These different operations can be repeated to allow batch processing of a product in the first and second chambers 1, 14 from a single generator 2.

[0096] The reader will have understood that numerous modifications can be made to the invention described above without materially departing from the new teachings and advantages presented here. For example, the treatment system described above may comprise more than two enclosures. Brief description of the drawings

[0097] Other advantages and features of the invention will become clearer from the following description of several embodiments, given by way of non-limiting examples, based on the accompanying drawings in which: - Figure [1] is a general schematic representation of a device for processing a product using electromagnetic waves, - Figure [Fig. 2] is a schematic representation of a processing system according to the invention for the preparation of a dry plant biomass extract, - Figure [Fig. 3a] is a schematic representation of a switching unit of the processing system illustrated in Figure [Fig. 2], said switching unit being in a first extreme position, - Figure [Fig. 3b] is a schematic representation of the switching unit in a second extreme position, - Figure 4 is a schematic representation of a connection cell of the switching unit illustrated in Figures 3a and 3b. - Fig. 5 is a schematic perspective representation of the switching unit illustrated in figures 3a and 3b.

Claims

Demands

1. A plant biomass treatment system, the treatment system comprising: - of the first and second enclosures (1, 1') intended to contain the plant biomass to be treated, each of the first and second enclosures (1, 1') comprising a lower partition (11, 11'), an upper partition (12, 12') and at least one lateral partition (13, 13') extending between the upper and lower partitions (11, 12; 11', 12'), the upper partition (12, 12') including a through-inlet (121, 121'), - a generator (2) for the production of electromagnetic waves, the generator (2) comprising a protective casing (21), at least one source of electromagnetic waves housed in the protective casing (21), and an outlet opening (22) provided in an upper plate of the protective casing (21), - the first and second mixing units (3, 3') contained respectively in the first and second enclosures (1, 1'), characterized in that the processing system further comprises a switching unit (4) including: - a tubular waveguide (41) for the circulation of electromagnetic waves between the generator (2) and the first and second enclosures (1, 1'), and - the first and second connection cells (42, 43) arranged at a respective end of the waveguide (41), said switching unit (4) being movable between: - a first extreme position in which the first connecting cell (42) is connected to the inlet (121) of the first enclosure (1) and the second connecting cell (43) is connected to the outlet (22) of the generator (2) so that the electromagnetic waves produced by the generator (2) are transmitted to the first enclosure (1) via the switching unit (4), and - a second extreme position in which the first cell (42) is connected to the outlet opening (22) of the generator (2) and the second connecting cell (43) is connected to the inlet mouth (121') of the second enclosure (1') so that the electromagnetic waves produced by the generator (2) are transmitted to the second enclosure (1') via the switching unit (4).

2. Processing system according to claim 1, further comprising a metal plate including first, second and third aligned through lights of identical dimensions, the distance between the centers of the first and second through lights being equal to the distance between the centers of the second and third through lights: - the first light being connected to the inlet (121) of the first enclosure (1), - the second light being connected to the outlet (22) of the generator (2), and - the third light being connected to the inlet (121') of the second enclosure (1'), the switching unit (4) being in contact with the metal plate in the first and second extreme positions.

3. A processing system according to any one of claims 1 or 2, wherein each of the first and second connecting cells (42, 43) comprises a rectangular-shaped, loop-curved metal frame, said frame including an electromagnetic wave inlet / outlet slot, the dimensions of said frame being determined so that electromagnetic waves entering the metal frame at the inlet / outlet slot emerge from said metal frame in opposite phase at the inlet / outlet slot.

4. A processing system according to claims 2 and 3 taken in combination, wherein the frame comprises: - an outer face (422) extending perpendicularly to the metal plate, - an inner face (424) parallel to the outer face (422), the distance between the metal plate and the edge (424b) of the inner plate (424) closest to the metal plate being non-zero when the switching unit (4) is in the first or second extreme position, - an upper plate (423) between the outer and inner plates (422, 424), the edges (423a, 423b) of the upper plate (423) being connected to the edges (422b, 424a) of the outer and inner plates (422, 424) furthest from the metal plate, and - a lower plate (421) parallel to the upper plate (423), the lower plate extending between the outer and inner plates (422, 424) and including: • a connecting edge connected to the edge (424b) of the inner plate (424) closest to the metal plate, • a free edge opposite the connecting edge, so that the lower plate (421) extends opposite the metal plate,at a non-zero distance from said metal plate when the switching unit (4) is in the first or second extreme position, said lower plate (421) not being in contact with either the metal plate or the outer plate (422).

5. Processing system according to claim 4, wherein each pan is of overall rectangular shape, the sum of the widths of: - the outer pan, - the upper pan, - the inner pan, and - the lower pan being equal to a multiple of the wavelength of the electromagnetic waves plus one-quarter of the wavelength of said electromagnetic waves.

6. Processing system according to any one of claims 4 or 5, wherein the thickness of the panels is substantially equal to the thickness of the walls of the waveguide (41).

7. A processing system according to any one of claims 3 to 6, wherein each of the first and second connecting cells (42, 43) has a central channel of identical dimensions

8.

9. to the dimensions of the first second and third through lights, the center distance between the first and second connecting cells (42, 43) being equal to the distance separating the centers of the first and second through lights. A processing system according to any one of claims 1 to 7, further comprising means for moving the switching unit (4) between the first and second extreme positions, said means for moving the unit between the first and second extreme positions being configured to carry out the following operations successively, when the switching unit (4) is in the first extreme position: - move the switching unit (4) vertically so as to: • Disconnect the first connecting cell (42) from the inlet (121) of the first enclosure (1), and • Disconnect the second connection cell (43) from the output opening (22) of the generator (2), - move the switching unit (4) horizontally so that: • Position the first connection cell (42) directly opposite the output opening (22) of the generator (2), and • Position the second connection cell (43) opposite the entrance mouth (121') of the second speaker (1'), - move the switching unit (4) vertically so as to: • Connect the first connection cell (42) to the output opening (22) of the generator (2), and • connect the second connection cell (43) to the inlet mouth (121') of the first enclosure (1'). A processing system according to claim 8, wherein the switching unit further comprises at least one sensor for detecting whether the switching unit (4) is in the first extreme position or the second extreme position, the generator being able to be activated for the production of electromagnetic waves only if said sensor and at least one sensor have detected that the switching unit (4) is in the first extreme position. extreme position or the second extreme position.

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