Microwave device for extracting volatile substances

Abstract

The invention relates to a device for extracting a liquid composition from an organic material, comprising: (i) a microwave chamber (2) comprising: a microwave extraction chamber (9) having an inlet (17a) and an outlet (17b) for the organic material, and a collection opening (3a) at the bottom thereof for collecting the liquid composition, a microwave generation chamber (13) separated from the microwave extraction chamber (9), (ii) at least one microwave generator (14), the heating device is used for heating organic materials in the microwave extraction chamber (9); (iii) an inlet duct (16a) opening into the inlet (17a) of the microwave extraction chamber (9) and an outlet duct (16b) extending from the outlet (17b) of the microwave extraction chamber (9), (iv) a transport mechanism (15) for transporting organic material through the inlet duct (16a), the microwave extraction chamber (9) and the outlet duct (16b).

Description

Field of the Invention

[0001] The present invention relates to the fields of perfumes, flavorings, and industrial ingredients. More specifically, the present invention relates to a method for microwave-assisted extraction of extracts for the manufacture or formulation of perfumes, flavorings, and / or industrial ingredients. Background Art

[0002] Microwave (MW) extraction is an environmentally friendly and advantageous method for extracting compounds from natural biomass without the use of solvents. It is particularly suitable for extracting volatile substances and food-grade compositions.

[0003] For industrial applications, continuous microwave extraction is generally preferred over batch (intermittent) processing.

[0004] Unfortunately, existing continuous microwave extraction devices for solid / liquid cannot provide safe extraction conditions for operators and / or other workers in the vicinity. In fact, the human body is mainly composed of water and is very sensitive to microwaves, especially the brain, lungs, heart, or eyes. For industrial microwave ovens operating in the 2450 MHz frequency band, the average specific absorption rate (SAR) of human body exposure must be limited to less than 0.4 W / kg, and the power density should not exceed 50 W / m 2 (5 mW / cm 2 )(Directive 2004 / 40 / EC; ICNIRP, 1998).

[0005] The usual method of protecting operators is to provide them with some personal protective devices or to reduce their exposure time to microwaves during the operation of the device.

[0006] It is necessary to provide safer working conditions for industrial-scale extraction using microwave devices.

[0007] Due to the increase in the temperature of the device, operators are also at risk of burns. This not only exposes workers to the danger of burns but also forms hot spots inside the raw materials, thereby reducing the extraction quality. In fact, during microwave extraction, the uniformity of raw material processing is also a challenge. Hot spots can char the raw materials, produce off-flavors, and reduce the extraction quality.

[0008] Another major problem associated with the increase in the temperature of the device is the limitation of its working time. In existing microwave extraction devices, it is usually necessary to regularly stop the extraction pipeline to reduce the temperature of the device. This severely limits the production efficiency.

[0009] There is a need for a microwave device that can not only provide safer working conditions for operators but also provide a continuous extraction process and uniformly process the raw materials. Summary of the Invention

[0010] One form relates to an apparatus for extracting a liquid composition from an organic material, comprising:

[0011] A microwave cavity, which comprises:

[0012] A microwave extraction chamber, which has an inlet and an outlet for the organic material, and a collection port at its bottom for collecting the liquid component,

[0013] A microwave generation chamber, which is separated from the microwave extraction chamber,

[0014] At least one microwave generator, which is used to heat the organic material in the microwave extraction chamber;

[0015] An inlet pipe, which opens into the inlet of the microwave extraction chamber, and an outlet pipe, which extends from the outlet of the microwave extraction chamber,

[0016] A conveying mechanism, which is used to convey the organic material through the inlet pipe, the microwave extraction chamber and the outlet pipe.

[0017] The microwave cavity, particularly the microwave generation chamber, may comprise at least one microwave generator.

[0018] At least one microwave generator may be arranged outside the microwave cavity.

[0019] At least one microwave generator may be connected to the microwave generation chamber via at least one waveguide.

[0020] In one embodiment, at least part of the inlet pipe and / or at least part of the outlet pipe are arranged outside the microwave cavity. In other words, preferably the microwave cavity does not include or contain at least part of the inlet pipe and / or at least part of the outlet pipe.

[0021] In one embodiment, the conveying mechanism extends into and out of the microwave cavity. Thus, the microwave cavity does not include or contain the complete conveying mechanism.

[0022] The conveying mechanism may extend along a path, where only a part of the path extends inside the microwave cavity. The remaining part of the path may extend on the side and / or below the microwave cavity.

[0023] At least the outlet pipe may be provided with a cooling mechanism for cooling the wall of at least part of the outlet pipe.

[0024] The outlet pipe may be arranged such that the liquid condensed in the outlet pipe flows towards the bottom of the microwave extraction chamber.

[0025] The inlet pipe and / or the outlet pipe may include at least one microwave trap.

[0026] The microwave trap may extend and / or cover at least 10%, or at least 25%, or at least 50%, or at least 75%, or at least 90%, or 100% of the longitudinal extension of the inlet pipe, wherein the longitudinal extension is preferably parallel to the extension and / or conveying direction of the conveying mechanism within the inlet pipe.

[0027] The microwave trap may extend and / or cover at least 10%, or at least 25%, or at least 50%, or at least 75%, or at least 90%, or 100% of the longitudinal extension of the outlet pipe, wherein the longitudinal extension is preferably parallel to the extension and / or conveying direction of the conveying mechanism within the outlet pipe.

[0028] The microwave trap can be an absorptive, reactive or hybrid microwave trap.

[0029] The inlet pipe and / or the outlet pipe may include two microwave traps, the microwave trap closer to the microwave extraction chamber is a reactive trap, and preferably, the microwave trap farther from the microwave extraction chamber is an absorptive trap.

[0030] The microwave transparent cover can hermetically separate the microwave extraction chamber from the microwave chamber.

[0031] The apparatus may include a mechanism for reducing the pressure within the microwave extraction chamber and directing the vapor to a condenser to condense the generated vapor.

[0032] The mechanism for reducing the pressure may be arranged to reduce the pressure below the conveying mechanism, for example, to create a vacuum below the conveying mechanism. Thus (i.e., via a pressure differential), a fluid flow (e.g., downward) may be provided through the conveying mechanism and / or toward the collection port and / or the bottom of the microwave extraction chamber, for example, to collect the liquid component in liquid and / or vapor form.

[0033] The mechanism for reducing the pressure may be a condenser.

[0034] The organic material arranged on the conveyor can be heated from above by at least one microwave generator (eg at least one microwave generator is arranged above the conveyor), wherein, optionally, the pressure can be reduced on the other side of the conveyor, ie below the conveyor.

[0035] By heating the organic material on the conveyor mechanism, the pressure in the microwave extraction chamber can be increased, which helps to guide the vapor to the condenser, so that the generated vapor condenses. For example, the pressure above the conveyor mechanism can be increased. In this way, and in combination with the lower pressure below the conveyor mechanism (which lower pressure can be reduced by using the mechanism for reducing pressure), a fluid flow (e.g., downward) can be provided through the conveyor mechanism and / or toward the collection port and / or the bottom of the microwave extraction chamber, for example, for collecting liquid components in liquid and / or vapor form.

[0036] The conveying mechanism includes a conveyor belt having a longitudinal axis that has an inclination of 0.5 to 60 degrees with respect to the horizontal plane at least within the microwave extraction chamber and the outlet duct.

[0037] The vapor nozzle in the microwave extraction chamber is preferably disposed on the sidewall of the microwave extraction chamber, above or near the conveyor belt.

[0038] The bottom of the inlet duct and / or the bottom of the outlet duct can be disposed at a height higher than the bottom of the microwave extraction chamber, preferably by means of a step.

[0039] The inlet duct can include a top wall and / or a bottom wall, from which one or more sidewalls extend respectively. Optionally, one or more sidewalls extend from the top wall to the bottom wall. Thus, on the one hand, the top wall and / or the bottom wall and, on the other hand, one or more sidewalls define a passage through which the conveying mechanism extends.

[0040] The microwave trap of at least a part of the inlet duct can be disposed in i) the top wall and / or the bottom wall, and / or ii) one or more sidewalls. At least a part of the microwave trap can be disposed in the top wall. At least a part of the microwave trap can be disposed in the bottom wall. At least a part of the microwave trap can be disposed in one or more sidewalls.

[0041] The outlet duct can include a top wall and / or a bottom wall, from which one or more sidewalls extend respectively. Optionally, one or more sidewalls extend from the top wall to the bottom wall. Thus, on the one hand, the top wall and / or the bottom wall and, on the other hand, one or more sidewalls define a passage through which the conveying mechanism extends.

[0042] The microwave trap of at least a part of the outlet duct can be disposed in i) the top wall and / or the bottom wall, and / or ii) one or more sidewalls. At least a part of the microwave trap can be disposed in the top wall. At least a part of the microwave trap can be disposed in the bottom wall. At least a part of the microwave trap can be disposed in one or more sidewalls.

[0043] Optionally, each duct can completely surround the conveying mechanism (such as the conveyor belt). In other words, each duct can completely surround the corresponding part of the extension path of the conveying mechanism.

[0044] The device can have a housing. The housing is arranged to ensure a reduction in the loss of volatile substances and / or to ensure a reduction in the loss of microwaves, i.e., to shield microwaves. The housing can accommodate or house the microwave extraction chamber, the inlet duct, the outlet duct, and / or the conveying mechanism.

[0045] The device can have an input end and an output end, through which the conveying mechanism can be loaded at the input end and unloaded at the output end. The input end can be provided by the housing. The output end can be provided by the housing.

[0046] The microwave cavity, in particular the microwave extraction chamber and the microwave generation chamber, may contain one or more completely microwave-transparent components. This has the advantage of reducing hot spots in the microwave cavity and providing a uniform microwave field. In addition, the use of microwave-opaque materials is reduced. The one or more components may include conveyor rollers, nozzles (e.g., steam nozzles), and / or operating structures (e.g., handles) of the conveyor mechanism. In one embodiment, all (machine) components placed in the microwave cavity are microwave-transparent.

[0047] In summary, the device specifically achieves the following advantages:

[0048] Particularly good extraction of liquids from the raw material by means of conveying mechanisms or by condensation of vapor, wherein the liquids can be used as flavoring and / or aroma products;

[0049] Avoiding the loss of vapors, in particular by ensuring that the loss of volatile substances is reduced by means of mechanisms for reducing the pressure, transparent covers and / or casings;

[0050] Avoiding microwave losses, in particular by preferably inlet and / or outlet ducts, and / or housings, with microwave traps, can at least help to avoid such losses;

[0051] Reduction of hot spots within the microwave cavity and formation of a particularly homogeneous microwave field, which can be enhanced by using materials made of microwave-transparent materials within the cavity (extraction chamber and / or generation chamber), such as the materials of the transfer rollers, nozzles, handles, etc.;

[0052] Reduce microwave opaque materials.

[0053] Another aspect relates to a method for extracting a liquid composition from an organic material, comprising the steps of:

[0054] (a) introducing an organic material into a central chamber positioned to receive microwave radiation from at least one microwave generator;

[0055] (b) reducing the pressure in the microwave extraction chamber to below atmospheric pressure;

[0056] (c) optionally, spraying steam onto the organic material;

[0057] (d) collecting vapor to be condensed by a condenser, and collecting liquid produced in the microwave extraction chamber and the condenser in a collection tank;

[0058] (e) Removing the processed organic material from the central chamber.

[0059] Yet another aspect relates to a method of extracting a liquid composition from an organic material by using the apparatus described above.

[0060] The method may include the following steps: raising the pressure in the central chamber (i.e., the microwave extraction chamber) to above atmospheric pressure. The raised pressure may be carried out in a region different from the region where the pressure is reduced. For example, the central chamber may be divided into an upper part and a lower part by a transfer mechanism, wherein, in the upper part, the organic material is arranged to receive microwave radiation; in the upper part, the pressure is raised; in the lower part, the pressure is reduced, for example, to provide a vacuum. This causes fluid (e.g., downward) to flow from the upper part to the lower part, for example, through the transfer mechanism, for collecting vapor and / or liquid.

[0061] Reducing the pressure may cause the pressure below the organic material in the central chamber to be reduced, for example, creating a vacuum below it. Thereby (i.e., through the pressure difference), fluid (e.g., downward) can be provided to convey the organic material through the transfer mechanism and / or flow to the condenser and / or the bottom of the microwave extraction chamber, for example, for collecting the liquid components in the form of liquid and / or vapor into a collection tank.

[0062] The mechanism for reducing the pressure may be a condenser.

[0063] The organic material in the central chamber (e.g., the organic material arranged on the transfer mechanism) can be heated by microwave radiation from above (e.g., at least one microwave generator is arranged above the transfer mechanism and / or the organic material in the central chamber), wherein, optionally, on the opposite side of the organic material and / or the transfer mechanism, i.e., below the organic material and / or the transfer mechanism, the pressure can be reduced.

[0064] By heating the organic material in the central chamber (preferably the organic material on the transfer mechanism), the pressure in the central chamber can be increased, which helps to direct the vapor to the condenser, thereby condensing the generated vapor or steam (water vapor). For example, the pressure above the organic material and / or the transfer mechanism can be increased. In this way, and through the lower pressure below the organic material and / or the transfer mechanism (which can be reduced by using the pressure reducing device), fluid (e.g., downward) can be provided to flow through the transfer mechanism and / or flow to the condenser and / or the collection tank and / or the bottom of the microwave extraction chamber, for example, for collecting the liquid components in the form of liquid and / or vapor into a collection tank.

[0065] One form relates to a device for extracting a liquid composition from an organic material, comprising:

[0066] (i) A microwave cavity, which includes:

[0067] - A microwave extraction chamber, which has an inlet and an outlet for the organic material, and a collection port at its bottom for collecting the liquid components,

[0068] - A microwave generation chamber, which is separated from the microwave extraction chamber,

[0069] (ii) At least one microwave generator for heating the organic material in the microwave extraction chamber;

[0070] (iii) An inlet duct opening into the inlet of the microwave extraction chamber and an outlet duct extending from the outlet of the microwave extraction chamber,

[0071] (iv) A conveying mechanism for conveying the organic material through the inlet duct, the microwave extraction chamber, and the outlet duct. Description of the Drawings

[0072] Figure 1 is a longitudinal sectional view of an embodiment of the device.

[0073] Figure 2 is a longitudinal sectional view of a second embodiment of the device.

[0074] Figure 3 is a longitudinal sectional view of a third embodiment of the device. Detailed Description of the Invention

[0075] In the following description and drawings, corresponding and similar components are denoted by the same reference numerals, and specific details will be set forth so that those skilled in the art can understand more thoroughly. However, in order to avoid unnecessarily obscuring the present disclosure, some well-known elements may not be shown or described in detail. Therefore, the description and drawings should be regarded as illustrative rather than restrictive.

[0076] The extraction device 1 includes a microwave cavity 2 in which the organic material is heated by microwaves generated by one or more microwave generators 14, thereby releasing substances from the organic material and extracting a liquid composition containing the substances. Then, the liquid composition is made to leave the microwave cavity 2 and collected in a collection tank 3.

[0077] The device 1 has an input end 4 and an output end 5 of the travel path for passing the organic material through the device, wherein at the input end 4 there is a raw organic material loading module 6, and at the output end 5 there is a processed organic material unloading module 7. According to one embodiment, the device 1 has a housing 8 located on a support frame (not shown).

[0078] The microwave extraction chamber 9 with openings on both sides axially extends into the inlet channel 16a and the outlet channel 16b at its inlet 17a and outlet 17b respectively. The microwave transparent cover 10 made of microwave transparent material forms the top plate inside the microwave extraction chamber 9.

[0079] According to the present invention, the microwave transparent material (such as a microwave transparent cover or a microwave transparent layer or a microwave transparent transmission mechanism) includes 1,2-polybutadiene (PBD, 1,2-polybutadiene), polyisoprene, polybutadiene-polyisoprene copolymer, polyetherimide (PEI, polyetherimide), polytetrafluoroethylene (PTFE, polytetrafluoroethylene) and other fluoropolymers, polyimide, polyetheretherketone (PEEK, polyetheretherketone), polyamideimide, polyethylene terephthalate (PET, polyethylene terephthalate), polyethylene naphthalate, polycyclohexyl terephthalate, polybutadiene-polyisoprene copolymer, polyphenylene ether, alkylated polyphenylene ether (polymer based on polyphenylene ether) or a combination thereof. Combinations of high and low polarity can be used, including epoxy and polyphenylene oxide, epoxy and polyetherimide, cyanate ester and polyphenylene oxide (non-limiting examples include cyanate ester and polyphenylene oxide), and 1,2-polybutadiene and polyethylene. The microwave transparent layer preferably comprises PEEK and / or PTFE (PEEK / PTFE-5).

[0080] The microwave extraction chamber 9 has a bottom 11 that can be tilted relative to the horizontal plane and is provided with a collection pipe opening 3a. The opening is preferably placed near the side wall 12 of the microwave extraction chamber 9 for collecting liquid; if the bottom is tilted, it is preferably near the lower end of the bottom 11 of the microwave extraction chamber 9. The side wall 12 is provided with an opening whose size is substantially the same as the inlet pipe and the outlet pipe, and is connected to the inlet pipe and the outlet pipe 16a and 16b respectively. Typically, the inner surface of the side wall 12 and the bottom 11 of the microwave extraction chamber 9 contains a material that reflects microwaves, such as a metal, typically copper, steel, aluminum, lead tin, zinc, brass, gold or silver.

[0081] At least the bottom of the microwave extraction chamber and / or the outlet duct may be horizontal or preferably inclined, and is preferably planar.

[0082] The longitudinal extension of each inlet duct and / or outlet duct is preferably at least 20%, preferably at least 40%, more preferably at least 60% of the extension (eg longitudinal extension) of the microwave cavity.

[0083] The longitudinal extension may be an extension parallel to the extension and / or transport direction of the conveying mechanism within the inlet duct, the microwave extraction chamber and / or the outlet duct.

[0084] The longitudinal extension length of the inlet duct is preferably at least 200%, preferably at least 400%, and more preferably at least 600% of the diameter of the microwave cavity side wall inlet opening. The longitudinal extension length of the outlet duct is preferably at least 200%, preferably at least 400%, and more preferably at least 600% of the diameter of the microwave cavity side wall outlet opening.

[0085] The longitudinal extension length of each inlet duct and / or outlet duct is preferably at least 200%, preferably at least 400%, more preferably at least 600% of the average diameter of the inlet and outlet openings in the side walls of the microwave cavity.

[0086] The longitudinal extension length of each inlet duct and / or outlet duct is preferably less than 150%, preferably less than 100%, more preferably less than 80% of the extension length (e.g., longitudinal extension length) of the microwave cavity.

[0087] The cross-sectional surface of the inlet duct and / or outlet duct is preferably smaller than the cross-sectional surface of the microwave cavity, preferably at least 20% or at least 40% smaller. Each cross-sectional surface may extend perpendicular to the longitudinal extension direction and / or the conveying direction of the conveying mechanism, along which the conveying mechanism conveys the organic material through the inlet duct, the microwave extraction chamber, and the outlet duct.

[0088] Preferably, the inlet duct and the outlet duct extend along the central axis of the microwave cavity. The conveyor belt 15 is arranged in the lower half of these ducts.

[0089] The cross-sectional shape of the inlet duct and the outlet duct can be circular or preferably rectangular.

[0090] The microwave generating chamber 13 is arranged above the microwave transparent cover 10 and the microwave extraction chamber 9. The microwave generating chamber 13: a) contains one or preferably a plurality of microwave generators 14, and the generated microwave radiation passes through the microwave transparent cover 10 separating the microwave generating chamber 13 and the microwave extraction chamber 9; or b) is connected to one or preferably a plurality of waveguides, or contains at least a part of each waveguide, and the waveguides are respectively connected to one or preferably a plurality of microwave generators 14, and the microwave generators 14 can be arranged outside the microwave generating chamber 13. The microwave transparent cover 10 seals and separates the microwave extraction chamber from the microwave chamber, so that for example, vapors or any volatile substances do not leak from the microwave extraction chamber 9 into the microwave generating chamber 13. The microwave generating chamber 13 is sealed from the microwave extraction chamber 9 but not from the atmosphere, and thus is filled with air and at atmospheric pressure. A preferably motor-driven microwave stirrer (not shown in the figure) is provided in the microwave generating chamber 13 for dispersing the generated microwaves to promote the uniform distribution of microwaves in the container. The microwave extraction chamber 9. Typical microwave stirrers include: a motor with an output shaft; and stirring blades, which have a central fixed part connected to the output shaft, and a fin extending radially outward. The teachings of EP1566986B1 are incorporated by reference as possible implementations of such microwave stirrers.

[0091] The conveyor mechanism includes at least one conveyor belt 15, conveyor rollers 15a, 15b, and 7a for guiding and supporting the conveyor belt, and a conveyor belt drive control system, which is used to continuously transport the organic material to be extracted from the loading module 6 through the inlet conduit 16a to the microwave cavity 2, the microwave extraction chamber 9, and the outlet conduit 16b at a controllable speed. In the microwave extraction chamber 9, the conveyor belt 15 extends substantially parallel to the lid 10, so that the organic material loaded on top of the conveyor belt 15 is in close contact with the lid 10, or even in direct contact. The conveyor belt 15 extends into the loading module 6 and the unloading module 7 (described below) and forms a continuous loop, for example, by running under the microwave cavity 2 and the inlet conduit 16a and outlet conduit 16b. The conveyor belt 15 is designed to be permeable to the liquid extracted from the raw material, for example by having pores or other openings or structural features that retain the processed organic material while allowing the liquid to drain by gravity. Typically, the average diameter (d) of the pores in the conveyor belt is 0.001 to 30 mm, preferably 0.01 to 20 mm. During the microwave heating extraction process, the organic material remains on the conveyor belt, while the liquid is discharged from the organic material and reaches the bottom of the microwave extraction chamber 9.

[0092] The path of the conveyor belt 15 can be inclined, preferably upwardly inclined along the direction of travel, at least in the microwave extraction chamber and / or the outlet conduit. The inclination angles of these regions can be the same or different. Preferably, the non-zero inclination angles in the inlet conduit, microwave extraction chamber, and outlet conduit are substantially the same.

[0093] The microwave extraction chamber 9 comprises at least one steam nozzle. In order to facilitate the extraction of soluble compounds from the organic material, water vapor is injected into the microwave extraction chamber 9 through a nozzle 18. The nozzle 18 is preferably arranged on one or two originally closed side walls of the microwave extraction chamber 9 (these side walls are arranged perpendicular to the open side walls) and is located below the cover 10. The nozzle position is preferably located substantially at the height of the organic material above the conveyor belt 15. Some nozzles can be placed below the height of the conveyor belt 15. The addition of steam is particularly important when extracting compounds from dry biomass or biomass with a low water content (such as seeds, berries, or spices).

[0094] The loading module 6 has a raw organic material feed distributor, such as a hopper 6a, which is located above the conveyor belt 15 and is configured to drop the raw organic material to be processed onto the conveyor belt 15. The conveyor belt 15 runs on conveyor rollers 15a in the loading module 6. Advantageously, the conveyor rollers are made of microwave transparent material or embedded in microwave transparent material.

[0095] A raw material supply tank (not shown) is connected to the raw material feed distributor 6a via a feed pipe. A feed controller may be provided to control the flow of raw material into the distributor. The supply tank is maintained at atmospheric pressure. The raw material is typically solid organic material, such as biomass, fruit, flowers, leaves, seeds, etc., and is therefore in bulk form. The raw material can be loaded onto the conveyor belt 15 via a pipe, screw conveyor, or other conveying mechanism capable of transporting the material to the conveyor belt 15.

[0096] The inlet pipe 16a opening into the inlet 17a of the microwave extraction chamber 9 is particularly advantageous because the organic material fills or thickens the thin part of the pipe before reaching the microwave extraction chamber 9 and reduces the leakage of microwaves to the outside of the microwave cavity 2. The height of the inlet pipe 16a can be lower than the height of the microwave extraction chamber 9 and the outlet pipe.

[0097] To prevent steam loss, and thus loss of volatile substances extracted from the raw materials, the loading module 6, and in particular the feed distributor 6a, can be sealed from the feed tank. The loading module's interior opening leads to the microwave cavity 2, and is therefore under reduced pressure during operation. An observation window (not shown) in the housing 8 allows for visual inspection of the loading module 6 and microwave extraction chamber 9.

[0098] An outlet pipe 16 b extends from the outlet 17 b of the microwave extraction chamber 9 to promote cooling of the processed organic material and complete the extraction of remaining volatile substances before reaching the unloading module 7 .

[0099] The bottom of outlet conduit 16b is preferably inclined toward microwave cavity 2 and positioned above the bottom of microwave cavity 2, preferably in a stepped downward direction, to facilitate the flow of condensed liquid back into microwave cavity 2 and to outlet 17b at its bottom. To facilitate the flow of liquid from the wall of outlet conduit 16b to microwave extraction chamber 9, the central axis of microwave cavity 2 and outlet conduit 16b is inclined at a degree of 0.5 to 40, preferably 2 to 10, to the ground.

[0100] The outlet conduit 16b may be provided with its own outlet pipe (not shown) at its bottom, which may be communicated with a tank, such as the collection tank 3 which is in fluid communication with the collection conduit 3b at the bottom of the microwave extraction chamber 9 .

[0101] Advantageously, in order to accelerate the cooling of the feedstock and the condensation of volatile substances on the side walls of the outlet duct 16b, a cooling system 19 is arranged, for example, in the side walls and / or ceiling and / or bottom of the outlet duct 16b.

[0102] The inlet and outlet pipes 16a, 16b also reduce the level of microwaves escaping from the microwave extraction chamber 9. To further reduce microwave leakage from the microwave extraction chamber 9, a microwave trap 20 is placed at least in the outlet pipe, preferably in both the inlet and outlet pipes 16a and 16b. Typically, the microwave trap 20 is an absorption trap, a reaction trap, or a hybrid trap, preferably a hybrid trap.

[0103] A reactive trap is characterized by a set of metal components, usually cylindrical in shape, arranged in a way that attenuates wave leakage. The number, height, diameter, and position of the metal components are related to the geometry of the device.

[0104] Absorption traps suitable for use in the present invention have the characteristics of microwave absorbing plates. Typically, the microwave absorbing plates are dielectrically heated by microwave leakage and are preferably combined with a cooling system 19. The absorption traps according to the present invention comprise metal or mineral powders selected from ferrite powder, silicon carbide powder, aluminum oxide powder, calcium oxide powder, magnesium oxide powder, titanium oxide powder, zirconium oxide powder, silica powder, kaolin, feldspar, gypsum, graphite, or combinations thereof. The metal or mineral powder has an average diameter of 5 to 100 μm. Typically, the absorbent trap comprises a mixture of the metal or mineral powder and an insulating material, preferably a mixture of metal powder and an insulating material. The insulating material is a natural or synthetic polymer, typically rubber, and the metal powder is ferrite powder.

[0105] According to another embodiment, the absorption trap is a cooling system 19 comprising a network of pipes, typically polymer pipes (eg polyvinyl chloride) that convey an absorbent liquid (advantageously water).

[0106] Advantageously, the trap system is a hybrid trap, which is a mixture of a reactive trap and an absorptive trap.

[0107] Examples of reactive, absorptive or hybrid traps suitable for the present invention are described in CN202282884, CN214481362, CN102752892 or US4182946.

[0108] According to the first embodiment of the pipeline ( Figure 1 and Figure 2 In the first part of the pipeline close to the microwave extraction chamber 9, a reactive trap is placed, and in the second part of the pipeline away from the microwave extraction chamber 9, an absorptive microwave trap is placed. According to this embodiment, the cooling system can be limited to the outlet pipeline portion away from the microwave cavity ( Figure 1 (shown in the inlet pipe), or a cooling system can be added to the entire outlet pipe ( Figure 1According to another embodiment, the microwave trap can be placed in the part of the pipe closest to the central cavity. Similarly, according to this second embodiment, the cooling system can be placed only on the outer wall of the pipe with the microwave trap ( Figure 2 outlet pipe), or on the entire outer wall of the pipe ( Figure 1 According to another embodiment, the cooling system is arranged on the outer wall of all pipes except the bottom of the pipe.

[0109] Microwave shielding of the device's housing 8 is optional, as the microwave traps 20 of the inlet and outlet conduits 16a and 16b effectively capture microwaves escaping from the microwave extraction chamber 9. However, this housing 8 is still highly advantageous depending on factors such as raw material safety, microbiology, and extraction yield.

[0110] According to another embodiment, the microwave cavity 2 comprises doors (not shown), preferably sliding doors, located at the inlet 17a and outlet 17b of the microwave extraction chamber 9. Such doors facilitate working in batch mode.

[0111] Advantageously, the central axis of the conveyor belt is inclined so that the liquid in the processed raw material flows along the conveyor belt to the microwave extraction chamber 9. Typically, the conveyor belt is inclined at least within the microwave extraction chamber 9, preferably at least from the inlet 17a of the microwave extraction chamber 9 to the opening 16c of the outlet pipe 16b, and optionally from the inlet 17a of the microwave extraction chamber 9 to the unloading module 7. Some measures can be used to prevent the liquid from flowing along the conveyor belt beyond the inlet opening 17a of the microwave extraction chamber 9. For example, the bottom of the inlet pipe is placed at a higher position than the bottom of the microwave extraction chamber 9. Typically, the axis of the conveyor belt is inclined by 0.5 to 60 degrees to the ground, preferably by 2 to 10 degrees.

[0112] Since the liquid extract is discharged from the organic material by gravity via the conveyor belt 15 located at the bottom of the microwave extraction chamber 9, it is particularly advantageous to form the conveyor belt 15 as a continuous loop extending below the microwave cavity 2. In addition, it is also conceivable to place another continuous loop on the side of the microwave cavity or inside the microwave cavity. It is conceivable to have a collection system for scraping the material on the surface of the conveyor belt before it leaves the microwave extraction chamber 9. It is also particularly advantageous to place a cooling system 19a in the wall of the microwave cavity to keep the liquid extract in liquid form and facilitate its collection in the collection pipe 3a. The cooling system 19a is also particularly beneficial for the continuous operation of the device.

[0113] Since the raw organic material is in close contact with the upper wall of the inlet duct 16a, the cover 10 of the microwave extraction chamber 9 and the outlet duct 16b, respectively, it is advantageous that the upper wall is protected by a microwave transparent layer made of a heat-resistant material.

[0114] The unloading module 7 is provided with a conveyor roller 7a for guiding the conveyor belt 15. A material collector 7c is located below the outer roller and is used to receive the processed material that comes from the outlet pipe 16b and falls from the conveyor belt 15. The drive roller 7a driven by a motor (not shown in the figure) drives the conveyor belt 15. The unloading module 7 is built into the device and is surrounded by a housing 8 ( Figure 1 and Figure 2 ), and the housing 8 is fixed and sealed to the output end 5 of the device 1; an observation window (not shown in the figure) can be arranged for visual inspection of the inside of the unloading module. The unloading module leads to the microwave extraction chamber 9 through the outlet pipe 16b, so it is in a decompressed state during the operation of the device.

[0115] Optionally, a screw conveyor 7b is located below the material collector 7c and is used to receive the processed material from the material collector 7c. The vacuum seal between the lower end of the material collector 7c and the screw conveyor 7b can maintain the vacuum in the microwave extraction chamber 9 and the screw conveyor 7b. The screw conveyor 7b is driven by a motor (not shown in the figure). An outlet valve (not shown in the figure) at one end of the screw conveyor 7b can be arranged to remove the processed material from the device 1. Such a valve can act as an air lock to allow the removal of the processed product. The container (7d) is preferably vacuum-sealed, used to receive the processed product, and is connected to the valve. One valve is opened at a time to allow one container 7d to receive the product from the screw conveyor 7b, while the other valve is closed to allow the removal of the filled container. The two valves are opened and closed alternately to allow the screw conveyor 7b to operate continuously.

[0116] A cooling system can also be arranged around the collection pipe 3b and the water tank 3.

[0117] The pump 3d is connected to the storage tank 3 and is used to suck the steam generated in the microwave extraction chamber 9 into the collection pipe 3b. In this way, the pressure in the storage tank can be reduced relative to the microwave extraction chamber. Ideally, a condenser is arranged before the vacuum pump 3d. The collection pipe 3b is connected to the condenser 3c, and the condenser 3c is in turn connected to the storage tank 3, and all the liquids extracted from the raw materials are stored in the storage tank 3.

[0118] The steam sucked from the microwave extraction chamber 9 is condensed by the condenser 3c, and the resulting liquid is stored in the tank 3.

[0119] The vacuum pump 3d reduces the pressure in the device 1 or at least in the microwave extraction chamber 9 to below atmospheric pressure, preferably to 0.99 to 0.001316 atmospheres, more preferably to 0.55 to 0.01316 atmospheres. This pressure difference is particularly beneficial for limiting the loss of steam, thereby reducing the loss of volatile substances in the device 1 or at least in the microwave extraction chamber 9. Extracting volatile substances from the microwave extraction chamber can also reduce the heating of volatile substances, thereby reducing potential degradation.

[0120] Alternatively, the water tank 3, the pump 3d, and the condenser 3c may be located within the housing 8 of the apparatus (see Figure 2 ).

[0121] As described above, the apparatus includes one or more cooling units (not shown) that include a compressor, a cooling fan, and a refrigerant pump, connected to convey refrigerant through refrigerant pipes extending along any and / or all walls of the microwave extraction chamber 9, the inlet pipe 16a, the outlet pipe 16b, the collection pipe 3b, and / or the tank 3.

[0122] According to the present invention, the apparatus 1 includes a programmable logic controller (PLC) that is programmed and connected to control the operation of the system, including controlling the inflow of raw materials, the motor, the microwave generator, the vacuum pump, and the refrigerant pump.

[0123] The extraction apparatus 1 operates according to the following method. The refrigerant pump, the microwave generator, the motor, and the raw material feed controller are all controlled by the PLC. The organic material to be processed is sent onto the conveyor belt 15 and is conveyed through the inlet pipe 16a and the inlet opening 17a to the microwave extraction chamber 9 located below the lid 10. The microwave intermediate frequency generated by the microwave generator is from 0.3 to 300 GHz, preferably from 0.5 to 5.2 GHz, from 0.8 to 3 GHz, and from 0.9 to 2.5 GHz. Typically, the microwave generator is a variable-frequency microwave generator. Advantageously, the microwave intermediate frequency generated by the microwave generator is 2450 MHz, and the power is from 300 W to 6000 W, preferably from 1000 W to 3000 W. According to another embodiment, the microwave intermediate frequency generated by the microwave generator is 915 MHz, and the power is from 300 W to 6000 W, preferably from 1000 W to 3000 W. The processing time can be in the range of 0.1 to 20 kg / h, typically 0.5 to 12 kg / h. Typically, the processing time is about 5 minutes to 2.5 hours, preferably 8 minutes to 2 hours, more preferably 10 minutes to 1 hour. The liquid flows through the conveyor belt 15 to the bottom of the microwave extraction chamber 9 and is collected at the collection port 3a and stored in the storage tank 3. The steam condenses on the side wall of the microwave extraction chamber 9 or the outlet pipe 16b, flows towards the side wall of the microwave extraction chamber 9, and reaches the collection pipe opening 3a at the bottom of the microwave extraction chamber 9. The radiation enhances the extraction of volatile substances, and the steam sprayed by the nozzle 18 onto the raw materials also enhances the extraction effect. The steam inhaled from the microwave extraction chamber 9 and the inlet pipe 16a and / or the outlet pipe 16b reaches the collection pipe 3b, is condensed by the condenser 3c, and is stored in the tank 3. The processed material falls into the material collector 7c, enters the screw conveyor 7b, and is discharged from the apparatus through the outlet valve 5.

Claims

1. An apparatus for extracting a liquid composition from an organic material, comprising: A microwave cavity (2), which includes: A microwave extraction chamber (9) having an inlet (17a) and an outlet (17b) for the organic material, and a collection port (3a) at its bottom for collecting the liquid composition, A microwave generation chamber (13) separated from the microwave extraction chamber (9), At least one microwave generator (14) arranged to heat the organic material in the microwave extraction chamber (9); An inlet pipe (16a) opening into the inlet (17a) of the microwave extraction chamber (9), and an outlet pipe (16b) extending from the outlet (17b) of the microwave extraction chamber (9), A conveying mechanism (15, 15a, 15b, 7a) for conveying the organic material through the inlet pipe (16a), the microwave extraction chamber (9) and the outlet pipe (16b).

2. The apparatus according to claim 1, wherein the microwave generation chamber (13) includes at least one microwave generator (14).

3. The apparatus according to claim 1 or 2, wherein one, more or all of the outlet pipe (16b), the microwave extraction chamber (9) and the conduit (3b) connected to the collection port (3a) are provided with a cooling mechanism.

4. The apparatus according to any one of the preceding claims, wherein the outlet pipe (16b) is arranged such that the liquid condensed in the outlet pipe (16b) flows towards the bottom of the microwave extraction chamber (9).

5. The apparatus according to any one of the preceding claims, wherein the inlet pipe (16a) and / or the outlet pipe (16b) includes at least one microwave trap.

6. The apparatus according to claim 5, wherein the microwave trap is an absorption type, reaction type or hybrid type microwave trap.

7. The apparatus according to any one of the preceding claims, wherein the inlet pipe (16a) and / or the outlet pipe (16b) includes two microwave traps, and the microwave trap closer to the microwave extraction chamber (9) is a reaction type trap, and preferably, the microwave trap farther from the microwave extraction chamber (9) is an absorption type trap.

8. The apparatus according to any one of the preceding claims, wherein a microwave transparent cover (10) seals and separates the microwave extraction chamber (9) from the microwave generation chamber (13).

9. The apparatus according to any one of the preceding claims, wherein the apparatus includes a mechanism for reducing the pressure in the microwave extraction chamber (9) and guiding the vapor to a condenser of the apparatus (1) to condense the generated vapor.

10. The apparatus according to any one of the preceding claims, wherein the conveying mechanism includes a conveyor belt 15 having a longitudinal axis, and the longitudinal axis has an inclination of 0.5 to 60 degrees with respect to the horizontal plane at least within the microwave extraction chamber (9) and the outlet pipe (16b).

11. The apparatus according to any one of the preceding claims, wherein the bottom of the microwave extraction chamber (9) and / or the outlet pipe (16b) has an inclination of 0.5 to 60 degrees with respect to the horizontal plane, and the lower end preferably faces the inlet of the microwave extraction chamber (9).

12. The apparatus according to any one of the preceding claims, wherein the microwave extraction chamber (9) comprises at least one steam nozzle, preferably arranged on the side wall of the microwave extraction chamber (9) above or in the vicinity of the conveyor belt (15).

13. The apparatus according to any one of the preceding claims, wherein the bottom of the inlet duct (16a) and / or the bottom of the outlet duct (16b) is arranged at a higher level than the bottom of the microwave extraction chamber (9), preferably by means of a step.

14. A method for extracting a liquid composition from an organic material, comprising the following steps: (a) introducing the organic material into a microwave extraction chamber arranged to receive microwave radiation from at least one microwave generator; (b) reducing the pressure in the microwave extraction chamber to below atmospheric pressure; (c) optionally, spraying steam onto the organic material; (d) collecting the steam to be condensed by a condenser and collecting the liquid produced by the microwave extraction chamber and the condenser in a collection tank; (e) removing the treated organic material from the microwave extraction chamber.

15. A method for extracting a liquid composition from an organic material, the method being carried out by using the apparatus (1) according to any one of claims 1 to 13.

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