Device and method for reducing water content in plant or animal inorganic and / or organic compounds

Abstract

The present invention relates generally to devices and methods for reducing the water content of inorganic and / or organic products or compounds of plant or animal origin, in particular to devices and methods for removing a majority of water present in products or compounds of plant or animal origin, the present invention relates to a method for preparing inorganic compounds or products to be used in other processes or to obtain finished products, such that it can be preserved (even over a long period of time) without undesirable fermentation and significant modifications in nutritional and organoleptic properties of organic compounds, and to prepare inorganic compounds or products to be used in other processes or to obtain finished products.

Description

Technical Field

[0001] The present invention generally relates to devices and methods for reducing the water content of inorganic and / or organic products or compounds of plant or animal origin, and in particular to devices and methods for removing a large part of the water present in products or compounds of plant or animal origin, so as to facilitate their preservation (even for long periods of time) without undesirable fermentation and significant changes in the nutritional and organoleptic properties of the organic compounds, and to prepare the inorganic compounds or products to be used for other processing or to obtain finished products. Background Art

[0002] In the prior art, two main methods are known for reducing the water content of inorganic and / or organic products or compounds of plant or animal origin: drying and freeze-drying.

[0003] Drying is the thermal treatment of an inorganic and / or organic product or compound (solid or liquid) of vegetable or animal origin in order to remove virtually all the water it contains (from a water content between 35% and 95% to a water content between 2% and 15%).

[0004] Drying can be carried out by artificial methods involving the use of devices or installations called dryers, which consist of an artificially heated and ventilated environment in which the inorganic and / or organic compounds to be treated are circulated or left to stand.

[0005] Industrial processes for producing dry inorganic and / or organic compounds involve thermal treatment involving the transfer of heat from a heating source to the product by convection, thermal conduction, radiation, and the transfer of water from the product to the outside.

[0006] To optimize the transfer of water from the product to the exterior, the thermal treatment needs to be calibrated according to how water is transferred from the product or compound to the exterior.

[0007] Initially, water migrates rapidly through the pores of the product or compound from the innermost layer to the outermost layer of the product or compound and evaporates once it reaches the surface. At a later stage, as the larger channels dry out, the remaining water slowly diffuses outward through the micro-perforations of the product or compound until the latter reaches thermal and moisture equilibrium with the surrounding environment.

[0008] From a technical point of view, this means that the first stage can occur very quickly with a sharp increase in temperature.

[0009] Known artificial drying methods mainly include: hot air drying, radiation drying and drying by direct contact of the product or compound with a heated surface.

[0010] Drying by infrared radiation involves irradiating the product or compound with the aid of a radiation source in the infrared spectrum or with electromagnetic waves in the low-frequency or high-frequency electromagnetic range.

[0011] However, drying by known methods by radiation sources in the infrared spectrum or using electromagnetic waves in the low-frequency or high-frequency electromagnetic range entails some disadvantages due to the fact that the inorganic and / or organic compounds may have an inhomogeneous composition and configuration.

[0012] For example, in high-frequency electromagnetic waves, there is an uneven distribution of heat and energy transferred to the product, because this type of electromagnetic wave propagates unevenly in space. This leads to an uneven absorption of the radiation by organic or inorganic compounds, and therefore to an uneven heating of inorganic or organic products or compounds of plant or animal origin.

[0013] By contrast, at low frequencies, the electromagnetic waves that hit the material allow uniform heat distribution of the water in the material, but change the impedance of the material. Therefore, it is difficult to select the optimal frequency value for the entire duration of the drying or dehydration operation of the compound, and after a certain time interval of the device operation, the drying yield decreases.

[0014] Furthermore, for both methods, gentle aeration means must be used to remove the extracted water, but high drying temperatures (above 70° C.) must still be used, which results in a high degree of degradation of the vitamins in the product, leading to a reduction in nutritional value.

[0015] US 4999925 A illustrates a device for heat treating bales of cotton lint containing moisture and contaminated by honeydew, comprising means for generating an electromagnetic field at an industrial frequency of 27.12 MHz ± 0.6% or in rare cases 13.56 MHz ± 0.05%. This electromagnetic field is used to heat the bales of cotton lint in order to reduce their moisture content and thus their stickiness.

[0016] WO 2020 / 254977 A1 shows an apparatus for producing dried pasta, in which pasta inside a first drying channel maintained under vacuum is subjected to an electromagnetic field oscillating at a frequency between about 10 MHz and about 100 MHz. When the pasta passes through the electromagnetic field between a pair of electrodes, it is heated. The power applied to the electrodes to generate the oscillating magnetic field is adjusted so that the pasta is heated to a temperature between 40°C and 55°C.

[0017] An object of the present invention is to provide a device and a method for reducing the water content of inorganic and / or organic products or compounds of plant or animal origin, making it possible to reduce the time required for drying such products without, on the one hand, modifying the structural properties of the inorganic compounds, such as a weakening of the structure, and, on the other hand, without modifying the dried organic products of plant or animal origin, such as a degradation of vitamins, modification of proteins and carbohydrates, and more generally without modifying the chemical-physical, nutritional and organoleptic properties of the compounds treated.

[0018] Another object of the invention is to provide a device and a method for reducing the water content of inorganic and / or organic products or compounds of plant or animal origin so that the inorganic or organic compounds of plant or animal origin can be heated uniformly throughout the substance and throughout the surface being treated.

[0019] Yet another object of the present invention is to provide a device and a method for reducing the water content of inorganic and / or organic products or compounds of plant or animal origin, making it possible to select the optimal frequency value for reducing the water content of these compounds or products.

[0020] A further object of the invention is to provide a device and a method for reducing the water content of inorganic and / or organic products or compounds of plant or animal origin, making it possible to dry the widest variety of such products, with low operating costs, significantly reducing energy consumption and environmental impact to the extent that the process is completely ecologically sustainable, and also recovering the extracted water. Summary of the invention

[0021] The objects of the present invention are achieved by a device for reducing the initial water content present in inorganic and / or organic products or compounds of plant or animal origin according to claim 1 and a method for reducing the initial water content present in inorganic and / or organic products or compounds of plant or animal origin according to claim 21.

[0022] It should be noted that the expression "reducing the initial water content" generally means a dehydration or drying operation of inorganic and / or organic products or compounds of plant or animal origin.

[0023] In particular, inorganic products or compounds may include, but are not limited to, salt, plastics, aggregates, sand. Organic products or compounds of plant or animal origin may include meat, fish, grains, fruits and vegetables, foods in general.

[0024] The device according to the present invention comprises:

[0025] A waterproof housing defining a drying chamber or defining a drying chamber within the waterproof housing.

[0026] In particular, according to one aspect, the drying chamber is designed to be used both as a propagation element for electromagnetic waves having at least one first frequency (f1 - high frequency) and as a pair of electrodes for propagating electromagnetic waves having at least one second frequency (f2 - low frequency). Thus, it is possible to use the drying chamber alone for the application of a high-frequency generator, or alone for the application of a low-frequency generator, or alternately or simultaneously for both. Thus, the device of the invention makes it possible to use two types of electromagnetic waves (high and low frequency) using the same propagation element incorporated in or mounted on the drying chamber.

[0027] Specifically, according to one aspect, wherein the drying chamber itself is contained within a waterproof housing, the drying chamber is made of a micro-perforated material.

[0028] The device according to the present invention further comprises means for adjusting the pressure value inside the drying chamber so that the pressure value is maintained below the atmospheric pressure value.

[0029] The device according to the present invention also includes a heating device for heating inorganic and / or organic compounds in a drying chamber, the device comprising at least a first generator of electromagnetic waves having at least one first frequency and / or at least a second generator of electromagnetic waves having at least one second frequency lower than the first frequency, wherein the generator may contain dedicated software for controlling and managing electromagnetic wave generation and control parameters.

[0030] Both of the generators may exist, that is, at least one first generator of electromagnetic waves having at least one first frequency and at least one second generator of electromagnetic waves having at least one second frequency lower than the first frequency may exist; or only one of the two may exist, for example, only at least one first generator of electromagnetic waves having at least one first frequency may exist, or only at least one second generator of electromagnetic waves having at least one second frequency lower than the first frequency may exist. When both are present, they may operate individually, alternately and / or simultaneously.

[0031] The device also includes:

[0032] at least one propagation element for propagating said electromagnetic waves having said first frequency in said drying chamber, said at least one propagation element being connected to said first generator of electromagnetic waves having said first frequency,

[0033] and / or at least one pair of electrodes for propagating the electromagnetic waves having the second frequency in the drying chamber, wherein a first electrode is connected to the second generator of electromagnetic waves having the second frequency and the second electrode is grounded.

[0034] According to one aspect, the at least one propagation element and / or the at least one pair of electrodes are integrated into the drying chamber and / or are mounted on the drying chamber.

[0035] Advantageously, the device according to the invention allows drying of inorganic compounds by heating them to a temperature that does not cause structural damage or undue chemical reactions.

[0036] Advantageously, the device according to the invention makes it possible to dry an organic compound or product, preferably a food, by heating it at a sufficiently low temperature so as not to cause degradation of the vitamins and alteration of the proteins and carbohydrates contained in the organic compound, thus maintaining substantially unchanged the nutritional, organoleptic or textural properties of the dried organic product or compound of plant or animal origin.

[0037] Due to the combined effect of the pressure variation and the action of the electromagnetic field, the heating of inorganic and / or organic products or compounds of vegetable or animal origin occurs quickly and uniformly without the formation of thermal gradients within the compounds, resulting in a better and faster elimination of the water they contain.

[0038] Advantageously, the presence of one and / or two or more generators makes it possible to select and utilize the most suitable type of electromagnetic waves even dynamically during the compound dehydration or drying operation: for example, the lower frequency generated by the second electromagnetic wave generator is suitable for having a better and more uniform distribution of the power delivered by the generator, for example for heating products with uniform thickness (for example powdered or cereal materials, such as salt, cereals or powdered food compounds), while the higher frequency generated by the first electromagnetic wave generator is suitable for obtaining a higher heating capacity even on products with uneven thickness (for example fruits and vegetables).

[0039] Advantageously, as will become clear from the description of the method according to the invention, one, two or more generators can be installed and used individually, alternately or simultaneously. This allows heating of organic and / or inorganic compounds with different frequency bands selected according to the material.

[0040] According to one aspect, the pressure regulating device is operated to adjust the pressure value in the drying chamber so that during the drying operation, the pressure is maintained at a constant value or so that during the duration of the drying operation, the pressure has a variable value between at least one minimum pressure value and at least one maximum pressure value.

[0041] Advantageously, the pressure regulating device can thus be operated in two different modes, to maintain a constant pressure value or a variable pressure value.The operating mode can be selected depending on the product to be dried and its dielectric properties.

[0042] According to one aspect, the dimensions of the drying chamber are defined as a function of the wavelength of the electromagnetic waves generated by the generator according to a mathematical relationship.

[0043] According to one aspect, the dimensions of the drying chamber are defined according to the type of one or more electromagnetic wave generators that heat the medium.

[0044] According to one aspect, the dimensions of the drying chamber (in the case where it has a parallelepiped shape) are preferably between 43 mm per side and 4000 mm per side, preferably between 200 mm and 4000 mm, or have sides of different sizes, which are however identified as being within the range of 43 mm to 4000 mm, preferably between 200 mm and 4000 mm. Even if the drying chamber is cylindrical in shape, the same size range applies with respect to the diameter.

[0045] Advantageously, according to this aspect, the geometry of the drying chamber is chosen so as to achieve a perfect resonance of the electromagnetic waves in the space containing the product.

[0046] According to one aspect, the drying chamber is made of a microperforated material, allowing electromagnetic waves to be confined by adjusting the size of the microperforations, for example and not exhaustively, at frequencies from 2400 MHz to 2500 MHz, the size of the microperforations used for drying can be 1 mm, with a vacuum / full ratio of 50%.

[0047] Specifically, after choosing the optimal frequency to use, the corresponding wavelength of the electromagnetic radiation that will be generated in the drying chamber is determined, depending on the dielectric properties of the product to be heated. Depending on this wavelength, the size adjustment of the drying chamber is determined so that a perfect resonance of the electromagnetic waves is achieved in the space containing the product.

[0048] According to one aspect, the device comprises a plurality of propagation elements for propagating electromagnetic waves having the first frequency in the drying chamber, the plurality of propagation elements being arranged on at least one surface of the drying chamber.

[0049] According to a variant, the plurality of propagation elements may comprise a first group of propagation elements and a second group of propagation elements.

[0050] For example, the propagation elements may be arranged at the surface of the drying chamber according to a pattern comprising a first group of propagation elements and a second group of propagation elements, wherein the first group of propagation elements and the second group of propagation elements are parallel to each other and the second group of propagation elements are placed at a different height than the first group of propagation elements, i.e., at a staggered (non-mirror) position.

[0051] According to one aspect, the first group of propagation elements is arranged along a first surface of the drying chamber and the second group of propagation elements is arranged along a second surface of the drying chamber, the second surface being opposite to the first surface.

[0052] According to a variant, the plurality of propagation elements may comprise a single group of propagation elements arranged along the same surface of the drying chamber.

[0053] Advantageously, the arrangement of the propagation elements is determined after selecting the dimensioning of the drying chamber according to the wavelength of the electromagnetic waves to be generated.

[0054] Advantageously, the presence of multiple propagation elements allows more power to be generated in a shorter period of time.

[0055] According to one aspect, the pressure regulating means comprises at least one regulating valve adapted to convey air from the environment to the interior of the drying chamber, and at least one vacuum pump adapted to draw fluid from the drying chamber to the external environment to place the fluid under vacuum.

[0056] Advantageously, the synergy of the control valve and the vacuum pump makes it possible for the pressure inside the drying chamber to assume variable values ​​while the device is in use.

[0057] According to one aspect, the first generator of electromagnetic waves having the at least one first frequency comprises a generator of high-frequency electromagnetic waves having a frequency between 900 MHz and 3000 MHz, preferably between 915 MHz and 3000 MHz.

[0058] Advantageously, such a frequency range is suitable for achieving higher heating capabilities on inorganic and organic compounds of uneven thickness (eg, fruits and vegetables).

[0059] According to one aspect, the second generator of electromagnetic waves having said second frequency comprises a generator of low-frequency electromagnetic waves having a frequency between 10 MHz and 920 MHz, preferably between 10 MHz and 914 MHz.

[0060] Advantageously, such a frequency range is suitable for a better and more uniform distribution of the power delivered by the generator, for example for heating products with uniform thickness (eg powdered or cereal materials such as salt, cereals or powdered food compounds).

[0061] According to one aspect, the device comprises a logic control unit connected at least to the pressure regulating device and at least to the electromagnetic wave generator.

[0062] According to another aspect, the second ground electrode includes a surface of the drying chamber.

[0063] According to one aspect, the device includes: a first filter for preventing electromagnetic waves having a frequency lower than the first frequency from being transmitted from the drying chamber to the first electromagnetic wave generator having the first frequency; and a second filter for preventing electromagnetic waves having a frequency higher than the second frequency from being transmitted from the drying chamber to the second electromagnetic wave generator having the second frequency.

[0064] According to one aspect, said at least one propagation element for propagating said electromagnetic waves having said first frequency in said drying chamber comprises a waveguide and / or a connector / antenna system.

[0065] According to one aspect, the drying chamber comprises at least one supporting element for the product to be dried or dehydrated, the supporting element being made of a material transparent to the electromagnetic waves generated by said electromagnetic wave generator.

[0066] The invention also relates to a method for reducing the water content present in inorganic and / or organic compounds of plant or animal origin by means of a device according to any one of claims 1 to 20, comprising the following steps:

[0067] (a) introducing the inorganic and / or organic compound to be dried into the drying chamber;

[0068] (b) heating the inorganic and / or organic compound to a temperature causing evaporation of water contained in the inorganic and / or organic compound;

[0069] (c) maintaining the temperature until the amount of water contained in the inorganic and / or organic compound decreases to a predetermined value;

[0070] (d) extracting the evaporated water from the drying chamber;

[0071] (e) extracting the dried inorganic and / or organic compound from the drying chamber,

[0072] It is characterized by the fact that said step (b) of heating said inorganic and / or organic compound comprises the following steps:

[0073] (b1) operating the pressure regulating device to adjust the pressure so that during the entire drying operation

[0074] During a duration, the pressure value inside the drying chamber is kept lower than the atmospheric pressure value;

[0075] (b2) operating the at least one first generator of electromagnetic waves having a first frequency and / or the at least one second generator of electromagnetic waves having a second frequency lower than the first frequency to generate electromagnetic waves in the drying chamber that are projected onto the inorganic and / or organic compound,

[0076] wherein the pressure value in the drying chamber is selected so that the evaporation of the water contained in the inorganic and / or organic compounds takes place at the drying temperature without damaging the nutritional and organoleptic properties of the organic compounds, in particular without damaging the vitamins, without degrading the proteins and carbohydrates contained in the organic compounds, without causing structural damage or undue chemical reactions to the inorganic compounds, in particular at temperatures from -40°C to +99.8°C, and wherein,

[0077] The first generator of electromagnetic waves having the at least one first frequency generates high-frequency electromagnetic waves having at least one frequency between 900 MHz and 3000 MHz, preferably between 915 MHz and 3000 MHz, and / or the second generator of electromagnetic waves having the at least one second frequency generates low-frequency electromagnetic waves having at least one frequency between 10 MHz and 920 MHz, preferably between 10 MHz and 914 MHz.

[0078] Advantageously, the method allows the first generator and / or the second generator to be installed and / or operated individually, alternately or simultaneously. In addition, the method allows the pressure regulating device to be operated simultaneously or alternately with the first generator and / or the second generator.

[0079] In this way, the optimal combination of pressure and frequency parameters for heating an organic or inorganic compound can be selected.

[0080] According to one aspect, the at least one first generator of electromagnetic waves having the at least one first frequency and the at least one second generator of electromagnetic waves having the at least one second frequency may also exist separately.

[0081] According to one aspect, at least one first generator of electromagnetic waves having the at least one first frequency and at least one second generator of electromagnetic waves having the at least one second frequency are operated alternately.

[0082] According to one aspect, at least one first generator of electromagnetic waves having said at least one first frequency and said at least one second generator of electromagnetic waves having said at least one second frequency operate simultaneously.

[0083] According to one aspect, the at least one first electromagnetic wave generator and / or the at least one second electromagnetic wave generator are configured to continuously change the frequency and / or phase shift (ie, propagation angle) of the electromagnetic waves by the dedicated electromagnetic wave generation and control software.

[0084] According to one aspect, the pressure value inside the drying chamber is between 0.01 mbar and 999 mbar, preferably between 0.05 mbar and 999 mbar, more preferably between 9 mbar and 100 mbar.

[0085] Advantageously, the pressure regulating device can thus be operated in two different ways to achieve the desired type of drying:

[0086] According to one aspect, in practice, in the step (b1), the pressure regulating device is operated to maintain the pressure inside the drying chamber at a constant value throughout the drying operation.

[0087] According to an alternative aspect, in step (b1), the pressure regulating device is operated to change the pressure within the drying chamber between at least one minimum pressure value and at least one maximum pressure value during the duration of the drying operation.

[0088] According to this aspect, the minimum pressure value is about 1 mbar and the maximum pressure value is about 200 mbar. Preferably, the maximum pressure value is equal to about 50 mbar.

[0089] According to one aspect, after said step (d) of extracting evaporated water from said drying chamber, it further comprises a step of condensing evaporated water from said inorganic and / or organic compounds by means of a condensate separator element.

[0090] According to one aspect, at the end of the drying operation, the percentage of residual water contained in the inorganic and / or organic compound is between 0% and 40% by weight, preferably between 1% and 20% by weight.

[0091] According to one aspect, the method of the invention enables operation with a plurality of drying chambers arranged in parallel (ie by a continuous process).

[0092] According to one aspect, the method of the invention enables operation with a plurality of drying chambers arranged in series (ie, by a continuous process).

[0093] According to a preferred embodiment, the method of the invention enables operation with at least one drying chamber (preferably a plurality of drying chambers) operated by an automated system comprising at least one frame, preferably a plurality of movable frames and configured to feed the product to be dried to the plurality of drying chambers and to remove the dried product from the plurality of drying chambers. In other words, each frame is suitable for conveying a certain amount of product to be dried in the corresponding drying chamber and, once the drying process is completed, conveying the dried product outside the drying chamber.

[0094] According to a variant, the automated system comprising said plurality of mobile frames allows operation by a discontinuous process.

[0095] According to a preferred variant and an alternative to the aforementioned variant, the automated system comprising said plurality of mobile frames is capable of operating by a continuous process.

[0096] The invention also relates to the use of a device according to any one of claims 1 to 18 for drying inorganic and / or organic compounds of plant or animal origin.

[0097] It should be noted that the invention allows a minimal impact on the environment, since since the heat for drying the inorganic and / or organic compounds is generated within the inorganic and / or organic compounds themselves and no heat carrier medium is required, the heat dissipation to the environment is very low and no fumes or vapors are generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] These and other aspects of the present invention will become apparent from the following detailed description, which is provided for illustrative and non-limiting purposes only, with reference to the accompanying drawings, in which:

[0099] Figure 1 is a schematic diagram of an embodiment of an apparatus according to the present invention;

[0100] Figure 2 is a perspective view of an embodiment of a drying chamber 2 of the device according to the present invention;

[0101] Figure 3A and Figure 3B are two partially transparent perspective views of an embodiment of a drying chamber 2 of the device according to the invention;

[0102] Figure 4 is a perspective view of an embodiment of the device according to the present invention;

[0103] Figure 5 is a perspective view of another embodiment of the device according to the present invention;

[0104] Figure 5A is a perspective view of an embodiment of the apparatus according to the present invention suitable for continuous cycle industrial scale production;

[0105] Figure 5B yes Figure 5A A perspective view of a device according to the invention is shown, showing the interior of the device;

[0106] Figure 5C is a schematic diagram of an embodiment of the apparatus according to the present invention suitable for continuous cycle industrial scale production;

[0107] Figure 5Dis a schematic diagram of another embodiment of the device according to the present invention suitable for continuous cycle industrial scale production;

[0108] Figure 6 A table with pressure and temperature values ​​for water vapor is shown. DETAILED DESCRIPTION

[0109] With reference to the accompanying drawings, some possible embodiments of the device according to the invention will be described.

[0110] Figure 1 An embodiment of the device according to the invention for drying inorganic and / or organic compounds of plant or animal origin is schematically shown.

[0111] The device comprises a waterproof housing 1 which defines a drying chamber 2 or defines a drying chamber 2 within the waterproof housing 1 .

[0112] In one embodiment, if Figure 4 As shown, the apparatus may include a plurality (eg, 4 to 12) of drying units 2 operating in parallel, depending on the desired throughput. Figure 4 The arrangement shown comprises six drying units.

[0113] The housing 1 is equipped with a door 1 ′ (also waterproof) through which the inorganic and / or organic compounds to be dried can be introduced into a drying chamber 2 defined in the housing 1 and also equipped with a door 22 .

[0114] exist Figure 5 In another embodiment shown, the apparatus may include a plurality (e.g., 2 to 20, preferably 8 to 16) of drying chambers 2 operating in parallel, depending on the desired throughput. Figure 5 The device shown comprises 12 drying chambers. In this embodiment, the housing 1 is constructed as two parts or shells 1' and 1", which are hinged to each other at one end and anchored to the ground by a column acting as a pivot and capable of providing a waterproof seal when closed. Advantageously, in a preferred variant of this embodiment, as Figure 5 As shown, the drying chamber is mounted on a sliding trolley with wheels, which is engaged in the waterproof cavity by means of specific guides in the cavity to ensure correct positioning. Advantageously, the shells 1 'and 1 "are also resting on the front of the wheels. This configuration facilitates the opening and closing of the shells 1 'and 1 "and accelerates the introduction and extraction of the inorganic and / or organic compounds to be dried, as well as the cleaning operations.

[0115] In one embodiment, a support element 2 ′ is arranged in the drying chamber 2 , on which the inorganic and / or organic compound to be dried is placed.

[0116] Attached Figure 1 , Figure 4 and Figure 5 An embodiment of the device comprising a housing 1 and a drying chamber of parallelepipedal shape is shown, but embodiments in which the housing 1 and the associated drying chamber 2 are of cubic or cylindrical shape are not excluded.

[0117] The device according to the invention comprises pressure regulating means 9, 10, 12 adapted to regulate the pressure value inside the drying chamber 2 such that the pressure value remains below the atmospheric pressure value.

[0118] Specifically, Figure 1 As shown, in one possible embodiment, the pressure regulating devices 9, 10, 12 include: at least one vacuum pump 12 suitable for sucking fluid from the drying chamber 2 to the external environment to place the fluid under vacuum, and at least one control valve 9 suitable for transporting air from the environment to the interior of the drying chamber 2 to increase the pressure value inside the drying chamber 2.

[0119] In addition, the pressure regulating device may further include a pressure gauge 10 or a vacuum gauge for measuring the depression generated by the vacuum pump 12 in the drying chamber 2 during the drying process.

[0120] As will be better described below, with regard to the method according to the invention for drying inorganic and / or organic compounds of plant or animal origin, it should be noted that the vacuum pump 12 and the regulating valve 9 can be used alternately: for example, in the event that the pressure gauge or vacuum gauge 10 detects a lower pressure value than desired, the vacuum pump 12 can be turned off and the regulating valve 9 can be operated to introduce air at atmospheric pressure into the interior of the drying chamber 2 in order to increase the pressure value inside the chamber.

[0121] In this way, the pressure regulating devices 9, 10, 12 can be operated to adjust the pressure value inside the drying chamber 2 so that the pressure is maintained at a constant value during the drying operation, or so that the pressure presents a variable value, such as between at least one minimum pressure value and at least one maximum pressure value, during the duration of the drying operation.

[0122] In an embodiment, a filter 14 is placed between the drying chamber 2 and the vacuum pump 12, which prevents any residual inorganic and / or organic compounds in the air from reaching the vacuum pump and damaging it.

[0123] The device according to the invention also comprises heating means 5 and / or 6 for heating the inorganic and / or organic compounds in the drying chamber 2. Such heating means 5 and / or 6 comprise a first generator 5 of electromagnetic waves having at least one first frequency f1 and / or a second generator 6 of electromagnetic waves having at least one second frequency f2 lower than the first frequency f1 of the electromagnetic waves emitted by the first generator 5.

[0124] Specifically, in a possible embodiment, the first generator 5 of electromagnetic waves having at least one first frequency f1 includes a generator of high-frequency electromagnetic waves having a frequency f1 between 900 MHz and 3000 MHz, preferably between 915 MHz and 3000 MHz, and the second generator 6 of electromagnetic waves having at least one second frequency f2 includes a generator of low-frequency electromagnetic waves having a frequency f2 between 10 MHz and 920 MHz, preferably between 10 MHz and 914 MHz.

[0125] The first generator 5 is a high frequency electromagnetic wave generator known in the art, called a solid state generator.

[0126] As will be better described below, with regard to the method according to the invention for drying inorganic and / or organic compounds of plant or animal origin, the first generator and / or the second generator 5 and / or 6 can be installed and operated individually, alternately or simultaneously, depending on the product or compound and the type of drying to be carried out.

[0127] This provides the opportunity to utilize the most suitable type of electromagnetic waves: for example, the lower f2 frequency between 10 MHz and 920 MHz, preferably between 10 MHz and 914 MHz, generated by the second generator 6 of electromagnetic waves, is suitable for a better and more uniform distribution of the power delivered by the generator on products with uniform thickness (such as powdered products or cereals, for example salt, cereals or powdered foods), while the higher f1 frequency between 900 MHz and 3000 MHz, preferably between 915 MHz and 3000 MHz, generated by the first generator 5 of electromagnetic waves, is suitable for achieving higher heating capabilities even on products with uneven thickness.

[0128] In this regard, as will become clearer from the description of the method according to the invention, the generator can scan those frequencies with a minimum test power (e.g. 10 Watts) to select the optimal frequency by measuring the percentage of power returned to the generator. This power is not absorbed by the product, so the software eliminates all frequencies with return values ​​greater than 10% and will only work with frequencies with return power values ​​less than 10%, preferably 5%.

[0129] The device according to the invention comprises at least one propagation element 3 for propagating electromagnetic waves having at least one first frequency f1 in the drying chamber 2. This propagation element 3 is connected to a first generator 5 of electromagnetic waves having a first frequency f1.

[0130] In particular, at least one propagation element 3 for propagating electromagnetic waves of at least one first frequency f1 in the drying chamber 2 may include electromagnetic wave transmission and limitation means known in the art, such as waveguides and / or connector / antenna systems. At least one propagation element 3 is arranged at the surface of the drying chamber 2 and faces inwardly into the drying chamber 2, in which the inorganic and / or organic compounds to be dried are contained.

[0131] like Figure 3A and Figure 3B As shown, by way of example and not exhaustive, in one possible embodiment, the device comprises a plurality of propagation elements 3 arranged on at least one surface of the drying chamber 2 for propagating electromagnetic waves having a first frequency f1 in the drying chamber 2 .

[0132] Such propagation elements 3 can be arranged on the surface of the drying chamber 2 according to a pattern including a first group of propagation elements 3' and a second group of propagation elements 3", wherein the first group of propagation elements 3' and the second group of propagation elements 3" are parallel to each other in the longitudinal development direction of the drying chamber 2, and the second group of propagation elements 3" is in a staggered (i.e., non-mirror) position relative to the first group of propagation elements 3'.

[0133] In other words, the propagation elements 3 ″ of the second series are placed at a different height than the propagation elements 3 ′ of the first series, along a direction orthogonal to the longitudinal development direction of the drying chamber 2 .

[0134] The number of propagation elements 3 and their arrangement are also determined according to the power delivered by the at least one first generator 5 for heating the organic or inorganic compound.

[0135] The power to be delivered is given by the type of compound and its percentage of water content and the time required for its evaporation to reach the desired residual water content.

[0136] In one embodiment, the first generator 5 (not shown in the figures) comprises four outputs connected to four respective propagation elements 3', 3', 3", 3", generating a total power value of 1 kW.

[0137] In one embodiment, not shown in the figures, the device comprises a plurality of generators 5 and / or 6. For example, in case the power required to heat the compound is 3 kW, three generators 5 can be used, each equipped with four outputs generating a total of 1 kW of power.

[0138] exist Figure 3A and Figure 3B In the embodiment shown, the device comprises eight propagation elements 3, in particular eight waveguides, of which four waveguides are placed on the first side surface 2a of the drying chamber 2 ( Figure 3A), and four additional waveguides are placed non-specularly on an additional side surface 2b of the drying chamber 2 ( Figure 3B ), in particular they are placed on the opposite side surfaces 2b.

[0139] In a variant embodiment not shown in the drawings, all waveguides are arranged along the same surface, side or otherwise of the drying chamber.

[0140] In more detail, at each side surface 2a, 2b, the two waveguides 3' of the first pair of waveguides are arranged at the same height and at opposite vertices of the corresponding side surface 2a, 2b of the drying chamber 2, that is, at a position away from the transverse axis of the corresponding surface 2a, 2b of the drying chamber 2, while the two additional waveguides 3" of the second pair of waveguides are arranged at the same height, which is, however, different from the height at which the two waveguides 3' are arranged, at a position close to the transverse axis of the corresponding surface 2a, 2b of the drying chamber 2.

[0141] In one embodiment, the device comprises a first filter 7 to prevent electromagnetic waves having a frequency lower than the first frequency f1 from being transmitted from the drying chamber 2 to the first generator 5 of electromagnetic waves having the first frequency f1.

[0142] Specifically, refer to Figure 1 , the first filter 7 is placed between the first generator 5 of electromagnetic waves having the first frequency f1 and its propagation element 3. Therefore, backflow into the first generator 5 of electromagnetic waves having the first frequency is prevented.

[0143] The device according to the invention may also comprise at least one pair of electrodes 4, 2 for propagating electromagnetic waves with at least one second frequency f2 generated by a possible second generator 6 in the drying chamber 2, wherein the first electrode 4 is connected to the second generator 6 of electromagnetic waves with the second frequency f2 and the second electrode 2 is grounded. The first electrode 4 is a positive electrode and the second electrode 2 is a negative electrode.

[0144] In one embodiment, the second ground electrode 2 comprises the actual surface of the drying chamber 2. The first electrode 4 is placed at the surface of the drying chamber 2 and faces inwards from the drying chamber 2, within which the inorganic and / or organic compounds to be dried are contained.

[0145] In one embodiment, the device comprises a second filter 8 to prevent electromagnetic waves having a frequency higher than the second frequency f2 from being transmitted from the drying chamber 2 to the second generator 6 of electromagnetic waves having the second frequency f2.

[0146] Specifically, refer to Figure 1 , the second filter 8 is placed between the second generator 6 of electromagnetic waves having the second frequency f2 and the first electrode 4. Therefore, backflow into the second generator 6 of electromagnetic waves having the second frequency is prevented.

[0147] refer to Figure 1 The device can be equipped with a control logic unit 13 which is connected at least to the pressure regulating devices 9 , 10 , 12 and at least to the generator 5 and / or the generator 6 of electromagnetic waves.

[0148] As expected, the drying chamber may include at least one supporting element 2' therein, which is arranged between a first positive electrode 4 and a second negative electrode 2, the first positive electrode 4 being connected to a second generator 6 of electromagnetic waves having a second frequency f2, the second generator 6 being suitable for generating an electromagnetic field with a frequency between 10 MHz and 920 MHz, preferably between 10 MHz and 914 MHz, the second negative electrode 2 being grounded. The supporting element 2' is made of a material transparent to electromagnetic waves in a frequency band between 10 MHz and 920 MHz, preferably between 10 MHz and 914 MHz, for example, the supporting element may be made of POM, PP, PIC, ceramics, glass.

[0149] In one embodiment, the support element 2' is mounted on a load cell system 200, by which the weight loss of the inorganic and / or organic compound placed on the support element 2' due to evaporation of water therein can be detected during the drying process.

[0150] As expected, the present invention also relates to a method for drying inorganic and / or organic compounds of plant or animal origin, which will be described below.

[0151] The method according to the invention comprises the step of introducing the inorganic and / or organic compound to be dried into the drying chamber 2 and possibly placing it on at least one supporting element 2 ′.

[0152] Next, the method according to the invention involves a step of heating the inorganic and / or organic compounds to a temperature that causes the evaporation of the water contained in these inorganic and / or organic compounds.

[0153] This temperature is maintained until the amount of water contained in the inorganic and / or organic compound decreases to a predetermined value.

[0154] The step of heating the inorganic and / or organic compounds is carried out by the synergistic effect of pressure changes inside the drying chamber 2, in particular by means of a depression inside the drying chamber 2 by means of pressure regulating devices 9, 10, 12, and by generating an electromagnetic field inside the drying chamber 2 by at least one of the electromagnetic wave generators 5 and / or 6.

[0155] In one possible embodiment, the pressure regulating devices 9 , 10 , 12 and the electromagnetic wave generators 5 and / or 6 are controlled and operated by a control logic unit 13 .

[0156] In particular, the step of heating the inorganic and / or organic compound is performed by operating the pressure regulating devices 9, 10, 12 to adjust the pressure so that throughout the drying operation, the pressure value inside the drying chamber 2 is maintained below the atmospheric pressure value, and operating at least one first generator 5 of electromagnetic waves with a first frequency f1 and / or at least one second generator 6 of electromagnetic waves with a second frequency f2 to generate a magnetic field projected onto the inorganic and / or organic compound inside the drying chamber 2. After the inorganic and / or organic compound to be dried is introduced into the drying chamber 2, the vacuum pump 12 is started until a pressure with a value less than the atmospheric pressure is obtained inside the drying chamber 2.

[0157] As expected above, since it is well known that the evaporation temperature of water is pressure-dependent and decreases as the pressure decreases, the pressure value inside the drying chamber 2 is selected so as to achieve evaporation of the water contained in the inorganic and / or organic compounds to be dried at a temperature ranging from -40°C to +99.8°C, preferably between -22°C and +70°C, more preferably between 5°C and 45°C.

[0158] In one embodiment, the pressure value inside the drying chamber 2 is selected so as to achieve evaporation of water contained in the inorganic and / or organic compounds to be dried at a temperature that does not damage the vitamins, does not degrade the proteins and carbohydrates contained in the organic compounds, and does not cause structural damage or inappropriate chemical reactions of the inorganic compounds, in particular at a temperature between 5°C and 45°C.

[0159] By Figure 6 The physical law expressed in the attached table shown in relates the values ​​of P and T, which identifies the evaporation temperature of water as a function of pressure. The frequency is selected over the entire spectrum according to the characteristics of the product to be treated and the yield on a determined working volume. The frequency of the electromagnetic waves is completely independent of the choice of drying pressure and temperature.

[0160] In another embodiment, drying may also be performed at lower temperatures, for example down to even 5°C, by reducing the pressure inside the drying chamber (as described above).

[0161] In another embodiment, drying can also be carried out at lower temperatures, for example down to even -40°C, preferably down to -22°C.

[0162] In one embodiment, the pressure value inside the drying chamber 2 may be between 0.01 mbar and 999 mbar, preferably between 0.05 mbar and 999 mbar, and more preferably between 9 mbar and 100 mbar.

[0163] In the method according to the present invention, at least one first generator 5 of electromagnetic waves having at least one first frequency f1 generates high-frequency electromagnetic waves having at least one frequency f1 between 915 MHz and 3000 MHz, and / or at least one second generator 6 of electromagnetic waves having at least one second frequency f2 generates low-frequency electromagnetic waves having at least one frequency f2 between 10 MHz and 914 MHz.

[0164] As anticipated, the two generators 5 and / or 6 may be installed and operated individually, alternately or simultaneously.

[0165] After the heating and drying operations of the inorganic and / or organic compounds inside the drying chamber are completed, the method according to the present invention includes a step of extracting evaporated water from the inorganic and / or organic compounds from the drying chamber 2, and then includes a step of extracting the dried inorganic and / or organic compounds from the drying chamber 2.

[0166] The pressure regulating devices 9 and 10 , 12 can be operated in two different ways.

[0167] According to the first mode M P1 , operate the pressure control devices 9, 10, 12 to maintain the pressure inside the drying chamber 2 at a constant value throughout the drying operation.

[0168] According to the second mode M P2 , the pressure control devices 9, 10, 12 are operated to change the pressure inside the drying chamber 2 between at least one minimum pressure value and at least one maximum pressure value during the duration of the drying operation. Preferably, the minimum pressure value is about 1 mbar and the maximum pressure value is about 200 mbar, preferably, the maximum pressure value is about 50 mbar.

[0169] The device according to the invention can be operated in four different modes.

[0170] Method 1:

[0171] In this operating mode, according to the above-mentioned mode M P1 The pressure control devices 9, 10, 12 are operated to maintain the pressure inside the drying chamber 2 at a constant value throughout the drying operation.

[0172] Depending on the product or compound to be dried and the type of drying desired, the optimum pressure value and the optimum frequency for performing the heating and drying operations are selected.

[0173] In one embodiment, the selection of the optimal frequency is performed by scanning the product or compound to be dried operated by the generator 5 and / or 6, which detects which frequency produces the highest yield based on the percentage of reflected power, as previously described.

[0174] In another embodiment, this selection can be performed by the control unit 13, in which drying recipes for different types of inorganic and / or organic compounds can be stored.

[0175] Once the optimal pressure and frequency values ​​are defined, the pressure control devices 9, 10, 12 are operated to maintain the selected pressure value in the drying chamber, and the first electromagnetic wave generator and / or the second electromagnetic wave generator 5 and / or 6 are operated to generate electromagnetic waves having the selected optimal frequency value, and the electromagnetic waves having the selected optimal frequency value will be maintained throughout the drying process.

[0176] According to this first mode, the inorganic and / or organic compound is heated to the evaporation temperature of water by means of electromagnetic waves generated by at least one of the electromagnetic wave generators 5 and / or 6 at a predetermined pressure inside the drying chamber 2. Specifically, the pump 12 is started until a predetermined pressure is reached inside the drying chamber 2, so that the water contained in the inorganic and / or organic compound begins to evaporate. When the desired residual moisture content in the inorganic and / or organic compound is reached, the evaporation ends.

[0177] Therefore, Mode 1 uses constant vacuum value and constant frequency operation.

[0178] Method 2:

[0179] In this operating mode, according to the above-mentioned mode M P1 The pressure regulating devices 9, 10, 12 are operated to maintain the pressure inside the drying chamber 2 at a constant value throughout the drying operation.

[0180] Depending on the product or compound to be dried and the type of drying desired, the optimum pressure value and the optimum frequency for performing the heating and drying operations are selected.

[0181] In one embodiment, the selection of the optimal frequency is performed by scanning the product or compound to be dried operated by the generator 5 and / or 6, which scans the electromagnetic waves and selects a frequency that produces a yield greater than 90%, preferably greater than 95%, and even more preferably greater than 98%. The generator 5 and / or 6 sequentially emits a series of sampling signals and selects a signal that produces a signal return of less than 10%.

[0182] In one embodiment of this second mode, once the scan is completed, at least one generator 5 and / or 6 selected by the operator according to the product to be dried starts delivering power, varying the frequency of the electromagnetic waves generated by selecting from time to time frequency values ​​from those previously selected, which allows a minimum yield of 90% at predetermined intervals that can be set, for example, from a control and command panel present in the device.

[0183] As an example, if the product has an irregular shape, a high frequency generator will be installed and activated, and / or if the product has a regular shape, a low frequency generator will be installed and activated.

[0184] As an example, the generated frequency may be varied at selected time intervals between 1 second and 300 seconds, preferably between 10 seconds and 200 seconds, more preferably between 20 seconds and 120 seconds.

[0185] At least one generator 5 and / or 6 continues to deliver power for a predefined time interval, which can be set from the control and command panel, after which a new scan of the product or compound is performed to determine a new optimal frequency range that produces maximum yield based on the newly detected product or compound characteristics (in particular residual weight and percentage of residual water), depending on the amount of residual water in the product.

[0186] In fact, while drying, the product changes its dielectric properties, so the most effective frequency for heating it changes accordingly.

[0187] Therefore, Mode 2 uses a constant vacuum value and variable frequency operation.

[0188] Method 3:

[0189] In this operating mode, according to the above-mentioned mode M P2 The pressure control means 9, 10, 12 are operated to vary the pressure inside the drying chamber 2 between at least one minimum pressure value and at least one maximum pressure value during the duration of the drying operation.

[0190] Preferably, the minimum pressure value is about 1 mbar and the maximum pressure value is about 999 mbar.

[0191] In one embodiment, the pressure value varies between at least one minimum value and at least one maximum value within a time that can be set via the control and command panel.

[0192] Again, as in Mode 2, in one embodiment, the optimal frequency is selected by scanning the optimal frequency to be used, and a frequency is selected that produces a yield greater than 90%, preferably greater than 95%, and even more preferably greater than 98%.

[0193] In one embodiment of such a third mode, once the scan is completed, at least one generator 5 and / or 6 selected by the operator according to the product to be dried starts delivering power, varying the frequency of the electromagnetic waves generated by selecting from time to time frequency values ​​from those previously selected, which allows a minimum yield of 90% at predetermined intervals that can be set, for example, from a control and command panel present in the device.

[0194] As an example, the generated frequency may be varied at selected time intervals between 1 second and 300 seconds, preferably between 10 seconds and 200 seconds, more preferably between 20 seconds and 120 seconds.

[0195] At least one generator 5 and / or 6 continues to deliver power for a predefined time interval, which can be set from the control and command panel, after which a new scan of the product or compound is performed to determine a new optimal frequency range that produces maximum yield based on the newly detected product or compound characteristics (in particular the residual weight and the percentage of residual water), depending on the amount of residual water in the product.

[0196] In fact, while drying, the product changes its dielectric properties, so the most efficient frequency for heating it changes accordingly.

[0197] Therefore, Mode 3 uses pulsed vacuum and variable frequency operation.

[0198] Method 4:

[0199] In this operating mode, according to the above-mentioned mode M P2 The pressure control means 9, 10, 12 are operated to vary the pressure inside the drying chamber 2 between at least one minimum pressure value and at least one maximum pressure value during the duration of the drying operation.

[0200] Preferably, the minimum pressure value is about 1 mbar and the maximum pressure value is about 999 mbar.

[0201] As in Mode 2 and Mode 3, the optimum frequency value is changed by continuously scanning the product or compound.

[0202] After the product or compound in the chamber has been heated, at least one generator 5 and / or 6 is switched off and the pressure control device is operated so that the pressure inside the drying chamber 2 reaches a value as close to 0 mbar as possible, thereby evaporating as much water as possible by rapidly reducing the water evaporation temperature.

[0203] Then, after reaching a pressure value close to about 0 mbar, the pressure is restored to the starting value varying from 100 mbar to 999 mbar, and at least one generator 5 and / or 6 is operated again to heat the product or compound.

[0204] The process is repeated until the product reaches the desired moisture content.

[0205] Thus, Mode 4 operates using pulsed vacuum and variable frequency alternating with each other.

[0206] In all four modes described, the inorganic and / or organic compounds to be dried, placed on a supporting element 2 ′ inside the drying chamber 2, are projected with electromagnetic waves generated by at least one generator 5 and / or 6, which causes the water contained therein to be heated to its evaporation temperature under the pressure prevailing inside the drying chamber 2.

[0207] The pressure inside the drying chamber 2 is chosen to a value such that the evaporation temperature of the water at this pressure is below a value at which the chemical, physical and structural properties of the treated product may be altered.

[0208] In particular, for organic compounds and products, the temperature is chosen within suitable values ​​so as not to damage the vitamins or degrade the proteins and lipids present, preferably between -40°C and +70°C, preferably between -22°C and +70°C, further preferably between 5°C and 45°C.

[0209] In particular, for inorganic products and compounds, the temperature is selected within a suitable value that does not change the physicochemical structure of the product or compound, and is therefore preferably between -40°C and +99.8°C, preferably between -22°C and +70°C, more preferably between 5°C and 45°C.

[0210] The temperature sensor 16 detects the evaporation temperature of the water at the pressure prevailing in the drying chamber 2 .

[0211] When the evaporation temperature is reached, the evaporation process of the water present in the inorganic and / or organic compound begins, which turns into vapor that expands inside the drying chamber 2 .

[0212] The generated steam is conveyed to the outside of the drying chamber and condensed by using a condensate separation device 11 and collected in a container via a discharge valve.

[0213] The achievement of the desired degree of drying (i.e. the percentage of residual moisture in the inorganic and / or organic compound) is detected by measuring the weight reduction of the inorganic and / or organic compound using the load cell system 200. In fact, the weight reduction measures the amount of water evaporated and therefore the reduction in the moisture content of the inorganic and / or organic compound.

[0214] A receiving portion may be provided below the housing 1 to accommodate an electromagnetic wave generator, a vacuum pump, and a cooler device for condensing moisture.

[0215] In a possible embodiment, the percentage of residual water contained in the inorganic and / or organic compound is 1 to 20% by weight.

[0216] The detection of residual water in inorganic and / or organic compounds is performed based on thermogravimetric analysis, for example, using a thermobalance or a moisture meter, for example, using a Instruments branded and supplied by the German manufacturer KERN&SOHN GmbH.

[0217] The drying modes described so far generally apply to static or discontinuous type drying systems, e.g. Figure 4 and Figure 5 As shown in the implementation method in .

[0218] In another possible embodiment, the same drying modes (modes 1 to 4) as described above can also be applied to a continuous drying system, such as FIG. 5A to FIG. 5C As shown, the drying chamber 102 is a modular drying chamber made by connecting in series at least two drying chambers 2 as described above.

[0219] The drying chambers 2 are connected in series with each other in a modular manner by means of vacuum-sealed flanges to make a single drying chamber 102, the volume of which is large enough to accommodate a single-stage or multi-stage automatic belt or frame handling system 112, wherein the frames 112 travel through the individual modules 2, passing through specific gaps 113 formed between each module, such as Figure 5B shown.

[0220] The gap 113 is preferably of such a size that it prevents electromagnetic waves generated in each individual module from escaping, thereby allowing each individual module 2 to operate independently of the other modules in one possible embodiment and thus applying different frequencies to each individual module that do not interfere with each other.

[0221] Such a single drying chamber 102 is equipped with a loading system 103 and an unloading system 104 for the products for feeding or unloading the products onto a belt or a frame in the loading chamber or the unloading chamber via respective automatic vacuum-tight rotary valves 103', 104'.

[0222] The individual drying chambers 102 are equipped with an automatic vacuum generation system 120 comprising pressure regulating means 9, 10, 12. In this possible embodiment, each module is equipped with one or more propagation elements 3 and / or electrodes 2, 4 as previously described.

[0223] Preferably, the device according to the present invention comprises a drying chamber 102, which is made with the aid of a plurality of drying chambers 2 connected in series to each other and can be operated individually (for example, only some of the drying chambers 2 are present in the drying chamber 102) or simultaneously (for example, all the drying chambers 2 are present in the drying chamber 102), wherein preferably, in each case (when they are operable individually and when they are operable simultaneously), each drying chamber 2 is set and programmed to operate with parameters that are different from or the same as the parameters of another drying chamber 2 within the drying chamber 102; wherein preferably, an automatic belt or frame handling system 112 travels through the drying chambers 2 connected in series, passing through the corresponding gaps formed between adjacent drying chambers 2.

[0224] Figure 5D An embodiment is shown relating to an automatically continuously operated drying system comprising a plurality of drying chambers which can be operated individually or simultaneously, and at least one frame 51 or preferably a plurality of frames, wherein a frame handling system is configured to move the frames and feed a certain amount of product to be dried to a drying chamber equipped with a device for adjusting the pressure P, and to retrieve the dried product from the drying chamber, wherein each module is equipped with one or more electromagnetic wave propagation elements which are preferably arranged along the same surface of the drying chamber.

[0225] The product to be dried is placed in a frame 51, which has an appropriate size to hold the desired amount of product based on the specific weight of the product and the desired production capacity. The size of the frame ranges from 500mm per side to 3500mm per side, for example. The frame can also be rectangular in shape. The frame 51 is transferred from the frame accumulator 52 into the product loading area 53. From there, it is evenly distributed over the entire surface of the frame via the distribution roller 55A. Next, the frame 51 is transferred to the elevator feeding area 54 (channel area), from which the frame 51 enters the entrance area 54A of the rising elevator 55, and once in the rising elevator 55, the sensor system (not shown in the figure) signals that the frame is in place. Next, the frame picking system 56 picks up the frame 51 and lifts it to the height of the drying chamber 57, which is ready to receive the frame 51 and is signaled via the PLC by a specific sensor (not shown in the figure) designed to select the nearest empty drying chamber ready to receive the frame 51, to start the drying phase. The generator 58 of electromagnetic waves is similar to those described above and is integrally mounted with the surface of the drying chamber. Once it is determined by means of other appropriate sensors (not shown in the figure) that the frame is positioned in the correct position, the top of the drying chamber is lowered onto the frame by means of a piston 59 and forms with it a waterproof parallelepiped-shaped cavity, at which a vacuum is generated by means of a pump P and an electric valve P1. The vacuum is maintained at a predetermined pressure by means of a pressure switch RV, which controls the air inlet and air discharge valves A1, which are connected to the suction and discharge system A. The product is subjected to the electromagnetic wave field introduced through appropriate waveguides. After drying is completed, the top of the cavity is raised via the piston 59 and the frame moves to the descending elevator zone 511, where it is picked up by the unloading device 510 and controlled by the PLC via appropriate positioning sensors, then descended via the descending elevator 511, and then moved to the tipping zone 512, where the frame is lifted laterally via a piston (not shown in the figure). In this way, the dried product slides onto a conveyor belt (not shown) for subsequent processing steps. From here, the frame is transferred to the frame downward zone 513, and returns to the beginning of the assembly line via the frame return device 514, to start a new cycle again.

[0226] Application Example 1:

[0227] With regard to plant products such as fruit and vegetables, where it is necessary to maintain the nutritional and organoleptic properties of the product, with the aid of the device of the invention it is possible to establish a drying profile which allows the vacuum level to reach very low pressures (for example, up to 30 mbar, at which water evaporates at 24.1°), thus ensuring that the product never exceeds this temperature, rather than being cooled by actual evaporation of water, which is known to absorb heat.

[0228] Additionally, a stabilization time may be established in which, while the system remains in vacuum, no energy is supplied for several minutes so that when energy application is resumed, the moisture within the product is evenly redistributed, thereby facilitating the drying process.

[0229] In the specific case of apples, for example, it was found that by applying a vacuum of 30 mbar and a heating time of 20 minutes with a pause of 3 minutes, it was possible to dry the product in 3.5 hours, with a completely uniform finished moisture of 11%-12%, and maintaining the integrity of the visual (color), olfactory and taste properties, while also stopping the typical oxidation processes characteristic of apple products in contact with air. In contrast, the drying time of conventional air drying systems varies between 24 hours and 36 hours.

[0230] Application Example 2:

[0231] With regard to inorganic products such as perhaps cement or brick products, it has been observed that the most effective and rapid method of carrying out effective drying is to heat the product to a pressure close to atmospheric pressure (about 500 mbar) and then suddenly reduce the pressure to a very low value (about 20 Mbar), since these products are able to withstand high temperatures very well. At this stage, there is a sudden evaporation of water and a large amount of water is expelled from the product itself and sucked out by the vacuum system. For example, for clay tiles using a pulsating vacuum system, starting with a pressure of 500 mbar, where the product reaches a temperature of 81 degrees, maintains this temperature for 5 minutes, and then reduces its pressure to 20 mbar over the next 10 minutes, and continues this type of cycle, using the device of the present invention, it is possible to dry the product in about 4 hours, instead of the 7 days required by traditional methods.

Claims

1. A device for reducing the water content present in inorganic and / or organic compounds of plant or animal origin, comprising: A housing (1) which is made waterproof and defines a drying chamber (2) or defines the drying chamber within the housing; A pressure regulating device (9, 10, 12), the pressure regulating device being suitable for adjusting the pressure value inside the drying chamber (2) so that the pressure value remains lower than the atmospheric pressure value; a heating device (5 and / or 6) for heating the inorganic and / or organic compound in the drying chamber (2), the heating device comprising at least one first generator (5) of electromagnetic waves having at least one first frequency (f1) and / or at least one second generator (6) of electromagnetic waves having at least one second frequency (f2) lower than the first frequency (f1), Wherein, the device further comprises: at least one propagation element (3) for propagating said electromagnetic waves having said at least one first frequency (f1) in said drying chamber (2), said at least one propagation element being connected to said first generator (5) of electromagnetic waves having said at least one first frequency (f1); and / or at least one pair of electrodes (4, 2), said at least one pair of electrodes being used to propagate said electromagnetic waves having said at least one second frequency (f2) in said drying chamber (2), wherein a first electrode (4) is connected to said second generator (6) of electromagnetic waves having said at least one second frequency (f2), and a second electrode (2) is grounded.

2. The device according to claim 1, wherein: The pressure regulating device (9, 10, 12) is operated to adjust the pressure value in the drying chamber (2) so that during the drying operation, the pressure is maintained at a constant value, or so that during the duration of the drying operation, the pressure assumes a value that changes between at least one minimum pressure value and at least one maximum pressure value.

3. The device according to claim 1 or 2, wherein: The dimensions of the drying chamber (2) are defined as a function of the wavelength of the electromagnetic waves generated by the generator (5 and / or 6), preferably between 43 mm per side and 4000 mm per side, or having sides of different sizes determined in the range between 43 mm and 4000 mm.

4. The device according to claim 1 or 2, wherein: The drying chamber (2) is cylindrical in shape and its dimensions are defined as a function of the wavelength of the electromagnetic waves generated by the generator (5 and / or 6), the drying chamber (2) preferably having a diameter between 43 mm and 4000 mm.

5. A device according to any one of the preceding claims, wherein: The drying chamber (2) comprises at least one wall made of a microperforated material.

6. A device according to any one of the preceding claims, comprising a plurality of propagation elements (3), which are used to propagate the electromagnetic waves having the first frequency (f1) in the drying chamber (2), and the plurality of propagation elements (3) are arranged on at least one surface of the drying chamber (2).

7. The device according to claim 6, wherein: The propagation elements (3) are arranged at the surface of the drying chamber (2) according to a pattern comprising a first group of propagation elements (3') and a second group of propagation elements (3"), wherein the first group of propagation elements (3') and the second group of propagation elements (3") are parallel to each other, and the second group of propagation elements (3") are in a staggered position relative to the first group of propagation elements (3'), wherein the propagation elements transmit the same frequency simultaneously in phase, or transmit the same frequency in a staggered pattern.

8. A device according to any one of the preceding claims, wherein: The pressure regulating device (9, 10, 12) comprises: at least one regulating valve (9) for conveying air from the environment to the interior of the drying chamber (2), and at least one vacuum pump (12) for sucking fluid from the drying chamber (2) to the external environment so that the fluid is placed under vacuum.

9. The device according to any one of the preceding claims, wherein: The first generator (5) of electromagnetic waves having the at least one first frequency (f1) comprises a generator of high-frequency electromagnetic waves having at least one frequency (f1) between 900 MHz and 3000 MHz, preferably between 915 MHz and 3000 MHz.

10. The device according to any one of the preceding claims, wherein: Said second generator (6) of electromagnetic waves having said at least one second frequency (f2) comprises a generator of low-frequency electromagnetic waves having at least one frequency (f2) between 10 MHz and 920 MHz, preferably between 10 MHz and 914 MHz.

11. A device according to any of the preceding claims, comprising a control logic unit (13) which is connected at least to the pressure regulating device (9, 10, 12) and at least to the generator (5 and / or 6) with electromagnetic waves.

12. The device according to any one of the preceding claims, wherein: The second ground electrode (2) includes a surface of the drying chamber (2).

13. The device according to any one of the preceding claims, comprising a first filter (7) for preventing electromagnetic waves having a frequency lower than the first frequency (f1) from being transmitted from the drying chamber (2) to the first generator (5) of electromagnetic waves having the first frequency (f1).

14. The device according to any of the preceding claims, comprising a second filter (8) for preventing electromagnetic waves having a frequency higher than the second frequency (f2) from passing from the drying chamber (2) to the second generator (6) of electromagnetic waves having the second frequency (f2).

15. A device according to any one of the preceding claims, wherein: The at least one propagation element (3) for propagating the electromagnetic waves having the first frequency (f1) in the drying chamber (2) comprises a waveguide and / or a connector / antenna system.

16. A device according to any one of the preceding claims, wherein: The drying chamber (2) comprises at least one supporting element (2'), which is made of a material that is transparent to the electromagnetic waves generated by the electromagnetic wave generator (5 and / or 6).

17. The device according to any of the preceding claims, comprising a drying chamber (102) made by means of a plurality of drying chambers (2) connected in series to one another and capable of being operated individually or simultaneously, wherein: An automatic belt or frame handling system (112) travels through said drying chambers (2) connected in series, passing through respective gaps formed between adjacent drying chambers (2).

18. The device according to any one of claims 1 to 16, comprising a plurality of drying chambers (2) which can be operated individually or simultaneously, wherein: The frame handling system is configured to feed a quantity of product to be dried into the drying chamber (2) and to withdraw a quantity of dried product from the drying chamber (2).

19. The device according to claim 18, wherein: The frame handling system is configured to handle at least one frame (51) to feed the quantity of product to be dried to the drying chamber (2) and to retrieve the quantity of dried product from the drying chamber (2).

20. The apparatus of claim 19, wherein the frame processing system is configured to process a plurality of frames (51).

21. A method for reducing the water content present in inorganic and / or organic compounds of plant or animal origin by means of a device according to any one of claims 1 to 20, comprising the following steps: (a) introducing the inorganic and / or organic compound to be dried into the drying chamber (2); (b) heating the inorganic and / or organic compound to a temperature causing evaporation of water contained in the inorganic and / or organic compound; (c) maintaining the temperature until the amount of water contained in the inorganic and / or organic compound decreases to a predetermined value; (d) extracting the evaporated water from the drying chamber (2); (e) extracting the dried inorganic and / or organic compound from the drying chamber (2), It is characterized by the fact that said step (b) of heating said inorganic and / or organic compound comprises the following steps: (b1) operating the pressure regulating device (9, 10, 12) to adjust the pressure so that the pressure value inside the drying chamber (2) remains lower than the atmospheric pressure value throughout the duration of the drying operation; (b2) operating the at least one first generator (5) of electromagnetic waves having at least one first frequency (f1) and / or the at least one second generator (6) of electromagnetic waves having at least one second frequency (f2) lower than the first frequency (f1) to generate electromagnetic waves in the drying chamber (2) to be projected onto the inorganic and / or organic compound, wherein the pressure value in the drying chamber (2) is selected so that the evaporation of the water contained in the inorganic and / or organic compound occurs at a drying temperature between -40°C and +99.8°C, preferably between -22°C and +70°C, more preferably between 5°C and +45°C, and wherein, The at least one first generator (5) of electromagnetic waves having the at least one first frequency (f1) generates high-frequency electromagnetic waves having at least one frequency (f1) between 900 MHz and 3000 MHz, preferably between 915 MHz and 3000 MHz, and / or the at least one second generator (6) of electromagnetic waves having the at least one second frequency (f2) generates low-frequency electromagnetic waves having at least one frequency (f2) between 10 MHz and 920 MHz, preferably between 10 MHz and 914 MHz.

22. The method according to claim 21, wherein: The at least one first generator (5) of electromagnetic waves having the at least one first frequency (f1) and / or the at least one second generator (6) of electromagnetic waves having the at least one second frequency (f2) can be present alone in the device according to any one of claims 1 to 20.

23. The method according to claim 21, wherein: The at least one first generator (5) of electromagnetic waves having the at least one first frequency (f1) and the at least one second generator (6) of electromagnetic waves having the at least one second frequency (f2) are operated alternately.

24. The method according to claim 21, wherein: The at least one first generator (5) of electromagnetic waves having the at least one first frequency (f1) and the at least one second generator (6) of electromagnetic waves having the at least one second frequency (f2) operate simultaneously.

25. The method according to any one of claims 21 to 24, wherein: The generator (5 and / or 6) is configured to continuously vary the frequency and / or phase shift of the electromagnetic waves.

26. The method according to any one of claims 21 to 25, wherein: The pressure value in the drying chamber (2) is between 0.01 mbar and 999 mbar, preferably between 0.05 mbar and 999 mbar, more preferably between 9 mbar and 100 mbar.

27. The method according to any one of claims 21 to 25, wherein: In the step (b1), the pressure regulating device (9, 10, 12) is operated to maintain the pressure in the drying chamber (2) at a constant value throughout the duration of the drying operation.

28. The method according to any one of claims 21 to 26, wherein: In the step (b1), the pressure regulating device (9, 10, 12) is operated to change the pressure in the drying chamber (2) between at least one minimum pressure value and at least one maximum pressure value throughout the duration of the drying operation.

29. The method according to claim 28, wherein: The minimum pressure value is about 1 mbar and the maximum pressure value is about 200 mbar.

30. The method according to any one of claims 21 to 29, further comprising, after the step (d) of extracting the evaporated water from the drying chamber (2): A step of condensing the evaporated water from said inorganic and / or organic compounds by means of a condensation separator element (11).

31. The method according to any one of claims 21 to 30, wherein: The step of introducing the inorganic and / or organic compound to be dried into the drying chamber (2) comprises the step of moving the at least one frame (51) configured to feed a quantity of the product to be dried into the drying chamber (2), and wherein the step of extracting the dried inorganic and / or organic compound from the drying chamber (2) comprises the step of retrieving the at least one frame (51) with the quantity of the dried product.

32. A method according to claim 31, comprising the step of moving a plurality of frames (51).

33. Use of a device according to any one of claims 1 to 20 for drying organic and / or inorganic compounds of plant or animal origin.

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