Microwave vacuum concentration / drying machine and microwave vacuum concentration / drying method

Abstract

To provide a compact and low-cost microwave vacuum concentrator / dryer capable of achieving highly accurate concentration / drying.SOLUTION: A microwave vacuum concentrator / dryer 1 according to the present invention, comprises: a concentrating / drying chamber body 5 provided with an opening 3 for setting, bringing in, and discharging a concentrating / drying tray T; opening / closing means 7 attached to the opening 3 to form a shielded space in the concentrating / drying chamber body 5; a microwave radiation device 9 comprising a microwave oscillator 10 and a waveguide 12; a depressurizing device 301 of depressurizing the concentrating / drying chamber body 5; a microwave intensity sensor 81 of detecting an incident wave intensity MA and a reflected wave intensity MB of microwaves; a light intensity detection sensor 85 of detecting the light intensity S of sparks and plasma generated in the concentrating / drying chamber body 5; and a concentration / drying controller 89 comprising a calculator 87 that determines the timing of finishing concentration / drying according to a mathematical relation calculated from the concentrating / drying rate H obtained from the weight change of the concentrating / drying object beforehand and a ratio F of the reflected wave intensity MB of microwaves with the light intensity S added thereto, relative to the incident wave intensity MA of microwaves.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a microwave vacuum concentrator / dryer that irradiates a material to be concentrated / dried with microwaves under a reduced pressure atmosphere to concentrate / dry the material to a predetermined concentrated / dried state, and a microwave vacuum concentrator / dryer method that is carried out by using the microwave vacuum concentrator / dryer. [Background technology]

[0002] Conventionally, microwave vacuum concentrator / driers have been used as devices for concentrating and drying materials to a desired concentrated and dried state, and can obtain a high-quality concentrated and dried state without damaging the components contained in the raw material, as disclosed in Patent Document 1 below. This microwave vacuum concentration / drying machine is equipped with a weight measuring device that measures the weight of the material to be concentrated / dried during concentration / drying, which changes from moment to moment, and the concentration / drying control of the material to be concentrated / dried and the timing of the end of concentration / drying are determined based on the weight of the material to be concentrated / dried measured by this weight measuring device. If microwave vacuum concentration / drying is performed while measuring the weight of the material to be concentrated / dried using such a weight measuring device, concentrated / dried products with the target concentration / drying rate can be accurately produced. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-172875 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a weight measuring device is provided in a microwave vacuum concentrator / dryer, the weight measuring device is susceptible to the effects of microwaves, and so a complex shielding structure is required to prevent microwaves from propagating to the weight measuring device. Incidentally, in the above-mentioned Patent Document 1, a microwave shielding space is formed at the installation location of the weight measuring device using an upper shielding plate, a lower shielding plate, and a microwave shielding panel, and a microwave influence prevention mechanism with an integrated double choke structure is provided in the shielding space. Furthermore, in the case of a multi-stage microwave vacuum concentrator / dryer in which the concentrating / drying chamber is divided into multiple stages, there are cases in which a weight measuring device cannot be installed due to structural reasons.

[0005] However, the addition of such a weight measuring device or a complex microwave propagation prevention structure results in an increase in the size of the equipment and in the production costs, so there was a need for the development of a microwave vacuum concentrator / dryer that could monitor the concentration / drying state of the materials to be concentrated / dried without using a weight measuring device.

[0006] The present invention has been made based on these points, and its purpose is to develop a new means of grasping the concentrated / dried state of the material to be concentrated / dried instead of weight, to provide a small and inexpensive microwave vacuum concentrator / dryer, and to enable efficient mass production of high-quality, inexpensive concentrated / dried products. [Means for solving the problem]

[0007] In order to achieve the above object, a microwave reduced pressure concentrating / drying apparatus according to claim 1 of the present invention comprises a concentrating / drying chamber body having at least one opening for placing and loading / unloading a material to be concentrated / dried, an opening / closing means attached to the opening in an openable / closable state and forming a shielded space within the concentrating / drying chamber body when closed, a microwave irradiation device having a microwave oscillator and a waveguide attached to the concentrating / drying chamber body and irradiating microwaves toward the material to be concentrated / dried contained within the concentrating / drying chamber body to concentrate / dry the material, a pressure reducing device connected to the concentrating / drying chamber body and reducing the pressure within the concentrating / drying chamber body, and a pressure reducing device attached to the waveguide. a microwave amount detection sensor mounted on the outside of the concentration / drying chamber body and detecting the amount of incident microwaves and the amount of reflected microwaves, a light amount detection sensor mounted on the outside of the concentration / drying chamber body and detecting the amount of light energy consisting of sparks and plasma generated within the concentration / drying chamber body through a detection window provided in the concentration / drying chamber body, and a calculation device for determining the timing of concentration / drying control and the end of concentration / drying of the material to be concentrated / dried based on a relational expression calculated from a concentration / drying rate previously determined from a weight change of the material to be concentrated / dried and a ratio of the amount of reflected microwaves to the amount of incident microwaves determined by the microwave amount detection sensor plus the amount of light determined by the light amount detection sensor; of It is characterized in that it is equipped with

[0008] Further, the microwave reduced pressure concentrator / dryer according to claim 2 is the microwave reduced pressure concentrator / dryer according to claim 1, characterized in that the concentration / drying control device is provided with an output value variable device that varies the output value or an output value regulator that adjusts the output value so that the output value range of the light quantity of light energy detected by the light quantity detection sensor falls within the output value range of the incident wave quantity and reflected wave quantity of microwaves detected by the microwave quantity detection sensor.

[0009] Further, the microwave reduced pressure concentrator / dryer according to claim 3 is the microwave reduced pressure concentrator / dryer according to claim 1 or 2, characterized in that the concentration / drying control device is provided with a concentration / drying completion notification / execution means for either notifying or executing the completion of concentration / drying, or both, when the completion of concentration / drying is determined by the calculation device.

[0010] Further, the microwave reduced pressure concentrator / dryer according to claim 4 is a microwave reduced pressure concentrator / dryer according to any one of claims 1 to 3, characterized in that the detection window has light transparency that allows light generated within the concentration / drying chamber body to pass outside the concentration / drying chamber body, airtightness that maintains a reduced pressure atmosphere within the concentration / drying chamber body, and microwave leakage prevention performance that prevents microwaves irradiated into the concentration / drying chamber body from leaking outside the concentration / drying chamber body.

[0011] Further, the microwave vacuum concentrator / dryer according to claim 5 is a microwave vacuum concentrator / dryer according to any one of claims 1 to 4, characterized in that the concentration / drying chamber main body is provided with a product temperature detection sensor for detecting the product temperature of the material to be concentrated / dried in the concentration / drying chamber main body, and the concentration / drying control device performs PID control for controlling the ON / OFF of microwave irradiation by the microwave irradiation device based on the change in product temperature of the material to be concentrated / dried detected by the product temperature detection sensor, and the calculation device takes a moving average value of values ​​that vary depending on the ON / OFF of microwave irradiation performed by the PID control and the timing of capturing the incident wave amount, reflected wave amount and light amount of the microwave, and judges whether the moving average value has reached a preset target value to determine the timing to end the concentration / drying of the material to be concentrated / dried.

[0012] In addition, the microwave vacuum concentration / drying method according to claim 6 of the present invention uses a test machine for a microwave vacuum concentration / drying machine, which is provided with a weight measuring device for measuring the weight of the object to be concentrated / dried, a microwave amount detection sensor for detecting the amount of incident microwave waves and the amount of reflected microwave waves, and a light amount detection sensor for detecting the amount of light energy from sparks and plasma generated in the main body of the concentration / drying chamber, to test the change in the concentration / drying rate of the object to be concentrated / dried and the amount of reflected microwave waves relative to the amount of incident microwave waves. The light quantity was obtained by the above-mentioned light quantity detection sensor. The apparatus is characterized in that the change in ratio taking into account the amount of light is calculated, a set ratio value corresponding to the target concentration / drying rate is calculated from the relational equation calculated from the change in the concentration / drying rate of the material to be concentrated / dried and the change in the ratio measured above, and when the actual ratio value measured by an actual microwave vacuum concentrator / dryer equipped with a microwave amount detection sensor that detects the amount of incident and reflected microwave waves, and a light amount detection sensor that detects the amount of light energy from the sparks and plasma generated in the concentration / drying chamber body, reaches the set ratio value, it is determined that the concentration / drying of the material to be concentrated / dried is completed.

[0013] The microwave reduced pressure concentration / drying method according to claim 7 is the microwave reduced pressure concentration / drying method according to claim 6, characterized in that in calculating the above-mentioned relational equation, an average ratio obtained by averaging the actual measured changes in ratio by a moving average method is used as the change in ratio used in calculating the relational equation.

[0014] The microwave reduced pressure concentration / drying method according to claim 8 is the microwave reduced pressure concentration / drying method according to claim 6 or 7, characterized in that in calculating the above relational equation, a regression analysis is performed on the amount of change in the concentration / drying rate of the material to be concentrated / dried and the amount of change in the ratio measured in the concentration / drying rate and ratio measurement work, and the relational equation is calculated using the power curve obtained. Effect of the Invention

[0015] The above means can provide the following effects: First, the microwave vacuum concentrator / dryer of the present invention is provided with a microwave irradiator having a microwave generator and a waveguide, and the waveguide is provided with a microwave amount detection sensor for detecting the amount of incident and reflected microwaves. Also, a light amount detection sensor is provided on the outside of the concentrating / drying chamber body of the microwave vacuum concentrator / dryer for detecting the amount of light energy from the sparks and plasma generated in the concentrating / drying chamber body.

[0016] Furthermore, the microwave reduced pressure concentrator / dryer of the present invention is provided with a concentration / drying control device having a calculation device which sets the timing of concentration / drying control and the end of concentration / drying of the material to be concentrated / dried based on a relational expression calculated from the concentration / drying rate previously determined from the weight change of the material to be concentrated / dried and the ratio of the reflected microwave wave amount to the incident microwave wave amount determined by the microwave amount detection sensor, taking into account the light amount determined by the light amount detection sensor.

[0017] Therefore, it becomes possible to accurately control the concentration and drying of the materials to be concentrated and dried and to determine the timing for ending the concentration and drying based on the above relational equation, without being based on the change in weight of the materials to be concentrated and dried measured by a weight measuring device. This makes it possible to provide a small, inexpensive microwave vacuum concentrator / dryer that does not require a weight measuring device or a complex shielding structure that prevents microwaves from propagating to the weight measuring device, enabling efficient mass production of high-quality, inexpensive concentrated and dried products.

[0018] In addition, when an output value adjuster that adjusts the output value or an output value adjuster that adjusts the output value is provided so that the output value range of the light energy amount detected by the light amount detection sensor falls within the output value range of the incident wave amount and reflected wave amount of the microwave detected by the microwave detection sensor, the light energy amount that has been adjusted or varied can be added directly to the reflected wave amount of the microwave to obtain a more accurate target ratio. This makes it possible to more accurately control the concentration and drying of the material to be concentrated and dried and to determine the timing of the end of the concentration and drying.

[0019] In addition, if a concentration / drying control device is provided with a concentration / drying completion notification / execution means that notifies or executes the completion or both of the concentration / drying completion when the completion of the concentration / drying is judged by the calculation device, it becomes possible to notify an operator of the completion of the concentration / drying of the material to be concentrated / dried.In addition, it becomes possible to automatically stop the operation of the microwave vacuum concentration / drying device. Furthermore, if the detection window is configured to be optically transparent, airtight, and have microwave leakage prevention properties, it becomes possible to place the light quantity detection sensor outside the concentration / drying chamber body where it is not directly affected by microwaves, and detect the quantity of light energy consisting of sparks and plasma generated inside the concentration / drying chamber body.

[0020] In addition, if a product temperature detection sensor that detects the temperature of the material to be concentrated / dried in the concentration / drying chamber body is provided in the concentration / drying chamber body, and the concentration / drying control device is configured to perform PID control that controls the ON / OFF of microwave irradiation based on the change in product temperature of the material to be concentrated / dried detected by the product temperature detection sensor, it becomes possible to perform highly accurate concentration / drying control of the material to be concentrated / dried that corresponds to the type and properties of the material to be concentrated / dried. Furthermore, if the calculation device takes a moving average value of the values ​​that fluctuate depending on the ON / OFF of microwave irradiation performed by the above-mentioned PID control and the timing of capturing the incident wave amount, reflected wave amount and light amount of microwaves, and determines whether the moving average value has reached a preset target value to determine the timing of completion of concentration / drying of the materials to be concentrated / dried, it becomes possible to determine the timing of completion of concentration / drying of the materials to be concentrated / dried with high accuracy, corresponding to the type and properties of the materials to be concentrated / dried.

[0021] Furthermore, in the microwave vacuum concentrating / drying method of the present invention, when measuring the concentration / drying rate and ratio, a test microwave vacuum concentrating / drying machine equipped with a weight measuring device capable of accurately measuring the concentration / drying rate of the material to be concentrated / dried is used to measure changes in the concentration / drying rate and changes in the ratio, so that it becomes possible to calculate the following relational equation with high accuracy. Since the concentration and drying of the materials to be concentrated and dried is actually carried out based on the above relational expressions using an actual microwave vacuum concentrator / dryer that is not equipped with the above weight measuring device, the structure is simplified and the timing for completing the concentration and drying of the materials to be concentrated and dried can be determined with high accuracy.

[0022] Furthermore, when calculating the above relational equation, if an average ratio obtained by averaging the actual measured changes in ratio using the moving average method is used as the change in ratio used to calculate the relational equation, it becomes possible to stably capture the reflected wave amount and light amount, which have large fluctuations, and a highly accurate relational equation can be calculated.

[0023] Furthermore, when calculating the above relational equation, if a regression analysis is performed on the change in the concentration and drying rates of the concentrated and dried materials measured when measuring the concentration and drying rates and the ratio, and the change in the ratio is used to calculate the relational equation as a power curve, it can be said that there is a negative correlation that would be a problem if it were calculated as a linear regression line, and furthermore, a relational equation based on a highly accurate power curve that is closer to the actual measurement data can be obtained. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a front view showing a microwave vacuum concentrator-dryer according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a diagram showing an embodiment of the present invention, and is a plan view showing a microwave vacuum concentrator-dryer. [Diagram 3] FIG. 1 is a right side view showing a microwave vacuum concentrator-dryer, illustrating an embodiment of the present invention. [Figure 4] FIG. 1 is a rear view showing a microwave vacuum concentrator-dryer according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a diagram showing an embodiment of the present invention, and is a front view showing an enlarged portion of a microwave leakage prevention mechanism applied to an opening of a concentrator / dryer body. [Figure 6] FIG. 2 is a side cross-sectional view showing an enlarged portion of a microwave leakage prevention mechanism applied to an opening of a concentrating / drying chamber body, illustrating an embodiment of the present invention. [Figure 7] FIG. 1 is a perspective view showing an embodiment of the present invention, illustrating a state in which a concentration / drying tray on which materials to be concentrated / dried are arranged is set on a mounting table. [Figure 8] FIG. 1 is a diagram showing an embodiment of the present invention, and is an explanatory diagram showing an example of a pressure reducing device applied to a microwave vacuum concentrator-dryer. [Figure 9] FIG. 1 is a diagram showing an embodiment of the present invention and is a block diagram showing the operation of a microwave reduced pressure concentration / drying method. [Figure 10] This is a schematic diagram showing the principle of the test machine used in measuring concentration / dryness rate and ratio. [Figure 11] This is a schematic diagram showing the principle of the actual machine used in the concentration / drying completion judgment work. [Figure 12] FIG. 13 is a diagram showing a flow for calculating a relational expression used in determining completion of concentration and drying of a material to be concentrated and dried, and is a graph showing the measurement results of the amount of incident microwaves. [Figure 13] FIG. 13 is a diagram showing a flow until a relational expression used for judging the completion of concentration and drying of a material to be concentrated and dried is calculated, and is a graph showing a measurement result of the amount of reflected microwaves. [Figure 14] FIG. 13 is a diagram showing a flow until a relational expression used for judging completion of concentration and drying of a material to be concentrated and dried is calculated, and is a graph showing a measurement result of the light amount of plasma, etc. [Figure 15] FIG. 13 is a diagram showing the flow of calculating the relational equation used to determine the completion of concentration and drying of the material to be concentrated and dried, and is an explanatory diagram showing an image of calculating the ratio from the above three measurement results. [Figure 16] FIG. 13 is a diagram showing a flow for calculating a relational expression used in determining the completion of concentration and drying of a material to be concentrated and dried, and is a graph showing a transition of the ratio. [Figure 17] This is a diagram showing the process for calculating the relational equation used to determine the completion of concentration and drying of the material to be concentrated and dried, and is a graph showing the correlation between the concentration / drying rate and the ratio, and the regression line when linear regression is performed. [Figure 18] This is a diagram showing the flow for calculating the relational equation used to determine the completion of concentration and drying of the concentrated and dried materials, and is a graph showing the correlation between the concentration / drying rate and the ratio, and the regression line when changed to a power curve. [Figure 19] This is a chart showing the effect of taking light intensity into account in calculating the ratio, comparing the error between the actual reflectance and the predicted reflectance at the end of concentration / drying when light intensity is taken into account and when it is not. [Figure 20] 10 is a flowchart showing a process for determining completion of concentration and drying of a material to be concentrated and dried by using a calculated relational expression. [Figure 21] This figure shows the results of a concentration / drying test of cellulose nanofiber (CNF), and is a graph showing the correlation between concentration / drying rate and ratio and the regression line as a power curve. [Figure 22] This figure shows the results of a concentration / drying test of cellulose nanofiber (CNF), and is a chart comparing the error between the actual reflectance and the predicted reflectance at the end of concentration / drying when light intensity is taken into account and when light intensity is taken into account. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The microwave vacuum concentrator / dryer and the microwave vacuum concentrator / dryer method of the present invention will be described in detail below, taking the illustrated embodiment as an example. First, the overall configuration of the microwave vacuum concentrator / dryer of the present invention will be outlined, and then the configuration of the main parts of the microwave vacuum concentrator / dryer of the present invention will be described in detail. Next, the microwave vacuum concentration and drying method of the present invention, which is carried out by using the microwave vacuum concentration and drying apparatus of the present invention as an actual machine, will be explained for each operation, together with the configuration of the test machine and the actual machine used in each operation. Furthermore, the conditions and methods of the concentration and drying test carried out on frozen mandarin oranges and cellulose nanofiber will be briefly explained. Finally, another embodiment of the present invention, which has a partially different configuration from the present embodiment configured as described above, will be mentioned.

[0026] (1) Overview of the overall configuration of the microwave vacuum concentrator / dryer (see Figures 1 to 8) The microwave vacuum concentrating / drying apparatus 1 of the present invention comprises a concentrating / drying chamber body 5 having at least one opening 3 for placing and carrying in / out an object A to be concentrated / dried, an opening / closing means 7 attached to the opening 3 in an openable / closable state and forming a shielded space within the concentrating / drying chamber body 5 when the opening 3 is closed, a microwave irradiating device 9 having a microwave oscillator 10 and a waveguide 12 attached to the concentrating / drying chamber body 5 and irradiating microwaves M toward the object A to be concentrated / dried contained in the concentrating / drying chamber body 5 to concentrate / dry the object A, and a microwave irradiating device 9 connected to the concentrating / drying chamber body 5 and making the atmosphere within the concentrating / drying chamber body 5 into a reduced pressure atmosphere. The apparatus is basically composed of a pressure reducing device 301 for reducing the pressure in the container 11, a microwave amount detection sensor 81 provided for the waveguide 12 and detecting the incident wave amount MA and reflected wave amount MB of the microwaves M, a light amount detection sensor 85 provided outside the concentration / drying chamber main body 5 and detecting the light amount S of the light energy consisting of sparks and plasma generated in the concentration / drying chamber main body 5 through a detection window 83 provided in the concentration / drying chamber main body 5, and a concentration / drying control device 89 having a calculation device 87 for determining the timing of concentration / drying control and the end of concentration / drying of the material A to be concentrated / dried based on a relational equation calculated from the concentration / drying rate H and ratio F obtained in advance.

[0027] The illustrated microwave vacuum concentrator / dryer 1 is a so-called batch-type microwave concentrator / dryer, and is provided with a sliding door 8 as an example of the opening / closing means 7. The concentrator / dryer body 5 is supported by a support stand 23 formed by assembling angle bars or the like into a rectangular frame shape, and slide rails 43A, 43B are provided above and below an opening 3 formed in the front surface of the support stand 23, extending horizontally in the left-right direction X. Meanwhile, two sliders 44A that engage with the slide rail 43A and two sliders 44B that engage with the slide rail 43B are provided on the upper and lower edges of the opening / closing door 8. In addition, two pressing members 47, 47 are provided near the upper slide rail 43A, and are configured to press the opening / closing door 8 that has come to the closed position toward the support stand 23, thereby increasing the airtightness of the opening 3.

[0028] The concentrating / drying chamber 25 is formed by attaching an opening / closing door 8 to the concentrating / drying chamber body 5 supported by the support stand 23. The concentrating / drying chamber 25 is divided into two chambers, a first concentrating / drying chamber 27 and a second concentrating / drying chamber 29, so that, for example, two stages of concentrating / drying trays T can be arranged in the vertical direction Z. Accordingly, the microwave irradiation devices 9 and the mounting tables 95 are also arranged, for example, in pairs, corresponding to the concentrating / drying trays T, T of each stage.

[0029] In the present embodiment, two microwave irradiators 9 are disposed so as to protrude leftward from the left side plate of the concentration / drying chamber main body 5 as an example. The microwave irradiators 9 are configured, as an example, by including a microwave oscillator 10 having a variable output of, as an example, 1.5 kW, and a waveguide 12 extending from the microwave oscillator 10. As a result, microwaves M are irradiated toward the inside of the concentration / drying chamber body 5 from the irradiation port 15 formed on the left side plate of the concentration / drying chamber body 5. Incidentally, a sheet (not shown) made of polytetrafluoroethylene (trade name "Teflon (registered trademark)") is attached to the irradiation port 15 as an example, and is configured to allow the microwaves M oscillated from the microwave oscillator 10 to pass but to prevent the evaporated moisture generated from the material A to be concentrated and dried by concentration and drying from entering the microwave oscillator 10 side. Also, on the left side plate of the concentrating / drying chamber body 5, as shown in FIG. 8, there are provided an outside air inlet pipe 31 for introducing air Q from the outside, and a control valve 32 for switching on / off the introduction of air Q and adjusting the amount of air introduced, for example, one set each on the top and bottom.

[0030] In addition, on the right side panel of the concentrating / drying chamber main body 5 as an example, product temperature detection sensors 79 constituted by radiation thermometers as an example for measuring the product temperature of the material A to be concentrated / dried during concentration / drying are provided at positions corresponding to the two concentration / drying trays T, T mentioned above. The product temperature information of the concentrated / dried material A measured by the product temperature detection sensor 79 is sent to a control device (not shown) and is configured to be used for PID control (described later) that controls the output of the microwaves M irradiated from the microwave irradiator 9 based on this product temperature information.

[0031] In addition, handles 41 are provided near the left and right ends of the front of the opening / closing door 8 to serve as handles for opening and closing the opening / closing door 8, and a locking member (not shown) is provided at an appropriate position on the front of the opening / closing door 8 as necessary to ensure that the opening / closing door 8 is closed.

[0032] Furthermore, a microwave leakage prevention mechanism 21 is provided on the back surface of the opening / closing door 8 when it is in the closed state so as to surround the opening 3 of the concentration / drying chamber main body 5. Also, on the outside of the microwave leakage prevention mechanism 21, a seal structure 13 is provided having a seal member 11 constituted, as an example, by a ring-shaped rubber packing that abuts against a seal surface 61 around the opening 3 of the concentration / drying chamber main body 5 when the opening / closing door 8 is in the closed state.

[0033] The microwave leakage prevention mechanism 21 is provided on the intermediate path 63 between the opening 3 and the above-mentioned sealing structure 13, and has a double choke integrated sealing structure in which the first choke 17 located on the opening 3 side and the second choke 19 located on the sealing structure 13 side are continuously arranged at a predetermined pitch in the circumferential direction so as to face each other. Specifically, as shown in FIG. 6, a base end 69 is raised vertically from one edge of a shielding plate 65 arranged along the back surface of the opening and closing door 8, and the tip of the base end 69 is bent inward by 90° to form a tip end 67, thereby providing a first choke 17 having an L-shaped cross section. Similarly, a second choke 19 of the same shape and size as the first choke 17 is provided on the other edge of the shielding plate 65, and the first choke 17 and second choke 19 are arranged in opposing positions to form a microwave leakage prevention mechanism 21.

[0034] Furthermore, a gap G is formed between the tip 67 of the first choke 17 and the tip 67 of the second choke 19, and the distance L1 from the midpoint O of the gap G to the connection point B of the tip 67 and base end 69 of each of the first choke 17 and the second choke 19 is approximately equal to the distance L2 to the tangent point C between a perpendicular line drawn from the midpoint O towards the shielding plate 65 and the opposing surface of the shielding plate 65, and both are set to be approximately 1 / 4 the length of the wavelength λ of the microwaves M used. Incidentally, by adopting such dimension settings, a detour having a length of 1 / 4 of the wavelength λ is formed in the intermediate path 63. Then, the phase difference between the reflected wave at the detour and the wave traveling from the connection point B to the midpoint O becomes 1 / 2 of the wavelength λ, and they cancel each other out, so leakage of the microwaves M to the outside of the concentrating / drying chamber 25 is prevented.

[0035] Next, the decompression device 301 will be described. In the microwave reduced pressure concentrating / drying apparatus 1 according to this embodiment, the concentrating / drying chamber body 5 has an airtight structure and a pressure-resistant structure that can withstand use under a reduced pressure atmosphere with the opening 3 closed by the opening / closing door 8. A decompression device 301 is disposed at the rear as an example of the concentrating / drying chamber body 5, and is configured to be able to perform concentration / drying by microwaves M under a reduced pressure atmosphere by connecting this decompression device 301 to the concentrating / drying chamber body 5 via appropriate piping 302 and branch pipe 337.

[0036] The pressure reducing device 301 may be a pressure reducing device of a basic structure only including a vacuum connector, a vacuum pump, a vacuum path, and a control valve (not shown), or it is possible to employ pressure reducing devices of various structures that exert the desired pressure reducing effect, such as a pressure reducing device having a structure including a water seal vacuum pump 305 and a circulating water supply and drainage device 307 as shown in FIG. 8. The pressure reducing device 301 shown in FIG. 8 includes the water ring vacuum pump 305 and the circulating water supply and drainage device 307 as described above, and further includes a water supply path 309 and a drainage path 311 disposed between them.

[0037] The water ring vacuum pump 305 is a pump used for evacuating gas containing water vapor or water droplets, and forms a water seal ring on the inner wall of the cylinder by utilizing the rotation of an impeller attached eccentrically to the cylinder, and performs pumping action by utilizing the volume change of the space surrounded by the water seal ring and the impeller blades.

[0038] The circulating water supply and drainage system 307 is configured, as an example, by having an upper tank 313 and a lower tank 315 inside the support frame 303, and the upper tank 313 is provided with a water supply nozzle 317 for supplying water from the outside, a ball tap 319 for measuring the water level in the upper tank 313, and a temperature sensor 321 for measuring the water temperature in the upper tank 313. Meanwhile, an underwater pump 323 is arranged in the lower tank 315, and is configured to pump up the water discharged from the above-mentioned water ring vacuum pump 305 and accumulated in the lower tank 315 through the discharge path 311 and supply it to the upper tank 313.

[0039] In addition, a three-way valve 327 driven by a motor, for example, is disposed in the middle of the circulation path 325 connecting the submersible pump 323 and the upper tank 313, and by appropriately switching the three-way valve 327, the water pumped up by the submersible pump 323 can be supplied into the upper tank 313 or discharged to the outside. The above-mentioned water supply path 309 extends from the bottom of the upper tank 313, and the other end of the water supply path 309 is connected to the above-mentioned water ring vacuum pump 305. Furthermore, a needle valve 247 is disposed in the middle of the discharge path 235 connecting the concentrating / drying chamber body 5 and the water ring vacuum pump 305, for taking in air Q from the outside and adjusting the pressure inside the path.

[0040] (2) Specific configuration of the main parts of the microwave vacuum concentrator / dryer (see Figures 1 to 8, 10 and 11) The characteristic configuration of the microwave reduced pressure concentrator / dryer 1 of the present invention is that, as a means for grasping the concentrated / dried state of the material A to be concentrated / dried, the weight of the material A to be concentrated / dried is not used, but a previously calculated relational equation is used to determine a set ratio value F0 corresponding to the target concentration / drying rate H0 obtained by the relational equation, and the concentrated / dried state of the material A to be concentrated / dried is grasped based on whether or not the measured actual ratio value F1 reaches the set ratio value F0. In addition, in calculating the above relational expression, a microwave vacuum concentrator / dryer testing machine 101 equipped with a weight measuring device 97 using a load cell or the like as shown in FIG. 10 is used, and the relational expression is calculated from the concentration / drying rate H obtained in advance from the weight change of the concentrated / dried object A measured by this testing machine 101 and the ratio F=(MB+S) / MA of the reflected wave amount MB of the microwave M to the incident wave amount MA of the microwave M obtained by the microwave amount detection sensor 81, taking into account the light amount S obtained by the light amount detection sensor 85. The specific calculation flow of the above relational expression will be explained in detail later in the explanation of the microwave vacuum concentration / drying method of the present invention.

[0041] First, a microwave amount detection sensor 81 that detects the incident wave amount MA and reflected wave amount MB of microwaves M will be described. As an example of the microwave amount detection sensor 81, a power monitor can be used. The power monitor is provided with an antenna unit that can receive incident waves and reflected waves together, and the incident wave received by the antenna unit is determined as the incident direction by a diode provided in an incident detection circuit and output as a voltage. Similarly, the reflected wave received by the antenna unit is determined as the reflected direction by a diode provided in a reflected wave detection circuit and output as a voltage. Moreover, the voltage detected and output by the power monitor is converted from an analog signal to a digital signal by an A / D converter 91 and sent to the arithmetic unit 87 in the concentration / drying control device 89 .

[0042] Next, the light amount detection sensor 85 that detects the light amount S of the light energy consisting of the sparks and plasma generated in the concentrating / drying chamber main body 5 will be described. An optical variable resistor (CdS cell) can be used as the light amount detection sensor 85, for example. The optical variable resistor (CdS cell) is small, with a diameter of about 5 mm, but has the characteristics of high sensitivity and fast response speed. In accordance with this, the concentration / drying control device 89 is provided with an output value variable device 92, for example constituted by a fixed resistor, which varies the output value so that the output value range of the light energy quantity S detected by the light quantity detection sensor 85 falls within the output value range of the incident wave quantity MA and reflected wave quantity MB of the microwave M detected by the microwave quantity detection sensor 81, or an output value adjuster 93, for example constituted by a variable resistor, which adjusts the output value.

[0043] The concentration / drying control device 89 is also provided with a concentration / drying end notification / execution means 99 which, when the end of concentration / drying is determined by the calculation device 87, notifies an operator of the end of concentration / drying or automatically executes the end of concentration / drying. Furthermore, the detection window 83 to which the light quantity detection sensor 81 is attached has a structure that combines light transmittance that allows light generated within the concentration / drying chamber body 5 to pass outside the concentration / drying chamber body 5, airtightness that maintains the reduced pressure atmosphere within the concentration / drying chamber body 5, and microwave leakage prevention performance that prevents the microwaves M irradiated into the concentration / drying chamber body 5 from leaking outside the concentration / drying chamber body 5. Specifically, a structure using a transparent glass plate and punching metal is adopted as one example.

[0044] In addition, the concentrating / drying chamber main body 5 is provided with the above-mentioned product temperature detection sensor 79 that detects the product temperature of the material A to be concentrated / dried in the concentrating / drying chamber main body 5, and the concentrating / drying control device 89 is configured to execute PID control 103 that controls the ON / OFF of microwave irradiation based on the change in product temperature of the material A to be concentrated / dried detected by this product temperature detection sensor 79. PID is an abbreviation of Proportional Integral Derivative, and PID control 103 is a control that controls the output of microwaves M in proportion to the change in temperature of the material A to be concentrated and dried, and further corrects the value by integral control and differential control.

[0045] For example, when the set product temperature is α under constant concentration / drying conditions, the output of the microwaves M is high immediately after the microwaves M are oscillated in the PID control 103, and after the product temperature reaches the set product temperature α, the output of the microwaves M decreases. After that, as the concentration / drying degree of the material A to be concentrated / dried progresses over time, the output of the microwaves M gradually decreases as the product temperature is maintained constant. The calculation device 87 is configured to calculate a moving average value of values ​​that fluctuate depending on the ON / OFF of the irradiation of the microwaves M performed by the PID control 103 and the timing of capturing the incident wave amount MA, reflected wave amount MB and light amount S of the microwaves M, and to determine whether the moving average value has reached a preset target value to set the timing for completing the concentration and drying of the material A to be concentrated and dried.

[0046] (3) Details of microwave vacuum concentration and drying method (see Figures 9 to 20) The microwave reduced pressure concentration / drying method of the present invention includes a concentration / drying completion determination step P3 that is performed during the concentration / drying operation based on the concentration / drying rate and ratio measurement step P1 that are performed before the concentration / drying operation and the relational equation calculated by the relational equation calculation step P2. Below, we will explain in detail the content of each of these tasks, the configuration of the test equipment and actual equipment used, the flow of calculating the relational equation, and the flow of judging the completion of concentration and drying using the relational equation. We will also explain the conditions and methods of the actual concentration and drying tests conducted on frozen mandarins and cellulose nanofibers.

[0047] (a) Concentration / drying rate and ratio measurement The concentration / drying rate and ratio measurement work P1 is a work to obtain the change in the concentration / drying rate H of the material A to be concentrated / dried and the change in the ratio F=(MB+S) / MA, which is the ratio of the reflected wave amount MB of microwave M to the incident wave amount MA of microwave M plus the light amount S, using a microwave vacuum concentration / dryer testing machine 101 equipped with a weight measuring device 97 for measuring the weight of the material A to be concentrated / dried, a microwave amount detection sensor 81 for detecting the incident wave amount MA and reflected wave amount MB of microwave M, and a light amount detection sensor 85 for detecting the light amount S of light energy consisting of sparks and plasma generated in the concentration / drying chamber main body 5.

[0048] 10 is a schematic diagram showing the principle of a testing machine 101. It has a configuration basically similar to that of the microwave vacuum concentrator-dryer 1 of the present invention described above, and only one microwave oscillator 10 with a microwave output of 1.5 kW and an initial output of 800 W is provided, and a vacuum pump with a pressure of -93 kPa is used. In addition, the testing machine 101 is equipped with a load cell as an example of a weight measuring device 97 that is not provided in the actual machine 105, and is configured so that the weight of the material A to be concentrated and dried can be measured at any time using this weight measuring device 97 during concentration and drying.

[0049] 12 is a graph showing the incident wave amount MA of the microwave M measured using a power monitor which is the microwave detection sensor 81. The horizontal axis is time (s) and the vertical axis is voltage (V). Also, Figure 13 is a graph of the reflected wave amount MB of the microwave M, measured using a power monitor. As in Figure 12, the horizontal axis is time (s) and the vertical axis is voltage (V). 14 is a graph of the amount of light measured using an optical variable resistor (CdS cell) which is the light amount detection sensor 85. As described above, the output value range of the amount of light S is adjusted by a variable resistor or fixed resistor so that it falls within the output value range of the incident wave amount MA and the reflected wave amount MB.

[0050] Next, the ratio F = (MB + S) / MA is calculated from the incident wave amount MA, reflected wave amount MB, and light amount S measured above, as shown in the image diagram in Figure 15. Figure 16 is a graph showing the transition of the calculated ratio F, which was calculated using the moving average method to reduce variation. The horizontal axis is time (s) and the vertical axis is the ratio (%). As is clear from the figure, when the moisture content of the concentrated / dried material A decreases, the reflected wave amount MB and light amount S increase. If only the output of the microwaves M were controlled, there would be no problem with only the reflected wave amount MB and light amount S, but in the case of PID control, the incident wave amount MA is not constant, so the ratio F is used.

[0051] Fig. 17 is a graph showing the correlation between the concentration / drying rate H and the ratio F and the regression line V when linear regression is performed by measuring the concentration / drying rate H=W÷W0 from the concentrated / dried weight W of the concentrated / dried material A measured by the weight measuring device 97 and the weight before the start of concentration / drying W0. The horizontal axis is the ratio F (%) and the vertical axis is the concentration / drying rate H (%). As is clear from the figure, when the concentrated and dried weight W decreases due to concentration and drying, the ratio F increases.

[0052] Next, the regression line was changed from the linear regression line V to the power curve regression line U. Figure 18 is a graph showing the correlation between the concentration / dryness rate H and the ratio F, and the case where the regression line was changed to a power curve. As in Figure 17, the horizontal axis is the ratio F (%) and the vertical axis is the concentration / dryness rate H (%). As is clear from the figure, the regression line U of the power curve is closer to the scatter plot than the linear regression line V shown in Figure 17, and it is therefore possible to determine the desired timing for the end of concentration / drying.

[0053] (b) Calculation of the relational equation The relational equation calculation task P2 is a task of finding the relational equation between the amount of change in the concentration / drying rate H of the concentrated / dried material A measured above and the amount of change in the ratio F. When the regression line U of the power curve in FIG. 18 is expressed in a mathematical expression, it becomes H=0.03×F to the power of -1.92. When this expression is transformed into an expression for calculating the ratio F, it becomes F=(H / 0.03) to the power of (1 / -1.92), and the relational expression for calculating the ratio F is calculated. Note that the regression line U of the power curve described above will be a different power curve if the type of the material A to be concentrated / dried is different. Therefore, if the same process is performed for various materials A to be concentrated / dried to create power curves and obtain the relational expression, it will be possible to determine the timing of the end of concentration / drying of various materials A to be concentrated / dried based on the above relational expression, even when using an actual machine 105 that does not have a weight measuring device 97 described next.

[0054] Next, based on FIG. 19, we will explain the results of an investigation into the amount of error that occurs between the actual reflectance and the predicted reflectance at the end of concentration / drying when the light intensity S is taken into account in the calculation of the ratio F and when the light intensity S is not taken into account. When the light intensity S was not taken into account, the actual reflectance at the end of concentration / drying was 42.0%, and the predicted reflectance at the end of concentration / drying was 38.4%. The error rate for both was calculated by taking the ratio of the predicted reflectance at the end to the actual reflectance at the end, and calculating how much this varies from 1 (error rate = absolute value of 1 - (predicted reflectance at end / actual reflectance at end)), which was 8.69%. On the other hand, when the light intensity S was taken into account, the actual reflectance at the end of concentration / drying was 45.0%, and the predicted reflectance at the end of concentration / drying was 43.1%, and the error rate for both was 4.26%. Therefore, taking into account the light intensity S resulted in a smaller error, confirming an improvement in the error rate of 4.43%. Therefore, it was confirmed that it is necessary to take the light amount S into consideration when calculating a relational expression with higher accuracy.

[0055] (C) Judging the completion of concentration and drying The concentration / drying completion judgment task P3 involves using an actual microwave vacuum concentration / dryer 105 equipped with a microwave quantity detection sensor 81 that detects the incident wave quantity MA and reflected wave quantity MB of microwaves M, and a light quantity detection sensor 85 that detects the light quantity S of light energy from the sparks and plasma generated in the concentration / drying chamber main body 5, to determine a set ratio value F0 corresponding to the target concentration / drying rate H0 derived from the above relational equation, and judging that the concentration / drying of the material A to be concentrated / dried is completed when the actual ratio value F1 measured by the actual device 105 reaches the above set ratio value F0.

[0056] 11 is a schematic diagram showing the principle of the actual machine 105, which is basically configured by removing the weight measuring device 97 from the configuration of the above-mentioned test machine 101. Also, a monitoring system 107 can be incorporated into the concentration / drying control device 89 provided in the actual machine 105, and for example, by simply inputting the type of the material A to be concentrated / dried, the weight W0 before the start of concentration / drying, and the target concentration / drying rate H0 from the input screen of the monitoring system 107 displayed on the monitor 109, a set ratio value F0 corresponding to the target concentration / drying rate H0 can be automatically derived from the above relational expression and used to determine the end of concentration / drying of the material A to be concentrated / dried.

[0057] The flow of the concentration / drying end judgment will be specifically described below with reference to the flowchart shown in Fig. 20. An operator starts concentration / drying by inputting necessary input information in step S1 using an input device such as the monitor 109. The necessary input information includes the above-mentioned type of the material A to be concentrated / dried, the weight W0 of the material A to be concentrated / dried before the start of concentration / drying, and the target concentration / drying rate H0. When necessary input information is input in step S1, a suitable relational equation is selected from pre-stored relational equations based on the input information in step S2, and a set ratio value F0 is calculated based on the relational equation in step S3.

[0058] Next, the process proceeds to step S4, where concentration and drying are performed based on PID control in accordance with a predetermined concentration and drying program. During the concentration and drying process, the incident wave amount MA, the reflected wave amount MB, and the light amount S are measured at any time in step S5, and the actual ratio value F1 is calculated each time in step S6. Next, the process proceeds to step S7, where it is determined whether the actual ratio value F1 has reached the set ratio value F0, and if the actual ratio value F1 has reached the set ratio value F0, the process proceeds to step S8, where it is determined whether the concentration / drying of the object to be concentrated / dried A has been completed. When it is determined that the concentration / drying has been completed, the concentration / drying completion notification / execution means 99 is activated to notify the operator of the completion of the concentration / drying, or to automatically terminate the concentration / drying of the microwave vacuum concentration / dryer 1, which is the actual device 105. On the other hand, if it is determined in step S7 that the actual ratio value F1 has not reached the set ratio value F0, concentration and drying are continued, and the process returns to step S5, where measurements of the incident wave amount MA, reflected wave amount MB, and light amount S are repeatedly performed.

[0059] (4) Conditions and methods for concentration and drying tests (a) Concentration and drying test of frozen mandarin oranges The measurement results shown in Figures 12 to 18 are a summary of the results of slicing frozen mandarins, arranging 12 of the slices in concentration / drying tray T and placing them on non-rotating mounting table 95, and conducting concentration / drying tests three times under different concentration / drying conditions. The first run had an initial weight of 200g, a final weight of 28g, and a concentration and drying time of 120 minutes. The second run had an initial weight of 222g, a final weight of 28g, and a concentration and drying time of 90 minutes. The third run had an initial weight of 203g, a final weight of 24g, and a concentration and drying time of 60 minutes. In addition, in this concentration / drying test, the product temperature was uniformly set at 48°C and PID controlled, and since the temperature was low in the early stages of concentration / drying, concentration / drying was performed at an output of 700-800 W. In addition, in the normal concentration / drying, 2000 g of frozen mandarin oranges were concentrated / dried for 4 hours to reduce the weight to 300 g, and the concentration / drying rate in this case was 15%.

[0060] (b) Cellulose nanofiber (CNF) concentration and drying test In this concentration / drying test, cellulose nanofiber (CNF) liquid with a concentration of 2.3% (moisture content 97.7%) was placed in the test machine 101, and the concentration / drying test was carried out three times by changing the concentration / drying conditions as described above. The weight was measured every minute, and the concentration / drying test was carried out by PID control at the following set temperatures. The first run had an initial weight of 505g, a set temperature of 40°, a final weight of 50g, a concentration and drying time of 50 minutes, a CNF concentration of 23%, and a moisture content of 77%. The second run had an initial weight of 507g, a set temperature of 33°, a final weight of 50g, a concentration and drying time of 238 minutes, a CNF concentration of 23%, and a moisture content of 77%. The third run had an initial weight of 501g, a set temperature of 40°, a final weight of 14g, a concentration and drying time of 61 minutes, a CNF concentration of 82%, and a moisture content of 18%.

[0061] Fig. 21 is a graph showing the correlation between the concentration / dryness rate H and the ratio F of the reflected wave amount MB and light amount S to the incident wave amount MA, and the regression line U of the power curve obtained by regression analysis, where the concentration / dryness rate H=W÷W0 is measured from the concentrated / dry weight W of cellulose nanofiber (CNF) measured by a weight measuring device 97 and the weight before the start of concentration / drying W0. The horizontal axis is the ratio F (%) and the vertical axis is the concentration / dryness rate H (%). And, when the regression line U of this power curve is expressed in a mathematical formula, it becomes H = 0.01 × F to the -2.32 power. When this formula is transformed into a formula for calculating the ratio F, it becomes F = (H / 0.01) to the (1 / -2.32) power, and the relational formula for calculating the ratio F can be calculated.

[0062] In addition, in the case of cellulose nanofiber (CNF), we also investigated the amount of error between the actual reflectance and the predicted reflectance at the end of concentration and drying when the amount of light S was taken into account in the calculation of the ratio F and when the amount of light S was not taken into account. The results of this investigation are shown in Figure 22. When the light intensity S was not taken into account, the actual reflectance at the end of concentration / drying was 33.2%, and the predicted reflectance at the end of concentration / drying was 33.4%. The error rate of both was calculated by taking the ratio of the actual reflectance at the end to the predicted reflectance at the end, and the ratio of how much this reflectance deviates from 1 (error rate = absolute value of 1-(predicted reflectance at end / actual reflectance at end)), which was 0.69%. On the other hand, when the light intensity S was taken into account, the actual reflectance at the end of concentration / drying was 34.56%, and the predicted reflectance at the end of concentration / drying was 34.72%, and the error rate of both was 0.45%. Therefore, in the case of cellulose nanofiber (CNF), the error was smaller when the light intensity S was taken into account, albeit slightly, and an improvement in the error rate of 0.24% was confirmed. In this way, in the concentration / drying test of cellulose nanofiber (CNF), a power curve was obtained, just as in the concentration / drying test of frozen mandarins described above, and a relational equation was calculated from this power curve, making it possible to concentrate and dry with high precision based on the above relational equation, just like in the case of frozen mandarins described above.

[0063] (5) Other embodiments The microwave vacuum concentrator / dryer and microwave vacuum concentrator / drying method of the present invention are not limited to the above-mentioned embodiments, and may be modified within the gist of the invention. For example, the microwave vacuum concentrator / dryer 1 of the present invention described above has a two-stage concentrator / dryer chamber 25 with the first concentrator / dryer chamber 27 and the second concentrator / dryer chamber 29 arranged above and below, but the microwave vacuum concentrator / dryer 1 may have only one concentrator / dryer chamber 25 as shown in the principle diagram of an actual device 105 in Fig. 11. Also, the microwave vacuum concentrator / dryer 1 may have three or more concentrator / dryer chambers 25.

[0064] In addition, in the microwave vacuum concentrator / dryer 1 of the present invention described above, only one light intensity detection sensor 85 is provided for the concentration / drying chamber main body 5, but in the case of a microwave vacuum concentrator / dryer 1 of a type having multiple concentration / drying chambers 25, it is possible to provide multiple light intensity detection sensors 85 corresponding to the number of concentration / drying chambers 25. In addition, even if the concentrated / dried material A is the same type, the concentrated / dried state may change depending on the cut size, etc., in the case of the concentrated / dried material A, it is also possible to make it possible to correct the reference set ratio value F0 based on the judgment of the operator, etc. In addition, in the case of a microwave reduced pressure concentrator / dryer 1 dedicated to the concentrated / dried material A, which has a relatively small moisture content and is less affected by sparks and plasma, it is also possible to omit the light quantity detection sensor 85 and calculate the above relational expression only from the incident wave quantity MA and reflected wave quantity MB of the microwave M.

[0065] In addition, the test apparatus 101 can also be configured in the same manner as the microwave reduced pressure concentrator-dryer 1 of the above-mentioned actual apparatus 105, and when manufacturing a new actual apparatus 105, it is also possible to manufacture the test apparatus 101 by using a microwave reduced pressure concentrator-dryer of the same specifications as the actual apparatus 105 and equipping it with a weight measuring device 97. As an example of a method for controlling the concentration and drying, PID control based on the product temperature was used, but it is also possible to use other methods for controlling the concentration and drying, such as time and output control. In addition, the mounting table 95 provided on the testing machine 101 and the actual machine 105 is not limited to a fixed type mounting table 95, but may be a rotating type mounting table 95 using a rotating table, or may be a system that does not use a drying tray. [Industrial Applicability]

[0066] The microwave vacuum concentrator / dryer and microwave vacuum concentrator / drying method of the present invention can be used in various concentrated / dried product manufacturing fields, such as the manufacturing of concentrated / dried foods made from frozen vegetables and fruits, and the manufacturing of concentrated / dried products for adjusting the concentration of cellulose nanofibers, etc., and can be particularly used when it is desired to provide a small, inexpensive microwave vacuum concentrator / dryer that is capable of concentrating and drying the material to be concentrated / dried with high precision. [Explanation of symbols]

[0067] 1. Microwave vacuum concentrator / dryer 3 Opening 5 Concentration / drying chamber body 7 Opening and closing means 8 Opening and closing doors 9. Microwave irradiation equipment 10 Microwave Oscillator 11 Sealing material 12 Waveguide 13 Seal structure 15 Irradiation port 17 First Chalk 19 Second Chalk 21 Microwave leakage prevention mechanism 23 Support stand 25 Concentration / drying room 27 1st concentration / drying room 29 Second concentration / drying room 31 Outside air intake pipe 32 Control valve 41 Handle 43 Slide rail 44 Slider 47 Holding member 51 Coupling 53 Drive sprocket 55 Chain 57 Driven sprocket 59 Tension sprocket 61 Sealing surface 63 Intermediate Path 65 Shielding plate 67 Tip 69 Proximal end 71 Bevel gear pair 79 Product temperature detection sensor (radiation thermometer) 81 Microwave quantity detection sensor (power monitor) 83 Detection window 85 Light quantity detection sensor (light variable resistor) 87 Arithmetic unit 89 Concentration and drying control device 91 A / D Converter 92 Output value variable device 93 Output value regulator 95 Placement table 97 Weight measuring device (load cell) 99 Concentration / drying completion notification / execution means 101 Testing Machine 103 PID Control 105 Actual Machine 107 Surveillance System 109 Monitor 235 Discharge route 247 Needle Valve 301 Pressure reducing device 302 Piping 303 Support stand 305 Water ring vacuum pump 307 Circulating water supply and drainage equipment 309 Water Supply Route 311 Drainage route 313 Upper Tank 315 Lower Tank 317 Water supply nozzle 319 Ball Tap 321 Temperature Sensor 323 Submersible Pump 325 Circulation Route 327 Three-way valve 337 Branch Pipe A Concentrated / dried material G Gap O midpoint B Connection point C contact L distance λ wavelength D Concentrated / dried products P1 Concentration / drying rate, ratio measurement work P2 Relational equation calculation work P3: Judging the completion of concentration and drying T Concentration and drying tray M Microwave Q Air X Left / right direction Y Depth direction Z vertical direction MA incident wave amount MB amount of reflected waves S Light amount F ratio F0 setting ratio value F1 Actual ratio value H concentration / drying rate H0 Target concentration / drying rate α Set product temperature W concentration / dry weight W0 Weight before starting concentration and drying V Regression Line (Linear) U regression line (power curve)

Claims

1. A concentration / drying chamber body having at least one opening for placing and carrying in / out the material to be concentrated / dried; an opening / closing means that is attached to the opening in an openable / closable state and that forms a shielded space in the concentration / drying chamber body when closed; A microwave irradiation device having a microwave oscillator and a waveguide, which is attached to the concentrating / drying chamber body and irradiates microwaves toward the material to be concentrated / dried contained in the concentrating / drying chamber body to concentrate and dry the material; a pressure reducing device connected to the concentration / drying chamber body and reducing the pressure in the concentration / drying chamber body; a microwave amount detection sensor provided for the waveguide and configured to detect an amount of incident microwaves and an amount of reflected microwaves; a light amount detection sensor provided outside the concentration / drying chamber body and detecting the amount of light energy consisting of sparks and plasma generated in the concentration / drying chamber body through a detection window provided in the concentration / drying chamber body; and a concentration / drying control device having a calculation device that determines the timing of concentration / drying control and the end of concentration / drying of the material to be concentrated / dried, based on a relational equation calculated from a concentration / drying rate previously determined from a weight change of the material to be concentrated / dried and a ratio of a reflected microwave wave amount to an incident microwave wave amount determined by the microwave amount detection sensor, taking into account a light amount determined by the light amount detection sensor.

2. The microwave reduced pressure concentrator / dryer according to claim 1, further comprising an output value adjuster or an output value regulator that adjusts the output value so that the output value range of the light amount of light energy detected by the light amount detection sensor falls within the output value range of the incident wave amount and reflected wave amount of microwaves detected by the microwave amount detection sensor.

3. The microwave reduced pressure concentrator / dryer according to claim 1 or 2, characterized in that the concentration / drying control device is provided with a concentration / drying end notification / execution means for either notifying or executing the end of the concentration / drying or both, when the end of the concentration / drying is determined by the calculation device.

4. The microwave reduced pressure concentrating / drying apparatus according to any one of claims 1 to 3, characterized in that the detection window has light transmittance that allows light generated within the concentrating / drying chamber body to pass outside the concentrating / drying chamber body, airtightness that maintains a reduced pressure atmosphere within the concentrating / drying chamber body, and microwave leakage prevention performance that prevents microwaves irradiated into the concentrating / drying chamber body from leaking outside the concentrating / drying chamber body.

5. The concentrating / drying chamber body is provided with a product temperature detection sensor that detects the temperature of the material to be concentrated / dried in the concentrating / drying chamber body, The concentration / drying control device performs PID control to control the ON / OFF of microwave irradiation by the microwave irradiation device based on the product temperature change of the concentrated / dried material detected by the product temperature detection sensor, and The microwave reduced pressure concentrator / dryer according to any one of claims 1 to 4, characterized in that the arithmetic device calculates a moving average value of values ​​that fluctuate depending on the ON / OFF of microwave irradiation performed by the PID control and the timing of capturing the incident wave amount, reflected wave amount and light amount of the microwave, and judges whether the moving average value has reached a preset target value to determine the timing of ending the concentration / drying of the material to be concentrated / dried.

6. A microwave vacuum concentration / drying method comprising: a test machine for a microwave vacuum concentration / drying machine, the test machine being equipped with a weight measuring device for measuring the weight of the material to be concentrated / dried in advance; a microwave amount detection sensor for detecting the amount of incident microwave waves and the amount of reflected microwave waves; and a light amount detection sensor for detecting the amount of light energy from sparks and plasma generated in the concentration / drying chamber body; a change in the concentration / drying rate of the material to be concentrated / dried and a change in a ratio obtained by adding the amount of light detected by the light amount detection sensor to the amount of reflected microwave waves relative to the amount of incident microwave waves; a set ratio value corresponding to a target concentration / drying rate calculated from a relational expression between the amount of change in the concentration / drying rate of the material to be concentrated / dried and the amount of change in the ratio; and a microwave vacuum concentration / drying machine equipped with a microwave amount detection sensor for detecting the amount of incident microwave waves and the amount of reflected microwave waves, and a light amount detection sensor for detecting the amount of light energy from sparks and plasma generated in the concentration / drying chamber body, the test machine being equipped with a weight measuring device for measuring the weight of the material to be concentrated / dried in advance;

7. 7. The microwave vacuum concentration / drying method according to claim 6, wherein in calculating the relational expression, an average ratio obtained by averaging the actual measured changes in ratio by a moving average method is used as the change in ratio used in calculating the relational expression.

8. The microwave reduced pressure concentration / drying method according to claim 6 or 7, characterized in that in calculating the above-mentioned relational expression, a regression analysis is performed on the change in the concentration / drying rate of the material to be concentrated / dried and the change in the ratio measured in the concentration / drying rate and ratio measurement work, and the relational expression is calculated using a power curve obtained.

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