JP2020021678A - Microwave heating device - Google Patents

Abstract

To eliminate the needs of a complicated rotation mechanism, a complicated real machine verification, an expensive semiconductor oscillator and a change of a control program in the case of a size change of a reaction vessel when heating a microwave heating subject in a uniform manner.SOLUTION: The present disclosure relates to a microwave heating device M in which multiple antennas 5-1 to 5-6 are disposed inside of a conductive storage 4 in such a manner that a storage position of a microwave reaction vessel 1 is enclosed and that a distance between adjacent antennas becomes substantially equal. A distance between a disposing position of each of the antennas and an inner wall of the conductive storage 4 is a length substantially equal to 1/4 of a wavelength λ of an irradiation microwave in a view of the disposing position of each of the antennas from the storage position of the microwave reaction vessel 1. The distance is a length different from 1/4 of the wavelength λ of the irradiation microwave in a view of the disposing position of each of the antennas from any other position than the storage position of the microwave reaction vessel 1.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a technique for uniformly heating a microwave heating target.

  2. Description of the Related Art In recent years, chemical processing using microwave heating has been in the spotlight, for example, a chemical product manufacturing plant having a small size, low power consumption, and a high reaction rate has been put to practical use. For example, in the production of chemical products such as nanoparticles and polymers, techniques for producing valuable products by irradiating microwaves to materials to be heated such as raw materials and microwave heating catalysts are disclosed in Non-Patent Documents 1 and 2. Have been.

Tsukahara and Yasuda, “Microwaves in Catalytic Chemistry”, Journal of the Institute of Electrical Engineers of Japan, The Institute of Electrical Engineers of Japan, 2012, Vol. 10-12 Takeuchi, Nagahata, "Microwave in Polymer Synthetic Chemistry", Journal of the Institute of Electrical Engineers of Japan, The Institute of Electrical Engineers of Japan, 2012, Vol. 13-16

  Here, a continuous-type reaction vessel is generally used as a reaction vessel because of the necessity of mass production of products in the chemical industry. However, in the case of a continuous reaction vessel, when a microwave is applied to a material to be heated having a high microwave absorptivity, uneven heating of the material to be heated occurs significantly. Therefore, in the case of a continuous reaction vessel, it is conceivable to improve the uneven heating of the substance to be heated by using a turntable, a stirrer fan, and interference pattern control.

  However, in the case of a continuous-type reaction vessel, a complicated rotation mechanism is required to improve the airtightness of the reaction vessel when using a turntable to improve heating unevenness of the substance to be heated.

  In the case of a continuous-type reaction vessel, when the heating unevenness of the substance to be heated is improved using a stirrer fan, a complicated actual machine is used to optimize the number of rotations of the fan, the number of blades, the length of the blades, and the like. Verification is required.

  Furthermore, in the case of a continuous reaction vessel, when improving the uneven heating of the substance to be heated by using the interference pattern control, (1) an expensive semiconductor oscillator is required to control the oscillation frequency and the oscillation phase with high accuracy. (2) When the size of the reaction vessel is changed, the control program needs to be changed.

  Therefore, in order to solve the above problems, the present disclosure, when heating the microwave heating target evenly, a complicated rotation mechanism, a complicated actual machine verification, an expensive semiconductor oscillator, and, when changing the size of the reaction vessel It is an object of the present invention to make it unnecessary to change the control program.

  In order to solve the above-mentioned problem, a plurality of antennas are arranged in a conductive storage so as to surround a storage position of a microwave heating target. Then, the directivity of each antenna is concentrated and directed to the storage position of the microwave heating target.

  Specifically, the present disclosure includes a conductive hangar that stores a microwave heating target substantially at the center, and a plurality of antennas that irradiate the microwave to the microwave heating target, and the plurality of antennas includes a microwave. It is arranged in the conductive storage so as to surround the storage position of the wave heating target and so that the distance between the adjacent antennas is substantially equal, and the arrangement position of each antenna and the position of the conductive storage are The distance between the inner wall and the inner wall is equal to approximately 1/4 of the wavelength of the irradiated microwave in the direction in which the arrangement position of each antenna is viewed from the storage position of the microwave heating target. The microwave heating device is characterized in that the length is different from １ ／ of the wavelength of the irradiated microwave in the direction in which the arrangement position of each antenna is viewed from a position other than the above.

  According to this configuration, a complicated rotating mechanism, a complicated actual machine verification, an expensive semiconductor oscillator, and a change in a control program when changing the size of the reaction vessel can be made unnecessary.

  Further, the present disclosure is characterized in that the timing at which the plurality of antennas irradiate microwaves is set such that the antennas facing each other via the storage position of the microwave heating target do not simultaneously irradiate microwaves. It is a wave heating device.

  According to this configuration, it is possible to prevent microwave power from flowing from one of the opposed antennas to the other of the opposed antennas.

  As described above, the present disclosure requires a complicated rotation mechanism, a complicated actual machine verification, an expensive semiconductor oscillator, and a change in the control program when the size of the reaction vessel is changed, in order to uniformly heat the microwave heating target. It can be unnecessary.

1 is a diagram illustrating a schematic configuration of a microwave heating device according to the present disclosure. FIG. 2 is a diagram illustrating an antenna arrangement of the microwave heating device according to the present disclosure. FIG. 3 is a diagram illustrating irradiation timing of the microwave heating device according to the present disclosure.

  Embodiments of the present disclosure will be described with reference to the accompanying drawings. The embodiments described below are examples of the present disclosure, and the present disclosure is not limited to the following embodiments.

  FIG. 1 shows a schematic configuration of the microwave heating device of the present disclosure. The microwave heating apparatus M includes a microwave reaction vessel 1, a raw material inlet 2, a product flow outlet 3, a conductive storage 4, and antennas 5-1, 5-2, 5-3, 5-4, 5-5, 5 -6.

  In the microwave reaction vessel 1, a product is generated from a raw material in chemical processing. In the case of a raw material having a high microwave absorptivity, the raw material itself generates heat by microwave absorption, so that a microwave heating catalyst having a high microwave absorptivity is not required in the microwave reaction vessel 1. In the case of a raw material having a low microwave absorption rate, the microwave heating catalyst generates heat by microwave absorption and heats the raw material by heat transfer. is necessary. The raw material inlet 2 flows the raw material into the microwave reactor 1. The product stream outlet 3 allows the product to flow out of the microwave reactor 1.

  The conductive storage 4 stores the microwave reaction vessel 1 substantially at the center. The antennas 5-1 to 5-6 irradiate the microwave to the microwave reaction vessel 1. Here, the antennas 5-1 to 5-6 are dipole antennas (in the case of FIG. 1) or monopole antennas (not shown in FIG. 1) and the like, and a power supply device outside the conductive housing 4 (not shown in FIG. 1). ). And, since the wavelength λ of the irradiation microwave is set so that the microwave absorptivity of the material to be heated such as the raw material or the microwave heating catalyst is high, the uneven heating of the material to be heated does not significantly occur. The configuration described below is adopted.

  The antennas 5-1 to 5-6 are arranged in the conductive housing 4 so as to surround the storage position of the microwave reaction container 1 and to make the distance between adjacent antennas substantially equal. The directivity of the antennas 5-1 to 5-6 is concentrated on the storage position of the microwave reaction vessel 1. Specifically, the configuration shown in FIG. 2 is employed.

  FIG. 2 shows an antenna arrangement of the microwave heating device of the present disclosure. The upper and lower sections of FIG. 2 show a plan view and a side sectional view of the microwave heating device M, respectively.

  The distance between the arrangement position of the antennas 5-1 to 5-6 and the inner wall of the conductive storage 4 is determined in a direction in which the arrangement positions of the antennas 5-1 to 5-6 are viewed from the storage position of the microwave reaction vessel 1. The length is almost equal to １ ／ of the wavelength λ of the irradiated microwave. That is, the resonance conditions of the antennas 5-1 to 5-6 are satisfied in the direction of the storage position of the microwave reaction container 1.

  Regarding the distance between the arrangement position of the antennas 5-1 to 5-6 and the inner wall of the conductive storage case 4, the arrangement position of the antennas 5-1 to 5-6 is viewed from a position other than the storage position of the microwave reaction container 1. In the direction, the length is different from １ ／ of the wavelength λ of the irradiated microwave. That is, the resonance conditions of the antennas 5-1 to 5-6 are not satisfied in directions other than the storage position of the microwave reaction container 1.

  Therefore, the directivity of the antennas 5-1 to 5-6 concentrates on the storage position of the microwave reaction vessel 1. If the size of the microwave reaction vessel 1 is within about twice or less of the power half-depth of the substance to be heated in the optimal temperature range of the chemical reaction, the uneven heating of the substance to be heated can be improved. .

  As described above, since the antennas 5-1 to 5-6 surround the storage position of the microwave reaction vessel 1, a complicated rotating mechanism is not required for ensuring the airtightness of the microwave reaction vessel 1.

  Then, since the distance between the arrangement position of the antennas 5-1 to 5-6 and the inner wall of the conductive housing 4 is optimized based only on the wavelength λ of the irradiation microwave, complicated actual device verification is not required. .

  Further, since the directivity of the antennas 5-1 to 5-6 is concentrated and directed to the storage position of the microwave reaction vessel 1, (1) the oscillation frequency and the oscillation phase do not need to be controlled with high accuracy, and the cost is high. (2) When the size of the microwave reaction vessel 1 is changed within a range of about twice or less the power half-depth, the control program does not need to be changed.

  Here, the antennas 5-1 and 5-4 face each other via the storage position of the microwave reaction vessel 1, and the antennas 5-2 and 5-5 face each other via the storage position of the microwave reaction vessel 1. , Antennas 5-3 and 5-6 face each other via the storage position of the microwave reaction vessel 1. The directivity of the antennas 5-1 to 5-6 is concentrated on the storage position of the microwave reaction vessel 1.

  Therefore, the microwave power flows from the antenna 5-1 (5-4) to the antenna 5-4 (5-1), and the microwave power flows from the antenna 5-2 (5-5) to the antenna 5-5 (5-2). , And the microwave power flows from the antenna 5-3 (5-6) to the antenna 5-6 (5-3). In order to prevent this, the configuration shown in FIG. 3 is adopted.

  FIG. 3 shows the irradiation timing of the microwave heating device of the present disclosure. The upper and lower parts of FIG. 3 show a first timing and a second timing, respectively.

  The timing at which the antennas 5-1 to 5-6 irradiate the microwaves is set so that the antennas facing each other via the storage position of the microwave reaction container 1 do not simultaneously irradiate the microwaves. Specifically, the first timing and the second timing are repeatedly switched.

  At the first timing, the antennas 5-1, 5-3, and 5-5 irradiate microwaves, while the antennas 5-2, 5-4, and 5-6 stop irradiating microwaves.

  At the second timing, the antennas 5-2, 5-4, and 5-6 irradiate the microwave, while the antennas 5-1, 5-3, and 5-5 stop irradiating the microwave.

  Thus, it is possible to prevent microwave power from flowing from one of the opposed antennas to the other of the opposed antennas.

  In the present embodiment, the shape of the conductive housing 4 on the plan view is circular. As a modification, the shape of the conductive housing 4 on the plan view may be a polygon. In short, the distance between the arrangement position of the antennas 5-1 to 5-6 (the number of antennas may be an arbitrary plural number) and the inner wall of the conductive housing 4 is determined by the wavelength λ of the irradiated microwave. It is only necessary to optimize based on only

  In the present embodiment, the number of antennas is six. As a modification, the number of antennas may be an arbitrary plurality. Specifically, the number of antennas may be set to a value not too small so that uneven heating of the material to be heated can be improved, and the number of antennas may be set so as not to complicate the configuration of the microwave heating device M. Should not be too many.

  The microwave heating apparatus according to the present disclosure, when heating the microwave heating object uniformly, requires complicated rotation mechanism, complicated actual machine verification, expensive semiconductor oscillator, and control program change when the size of the reaction vessel is changed. Can be eliminated.

M: Microwave heating apparatus 1: Microwave reaction vessel 2: Raw material inlet 3: Product stream outlet 4: Conductive storage 5-1 5-2, 5-3, 5-4, 5-5, 5-6 :antenna

Claims (2)

A conductive hangar for storing the microwave heating target substantially at the center, and a plurality of antennas for irradiating the microwave to the microwave heating target,
The plurality of antennas are arranged in the conductive housing so as to surround the storage position of the microwave heating target, and so that the distance between adjacent antennas is substantially equal,
The distance between the position where each antenna is disposed and the inner wall of the conductive storage is equal to approximately １ ／ of the wavelength of the irradiated microwave in the direction in which the position where each antenna is disposed is viewed from the position where the microwave is heated. A microwave heating device having a length different from one-fourth of the wavelength of the irradiated microwave in a direction in which the arrangement position of each antenna is viewed from a position other than the storage position of the microwave heating object. . The timing at which the plurality of antennas irradiate microwaves is set so that antennas facing each other via the storage position of the microwave heating target do not simultaneously irradiate microwaves. The method according to claim 1, wherein: Microwave heating device.

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