JP2017162668A - Microwave heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microwave heater capable of controlling the heating for each region of a work to be heated when heating the work to be heated.SOLUTION: The above problem is solved by a microwave heater comprising: a microwave source; a heating chamber in which a work to be heated is set; first and second microwave radiation parts connected to the heating chamber; a first filter provided between the microwave source and the first microwave radiation part; and a second filter provided between the microwave source and the second microwave radiation part. The microwave source is arranged to be able to change the frequency of microwaves to generate. The first and second filters are different from each other in the frequency of microwaves that are allowed to pass therethrough.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a microwave heating apparatus.

  The microwave heating device is to be heated by placing the object to be heated in the heating chamber of the microwave heating device, irradiating the object to be heated with the microwave generated by the microwave generation source, and absorbing it. An apparatus for heating an object (for example, Patent Document 1). In such a microwave heating apparatus, the microwave radiated into the heating chamber is repeatedly reflected on the wall surface of the heating chamber and is irradiated to the object to be heated.

  In general, a microwave heating device uses a magnetron, which is a kind of vacuum tube, as a microwave generation source. By using a semiconductor element instead of a magnetron, the microwave heating device can be reduced in size and weight. Output controllability can be improved. As such a semiconductor element, for example, a semiconductor element using gallium nitride or the like capable of flowing a large current with a high breakdown voltage even in a high frequency region can be given.

JP 2009-16149 A JP2013-201096A Japanese Patent No. 10-172750

  In the microwave heating apparatus, the object is usually to uniformly heat the object to be heated, but there are cases where it is desired to heat only a part of the object to be heated. For example, when a lunch box containing food, such as salad, rice, and meat, is heated, rice and meat may be warmed, but the salad may not be warmed. In such a case, if it is heated with a microwave heating device that uniformly heats the entire lunch box, the salad that is not desired to be heated will be heated.

  In addition, even when the object to be heated is heated by a microwave heating device for the purpose of uniform heating, the object to be heated is not heated uniformly, resulting in a heated area and an unheated area. There is. In such a case, in order to uniformly heat the entire object to be heated, it is required to heat the region that is not warmed more strongly than the region that is warmed. For example, even when microwaves are uniformly irradiated so that an object to be heated is heated uniformly, heating unevenness occurs because there are items that are easily heated and items that are not easily heated depending on the type of food. There is a case. Specifically, foods that contain a large amount of oil components are more likely to be warmed when irradiated with microwaves than foods that do not contain much oil components. For this reason, even if it is a case where a microwave is irradiated uniformly, a temperature nonuniformity may arise in a to-be-heated material. Also, some of the small microwave heating devices for heating foods and the like do not have a turntable, and in a microwave heating device without a turntable, the temperature unevenness of the object to be heated becomes more prominent. Conceivable.

  Therefore, when heating the object to be heated, if it can be heated for each area of the object to be heated, the desired area of the object to be heated can be concentrated and heated, and when microwaves are evenly irradiated Even when temperature unevenness occurs, the object to be heated can be heated uniformly.

  Therefore, there is a demand for a microwave heating apparatus that can heat an object to be heated for each predetermined region when the object to be heated is heated.

  According to one aspect of the present embodiment, a microwave generation source, a heating chamber in which an object to be heated is installed, a first microwave radiating unit and a second microwave radiating unit connected to the heating chamber And a first filter provided between the microwave generation source and the first microwave radiation unit, and provided between the microwave generation source and the second microwave radiation unit. A second filter, wherein the microwave generation source is capable of changing a frequency of the generated microwave, and the first filter and the second filter transmit microwaves. It is characterized by different wave frequencies.

  According to the disclosed microwave heating apparatus, the object to be heated can be heated for each predetermined region when the object to be heated is heated.

Structural drawing of microwave heating apparatus in the first embodiment Explanatory drawing of a 1st filter and a 2nd filter The flowchart of the heating method of the microwave heating device in 2nd Embodiment Structure diagram of microwave heating apparatus in third embodiment Structure diagram of microwave heating apparatus in fourth embodiment Explanatory drawing of the microwave heating apparatus in 5th Embodiment

  The form for implementing is demonstrated below. In addition, about the same member etc., the same code | symbol is attached | subjected and description is abbreviate | omitted.

[First Embodiment]
A microwave heating apparatus according to the first embodiment will be described with reference to FIG. The microwave heating apparatus in this embodiment includes a microwave generation source 110 that generates a microwave, a heating chamber 120, a control unit 130, a first microwave radiating unit 151 that radiates microwaves into the heating chamber 120, a first 2 microwave radiation portions 152 and the like. In the case illustrated in FIG. 1, the first microwave radiating unit 151 is connected to the right side of the heating chamber 120, and the second microwave radiating unit 152 is connected to the left side of the heating chamber 120.

  A microwave transmission unit 140 formed of a waveguide or the like is connected to the microwave generation source 110, and the microwave transmission unit 140 is connected to the first microwave radiation unit 151 side at the branching unit 141. Branches to the second microwave radiation unit 152 side. On the first microwave radiation unit 151 side, a first filter 161 is provided between the branching unit 141 and the first microwave radiation unit 151. On the second microwave radiation unit 152 side, a second filter 162 is provided between the branching unit 141 and the second microwave radiation unit 152.

  In addition, a temperature measuring unit 170 for measuring the temperature of the object to be heated 10 is provided inside the heating chamber 120. The temperature measurement unit 170 is formed by a radiation thermometer or the like, and can obtain, for example, a temperature distribution in the article to be heated 10 as a two-dimensional image. Note that the temperature measurement unit 170 may be configured to arrange a plurality of thermometers at different locations and measure the temperature at each location. The heating chamber 120 is formed of a material containing a metal such as iron, and the microwave in the heating chamber 120 is reflected on the inside of the heating chamber 120, so that it does not leak outside the heating chamber 120.

  The microwave generation source 110 is formed of a semiconductor element formed of a semiconductor such as gallium nitride, and can change the frequency of the generated microwave. For example, the microwave generation source 110 can generate microwaves by changing the frequency in the range of 2400 MHz to 2500 MHz. The frequency of the microwave generated in the microwave generation source 110 is controlled by the control unit 130. Specifically, the control unit 130 controls the frequency of the microwave generated by the microwave generation source 110 based on the temperature information obtained by the temperature measurement unit 170. Note that a semiconductor element formed of a semiconductor material such as gallium nitride can generate a high-output microwave by changing the wavelength. For this reason, the microwave generation source 110 is preferably formed of a semiconductor element formed of a semiconductor such as gallium nitride.

The first filter 161 and the second filter 162 are band-pass filters, and have a structure in which a plurality of fins are provided at predetermined intervals on a waveguide formed of a metal material as shown in FIG. It is. Specifically, as shown in FIG. 2 (a), the first filter 161 is disposed a plurality of fins 161a are at intervals _{L 1,} as shown in FIG. 2 (b), the second filter 162, a plurality of fins 162a are arranged at intervals _{L 2.} As a result, the first filter 161 passes (transmits) the microwave of the frequency f _{1 at which} the in-tube wavelength (the wavelength of the electromagnetic wave propagating in the waveguide) λ _1g is 2L ₁ , but the micro wave of other frequencies A band-pass filter that does not transmit (permeate) waves. The second filter 162 is a band through which microwaves having a frequency f ₂ with an in-tube wavelength (wavelength of electromagnetic waves propagating in the waveguide) λ _2g of 2L ₂ pass but microwaves of other frequencies are not passed. It becomes a pass filter. In the present embodiment, for example, the frequency f ₁ is 2400 MHz and the frequency f ₂ is 2450 MHz. In FIG. 2, for the sake of convenience, fins existing in the waveguide are indicated by solid lines. Further, the first filter 161 and the second filter 162 shown in FIG. 2 are examples, and may be bandpass filters having other configurations.

Therefore, from the first microwave radiating unit 151, the microwave having the frequency f ₁ among the microwaves generated in the microwave generation source 110 is radiated through the first filter 161. Further, from the second microwave radiating unit 152, the microwave having the frequency f ₂ out of the microwaves generated in the microwave generation source 110 is radiated through the second filter 162.

  Next, the case where the object to be heated 10 is heated in the microwave heating apparatus in the present embodiment will be described. The object to be heated 10 includes an area to be heated and an area not to be heated. For example, the first area 11 of the object to be heated 10 is an area to be heated, and the second area 12 is to be heated. It is assumed that there is no area. In the heating chamber 120, the object to be heated 10 is placed so that the first region 11 is on the first microwave radiation unit 151 side and the second region 12 is on the second microwave radiation unit 152 side. It is.

When the first region 11 is heated without heating the second region 12 of the article to be heated 10 by the microwave heating device in the present embodiment, the microwave generation source 110 has the frequency f ₁ . Generate microwaves. The microwave having the frequency f ₁ generated by the microwave generation source 110 propagates through the microwave transmission unit 140, and at the branching unit 141, the first microwave radiating unit 151 side and the second microwave radiating unit. Branches to the 152 side.

The microwave having the frequency f ₁ propagated to the first microwave radiating unit 151 side passes through the first filter 161 and is radiated from the first microwave radiating unit 151 into the heating chamber 120. Since the first region 11 of the article to be heated 10 is close to the first microwave radiating unit 151, the first region 11 of the object to be heated 10 absorbs the microwave of the frequency f ₁ radiated from the first microwave radiating unit 151 and is heated. At this time, the second region 12 of the article to be heated 10 is far from the first microwave radiating portion 151 and is hardly heated because the amount of microwaves that reach it is small.

On the other hand, since the microwave with the frequency f ₁ propagated to the second microwave radiating unit 152 cannot pass through the second filter 162, the second microwave radiating unit 152 receives the microwave with the frequency f ₁ . Waves are not radiated. Therefore, the microwave having the frequency f ₁ generated in the microwave generation source 110 is radiated into the heating chamber 120 from the first microwave radiating unit 151, but is not radiated from the second microwave radiating unit 152. . Therefore, the object 10 to be heated placed in the heating chamber 120 is heated in the first region 11 on the side close to the first microwave radiating portion 151 from which the microwave having the frequency f ₁ is radiated. The second region 12 is hardly heated. Thereby, the 1st area | region 11 can be heated, without heating the 2nd area | region 12 of the to-be-heated material 10. FIG.

In the present embodiment, contrary to the above, the second region 12 can be warmed without warming the first region 11 of the article to be heated 10. That is, in the case where the second region 12 is heated without heating the first region 11 of the article to be heated 10 by the microwave heating apparatus in the present embodiment, the frequency f _Two microwaves are generated. The microwave having the frequency f ₂ generated by the microwave generation source 110 propagates through the microwave transmission unit 140, and at the branching unit 141, the first microwave radiating unit 151 side and the second microwave radiating unit. Branches to the 152 side.

Microwave frequency f ₂ which is propagated to the first microwave radiation portion 151 side, it is not possible to pass through the first filter 161, from the first microwave radiation unit 151, the microwave of the frequency f ₂ is Not emitted.

On the other hand, the microwave of the frequency f ₂ propagated to the second microwave radiation unit 152 side passes through the second filter 162 and is radiated from the second microwave radiation unit 152 into the heating chamber 120. Since the second region 12 of the article to be heated 10 is close to the second microwave radiating unit 152, the second region 12 of the object to be heated 10 absorbs the microwave of the frequency f ₂ radiated from the second microwave radiating unit 152 and is heated. At this time, the first region 11 of the object to be heated 10 is separated from the second microwave radiating portion 152 and is hardly heated because the amount of the reaching microwave is small.

Accordingly, the microwave having the frequency f ₂ generated in the microwave generation source 110 is radiated into the heating chamber 120 from the second microwave radiating unit 152, but is not radiated from the first microwave radiating unit 151. . Therefore, the object to be heated 10 is placed in the heating chamber 120 is a microwave frequency f ₂ is the second region 12 closer to the second microwave radiation 152 emitted is heated, The first region 11 is hardly heated. As a result, the second region 12 can be heated without heating the first region 11 of the article to be heated 10.

  In the above, the case where either one of the first region 11 and the second region 12 of the article to be heated 10 is heated has been described. However, the microwave heating apparatus in this embodiment is configured so that one region has a higher temperature than the other region by making the irradiation time of the microwave irradiated to one region longer than the other region. The whole object to be heated 10 can be heated. The information for heating the object to be heated 10 may be information that can be read from a barcode or the like attached to the object to be heated 10.

  Moreover, although the case where the to-be-heated material 10 was a food was demonstrated in the above, the to-be-heated material 10 is not limited to a foodstuff, A timber etc. may be sufficient. That is, the microwave heating apparatus in the present embodiment may be used for industrial use for drying timber and the like. In this case, the moisture contained in the timber can be evaporated by heating by irradiating the microwave concentrated on the wet part of the timber, so that the timber can be dried uniformly. For example, when it is left outdoors for a long time, the surface on the front side that was exposed to the sun is relatively dry, but the surface on the back side is often moist. As described above, when the amount of moisture contained in the timber is uneven, even if the timber is uniformly irradiated with microwaves, it cannot be uniformly dried. In this embodiment, by changing the frequency of the microwave generated in the microwave generation source, it is possible to concentrate the microwave on the wet part on the back side, so that the timber is dried uniformly Can do.

[Second Embodiment]
Next, a case where the object to be heated is uniformly heated using the microwave heating apparatus according to the first embodiment will be described. Control of the microwave heating apparatus in the present embodiment is performed by control unit 130. In the present embodiment, a case where heating is performed so that the first region 11 and the second region 12 of the article to be heated 10 have substantially uniform temperatures will be described with reference to FIG.

  As described above, not only when the object to be heated 10 is not uniformly irradiated with microwaves, but also when the object to be heated 10 is uniformly irradiated with microwaves, temperature unevenness occurs in the object to be heated 10. May occur. For example, when the object to be heated 10 is a food, even if the amount of microwaves to be irradiated is the same, food materials such as mayonnaise containing a large amount of oil are likely to be hotter than rice and the like not containing oil. In such a case, it is required to heat the article to be heated 10 so as to have a substantially uniform temperature as a whole.

First, as shown in step 102 (S102), a microwave is generated in the microwave generation source 110, and the microwave is radiated into the heating chamber 120. For example, the microwave generated by the microwave generation source 110 alternately generates the microwave having the frequency f _{1 and} the microwave having the frequency f ₂ at equal intervals. Specifically, the time for generating the microwave with the frequency f _{1 in} the microwave generation source 110 is the same as the time for generating the microwave with the frequency f ₂ , that is, the frequency of the microwave with the frequency f ₁ . The time and the time of the microwave with the frequency f ₂ are set to 1: 1.

  Next, as shown in step 104 (S104), the temperature of the article to be heated 10 is measured by the temperature measuring unit 170. The temperature measuring unit 170 can obtain the temperature distribution of the object to be heated 10 as a two-dimensional image, and thereby obtain information on the temperature distribution of the object to be heated 10.

  Next, as shown in step 106 (S106), based on the temperature distribution obtained in the temperature measurement unit 170, it is determined whether or not the first region 11 is at a higher temperature than the second region 12. . When the first region 11 is at a higher temperature than the second region 12, the process proceeds to step 108. If the first region 11 is not at a higher temperature than the second region 12, the process proceeds to step 110.

Next, as shown in step 108 (S108), the microwave source 110, than the microwave frequencies _{f 1} to generate, increasing the microwave frequency _{f 2.} Specifically, temporarily or is generated continuously microwave frequency f _2, than the microwave time frequency f ₁ to generate the microwave generating source 110, the time of the microwave frequency f ₂ The control unit 130 performs control so as to increase the length. Thereby, in the to-be-heated material 10, the microwave irradiated to the 2nd area | region 12 is increased, and it heats intensively.

  Next, as shown in step 110 (S110), based on the temperature distribution obtained in the temperature measurement unit 170, it is determined whether or not the second region 12 is at a higher temperature than the first region 11. . If the second region 12 is hotter than the first region 11, the process proceeds to step 112. If the second region 12 is not at a higher temperature than the first region 11, the process proceeds to step 114.

Next, as shown in step 112 (S112), the microwave source 110, than the microwave frequency _{f 2} for generating, increasing the microwave frequency _{f 1.} Specifically, or temporarily generated continuously microwave frequency f _1, than the microwave time frequency f ₂ to generate the microwave generating source 110, the time of the microwave frequency f ₁ The control unit 130 performs control so as to increase the length. Thereby, in the to-be-heated material 10, the microwave irradiated to the 1st area | region 11 is increased, and it concentrates and heats.

  Next, as shown in step 114 (S114), based on the temperature distribution obtained in the temperature measurement unit 170, it is determined whether or not the entire object to be heated 10 has reached a predetermined temperature. When the entire object to be heated 10 is at a predetermined temperature, generation of microwaves in the microwave generation source 110 is stopped, and emission of microwaves into the heating chamber 120 is stopped and terminated. If the entire object to be heated 10 is not at the predetermined temperature, the process proceeds to step 102.

As described above, in the present embodiment, the object to be heated 10 can be heated so that the entire object to be heated 10 has a uniform temperature. The above method is a method of controlling the ratio of the time of the microwave of the frequency f ₁ to be alternately generated and the time of the microwave of the frequency f ₂ , but the microwave of the frequency f ₁ to be generated and the frequency f ₂ are generated. It may be a method of controlling by changing the intensity of the microwave. When the frequency f ₁ and the frequency f ₂ are relatively close, the frequency of the microwave generated by the microwave generation source 110 may be changed between the frequency f ₁ and the frequency f ₂ . Specifically, when the first region 11 is in a higher temperature than the second region 12, the control is as close to the frequency of the microwave to be generated in the microwave generating source 110 to the frequency f ₂ Do. The second region 12 when they are hot than the first region 11 controls such that nearly frequency of the microwave to be generated in the microwave generating source 110 to the frequency f _1.

Further, based on the temperature measured by the temperature measurement unit 170, the rate of temperature rise in the first region 11 and the second region 12 is calculated, and the frequency f ₁ that is alternately generated based on the rate of temperature rise. The time of the microwave and the time of the microwave of frequency f ₂ may be controlled. Specifically, first, a microwave having a frequency f _{1 and} a microwave having a frequency f ₂ are alternately generated at equal intervals, and then the temperature distribution of the object to be heated 10 after a predetermined time has elapsed is measured. The rate of temperature rise in the first region 11 and the second region 12 in the object 10 is calculated. Based on the rate of temperature rise in the first region 11 and the second region 12 calculated in this way, the ratio of the time of the microwave of the frequency f ₁ and the time of the microwave of the frequency f _{2 that} are alternately generated is calculated. You may calculate and control.

  The contents other than the above are the same as in the first embodiment.

[Third Embodiment]
Next, a microwave heating apparatus in the third embodiment will be described. As shown in FIG. 4, the microwave heating apparatus in the present embodiment is provided with three microwave radiating portions.

  Specifically, as shown in FIG. 4, the first microwave radiating unit 151 is connected to the right side of the heating chamber 120, and the second microwave radiating unit 152 is connected to the left side of the heating chamber 120. The third microwave radiation unit 153 is connected to the lower side of the heating chamber 120. In the microwave heating apparatus in the present embodiment, a microwave transmission unit 240 formed of a waveguide or the like is connected to the microwave generation source 110. The microwave transmission unit 240 branches at the branching unit 241 into the first microwave radiating unit 151 side, the second microwave radiating unit 152 side, and the third microwave radiating unit 153 side. On the first microwave radiation unit 151 side, a first filter 161 is provided between the branching unit 241 and the first microwave radiation unit 151. On the second microwave radiation unit 152 side, a second filter 162 is provided between the branching unit 241 and the second microwave radiation unit 152. On the third microwave radiation unit 153 side, a third filter 163 is provided between the branching unit 241 and the third microwave radiation unit 153.

Similar to the one shown in FIG. 2, the third filter 163 has a plurality of fins arranged at predetermined intervals in a waveguide formed of a metal material, and allows microwaves of frequency f ₃ to pass therethrough. It is a bandpass filter that does not pass microwaves of other frequencies. The first filter 161 is a band-pass filter that passes microwaves of frequency f ₁ but does not pass microwaves of other frequencies. The second filter 162 is a band-pass filter that passes microwaves of frequency f ₂ but does not pass microwaves of other frequencies. In the present embodiment, for example, the frequency f ₁ is 2400 MHz, the frequency f ₂ is 2450 MHz, and the frequency f ₃ is 2500 MHz.

  Next, a case where the object to be heated 20 is heated in the microwave heating apparatus in the present embodiment will be described. The object to be heated 20 has a first region 21, a second region 22, and a third region 23. In the heating chamber 120, the object to be heated 20 includes a first region 21 on the first microwave radiation unit 151 side, a second region 22 on the second microwave radiation unit 152 side, and a third region. It arrange | positions so that the area | region 23 may become the 3rd microwave radiation | emission part 153 side.

When the first region 21 of the article to be heated 20 is heated by the microwave heating apparatus in the present embodiment, the microwave generation source 110 generates a microwave having the frequency f ₁ . The microwave having the frequency f ₁ generated by the microwave generation source 110 propagates through the microwave transmission unit 140, and at the branching unit 141, the first microwave radiating unit 151 side and the second microwave radiating unit. Branches to the 152 side and the third microwave radiation unit 153 side.

The microwave having the frequency f ₁ propagated to the first microwave radiating unit 151 side passes through the first filter 161 and is radiated from the first microwave radiating unit 151 into the heating chamber 120. Since the first region 21 of the object to be heated 20 is close to the first microwave radiating unit 151, the first region 21 of the object to be heated 20 absorbs the microwave of the frequency f ₁ radiated from the first microwave radiating unit 151 and is heated. The second region 22 and third region 23 of the heated object 10 is spaced from the first microwave radiation unit 151, since a small amount of arriving microwave, microwave frequency f ₁ Is hardly heated.

On the other hand, the microwave of the frequency f ₁ propagated to the second microwave radiating unit 152 side and the third microwave radiating unit 153 side cannot pass through the second filter 162 and the third filter 163. Therefore, the microwave having the frequency f ₁ is not radiated from the second microwave radiating unit 152 and the third microwave radiating unit 153. Therefore, the first region 21 of the article to be heated 20 can be concentrated and heated by generating the microwave having the frequency f _{1 in} the microwave generation source 110.

Further, in the case of heating the second region 22, the microwave source 110 to generate a microwave having a frequency of f _2. The microwave having the frequency f ₂ generated by the microwave generation source 110 propagates through the microwave transmission unit 140, and at the branching unit 141, the first microwave radiating unit 151 side and the second microwave radiating unit. Branches to the 152 side and the third microwave radiation unit 153 side.

The microwave having the frequency f ₂ propagated to the second microwave radiating unit 152 side passes through the second filter 162 and is radiated from the second microwave radiating unit 152 into the heating chamber 120. Since the second region 22 of the article to be heated 10 is close to the second microwave radiating unit 152, the microwave of the frequency f ₂ radiated from the second microwave radiating unit 152 is absorbed and heated. The first region 21 and third region 23 of the heated object 20 is spaced from the second microwave radiation unit 152, since a small amount of arriving microwaves, the microwave frequency f ₂ Is hardly heated.

On the other hand, the microwave having the frequency f ₂ propagated to the first microwave radiating unit 151 side and the third microwave radiating unit 153 side cannot pass through the first filter 161 and the third filter 163. Therefore, from the first microwave radiating portion 151 and the third microwave radiation unit 153, the microwave of the frequency f ₂ is not emitted. Therefore, by generating the microwave with the frequency f _{2 in} the microwave generation source 110, the second region 22 of the article to be heated 20 can be heated in a concentrated manner.

In addition, when the third region 23 is heated, the microwave generation source 110 generates a microwave having a frequency f ₃ . The microwave having the frequency f ₃ generated by the microwave generation source 110 propagates through the microwave transmission unit 140, and at the branching unit 141, the first microwave radiating unit 151 side and the second microwave radiating unit. Branches to the 152 side and the third microwave radiation unit 153 side.

The microwave having the frequency f ₃ propagated to the third microwave radiating unit 153 side passes through the third filter 163 and is radiated from the third microwave radiating unit 153 into the heating chamber 120. Since the third region 23 of the article to be heated 10 is close to the third microwave radiating unit 153, the third region 23 of the object to be heated 10 absorbs the microwave of the frequency f ₃ radiated from the third microwave radiating unit 153 and is heated. The first region 21 and second region 22 of the heated object 20 is spaced from the third microwave radiation unit 153, since a small amount of arriving microwave, microwave frequency f ₃ Is hardly heated.

On the other hand, the microwave having the frequency f ₃ propagated to the first microwave radiation unit 151 side and the second microwave radiation unit 152 side cannot pass through the first filter 161 and the second filter 162. Therefore, from the first microwave radiating portion 151 and a second microwave radiation unit 152, the microwave of the frequency f ₃ is not emitted. Therefore, by generating the microwave with the frequency f _{3 in} the microwave generation source 110, the third region 23 of the article to be heated 20 can be heated in a concentrated manner.

  In the microwave heating apparatus in the present embodiment, a desired region of the object to be heated 20 can be concentrated and heated by changing the frequency of the microwave generated by the microwave generation source 110. Further, as in the second embodiment, the entire object to be heated 20 can be heated to a uniform temperature by the control of the control unit 130.

In the above description, the case where three microwave radiating portions are provided has been described. However, the microwave heating apparatus according to the present embodiment may be provided with four or more microwave radiating portions. Good. In the above description, the first filter 161, the second filter 162, and the third filter 163 pass microwaves having different frequencies, but include a part that passes the same frequency. Also good. For example, the first filter 161 and the third filter 163 may pass microwaves having the frequency f ₁ , and the second filter 162 may pass microwaves having the frequency f ₂ . In this case, the first region 21 and the third region 23 of the article to be heated 20 can be heated simultaneously.

  The contents other than those described above are the same as those in the first embodiment and the second embodiment.

[Fourth Embodiment]
A microwave heating apparatus according to the fourth embodiment will be described with reference to FIG. The microwave heating apparatus in this embodiment includes a microwave generation source 110 that generates microwaves, a heating chamber 120, a control unit 130, a first microwave radiating unit 351 that radiates microwaves into the heating chamber 120, 2 microwave radiation portions 352 and the like. In the case shown in FIG. 5, the first microwave radiating section 351 is connected to the right side of the heating chamber 120, and the second microwave radiating section 352 is connected to the left side of the heating chamber 120.

  A microwave transmission unit 140 formed of a waveguide or the like is connected to the microwave generation source 110, and the microwave transmission unit 140 is connected to the first microwave radiation unit 351 side at the branching unit 141. Branches to the second microwave radiation unit 352 side. On the first microwave radiation unit 351 side, no filter or the like is provided between the branching unit 141 and the first microwave radiation unit 351. On the second microwave radiating unit 352 side, a filter 362 is provided between the branching unit 141 and the second microwave radiating unit 352.

The filter 362 is a band-pass filter, for example, a band-pass filter that passes microwaves of the same frequency f ₂ as the second filter 162 in the first embodiment but does not pass microwaves of other frequencies. is there.

Therefore, in the present embodiment, the microwave having the frequency f _{1 and} the microwave having the frequency f ₂ out of the microwaves generated in the microwave generation source 110 are radiated from the first microwave radiating unit 351. . Further, from the second microwave radiating unit 352, the microwave having the frequency f ₂ among the microwaves generated in the microwave generation source 110 is radiated through the filter 362.

  Next, the case where the object to be heated 10 is heated in the microwave heating apparatus in the present embodiment will be described. In the present embodiment, in the article to be heated 10, both the first region 11 and the second region 12 are desired to be heated, but the first region 11 is heated so as to be higher in temperature than the second region 12. The case where it wants to do is demonstrated. In the heating chamber 120, the object to be heated 10 is arranged such that the first region 11 is on the first microwave radiating portion 351 side and the second region 12 is on the second microwave radiating portion 352 side. Is placed in.

First, the case where the microwave generation source 110 generates a microwave having the frequency f ₁ will be described. In this case, the microwave with the frequency f ₁ generated by the microwave generation source 110 propagates through the microwave transmission unit 140, and at the branching unit 141, the first microwave radiating unit 351 side and the second microwave are transmitted. Branches to the wave radiation unit 352 side.

The microwave having the frequency f ₁ propagated to the first microwave radiating unit 351 side is radiated as it is from the first microwave radiating unit 351 into the heating chamber 120.

On the other hand, the microwave having the frequency f ₁ propagated to the second microwave radiating unit 352 cannot pass through the filter 362, and therefore, the microwave having the frequency f ₂ is radiated from the second microwave radiating unit 352. Not. Accordingly, the microwave having the frequency f ₁ generated in the microwave generation source 110 is radiated into the heating chamber 120 from the first microwave radiating unit 351, but is not radiated from the second microwave radiating unit 352. . Therefore, the object 10 to be heated placed in the heating chamber 120 is heated in the first region 11 on the side close to the first microwave radiating unit 351 from which the microwave having the frequency f ₁ is radiated. The second region 12 on the far side is hardly heated.

Next, the case where the microwave generation source 110 generates a microwave with the frequency f ₂ will be described. In this case, the microwave having the frequency f ₂ generated by the microwave generation source 110 propagates through the microwave transmission unit 140, and at the branching unit 141, the first microwave radiating unit 351 side and the second microwave are transmitted. Branches to the wave radiation unit 352 side.

The microwave having the frequency f ₂ propagated to the first microwave radiating unit 351 side is radiated as it is from the first microwave radiating unit 351 into the heating chamber 120. Further, the microwave having the frequency f ₂ propagated to the second microwave radiating unit 352 side is radiated into the heating chamber 120 from the second microwave radiating unit 352 through the filter 362. Accordingly, the object to be heated 10 placed in the heating chamber 120 includes the first region 11 and the second microwave on the side close to the first microwave radiating portion 351 from which the microwave having the frequency f ₂ is radiated. Both of the second regions 12 on the side close to the radiating portion 352 are heated.

Therefore, when it is desired to uniformly heat the entire object to be heated 10, the microwave generation source 110 generates microwaves having a frequency f ₂ , so that the entire object to be heated 10, that is, the first region 11 is formed. The second region 12 is irradiated with microwaves. Further, when it is desired to heat the first region 11 in a concentrated manner, a microwave having a frequency f ₁ is generated in the microwave generation source 110. In this case, the microwave with the frequency f ₁ is radiated only from the first microwave radiating unit 351, and thus the first region 11 of the object to be heated 10 close to the first microwave radiating unit 351 is concentrated and heated. can do. Further, the first region 11 and the second region 12 of the object to be heated 10 are respectively desired by controlling the ratio of the time of the microwave of the frequency f ₁ and the time of the microwave of the frequency f ₂ that are alternately generated. It is also possible to heat so that it may become this temperature.

  The contents other than the above are the same as in the first embodiment.

[Fifth Embodiment]
Next, a fifth embodiment will be described. In the present embodiment, the microwave heating device or the like in the first embodiment is applied to a DPF, and is an exhaust gas processing device having a DPF to be heated and a microwave heating device.

  By the way, diesel engine exhaust contains particulate matter (PM) such as soot, so DPF (Diesel particulate filter: Diesel particulate filter) ) Must be used. In such a DPF, in order to prevent clogging due to soot or the like, it is necessary to periodically heat and regenerate the DPF. However, microwave irradiation or microwave irradiation is one of the methods for heating the DPF. Suitable DPF materials are also disclosed.

  Specifically, as shown in FIG. 6, the DPF 400 is installed in the DPF chamber 420. The DPF chamber 420 is provided with a gas inlet 421 through which exhaust gas such as a diesel engine flows, and a gas outlet 422 through which the gas purified by the DPF 400 flows out.

  A microwave transmission unit 140 formed of a waveguide or the like is connected to the microwave generation source 110, and the microwave transmission unit 140 is connected to the first microwave radiation unit 151 side at the branching unit 141. Branches to the second microwave radiation unit 152 side. In FIG. 6, the first microwave radiation unit 151 is connected to the lower side of the DPF chamber 420, and the second microwave radiation unit 152 is connected to the upper side of the DPF chamber 420.

In the present embodiment, the microwave having the frequency f ₁ generated by the microwave generation source 110 is radiated from the first microwave radiating unit 151, and the microwave having the frequency f ₂ is radiated from the second microwave. Radiated from the unit 152. The frequency of the microwave generated by the microwave generation source 110 can be controlled by the control unit 130, and the control of the control unit 130 can uniformly heat the DPF 400 or heat a desired region intensively. Is possible.

  The contents other than the above are the same as those in the first embodiment.

  Although the embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes can be made within the scope described in the claims.

In addition to the above description, the following additional notes are disclosed.
(Appendix 1)
A microwave source;
A heating chamber in which an object to be heated is installed;
A first microwave radiating section and a second microwave radiating section connected to the heating chamber;
A first filter provided between the microwave generation source and the first microwave radiation unit;
A second filter provided between the microwave generation source and the second microwave radiation unit;
Have
The microwave generation source is capable of changing the frequency of the generated microwave,
The microwave heating apparatus, wherein the first filter and the second filter have different frequencies of transmitted microwaves.
(Appendix 2)
A third microwave radiation unit connected to the heating chamber;
A third filter provided between the microwave generation source and the third microwave radiation unit;
Have
The microwave heating apparatus according to appendix 1, wherein the third filter is different in frequency of transmitted microwaves from the first filter and the second filter.
(Appendix 3)
A microwave source;
A heating chamber in which an object to be heated is installed;
A first microwave radiating section and a second microwave radiating section connected to the heating chamber;
A filter provided between the microwave generation source and the second microwave radiation unit;
Have
The microwave heating apparatus, wherein the microwave generation source is capable of changing a frequency of a generated microwave.
(Appendix 4)
4. The microwave heating apparatus according to any one of appendices 1 to 3, further comprising a control unit that controls a frequency of a microwave generated in the microwave generation source.
(Appendix 5)
A temperature measuring unit for measuring the temperature distribution of the object to be heated is provided;
The microwave heating apparatus according to appendix 4, wherein the control unit controls a frequency of a microwave generated in the microwave generation source based on temperature information measured in the temperature measurement unit.
(Appendix 6)
The microwave heating apparatus according to appendix 3 or 4, wherein the control unit performs control to generate a microwave having a frequency in which one region of the object to be heated is heated and the other region is not heated.
(Appendix 7)
The microwave heating apparatus according to appendix 4, wherein the control unit performs control to alternately generate microwaves having different frequencies so that the entire temperature of the object to be heated is uniform.
(Appendix 8)
The microwave heating apparatus according to any one of appendices 1 to 7, wherein the microwave generation source is formed of a semiconductor element.

DESCRIPTION OF SYMBOLS 10 To-be-heated object 11 1st area | region 12 2nd area | region 110 Microwave generation source 120 Heating chamber 130 Control part 140 Microwave transmission part 141 Branch part 151 1st microwave radiation part 152 2nd microwave radiation part 161 First filter 162 Second filter 170 Temperature measurement unit

Claims (6)

A microwave source;
A heating chamber in which an object to be heated is installed;
A first microwave radiating section and a second microwave radiating section connected to the heating chamber;
A first filter provided between the microwave generation source and the first microwave radiation unit;
A second filter provided between the microwave generation source and the second microwave radiation unit;
Have
The microwave generation source is capable of changing the frequency of the generated microwave,
The microwave heating apparatus, wherein the first filter and the second filter have different frequencies of transmitted microwaves. A third microwave radiation unit connected to the heating chamber;
A third filter provided between the microwave generation source and the third microwave radiation unit;
Have
2. The microwave heating apparatus according to claim 1, wherein the third filter is different in frequency of transmitted microwaves from the first filter and the second filter. A microwave source;
A heating chamber in which an object to be heated is installed;
A first microwave radiating section and a second microwave radiating section connected to the heating chamber;
A filter provided between the microwave generation source and the second microwave radiation unit;
Have
The microwave heating apparatus, wherein the microwave generation source is capable of changing a frequency of a generated microwave.   The microwave heating apparatus according to any one of claims 1 to 3, further comprising a control unit that controls a frequency of a microwave generated in the microwave generation source. A temperature measuring unit for measuring the temperature distribution of the object to be heated is provided;
5. The microwave heating apparatus according to claim 4, wherein the control unit controls a frequency of a microwave generated in the microwave generation source based on temperature information measured in the temperature measurement unit.   The microwave heating apparatus according to any one of claims 1 to 5, wherein the microwave generation source is formed of a semiconductor element.

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