Microwave processing apparatus and microwave processing method

Abstract

To provide a microwave processing device capable of appropriately processing an object to be processed using microwaves.SOLUTION: A microwave processing device includes a container 10c inside which an object to be processed 2 moves, microwave irradiation means 21 having an irradiation portion 203 that irradiates the container 10c with microwaves, and a heat generating member 30 that is partially provided within the container 10c along a movement path 2a of the object to be processed 2 so as to cover the object to be processed 2 and is not provided in other parts along the movement path 2a, and absorbs microwaves irradiated from the microwave irradiation means 21 to generate heat, and the microwave irradiation means 21 irradiates, with microwaves, a part of the movement path 2a where the heat generating member 30d is provided to heat the heat generating member 30, and irradiates, with microwaves, to a part of the movement path 2a where the heat generating members 30d, 30f are not provided to heat the object to be processed 2.SELECTED DRAWING: Figure 7

Description

【Technical Field】 【0001】 The present invention relates to a microwave processing apparatus and the like that perform processing such as heat treatment using microwaves. 【Background Art】 【0002】 As a conventional technique for performing processing using microwaves, there has been known a configuration including a heating furnace body made of a microwave shielding material, microwave means for introducing microwave power into the heating furnace body, a heating cylinder formed of a heat conductive material having a microwave shielding function and linearly disposed between an inlet provided on one side of the heating furnace body and an outlet provided on the other side, a microwave heating element provided on the outer peripheral side of the heating cylinder to transfer heat to the heating cylinder, a filter provided near the inlet and outlet of the heating furnace body and disposed around the end of the heating cylinder to prevent leakage of microwave power, and a configuration in which a workpiece supplied from the inlet passes through the heating cylinder, is discharged from the outlet, and is heated in the heating cylinder. (For example, see Patent Document 1). 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent No. 5877448 (page 1, FIG. 1, etc.) 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 However, in the conventional technique, there has been a problem that a processing object cannot be appropriately processed using microwaves. 【0005】 For example, in the conventional technique, since heating is performed by the radiant heat of a microwave heating element heated using microwaves, it is difficult to heat a processing object such as a workpiece from the outside only, and to perform desired heating such as uniform heating. 【0006】 Furthermore, because the object being processed is not directly irradiated with microwaves, it cannot be directly heated by the microwaves, resulting in poor heating efficiency. 【0007】 The present invention was made to solve the above-mentioned problems, and aims to provide a microwave processing apparatus, etc., that can appropriately process objects to be processed using microwaves. [Means for solving the problem] 【0008】 The microwave processing apparatus of the present invention comprises a container in which an object to be processed moves; a microwave irradiation means equipped with an irradiation unit for irradiating microwaves into the container; and a heating element partially provided in the container along the movement path of the object to be processed so as to cover the object to be processed, but not in other parts along the movement path, and which absorbs microwaves irradiated from the microwave irradiation means and generates heat, wherein the microwave irradiation means irradiates microwaves to the portion of the movement path in which the heating element is provided to heat the heating element, and irradiates microwaves to the portion of the movement path in which the heating element is not provided to heat the object to be processed. 【0009】 With this configuration, the object to be processed can be appropriately processed using microwaves. 【0010】 Furthermore, the microwave processing apparatus of the present invention may be provided with a first microwave irradiation position in which the intensity of microwaves irradiated by the irradiation unit is stronger in the heating element, a second microwave irradiation position in which the intensity of microwaves irradiated by the irradiation unit is stronger in the portion of the object to be processed where the heating element is not provided, and a third microwave irradiation position in which the intensity of microwaves irradiated by the irradiation unit is stronger in the portion of the object to be processed where the heating element is provided. 【0011】 With this configuration, the portion of the object to be processed that is not provided with a heating element can be directly heated, and in the portion where a heating element is provided, there can be a portion where the object to be processed is strongly heated by the heat generated by the heating element, and a portion where the object to be processed inside the heating element can be directly heated. 【0012】 Furthermore, in the microwave processing apparatus of the present invention, the position of one or more first microwave irradiation positions and one or more third microwave irradiation positions may be the same in the direction along the movement path. 【0013】 With this configuration, both heating of the object to be processed by the heat generated by the heating element and direct heating of the object to be processed can be strongly achieved at the same location where the heating element is provided. 【0014】 Furthermore, in the microwave processing apparatus of the present invention, two or more heating elements are provided along a movement path with a region where no heating elements are provided in between, and one or more first microwave irradiation positions and one or more third microwave irradiation positions are located in portions where different heating elements are provided. 【0015】 With this configuration, it is possible to strongly heat the object to be treated by the heat generated by the heating element in different heating elements, and to strongly heat the object to be treated by directly heating the object within the heating element. 【0016】 Furthermore, in the microwave processing apparatus of the present invention, a plurality of irradiation units may be provided, and the phase of the microwaves irradiated by the irradiation units may be controlled so that the microwave intensity increases at the first microwave irradiation position, the second microwave irradiation position, and the third microwave irradiation position. 【0017】 With this configuration, by controlling the phase of the microwaves, microwave irradiation can be easily performed so that the microwave intensity is increased at the first microwave irradiation position, the second microwave irradiation position, and the third microwave irradiation position. 【0018】 Furthermore, in the microwave processing apparatus of the present invention, the microwave irradiation means may perform a first microwave irradiation, which irradiates microwaves onto the portion of the moving path where the heating element is provided to heat the heating element, and a second microwave irradiation, which irradiates the portion of the moving path where the heating element is not provided with microwaves of a different frequency than the first microwave irradiation to heat the object to be processed. 【0019】 With this configuration, the object to be processed can be appropriately heated in both the area where the heating element is provided and the area where the heating element is not provided. 【0020】 Furthermore, in the microwave processing apparatus of the present invention, the frequency of the microwave used for the first microwave irradiation may be such that the dielectric loss to the heating element is greater than the dielectric loss to the object being processed. 【0021】 With this configuration, in areas where a heating element is provided, the heating element can be efficiently heated to heat the object to be processed, and in areas where a heating element is not provided, the object to be processed can be heated directly. 【0022】 Furthermore, in the microwave processing apparatus of the present invention, the microwave irradiation means may further perform a third microwave irradiation, which involves irradiating the portion where the heating element is provided with microwaves of a frequency such that the dielectric loss to the heating element is smaller than the dielectric loss to the object to be processed, thereby heating the object to be processed in the portion where the heating element is provided. 【0023】 With such a configuration, in a portion where no heating member is provided, the object to be processed can be directly heated, and in a portion where a heating member is provided, the heating member can be efficiently heated, and positions for heating the object to be processed and positions for directly heating the object to be processed can be provided. 【0024】 Further, in the microwave processing apparatus of the present invention, in the microwave processing apparatus, one or more positions irradiated with microwaves by the first microwave irradiation and one or more positions irradiated with microwaves by the third microwave irradiation may be the same in the direction along the moving path. 【0025】 With such a configuration, in a portion where no heating member is provided, the object to be processed can be directly heated, and at the same position in a portion where a heating member is provided, both heating of the object to be processed by the heat generation of the heating member and direct heating of the object to be processed can be strongly performed. 【0026】 Further, in the microwave processing apparatus of the present invention, in the microwave processing apparatus, two or more of the heating members are provided along the moving path with a region where no heating member is provided therebetween, and one or more positions irradiated with microwaves by the first microwave irradiation and one or more positions irradiated with microwaves by the third microwave irradiation may be located in portions where different heating members are provided. 【0027】 With such a configuration, in a portion where no heating member is provided, the object to be processed can be directly heated, and in different heating members, heating the object to be processed strongly by the heat generation of the heating member and strongly heating the object to be treated in the heating member by direct heating can be performed. 【0028】 Further, in the microwave processing apparatus of the present invention, the object to be processed may be a precursor fiber of carbon fiber, and the microwave processing apparatus may be used for the flame resistance treatment of the precursor fiber. 【0029】 This configuration makes it possible to obtain precursor fibers of flame-retardant treated carbon fibers. 【0030】 Furthermore, the present invention relates to a method for manufacturing carbon fibers, which includes a step of heating precursor fibers of carbon fibers that move along the heating element by irradiating microwaves into a container that has a heating element inside that absorbs microwaves and generates heat, wherein the heating element is partially provided along the movement path of the precursor fibers and not provided in other parts along the movement path, and in the heating step, heating of the heating element is performed by irradiating the portion of the movement path where the heating element is provided with microwaves, and heating of the object to be processed is performed by irradiating the portion of the movement path where the heating element is not provided with microwaves. 【0031】 This configuration allows for the proper external and direct heating of carbon fiber precursors, thereby obtaining high-quality carbon fibers. [Effects of the Invention] 【0032】 According to the present invention, objects to be processed can be appropriately processed using microwaves. [Brief explanation of the drawing] 【0033】 [Figure 1] Cross-sectional view of a microwave processing apparatus in Embodiment 1 of the present invention [Figure 2] Figure 2(a) shows the heating element of the microwave processing apparatus, and Figures 2(b) to 2(d) show modified examples thereof. [Figure 3] Cross-sectional view showing a modified example of the microwave processing device. [Figure 4] Cross-sectional views (Figures 4(a) to 4(b)) showing modified versions of the microwave processing apparatus. [Figure 5] Cross-sectional view (Figure 5(a)) and schematic cross-sectional view (Figures 5(b) to 5(c)) of the microwave processing apparatus in Embodiment 2 of the present invention. [Figure 6] Cross-sectional view (Figure 6(a)) and schematic cross-sectional view (Figures 6(b) to 6(d)) of the microwave processing apparatus in Embodiment 3 of the present invention. [Figure 7] Schematic cross-sectional diagram (Figure 7(a)) and schematic diagrams (Figures 7(b) to 7(d)) ​​illustrating a modified example of the microwave processing apparatus in Embodiment 2 of the present invention. [Figure 8] Schematic diagrams illustrating modified examples of the microwave processing apparatus in Embodiment 3 of the present invention (Figures 8(a) to 8(d)). [Modes for carrying out the invention] 【0034】 Embodiments of microwave processing equipment and the like will be described below with reference to the drawings. Note that components denoted by the same reference numerals in these embodiments perform similar operations, and therefore, further explanation may be omitted. 【0035】 (Embodiment 1) The following explanation of microwave processing equipment will use as an example a device used to flame-retardantize precursor fibers used in the manufacture of carbon fibers. 【0036】 First, let's describe an example of the carbon fiber manufacturing process. Precursor fibers such as polyacrylonitrile (PAN) are oxidized by heating them in hot air at 200-300°C for 60-120 minutes. This process is called flame-retardant treatment. This process induces a cyclization reaction in the precursor fibers, and flame-retardant fibers are obtained through oxygen bonding. Subsequently, the obtained flame-retardant fibers are heated in a nitrogen atmosphere to 1000°C to 1500°C for several minutes, which carbonizes the fibers and yields carbon fibers. 【0037】 Figure 1 is a cross-sectional view parallel to the direction of movement of the object to be processed, illustrating the microwave processing apparatus in this embodiment. 【0038】 The microwave processing device 1 comprises a container 10, a microwave irradiation means 20, a heating element 30, one or more sensors 40, a control means 50, and a transport means 60. 【0039】 Container 10 is made of a microwave-reflective material such as stainless steel. Container 10 is hollow and has a horizontally elongated box shape. The object to be processed 2 is placed inside container 10. Here, the object to be processed 2 is assumed to be, for example, a PAN-based precursor fiber. The precursor fiber, which is the object to be processed 2, may be, for example, a single precursor fiber, or multiple precursor fibers bundled together to form a thread or string. The object to be processed 2 placed inside container 10 may be singular or multiple. Here, an example is described in which the object to be processed 2 placed inside container 10 moves within container 10. The movement here may be continuous, or it may be discontinuous, combining movement and stopping. For example, the movement of the object to be processed 2 may be stopped while microwave irradiation is being performed inside container 10, and the object to be processed 2 may be moved when microwave irradiation is not being performed. Furthermore, the movement here may be movement at a constant speed, or movement where the speed changes continuously or discontinuously. The same applies to other embodiments. In the following explanation, we will describe the case where the object to be processed 2 is moving continuously, as an example. 【0040】 An inlet 101a for the material to be processed 2 is provided at one end of the longitudinal direction of the container 10, and an outlet 101b is provided at the other end. The material to be processed 2 enters the container 10 through the inlet 101a, moves inside the container 10, and exits to the outside through the outlet 101b. Here, as an example, we will explain the case in which the material to be processed 2 moves substantially horizontally inside the container 10. However, the direction of movement and the path of movement of the material to be processed inside and outside the container 10 are not specified. For example, the direction of movement of the material to be processed may be changed along the way by rollers, etc. For example, the direction of movement of precursor fibers may be reversed once or more by rollers, etc. The container 10 is usually arranged so that its longitudinal direction is horizontal, but the container 10 may be arranged at an angle. Filters (not shown) are provided at the inlet 101a and the outlet 101b to prevent microwaves irradiated into the container 10 from leaking to the outside. As a filter, for example, one that has a choke structure utilizing the properties of microwave wavelengths and prevents the passage of microwave power without contact is used. The inlet 101a and outlet 101b may have a structure that prevents microwave leakage other than that of the filter. The size of the container 10 and the thickness of the outer wall of the container 10 are not specified. The outer wall of the container 10 may be provided with insulating material (not shown). The size of the container 10, etc., is determined, for example, according to the object to be processed, the processing time, etc. 【0041】 The shape of the container 10 described above is merely an example, and the container 10 may take any other shape. For example, the container 10 may be a cylindrical shape extending horizontally, a polygonal prism shape, or a combination of these shapes. It may also be vertically elongated. Furthermore, the movement path 2a of the object to be processed 2 may be folded using rollers (not shown) or the like so that the direction of movement of the object to be processed 2 alternately reverses horizontally, and the container 10 may be shaped to cover at least the portion of this movement path 2a in which the object to be processed 2 moves parallel to. For the sake of explanation, the movement path 2a is shown superimposed on the object to be processed 2 here. Also, in the movement path 2a, the direction of movement of the object to be processed 2 is indicated by the direction of the arrow. The same applies below. 【0042】 The shape and size of the container 10 are determined, for example, according to the distribution of microwaves irradiated onto the container 10. For example, it is preferable that the shape and size of the container 10 are set so that the microwave mode inside the container 10 is multimode. A multimode microwave is, for example, a mode in which no standing waves of microwaves are generated inside the container 10. 【0043】 The location of the inlet 101a and outlet 101b of the container 10 is not specified. For example, the inlet 101a and outlet 101b may be located at the same end or side of the container 10. Furthermore, the container 10 may have multiple inlets 101a and outlets 101b. For example, the direction of movement of the object to be processed 2 may be changed by rollers (not shown) to move the object to be processed 2 in and out of the container 10 through multiple inlets 101a and outlets 101b. 【0044】 Furthermore, it is preferable that the container 10 has a structure that is closed to prevent microwave leakage, except for parts where openings are necessary, such as the inlet 101a of the object to be processed 2, the outlet 101b, and the opening 102 described later. 【0045】 Although not shown in the figures, the outer circumference of container 10 may be equipped with a hot water jacket, a cold water jacket, a heater, etc., for adjusting the temperature of container 1. Furthermore, container 10 may be equipped with an observation window for observing the interior (not shown), as well as ventilation openings or fans for intake and exhaust. 【0046】 Figure 2 shows a schematic perspective view of the heating element 30 of the microwave processing apparatus 1 of this embodiment (Figure 2(a)), schematic perspective views of modified versions of the heating element 30 (Figures 2(b) to 2(c)), and a cross-sectional view along the movement path 2a of the object to be processed 2 for explaining the modified version of the heating element 30 shown in Figure 2(a) (Figure 2(d)). The container 10 is provided with a heating element 30 that absorbs microwaves irradiated from the microwave irradiation means 20 and generates heat. Preferably, the heating element 30 absorbs a portion of the microwaves irradiated from the microwave irradiation means 20 and generates heat, while transmitting a portion. The heating element 30 is arranged along the object to be processed 2 placed inside the container 10. Being arranged along the object to be processed 2 can mean, for example, being arranged along the outer circumference of the object to be processed 2, or being arranged around the object to be processed 2. The distance between the heating element 30 and the object to be processed 2 may be constant or different in the longitudinal direction and the direction of movement of the object to be processed 2, and in either case, it may be considered that the heating element 30 is positioned along the object to be processed. Similarly, the distance between the portion of the heating element 30 facing the object to be processed 2 and the heating element 30 may be constant or different, and in either case, it may be considered that the heating element 30 is positioned along the object to be processed. Here, since the object to be processed 2 moves inside the container 10, the heating element 30 is positioned along the movement path 2a of the object to be processed 2. For example, the shape of the heating element 30 may be any shape as long as it covers the object to be processed 2. The shape of the heating element 30 is preferably a cylindrical shape that surrounds the outer circumference of the object to be processed 2, as shown in Figure 2(a), but it may also be a cylindrical shape other than a cylinder, or an annular shape, or as shown in Figure 2(b), it may be a shape in which the cross section perpendicular to the direction of movement of the object to be processed 2 is U-shaped. Furthermore, the heating element 30 may be two plate-shaped members arranged to sandwich the object to be processed 2, as shown in Figure 2(c). The heating element 30 may also have a partially bulging cylindrical shape, a partially concave cylindrical shape, a partially curved cylindrical shape, or the like. 【0047】 As shown in Figures 2(a) to 2(c), the heating element 30 includes a heating medium 301 that absorbs irradiated microwaves and generates heat, and a support 302 that supports the heating medium 301. The heating medium 301 is usually provided on a side of the support 302 that does not face the object to be processed 2. Here, the side is, for example, a surface parallel to the direction of movement of the object to be processed 2. The heating medium 301 is formed of, for example, a heating element such as carbon, SiC, carbon fiber composite material, metal siliconides such as silicified molybdenum, silicified tungsten, or a ceramic material containing powder of these heating elements. As the heating medium 301, for example, a material or thickness is used that absorbs a portion of the microwaves irradiated to the heating element 30 and generates heat, and allows a portion of the irradiated microwaves to pass through. As the heating medium 301, for example, a material or thickness is used that allows a portion of the microwaves irradiated to the heating element 30 to pass through. Furthermore, a metal layer with a thickness that allows microwaves to partially pass through, for example, a metal layer with a thickness of several micrometers, may be used as the heating medium. The support 302 is made of a material with high microwave permeability, such as ceramic or glass. The heating medium 301 is provided, for example, by coating or attaching the material of the heating medium 301 to the surface of the support 302. However, if the heating medium 301 alone has sufficient strength, such as when the heating medium 301 is a ceramic containing a heating element, the support 302 may be omitted. As the heating medium 301, for example, a material and thickness that allows a portion of the microwaves irradiated onto the heating element 30 to pass through is used. Also, if the support 302 is used to reinforce the heating medium 301 or to maintain the shape of the heating medium 301, the heating medium 301 alone may be considered as the heating element 30. Preferably, the heating element 30 is such that the heat generated by microwave irradiation of the heating element 30 is greater than the heat generated by the microwaves that pass through the heating element 30 to the object being processed 2. Preferably, the heating element 30 has a material and thickness such that the heat generated by microwave irradiation of the heating element 30 is greater than the heat generated by the microwaves that pass through the heating element 30 to the object being processed 2. In this case, the material and thickness of the heating element 30 may be considered as the material and thickness of the heating medium 301.For example, if the object to be processed 2 is a single precursor fiber, the inner diameter of the cylindrical heating element 30 is approximately 9-12 mm or 11-14 mm, and the thickness of the heating element 30 is approximately 2-5 mm. However, other sizes are also acceptable. 【0048】 The heating element 30 may be partially provided within the container 10 in the longitudinal direction or direction of movement of the object to be processed 2, or it may be provided throughout the entire longitudinal direction or direction of movement of the object to be processed 2 within the container 10. For example, multiple heating elements 30 may be arranged at desired intervals in the longitudinal direction or direction of movement of the object to be processed 2. Here, we will describe the case in which cylindrical heating elements 30, as shown in Figure 2(a), are partially arranged along the movement path 2a of the object to be processed 2. Specifically, as shown in Figure 1, three cylindrical heating elements 30 are arranged at intervals such that the object to be processed 2 moves through the interior of each. Here, the three heating elements 30 are referred to as heating elements 30a to 30c in order from the inlet 101a side of the container 10. However, if there is no need to distinguish between them, they are simply called heating elements 30. The same applies to the other irradiation units 201, 202, sensors 40, etc. The length of each heating element 30 in the direction of movement of the object to be processed 2 (hereinafter referred to as the length of the heating element 30), that is, the length in the longitudinal direction of the cylindrical shape, may be the same or different, and the respective lengths are not specified. For example, when the object to be processed 2 is moving inside the container 10, the length of the heating element 30 may be considered to correspond to the heating time using the heating element 30. Also, the spacing between the heating elements 30 may be equal or not, and the respective distances are not specified. For example, when the object to be processed 2 is moving inside the container 10, the spacing between the heating elements 30 in this direction of movement, the distance between the heating element 30 closest to the inlet 101a and the inlet 101a, and the distance between the heating element 30 closest to the outlet 101b and the outlet 101b (hereinafter referred to as the length of the portion where no heating elements are provided) may be considered to correspond to the heating time when the heating elements 30 are not used. Furthermore, the distance between the heating element 30 and the inlet 101a of the container 10, and the distance between the heating element 30 and the outlet 101b of the container 10, may or may not be equidistant, and the distance is not specified. Also, the diameter of the cylindrical heating element 30 here is not specified. Furthermore, the diameters of each heating element 30 may be the same or different. In this case, the heating element 30 does not come into contact with the object to be processed 2, but at least a part of the heating element 30 may come into contact with the object to be processed.The sides of the heating element 30 are positioned so as not to come into contact with the container 10. 【0049】 For the sake of explanation, the case described here involves three heating elements 30, but the number of heating elements 30 can be one or more. For example, when using the microwave processing device 1 to flame-retardantize carbon fiber precursor fibers moving within a container 10, heating elements 30 should be provided only as many times as heating is required using the heating elements 30. In this case, the length of each heating element 30 should be, for example, the length corresponding to the time required for heating using the heating element 30, and the length of the portion without a heating element 30 should be the length corresponding to the time required for heating without using the heating element 30. Furthermore, if the movement path 2a of the object to be processed 2 is bent or curved, one or more heating elements 30 may be placed in both the portion before the bend and the portion after the bend, and in this case, the heating elements 30 do not need to be arranged in the same straight line. 【0050】 The microwave irradiation means 20 irradiates microwaves into the container 10. The microwave irradiation means 20 is, for example, attached to the container 10. The microwave irradiation means 20 performs a first microwave irradiation to heat the heating element 30 and a second microwave irradiation to heat the object to be processed 2. Heating the heating element 30 may mean, for example, heating only the heating element 30, or heating the heating element 30 more strongly than the object to be processed 2. Heating the object to be processed 2 may mean, for example, heating only the object to be processed 2, or heating the object to be processed 2 more strongly than the heating element 30. However, it is preferable that the first microwave irradiation also heats the object to be processed 2. 【0051】 The first type of microwave irradiation is, for example, microwave irradiation in which the heat generated by the heating element 30 due to microwave irradiation is greater than the heat generated by the object to be processed 2. The first type of microwave irradiation can also be considered as microwave irradiation in which the heat generated by the heating element 30 is dominant. The heat generated here can be considered as, for example, the amount of heat generated. Furthermore, the heat generated by the heating element 30 here can be considered as the amount of heat that the object to be processed 2 receives from the heating element 30 that has been heated by the microwaves. 【0052】 The second type of microwave irradiation is, for example, microwave irradiation in which the heat generated by the object to be processed 2 is greater than the heat generated by the heating element 30. The second type of microwave irradiation can also be considered as microwave irradiation in which the heat generated by the object to be processed 2 is dominant. The heat generated here can be considered as the amount of heat or heating directly received by the object to be processed 2 by the microwaves. 【0053】 In this embodiment, we will describe a case in which the microwave irradiation means 20 has one or more first irradiation units 201 that perform first microwave irradiation and one or more second irradiation units 202 that perform second microwave irradiation. 【0054】 The first irradiation unit 201 performs a first microwave irradiation to heat the heating element 30 by irradiating microwaves onto the portion of the movement path 2a of the object to be processed 2 where the heating element 30 is located. In other words, the first microwave irradiation performed by the first irradiation unit 201 is the irradiation of microwaves onto the portion of the movement path 2a of the object to be processed 2 where the heating element 30 is located. It is preferable that the first microwave irradiation also causes heat to be generated in the object to be processed 2. For example, the first microwave irradiation performed by the first irradiation unit 201 is a microwave irradiation in which heat is generated in the heating element 30 due to the absorption of a portion of the irradiated microwaves and heat is generated in the object to be processed 2 due to the absorption of a portion of the microwaves that have passed through the heating element 30, and the heat generated in the heating element 30 is greater than the heat generated in the object to be processed 2. The first microwave irradiation is the irradiation of the heating element 30 with microwaves such that the external heating of the object to be processed 2 due to the heat generated by the heating element 30 is greater than the direct heating of the object to be processed by microwaves that have passed through the heating element 30. For example, it is preferable to set the material and thickness of the heating element 30 such that the object to be processed 2 is heated as described above by the microwaves absorbed by the heating element 30 and the microwaves that have passed through the heating element 30. 【0055】 Furthermore, the second irradiation unit 202 performs a second microwave irradiation to heat the object to be processed 2 by irradiating microwaves onto the portion of the object to be processed 2a's movement path 2a where the heating element 30 is not provided. In other words, the second microwave irradiation performed by the second irradiation unit 202 is the irradiation of microwaves onto the portion of the object to be processed 2a's movement path 2a where the heating element 30 is not provided. In the second microwave irradiation performed by the second irradiation unit 202, since the heating element 30 is not provided at the position where the microwaves are irradiated, the object to be processed 2 is not heated from the outside by the heat generated by the heating element 30, etc. As a result, the direct heating of the object to be processed 2 by microwave irradiation is greater than the heating from the outside of the object to be processed 2 by the microwave-irradiated heating element 30, etc. 【0056】 In this embodiment, as an example, the microwave processing device 1 is shown as having three first irradiation units 201 and three second irradiation units 202, as shown in Figure 1, but the number of each is not limited. For the sake of explanation, the three first irradiation units 201 are referred to as first irradiation units 201a to 201c in order from the inlet 101a side of the container 10, and the three second irradiation units 202 are referred to as second irradiation units 202a to 202c in order from the inlet 101a side of the container 10. It is preferable that the one or more first irradiation units 201 and one or more second irradiation units 202 of the microwave irradiation means 20 can individually change the microwave output (e.g., wattage). For example, the output of the first irradiation units 201 and the second irradiation units 202 is controlled according to a control signal from the control means 50, which will be described later. As shown in Figure 1, in a microwave processing apparatus 1 in which a plurality of heating elements 30 are arranged, it is preferable that one or more first irradiation units 201 be provided at positions that allow microwaves to be directly irradiated onto each heating element 30, and it is preferable that one or more second irradiation units 202 be provided at positions that allow microwaves to be directly irradiated onto at least one of the following regions: the region between each heating element 30, the region between the heating element 30 closest to the inlet 101a and the inlet 101a, and the region between the heating element 30 closest to the outlet 101b and the outlet 101b. 【0057】 Each first irradiation unit 201 and second irradiation unit 202 comprises, for example, a microwave oscillator 2001 and a transmission unit 2002 that transmits the microwaves generated by the microwave oscillator 2001 to irradiate the container 10 with microwaves. The microwave oscillator 2001 can be any type of microwave oscillator 2001, such as a magnetron, klystron, gyrotron, or semiconductor oscillator. The frequency and intensity of the microwaves emitted by each microwave oscillator 2001 are not specified. The frequency of the microwaves emitted by each microwave oscillator 2001 may be, for example, 915 MHz, 2.45 GHz, 5.8 GHz, or any other frequency within the range of 300 MHz to 300 GHz, and is not specified. The transmission unit 2002 is, for example, a waveguide or a coaxial cable for transmitting microwaves. 【0058】 Each first irradiation unit 201 and second irradiation unit 202 is, for example, attached to a container 10 to irradiate microwaves into the container 10. For example, the ends of each first irradiation unit 201 and second irradiation unit 202 that do not have the microwave oscillator 2001 attached are attached to an opening 102 provided in the wall of the container 10, and the microwaves transmitted by the microwave oscillator 2001 are emitted through this opening 102 and irradiated into the container 10. The end of the transmission unit 2002 attached to the opening 102 may also be provided with an antenna (not shown) or the like for irradiating the microwaves transmitted by the transmission unit 2002. The opening 102 may also be blocked with a plate or the like made of a fluorinated polymer such as PTFE (polytetrafluoroethylene) which has high microwave transparency, glass, rubber, or nylon. The first irradiation unit 201 and the second irradiation unit 202 may be other types of devices, as long as they are capable of irradiating microwaves into the container 10. 【0059】 Each first irradiation unit 201 is attached to the container 10 so as to irradiate microwaves onto the portion of the container 10 where each heating element 30 is located along the movement path 2a of the object to be processed 2. Here, "portion" can be thought of as "area." For example, the ends of the transmission units 2002 of each first irradiation unit 201 are attached to openings 102 provided on the wall of the container 10, facing the portion of the movement path 2a where each heating element 30 is located. Here, an example is shown where one first irradiation unit 201 is provided in one opening 102 provided in the portion where one heating element 30 is located, but multiple first irradiation units 201 may be attached to multiple openings 102 provided in the portion where one heating element 30 is located. 【0060】 Each second irradiation unit 202 is attached to the container 10 so as to irradiate microwaves to the portion of the movement path 2a of the object to be processed 2 in the container 10 where the heating elements 30 are not located. Specifically, each of the multiple second irradiation units 202 is attached so as to irradiate microwaves to the portion between the heating elements 30 and to the portion between the heating element 30 located at the rearmost end of the movement path 2a and the outlet 101b of the container 10. For example, the end of the transmission unit 2002 of each second irradiation unit 202 is attached to an opening 102 on the wall of the container 10, which is located facing the portion of the movement path 2a where the heating elements 30 are not provided. Here, an example is shown in which one first irradiation unit 201 is provided in one opening 102 provided in a portion where the heating elements 30 are not provided, but multiple first irradiation units 201 may be attached to multiple openings 102 provided in a portion where the heating elements 30 are not provided. 【0061】 Here, it is assumed that the microwaves emitted by each first irradiation unit 201 and second irradiation unit 202 are of the same frequency. However, one or more of the multiple first irradiation units 201 and multiple second irradiation units 202 may emit microwaves of a different frequency than the others. 【0062】 The container 10 is equipped with one or more sensors 40 that acquire information such as the condition of the object to be processed and the conditions inside the container. The sensors 40 can be sensors that acquire information on any condition. For example, they may be temperature sensors that acquire information on the temperature inside the container, or humidity sensors that acquire information on the humidity inside the container, etc. Alternatively, they may be sensors that detect discharge inside the container using microwaves, etc. 【0063】 Here, we will explain using the example of a case where sensor 40 is a radiation thermometer and six sensors 40 are installed inside the container 10. For the sake of explanation, the six sensors 40 are referred to as sensors 40a to 40f in order from the inlet 101a side of the container 10. A radiation thermometer is a thermometer that measures the temperature of an object by measuring the intensity of infrared rays and visible light emitted from the object. Here, the radiation thermometers sensors 40a to 40c are installed near the outlet 101b side within the area where the heating elements 30 are installed in the movement path 2a, in order to measure the temperature of the object to be processed 2 just before it leaves the area where each heating element 30 is installed. Specifically, sensors 40a to 40c are attached to the container 10 so that their horizontal position is near the outlet 101b side of the heating elements 30a to 30c. Although not shown in the diagram, as an example, the heating elements 30a to 30c are provided with horizontally extending slits or other openings in the portion between the sensors 40a to 40c and the object to be processed 2, in order to detect the temperature of the object to be processed 2. The remaining radiation thermometers, sensors 40d to 40f, are installed in the region of the movement path 2a where the heating elements 30 are not provided, near the exit 101b, in order to measure the temperature of the object to be processed 2 just before it exits the region where the heating elements 30 are not provided. Specifically, sensors 40d to 40e are mounted on the container 10 at a position where their horizontal position is closer to the heating elements 30b to 30c in the direction of movement of the object to be processed 2, and sensor 40f is mounted just before the exit 101b. Here, the sensors 40 obtain temperature information by measuring the intensity of infrared radiation, etc., emitted from the object to be processed 2 in a direction perpendicular to the movement path 2a. However, the position where the sensors 40 are mounted may be other positions. The sensor 40 is attached, for example, to an opening in the wall of the container 10. Note that, since precursor fibers are made up of thousands of strands twisted together to form a single fiber with a thickness of about 1 mm, if the object to be processed 2 is a precursor fiber, its surface temperature can be considered to be the same as the internal temperature of the precursor fiber. 【0064】 The control means 50 controls the microwaves emitted by the microwave irradiation means 20. For example, the control means 50 controls the output of the microwaves emitted by the microwave irradiation means 20. For example, the control means 50 controls the output of the microwaves emitted by the microwave irradiation means 20 according to the information acquired by the sensor 40. 【0065】 Specifically, the control means 50 uses temperature information acquired by a sensor 40 located on the exit 101b side of the area where each heating element 30 is located to feedback control the output of microwaves irradiated by the first irradiation unit 201, which irradiates microwaves onto the area where each heating element 30 is located in the movement path 2a. The control means 50 also uses temperature information acquired by a sensor 40 located on the exit 101b side of the area where each heating element 30 is not located to feedback control the output of microwaves irradiated by the second irradiation unit 202, which irradiates microwaves onto the area where each heating element 30 is not located in the movement path 2a. The areas where the heating elements 30 are located and the areas where the heating elements 30 are not located here are, for example, areas demarcated by a virtual plane perpendicular to the movement path 2a. For example, if the temperature acquired by the sensor 40a is higher than the first threshold, the control means 50 lowers the output of microwaves irradiated by the corresponding second irradiation unit 202a, and if it is lower than the second threshold, it increases the output of the irradiated microwaves. Here, the first threshold is assumed to be a higher value than the second threshold. 【0066】 Furthermore, the control performed by the control means 50 may be a control other than feedback control. Also, it is not specified which sensor 40 the control means 50 controls the output of which irradiation unit in response to the information acquired by which sensor 40. For example, the control means 50 may control the output of one or more irradiation units in response to the outputs of multiple sensors 40. Alternatively, the control means 50 may control the outputs of multiple irradiation units in response to the output of one sensor 40. 【0067】 Furthermore, one or more sensors 40 may acquire information indicating the status of one or more heating elements 30, or the temperature of one heating element 30 at different locations, and the control unit 50 may use this status information to control the output of one or more irradiation units (for example, feedback control). For example, the output of the microwaves used for the first microwave irradiation performed on each heating element 30 may be feedback controlled using the temperature information of each heating element 30 acquired by each sensor 40 that acquires the temperature information of each heating element 30. 【0068】 Alternatively, a portion of the sensor 40 may be provided as a first sensor to acquire temperature information of the portion of the heating element 30 that is subjected to the first microwave irradiation, and a portion of the sensor 40 may be provided as a second sensor to acquire temperature information of the portion of the object to be processed 2 that is subjected to the second microwave irradiation. The control means 50 may then use the temperature information acquired by the first sensor to feedback control the output of the microwaves used for the first microwave irradiation, and use the temperature information acquired by the second sensor to feedback control the output of the microwaves used for the second microwave irradiation. For example, the heating elements 30a to 30c may be configured such that no slits or the like are provided in the portion between the sensors 40a to 40c and the object to be processed 2, so that the first sensors, sensors 40a to 40c, acquire temperature information of the heating elements 30a to 30c. The control means 50 then uses the temperature information of the heating elements 30a to 30c acquired by sensors 40a to 40c to feedback control the output of the microwaves irradiated by the first irradiation units 201a to 201c, and also uses the temperature information of the object to be processed 2 in the region where the heating elements 30 are not provided, acquired by the second sensors 40d to 40f, to feedback control the output of the microwaves irradiated by the second irradiation units 202a to 202c. In this way, it becomes possible to appropriately control the heating of the heating elements 30 by the first microwave irradiation and the heating of the object to be processed 2 by the second microwave irradiation. 【0069】 The conveying means 60 is a means for conveying the material to be processed 2 within the container 10. The conveying means 60 may be provided inside the container 10 or outside the container 10. Here, as an example, the conveying means 60 is shown to include a holding part 62 that rotatably holds a reel 61 on which the precursor fibers, which are the material to be processed 2, are wound, on the inlet 101a side of the container 10, a roller 63 that changes the direction of movement of the material to be processed 2 and sends the material to be processed 2 from the inlet 101a into the container 10, a roller 64 that changes the direction of movement of the material to be processed 2 coming out of the outlet 101b of the container 10, and a winding part 65 that winds up the material to be processed 2 whose direction of movement has been changed by the roller 64. However, any conveying means may be used as the conveying means 60. Also, if multiple material to be processed 2 are to be moved into the container 10, there may be multiple conveying means 60. 【0070】 Next, the operation of the microwave processing apparatus 1 of this embodiment will be explained with specific examples. Here, the example will be that the microwave processing apparatus 1 is used to perform flame-retardant treatment on PAN-based precursor fibers, which are the object to be processed 2. For the sake of simplicity, the microwave processing apparatus 1 shown in Figure 1 will be used for this explanation. The object to be processed 2 is, for example, a precursor fiber with a width of about 5 to 10 mm and a thickness of about 1 to 2 mm. As for the microwaves used for irradiation, for example, a microwave with a frequency of 915 MHz or 2.45 GHz and an output of 6 to 20 KW is used. 【0071】 First, the PAN-based precursor fiber, which is the material to be processed 2, is placed in the transport means 60 such that one end enters the container 10 through the inlet 101a, passes inside the cylindrical heating elements 30a to 30c, and exits the container 10 through the outlet 101b. The transport means 60 then moves the material to be processed 2 within the container 10. The transport speed of the transport means 60 is controlled, for example, to a predetermined speed. Microwave irradiation is also started from the first irradiation units 201a to 201c and the second irradiation units 202a to 202c. Here, it is assumed that the frequencies of the microwaves irradiated by the first irradiation units 201a to 201c and the second irradiation units 202a to 202c are the same frequency (for example, 2.45 GHz). The transport speed of the transport means 60 is controlled, for example, to a predetermined speed by the control means 50 or other control means (not shown). The control means 50 controls the first irradiation units 201a to 201c and the second irradiation units 202a to 202c so that the microwaves irradiated by each first irradiation unit 201a to 201c and the second irradiation units 202a to 202c emit microwaves of a predetermined output. 【0072】 The portion of the object to be processed 2 that enters the container 10 from the inlet 101a and is inside the heating element 30 is heated from the outside by radiant heat from the heating element 30, which generates heat by absorbing a portion of the microwaves irradiated by the first irradiation unit 201, and is also directly heated by microwaves that are not absorbed by the heating element 30 and are transmitted through it. Here, for example, if the material and thickness of the heating element 30a to 30c are set such that the amount of heat generated by the absorption of microwaves irradiated by the first irradiation units 201a to 201c by the heating element 30a to 30c is sufficiently greater than the amount of heat generated by the microwaves transmitted through the heating element 30 on the object to be processed 2, then in the region inside the heating element 30, the heating of the object to be processed 2 will be stronger from the external heating by the heating element 30 than from the direct heating by the microwaves transmitted through the heating element 30. Furthermore, the output of microwaves irradiated from the first irradiation units 201a to 201c is feedback-controlled according to the temperature of the object 2 to be processed, which is acquired by sensors 40a to 40c, and is controlled so that the object 2 reaches a desired temperature range. 【0073】 When the portion of the object to be processed 2 that was inside the heating element 30 comes out, it enters the area immediately behind the heating element 30 where the heating element 30 is not provided, and is irradiated with microwaves from the second irradiation unit 202 without passing through the heating element 30, and is heated by the microwaves. In other words, it is heated directly by microwaves. In this area where the heating element 30 is not provided, the object to be processed is not heated by the heat generated by the heating element 30, so the direct heating by microwaves becomes stronger than the heating from the heating element 30 or other external sources. The output of the microwaves irradiated from the second irradiation units 202a to 202c is feedback controlled according to the temperature of the object to be processed 2 acquired by sensors 40d to 40f, respectively, and is controlled so that the object to be processed 2 reaches a desired temperature range. 【0074】 In this way, the first irradiation unit 201 and the second irradiation unit 202 can appropriately switch between strong heating from the heating element 30 and strong direct heating by microwave irradiation on the object to be processed 2 moving inside the container 10. This makes it possible, for example, to appropriately switch between heating from the outside of the object to be processed 2 and direct heating to the object to be processed 2, thereby heating the object to be processed 2 evenly without uneven heating from the outside or direct heating. 【0075】 In particular, in PAN-based precursor fibers that have not undergone flame-retardant treatment, microwaves are not easily absorbed. Therefore, even when the heating element 30 is heated by microwave irradiation by the first irradiation unit 201, the microwaves that pass through the heating element 30 directly heat the object to be treated 2, thereby reducing the time required for the object to be treated 2 to be heated by the second irradiation unit 202. 【0076】 Furthermore, when the object to be processed 2 reaches a certain temperature due to heating, the heat generation of the object to be processed 2 reaches its peak, causing the object to rapidly heat up and potentially carbonize, making it impossible to perform the desired processing. For example, when the precursor fibers, which are the object to be processed 2, reach a certain temperature due to heating, the heat generation of the precursor fibers reaches its peak due to oxidation, and the precursor fibers may carbonize. In particular, when the object to be processed 2 is strongly heated by direct heating with a second microwave irradiation, the thermal efficiency is high, and the heat generation is concentrated in one place, so the object is heated from the temperature just before the heat generation peak to the temperature at which the heat generation peak occurs in a short time, making it difficult to control the heating before and after the heat generation peak. For this reason, when the object to be processed is heated by a second microwave irradiation, by arranging the heating element 30 so that it switches from the second microwave irradiation to the first microwave irradiation when the temperature of the object to be processed 2 reaches a temperature just before the heat generation peak, it is possible to heat the object to be processed 2 by radiant heat from the heating element 30, thereby suppressing rapid heating and preventing carbonization. 【0077】 For example, in a microwave processing apparatus 1 as shown in Figure 1, when a workpiece 2 is moved within a container 10 and heated, the peak of heat generation at which the workpiece 2 reaches can be determined in advance by the moving speed, the number and arrangement of the first irradiation unit 201 and the second irradiation unit 202, their output, etc. This position may be detected by experimentation or other means. For this reason, for example, by placing a heating element 30 in the moving path 2a of the workpiece 2 at the position where the temperature of the workpiece 2 reaches its peak of heat generation, or at a position covering this position and the areas immediately before and after it, and irradiating the heating element 30 with microwaves from the first irradiation unit 201, it becomes possible to appropriately process the workpiece 2 while avoiding the rapid heating that occurs when the workpiece 2 reaches its peak of heat generation. Furthermore, in positions that do not include this peak of heat generation, the heating element 30 can be appropriately placed or not placed to switch between first and second microwave irradiation on the moving workpiece 2, thereby enabling uniform heating or desired heating of the workpiece 2. The peak temperature of heat generation in the processed object can be measured, for example, by TG-TDA measurement (thermogravimetric and differential thermal analysis). 【0078】 Note that the number of heating elements 30, the number and arrangement of the first irradiation section 201 and the second irradiation section 202 in this specific example are just examples, and the number of heating elements 30, the number and arrangement of the first irradiation section 201 and the second irradiation section 202 are not specified. 【0079】 As described above, in this embodiment, a first microwave irradiation to heat the heating element and a second microwave irradiation to heat the object to be processed are performed inside the container, so that the object to be processed can be appropriately processed using microwaves. For example, appropriate heating can be achieved by controlling the combination and ratio of heating from the outside of the object to be processed by the heating element heated by microwaves and direct heating by heating the object to be processed by microwaves. 【0080】 Furthermore, by performing the first microwave irradiation in the first irradiation unit 201 and the second microwave irradiation in the second irradiation unit 202, it becomes possible to individually control the output of the first microwave irradiation and the output of the second microwave irradiation. This allows for precise control of heating of the object being processed, resulting in high-quality processing results. 【0081】 As shown in Figure 2(d), a non-transparent portion 303 that does not transmit microwaves may be provided on at least a part of the heating element 30 on the side facing the object 2. Figure 2(d) is a cross-sectional view along the direction of movement of the object 2, showing an example of a heating element 30 in which a non-transparent portion 303 is provided on the inside of the cylindrical heating element 30 shown in Figure 2(a). Preferably, at least a part of the heating element 30 on the side facing the object 2 is a part of the heating element 30 on the side facing the object 2, but it may be the entire side facing the object 2. For example, as shown in Figure 2(d), at least a part of the heating element 30 on the side facing the object 2 is a part of the inside of a cylindrical heating element 30. When multiple heating elements 30 are provided in the container 10, the part of the heating element 30 on the side facing the object 2 here may be the entire surface of one or more of the multiple heating elements 30 on the side facing the object. Preferably, the non-transparent portion 303 is made of a material that does not transmit microwaves and has good thermal conductivity. For example, graphite or metal can be used as the material for such an opaque portion 303. Alternatively, the opaque portion 303 may be used instead of a part of the support 302, in which case it can also be considered that the opaque portion 303 is provided on the side of the heating element 30 facing the object 2. By providing such an opaque portion 303, microwaves are prevented from irradiating the object 2 in the area where the opaque portion 303 is provided, thus preventing direct heating of the object 2. Furthermore, the heating element 30 generates heat that allows the object 2 to be heated from the outside. In other embodiments, an opaque portion may also be provided on at least a part of the heating element 30. 【0082】 In the above, the thickness of the heating element 30 may or may not be uniform. The concept that the thickness of the heating element 30 is not uniform includes the presence of parts with different thicknesses. The thickness of the heating element 30 may also be considered as the thickness of the heating medium 301 of the heating element 30. For example, the thickness of the heating element 30 may or may not be uniform in the longitudinal direction of the heating element 30 or in the direction of movement of the object to be processed 2. For example, if multiple heating elements 30 are arranged in the container 10, the thickness of one or more of the multiple heating elements 30 (but not all of them) may be different from that of the other heating elements 30. In this case, the thickness of each of the multiple heating elements 30 may be uniform in the longitudinal direction or in the direction of movement of the object to be processed 2. The same applies below. 【0083】 For example, in a microwave processing apparatus as shown in Figure 1 above, instead of defining the microwave irradiation performed on a portion of the movement path 2a of the object to be processed 2 that does not have a heating element 30 as the second microwave irradiation, a second heating element (not shown) thinner than the heating element 30 may be provided in one or more portions that do not have a heating element 30, and the microwave irradiation performed on this second heating element from the second irradiation unit 202 may be defined as the second microwave irradiation. By reducing the thickness of the second heating element, the penetration depth of the irradiated microwaves changes, so by adjusting the thickness of the second heating element, the absorption of microwaves irradiated onto the second heating element by the second heating element can be reduced, increasing the amount of microwaves that pass through the second heating element, and thus heating the object to be processed 2 more strongly than the second heating element. In this case, the object to be processed 2 can also be heated from the outside by the heat generated by the second heating element. 【0084】 Furthermore, the thickness of one or more of the multiple heating elements 30 may be different from that of the other heating elements 30. This makes it possible to change the ratio of heating of the heating elements 30 by the first microwave irradiation to heating of the heating elements 30 by changing the microwaves absorbed by the heating elements 30 according to the thickness of the heating elements 30. The same applies to the second microwave irradiation using the second heating element 30. The same also applies to the following. 【0085】 Furthermore, in the above, the material of the heating element 30 may be the same in the longitudinal direction of the heating element 30 and in the direction of movement of the object to be processed 2, or it may be a different material. Different materials may be materials with different compositions, components, material ratios, etc. The concept that the heating element 30 is made of different materials includes the idea that parts of different materials are mixed together. The material of the heating element 30 here may also be considered as the material of the heating medium 301 of the heating element 30. For example, if multiple heating elements 30 are arranged in the container 10, the material of one or more of the multiple heating elements 30 (except all of them) may be a different material from the other heating elements 30. Also, three or more heating elements 30 may be composed of three or more heating elements 30 made of three or more different materials. In this case, the material of each of the multiple heating elements 30 may be a uniform material. The same applies below. 【0086】 For example, in a microwave processing apparatus as shown in Figure 1 above, instead of defining the microwave irradiation performed on a portion of the movement path 2a of the object to be processed 2 that is not provided with a heating element 30 as the second microwave irradiation, a second heating element (not shown) made of a different material than the heating element 30 may be provided in one or more portions that are not provided with the heating element 30, and the microwave irradiation performed on this second heating element from the second irradiation unit 202 may be defined as the second microwave irradiation. By changing the composition of the second heating element, the penetration depth of the irradiated microwaves changes, so by selecting the composition of the second heating element, the absorption of microwaves irradiated onto the second heating element by the second heating element can be reduced, increasing the amount of microwaves that pass through the second heating element, and thus heating the object to be processed 2 more strongly than the second heating element. In this case, the object to be processed 2 can also be heated from the outside by the heat generated by the second heating element. 【0087】 Furthermore, for multiple heating elements 30, one or more of them may be made of a different material than the other heating elements 30. This makes it possible to change the ratio of heating of the heating elements 30 by the first microwave irradiation to heating of the heating elements 30 by changing the microwaves absorbed by the heating elements 30 according to the material of the heating elements 30. The same applies to the second microwave irradiation using the second heating element 30. The same also applies to the following. 【0088】 It goes without saying that the combination of materials and thicknesses of the heating element 30 and the second heating element may also be changed. 【0089】 Furthermore, although the above describes an example in which the processing target unit 2 moves, the processing target unit 2 may be configured not to move within the container 10, allowing the processing target object 2 to be left stationary within the container 10. This is also true in other embodiments. Note that if movement is not required, the transport means 60 may be omitted. In addition, one or more irradiation units (not shown) of the microwave irradiation means 20 may each irradiate microwaves to both the portion where the heating element 30 is located and the portion of the processing target object 2 where the heating element 30 is not provided. This can be thought of, for example, as one or more irradiation units (not shown) of the microwave irradiation means 20 each performing both a first microwave irradiation and a second microwave irradiation. In this case, the irradiation units are positioned to irradiate microwaves to, for example, one or more heating elements 30 and one or more portions of the movement path 2a where the heating element 30 is not provided. For example, the irradiation unit may be positioned near the boundary between the heat-generating member 30 and the portion of the movement path 2a adjacent to the heat-generating member 30 where the heat-generating member 30 is not provided. In this case, for example, an irradiation unit similar to the first irradiation unit 201 and the second irradiation unit 202 described above can be used. 【0090】 (First variation) Figure 3 shows a first modified example of the microwave processing apparatus 1 of this embodiment. In this first modified example, the microwave processing apparatus 1 has a cylindrical heating element 30, and is further provided with a gas supply means 70 for supplying oxygen to the inside of the heating element 30. The gas supply means 70 includes a supply unit 701 for supplying oxygen, such as an oxygen cylinder or an oxygen generator, an oxygen supply pipe 702 attached to the heating element 30 so that one end opens to the inside of the heating element 30 and the other end is connected to the supply unit 701, and a valve 703 for adjusting the amount of oxygen supplied through the path of the pipe 702. The position in which one end of the pipe 702 is attached to the heating element 30 is irrelevant. The valve 703 may be controlled by, for example, a control means 50, or it may be controlled according to user operation, etc. Supplying oxygen here is a concept that also includes supplying a gas with a higher oxygen concentration than the air in the container 10 (for example, air with added oxygen). Multiple gas supply means 70 may share a single supply unit 701. Furthermore, if an external supply unit (not shown) is used instead of the supply unit 701, the gas supply means 70 does not need to have a supply unit 701. 【0091】 Furthermore, in order to prevent the oxygen supplied to the inside of the heating element 30 from escaping to the outside of the heating element 30, both ends of the heating element 30 through which the object to be processed 2 enters and exits may be sealed, except for the openings that allow the object to be processed 2 to enter and exit. 【0092】 Furthermore, although the case in which the gas supply means 70 is individually provided for all of the multiple heating elements 30 has been described here, the gas supply means 70 may be provided for only some of the multiple heating elements 30. 【0093】 In this way, by supplying oxygen into the heating element 30 using the gas supply means 70, it becomes possible to control the oxygen concentration and appropriately control the processing performed in the microwave processing apparatus 1. For example, by supplying oxygen according to the object to be processed, it becomes possible to shorten the processing time and promote uniformity of the processing. 【0094】 Furthermore, the provision of such gas supply means 70 is also possible in microwave processing devices having cylindrical heating elements or the like in other embodiments. 【0095】 Furthermore, the gas supply means 70 may also supply a predetermined gas other than oxygen. For example, the predetermined gas may be nitrogen gas, a noble gas such as argon gas, hydrogen gas, or one or more combinations thereof. Supplying a predetermined gas here includes the concept of supplying a gas in which the concentration of the predetermined gas is higher than that of the air or other gas in the container 10 (for example, a gas in which the predetermined gas has been added to air). The configuration of the gas supply means 70 is the same as above, except that the gas supplied by the supply unit 701 is a predetermined gas. Note that if the container 10 is filled with a gas other than air, the gas supplied by the gas supply means 70 may be air. Also, the gases supplied by the gas supply means 70 connected to different heating elements 30 may be the same gas or different gases. Also, the gases supplied by the gas supply means 70 connected to different heating elements 30 may be gases with different predetermined concentrations or gases with different composition ratios. 【0096】 (Second variation) Figures 4(a) and 4(b) show a second modified example of the microwave processing apparatus 1 of this embodiment. In this second modified example of the microwave processing apparatus 1, as shown in Figures 4(a) and 4(b), instead of the heating element 30, a member such as a roller or belt is used as the heating element. This member assists in the transport of the object to be processed 2 within the container and has a portion that contacts the object to be processed 2. This portion that contacts the object to be processed 2 has a heating medium that absorbs microwaves and generates heat. In Figures 4(a) and 4(b), containers 10a and 10b correspond to container 10. Although not explained here, the modified example of the microwave processing apparatus 1 shown in Figures 4(a) and 4(b) may also have control means similar to the control means 50 shown in Figure 1 and sensors similar to the sensor 40, and feedback control of the microwave output may be performed according to the sensor output. 【0097】 For example, in Figure 4(a), the movement path 2a is a multi-layered path folded back by a plurality of rollers 11 provided on the outside of the container 10a, and the container 10a has a shape that covers the parts of the movement path 2a other than the folded parts, and a plurality of inlets 101a and outlets 101b for the object to be processed 2 to be put in and taken out are provided near the folded parts of the movement path 2a. The size of the rollers 11 is not specified. Also in Figure 4, the container 10a has two cavities 110a and 110b provided to divide the movement path 2a into a plurality of regions, and the plurality of inlets 101a and outlets 101b are provided as openings for the object to be processed 2 to enter and exit each of the respective cavities 110a and 110b. 【0098】 Within the cavity 110a, a plurality of belts 32a, which are heating elements having the aforementioned heating medium on their surface, are stretched across rollers 33 so as to sandwich and contact the object to be processed 2 moving along the movement path 2a from above or below. The material of the belts 32a is, for example, a material that is partially permeable to microwaves. The first irradiation unit 201 described above is provided to irradiate microwaves onto the portion of the movement path 2a sandwiched between the belts 32a. The belts 32 move in the direction of movement of adjacent movement paths 2a, for example, when the rollers 33 are rotated by a motor or the like. Note that the entire belt 32a may be heated by microwaves. For example, a material containing the aforementioned heating medium may be used as the material for the belts 32a. Suitable materials for the belts 32a include heat-resistant resins and graphite fibers. As a heating medium for the surface of belt 32a, heating elements such as carbon, SiC, carbon fiber composite materials, metal siliconides such as molybdenum silicidate and tungsten silicidate, or ceramic materials containing powders of these heating elements can be used. 【0099】 Furthermore, within the cavity 110b, multiple belts 32b are stretched across rollers 33 so as to sandwich and contact the object to be processed 2 moving along the movement path 2a from above or below. The material of these belts 32b is a material with high microwave permeability. Also, these belts 32b do not have the heating medium described above on their surface. The second irradiation unit 202 described above is provided to irradiate microwaves onto the portion of the movement path 2a sandwiched between the belts 32b. The belts 32b move in the direction of movement of adjacent movement paths 2a, for example, when the rollers 33 are rotated by a motor or the like. 【0100】 Furthermore, the portions of belts 32a and 32b that grip the object to be processed 2 are arranged so that they are in contact with the object to be processed 2, except for the portions near the roller 33. However, there may be some areas that are not in contact. 【0101】 The belt 32a assists in conveying the object to be processed 2 by contacting it, preventing slack from occurring in the object to be processed 2 during processing, which could lead to the object being cut or uneven heating. Furthermore, within the cavity 110a, the surface of the belt 32a is heated by microwave irradiation, and the radiant heat generated by this heating heats the object to be processed near the belt 32. This allows the first microwave irradiation described above to be performed by the first irradiation unit 201, and also allows the portion of the object to be processed 2 in contact with the belt 32 to be efficiently heated by heat conduction. 【0102】 Furthermore, similar to belt 32a, belt 32b assists in transport by contacting the object to be processed 2, preventing slack from occurring in the object to be processed 2 during processing, which could lead to the object being cut or uneven heating. In addition, the surface of belt 32b within cavity 110b generates almost no heat from microwave irradiation, and the object to be processed 2 is directly heated by microwaves that pass through belt 32b, allowing the second microwave irradiation described above to be performed by the second irradiation unit 202. 【0103】 Alternatively, instead of using belt 32b, belt 32b may be omitted, and a second microwave irradiation may be performed by irradiating the area where belt 32b was omitted with microwaves. 【0104】 Furthermore, although this explanation describes the case where the container 10 has two cavities 110a and 110b, the number of cavities in the container 10 is not limited to one or two or more. The size of each cavity is also not limited. The number of cavities irradiated with microwaves by the first irradiation unit 201 and the number of cavities irradiated with microwaves by the second irradiation unit 202, as well as their arrangement order along the movement path 2a, are not limited. In addition, the multiple cavities in the container 10 may be connected or separated. For example, multiple cavities connected or separated to perform the above processing on the same object 2 may be considered as one container 10. Also, the object 2 that has moved outside from one cavity may be returned to the same cavity. Note that the fact that the container 10 may have two or more cavities is also true for microwave processing devices other than the microwave processing device shown in Figure 4(a). 【0105】 Furthermore, in the microwave processing apparatus 1 shown in Figure 4(a), a container 10 that is not divided into multiple cavities may be used, and one or more belts 32a and 32b as described above may be provided inside this container 10, and a first microwave irradiation may be performed on belt 32a from one or more first irradiation units 201, and a second microwave irradiation may be performed on belt 32b from one or more second irradiation units 202. 【0106】 Note that the shape of container 10a and the movement path 2a described here are just examples, and the shape of container 10 and the movement path of the object to be processed 2 may be any shape or movement path. 【0107】 Alternatively, for example, as shown in Figure 4(b), a plurality of rollers 31a having a heating medium on their surface may be arranged so that their surfaces are in contact with the object to be processed 2 moving along the movement path 2a, and a plurality of rollers 31b that do not have a heating element on their surface and hardly absorb microwaves may be arranged in a region different from the region where the plurality of rollers 31a are provided, so that their surfaces are in contact with the object to be processed 2 moving along the movement path 2a, and a first irradiation unit 201 may be provided to irradiate the region of the movement path 2a where the rollers 31a are provided with microwaves, and a second irradiation unit 202 may be provided to irradiate the region of the movement path 2a where the rollers 31b are provided with microwaves, so that microwaves are irradiated from the first irradiation unit 201 and the second irradiation unit 202. Note that the entire roller 31a may be heated by microwaves. For example, a material containing the heating medium as described above may be used as the material for the roller 31a. Suitable materials for the roller 31a include heat-resistant resins, ceramics, glass, graphite, etc. As a heating medium for the surface of belt 32a, heating elements such as carbon, SiC, carbon fiber composite materials, metal siliconides such as molybdenum silicidate and tungsten silicidate, or ceramic materials containing powders of these heating elements can be used. 【0108】 For example, in Figure 4(b), the movement path 2a is a multi-layered path folded back by a plurality of rollers 11 provided on the outside of the container 10a, and the container 10a has a shape that covers the parts of the movement path 2a other than the folded parts, and a plurality of inlets 101a and outlets 101b for loading and unloading the object to be processed 2 are provided near the folded parts of the movement path 2a. The size of the rollers 11 is not specified. 【0109】 The multiple rollers 31a assist in transport by contacting the object to be processed 2, preventing sagging during processing, which could lead to the object being cut or uneven heating. Furthermore, the multiple rollers 31a are used as heating elements as described above, and their surfaces are heated by microwave irradiation. The radiant heat generated by this heating heats the object to be processed near the rollers 31, and the portion of the object to be processed 2 in contact with the rollers 31 is efficiently heated by heat conduction. As a result, the microwave irradiation performed by the first irradiation unit 201 becomes the first microwave irradiation. 【0110】 The multiple rollers 31b assist in transport by contacting the object to be processed 2, preventing sagging during processing, which could lead to the object being cut or uneven heating. Furthermore, since the multiple rollers 31b generate almost no heat from microwave irradiation, and the object to be processed 2 is directly heated by microwaves that pass through the rollers 31b, the second irradiation unit 202 can perform the second microwave irradiation described above. 【0111】 These rollers 31a and 31b may be connected to a motor (not shown) and rotate, or they may not rotate. Furthermore, the number of rollers 31a and 31b can be one or more. 【0112】 Alternatively, instead of using roller 31b, the roller 31b may be omitted, and a second microwave irradiation may be performed by irradiating the area where roller 31b was omitted with microwaves. Furthermore, the arrangement and order of rollers 31a and 31b may be different from those described above. Also, the number of rollers 31a and 31b is not limited. 【0113】 Alternatively, instead of the container 10b shown in Figure 4(b), a container having multiple cavities as shown in Figure 4(a) may be used. For example, a first irradiation unit 201 or a second irradiation unit 202 may be attached to each cavity, with a roller 31a placed in the cavity where the first irradiation unit 201 is attached, and a roller 31b placed in the cavity where the second irradiation unit 202 is attached. 【0114】 (Embodiment 2) Figure 5 shows a cross-sectional view parallel to the direction of movement of the object to be processed (Figure 5(a)), a schematic cross-sectional view perpendicular to the longitudinal direction passing through point A in Figure 5(a) of the heating element of the microwave processing apparatus in this embodiment (Figure 5(b)), and a schematic cross-sectional view perpendicular to the longitudinal direction passing through point B of the heating element of the microwave processing apparatus (Figure 5(c)). The microwave processing apparatus 1a in this embodiment performs a first microwave irradiation and a second microwave irradiation by controlling the phase of multiple microwaves output from different positions by the microwave irradiation means 21. 【0115】 The microwave processing device 1a comprises a container 10c, a microwave irradiation means 21, a heating element 30, one or more sensors 40, a control means 51, and a transport means 60. 【0116】 The container 10c is the same as the container 10 shown in Figure 1 in the above embodiment, except that it is fitted with two or more irradiation units 203 of the microwave irradiation means 21, which will be described later. In addition, any container as described in the above embodiment can be used as the container 10c, for example, a container having multiple cavities can also be used. 【0117】 The following describes a case where a single cylindrical heating element 30 is provided inside the container 10c along the movement path 2a of the object to be processed 2. However, there may be multiple heating elements 30. In addition, the same heating elements 30 as those described in the above embodiment can be used. 【0118】 The microwave irradiation means 21 comprises two or more irradiation units 203 that irradiate microwaves from different positions. The microwave irradiation means 21 comprises two or more irradiation units 203 that are attached to openings 102 provided at different positions on the wall surface of the container 10c and irradiate microwaves into the container 10c. At least some of the two or more irradiation units 203 are irradiation units 203 that can control the phase of the irradiated microwaves. An irradiation unit 203 with controllable phase is, for example, an irradiation unit 203 that comprises a microwave oscillator 2001 and a transmission unit 2002 as described in the above embodiment, and further comprises a phase shifter (not shown) with controllable phase. It is preferable to use a semiconductor type oscillator as the microwave oscillator 2001 in the irradiation unit 203 with controllable phase. For irradiation units 203 that do not control the phase, irradiation units similar to the first irradiation unit 201 and second irradiation unit 202 in the above embodiment can be used. However, the irradiation unit 203, which can control the phase of the irradiated microwaves, may have any configuration as long as the phase is controllable. Here, phase control can be considered to include setting the phase to a specific phase. 【0119】 The microwave processing apparatus 1a of this embodiment controls the phase of microwaves irradiated by two or more irradiation units 203 to perform a first microwave irradiation in which the microwaves irradiated by two or more irradiation units 203 reinforce each other on the heating element 30, and a second microwave irradiation in which the microwaves irradiated by two or more irradiation units 203 reinforce each other on the object to be processed 2. For example, the microwave processing apparatus 1a performs the first microwave irradiation and the second microwave irradiation by controlling the phase of microwaves irradiated by each irradiation unit 203 using a control means 51, etc., which will be described later. Reinforcement of microwaves means, for example, that the intensities of the microwaves reinforce each other. For example, reinforcement of microwaves may mean that the electric field strengths of the microwaves reinforce each other, or that the magnetic field strengths reinforce each other, or both. For example, the microwave processing device 1a uses control means 51, etc., to control the phases of microwaves irradiated by two or more irradiation units so that the phases of the microwaves irradiated from each unit reinforce each other through interference at a desired position. For example, the microwave processing device 1a uses control means 51, etc., to control the phases of microwaves irradiated by two or more irradiation units so that the phases of the microwaves irradiated from each unit become in phase at a desired position, thereby causing the microwaves to reinforce each other. Reinforcing microwaves at a desired position can also be thought of as concentrating microwaves at a desired position. Furthermore, the microwave processing device 1a prevents the microwaves from being reinforced by preventing them from reinforcing each other through interference at a desired position. Furthermore, the microwave processing device 1a prevents the microwaves from being reinforced by preventing them from becoming in phase at a desired position, for example, by causing them to be out of phase. In order to ensure that microwaves irradiated from multiple positions reinforce each other at a desired position, if the microwaves irradiated by the irradiation unit 203 all have the same frequency, for example, the distance between the desired position and each position irradiating the microwaves may be divided by the wavelength of the microwave, and the remainder may be divided by the wavelength of the microwave and multiplied by 2π to set the phase to advance relative to the reference phase by that value. However, how the phase of the microwaves is controlled to be in phase at the desired location is not a concern.Furthermore, since the process of controlling the phase of microwaves to increase the microwave intensity at a desired position is publicly known, for example, in Japanese Patent Publication No. 2017-212237, a detailed explanation will be omitted here. 【0120】 The first microwave irradiation, performed by controlling the phase of microwaves irradiated by two or more irradiation units 203, involves irradiating from multiple positions within the container 10c with microwaves whose phase is controlled so that the microwaves do not reinforce each other at a desired position on the object to be processed 2, but reinforce each other at one or more parts of the heating element 30 surrounding this desired position. One or more parts surrounding the desired position on the object to be processed 2 are one or more parts located perpendicular to the direction in which the object to be processed 2 extends or the direction in which the object to be processed 2 moves. The desired position on the object to be processed 2 is, for example, a desired position on the movement path 2a of the object to be processed 2. The same applies below. Furthermore, the first microwave irradiation here may involve irradiating from multiple positions within the container 10c with microwaves whose phase is controlled so that the intensity of microwaves at one or more parts of the heating element 30 surrounding this desired position is higher than the intensity of microwaves at the desired position on the object to be processed 2. One or more parts around the desired position are, for example, one or more parts of the heating element 30 that intersect with a virtual plane perpendicular to the direction of travel of the movement path 2a at the desired position on the movement path 2a of the object to be processed 2. Furthermore, the first microwave irradiation here may involve, for example, irradiating the heating element 30 with phase-controlled microwaves from multiple positions within the container 10c so that the microwaves reinforce each other at the desired position of the object to be processed 2, and irradiating the heating element 30 with phase-controlled microwaves from multiple positions within the container 10c different from the above-mentioned multiple positions so that the microwaves reinforce each other at one or more parts around this desired position, while also setting the output of the microwaves output with phase control so that they reinforce each other at the heating element 30 to be higher than the output of the microwaves output with phase control so that they reinforce each other at the object to be processed 2. 【0121】 Furthermore, the second microwave irradiation, which is performed by controlling the phase of microwaves irradiated by two or more irradiation units 203, is, for example, irradiating from multiple positions within the container 10c with microwaves whose phase is controlled so that microwaves reinforce each other at a desired position on the object to be processed 2, and microwaves whose phase is controlled so that microwaves do not reinforce each other around this desired position on the heating element 30. Alternatively, the first microwave irradiation here may be, for example, irradiating from multiple positions within the container 10c with microwaves whose phase is controlled so that the intensity of microwaves at a desired position on the object to be processed 2 is higher than the intensity of microwaves at one or more parts of the heating element 30 around this desired position. Furthermore, the second microwave irradiation here may involve, for example, irradiating the object to be processed 2 with phase-controlled microwaves from multiple positions within the container 10c so that the microwaves reinforce each other at a desired position, and irradiating the heating element 30 with phase-controlled microwaves from multiple positions within the container 10c different from the above-mentioned multiple positions so that the microwaves reinforce each other at one or more parts around this desired position, and also setting the output of the microwaves output with phase-controlled microwaves so that they reinforce each other at the object to be processed 2 to be higher than the output of the microwaves output with phase-controlled microwaves so that they reinforce each other at the heating element 30. 【0122】 The positions and number of locations where the microwaves are reinforced during the first microwave irradiation, and the positions and number of locations where the microwaves are reinforced during the second microwave irradiation, are not specified. These positions and numbers may be set appropriately according to experimental results, simulation results, etc., depending on the object to be treated 2, etc. 【0123】 Furthermore, the two or more irradiation units 203 that perform the first microwave irradiation and the two or more irradiation units 203 that perform the second microwave irradiation may be the same irradiation unit 203, different irradiation units 203, or partially the same irradiation unit 203. The microwaves irradiated by the two or more irradiation units 203 that perform the first microwave irradiation and the microwaves irradiated by the two or more irradiation units 203 that perform the second microwave irradiation may be the same frequency or different frequencies. 【0124】 One or more sensors 40 are, for example, similar to the sensors in the above embodiment. Each sensor 40 is installed, for example, near the location where the first microwave irradiation is performed or near the location where the second microwave irradiation is performed within the container 10c. 【0125】 Since the transport means 60 is the same as in the above embodiment, a detailed explanation is omitted here. 【0126】 The control means 51 controls the phase of the microwaves irradiated by the microwave irradiation means 21 from multiple positions. Controlling the phase of microwaves irradiated from multiple positions can be considered a concept that includes controlling the phase of other microwaves while not controlling the phase of one or more reference microwaves. As described above, the control means 51 controls the phase of the microwaves irradiated by the microwave irradiation means 21 so that first microwave irradiation is performed at one or more desired positions on the movement path 2a of the object to be processed 2, and second microwave irradiation is performed at one or more desired positions on the movement path 2a of the object to be processed 2, excluding the position where the first microwave irradiation is performed. For example, the control means 51 controls the phase of the microwaves irradiated by each of the multiple irradiation units 203 so that such first and second microwave irradiations are performed. The control means 51 may also individually control the output of the microwaves irradiated by the microwave irradiation means 21 from multiple positions. For example, the control means 51 may individually control the output of the microwaves irradiated by each irradiation unit 203. For example, the control means 51 provides feedback control to the output of the irradiation unit 203 that performs first microwave irradiation at a desired position, according to temperature information output by a sensor 40 located near this desired position. Also, for example, the control means 51 provides feedback control to the output of the irradiation unit 203 that performs second microwave irradiation at a desired position, according to temperature information output by a sensor 40 located near this desired position. However, control other than feedback control may also be performed. 【0127】 Furthermore, if the phase of each irradiation unit 203 is set once so that microwaves reinforce each other at one or more desired positions, and no further changes are needed, or if the phase of each irradiation unit 203 is set manually, the control means 51 does not need to control the phase irradiated by the irradiation unit 203, and no control means for controlling the phase is provided. 【0128】 Next, the operation of the microwave processing apparatus 1a of this embodiment will be explained with specific examples. Here, the example will be that the microwave processing apparatus 1a is used to perform flame-retardant treatment on PAN-based precursor fibers, which are the object to be processed 2. For the sake of simplicity, the microwave processing apparatus 1a shown in Figure 5(a) will be used for this explanation. 【0129】 Here, we assume that the object to be processed 2 is moving along the movement path 2a by the transport means 60, and that a first microwave irradiation is performed on point A on the movement path 2a of the object to be processed 2 as shown in Figure 5, and a second microwave irradiation is performed on point B. Specifically, the control means 51 controls the multiple irradiation units 203 to irradiate the multiple irradiation units 203 with microwaves whose phase is controlled so that the microwaves do not reinforce each other at point A on the movement path 2a of the object to be processed 2, but the microwaves reinforce each other at one or more parts of the heating element 30 surrounding point A. Here, for example, we assume that half of the multiple irradiation units 203 attached to the inlet 101a side irradiate microwaves so that they reinforce each other at point A. In other words, we assume that the first microwave irradiation is performed by half of the multiple irradiation units 203 attached to the inlet 101a side. Furthermore, the control means 51 controls the multiple irradiation units 203 to irradiate the multiple irradiation units 203 with microwaves whose phase is controlled so that the microwaves reinforce each other at point A on the movement path 2a of the object to be processed 2, and do not reinforce each other at one or more parts of the heating element 30 surrounding point A. Here, for example, let's assume that half of the multiple irradiation units 203 attached to the exit 101b side irradiate microwaves so that they reinforce each other at point B. In other words, let's assume that the second microwave irradiation is performed by half of the multiple irradiation units 203 attached to the exit 101b side. Note that the first microwave irradiation and the second microwave irradiation may also be performed in parts other than the above-mentioned points A and B. 【0130】 As a result of the first microwave irradiation, at point A, as shown in Figure 5(b), points 35 are created where microwaves reinforce each other at multiple locations (four points in this example) on the heating element 30. The microwaves that reinforce each other at these points 35 heat up the heating element 30, and the radiant heat from the heating element 30 heats the object to be treated 2 from the outside. At point A, the object to be treated 2 is also directly heated by microwaves unless the multiple microwaves irradiated from the multiple irradiation units 203 completely cancel each other out to "0". However, since these are not points where multiple microwaves reinforce each other, the amount of heat generated is small. 【0131】 Furthermore, due to the second microwave irradiation, at point B, as shown in Figure 5(c), a region 35 is created where microwaves reinforce each other on the object 2 being treated. The object 2 is then directly heated by the microwaves that reinforce each other at this region 35. In addition, the heating element 30 around point B also generates heat due to microwaves unless the multiple microwaves irradiated from the multiple irradiation units 203 completely cancel each other out to "0," and this heat also heats the object 2 from the outside. However, since this is not a region where multiple microwaves reinforce each other, the amount of heat generated is small. 【0132】 Based on the temperature acquired by the sensor 40 located near point A, the control means 51 provides feedback control to the output of multiple irradiation units 203 that perform the first microwave irradiation on point A. This increases or decreases the output of microwaves that reinforce each other around the heating element 30 surrounding point A, thereby enabling heating of the object to be processed 2 to a desired temperature at point A. Similarly, based on the temperature acquired by the sensor 40 located near point B, the control means 51 provides feedback control to the output of multiple irradiation units 203 that perform the first microwave irradiation on point B. This increases or decreases the output of microwaves that reinforce each other around the object to be processed 2 at point B, thereby enabling heating of the object to be processed 2 to a desired temperature at point B. 【0133】 For example, as described in the above embodiment, at or near the position where the heat generation of the object to be processed 2 peaks, the phase is controlled to ensure that microwaves reinforce each other at the surrounding heating element 30 but not at the object to be processed 2, similar to point A above. This allows for the first microwave irradiation to be performed in this manner, thereby avoiding rapid heating when the object to be processed 2 reaches its heat generation peak and enabling appropriate processing of the object to be processed 2. At other locations, for example, by irradiating the object to be processed 2 with microwaves so that they reinforce each other, the object to be processed 2 can be efficiently heated primarily by direct microwave heating, thereby improving the processing speed. At other locations, for example, by ensuring that microwaves reinforce each other at the object to be processed 2 or at the heating element 30, the first microwave irradiation and the second microwave irradiation can be appropriately switched over for the moving object to be processed 2, enabling uniform heating or desired heating of the object to be processed 2. 【0134】 Note that the arrangement of the multiple irradiation units 203 in this specific example is just one example, and the arrangement and number of the multiple irradiation units 203 are not limited to this. Furthermore, the number of locations and their arrangements are not restricted for each of the locations on the movement path 2a of the object to be processed 2 within the container 10c, such as location A where microwaves reinforce each other at the heating element 30, such as location B where microwaves reinforce each other at the object to be processed 2, and such as location C where microwaves reinforce each other at both the heating element 30 and the object to be processed 2. In the microwave processing device 1a, for example, it is sufficient that at least one location on the movement path 2a is set for each of the locations on the movement path 2a where microwaves reinforce each other at the heating element 30 and where microwaves reinforce each other at the object to be processed 2. 【0135】 As described above, according to this embodiment, the microwave irradiation means 21 controls the phases of multiple microwaves irradiated from different positions to perform a first microwave irradiation in which two or more microwaves reinforce each other on the heating element 30, and a second microwave irradiation in which two or more microwaves reinforce each other on the object to be processed 2. This makes it possible to appropriately process the object to be processed 2 using microwaves. For example, appropriate heating can be achieved by controlling the combination and ratio of heating from the outside of the object to be processed by the heating element heated by microwaves and direct heating of the object to be processed by microwaves. 【0136】 In the above, the output of the irradiated microwaves is feedback-controlled according to the temperature information acquired by the sensor 40. However, heating of the object to be processed 2 may also be controlled by controlling the phase of the microwaves irradiated by the microwave irradiation means 21 according to the temperature information acquired by one or more sensors 40, thereby moving the position where the microwaves reinforce each other due to the first microwave irradiation and the second microwave irradiation along the movement path 2a of the object to be processed 2. For example, in the above, if the temperature acquired by the sensor 40 at point B is high, the position of point B may be moved towards the exit side to delay the timing of heating by the second microwave irradiation. 【0137】 Furthermore, in the above, a first microwave irradiation, in which microwaves are irradiated at the heating element 30 so as to reinforce each other, and a second microwave irradiation, in which microwaves are irradiated at the object to be processed 2 so as to reinforce each other, may be performed simultaneously at the same position on the movement path 2a of the object to be processed 2. In this case, the microwave output of the first microwave irradiation and the microwave output of the second microwave irradiation may be different. 【0138】 Furthermore, although the above embodiment was described using the example of moving the object to be processed 2 within the container 10c, the object to be processed 2 may be kept stationary within the container 10c, and the phases of the multiple microwaves irradiated into the container 10c may be controlled to move over time the position where the microwaves reinforce each other due to the first microwave irradiation on the heating element 30 and the position where the microwaves reinforce each other due to the second microwave irradiation on the object to be processed 2, thereby changing over time the position where the heating element 30 is heated and the position where the object to be processed 2 is directly heated. In this way, for example, appropriate heating can be performed on the object to be processed 2. 【0139】 In the above embodiment, when the microwave irradiation means 21 controls the phase of microwaves irradiated from a plurality of irradiation units 203, it is preferable to design the container 10c such that a first microwave irradiation position where the intensity of microwaves irradiated by the irradiation unit 203 becomes stronger at the heating element 30, and a second microwave irradiation position where the intensity of microwaves irradiated by the irradiation unit 203 becomes stronger at the object to be processed 2, are provided along the movement path 2a of the object to be processed 2. 【0140】 Furthermore, in the above embodiment, the microwave irradiation means 21 may not control the phase of the microwaves irradiated from the plurality of irradiation units 203. For example, when the microwave irradiation means 21 is equipped with one or more irradiation units 203 that irradiate microwaves, instead of controlling the phase of the microwaves irradiated by each irradiation unit 203, the container 10c may be designed so that a first microwave irradiation position in which the intensity of the microwaves irradiated by the irradiation unit 203 becomes stronger at the heating element 30, and a second microwave irradiation position in which the intensity of the microwaves irradiated by the irradiation unit 203 becomes stronger at the object to be processed 2, are provided along the movement path 2a of the object to be processed 2. 【0141】 (modified version) Furthermore, in the microwave processing apparatus 1a of the second embodiment described above, one or more heating elements 30 may be partially provided in the container 10c along the movement path 2a of the object to be processed 2, similar to the first embodiment described above. The phase of microwaves irradiated by two or more irradiation units 203 that irradiate microwaves from different positions may be controlled by a control means 51 or the like, so that a first microwave irradiation position is provided where the intensity of the microwaves irradiated by the irradiation unit 203 is stronger at the heating elements 30, a second microwave irradiation position is provided where the intensity of the microwaves irradiated by the irradiation unit 203 is stronger in the parts of the object to be processed where no heating elements are provided, and a third microwave irradiation position is provided where the intensity of the microwaves irradiated by the irradiation unit 203 is stronger in the parts of the object to be processed 2 where heating elements are provided. 【0142】 Figure 7(a) is a schematic cross-sectional view parallel to the direction of movement of the object to be processed, illustrating an example of a modified microwave processing apparatus 1a. In this microwave processing apparatus 1a, as in the microwave processing apparatus 1a of Embodiment 2, two heating elements, heating elements 30d and 30e, are installed in the container 10c at predetermined intervals so as to partially cover the object to be processed 2 along the movement path 2a of the object to be processed 2. The microwave irradiation means 21 comprises two or more irradiation units 203, consisting of three irradiation units 203a, three irradiation units 203b, and three irradiation units 203c that irradiate microwaves from different positions. Each of the three irradiation units 203a, three irradiation units 203b, and three irradiation units 203c is attached to the container 10c in the same way as the above irradiation unit 203. The heating elements 30d and 30e may be considered to be arranged with a region where no heating elements are provided in between. Here, an example is shown in which three irradiation units 203a, three irradiation units 203b, and three irradiation units 203c are arranged in order from the inlet side of the container 10c along the movement path of the object to be processed 20, but these arrangements are not limited to the above arrangement. For example, each irradiation unit 203 is positioned so that the microwave intensity can reinforce each other at a desired level of 1 or more by controlling the phase. Note that sensors and control means are omitted in the figure. 【0143】 Figures 7(b) to 7(d) are schematic diagrams showing the heating elements 30d and 30e of the microwave processing apparatus shown in Figure 7(a), and their vicinity, to explain the location where the microwave intensity is high. 【0144】 For example, in the microwave processing apparatus 1a shown in Figure 7(a), the phase of the microwaves irradiated by the three irradiation units 203a is controlled so that the microwave intensity is stronger at position 400a where the heating element 30d is located in the direction of movement of the object to be processed 2. At position 400b between heating elements 30d and 30e where no heating element 30e is located in the direction of movement of the object to be processed 2, the phase of the microwaves irradiated by the three irradiation units 203b is controlled so that the microwave intensity is stronger at the object to be processed 2. At position 400c where the heating element 30d is located in the direction of movement of the object to be processed 2, the phase of the microwaves irradiated by the three irradiation units 203c is controlled so that the microwave intensity is stronger at the part of the object to be processed located inside the heating element 30. Here, it is assumed that the positions 400a and 400c are different positions in the direction along the movement path 2a of the object to be processed 2. Furthermore, in this case, the phase of position 400c is controlled so that it is located on the member 30e side relative to position 400a, but the phase of position 400a may also be controlled so that it is located on the member 30e side relative to position 400c. Phase control is performed, for example, using control means similar to control means 51. 【0145】 When the microwave irradiation means 21 irradiates with microwaves as described above, as shown in Figure 7(b), positions 400a, 400b, and 400c become positions with high microwave intensity. As a result, the heating element 30d is strongly heated at position 400a, and the object to be processed 2 is strongly heated at positions 400b and 400c. Position 400b is assumed to be a position inside the heating element 30d that overlaps with the object to be processed 2. Here, position 400a corresponds to the first microwave irradiation position, position 400b to the second microwave irradiation position, and position 400c and its vicinity to the third microwave irradiation position. Note that these positions may also be considered as regions. 【0146】 In this way, by making the areas where the microwave intensity is high the area where the heating element 30 is provided, the area of ​​the object to be processed 2 where the heating element 30 is not provided, and the area of ​​the object to be processed 2 where the heating element 30 is provided (for example, the area located inside the heating element 30 of the object to be processed 2), it becomes possible to perform desired heating on the object to be processed 2. 【0147】 Furthermore, in the above, by controlling the phase of the microwaves irradiated by each of the three irradiation units 203a and the phase of the microwaves irradiated by each of the three irradiation units 203c, microwaves may be irradiated so that the position of the first microwave irradiation position, position 400a, and the third microwave irradiation position, position 400c, are the same in the direction along the movement path 2a of the object to be processed, as shown in Figure 7(c). 【0148】 Furthermore, in the above, by controlling the phase of the microwaves irradiated by each of the three irradiation units 203 and the phase of the microwaves irradiated by each of the three irradiation units 203c, the first microwave irradiation position 400a and the third microwave irradiation position 400c may be located in areas where different heating elements 30 are provided. For example, as shown in Figure 7(d), the first microwave irradiation position 400a may be located at the heating element 30d, and the second microwave irradiation position 400c may be located at the heating element 30e. 【0149】 In the above explanation, we used the example of a case where there are two heating elements 30. However, as shown in Figures 7(b) and 7(c), if the first microwave irradiation position and the third microwave irradiation position are located in the same area where the same heating element 30 is provided, then there only needs to be one or more heating elements 30. Furthermore, the length, material, etc., of at least some of the two or more heating elements 30 may be the same or different. 【0150】 Furthermore, as shown in Figure 7(c), if the first microwave irradiation position and the third microwave irradiation position are located in areas where different heating elements 30 are provided, then there should be two or more heating elements 30. 【0151】 Furthermore, the heating element 30 where the first microwave irradiation position is located and the area of ​​the object to be processed 2 where the heating element is not provided, where the second microwave irradiation position is located, may or may not be adjacent, as shown in Figure 7(b). 【0152】 Furthermore, if the first microwave irradiation position, position 400a, and the third microwave irradiation position, position 400c, are located in areas where different heating elements 30 are provided, the first microwave irradiation position and the third microwave irradiation position may be adjacent heating elements 30 separated by only one area where no heating elements are provided, or they may be adjacent heating elements 30 separated by two or more areas where no heating elements are provided. 【0153】 Furthermore, the number of irradiation units 203a is not limited as long as it is two or more. The same applies to irradiation units 203b and 203c. Also, at least a portion of two or more irradiation units 203a and two or more irradiation units 203b may be realized in the same irradiation unit. That is, at least a portion of two or more irradiation units 203a may be used as at least a portion of two or more irradiation units 203b, so that at least a portion of irradiation units 203a and at least a portion of irradiation units 203b may be shared. The same applies to at least a portion of two or more irradiation units 203a and two or more irradiation units 203c, and at least a portion of two or more irradiation units 203b and two or more irradiation units 203c. Similarly, at least a portion of two or more irradiation units 203a, two or more irradiation units 203b, and two or more irradiation units 203c may be realized in the same irradiation unit. In other words, at least a portion of two or more irradiation units 203a may be used as at least a portion of two or more irradiation units 203b, and also as at least a portion of two or more irradiation units 203c. Furthermore, the microwave irradiation means 21 may have multiple sets composed of two or more first irradiation units 203a. The same applies to the second irradiation unit 203b and the third irradiation unit 203c. 【0154】 Furthermore, the microwave irradiation means 21 may irradiate the microwaves with phase-controlled microwaves so that multiple first microwave irradiation positions are arranged within the microwave processing apparatus 1b. The same applies to the second and third microwave irradiation positions. Furthermore, the microwave irradiation means 21 may irradiate a single heating element 30 with phase-controlled microwaves so that multiple first microwave irradiation positions are arranged within it. The same applies to the second and third microwave irradiation positions. 【0155】 In the above, the first to third microwave irradiation positions were arranged as described above by controlling the phase of the microwaves irradiated by the irradiation unit 203. However, the first to third microwave irradiation positions may also be arranged as described above by designing the container 10c, etc. In this case, it is sufficient for the microwave irradiation means 21 to have one or more irradiation units 203. The design of the container 10c, etc. may be considered as the design of the cavity to which the microwaves are irradiated, etc. The design of the container 10c, etc. may also be considered as a design that includes the arrangement of the irradiation units 203, etc. 【0156】 (Embodiment 3) Figure 6 shows a cross-sectional view parallel to the direction of movement of the object to be processed (Figure 6(a)), a schematic cross-sectional view perpendicular to the longitudinal direction passing through point A in Figure 6(a) (Figure 6(b)), a schematic cross-sectional view perpendicular to the longitudinal direction passing through point B in Figure 6(c), and a schematic cross-sectional view perpendicular to the longitudinal direction passing through point C in Figure 6(d) for illustrating the microwave processing apparatus in this embodiment. The microwave processing apparatus 1b in this embodiment performs a first microwave irradiation and a second microwave irradiation by irradiating with microwaves of different frequencies using a microwave irradiation means 22. 【0157】 The microwave processing device 1b comprises a container 10d, a microwave irradiation means 22, a heating element 30, one or more sensors 40, a control means 52, and a transport means 60. 【0158】 Container 10d is the same as container 10 shown in Figure 1 in the above embodiment, except that the irradiation unit of the microwave irradiation means 22 is attached to it. Furthermore, as container 10d, any container as described in the above embodiment can be used, for example, a container having multiple cavities can also be used. 【0159】 The following describes a case where a single cylindrical heating element 30 is provided inside the container 10d along the movement path 2a of the object to be processed 2. However, there may be multiple heating elements 30. In addition, the same heating elements 30 as those described in the above embodiment can be used. 【0160】 The microwave irradiation means 22 is capable of irradiating with microwaves of different frequencies, and by irradiating with microwaves of different frequencies, it performs the first microwave irradiation and the second microwave irradiation as described above. For example, the microwave irradiation means 22 performs a first microwave irradiation by irradiating with microwaves of a frequency such that the heat generated by the heating element 30 is greater than the heat generated by the object to be processed 2, and a second microwave irradiation by irradiating with microwaves of a frequency such that the heat generated by the object to be processed 2 is greater than the heat generated by the heating element 30. For example, the microwave irradiation means 22 performs a first microwave irradiation by irradiating with microwaves of a frequency such that the microwaves absorbed by the heating element 30 are greater than the microwaves transmitted through the heating element 30, and a second microwave irradiation by irradiating with microwaves of a frequency such that the microwaves absorbed by the heating element 30 are less than the microwaves transmitted through the heating element 30. The frequency of the microwaves irradiated by the microwave irradiation means 22 in such a first microwave irradiation will be referred to as the first frequency below. Furthermore, the frequency of the microwaves irradiated by the microwave irradiation means 22 in such a second microwave irradiation will be hereinafter referred to as the second frequency. 【0161】 For example, the microwaves that pass through the heating element 30 depend on the frequency of the irradiated microwaves. For example, if a heating element 30 with a complex permittivity of ε'=100 and ε''=10 is used, the power half-thickness depth at which the power of the microwaves that have entered the heating element 30 is halved is 36.3 mm at 915 MHz and 13.6 mm at 2.45 GHz. Therefore, if the thickness of the heating element 30 is set to an appropriate thickness, for example, when irradiated with 2.45 GHz microwaves, more than half, preferably most of the microwaves, are absorbed by the heating element 30, and the microwaves do not reach the object to be processed 2 such as carbon fiber precursor fibers. On the other hand, when irradiated with 915 MHz microwaves, more than half, preferably most of the irradiated microwaves, are allowed to pass through the heating element 30, making it possible to irradiate the carbon fiber precursor fibers with microwaves. Note that the heating element 30 here The thickness can be considered as the thickness of the heating medium 301 of the heating element 30. Therefore, in the first microwave irradiation, the heating element 30 is heated by irradiating it with microwaves at a frequency that results in a power half-depth where the microwaves absorbed by the heating element 30 are greater than the microwaves that pass through the heating element 30. In the second microwave irradiation, the heating element 30 is heated by irradiating it with microwaves at a frequency that results in a power half-depth where the microwaves absorbed by the heating element 30 are smaller than the microwaves that pass through the heating element, and irradiating the object to be processed 2 with the microwaves that have passed through the heating element 30. 【0162】 For example, if the electrical resistivity is 2.8 × 10⁻⁶ -8When aluminum or the like with a complex dielectric constant of Ωm is used as the heating element 30 (for example, the heating medium 301 of the heating element 30), the skin depth at which the electric field strength of microwaves penetrating the heating element 30 becomes 1 / e is 2.2 μm at a frequency of 915 MHz and 1.3 μm at 2.45 GHz. Therefore, by controlling the thickness of the heating element 30 (for example, the thickness of the heating medium 301 of the heating element 30) to a minimum of several hundred nm, in the first microwave irradiation with a first frequency of 2.45 GHz, most of the microwaves are absorbed by the heating element 30, preventing the microwaves from reaching the object to be treated 2, such as a carbon fiber precursor. On the other hand, in the second microwave irradiation with a second frequency of 915 MHz, most of the microwaves are not absorbed by the heating element 30, allowing the object to be treated 2 to be irradiated with microwaves and heated. The imaginary part ε'' of the complex dielectric constant mentioned above is sometimes called the relative dielectric loss. 【0163】 The microwave irradiation means 22 may, for example, perform the first microwave irradiation and the second microwave irradiation at different positions along the movement path 2a of the object to be processed 2 when the object to be processed 2 is moving. Alternatively, the microwave irradiation means 22 may perform the first microwave irradiation and the second microwave irradiation simultaneously at the same position along the movement path 2a of the object to be processed 2. Alternatively, the microwave irradiation means 22 may switch between performing the first microwave irradiation and the second microwave irradiation at the same position along the movement path 2a of the object to be processed 2. Furthermore, the microwave irradiation means 22 may change the output power of each microwave frequency being irradiated. 【0164】 The microwave irradiation means 22 may have, for example, one or more irradiation units (not shown) capable of changing the frequency of the irradiated microwaves, and by changing the output frequency, it may switch between first microwave irradiation and second microwave irradiation. Alternatively, the microwave irradiation means 22 may have one or more irradiation units (hereinafter referred to as first frequency irradiation units 204) that irradiate microwaves of a first frequency for first microwave irradiation, and one or more irradiation units (hereinafter referred to as second frequency irradiation units 205) that irradiate microwaves of a second frequency different from the first frequency for second microwave irradiation, and by irradiating with microwaves of different frequencies irradiated by these units, first microwave irradiation and second microwave irradiation may be performed. In the following description of this embodiment, the case in which first microwave irradiation is performed using one or more first frequency irradiation units 204 and second microwave irradiation is performed using one or more second frequency irradiation units 205 will be described as an example. 【0165】 The first frequency irradiation unit 204 and the second frequency irradiation unit 205 are, for example, attached to openings 102 provided at different positions on the wall surface of the container 10d to irradiate microwaves into the container 10d. The first frequency irradiation unit 204 and the second frequency irradiation unit 205 may be arranged to irradiate microwaves at different positions along the movement path of the object to be processed 2, or they may be arranged to irradiate microwaves at the same position. 【0166】 Figure 6 illustrates an example in which one of the first frequency irradiation units 204 is mounted on the container 10d so that the microwave of the first frequency to be irradiated irradiates the area including point A, and one of the second frequency irradiation units 205 is mounted on the container 10d so that the microwave of the first frequency to be irradiated irradiates the area including point B, and one of the first frequency irradiation units 204 and one of the second frequency irradiation units 205 are mounted so that the microwave of the first frequency and the microwave of the second frequency, respectively, irradiate the area including point C. For example, an example is shown in which the first frequency irradiation unit 204 is positioned for information of points A and C, and the second frequency irradiation unit 205 is positioned above and below point B. However, the positions of the first frequency irradiation unit 204 and the second frequency irradiation unit 205, and the number of each, are not specified. 【0167】 The first frequency irradiation unit 204 and the second frequency irradiation unit 205 are equipped with, for example, a microwave oscillator 2001 and a transmission unit 2002, as described in the above embodiment. However, the first frequency irradiation unit 204 and the second frequency irradiation unit 205 have different microwave frequencies oscillated by the microwave oscillator 2001. It is preferable to use a semiconductor type oscillator as the microwave oscillator 2001 in the irradiation unit 203. The first frequency irradiation unit 204 and the second frequency irradiation unit 205 may have structures other than those described above. 【0168】 One or more sensors 40 are, for example, similar to the sensors in the above embodiment. Here, we show as an example a case where three sensors 40 are each located near points A, B, and C on the container 10d, for example, located above points A, B, and C on the container 10d. 【0169】 Since the transport means 60 is the same as in the above embodiment, a detailed explanation is omitted here. 【0170】 The control means 52 controls the output of microwaves emitted by the first frequency irradiation unit 204 and the second frequency irradiation unit 205 of the microwave irradiation means 22. For example, the control means 52 provides feedback control to the outputs of the first frequency irradiation unit 204 and the second frequency irradiation unit 205 that irradiate microwaves at points A, B, and C, respectively, according to the temperature information of the object to be processed 2 acquired by the three sensors 40. However, the control does not have to be feedback control. If the microwave irradiation means 22 has a plurality of irradiation units (not shown) capable of controlling the phase of the irradiated microwaves, the control means 52 may control the frequency of the irradiated microwaves of each irradiation unit of the microwave irradiation means 22. 【0171】 Next, the operation of the microwave processing apparatus 1b of this embodiment will be explained with specific examples. Here, the example will be that the microwave processing apparatus 1b is used to perform flame-retardant treatment on a PAN-based precursor fiber, which is the object to be processed 2. For the sake of simplicity, the microwave processing apparatus 1b shown in Figure 6 will be used for this explanation. The microwaves irradiated by the first frequency irradiation unit 204 here are first-frequency microwaves in which the microwaves absorbed by the heating element 30 are greater than the microwaves transmitted through the heating element 30, and the microwaves irradiated by the second frequency irradiation unit 205 are second-frequency microwaves in which the microwaves absorbed by the heating element 30 are smaller than the microwaves transmitted through the heating element 30. Furthermore, the heating element 20 here is assumed to have a thickness that absorbs more than half, preferably most of, of the first-frequency microwaves being irradiated, and transmits more than half, preferably most of, of the second-frequency microwaves being irradiated without absorption. 【0172】 For example, while the object to be processed 2 is being transported by the transport means 60, the first frequency irradiation unit 204 continuously irradiates the object with microwaves 16 of a first frequency, and the second frequency irradiation unit 205 continuously irradiates the object with microwaves 17 of a second frequency. Here, the output of the microwaves 16 irradiated by the first frequency irradiation unit 204 and the output of the microwaves 17 irradiated by the second frequency irradiation unit 205 are feedback controlled according to temperature information acquired by sensors 40 located in their vicinity. 【0173】 At location A, microwaves 16 of a first frequency are irradiated from the first frequency irradiation unit 204, resulting in first microwave irradiation. As a result, the microwaves are easily absorbed by the heating element 30, and the microwaves 16 are less likely to irradiate the object to be processed 2. Therefore, as shown in Figure 6(b), the heat generated by the heating element 30 becomes higher than the heat generated by the object to be processed 2. Consequently, the object to be processed 2 is heated from the outside by radiant heat from the heating element 30. In addition, although the heat generated is less than that of the heating element 30, the object to be processed 2 is also directly heated by a portion of the irradiated microwaves 16. 【0174】 At location B, microwaves 17 of a second frequency are irradiated from the second frequency irradiation unit 205, resulting in a second microwave irradiation. As a result, the microwaves are less absorbed by the heating element 30, and the transmitted microwaves 17 irradiate the object to be processed 2. As shown in Figure 6(c), the heat generated by the object to be processed 2 is higher than the heat generated by the heating element 30. Consequently, the object to be processed 2 is directly heated by the irradiated microwaves 17. In addition, the heating element 30 is also heated by a portion of the irradiated microwaves 17, and is therefore heated from the outside by radiant heat from the heating element 30. 【0175】 At point C, microwaves 16 of a first frequency are irradiated from the first frequency irradiation unit 204 to perform first microwave irradiation, and microwaves 17 of a second frequency are irradiated from the second frequency irradiation unit 205 to perform second microwave irradiation. The heat generated by the heating element 30 due to the first frequency microwaves 16 is higher than the heat generated by the object to be processed 2. On the other hand, the heat generated by the object to be processed 2 due to the second frequency microwaves 17 is higher than the heat generated by the heating element 30. As a result, as shown in Figure 6(d), the object to be processed 2 is heated from the outside by radiant heat from the heating element 30 in response to the irradiation of the first frequency microwaves 16, and is also directly heated in response to the irradiation of the second frequency microwaves 17. 【0176】 The outputs of the microwaves 16 and 17 irradiated to each point A to C are feedback controlled by the control means 52 controlling the outputs of the first frequency irradiation unit 204 and the second frequency irradiation unit 205 that irradiate microwaves to each point, for example, according to the temperature information of the object to be processed 2 acquired by the sensor 40 installed near each point. 【0177】 Furthermore, by individually changing the output of the first frequency irradiation unit 204 and the second frequency irradiation unit 205, which irradiate point C with microwaves 16 and 17 of different frequencies, the ratio of the amount of heat generated by the heating element 30 and the amount of heat generated by the object to be processed 2 at point C can be controlled. For example, by increasing only the output of the first frequency microwave 16 output by the first frequency irradiation unit 204, the amount of heat generated by the heating element 30 can be increased relative to the amount of heat generated by the object to be processed 2, and by increasing only the output of the second frequency microwave 17 output by the second frequency irradiation unit 205, the amount of heat generated by the object to be processed 2 can be increased relative to the amount of heat generated by the heating element 30. 【0178】 For example, as described in the above embodiment, at or near the position where the heat generation of the object to be processed 2 reaches its peak in the movement path 2a, by irradiating with microwaves of a first frequency, similar to point A above, where the heat generation of the heating element 30 is higher than that of the object to be processed 2, it is possible to avoid rapid heating when the object to be processed 2 reaches its peak heat generation and to process the object to be processed 2 appropriately. Furthermore, at other positions in the movement path 2a, for example, by irradiating with microwaves of a first frequency, microwaves of a second frequency, or both microwaves of the first and second frequencies as appropriate, the moving object to be processed 2 can be appropriately combined with microwave irradiation of the first and second frequencies, thereby achieving the desired heating of the object to be processed 2. 【0179】 Note that the arrangement of the first frequency irradiation unit 204 and the second frequency irradiation unit 205 in this specific example is just one example, and the arrangement and number of the first frequency irradiation unit 204 and the second frequency irradiation unit 205 are not specified. The microwave processing device 1b only needs to have at least one of each of the first frequency irradiation unit 204 and the second frequency irradiation unit 205. For example, multiple first frequency irradiation units 204 and second frequency irradiation units 205 may be attached to the container 10. 【0180】 Furthermore, in the above specific example, similar to location C, the first frequency irradiation unit 204 and the second frequency irradiation unit 205 may be provided as irradiation units that irradiate microwaves to each of the multiple locations, and microwaves of different frequencies may be irradiated to one or more of these multiple locations. In this case, microwaves of only one frequency may be irradiated to a single location by irradiating it with microwaves from only one of the first frequency irradiation unit 204 and the second frequency irradiation unit 205, and the frequency of microwaves irradiated to a single location may be changed by switching between the first frequency irradiation unit 204 and the second frequency irradiation unit 205. 【0181】 Furthermore, in the above specific example, instead of providing a first frequency irradiation unit 204 and a second frequency irradiation unit 205, multiple irradiation units (not shown) with changeable frequencies may be provided, for example, along the movement path 2a, and microwaves of a frequency suitable for each position may be irradiated from each of them. For example, multiple irradiation units with changeable frequencies may be arranged above points A to C as shown in Figure 6, and microwaves of a first frequency may be irradiated from the irradiation units above points A and C, and microwaves of a second frequency may be irradiated from the irradiation unit above point B. In this way, one irradiation unit that irradiates microwaves of a first frequency and one irradiation unit that irradiates microwaves of a second frequency may be realized by a single irradiation unit. 【0182】 In this case, the frequency of the microwaves emitted from each irradiation unit may be changed as appropriate. For example, the frequency of the microwaves emitted from the irradiation unit above point B may be changed from the second frequency to the first frequency depending on the material, thickness, and movement speed of the object to be processed 2, and the frequency of the microwaves emitted from the irradiation unit above point C may be changed from the first frequency to the second frequency. In addition, the frequency of the microwaves emitted by each irradiation unit may be changed according to the temperature information acquired by the sensor 40. 【0183】 Furthermore, multiple irradiation units (not shown) that irradiate microwaves to one or more locations may be provided, and each irradiation unit may be made capable of changing the frequency of the microwaves it irradiates. By setting the microwave frequencies of the multiple irradiation units that irradiate microwaves to each location to different frequencies, it may be possible to irradiate each location with microwaves of different frequencies. In this case, the microwaves of the multiple irradiation units that irradiate microwaves to a single location may be set to the same frequency, or only one irradiation unit may irradiate microwaves, so that locations that do not require irradiation with microwaves of different frequencies can be irradiated with microwaves of only one frequency. 【0184】 As described above, in this embodiment, by irradiating the container with microwaves of different frequencies to perform a first microwave irradiation and a second microwave irradiation, the object to be processed can be appropriately processed using microwaves. For example, appropriate heating can be achieved by controlling the combination and ratio of heating from the outside of the object to be processed by a heating element heated by microwaves and direct heating of the object to be processed by heating the object with microwaves. 【0185】 In the above embodiment 3, the microwave irradiation means 22 may perform a first microwave irradiation, which irradiates the heating element 30 with microwaves at a frequency greater than the loss to the object to be processed 2, and a second microwave irradiation, which irradiates the heating element 30 with microwaves at a frequency less than the loss to the object to be processed 2, instead of the first and second microwave irradiations described above. The microwave loss here can be considered as the heat generated by the heating element 30 or the object to be processed 2 due to the microwaves. The microwave loss can be expressed, for example, as relative dielectric loss. Relative dielectric loss is the imaginary part ε'' of the complex dielectric constant. Generally, a larger relative dielectric loss results in greater heat generation due to microwave irradiation, while a smaller relative dielectric loss results in less heat generation. The frequency of the microwaves irradiated in this first microwave irradiation may be considered as the first frequency described above. Similarly, the frequency of the microwaves irradiated in this second microwave irradiation may be considered as the second frequency described above. Note that the relative dielectric loss of the heating element 30 here may be considered as the relative dielectric loss of the heating medium 301 of the heating element 30. 【0186】 Furthermore, in the above configuration, the container 10d may be configured to have multiple cavities, and one or more of either the first frequency irradiation unit 204 or the second frequency irradiation unit 205 may be installed in each cavity to irradiate each cavity with microwaves of different frequencies. With such a configuration, the object to be processed 2 can be irradiated with microwaves of different frequencies in each cavity, and the output of the different frequency microwaves being irradiated can be easily controlled. 【0187】 Furthermore, although the above embodiment was described using the example of moving the object to be processed within the container, it is also possible to prevent the object to be processed 2 from moving into the container 10d and to change the frequency of the microwaves irradiated into the container 10d over time, thereby switching between the first microwave irradiation for heating the heating element 30 and the second microwave irradiation for heating the object to be processed 2 on an hourly basis, and switching between heating the object to be processed 2 from the heating element 30 and direct heating of the object to be processed 2 by microwaves on an hourly basis. 【0188】 In the above embodiment 3, the case in which the microwave irradiation means 22 irradiates microwaves of two different frequencies was described, but the microwave irradiation means 22 may be capable of irradiating microwaves of three or more different frequencies. For example, the microwave irradiation means 22 may have one or more irradiation units, each of which emits microwaves of three or more different frequencies. Alternatively, the microwave irradiation means 22 may have three or more irradiation units, each capable of changing the frequency of the microwaves it emits, and three or more of these irradiation units may be configured to control the frequency of the microwaves they emit so that they emit microwaves of different frequencies. Furthermore, in the above embodiment, any parts of the multiple irradiation units that can be shared may be made shared. 【0189】 Furthermore, in the second embodiment described above, as explained in the third embodiment, two or more irradiation units 203 that perform the first microwave irradiation may irradiate with microwaves of a first frequency, and two or more irradiation units 203 that perform the second microwave irradiation may irradiate with microwaves of a second frequency. 【0190】 (Variation 1) In addition, in the microwave processing apparatus 1b of the third embodiment described above, one or more heating elements 30 may be partially provided in the container 10d along the movement path 2a of the object to be processed 2, similar to the first embodiment described above. The microwave irradiation means 22 may perform a first microwave irradiation, which heats the heating elements 30 by irradiating microwaves onto the portion of the movement path 2a where one or more heating elements 30 are provided, and a second microwave irradiation, which heats the object to be processed by irradiating microwaves of a different frequency than the first microwave irradiation onto one or more portions of the movement path 2a where no heating elements 30 are provided. In other words, the microwave irradiation means 22 may irradiate microwaves of different frequencies onto the portion of the movement path 2a where one or more heating elements 30 are provided and onto one or more portions of the movement path 2a where no heating elements 30 are provided. 【0191】 In this case, it is preferable that the frequency of the microwaves used for the first microwave irradiation be set to a frequency at which the dielectric loss to the heating element 30 is greater than the dielectric loss to the object being treated 2. Furthermore, it is preferable that the frequency of the microwaves used for the second microwave irradiation be set to a frequency at which the dielectric loss to the object being treated 2 is greater than the dielectric loss to the heating element 30. However, the frequency of the microwaves used for the second microwave irradiation may be a frequency at which the dielectric loss to the object being treated 2 is not greater than the dielectric loss to the heating element 30. 【0192】 Figure 8(a) is a schematic diagram illustrating an example of a modified microwave processing apparatus 1b. This microwave processing apparatus 1b is an example of the microwave processing apparatus 1b of Embodiment 3, in which two heating elements 30, namely heating elements 30d and 30e, as described in the modified example of Embodiment 2, are installed in the container 10d along the movement path 2a of the object to be processed 2 at predetermined intervals, and the microwave irradiation means 22 is equipped with two irradiation units 206a and 206b that irradiate microwaves of different frequencies from different positions, instead of irradiation units 204 and 205. Note that in Figure 8(a), the container, sensors, and control means are omitted from the illustration. The solid arrows in the figure schematically indicate the microwaves irradiated by irradiation units 206a and 206b. 【0193】 As shown in Figure 8(a), the irradiation unit 206a is mounted at a position where microwaves can be irradiated onto the heating element 30d (for example, a position facing the side surface of the heating element 30d in a container not shown), and performs first microwave irradiation by emitting microwaves at a frequency where the dielectric loss to the heating element 30d is greater than the dielectric loss to the object to be processed 2. As shown in Figure 8(a), the irradiation unit 206b is mounted at a position where microwaves can be irradiated onto the object to be processed 2 located in the area between the heating element 30d and the heating element 30e where the heating element 30 is not provided (for example, a position facing the area between the heating element 30d and the heating element 30e in a container not shown where the heating element 30 is not provided), and performs second microwave irradiation by emitting microwaves at a different frequency than the first microwave irradiation. Irradiation units 206a and 206b can use irradiation units similar to irradiation units 204 and 205, which are capable of irradiating microwaves at the frequencies described above. 【0194】 In the microwave processing apparatus 1b shown in Figure 8(a), when the irradiation unit 206a performs a first microwave irradiation, at position 500a where the irradiated microwaves overlap with the heating element 30d, the dielectric loss to the heating element 30d becomes greater than the dielectric loss to the object to be processed 2, depending on the frequency used for the first microwave irradiation. As a result, the heating efficiency is higher at this position than at position 500a of the heating element 30d, allowing the heating element 30d to be heated efficiently, and the object to be processed 2 inside to be efficiently heated from the outside by the heated heating element 30d. Furthermore, direct heating of the object to be processed 2 can be suppressed inside position 500a of the heating element 30d. Additionally, when the irradiation unit 206b performs a second microwave irradiation, at position 500b where the irradiated microwaves overlap with the object to be processed 2 located in a part where no heating element is provided, only direct heating of the object to be processed 2 can be performed because the heating element 30 is not provided in that area. Furthermore, by setting the frequency of the microwaves used for the second microwave irradiation by the irradiation unit 206b to a frequency that has a high relative dielectric loss with respect to the object to be processed 2, the heating efficiency of the direct heating of the object to be processed 2 can be improved. Note that the positions 500a and 500b shown in Figure 8(a) are for illustrative purposes only and do not strictly indicate the actual positions where microwaves are irradiated. The same applies to Figures 8(b) to 8(d) described later. The same also applies to position 500c described later. 【0195】 Thus, in this modified example, by irradiating the heating element 30 and the object to be processed 2 located in the area where the heating element 30 is not provided with microwaves of different frequencies, it becomes possible to perform desired heating on the object to be processed 2 in the areas where the heating element 30 is provided and in the areas where it is not provided. In particular, by irradiating the heating element 30 with a frequency at which the relative dielectric loss with respect to the heating element 30d is greater than the relative dielectric loss with respect to the object to be processed 2, heating of the object to be processed 2 in the area where the heating element 30 is provided can be suppressed. 【0196】 (Modification 2) Furthermore, in the microwave processing apparatus 1b described in the above modified example 1, the microwave irradiation means 22 may, in addition to the first microwave irradiation and the second microwave irradiation described above, irradiate the portion of the partially provided heating element 30 with microwaves of a frequency such that the dielectric loss to the heating element 30 is smaller than the dielectric loss to the object to be processed 2, thereby performing a third microwave irradiation to heat the portion of the object to be processed where the heating element 30 is provided. 【0197】 Figures 8(b) to 8(d) are schematic diagrams showing the heating elements 30d and 30e and their vicinity to illustrate a modified microwave processing apparatus 1b that performs a third microwave irradiation, and the same reference numerals as in Figure 8(a) indicate the same or corresponding parts. In the figures, the irradiation unit 206c performs a third microwave irradiation by irradiating the portion where the heating element 30 is provided with microwaves at a frequency such that the relative dielectric loss to the heating element 30 is smaller than the relative dielectric loss to the object to be processed 2. As the irradiation unit 206c, an irradiation unit similar to the irradiation unit 204 and irradiation unit 205, which can irradiate microwaves at the above frequency, can be used. The irradiation unit 206c is attached to a container (not shown). The solid arrows in the figures schematically show the microwaves irradiated by the irradiation units 206a and 206b, and the dotted arrows schematically show the microwaves that have passed through the heating element 30. In the diagram, position 500c, which will be described later, represents the position inside the heating element 30d. 【0198】 As shown in Figure 8(b), the irradiation unit 206c is mounted on the side of the heating element 30d of the container (not shown) so that microwaves are irradiated to a position different from the position 500a where the microwaves irradiated by the first microwave irradiation from the irradiation unit 206a overlap with the heating element 30d. Here, we will explain using the example where the irradiation unit 206 is mounted so that the position where the microwaves irradiated by the irradiation unit 206c overlap with the heating element 30d is closer to the heating element 30e than position 500a. However, the irradiation unit 206 may also be mounted so that the position where the microwaves irradiated by the irradiation unit 206c overlap with the heating element 30d is further away from the heating element 30e than position 500a. 【0199】 In the microwave processing apparatus 1b shown in Figure 8(b), similar to the microwave processing apparatus 1b in Figure 8(a), when the irradiation unit 206a performs a first microwave irradiation, the heating element 30d is efficiently heated at position 500a where the irradiated microwaves overlap with the heating element 30d, thereby suppressing direct heating of the object to be processed 2 in the area inside this position 500a. Furthermore, when the irradiation unit 206b performs a second microwave irradiation, only direct heating of the object to be processed 2 can be performed at position 500b where the irradiated microwaves overlap with the area of ​​the object to be processed 2 where no heating element is provided. Furthermore, when the irradiation unit 206c performs a third microwave irradiation, the dielectric loss to the object to be processed 2 becomes greater than the dielectric loss to the heating element 30d, depending on the frequency used for the third microwave irradiation. Therefore, at the position 500c where the microwaves irradiated from the irradiation unit 206c overlap with the object to be processed 2 located inside the heating element 30d, the heating efficiency of the object to be processed 2 increases, allowing for efficient and direct heating of the inner object to be processed 2. In addition, in the portion where the microwaves irradiated from the irradiation unit 206c overlap with the heating element 30d, the heating efficiency decreases. This suppresses the heating of the heating element 30d on the outside of the object to be processed 2 by microwave irradiation from the irradiation unit 206c, thereby suppressing external heating of the object to be processed 2 by the heated heating element 30d. 【0200】 Thus, in this modified example, the object to be treated 2 can be appropriately heated by performing a first microwave irradiation, a second microwave irradiation, and a third microwave irradiation. 【0201】 In the microwave processing apparatus 1b described using Figure 8(b), microwaves may be irradiated such that the position 500a irradiated by the first microwave irradiation and the position 500c irradiated by the third microwave irradiation are at the same position along the movement path 2a of the object to be processed 2. For example, as shown in Figure 8(c), in the microwave processing apparatus 1b described using Figure 8(b), the irradiation unit 206a and the irradiation unit 206c may be mounted in a container (not shown) such that the positions from which the microwaves are emitted are opposite to each other via the heating element 30d, so that the positions 500a and 500c are at the same position along the movement path 2a of the object to be processed 2. However, the arrangement of the irradiation units 206a and 206c is not limited to the above, as long as the first microwave irradiation and the second microwave irradiation can be performed so that the positions of the treated object 2 at the positions where the microwaves are irradiated are the same in the direction along the movement path 2a of the treated object 2. For example, the irradiation units 206a and 206c may be attached to the container such that the positions from which the microwaves are emitted are the same in the direction along the movement path 2a of the treated object 2, and that they do not face each other via the heating element 30d. Furthermore, in the above, the microwaves may be irradiated so that the positions in the width direction of the container 10d of the position 500a irradiated by the first microwave irradiation and the position 500c irradiated by the third microwave irradiation are the same. Furthermore, the position 500a where microwaves are irradiated by the first microwave irradiation may be considered as the position where one heating element 30 is heated by the first microwave irradiation, and the position 500c where microwaves are irradiated by the third microwave irradiation may be considered as the position where the object to be processed 2 located in the part where one heating element 30 is provided is heated by the third microwave irradiation. The same applies below. 【0202】 Furthermore, in the microwave processing apparatus 1b described using Figure 8(b), the position 500a irradiated by the first microwave irradiation and the position 500c irradiated by the third microwave irradiation may be located in parts where different heating elements 30 are provided. For example, as shown in Figure 8(d), the position 500a irradiated by the first microwave irradiation may be located in a part where a heating element 30d is provided, and the position 500c irradiated by the second microwave irradiation may be located in a part where a heating element 30e is provided. In this case, for example, the irradiation unit 206a may be positioned facing the side surface of the heating element 30d so that the position 500a irradiated by the first microwave irradiation is located in a part where a heating element 30d is provided, and the irradiation unit 206c may be positioned facing the side surface of the heating element 30e so that the position 500c irradiated by the second microwave irradiation is located in a part where a heating element 30e is provided. However, the arrangement of the irradiation unit 206a and the irradiation unit 206c is not limited to the above, as long as the microwaves can be irradiated such that the position 500a irradiated by the first microwave irradiation and the position 500c irradiated by the third microwave irradiation are located in areas where different heating elements 30 are provided. 【0203】 In the above explanation, we have used the case where there are two heating elements 30 as an example. However, as shown in Figure 8(a), when a third microwave irradiation is not performed, or as shown in Figures 8(b) and 8(c), when the position irradiated by the first microwave irradiation and the position irradiated by the third microwave irradiation are located in the same area where the same heating element 30 is provided, or when it is not necessary to irradiate different heating elements with microwaves, there may be one or more heating elements 30. Furthermore, the length, material, etc., of at least some of the two or more heating elements 30 may be the same or different. 【0204】 Furthermore, as shown in Figure 8(c), if the position where microwaves are irradiated by the first microwave irradiation and the position where microwaves are irradiated by the third microwave irradiation are located in different areas where different heating elements 30 are provided, then there should be two or more heating elements 30. 【0205】 Furthermore, the heating element 30 that is irradiated with microwaves by the first microwave irradiation and the region where no heating element is provided that is irradiated with microwaves by the second microwave irradiation may or may not be adjacent, as shown in Figure 8(b). 【0206】 Furthermore, if the position irradiated by the first microwave irradiation and the position irradiated by the third microwave irradiation are located in areas where different heating elements 30 are provided, the first microwave irradiation position and the third microwave irradiation position may be adjacent heating elements 30 separated by only one area where no heating element 30 is provided, or they may be heating elements 30 separated by two or more areas where no heating element 30 is provided. 【0207】 Furthermore, the number of irradiation units 206a in the microwave processing device 1b is not limited to one or more. The same applies to irradiation units 206b and 206c. 【0208】 Furthermore, the microwave irradiation means 21 may irradiate microwaves such that positions to be irradiated by the first microwave irradiation are located at multiple different positions within the microwave processing apparatus 1b. For example, the microwave irradiation means 21 may have multiple irradiation units 206a that perform the first microwave irradiation at multiple different positions. The same applies to the second microwave irradiation position and the third microwave irradiation position. 【0209】 Furthermore, in the above embodiments, the microwave processing apparatus was described using the example of performing flame-retardant treatment on precursor fibers such as PAN-based fibers. However, this microwave processing apparatus can also be used for processing materials other than precursor fibers, and for processing other than flame-retardant treatment, and will produce the same effects as in the above embodiments. For example, the material of the material to be processed is not limited. For example, the material to be processed may be cotton yarn, wool yarn, cashmere yarn, polymer yarn, or metal yarn. Polymer yarns include, for example, nylon yarn, fluorocarbon yarn, or polyethylene yarn. For example, the above microwave processing apparatus may be used for drying cotton yarn, wool yarn, cashmere yarn, etc. Also, for example, the microwave processing apparatus of each embodiment may be used for heating, firing, sintering, etc., of polymer yarns, metal yarns, etc. Also, the microwave processing apparatus of each embodiment may be used for carbonization treatment of flame-retardant precursor fibers, that is, for the process of manufacturing carbon fibers using flame-retardant precursor fibers. Furthermore, in the microwave processing apparatus of each of the above embodiments, carbon fibers may be produced by performing a carbonization treatment on the precursor fibers in the same container after performing the flame-retardant treatment described above. Also, the object to be processed 2 is not limited to fibrous material, but may be in other shapes such as rods, chains, sheets, films, or tubes. Moreover, the object to be processed 2 does not necessarily have to be a shape that extends continuously in a predetermined direction or is continuously connected, as long as it can be placed inside the heating element or move inside the heating element. For example, it may be a non-continuous solid object placed on a belt (not shown) made of a highly microwave-transparent material that moves from the inlet side to the outlet side of the container, or it may be a fluid such as a liquid or powder, or a gel, that moves in a cylinder or trough made of a highly microwave-transparent material such as glass that extends from the inlet side to the outlet side of the container. The number of microwaves emitted by the microwave irradiation means within the microwave device, the irradiation position of the microwaves, the output strength of the microwaves, the frequency of the microwaves, etc., are set appropriately according to the object to be processed and the processing to be performed on the object. 【0210】 Furthermore, when manufacturing carbon fibers using flame-retardant treated precursor fibers within a microwave processing apparatus, it is preferable that the gas supply means 70 described above supplies, for example, a gas such as nitrogen necessary for the production of carbon fibers. 【0211】 Furthermore, in the above embodiment, an example was described in which a winding unit 65 for winding up the processed material was provided behind the microwave processing apparatus. However, the flame-retardant processed material may be supplied to another processing apparatus (not shown) without being wound up. For example, the flame-retardant processed precursor fibers in the above microwave processing apparatus may be directly fed to an apparatus (not shown) that performs carbonization on the flame-retardant processed precursor fibers using a conveying means 60. 【0212】 Furthermore, the flame-retardant treatment of carbon fiber precursor fibers described in each of the above embodiments may be considered as one step in the carbon fiber manufacturing method. That is, the carbon fiber manufacturing method including this flame-retardant treatment is a carbon fiber manufacturing method that includes a step of heating carbon fiber precursor fibers arranged along a heating element, by irradiating microwaves into a container equipped with a heating element that absorbs microwaves and generates heat, wherein the heating step includes a first microwave irradiation to heat the heating element and a second microwave irradiation to heat the precursor fibers. 【0213】 In this carbon fiber manufacturing method, when the precursor fiber reaches the temperature at which it exhibits its heat-generating peak, it is preferable to stop the second microwave irradiation and resume the first microwave irradiation. The time at which it exhibits its heat-generating peak refers to, for example, the period including the time at which it exhibits its heat-generating peak, and preferably the time at which it exhibits its heat-generating peak and the period before and after. 【0214】 It goes without saying that the present invention is not limited to the embodiments described above, and various modifications are possible, all of which are also included within the scope of the present invention. [Industrial applicability] 【0215】 As described above, the microwave processing apparatus, etc., according to the present invention is suitable as an apparatus, etc., for performing a desired treatment on an object to be processed by irradiating it with microwaves, and is particularly useful as an apparatus, etc., for performing heat treatment. [Explanation of symbols] 【0216】 1, 1a, 1b Microwave processing equipment 2. Objects to be processed 2a Travel Path 10, 10a~10d container 20, 21, 22 Microwave irradiation means 30, 30a~30e Heat-generating element 31, 31a, 31b Laura 32, 32a, 32b belts 40 40a~40f Sensor 50, 51, 52 Control means 60 Conveying means 70 Gas supply means 201, 201a~201c First irradiation section 202, 202a~202c Second irradiation section 203, 203a~203c, 206a~206c irradiation section 204 First frequency irradiation section 205 Second frequency irradiation section 301 Heating medium 302 Support 303 Non-transparent part 701 Supply section 2001 Microwave Oscillator 2002 Transmission Section

Claims

[Claim 1] A container through which the object to be processed moves, A microwave irradiation means equipped with an irradiation unit that irradiates microwaves into the container, A heating element is partially provided within the container so as to cover the object to be processed along the movement path of the object to be processed, but not in other parts along the movement path, and which absorbs microwaves irradiated from the microwave irradiation means and generates heat. A microwave processing apparatus used for heating the object to be processed, comprising: The microwave irradiation means is configured to irradiate microwaves onto the portion of the moving path where the heating element is provided in an oxygen-containing gas to heat the heating element, and to irradiate microwaves onto the portion of the moving path where the heating element is not provided to heat the object to be processed. [Claim 2] A microwave processing apparatus according to claim 1, The irradiation unit is a microwave processing device provided with multiple units. [Claim 3] A microwave processing method comprising the step of irradiating microwaves into a container equipped with a heating element that absorbs microwaves and generates heat, thereby heating an object to be processed that moves along the heating element, The heat-generating element is partially provided along the movement path of the object to be processed, and is not provided in other parts along the movement path. A microwave processing method comprising the steps of heating, in which the heating element is heated by irradiating the portion of the transfer path where the heating element is provided with microwaves, and the object to be processed is heated by irradiating the portion of the transfer path where the heating element is not provided with microwaves, in a gas containing oxygen.

Images