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JP-7857183-B2 - Cylindrical member for microwave heating device

JP7857183B2JP 7857183 B2JP7857183 B2JP 7857183B2JP-7857183-B2

Inventors

  • 井上 徹彌

Assignees

  • 京セラ株式会社

Dates

Publication Date
20260512
Application Date
20220728

Claims (10)

  1. A tubular body made of porous ceramic having breathability and microwave permeability, A coating located on at least a portion of the outer and inner circumferential surfaces of the cylindrical body, having a microwave transmittance lower than that of the cylindrical body, Includes , The outer surface of the cylindrical body has a region where the coating is located and a region where the coating is not located. A cylindrical component for microwave heating equipment.
  2. The tubular member according to claim 1, wherein the coating has a thickness smaller than the average pore diameter of the tubular body.
  3. The coating is located at at least one end of the cylindrical body, as described in claim 1 or 2.
  4. The cylindrical member according to claim 1 or 2, wherein the coating is located on both the outer and inner surfaces of the cylindrical body.
  5. The cylindrical member according to claim 1 or 2, wherein the coatings having different microwave transmittances are located at multiple locations along the axial direction of the cylindrical body.
  6. The tubular member according to claim 1 or 2, wherein the coating is a DLC film.
  7. The cylindrical member according to claim 6, wherein the DLC film has a SP3 bond ratio of 10% or more and 40% or less.
  8. The cylindrical member according to claim 6, wherein the DLC film is located on the inner circumferential surface of the cylindrical body.
  9. The microwave heating apparatus according to claim 6, wherein the DLC film is located on the inner and outer circumferential surfaces of the cylindrical body, and the ratio of SP3 bonds in the DLC film on the inner circumferential surface is higher than the ratio of SP3 bonds in the DLC film on the outer circumferential surface.
  10. A microwave heating apparatus comprising a cylindrical member as described in claim 1 or 2, and an irradiation unit for irradiating with microwaves.

Description

This invention relates to a cylindrical member for a microwave heating apparatus. Conventionally, carbon fibers have been manufactured using a microwave dielectric heating method. Such carbon fiber manufacturing equipment has a structure in which precursor organic fibers are supplied from one end of a microwave-transmitting cylindrical body, subjected to dielectric heating, and carbon fibers are extracted from the other end. If the cylindrical body has insulating properties, heating efficiency can be improved and power consumption reduced. In recent years, axial temperature profile control (heating rate and holding temperature) has become required for carbon fiber manufacturing equipment. To control the temperature profile, the intensity of microwaves irradiated onto the organic fibers is controlled by the cylindrical body. For example, the carbon fiber manufacturing apparatus described in Patent Document 1 uses a microwave-absorbing and transmitting member as a tubular body. Reference Document 1 describes how the intensity of microwaves irradiated onto organic fibers can be changed by combining multiple tubular bodies with different microwave transmittances. Patent Document 2 describes how the intensity of microwaves irradiated onto organic fibers can be changed by arranging tubular bodies that partially absorb microwaves along the movement path of the organic fibers so as to partially cover them. Japanese Patent Publication No. 2013-231244Japanese Patent Publication No. 2020-98716 This is an explanatory diagram showing a cylindrical member for a microwave heating apparatus according to one embodiment of the present disclosure.Figure 1 is an explanatory diagram showing a cross-section obtained when the section is cut along the line X-X.This is a schematic diagram showing a microwave heating apparatus according to one embodiment of the present disclosure. The cylindrical member for a microwave heating apparatus according to this disclosure will be described below with reference to the drawings. Figure 1 is an explanatory diagram showing a cylindrical member for a microwave heating apparatus (hereinafter sometimes simply referred to as "cylindrical member") according to one embodiment of this disclosure. As shown in Figure 1, the cylindrical member 1 for a microwave heating apparatus according to one embodiment includes a cylindrical body 11 and a coating 12. In one embodiment of the cylindrical member 1, the cylindrical body 11 is made of porous ceramic and has both air permeability and microwave permeability. Specifically, the cylindrical body 11 has both air permeability and microwave permeability between its outer and inner surfaces. Porous ceramics are not limited to ceramics having a porous structure. In this specification, "porous ceramic" means a ceramic with a porosity exceeding 10 volume percent. The porosity of a porous ceramic may be, for example, 25 volume percent or more and 35 volume percent or less. Examples of ceramics forming the cylindrical body 11 include those primarily composed of aluminum oxide, zirconium oxide, yttrium oxide, yttrium aluminum composite oxide, magnesium oxide, silicon carbide, silicon nitride, titanium oxide, and sialon. Among these ceramics, a ceramic primarily composed of aluminum oxide is preferable. Using a ceramic primarily composed of aluminum oxide allows for a lower cost for the cylindrical member 1. If the ceramic is primarily composed of aluminum oxide, it may also contain oxides of magnesium, calcium, silicon, sodium, etc. In this specification, "main component" refers to a component present in a proportion of 80% by mass or more when the total composition of the ceramic components is considered to be 100% by mass. The identification of each component contained in the ceramic is performed using an X-ray diffractometer employing CuKα rays, and the content of each component can be determined, for example, by an ICP (Inductively Coupled Plasma) emission spectrometer or an X-ray fluorescence analyzer. The size of the cylindrical body 11 is appropriately set according to the size of the microwave heating device, etc. The cylindrical body 11 may, for example, have a length of 100 mm to 2500 mm, an outer diameter of 20 mm to 60 mm, and an inner diameter of 15 mm to 55 mm. The cylindrical body 11 may have a cylindrical shape, an elliptical shape, or a rectangular shape, as long as it is cylindrical. In the elliptical and rectangular shapes, the outer diameter and inner diameter refer to the diameter of the longest part. In one embodiment of the cylindrical member 1, the coating 12 is located on at least a portion of the outer and inner surfaces of the cylindrical body 11. The coating 12 has a lower microwave transmittance than the cylindrical body 11. Because the coating 12 has a lower microwave transmittance than the cylindrical body 11 and is located on at least a portion of the outer and inner surfaces of the cylindrical body 11, it is possible to provide parts w