JP2005241143A - Fireproof heat insulation block - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fireproof heat insulation block capable of preventing the generation of discharge by microwaves in the fireproof heat insulation block used in a microwave heating furnace. <P>SOLUTION: This fireproof heat insulation block has a laminated body formed by laminating inorganic fiber transmitting microwaves, and a fixing means for fixing the laminated body to a furnace shell composed of a steel material. The fixing means has a supporting member for inserting and supporting the laminated body, and a base comprising an engagement part engaged with the supporting member and a fixed part fixed to the furnace shell for supporting the laminated body, and at least the supporting member is a ceramic rod member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a refractory heat insulation block, and more particularly to a refractory heat insulation block used for a furnace wall of a microwave heating furnace that heats and heats an object to be heated by microwaves.

Conventionally, refractory heat insulation blocks have been widely used as furnace wall materials for various industrial furnaces.
In general, a fireproof heat insulating block is composed of a laminated body such as felt or blanket made of inorganic fibers such as alumina and silica, and a fixing metal fitting for supporting the laminated body. In other words, it is an integrated laminate by inserting a plurality of felts or blankets with a metal rod or pipe such as stainless steel, and the metal rod or pipe is formed by engaging with a fixing bracket. is there. And a fixing wall and a furnace shell are fixed by a suitable method, and a furnace wall is comprised.

  By the way, in recent years, microwave heating, which is more productive than conventional radiant heating using a burner or heater as a heat source and has a remarkable energy saving effect, has been used for heating and firing ceramics and fine ceramics. Research and development has been done. For example, in a continuous firing furnace using microwave heating, the temperature distribution in the furnace length direction in the firing chamber is formed in an arbitrary pattern by making the thickness of the heat insulating layer on the furnace wall surrounding the firing chamber different in the furnace length direction. A continuous microwave firing furnace has been proposed (see Patent Document 1).

  However, the use of the above-described conventional refractory heat insulation block to form the heat insulation layer of such a microwave baking furnace may cause the following problems.

  The microwaves irradiated into the furnace are absorbed by the object to be heated, its mounting table, etc., and heat them up. However, when the laminated body is made of ceramic fibers that easily transmit microwaves, the microwaves that are not absorbed by the object to be heated or the mounting table pass through the laminated body of the refractory insulation block and are made of steel. And is again transmitted through the laminate and absorbed by the object to be heated or the mounting table.

  However, the microwave passing through the laminate in this manner may cause a discharge phenomenon between the fixture and the furnace shell that supports the laminate. When this discharge phenomenon occurs in a gap between a support member such as a stainless steel bar inserted into the laminate and a fixing metal fitting engaged with the support member, the engaging part of the stainless steel bar or the fixing metal As a result of the fusing, there was a risk that the blanket of the laminated body would be relatively displaced and deformed, and sometimes the blanket of the refractory heat insulation block installed on the ceiling portion of the furnace would fall off.

  In addition, when a microwave discharge occurs in a slight gap between the fixture and the furnace shell, the furnace shell is heated and deformed by the discharge, or the microwave leaks to the outside of the furnace due to this deformation. I was in danger.

For this reason, development of the fireproof heat insulation block which can avoid generation | occurrence | production of the discharge by a microwave was desired.
JP 2003-75070 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a refractory heat insulation block capable of avoiding the occurrence of discharge due to microwaves in a refractory heat insulation block used in a microwave heating furnace. It is.

  The fireproof heat insulation block of the present invention is a fireproof heat insulation block comprising a laminate formed by laminating inorganic fibers that transmit microwaves, and a fixing means for fixing the laminate to a furnace shell made of steel. Has a support member that inserts and supports the laminate, an engagement portion that engages with the support member, and a base that supports the laminate, and includes a fixing portion that is fixed to the furnace shell, and at least the support member Is a ceramic rod.

  In the refractory heat insulation block of the present invention, it is desirable to provide a choke on the contact surface of the base with the furnace shell. Further, a metal mesh may be provided instead of the chalk.

  In the refractory heat insulation block of the present invention, the base can be made of ceramic. Here, the ceramic is preferably alumina or silica.

  In the refractory heat insulation block of the present invention, since the support member that supports the laminated body made of inorganic fibers is made of ceramic, the microwave discharge is not generated in the gap between the support member and the engaging portion of the base. Accordingly, the support member and the engaging portion of the base are not melted by the microwave discharge, so that deformation and dropout of the laminate can be avoided.

  Further, since the choke for preventing the discharge by the microwave is provided between the furnace shell and the base, the discharge by the microwave in the gap between the furnace shell and the base does not occur. Therefore, the furnace shell is not heated by the microwave discharge, and the resulting deformation of the furnace shell does not occur, and there is no risk of leakage of the microwave to the outside of the furnace due to the deformation of the furnace shell.

  In addition, by providing a metal mesh in place of the choke that prevents discharge due to microwaves provided between the furnace shell and the base, an effect similar to that of the choke can be achieved with an inexpensive material.

  Furthermore, by making the base of the refractory heat insulation block from metal to ceramic, it is possible to reliably avoid the occurrence of discharge due to microwaves.

  Here, alumina or silica can be used as the rod of the support member or the ceramic of the base. Since alumina and silica have a low microwave absorption rate, the support member and base are not heated by the microwave, so energy loss can be suppressed, and the support member rod and base ceramic Is preferred.

  By using the refractory heat insulation block of the present invention as described above, damage to the furnace shell and the like due to microwave discharge can be prevented. Therefore, it is possible to improve the safety of the microwave heating furnace and reduce the repair maintenance cost.

  Embodiments of the fireproof and heat insulating block of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view schematically showing an embodiment of the fireproof and heat insulating block of the present invention.

  The refractory heat insulation block 10 of the present invention includes a laminate 12 formed by laminating inorganic fibers and a fixing means 14 for fixing the laminate 12 to a furnace shell.

  The laminate 12 is a felt or blanket-like heat insulating material that transmits microwaves, and is formed by laminating alumina fibers, ceramic fibers, glass fibers, or rock wool. These inorganic fibers have different heat resistance temperatures, and the higher the heat resistance temperature, the more expensive the fibers. Therefore, it is desirable to select appropriately according to the maximum operating temperature of the target heating furnace, but generally, ceramic fibers that are inexpensive and easily available are desirable. As the ceramic fiber, for example, a fiber mainly composed of alumina and silica whose alumina is 65% by weight or less, and a fiber mainly composed of alumina, silica and zirconia are preferable. Furthermore, heat resistance can be improved by heat-treating these fibers at 1000 ° C. or higher and precipitating mullite or zirconia crystals. The maximum use temperature of these is 1260 ° C.

  The fixing means 14 includes a pipe or rod-like support member 16 that inserts and supports the laminated body 12 and a base 18 that engages with the support member 16 and supports the laminated body 12.

  The support member 16 is a member that engages with the base 18 while forming a laminated body 12 in which a plurality of blankets made of inorganic fibers are inserted and integrated. The support member 16 of the present invention is a rod made of ceramic, and is formed of ceramic such as alumina, alumina silica, or silica. Among these, alumina is suitable as a support member because it has a low microwave absorption rate and can transmit microwaves and has high strength.

  The base 18 is formed in a U-shaped cross-section that hangs into the laminated body 12 so that the engaging portions 18b with the support member 16 sandwich the laminated body 12 at both ends of the bottom 18a. In this embodiment, a fixing portion 18c that is fixed to the furnace shell is formed integrally with the bottom portion 18a.

  An engagement hole 20 is provided in the engagement portion 18 b, and the support 18 can be engaged with the base 18 by inserting the support member 16 through the engagement hole 20.

  The fixing portion 18c is formed integrally with the bottom portion 18a of the base 18, and can be fixed to the furnace shell with a nut or the like, for example.

  Here, the bottom portion 18a and the engaging portion 18b of the base 18 can be formed by bending a stainless steel plate or the like into a predetermined shape, a channel, or the like. The fixing portion 18c may be formed by fixing a stainless steel bolt to the bottom portion 18a by welding or the like.

  The fireproof insulation block as described above is formed by the following procedure. First, a blanket is inserted into a space defined by the left and right engaging portions 18b, 18b of the base 18. Next, the support member 16 is inserted into the engagement hole 20, and the blanket inserted as it is is inserted to engage the support member 16 and the base 18. At this time, both ends of the support member 16 are projected for a predetermined length on both sides of the engaging portions 18b and 18b, and a blanket is inserted into the projecting portion of the support member to form the laminate 12.

  In the fireproof and heat insulating block 10 formed in this way, there is a slight gap between the support member 16 and the engagement hole 20, so in a conventional metal rod such as a stainless steel tube, this gap Microwave discharge sometimes occurred. However, in the present invention, since the support member 16 is made of a ceramic rod, even if there is a gap between the engagement hole 20, the discharge due to the microwave does not occur. Therefore, the laminated body is not deformed (for example, relative positional deviation between adjacent blankets) or dropped due to fusing of the support member or the engaging portion.

  Next, the state which applied the fireproof heat insulation block of this embodiment to the heating furnace is typically shown in FIG. In FIG. 2, the refractory heat insulation block 10 is installed so that the fixing portion 18 c protrudes out of the furnace through a fixing hole 22 provided in advance in the furnace shell 20 of the heating furnace, and is fastened to the furnace shell 20 with bolts 24. Yes.

  Here, if there is a gap α between the bottom surface of the bottom 18a of the base 18 of the base 18 of the refractory heat insulating block 10 facing the furnace shell 20 and the furnace inner surface 20a of the furnace shell 20, a microwave discharge occurs in this gap α. There are things to do. In such a case, a choke for preventing discharge due to microwaves is provided at the bottom peripheral edge of the bottom 18a of the base 18. As the chalk, a commercially available finger choke can be used. It is also desirable to use a metal mesh instead of chalk. As the metal mesh, for example, a mesh of about # 16 to # 1000 made of copper can be suitably used.

  By the way, in the fireproof heat insulation block of this invention demonstrated above, the base which supports a laminated body is formed using metals, such as stainless steel and aluminum. However, it is also preferable that the metal base is made of ceramic, like the support member. That is, all the fixing means for the laminated body composed of the support member and the base is formed of ceramic. If all the fixing means are ceramic and no metal is used in the refractory insulation block, microwave discharge does not occur in the refractory insulation block.

  When the base is made of ceramic, it is desirable to use alumina, silica or the like as the ceramic. Alumina, silica, and the like are easy to mold, have high strength, have a low microwave absorption rate, and can penetrate most of them, and thus are suitable as a base as well as the support member.

  As described above, the refractory heat insulation block of the present invention can extremely effectively avoid the occurrence of discharge due to microwaves even when used as a heat insulating material for a heating furnace using microwaves as a heat source.

  In addition, the fireproof heat insulation block of this invention is not limited to said embodiment, It is also possible to change suitably in the range which does not deviate from the main point of this invention.

  For example, in the fireproof and heat insulating block 10 of the above-described embodiment, the fixing portion 18c is fixedly provided standing on the base bottom portion 18a, and the fixing portion 18c is inserted into the fixing hole 22 provided in the furnace shell 20. Thus, the bolts 24 were fastened from the outside of the furnace shell 20.

  However, the shape of the base 18 may be changed to fix the refractory heat insulation block from the inside of the furnace shell. That is, without providing the base 18 with the fixing portion 18c, as shown in FIG. 3, the fixing hole 22 is provided in the center of the bottom 18a of the base, and the fixing hole 22 is fixed in advance to the furnace shell 20 by welding or the like. This is a mode in which the stud 30 provided is inserted and fastened with a bolt 24 from the inside of the furnace shell to fasten the refractory heat insulating lock 10 to the furnace wall 20. Also in this case, the occurrence of microwave discharge can be avoided by taking the respective measures described in the above embodiments.

  Moreover, the fireproof heat insulating block of the present invention is suitably used not only in a microwave heating furnace for heating an object to be heated by microwaves but also in a hybrid heating furnace in which radiation heating by a conventional burner or heater and microwave heating are used in combination. be able to.

  The refractory heat insulation block of the present invention is a microwave heating furnace that heats an object to be heated such as ceramics, fine ceramics, or metal powder, and a hybrid that can use both radiation heating and microwave heating by a conventional burner or heater. It can be suitably used as a heat insulating material for a furnace wall such as a heating furnace.

It is a schematic perspective view which shows the structure of the fireproof heat insulation block of this invention. It is a cross-sectional schematic diagram which shows the aspect of construction of the fireproof heat insulation block of this invention. It is a cross-sectional schematic diagram which shows the aspect of another construction.

Explanation of symbols

10: Fireproof heat insulating block 12: Laminated body 14: Fixing means 16: Support member 18: Base 20: Furnace shell 22: Fixing hole 30: Stud

Claims (5)

A laminate formed by laminating inorganic fibers that transmit microwaves;
In a refractory heat insulation block having fixing means for fixing the laminate to a furnace shell made of steel,
The fixing means includes a support member that inserts and supports the laminate,
An engagement portion that engages with the support member, and a base that supports the laminated body, and a fixing portion that is fixed to the furnace shell;
A fireproof heat insulating block characterized in that at least the support member is a ceramic rod.   The fireproof and heat insulating block according to claim 1, wherein a choke is provided on a contact surface of the base with the furnace shell.   The fireproof heat insulation block according to claim 1, wherein a metal mesh is provided on a contact surface of the base with the furnace shell.   The fireproof heat insulating block according to claim 1, wherein the base is ceramic.   The refractory heat insulation block according to claim 1 or 4, wherein the ceramic is alumina or silica.

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