JP2000053462A - Calcining device and calcining of ceramic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a calcining device and a calcining method of ceramics with improved mass productivity. SOLUTION: A ceramic source material preform 30 formed into a sealed tube is housed in a calcining vessel 20. A tunnel furnace 10 consists of connected zones of a first heating zone 12 to remove a binder and a second heating zone 14 for sintering. The calcining vessel 20 is introduced into the tunnel furnace 10 and successively moved from the first heating zone 12 to the second heating zone 14. In the first heating zone 12, the binder is removed, and the calcining vessel 20 is covered with a lid 22 between the first heating zone 12 and the second heating zone 14 so as to render the calcining vessel 20 into a sealed state. Then, the ceramic material is sintered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for firing ceramics, and more particularly, to a high-temperature sodium secondary battery used in a battery system such as an electric power storage device, an electric vehicle, and a peak shift device of an electric power system. The present invention relates to a ceramic sintering apparatus and a sintering method suitable for use in sintering a beta alumina ceramic tube.

[0002]

2. Description of the Related Art A high-temperature sodium secondary battery uses sodium as a negative electrode and a positive electrode active material such as sulfur, selenium, tellurium, or metal halide, or a reaction product of a positive electrode active material and sodium for a positive electrode. High temperature sodium secondary battery
Attention is paid to its high efficiency and energy density.
It is expected to be used for power storage devices and electric vehicles.

In such a high-temperature sodium secondary battery, β-type or β ″ -type beta alumina ceramic bag tubes are generally used as an electrolyte. -A mixture of a raw material of alumina powder and a binder is formed into a bag-like tube to obtain a raw material compact, or a raw material of alumina powder such as alpha alumina or gamma alumina, a raw material of sodium containing powder such as sodium carbonate, lithium carbonate or carbonate A mixture of a sintering aid powder material such as magnesium, magnesium aluminum spinel, etc. and a binder is formed into a sack-shaped tube to obtain a raw material molded body. After burning off and removing, it is common to sinter at high temperature while preventing sodium volatilization in a closed state It is.

[0004] Here, as a method for performing the binder removal and the main baking in a consistent manner, for example, as described in Japanese Patent Application Laid-Open No. 4-108671, a ceramic tube is provided on a co-base having a through hole at the bottom. The molded body is placed on a base provided with a through-hole communicating with the formed body and crucible (sintering vessel)
There is known a method in which the communication state is interrupted at the time of main firing (sintering) by utilizing the heat shrinkage of the co-base after degreasing (binder removal). Similarly, other methods for consistently performing binder removal and main firing include, for example, Japanese Patent Application Laid-Open No. 7-14-14.
As described in Japanese Patent Application Laid-Open No. 605, the space forming material interposed between the opening edge of the firing vessel and the lid is degreased and then burned out or shrunk to close the gap between the opening edge and the lid and final firing. There are known ways to do this.

[0005]

However, in the conventional method, it is necessary to replace the base material and the space forming material with new ones every firing, and the firing process becomes complicated, resulting in low mass productivity. There was a point. In addition, none of the conventional methods takes into account firing of the raw material molded article in the tunnel, and also in this respect, mass productivity is low.

Further, in the conventional methods, since the ceramic moldings are all mounted on a base plate such as a foundation or the like and fired with the opening edge of the ceramic molded body facing down, the ceramics are easily bent under their own weight during sintering, and the ceramic firing is performed. There was also a problem that the production yield of the aggregate was low.

An object of the present invention is to provide an apparatus and method for firing ceramics having improved mass productivity.

It is another object of the present invention to provide an apparatus and method for firing ceramics having improved production yield.

[0009]

(1) In order to achieve the above object, according to the present invention, a first heating region for removing a binder and a second heating region for sintering are connected. A tunnel furnace in which a firing container formed and accommodating a raw material molded body of a ceramic formed in a tubular shape is sequentially moved from the first heating area to the second heating area; Between the heating area and the second heating area, there is provided handling equipment for covering the upper part of the firing vessel and closing the firing vessel. With such a configuration, by removing the binder in the first heating region and closing the baking container between the first heating region and the second heating region using the tunnel furnace, Sintering,
Mass productivity can be improved. Also, the raw material molded body is
Since binder removal and sintering are performed in a state of being suspended in the firing container, the bag tube does not bend and the production yield can be improved.

(2) In the above (1), preferably,
The lid moves in the tunnel furnace together with the firing vessel, and is placed on the firing vessel by the handling equipment. With this configuration, the lid is heated together with the firing container,
The temperature is kept the same, so that the thermal shock when the firing container is covered can be reduced.

(3) In the above (2), preferably,
The lid is supported in the first heating area in the forward direction of the baking vessel, and the handling equipment includes a lid provided between the first heating area and the second heating area. By stopping the movement, the lid is placed on the moving firing container. With such a configuration, the lid can be easily placed, so that the handling equipment can be simplified.

(4) In the above (2), preferably,
In the first heating area, the lid is placed in a rotating state on the firing container so that an opening is formed in an upper portion of the firing container. By rotating the lid between the heating area and the second heating area, the lid is placed on the firing container.

(5) In the above (3) or (4), preferably, the lid has a box shape having a side surface and an upper surface. With such a configuration, when the lid is supported by the firing container, the flow of air from the upper portion of the firing container can be improved, and the binder can be efficiently removed.

(6) In order to achieve the above object, the present invention provides a method in which a firing vessel containing a ceramic raw material formed in a bag shape is passed through a first heating area of a tunnel furnace. The binder is removed, and between the first heating area and the second heating area connected to the first heating area, using a handling facility, the firing vessel is covered, and the firing vessel is closed, Further, the closed firing container is passed through the second heating area of the tunnel furnace to sinter the raw material compact.
With such a configuration, by removing the binder in the first heating region, by using a tunnel furnace to cover the firing container between the first heating region and the second heating region,
Sintering in the second heating region can be performed, and mass productivity can be improved. Further, since the binder removal and sintering are performed in a state where the raw material molded body is suspended in the firing container, the bag tube portion is not bent, and the production yield can be improved.

(7) In the above (6), preferably,
A through-hole is provided in the upper part of the raw material molded body of the ceramics,
A raw material compact is suspended in a through-hole through the heat-resistant rod and stored in the firing container.

(8) In the above (6), preferably,
A flange is provided on an upper part of the ceramic raw material molded body, and the flange is supported by a supporting portion of the firing container, and the raw material molded body is stored in the firing container in a suspended state.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a ceramic firing apparatus according to a first embodiment of the present invention will be described below with reference to FIGS. First, the overall plan configuration of the ceramic firing device according to the present embodiment will be described with reference to FIG. 1, and then the main part of the ceramic firing device according to the present embodiment will be enlarged with reference to FIG. 2. The front cross-sectional configuration will be described.

As shown in FIG. 1, the tunnel furnace 10 has a first heating area 12 for removing the binder and a second heating area 14 for sintering. First heating area 12
Is set to, for example, 700 to 800 ° C.
The heating temperature of the second heating area 14 is, for example, 1550 ° C.
~ 1600 ° C. Firing containers 20A, 20B,
, 20I house therein bag-shaped raw material molded bodies 30A,..., 30E of beta alumina ceramics, and are continuously fed into the tunnel furnace 10.

The firing containers 20A,...
, 22I. In the first heating area 12, as shown, the lids 22A,..., 22D are held between the adjacent firing containers 20A,. I have. The details of the holding structure of the lid 22 will be described later with reference to FIG. Further, in the second heating region 14, the lids 22F,..., 22I are placed on the firing containers 20F,.
.., 20I are in a closed state.

At the intermediate position between the first heating area 12 and the second heating area 14, the handling equipment 40
For example, the lid 22E is moved and mounted on the firing container 20E. At the tip of the handling equipment 40, a tip 42 made of heat-resistant ceramics is provided. The tip 42 is inserted into the tunnel furnace 10 through an opening provided in a ceiling portion of the tunnel furnace 10.
The tip 42 is slidable in the up-down direction (perpendicular to the plane of the paper), and when the tip 42 is lowered,
In a state where a part of the cover 2 is engaged with the front side surface in the moving direction of the lid 22 and is pulled up, the engagement between the distal end portion 42 and the lid 22 is released. Therefore, when the lid 22E supported by the firing container 20E and the firing container 20F moves in a state where the distal end portion 42 is lowered,
Since a part of the distal end portion 42 is engaged with the lid 22E and the movement of the lid 22E is prevented, and the firing containers 20E and 20F continue to move, the lid 22E moves on the firing container 20E in the horizontal direction. Then, the lid 22E is placed on the firing container 20E, and the firing container 20E is closed.

Next, the closing operation of the lid holding structure and the handling equipment will be described with reference to FIG. As shown in the figure, a bag-shaped raw material molded body 30C of beta-alumina ceramics has a bag tube portion 30C1 and a flange portion 30C2. The bag-shaped raw material molded bodies 30D,.
It has the same configuration as the raw material molded body 30C. Firing container 2
0C includes support portions 24C1 and 24C2 that extend horizontally in two directions, that is, the movement direction X and the direction opposite to the movement direction. Similarly, the sintering container 20D also includes the support portion 24D1
1,24D2. Lid 22C of firing container 20C
Has a flat plate shape, and is placed across the support portions 24C1 and 24D2 of the adjacent firing containers 20C and 20D.

On the other hand, the tip 42 of the handling equipment
It is inserted inside the tunnel furnace and can move up and down in the Y direction shown in the figure. For example, when the firing container 20E approaches the front end portion 42 in a state where the front end portion 42 is lowered, the front end portion 42 is engaged with the front side surface in the moving direction of the lid 22E, and the movement of the lid 22E is prevented. And firing container 20E,
Since 20F continues to move, lid 2 is placed on firing container 20E.
2E moves in the horizontal direction, and the lid 22E is placed in the firing container 20E.
Is placed, and the firing container 20E is closed.

A support plate 26C is mounted above the inside of the firing vessel 20C. An opening 26C1 into which the bag tube portion 30C1 of the raw material molded body 30C can be inserted is formed at the center of the support plate 26C. The bag tube portion 30C1 of the raw material molded product 30C is inserted into the opening 26C1, and the raw material molded product 3C
The raw material compact 30C is set so that 0C is suspended.
Supports the flange 30C2 formed on the outer peripheral side of the upper part of the upper part. An annular raw material compact 28C is interposed between the support plate 26C and the raw material compact 30C to reduce the influence of sintering shrinkage. In addition, a raw material powder may be interposed instead of the annular raw material molded body. Further, a through hole 26C2 is formed in the support plate 26C, and is provided to improve the flow of air at the time of binder removal.

Next, the method for firing ceramics according to the present embodiment will be explained. Alpha-alumina, sodium carbonate, and lithium carbonate were used as raw material powders, and after mixing, calcined at 1300 ° C. once, water and polyvinyl alcohol were added to the obtained powder, and granulation was performed using a spray dryer. I do. In this example, the raw material powder was calcined once after being mixed, but the calcining may be omitted to perform granulation.
Further, as a binder for maintaining the shape and strength of the molded body, besides polyvinyl alcohol, methylcellulose may be used.
Organic substances such as powders, polyacrylic acid, latex, and starch can also be used.

Next, the obtained granulated powder is molded using a dry type hydrostatic molding apparatus, and has an outer diameter of about 50φ, a length of about 440 mm,
A molded bag-shaped raw material powder 30 having a thickness of about 2.4 mm is obtained. The raw material molded body 30C is housed in a magnesia ceramics firing container 20C in a state of being suspended by the support plate 26C of the firing container 20C. Another raw material molded body 30D,
,..., 30F, similarly, firing containers 20D,.
It is stored in a state of being suspended in F.

Next, the lids 22C,..., 22F are respectively mounted on the supporting portions 24C1, 24C2, 24D1,.
With the upper portions of the firing containers 20C,... Partially open, they are introduced into the tunnel furnace 10 as shown in FIG. In the first heating zone 12 of the tunnel furnace 10, about 700
Heat to <RTIgt; C </ RTI> to thermally decompose and remove the polyvinyl alcohol. Here, the pyrolysis gas generated from the bag tube section 30C1 moves to the upper part through the through hole 26C2, and further,
The binder is released to the outside from the opening at the top of the firing container 20C, and can be removed very smoothly. This first
In the heating region 12, the upper portion of the firing container 20 is in an open state.
It is supplied within 0, and there is no possibility that the binder removal becomes insufficient. The gas generated at the time of binder removal is heated by heat generated when the binder reacts with the air, and rises together with the heated air. By doing so, binder removal can be performed smoothly.

Next, as shown in FIG. 1 and FIG.
Between the heating zone 12 and the second heating zone 14, the tip end portion 42 of the handling equipment 40 is inserted into the tunnel furnace 10, the lid 22E is moved, and placed on the firing vessel 20E. After closing the firing containers 20E and 20F,
About 1550 to 1600 ° C.
And sinter. By using a bag tube obtained by sintering as an electrolyte, a sodium-sulfur battery of about 550 Wh with excellent characteristics can be obtained.

Here, since the firing vessel 20 is closed by the lid 22, there is no problem that the properties of the beta alumina ceramics obtained by volatilization of sodium during sintering are impaired. In addition, the bag tube section 30 of the firing container 30C
Since C1 is suspended and sintered, no problems such as bending and deformation are recognized at all. The support plate 26
C and the raw material molded body 30C, an annular raw material molded body 28
Since C is interposed, unnecessary force is not applied to the flange portion 30C2 of the raw material molded body 30C even when the raw material molded body 30C is fired, so that the influence of sintering shrinkage can be reduced. The same effect can be obtained when a raw material powder is interposed instead of the annular raw material molded body.

In the second heating area 14, the firing vessel 2
Since 0 covers the lid 22, there is no danger of sodium volatilizing in this step, and low-resistance, high-strength beta-alumina ceramics can be sintered with good yield.

The firing vessel 20 and the lid 22 are kept at the same temperature because they both move in the tunnel furnace 10, and when the firing vessel 20 is covered with the lid 22, the temperatures of both are equal. The thermal shock is not applied when performing.

Further, by moving the lid 20 backward with respect to the moving direction between the first heating area 12 and the second heating area 14 to cover the firing vessel 20, the tunnel furnace 10 The width of the tunnel furnace can be reduced to a size that matches the width of the firing container 20, and the width of the tunnel furnace can be reduced. Further, the lid 22 is provided so as to straddle between the two firing containers arranged in front and back, and the lid 22 is moved backward in the traveling direction between the first heating area and the second heating area. According to the method of placing a lid on the firing container, the stability when the lid is shifted back and forth and installed over the side upper edges of the two firing containers increases, and even with respect to vibration accompanying movement in the tunnel furnace, There is no danger that the lid will fall from the upper edge of the side surface of the firing vessel.

The firing container may be a closed box type having a bottom surface and a side surface integrated with each other, a cylindrical shape having a side surface stacked on a flat plate forming the bottom surface, or a square or square shape. It may be a box type. Materials for the firing vessel and the lid include oxide ceramics such as magnesia, magnesium aluminum spinel, zirconia, and beta alumina, silicon nitride, sialon, and the like.
Silicon carbide ceramics, or those obtained by coating these surfaces with oxide ceramics can be used.

As described above, the first heating region and the second heating region are used by using a tunnel furnace in which the first heating region for removing the binder and the second heating region for sintering are connected. In the meantime, since the handling equipment for covering the upper part of the firing vessel is provided, the raw material body of beta alumina ceramics is heated and fired in the second heating area following the first heating area. In addition, continuous firing of beta alumina ceramics can be easily performed, and mass productivity is improved. In addition, the lid can be used any number of times, and the firing container can be easily closed using the handling equipment. Therefore, it is not necessary to use a new jig every time firing is performed, and mass productivity is improved. Is what you do. In the first heating region, the upper part of the firing vessel is opened, so that in this step, air is sufficiently supplied and the binder is removed smoothly.

On the other hand, in the second heating area, since the firing vessel is in a closed state, there is no danger of sodium volatilizing in this step, and low-resistance, high-strength beta-alumina ceramics can be sintered with a high yield. .

In addition, between the first heating area and the second heating area, the tip of the handling equipment for covering the firing vessel is used to easily cover the sintering vessel during the continuous firing. can do. In the case of binder removal and sintering, the temperature of the molded body is preferably as uniform as possible in view of the characteristics of the ceramics.Therefore, a gap is provided in a part of a normal batch furnace to cover the sintering vessel. It is not preferable in terms of characteristics. However, in the case of the tunnel furnace in the present embodiment, the binder removal and sintering are performed in a zone having a relatively uniform temperature distribution without any gaps in the ceiling or side walls of the furnace, and the influence of the temperature distribution between the two is relatively large. By inserting the tip of the handling equipment in a low temperature range, the lid can be attached to the firing container during firing without impairing the characteristics of the obtained ceramics. In this case, the tip of the handling equipment is always inserted into the tunnel furnace and heated so that when the sintering vessel is covered, thermal shock is applied to the lid, the tip and the sintering vessel. It becomes difficult to prevent damage to the handling equipment and the sintering container and the life can be improved.

When used in a high-temperature sodium secondary battery, the battery characteristics are greatly affected by the body and bottom of the bag tube, and it is required that the bend in this portion be small, and the bend near the opening is required. Has a small effect. In the method of the present embodiment, the body and bottom of the bag tube are sintered without bending in a state of hanging down in the vertical direction, so that the beta alumina having excellent characteristics suitable for application to a high-temperature sodium secondary battery is provided. A ceramic bag tube is obtained.

As described above, according to this embodiment, since the raw material compacts housed in the firing vessel are continuously introduced into the tunnel furnace, continuous firing becomes possible, and the firing time of the ceramics is reduced. Mass productivity can be improved.
In addition, since the firing container is closed by moving the lid, there is no need to use a co-base or a space forming material as in the prior art. Performance can be improved. Further, by firing the raw material molded article in a state of being suspended in the firing vessel, the production yield can be improved without bending of the bag tube portion or the like. It should be noted that the raw material compact and the sintered compact are easily maintained in the vertical direction even with the vibration caused by the movement in the tunnel furnace, and the production yield is improved.

Next, the structure of a ceramic firing apparatus according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 shows the overall plan configuration of the ceramic baking apparatus according to the present embodiment, and FIG. 4 shows an enlarged front sectional configuration of a main part of the ceramic baking apparatus according to the present embodiment. 1 and 2 denote the same parts.

In the present embodiment, the handling equipment 40 has two tip portions 42A and 42B. The tip portions 42A and 42B are movable in the Z direction shown in FIG. 3 and also movable in the Y direction shown in FIG.
The tip portions 42A and 42B can lift the lid 22E, for example, by sandwiching both side end surfaces of the lid 22E.
That is, by moving the distal ends 42A and 42B in the opposite directions of the Z direction to reduce the distance between the distal ends 42A and 42B, the lid 22E can be sandwiched. , 42B, the lid 22E can be separated. In the example shown in the figure, the lid 22E is sandwiched between two locations, one each on the left and right sides. However, in practice, the lid 22E is stably secured by sandwiching two locations on the left and right sides, a total of four locations. Make sure you can lift it. The other configuration is the same as that described with reference to FIGS.

As shown in FIG. 4, the lid 2 of the firing vessel 20C
2C is a flat plate, and the adjacent baking containers 20C and 20D
Are mounted on the respective support portions 24C1, 24D2. On the other hand, the leading end portions 42A, 42
B can move up and down in the illustrated Y direction. Tip 42
By lowering the distance between the distal ends 42A and 42B shown in FIG.
2E can be clamped. In this state, by moving upward in the Y direction, the lid 22E
C, 24D floats. In this state, if the firing containers 20E and 20F continue to move, the lid 22E moves in the horizontal direction on the firing container 20E, and moves the tips 42A and 42B downward just above the firing container 20E. By doing so, the lid 22E can be placed on the firing container 20E, and the firing container 20E can be closed. In the present embodiment, since the lid 22 is lifted by the distal end portion 42 of the handling equipment, the length of the support portions 24C1 and 24D2 is, as shown in FIG.
2 can be made shorter than the supporting portions 24C1 and 24D2 when sliding.

As described above, according to the present embodiment, since the raw material compact housed in the firing vessel is continuously introduced into the tunnel furnace, continuous firing becomes possible, and the firing time of the ceramics is reduced. Mass productivity can be improved.
In addition, since the firing container is closed by moving the lid, there is no need to use a co-base or a space forming material as in the prior art. Performance can be improved. Furthermore, since the raw material molded body is fired in a state of being suspended in the firing container, the production yield can be improved without bending of the bag tube or the like. It should be noted that the raw material compact and the sintered compact are easily maintained in the vertical direction even with the vibration caused by the movement in the tunnel furnace, and the production yield is improved.

Next, the structure of a ceramic firing apparatus according to a third embodiment of the present invention will be described with reference to FIG. FIG. 5 shows an enlarged front sectional configuration of a main part of the ceramic firing apparatus according to the present embodiment. In addition,
3 and 4 denote the same parts.

The overall configuration of the ceramic firing apparatus according to the present embodiment is the same as that shown in FIG. 3, and the handling equipment 40 has two tips 42A and 42B. The tip portions 42A and 42B are movable in the Z direction shown in FIG. 3 and also movable in the Y direction shown in FIG. The tip portions 42A and 42B are, for example, a lid 22E.
, The lid 22E can be lifted by sandwiching both side end surfaces of the cover 22E. That is, by moving the distal ends 42A and 42B in the opposite directions in the Z direction to reduce the distance between the distal ends 42A and 42B, the lid 22E can be sandwiched. By increasing the distance between 42B, the lid 22E can be separated. In addition,
In the example shown in the figure, the lid 22E is sandwiched by one place on the left and right sides. However, in practice, the lid 22E can be stably lifted by sandwiching two places on the left and right sides in total. ing.

Further, as shown in FIG. 5, in this embodiment, the firing container 20C has a box shape enclosing the upper, lower, left and right sides, and the central portion of the upper surface 27C is provided with the raw material molded product 30C. An opening 27C1 into which the bag tube portion 30C1 can be inserted is formed. Bag section 30C1 of raw material molded body 30C
Is inserted into the opening 27C1 and supports the flange 30C2 formed on the outer peripheral side of the upper part of the raw material molded body 30C so that the raw material molded body 30C is suspended. Upper surface 27
C and the raw material molded body 30C, an annular raw material molded body 28
The effect of sintering shrinkage is reduced by interposing C. Further, a through hole 27C2 is formed in the upper surface 27C, and is provided to improve the flow of air at the time of binder removal.

The lid 22C 'in this embodiment has a box shape without a bottom surface. Lid 22D ', ..., 22F'
Also has the same shape as the lid 22C ′. The lid 22C 'is placed over the upper surfaces of the firing containers 20C and 20D. On the other hand, the distal end portions 42A, 42B of the handling equipment
Can move up and down in the illustrated Y direction. The tip portion 42A,
In a state where 42B is lowered, the distal end portion 42 shown in FIG.
By reducing the distance between A and 42B, the lid 22
E 'can be clamped. In this state, the lid 22E 'is moved upward in the Y direction, so that the lid 22E'
Floating from 0E and 20F. In this state, if the firing containers 20E and 20F continue to move, the firing container 20E
The lid 22E moves in the horizontal direction on the baking container 20E.
The lid 22E is placed on the firing container 20E by moving the tips 42A and 42B downward at a position directly above the
The firing container 20E can be closed.

As described above, according to the present embodiment, since the raw material compacts housed in the firing vessel are continuously introduced into the tunnel furnace, continuous firing becomes possible, and the firing during the firing of ceramics becomes possible. Mass productivity can be improved.
In addition, since the firing container is closed by moving the lid, there is no need to use a co-base or a space forming material as in the prior art. Performance can be improved. Furthermore, since the raw material molded body is fired in a state of being suspended in the firing container, the production yield can be improved without bending of the bag tube or the like. It should be noted that the raw material compact and the sintered compact are easily maintained in the vertical direction even with the vibration caused by the movement in the tunnel furnace, and the production yield is improved.

Next, the configuration of a ceramic firing apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 6 shows a firing container used in the ceramic firing apparatus according to the present embodiment.

The overall configuration of the ceramic firing apparatus according to the present embodiment is the same as that shown in FIG. 3, and the handling equipment 40 has a front end, and the front end of the firing equipment closes the firing vessel lid. It is configured to be able to hold and rotate.

The firing container according to the present embodiment is the firing container 2
0 and a lid 22. The firing container 20
It has a bottom surface 20X, and rectangular tubes 20Y1 and 20Y2 stacked on the bottom surface 20X to form side surfaces, and has a structure in which the bottom surface and side surfaces are closed. Inside the firing container 20, a raw material molded body of beta-alumina ceramics is accommodated. The lid 22 has an upper surface 22X and a side surface 22Y.
It has a box-like shape without a bottom surface.

At the time of binder removal, as shown in FIG. 6A, the lid 22 is shifted from the firing vessel 20 by about 45 degrees in the horizontal direction with respect to the firing vessel 20 to form the square cylinder 20Y2 forming the side face of the firing vessel 20. It is placed on the upper edge and the upper part is partially open. Between the first heating area and the second heating area, the lid 22 is rotated in the horizontal direction by the handling equipment, and sintered as shown in FIG. 6B with the firing vessel 20 closed. You.

As described above, since the box-shaped lid is placed on the upper edge of the rectangular cylinder at a shifted angle, only the upper edge of the firing container and the lower edge of the lid come into contact with each other. The air easily enters the inside, and the binder can be easily and reliably removed.

As described above, according to the present embodiment, the raw material compacts housed in the firing vessel are continuously introduced into the tunnel furnace, so that continuous firing is possible, and the firing during the firing of ceramics is possible. Mass productivity can be improved.
In addition, since the firing container is closed by rotating the lid, it is not necessary to use a common base or a space forming material as in the related art. Mass productivity can be improved. Furthermore, since the raw material molded body is fired in a state of being suspended in the firing container, the production yield can be improved without bending of the bag tube or the like. It should be noted that the raw material compact and the sintered compact are easily maintained in the vertical direction even with the vibration caused by the movement in the tunnel furnace, and the production yield is improved.

Next, the structure of a ceramic firing apparatus according to a fifth embodiment of the present invention will be described with reference to FIG. FIG. 7 shows a firing vessel used in the ceramic firing apparatus according to the present embodiment.

The overall configuration of the ceramic firing apparatus according to the present embodiment is the same as that shown in FIG. 3, and the handling equipment 40 has two tips 42A and 42B. The tip portions 42A and 42B are movable in the Z direction shown in FIG. 3 and also movable in the Y direction shown in FIG. The tip portions 42A and 42B are configured to be able to lift the lid 22 by sandwiching both end surfaces of the lid 22, for example.

In the present embodiment, a through hole 32 is provided in the upper part of the raw material compact 30 of beta alumina ceramic, and the heat resistant rod 29 is passed through the through hole 32, and the raw material compact 30 is hung. It is housed in the firing container 20 'in the state. Further, the lid 22 is used to remove the baking container 20 ′ when the binder is removed.
, And the position of the lid 22 is shifted in the horizontal direction between the first heating area and the second heating area, and sintering is performed in a state where the firing vessel 20 is closed.

Further, after firing, the through-hole 32 of the obtained beta-alumina ceramic bag tube is cut and removed, and the lower bag tube is used as a solid electrolyte tube. In addition, it was confirmed that by cutting the part of the cut through hole, mixing it with the raw material powder and reusing it, a beta-alumina ceramic bag tube with the same performance as that made with only new raw material powder was obtained. Was done.

Here, as the heat-resistant rod, magnesia, magnesium aluminum spinel, zirconia,
Oxide ceramics such as beta alumina, ceramics such as silicon nitride, sialon, and silicon carbide, or those whose surfaces are coated with oxide ceramics can be used.

When the battery is used in a high-temperature sodium secondary battery, the battery characteristics are greatly affected by the body and the bottom of the bag tube, and it is required that the portion bend less, and the bend near the opening is required. Has a small effect. In the method of the present embodiment, the body and bottom of the bag tube are sintered without bending in a state of hanging down in the vertical direction, so that the beta alumina having excellent characteristics suitable for application to a high-temperature sodium secondary battery is provided. A ceramic bag tube is obtained.

When a through-hole is provided and hung with a heat-resistant rod, the portion provided with the through-hole must be cut off after sintering, but the cut-off portion is pulverized, mixed with raw material powder, molded and fired. Can be reused in any way.

As described above, according to this embodiment, since the raw material compacts housed in the firing vessel are continuously introduced into the tunnel furnace, continuous firing becomes possible, and the firing time of the ceramics is reduced. Mass productivity can be improved.
In addition, since the firing container is closed by performing horizontal movement of the lid, it is not necessary to use a common base or a space forming material as in the related art. Mass productivity can be improved. Furthermore, since the raw material molded body is fired in a state of being suspended in the firing container, the production yield can be improved without bending of the bag tube or the like. It should be noted that the raw material compact and the sintered compact are easily maintained in the vertical direction even with the vibration caused by the movement in the tunnel furnace, and the production yield is improved.

In the above description, the lid of the firing container is
It moves in the tunnel furnace together with the baking vessel, and is moved by the handling equipment between the first heating area and the second heating area so as to close the baking vessel. For example, the first heating area Between the first heating zone and the second heating zone, an opening large enough to allow a lid to be introduced is provided at the top of the tunnel furnace;
A lid may be introduced into the tunnel furnace from the outside of the tunnel furnace from outside through the opening using a handling facility, and the lid may be placed on the firing vessel to close the firing vessel.

In the case where an opening large enough to allow a lid to be introduced from the outside is provided between the first heating area and the second heating area of the tunnel furnace, the raw material molded body of the beta alumina ceramic or the firing vessel is required. Although the time required for baking is slightly longer because the temperature drops once during the temperature rise process during baking, the heat resistant temperature of the tip of the handling equipment to be inserted into the tunnel furnace can be lowered, and the selection range of materials to be used is expanded, Advantages such as longer life, and since the molded body of the ceramics after the binder removal is covered in the firing vessel at a lower temperature than at the time of the binder removal, it is less affected by the temperature distribution in the furnace when the cover is closed, There is an advantage that the characteristic yield of the obtained beta-alumina ceramics is easily increased. In this case as well, by preventing the temperature from decreasing so much after the first heating region, the temperature is lowered to near room temperature after the binder is removed once, as in the case of firing in a normal batch furnace. The time required for sintering is greatly reduced as compared with the case where the container is covered and heated again for sintering.

[0063]

According to the present invention, the mass productivity of firing ceramics can be improved. In addition, the production yield of firing ceramics can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing the overall configuration of a ceramic firing apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged front sectional view of a main part of the ceramic firing apparatus according to the first embodiment of the present invention.

FIG. 3 is a plan view showing the entire configuration of a ceramic firing apparatus according to a second embodiment of the present invention.

FIG. 4 is an enlarged front sectional view of a main part of a ceramic firing apparatus according to a second embodiment of the present invention.

FIG. 5 is an enlarged front sectional view of a main part of a ceramic firing apparatus according to a third embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of a firing vessel used in a ceramic firing apparatus according to a fourth embodiment of the present invention.

FIG. 7 is a perspective view showing a configuration of a firing vessel used in a ceramic firing apparatus according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Tunnel furnace 12 ... 1st heating area 14 ... 2nd heating area 20 ... Firing container 22 ... Lid 30 ... Raw material molded body 32 ... Through-hole 40 ... Handling equipment 42 ... Tip part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yu Suzuki 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant (72) Inventor Katsumi Imagawa 3-chome Bentencho, Hitachi-shi, Ibaraki No. 2 Hitachi Kyowa Engineering Co., Ltd. (72) Inventor Shigeo Maeno 3-10-2 Bentencho, Hitachi City, Ibaraki Prefecture F K term in Hitachi Kyowa Engineering Co., Ltd. 5H029 AJ14 AK04 AK05 AL13 AM14 BJ02 CJ02 CJ30

Claims (8)

[Claims] A first heating region for removing a binder and a second heating region for sintering are formed so as to be connected to each other. A tunnel furnace in which the firing container accommodated in the first heating region sequentially moves from the first heating region to the second heating region; and between the first heating region and the second heating region, And a handling device for closing the firing container with a lid to close the firing container. 2. The apparatus for firing ceramics according to claim 1, wherein said lid moves in said tunnel furnace together with said firing vessel and is placed on top of said firing vessel by said handling equipment. Ceramic firing equipment. 3. The apparatus for firing ceramics according to claim 2, wherein the lid is supported in the first heating area in a forward direction of the firing vessel, and the handling equipment is provided with the first heating area. Wherein the lid is stopped on the moving firing container by stopping the movement of the lid between the heating area and the second heating area. 4. The firing apparatus for ceramics according to claim 2, wherein said lid is rotated on said firing vessel so that an opening is formed in an upper portion of said firing vessel in said first heating area. The handling equipment places the lid on the firing container by rotating the lid between the first heating area and the second heating area. An apparatus for firing ceramics, comprising: 5. The ceramic firing apparatus according to claim 3, wherein the lid has a box shape having a side surface and an upper surface. 6. A sintering vessel containing a ceramic raw material formed in a tubular shape therein is passed through a first heating area of a tunnel furnace to remove a binder. Between the second heating area and the second heating zone, the handling apparatus is used to cover the firing vessel, the firing vessel is closed, and the firing vessel in the closed state is closed in the tunnel furnace. A firing method for ceramics, wherein the raw material compact is sintered by passing through a second heating zone. 7. The method for firing ceramics according to claim 6, wherein a through-hole is provided at an upper portion of the raw material molded body of ceramics.
A method for firing ceramics, wherein a raw material compact is suspended in a through-hole through a heat-resistant rod and housed in the firing container. 8. The method for firing ceramics according to claim 6, wherein a flange is provided on an upper portion of the raw material molded body of ceramics, and the flange is supported by a support portion of the firing container to suspend the raw material molded body. A method for firing ceramics, wherein the ceramics is housed in the fired container in the fired state.