JP2003109613A - Method of manufacturing fuel cell pipe and ceramics manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a ceramic component by arbitrarily controlling its dimensions, and improving the yield ratio in manufacturing the ceramic component. SOLUTION: This method of manufacturing a fuel cell pipe comprises a step for forming a base pipe by using the slurry having a basic ingredient and an organic solvent, a step for forming elements such as a fuel pole, an electrolyte and an inter-connector on the base pipe, a step for setting the base pipe 12 on a sintering furnace 1 having an observation window 4 for observing the inside, a step for detecting the position of an end of the base pipe 12 during sintering, through the observation window 4, a step for controlling the sintering furnace 1 on the basis of a result of detection, a step for forming an air pole on the sintered base pipe 11, and a step for sintering the base pipe with the air pole.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a fuel cell tube and a ceramics manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, in order to manufacture a ceramic sintered body part or product (hereinafter referred to as "product etc."), the following process is performed. First, an organic solvent is added to a raw material (oxide, nitrate, etc.) of ceramic powder to form a slurry. Next, to produce a sheet-shaped product or the like, a sheet-shaped molded body is produced by the doctor blade method. In order to produce a tubular product or the like, a tubular shaped body is produced by an extrusion molding method. To make a plate-shaped product, etc., put the slurry in the formwork and press,
A plate-shaped molded body is produced. At this point, the shape of the molded body is a shape that does not need to be processed in principle after sintering. Subsequently, the shaped bodies are fired at an appropriate temperature in an electric furnace. The shape of the fired sintered body is slightly adjusted (surface processing, cutting, polishing, and other mechanical processing) to obtain a final product or the like.

However, when a ceramic product is machined after firing, its strength may be significantly reduced due to minute scratches and irregularities generated during the process. Therefore,
After firing, it is desirable that the machining for adjusting the shape is not performed as much as possible. Here, in the above-mentioned process, each molded product undergoes a significant shape shrinkage during firing (for example, shrinkage of about 20% in length). That is, when the machining after firing is not performed, the molded body is manufactured in a size that allows for shrinkage in advance.

However, in order to accurately manufacture a product or the like which requires high dimensional accuracy even if the molded body undergoes a large shrinkage during firing, a high level of technology and know-how is required. . For example, the type and concentration of the solvent for preparing the slurry, the size of the molded body in consideration of the shrinkage amount, the firing temperature, the firing time, and the like. However, it is not always easy to increase the yield depending on the type of product or the like.

A specific description will be given with reference to FIG. Figure 2
[Fig. 3] is a graph showing a firing temperature process and a change in length of a molded body with time when a molded body is fired to produce a sintered body. Regarding the vertical axis, the left axis shows the length of the molded body (however, it shows a certain length L ₀ or more). The right axis is the firing temperature. The horizontal axis is the time course in the firing process. Curve c, curve b, and curve a have a length L _c , a length L _b , and a length L _a , respectively, and a shaped body is fired in a firing furnace (electric furnace) at a firing temperature profile shown by a curve d. In this case, the change in length is shown.
However, the target length of time to form a compact (or mean length) and L _a, typically, the length of the molded body from the relationship of the yield, with the maximum L _c, the width of the minimum L _b.

Here, the target length L _{T of the} sintered body is L _N ≧
Let L _T ≧ L _M. At that time, from the graph, in the case of the molded body having the length L _c , when the firing time t is in the range of t _c2 ≧ t ≧ t _c1 , the length falls within the above range. Therefore, it is necessary to finish the firing at that point (stop holding the temperature and lower the temperature). Similarly, _a molded body having _a length of L _a is t _a2 ≧ t ≧
In the range of t _a1 , the molded body having the length L _b is t _b2 ≧ t
When it is in the range of ≧ t _b1 , it is necessary to finish the firing.

In the manufacture of ceramic products in the prior art, the above time was estimated from experiments and experience. However, to align the yield in the step of the molded body, all molded body same length L _a is difficult,
The length varies in the range of L _{c to} L _b . In that situation, it is not always easy to set the firing time so that all of the formed bodies having the lengths L _{c to} L _b fall within the above target length range.

In addition, the final length of the molded body after firing is not always determined only by the initial length of the molded body, as shown in FIG. Since it may change depending on the particle size distribution of the ceramic powder and the like, it has been unavoidable to produce a sintered body that does not fall within the above target length range to some extent. In that case, a slight machining process after firing was used.

In the solid electrolyte fuel cell, since the operating temperature is high, many ceramic products are used. Improving the yield of such ceramic products is very important because it not only improves work efficiency, but also leads to reduction of manufacturing cost and delivery time.

[0010]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method of manufacturing a fuel cell tube and a ceramics manufacturing apparatus which improve the yield in manufacturing a ceramic member.

Another object of the present invention is to provide a method for manufacturing a fuel cell tube and a ceramics manufacturing apparatus which can accurately control the firing of a ceramic member.

Another object of the present invention is to provide a method for manufacturing a fuel cell tube and a ceramics manufacturing apparatus, in which the dimensions of the ceramic member can be freely controlled.

Still another object is to provide a method of manufacturing a fuel cell tube and a ceramics manufacturing apparatus which can reduce the manufacturing cost of a ceramic member.

Still another object is to provide a method for manufacturing a fuel cell tube which can significantly reduce the manufacturing cost of a fuel cell.

[0015]

Means for Solving the Problem In the section of the means for solving the problem, the reference numerals and symbols are given to show the correspondence between the claims and the embodiments of the invention. It should not be used to interpret the claims.

In order to solve the above-mentioned problems, the method for producing a fuel cell tube according to the present invention comprises a step of forming a base tube (FIGS. 6 and 19) from a slurry containing a raw material and an organic solvent, and the base tube. (Fig. 6, 19), the fuel electrode (Fig. 6, 1
4), electrolyte (Fig. 6, 15), interconnector (Fig. 6,
17) a step of forming each element, a step of firing the base tube (FIGS. 6 and 19) on which the elements are formed while observing the shrinkage amount due to firing, and the fired base tube ( 6 and 19), a step of forming an air electrode (FIGS. 6 and 16) and a step of firing the substrate tube (FIGS. 6 and 19) having the air electrode (FIGS. 6 and 16) formed therein. To do.

Further, in the method for producing a fuel cell tube of the present invention, a step of forming a base tube (FIGS. 6 and 19) from a slurry having a raw material and an organic solvent, and the base tube (FIG. 6, FIG. 6).
19), the fuel electrode (FIGS. 6 and 14) and the electrolyte (FIGS. 6 and 1).
5), interconnector (Fig. 6, 17), air electrode (Fig. 6,
16) forming each element, and observing the shrinkage amount due to baking, baking the substrate tube (FIGS. 6 and 19) on which each element is formed.

Further, in the method for manufacturing a fuel cell tube according to the present invention, the base tube on which each of the elements is formed (FIGS. 6 and 19).
And firing the base tube (FIGS. 6, 19/12) in a firing furnace (FIG. 1, 1) having an observation window (FIGS. 1, 4) for observing the inside. , Detecting the position of the end portion of the substrate tube (FIG. 6, 19 / FIG. 1, 11/12) during firing through the observation window (FIGS. 1, 4), and based on the detection result. , Controlling the firing furnace (FIGS. 1, 1).

Further, in the method for producing a fuel cell tube according to the present invention, the base tube on which the above-mentioned elements are formed (FIGS. 6 and 19).
And firing the base tube (FIGS. 6, 19 / FIG. 12, 12) in a firing furnace (FIG. 4, 1) having an observation window (FIGS. 4, 4) for observing the inside. Emitting a laser beam (FIGS. 4 and 10) toward the substrate tube (FIGS. 6, 19 / FIG. 4, 11/12) through the observation window (FIGS. 4 and 4), and the observation window. Based on the result of receiving the reflected light of the laser light (FIGS. 4 and 10) via (FIGS. 4 and 4),
Controlling the firing furnace (FIGS. 4 and 1).

Further, in the method for manufacturing a fuel cell tube according to the present invention, the base tube on which each of the elements is formed (FIGS. 6 and 19).
The step of firing the substrate is performed by adding the substrate to a firing furnace (FIGS. 5 and 1) having a first observation window (FIGS. 5 and 4) and a second observation window (FIGS. 5 and 13) capable of observing the inside. Tube (Figs. 6 and 19)
/ Figs. 5 and 12), and through the second observation window (Figs. 5 and 13), the base tube (Fig. 6,
19 / Fig. 5, 11/12) toward the laser light (Fig. 5,
10) firing the first observation window (FIG. 5,
4) through which the laser light (FIGS. 5 and 10) is received, and the step of controlling the firing furnace (FIGS. 5 and 1) based on the light reception result.

In order to solve the above problems, the ceramics manufacturing apparatus of the present invention has an observation window (FIGS. 1 and 4) for observing the inside, and fires the ceramics (FIG. 1, 11/12). Furnace (Fig. 1, 1) and the observation window (Fig. 1,
4) via the detection unit (FIG. 1, 6) that detects the position of the end of the ceramics (FIG. 1, 11/12) and outputs the detection result, and the firing furnace based on the detection result. And a control unit (FIGS. 1 and 7) for controlling (FIGS. 1 and 1).

Further, the ceramics manufacturing apparatus of the present invention is
A firing furnace (FIG. 4, 1) having an observation window (FIGS. 4, 4) for observing the inside and firing ceramics (FIG. 4, 11/12) and the observation window (FIGS. 4, 4) Via the electromagnetic wave output part (FIG. 4, 8) for emitting an electromagnetic wave toward the ceramics (FIG. 4, 11/12) via the observation window (FIG. 4, FIG.
4) via which a reflected wave of the electromagnetic wave (Figs. 4 and 10) is received and a detection result is output (Figs. 4 and 6);
And a control unit (FIGS. 4 and 7) for controlling the firing furnace (FIGS. 4 and 1) based on the reception result.

Further, the ceramics manufacturing apparatus of the present invention is
A first observation window (FIGS. 5 and 4) for firing the ceramics (FIG. 5, 11/12) to observe the inside, and the first observation window (FIG. 5, 11/12) sandwiching the ceramics (FIG. 5, 11/12) Second observation window (Figs. 5 and 13) symmetrically positioned with respect to Figs.
And the ceramics (Figs. 5 and 11 /) through the second observation window (Figs. 5 and 13) having a firing furnace (Figs. 5 and 1 /).
12) which emits an electromagnetic wave (Figs. 5 and 10) toward the electromagnetic wave output unit (Figs. 5 and 8) and the electromagnetic waves (Figs. 5 and 10) without being blocked by the ceramics (Figs. 5 and 11/12). , A detection unit (FIGS. 5 and 6) that receives the passing electromagnetic waves that have reached the first observation window (FIGS. 5 and 4) and outputs the reception result, and the firing furnace (FIG. 5) based on the reception result. 1) and a control unit (FIGS. 5 and 7) for controlling the above.

Further, the ceramics manufacturing apparatus of the present invention is
The electromagnetic wave is laser light.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a method for manufacturing a fuel cell tube and a ceramics manufacturing apparatus according to the present invention will be described below with reference to the accompanying drawings. In the present embodiment, an example of a ceramic firing apparatus for firing a cell tube of a cylindrical fuel cell will be described, but the present invention can be applied to the production of all other ceramic products requiring dimensional control. Note that the same or corresponding portions in the respective embodiments will be described with the same reference numerals.

(Embodiment 1) The structure of a first embodiment of a method for manufacturing a fuel cell tube and a ceramics manufacturing apparatus according to the present invention will be described with reference to the drawings.

Conventionally, the control of the size of a ceramic molded body during firing has been performed without observing the actual size in real time while firing, depending on the firing time and firing temperature. However, in the present invention, the size control is
The difference from the conventional technique is that the actual length is observed in real time. That is, the length of the ceramic molded body is observed through an observation window newly installed in the firing furnace, and the firing is terminated when the length reaches the target length. As a result, the problem of yield that has occurred in the past can be solved, and all the fired ceramics compacts can be made into sintered compacts of a desired size.

In particular, the fuel cell shown in this example is on a base tube for firing a base tube, a fuel electrode and an air electrode, which need to be manufactured in a porous state, and an electrolyte, which needs to be densely manufactured. Must be simultaneously laminated and fired at the same time. Since the optimum size range for simultaneously satisfying the porosity and the denseness of the laminated base tube and each film is extremely narrow, not only the control by the firing time and firing temperature which depend on the yield but also during the actual firing The control by the size of the molded body of is very effective.

FIG. 1 is a diagram showing the construction of a first embodiment of a method for producing a fuel cell tube and a ceramics producing apparatus according to the present invention (however, the firing furnace 1 is a sectional view). The ceramics manufacturing apparatus includes a combustion furnace 1 having a heater 2, a heat insulating material 3, an observation window 4, and a molded body mounting portion 5.
And a detection unit 6 and a control unit 7.

The firing furnace 1 is an electric or gas furnace for firing a ceramic body such as a sheet or tube. Temperature (by a thermometer such as a thermocouple, not shown), atmosphere (by a gas flow meter, gas sensor, etc., not shown), electric power (ammeter, voltage) supplied to the heater 2 by the control unit 7 (described later). According to the total,
The flow rate of fuel supplied to the burner (not shown), the condition of the ceramic molded body 12 (described later) (by the detection unit 6 and the like), etc. are grasped at any time and control is performed. In addition, the control unit 7
The firing temperature is controlled moment by moment on the basis of a control program owned by.

The heater 2 is a heater that heats and heats the molded body in the firing furnace 1. It is installed around the room in the firing furnace 1 where the sample is placed. Various heating methods can be used depending on the temperature and atmosphere. However, the firing of the ceramic molded body 12 is performed at a high temperature (1000
In the case of an electric furnace, a heating element corresponding thereto is used because it is performed in an oxidizing atmosphere of (° C. For example, Fe-C
r-Al alloy heating element, Pt-Rh alloy heating element, SiC
There are heating elements. In addition, gas (city gas, etc.) furnaces, heavy oil furnaces, etc. that can lower running costs than electric furnaces can also be used. Both gas furnaces and heavy oil furnaces are furnaces that burn fuel to heat it with a burner.

The heat insulating material 3 is the heat insulating material of the firing furnace 1. During firing at high temperature, it retains internal heat and prevents (suppresses) heat dissipation to the outside. It is attached so as to enclose the entire firing furnace 1. Porous ceramics such as alumina, silica, magnesia and zirconia are used.

The observation window 4 is a hole for observing the inside of the firing furnace 1 from the outside. The size of the hole is such that almost no heat inside escapes to the outside and a specific site inside can be observed. However, in order to satisfy the above-mentioned conditions, windows such as quartz glass and artificial sapphire are attached to the holes as necessary. In this embodiment, a hole having a diameter of about 1 cm is opened at a target length position of the ceramic molded body 12, and quartz glass is fitted therein to prevent heat dissipation.

The molded body mounting portion 5 is a ceramic molded body 1.
This is a jig for attaching one end of No. 2 and fixing its position. The ceramic molded body 12 shrinks entirely during firing. At this time, considering that the tubular ceramics molded body 12 is fired, for example, if there are no fixing points, both ends contract with the contraction in the diameter direction. Therefore, in order to observe the length of the tube, it is necessary to observe at two points at both ends. However, if one end is fixed, it will not move and the other end will contract toward it. That is, by observing only one point which is the other end, it is possible to know the length of the tube which is the ceramic molded body 12 in the firing furnace 1. And
The position of the molded body attaching portion 5 can be freely controlled so that the position of the one point becomes the position of the observation window 4. In the case of the tube-shaped ceramic molded body 12, the molded body mounting portion 5 is a jig for fixing one end portion thereof. Then, the ceramic molded body 12 is fixed and fired in a form suspended from the ceramic molded body 12.

The detector 6 is connected to the firing furnace 1 through the observation window 4.
This is a detector for detecting a change in length of the ceramic molded body 12 inside. It is an image pickup device such as a CCD camera capable of capturing an image observed through the observation window 4. If necessary, use a filter to select the wavelength,
It is also possible to make it easier to detect. The captured image data is output to the control unit 7.

The control unit 7 is a control device for controlling the firing furnace 1 and the detection unit 6. In the controller 7, a program for firing the ceramic molded body 12 of the firing furnace 1 is input, and the ceramic molded body 12 is fired based on the program. The control unit 7 controls the heater 2 based on the program to control the temperature inside the furnace. on the other hand,
The control unit 7 grasps the firing status of the ceramic molded body 12 based on the image data from the detection unit 6. And
When it is determined that the length has reached the preset length, the firing (state of maintaining the temperature) is ended, and the temperature of the firing furnace 1 is lowered.

The ceramic molded body 12 is shown by a broken line. A ceramic powder material (oxide, nitrate, etc.) added with an organic solvent and made into a slurry is formed into a sheet or a tube. , Molded into a plate shape,
It is dried. That is, it is a ceramic in a state before sintering. In principle, it has a shape that requires almost no machining after sintering. In this example,
The ceramic molded body 12 is also being fired in the firing furnace 1.
Is to be expressed.

The ceramic sintered body 11 is obtained by firing the ceramic molded body 12 in the firing furnace 1 into a sintered body. It also means the ceramics after firing. In principle, little machining is done, but some dimensional adjustments are made. In the figure,
This indicates that the ceramic molded body 12 having the size shown by the broken line has contracted to the size of the ceramic molded body 11 shown by the solid line by firing in the firing furnace 1.

Next, the operation of the first embodiment of the method for manufacturing a fuel cell tube and the ceramics manufacturing apparatus according to the present invention will be described with reference to the drawings. Here, FIG.
With reference to FIG. 2 and FIG. 2, a firing process of the tubular ceramic molded body 12 in the manufacture of a ceramic tube as a fuel cell tube having a fuel cell will be described as an example.

First, an organic solvent (including additives) is mixed with a well-polished raw material of ceramic powder (such as zirconia powder) to form a uniform slurry. Next, in order to produce a tubular product or the like, the slurry is put into an extrusion molding machine and extruded to produce a tubular ceramic molded body 12. The size and shape of the ceramic molded body 12 at this point are those taking into consideration shrinkage due to subsequent firing. In addition, in principle, the shape does not need to be processed after sintering. For example, regarding the tube length, when shrinkage of 20% is expected as a whole, assuming that the length (target length) of the sintered body is 1 m, a ceramic molded body of 1 m25 cm is produced. The ceramic molded body 12 is a drying furnace,
It is dried at 50 to 200 ° C.

Subsequently, the unsintered ceramic molded body 12
Screen-printed on top of the paste fuel electrode (N
i / zirconia), and dried at 50 to 200 ° C. in a drying oven. The fuel electrode is printed on the outer periphery of the tubular ceramic molded body 12 in a striped pattern with a constant width in the longitudinal direction. Next, a paste electrolyte (zirconia) is overlaid and applied (screen printing) on it, and dried in a drying oven at 50
Dry at ~ 200 ° C. Stripes are printed in the same way as the fuel electrode. However, it should be slightly shifted in one direction. Then, a paste-like interconnector (lanthanum chromite) is overlaid and applied (screen printing) on it so that the electrolyte of a certain stripe and the fuel electrode of the adjacent stripe are connected by an interconnector film. And dried at 50-200 ° C.

The ceramic molded body 12 on which the electrodes and the like have been applied and dried is set in the firing furnace 1 as follows for firing. First, the position of the molded body mounting portion 5 is adjusted based on the target length of the ceramic molded body 12 after firing (the length of the ceramics sintered body 11, for example, 1 m). The position of the molded body mounting portion 5 is set to the ceramic molded body 12
When one end of the ceramic molded body 12 is fixed to the molded body mounting portion 5 and fired, when the ceramic molded body 12 contracts due to firing and reaches the target length, the position of the end portion is the observation window 4
It is located at the center of the observation window 4 when observed from the outside through. That is, the length from the height of the molded body mounting portion 5 to the height of the center of the observation window 4 is the target length (1 m). Regarding the position adjustment, it is possible to attach a mechanism in which the control unit 7 automatically moves the position of the molded body attachment unit 5 by inputting the target length to the control unit 7.

Next, the ceramic molded body 12 is mounted on the molded body mounting portion 5. The control unit 7 starts firing according to the control program. During firing, the state of the firing furnace 1 is photographed by the detection unit 6. The image data is output to the control unit 7. Referring to FIG. 2, the length of the ceramic molded body 12 and _L a _(1m25cm), the target length and _L M _~L N _{(99.5cm~100.5cm).}
The control unit 7 heats the firing furnace 1 with the heater 2 and raises the temperature to the holding temperature (1200 to 1700 ° C.) at an appropriate temperature rising rate (for example, 1 ° C./minute) as shown by the curve d. And
When the temperature reaches the holding temperature, hold the temperature for an appropriate time.

At this time, the ceramic molded body 12 shrinks as the temperature rises, showing a change in the length shown by the curve a. That is, at low temperature, since the sintering does not occur, the length does not change, but the sintering proceeds rapidly from a certain temperature and shrinks. Then, at the time t ₁ when the holding temperature is reached,
The degree of contraction is subsided, and a gentle contraction is occurring. Then, between the time _t a1 _{~t a2,}
Target length L _{M to} L _N (99.5 cm to 100.5 cm)
Becomes However, this time is affected by the yield of the size of the ceramic molded body 12 and the yield of the material,
It is not always constant.

In the present embodiment, the detection unit 6 takes an image of the end of the ceramic molded body 12 through the observation window 4 for the size of the ceramic molded body 12 during firing. The image data is output to the control unit 7 and analyzed.
The control unit 7 recognizes the ceramic molded body 12 and its end portion and the other portions based on the analysis result.
Then, on the basis of the information, the control unit 7 causes the end of the ceramic molded body 12 to reach the center of the observation window 4,
The holding of the firing temperature is completed, and the temperature of the firing furnace 1 is lowered (in FIG. 2, t ₂ = t _{a1 to} t _a2 ). If it does not shrink to a predetermined length even if the firing temperature is maintained for a certain period of time or more, raise the firing temperature slightly (10 to 100 ° C).
The contraction amount can be adjusted also by this. When the firing temperature begins to drop, the ceramic molded body 12 stops shrinking. Therefore, the ceramic molded body 12 has a target length from the molded body mounting portion 5 to the height of the center of the observation window 4. The temperature is lowered at an appropriate rate (for example, 2 ° C./minute).

Although the firing may take several days, the control unit 7 performs the observation of the length of the ceramic molded body 12 and the determination of the temperature decrease of the combustion furnace 1, so that no extra labor or trouble is required. Moreover, the fired ceramics sintered body 11
Is surely within the range of the target length, so that the yield is improved. Therefore, the cost can be reduced.

Next, the fired ceramics sintered body 11
A pasty air electrode is applied by screen printing onto (the fuel electrode-electrolyte-interconnector formed) and dried at 50 to 200 ° C in a drying oven. Similar to the electrolyte, printing is performed on the electrolyte in a striped pattern with a constant width in the longitudinal direction, with a slight shift in the same direction as the electrolyte. Furthermore, a paste-like protective film (insulating film) is applied between the air electrode so as to overlap the ends of both, and dried at 50 to 200 ° C. in a drying oven. Then, in the firing furnace 1 again, 1000 to 14
Bake at 00 ° C. In this case, the firing of the base body tube does not occur because the firing is performed once and the temperature is set lower than that of the first time.

By the above process, a fuel battery cell tube in which a plurality of fuel battery cells (one fuel battery cell of interconnector-fuel electrode-electrolyte-air electrode-interconnector) are assembled on the base tube is completed. FIG. 6 shows a sectional view of the fuel cell tube. Base tube made of ceramics 19
A fuel cell 13 having a fuel electrode 14, an electrolyte 15, and an air electrode 16, an interconnector 17, and a protective film 18 (all are screen-printed and fired) are formed on (extrusion molding and firing). However, in FIG. 6, only the fuel cells 13 on the upper half side of the surface of the base tube are shown.

The fuel cell cell pipe is connected to equipment for supplying fuel gas and oxidant gas, and those pipes are connected to a gas source for supplying gas. On the other hand, the components for current collection are connected to the fuel cell tube and their wirings are drawn to the outside. With the above, the fuel cell system is completed.

According to the present invention described above, the problem of the yield of the ceramics sintered body 11 that has conventionally occurred is solved, and all the fired ceramics sintered bodies 11 are made into sintered bodies of a desired size. Is possible. And the cost is reduced by improving the yield. That is, since the yield of the fuel cell tube is also improved, the cost of the fuel cell can be reduced. In addition, even if it was necessary to fabricate other parts in accordance with the fuel cell pipes of different sizes, it is now possible to use parts of the same size, reducing costs and man-hours. It is possible to reduce the number of items and shorten the delivery time.

(Embodiment 2) A second embodiment of the method for producing a fuel cell tube and the ceramic production apparatus according to the present invention will be described below with reference to the accompanying drawings.

FIG. 4 is a diagram showing the construction of the second embodiment of the method for producing a fuel cell tube and the ceramics producing apparatus of the present invention (however, the firing furnace 1 is a sectional view). The ceramics manufacturing apparatus includes a combustion furnace 1 having a heater 2, a heat insulating material 3, an observation window 4, and a molded body mounting portion 5.
The detection unit 6, the control unit 7, the laser unit 8 as an electromagnetic wave output unit, and the half mirror 9.

The laser section 8 as an electromagnetic wave output section is a laser for emitting a laser beam. The laser selects light having a wavelength such that reflected light is not affected by thermal radiation from each member due to the temperature during firing in the firing furnace 1. The emitted laser light 10 passes through the half mirror 9 and enters the firing furnace 1 from the observation window 4 at the center of the observation window 4. Then, it is reflected on the surface of the ceramic molded body 12, or passes through the vicinity of the end of the ceramic molded body 12 and reaches the wall surface on the rear side of the ceramic molded body 12 as viewed from the laser section 8 and is diffusely reflected. When reflected on the surface of the ceramic molded body 12, a part of the reflected light exits the observation window 4 and reaches the half mirror 9. Then, the light is reflected there and enters the detection unit 6 ahead.

The half mirror 9 allows the laser beam 10 output from the laser section 8 to pass through the observation window 4 as it is,
In addition, it is a half mirror that reflects the reflected light from the direction of the observation window 4 toward the detector 6.

The detection section 6 is a spectroscope for receiving the laser light 10 output from the laser section 8 through the observation window 4 and the reflected light reflected on the surface of the ceramic molded body 12. If there is reflected light (or if it has a certain intensity or more), it means that the ceramic molded body 12 inside the firing furnace 1 has not reached the preset length. The spectral result is output to the control unit 7. An optical sensor that responds to the laser light 10 may be used. If necessary, a filter for selecting a wavelength can be used to facilitate detection.

The control unit 7 is a control device for controlling the firing furnace 1 and the detection unit 6. In the controller 7, a program for firing the ceramic molded body 12 of the firing furnace 1 is input, and the ceramic molded body 12 is fired based on the program. The control unit 7 controls the heater 2 based on the program to control the temperature inside the furnace. on the other hand,
The control unit 7 grasps the firing status of the ceramic molded body 12 based on the spectral result from the detection unit 6. When it is determined that the length has reached the preset length, the firing (state of maintaining the temperature) is ended, and the temperature of the firing furnace 1 is lowered.

The firing furnace 1, the heater 2, the heat insulating material 3, the molded body mounting portion 5, the ceramics sintered body 11, and the ceramics molded body 12 are the same as those in the first embodiment, and therefore their explanations are omitted.

Next, the operation of the second embodiment of the method for manufacturing a fuel cell tube and the ceramics manufacturing apparatus according to the present invention will be described with reference to the drawings. Here, FIG.
Also, referring to FIG. 2 and FIG. 2, description will be made by taking as an example a firing process of the tubular ceramic molded body 12 in the production of a ceramic tube as a fuel cell tube having the fuel cell 13.

First, an organic solvent is added to raw materials (oxides, nitrates, etc.) of well-polished ceramic powder to form a uniform slurry. Next, in order to produce a tubular product or the like, the slurry is put into an extrusion molding machine,
A tubular ceramic molded body 12 is produced by extrusion. The size and shape of the ceramic molded body 12 at this point are those taking into consideration shrinkage due to subsequent firing. In addition, in principle, the shape does not need to be processed after sintering. For example, with regard to the tube length, when shrinkage of 20% is expected as a whole, if the length of the sintered body (target length) is 1 m, then 1
A ceramic molded body of m25 cm is prepared. The ceramic molded body 12 is dried at 50 to 200 ° C. in a drying furnace.

Subsequently, the unsintered ceramic compact 12
Screen-printed on top of the paste fuel electrode (N
i / zirconia), and dried at 50 to 200 ° C. in a drying oven. The fuel electrode is printed on the outer periphery of the tubular ceramic molded body 12 in a striped pattern with a constant width in the longitudinal direction. Next, a paste electrolyte (zirconia) is overlaid and applied (screen printing) on it, and dried in a drying oven at 50
Dry at ~ 200 ° C. Stripes are printed in the same way as the fuel electrode. However, it should be slightly shifted in one direction. Then, a paste-like interconnector (lanthanum chromite) is overlaid and applied (screen printing) on it so that the electrolyte of a certain stripe and the fuel electrode of the adjacent stripe are connected by an interconnector film. And dried at 50-200 ° C.

The ceramic molded body 12 on which the electrodes and the like have been applied and dried is set in the firing furnace 1 as follows for firing. First, the position of the molded body mounting portion 5 is adjusted based on the target length of the ceramic molded body 12 after firing (the length of the ceramics sintered body 11, for example, 1 m). The position of the molded body mounting portion 5 is set to the ceramic molded body 12
When one end of the ceramic molded body 12 is fixed to the molded body mounting portion 5 and fired, when the ceramic molded body 12 contracts due to firing and reaches the target length, the position of the end portion is the observation window 4
It is located at the center of the observation window 4 when observed from the outside through. That is, the length from the height of the molded body mounting portion 5 to the height of the center of the observation window 4 is the target length. The position is adjusted by inputting the target length into the control unit 7.
It is also possible to attach a mechanism that is performed by the control unit 7 automatically moving the position of the molded body attachment unit 5.

Next, the ceramic molded body 12 is attached to the molded body mounting portion 5. The control unit 7 starts firing according to the control program. During firing, the detection unit 6 detects the condition inside the firing furnace 1 based on the reflected light of the laser beam 10 emitted from the laser unit 8. The spectral result is output to the control unit 7. Referring to FIG. 2, the length of the ceramic molded body 12 and _L a _(1m25cm), the target length _L M _~L N _{(99.5cm~100.5cm)}
And The control unit 7 heats the firing furnace 1 with the heater 2,
An appropriate heating rate (for example, 1 ° C / min) as shown by the curve d
Then, the temperature is raised to the holding temperature (1200 to 1700 ° C.).
Then, when the holding temperature is reached, the temperature is held for an appropriate time.

At this time, the ceramic molded body 12 shrinks as the temperature rises, showing a change in the length shown by the curve a. That is, at low temperature, since the sintering does not occur, the length does not change, but the sintering proceeds rapidly from a certain temperature and shrinks. Then, at the time t ₁ when the holding temperature is reached,
The degree of contraction is subsided, and a gentle contraction is occurring. Then, between the time _t a1 _{~t a2,}
Target length L _{M to} L _N (99.5 cm to 100.5 cm)
Becomes However, this time is affected by the yield of the size of the ceramic molded body 12 and the yield of the material,
It is not always constant.

In the present embodiment, the laser section 8 emits the laser beam 10 according to the size of the ceramic molded body 12 during firing, and the reflected light is constantly observed at the detection section 6. The laser light 10 is output so as to irradiate the center position of the observation window 4, that is, the target length position on the ceramic molded body 12. However, laser light 1
Instead of constantly outputting 0, the laser light 10 is output from time t _{1 at which} the holding of the firing temperature in FIG. 2 starts, for example. This makes unnecessary laser light 1
The output of 0 can be suppressed. Further, since the contraction speed near the target length can be predicted, the firing interval of the laser light 10 is widened accordingly. That is, the permissible error at the target length is 1 cm, and the contraction speed near that length is 1 cm.
In cm / hour, an output of about once every 30 minutes is sufficient. Thereby, the unnecessary output of the laser beam 10 can be suppressed.

The reflected light of the laser light 10 is reflected by the half mirror 9 and measured by the spectroscope which is the detector 6. Then, the spectral result is output to the control unit 7 and analyzed. Based on the analysis result, the control unit 7 determines whether the reflected light is from the ceramic molded body 12 or from other portions. Then, the control unit 7
Based on the information, the reflected light reflects the ceramic molded body 12
At the first time when it is determined that the temperature is other than the above, the holding of the firing temperature is terminated, and the temperature of the firing furnace 1 is lowered (in FIG. 2, t ₂ = t _{a1 to} ta _a2 ). If it does not shrink to a specified length even if the firing temperature is maintained for a certain period of time,
The shrinkage amount can be adjusted by slightly increasing the firing temperature (10 to 100 ° C.). When the firing temperature begins to drop, the ceramic molded body 12 stops shrinking. Therefore, the ceramic molded body 12 has a target length from the molded body mounting portion 5 to the height of the center of the observation window 4. The temperature is lowered at an appropriate rate (for example, 2 ° C./minute).

The firing may take several days, but the control unit 7 observes the length of the ceramic molded body 12 and determines the temperature decrease of the firing furnace 1. Therefore, no extra labor or trouble is required. Moreover, the fired ceramics sintered body 11
Is surely within the range of the target length, so that the yield is improved. Therefore, the cost can be reduced.

Next, the fired ceramics sintered body 11
A pasty air electrode is applied by screen printing onto (the fuel electrode-electrolyte-interconnector formed) and dried at 200 ° C in a drying oven 50-. Similar to the electrolyte, printing is performed on the electrolyte in a striped pattern with a constant width in the longitudinal direction, with a slight shift in the same direction as the electrolyte. Furthermore, a paste-like protective film (insulating film) is applied between the air electrode so as to overlap the ends of both, and dried at 50 to 200 ° C. in a drying oven. Then, in the firing furnace 1 again, 1000 to 14
Bake at 00 ° C. In this case, the firing of the base body tube does not occur because the firing is performed once and the temperature is set lower than that of the first time.

By the above process, a fuel battery cell tube in which a plurality of fuel battery cells (one fuel battery cell of interconnector-fuel electrode-electrolyte-air electrode-interconnector) are assembled on the base tube is completed. FIG. 6 shows a sectional view of the fuel cell tube. Base tube made of ceramics 19
A fuel cell 13 having a fuel electrode 14, an electrolyte 15, and an air electrode 16, an interconnector 17, and a protective film 18 (all are screen-printed and fired) are formed on (extrusion molding and firing). However, in FIG. 6, only the fuel cells 13 on the upper half side of the surface of the base tube are shown.

The fuel cell cell pipe is connected to a device for supplying fuel gas and oxidant gas, and those pipes are connected to a gas source for supplying gas. On the other hand, the components for current collection are connected to the fuel cell tube and their wirings are drawn to the outside. With the above, the fuel cell system is completed.

According to the present invention described above, the problem of the yield of the ceramics sintered body 11 that has been conventionally generated is solved, and all the fired ceramics sintered bodies 11 are made into sintered bodies of a desired size. Is possible. And the cost is reduced by improving the yield. That is, since the yield of the fuel cell tube is also improved, the cost of the fuel cell can be reduced. In addition, even if it was necessary to fabricate other parts in accordance with the fuel cell pipes of different sizes, it is now possible to use parts of the same size, reducing costs and man-hours. It is possible to reduce the number of items and shorten the delivery time.

Instead of utilizing the reflected light of the laser light 10, it is also possible to use transmitted light as shown in FIG. That is, from the second observation window 20 to the laser section 8
Laser beam 10 is emitted to the ceramic molded body 12 by means of the laser beam 10 that has passed through the firing furnace 1 without being blocked by the ceramic molded body 12, and is detected by the detection unit 6 via the observation window 4 as the first observation window. Receive light. In this case, the determination as to whether or not the target length is reached is made at the time when the laser light 10 from the laser unit 8 is first detected by the detection unit 6.

Further, the laser section 8 of the present embodiment does not necessarily have to be a laser, but may be an electromagnetic wave having a wavelength that cannot pass through the ceramic molded body. The detecting unit 8 may be a sensor or a spectroscope that can detect the electromagnetic wave correspondingly.

(Embodiment 3) The construction of a third embodiment of the method for producing a fuel cell tube and the ceramics producing apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a view showing the structure of a first embodiment of a method for manufacturing a fuel cell tube and a ceramics manufacturing apparatus according to the present invention (however, the firing furnace 1 is a sectional view). The ceramics manufacturing apparatus includes a combustion furnace 1 having a heater 2, a heat insulating material 3, an observation window 4, and a molded body mounting portion 5.
And a detection unit 6 and a control unit 7.

The firing furnace 1, the heater 2, the heat insulating material 3, the observation window 4, the molded body mounting portion 5, the detection portion 6, the control portion 7, the ceramic sintered body 11, and the ceramic molded body 12 are the same as in the first embodiment. Therefore, the description thereof will be omitted.

Next, the operation of the third embodiment of the method for manufacturing a fuel cell tube and the ceramics manufacturing apparatus according to the present invention will be described with reference to the drawings. Here, FIG.
Also, referring to FIG. 2 and FIG. 2, description will be made by taking as an example a firing process of the tubular ceramic molded body 12 in the production of a ceramic tube as a fuel cell tube having the fuel cell 13.

First, an organic solvent is added to a well-ground ceramic powder raw material (oxide, nitrate, etc.) to form a uniform slurry. Next, in order to produce a tubular product or the like, the slurry is put into an extrusion molding machine,
A tubular ceramic molded body 12 is produced by extrusion. The size and shape of the ceramic molded body 12 at this point are those taking into consideration shrinkage due to subsequent firing. In addition, in principle, the shape does not need to be processed after sintering. For example, with regard to the tube length, when shrinkage of 20% is expected as a whole, if the length of the sintered body (target length) is 1 m, then 1
A ceramic molded body of m25 cm is prepared. The ceramic molded body 12 is dried at 50 to 200 ° C. in a drying furnace.

Subsequently, the unsintered ceramic compact 12
Screen-printed on top of the paste fuel electrode (N
i / zirconia), and dried at 50 to 200 ° C. in a drying oven. The fuel electrode is printed on the outer periphery of the tubular ceramic molded body 12 in a striped pattern with a constant width in the longitudinal direction. Next, a paste electrolyte (zirconia) is overlaid and applied (screen printing) on it, and dried in a drying oven at 50
Dry at ~ 200 ° C. Stripes are printed in the same way as the fuel electrode. However, it should be slightly shifted in one direction. Then, a paste-like interconnector (lanthanum chromite) is overlaid and applied (screen printing) on it so that the electrolyte of a certain stripe and the fuel electrode of the adjacent stripe are connected by an interconnector film. And dried at 50-200 ° C. further,
A paste-like air electrode is overlaid and applied (screen printing) so as to connect the striped fuel electrode and the interconnector film, and dried at 50 to 200 ° C. in a drying oven.

The ceramic molded body 12 on which the electrodes and the like have been applied and dried is set in the firing furnace 1 as follows for firing. First, the position of the molded body mounting portion 5 is adjusted based on the target length of the ceramic molded body 12 after firing (the length of the ceramics sintered body 11, for example, 1 m). The position of the molded body mounting portion 5 is set to the ceramic molded body 12
When one end of the ceramic molded body 12 is fixed to the molded body mounting portion 5 and fired, when the ceramic molded body 12 contracts due to firing and reaches the target length, the position of the end portion is the observation window 4
It is located at the center of the observation window 4 when observed from the outside through. That is, the length from the height of the molded body mounting portion 5 to the height of the center of the observation window 4 is the target length. The position is adjusted by inputting the target length into the control unit 7.
It is also possible to attach a mechanism that is performed by the control unit 7 automatically moving the position of the molded body attachment unit 5.

Next, the ceramic molded body 12 is attached to the molded body mounting portion 5. The control unit 7 starts firing according to the control program. During firing, the state of the firing furnace 1 is photographed by the detection unit 6. The image data is output to the control unit 7. Referring to FIG. 2, the length of the ceramic molded body 12 and _L a _(1m25cm), the target length and _L M _~L N _{(99.5cm~100.5cm).}
The control unit 7 heats the firing furnace 1 with the heater 2 and raises the temperature to the holding temperature (1200 to 1700 ° C.) at an appropriate temperature rising rate (for example, 1 ° C./minute) as shown by the curve d. And
When the temperature reaches the holding temperature, hold the temperature for an appropriate time.

At this time, the ceramic molded body 12 shrinks as the temperature rises, showing a change in length shown by the curve a. That is, at low temperature, since the sintering does not occur, the length does not change, but the sintering proceeds rapidly from a certain temperature and shrinks. Then, at the time t ₁ when the holding temperature is reached,
The degree of contraction is subsided, and a gentle contraction is occurring. Then, between the time _t a1 _{~t a2,}
Target length L _{M to} L _N (99.5 cm to 100.5 cm)
Becomes However, this time is affected by the yield of the size of the ceramic molded body 12 and the yield of the material,
It is not always constant.

In the present embodiment, the detection unit 6 photographs the end portion of the ceramic molded body 12 through the observation window 4 for the size of the ceramic molded body 12 during firing. The image data is output to the control unit 7 and analyzed.
The control unit 7 recognizes the ceramic molded body 12 and its end portion and the other portions based on the analysis result.
Then, on the basis of the information, the control unit 7 causes the end of the ceramic molded body 12 to reach the center of the observation window 4,
The holding of the firing temperature is completed, and the temperature of the firing furnace 1 is lowered (in FIG. 2, t ₂ = t _{a1 to} t _a2 ). If it does not shrink to a predetermined length even if the firing temperature is maintained for a certain period of time or more, raise the firing temperature slightly (10 to 100 ° C).
The contraction amount can be adjusted also by this. When the firing temperature begins to drop, the ceramic molded body 12 stops shrinking. Therefore, the ceramic molded body 12 has a target length from the molded body mounting portion 5 to the height of the center of the observation window 4. The temperature is lowered at an appropriate rate (for example, 2 ° C./minute).

The firing may take several days, but the control unit 7 performs the observation of the length of the ceramic molded body 12 and the determination of the temperature decrease of the combustion furnace 1, so that no extra labor or trouble is generated. Moreover, the fired ceramics sintered body 11
Is surely within the range of the target length, so that the yield is improved. Therefore, the cost can be reduced.

By the above process, a fuel battery cell tube in which a plurality of fuel battery cells (one fuel battery cell of interconnector-fuel electrode-electrolyte-air electrode-interconnector) are assembled on the base tube is completed. FIG. 6 shows a sectional view of the fuel cell tube. Base tube made of ceramics 19
A fuel cell 13 having a fuel electrode 14, an electrolyte 15, and an air electrode 16, an interconnector 17, and a protective film 18 (all are screen-printed and fired) are formed on (extrusion molding and firing). However, in FIG. 6, only the fuel cells 13 on the upper half side of the surface of the base tube are shown.

The fuel cell tube is connected to a device for supplying the fuel gas and the oxidant gas, and those pipes are connected to a gas source for supplying the gas. On the other hand, the components for current collection are connected to the fuel cell tube and their wirings are drawn to the outside. With the above, the fuel cell system is completed.

According to the present invention described above, the problem of the yield of the ceramics sintered body 11 that has been conventionally generated is solved, and all the sintered ceramics sintered bodies 11 are made into sintered bodies of a desired size. Is possible. And the cost is reduced by improving the yield. That is, since the yield of the fuel cell tube is also improved, the cost of the fuel cell can be reduced. Moreover, since the air electrode is also integrally fired, the number of manufacturing steps is reduced, so that the cost is reduced.
In addition, even if it was necessary to fabricate other parts in accordance with the fuel cell pipes of different sizes, it is now possible to use parts of the same size, reducing costs and man-hours. It is possible to reduce the number of items and shorten the delivery time.

The base tube / fuel electrode / electrolyte of this embodiment /
The manufacturing method of integrally firing the interconnector / air electrode is
It is also applicable to the manufacturing equipment of the second embodiment.

In Examples 1, 2 and 3, the observation window 4 is used to observe the ceramic molded body 12 at one point in the firing furnace 1, but FIG. As shown in the figure), if the observation window 4 is formed in a slit shape on the side surface of the firing furnace 1 so that the inside can be observed in a wide range, the length can be controlled in a wide range. . Further, in the case of FIG. 5, slit-shaped observation windows 4 may be provided on both sides of the firing furnace 1.

Further, in the first, second and third embodiments, the tube-shaped ceramic molded body 12 has been described, but the present invention can be carried out in a sheet shape or a plate shape. For example, in the case of a sheet or plate whose one end is difficult to fix, a horizontal firing furnace 1 having a slit-like observation window 4 as shown in FIG. (2 is a vertical firing furnace), by detecting the both ends of one side of the ceramic molded body 12 by the two detection units 6,
One side length detection can be performed. In this case, the size can be controlled with a square plate or sheet. In the case of a rectangle, the observation windows 4 may be provided on two side surfaces.

[0090]

According to the present invention, the dimensions of the ceramic member can be freely controlled, and the yield in manufacturing the ceramic member can be improved.

According to the present invention, the manufacturing cost of the ceramic member can be reduced, and at the same time, the manufacturing cost of the fuel cell can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of a method for manufacturing a fuel cell tube and a ceramics manufacturing apparatus according to the present invention.

FIG. 2 is a diagram showing the relationship among the length of a ceramics compact, the firing time, and the firing temperature profile.

FIG. 3 is a schematic diagram showing another configuration of the first and second embodiments of the method for manufacturing a fuel cell tube and the ceramics manufacturing apparatus according to the present invention.

FIG. 4 is a diagram showing a configuration of a second embodiment of a method for producing a fuel cell tube and a ceramics producing apparatus according to the present invention.

FIG. 5 is a diagram showing another configuration of the second embodiment of the method for producing a fuel cell tube and the ceramics producing apparatus of the present invention.

FIG. 6 is a view showing a cross section of a fuel cell tube. 1 fuel furnace 2 heater 3 insulation 4 Observation window 5 Molded body mounting 6 detector 7 control unit 8 laser section 9 Half mirror 10 laser light 11 Ceramics sintered body 12 Ceramics molded body 13 Fuel cells 14 Fuel pole 15 Electrolyte 16 air pole 17 Interconnector 18 Protective film 19 Base tube 20 Second observation window

Continued front page    (72) Inventor Nagao Kurume             1-1 Satinoura Town, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries             Nagasaki Shipyard Co., Ltd. (72) Inventor Katsumi Nagata             1-1 Satinoura Town, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries             Nagasaki Shipyard Co., Ltd. (72) Inventor Koji Ikeda             1-1 Satinoura Town, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries             Nagasaki Shipyard Co., Ltd. (72) Inventor Junichi Kamae             1-1 Satinoura Town, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries             Nagasaki Shipyard Co., Ltd. F-term (reference) 5H018 AA06 BB01 BB06 BB08 BB12                       CC03 DD08 EE02 EE11 EE12                       EE13                 5H026 AA06 BB01 CV02 CX06 EE11

Claims (9)

[Claims] 1. A step of forming a base tube from a slurry containing a raw material and an organic solvent; a step of forming each element of a fuel electrode, an electrolyte and an interconnector in the base tube; and observing the amount of shrinkage due to firing. However, a step of firing the base tube on which each of the elements is formed, a step of forming an air electrode on the fired base tube, and a step of firing the base tube on which the air electrode is formed A method of manufacturing a fuel cell tube, comprising: 2. A step of forming a base tube from a slurry containing a raw material and an organic solvent; a step of forming each element of a fuel electrode, an electrolyte, an interconnector, and an air electrode in the base tube; A method of manufacturing a fuel cell tube, comprising the steps of calcination of the base tube on which each element is formed while observing the amount. 3. The step of firing the base tube on which each of the elements is formed includes the step of setting the base tube in a firing furnace having an observation window for observing the inside, and through the observation window, The manufacturing of the fuel cell tube according to claim 1 or 2, further comprising: a step of detecting a position of an end portion of the base tube during firing, and a step of controlling a firing furnace based on the detection result. Method. 4. The step of firing the substrate tube on which each of the elements is formed includes the step of setting the substrate tube in a firing furnace having an observation window for observing the inside, and through the observation window, Emitting a laser beam toward the base tube, receiving reflected light of the laser beam through the observation window, and controlling the firing furnace based on the light reception result. The method for manufacturing a fuel cell tube according to claim 1, comprising: 5. The step of firing the substrate tube on which each of the elements is formed includes setting the substrate tube in a firing furnace having a first observation window and a second observation window through which the inside can be observed. A step of emitting a laser beam toward the base tube through the second observation window; a step of receiving the laser beam through the first observation window; The method for manufacturing a fuel cell tube according to claim 1, further comprising: controlling the firing furnace. 6. A firing furnace having an observation window for observing the inside, and a firing unit for firing ceramics, and a detection unit for detecting the position of an end of the ceramics through the observation window and outputting the detection result. And a control unit that controls the firing furnace based on the detection result. 7. A firing furnace having an observation window for observing the interior, for firing ceramics, an electromagnetic wave output section for emitting an electromagnetic wave toward the ceramics through the observation window, and the observation window. A ceramic manufacturing apparatus comprising: a detection unit that receives the reflected wave of the electromagnetic wave and outputs the reception result; and a control unit that controls the firing furnace based on the reception result. 8. A first observation window for firing ceramics to observe the inside, and the first observation window sandwiching the ceramics.
A firing furnace having a second observation window that is symmetrical to the observation window, an electromagnetic wave output unit that emits electromagnetic waves toward the ceramics through the second observation window, and the electromagnetic waves are shielded by the ceramics. Without the first
A ceramics manufacturing apparatus comprising: a detection unit that receives a passing electromagnetic wave that has reached an observation window and outputs the reception result; and a control unit that controls the firing furnace based on the reception result. 9. The electromagnetic wave is laser light, The ceramic manufacturing apparatus according to claim 7.