JPH10274486A - Burning apparatus for ceramic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel burning apparatus having a kiln for housing and burning ceramics to be burned, strictly controlling characteristics and fine structure of ceramics to be burned, and suitable for imparting specific characteristics and fine structure to the ceramics. SOLUTION: This burning apparatus is provided with an atmosphere supply source 8 for supplying a predetermined atmosphere to a kiln 10, a gas analyzer 13 for analyzing an exhaust gas discharged from the kiln 10 to obtain predetermined information, and a control mechanism for performing feedback control of the operational condition of the kiln 10 on the basis of information thus obtained. For example, feedback control such as a temperature in the kiln, the composition of an atmosphere and a flow rate is performed on the basis of the aforementioned information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to various ceramics,
For example, the present invention relates to an apparatus and a method for firing functional ceramics in which the oxygen content affects properties.

[0002]

2. Description of the Related Art At present, as a firing furnace for firing various ceramics, a hydrogen furnace, a nitrogen furnace, an argon furnace, an ammonia / nitrogen furnace, and a hydrogen / steam furnace are known. For example, "Heat measurement" 17 (1) 1990, pp. 41-5
On page 4, one of the superconductors, YBa ₂ Cu ₃
For O _7-x and Mn—Zn ferrite, an oxygen sensor is used to measure the oxygen partial pressure in the atmosphere.
Further, as a method of controlling the oxygen partial pressure in the atmosphere under normal pressure, a so-called simple gas mixing method and a buffer gas mixing method are described.

In the simple gas mixing method, 10 ² to 10
Pure oxygen and an inert gas such as argon or helium are mechanically mixed under a relatively high atmospheric pressure of ⁵ Pa.
It also describes that a stabilized zirconia oxygen pump is used to remove oxygen from an inert gas or to add oxygen to an inert gas.
In the buffer gas mixing _{method, CO-CO 2, H 2} -H 2
A constant oxygen partial pressure is obtained by utilizing the gas equilibrium of a buffered gas mixture such as O, H ₂ -CO _{2 at} a high temperature. At this time, an attempt has been made to control the oxygen partial pressure at an extremely low pressure by supplying oxygen to the purified hydrogen gas using a stabilized zirconia oxygen pump. In particular, when using an atmosphere in which an argon gas and an oxygen gas are mixed, an oxygen sensor and an oxygen pump are provided in a single tubular body made of stabilized zirconia, and a mixed gas of argon and oxygen is provided in the tubular body. The atmosphere is flowing. Then, the driving voltage of the oxygen pump corresponding to the target oxygen partial pressure is set, the electromotive force in the oxygen sensor is measured, and the electric feedback is performed so that the difference between the driving voltage value and the electromotive force becomes zero. Trying to act on the oxygen pump.

[0004]

However, the present inventor has
When applying the above technology to an actual atmosphere furnace, even if the oxygen partial pressure in the atmosphere furnace is kept constant,
In some cases, the characteristics of a fired body, particularly a ceramic fired body made of a functional composite oxide, cannot be strictly controlled. In particular, recently, the particle size, porosity,
Research has been advanced to precisely control various microstructures such as pore diameter, grain shape, and thickness of the neck between particles. It is considered to be.

An object of the present invention is to provide a sintering apparatus provided with a sintering furnace for accommodating and sintering an object to be sintered of ceramics, wherein the characteristics and microstructure of the sintered body are strictly controlled. It is an object of the present invention to provide a new sintering apparatus suitable for imparting specific characteristics and microstructures to sintering.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a firing apparatus provided with a firing furnace for housing and firing a ceramic body to be fired, for supplying a predetermined atmosphere to the firing furnace. An atmosphere supply source, a gas analyzer for analyzing exhaust gas from the firing furnace to obtain predetermined information, and a control mechanism for performing feedback control of operating conditions of the firing furnace based on the information. The present invention relates to an apparatus for firing ceramics.

The inventor of the present invention has conducted firing experiments while keeping the composition of the atmosphere on the inlet side of the atmosphere firing furnace, for example, the oxygen partial pressure constant, but strictly controls the characteristics and microstructure of the fired body. It was difficult. In the course of examining the reason, attention was paid to the fact that oxygen and other components diffuse into the atmosphere from the fired body, or that components such as oxygen in the atmosphere are taken into the fired body from the atmosphere. Due to the interaction between the fired body and the atmosphere in the firing furnace, such as divergence and incorporation of components, the atmosphere in the firing furnace is not strictly controlled. As a result, it has been found that the characteristics and microstructure of the fired body cannot be strictly controlled.

[0008] For example, the oxygen partial pressure in the atmosphere in the firing furnace 10 ^{- 6} atm or less, more 10 ^{- 1 8} atm very held to a low pressure such as below, thereby exactly the composition and microstructure in the sintered body When the control is attempted, even if the oxygen partial pressure in the atmosphere supplied to the firing furnace is kept strictly constant, the oxygen partial pressure in the atmosphere in the firing furnace is affected by the oxygen radiating from the fired body. As a result, the intended control becomes impossible.

In the process of degreasing a ceramic powder compact, a change in the amount of hydrocarbons, moisture, carbon monoxide, carbon dioxide, and other gases generated from the compact results in
The oxygen concentration cannot be kept constant, and the behavior of the molded body during degreasing may fluctuate. In addition, the hydrocarbons and moisture may remain in the firing furnace and affect the atmosphere in the firing furnace during firing.

For this reason, the present inventor has conceived of analyzing exhaust gas on the outlet side or downstream side of the atmosphere firing furnace and performing feedback control of the operating conditions of the firing furnace based on the analysis information. This makes it possible to strictly control the characteristics of a fired body, particularly a fired ceramic body made of a functional composite oxide. In addition, for the first time, a firing device suitable for precisely controlling various microstructures such as the particle size, porosity, pore size, particle shape, pore shape, and neck thickness between particles of a ceramic fired body has been developed. Can be provided. In addition, by utilizing the firing apparatus of the present invention, various types such as particle diameter, porosity, pore diameter, particle shape, pore shape, and neck thickness between particles, which could not be produced conventionally, were used. It seems that a fired body having a unique microstructure can be produced.

Examples of the ceramic body to be fired include a ceramic raw material powder, a molded body of the ceramic raw material powder,
There are a degreased body of this molded body and a calcined body of this molded body.

A firing furnace for housing and firing a ceramic body to be fired is preferably a firing furnace provided with a furnace core tube which is kept airtight to the outside, and an electric furnace is particularly preferable.

Examples of the gas to be analyzed by the gas analyzer include oxygen, nitrogen, argon, hydrocarbon, carbon monoxide, carbon dioxide, nitrogen monoxide, nitrogen dioxide, and water vapor. For these individual gases, measuring devices are respectively known. Among them, as the oxygen partial pressure measuring device, a solid electrolyte oxygen sensor or an oxide semiconductor oxygen sensor can be used, but a zirconia oxygen sensor is particularly preferable. Further, as a general gas concentration measuring device, a gas chromatography or a mass analyzer can be used.

The ceramics to be fired are not particularly limited, but oxygen-containing functional ceramics whose oxygen content affects the properties are particularly preferred. Also, stabilized zirconia such as alumina, magnesia, mullite, silica, spinel, titania, zirconia, yttria-stabilized zirconia, and partially stabilized zirconia such as yttria partially stabilized zirconia are preferred. Further, a perovskite-type composite oxide is particularly preferable, and among them, a lanthanum-containing perovskite-type composite oxide is preferable, and lanthanum manganite, lanthanum cobaltite, and lanthanum chromite are particularly preferable. The perovskite-type composite oxide containing lanthanum may be doped with an alkaline earth metal or a rare earth metal, for example, magnesium, strontium, calcium, chromium, cobalt, iron, nickel, aluminum, or the like. Furthermore, nitrides such as silicon nitride and aluminum nitride, and carbides such as silicon carbide and boron carbide can also be exemplified.

In the control mechanism, the temperature of the firing furnace can be feedback-controlled based on information from the gas analyzer. Further, the composition and flow rate of the atmosphere can be feedback controlled.

In one embodiment of the present invention, an oxygen partial pressure measuring device is used as a gas analyzer, the oxygen partial pressure in the exhaust gas discharged from the firing furnace is measured, and an oxygen pump is provided upstream of the firing furnace. The driving of the oxygen pump can be feedback-controlled based on the measured value of the oxygen partial pressure in the exhaust gas. This makes it possible to compensate for a change in the oxygen partial pressure of the firing furnace atmosphere due to the transfer of oxygen between the fired body and the atmosphere.

In another embodiment of the present invention, moisture can be added to a hydrogen-containing gas containing hydrogen at a predetermined partial pressure, and then this hydrogen-containing gas can be supplied to a firing furnace. In this case, the oxygen partial pressure in the exhaust gas discharged from the firing furnace is measured by the oxygen partial pressure measuring device, and the driving of the water adding device can be feedback-controlled based on the measured value of the oxygen partial pressure. This makes it possible to compensate for a change in the oxygen partial pressure of the firing furnace atmosphere due to the transfer of oxygen between the fired body and the atmosphere.

[0018] In still another embodiment of the present invention,
An upstream gas analyzer for analyzing the atmosphere to obtain predetermined information is provided, and information on the atmosphere and information on the exhaust gas are compared in the control device. This makes it possible to know the presence or absence of the interaction between the atmosphere and the molded body or the fired body and the degree of the interaction with the specific information.

Hereinafter, an embodiment of an apparatus and method for firing ceramics according to the present invention will be described with reference to the accompanying drawings. FIGS. 1 and 2 are schematic diagrams each showing a firing apparatus according to an embodiment of the present invention, and FIG. 3 is a graph illustrating a range of an oxygen partial pressure which can be controlled by each atmosphere supplied into a firing furnace. It is.

1 and 2, the firing furnace 1
Atmosphere supply device 8 is installed on the upstream side of zero. An inert gas supply source 1 for supplying an inert gas at normal temperature, an oxygen-containing gas supply source 2 for supplying an oxygen-containing gas having a predetermined oxygen partial pressure, and a predetermined A hydrogen-containing gas supply source 3 for supplying a hydrogen-containing gas having a partial pressure of hydrogen is provided.

As the inert gas which is inert at room temperature, a rare gas such as argon or helium or a nitrogen gas is preferable. As the oxygen-containing gas having a predetermined oxygen partial pressure, pure oxygen, air, or a mixed gas of nitrogen or a rare gas and oxygen,
A mixed gas having a predetermined oxygen partial pressure is preferred. As the hydrogen-containing gas, pure hydrogen, a mixed gas of nitrogen or a rare gas and hydrogen, and a mixed gas having a predetermined hydrogen partial pressure are preferable. A supply source of each of these gases is preferably a cylinder or a compressor.

Each supply source 1, 2, 3 is connected to each supply path 15A, 15B, 15C, respectively. Each supply path 1
The valves 5A, 15B, and 15C are provided with valves 6A, 6B, and 6C, respectively, for selecting between gas flow and cutoff.

Each of the supply paths 15A, 15B, and 15C is integrated into one supply path 15D on the downstream side.
D is provided with an oxygen pump 7. In addition, 4 is a gas purifier and 5 is a water addition device.

In the firing furnace 10, a furnace tube 12 is fixed inside a heater 11. The downstream end of the supply path 15 </ b> D is connected to a supply port (not shown) of the furnace tube 12, and an outlet (not shown) of the furnace tube 12 is connected to a discharge path 16.

The use of such a sintering apparatus makes it possible for the first time to control the atmosphere in a sintering furnace as follows.

That is, (i) an inert gas from the inert gas supply source 1 and an oxygen-containing gas from the oxygen-containing gas supply source 2 are mixed to obtain a mixed gas. 10 continuously. Thus, in the case of normal pressure furnace 1 to 10 ^{- 6} oxygen partial pressure can be freely controlled within the range of atm. In a firing furnace, the temperature is usually between room temperature and 2
The temperature is controlled in the temperature range of 000 ° C., particularly room temperature to 1700 ° C., and the object to be fired is dried, degreased, and fired.

The lower limit that can be precisely controlled by this method is 10
^The reason why the pressure is −6 atm is that the lower limit of the oxygen partial pressure in the mixed gas that can be produced with high accuracy is usually about 1 ppm. Further, the upper limit is 1 atm in a normal pressure firing furnace, but a higher oxygen partial pressure can be applied in a pressure furnace.

The control of the oxygen partial pressure by the mixed gas corresponds to the region E in FIG. Thus, it can be used in the entire temperature range from room temperature to the maximum temperature during firing.

As shown in FIG. 3, in order to precisely control the oxygen partial pressure in the region F having a lower oxygen partial pressure than the region E, it is necessary to (ii) reduce the oxygen partial pressure in the inert gas by The atmosphere obtained by changing with the pump is supplied into the firing furnace.

Specifically, the valves 6B and 6C are closed, and the valve 6B is closed.
A is opened, and the inert gas is supplied from the inert gas supply source 1 to the supply path 15D through the supply path 15A. At this time, preferably, a trace amount of impurities, particularly oxygen and water, present in the inert gas are removed by passing the inert gas through the gas purifier 4.

As the gas purifier 4, a platinum catalyst or a copper catalyst is used, and a device that adsorbs oxygen to these catalysts, a nickel catalyst or a titanium catalyst is used, and oxygen is removed by an oxidation reaction of these catalysts. There are types of devices that do this.

The purified inert gas is supplied to an oxygen pump 7
And a certain amount of oxygen is added to the inert gas by the oxygen pump 7 or a certain amount of oxygen is removed.

In the case of a zirconia oxygen pump, the cell 1
A current is applied by applying a DC voltage of 0 to 2 volts per unit, and oxygen can be injected or removed in an amount proportional to the current value. In particular, by removing a trace amount of oxygen that could not be completely removed by the gas purifier 4 with an oxygen pump,
0 ^{- 1} to ⁸ atm as low pressure, can control the oxygen partial pressure.

[0034] By this method, as shown in area F in FIG. 3, 10 ^{- 1 8} atm~10 ^- it is preferable to control the oxygen partial pressure at ² atm range. This method can be applied to the entire temperature range. 10 the oxygen partial pressure in the atmosphere by this method ^- to the ² atm or more, it is necessary a large current, and because it is necessary to number of cells is also very often not practical. Further, 10 ^- controlling the oxygen partial pressure is ^{1 8} within the pressure below atm, it is difficult when viewed from the ability of such zirconia oxygen pump.

(Iii) For example, the area G shown in FIG.
As described above, in a high-temperature region of 900 ° C. or more, an atmosphere obtained by adding a predetermined amount of moisture to a hydrogen-containing gas can be supplied to the firing furnace in order to precisely control the oxygen partial pressure in the firing furnace. . Thus, 10 ^{- 1 9-10 - 2} within the range of atm, it can be precisely controlled partial pressure of oxygen in the atmosphere in the firing furnace.

More specifically, hydrogen or a mixed gas of hydrogen and a rare gas or nitrogen is supplied from the hydrogen-containing gas supply source 3 to the supply path 15C, passes through the humidifier 5, and is supplied by opening the valve 6C. Flow to Road 15D. In the humidifier 5, the hydrogen-containing gas is preferably bubbled into water whose temperature is controlled to a constant value to saturate the water. Next, the hydrogen-containing gas is continuously supplied to the furnace tube 12, and the object to be fired is degreased and fired in the range of room temperature to 1700 ° C, for example.

In this method, chemical equilibrium is used, and water is used.
Oxygen partial pressure is determined by element concentration, humidification water temperature, and core tube temperature.
Is determined. For example, pass 0.01% hydrogen through water at 50 ° C.
When the temperature of the furnace tube is 1000 ° C
10^-9atm and 10 at 1600 ° C.^-2atm
become. In addition, 1% hydrogen was passed through water at 50 ° C. and humidified.
In this case, if the temperature of the core tube is 1000 ° C., the oxygen partial pressure becomes 1
0^{- 13}atm and the core tube temperature is 1600 ° C.
Then the oxygen partial pressure is 10^-8atm. Also, 100%
If hydrogen is passed through water at 0 ° C and humidified, the temperature of the furnace tube
Is 1000 ° C., the oxygen partial pressure is 10^{-1 9}atm
At 1600 ° C ^{- 13}atm.

As described above, it is extremely effective that the oxygen partial pressure in the firing furnace can be accurately controlled over a wide range only by accurately controlling the temperature of the water in the humidifier 5.

Also, like when the temperature of the firing furnace is raised or lowered,
When the temperature in the firing furnace changes, the oxygen partial pressure in the firing furnace changes with the temperature change. In this case, the oxygen partial pressure can be controlled to a certain degree by changing the temperature of the water in the humidifier according to the temperature change in the firing furnace.

In the region H where the oxygen partial pressure is lower,
(Iv) The oxygen partial pressure can be controlled by supplying the atmosphere obtained by changing the oxygen partial pressure in the hydrogen-containing gas with an oxygen pump into a firing furnace. Controllable temperature range is, for example, 900 ° C. to 1700 ° C., controllable oxygen partial pressure, for example 10 ^{- 2 2-10 - 1 8} is atm.

In this case, a small amount of oxygen can be added to the hydrogen-containing gas by the oxygen pump 7 by flowing the hydrogen-containing gas to the supply paths 15C and 15D without humidification. However, in the oxygen pump 7, a trace amount of oxygen was further removed from the hydrogen-containing gas, and the oxygen partial pressure could be controlled within a lower pressure range than before. For example, if the temperature of the core tube is 1
When the temperature is 200 ° C., the oxygen partial pressure in the atmosphere is reduced to 10
^- it could be precisely controlled to ^{2 2} atm.

Here, according to the present invention, the oxygen partial pressure in the exhaust gas is measured in the discharge path 16 on the downstream side of the firing furnace 10. In FIG. 1, an oxygen partial pressure measuring device 13 is provided in a discharge path 16 on the downstream side of the furnace tube 12. In FIG. 2, oxygen partial pressure measuring devices 9 and 13 are provided on both the upstream side and the downstream side of the furnace core tube 12, respectively.

For example, when oxygen is exhausted from the object to be fired in the firing furnace 10, the oxygen is used as the oxygen partial pressure measuring device 13.
When the oxygen partial pressure increases in the firing furnace 10 and oxygen is taken into the object to be fired, the oxygen partial pressure in the oxygen partial pressure measuring device 13 decreases. Thus, the oxygen partial pressure measuring device 1
The value measured by 3 fluctuates, reflecting the transfer of oxygen between the object to be fired and the atmosphere.

Then, as shown in FIGS. 1 and 2, the oxygen partial pressure in the exhaust gas is measured by the oxygen partial pressure measuring device 13, and the output signal of the measuring device 13 is supplied to the control device 17 as shown by the arrow A. (See FIG. 1) or control device 18 (see FIG. 2)
Send to

The control devices 17 and 18 perform necessary calculations and send control signals to the oxygen pump 7 as shown by arrows C. As a result, the amount of oxygen added to the atmosphere from the oxygen pump 7 is determined, whereby the oxygen partial pressure in the exhaust gas discharged from the firing furnace can be kept constant. Or
The amount of oxygen removed from the atmosphere can be determined by the oxygen pump 7.

Further, based on the output signal of the measuring device 13, a required calculation can be performed and used as a control signal for the temperature in the firing furnace 10 as shown by an arrow B. This makes it possible to control the amount of oxygen released from the fired body into the atmosphere. Further, the temperature schedule at the time of degreasing can be finely adjusted.

Further, for example, in order to more precisely control the oxygen partial pressure in the atmosphere in the firing furnace, as indicated by an arrow D in FIG. The output signal of the measuring device 9 is sent to the control device 18 and the control device 1
The required calculation is performed at 8 and the oxygen pump 7
Can be used as a control signal. Also, as indicated by arrow F,
It can be used as a control signal for the temperature of the firing furnace.

In this case, the measured value of the oxygen partial pressure in the oxygen partial pressure measuring device 9 and the measured value of the oxygen partial pressure of the exhaust gas in the oxygen partial pressure measuring device 13 are compared with each other. The transfer of oxygen between the fired body and the atmosphere is calculated, and the driving voltage of the oxygen pump 7 and the temperature of the firing furnace can be controlled accordingly.

Hydrocarbon, H ₂ O, CO, C
By analyzing O ₂ , cracks can be prevented, microstructure can be controlled, characteristics can be improved, and the like. For example, when manufacturing a porous sintered body, since a large amount of cellulose or carbon is contained as a pore-forming material, if there is excessive oxygen, cracks are generated due to rapid release of gas from the molded body due to rapid degreasing. May occur. By converting the gas analysis value to a gas generation rate from the molded body and reducing the gas generation rate, degreasing is performed gradually, thereby preventing cracks during degreasing.

Further, for example, it is possible to detect the end time of degreasing, and this can be reflected in the firing conditions. The oxygen partial pressure required for the degreasing step and the baking step is preferably set and supplied separately. For example, first, the oxygen partial pressure required for degreasing is set when the temperature is raised, and when degreasing is completed, CO or CO ₂ Since the concentration decreases, the end of degreasing can be detected,
At that timing, the gas can be supplied by changing the oxygen partial pressure to the oxygen partial pressure necessary for firing. This makes it possible to obtain a fired body having optimal characteristics and a microstructure.

Further, for example, hydrocarbons generated, H
By detecting the gas composition of ₂ O, CO, and CO ₂ and controlling the oxygen partial pressure of the supply gas and the temperature of the firing furnace so as to keep the composition constant, it is possible to control the microstructure such as the pore shape and the fired body. Properties such as electrical conductivity and strength of the sphere can be controlled.

The control signals from the control devices 17 and 18 control the operation of the solenoid valves 6A, 6B and 6C.
The flow rate of each gas can be controlled.

The humidifier 5 can be controlled by the control signals from the control devices 17 and 18 to control the amount of water added to the hydrogen-containing gas.

[0054]

As described above, according to the present invention, the characteristics and microstructure of the fired body are strictly controlled, or the fired body is provided with specific characteristics and microstructure. ,
A new firing device can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a firing apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic block diagram of a firing apparatus according to another embodiment of the present invention.

FIG. 3 is a graph showing a range of an oxygen partial pressure range and a temperature range that can be controlled by each of the methods (i) to (iv).

[Explanation of symbols]

1 inert gas supply source 2 oxygen-containing gas supply source
Reference Signs List 3 Hydrogen-containing gas supply source 4 Gas purifier 5 Humidifier 6A, 6B, 6C Valve 7 Oxygen pump 8 Inert gas supply device 9 Upstream oxygen partial pressure measurement device 10 Firing furnace 11 Heater 12 Furnace tube
13 Oxygen partial pressure measuring device downstream of the firing furnace 15A,
15B, 15C, 15D Supply path 16 discharge path 1
7, 18 Control device A Signal from oxygen partial pressure measuring device 13 B, F Control signal for firing furnace temperature C, E Control signal for driving voltage of oxygen pump 7 D Signal from upstream oxygen partial pressure measuring device 9

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigenori Ito 2-56, Sudacho, Mizuho-ku, Nagoya, Aichi Prefecture Inside Nihon Insulators Co., Ltd. (72) Inventor Makoto Murai 2-56, Sudacho, Mizuho-ku, Nagoya, Aichi Prefecture No. Japan Insulators Co., Ltd.

Claims (7)

[Claims] 1. A firing apparatus comprising a firing furnace for housing and firing a ceramic body to be fired, wherein an atmosphere supply source for supplying a predetermined atmosphere to said firing furnace; A gas analyzer for analyzing exhaust gas from the furnace to obtain predetermined information and a control mechanism for performing feedback control of operating conditions of the firing furnace based on the information, Ceramic firing equipment. 2. A ceramic firing apparatus according to claim 1, wherein said control mechanism is a control mechanism for feedback-controlling the temperature of said firing furnace based on said information. 3. The control mechanism according to claim 2, wherein:
3. The ceramic firing device according to claim 1, wherein the control device is a control mechanism for feedback-controlling a flow rate of the atmosphere into the firing furnace. 4. The apparatus according to claim 1, wherein the control mechanism is a control mechanism for performing feedback control of the composition of the atmosphere based on the information. Ceramic firing equipment. 5. The oxygen analyzer according to claim 1, wherein the gas analyzer is an oxygen partial pressure measuring device for measuring an oxygen partial pressure in exhaust gas discharged from the firing furnace, and the firing device is provided on an upstream side of the firing furnace. The ceramics according to claim 4, further comprising an oxygen pump, wherein the driving voltage or the current of the oxygen pump is feedback-controlled based on the measured value of the oxygen partial pressure in the oxygen partial pressure measuring device. Baking equipment. 6. A hydrogen-containing gas supply source for supplying a hydrogen-containing gas containing hydrogen at a predetermined partial pressure to the calcining furnace, and a water addition for adding water to the hydrogen-containing gas. A gas analyzer, wherein the gas analyzer is an oxygen partial pressure measuring device that measures an oxygen partial pressure in exhaust gas discharged from the firing furnace, and the oxygen partial pressure in the oxygen partial pressure measuring device. 5. The ceramic sintering apparatus according to claim 4, wherein the driving of the water addition apparatus is feedback-controlled based on the measured value. 7. An upstream gas analyzer for analyzing the atmosphere to obtain predetermined information, so that the information of the atmosphere and the information of the exhaust gas can be compared in the control device. The ceramic firing device according to any one of claims 1 to 6, wherein the control device is configured.