JPH0674951B2 - Ceramic firing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a ceramic firing apparatus for firing a ceramic body that has undergone a forming process.

(Prior Art) As a conventional ceramic firing apparatus of this type, there are a mode using a tunnel furnace or a batch furnace and a mode using a rotary hearth furnace.

(Problems to be Solved by the Invention) The former is the most commonly used form, but has the following drawbacks. A box or a base plate for accommodating the ceramic body and supplying it into the furnace is required, and therefore there is energy loss for heating these. Further, since the box and the base plate are consumable items, the cost of the baking apparatus as a whole increases. This requires the step of loading the ceramic body into the box or the base plate, which hinders improvement in workability. Variations in temperature and atmosphere in the furnace and in the box are likely to occur, resulting in non-uniform firing characteristics.

On the other hand, in the latter case of using the rotary hearth furnace, the ceramic body is supplied from the front inlet of the rotary hearth tube and is sequentially sent out to the rear outlet with the rotation of the hearth. No base plate is required, and there is an advantage that the drawbacks seen in the former form can be eliminated.

However, in such a rotary hearth configuration, the following problems newly occur.

That is, in the vicinity of the front inlet of the rotary core tube, the binder (binder) contained in the ceramic body escapes by heating during firing, and the binder decomposition gas that is a combustible gas has a relatively low temperature. As a result of condensation and adhesion on the inner wall surface near the pipe inlet, smooth flow of the ceramic body is hindered. Also,
Since the strength of the ceramic body immediately after the binder has come out decreases, the ceramic body tends to be damaged during rolling transfer.

The present invention has been made in view of the above circumstances, and an object thereof is to eliminate the above-mentioned drawbacks in a ceramics firing apparatus configured by using a rotary furnace core tube.

(Means for Solving the Problems) In order to achieve such an object, the present invention supplies a ceramic body in which a combustible gas is generated during firing from a front inlet of a rotary core tube, and the rotary core. In a ceramics firing apparatus configured to take out a fired product from a rear outlet of a tube, a supply tube of the ceramic body made of a heat-resistant material is inserted from the front inlet of the rotary furnace tube toward the inside, The supply tube is provided with means for forcibly supplying air or oxygen inside while supplying the ceramic body to a relatively high temperature portion in the rotary furnace core by being driven to vibrate. It is characterized by being.

(Operation) According to the above configuration, the binder contained in the ceramic body by heating through the supply tube while the ceramic body is being sent through the supply tube that is driven to vibrate It comes out and is disassembled. The binder decomposed gas, which is the combustible gas generated in this way, is burned by the air or oxygen that is forcibly supplied to the inside of the supply tube. Also, the binder comes out,
That is, the ceramics body that has been debindered is baked and solidified to some extent while passing through the supply tube, and then supplied to a relatively high temperature portion in the rotary furnace core tube, and then tumbled and transferred as in the conventional example. While being fired.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings. FIG. 1 is a vertical sectional view of a ceramics firing apparatus according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a rotary mandrel constituting a rotary hearth furnace, and the furnace mandrel 1 has excellent heat resistance and is a ceramic as a material that does not react with a ceramic body W that is a material to be fired. For example, it is made of alumina, zirconia, or the like. 2 is the core tube 1
Is a roller that supports a tilt angle of about 0.5 to 2 degrees in a forward rising inclination, and is driven by a motor (not shown) to give the core tube 1 rotation in a fixed direction. 3 is an electric heater wound around the core tube 1 and 4 is a heat insulating material for keeping the temperature of the furnace as a whole. Reference numeral 5 denotes an inlet cover plate which is attached by closing the front inlet of the core tube 1. 6 is an entrance cover plate 5
Is a supply tube inserted through the central hole 5a into the core tube 1 and is made of high-rigidity and high-heat-resistant ceramics. Reference numeral 7 is a vibrating feeder as a vibrating mechanism that supports the front part of the supply tube 6, and slightly vibrates the supply tube 6 back and forth to gently send the ceramic body W inside, and from the front end of the core tube 1. The ceramic body W is supplied to a portion located inside by an appropriate distance, that is, a portion having a relatively high temperature in the core tube 1. 8 is a core tube 1
This is a barrier provided in the core tube 1 for preventing the backflow of the ceramic body W supplied into the inlet side. Reference numeral 9 denotes a supply chute that is provided at the front end open portion of the supply tube 6, and supplies the ceramic body W down the supply tube 6 from a hopper (not shown). Reference numeral 10 is a pipe for forcibly blowing air, air containing a high concentration of oxygen, or oxygen itself into the supply tube 6.

That is, in the firing apparatus configured as described above,
While the ceramic body W is being fed through the supply tube 6 by the supply tube 6 that is driven to vibrate, the binder contained in the ceramic body W heated through the supply tube 6 escapes and Be disassembled. Then, the binder decomposition gas generated from these ceramic bodies W is burned by the air or oxygen that is forcibly supplied to the inside of the supply tube 6, and also from the front end open portion of the supply tube 6 to the outside. It will be discharged. Further, each of the ceramic bodies W for which the binder removal is completed is burned to some extent while passing through the supply tube 6 to be solidified, and then supplied to a relatively high temperature portion in the core tube 1 and then, as in the conventional example. It will be fired while being rolled and transferred to.

The ceramic calcination apparatus of the present invention performs debinding processing of the ceramic body W being transferred in the supply tube 6 and also by rolling transfer of the ceramic body W after debinding processing in the core tube 1. The firing is performed until the strength is high enough not to be damaged, and the end position temperature of the supply tube 6 at this time needs to be 900 ° C. or higher, preferably 1100 ° C. or higher.

By the way, using the firing apparatus according to the present invention, TiO ₂
When a firing test was performed on the dielectric composition (subject to be fired) containing as a main component under the temperature distribution state shown in FIG. 2, the results shown in the table below were obtained. That is, according to this table, it is understood that both the warp and the crack defect rate of the object to be fired are improved. Here, the material to be fired was molded with methyl cellulose as a binder, the diameter was 7 mm, and the thickness was 0.3 mm.
The disk-shaped one was used.

(Effects) As described above, according to the present invention, since the binder decomposition gas, which is the combustible gas generated from the ceramic body, is burned and discharged in the supply tube, the binder decomposition gas has a relatively high temperature. Condensation and adhesion do not occur on the inner wall surface near the low rotary core tube inlet, and a smooth flow of the ceramic body can be secured. Also,
The ceramic body has been debindered, and
Since the material is supplied to the core tube from the supply tube after being solidified by being fired to some extent to improve the strength, it is possible to obtain an effect that it is not damaged even during rolling transfer in the core tube.

[Brief description of drawings]

The drawings show a ceramic firing apparatus according to an embodiment of the present invention,
FIG. 1 is a vertical sectional side view thereof, and FIG. 2 is an explanatory diagram showing a temperature distribution state during a firing test. In the figure, reference numeral 1 is a rotary core tube, 6 is a supply tube, a is a front inlet, b is a rear outlet, and W is a ceramic body.

Claims (1)

[Claims] 1. A ceramic body, in which a combustible gas is generated during firing, is supplied from a front inlet of a rotary furnace core tube, and
In a ceramics firing apparatus configured to take out a fired product from a rear outlet of the rotary furnace core tube, a ceramics body supply tube made of a heat-resistant material is inserted from the front inlet of the rotary furnace tube toward the inside. The supply tube is driven to vibrate to supply the ceramic body to a relatively high temperature portion in the rotary core tube, and a means for forcibly supplying air or oxygen is provided inside the supply tube. A ceramics firing apparatus characterized by being