JPH08200958A - Burning device of ceramic forming material - Google Patents

Abstract

PURPOSE: To uniformly burn a ceramic forming material by heating a core pipe having an elliptical or polygonal inner structure and passing the ceramic forming material therethrough. CONSTITUTION: A core pipe 3 is rotated by a driving part 6 and the temperature of the core pipe 3 is set to a prescribed temperature by a heater 4. When a ceramic forming material is charged from an inlet, it moves laterally while rotating owing to the rotation and inclination of the core pipe 3 and is discharged from an outlet after the lapse of a prescribed time. The ceramic forming material is heated and burnt by the heater 4 during this period. Since the inner structure of the core pipe is elliptical or polygonal in its shape, the reversibility of the ceramic forming material is improved when the core pipe 3 rotates. Thus, all the ceramic forming material can be uniformly burnt. Further, since the rotating capability of the ceramic forming material is improved. the ceramic forming material is prevented from adhering to an inner wall. Thus, an operating time can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic compact firing apparatus.

[0002]

2. Description of the Related Art FIG. 3 shows a vertical cross-sectional view of the internal structure of a conventional ceramic compact firing apparatus. Details of this structure will be supplementarily described in the following description of the embodiments. The internal structure of the furnace core tube 3 shown in the same figure is a perfect circle as shown in the cross sectional view of FIG.

The furnace core tube 3 is slightly inclined from the horizontal, and when the ceramic molded body is put into the inlet 3a of the furnace core tube and the furnace core tube is rotated by the rotation imparting mechanism 6, the ceramic molded body 2 becomes Slide along the slope to the right in Fig. 3,
Discharged from the outlet. The ceramic molded body 2 is fired by heating the heater 4 while staying in the furnace core tube.

[0004]

However, since the cross section of the furnace core tube is a perfect circle, even if the furnace core tube is rotated,
The ceramic molded body does not turn over because it only slides laterally along the inclination of the furnace core tube, and the ceramic molded body adheres to the inner wall of the furnace core tube, resulting in variations in residence time. Since there is variation in heat conduction, there is a problem that the ceramic molded body is not uniformly fired.

[0005] Therefore, an object of the present invention is to provide a ceramic compact firing apparatus capable of homogeneous firing.

[0006]

In order to achieve the above object, the apparatus for firing a ceramic compact according to the present invention comprises a ceramic compact for calcining the ceramic compact by passing the ceramic compact through a heated furnace core tube. In the apparatus, the furnace core tube internal cross-sectional structure is elliptical or polygonal.

[0007]

According to this structure, since the ceramic molded body charged from the inlet of the furnace core tube has an elliptical or polygonal internal structure, the ceramic molded body is well formed by the rotation of the furnace core tube. While rotating and uniformly firing the entire ceramic molded body, the ceramic molded body moves in the outlet direction along the inclination of the furnace core tube and the ceramic molded body is heated and fired in the meantime. Since the furnace core tube has an elliptical or polygonal structure, when the furnace core tube rotates, the molded body has a good turning-over rotatability, and uniform firing of the entire ceramic molded body is possible. Further, since the rotatability of the ceramic molded body is improved, the ceramic molded body is less likely to adhere to the inner wall, and it is not necessary to drop the ceramic molded body, so that the working time can be shortened and the ceramic molded body adheres to the inner wall. As a result, heat conduction is less hindered, so that homogeneous firing is possible.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a furnace core tube of a ceramic compact firing apparatus according to the present invention.

FIG. 2 is a cross-sectional view of another furnace core tube of the ceramic molded body firing apparatus of the present invention.

The ceramic compact firing apparatus shown in FIG.
Furnace core tube 3 horizontally installed at an inclination of 1 to 15 ° with respect to the ground, heater 4 arranged around the furnace core tube 3 and having heating ability up to 900 to 1400 ° C, furnace core tube 3 and heater Four
10 to 100 rp for the heat insulating member 5 surrounding the
It is roughly configured to have a drive unit 6 having the ability to rotate m times. The furnace core tube 3 is made of alumina and has an internal structure of an elliptical shape having a ratio of major axis to minor axis of 2: 1 as shown in FIG. 1 and a hexagonal shape as shown in FIG. It was used. The outer diameter of this furnace core tube is about 15 cm for both.

Next, the operation of this device will be described. The furnace core tube 3 is rotated by the drive unit 6, and the furnace core tube 3 is set to a predetermined temperature by the heater 4. When the ceramic molded body is charged from the inlet, it moves laterally while rotating due to the rotation and inclination of the furnace core tube 3, and is discharged from the outlet after a lapse of a certain time (about 3 to 12 hours). In the meantime, the ceramic molded body is heated by the heater 4 and fired. The residence time in the furnace core tube 3 can be changed by the rotation speed and the inclination angle of the furnace core tube 3. Table 1 shows the variation in resistance value of the element obtained through the above steps and the element obtained in the conventional step, and the adhesion rate to the inner wall of the ceramic molded body.

[0013]

[Table 1]

As shown in (Table 1), by making the internal structure of the furnace core tube 3 elliptical or polygonal, it is possible to perform uniform firing and improve the resistance variation (RC.V). Further, it can be seen that the adhesion rate on the inner wall of the ceramic molded body is also improved.

The molded body used here is a disk-shaped pellet having a thickness of about 2 mm and a diameter of about 8 mm. The pellets are not added one by one, but continuously with a density such that several pellets overlap each other.

According to the ceramic compact burning apparatus constructed as described above, the following effects can be obtained.

(1) By making the inner structure of the furnace core tube into an elliptical shape or a polygonal shape, the rotatability of the molded body is improved, so that homogeneous firing is possible. The rotatability is improved by increasing the number of times the one molded body is turned upside down, and the rotatability is also improved with respect to the mutual positions of a large number of the molded bodies that are overlapped with each other, because the outer side and the inner side are often interchanged.

(2) Since the rotatability of the molded body is improved, the molded body is less likely to adhere to the inner wall, and it is not necessary to drop the molded body adhered to the inner wall, so that the working time can be shortened and the molding can be performed. Since it is less likely that the body adheres to the inner wall and hinders heat conduction, it is possible to perform homogeneous firing.

The internal structure of the furnace core tube has been described using the elliptical shape and the hexagonal shape in which the ratio of the major axis to the minor axis is 2: 1 in the embodiments, but the same effect can be obtained under the following conditions.

(1) Ellipse: The ratio of the major axis to the minor axis is 1.3:
1 to 3: 1 (2) Polygon: Triangle to Decagon If the amount exceeds the above range, the rotational performance of the molded product deteriorates and the effect of performing homogeneous firing cannot be obtained.

Further, a furnace core tube in which projecting ribs are protruded from the inner wall of the furnace core tube having a perfect circular cross section as in the conventional example was also examined, but the number of sticking to the ribs and adhering to the inner wall was increased. And it didn't work.

Although alumina is used for the furnace core tube in the above embodiments, the same effect can be obtained by using zirconia, SiC, ceramics or the like.

[0023]

According to the inventions described in the above-mentioned claims, the rotatability of the molded article is improved, so that homogeneous firing is possible. Further, the molded body is less likely to adhere to the inner wall, it is not necessary to drop the molded body adhered to the inner wall, the time can be shortened, and the molded body is less likely to adhere to the inner wall and hinder heat conduction, Homogeneous firing becomes possible. Therefore, it is possible to provide a ceramic molded body firing apparatus capable of performing homogeneous firing.

[Brief description of drawings]

FIG. 1 is an internal sectional view of a furnace core tube according to an embodiment of the present invention.

FIG. 2 is a sectional view of a furnace core tube according to another embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view of a ceramic compact firing device.

FIG. 4 is a diagram of an internal structure of a furnace core tube of a conventional ceramic molded body firing apparatus.

[Explanation of symbols]

 2 molded body 3 furnace core tube 3a inlet 3b outlet 4 heater 5 heat insulating member 6 drive unit

Claims (3)

[Claims] 1. A molded body firing apparatus for firing a ceramic molded body by passing the ceramic molded body through a heated furnace core tube, wherein the furnace core tube rotates and its internal structure is elliptical or polygonal. And a ceramic molded body firing apparatus. 2. The elliptical shape has a ratio of the major axis to the minor axis of 1.
2. The range of 3: 1 to 3: 1.
A ceramic molded body firing apparatus as described. 3. The ceramic molded body firing apparatus according to claim 1, wherein the polygonal shape is in the range of a triangle to a triangle.