JPH05164467A - Kiln - Google Patents

Abstract

PURPOSE:To bake a raw material in uniform quality even when the raw material is not cracked and coarse-crushed previously. CONSTITUTION:A kiln has a rotated and driven kiln core pipe 1, an inserting rod 7 being penetrated into the kiln core pipe 1 and capable of being turned around the axial core S of the pipe 1 and a turning driving means 13 rotating the inserting rod 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a firing furnace used for calcination or main firing of ceramic raw materials such as dielectric materials and piezoelectric materials.

[0002]

2. Description of the Related Art Conventionally, a calcination furnace which is a rotary kiln is used for calcination and main calcination of ceramic raw materials.
As shown in the vertical sectional side view of FIG. 4, this firing furnace includes a cylindrical core tube 21 and a furnace body 23 having a heater 22 inside. The core tube 21 is rotatably supported by the support rollers 24, 24 in a posture inclined at a small angle, and is driven by a motor 25 to rotate around the central axis of the cylinder.

The raw material M to be fired is charged into the upper end of the tilt of the core tube 21, and is fired by the heating of the heater 22 while flowing downward due to the tilt and rotation of the tube inside the core tube 21.

[0004]

By the way, in the above-described firing furnace, a part of the raw material may reach the outlet early due to a short pass, and the difference in the residence time between the portions becomes large, resulting in a high firing quality. There was a problem that variations occurred.

In order to eliminate the above-mentioned variation in firing, it is necessary to make the particle sizes of the raw materials to be uniform and to make the residence time of the raw materials in the core tube 21 uniform. Since the raw material must be crushed and coarsely crushed, the number of steps is large.

The present invention has been made in view of such a conventional problem, and it is possible to fire the raw material to a uniform quality without crushing or coarsely pulverizing the raw material in advance. The purpose is to provide a furnace.

[0007]

The firing furnace according to the present invention comprises:
In order to achieve such an object, a core tube that is driven to rotate, an insertion rod that penetrates through the core tube and is rotatable around its axis, and a rotation drive means that rotates the insertion rod. It is characterized by having.

[0008]

According to the above construction, the insertion rod pivots inside the core tube, so that a narrow clearance can be periodically provided between the inner wall of the core tube and the insertion rod. Therefore, the raw material flows downward in the slope while passing through a narrow clearance in each swirling cycle, so that the flow speeds are made uniform, and the raw material is sufficiently stirred and pulverized during the process.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional side view of an entire firing furnace according to an embodiment of the present invention, FIG. 2 is a vertical sectional side view of a main portion thereof, and FIG.
(A), (B) is a vertical cross-sectional front view of the main part, FIG.
3A shows the case where the amount of raw material is small, and FIG. 3B shows the case where the amount of raw material is large.

As shown in FIG. 1, the conventional firing furnace is that the firing furnace of this embodiment is a rotary kiln comprising a cylindrical core tube 1 and a furnace body 3 having a heater 2 inside. Is the same as. Further, the core tube 1 is rotatably supported by the front and rear support rollers 4 and 5 in a posture inclined at a small angle, and is rotated around the central axis of the cylinder by the drive of the rotation motor 6, which is also different from the conventional example. Is the same.

The difference of the firing furnace of this embodiment from the conventional one is that an insertion rod 7 is inserted into the inside of the core tube 1 in a penetrating manner.
It is configured so as to turn around a turning axis S).

In this example, the insertion rod 7 is made of a ceramic or metal tube, and disks 8 and 9 are attached to both ends thereof, respectively. And, of both ends of the insertion rod 7, the upper end side of the inclination (the raw material input side, the right side in the figure)
Of the disk 8 on the same side, and the end on the inclined lower end side (on the material discharge side, left side in the figure) is the disk 9 of the same side.
Are installed at eccentric positions. Each disk 8,
The reference numeral 9 designates the core tube 1 by the supporting rollers 10 and 11, respectively.
It is rotatably supported about a turning axis S which is set substantially parallel to the central axis of the cylinder. Therefore, the insertion rod 7
Is capable of swiveling around the swivel axis S in the inside of the core tube 1 in an inclined posture in which it is closer to the inner wall of the core tube 1 on the raw material discharge side than on the raw material charging side.

Further, one disc supporting roller 11 has
A swivel motor 12 is interlockingly connected, and the insertion rod 7 is swung in the inside of the core tube 1 via the disc supporting roller 12 in the direction b opposite to the rotation direction a of the core tube 1. There is. The disk 9 on the drive side (left side in the illustrated example)
The swivel drive unit 13 including the disc support roller 11 and the swivel motor 12 can be slightly adjusted vertically and horizontally within its axial position, and the swivel axis S can be adjusted by the position adjustment.
Is inclined with respect to the central axis of the core tube 1.

In the above structure, the raw material M charged into the upper end of the tilt of the core tube 1 is burned by the heating of the heater 2 while flowing downward due to the tilt and rotation of the core tube 1. Inside the core tube 1, since the insertion rod 7 is swiveling in the direction B opposite to the rotation direction a of the core tube 1, as shown in FIGS. 2 and 3A and 3B, the insertion rod 7 is rotated. 7 approaches the inner wall of the core tube 1 at each turning cycle and forms a narrow clearance C with the core tube 1.
The raw material enters the clearance C at every swirling cycle, so that the flow rate is regulated and the occurrence of short path is prevented.

Further, since the raw material is sandwiched between the core tube 1 and the insertion rod 7, the raw material is pulverized, and is fired in a state where the grain size is uniform. Furthermore, since the insertion rod 7 scrapes down the raw material lifted by the core tube 1, the raw material is sufficiently stirred during this period.

In this case, the insertion rod 7 is closer to the core tube 1 on the raw material discharge side than the raw material input side, and the clearance C between the core tube 1 and the insertion rod 7 is narrower on the raw material discharge side. The closer to the raw material discharge side, the stronger and finer the crushing is performed, and the crushing action is reasonably performed, and efficient crushing is performed in a state where an excessive load does not act on the insertion rod 7.

Further, since the position of the center of rotation of the insertion rod 7 on the raw material discharge side can be changed by adjusting the position of the rotary drive unit 13, when the raw material input is small,
As shown in FIG. 3A, the lower clearance is narrowed and the crushing point is set lower so that the insertion rod 7 can sufficiently act on the raw material. As shown in FIG. 3 (B), the higher clearance can be narrowed to move the crushing point to the higher position, and the resistance of the insertion rod 7 against turning can be reduced.

The insertion rod 7 may be a double pipe, a triple pipe or a solid rod. Also, the insertion rod 7
When a tube is used as the tube, a large number of small holes may be opened in this tube to form a gas injection tube, which may be used for controlling the atmosphere in the core tube 1. In that case, the circular plates 8 and 9 provided at one end of the insertion rod 7 are formed hollow, and this is used as a gas distributor, and a gas supply pipe may be connected to the hollow circular plate through a rotary joint. ..

[0020]

As described above, according to the present invention,
The flow rate of the raw material is regulated by the insertion rod that swirls inside the core tube, so that the residence time of the raw material in the core tube becomes constant, and the effect that homogeneous firing can be performed is obtained.

Further, since the raw material is crushed between the inner wall of the furnace tube and the insertion rod, a fired powder having a uniform particle size can be obtained, and the raw material before charging, which is conventionally required, is crushed and coarsely crushed. Can be omitted, and the man-hour can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an entire firing furnace according to an embodiment of the present invention.

FIG. 2 is a vertical sectional side view showing a main part of the embodiment.

FIG. 3 is a vertical sectional front view showing a main part of the above embodiment,
(A) shows the case where the amount of raw material is small, and (B) shows the case where the amount of raw material is large.

FIG. 4 is a vertical sectional side view of a conventional firing furnace.

[Explanation of symbols]

 1 core tube 7 insertion rod 13 turning drive means S turning shaft (axial core)

Claims (1)

[Claims] 1. A rotatively driven core tube (1), an insertion rod (7) which penetrates through the core tube (1) and is rotatable around its axis (S), and this insertion rod. Turning drive means (1) for turning (7)
3) A firing furnace comprising: