JPH06294581A - Heat treating furnace - Google Patents

Abstract

PURPOSE:To provide a heat treating furnace which eliminates shortcomings of a conventional feeding pipe, can uniformly feed a gas in the furnace, and can uniform an atmosphere in the furnace. CONSTITUTION:A gas feeding pipe 2 and discharging pipe 3 for an exhaust gas are equipped on a furnace main body 1, and the gas feeding pipe 2 consists of a first pipe 11, one end of which is open, and a second pipe 2 which is fitted in the first pipe 11, and one end of which is open. On the top of the furnace main body 1, a motor 5 to depress the second pipe 12 and a cam 4 which is connected to the motor 5 are provided as a height adjusting means for the second pipe 12 to the first pipe 11. Then, a spring to make a pushing up force from the bottom work when the cam 4 turns by 180 deg. is provided on the bottom part of the first pipe 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment furnace capable of uniformly supplying gas into the furnace.

[0002]

2. Description of the Related Art Conventionally, various methods are well known for supplying gas to a ceramic firing furnace and discharging gas from the ceramic firing furnace. FIG. 13 shows one of such methods. This FIG. 13 shows a batch furnace, and the furnace body 1 has an opening 1a at the bottom for inserting and removing a box 7 containing a ceramic object to be fired, and the box 7 is opened from the opening 1a to the furnace body. It is inserted into the inside of 1 and baked. On the ceiling part 1b of the furnace body 1, a gas (atmosphere gas) supply pipe 2 and an exhaust gas discharge pipe 3 which are directed from the ceiling part 1b to the hearth 1c are attached.

The supply pipe 2 and the discharge pipe 3 are
As shown in FIG. 14, it is made of a heat-resistant material such as alumina porcelain and has one end opening, and each side wall of the supply pipe 2 and the discharge pipe 3 is provided with gas from one end to the other end. Holes 8 for supplying or exhausting exhaust gas, ...
Are formed in a line. The hole diameter, pitch, forming position, number and the like of each hole 8 are set in accordance with the heat treatment conditions of the ceramic object to be fired in the furnace body 1.
Then, the gas flows inside the supply pipe 2 in FIG.
The exhaust gas flows in the direction indicated by 1 and is supplied into the furnace main body 1, and the exhaust gas flows through the discharge pipe 3 in the direction indicated by the arrow A2 and is discharged outside the furnace main body 1.

[0004]

By the way, in the above-mentioned supply pipe 2, since the diameter of each hole 8 is constant,
These supply pipes 2 cannot be used to adjust the furnace pressure of the furnace body 1 or the gas supply amount, and the gas supply amount from the holes 8 of the supply pipe 2 to the furnace body is Since it is determined by the internal pressure, the bottom has a high pressure and the ceiling has a low pressure, the amount of gas supplied from the hole 8 at the bottom of the supply pipe 2 increases, and decreases as it approaches the ceiling 1c. Furthermore, since the gas is continuously supplied into the furnace body 1,
There is a problem that a steady gas flow can be generated in the furnace body 1 and it is difficult to control the atmosphere in the furnace body 1.

In addition, by using the supply pipe 2, the furnace body 1
In order to supply the gas from any position, the pipes having different hole diameters, pitches, and the number of holes of the holes 8, 8, ... Of each supply pipe 2 are required. The plurality of different supply pipes 2, 2, ... Must be attached to the furnace body 1, and the respective supply pipes 2, 2, ... Must be opened and closed by valves (not shown). However, there is a problem that the size becomes large and the structure becomes complicated.

An object of the present invention is to solve the above-mentioned drawbacks of the conventional supply pipe, and to provide a heat treatment furnace capable of uniformly supplying gas into the furnace and making the atmosphere in the furnace uniform. .

[0007]

In order to solve the above-mentioned problems, the present invention relates to a first pipe having an opening at one end, wherein holes are formed in the peripheral wall of the pipe at least at intervals in the axial direction, The second pipe has an outer diameter substantially equal to the inner diameter of the first pipe and is fitted into the first pipe. The second pipe has an opening at one end. The second pipe is disposed on the peripheral wall of the second pipe relative to the first pipe. And by moving up and down in the axial direction, the first
The hole is formed so that the overlap with the hole of the pipe is changed, and the second pipe is fitted inside the first pipe, and the axial height of the second pipe with respect to the first pipe is adjusted. And a means for adjusting the gas supply amount by overlapping the holes of the first pipe and the holes of the second pipe.

The second pipe may be provided with a gas supply port, and a slit into which the gas supply port is fitted may be provided in the first pipe.

In the first pipe or the second pipe, the holes may be provided with longitudinal holes or lateral holes at intervals in the axial direction.

In the first pipe or the second pipe, the holes may be axially spaced and a plurality of holes may be provided in the lateral direction.

[0011]

With the above construction, by vertically moving the second pipe with respect to the first pipe, the overlapping of the holes of the first pipe and the second pipe changes, and as a result, the apparent position of the hole, You can change the pitch of holes, the size of holes, and the number of holes. Thereby, the gas can be uniformly released into the furnace body, and the atmosphere in the furnace can be made uniform.

[0012]

EXAMPLE A sectional view of an example of a heat treatment furnace according to the present invention is shown in FIG. This heat treatment furnace is a batch furnace for firing ceramics, and has an opening 1a at the bottom of the furnace body 1 for inserting and removing a box 7 containing a material to be fired of ceramics. It is inserted inside and fired. In the ceiling part 1b of the furnace main body 1, a gas (atmosphere gas) supply pipe 2 and an exhaust gas are sent from the ceiling part 1b to the hearth 1c through the box 7 containing the ceramic object to be fired and the inner wall of the furnace main body 1. And the discharge pipe 3 of the above are attached. The ceramic firing furnace gas supply pipe 2 includes a first pipe 11 having an opening at one end.
And a second pipe 12 that is fitted into the first pipe 11 and has an opening at one end. And, as a height adjusting means of the second pipe 12 with respect to the first pipe 11, a motor 5 for pushing down the second pipe 12 is provided above the furnace body 1.
And a cam 4 connected to the motor 5. Further, as shown in FIG. 4, a spring 6 is provided on the bottom of the first pipe 11 so that when the cam 4 rotates 180 degrees, a pushing force is exerted from below. The first pipe 11 and the second pipe 12 have heat resistance such as alumina porcelain, and the spring 6 has heat resistance such as zirconia.

2 and 3 are perspective views of the first pipe 11 and the second pipe 12, respectively. As shown in FIG.
On the side wall of the first pipe 11, holes 14, 14, ... With a diameter of several millimeters are formed at equal intervals in a straight line in the axial direction.

On the other hand, as shown in FIG. 3, the second pipe 12
Has an outer diameter approximately equal to the inner diameter of the first pipe 11,
It can be fitted into the pipe 11. The side wall of the second pipe 12 has a hole 1 with a diameter of several millimeters which is aligned linearly in the axial direction.
5, 15, ... Are formed at equal intervals. However, the distance between the holes 14 and 15 in the side walls of the first pipe 11 and the second pipe 12 is different. These holes 14 and 15 are formed in the first pipe 11 with the second pipe 12 fitted therein.
As you move up and down, they will overlap in the process.
A hole 13 is provided at the bottom of the first pipe 11 so that the gas in the bottom can be supplied and exhausted so that the vertical passage of the second pipe 12 is not obstructed. Further, a gas supply port 16 is provided on the upper portion of the second pipe 12 so that gas is supplied into the inside of the second pipe 12.

4, FIG. 5, FIG. 6, FIG. 7, and FIG. 8, the vertical movement of the second pipe 12 and the accompanying first pipe 11 are shown.
The change of the positions of the holes 14 and 15 between the second pipe 12 and the second pipe 12 is shown. In the order of FIG. 4 → FIG. 5 → FIG. 6 → FIG. 7 → FIG. The second pipe 12 is pushed downward due to the rotation of, and the positions of the holes 14 and 15 are changed accordingly. Figure 8 → Figure 7 →
In the order of FIG. 6 → FIG. 5 → FIG. 4, after the cam 4 rotates 180 degrees, the second pipe 12 is pushed up by the repulsive force of the lower spring 6, and the positions of the holes 14 and 15 change accordingly. There is.

As shown in FIG. 9, a slit 17 is provided in the upper portion of the first pipe 11. The gas supply port 16 of the second pipe 12 is fitted in the slit 17, and when the second pipe 12 moves up and down with respect to the first pipe 11, the movement is restricted so as not to rotate.

As shown in FIG. 10, the hole 1 of the first pipe 11
By providing a plurality of holes in the lateral direction at intervals of 4 in the axial direction, the gas can be supplied into the furnace body 1 in a laterally widened manner. Further, such a structure can be similarly applied to the second pipe 12.

As shown in FIG. 11, by making the holes 14 of the first pipe 11 longitudinally long at intervals in the axial direction, gas is continuously supplied in the axial direction into the furnace body 1. Even if the boxes 7 containing the ceramic objects to be fired are vertically stacked, they can be supplied into each box 7. Further, such a structure can be similarly applied to the second pipe 12.

As shown in FIG. 12, the hole 1 of the second pipe 12
5 is made into a horizontally long hole at intervals in the axial direction,
Even if the holes 14 and 15 of the pipe 11 and the second pipe 12 move vertically due to the vertical movement of the second pipe 12, the second pipe 12 may rotate and cause a positional shift. Further, such a structure can be applied to the first pipe 11.

In the above embodiment, the first pipe 1
The shape and arrangement of each hole 14 of No. 1 and each hole 15 of the second pipe 12 can be arbitrarily set according to the heat treatment conditions of the box 7 in which the ceramic firing target is placed. Furthermore, the second
In addition to the above method, the pipe 12 may be driven up and down by using an air cylinder or a rack and pinion. Further, although the gas supply pipe has been described in the present embodiment, it can be applied to an exhaust gas discharge pipe.

[0021]

According to the present invention, when the second pipe is moved up and down with respect to the first pipe, the holes of the first pipe and the holes of the second pipe are overlapped, that is, 1
Since the number, area and position of the communication holes communicating with the pipe and the second pipe are changed, the atmosphere in the furnace body can be made uniform. Further, according to the present invention, since the gas supply pipe may be attached to the furnace body, the shape of the heat treatment furnace can be downsized and the structure can be simplified.

[Brief description of drawings]

FIG. 1 is a sectional view of a ceramic firing furnace according to an embodiment of a heat treatment furnace of the present invention.

FIG. 2 is a perspective view of a first pipe of a gas supply pipe used in the ceramic firing furnace of FIG.

3 is a perspective view of a second pipe of a gas supply pipe used in the ceramic firing furnace of FIG.

FIG. 4 is a cross-sectional view showing vertical movement of the second pipe in a state where the second pipe is fitted in the first pipe, and the second pipe is at the uppermost position.

5 is a cross-sectional view showing the vertical movement of the second pipe when the second pipe is fitted in the first pipe, and the second pipe is in a position lower than that in FIG. 4. FIG.

FIG. 6 is a cross-sectional view showing vertical movement of the second pipe in a state where the second pipe is fitted in the first pipe, and the second pipe is at a position lower than that in FIG. 5;

FIG. 7 is a cross-sectional view showing vertical movement of the second pipe in a state where the second pipe is fitted in the first pipe, and the second pipe is at a position lower than that in FIG. 6;

FIG. 8 is a cross-sectional view showing vertical movement of the second pipe in a state where the second pipe is fitted in the first pipe, and the second pipe is at the lowest position.

FIG. 9 is a front view of the upper portion of the first pipe with the second pipe fitted therein.

FIG. 10 is a front view of a part of another structural example of the first pipe.

FIG. 11 is a front view of a part of still another structural example of the first pipe.

FIG. 12 is a front view of a part of another structural example of the second pipe.

FIG. 13 is a sectional view of a conventional ceramic firing furnace.

FIG. 14 is a perspective view of a conventional gas supply / discharge pipe.

[Explanation of symbols]

 2 supply pipe 3 discharge pipe 4 cam 5 motor 6 spring 11 first pipe 12 second pipe 14 first pipe hole 15 second pipe hole 16 gas supply port 17 slit

Claims (4)

[Claims] 1. A heat treatment furnace having a pipe for supplying gas from outside the furnace body, wherein the pipe is a first pipe having an opening at one end and having holes formed at least in the circumferential wall at intervals in the axial direction. And a second pipe having an outer diameter substantially equal to the inner diameter of the first pipe and having one end opening fitted in the first pipe. The second pipe is provided on the peripheral wall of the second pipe. A hole is formed so that the overlap with the hole of the first pipe is changed by moving the first pipe up and down in the axial direction, and the first pipe is fitted with the second pipe.
Adjusting means for adjusting the height of the second pipe in the axial direction with respect to the pipe, and adjusting the gas supply amount by overlapping the holes of the first pipe and the holes of the second pipe. Heat treatment furnace. 2. The heat treatment furnace according to claim 1, wherein the second pipe has a gas supply port, and a slit into which the gas supply port is fitted is provided in the first pipe. 3. The heat treatment furnace according to claim 1, wherein the first pipe or the second pipe is provided with vertically long holes or horizontally long holes with axially spaced holes. 4. The heat treatment furnace according to claim 1, wherein in the first pipe or the second pipe, holes are provided at intervals in the axial direction and a plurality of holes are provided in the lateral direction.