JPH04288478A - Continuous baking furnace - Google Patents

Abstract

PURPOSE:To provide a continuous baking furnace capable of regulating a temperature in the cooling zone of a furnace body freely. CONSTITUTION:A continuous baking furnace is constituted of a furnace body 2 having a tunnel type internal space 23 consisting of a preheating zone, a baking zone and a cooling zone from one end to the other end thereof while works to be baked are baked in a process moving from said one end opening to the other end opening. The cooling zone is constituted of a ceiling 2a and a hearth 2b, which are crossing said internal space 23, while air-cool pipes 22 are arranged with a space in the moving direction of the works to be baked. Heat, brought into the cooling zone from the baking zone of the furnace body 2, is absorbed by cooling air supplied to the inside of the furnace body 2, and, thereafter, is discharged to the outside of the furnace body.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous firing furnace used for manufacturing ceramic electronic components such as ceramic capacitors and ceramic piezoelectric components.

0002

2. Description of the Related Art Generally, continuous firing furnaces and vertical batch type firing furnaces are used for manufacturing ceramic electronic components such as ceramic capacitors and ceramic piezoelectric components.

FIG. 3 shows an example of a conventional continuous firing furnace used for manufacturing ceramic electronic components. The continuous firing furnace shown in FIG. 3 has a tunnel-shaped furnace body 2 arranged horizontally on a base 1. Boxes 4 stacked in multiple stages on a base plate 3 and containing ceramic molded bodies (not shown) inside.
is moved from the outside of the inlet 5 of the furnace body 2 through the inside of the furnace body 2 toward the outlet 6 of the furnace body 2 by the pusher 7 as indicated by the arrow A.
1, it is first automatically pushed into the preheating zone following the inlet 5 of the furnace body 2. After the binder (molding aid) in the ceramic molded body is burned in this preheating zone, the base plate 3 is pushed to the firing zone of the furnace body 2 following the preheating zone to fire the ceramic molded body. When this firing is completed, the ceramic molded body is pushed to a cooling zone of the furnace body 2 following the firing zone, cooled, and then pulled out from the furnace body 2.

As shown in FIG. 4, the cooling zone in the furnace body of the continuous firing furnace 2 is divided into several small cooling zones 9, 9, . . . by partition walls 8, 8, . 9, an intake port (not shown) is provided on the side or bottom surface, and natural or forced exhaust is performed by opening and closing a damper (not shown) provided at the exhaust port 11 installed on the ceiling or side surface. The exhaust volume is adjusted.

[0005] Furthermore, in cases where a large cooling capacity is required, cooling air is forcibly supplied to the inside of the furnace body 2.

[0006]

[Problems to be Solved by the Invention] In the above-mentioned conventional firing furnace, the cooling air introduced from the intake port is directly heat-exchanged within the furnace body and the amount of heat discharged is adjusted, so that the ceramic molded body is moved to the cooling zone. Since the cooling process takes away the heat brought into the room, the following problems arise.

[0007] The heat exchange efficiency between the outside air supplied from the intake port and the object to be fired is poor, and sufficient cooling is not achieved.

[0008] Furthermore, when the amount of outside air introduced is increased in order to improve the cooling efficiency, cracks occur due to spalling in the furnace material, bricks, or objects to be fired that are in direct contact with the injected cooling air.

Furthermore, it is difficult to balance the large amount of cooling air that is injected with the amount of exhaust air, and the atmosphere inside the furnace body 2 flows in the direction through the furnace body, causing the temperature inside the furnace body 2 to decrease. It is difficult to adjust according to the settings.

An object of the present invention is to provide a continuous firing furnace in which the temperature in the cooling zone of the furnace body can be freely adjusted.

[0011]

[Means for Solving the Problems] Therefore, the present invention is provided with a furnace body having a tunnel-shaped internal space leading from one end opening side to the other end opening side, and the interior of the furnace body is from one end opening side to the other end opening side. A continuous firing furnace, which has a preheating zone, a firing zone, and a cooling zone toward the opening side, and is fired in the process of moving the object to be fired from the opening at one end to the opening at the other end,
The furnace body includes air-cooled pipes that each cross the internal space on at least one side of the ceiling side and the hearth side of the cooling zone and are arranged at intervals in the direction of movement of the object to be fired. Provided is a continuous firing furnace characterized by comprising an air supply source that supplies cooling air to these air-cooled tubes, and an air supply control means that controls the amount of cooling air supplied to the air-cooled tubes. It is something.

0012

[Operation] Cooling air is supplied from the air supply source to each air cooling pipe with the supply amount controlled by the air supply control means. The amount of heat brought into the cooling zone from the firing zone of the furnace body is absorbed by the cooling air supplied into the interior through each of the air cooling tubes, and is taken out of the furnace body.

[0013]

According to the present invention, the amount of heat brought into the cooling zone from the firing zone of the furnace body is absorbed by the cooling air flowing inside the air-cooled tubes and taken out of the furnace body. By controlling the amount of air passing through the cooling zone, it is possible to reliably control the temperature in the cooling zone without disturbing the atmosphere inside the furnace.
Since the exhaust gas released into the atmosphere only passes through the inside of the air-cooled pipe, it is completely clean hot air and can be used for various purposes such as space heating. Furthermore, according to the present invention, since the temperature of the cooling zone inside the furnace body is controlled by arranging cooling pipes in the cooling zone, the structure is relatively simple, there are few failures, and the cooling pipes can be easily replaced. It is.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a longitudinal section of an example of the cooling zone of the furnace body of the continuous firing furnace according to the present invention.

As shown in FIG. 1, on the ceiling 2a side and the hearth 2b side of the cooling zone of the furnace body 2, air cooling pipes 22,
...is placed. Each air-cooled tube 22 is made of silicon carbide (S
iC) or heat-resistant steel, on the ceiling 2a side and hearth 2b side of the small cooling zones 24, 24, ... constituting the cooling zone, respectively, along the ceiling 2a and hearth 2b of the cooling zone. They traverse the internal space 23 of the furnace body 2 and are arranged at intervals in the direction of movement of the object to be fired, which is indicated by the arrow A2. These air-cooled pipes 22, 22, . . . are arranged as shown in FIG. 2, for example.

That is, the ceiling 2a of each small cooling zone 24
side air cooling pipes 22, 22,..., and each small cooling zone 24
The air cooling pipes 22, 22, .
Connected to the output side of the The inlet side of this flow rate control valve 26 is connected to a blower 27 .

The cooling air sent out from the blower 27 is increased or decreased to the required flow rate via the flow rate control valve 26, which is controlled according to the temperature inside the furnace body 2, and then passed through the installed air cooling pipe 22. It is branched into a number equal to the number of air-cooled pipes 22, passes through the air-cooled pipes 22 through the flow rate setting valve 25 for setting the flow rate balance of each air-cooled pipe 22, and is exhausted into the atmosphere.

With such a configuration, the high temperature furnace body 2
The radiant energy emitted from the inner wall surface of the furnace body 2 or the surface of the object to be fired passing through the inside of the furnace body 2 is transmitted to the air-cooled tubes 22, 22, etc., which are kept at a lower temperature than the internal temperature of the furnace body 2. It is absorbed by. And the absorbed energy is
The heat is transferred to the cooling air flowing through the air-cooled pipes 22, 22, .

The amount of heat transferred from the inner wall surface of the furnace body 2 or the object to be fired to the air-cooled tubes 22, 22, . . .
The surface temperature of the air-cooled pipes 22, 22, . . . is determined by the balance between the air flow rate temperature passing through the air-cooled pipes 22, 22, . . . and the amount of radiant heat absorbed by the air-cooled pipes 22, 22, .

Therefore, the current in the heater (not shown) disposed in the furnace body 2 for firing the object to be fired and the amount of air introduced into the air cooling tube can be considered in exactly the same way.
By controlling the amount of cooling air input, the temperature inside the furnace body 2 can be reliably controlled.

In the above description, an embodiment has been described in which the cooling pipes 22, 22, . . . are arranged on the ceiling side and the hearth side of the cooling zone inside the furnace body 2.
may be arranged on at least one of the ceiling side and the hearth side of the cooling zone inside the furnace body 2.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of the structure of a cooling zone of a continuous firing furnace according to the present invention.

FIG. 2 is an explanatory diagram of air-cooled pipe piping of the continuous firing furnace in FIG. 1;

FIG. 3 is an explanatory diagram of a general continuous firing furnace.

FIG. 4 is a longitudinal sectional view of a cooling zone of a furnace body of a conventional continuous firing furnace.

[Explanation of symbols]

1 Base 2 Furnace body 2a Ceiling 2b Hearth 5 Entrance 6 Exit 8 Partition wall 9 Small cooling zone 22 Air-cooled pipe 23 Internal space 24 Small cooling zone 25 Flow rate setting valve 26 Flow control valve 27　Blower

Claims (1)

[Claims] Claim 1: A furnace body having a tunnel-shaped internal space communicating from one open end side to the other end open side, the interior of the furnace body extending from the one end open side to the other end open side as a preheating zone, a firing zone, and a cooling zone. It is a continuous firing furnace in which the object to be fired is fired in the process of moving from the opening at one end to the opening at the other end, and the furnace body has at least one side on the ceiling side and the hearth side of the cooling zone. air-cooled tubes, each of which crosses the internal space and is arranged at intervals in the direction of movement of the object to be fired; an air supply source that supplies cooling air to these air-cooled tubes; 1. A continuous firing furnace comprising: air supply control means for controlling the amount of cooling air supplied.