JPH024395Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an improvement of a tunnel kiln used for firing ceramics, etc.

(Prior Art) Tunnel kilns have a disadvantage in that the temperature difference between the upper and lower parts of the furnace chamber becomes large in the preheating zone where no burner is provided, which tends to cause uneven firing. For this reason, conventionally, the preheating zone is divided into a plurality of blocks, and the furnace gas is sucked from the lower part of the furnace chamber of each block, and it is blown into the furnace chamber from the ceiling of the furnace chamber, thereby forming a circulating flow in the furnace. It uses a structure that eliminates temperature differences between the top and bottom. However, in blocks where the temperature inside the furnace near the entrance of the preheating zone is around 100 to 200°C, dew condensation tends to occur in the circulation fan equipment, which may adversely affect the quality of the fired product. In addition, blocks with a furnace temperature of 200°C or higher do not have the problem of condensation as described above, but there is a problem in that there is a temperature difference between them and the circulation block on the low temperature side, making it difficult to form a smooth heat curve. .

(Problems that the invention attempts to solve) This invention solves these conventional problems,
It was completed with the aim of creating a tunnel kiln that not only can reduce the temperature difference between the top and bottom of the furnace chamber, but also can easily form a smooth heat curve, and there is no risk of condensation forming on the circulation fan, etc.

(Means for solving the problem) The present invention divides the preheating zone into a plurality of blocks, and each block has a system in which the furnace gas is sucked in from the suction port at the bottom of the furnace chamber, and the gas is transferred into the furnace from the air outlet in the ceiling of the furnace chamber. A circulation fan is provided to blow air to the furnace, an outside air intake is formed in this circulation path, and a communication path is provided to take in part of the furnace gas from the high temperature side block into the circulation path of the low temperature side block. It is characterized by:

(Embodiment) Next, the present invention will be explained in more detail with reference to the illustrated embodiment. Reference numeral 1 denotes a furnace body of a preheating zone of a tunnel kiln, which is divided into a plurality of blocks as shown in the figure. Each block has multiple suction ports 2 at the bottom of the furnace chamber.
A suction-side manifold chamber 3, a circulation fan 4, a discharge-side manifold chamber 5, and a large number of blow-off ports 6 on the ceiling of the furnace chamber are respectively provided for the furnace gas sucked from these suction ports 2. The structure is such that the furnace gas sucked from the lower part of the furnace chamber can be blown into the furnace chamber from the ceiling of the furnace chamber. In the present invention, the discharge side manifold chamber 5 of the block on the high temperature side and the suction side manifold chamber 3 of the block on the low temperature side are used.
A communication passage 7 is provided between the two blocks, so that a part of the high temperature furnace gas of the high temperature side block is introduced into the circulation path of the low temperature side block. Further, in the present invention, an outside air intake port 8 is formed on the suction side of the circulation fan 4, so that the required amount of outside air can be taken in. In addition, in the block closest to the firing zone, a gas discharge port 9 is formed on the discharge side of the circulation fan 4 to discharge the furnace gas into the atmosphere, so that high-temperature gas flowing from the firing zone can be extracted. There is.

(Function) In the device configured as described above, the furnace gas is sucked from the suction port 2 at the bottom of the furnace chamber for each of the plurality of partitioned blocks, and the gas is sucked from the air outlet 6 at the ceiling of the furnace chamber by the circulation fan 4. Similar to the conventional method, a circulation flow is formed by blowing into the furnace chamber to reduce the temperature difference between the upper and lower sides of the furnace chamber. However, in the present invention, a part of the furnace gas of the block on the high temperature side is taken into the circulation path of the block on the low temperature side, so there is no condensation on the circulation fan 4 even in blocks where the furnace temperature is about 100 to 200°C. This eliminates the temperature gap between the block on the low temperature side and the block on the high temperature side, making it possible to form a smooth heat curve. Moreover, in the present invention, by introducing outside air into the circulation path from the outside air intake port 8, the temperature of the gas blown into the furnace chamber from the air outlet 6 on the ceiling of the furnace chamber can be freely adjusted. The temperature difference between the upper and lower sides can be effectively eliminated. This reduces the temperature difference between the top and bottom, which was around 100℃ with conventional circulation methods.
We were able to reduce the temperature to about 50-60℃.

(Effects of the invention) As is clear from the above explanation, the present invention can reduce the temperature difference between the top and bottom of the furnace chamber in the pre-heating zone, form a smooth heat curve in the longitudinal direction of the furnace, and It has many advantages such as no condensation on the circulation fan, which prevents "drying failure" of ceramics and stabilizes the quality of fired products. . Therefore, the present invention has extremely great practical value as a tunnel kiln that eliminates the problems of the conventional method.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of the present invention. 2...Suction port, 4...Circulation fan, 6...Blowout port, 7...Communication path, 8...Outside air intake port.

Claims (1)

[Scope of utility model registration request] The preheating zone is divided into a plurality of blocks, and each block is provided with a circulation fan 4 that blows the furnace gas sucked in from the suction port 2 at the bottom of the furnace chamber into the furnace chamber from the air outlet 6 on the ceiling of the furnace chamber. A tunnel kiln characterized in that an outside air intake port 8 is formed in the passage, and a communication passage 7 is provided for introducing a part of the furnace gas of the high temperature side block into the circulation passage of the low temperature side block.