JPH0230435B2 - TONNERUKIRUN - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tunnel kiln, and particularly to a tunnel kiln configured to uniformly heat a product to be fired.

(Problems to be solved by conventional technology and invention) Conventionally, tunnel kilns have a side combustion type,
A top combustion chamber method or a method in which burners are installed on the top or bottom of the side wall are known, but these conventional tunnel kilns are known to have the following drawbacks: (1) Side combustion chamber In this type of tunnel kiln, the combustion gas rises to the top due to thermal buoyancy, which creates a temperature difference between the top and bottom of the product on the cart, making uniform heating impossible.

(2) In the top combustion method, conventionally there was no space between the products to be treated.
It is necessary to install a large number of burners facing each other between these burners, which makes the equipment complicated, and because combustion and combustion stop are repeated, the temperature inside the furnace fluctuates, making it impossible to achieve uniform heating.

(3) With the method of installing burners on the top and bottom of the side walls, when the tunnel kiln is enlarged, a low temperature zone is created in the middle of the processed products loaded on the trolley, making it impossible to achieve uniform heating.

(Means for Solving the Problems) As a result of various studies and experiments, the inventors of the present invention succeeded in developing the tunnel kiln of the present invention in order to solve the various drawbacks of the conventional tunnel kiln mentioned above. The technical configuration of the tunnel kiln is as specified in each of the claims above, and will be explained in detail based on the accompanying drawings showing one embodiment of the present invention.

Figure 1 is a cross-sectional view of a tunnel kiln for tile firing showing an example in which the configuration of the present invention is applied to a firing zone, Figure 2 is a schematic vertical cross-sectional view of a tunnel kiln similar to Figure 1, and Figure 3 is a burner mechanism. FIG. 3 is a detailed sectional view showing the arrangement of each member.

As shown in the figure, a plurality of burner mechanisms 3 are arranged above the shoulders of both sides of the tunnel kiln at predetermined intervals and alternately in the longitudinal direction. This burner mechanism 3 has a configuration that will be described later, and its combustion gas exhaust port (throttle port)
is arranged to coaxially communicate with the mixing section 5 provided in the kiln ceiling 2 through the furnace gas intake section 24, and the furnace gas intake section 24 communicates with the inside of the furnace through the ventilation hole 4 provided in the kiln ceiling 2. It is configured to communicate with

The lower surface of the kiln side wall 1 has a structure that is inclined toward the inside of the furnace in order to deflect the combustion gas injected from the mixing section toward the product to be processed.

FIG. 3 is a detailed view of the manner of communication between the burner mechanism 3 and the kiln ceiling. A burner gun 21 is disposed in the burner mechanism 3 through a secondary air chamber, surrounding the burner gun 21. A swirling vane 22 is provided which is rotated by a drive source (not shown). The burner tile 23 provided in the combustion gas injection part of the burner mechanism 3 serves as a throttle opening, and is disposed coaxially with the mixing part 5 provided in the kiln ceiling 2 as described above, and between the burner tile 23 and the mixing part 5. is furnace gas intake part 2
4, and the intake portion 24 is opened with the ventilation hole 4 as described above.

Furthermore, as shown at 20a, 20b and 20c in FIG. 1, by vertically disposing partition plates in the furnace for each burner mechanism, uniform heating in the kiln of the present invention can be made even more effective. As shown in FIG. 1, these partition plates may be arranged as appropriate, such as by partially hanging down from the ceiling 2 on the inside wall of the furnace, 20a, 20c, or 20b hanging over the entire length of the inside wall.

The kiln of the present invention has the above-mentioned configuration, and its operating mode will be briefly explained below; Combustion gas injected from the orifice of the burner tile 13 draws in-furnace gas from the ventilation hole 4 with its ejection energy. Both gases are mixed in the mixing section 5 and injected into the furnace. The injected hot gas descends down the kiln side wall (along with the action of the partition plate), and is deflected by the sloped surface at the bottom of the side wall toward the trolley 6 loaded with the products to be processed, as shown by the arrow, and spreads between the loaded products. The hot gas flow flows into the gap 7 and the gap 8 on the cart 6, and rises between the central portions of the cart, which has the effect of uniformly heating the product.

Although the example of the firing zone has been described above, it is obvious to those skilled in the art that the present invention can be applied to the kiln preheating zone in almost the same way. Further, the ceiling height, furnace width, lower side wall inclination angle, etc. of the kiln of the present invention are appropriately selected depending on the scale of the kiln, the purpose of use, etc.

FIG. 4 shows an example of temperature measurements at various parts within the furnace during operation of the tunnel kiln of the present invention. It was confirmed that the temperature of the object to be fired was approximately uniformly heated at 1288°C to 1300°C.

(Effects of the Invention) The tunnel kiln of the present invention has the above-mentioned configuration, and its main effects are listed as follows: (1) The hot gas discharged from the mixer is converted into the furnace circulating gas. Because it is mixed with the furnace atmosphere, the temperature difference between it and the furnace atmosphere is small. Therefore, a uniformly fired product can be obtained without giving a large shock to the product.

(2) The inner wall of the furnace is wide at the top and narrow at the bottom, and the hot gas ejected from the furnace shoulder hits the side wall and is forced into the product. Furthermore, since the hot gas flows from the top to the bottom, temperature non-uniformity due to thermal buoyancy is eliminated. This allows the firing zone temperature to be uniform even in a relatively large tunnel kiln.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a tunnel kiln for tile firing showing an example in which the configuration of the present invention is applied to a firing zone, Figure 2 is a schematic vertical cross-sectional view of a tunnel kiln similar to Figure 1, and Figure 3 is a burner mechanism. A detailed sectional view showing the arrangement of each member, FIG. 4 shows an example of the temperature measurement results inside the furnace, and in the figure: 1: kiln side wall, 2: kiln ceiling, 3: burner mechanism, 4: ventilation hole, 5: Mixing section, 6: Trolley, 7:
Product to be fired, 8: Cart leg, 9-12: Gas flow direction in furnace space, 20a, 20b, 20c: Partition plate, 21: Burner gun, 22: Swivel blade, 23:
Burner tile, 24: Furnace gas intake part.

Claims (1)

[Scope of Claims] 1. A tunnel kiln characterized in that a plurality of burner mechanisms are arranged at predetermined intervals outside both sides of the furnace shoulders of the tunnel kiln, and the lower surface of the inside wall of the furnace is inclined toward the inside of the furnace. . 2. The combustion gas throttle port of the burner mechanism and the mixing section provided on the furnace shoulder are coaxially connected via a furnace gas intake section, and the furnace gas intake section is connected through a ventilation hole provided on the furnace ceiling. Claim 1, which communicates with the inside of the furnace.
Tunnel kiln as described in section. 3. The tunnel kiln according to claim 1, wherein the burner mechanisms are arranged alternately in the longitudinal direction of the tunnel kiln. 4. A plurality of burner mechanisms are arranged at predetermined intervals on the outside of both sides of the furnace shoulders of the tunnel kiln, and the lower surface of the inner wall of the furnace is inclined toward the inside of the furnace, and a partition plate is provided inside the furnace below each of the burner mechanisms. A tunnel kiln characterized by: