JPH0364799B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an industrial furnace with an improved burner arrangement. Although this invention can be applied to industrial furnaces other than tunnel kilns, the following description will be made using tunnel kilns as an example for convenience.

To explain the structure of a general tunnel kiln, as shown in FIGS. 1 to 3, a furnace body 1 is equipped with a pre-preparation zone X, a firing zone Y, and a cooling zone Z in this order.
The fired product 5 is loaded onto the trolley 4 on the rail 3, and is placed at the entrance M.
Then, the preheating zone X, the firing zone Y, and the cooling zone Z are successively passed through the furnace body 1 in this order toward the outlet N.

A plurality of burners 2 are arranged in the firing zone Y. The flame from the burner 2 flows as waste gas in the direction of the preheating zone X while heating the fired product 5 in the firing zone Y, and is discharged from the chimney O after preheating the fired product 5 in the preheating zone X.

The fired product 5 that has passed through the pre-heating zone

As shown in FIG. 4, in the conventional tunnel kiln, a plurality of burners 2 are arranged at symmetrical positions on both side walls of the firing zone Y at regular intervals. In other words, the burners 2 on both sides were arranged at the same position facing each other, and the installation positions were aligned on both sides.

With this arrangement of the burner 2, the flame from the burner 2 flows in the direction of arrow C, as shown in FIG. That is, it flows symmetrically about the center line D of the firing zone Y. Then, the flame passes through the preheating zone X, becomes waste gas, and is discharged from the chimney O.

In this case, the flame from burner 2 is
rises from the front of the furnace body 1 and once reaches the ceiling of the furnace body 1,
Thereafter, it descends and flows toward the preheating zone X while heating the fired product 5.

In this way, in the case of conventional tunnel kilns,
The flow of flames from the plurality of burners 2 has a certain directionality as shown in FIG. 5, and the fired product 5 is heated along this flow.

As a result, the temperature of the flame from burner 2 reaches its maximum temperature immediately before burner 2, and decreases as the flow progresses.

For this reason, in the case of conventional tunnel kilns,
The temperature distribution in the furnace of the firing zone Y is in the front part of the burner 2,
Temperature differences were likely to occur at the ceiling of the furnace and at the portions directly above and below the fired product 5. As a result, uneven baking occurs in the baked product 5.

As a countermeasure against such a situation, the type and material of the fired product 5 loaded on the trolley 4 is generally changed in the upper part where the temperature is higher and the lower part where the temperature is lower. With conventional tunnel kilns, it was not easy to uniformly fire products made of the same material or type.

In particular, when firing new ceramic products, which have recently undergone remarkable development, uniformity of temperature distribution within the furnace is strongly required. In view of these circumstances, the disadvantage of non-uniform temperature distribution of conventional tunnel kilns becomes serious.

An object of the present invention is to provide an industrial furnace such as a tunnel kiln that can improve the arrangement of burners in the firing zone and make the temperature distribution inside the furnace uniform.

In order to achieve such an object, the present invention has a preheating zone, a firing zone, and a cooling zone in this order, and one side wall of the opposite side walls in one cross section perpendicular to the furnace length direction of the firing zone. The burners are arranged in the upper part of the side wall, and the burners are arranged in the lower part of the other side wall, and the burner arrangement in the one section is such that the arrangement of the burners in the other vertical section adjacent to each other and the burner arrangement in the one section are alternated vertically. The gist is industrial furnaces, which are characterized by the fact that they are installed.

Since the present invention has the above-described configuration, it is possible to make the temperature distribution uniform in the firing zone of an industrial furnace such as a tunnel kiln, and it is possible to significantly improve the firing performance.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIG. 6 and subsequent figures.

A tunnel kiln according to an embodiment of the present invention is equipped with a pre-preparation zone Since the band Y can be substantially the same as the conventional one, a detailed explanation will be omitted here. Note that the preheating zone X and the cooling zone Z are not fixed to the shapes shown in the drawings, and the present invention is also applicable to other shapes.

FIG. 6 shows in detail a portion of the firing zone of a tunnel kiln according to an embodiment of the invention. A plurality of burners 6 and 7 are arranged on both side walls of the firing zone at different angles in the vertical direction.

In the burner arrangement example shown in Fig. 6,
An upper burner 6 and a lower burner 7 are arranged on one side wall in a staggered or zigzag pattern. On the other side wall, an upper burner 6 and a lower burner 7 are arranged staggered or staggered. On both side walls, the upper burner 6 and the lower burner 7 are arranged at two levels in the vertical direction. In the front-back direction, the upper burner 6 and the lower burner 7 on both side walls are arranged one space apart from each other. In other words, as a combination of an upper burner 6 on one side wall and a lower burner 7 located at the bottom of the opposite side wall, a large number of combinations of upper burners 6 and lower burners 7 are arranged on both side walls. . By doing so, the burners 6 or 7 located next to each other are arranged so that their positions in the vertical direction are not the same.

In addition, as shown in FIG. 7, a trolley 8 and a fired product 9
A plurality of refractory bricks 11 are assembled to form a space 10 between them so that the flame from the lower burner 7 can pass in the direction of arrow R.

When the bricks 11 are assembled on the cart 8 to form the space 10 in this way, the flame from the lower burner 7 passes under the baked product 9 as indicated by the arrow R and rises along the opposing side wall surface. After that, it reaches the ceiling and begins to flow towards the preheating zone. The flame from the upper burner 6 passes through the space above the fired product 9, flows in the direction of arrow S, descends along the opposing side walls, and eventually flows toward the preheating zone.

Figure 8 clearly shows the flow of flame as described above. The flame from the upper burner 6 flows from the upper part of the furnace to the lower part, and the flame from the lower burner 7 flows from the lower part to the upper part of the furnace in a spiral shape and heads toward the pre-heating zone.
Furthermore, the flames from the adjacent burners 6 and 7 flow in a completely opposite direction to the swirling of the flames from the burners 6 and 7 adjacent before and after the burners 6 and 7.

Due to this combination of completely opposite flame swirls, the flame flow in the furnace of the firing zone mixes with the flow of adjacent flames while interfering with each other, forming a uniform temperature distribution while flowing to the preheating zone. I'm going. Therefore, the temperature distribution in the furnace of the firing zone is maintained uniform not only vertically but also horizontally.

When a tunnel kiln according to the present invention was prototyped and its effects were measured, the results were as follows.

A tunnel kiln with a total length of 33 m, a width of 1.9 m, and a height of 2.3 m is constructed, and a 9 m long firing zone with a cross section as shown in Figure 7 is installed in the furnace body, and an upper burner 6 is installed in the firing zone. A total of 12 lower burners 7 are installed (6 on one side wall and 6 on the other side), for a total of 24 lower burners 7 (6 on one side wall and 6 on the other side wall). A book burner was placed. When firing new ceramic products at 1350℃, the temperature distribution in each part of the furnace in the firing zone was ±
It was possible to operate while continuously maintaining the temperature at 5°C.

When an experiment was conducted under similar conditions using the conventional tunnel kiln burner arrangement shown in Figures 1 to 3, the temperature distribution inside the furnace varied by ±20°C. Therefore, continuous firing of new ceramic products has been impossible.

The present invention is not limited to the trolley-type tunnel kiln as in the above-described embodiment, but can also be applied to other types of tunnel kilns.

In the tunnel kiln according to the present invention shown in FIG. 9, no truck is used. The fixed hearth 12 is fixed in a predetermined position by assembling the bricks 17, and a space 14 is formed between the bricks 17. This allows the flame from the burner 13 to pass through the space 14 below the hearth 12. A base plate 15 is slidably provided on the upper surface of the hearth 12 so that the fired product 16 on the base plate 15 can be transported. That is, the fired product 16 is slid on the upper surface of the fixed hearth 12 by the base plate 15 and sequentially moves through the preheating zone, the firing zone, and the cooling zone.

The invention is also applicable to other configurations of tunnel kilns. For example, a single furnace with a space in the hearth through which the flame from the burner can pass,
It can also be applied to shuttle furnaces.

By applying the present invention to any tunnel kiln, it is possible to maintain a uniform temperature distribution within the furnace.

Furthermore, the same effects can be obtained even when the present invention is applied to industrial furnaces other than firing furnaces.

Furthermore, the present invention can also be applied to heat treatment or drying operations using a temporary furnace.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view schematically showing a conventional tunnel kiln, Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, and Fig. 3 is a cross-sectional view taken along line B-B in Fig. 1. figure,
Fig. 4 is a schematic diagram showing the burner arrangement in the firing zone in a conventional tunnel kiln, Fig. 5 is an explanatory diagram showing the flow of flame generated by the burner arrangement shown in Fig. 4, and Fig. 6 is a diagram showing the tunnel kiln according to the present invention. 7 is a longitudinal sectional view showing the burner arrangement shown in FIG. 6; FIG. 8 is an explanatory diagram showing the flow of flame in the burner arrangement shown in FIG. 6; FIG. 9 is a schematic vertical sectional view showing still another embodiment of the invention. 6, 7... Burner, 8... Cart, 9... Baked product, 10... Space, 12... Hearth, 13... Burner, 14... Space, 15... Base plate, 16...
Baked product, 18...burner.

Claims (1)

[Claims] 1. It has a pre-preparation zone, a firing zone and a cooling zone in this order, and among the opposite side walls in one section perpendicular to the furnace length direction of the firing zone, one side wall has an upper part and the other side wall has a lower part. An industrial furnace characterized in that burners are arranged, and the burners in one section are alternately arranged vertically with the burners in another vertical section adjacent to each other.