JPS608314Y2 - Industrial furnace wall structure - Google Patents

Description

[Detailed explanation of the idea] This idea relates to the furnace wall structure of various industrial furnaces.

There are two types of industrial furnaces: continuous furnaces and intermittent furnaces, and the firing chambers of these furnaces in particular need to have a high insulation effect.In general, the furnace wall structure of the ceiling and side walls of the firing chambers of various industrial furnaces is as follows. It is being organized.

That is, as shown in Fig. 1, each furnace is constructed by arranging fireproof bricks 1 as the inner wall, fireproof insulation bricks or insulation bricks 2 as the intermediate wall, insulation fiber or insulation board 3 as the outer wall, and the side walls are made of fireproof bricks. A burner 5 for heating the object 4 is installed.

The refractory bricks 1, refractory insulating bricks, or insulating bricks 2 used for the furnace walls are mainly bricks with standard shapes and sizes according to JIS. The thickness of the furnace wall is 115TIr! It is often a multiple of n.

The fired product consumes a large amount of heat generated by the combustion of the fuel injected from the burner 5, but this heat is not only consumed directly for the original purpose of the firing chamber, which is firing the fired product 4, but also for other purposes. An extremely large amount of heat is absorbed and dissipated by the firing tools, waste gas, and furnace walls.

Therefore, various measures have been taken to prevent the dissipation of heat.

In order to suppress heat dissipation from the furnace walls, the insulation structure of the furnace walls is strengthened.

In order to suppress heat dissipation from the furnace wall of the firing chamber, it is necessary to strengthen the insulation of the furnace wall and to reduce the amount of heat stored in the large furnace wall.

For this reason, refractory bricks are generally not used on the walls of the firing chamber.
The furnace wall structure has excellent insulation properties using fireproof insulation bricks, insulation bricks, insulation fibers, or insulation boards.

However, when bricks are mainly used for the furnace wall structure, there is a limit to the reduction in the amount of heat storage and heat dissipation.

Furthermore, it is known to employ a furnace wall structure mainly made of ceramic fibers when it is desired to reduce the amount of heat storage and heat dissipation.

Ceramic fiber has low thermal conductivity, high heat insulation properties, light weight, and low heat storage, making it an extremely effective fireproof insulation material for suppressing heat dissipation from furnace walls.

However, when ceramic fibers are used for a long time at high temperatures of 1250° C. or higher, they deteriorate and cause peeling and other problems.

Mechanical strength is extremely low at high temperatures, but no method of supporting furnace walls has yet been established at such high temperatures.

In other words, it cannot be supported unless the temperature is below the withstand temperature of the heat-resistant metal.

Furthermore, it has disadvantages such as being weak against wind and having high air permeability.

For this reason, ceramic fibers generally cannot be used in continuous furnace firing chambers or intermittent furnace firing chambers at high temperatures of 1250° C. or higher.

It is usually used by supporting heat-resistant steel ceramic fibers on the furnace wall, which has a relatively low temperature of 1200° C. or less.

Currently, in high-temperature areas of 1250° C. or higher, refractory bricks or refractory insulation bricks are mainly used instead of ceramic fibers.

This idea was made in view of the actual state of the prior art as described above, and is an improvement of the furnace wall structure in order to take advantage of the characteristics of ceramic fibers.

Hereinafter, a preferred embodiment of this invention will be described with reference to the drawings, particularly FIG. 2 and subsequent figures.

In this invention, for example, the furnace wall structure of the firing chamber is made mainly of ceramic fibers.

As the lining of the ceiling and side walls of the firing chamber, thin-walled deformed ceiling refractory bricks 6 and similarly thin-walled side wall refractory bricks 7 are assembled into a predetermined shape, and between them and the outer furnace shell 11 (for example, made of iron plate). The furnace wall structure is equipped with ceramic fibers 8.

As illustrated in FIG. 3, the deformed refractory brick 6 for the ceiling is constructed entirely in a thin plate shape, with the central main body portion 6A having an arc shape, and flanges 6B and 6C on both sides arranged at a predetermined angle. It is formed by bending slightly outward.

FIG. 4 shows an example of a deformed refractory brick 7 for side walls.

The entire irregularly shaped refractory brick 7 is formed into a thin plate shape having a flange portion, and is shaped like a box.

The upper part 7A is inclined corresponding to the flange part 6C of the deformed refractory brick 6 for ceiling.

Ribs 7B are provided in the vertical direction for reinforcement.

There is a notch in the corner of one side where the burner 12
It is designed to be placed.

These refractory bricks 6.7 are preferably formed by casting and then fired.

Also, the wall thickness of firebrick 6.7 is approximately 5~5077!171
It is desirable to use a material with high heat resistance and mechanical strength.

. FIG. 5 shows the refractory bricks 6 and 7 as described above and other associated parts assembled accordingly.

The deformed refractory bricks 6 for the ceiling and the deformed refractory bricks 7 for the side walls are a beam-shaped refractory insulation brick 9 and a furnace shell 1 at the upper part of the side wall.
1, and its lower part is entirely supported by foundation refractory bricks 10.

These fireproof bricks 6.7 and fireproof insulation bricks 9,10
are joined together with refractory mortar.

Furthermore, ceramic fibers 8 are provided in the space inside the furnace shell 11.
are filled in layers, forming the shape shown in Figure 2.

In other words, thin deformed refractory bricks 6.7 for the ceiling and side walls are lined at a predetermined distance inside the furnace shell 11 similar to the conventional method, and a relatively thick layer of ceramic fiber 8 is placed in the space between them. is arranged.

Therefore, the proportion of the ceramic fiber layer in the entire furnace wall is extremely large.

When the above-mentioned furnace wall structure was adopted in the firing chamber of a tunnel kiln with an operating temperature of 1350°C, it was possible to use a large amount of ceramic fibers effectively and stably.
Compared to the conventional furnace wall structure shown in the figure, we were able to achieve the following remarkable effects.

In other words, if we show a specific example of the furnace wall structure of a conventional tunnel kiln as shown in Fig. 1, as shown in Fig. 6, when viewed from the inside of the furnace, high alumina refractory brick 1 (JIS 5K
36) Thickness: 114mm, fireproof insulation brick 20IS C1
) thickness 114mm, fireproof insulation brick 3 (JIS B3
) thickness l 147Mt, and veteran G thickness 25m+y
+, and the total thickness of the furnace wall including joint mortar is 37
It was 5m.

On the other hand, a specific example of a furnace wall structure that adopts this idea is 6 or 6 deformed refractory bricks with higher alumina content than the inside of the furnace. (SK37) has a thickness of 251rrIn, and the thickness of the ceramic fiber single layer 8 (FIBERF RAX) is 100 mm for the high temperature type H and 1 mm for the medium temperature type M.
00m, low-temperature L was 100mm, veteran G was 5-, and the total length was 375mm.

Table 1 shows the results of an experiment comparing the differences between the two furnace wall structures in tunnel kiln firing chambers constructed with these two furnace wall structures.

Note that temperature changes were measured at the ceiling.

The effects of this invention are shown in Table 2, and it was extremely effective in saving energy.

In addition to this, for example, reduction of the amount of heat stored in the furnace wall will shorten the temperature rise time from startup to operation during shutdown, reduction of the weight of the furnace to reduce the weight of the furnace shell metal, and reduction of large amounts of moisture during furnace construction. This had the effect of shortening the drying time of the furnace body due to the reduction in the amount of mortar used.

Note that this invention is not limited to the above-mentioned embodiments.

For example, it is most effective when applied to the furnace wall structure of the firing chamber of a continuous furnace or an intermittent furnace, but even if this idea is applied to the preheating zone or cooling zone of a continuous furnace, such as a tunnel kiln, the ceramic fiber will be more stable than before. In addition to being used as a furnace wall, it can also have effects such as improving thermal efficiency or reducing the weight of the furnace wall by reducing heat dissipation from the furnace wall.

Further, the special thin-walled special deformed refractory brick, which is a feature of this invention, can also be obtained as a precast block of castable refractory material.

Furthermore, even if part or all of the ceramic fiber of this invention is configured as a fireproof heat insulating castable, the energy saving effect can be improved compared to the conventional furnace wall structure.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the conventional furnace wall structure, Figure 2 is a cross-sectional view showing the furnace wall structure according to this invention, and Figures 3 and 4 are for the ceiling and side walls used in this invention, respectively. FIG. 5 is a partially omitted perspective view showing an example of the furnace wall assembly structure of this invention. FIG. 6 is a diagram of the refractory lining structure of the conventional furnace wall structure. FIG. 7 is a diagram showing the configuration of the refractory lining of the furnace wall structure of this invention. 6... Deformed refractory bricks for ceilings, 7. Deformed refractory bricks for open side walls, 8. Mamma ceramic fiber, 9.10... Refractory insulation bricks, 11. Bent furnace shell, 12 ······burner. Table 1 Comparison of the furnace wall structure of this invention and the conventional furnace wall structure;
Furnace wall structure Furnace wall structure Furnace inner wall surface temperature (°C) Furnace outer wall surface temperature (°C) Amount of heat dissipated (k a IA”h, r ) Amount of heat storage (kc
alA") Furnace wall weight (k□□□°) Fuel usage (ratio) 350 21 98 43700 77 350 6 80 0300 9 0.7 Table 2 Effect furnace outer wall temperature reduction rate (heat dissipated by hook) l/ (4)) Amount of heat storage l/ )) Furnace wall weight 〃 Horizontal) 1 layer of mold piece per 1 momme 〃 ($) 28.9 41.9 78.9 79.2 30.0

Claims (2)

[Scope of utility model registration request] (1) One layer 8 of thick ceramic fibers is provided in the furnace shell 11, and thin irregularly shaped refractory bricks 6.7 are arranged inside the one layer 8 of ceramic fibers, and the irregularly shaped refractory bricks 6.
．． 7 is made up of deformed refractory bricks 6 for the ceiling and deformed refractory bricks 7 for the side walls, and the deformed refractory bricks 6 for the ceiling and the deformed refractory bricks 7 for the side walls are joined with refractory mortar,
Moreover, except for the joints, the furnace shell 11 and the irregularly shaped refractory bricks 6
．． 7. A furnace wall structure for an industrial furnace, characterized in that only a single layer of ceramic fiber 8 is provided without any supporting means such as a rod between the wall structure and the ceramic fiber layer 8. (2) The furnace wall structure of an industrial furnace according to claim 1, wherein the thickness of the deformed refractory bricks 6.7 is set in the range of 5 to 50 mm.