JPS6246792B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention mainly relates to the structure of lined refractory bricks used in rotary kilns. Rotary kilns are used for manufacturing cement, lime, etc. Many efforts have been made to insulate the refractory brick lining used in rotary kilns. As a result, the thermal conductivity was 0.2kcal/m・
Excellent inorganic fiber insulation materials with temperatures below hr・℃ have also been developed. However, since such heat insulating materials are cotton-like, they have poor abrasion resistance and mechanical strength, and their uses are limited. FIGS. 1 and 2 are side views of bricks having a conventional fireproof and heat-insulating structure using the above-mentioned inorganic fiber heat insulating material. FIG. 1 shows a two-legged insulating brick, and FIG. 2 shows a three-legged insulating brick. The brick main body 1 made of a fire-resistant material and the inorganic fibrous heat insulating material 2 having low mechanical strength are skillfully combined to achieve heat insulation utilizing the high heat insulation properties of the inorganic fibrous heat insulating material 2. In the conventional fire-resistant heat-insulating structural bricks shown in FIGS. 1 and 2, high heat-insulating properties can be obtained with a relatively thin heat-insulating layer. However, upon closer examination,
There was more heat drift inside than expected. FIG. 3 is an explanatory diagram showing the flow of heat inside a conventional fireproof insulation structure brick. Arrows 5 indicate the heat flow flowing within the brick body 1. Since the brick main body 1 made of a fire-resistant material has a relatively higher thermal conductivity than the heat insulating material 2, the heat flow 5 avoids the heat insulating material 2 and concentrates on the foot portion 3. Therefore, on the surface B where the insulation material 2 and the shell 4 are in contact, a large temperature drop was observed compared to the case without the insulation material 2, but on the surface A where the foot part 3 and the shell 4 are in contact, It has been confirmed through experiments that the temperature is even higher than that of ordinary non-insulating bricks (see Figure 7) that do not have 2. As a result, the conventional fireproof insulation structure shown in FIGS. 1 and 2 had the following drawbacks. (1) A temperature difference occurs between a portion C corresponding to the foot portion 3 on the outer surface of the shell 4 and a portion D corresponding to the inorganic fiber heat insulating material 2. (2) Even if there is no temperature difference on the outer surface of the shell 4, the temperature on the outer surface and the amount of heat dissipated are considerably larger than when the inorganic fiber heat insulating material 2 is placed under the shell 4 with the same thickness. (3) When the shell 4 is made of iron skin, the iron skin is easily damaged because heat is concentrated on the foot portion 3. (4) Also, depending on the furnace, alkali,
Sulfuric acid, hydrochloric acid, and their compound components (hereinafter referred to as alkalis, etc.) enter the brick body 1, reach the heat insulating material 2, concentrate, and alter the quality of the heat insulating material 2. As a result, the thermal conductivity of the heat insulating material 2 and the entire heat insulating structure increases, and the heat insulating effect decreases. An object of the present invention is to eliminate the drawbacks of the above-mentioned prior art, and to reduce the temperature of the outer surface of the shell and the amount of heat dissipated.
To provide a structure of a lined refractory brick that consumes less fuel and is not attacked by alkali or the like. Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 4 shows the structure of the lining refractory brick 13 of the present invention. A predetermined number of recesses 11 are formed in the shell side surface 10 of the brick body 7. This brick body 7
is a refractory made of a material with high thermal conductivity, such as spinel brick or maguro brick.
However, it is not limited to these. A support leg 8 made of a refractory having a low thermal conductivity is fitted into or bonded to the recess 11 . The material of the support leg 8 may be, for example, dense clay brick. The support legs 8 made of low thermal conductivity refractory have (1) a thermal conductivity lower than that of the high thermal conductive material forming the brick body 7, and (2) relative to the total weight of the bricks and external forces received in an actual furnace. It has enough strength to withstand. In addition, (3) resistance to thermal effects in actual furnaces and to alkali, sulfuric acid, hydrochloric acid, and their compounds (hereinafter referred to as
It is a fire-resistant material with excellent alkali penetration resistance). The remaining space is filled with inorganic fiber insulation material 2.
are bonded together using a heat-resistant adhesive 9 having excellent alkali penetration resistance and the like. The inorganic fiber heat insulating material 2 preferably has a thermal conductivity of 0.2 kcal/m·hr·°C or less at 1000°C. The adhesive 9 has such adhesive strength that the supporting legs 8 and the brick body 7 made of a high thermal conductivity material do not shift from each other under the conditions of an actual furnace, and the alkali etc. that permeate from the heating surface 18 are absorbed by the inorganic fibers. It is a heat-resistant and alkali penetration-resistant adhesive that prevents the heat insulating material 2 from leaking. For example, there is TOBOND201 (trade name of Toshiba Ceramics Corporation). In addition, in order to prevent penetration of alkali etc., inorganic fiber insulation material 2
It is also effective to sandwich a thin metal plate between the brick and the main body 7. On the shell-side surface 10 of the refractory brick main body 7, the ratio of the support feet 8 and the inorganic fiber insulation material 2 is such that the area of the support feet 8 is 30% of the area of the surface 10.
In the above, it is desirable that the area of the inorganic fiber heat insulating material 2 is 15% or more. FIG. 5 is an explanatory diagram showing the state of the heat flow 12 within the lining refractory brick 13 according to the structure of the present invention, and no uneven heat flow is observed. Next, lined refractory brick 13 with the structure of the present invention
The results of measurements are shown comparing the performance of normal non-insulating refractory bricks 14 and conventional three-legged insulating structure bricks 15. 6 to 8 show side views of the lining refractory brick 13, the normal non-insulating refractory brick 14, and the conventional three-legged refractory insulating structure brick 15 used in the measurements. Magnesia-spinel bricks were used for each brick body 7, 16, and 1. The measurements were carried out on each heating surface 18, 19 and 6.
The temperature distribution and heat dissipation of each brick when heated to 1375°C were investigated. In the conventional three-legged insulating structure insulating brick 15 shown in FIG. 8, the temperature of the end surface A of the foot 3 in contact with the shell 4 is 515°C, which is higher than 496°C of the surface A of the non-insulating refractory brick 14 in FIG. On the contrary, the temperature was high and there was a drift of heat. Therefore, the temperature of the surface B of the insulating brick 15 where the insulating material 2 and the shell 4 are in contact is 448°C, and the temperature of the surface A of the non-insulating refractory brick 14 directly below the shell 4 in Fig. 7 is 448°C.
Although the temperature is considerably lower than 496℃, the temperature of non-insulating refractory brick 14 on the outer surface C of shell 4 is 351℃.
℃, there is not much difference between 3-leg insulation structure brick 15 and 324℃. On the other hand, in the lining refractory brick 13 according to the present invention shown in FIG. 6, the temperature of the tip surface A of the support leg 8 in contact with the shell 4 is as low as 369°C, and the temperature of the surface B in contact with the heat-resistant material 2 and the shell 4 is 357°C. There is no big difference from ℃.
This indicates that thermal drift was prevented by making the support legs 8 from a refractory material with low thermal conductivity. Therefore, the temperature of the outer surface C of the shell 4 was 265° C., and the amount of heat dissipated was significantly reduced to 6400 kcal/m ² ·hr. Table 1 shows the measurement results. A to F indicate the surfaces where the temperature was measured, and correspond to A to F in FIGS. 6 to 8.

[Table] The lined refractory brick according to the present invention is not limited to the one shown in FIG. 4, but can be modified in various other ways. Moreover, the lined refractory brick having the structure of the present invention can also be used for the walls of various kilns other than rotary kilns. 9 to 15 show other examples of the structure of the lined refractory brick according to the present invention. The structure of the lining refractory brick according to the present invention has the following effects because the inorganic fiber heat insulating material 2 having excellent heat insulation properties and the brick body 7 made of a refractory material are well combined. (1) The inorganic fibrous heat insulating material 2 is mechanically protected by the support legs 8, and the high heat insulation properties of the inorganic fibrous heat insulating material 2 can be exhibited. (2) By forming the support legs 8 from a material with lower thermal conductivity than the brick body 7, the brick body 7
It is possible to prevent thermal drift within the structure, and it is possible to achieve high thermal insulation properties that are far superior to conventional examples. (3) An adhesive with excellent alkali penetration resistance is used to bond the brick body 7 and the inorganic fiber heat insulating material 2 and to reinforce the bond or fit between the brick body 7 and the support legs 8. Legs 8 are also made of refractory material with excellent alkali penetration resistance.
It is possible to block permeation of alkali and the like from the heating surface 18 side and prevent the inorganic fibrous heat insulating material 2 from deteriorating in quality and deteriorating its heat insulating properties.

[Brief explanation of the drawing]

Figures 1 and 2 are side views of a conventional fireproof and insulating brick, Figure 3 is an explanatory diagram showing the state of heat flow inside the conventional fireproof and insulating brick, and Figure 4 is a fireproof lining according to the present invention. A perspective view showing the structure of the brick, FIG. 5 is an explanatory diagram showing the state of heat flow inside the refractory lining brick according to the structure of the present invention, and FIG. 6 is a side view of the refractory brick lining according to the structure of the present invention.
Figure 7 is a side view of a normal non-insulated refractory brick, Figure 8
The figure is a side view of a conventional three-legged insulation structure brick, No. 9
15 are perspective views showing other examples of the structure of the lined refractory brick according to the present invention. 1...Brick body, 2...Inorganic fiber insulation material,
6... Heating surface, 7... Brick body, 8... Support leg, 9... Adhesive, 12... Heat flow, 13... Lining refractory brick, 14... Non-insulated refractory brick, 15
...3-leg insulation structure brick.

Claims (1)

[Claims] 1 Any one surface of the refractory brick is occupied by a support leg made of a low thermal conductivity refractory and an inorganic fibrous heat insulating material, and the support leg made of a low thermal conductivity refractory has excellent alkali penetration resistance. and has a thermal conductivity lower than that of the refractory brick, and further adheres the inorganic fibrous heat insulating material to the refractory brick or the support leg with a heat-resistant adhesive having excellent alkali penetration resistance, etc. A refractory brick lining structure featuring: