JPH0243037Y2 - - Google Patents

Description

[Detailed explanation of the idea]

INDUSTRIAL APPLICATION FIELD The present invention relates to improvements in the operating conditions of a rotary kiln, particularly to the refractory lining structure during initial temperature rise. BACKGROUND ART Heating of a rotary kiln to a predetermined temperature is preferably carried out at a low heating rate, especially in order to prevent damage to surrounding refractory bricks near the flame due to thermal shock. In addition, in recent years, it has become common to use solid fuel, which is cheaper than liquid fuel, to heat rotary kilns. The switch to solid fuel was made when stable combustion with solid fuel became possible. In order to reduce the amount of liquid fuel initially used in order to reduce the cost of heating up, there are many cases where heating is done rapidly to the desired temperature.
In cases where it took 10 hours or more, heating to the target temperature was performed in 3 to 6 hours. Problems that the invention aims to solve However, with the method described above, there is a risk that the refractory bricks will crack and break due to expansion due to rapid temperature rise, which will shorten the lifespan of the refractory bricks. . Means and Effects for Solving the Problems The present invention proposes the use of heat insulating materials such as asbestos, vermiculite, and ceramic fibers in accordance with the intended operating temperatures of various types of rotary kilns. It reduces the rate of heat transfer to the refractory bricks during a certain period of temperature rise, and until the material to be fired is introduced into the inner surface of the rotary kiln and plays the role of protecting the refractory bricks from the flames. By alleviating the thermal shock to which the refractory bricks are subjected and thereby protecting the refractory bricks, it is possible to rapidly raise the temperature of the rotary kiln, and it is possible to improve the life of the refractory bricks. Embodiment FIG. 1 is a partial sectional view of a known rotary kiln, in which numeral 1 indicates a refractory brick and numeral 2 indicates a can body. That is, the known rotary kiln has a structure in which the flame comes into direct contact with the ignition surface of the refractory brick 1. As a result, there was significant damage to the contact surface of the bricks. FIG. 2 is a diagram similar to FIG. 1 showing a typical first embodiment of the present invention. Number 10 indicates a part of the rotary kiln. Number 11 is a refractory brick known per se,
Number 12 indicates the can body of the rotary kiln, and number 13 indicates a heat insulating material sprayed onto the inner surface of the refractory brick 11, that is, the contact surface. Insulating materials include asbestos, vermiculite, ceramic fiber, etc., as mentioned above. This method is advantageous in that the application of the insulation material can be achieved very easily. Spraying is performed by a known method. FIG. 3 is a view similar to FIG. 2 showing a second embodiment of the present invention, and in this embodiment, a blanket made of inorganic fiber is attached to the inner surface of a refractory brick 11 lined in a can body 12 of a rotary kiln. Insulating materials such as 14
Shows the state in which it is stretched. In the first embodiment, the insulation material 1
Although it is difficult to make the thickness of the heat insulating material 3 constant, this embodiment does not have such difficulty and has the advantage that it is possible to easily attach the heat insulating material to a constant thickness. FIG. 4 is a diagram similar to FIG. 3 showing a third embodiment of the present invention, and in this embodiment, a heat insulating material 15 made of felt-like inorganic fiber is pasted on the inner surface of each refractory brick 11 in advance. After this, the can body 12 of the rotary kiln is lined with the refractory bricks 11. The feature of this embodiment is that since the inner surface of the refractory bricks is preliminarily affixed with a heat insulating material, the only work required at the site is to line the bricks, resulting in less work time. In this invention, the inner surface of the refractory brick is made into a two-layer structure consisting of the brick and the heat insulating material. Insulating materials such as blankets and paper are placed on the heated surface of the refractory bricks in advance, and insulating materials such as inorganic fiber felt or paper are placed on the heated surface of the refractory bricks, and then the inner lining is applied together with the refractory bricks. A specific example is given. The selection of these lining structures can be made depending on various conditions such as the time allowed for the work and the cost of implementation. In any of the above structures, it is also possible to change the thickness of the heat insulating layer depending on the desired heat insulating effect. In addition, in any structure, after the rotary kiln enters steady operation, the heat insulating material is worn away by the heated object or disappears due to chemical reaction, but after it has fulfilled its purpose of mitigating the thermal shock that occurs when the temperature rises, It is a phenomenon and does not affect the usefulness of the idea. Of course, the first to third embodiments can be used individually, but it is also effective to use them in appropriate combinations, or to use two of them in combination. Also the third
If the heat insulating material of the embodiment is burnt out, it can be repaired by the method of the first or second embodiment. The refractory bricks used for this purpose include basic bricks, high alumina bricks, etc. that have been conventionally used in rotary kilns, and the type thereof is not limited by the present invention. Effects of the invention In order to show the effects of the invention, if the conditions in Figures 1 and 3 are changed to Table 1, the surface temperature of the refractory brick calculated as an example is shown in Table 2. Shown below. Under the conditions set in Table 1, the surface temperature of refractory bricks can be lowered by 404.6°C in the case of the present invention compared to the conventional conditions, indicating that the usage conditions of refractory bricks are significantly improved. Become.

【table】

【table】

[Table] It has been found that almost the same excellent effects can be obtained in the embodiments shown in FIGS. 2 and 4.

[Brief explanation of the drawing]

FIG. 1 shows a part of a circumferentially cut surface of a known rotary kiln equipped with refractory bricks. Figure 2,
FIGS. 3 and 4 show a part of a circumferentially cut surface of the rotary kiln of the present invention equipped with heat insulating material and refractory bricks. Explanation of the symbols: 10...Rotary kiln, 11...Refractory brick, 12...Can body, 13, 14, 15...Insulating material.

Claims (1)

[Scope of claim for utility model registration] (1) In order to reduce thermal shock and protect the refractory bricks when the temperature of the rotary kiln increases, a heat insulating material is applied to the contact surface of the refractory bricks lined in the rotary kiln. Features a rotary kiln lined with refractory structure. (2) The scope of the utility model registration claim is a refractory lining structure for a rotary kiln according to paragraph 1, in which a heat insulating material made of asbestos, vermiculite, or ceramic fiber is sprayed onto the inner surface of a refractory brick. (3) A refractory lining structure for a rotary kiln according to claim 1, wherein the heat insulating material is a blanket or paper made of inorganic fibers. (4) The utility model registration claim described in paragraph 1 is formed by pre-pasting the heated surface of the refractory bricks with a heat insulating material such as felt or paper made of inorganic fibers, and then lining with the refractory bricks. Refractory lining structure of rotary kiln.