KR840002630Y1 - Fire brick for a rotary kiln - Google Patents

Abstract

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Description

Firebrick for Rotary Kiln

1 is a perspective view showing a conventional brick shape

FIG. 2 is a partial cross-sectional view taken along line II-II of FIG. 1 showing the production situation of a furnace using a conventional brick.

3 is a perspective view showing one embodiment of a brick

FIG. 4 is a partial cross-sectional view taken along line IV-IV of FIG. 3 showing the creation of a furnace using the brick of FIG.

5 and 6 are perspective views showing another embodiment of a brick

7 is a perspective view showing a steel plate used between bricks according to the present invention

8 is a perspective view showing another embodiment of a steel sheet with a brick

The present invention relates to a refractory brick used in a cement rotary kiln light rotary furnace, and more particularly to its shape and configuration.

Grooving grooves are installed on the largest flat surface of the refractory bricks to promote early attachment and stabilization of coatings, thereby protecting the refractory bricks and increasing the thermal insulation effect of the coatings. It contributes to the reduction of defense, namely energy saving. In the rotary furnace including the cement rotary kiln, which is one of the energy-saving industries, the reduction measures are particularly taken in the recent oil situation.

The cement rotary kiln will be described as an example. The cement kiln is converted from a kiln to a rotary furnace, and is transferred to a new dry type where a preheater is climbed through wet, semi-dry, and dry. In other words, the development of the technique is so remarkable that no one else can see it.

For this reason, it is known that the fuel unit per tonne of cement clinker is also greatly reduced to less than 80 l / t from 120 l / t. However, despite the deterioration of fuel costs accompanied by the development of such device technology, the recent energy situation requires further energy saving.

On the other hand, the development of device technology has reached an advantage by the completion of the NSP method, there is little room for further improvement.

The heat balance of the current NSP kiln is shown in the table below.

Table 1 Kiln overall system thermal evaluation results (average by kiln type)

Unit 10 ³⁰ Kcal / Klinky / Ton

( ) : ratio(%)

* Investigation of SP Kiln by T-12 Cement Fuel Expert Committee Report T-12 Digestion January, 51

The first table shows how important it is to reduce the amount of heat dissipated.

This heat dissipation is mostly from the body of the rotor kiln. In other words, in order to save energy in these rotary furnaces, insulation measures for reducing heat loss from the shell of the rotary kiln are indispensable.

In cement rotary kilns and the like, there are examples in which refractory heat-resistant bricks are already employed, but are inferior to some extent in comparison with fire bricks generally used in terms of low temperature.

In addition, there is a two-layer winding method in which a refractory brick of low thermal conductivity is arranged on the side of the bark, but it is rarely employed in large diameter kilns because it is easy to cause loosening from "gaps" with the built-in brick during use. In the baking table exposed to high temperature, there are also two-layer bricks in which the grooved portion is provided on the back side of the refractory brick and the fireproof insulation material is attached to the hook, and the so-called clogs and the bark side of the refractory brick are made of low thermal conductivity material. Low strength, not suitable for long-term operation.

Cement clinker is attached to the refractory used in the baking table of the cement rotary kiln, and a coating is formed, but the coating has a thermal conductivity significantly lower than that of the refractory brick, so that a thermal insulation effect is obtained to strengthen the temperature of the refractory brick. Thus, the coating has two roles, energy saving and brick protection.

In the cement rotary kiln, the relationship between the coating thickness and the shell surface temperature is shown below.

Table 2: Relationship between shell surface temperature and coating thickness

Brick → Quality high temperature calcined basic brick 200mm thickness

Iron shell: 40mm thickness, inner diameter 5,000mm (blackness of steel shell) = 0.85

Coating inner wall temperature = 1,450 ℃

Ambient temperature: 20 ℃ (non-wind)

Thermal Conductivity: Kcal / m.h. ℃

Brick = 2.35

Coating = 1 0

* Cement Association, Fuel Expert Committee Report T-10 Digestion of Refractories for Rotary Kilns, page 46 Digestion March 47

It is an object of the present invention to provide a brick having a shape and configuration so that the coating is more easily and stably attached to the embedded refractory brick used in the rotary furnace.

Conventionally, the nose phase used for rotary furnaces is a buttercup type and a fan type as JIS is also determined. The bricks used in this design are in contact with adjacent bricks in their shape, and one or more grooves are provided on one side or both sides of the brick surface of the side having the largest planar area, and the grooves extend in the radial direction. At least open to the use surface. In the case where the grooves are provided on both sides, the adjacent bricks also have grooves that face each other in use. The groove may penetrate from the surface to the side of the steel bar or may end in the middle. The purpose of this recess is to increase the contact area between the refractory brick and the workpiece (clinker) within a range that does not damage the contents of the brick, and furthermore, the coating is continuously generated to the inside of the recess of the brick, The coating is firmly attached so that it does not fall easily. As a result, heat insulation and the improvement of the brick's durability are attained.

In the conventional shape, even if the coating is attached, the stability is lacking, and it is easily fallen off by heat shock, and as a result, the brick is suddenly raised in temperature, resulting in a large factor of damage and a large heat loss. The shape and number of the grooves are determined by the properties of the workpiece and the material and shape of the refractory brick to be applied, but the shape of the grooves must be easily filled in the grooves. When the filling is sufficient, a solid coating is formed on the heating surface and the recessed portion by the reaction of brick or the like during use to achieve the desired purpose.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated about an Example shown.

In Fig. 1, a conventional brick shape is shown, and the furnace inner surface side, that is, the use surface of the brick 2, is indicated by the reference numeral 3, and the iron skin side is indicated by the reference numeral 4. FIG. 2 shows the production state of the coating 10 in which a part of the kiln using the first brick is cut according to the arrow II-II of FIG.

As shown in FIG. 3, at least one (two in FIG. 3) of one or both (both in FIG. 3) of the use surface 3 and the largest planar portion 5 other than the iron-clad shaft 4 The recessed part 1 of the dog) is provided. The recessed part 1 is open to the use surface 3, extends radially, and ends without reaching the side of the steel surface 4, but may be penetrated (figure 5). And positions can be appropriately selected as shown in FIGS. 5 and 6.

The basic bricks (magnesia, chromium, magnesia spinal) used in the firing table of the cement rotorer kiln, lime rotary gill, etc. of the present invention are inserted with a steel tube as a base between the respective bricks. This is the role of expansion absorption using the creep properties of the steel sheet under high temperature, and the steel sheet reacts with the components in the brick to produce minerals of low melting, which serves as a kind of adhesive, and serves to structure each brick one layer. Have

On the other hand, in the case of the cement rotary kiln in addition to these steel sheet, half of the clinker to produce a low melt, thereby promoting the production of coating. Therefore, in the present invention, the brick is cut along the two recesses, or as shown in FIG. 7, the combination with the steel plate 6 in which the recesses 7 are processed along the recesses further ensures the effect. . As shown in FIG. 8, the effect is further enhanced when the portion 6a integrated with the steel sheet 6 used between the bases is extended to the use surface of the brick.

The above is based on the premise that the coating 10 is formed by filling a material such as a clinker with the clinker during use as shown in FIG. 4, but the material accelerating the adhesion of the coating 10 in the groove beforehand. You can also charge by charging. This filler is based on the intermediate between the workpiece and the embedded brick, and metal sulfides and carbonates may be added with iron oxide or alkali to make it easier to attach chromium oxide or coating to add corrosion resistance to it.

The following effects are obtained by the shape of the brick as described above.

Compared to the conventional shape, there is less coating early dropping and dropping after attaching, and the thermal insulation of the coating can be used more effectively, and the fuel raw unit can be reduced, and the stable coating of the coating is incorporated in the rotary kiln. By acting as a protection of the refractory bricks, the damage caused by thermal shock or chemical erosion can be alleviated, enabling the long-term operation of the first floor, resulting in the reduction of the basic unit of the bricks, and saving the amount of refractory fuel equivalent to the groove part. It is possible to save resources, thereby improving the recurring efficiency by reducing the amount of material.

In addition, the following effects are obtained by inserting the steel sheet according to the present invention.

1) It plays a role of expansion absorption without creep property of steel plate under high temperature.

2) The steel sheet is half of the components in the brick to produce minerals of low melting and act as a kind of adhesive.

3) It serves to structure each brick on the first floor,

4) Produces the coating because it reacts with the clinker to produce low melt.

Claims (1)

At least one recess 1 extending in the radial direction of the largest planar section 5 of the bricks, or open to the use surface 3, is provided, and the depth of the recesses 1 of the bricks is provided. Refractory brick for rotary kiln, in which a steel plate 6 having grooves 1 having a dimension added to the expansion absorbing band is superimposed on the grooves 1 of the largest flat part 5 of the brick.