JPH0129518Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat insulating structure for a rotary kiln lining furnace material.

As energy-saving measures for rotary kilns, various measures have been taken for the lining furnace material of rotary kilns in order to reduce heat dissipation from the rotary kiln's shell. Attempts have been made to create two-layer bricks (bokashi bricks), which are made by combining refractory bricks and heat-insulating bricks at the same time, and porous direct-lined bricks with durability in mind.

However, since a rotary kiln is a rotary furnace unlike a static furnace, each method has drawbacks in terms of workability, durability, heat insulation, etc., and is not always in a satisfactory state. The insulation structure of the lining furnace material in the firing zone, which is currently most widely used, is based on the geta-baki shape method, as shown in Figs. A heat insulating material such as fibers, fireproof insulating bricks, or lightweight heat insulating castables is attached thereto using an adhesive.

However, during long-term use, sulfates and chlorides such as K and Na present in the raw materials and fuel penetrate from the inside of the geta-brick furnace due to the insulation structure of the lining furnace material based on this geta-brick shape method. As it condenses and deposits on the insulation material, its original low thermal conductivity is lost.

The present inventors used direct bond magnesia chromium and fireproof insulation bricks [JISR2611,
As a result of the investigation after using the geta shape method consisting of the combination of Type C in Table 1 of (76), hereinafter simply referred to as JIS-C1, it was found that the JIS-C1 has a low porosity in terms of physical properties. 26.7 after use compared to 60.5% before
%, the bulk density significantly increased from 1.0 to 1.9, and the spaces were filled with K ₂ Ca (SO ₄ ) ₂ , K ₂ Na (SO ₄ ) ₂ ,
Filled with NaCl and KCl, the thermal conductivity is 1.5~
It has been revealed that the number has doubled. This tendency progresses in proportion to the usage time. That is, the geta-shaped method has the disadvantage that the heat insulating material, which is originally porous, becomes extremely dense, which greatly impairs its initial low thermal conductivity.

In order to solve the above drawbacks, the inventors of the present invention
As a result of various tests, it was found that the geta-shaped method is effective in solving the problem by blocking the passage of salts from penetrating into the insulation material. In other words, by creating a structure in which the boundary between the bricks and the insulation material is isolated and blocked by a non-breathable material, the deterioration of the insulation material due to the intrusion of K and Na salts can be prevented, thereby maintaining the original low thermal conductivity. It becomes possible to reduce heat dissipation from the rotary kiln shell over a long period of time.

Hereinafter, the present invention will be explained in more detail based on the drawings showing several examples. Fig. 1 shows the current general shape, which is a seri-type, and Fig. 2 shows the current general shape, which is a fan-type. Figure 3 shows one way to insulate these shapes made of magnesia chromium, magnesia spinel, high alumina, clay, etc.
A so-called geta-baki shape is obtained by providing a depression in the iron skin side 4 of a general shape as shown in FIG. 4, and pasting a heat insulating material 5 such as ceramic fiber or heat insulating castable into the depression. Insulating materials such as fibers used in this geta-baki shape are used, for example, during use in cement kilns, where alkaline sulfates and chlorides derived from raw fuel permeate through the bricks in gaseous or liquid form, and then the insulating material is removed. As it condenses and deposits in some areas, it becomes denser and loses its original low thermal conductivity.

FIG. 5, FIG. 6, FIG. 7, and FIG. 8 show schematic diagrams based on the present invention. FIG. 5 shows a case where the contact surface of the heat insulating material 5 with bricks is blocked by a non-breathable substance 6. FIG. 6 is a cross section taken along the - line of the heat insulating section in FIG. FIGS. 7 and 8 show a cross section of a heat insulating part when, in addition to the brick contacting surface of the heat insulating material, the side surface 3 and/or the steel shell side 4 are covered with a non-breathable material. The purpose of covering the side surfaces 3 and/or the shell side 4 is to prevent alkaline salts from penetrating into the insulation material through the joints between the bricks. Note that these non-breathable materials are bonded to the bricks and the insulation material using an adhesive. Note that the non-air permeable material here is a thin plate or foil made of steel or non-ferrous metal. Although FIGS. 5 to 8 show a serpentine shape as an example, it goes without saying that the same effect can be achieved even when the present invention is applied to a fan shape as shown in FIG.

[Brief explanation of the drawing]

Figure 1 shows the conventional seri-shaped shape, Figure 2 shows the conventional fan-shaped shape, Figure 3 shows the current seri-shaped geta-baki method shape, Figure 4 shows the current fan-shaped geta-baki method shape, and the fifth The figure is a perspective view showing the external appearance of the serrated brick according to the present invention, FIG. 6 is a sectional view taken along the line - - of FIG. 5, and FIGS. FIG. In the figure, 1...Brick body, 2...Heating surface side, 3
...Side side, 4...Steel skin side, 5...Insulation material, 6...
Non-breathable material.

Claims (1)

[Scope of utility model registration request] An air-impermeable material 6 made of a thin plate or foil of steel or non-ferrous metal is inserted into the recess of the brick skin side 4,
A rotary kiln lining brick consisting of a geta-shape with a heat insulating material 5 isolated.