JPS60200081A - Firebrick and rotary kiln, on inside thereof firebrick is lined - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the shape of a refractory brick for lining a rotary kiln and a rotary kiln lined with the refractory brick.

(Prior art) A rotary kiln or rotary roasting furnace with a cylindrical model has traditionally been used for the production of Portland cement clinker, roasting of sulfide ore, bauxite during the production of aluminum, and firing. It is used for the production of phosphorous fertilizer, lime nitrogen production, baking of pitch coke or petroleum coke, and drying of ore or mineral granular production.

Its structure is that a large cylinder lies slightly inclined, and raw materials are charged from above while rotating it, and the raw materials are
As the rotary kiln rotates, it moves downward and is taken out from the lower discharge port. meanwhile,
By appropriately heating the cylinder from inside or outside, the contents are baked or dried.

The reason why rotary kilns with this type of structure are used in many industries is that (1) The raw materials are stirred in the tank while moving through the rotating cylinder, so they are heated relatively uniformly. This is because it has characteristics such as being able to process; ■ being able to freely change its processing capacity; and being able to perform continuous processing.

However, even in rotary kilns with these characteristics, depending on the type of raw materials charged, since the rotary kiln is cylindrical, while the raw materials are moving on the inner surface, side slip (perpendicular to the direction of rotation) due to rotation may occur. Only the wave-like movement of the raw material occurs, and stirring and mixing may not be performed sufficiently.The part where the raw material is exposed to the heat source can be sufficiently dried or baked, but the part that is not exposed to the heat source is The purpose of drying cannot be achieved, resulting in uneven drying and burning.

One way to counter this is to increase the rotation speed of the rotary kiln, but increasing the rotation speed unnecessarily is not economical, and depending on the type of raw material, it may still be insufficient. In some cases. In addition, by increasing the rotational speed of the rotary kiln, the desired drying or baking may not be achieved due to an increase in the raw material discharge speed, and there are many disadvantages.

(Object, Structure, and Effect of the Invention) The present inventors have completed the present invention as a solution to the drawbacks of those rotary kilns.

The present invention will be explained by taking as an example a conventional rotary kiln for manufacturing pitch coke with one type of derate coker. The volatile content of raw pitch coke discharged from the coke drum of a derate coker device is generally 7 to 15%.
Contains some degree.

Next, in order to remove the volatile matter, the fresh pitch coke is charged from the top of the kiln. There, the charged raw pituti coke is heated at a temperature of approximately 1200 to 1600°C.
It is burnt and becomes burnt pitch coke with a volatile content of less than 0.3%.

In order to maintain the volatile content of this one-cooked pitch coke at a constant quality, the actual situation is that the rotary kiln is operated while appropriately adjusting the rotation speed so that the keyaki mixing in the rotary kiln is uniformly performed. .

It is an object of the present invention to further improve the quality of products by changing the shape of refractory bricks beyond the conventional shape.

Next, the present invention will be explained with reference to the drawings.

The refractory bricks used are shown in Figure 2 (1).
As shown in T2), the inner surface of the rotary kiln 5 is a perfect circle V.
So that the inside is laid out in an orderly manner,
Contact with the kiln shell 111'i! Broadly follow the rules to
The kiln has a fan shape with a concave or flat inner surface.

Therefore, the raw material passing through the inner surface of the rotary kiln is only mixed by centrifugal force due to the rotation of the kiln and friction with the refractory surface, and depending on the seed furnace for the raw material, it may not be sufficiently mixed. be.

In the present invention, a refractory brick having a convex surface on the inner surface of the rotary kiln is used. Its implementation, Q￥
In this method, the inner surface of the rotary kiln is made uneven by combining convex, concave, and planar bricks as necessary. The shape of the refractory brick of the present invention is an arc type with a convex part 3 as shown in Fig. 4, an oblique arc type with a convex part 4 as shown in Fig. 5, etc. While they are arranged in various inverted arc shapes (Fig. 2) with concentric circles on the inner surface, they are made in an inverse convex shape.

If refractory bricks having these shapes are laid all over the inner surface of the rotary kiln, the inner surface of the rotary kiln 7 will become uneven as shown in FIG.

In addition, other refractory bricks and refractory bricks conforming to the conventional shape may be combined and arranged in a staggered manner (Figures 6 and 7), or at a certain location of the rotary kiln, for example, at the back of the rotary kiln's discharge port. There is also an embodiment in which only a certain length is tightened.

In either case, as long as firebricks having the shape according to the present invention are used, they do not depart from the scope of the present invention.

Based on the conventional thinking, efforts were made to make the inner surface of the rotary kiln a perfect circle in consideration of wear and spalling of the refractory bricks, but the development agency developed a material with excellent wear resistance. The background of the present invention is that even the above-mentioned mechanically convex shape can be used satisfactorily. Further, the method for lining the rotary kiln may be the same as the conventional construction method, and does not require any special method.

(Example) Next, the mixability of the raw materials charged in a rotary kiln lined with firebrick of the present invention will be explained with reference to an example.

EXAMPLE The inner surface of a rotary kiln for baking raw pitch coke was lined in a staggered manner as shown in FIG. 6 using refractory bricks shown in FIG. 4 and refractory bricks having the conventional shape shown in FIG. 2. .

When raw pinch coke was charged into the rotary kiln and the inside of the rotary kiln was looked into, it was found that when the interior of the rotary kiln was lined with refractory bricks of the conventional shape, the motion of the raw pinch coke was a sideways slip (wavy shape perpendicular to the direction of rotation). On the other hand, the one lined with the refractory brick having the shape of the present invention had a spiral shape, and it was confirmed that stirring and mixing were good.

[Brief explanation of drawings]

FIG. 1 is an explanatory circumferential cross-sectional view of the inner surface of a rotary kiln lined with refractory bricks having the shape shown in FIG. 2. FIG. Fig. 2 (1) (2) il-i' Conventional refractory brick. FIG. 3 is an explanatory cross-sectional view in the circumferential direction of the inner surface of a rotary kiln lined with refractory bricks having the shape of the present invention shown in FIG. Figure 4 shows a refractory brick according to the present invention. FIG. 5 shows another example of the refractory brick according to the present invention. Fig. 6 shows a conventional refractory brick having the shape 't+ (Fig. 2) and a refractory brick having the shape of the present invention (Fig. 4).
FIG. 2 is a circumferential cross-sectional explanatory diagram of the inner surface of a rotary kiln lined in a staggered manner as shown in the figure. FIG. 7 is a partial plan view of a conventional refractory brick and a refractory brick of the present invention lined in a staggered manner. 1... Firebrick having a conventional shape 2 - Firebrick having the shape of the present invention Figure 1 Figure 2

Claims (1)

[Claims] (11) A refractory used for lining a rotary kiln, characterized in that the surface of the part of the refractory that faces the inner surface of the rotary kiln is a convex surface. (2) Rotary kiln In the refractory used for the lining of the rotary kiln, use refractory bricks whose inner surface is convex. The rotary kiln according to claim 2, characterized in that the portion of the rotary kiln is made of a convex surface, a concave refractory brick, and/or a flat refractory brick.