JPS609234B2 - Brick joint construction method during furnace construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing brick joints during furnace construction that can uniformly control the thickness of brick joints in a furnace body.

Firebricks and insulation bricks used for lining blast furnaces and steelmaking furnaces have almost no shrinkage performance on their own.

Therefore, in addition to adhering the bricks together, the brick joints also serve to absorb the thermal stress caused by the expanded bricks. For this reason, the thickness of the brick joints is important (usually the joint thickness of large blast furnaces is 2 to 3 skins). Therefore, the inventor constructed a small experimental blast furnace model with an outer diameter of 4 m and a height of 3 kites and began experiments.

After the bonito flakes experiment was suspended for three months after the start of heating, the inside of the furnace was investigated and it was discovered that many of the bricks on the furnace wall were cracked and had partially fallen off. When the cause of this was investigated, it was found that the joint thickness of the furnace wall varied within a range of 1'3 to 3 times the predetermined dimension, and many cracks were observed especially at locations where the thickness deviated greatly from the predetermined dimension. As is clear from the results of the above experiments, when the brick joints are thin, the amount of thermal stress absorption deformation at the joints is small, restraining each furnace wall brick, generating large thermal stress, and causing the bricks to break. or cause the furnace wall to collapse.

On the other hand, when the brick joints are thick, the strength of the joints is weaker than that of the bricks, so the bricks cannot be supported sufficiently.Furthermore, cracks occur in the joints at low temperatures due to fluctuations in the temperature inside the furnace, and eventually It can also cause the furnace wall to collapse. Therefore, it is necessary to have a uniform joint thickness that allows opposing bricks to stick together without causing the bricks to break due to large thermal stress. However, conventionally, building a furnace with a predetermined uniform joint thickness requires a skilled worker, and it is extremely difficult for an unskilled person to construct a furnace with a predetermined uniform joint thickness in the same number of man-hours as an expert. It was difficult.

This invention enables uniform joint thickness to be easily and reliably obtained even in bricklaying by an unskilled person.Next, the method will be explained with reference to the drawings.

First, as shown in Figure 1, the material is the same as the joint mortar.
After a joint plate having a predetermined joint thickness is dried by baking or the like, the joint plate is crushed and sieved to select the granular refractory material 1 corresponding to the predetermined joint thickness. The above granular refractory 1 has an arbitrary shape, and its size is the average value 1 (a + b/2 =
1) is the dimension of the brick joint thickness. Then, about 5% of the granular refractory 1 is mixed into the joint mortar 2 during hawking to prepare a mixed mortar 3. When the mixing ratio of the granular refractories in the mixed mortar 3 is less than 5%, the effect of mixing the granular refractories decreases and it becomes difficult to make the joint thickness uniform.

Moreover, when 5% or more is mixed, the granular refractories overlap and the joint thickness becomes thick, which is not preferable. When constructing a furnace using the above-mentioned mixed mortar, as shown in FIG. 2, the mixed mortar 3 is applied to the upper surface of the bricks 4, and opposing bricks 5 are pressed against each other.
Then, the mixed mortar 3 is pushed out by the pressure of the bricks 5 and sufficiently spreads over the entire pressed surface between the bricks 4 and 5, and comes into contact with the intervening solid granular refractories 1 to form the bricks 5.
The lowering of the joints is prevented, and joints of uniform thickness are formed. In this way, brickwork is carried out one after another while forming horizontal joints and seams of a predetermined thickness. Furthermore, in steelmaking furnaces, granular refractories having joint thicknesses corresponding to the brick expansion of each furnace are made and constructed. Embodiment In accordance with the above brick joint construction method, the inventor has created an outer diameter of 4
A small experimental furnace with a blast furnace model measuring 3 feet tall was rebuilt.

However, at this time, we applied a thin coat to prevent the joints from becoming too thick. After that, the experiment was resumed, and after 3 months, 6 months, and 9 months, the experiment was stopped to investigate the cracks in the furnace wall bricks, and the relationship with the furnace life was investigated. No abnormalities were observed, and some cracks were detected 12 months later.

As is clear from this experiment, the life span was significantly extended compared to the conventional experimental method, which caused many cracks within 3 months. As mentioned above, this invention prevents variations in joint thickness by interposing granular refractories in joint mortar, and enables furnace construction to easily ensure a predetermined uniform joint thickness. First, it is possible to simplify the Aoi furnace technology, shorten the furnace construction time, and extend the life of the blast furnace.

[Brief explanation of drawings]

Fig. 1 is an enlarged front view showing the granular refractory of the present invention;
The figure is a partially enlarged longitudinal sectional front view showing the state of use of the present invention. 1... Granular refractory, 2... Joint mortar,
3...Mixed mortar, 4,5...Brick, 1
...Average value of granular refractories. Figure 1 Figure 2

Claims (1)

[Claims] 1. In bricklaying for constructing furnace bodies such as blast furnaces or steelmaking furnaces, a hybrid mortar made by mixing granular refractories of the same material as the joint mortar and with dimensions corresponding to the specified joint thickness into the joint mortar is used for the joints. A method for constructing brick joints during furnace construction, which is characterized by the ability to lay bricks and uniformly control the thickness of the brick joints.