JP4821160B2 - Coke oven door repair method - Google Patents

Description

  The present invention relates to a method for repairing a coke oven door, and more particularly, to a repair method for enabling the service life of a coke oven door to be significantly extended as compared with the related art.

  Generally, so-called “metallurgical coke” having high strength used in a blast furnace or the like is manufactured by charging raw coal containing a large amount of coal having strong caking properties into a chamber-type coke oven and subjecting it to dry distillation. In addition, many coke ovens that are currently in operation have deteriorated, but new construction is difficult from the viewpoint of the global environment. Therefore, it is an important task for iron makers to make efforts to use a coke oven as long as possible.

  By the way, each coking chamber of the coke oven is provided with an openable / closable door in order to push the produced coke out of the furnace. As shown in FIG. 1, this door has a structure in which a refractory castable 3 is incorporated in an iron frame 1, but wear is severe because it is used at a high temperature. That is, the impact is repeated after about one year of use, and a part of the castable 3 is lost as shown in FIG. Therefore, the defect portion 4 is repaired with a repair material and reused.

However, in the repair method currently employed, the close contact with the defective portion is just one step, and a satisfactory repair state is not obtained. That is, as a method of repairing the furnace lid of the coke oven, there is a proposal that a repair material including an aggregate of the same material as the defect portion is poured into the defect portion that needs repair (see Patent Document 1). Not only is it necessary to have enough spare furnace lids, ie coke oven doors, to wait for natural drying, but also refractory (repair material) adhesives (binders) that are normally used at high temperatures. In other words, a bonding agent that exhibits bonding strength at high temperatures is used to extend the life of the repair material at high temperatures. This is because if an adhesive that exhibits bonding strength at room temperature (normal temperature) is used, when used at a high temperature, it will burn out and the strength of the repair material cannot be maintained. In such a conventional repair method, an adhesive that exhibits bonding strength at a high temperature is used, and therefore, the repaired coke oven door has to be reused after waiting for complete natural drying.
JP 2000-73066 A

  In view of such circumstances, an object of the present invention is to provide a method for repairing a coke oven door in which not only the repair is performed quickly, but also the life of the repaired material after the repair can be extended as compared with the conventional one.

  In order to achieve the above-mentioned object, the inventor diligently tried to develop a new repair material, and the result was embodied in the present invention.

That is, in the present invention, when repairing the castable part of the coke oven door, the adhesive added to the repair material is one or more selected from polyvinyl alcohol, gum arabic, carboxymethylcellulose, dextrin and methylcellulose. from it, a first adhesive which express the bonding strength at room _{temperature, SiO 2: 30~60mass%, Al} 2 O 3: 5~20mass%, B 2 O 3: 15~40mass%, Na 2 O: consists 10～20Mass%, a combination of a second adhesive which express adhesive strength at high temperature, and the 10 to 16 parts by mass with respect to the mortar 100 parts by mass of the first adhesive configuring the repair material a method of repairing a coke oven door, characterized in Rukoto is contained the second adhesive, respectively 10 to 15 parts by weight.

According to the present invention, is performed and a first adhesive which express the bonding strength at room temperature, the repair in combination with a second adhesive which express adhesive strength at high temperature, during the repair, the first Bonding strength due to the adhesive is developed, and repair of the coke oven door is completed without waiting for complete natural drying. As a result, the installation of the door to the repaired coke oven is quick, and the bonding strength of the second adhesive is developed due to the thermal history that the door receives during the coke manufacturing process. Can achieve the same long life as a new product.

  Embodiments of the present invention will be described below based on the background to the invention.

  First, the inventor reviewed the conventional repair method, and if the repair material contains not only an adhesive that develops bonding strength at high temperatures but also an adhesive that develops bonding strength at room temperature, the inventor will be able to It was thought that the adhesion between the repair material and the substance (for example, a castable block) at the repaired site was improved. Then, a castable block (hereinafter simply referred to as a block) is cut out from the actual coke oven door as a specimen, and this block is mixed with an adhesive that exhibits bonding strength at high temperature and an adhesive that exhibits bonding strength at room temperature. An experiment was conducted on the adhesion performance with the repaired material.

The blocks were cut from unused coke oven doors with a size of 40 × 40 × 160 mm (block A), cut out from the smooth surface of the used coke oven doors (block B), and uneven surfaces. Three types of cutouts (Block C) were selected. In the experiment, a trapezoidal columnar (40 mmφ, 37 mmφ, height 25 mm) PP (polypropylene) mold is placed on the upper surface of these blocks, and mortar and the two types of adhesives (hereinafter referred to as “the following”) are used. the valid at room temperature first, after filling the a valid at high temperature of the second adhesive) were kneaded with water substance (corresponding to repair material), left for 2-5 days at room temperature Then, it was naturally dried and then fired at 800 ° C. for 2 hours or more. The experimental results were evaluated by measuring the adhesive strength between the block and the filling material and the compressive strength of the filling material for each sample after firing. The compressive strength of the filling material (that is, the repair material) was determined by compressing the trapezoidal column in the horizontal direction (because the strength from the top surface is over 500 kgf and there is no difference between the samples). . Moreover, in experiment, the kind and quantity of mortar and an adhesive agent were changed suitably, and it filled on various conditions.

  As a result, there is no problem even if normal mortar is mixed with appropriate amounts of the above first and second adhesives that exhibit adhesive strength at room temperature and high temperature (about 500 to 900 ° C.) and kneaded with water. A coke oven door repair method was developed that required the use of such adhesives.

A first adhesive which express the bonding strength in this room temperature, according to the method of repairing a coke oven door to use the second repair material to the adhesive in combination of expressing the bonding strength at high temperature, first, deficient Remove the coke oven door that caused the damage and fill the defect with the repair material. Since the first adhesive quickly develops bonding strength after filling, the coke oven door to be repaired can be transported, moved to the position where the coke oven was removed, and installed as a new repaired door. In addition, the repair material filled during conveyance did not fall off, and the handling could be performed smoothly. This not only shortens the repair time compared to conventional repair methods, but also prevents cracks at the repaired part and cracks when installing the door due to insufficient natural drying, etc. To contribute.

  In addition, in this invention, it does not specifically limit about the chemical composition of the mortar utilized as a repair material. This is because any chemical composition can be used as long as it can withstand the temperature during use. In addition, two types of adhesives that exhibit adhesive strength (referred to as first and second adhesives, respectively) at room temperature and high temperature are necessary. This is because an adhesive force is required at the time of construction and use.

Example 1
Examples of specific experimental results for the block A, block B, and block C are shown in Tables 1-3. In this case, the first adhesive and the second adhesive are the same as those used in Example 2 later. In Tables 1 to 3, for comparison, the first and second adhesives are not blended and only mortar is shown. From these tables, it is clear that the kneaded product according to the present invention, that is, the repair material, has both high adhesive strength and compressive strength.

(Example 2)
As the first adhesive, one or more selected from polyvinyl alcohol, gum arabic, carboxymethylcellulose, dextrin and methylcellulose are used. Further, as a second _{adhesive, SiO 2: 30~60mass%, Al} 2 O 3: 5~20mass%, B 2 O 3: 15~40mass%, Na 2 O: 10~20mass% than made an inorganic glassy A frit was used.

  Moreover, the compounding quantity with respect to the mortar of these bonding agents needed to make 10-16 mass parts of 1st adhesive agents, and 10-15 mass parts of 2nd adhesive agents into 100 mass parts of mortars. When both the first adhesive and the second adhesive are less than 10 parts by mass, the adhesive force is insufficient, and the adhesion with the castable cannot be maintained, and the first adhesive is 16 parts by mass, the second adhesive This is because if the adhesive exceeds 15 parts by mass, the blending effect is saturated, and excessive blending becomes economically negative. Furthermore, about the water used at the time of kneading | mixing, 10-30 mass parts is good. If the amount is less than 10 parts by mass, the hydration effect of the mortar does not appear, and if it exceeds 30 parts by mass, the water is too much to solidify.

  By inspection of the coke oven, castable defects were found in 50 of the total carbonization chambers (465 chambers). Therefore, the repair material according to the present invention was applied to those repairs. This door has a width of 412 mm × a height of 440 mm, and the lining castable has a thickness of 700 mm.

  First, the carbon adhering to the surface of the defective portion (see FIG. 1) is removed by a keren hammer, and the first adhesive is applied to the repair material (100 parts of mortar) prepared in advance there. 12 parts of the agent, 14 parts of the second adhesive and 15 parts of water were added and kneaded) and embedded. Then, after two days of natural drying, the mixture was heated and baked at about 800 ° C. using a gas burner for 2 hours. In addition, the average size of the defect | deletion part of a castable was length 600mm, width 700mm, and thickness 400mm.

  The repaired doors are used again in the carbonization chamber, but 430 days have passed since then, but there is no need to repair these doors yet.

  As described above, according to the present invention, the coke oven door can be repaired quickly and easily, and the service life of the repaired portion is extended as compared with the conventional case. As a result, it can be expected that the coke oven can be used for many years.

It is a perspective view which shows the defect | deletion condition of the castable of a coke oven door.

Explanation of symbols

1 Iron frame of coke oven door 2 Angle 3 Castable 4 Missing part

Claims (1)

In repairing the missing castable part of the coke oven door,
As the adhesive to be added to the repairing material, polyvinyl alcohol, gum arabic, consists carboxymethylcellulose, one selected from dextrin and cellulose or two or more, a first adhesive which express the bonding strength at room temperature, SiO _{2: 30~60mass%, Al 2 O} 3: 5~20mass%, B 2 O 3: 15~40mass%, Na 2 O: consists 10~20mass%, second adhesive expressing adhesion strength at high temperature using both the agent and the 10-16 mass parts with respect to the mortar 100 parts by mass of the first adhesive configuring the repair material, the second Rukoto the adhesive is contained respectively 10 to 15 parts by weight Coke oven door repair method characterized.

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