JPS6372786A - Door for coke oven - Google Patents

Abstract

PURPOSE:To obtain the title door free from carbon adhesion and having excellent abrasion resistance and strength, by coating the surface of a cordierite refractory material with a glass layer-forming material. CONSTITUTION:At least 90% particle size-regulated cordierite (A) (2MgO.2Al2 O3.5SiO2) and, if necessary, additives (B), such as a sintering conditioner (e.g., alumina), an applicability material (e.g., silica flour), and a binder (e.g., alumina cement), are blended together and molded, thereby obtaining a cordierite refractory material. Separately, water (E), according to necessity together with a conditioner, is added to a glass layer-forming material having a melt fall softening temp. (JIS R2204) of 1,030-1,330 deg.C and a particle size of 100mum or less obtd. by adding a frit (D) to a raw material of Li2O.Al2O3.SiO2 (C), thereby obtaining a slurry having a solid content of 50-60%. This slurry is applied to the surface of the aforesaid refractory material so as to have a thickness of 0.3-2mm, and heated at a temp. of 1,100-1,400 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application] The present invention relates to a coke oven door that suppresses carbon adhesion.

[Prior Art] Coke ovens are used continuously for a long period of 20 to 30 years after they are newly built, but recently there is a trend toward extending their lifespan to over 30 years.

However, carbon adheres to the inner surface of the coke oven door due to tar generated during coal carbonization during operation and hydrocarbons derived from the petroleum binder used during pulverized coal granulation. If the green return operation is continued, the amount of carbon adhesion will gradually increase ++ 1- 7 N
k γ It becomes impossible to move the heart to the body and cause the coke oven gas calorie to decrease due to gas leakage or air intake, which may cause problems in the operation.

Therefore, if there is a large amount of carbon attached, carbon is removed every time the product is taken out of the kiln. The working environment for carbon removal work is poor, and the work becomes extremely harsh in the summer. Additionally, mechanical carbon removal may cause cracks on the surface of the coke oven door, resulting in reduced durability and, in some cases, the need to replace the door within a short period of time.

[Problems to be solved by the invention] When the coke oven is unloaded during coke oven operation, the inner surface of the door is rapidly cooled and cracks occur due to thermal spalling. Although thermal spalling can be suppressed by using relatively low-expansion materials such as carbon fibers and cordierite refractories, this is not a sufficient measure to prevent carbon adhesion, and there is a growing demand for improvements. There is.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to provide a coke oven door that does not allow carbon to adhere to it, or to provide a door brick with pores so that even if carbon adheres to it, it can be easily peeled off without damaging the door brick during removal work. It is an object of the present invention to provide a coke oven door that has low wear resistance, good wear resistance, and strength.

[Means for Solving the Problems] As a result of various tests and studies conducted by the present inventors on coke oven doors, it was found that carbon adhesion on the inner surface of coke oven doors is caused by pores existing on the surface of refractories. I found out. Therefore, if this pore can be blocked,
The purpose of the present invention can be achieved.

That is, the present invention provides a coke oven door having a glass layer provided on the surface of a cordierite refractory.

[Function] The present invention provides a glass layer by coating the cordierite refractory surface of a coke oven door with a raw material for forming a glass layer, thereby blocking the pores on the surface with the glass layer and preventing the intrusion of hydrocarbons. This prevents gas from penetrating, thereby preventing coke adhesion.

Cordierite refractories that can be used in the coke oven door of the present invention include cordierite (2Mg0.2A 120
Clinker containing 90% or more of s ・5 S io z) can be adjusted in particle size and used alone, or alumina, calcined alumina, chamotte, etc. can be used as a sintering adjustment material, silica flour can be used as a workability material, or clinker can be used as a binding material. Alumina cement, phosphates, etc. can be added. The larger the shape of the cordierite refractory, the fewer the joints, so it is preferable, and press molding or pour molding can be used as the molding method.

For example, a slurry of a glass layer forming material is applied to the surface of the cordierite refractory by spraying, brushing, dipping, etc.

The raw material for forming the glass layer is L; 20, 12o), 5if
Frit is added to the T-based raw material, and the melting softening temperature is set to 1030.
Preferably, the temperature is 1330°C.

In addition, the melting softening temperature is the temperature when the tip of the test cone contacts the pedestal according to JIS R2204. If the melting softening temperature of the raw material for forming the glass layer is less than 1030°C, the coke oven cannot be operated. The glass layer (which is unfavorable because it lacks mechanical strength, and whose melting softening temperature is 133
If it exceeds 0°C, the heat treatment temperature of the raw material for forming the glass layer becomes high, which is not preferable in terms of cost and deformation of the coke oven door brick during baking, resulting in poor stopping.

The particle size of the raw material for forming the glass layer, such as L1□OAl2O, .5ift, is preferably fine powder with a particle size of 100 μm or less.

Water is added to this raw material fine powder, and the solid content ratio is 50 to 60%.
It is used as a slurry to treat the surface of cordierite refractories. In addition, known adjusting agents such as thickeners and peptizers can be used for the slurry.

The coating thickness of the slurry is preferably 0.3 to 21 IIm.If the coating thickness of the slurry is less than 0.3mm, parts may disappear due to wear during use, or the bricks may become smooth due to absorption of flux into the pores of the bricks themselves. Moreover, it is not preferable because it is difficult to obtain a uniform glass layer, and the coating thickness of the slurry is 2ffI11.
If it exceeds 1, it is easy to cause hexagonal cracks due to distortion due to thermal changes during coke oven operation, and there is also a slight difference in thermal expansion between the brick and glass layers, which causes problems such as peeling from the boundary. It is undesirable because of

The cordierite refractory whose surface has been treated with the slurry as described above is vitrified by heating to form a sintered body in which the glass layer and the cordierite refractory are firmly bonded.

The heating temperature is higher than the melting softening temperature of the raw material for forming the glass layer,
For example, a temperature of 1,100 to 1,400°C is preferable, and the temperature used is such that the heating causes physical welding to the irregularities on the surface of the cordierite refractory, and the reaction between the surface of the cordierite refractory and the glass to form a strong bond. is desirable.

[Example] The present invention will be further explained by referring to Examples (hereinafter, unless otherwise specified, "example" will be indicated with a star).

15 parts of water was mixed with aggregate made by adding 10 parts of alumina cement to 90 parts of cordierite clinker whose grain size had been adjusted, poured into a 600 x 450 x 450 + U++ mold, and dried at 110°C for 48 hours. Then, it was cured at room temperature for 24 hours to obtain a cordierite refractory.

9-1 The surface of the cordierite refractory obtained in Example 1 was mixed with 55% moisture in the formulation shown in Table 2 (particle size 100 μm or less) using Betalite and frit shown in Table 1 below. The added slurry was sprayed to a thickness of 0.5 mm, and the resulting cordierite refractory was heated at 1100 to 1400°C for 2 hours to sinter the cordierite refractory and vitrify the sprayed slurry. I let it happen. The properties of the obtained cordierite refractories are also listed in Table 2.

1-1-One person (weight%) Chopsticks - Sui (*1> 1000℃-air cooling test result repeated 10 times.

(*2) A cordierite refractory with a glass layer formed on its surface was cut out into a 60 x 60 x 60 m+m opening, and coal, coke powder, and petroleum binder (1:1:1) were placed on the sample, and the sample was heated for 1200 m in a reducing atmosphere. Based on visual measurements after treatment at ℃ for 10 hours.

[Effects of the Invention] According to the present invention, the surface of a cordierite refractory is coated with a raw material for forming a glass layer, and then heated to firmly bond and adhere to the surface of the refractory at the same time as vitrification.

By forming a glass layer on the surface of the refractory, the refractory has low porosity and carbon adhesion can be suppressed.Furthermore, it is not only a refractory with durable poling properties, but also a coke oven door with no peeling of the glass layer. can be provided.

Claims (1)

[Claims] A coke oven door with a glass layer on the cordierite refractory surface.