General treatment methods for cracks and concave surfaces in coke oven refractory installation

Coke oven refractory masonry is a key component of the coke oven structure, and its stability and integrity directly affect the production efficiency and safety of the coke oven. However, in the actual production process, due to various reasons, cracks, concave surfaces and other defects may appear in the refractory masonry, which will not only affect the thermal performance of the coke oven, but also may cause safety hazards. Therefore, it is particularly important to deal with cracks and concave surfaces in the refractory masonry of the coke oven in a timely and effective manner.

1. Causes and treatment methods of cracks

Cracks are one of the common defects in the refractory installation of coke ovens. The main reasons for their occurrence are as follows:

1. Thermal stress caused by temperature changes: During the production process of the coke oven, the temperature will undergo periodic changes, which will cause thermal stress in the refractory masonry, thereby causing cracks.

2. Material quality problems: The quality of refractory materials does not meet the standards, such as excessive impurity content, uneven particles, etc., which will lead to insufficient material strength and easy cracking.

3. Improper construction: Improper operation during construction, such as uneven vibration and insufficient compaction, can also cause cracks in refractory installation.

There are several main methods for dealing with cracks:

(1) Surface treatment method

For smaller cracks, surface treatment method can be used. The specific method is to apply a layer of refractory repair agent on the surface of the crack. The repair agent should have good adhesion and temperature resistance. After applying the repair agent, it needs to be baked and cured to improve the repair effect.

(2) Filling method

For larger cracks, filling method is required. First, remove the debris and loose particles in the crack to ensure that the inside of the crack is clean. Then, mix the refractory repair agent with an appropriate amount of water or adhesive into a slurry, and use a tool to fill the repair agent into the crack until it is filled. Finally, bake and cure to make the repair agent tightly bonded to the refractory masonry.

(3) Mechanical reinforcement method

For severe cracks or deep cracks, mechanical reinforcement method can be used. The specific method is to drill holes on both sides of the crack, then insert steel bars or steel chisels, and fix the steel bars or steel chisels together by welding or bolting to increase the overall strength of the refractory masonry.

2. Causes and treatment methods of concave surface

Concave surface is another common defect of coke oven refractory masonry. The main causes are as follows:

1. Wear of refractory materials: As the use time of coke oven increases, the refractory materials will be worn, thus forming concave surfaces on the surface.

2. Uneven construction: Uneven vibration or compaction during construction will cause the surface of the refractory masonry to be uneven and concave surfaces will appear.

There are mainly the following treatment methods for concave surfaces:

(1) Local repair method

For smaller concave surfaces, local repair method can be used for treatment. First, remove the debris and loose particles in the concave surface to ensure that the inside of the concave surface is clean. Then, use a refractory repair agent that is the same or similar to the original refractory material for repair. During repair, attention should be paid to the uniformity and compaction of the repair agent to ensure that the repaired surface is flat and consistent with the original surface. Finally, the repair agent is baked and cured to make it tightly bonded to the refractory masonry.

(2) Overall repair method

For larger concave surfaces or more concave surfaces, the overall repair method is required. The specific method is to first clean and polish the entire concave area to ensure the surface is flat. Then, according to the size and depth of the concave surface, select a suitable refractory repair agent for overall repair. During repair, attention should be paid to the uniformity and compaction of the repair agent, and the thickness and shape of the repair layer should be controlled. Finally, the repair agent is baked and cured to make it tightly bonded to the refractory masonry.

(3) Replacement method

If the concave surface is too large or the repair effect is not good, the replacement method can be considered. The specific method is to remove the part of the refractory masonry with the concave surface and then replace it with a new refractory material. During the replacement process, attention should be paid to the bonding and sealing of the new and old materials to ensure that the replaced refractory masonry has good integrity and stability.

In short, when cracks, concave surfaces and other defects appear in the refractory masonry of the coke oven, appropriate treatment methods should be selected according to the actual situation. At the same time, in the daily production process, the maintenance and care of the coke oven should be strengthened to reduce the damage and defects of the refractory masonry.