Refractory bricks are widely used materials in high-temperature equipment. They are mainly used in high-temperature environments such as furnaces, kilns, and boilers, and are subjected to multiple tests such as high temperature, impact, and wear. Although refractory bricks have excellent high-temperature resistance, some failures are inevitable during long-term use, affecting the normal operation of the equipment. This article will discuss common refractory brick failures and their solutions.

1. Cracks or breakage of refractory bricks
Cause of failure: After long-term use, refractory bricks are prone to cracks or breakage due to factors such as temperature fluctuations, mechanical vibrations, and thermal expansion. The appearance of cracks is usually due to excessive temperature changes, resulting in uneven stress in the brick body, or physical impact that causes the brick body structure to be damaged.

Solution:

Control temperature changes: Avoid excessive temperature changes in equipment such as kilns and boilers, especially during the start-up and shutdown process. Sudden temperature rises and falls will accelerate the aging of refractory bricks.
Select suitable refractory bricks: When selecting refractory bricks, suitable refractory brick materials should be selected according to the temperature and load conditions of the use environment, especially bricks with strong high temperature and impact resistance.
Regular inspection and maintenance: Check the status of refractory bricks regularly to find cracks and damaged parts in time to avoid expansion to a larger area. Partial replacement can be performed if necessary.
2. Refractory bricks fall off or peel off
Cause of failure: The fall off or peeling off of refractory bricks often occurs in high temperature, strong acid and alkali, chemical erosion and other environments. Under high temperature working environment, the surface of refractory bricks will gradually age, the hardened layer will peel off, resulting in damage to the brick structure and eventually causing fall off.

Solution:

Improve construction quality: When installing refractory bricks, ensure proper construction technology to avoid bricks falling off due to loose bonding or improper construction.
Choose high-quality refractory bricks: Different types of refractory bricks should be used in different environments. For example, acid-resistant bricks should be used in acidic environments, and alkali-resistant bricks should be used in alkaline environments to improve the erosion resistance of refractory bricks.
Strengthen maintenance: Avoid direct contact with acidic and alkaline substances during use, and strengthen regular cleaning and maintenance of the surface of refractory bricks to avoid erosion of bricks by dust or scale accumulation.
3. Expansion or contraction of refractory bricks
Cause of failure: Refractory bricks are often thermally expanded or contracted due to high temperatures during use. Under long-term high temperature, the physical structure of the bricks may change, causing deformation of the bricks. Severe expansion or contraction may affect the stability of the overall structure.

Solution:

Choose a suitable thermal expansion coefficient: Refractory bricks should use a suitable thermal expansion coefficient according to the temperature change range of the actual use environment to reduce the impact of expansion or contraction on the equipment.
Temperature control: Avoid rapid temperature changes during use, and avoid sudden heating or cooling that causes the bricks to expand or contract violently. The heating and cooling process should be carried out step by step.
Preheating treatment: For newly installed refractory bricks, they can be preheated by gradually increasing the temperature to reduce the structural stress caused by temperature changes.
4. Slag or ash accumulation on the surface of refractory bricks
Fault cause: After long-term use of refractory bricks, the contact between the materials in the furnace and the high-temperature gas may cause ash or slag accumulation on the furnace wall. Especially in industries such as metallurgy and fertilizer, the deposition of chemical components will gradually adhere to the surface of refractory bricks, affecting heat conduction and the stability of the furnace body.

Solution:

Regularly clean up ash accumulation: Regularly remove ash and slag in the furnace to prevent them from adhering to the surface of refractory bricks for a long time. Use appropriate tools for physical cleaning to avoid scratching the brick surface.
Use anti-bonding refractory bricks: You can choose refractory bricks with better anti-bonding properties. This type of brick has strong slag resistance and corrosion resistance.
Furnace airflow adjustment: Improve the airflow circulation in the furnace to avoid excessive concentration of hot air flow in certain locations, resulting in local ash accumulation.
5. Aging and fatigue of refractory bricks
Cause of failure: In a long-term high-temperature operating environment, refractory bricks will age, especially in an environment with frequent temperature changes, the performance of refractory bricks will gradually decline, resulting in weakening of its fire resistance, impact resistance, thermal shock resistance and other properties, and fatigue.

Solution:

Regularly replace aging bricks: Regularly check the use status of refractory bricks, and replace aging bricks in time to avoid further damage.
Reducing operating intensity: Reasonably control the frequency of use and high temperature fluctuations of equipment to avoid overload operation.
Use high-performance refractory bricks: Choose refractory bricks with longer service life and stronger high temperature resistance, which can effectively delay the occurrence of aging and fatigue.
6. Thermal shock damage of refractory bricks
Cause of failure: At high temperatures, the thermal shock performance of refractory bricks is extremely important. If refractory bricks are used under large temperature fluctuations, thermal shock damage may occur due to uneven thermal expansion and contraction, which manifests as cracks, peeling or fragmentation.

Solution:

Avoid sudden temperature changes: Avoid using refractory bricks in conditions of drastic temperature fluctuations, and try to ensure a smooth rise and fall of the temperature.

Rationally select refractory brick materials: Select refractory brick materials with good thermal shock stability to adapt to operating environments with large temperature fluctuations.

Gradually heat up and cool down: When starting and shutting down the equipment, a slow heating and cooling method should be used to avoid damage to the bricks due to excessive temperature differences.

Summary
Refractory bricks play an important role in high temperature environments, but with the increase of use time, different forms of failures may occur. By selecting suitable refractory brick materials, controlling equipment operating conditions, regularly checking and promptly replacing aging or damaged refractory bricks, the occurrence of failures can be effectively reduced, the service life of refractory bricks can be extended, and the operating efficiency and safety of the equipment can be improved. When facing failures, timely and scientific and reasonable solutions can minimize equipment downtime and ensure continuous and stable production.