Causes of spalling of furnace wall refractory materials

The stability and durability of the furnace wall refractory materials of the furnace working in high temperature and harsh environment directly affect the smooth progress of the entire production process. However, the furnace wall refractory materials often peel off during use, which will seriously affect production efficiency and safety. So, what is the reason for the spalling of the furnace wall refractory materials? Next, I will analyze it for you.

Poor construction quality: The quality of the furnace wall refractory materials is not up to standard during the construction process. For example, too much water is added to the refractory materials during the construction process, the mixing is uneven, and the anchor nails are not arranged according to the construction specifications. These problems may cause cracking and peeling of the refractory materials.

Unreasonable furnace wall design: If the furnace wall is not designed properly, it is easy to cause deformation and damage to the furnace wall, resulting in refractory material peeling. The thermal expansion and contraction characteristics of the furnace must be fully considered during the design.

Influence of thermal stress: Since the furnace wall often experiences rapid cooling and heating changes in the working process, the refractory material will frequently expand and contract with heat, causing thermal fatigue and cracking of the material, and then spalling.

Affected by material scouring: The furnace wall is often scour by high-temperature materials, especially when loading and unloading materials. If the selected refractory material does not have sufficient anti-scouring performance, it is easy to be worn and peeled off by high-speed flying sand and hot flue gas.

Mechanical stress: The rapid operation of the furnace and the high temperature environment may lead to the concentration of mechanical stress, squeezing the refractory material and causing it to fall off.

Improper selection of refractory materials: Please choose high-quality refractory materials suitable for high-temperature environments. If the wrong refractory materials are selected, the chance of spalling will increase greatly.

Negative pressure in the furnace: The negative pressure in the furnace will affect the sealing effect of the refractory material. Excessive positive pressure may cause severe wear of the refractory material and eventually lead to spalling.

Solution

In view of the above reasons, we can take the following measures to reduce or avoid the spalling problem of furnace wall refractory materials:

Optimize furnace wall design: Fully consider the temperature changes and physical stress distribution in the furnace during the design phase to ensure a reasonable and durable design.

Improve construction quality: strictly follow the construction specifications to ensure that the refractory materials are reasonably proportioned, mixed evenly, and the anchor nails are reasonably arranged during the construction process.

Choose suitable refractory materials: select high-quality refractory materials that are wear-resistant, erosion-resistant, and thermal fatigue-resistant according to the specific working conditions of the furnace.

Control the negative pressure in the furnace: adjust the negative pressure in the furnace to ensure that the refractory materials remain in good condition and are not damaged even under negative pressure.

By taking the above measures, the spalling phenomenon of the furnace wall refractory material can be effectively reduced, thereby improving the service life and production efficiency of the furnace.