What is the maximum allowable cool down rate included in the dryout plan?

The maximum allowable cool down rate included in the dryout plan is important to ensure the refractory materials do not experience thermal shock, which can lead to cracking, spalling, or other failures. A cool down rate of 150°F (85°C) per hour is generally accepted as a safe maximum. This rate allows the refractory to adjust to temperature changes without inducing stress that could compromise its structural integrity.

Adhering to this maximum cool down rate is key during the initial stages of drying out newly installed refractories or after hot repairs. Exceeding this rate could introduce rapid temperature differentials within the refractory material, increasing the risk of degradation. Thus, the inclusion of a 150°F (85°C) per hour rate aligns with industry best practices for maintaining the longevity and durability of refractory linings in high-temperature applications.