What is Refractory Dryout?

The refractory material was not normally thermally cured at the factory. It is not uncommon for moisture to be absorbed by the refractory during final stages of in-shop fabrication, transit to the job site, and before the upstream combustion products are first passed through the unit. Therefore, residual moisture and any absorbed moisture must be removed after installation but prior to commencement of start-up operations. Otherwise, trapped moisture will steam, causing cracking, and in many cases, the refractory will separate from the metal in large pieces

To Protect the refractory from damage. see: refer to the following site http://www.banksengineering.com/Refracdryout.htm

I can recomend a company called Cooperheat if you need any Dryout services