In primary reformer operation, combustion air ID Fan Failure might be  one of highest level emergency shut down cases. All the Feed, Fuel, hydrogenation gas feed should be cut off except only minimum steam feed

In this case,  I'm concerned about  thermal shock of reformer tubes because of overheating or overcooling.

Dose anybody has experences about above case??? what could be happen in reformer furnance and tubes?  overheating? overcooling?

what kinds of protection or control system could be installed to prevent from thermal shock of reformer tubes in this case???