AN ANALYSIS OF THE HEAT-TRANSFER CHARACTERISTICS OF THE FIN REFRACTORY SYSTEM IN A CYCLONE FURNACE

Cyclone furnaces have been in use for steam generation for over 45 yea rs. The tubes that form the rear wall of the cyclone furnace, called t he reentrant throat, are prone to warping, which results in gaps betwe en the tubes. These gaps should not be present, as they allow fuel to escape from the furnace without burning. The colloquial term, ''picket fence, '' is used to describe these gaps because of their resemblance to a wooden picket fence. Many gap-filling techniques have been utili zed over the years, but none has completely solved the problem of recu rring gaps. An investigation, both theoretical and experimental, has b een conducted to determine the heat transfer characteristics of the fi n / refractory system used to fill these gaps. Ample evidence suggests that thermal stresses in the weld joint between the fin and the tubes contribute to the failure of the fins.