Designing Furnace Lining/Cooling Systems to Operate with a Competent Freeze Lining

The formation of a freeze lining on the hot face of furnace sidewalls to increase campaign life is an accepted concept in industry today. This is achieved through a well-engineered sidewall cooling system typically consisting of cooled copper elements, either on their own or in combination with a refractory lining. The design of the lining/cooling system to form and maintain a competent freeze lining is discussed. Heat losses under normal operating conditions are calculated as an input to the furnace energy balance. The lining/cooling system is evaluated under extreme operating conditions as this ultimately determines campaign life. Variables to be evaluated include freeze lining thickness and formation rate, copper element temperatures, cooling medium used, and required cooling density and arrangement. Steady-state and transient thermal FEA are used as tools to evaluate the lining/cooling system design.