Heating a Graphite Susceptor in a Bell Jar
To heat a graphite susceptor to 1200°C through the use of a helical inductor with a minimum inside diameter of 4”. Time to temperature and temperature gradients throughout the sample are of special concern.
Parts & Materials Description
Graphite susceptor “boat” measuring 4” wide, 2.5” long, 0.5” thick
Induction Heating Equipment
Bell jar protective atmosphere heating system with 7.5 kW induction supply, IR optical pyrometer, specially designed inductor (coil)
A specially-designed seven-turn helical inductor was used to provide optimal heating efficiency. An optical pyrometer was utilized to ensure accurate temperature measurement. Initial tests were conducted to establish a heating profile and determine time to temperature. RF power was applied for 7 minutes. The susceptor reached a temperature of 1200°C with a temperature gradient of 55°C across the boat.
Successful, even heating was achieved by heating the graphite susceptor with the 7.5 kW power supply in a protective atmosphere.
Innovative Induction Heating