Lucifer Furnaces designed a furnace to meet the heavy loads of a supplier of automotive safety equipment. A box furnace with a chamber size of 24 inches high x 24 inches wide x 24 inches long was customized to support a 1,000-pound load of molds for heat treating at 750°F. It will be used for annealing and stress relief of die-cast tools. The furnace is lined with 6.5 inches of insulating firebrick and mineral-wool block on sidewalls and below hearth, and ceramic-fiber pyroblock modules line the roof.
Coiled-wire heating elements in easy-to-replace holders are located on both sidewalls as stacked arrays. A special 1.5-inch-thick hearth plate was designed to sit atop heavy-duty piers to support the load, protect the floor insulation and provide a flat working surface.
Safety features include an auto-disengage feature to shut off power to heating elements when the door is opened to eliminate electric-shock hazard. Controls include a Honeywell DC2500 microprocessor-based digital time-proportioning temperature controller programmed with a single-setpoint heat ramp.