Lucifer Furnaces Inc. received an order for an electric ceramic-fiber-lined box furnace from a U.S. stamping manufacturer of automotive products. The furnace, which has a chamber size of 12 inches wide x 18 inches long x 18 inches high, quickly heats to a uniform 2200°F (1205°C). A hot face of 2 inches of ceramic-fiber insulation with 3 inches of cold-face mineral-wool block insulation around the entire chamber maximizes heating efficiency with low power input.
Heavy-gauge, coil-wound Kanthal A1 iron-chromium-aluminum wire heating elements are supported on ceramic rods, effecting rapid heat-up. A 1-inch-thick hearth plate protects the floor insulation and supports up to 40 pounds per square foot of hearth area. Temperature is monitored by a rear-mounted Type K thermocouple and regulated by a Honeywell DC2500 microprocessor-based digital time-proportioning temperature controller.