The Grieve Corp.
No. 943 is an electrically heated 2000°F (1095°C) top-loading pit furnace with workspace dimensions measuring 24 in. wide °- 24 in. deep °- 24 in. high. Nickel chrome wire coils are supported by vacuum-formed ceramic fiber and supply 26 kW of heat to the workload. The furnace has 7-in. thick insulated walls comprising 5 in. of 2300°F (1260°C) ceramic fiber blanket and 2 in. of block insulation. A 6.5-in. thick furnace door is made of castable refractory materials. The furnace also includes an air-operated vertical lift door and a reinforced 0.5 in. steel top plate to protect the unit while loading and unloading. Safety equipment includes an adjustable, thermocouple-actuated, manual reset excess temperature controller, separate heating element control contactors and a door interlock switch.