The Grieve Corp.
No. 789 furnace is electrically heated to 1800 F (980 C) for use in stress relieving short metal shafts. Workspace dimensions measure 36 in. wide x 80 in. deep x 36 in. high (915 x 2,030 x 915 mm), which features 72-kW installed power in Kanthal wire heaters, supported by vacuum-formed ceramic fiber modules. Workloads are introduced on a motorized car bottom with 2500-lb load capacity, powered by a 2-hp brake motor. A roof-mounted, heat-resistant alloy-circulating fan is powered by a 2-hp motor, with V-belt drive and water-cooled bearings. Also included is a motorized damper exhaust for accelerated cooling, which uses a 975 cfm (460 liter/s) powered forced exhauster and fresh air inlet by opening the bottom car seals.