Grieve’s No. 847 electrically heated, 500ºF, rotary hearth oven is designed to preheat magnesium alloy castings prior to a shrink-fit operation. The 48" × 48" × 60" oven is heated by 34.8-kW Nichrome heating elements, while a 2,000-cfm, 2-hp, recirculating blower provides horizontal airflow across the load. A two-tiered, 44" diameter solid hearth with perforated separators at 90 degrees is manually rotated during loading and unloading.
The oven features 4" insulated walls, an aluminized steel interior and exterior, plus two independent, air-operated doors for access to the workspace.
To handle flammable solids, on-board safety equipment includes explosion-venting door hardware, a manual reset controller for excess temperature, a back-up heating element relay, a separately powered forced exhauster, an exhauster airflow safety switch, a recirculating blower airflow safety switch and a purge timer. A digital indicating temperature controller is also included on this oven.