1000ºF Rotary Hearth Oven Treats Machined Metal Shafts

Grieve Corp.’s No. 982 is a 1000ºF, electrically-heated rotary hearth oven used for heat treating machined metal shafts. The oven’s workspace dimensions measure 24” W × 11” D × 30” H with a 26” diameter hearth constructed from overlapping steel plates with 24 pipes holding pin inserts to support the workpieces.  

24-kW installed in Incoloy sheathed tubular heating elements provide power, while a 1,000-cfm, 1-hp recirculating blower provides radiant horizontal airflow to the workload. An additional cooling blower is mounted beneath the loading table to cool the parts in the front middle three positions of the hearth. 

The hearth is driven by a ¼-hp motor through a gear reducer with torque limiting device, variable from 0.1 to 0.5 revolutions per hour. A loading table is provided in front of the oven to hold extra pin inserts.

This oven features an aluminized steel exterior and interior, an exhaust hood around the openings in the face of the unit with a 130-cfm exhaust fan, plus an integral oven leg stand.  The 8” thick wall insulation comprises 2” of 1900ºF block and 6” of 10-lbs/cf density rockwool. 

Controls on the rotary hearth oven include a digital indicating temperature controller, manual reset excess temperature controller with separate contactors, recirculating blower airflow safety switch, fused disconnect switch and a 10” circular chart recorder.