Lucifer Furnaces supplied several convection ovens to a manufacturer of small medical parts in the southern U.S. The ovens all have a work-chamber size of 9 inches high x 9 inches wide x 18 inches long and heat to 1200°F. Uniformity is achieved with recirculating airflow. A rear-mounted, heavy-duty fan directs air alongside wall heating elements and then through the work zone. Parts are protected from the heating elements with a 16-gauge stainless steel liner.
The furnaces are insulated with 4.5 inches of multilayered firebrick and 2 inches of insulating cold-face block with overlapped seams for reduced thermal loss. Controls onboard include a Honeywell UDC3500 digital time proportioning temperature controller with four 20-segment setpoint programs as well as a Honeywell high-limit controller to prevent temperature excursions. A horizontal swing door with adjustable latch provides a firm brick-to-brick seal while the safety switch powers off both fan and heating elements when the door is opened to protect the user.