Lucifer Furnaces supplied several convection ovens to a manufacturer of small medical parts in the southern U.S. Model 42-B18 has a working chamber size of 9”H x 9”W x 18”L and heats to 1200°F. Uniformity is achieved with recirculating air flow; a rear mounted heavy duty fan directs air along side wall heating elements then through the working zone. Parts are protected from heating elements with a 16 gauge stainless steel liner. Furnaces are insulated with 4.5” of multilayered firebrick and 2” insulating cold face block with overlapped seams for reduced thermal loss. Controls onboard include a Honeywell UDC3500 digital time proportioning temperature controller with 4 20-segment setpoint programs as well as a Honeywell high limit controller to prevent temperature excursions. Side wall heating element banks consist of coil wound resistance wire in ceramic holders, making replacement easy. The furnace shell is constructed with heavy gauge sheet steel reinforced throughout to form a rigid freestanding floor model. 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 door is opened, to protect the user.
Submitted by Lucy Jones, Ljones@luciferfurnaces.com