Pennsylvania-based Lucifer Furnaces Inc. has designed a dual-chamber furnace for heat treating high-speed steels, such as molybdenum and chromium. The HS8 furnace heats to 2450°F in the upper chamber, and has silicon carbide heating elements mounted across the roof and below the hearth.
The upper chambers of these furnaces are insulated with 6.5 inches of combined ceramic fiber hot face and mineral wool cold face insulation for lower power demand. The lower chamber is a recirculating oven reaching up to 1600°F with a high volume rear-mounted fan directing air flow horizontally through the chamber for temperature uniformity.
A stainless-steel liner isolates the coiled heating elements from the workload. Lower chamber insulation consists of multilayered lightweight insulating firebrick hot face and mineral wool backup, dry fit to allow for thermal expansion.