Solar Manufacturing’s new vacuum purge/gas nitriding furnace will utilize two graphite gas recirculation radial fan wheels for processing ammonia gas at atmospheric pressure. The 14-inch-diameter fan wheels employ a reinforced radial-wheel design with six straight blades of 3/8-inch fan blade width. The specially engineered wheels will enable convection heating within the furnace, circulation during nitriding and will also run to assist in gas cooling. This convection process is performed in temperatures up to 1250°F, with the graphite wheels rotating to 1,800 rpm, and driven from dual 3-HP vacuum-sealed motors operating from a variable speed drive.