High temperature vacuum furnace hot zone with improved thermal efficiency

Abstract

This invention provides a high temperature vacuum furnace including a hot zone designed for improved energy efficiency resulting in lower electrical power usage, lower manufacturing costs and easier replacement of components for lower maintenance costs. The hot zone has an outer supporting wall and an inner insulating wall surrounded by a new HEFVAC high density, high strength, low conductivity and low moisture-sensitive graphite insulation board ring connected in a unique z-shaped arrangement that contains radiant energy within the hot zone during the heat treating cycle. The hot zone further includes heating elements made of high quality graphite for increased thermal efficiency of the furnace. Also included in the hot zone are lower mass, tapered graphite nozzles that can sustain high pressure gas flow and decrease conductive heat losses from the nozzles to the hot zone chamber outer supporting wall during the heat treating cycle.