Efficient high temperature radiant furnace

Abstract

A tubular radiant furnace having multiple radiation shields is capable of producing very high working temperatures in an extremely clean environment. A cool-walled quartz muffle tube surrounded by high temperature electrical heaters in a high temperature cavity defines the work chamber. Concentric radiation shields around the tube and the heaters are supplemented by end shields at both ends to form the high temperature cavity. The shields reduce the radiative loss from the tube and create a uniform high temperature cavity without adding significant thermal inertia to the system. The low thermal inertia leads to a fast response time for the furnace to heat up or cool down. A workpiece located within the working chamber sees the radiant field with a view factor that approaches 100 percent (100%), and this helps make possible the attainment of very high and uniform temperatures. The effect is enhanced by the proximity of the workpiece to the center of the working chamber. The furnace is capable of producing temperatures above 1,800K, and it is believed capable of operating in ranges up to 3,300K. Furnaces of this type are useful in the production of semiconductors and other materials that require very clean and uniform high temperature conditions. They are also useful in the production of materials that require very rapid heat up or cool down conditions.