Heat-shield design for glovebox applications

摘要

Heat shields can often be used in place of insulation materials as an effective211u001emeans of insulating glovebox furnace vessels. If used properly, shields can 211u001eaccomplish two important objectives: thermal insulation of the vessel to maintain 211u001ea desired process temperature and protection of the glovebox, equipment, and 211u001euser. A heat-shield assembly can be described as an arrangement of thin, properly-211u001espaced, metal sheets that reduce radiation heat transfer. The main problem 211u001eencountered in the design of a heat shield assembly is choosing the number of 211u001eshields. In determining the heat transfer characteristics of a heat-shield 211u001eassembly, a number of factors must be taken into consideration. The glovebox or 211u001eoutside environment, material properties, geometry, and operating temperature all 211u001ehave varying effects on the expected results. A simple method, for planar-211u001ehorizontal and cylindrical-vertical shields, allowing the approximation of the 211u001eoutermost shield temperature, the practical number of shields, and the net heat-211u001etransfer rate will be presented. Methods used in the fabrication of heat-shield 211u001eassemblies will also be discussed.