Theoretical Analysis of Temperature of Substrate Inserted between Parallel Plates Based on Radiation Heat Transfer Model

Abstract

An effective design method of the infrared heating furnace has not yet established, because there are the complexity and variety in the products and the heating form. We focused on the heating system of the emission subject for a thin substrate such as film, and expressed it in a concise unsteady numerical model within the three parallel plates. As a result, it was shown that the temperature of the intermediate surface “substrate” changes depending upon the combination of the emissivity of each surface, even with the constant injection energy. Especially, in the case of vacuum furnaces, a combination of “high emissivity of heating surface and low emissivity of non heating surface” is desirable to raise the temperature of substrate more. In addition, the lower emissivity of substrate surface is, the higher arrival temperature of substrate becomes, in the case that the heating surface and non heating surface have the same emissivity, and both walls have the same thickness, thermal conductivity and outer heat transfer coefficient. Since this tendency is extremely difficult to grasp intuitively, it is very worthy in the efficient design of furnaces to calculate a large number of patterns using the numerical model proposed in this article, and to conduct careful comparisons and evaluations.

Keywords

• thermal radiation
• emissivity
• furnace
• heat transmission
• numerical analysis