QUENCHING OF FLAT GLASS BY IMPINGING AIR JETS

Abstract

Quenching of hot glass by impinging round air jets is analyzed. Understanding of the temperature distribution in glass is required for thermal tempering operations. In the analysis the spectral dependence of the absorption coefficient on wavelength is appropriately accounted for by solving the radiative transfer equation for the axisymmetric cylindrical geometry. Specularly reflecting boundaries are considered, and Fresnel's equations are used to predict the spectral directional reflection and transmission characteristics of the interfaces. The finite volume method is used to solve numerically the thermal energy equation. The numerical calculations have been carried out for combined forced convection and radiation cooling from the surfaces. Transient temperature distributions for parametric calculations are presented and discussed. Determination of the resulting stresses under given impingement and thermal conditions is also discussed.

Notes

Address correspondence to Dr. Raymond Viskanta, Heat Transfer Laboratory, School of Mechanical Engineering, Purdue University, 1288 Mechanical Engineering Building, West Lafayette, IN 47907-1288, USA. E-mail: [email protected]