The Analysis of Affect Factors in Correct Coefficient of Surface Convective Heat Transfer Coefficient during Film Drying Process

Abstract

In the process of impinging dryness, surface convective heat transfer coefficient is one of the most important parameters of effecting dryness effectiveness. It is usually confirmed by testing, this paper, for film drying craftwork under impingement jet, gives the computational method of surface convective heat transfer coefficient, and analyses the effect of the three factors, which are the difference in temperature between drying medium and the surface of damp material, latent heat of solvent vaporization and pressure of drying medium, on the coefficient of correction of surface convective heat transfer coefficient by the graph. The conclusion is solvent vaporization is leading factor, if ignore its effect, the maximum error can be 20%. But when solvent is water, each factori¯s effect on coefficient of correction is less than 2%, so we can ignore the effect of coefficient of correction. At last for special dryness processing of pressure sensitive adhesive tap, relative error between calculated value and known theoretical value is5.08% by making use of the given computational method of the surface convective heat transfer coefficient, after amending it, the relative error could reduce to be3.57%. The research result can improve energy efficiency.