화학공학소재연구정보센터
KAGAKU KOGAKU RONBUNSHU, Vol.35, No.6, 639-645, 2009
Correlative Method for Drying Rate Curves of Coated Film with Constant Temperature of Hot Air
A correlative method for predicting a batch-type drying rate curve of coated film with a single volatile component upon drying with hot air at high velocity, with high humidity and in double-sided mode was proposed by using a batch-type drying rate curve for hot air of the same temperature with low velocity, low humidity and in single-sided mode. The proposed method was composed of the following three patterns: (1) changing hot air velocity, (2) changing supply mode of hot air, and (3) changing hot air humidity. No fitting parameter was included in patterns (2) and (3), while a parameter n was included in pattern (1). No transport property within the coated film was required in these applications of the correlative method. The correlative method was examined in comparison with numerically simulated results based on a numerical strict method previously proposed. Two examples were examined: a Fick-type mass transfer case and a non-Fick type case considering an accelerative effect of mass transfer caused by drying stress in the solidified part of the coated film during drying in addition to a Fick-type mass transfer. A predicting procedure and calculation were tried to obtain a batch-type drying rate curve for drying with hot air at high velocity, with high humidity and in double-sided mode from a batch-type drying rate curve for hot air of the same temperature with low velocity, low humidity and in single-sided mode. Results calculated by the correlative method proposed in this study agreed well with numerically experimental results. Accuracy of the approximation for the Fick-type case was higher than that for the non-Fick type case. A common value of the fitting parameter n was obtained from the both Fick-type and non-Fick type cases in pattern (1) of the correlative method, and the value may be correct in other cases.