Mechanism of the First Falling Rate Period: An Alternative Approach by Image Analysis

Abstract

An alternative experimental approach using the image luminosity of a drying surface photographed by a bore scope was conducted in order to elucidate the drying mechanism for the first falling rate period including the critical moisture content. The observed luminosity was in fair agreement with the luminosity predicted from the model of the configuration of water, indicating that the configuration of water plays a critical role for the drying mechanism, especially for the first falling rate period and the critical moisture content. The parameters of the configuration of water estimated in this work could be effective for prediction of drying rates along with other transport properties.

Keywords:

• Critical moisture content
• Funicular state
• Luminosity
• Moisture distributions
• Pendular state

Notes

^a The value of φ _fs is cited from the data of packed particle beds. ^[31]

^b The value of k ₀ is cited from the data of packed particle beds. ^[34]

^c k _r is Verma correlation. ^[35]