RADIATIVE DRYING MODEL OF POROUS MATERIALS

A transient one dimensional first principles model is developed for th e drying of a porous material (paper) that includes both heat and mass transfer. All three modes of heat transfer are considered; conduction , convection and radiation. The conduction is assumed to be in one dim ension, through the porous material. The convection is assumed to exis t only at the surface as a boundary condition. The radiation is assume d to be a volumetric phenomenon, so that the material internally absor bs, emits, and scatters energy. The absorption and scattering coeffici ents are spectrally dependent. Furthermore, the material is considered to have a non-unity refractive index with diffuse surfaces. In the ma ss transfer it is assumed that water exists in three phases: bound, fr ee and vapor. The results provide profiles within the material for eac h moisture phase, temperature, and pressure and the effect of radiatio n on these distributions.