INFRARED DRYING OF A PLATE IN A CONTINUOUS ELECTROMAGNETIC FIELD

Absorption of electromagnetic energy by a plate in an infrared frequency range is considered. A linear problem (constancy of process parameters) of infrared heating of the plate under conditions of convective heat and mass transfer of its surface with an external gas medium is formulated and solved analytically both for the general process of drying and for drying in the fi rst period. In formulating the heat conduction problem, it is assumed that the internal heat source caused by the absorption of radiant energy is distributed exponentially over the plate thickness and that phase transformations during moisture evaporation occur near the plate surface. The drying intensity is described on the basis of the analytical solution of the linear (constancy of mass conductivity) problem of mass conductivity (diffusion of moisture) for the plate under the boundary condition of mass transfer of the third kind. Solutions of the problems of heating are obtained in relation to local and body volume-averaged temperatures. They are used as the basis for numerical simulation of the process of heating a plate with account for its drying: the infl uence of the drying intensity and radiant fl ux density on the plate heating dynamics is shown. As applied to the fi rst period of drying, it is shown that the particular solution obtained in this case for the problem makes it possible to calculate the drying intensity, as well as the local and volume-averaged temperatures of the plate under the conditions of infrared energy supply. The article presents the procedure of determining the drying intensity in the fi rst period with the use of the Antoine equation for calculating the saturated vapor pressure near the plate surface from the plate surface temperature determined from the solution obtained
   
Author:  S. P. Rudobashta ,  É. M. Kartashov ,  G. A. Zueva
Keywords:  drying, infrared (IR) heating, convective heat and mass transfer, analytical solution
Page:  357