STUDY OF HEAT AND MASS-TRANSFER DURING IR DRYING OF PAPER

A mathematical model has been developed to study the drying of paper u sing a gas-fired IR dryer. The model accounts for various phenomena : water and vapour mass transfer, conduction, convection and radiation h eat transfer. The phenomenological equations are solved with a finite difference scheme, including a modified upwind differencing scheme to account for water migration within the paper sheet. The simulation res ults illustrate the basic underlying phenomena involved in IR paper dr ying and can be instrumental to the engineer to make the detailed anal yses of such a drying process. A sensitivity analysis has shown that t he drying rate is most sensitive to parameters governing the IR heat t ransfer process whereas the paper sheet temperature is most sensitive to parameters governing the mass transfer process with the surrounding s.