(409b) Experimental Analysis of Drying of Paper and Board

In conventional multi cylinder drying of paper and board both conductive drying from steam heated dryer cylinders and convective drying by flowing air over the surface in the pockets are used. Conductive drying from steam heated drying cylinders is a critical component in providing the necessary thermal energy to paper and board as they are dried. Steam temperature, internal and external resistances at the contacting surface are critical process parameters influencing the conductive drying process. An experimental setup was developed to study the conductive drying of paper and board. Paper sheet moisture, temperature as well as the temperature distribution within the heated platen and the instantaneous heat flux as the sheet is being dried were measured. The instantaneous heat flux, contact heat transfer coefficient and the drying rates were determined as drying proceeds. Experimental results as well as comparison to literature and commercial data are presented. The conductive heat transfer coefficients determined were compared to traditional correlations normally used in the modeling of paper drying. We are also developing a combined conductive and convective drying of paper and board and the potential inclusion of auxiliary energy components. Preliminary experimental results from the conduction and convection drying system will also be presented. This data will be useful in process development, intensification of manufacturing processes and modeling and simulation of paper drying processes.