Heat and mass transfer transients in cylinder drying: Part I. Unfelted cyclinders



An investigation has been made of transient heat transfer and water removal on an unfelted cylinder dryer. This investigation has included the development of a theory for describing conduction of heat in the drying material and an experimental testing of the adequacy of the theory.

The theory describes the heat transfer and evaporation of water in terms of a second-order partial-differential equation and appropriate boundary conditions. Numerical solutions obtained on a digital computer are presented.

The experimental work, performed on a specially constructed laboratory dryer, included measurements of temperatures at internal points in a drying sheet and also measurements of water removed during drying.

Good agreement was found between theory and experiment, and the usefulness of the theory is demonstrated in the analysis of water removal in some drying experiments.

Although the work was primarily concerned with a description of the paper drying process, the methods should apply equally well to the drying of other materials on heated cylinders.