Drying paper by impinging jets of superheated steam. Part 1: Constant drying rate in superheated steam

Over a wide range of operating conditions, the drying of paper by impinging jets of superheated steam proceeds by a constant rate period followed by a falling rate period. The constant drying rate, investigated here in the jet temperature range 150 ≤ Tj/ ≤ 465°C and over jet Reynolds numbers of 1000 ≤ Rej ≤ 12000, is predicted within + 12% by a heat transfer expression using Martin's (1977) correlation for the heat transfer coefficient corrected for mass transfer by the Couette flow approximation factor, and a property ratio to account for the large temperature difference between the jet and the paper.