Computer aided engineering of paper machine dryer sections at Kruger's Bromptonville mill

Computer simulation was used to study drying on three paper machines. For one machine in which condensate flow measurements seemed to indicate abnormal behavior, simulation showed that the unusual flow rate profile was in fact consistent with the detailed distribution of steam pressure and cylinder arrangement. In a second machine, simulation predicted that a 30 % speedup could be achieved by either use of a shoe press to decrease incoming moisture content from 154 % to 100 % (dry basis) or by addition of nine drying cylinders. Conversion of a third machine from newsprint to LWC production was shown to be feasible with no increase of machine room length if an impingement dryer and IR dryers were used to supplement cylinder drying to handle the increased drying load. This dryer simulator was thus shown to be very useful in assessing the performance of paper machine dryer sections, and for analyzing a great variety of options for modifications, quickly and accurately.