Impulse Drying of a South African Furnish, 2000 Engineering Conference Proceedings

David I. Orloff, Paul M. Phelan, Cristina Asensio--In June 1999, a South African furnish was used to produce linerboard on the Beloit #4 pilot machine under impulse drying conditions. Pilot experiments compared the performance of impulse drying against single-felted wet pressing, explored the impact of steam preheating, and documented the use of impulse drying in reducing furnish basis weight and increasing paper machine speed.

A major conclusion was that the furnish was a viable candidate for implementation of impulse drying technology. In particular, it was demonstrated that the technology could be used to increase production speeds by more than 14.5% and reduce basis weight by 2.5 - 5.0%, depending on basis weight. In addition, experiments confirmed that even more attractive performance could be expected if steam preheating was combined with impulse drying.

Economic calculations demonstrated that the impulse drying technology could be used to increase paper-machine productivity, on a tonnage basis, by about 13% for a dryer-limited machine. On an area basis, basis weight reductions can be used to improve productivity by as much as 21% with overall operating- cost savings of as much as $0.20/1000 square feet of production.