New approach to wet end management

Improvements in paper quality, paper machine speed and efficiency have been among the targets in papermaking. Attempts to achieve these targets have resulted in changes to the stock and water circulations. New chests, individual items of process equipment, controls and measurements have been added to overcome "bottlenecks". This cannot continue beyond the year 2000. Valmet's new approach to the stock and water system is called OpfiFeed. The company has developed a wet end concept that caters for the requirements of the papermaking process, with particular attention to the fast machines of the future. The key considerations guiding the development work were. integrated concept, simplified solutions, cost reductions and environmental aspects. The main features of the subprocesses are introduced and the main benefits are summarized. A highly efficient wet end cane achieved if the processes around the paper machine are carefully integrated with the machine. The concept features advanced measurements and controls. This means stability. A low process volume gives flexible grade changes. A simplified concept means reduced investment and operating costs. A stable and effective process is environmentally friendly. The concept has been developed for fast machines. However the subprocesses can also be utilized in rebuilds.