PAPPERSTILLVERKNINGSAPPARATUR SAMT FORFARANDE FOR BILDNING AV EN FUKTIG PAPPERSBANA

摘要

A microturbulence generator (8) for a papermachine headbox flow channel (1) complying with newly developed parametric criteria for optimizing its effectiveness and methods of adjusting the position of said microturbulence generator while said papermachine is in-use to accommodate changes in operating conditions and/or machine speed are disclosed. A microturbulence generator complying with the optimization criteria of the present invention serves to generate a sufficient degree of microturbulence near the headbox throat (14) to effectively disperse pulp floc in a macroturbulent stream of papermaking fibers to improve formation characteristics, randomize fiber orientation and reduce tensile ratio in the resulting paper web. The disclosed criteria are generally applicable to headbox flow channels having an angle of convergence between about 4 DEG and about 20 DEG and are particularly effective at papermachine speeds in excess of about 244 metres per minute.