HEADBOX SYSTEM FOR A PAPER MACHINE, AND PROCESS FOR ITS OPERATION

摘要

In a headbox system for a paper machine with an adjustable distribution of the pulp over the width of the web the flow in the delivery gap (8) is controlled in such a way that, over the width of the web, also the distribution of the fibres in respect of fibre orientation and quantity has a desired profile. For this, the flow of the pulp suspension is so controlled that in the event of a change on the pulp distribution over the width of the web the horizontal component of the flow direction in the delivery gap (8) remains, at all places, always in the direction of the machine, and thus transverse flows are avoided and the flow speed in the delivery gap (8) has a preset profile.