Method and device for controlling a wire in a forming gap of a web former

摘要

Method and device for controlling a wire in the forming gap of a twin-wire web former of a paper machine, which gap is defined between two opposite forming wires. A pulp suspension jet is fed out of the discharge opening of the headbox of the paper machine into the forming gap. The jet has a free flight distance before it meets the forming wires. In the area of the forming gap, a variable-crown or adjustable-crown breast roll is employed as the breast roll of at least one of the wires. The deflection of the mantle of this breast roll is regulated actively from inside the mantle of the breast roll. In this manner, the transverse tightness profile of the wire guided by the breast roll and/or possible instabilities of the wire is/are controlled in particular in the area of the forming gap.