Patent ID: 6770171
Filing Date: 2004-08-03
Classification: D21F,Y10S

Abstract:
A method for controlling a headbox in a paper/board machine, wherein the headbox comprises a stock inlet header, a tube bank, a turbulence generator and a slice channel the slice opening of which is provided with a profile bar, and wherein the headbox is provided with a cross direction measuring assembly selected from the group consisting of a plurality of cross direction sensors and at least one traversing sensor, the method comprising the steps of:determining a flow rate profile in the slice channel of the headbox by means of the cross machine direction measuring assembly; adjusting the profile bar of the slice opening in the cross direction on basis of the flow rate profile; and wherein the flow rate profile is determined by measuring the pressure profile before and after the turbulence generator and the flow rate profile is determined based on the difference in the pressure profiles.