Headbox and sheet formation unit with a headbox

摘要

The present invention relates to a headbox (1) with at least one, the at least one fibrous suspension (fs) supplying feed device (5), a an outlet slot (11) having a nozzle (4) for delivering the fibrous suspension (fs) in a free jet and a in the direction of flow of the nozzle (4) directly upstream turbulence generator for generating (6), in which during operation of the headbox (1) the at least one fibrous suspension (fs) by means of a plurality of turbulence-generating channels (7, 7.xy, 7.11 – 7.4n) in a partial flow is guided, within the individual turbulence-generating channel (7, 7.xy, 7.11 – 7.4n) at least one, a fluidization region (12, 12.11 – 12.31) area is provided forming.The head box of the invention (1) is characterized in that the nozzle (4) has a length (l), which as a function of the size of the one individual turbulence-generating channel associated proportion of area of the cross-sectional area at the nozzles start be described in the parting surface (b_T) is: withL length of the nozzle (4);k is the constant, wherein 10 ≦ k ≦ 20; andBt parting interface.