| 摘要 |
<p>The invention relates to a headbox (1) for a machine for producing a fibre-material web (3), in particular a paper web, cardboard web or packing-paper web, from at least one fibre-material suspension (2), having a feed arrangement (4), which feeds the at least one fibre-material suspension (2) and comprises a transverse distributing tube (4.1), having a perforated distributor tube plate (5), which follows the feed arrangement downstream and has a multiplicity of flow channels (6) arranged in lines (Z; Z1 to Z5) and in columns (S), having an intermediate channel (7), which is located downstream of the perforated distributor tube plate and extends over the width (B) of the headbox (1), having a downstream turbulence generator (8), with a multiplicity of flow channels (9) arranged in lines (Z) and in columns (S; S1 to S4), and having a headbox nozzle (11), which immediately follows the turbulence generator (8) and has a nozzle gap (12). The headbox (1) according to the invention is characterized in that a system pressure loss (ps) is provided, this being made up substantially of a first pressure loss (p1) between the feed arrangement (4, 4.1) and the intermediate channel (7) and a second pressure loss (p2) in the turbulence generator (8), wherein the first pressure loss (p1) assumes a value of from 15 to 85%, preferably of from 25 to 85%, in particular of from 40 to 85%, in that the intermediate channel (7), which is arranged between the perforated distributor tube plate (5) and the turbulence generator (8), has a free intermediate-channel length (7.L) of = 50 mm, preferably of = 120 mm, in particular of = 200 mm and in that the cross-sectional ratio (Q) between the infeed (4.Z) and an intermediate channel (7) assumes a value from 0.1 to 2, preferably from 0.15 to 1.5, in particular from 0.2 to 1.</p> |
