Patent ID: 6464837
Filing Date: 2002-10-15
Classification: D21F

Abstract:
A process for a metered addition of a fluid medium into a material suspension stream of a headbox comprising:feeding a material suspension in a main flow direction through at least one turbulence-producing conduit to a headbox nozzle, said at least one turbulence-producing conduit having an entrance, a graduated pressure loss area, and an exit; causing a total pressure loss &Dgr;Ptotal in said at least one turbulence-producing conduit such that said total pressure loss &Dgr;Ptotal comprises at least one intake pressure loss &Dgr;Pintake formed at said entrance and a graduated pressure loss &Dgr;Pgrad formed at said graduated pressure loss area; and providing the metered addition of the fluid medium in a region between said entrance and said exit, wherein at least approximately 50% of said total pressure loss &Dgr;Ptotal is produced downstream of said metered addition.