Headbox of paper machine or such

A headbox of a papermaking machine comprising:

• a pulp flow manifold;
• a lip cone having a length of between 100 mm and 800 mm and having a lip discharge opening through which stock flows to a former, wherein a pulp flow direction is defined from the pulp flow manifold to the lip discharge opening;
• a turbulence generator extending between the pulp flow manifold and the lip cone, the turbulence generator comprised of a plurality of first pipes, having first inside diameters between 10 mm–20 mm, each first pipe terminating in a fluidization element step comprising an annular wall structure, which extends to an inner surface of a second pipe which has a circular cross-section, the second pipe being coaxial with the first pipe and the second pipe having an inside diameter of the inner surface which is between 20 mm and 40 mm and which is greater than the first inside diameter, the second pipes having outlet ends leading into the lip cone, each second pipe defining an interior flow surface;
• wherein the fluidization element step has a height defined as the inside diameter of the inner surface of the second pipe minus the first inside diameter divided by two, and wherein the height of the fluidization element step is in the range of 1 mm–12 mm;
• wherein the second pipe has a first part which has the circular cross-section and a second part of rectangular cross-section joining the first part, and the second part narrows in the flow direction so pulp flow is accelerated as it flows through the second pipe;
• wherein a cross-sectional area is defined at each point in the headbox between the turbulence generator and the lip discharge opening of the lip cone, and wherein the cross-sectional area continuously decreases as the lip discharge opening is approached so that the pulp flow accelerates essentially all the time all the way from the turbulence generator to the lip discharge opening;
• wherein the length of the first pipes is at least 150 mm, and the length of the first part of the second pipes is at least 50 mm and the length of the second part of the second pipes is no more than 200 mm;
• lamellas joined at their inlet ends to the outlet ends of the turbulence generator second pipes, the lamellas positioned in the lip cone, wherein flow along the interior flow surfaces of the second pipes on to surfaces defined by the lamellas has a step of no more than the pipe thickness of the second pipes at the outlet ends, said pipe thickness being approximately 2 mm;
• wherein the lamellas narrow in a wedge-like fashion as the lamellas extend toward the lip discharge opening, the lamellas having downstream ends which have a thickness in a range of 0–2 mm;
• and
• wherein between the turbulence generator, and the lip discharge opening, there is no vertical step which is more than approximately 2 mm.