Patent ID: 6875312

Claim:
A method for fluidization of pulp flow in a headbox of a paper machine comprising the steps of: causing pulp to flow from a manifold through, a turbulence generator defined by a plurality of first pipes, wherein each first pipe has a first inside diameter and is joined by a fluidizer step to a second pipe which is concentric with the first pipe to which it is joined, each second pipe having a second inner diameter, wherein the ratio between the inner diameters of the second pipes and the inner diameters of the first pipes is in the range of 1.1 to 4, and wherein the pulp contains fibers which define an average length between one and three millimeters, and wherein the pulp is caused to flow from the first pipes to the second pipes and into a lip cone, and from the lip cone to a former; wherein each fluidizer step has a height, and wherein the height is defined as one half of the quantity of the second inside diameter less the first inside diameter, said height being at least equal to said average length of the fibers; and wherein fluidization takes place only at the fluidizer step, and all step expansions between the fluidizer step and a lip opening of the lip cones extend in a z direction less than the average length of the fibers.