Abstract: A method of, and apparatus for, measuring the throughflow quantity of a liquid substance per unit of time in a papermaking machine, wherein the measurement is undertaken on the basis of the pressure drop at a throttling element, there being used as the throttling element a perforated plate having a multiplicity of parallel channels through which the substance flows.

Abstract: The damping device has a transition section of increasing cross-sectional area with a perforated plate extending across the downstream end. The perforated plate has ducts which increase in cross-sectional area in a step-wise manner. The transition section may have a parabolic profile, a conical profile, an arcuate profile or may be formed of a sequence of conical parts.

Abstract: The head box is provided with a distributor having a plurality of pulp distributing ducts which have terminal sections converging towards the throat of the box. The distributing ducts also have step-like widenings upstream of the terminal sections to create a strong turbulence in the pulp flow to maintain the solids content of the pulp in suspension. The terminal sections terminate short of the throat so as to reduce any risk of cross-flow and thus improve the flow of the pulp.

Abstract: The distribution pipe is of narrowing circular cross-section with an elongated aperture. The pulp guide is mounted via a tongue and groove connection on the pipe to both sides of the aperture in order to hold the pipe together against the peripherally operative tangential force of the pipe. The plates which form the throat can be replaced from time-to-time to change the size of the throat.

Abstract: The auxiliary roll of the separating system is located downstream of the main roll and is spaced from the main roll at a distance less than 0.25 times the diameter of the auxiliary roll and greater than the combined thickness of the two wires and paper web therebetween, e.g. a distance of 10 millimeters. A separating wall is located between the main roll and main wire on the upstream side to block the entry of air between the main wire and main roll. The spacing of the two rolls ensures a positive separation of the paper web on the main wire.