Abstract: A valve for a vacuum drainage system includes a valve body having an interior chamber operatively connectable to a suction device and through an outlet to a vacuum source. A movable member having an aperture is secured within the chamber and movable through points between closed and open positions to adjust the open area of the aperture and the fluid flow through the outlet. The aperture is configured such that during adjustment to increase the effective operational area of the aperture, a rate of change of the effective operational area increases non-linearly in relation to a linear increase in the distance of travel, while providing advantageous and more controllable linear adjustment of the applied vacuum. The aperture can have a trilateral shape including at least one curved side, or comprise a plurality of sub-apertures, and the movable member can comprise a rotary sleeve.

Abstract: A valve for a vacuum drainage system includes a valve body having an interior chamber operatively connectable to a suction device and through an outlet to a vacuum source. A movable member having an aperture is secured within the chamber and movable through points between closed and open positions to adjust the open area of the aperture and the fluid flow through the outlet. The aperture is configured such that during adjustment to increase the effective operational area of the aperture, a rate of change of the effective operational area increases non-linearly in relation to a linear increase in the distance of travel, while providing advantageous and more controllable linear adjustment of the applied vacuum. The aperture can have a trilateral shape including at least one curved side, or comprise a plurality of sub-apertures, and the movable member can comprise a rotary sleeve.

Abstract: A headbox including a stock dilution profiling arrangement and associated stock delivery systems are provided, which together deliver to the forming section of a papermaking machine a uniform stock flow with more consistent basis weight and fiber orientation profiles than has previously been possible. These improvements in basis weight uniformity and fiber orientation profile provide benefits in paper sheet formation and related paper properties.

Abstract: A method and apparatus for beginning the formation of a paper web on a traveling forming wire, or between a pair of converging forming wires, includes a headbox on a papermaking machine for projecting a stock stream onto the forming wire, or between the forming wires over the porous face surface of a forming shoe. The forming wire or wires are looped to travel in a continuous path, and within at least one of the looped forming wires is the forming shoe, which is porous by way of grooves or openings over at least a portion of its face surface. The grooves are in the surface of the forming shoe which engages the inner surface of the looped forming wire to define a portion of the path of travel of the forming wire adjacent the headbox from which the stock stream is projected onto, or between, the forming wire(s). The grooves extend in the surface facing the forming wire from a point downstream of the leading edge in the nose portion of the face surface of forming shoe in the direction of forming wire travel.

Abstract: The headbox apparatus of this invention contributes to the production of a paper web of uniform fiber orientation by controlling the edge flow of stock into the headbox nozzle through adjustable valves positioned in edge tubes in closed loop with a fiber orientation sensor. At the same time that fiber orientation is being control through adjustable valves position in the edge tube, basis weight of the web being formed is controlled by a stock dilution systems and an adjustable slice lip, in closed loop with a basis weight profiler sensor.

Abstract: A headbox tube bank apparatus and method of directing flow through same is disclosed for permitting the flow therethrough of stock in a papermaking machine. The apparatus includes a tube bank frame for rigidly supporting the tube bank, the frame defining a plurality of openings. A plurality of tubes cooperate with the frame such that each tube extends through and is supported by an opening. Each tube has an upstream and a downstream portion, the upstream portion defining an internal cross-machine direction section of substantially circular configuration for maximizing the velocity of the stock through the tube.

Abstract: A system for forming a web from a dilute, aqueous slurry of fibers wherein a thin, horizontally-extending aqueous stream of fibers is projected onto a travelling foraminous forming wire. The forming wire is disposed to travel over a forming board which has a leading lip which is deflected downwardly with respect to the oncoming jet stream. The lower surface of the jet stream is disposed substantially parallel with the surface of the travelling foraminous wire wire at the point where the stream contacts the wire to minimize turbulence at the point of initial contact of the jet stream on the wire and subsequent spouting of the fibrous stock downstream in the forming zone.