Abstract: The present invention introduces a fiber suspension thickener, particularly adapted for thickening cellulose fiber. The thickener comprises a vat; a hollow filter assembly in the form of a horizontal cylindrical drum disposed within the vat, whereby the drum may be rotated by a motor around its horizontal axis, and whereby the cirumferential walls of the drum are made of a filter material; either a spray nozzle or some other supply conduit that furnishes a fiber suspension into the interior of the vat, so that the drum becomes submerged within a pool of the fiber suspension; a discharge outlet for discharging the fiber suspension on the ascending side of the rotating drum; and a turbulence creating device, that can take many forms, for creating turbulence and mixing the fiber suspension on the ascending side of the rotating drum.

Abstract: A cylinder type paper pulp washer or thickener apparatus includes a rotatable cylinder mold with a forming wire surface. The mold rotates at least partially submerged in a vat of dilute paper pulp stock and a differential pressure across the wire surface draws stock from the vat through the cylinder mold and forms a pulp mat on the wire surface, and a plurality of disrupters are positioned within the vat and in arcuately spaced relation to the wire surface to cause a disruption of the fiber mat which obstructs the flow of the stock liquid through the wire surface and thereby provides for the reestablishment of flow. Various disrupters are shown, including a rotating non-circular bar, a doctor blade, a foil, a fluid jet, a brush, and a triangular protuberance. A plurality of such disrupters are positioned in peripherally spaced relation to cause repeated disruption and reformation of a fiber mat to increase the throughflow and washing or thickening efficiency of the apparatus.

Abstract: The invention relates to an apparatus or plant or arrangement for the treatment of a dilute suspension of fibers or layer of material passed between two endless foraminous belts or wires or the like conveying means, the forming fibrous board being made to pass between the foraminous belts along at least one container for a treatment medium and at least some of the treatment containers being provided with a wall having orifices on the side facing the fibrous board for generating a pressure difference on the same, but being otherwise closed against the environment, and/or at least some of the treatment containers closed against the environment having walls closed against the foraminous belts and thus against the fibrous board, but otherwise open towards the foraminous belts. According to the invention, a reduction of the energy requirement in the displacement washing of filter cakes is sought above all.

Abstract: A method of and apparatus for regulating the pulp density above the moving screen of a machine which forms a continuous web from a fibrous suspension is disclosed. In its method aspects, the present invention discloses introducing water into the suspension located above the moving screen while also controlling the rate of flow and quantity of the water passing through the screen. In its apparatus aspects, the present invention discloses at least one plate arranged between the screen and a suspension containing chamber located beneath said screen, which plate includes water discharge openings on the side facing the chamber, at least one water support line communicating with the opposite side of the chamber and means for regulating the water discharge of the water supply into the chamber.

Abstract: This relates to the manufacture of wet process hardboard. The invention involves supplying additional heat curable resin to the mid-thickness regions of the panel by injecting additional resin into the moving mat as it is being formed on a forming surface. The region of injection of the resin is selected so that the bottom of the partially formed mat is sufficiently consolidated to resist the passage of resin therethrough while at the same time the top of the mat is still sufficiently liquid so that disturbances of the fibers of the partially dewatered mat caused by the injection of the resin have an opportunity to mend. The resin may be injected into the longitudinal marginal portions of the mat in continuous fashion such that, after the edges of the final board product have been trimmed, the resin treated areas are exposed to view. The additional resin reinforces the edge portions and assists in providing uniform caliper of the board across its width.

Abstract: Hard and medium density board made of lignocellulosic fibers having a central layer with substantially higher concentration of set resin than both the outer layers of said board have as good strength properties as a corresponding board having said higher concentration of said resin throughout the thickness of the board. Said board is produced by introducing a thermosetting resin solution or a high resin content pulp into and evenly across the width of the central layer of the pulp or the wet lap to be pressed and heat treated, the pressing period being shortened as well as the press cycle. Said process can be carried out with an apparatus including a member to be inserted in the pulp slurry flow in the headbox of a board machine or in the flow on the moving continuous wire screen of the board machine comprising an element having nozzles or slits through which a thermosetting resin solution or a high resin content slurry can be brought to flow.