A compactly configurable device that classifies material containing fiber can more reliably recover classified content. A classifier has a mesh disc with numerous holes, and separates screenings that pass through the holes from remnants that do not pass through; a defibrated material spray nozzle disposed to one side of the mesh disc sprays defibrated material containing fiber onto the mesh disc; a suction conduit disposed to the other side of the mesh disc suctions the waste screenings that pass through the holes; and a recovery conduit disposed on the one side of the mesh disc suctions the processing feedstock that do not pass through the holes and in the mesh disc and remain on the mesh disc. The mesh disc is disposed so the a position of the holes can move from a spraying position opposite the defibrated material spray nozzle to a suction position opposite the recovery conduit. The recovery conduit suctions, at the suction position, processing feedstock that was left at the spraying position.

A compactly configurable device that classifies material containing fiber can more reliably recover classified content. A classifier has a mesh disc with numerous holes, and separates screenings that pass through the holes from remnants that do not pass through; a defibrated material spray nozzle disposed to one side of the mesh disc sprays defibrated material containing fiber onto the mesh disc; a suction conduit disposed to the other side of the mesh disc suctions the waste screenings that pass through the holes; and a recovery conduit disposed on the one side of the mesh disc suctions the processing feedstock that do not pass through the holes and in the mesh disc and remain on the mesh disc. The mesh disc is disposed so the a position of the holes can move from a spraying position opposite the defibrated material spray nozzle to a suction position opposite the recovery conduit. The recovery conduit suctions, at the suction position, processing feedstock that was left at the spraying position.

A screen feed arrangement for a pulp production process, comprising a discharge tank having an outlet, which is connected to an inlet of a discharge tank pump having an outlet, a dilution tank having an outlet, a screen feed pump having an inlet and an outlet, and a screening arrangement, wherein the outlet of the discharge tank and the outlet of the dilution tank are connected to the inlet of the screen feed pump, the outlet of which is connected to the screening arrangement, and that pulp which passes the outlet of the discharge tank has a mass concentration from about 8% to about 15%. A corresponding method for feeding pulp to a screen feed arrangement is also presented.

A screen feed arrangement for a pulp production process, comprising a discharge tank having an outlet, which is connected to an inlet of a discharge tank pump having an outlet, a dilution tank having an outlet, a screen feed pump having an inlet and an outlet, and a screening arrangement, wherein the outlet of the discharge tank and the outlet of the dilution tank are connected to the inlet of the screen feed pump, the outlet of which is connected to the screening arrangement, and that pulp which passes the outlet of the discharge tank has a mass concentration from about 8% to about 15%. A corresponding method for feeding pulp to a screen feed arrangement is also presented.

The present invention is directed to methods and apparatus for screening a pulp suspension where the pulp suspension is directed to a screening space, where a part of the fibres in the pulp is screened using a drum-type rotor. The residual pulp suspension is then directed to a dilution space where it is mixed with recirculated pulp flow and the pulp suspension in the dilution space will be screened. Resulting preliminary reject flow is directed to a mixing space where it mixes with a dilution flow. The recirculated pulp flow is then directed back to the dilution space.

The invention relates to a blade for screens for the treatment of a fibrous suspension, said blade being mountable on a rotor of the screen. According to the invention, the blade has a curved leading edge or curved envelope of the leading edge, the curvature extending in the direction of the trailing edge, and a curved trailing edge or curved envelope of the trailing edge, said curvature extending in the same direction as the other one. The invention also relates to a screen comprising a rotor on which the disclosed blades are mounted.

A sheet manufacturing apparatus includes a raw material detection unit that detects a raw material amount stacked on a stacking unit, a calculation unit that calculates a first amount of the sheet able to be manufactured in the sheet manufacturing apparatus based on a detection result of the raw material detection unit, and an output unit that outputs the sheet amount calculated by the calculation unit.

The present disclosure is directed to rotors for pressure screens with cylinders for screening solid contaminants from a solid slurry. The rotor includes a cylindrical hub, a plurality of foils spaced radially outward from the hub, and a plurality of struts coupling the plurality of foils to the hub. The struts include a forward edge having a forward-swept shape that creates streamlines that move contaminants and fibers from the general local flow field and those dislodged from the inner surface of the pressure screen cylinder radially inboard towards the hub. The streamlines produced by the forward-swept struts can reduce or prevent deposition of solid contaminants on the forward edge of the strut and on the leading edge of the foil. The struts can also include a release region proximate the inboard end of the strut.

Disclosed herein are novel methods to prepare paper pulp from non-wood fiber sources, and preferably from a variety of different non-homogeneous fiber sources. The methods use a unique combination of caustic and temperature without a digestor to improve performance of the resulting fibers.

A device including a hollow body defining axially extending compartments therein for receiving a slurry of pulp fibers in a carrying flow. The device includes a stationary screen within the hollow body defining a slurry compartment on one side of the screen, and a screened compartment on the other side of the screen. The hollow body also includes a slurry inlet into the slurry compartment, an elutriation suction outlet in communication with the slurry inlet, and elutriation nozzles into the slurry compartment. The device also includes an elutriation pump outside of the hollow body, the elutriation suction outlet being in fluid communication the elutriation pump, and the elutriation pump being in fluid communication with the elutriation nozzles.