A separation device having a housing (10) with a feed conduit (1) and a reject conduit (2), between which conduits (1, 2) and an accept conduit (3) of the housing (10) is a rotor unit (13) having a shaft (4) transverse to the through-flow direction of the separation device, which shaft rotates discs (5) attached to the shaft (4), the outer surface and/or side surfaces of which discs are jagged, i.e. they have protrusions (6) and/or notches and/or these surfaces are substantially rough and the teeth (9) of at least two sieves (7, 8) attached to the housing (10), extend between the discs (5), the first sieve (7) being between the reject conduit (2) and the accept conduit (3) and the second sieve (8) being between the feed conduit (1) and the accept conduit (3).

A separation device having a housing (10) with a feed conduit (1) and a reject conduit (2), between which conduits (1, 2) and an accept conduit (3) of the housing (10) is a rotor unit (13) having a shaft (4) transverse to the through-flow direction of the separation device, which shaft rotates discs (5) attached to the shaft (4), the outer surface and/or side surfaces of which discs are jagged, i.e. they have protrusions (6) and/or notches and/or these surfaces are substantially rough and the teeth (9) of at least two sieves (7, 8) attached to the housing (10), extend between the discs (5), the first sieve (7) being between the reject conduit (2) and the accept conduit (3) and the second sieve (8) being between the feed conduit (1) and the accept conduit (3).

A powder collection unit includes a powder storage having an inlet through which powder including fibers enters and an outlet through which the powder exits, a delivery screw having an elongated shape, disposed in the powder storage, and configured to rotate about a rotation axis to send out and discharge the powder through the outlet, and a powder collection portion coupled to the outlet and having an inner space that collects the powder discharged through the outlet. An end portion of the delivery screw that is adjacent to the outlet protrudes outwardly from the powder storage through the outlet and resides in the inner space of the powder collection portion.

A powder collection unit includes a powder storage having an inlet through which powder including fibers enters and an outlet through which the powder exits, a delivery screw having an elongated shape, disposed in the powder storage, and configured to rotate about a rotation axis to send out and discharge the powder through the outlet, and a powder collection portion coupled to the outlet and having an inner space that collects the powder discharged through the outlet. An end portion of the delivery screw that is adjacent to the outlet protrudes outwardly from the powder storage through the outlet and resides in the inner space of the powder collection portion.

Variation in the thickness of accumulated material is suppressed when material containing fiber is dispersed by the sieve and accumulated. A sheet manufacturing apparatus includes a drum that sieves defibrated material containing fiber, a first web former that accumulates first screened material discharged from the drum, and a processor that processes a first web accumulated in the first web former. During processing by the processor, the mesh belt operates at a first speed. When operation starts with the drum not operating, a startup operation including the mesh belt operating at a higher speed than the first speed in a first period after the drum starts is executed.

Variation in the thickness of accumulated material is suppressed when material containing fiber is dispersed by the sieve and accumulated. A sheet manufacturing apparatus includes a drum that sieves defibrated material containing fiber, a first web former that accumulates first screened material discharged from the drum, and a processor that processes a first web accumulated in the first web former. During processing by the processor, the mesh belt operates at a first speed. When operation starts with the drum not operating, a startup operation including the mesh belt operating at a higher speed than the first speed in a first period after the drum starts is executed.

A method for controlling a fiber fractionation system for fractionating an input material into a long fraction (LF) stream comprising LF fibers and a short fraction (SF) stream comprising SF fibers includes measuring an average LF fiber length at one or more locations post-fractionation, and maintaining the average LF fiber length within a target variability range by automatically altering a rotational speed of a rotor of the fiber fractionation system.

A method for controlling a fiber fractionation system for fractionating an input material into a long fraction (LF) stream comprising LF fibers and a short fraction (SF) stream comprising SF fibers includes measuring an average LF fiber length at one or more locations post-fractionation, and maintaining the average LF fiber length within a target variability range by automatically altering a rotational speed of a rotor of the fiber fractionation system.

The present invention relates to a turbulence element for use with a rotor and a rotor featuring turbulence elements. The rotor is used in a screening apparatus of the pulp and paper industry. The turbulence element has a longitudinal centerline (CL); two longitudinal edges, a leading edge and a trailing edge; two opposite ends, a first end and a second end; and two surfaces, a top surface and a bottom surface arranged between the leading edge and the trailing edge. The top surface is divided into a leading surface having its origin at the leading edge, and a trailing surface having its origin at the trailing edge. The leading edge and the leading surface are provided with undulations (U).

The present invention relates to a turbulence element for use with a rotor and a rotor featuring turbulence elements. The rotor is used in a screening apparatus of the pulp and paper industry. The turbulence element has a longitudinal centerline (CL); two longitudinal edges, a leading edge and a trailing edge; two opposite ends, a first end and a second end; and two surfaces, a top surface and a bottom surface arranged between the leading edge and the trailing edge. The top surface is divided into a leading surface having its origin at the leading edge, and a trailing surface having its origin at the trailing edge. The leading edge and the leading surface are provided with undulations (U).