Abstract: An apparatus for processing fiber suspensions containing usable fibers and suspended dirt particles to be separated from the usable fibers, the specific weight of the particles differing distinctly from that of the usable fibers, is described. The apparatus comprises a drum-shaped outer housing having (i) and inflow end accommodating a body rotationally symmetric to the housing axis and being provided with a tangential inlet pipe for the fiber suspension to be processed, and (ii) an outflow end being provided with an axial outlet pipe for a lightweight dirt component of the suspension and an outlet pipe for a usable component of the suspension.

Abstract: Rotor for pressure sorters for sorting fibrous suspensions, comprising a plurality of cleaning vanes provided for the circulation on the inlet side of a screen cylinder of the pressure sorter, these vanes being designed in sections as return regions and in sections as supply regions; the return regions are designed such that they urge the fibrous suspension portions adjacent the screen inlet side away from the screen cylinder, whereupon these fibrous suspension portions are diverted by the supply regions of the cleaning vanes towards the screen inlet side and fed back to the latter.

Abstract: A pressure sorter for fiber suspensions comprises a rotating screen basket and cleaning blades associated therewith. To improve the operating characteristics, stationary cleaning blades are provided on both the inside and the outside of the screen basket, and the screen basket is provided at one end with an axial channel whose diameter is substantially smaller than that of the screen formed by the screen basket.

Abstract: Apparatus for dissolving and sorting waste paper supplied in the form of bales, comprising a bale shredding device having a spray pipe for steeping water, a subsequent steeping drum driven about an approximately horizontal axis and followed by a mixing device for mixing the steeped waste paper with diluting water as well as a sorting drum also rotatable about an approximately horizontal axis. The circumferential wall of this sorting drum has openings in a first sorting area which are smaller than the openings in a second sorting area which follows the first sorting area in the direction of flow. A deflaking device is provided for the suspension passing through the openings of the second sorting area, the outlet of this device being connected to the mixing device via a pump.

Abstract: Roller for machines in the paper-making industry or similar, with a honeycomb-shaped roller element formed by upright straight and corrugated bands, extending approximately in the circumferential direction and alternating with each other in the axial direction, said bands being connected by welded joints. To make passages, which allow a throughflow in the circumferential direction, between the roller element and a fabric cover supported by the latter, openings adjoining the fabric cover are provided in the roller element between the fabric cover and the radially outer edges of the corrugated bands in the area of the connecting points and in the center between the connecting points, and in order to increase the open-passage area of the fabric cover, the latter rests directly on the roller element.

Abstract: Sorting screen for fibre suspensions comprising a screen wall having recesses on a first side and narrower sorting apertures on the other, second side, these apertures opening into the recesses and the recesses each extending over a plurality of sorting apertures and being spaced in all directions from one another such that the screen wall has a net structure on its first side between the apertures. In order to achieve the utmost fineness when sorting with such a screen the recesses are arranged on the inflow side of the screen wall and the sorting apertures are designed as bores.

Abstract: The invention relates to a method of treating waste paper, wherein the waste paper is steeped, under certain circumstances chemically treated at the same time, and is thereafter adjusted to a lower substance density and sorted. Furthermore, the invention relates to apparatus for performing such a method.

Abstract: Screen cage for pressure sorters, with which, in order to increase the stability of the screen cage wall and the sum total of the inside screen cage apertures, the screen cage wall has a regular pattern of cylindrical recesses on its outlet side and grooves extending parallel to each other on its inflow side, the grooves and the recesses together forming screen aperture slots.

Abstract: The invention relates to a method of treating waste paper, wherein the waste paper is steeped, under certain circumstances chemically treated at the same time, and is thereafter adjusted to a lower substance density and sorted. Furthermore the invention relates to apparatus for performing such a method.

Abstract: Pressure sorting method and apparatus in which the velocity of the rejected suspension component along the screen surface in a substantially direct path to a rejected suspension outlet has a vertical velocity component which is a multiple of the velocity of the accepted suspension through the screen openings by virtue of the cross-sectional area of the unsorted and rejects annular chamber at the inlet end being less than one third the sum of the clear cross-sections of the screen openings. The velocity ratio is maintained by decreasing the area of the annular chamber from the inlet to the rejects outlet. In a preferred embodiment, the accepts annular chamber increases towards the accepts outlet to compensate for the decrease in the unsorted and rejects annular chamber area.

Abstract: An apparatus for sorting fiber suspensions comprising a stationary cylindrical screen cage and a rotor having a cylindrical wall mounted concentrically relative to the screen cage to form an annular space, the unsorted fiber suspension entering the annular space at one end and flowing generally toward the other end of the annular space, the fiber suspension increasing in consistency as it flows toward the other end of the annular space, the rotor having openings and/or elevations to cause the dilution of at least a portion of the thickened stock in the annular space not passing through the screen with a portion of lower consistency fibrous suspension to allow it to flow more readily. In one embodiment the rotor is mounted within the screen cage and a portion of the unsorted fiber suspension is introduced to the interior of the rotor, passing outwardly through openings in the rotor along the length of the annular space to dilute the thickened, dewatered suspension within the annular space.

Abstract: A screening apparatus for fiber suspensions comprising a stationary cylindrical screen one side of which is in flow communication with the inlet for the fiber suspension and the other side, from which the accepted stock emerges, forming an annular space with a rotor comprising a cylindrical wall having elevations for producing positive and negative pressure thrusts serving to keep the screen clear and openings behind the projections through which some of the accepted stock passes to provide an alternative path to the outlet for the accepted stock.

Abstract: A method and a system for cleaning and classifying fibrous suspensions whereby the suspension, by screening, is divided into a first stream of accepted stock and a second stream of rejected stock. The latter is then screened once more and thereby divided into a third stream of accepted stock and a fourth stream of rejected stock. The third stream is added to the first stream, whereas only the fourth stream is subjected to a fibre flake break-up process followed by a further screening process resulting in a stock finally rejected and an accepted stock added to the fibrous suspension upstream of the means for carrying out the first screening.

Abstract: A suction roll, for a paper-making machine having a hollow cylindrical roll shell with a cylindrical inner surface from which a suction box draws water, has members inserted into the roll shell openings. The insert members are apertured with radially-extending ducts for the suction of water to the roll shell inner surface. The insert members form a major portion of the shell inner surface and characterize that surface for relatively low-wear sealing with a suction box movable relative to the roll shell.

Abstract: An apparatus for defibering conglomerates of fiber in fibrous suspensions, particularly useful with fibrous suspensions of low stock density, comprising a housing having an inlet and outlets for the fibrous suspension, a hollow cylinder within the housing, and a rotor mounted for rotation within the hollow cylinder. The annular space between the hollow cylinder and the rotor comprises a first region to dewater and screen the fibrous suspension and a second region to defiber conglomerates of fiber in the dewatered portion of the fibrous suspension. In a preferred embodiment, the annular space comprises a third region to wash dirt particles from the processed fibrous suspension and also to dilute said suspension to accommodate a further screening operation.

Abstract: An apparatus for cleaning fibrous suspensions of low stock consistency comprising, in combination, a specially adapted vortex cleaner and pressure screen. The vortex cleaner has a cone angle of less than 20.degree., between 7.degree. and 15.degree. in a preferred embodiment, to increase the residence time therein. The pressure screen comprises a rotor having a lower surface with acceleration elements to set the suspension in motion within the vortex cleaner while effectively sealing the space between a stationary screen basket and the rotor of the pressure screen to prevent short-circuiting of the fibrous suspension directly from the vortex cleaner inlet into the pressure screen. The rotor has a central opening in the lower surface thereof to accept the suspension leaving the vortex cleaner and further comprises peripheral openings in flow communication with this central opening through which the suspension passes to enter the annular space between the rotor and the screen basket.

Abstract: A strainer drum has a series of axially juxtapositioned, apertured carrier discs which define axially spaced, alternating, circumferentially extending crests and roots. The carrier discs support a prefolded one-piece filter fabric of the weft-and-warp type which is wrapped substantially 360.degree. around the discs and which conforms to the crests and roots defined by the carrier discs. The wefts and warps of the filter fabric are oriented obliquely with respect to the drum axis.

Abstract: A classifying apparatus is disclosed for use in separation of different portions of fibrious suspensions such as waste papers stock coming from a pulper. The apparatus is a unit comprising a vortex cleaner combined with a pressure screen. It includes a cylindric rotor whose circumferential portion carries agitating rods for the screen, the bottom of the rotor being provided with means for intensifying the motion of the stock fed into the vortex cleaner portion of the apparatus. The cylindric rotor defines a comparatively narrow gap between the rotor and the screen cage.