Abstract: A rotationally symmetrical screen for fiber suspensions with an inlet and outlet side, having a series of profiled bars which extend transversely to the circumferential direction of the screen, the cross-section of the profiled bars having a first end region facing away from the screen outlet side and a second end region facing away from the screen inlet side, and with metallic supporting rings lying in planes extending perpendicularly to the screen axis, each of the supporting rings having a series of cutouts open at their edge towards the screen inlet side, the shape of the cutouts corresponding to the configuration of the second cross-sectional end regions of the profiled bars lying in the cutouts, and forming an undercut in which a projection of the profiled bar cross section engages so that the profiled bars are held positively in a radial direction in relation to the screen axis and in the circumferential direction of the screen with their second cross-sectional end regions in the supporting ring cutout

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: A sieve for sorting fiber suspensions, symmetrical in relation to an axis, with an inflow side for the fiber suspension to be sorted and an opposite outflow side. This sieve is useful for pressure sorting machines having a rotor that may be rotated around the axis of the sieve and that is provided with profiled elements around the inflow side of the sieve in order to generate positive and negative pressure pulses in the fiber suspension that is to be sorted. The inflow side of the sieve has grooves approximately parallel to the axis of the sieve that follow each other in the circumferential direction of the sieve. A through-channel opens into each groove. The grooves are delimited by a front and a rear side wall, seen in the direction of rotation of the profiled elements.

Abstract: Pressure sorter for the preparation of fiber suspensions obtained from waste paper, with a screen surrounding a rotor, a supply chamber between rotor circumference and screen as well an accepts chamber outside the screen and with profiled elements provided at the circumferential surface of the rotor for generating positive and negative pressure pulses, whereby in order to achieve good sorting results as well as a long service life of the screen, a rotor peripheral surface sector is provided between two profiled elements following one another in circumferential direction of the rotor, in every axial section of the circumferential surface of the rotor acting on the screen, this rotor peripheral surface sector being part of a peripheral surface area parallel to the screen inlet side, wherein--measured in circumferential direction of the rotor--the length of each profiled element is at least approximately equal to the length of the following rotor peripheral surface sector, the length of the latter, however, bein

Abstract: In a screen for pressure sorters for fiber suspensions which is of rotationally symmetrical shape in relation to a screen axis and the screen wall of which is provided with screen opening channels connecting the screen inlet side with the screen outlet side and on its inlet and outlet sides with recesses into which the screen opening channels open, in order to improve the throughput capacity of the screen, to simplify its manufacture, to achieve good fatigue strength of the screen and to generate turbulences at the screen inlet side, each of the recesses on the inlet side extends over several screen opening channels and is in the form of a groove extending transversely to the circumferential direction of the screen, a recess is provided for each screen opening channel on the screen outlet side, and the largest width of the recesses on the outlet side is at least as large as the largest width of the grooves on the inlet side.

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: 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.