Abstract: In the rotationally symmetrical screen for fiber suspensions with a series of straight profiled bars which extend the direction of the screen axis and form slot-shaped screen openings between them, and with several ring-shaped profiled bar supports lying in planes extending perpendicularly to the screen axis, each of the profiled bar supports having in its edge region adjacent to the inlet side of the screen a series of cutouts opening towards the inlet side of the screen for insertion of the profiled bars, with the shape of these cutouts corresponding to the configuration of the cross-sectional regions of the profiled bars held positively in these cutouts, in order to simplify insertion of the profiled bars into the cutouts of the profiled bar supports each profiled bar has for each profiled bar support a recess which decreases the width of this cross-sectional region of the profiled bar, and the recesses lie outside the profiled bar supports in the finished screen.

Abstract: In a rotationally symmetrical screen for fiber suspensions with a series of straight profiled bars which extend in the direction of the screen axis and form slot-shaped screen openings between them, and with several ring-shaped profiled bar supports lying in planes extending perpendicularly to the screen axis, each of the profiled bar supports having in its edge region adjacent to the inlet side of the screen a series of cutouts opening towards the inlet side of the screen for insertion of the profiled bars, with the shape of these cutouts corresponding to the configuration of the cross-sectional regions of the profiled bars held positively in these cutouts, in order to simplify insertion of the profiled bars into the cutouts of the profiled bar supports each profiled bar has for each profiled bar support a recess which decreases the width of this cross-sectional region of the profiled bar, and the recesses lie outside the profiled bar supports in the finished screen.

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: A pressure sorter for fiber suspensions, and a process for the preparation of fiber suspensions, are disclosed wherein a rotor is disposed concentrically within a cylindrical screen that has spaced circumferential rows of narrow through slots through which a portion of the fiber suspension fed into the screen passes radially outward to an accepts chamber external to the screen. The fraction of the suspension which does not pass through the screening slots passes axially out of the screen cylinder as a "rejects" flow. V-shaped grooves around the inflow ends of the screening slots create turbulences in the adjacent suspension material. The rotor includes external profiled elements which generate positive and negative pressure pulses at the adjacent inflow side of the screen as the rotor is rotated.

Abstract: An appliance for sorting and deflaking fiber suspensions has a rotor with a horizontal axis rotatively mounted in a housing. In a first, inlet rotor zone the rotor is provided with entraining means for extracting by centrifugation contaminating particles of high relative density. The rotor is surrounded donwstream by a screening cylinder and is also provided with entraining means for the fiber suspension, which deflake and sort out the fiber suspension in a second rotor zone. In a third rotor zone the fibers are washed out of the rejects after water has been added and in a fourth zone the rejects are dehydrated.

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.