J. M. Voith Gmbh

Josef Tra

Walter Musselmann

Herbert Kinzler

Reimund Rienecker

Klaus Kurth

Werner Lorenz

The screen wire has depressions (5), on the base of which there are fine slits (4) or wire holes. The depressions are generally oblong, their longitudinal extension being parallel or slightly inclined to the axis of rotation of a rotor and the screening blades (2) skirting close to the screen surface. The front edge of the depressions (5)--viewed in the direction of rotation of the screening blades (2)--is inclined towards the enveloping surface of the screen, and has an angle of between 15.degree. and 60.degree. from the surface perpendicular and is preferably inclined at 30.degree.. The slits or rows-of-holes run parallel to the front edge of the depressions (5). These screen cages for the screening of screening fiber suspensions provide better screening efficiency and they have less blockage.

Screen cage

A rotating sorter is provided for the removal of minuscule pollutants from fiber material suspensions by means of a symmetrical fixed filter basket disposed in a fixed spiral-shaped housing and in whose interior a generally vertical axle rotates sorter vanes in close proximity to the filter basket. Fiber material suspension to be sorted is delivered to a generally ring-shaped sorting space formed between the filter basket and housing. The direction of flow of fiber material suspension delivered to the filter basket occurs substantially tangentially thereto and generally perpendicular to the rotating axle, and quality material is sorted into the interior of the filter basket. The apparatus of the present invention is distinguished by an inlet nozzle which communicates with the sorting space through a generally vertically disposed slit, and by the sorting space steadily narrowing or tapering from a width equal to the width of the slit and along the axial length of the filter basket beginning at least at a point level with the slit, whereby the tapering of the sorting space occurs in a spiral fashion in the direction of flow of the fiber material suspension along the filter basket. This results in a higher degree of sorting effectiveness, especially in preventing the removal of long fibers with ejected material.

Rotating sorter for fiber material suspensions

The disclosure concerns an apparatus for separating impurities from a fibrous suspension. The apparatus includes a tiltable housing having a screen basket supported coaxially therein. A rotor is supported inside the screen basket. The rotor has three zones. There is an upstream zone communicating with the fiber suspension inlet, and inlet in the upstream zone is into the interior of the rotor and then outward past sorting vanes formed at the exterior of the rotor in the first zone and inside of the basket. Downstream of the transport vanes is a second baffle zone defined by a closed drum having transport vanes on the outside thereof. The suspension and impurities are moved downstream by the transport vanes in the second zone. Downstream of the second zone is a third zone with further means for moving impurities downstream, comprising either a centrifugal impeller in the form of vanes or a helical ring. The impurities outlet from the housing is downstream of the rotor and at the other end of the housing away from the inlet. The outlet for purified suspension is outside the screen basket nearer the inlet. A weir establishes a level of suspension in the housing.

Apparatus for separating impurities from fiber suspensions

Apparatus for segregation of fibers from a suspension which contains relatively heavy contaminants has two elongated parallel but not coaxial horizontal vessels which are welded or strapped together and one of which is located below the other. One end of the lower vessel is connected with a pipe which admits the suspension and the other end of the upper vessel is connected with a pipe for evacuation of segregated fibers. The vessels have openings for portions of at least one row of discrete centrifugal separators each having a tangential inlet for suspension which communicates with the first vessel, an upwardly extending first outlet which discharges fibers into the upper vessel, and a downwardly extending second outlet for impurities. Each separator is detachable from and reattachable to both vessels.

Apparatus for classifying the constituents of dilute suspensions of

Apparatus for removing impurities entrapped in a suspension of fibrous material includes a fluidized bed chamber having opposite ends, a top wall, and a perforated bottom wall. An inlet feeds the suspension to be purified to a diffusing chamber which imparts laminar flow thereto and, in turn, feeds the suspension to the fluidized bed chamber through one end thereof for flow across the bottom wall toward the other end. A pressure chamber is positioned below the fluidized bed chamber and communicates with the bottom wall thereof, the pressure chamber having a plurality of walls thereacross dividing the same into a plurality of sections. A manifold has branches communicating with each section of the pressure chamber for introducing a fluidizing agent under pressure thereto for upward flow through the perforations in the bottom wall and through the suspension therein thereby to separate impurities from the suspension by flotation. A separation chamber has a forward end communicating the other end of the fluidized bed chamber for receiving the suspension therefrom and has top and bottom walls and a rear wall. A light impurities withdrawal conduit extends upwardly from the top wall of the separation chamber in the forward region thereof for removing separated impurities from the suspension which have relatively low specific gravity and float to the top thereof. A fibrous suspension withdrawal conduit extends from the rear upper region of the separation chamber for removing the purified fibrous suspension therefrom, and a heavy impurity withdrawal conduit extends from the lower region of the separation chamber for removing separated impurities from the suspension which have relatively high specific gravity and settle to the bottom wall of the separation chamber.

Apparatus for purifying a suspension of fibrous material

An apparatus for straining liquid fibrous suspensions to remove contaminants and foreign objects has a stationary screen basket located in a housing. Purging blades rotate in the interior of the screen basket in close proximity to the interior walls of the screen and create pressure pulses, causing trapped contaminants and foreign objects to migrate toward an outlet, whereas the purified suspension, including the useful fibers, passes through the screens. The average path traversed in the apparatus by contaminants and foreign objects is shortened due to the disposition of an intermediate chamber, at mid-height of the screen basket, through which contaminants may also be eliminated from the apparatus. The purging blades are appropriately extended to sweep the walls of this intermediate chamber. The shortened average path reduces the probability that contaminants will pass through the screen on their way to the outlet.

Apparatus for straining suspensions

Disclosure is made of improved apparatus for continuously processing waste papers, contaminated with inks, adhesives, resins, groundwood, foreign objects, paper fasteners and the like, into usable grades of cellulosic fiber pulps. The disclosure is also of a method for the continuous processing of contaminated waste papers into nearly quantitative yields of usable cellulosic fiber pulps.

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Heidenheim, Germany

Josef Tra