Abstract: An arrangement for separation by flocculation of flocculable substances contained in a suspension, as such is used particularly for purifying the backwater of deinking installations for waste paper processing, comprises a container supplied by a conduit with a suspension coming from a reservoir and admixed with flocculating agents and with air. The container contains a rotor with vertical shaft from which two arms extend outwardly at different heights. The suspension to be purified is delivered by the shaft and the upper arm, and by means of the lower situated arm leading the upper arm at an acute angle the purified water is removed. The floated-up flocculated substances are withdrawn from the surface as flotation scum and optionally by means of a conveying device through a scum conduit.

Abstract: Waste paper is defiberized within a container or receptacle in a thick stock range at a low water level. Thereafter, by further infeeding water, the obtained slurry or the like is diluted to a consistency of less than 7% while continuing the defiberizing operation. Finally, the obtained stock suspension is withdrawn through a sieve or screen located at the floor of a defiberizing container. The defiberizing container or receptacle used for performing the method possesses a lower region having a smaller diameter, above which there is located an upper region having a larger diameter.

Abstract: A housing is equipped with a set of grinding tools and a rotor equipped with a second set of grinding tools. One of the parts carrying the grinding tool set is moveable in relation to the other part, which may be constituted by the rotor, in axial direction of the rotor and can be adjusted by a piston-and-cylinder unit impingeable with a pressurized fluid medium, preferably compressed air. The compressed air infeed into the piston-and-cylinder unit is accomplished by a compensation force regulator controlled as a function of the pressure of the stock suspension within the internal compartment of the housing and a grinding force regulator controlled independently of the compensation force regulator in accordance with a set value signal infed by a control line.

Abstract: An installation for processing waste paper containing a stock pulper or slusher equipped with a rotor and two sieves or screens having different size holes or openings. By means of the sieve having the larger size openings there is conducted the obtained stock suspension through a primary line system which, for instance, leads to a papermaking machine. Cooperating with the sieve having the larger size openings or holes is an auxiliary circulation circuit containing a device for the removal of contaminants or rejects. There is preferably arranged at the auxiliary circulation circuit or system a separator for heavy contaminants or rejects, a pump, a secondary stock pulper or fiberizer and a sieve or filtering device.

Abstract: The fiberizer is constructed with a closed chamber provided with an inlet for a waste paper suspension as well as with discharge openings for stock, impurities of low specific gravity and impurities of high specific gravity. The rotor which serves to rotate the stock suspension within the vessel has a central duct which communicates the central part of the chamber with the discharge opening for the impurities of low specific gravity.In one embodiment, the vessel is mounted vertically and has a downwardly tapering wall which terminates at an opening for the discharge of impurities of high specific gravity. In a second embodiment, the vessel has a conical end wall opposite the rotor which has an apex directed towards the rotor. In this embodiment, the opening for the discharge of impurities of high specific gravity can be disposed in the base of this end wall if the vessel is vertically positioned or in a sidewall if the vessel is horizontally oriented.

Abstract: The hydrocyclone is provided with a hollow rotor which is constructed in the form of a radial pump rotor and the outlet orifice of the rotor is disposed in a casing having a tangential outlet aperture. The bend in the rotor produces an increase in pressure during use so as to compensate for any pressure losses as well as to allow the use of a feed pump of low-pressure capacity. A disc is also mounted on the rotor in place of a seal to prevent heavy particles from entering the upper casing.

Abstract: The teeth of the stator and rotor of the refiner are each formed with a surface layer on the leading flanks which is harder than the end faces so as to maintain a sharp cutting edge. The hardness of the surface layer is at least 600 HB while the end face is of a hardness of from 280 to 320 HB.

Abstract: The stock pulper has a container in which the screen has a dimensional component disposed axially of the container to receive an inwardly directed radial flow of the stock suspension. The screen can be cylindrical or conical. Breaker dogs are also fixedly mounted in the container to extend to the ends of the rotor arms.

Abstract: The container for the stock suspension is made as a body of revolution with a conical circumferential wall and a conical end wall which defines an acute angle with the circumferential wall to facilitate separation of materials. A compartment is formed in the circumferential wall near the end wall. This compartment is of increasing radial thickness in the direction of rotation of the rotor and terminates at the location of an outlet for heavy impurities.