Abstract: An apparatus and method serves, e.g., to deaerate, clean or screen a fibrous suspension and is provided with a closed housing and a rotor arranged centrally therein. The rotor puts at least a part of the fibrous suspension guided into the housing into a rotational flow. The fibrous suspension flowing into the housing through the inlet is put into rotation by a guide element acting hydraulically. This increase the efficiency of the apparatus and prevents disturbing turbulences in the apparatus.

Abstract: An apparatus and method serves, e.g., to deaerate, clean or screen a fibrous suspension and is provided with a closed housing and a rotor arranged centrally therein. The rotor puts at least a part of the fibrous suspension guided into the housing into a rotational flow. The fibrous suspension flowing into the housing through the inlet is put into rotation by a guide element acting hydraulically. This increase the efficiency of the apparatus and prevents disturbing turbulences in the apparatus.

Abstract: Method and flotation vessel for removing contaminants from aqueous fibrous suspension. Method includes damming up fibrous suspension at head level above base of flotation vessel, forming a bubble flow of gas bubbles rising counter to field of gravity in dammed up fibrous suspension, and guiding fibrous suspension crosswise to bubble flow, such that as contaminants are deposited on gas bubbles to form thickened flotation foam, fibrous suspension is cleaned. Method also includes discharging cleaned fibrous suspension as accepts, and discharging thickened flotation foam. A flow cross section of flotation vessel lying crosswise to bubble flow is straight on at least 80% of at least one side wall and a length of side wall is at least 1.5 times as great as that of an end wall. This abstract is neither intended to define invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: Method and flotation vessel for removing contaminants from aqueous fibrous suspension. The method includes damming up fibrous suspension at a head level above a bottom of flotation vessel, and forming a bubble flow via gas bubbles rising counter to gravity in dammed fibrous suspension, such that fibrous suspension is carried counter to ascending direction of bubble flow and contaminants are deposited on gas bubbles. Accepts, discharged in cleaned form, are carried counter to bubble flow, and contaminants and bubbles are discharged in thickened flotation foam. A flow cross-section of flotation vessel transverse to bubble flow is formed straight on at least 80% of at least one side wall, and length of side wall is at least 1.5 times greater than width of end wall. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: The process targets the removal of interfering materials from an aqueous fibrous material suspension, especially if this is produced from recycled paper. Thereby interfering materials, such as printing ink particles, small synthetic particles, or sticky contamination, are eliminated by flotation in a particularly advantageous manner. In accordance with the invention, the combination of low-intensity and high-intensity flotation is undertaken, whereby the low-intensity flotation generally works in the gravitational field and the high-intensity flotation in a centrifugal field.

Abstract: The flotation apparatus removes ink- and contaminant particles from a fiber stock suspension which is produced during the preparation of waste paper. Admixing of air to the fiber stock suspension is accomplished in stepped diffusors. The fiber stock suspension admixed with air, prior to infeed into a flotation container, is guided through a deflection element effective as an impact mixer and followed by a mixing diffusor having a preferred flow direction. This flotation apparatus is especially suited for eliminating disturbing or spurious substances which are present throughout a relatively wide grain size spectrum. A particularly preferred construction uses one or more closed flotation containers, wherein the air effluxing from the flotation foam can be advantageously re-used for aeration of further infed fiber stock suspension.

Abstract: The flotation apparatus comprising a container having a free liquid level of the fiber stock suspension which is fed essentially horizontally to the container by at least one infeed device. The infeed device contains at least one aeration element having an outlet cross-section located at a predetermined region which is 100 to 600 mm, preferably 50 to 250 mm, below the liquid level of the fiber stock suspension in the container. Between the end of the aeration element and the discharge mouth or opening of the infeed device which opens into the container there can be arranged an essentially horizontally extending starting path for quieting or stabilizing the flow of the fiber stock suspension. This starting path is provided at its initial region with an ascending cover member at which merges a channel having a free liquid level.