Abstract: The invention relates to a method for directly or indirectly applying a liquid or pasty application medium (2) onto one or both sides of a continuous surface (4), wherein the application medium (2) is applied to the surface (4) in a plurality of single application regions by means of a plurality of single application nozzles (12) spaced apart from one another side by side and/or in succession in the direction of width (B) and/or longitudinal direction of the surface (4) and clearly distanced (D) from the surface (4), the application medium (2) emerging from each of these nozzles, wherein adjacent single application regions each intersect (U) at least in part in their respective edge regions, causing a layer of application medium to be produced across substantially the entire width (B) of the surface (4) to be coated. The invention also relates to an apparatus for performing this method.

Abstract: The invention relates to a method for directly or indirectly applying a liquid or pasty application medium (2) onto one or both sides of a continuous surface (4), wherein the application medium (2) is applied to the surface (4) in a plurality of single application regions by means of a plurality of single application nozzles (12) spaced apart from one another side by side and/or in succession in the direction of width (B) and/or longitudinal direction of the surface (4) and clearly distanced (D) from the surface (4), the application medium (2) emerging from each of these nozzles, wherein adjacent single application regions each intersect (U) at least in part in their respective edge regions, causing a layer of application medium to be produced across substantially the entire width (B) of the surface (4) to be coated. The invention also relates to an apparatus for performing this method.

Abstract: The invention relates to a method for directly or indirectly applying a liquid or pasty application medium (2) onto one or both sides of a continuous surface (4), wherein the application medium (2) is applied to the surface (4) in a plurality of single application regions by means of a plurality of single application nozzles (12) spaced apart from one another side by side and/or in succession in the direction of width (B) and/or longitudinal direction of the surface (4) and clearly distanced (D) from the surface (4), the application medium (2) emerging from each of these nozzles, wherein adjacent single application regions each intersect (U) at least in part in their respective edge regions, causing a layer of application medium to be produced across substantially the entire width (B) of the surface (4) to be coated. The invention also relates to an apparatus for performing this method.

Abstract: An apparatus for selective particle flotation includes a static mixer connected to a flotation section in lieu thereof of the apparatus. The static mixer is disposed upstream of the flotation section in lieu thereof with respect to a direction of fluid flow through the apparatus. The static mixer mixes sludge with small gas bubbles. A flotation cyclone is disposed in an upstream portion of the flotation section in lieu thereof with respect to the direction of fluid flow through the apparatus. The flotation cyclone is the initial separation device through which the sludge flows.

Abstract: The present invention relates to a method of processing printed waste paper, in particular waste paper containing at least 80% newsprint or magazine paper by digestion, various cleaning steps, flotation or washing and disintegrating, the latter with a high consistency of at least 20%, and possibly bleaching. The invention is characterized by the fact that a final second disintegrating step, arranged possibly before a bleaching step, with treatment of the waste paper under strong kneading action of individual bar-shaped or block-shaped kneading elements of both the stator and the rotor of the disintegrating machine which are arranged in a kneading chamber thereof which is delimited by two concentric cylindrical surfaces, at temperatures between 20.degree. and 110.degree. C., and preferably 38.degree. to 65.degree. C., and with a specific power consumption of between 30 and 100, and preferably 80, kilowatt hours/ton oven-dried pulp.

Abstract: A flotation cell with at least one injector for introducing a fluid and aspirating air therethrough has a multi-hole aperture plate. Premixing tube sections are disposed in the injector downstream from the aperture plate at a distance from the plate of at least 0.1 times the diameter of a hole in the aperture plate. The tube sections are oriented perpendicular to the aperture plate and open into a mixing tube.

Abstract: The invention concerns the recycling of waste paper in a deinking process with flotation with at least one other cleaning stage downstream. According to the invention, selective flotation is performed in multiple stages. After no more than a third flotation stage, the flotation foam collected up to that point is removed and purified by means of flash flotation, which produces sludge, clear water and separated foam that contains the contaminants from the waste paper feed. Subsequently, the sludge is removed from the paper recycling process. Large impurities are removed from the sludge (foam) (except for the foam from up to the three last stages) in up to two washing units (including thickeners) or screen units. The fibers are then separated from the relatively fine contaminants, and these contaminants are primarily removed as sludge from the resulting low-fiber fractions by flash flotation.

Abstract: The invention is directed to a method of regulating a flotation system having an inflow quantity of suspension flow dependent on production demands, including a primary flotation stage and a secondary flotation stage where the secondary flotation stage treats the froth of the primary stage, transporting de-aereated froth from the primary flotation stage to a collection vessel which is in fluid communication the secondary flotation stage; recycling suspension flow from the secondary flotation cells of the secondary flotation stage in part to an inlet of the primary flotation stage, and in part to an inlet of the secondary flotation stage, and regulating the level of de-aereated froth in the collection vessel by controlling the amount of suspension flow recycled from said secondary flotation stage to the inlet of the secondary flotation stage.

Abstract: A device for separation of air from fiber suspensions of flotation devices which are heavily air- and foam-laden or represent a mixture of fluid and foam features a hydrocyclone whose inlet opening is arranged least 2.5 m below the outlet opening of the flotation device for the air-laden fluid or mixture. The separation section of the hydrocyclone is a slender, truncated cone-shaped body on whose pointed (thin) end the deaerated fluid is withdrawn. In this outlet opening there is a back pressure maintained, so that the inlet opening is not completely covered by the vortex of the fluid, leaving still a sufficiently free entrance cross section for the foam. Above the entrance section of the hydrocyclone a mechanical foam eliminator with a rotor is arranged, the rotor comprising an impeller wheel which is provided with radial blades. A funnel-shaped suction socket feeds the foam-air mixture to the impeller wheel.

Abstract: A hydrocyclone has a separating part A with a diameter which toward its outlet end for the heavier fraction decreases gradually from a diameter 2 R.sub.a, with the radius being subject to the formula:R=R.sub.a .multidot..sqroot.1-x/1.This describes essentially the shape of a parabola, so that the separating part can practically be considered as a paraboloid. Achieved thereby is an optimum separating performance of the hydrocyclone.

Abstract: A defrothing apparatus whose inlet opening of the foamed liquid contained in a foam duct of a primary flotation apparatus is provided in the bottom of the foam duct. Starting from the lower area of the defrothing apparatus, a rotary flow (potential vortex) is generated in the apparatus by a recirculated lqiuid quantity from a secondary flotation apparatus. In the core of the rotary flow the gas quantity (air) is collected and removed through a removal pipe. Consequently, the foamed liquid from the foam duct of the primary flotation stage which is pumped to the secondary flotation stage contains small shares of gas relative to the total quantity of liquid, thereby allowing the pump to be optimally sized of efficiency and better control of the system.

Abstract: A flotation cell featuring a mixing pipe which enters the suspension essentially vertically, follows the point of air intake, and generally receives the entire suspension quantity per flotation cell, the injector of the flotation cell is offset sideways relative to the vertical center axis of the round container cross-section and away from the side on which the foam removal opening and the liquid drain opening are located. The mixing pipe (1) enters the suspension only for a distance such that its discharge opening, mouth (2), is located at least at one-half the height of the level of the overflow edge (7) of the foam removal channel (8), figured from the container bottom. The liquid drain opening (9) is preferably provided in the immediate vicinity of the container bottom, with a cover plate (11) extending across the length of the flotation cell and forming a drain channel (12) into which proceeds the clean liquid through an upper (14) and a lower (13) slot.

Abstract: The injector apparatus is of the kind having a constriction which lies, in the flow direction, immediately before a following adjoining mixing section, in which fibrous stock suspension is mixed with air for the purpose of subjecting the suspension to flotation in a flotation tank. The mixing pipe in which the mixing section is disposed has a radial diffusor at its outlet end, and, for a greater flow rate of air, additional air intake bores are disposed therein a short distance in the flow direction after the constriction.A favorable arrangement is achieved if the injector apparatus with the mixing pipe is arranged perpendicularly in a flotation tank, which may have the form of a reclining cylinder. In this case, the froth, like the cleaned suspension, is drawn off on one long side, i.e., a side which extends parallel to the cylinder axis; the extraction opening for the cleaned suspension being provided preferably immediately below the level of the suspension and/or the froth extraction arrangement.