Abstract: Pulp and oxygen are mixed by feeding the pulp and also feeding the oxygen to a mixer which has a grooved rotor closely spaced between two grooved discs to provide high intensity mixing zones.

Abstract: The system comprises a stationary drum with at least one end having a large open area, and a coaxial, rotatable cylinder of larger diameter than the stationary drum mounted for rotation about the stationary drum.The stationary drum has a plurality of circumferentially-separated, longitudinally-extending sets of gas baffles on its outside surface and a plurality of circumferentially-separated, longitudinally-extending sets of inwardly-extending louvers adapted to direct gas in an axial direction inside the stationary drum.First sealing members and circumferentially-separated second sealing members each extend across the annular space between the stationary drum and the rotatable cylinder to divide the annular space into two different pressure zones.

Abstract: The nozzle is used with a system for removing contaminants from a liquid including a source of dissolved air in water under pressure and includes a first member with a hole through which the dissolved air and water flows. A floating member is also provided. The shapes of the first member and the floating member are such that the hydraulic forces resulting from the flow of water outwardly between the two members causes the floating member to float a predetermined distance from the first member. The shortest distance separating the first member and the floating member is such that most bubbles exiting from between the two members have a diameter less than 100 microns.

Abstract: A pair of rotatable shafts are mounted within a housing. The shafts are spaced apart along the same plane with each shaft having a plurality of longitudinally spaced disks mounted thereon. The space between the shafts and the dimensions of the disks are such that disks on each shaft extend into the space between adjacent disks on the other shaft to provide pressing areas. One shaft is rotated clockwise; the other shaft is rotated counterclockwise.A slurry or semi-solid is fed into the in-running sides of the disks. A cake forms on the disks by the flow of liquid through liquid passageways in the disks. Pressing to a high consistency takes place in the pressing areas. The cake thus formed is removed from the disks at the out-running sides of the disks.

Abstract: A continuous sheet of paper fibers is fed to a rotatable drum, moved around the rotatable drum by the rotatable drum, and is fed from the rotatable drum at an area circumferentially spaced from the paper fiber feed-in area. The sheet is supported on the drum by a high percentage open area sheet support. The sheet support has channels for conducting hot gas from the inside of the drum against the inside surface of the sheet. The support also has means for conducting the hot gas along the inside surface of the sheet.

Abstract: The separator is particularly suitable for separating impurities from a pulp slurry. The separator includes a vertical vessel with an upper chamber and a lower chamber. The pulp slurry is fed into the upper chamber by means of a tangential pulp slurry inlet. A strong rotational movement is imparted to the pulp slurry in the upper chamber to cause the heavy impurities to move outwardly. Means are provided to change the strong rotational movement of the pulp slurry in the upper chamber to a primarily translational movement downwardly within the lower chamber so that the heavy impurities will move downwardly within the lower chamber. The heavy impurities are removed from the lower chamber.

Abstract: Hot gas is used to dry the paper on a rotatable drum. A plurality of spokes interconnect a rotatable shaft and the drum. The hot gas flows within the drum and directly contacts the spokes. The spokes extend tangentially from the shaft to the drum.

Abstract: The paper web is directly contacted with superheated steam to evaporate the water in the paper web by direct contact and to remove some of the superheat from the steam. The exhaust steam is again superheated and recycled back to the direct contact dryer.The paper web drying system includes a direct contact dryer, a superheater such as a heat exchanger, means for feeding the exhaust steam from the direct contact dryer to the heat exchanger, and means for feeding superheated steam from the heat exchanger back to the direct contact dryer.

Abstract: A substantially air-tight vat completely encloses the rotatable cylinder. The pulp slurry fed into the vat is compacted to form a mat of high consistency. The differential pressure across the circumferential wall of the rotatable cylinder washes the mat with liquid contained in the wash chamber. The mat is removed from the cylindrical wall of the rotatable cylinder to provide a low consistency pulp slurry.

Abstract: A high consistency pulp slurry is prevented from floccing by at least one pivotable member located in the vat at the area where the pulp slurry leaves the inlet box and enters the vat. The pivotable member is located with respect to the inner surface of the vat and is structured to speed-up the pulp slurry as it enters the vat to prevent floc formations.If pulp fibers should become stuck in the small space between the outer surface of the pivotable member and the inner surface of the vat, the pivotable member will automatically pivot away from the inner surface of the vat, thereby automatically loosening the stuck fibers. As soon as the stuck fibers are loosened, the pivotable member will return to its initial position.

Abstract: At least one longitudinal baffle extends from an area within the forming zone into the compaction zone. In the forming zone the baffle is pivotally connected to the vat and also has a pivotal structure in the area where the forming zone changes into the compaction zone. Actuating means are located in the compaction zone and apply actuating forces against the outside surface of the baffle to cause the baffle to automatically adjust the convergence angle in response to changes in pulp mat thickness.