Abstract: A screen bowl centrifuge having slots which have successive portions which slope lengthwise toward a common axis, and additionally, slots which slope laterally toward the common axis. The screen bowl centrifuge may also have slots which conform to the predominant path of solids through the centrifuge by providing helically shaped screen bowl elements.

Abstract: A process of making a liquid absorbing laminated structure comprising long lengths of absorptive tissues and an intermediate layer of absorptive particles is performed while the tissues are traveling in the direction of their lengths. A film of moistening liquid is transferred to a surface of a first tissue which is then supported in substantially horizontal position and showered with dry absorbent particles, which are rendered adhesive by absorption of the moistening liquid. A second tissue is superposed and the assembly is bonded together by passing it through the nip between a heated roller having a surface temperature of at least 110.degree. C. and a pressure roller. These rollers are pressed together at the nip by a pressure of at least 350 pounds per square inch and each has a surface hardness in excess of 90 Shore A Durometer.

Abstract: Microcreping apparatus has an assembly of superposed sheet members which are pressed by presser means against a surface of a material being treated to compress the material against the surface of a drive roll preliminary to engagement of the material with a retarding means. The sheet member assembly is supported as a cantilever by holder means to which at least the primary and outer sheet members of the assembly are connected by a plurality of pins on the holder means received in slots in the connected superposed sheet members spaced inwardly across the path of travel of the material adjacent the rearward edge of the sheet members. The slots extend transversely of the direction of travel of the material and have sufficient clearance from the pins to permit movement thereof relative to the pins corresponding to local expansion or contraction of the respective sheet members under heating and cooling respectively.

Abstract: Hydrocyclone separator apparatus includes hydrocyclone separator(s) capable of separating light impurities from a paper-making fiber slurry. The separator inner wall is cylindrical with an apertured inlet portion adjacent one end which directs feed slurry in a vortical path along the wall to an enlarged inlet to an axial flow passage adjacent the other end. This inlet has a rim spaced radially from the wall which skims an inner part from the vortex containing predominantly the light impurities into the axial passage from which it is discharged through an apertured outlet portion of the sidewall. The remainder of the slurry vortex passes the rim to be discharged through another apertured outlet portion of the sidewall.

Abstract: A flotation cell for removal of solid particles contained in a liquid has, upstream of its inlet, a mixing chamber providing a passage through which the liquid passes to the cell inlet and in which the liquid is charged with air or other gas to form bubbles therein. This chamber is provided with at least one pair of opposed, converging walls extending across the passage to form opposite faces of a liquid flow path to a restricted gap between these walls at their greatest convergence, and so arranged that substantially all the liquid flowing through the chamber is forced to pass through such a flow path. Gas injection means provides a flow of gas under super-atmospheric pressure into the liquid flowing between these walls in the vicinity of the restricted gap between them to form bubbles in the liquid distributed across the path of flow.

Abstract: A centrifugal separator having a rotary bowl for receiving feed which forms a pool within the bowl a skimmer movably mounted to fixed structure within the bowl for removing liquid from the pool to a discharge system with an outlet external to the bowl, and adjustment means operable from outside the bowl for adjustably moving the skimmer oppositely toward and away from the bowl axis to vary the pool depth. However, in accordance with the invention, the skimmer adjustment means includes skimmer mounting means movably connecting the skimmer to the fixed structure within the bowl so as to enable adjustment movements thereof by the adjustment means and so that the hydraulic thrust of the pool liquid against the skimmer is applied by the mounting means substantially entirely to the fixed structure. Preferably, the adjustment movement of the skimmer enabled by the mounting means are essentially radial only to the axis of the bowl, thus greatly reducing the amount of adjustment movement required.

Abstract: A solids-liquid slurry separating centrifuge has a rotary bowl, a conveyor rotatable coaxially therein, an outlet for solids, and a liquids outlet permitting retention in the bowl of a pool of slurry with an inner surface at or close to the axis of the bowl. Mechanism for discharging solids from the solids outlet includes a frusto-conical inner portion of the bowl and a coaxial frusto-conical hub on the conveyor within it having their smaller ends at the solids outlet, the hub being formed to a larger cone angle than the bowl portion such that the outlet end of the passage between them is wider than its inlet end and is approximately equal in cross-sectional area to the passage inlet. The hub has a conveyor blade helix of diminishing spacing between turns from the larger diameter end toward the smaller diameter end of the passage.

Abstract: A centrifuge includes a power exchange rotor of efficient design which is provided with at least one channel member for guiding the flow of material therethrough from a first end exposed to a source of the material, which is a feed source in a rotor used as a feed accelerator and is material discharging from the bowl treating zone in a rotor used in power recovery. The channel is so formed as to change the direction of flow of the material at least about 90 degrees as it flows therein to a discharge outlet at the other end and is spaced from the rotor axis less than the maximum radius of the bowl in the area of the treating zone. The rotor is mounted for rotation at a rate such that the tangential velocity of the channel ends is substantially less than that of the bowl treating zone.

Abstract: A rotary centrifuge has a bowl and an end member provided with mutually attachable flanges at least one of which has a series of plugs secured in transverse cavities near its periphery with a portion of the plugs less than their full width protruding from the flange periphery through slots communicating with the cavities at regular intervals spaced peripherally less than 15 inches between slot center lines. At least the protruding plug portions have a resistance to abrasive wear approximately equal to or greater than that of 90% aluminum oxide ceramic.

Abstract: Apparatus for screening pulp slurry in an annular screening zone in the space between a screen of circular cross-section and a closed surface drum carrying pulse creating means, the screen and drum being coaxially mounted for relative rotation about their common axis, is characterized by means for feeding the slurry providing at least one inlet to the space extending substantially the full axial length of the screening zone, and means for removing from the space rejects not passing through the screen having at least one rejects outlet from the space extending substantially the full axial length of the screening zone.

Abstract: A solids-liquid separating centrifuge of the type having a bowl, a conveyor and drive gearing for rotating the bowl and conveyor at differential speeds, so that the conveyor continuously moves settled solids longitudinally of the bowl to discharge from an outlet in a reduced diameter end of the bowl, has one or more nozzle outlets through the bowl wall with their inlets exposed to the path of movement of a portion of settled solids by the conveyor toward the bowl end solids outlet to remove therethrough a relatively slow settling and difficult to convey portion of the solids.

Abstract: Apparatus for treating lengthwise traveling material has a material driving member provided with alternating grooves and lands extending parallel to the direction of drive of the material, presser means to press the material against the lands, and a retarder member downstream of the presser member for deflecting the material away from the driving member, the retarder member having an edge portion extending across the path of travel of the material provided with teeth extending into the driving member grooves with clearance from the groove walls, and intervening slots receiving therethrough the lands of the driving member with clearance from the slot walls. The construction avoids snagging of the material by, or diving of the material under, the retarding member, and wear of the retarder member.

Abstract: A system for spray cooling large quantities of heated water has a plurality of spray forming means each consisting of a plurality of associated nozzles connected by piping to pumps, each of the associated nozzles having an outlet constructed and arranged to discharge the water in a coherent stream which impinges upon the stream ejected by each other associated nozzle in a common zone beyond the nozzle with a force which breaks the streams into a spray of drops having a resultant trajectory away from the nozzles into a receiver. The water may be aerated before discharge from the nozzles, this being effectively accomplished by means of air inlets to a venturi passage in each nozzle.

Abstract: A solids-liquid separating centrifuge with bowl and conveyor members rotated about a common axis at a differential speed has means for sensing torsional vibration of at least one of the members about its axis and providing an output representative of the vibration amplitude, and signal means which provides an indicative signal when the output indicates vibration amplitude above a predetermined level. The indicative signal may operate an alarm, or an automated centrifuge throughput reducing system, or both.

Abstract: Chatter is suppressed in a solids-liquid separating centrifuge by including, in an external connection to a holder of the speed change gearing between the centrifuge bowl and conveyor, a spring and mass means which is torsionally resilient about the axis of the connection such that it will vibrate about that axis under chatter conditions at the chatter frequency, and which has a spring rate within +40% to -25% of the spring rate at which the spring and mass means will vibrate in resonance with the vibration during chatter of the bowl-gearing-conveyor assembly.

Abstract: Chatter is suppressed in a solids-liquid separating centrifuge by including, in an external connection to a holder of the speed change gearing between the centrifuge bowl and conveyor, a spring and mass means which is torsionally resilient about the axis of the connection such that it will vibrate about that axis under chatter conditions at the chatter frequency, together with damping means acting in parallel with the spring and mass means to apply resistance to the torsional vibration thereof and thereby irreversibly extract energy therefrom.

Abstract: A helical bladed conveyor for use in a centrifuge is provided with a wear-resistant outer foward edge by securing to the blade a thin band of metal having an upstanding marginal portion extending beyond the forward face and forming with it a cavity which is filled to the desired depth by fusing a wear-resistant material in place.

Abstract: A hard-surfaced screw conveyor for centrifuges has a helical metal blade with a plurality of wear-resisting segments mounted on one side thereof, there being mating parts on the opposed surfaces of the segments and the blade which are slidably interengaged to prevent radial outward and axial relative movements of the segments and the blade.

Abstract: In filters of the type in which a cake of solids deposited from a liquid slurry thereof on a generally horizontal filter medium is subjected to treatment involving passage of liquid through the cake while on the filter medium, means is provided for increasing the drainage rate of the formed cake by causing the cake to form on the medium from the slurry fed thereto by gravity settling in the liquor of the slurry and by removing liquor of the slurry from above the cake while the liquor still contains unsettled fine particles, such means including means providing a backflushing flow of liquid through the underside of the filter medium and the cake forming thereon into the slurry.

Abstract: In filters of the type in which a cake of solids deposited from a liquid slurry thereof on a generally horizontal filter medium is subjected to treatment involving passage of liquid through the cake while on the filter medium, means is provided for increasing the drainage rate of the formed cake by causing the cake to form on the medium from the slurry fed thereto by gravity settling in the liquor of the slurry and by removing liquor of the slurry from above the cake while the liquor still contains unsettled fine particles.