Abstract: A vortex grit trap comprising a generally vertically extending tank of circular cross-section including a separation zone having an inlet and an outlet for liquid flow to and from the tank, and in which liquid is circulated about a longitudinal axis of the tank, and, a grit collection zone positioned beneath the separation zone in use, the trap being characterized by a generally circular tank divider centered on the vertical longitudinal axis of the tank and extending transverse thereto, the divider defining a notional boundary between the separation and collection zones of the tank and being of smaller diameter than the adjacent region of the tank so as to define with the adjacent tank wall an annulus through which grit passes from the separation zone to the collection zone in use, and, means for generating a cloud of gas bubbles migrating in use upwardly through substantially the whole of said annulus whereby substantially all grit passing from the separation zone into the collection zone passes through the

Abstract: The method is for bleaching cellulose pulp in a bleach line that has at least two bleaching steps. The filtrate distribution is led up through the bleaching line counter-currently to the flow of cellulose pulp established in the bleaching line. A single joint main conduit is used for the bleaching steps. Wash filtrates obtained from the wash steps, used after or before the bleaching step, are led in conduits to branch locations on the main conduit that are positioned downstream of the branch location for drawing off of wash and/or dilution liquor for the wash step in question. All branch points in the joint main conduit are in fluid communication with one another along the main conduit.

Abstract: A control system with a sensor mounted in direct mechanical connection to a non-rotating refining member so that the sensor is responsive to axial vibration movement of the support, and an analog to digital converter directly connected to the output of the sensor without filtering. The control system also includes a controller connected to the analog to digital converter and responsive to the analog to digital converter to compare the amplitude of the output signal from the sensor to a baseline value based on the level of vibration associated with the pulp refiner when it is operating without plate clashing. When the signal exceeds the baseline value, an action is taken to help alleviate the plate clashing.

Abstract: A cylindrical rotating thickening device including an axial core, a plurality of longitudinally extending spaced apart support ribs extending radially from the axial core, and a shell surrounding the support ribs and supported thereon. The shell includes a plurality of longitudinally extending spaced apart grooves, and a perforated deck surrounding and supported on the shell. The deck includes a plurality of closely adjacent deck segments, and each deck segment includes a leading edge and a trailing edge. Each deck segment further includes an integral bar attached to the leading edge and received in the shell groove, and a plurality of fasteners for securing the bar to the shell.

Abstract: The method is for distributing cellulose pulp that has a 2-12% consistency. A manifoid housing is in fluid communication with distributor housing. The distributor housing has holes that are distributed along a generatrix of the distribution housing. The cellulose pulp is fed into an inlet of the manifold housing. The feed screw is rotated to convey the cellulose pulp in the transverse direction through the distributor housing. The feed screw sweeps across the holes in the distributor housing to urge the cellulose pulp through the holes. The cellulose pulp is uniformly fed through the holes and then through an inlet to dewatering drums. The cellulose pulp is run between the dewatering drums and a trough to form a pulp web. The pulp web is dewatered in a press nip formed between the dewatering drums. The dewatered pulp web is collected by a feed screw.

Abstract: A refiner including a material-admitting inlet and an outlet; and spaced apart first and second refining discs mounted in the chamber. The refiner further includes a rotary third ref refining disc disposed between the first and second discs. A first path for the movement of material from the inlet is defined between the first and third refining disks. A second path for the movement of material to the outlet is defined between the second and third refining disks. The refiner further includes a shaft extending through a central opening provided in the first disc, and a hub rigid with the shaft and having a center, the hub being received in the third refining disc central opening. The hub has at least one port in the hub from the first path to the second path and between the third refining disc central opening and the center of the hub.

Abstract: An orbital wastewater treatment system includes a tank and a partition disposed in the tank to define a pair of channels in the tank. The tank has a turning wall bounding contiguous portions of the channels. The partition has an end spaced from the turning wall, whereby the channels communicate with one another. A driven shaft is disposed vertically in the tank between the end of the partition and the turning wall. The driven shaft is provided at an upper end with a surface aerator and at a lower end with a horizontal impeller. At least one baffle member is disposed in the tank partially about a lower end of the shaft including the impeller.

Abstract: A positive pressure disc-type filtration apparatus including a collection trough internal to the cylindrical pressure vessel housing the filter discs. The collection trough is entirely disposed within the cylinder of the pressure vessel and configured and located to receive and direct filter cake removed from the discs and then reslurried and sluiced toward the center of the trough using jets of liquid, to be discharged longitudinally centrally through a single outlet extending downwardly from the trough and through the wall of the pressure vessel. A method of filtration is also disclosed.

Abstract: An apparatus and method of diluting a solid particle-containing slurry in conjunction with a sedimentation process. A slurry is introduced into the launder portion of a feedwell and flowed vertically downward through an eductor nozzle having its exit location placed below the liquid level of a volume of clarified liquor. The eductor nozzle is positioned adjacent a diluent inlet such that discharge of the slurry through the eductor nozzle creates a low pressure zone, drawing clarified liquor through the diluent inlet for mixing and dilution of the slurry. A flocculating reagent may additionally be introduced into the diluted slurry for producing a floc and expediting settling of the solid particles.

Abstract: An orbital wastewater treatment system includes a tank and a partition disposed in the tank to define a pair of channels in the tank. The tank has a turning wall bounding contiguous portions of the channels. The partition has an end spaced from the turning wall, whereby the channels communicate with one another. A driven shaft is disposed vertically in the tank between the end of the partition and the turning wall. The driven shaft is provided at an upper end with a surface aerator and at a lower end with a horizontal impeller. At least one baffle member is disposed in the tank partially about a lower end of the shaft including the impeller.

Abstract: A rotor adapted for use in a hydrodynamic device comprising a cylindrical screen having a circumferentially continuous apertured zone. The rotor has an axis of rotation and includes a substantially cylindrical outer surface adjacent the cylindrical screen surface. The rotor further includes a plurality of sets of a plurality of adjacent vane members supported above a substantially cylindrical outer surface of a rotor by a plurality of brackets. The rotor has an axis of rotation and is mounted within and co-axial with the cylindrical screen to define an annular screening chamber between the rotor and the screen. The sets are equally spaced apart in a direction circumferential to the rotor axis, and the vane members extend the length of the screening chamber parallel to the rotor axis.

Abstract: A fluid level control apparatus for selectively controlling the movement of liquid flowing out of a flotation cell is described. The fluid level control apparatus is significantly reduced in size in comparison with the flotation cell or cells to which it is connected which enables less expensive construction and reduced operating costs in terms of both the equipment and the plant as a whole. The fluid level control apparatus comprises a vessel having a valve positioned therein which includes a valve body structured with a curved surface which provides selective and finite control of fluid flowing through the vessel of the control apparatus. In one embodiment at least one of the inlet and outlet of the control apparatus exhibit a cross-sectional area taken transverse to the intended fluid flow therethrough having a substantially horizontal dimension which is greater than a substantially vertical dimension.

Abstract: A precoat renewal system for a filter, such as a disc filter. The renewal system includes a plurality of nozzles coupled to spray piping and valving with each nozzle being positioned for spraying an area of one side of a disc. The nozzles and at least a portion of the spray piping is movable such that the nozzles may be displaced relative to the discs. The nozzles and piping are arranged in groups or zones with each zone covering a specified percentage of the discs in the filter and each zone representing about 40% or less of the surface area of the filter media of the discs in the filter. The system may be configured such that high pressure fluid may be supplied to that particular zone for removal of a precoat layer on the disc while other zones may be concurrently washed with a lower pressure fluid.

Abstract: A guide assembly for a floating cover of a sludge digester tank includes a track having a pair of opposing surfaces facing one another to define a vertical guide channel or track connected to the tank or the floating cover. At least one slider member is disposed in the channel for vertical motion therein. The slider member is connected to the other of the tank or the floating cover. Two bearing strips are attached to the slider member for engaging opposing surfaces of the track in a low-friction slidable contact. The bearing strips are vertically removable from the slider member, so that the bearing strips may be replaced without removing the slider member from the guide channel.

Abstract: A refiner for pulp or like materials, comprising a housing having a chamber, a material-admitting inlet and an outlet; and spaced apart first and second refining discs mounted in the chamber. The refiner further includes a rotary third refining disc disposed in the chamber between the first and second discs and defining therewith first and second paths for the movement of material from the inlet to the outlet. The third refining disc has a central opening, and the discs are coaxial with each other. The first and second discs respectively also have first and second comminuting projections adjacent to the first and second path and the third disc has third and fourth comminuting projections adjacent to the first and second path and respectively cooperating with the first and second projections to refine the material flowing along the first and second paths.

Abstract: The enhanced deliquifying of the compacted bed of deep bed thickener/clarifier is disclosed. Such an apparatus comprises a vessel receiving a slurry of liquid and solid particles suspended in the liquid. The vessel defines a free settling zone, a hindered settling zone intermediate, an upper clarification zone and a lower compaction zone. A deliquifying member is provided in the vessel extending up between at least two zones for facilitating the upward flow of free liquid from one of the lower zones and the settling of particulates. A rotating rake shaft with pickets are so designed to release the interstitial liquid trapped in a lower zone. The pickets provide pathways for liquid to release generally vertically. The release liquid travels upward to the deliquifying member and on into the clarification zone. The lower zone, freed of the interstitial water, further collapses becoming more concentrated or dense.

Abstract: This invention provides a winding machine comprising a support drum, a winding tube at least partially supported on the support drum, and a web of material being wound around the winding tube to form a web reel in response to rotation of the support drum and the web reel, the point where the web reel rotates into contact with the support drum being called the nip. The winding machine further includes a nip safety guard comprising a finger presence sensor, a support mechanism supporting the finger presence sensor adjacent one of the web reel and the support drum, and a moving mechanism that moves and locates the finger presence sensor support mechanism depending on the size of the web reel so that the finger presence sensor is located closely adjacent the one of the web reel and the support drum and spaced a safe distance from the nip. The safety guard moving mechanism further includes a control for determining the size of the web reel and operating the moving mechanism to position the finger sensor.

Abstract: This invention provides a winding machine comprising a support drum, a winding tube at least partially supported on the support drum, and a web of material being wound around the winding tube to form a web reel in response to rotation of the support drum and the web reel, the point where the web reel rotates into contact with the support drum being called the nip. The winding machine further includes a nip safety guard comprising a finger presence sensor, a support mechanism supporting the finger presence sensor adjacent one of the web reel and the support drum, and a moving mechanism that moves and locates the finger presence sensor support mechanism depending on the size of the web reel so that the finger presence sensor is located closely adjacent the one of the web reel and the support drum and spaced a safe distance from the nip. The safety guard moving mechanism further includes a control for determining the size of the web reel and operating the moving mechanism to position the finger sensor.

Abstract: A process for washing pulp including a dilution step, an extraction step and a subsequent displacement step. The process further includes the steps of: diluting the pulp; passing the diluted pulp to the extraction step; developing a first filtrate from the extraction step; passing the pulp from the extraction step to the displacement step; developing a second filtrate from the displacement step; segregating the first and second filtrates; providing the second filtrate to the dilution step; providing a determined minimum volume of the first filtrate needed for the dilution step; and eliminating the remaining volume of the first filtrate from further use in the washing of the pulp.

Abstract: A papermaking refiner has two stationary disks mounted to the support structure of a fixed housing. A rotating disk is mounted on a shaft which extends through the housing. The support structure allows stock to circulate on both sides of the disk support structure, thus balancing fluid pressures on both sides of the fixed disk and preventing thermal gradients for reduced deflection of the disks. The incoming stock is centrifugally accelerated in a shroud which separates and traps tramp metal or the like before the stock passes to the refiner disks. The shroud has passageways which allow the rotating fluid to enter a reservoir which surrounds the drive shaft and feeds the gaps between the rotor and the stationary plates.