Abstract: The invention provides multiple steam applicators which are used to distribute steam against a web during calendering. The invention includes a primary steam applicator located adjacent a side of the web to which steam is applied. The primary steam applicator has a manifold, a primary inlet valve, and a plurality of steam valves spaced along the primary manifold. Each steam valve regulates a steam flow distributed to a cross-directional section of the web. A secondary steam applicator is located adjacent the side of the web to which steam is applied. The secondary steam applicator has a manifold, a secondary inlet valve, and a plurality of steam valves spaced along the secondary manifold, each steam valve regulating a steam flow distributed to a cross-directional section of the web. A gloss sensor measures the gloss finish of the web.

Abstract: A mechanism and method for initially dewatering a paper stock slurry between looped traveling forming wires wherein the wires pass over turning bars, controlling the cross machine curvature of the turning bars to compensate for variations in curvature due to temperature effects on the turning bar and to control the cross machine curvature of the turning bar to a predetermined fixed shape for wide machines to control the travel of the wire over the bars by applying bending moments to a support beam for the turning bar such as by providing separate liquid chambers in the beam and directing heated or cooled water into the chambers to bend the bar to either a positive crown, to be straight or to a negative crown.

Abstract: In the manufacture of stretchable webs such as creped tissue, nonwovens, and the like, in which the web is formed and thereafter wound onto a reel, basis weight control of the web on the reel is accomplished by measuring the speed and basis weight of the web prior to winding the web onto the reel and calculating the basis weight of the web on the reel. In response to this calculated value, the downstream speed of the web (reel speed) is adjusted to obtain the desired basis weight of the web at the reel.

Abstract: A method for controlling high-speed sheetmaking machine after abrupt process changes and during start-up periods and the like, includes operating a scanning sensor to periodically traverse back and forth across a sheet in the cross direction to detect values of selected sheet property along each scan while the cross-directional width of each scan is controlled to be substantially less than the width of the sheet being scanned.

Abstract: A system for controlling the calendering of sheet materials includes means for receiving measurements of one property of sheet material during production wherein the input to the system represents the setpoints of a calender profile actuator system. In operation, the system first calculates a linear trend line from a pattern of setpoints. Then, the linear trend line is substrated from the pattern of setpoints and used to control an edge loading system. The residual setpoints are provided to a frequency splitter whose low frequency output is used to determine the setpoints of a crown roll system and whose high frequency output is used to determine the setpoints of a calender profile actuator system.

Abstract: The present invention provides an apparatus for straightening sheet curls in which a wrap angle .theta. is provided for a sheet wound off from a winding roll by applying a decurler bar to the sheet between two backup rolls, the apparatus comprising a wrap angle adjusting device for adjusting the wrap angle of the sheet by relatively displacing the backup rolls and the decurler bar, and a controller which serves to calculate an optimum wrap angle in accordance with changes in the diameter of the winding roll using the logical equation: .theta.=A/D.sup.q +B (wherein A, B, q are constants which are previously determined) from which the optimum wrap angle .theta. can be calculated for the diameter D of the winding roll, and to control the wrap angle adjusting device on the basis of the results of this calculation. In consequence, the present invention is able to realize automatization of straightening of curls with a simple configuration and in a rapid and highly precise manner.

Abstract: A method for controlling high-speed sheetmaking machine after abrupt process changes and during start-up periods, includes operating a scanning sensor to periodically traverse back and forth across a sheet in the cross direction to detect values of selected sheet property along each scan while the cross-directional width of each scan is controlled to be substantially less than the width of the sheet being scanned, the progressively increasing the width of the scan until each scan encompasses the full width of the moving sheet.

Abstract: For dewatering a paper web the pressing or press section has two separate or spaced pressing locations arranged in tandem and comprising extended nips. These pressing locations are each formed between an upper pressing surface and a lower pressing surface. The paper web to be dewatered travels between an upper felt belt and a lower felt belt. One of the felt belts extends through both pressing locations while the other felt belt only travels through the first pressing location as viewed in the direction of travel of the paper web. The paper web is only sandwiched between the two felt belts in the first pressing location. The other felt belt which is guided solely through the first pressing location is diverted away from the paper web directly downstream of the first pressing location by a pivotably mounted guide roll, so that the paper web passes through the second pressing location while being supported solely by the one felt belt guided through both pressing locations.

Abstract: A wet press of a paper-making machine includes a pair of rolls defining a roll gap through which the paper to be treated and belt-shaped felt are simultaneously conducted. The felt is guided in a closed loop path by additional rolls which include a tightening roll. The tightening roll can be tilted to reduce roll vibrations by tightening the felt to set vibratory marks formed in the felt at an angle relative to the transverse width of the felt and the roll gap. A controllable positioning device is provided which includes a motor operated by a controller during predetermined time intervals or as a function of actual vibrations sensed at the pair of rolls forming the roll gap to automatically vary the tilt angle.

Abstract: An extended nip press has a looped belt mounted over a shoe having a concave surface which presses the belt against a mating surface on a roll to provide an extended nip. The shoe has a support which is movable in a skewing sense relative to the longitudinal axis of the roll. Lateral movement of the belt is monitored. When it has moved beyond predetermined limits in either direction, the shoe is skewed to alter the frictional forces on the belt as it passes over the shoe's surface. This controls the position of the belt and keeps it centered in the nip.

Abstract: Apparatus for sensing the thickness of a pulp suspension, having zones or slices, on the forming wire of a paper making machine includes an array of ultrasonic transducers located in the apertures of a structural member mounted in a cross-direction under the forming wire near the headbox of the machine. Each ultrasonic transducer is mounted on a flexible sheet which is mounted to an aperture and the transducer moved into close proximity to the bottom of the forming wire by means of air pressure in the structural member. A second array of transducers downstream of the first can be utilized for diagnostics.

Abstract: A surge control system for dewatering press felts on a papermaking machine which includes a suction pipe, a variable speed drive motor, a centrifugal exhauster driven by the variable speed drive motor and connected to the suction pipe to provide vacuum to a felt passing over a slot for dewatering thereof. A surge valve is provided and is opened to admit air to the centrifugal exhauster so as to prevent surge when the centrifugal exhauster is operating at a predetermined level at which the centrifugal exhauster will surge.

Abstract: A method and apparatus for monitoring and controlling the operation of a counter-current pulp washing system. The dilution factor, soda loss, wash liquor ratio and displacement ratio of the washing system are determined on-line. The value of either the soda loss or of dilution factor is continuously maintained within a preselected range and changes in the value of the other variable are monitored to provide an indication of whether the washing system is operating optimally. Based on the on-line determination of displacement ratio and wash liquor ratio, the efficiency of the washers is monitored, the cause of any decrease in efficiency is identified and the appropriate control action is applied to adjust the operating parameters of the washers to compensate for changed wshing conditions or changed processing conditions.

Abstract: An improved papermaking apparatus of the type in which a headbox directs a jet of papermaking slurry onto the upper surface of the wire which moves longitudinally over and is supported by a forming board. The improvement is means for adjusting the length of the leading forming board strip and means for adjusting the position of that strip to properly relate the strip to the intercept of the jet with the wire.

Abstract: A method for operably adjusting a leading strip of a forming board of papermaking wire wherein the position and length of an impinging papermaking slurry is detected and the length of the leading strip adjusted.

Abstract: Method and apparatus for regulating pressure in a wedge-shaped space between the wall of the headbox lip beam or the like and the breast roll. An arrangement is provided by which air jets are directed in a direction opposite to the direction in which the forming wire moves on the breast roll to eject air out of the wedge-shaped space to maintain the pressure induced therein at a desired level. The apparatus includes a blow box coupled to a source of pressurized air and the box having a wall in opposed relationship to the forming wire in which nozzle openings or slots are formed through which the air jets are directed. The blow box has a wider side which substantially closes the wedge-shaped space. Water jets are directed into the wedge-shaped space by water supply devices provided on the blow box for cleaning purposes.

Abstract: An apparatus for controlling the rate at which a defoaming agent is supplied to a processing vessel. A first sensing element senses the quantity of liquid in the vessel. A second sensing element senses the position of the upper surface of the foam. A signal processing circuit combines the outputs of the first and second sensing elements to produce a signal that is used to optimize the rate at which defoaming agent is supplied to the vessel. In this manner, the amount of defoaming agent that is used is reduced, thereby reducing the cost of operating the process.

Abstract: A vacuum control system and method for dewatering felts or fabrics on a papermaking machine including a suction pipe and a centrifugal exhauster connected to the suction pipe to supply a variable vacuum level. The fabric is passed over a slot in the suction pipe so that suction applied therethrough will dewater the fabric. A variable drive device is connected to the centrifugal exhauster for its operation with the variable drive device being responsive to an increase in the vacuum level in the suction pipe as fabric permeability decreases to correspondingly increase the speed of the centrifugal exhauster so as to increase the vacuum level in the suction pipe as a function of the decrease in felt permeability.

Abstract: Mechanism for automatically controlling and maintaining a selectively differentiated vacuum pressure in a vacuum head accommodating to the transverse width of a moving web passing relative thereto involving means for supplying air to the vacuum head at spaced points along the width and control means for detecting the need for an increase or decrease in the vacuum at the spaced points along the length and selectively charging more or less air to the vacuum head at the corresponding points along the length.

Abstract: A steam box or hood for controlling the moisture profile of a fibrous web such as paper during forming and pressing is described. The steam hood includes a plenum filled with nonturbulent, substantially atmospheric pressure steam which delivers the steam into a series of side-by-side compartments which extend across the width of and adjacent to the web. Each compartment includes a damper, the position of which is individually controllable through a rod adjustment from the operating side of the machine. The position of the damper determines the amount of steam applied to the web from a compartment and hence the moisture content of the web adjacent to the particular compartment being adjusted. Each compartment is adjusted to achieve a desired uniform moisture content across the width of the web.

Abstract: The invention relates to a method and an apparatus for detecting and counteracting a deformation of the stock discharge gap in a paper machine headbox, which is caused by thermal expansion due to the temperature of the stock and/or the pressure of the stock. This is achieved by ultrasonic transducers located close to the slice opening which obtain measurement results relating to the distance between the roof member and the apron beam member of the headbox. At least two such transducers, one preferably located close to a side wall of the discharge gap and the other preferably located midway between the side walls, give information about a possible difference between the measurement results caused by the deformation. This difference serves as a guide for adjusting the temperature of the apron beam member and/or the roof member in such a way that the deformation is reduced in magnitude or entirely eliminated.

Abstract: A paper machine wet line monitor is provided by photographing the surface of the wire of a paper machine in the area of the wet line (sometimes known as the dry line) with a video camera to generate video signals. The video signals are digitized and define a line corresponding to the wet line of the machine and this line is displayed preferably while also indicating the average location of the wet line across the machine. The processed digitized signal may be imposed on an automatic headbox control to influence this control and maintain the position of the wet line.

Abstract: Apparatus for processing paper wherein a pair of endless curved wire devices operate to pass therebetween a sheet material to be treated for a dewatering operation or the like. A support structure in the form of individual support segments made from sintered oxide ceramics are arranged to extend over the width of the apparatus and are in contact with one another, with a plurality of the segments being arranged consecutively in the direction of the course of the wire devices, the segments having a maximum linear expanse of 700 mm per segment and having junction areas between consecutively arranged segments defining a gap for feeding cooling water to the guide wire devices.

Abstract: A felt conditioning system for a papermaking machine in which a stationary air supply plenum chamber is positioned on the back side, i.e., obverse of paper side, of the felt for delivering heated conditioning air to and through the felt to remove water and dirt taken up by the felt from the paper sheet.

Abstract: A vacuum dual control system for the flat box section of a papermaking machine. The system includes a plurality of serially arranged vacuum boxes and a header interconnecting the boxes. A vacuum pump is operatively connected to the boxes in a manner so that vacuum applied to the boxes is a function of the speed of the pump. A first control operates the pump to run at an initial substantially constant high speed for providing vacuum necessary to dewater a web in its initial condition. The web is passed over the boxes so that suction applied therethrough by the pump running at its initial substantially constant high speed dewaters the web until the condition of the web changes sufficiently to cause the vacuum in the last box to increase to a predetermined maximum level. A second control is provided with set point adjustment capabilities to enable selection of a predetermined set point corresponding to the predetermined maximum vacuum level.

Abstract: A moisture control system is provided for controlling the amount of chemical added to a fabric. The system includes a suction pipe having a slot therein and a fabric positioned to pass over the slot. A vacuum source is connected through conduit means to the suction pipe. A source of liquid is provided including a predetermined percentage of chemical therein to be added to the fabric. Liquid from the liquid source is added to the fabric and the fabric containing the liquid from the liquid source is advanced over the suction pipe whereupon vacuum is applied to the fabric to deliquefy it. The vacuum source is set to provide a predetermined vacuum depending on the chemical concentration of the liquid and the composition of the fabric. As the fabric passes over the slot a change in the vacuum is sensed and the vacuum source is actuated to retain the vacuum to the predetermined condition thereby maintaining a constant moisture level and amount of added chemical in the fabric.

Abstract: A hydrofoil blade support member comprising a longitudinal extending hydrofoil body having a mounting element attached thereto. Hydrofoil blades are attached to the mounting element by a mounting device which allows the blades to extend in such longitudinal direction and further allows for spacing of such blades relative to each other in a variably selective dimension measured transverse to such longitudinal dimension. Spacing can be manual, semi-automatic or fully automatic.

Abstract: A vacuum control system and method for dewatering fabrics on a papermaking machine including a suction pipe and a vacuum pump connected to the suction pipe to supply a desired vacuum level. The fabric is passed over a slot in the suction pipe so that suction applied therethrough will dewater the fabric. Controls are connected to the suction pipe and to the vacuum pump responsive to an increase in the vacuum level in the suction pipe as fabric permeability decreases to correspondingly lower the speed of the vacuum pump and retain the desired vacuum level in the suction pipe.

Abstract: A basementless separator system for removing liquid from a liquid/gaseous mixture. The system includes a separator for separating the liquid and gas therein. A first conduit communicates the separator with the source of the liquid/gaseous mixture. A secnd conduit communicates the separator with a vacuum source to draw the liquid/gaseous mixture into the separator and to remove the separated gas from the separator. A first valve is on the separator in alignment with a liquid storage tank to open and close a discharge opening for separated liquid from the separator to be collected in the storage tank. A second valve is on the storage tank to open and close a drainage opening in the tank to control drainage of liquid therefrom. A level sensor is on the tank to indicate a predetermined level of collected liquids stored in the tank. Controls are responsive to the liquid condition in the tank to open and close the valves and periodically drain from the tank the liquid collected therein.

Abstract: The flammability of non-condensible blow gases from a wood pulping digester is continuously monitored by venting a low volume sample flow stream of such gases through a small combustion chamber where the stream is subjected to an intermittent ignition source. Unusually high pressures in the combustion chamber resulting from ignition of a flammable mixture are detected by pressure measuring means providing the operative result of automatically venting a dangerous flow increment of the gas.

Abstract: Apparatus to supply steam to a paper sheet that passes by the apparatus from a leading edge to a trailing edge of the apparatus. The apparatus is adapted to be positioned adjacent the nip of two rolls and comprises a first header for steam and a first chamber to receive steam from the first header. Passages for steam are formed between the first header and the first chamber. An outlet in the first chamber permits steam to be forced against the paper sheet adjacent the leading edge of the apparatus to form a steam curtain to reduce the amount of air drawn under the apparatus by the paper sheet. A second chamber receives steam from the first header. There are passages for steam between the first header and the second chamber and outlets in the second chamber so that steam may be forced against the paper sheet to heat the sheet. The flow of steam along the length of the apparatus can be controlled.

Abstract: An apparatus for aiding water removal from a moving paper web directs steam to a portion of the web and controls the distribution of steam in both the cross-machine and the machine direction of the web. In the preferred embodiment, a matrix of compartments is used to supply steam to the web, and the steam supply to each compartment is independently controlled.

Abstract: A steam shower for reducing paper web moisture content variability in the cross machine direction is described. The local dewatering effect of the shower on the moving supported web is controlled by varying its bottom steam discharge area incrementally across the width of the web. In one embodiment the hood is divided across the width of the machine into compartments, each having at least one cross machine direction wall whose bottom edge may be adjusted relative to the rear wall of the hood. A second embodiment has a pleated curtain whose bottom edge is controlled by lever arms with respect to the hood's rear wall. Local adjustments are made based on a comparison of moisture measurements at the finished product reel with the desired level.

Abstract: A constant vacuum felt dewatering system including first and second suction pipes with a slot in each pipe. A felt is positioned to pass over the slots of the pipes. A liquid ring pump is connected by conduits to the first and second suction pipes. Drive structure is provided to operate the liquid ring pump and apply suction to the first and second suction pipes. The felt is advanced over the pipes whereupon suction is applied thereto to dewater the felt. Controls are responsive to change in felt conditions to vary the dwell time of the felt with respect to the slots in order to maintain a substantially constant vacuum.

Abstract: A particular papermachine and type of pulp stock for forming a particular basis weight web are analyzed for deriving a correlation between pulp stock drainage rate and the lowest obtainable critical moisture content of said paper web. From knowledge of the lowest critical moisture content and main steam pressure, differential pressure values between the several dryer pressure sections of the papermachine are determined for drying said web along the most energy-efficient drying rate trajectory. Also disclosed is a dryer steam pressure differential control program for maintenance of a pre-determined magnitude of condensate inventory within the drying cylinders under normal running conditions and under conditions of interrupted web continuity.

Abstract: A constant flow felt dewatering system including first and second suction pipes with a slot in each pipe. A felt is positioned to pass over the slots of the first and second pipes. A centrifugal exhauster is connected by conduits to the first and second suction pipes. Drive structure is provided to operate the centrifugal exhauster and apply suction to the first and second suction pipes and to advance the felt over the pipes whereupon suction is applied thereto to dewater the felt. Controls are responsive to change in felt conditions to vary the dwell time of the felt with respect to the slots in order to maintain a substantially constant flow.

Abstract: A suction dewatering system including a suction device adapted to be connected to a suction source and having a longitudinal opening therein through which suction is applied. A cover is provided for the device including at least two spaced lands to be mounted to the device with the space therebetween forming a slot in alignment with the longitudinal opening in the suction device. A wear strip is removably mounted on each land and has a wear surface thereon for a medium to be passed thereover for dewatering. At least one of the wear strips is adjustable so that the shifting of each adjustable strip in the longitudinal direction causes the strip to shift laterally and vary the slot width in the direction of travel of the medium across the wear surface and varying the dwell time of the medium over the slot to which suction is being applied. A cam arm longitudinally extends in a longitudinal track in the cover.

Abstract: A suction dewatering system which includes a suction device adapted to be connected to a source of suction and having at least one longitudinal opening therein to which suction can be applied. The opening is positioned substantially perpendicular to the direction of medium travel across the suction device for dewatering thereof. An adjustable slot cover is provided for the suction device and includes a base. The base is mounted to the suction device in fixed position and has surfaces thereon forming spaced longitudinal lands and defining a longitudinal slot between each pair of adjacent lands in alignment with the suction device opening. A wear strip is removably positioned on each of the lands for engagement with the medium passing thereover. The wear strip on one of each pair of adjacent lands is stationary in respect to the direction of medium travel and the wear strip on the other of the pair of adjacent lands is automatically adjustable with respect to the direction of medium travel.

Abstract: A process is provided for continuously washing fibrous suspensions in aqueous suspending liquors containing dissolved impurities to remove such impurities by exchanging aqueous suspending liquid substantially free from such impurities for the aqueous suspending liquor, which comprises washing fibrous material of the suspension in aqueous suspending liquid substantially free from dissolved impurities; and forming a washed fibrous suspension in such liquid; withdrawing aqueous suspending liquor containing dissolved impurities; diluting the washed fibrous suspension by adding aqueous suspending liquid substantially free from dissolved impurities; measuring the volume amount of such diluting aqueous suspending liquid added; measuring the volume amount of diluted washed fibrous suspension; and then adjusting the volume amount of wash liquid added to maintain substantially constant the difference between the amount of wash liquid added and the liquid content of the undiluted washed fibrous suspension.

Abstract: A steam shower for reducing paper web moisture content variability in the cross machine direction is described. The local dewatering effect of the shower on the moving supported web is controlled by varying its bottom steam discharge area incrementally across the width of the web. In one embodiment the hood is divided across the width of the machine into compartments, each having at least one cross machine direction wall whose bottom edge may be adjusted relative to the rear wall of the hood. A second embodiment has a pleated curtain whose bottom edge is controlled by lever arms with respect to the hood's rear wall. Local adjustments are made based on a comparison of moisture measurements at the finished product reel with the desired level.

Abstract: The paper-making stock is fed continuously to a tank with two chambers separated by a partition having an opening for passage of stock from the first to the second chamber, evacuation means being provided for maintaining equally low gas pressures in the two chambers. A stock consumer is connected to a stock outlet of the first chamber, and stock from an outlet of the second chamber is returned to the tank via a recycle line. Means for sensing the stock level in the first chamber are provided to control valve means in the recycle line, whereby said stock level is maintained constant.

Abstract: A method and apparatus for the delignification of cellulosic fiber material to minimize the amount of reject material in the final pulp produced. The fiber material is digested, washed, oxygen delignified, and passed through a screening stage to provide a main pulp stream, and a reject stream from the separation stage. The flow and consistency of the separated reject material is determined, the reject material is refined, and sufficient chemical is added to the separated reject material, based upon the flow and consistency thereof, so that subsequent delignification of the reject material may be effected. This may be accomplished either by passing the reject material through a separate oxygen delignification stage and then returning it to the main pulp stream, or adding caustic to it and soaking it in a soak tank for predetermined period of time, and then returning it to the main pulp stream before the oxygen delignification stage therein.

Abstract: A method of controlling the amount of a liquid shower flow introduced onto a slurry mat such as a pulp mat which is undergoing incomplete liquid separation on a vacuum filter drum. The flow rate of the liquid being discharged with the slurry mat is determined by a capacitance measurement which is taken after the slurry mat has passed to a point on the filter means where liquid separation no longer occurs. The shower flow is controlled by a correlation of the flow rate of the liquid in the slurry mat with the rate of slurry mat transfer from the vacuum filter drum and the necessary liquid shower flow as expressed by a dilution factor.The present control system may be combined with secondary apparatus to measure the flow rate and thickness of the total slurry mat in order to determine by correlation the slurry mat consistency, the rate of solid material production from the slurry mat and the amount of air contained in the slurry mat.

Abstract: A method and apparatus for forming a multi-ply web of paper wherein a first layer is carried on the underside of a traveling felt to a bonding station located over the top of a forming cylinder on which a second layer is formed with a water bead in the nip between the layers and a laser or other device for generating a beam of energy at one end of the nip directing the energy along the water bead parallel to the nip and a receiver at the other end to detect the laser beam with means operated by the receiver for controlling the size of the water bead.

Abstract: The characteristic profile of a paper web is adjusted on the fourdrinier by means of a number of fluid spray stations positioned across the papermachine. Each spray station is provided with two or more fan spray nozzles of different flow capacity oriented to impact the pond with fluid along a common line. Flow to each nozzle is binary controlled with respective binary command, full flow valves. By discrete manipulation of valve selection, total flow rate to the web may be adjusted without flow throttling and consequent impact velocity variations.

Abstract: A papermaking machine having pulp supplied in a regulated excess amount through a feed channel onto a movable water-pervious element and having a sump positioned at the end of the feed channel to receive the overflow. The amount of pulp in the sump relative to the desired overflow rate is used to produce a control signal for regulating the machine. Should there be an excess amount of pulp in the sump over the desired amount, the negative pressure in the vacuum box is increased to withdraw more water. Also, the degree of grinding of the pulp can be varied in dependence on the control signal.

Abstract: A process and apparatus are provided for controlling the supply of aqueous suspending liquid in continuously washing fibrous suspensions in aqueous suspending liquors containing dissolved impurities, to remove such impurities by exchanging aqueous suspending liquors substantially free from such impurities for the aqueous suspending liquor, which comprises washing fibrous material of the suspension in aqueous suspending liquid substantially free from dissolved impurities, and forming a washed fibrous suspension in such liquid; withdrawing aqueous suspending liquor containing dissolved impurities; diluting the washed fibrous suspension by adding aqueous suspending liquid substantially free from dissolved impurities; determining the amount of dissolved impurities remaining with the fibrous suspension after the washing has been completed by measuring (1) the volumetric flow rate of the washed suspension; (2) the liquid content of the washed suspension; and (3) the content of dissolved impurities in the suspending

Abstract: A technique for controlling the amount of dissolved material in a slurry liquid stream containing dispersed particulate solids which is being continuously processed in a zone of countercurrent particulate solids separation and washing. Flow rates and conductivity measurements are made on streams entering such zone which are then used to estimate the amount of dissolved material in a starting slurry liquid. Preferably, conductivity measurements are made with electrodeless conductivity measuring probes. The technique is well adapted for use in a brown stock washing system employing a plurality of counterflow washers. The technique can be used for measurement of the quantity of gas in an agitated process stream in such a zone.

Abstract: An endless belt comprising a signal element affixed thereto for identifying one complete revolution of such belt and an apparatus for cleaning such belt. Advantageously, such belt and cleaning apparatus may be used in combination with an apparatus such as, for example, a papermaking machine.

Abstract: At least one channel in a multi-channel paper machine distributor is maintained in flow velocity slave relation to another of the channels by monitoring the velocity with a pressure transducer of stock flow through the latter channel and by such monitoring controlling the stock velocity in the slave channel.