Abstract: A method for washing pulp in a multistage pulp washing operation involves controlling operating conditions so as to maximize the efficiency of the operation particularly in response to determination of the percent consistency off the discharge side of each drum washer. The major variables that are useful to control are vat dilution flow, drum speed, vat level set point, drainage aids or defoamers, press roll pressures, vacuum break position, and temperature of the last stage showers.

Abstract: A sheet measurement and control system that enables easy installation and/or change of types of sensors to be disposed in or about a sensor head that reciprocally scans a sheet along a cross direction transverse to the sheet flow; wherein a plurality of sensors are disposed in or about the sensor head to measure characteristics of the sheet; a plurality of computation devices corresponding to the plurality of sensors are disposed in or about the sensor head to implement computation of the measuring signals from the sensors; a plurality of communication control devices corresponding to the plurality of computation devices are disposed in or about the sensor head for transmitting the processed measuring signals through a general network communication link attached thereto; and man-machine interface connected to the general network communication link monitors data from said communication control devices related to the measured signal and issues instructions to control the sheet manufacturing process.

Abstract: Suction device for use in a machine for producing a sheet and a method to vacuum a web section of a paper machine. The suction device includes a contact surface to place on the web section and a suction box. The suction box is designed to have a vacuum pressure applied to drain the web section. The suction device further includes a control device and a release mechanism or an adjustment mechanism for releasing the suction box from the web section while the vacuum pressure is applied or thereafter so that the web section is guided along the contact surface with less friction and without the web section detaching from the contact device. A method to suction a web section in a paper machine including arranging a contact surface a suction device on the web section and applying a vacuum pressure to the suction device to vacuum the web section.

Abstract: A calender for a sheet material, e.g., paper, having at least two treatment stations through which the sheet material passes in succession. To regulate a desired parameter of the sheet material, each treatment station may include a plurality of adjacently arranged adjustment zones positioned in a row extending across a width of the sheet material. The adjustment zones of one of the treatment stations are positioned to be offset relative to the adjustment zones of the other treatment station by a fraction of a width of the adjustment zones, e.g., one-half the width. The particular arrangement enabling improved correction potential without increasing structural expenditure.

Abstract: Apparatus for safely carrying out pressurized peroxide bleaching of pulp in a bleaching vessel at a consistency exceeding 8%, the bleaching vessel designed for at least 0.5 MPa overpressure, with the pulp being pumped to the bleaching vessel through a mixer at a temperature exceeding 90.degree. C., wherein a bypass conduit is provided to bypass the mixer and wherein a valve is provided in the bleaching vessel, the valve opening when the pressure in the bleaching vessel or an affiliated part thereof reaches a first set point.

Abstract: A system for applying a suspension of uncooked starch particles in water to a web on a forming wire includes a source of such suspension and a source of dilution water, an application die positioned transversely of the web with an internal manifold opening into a downwardly opening die slot through which material flows from the manifold as a falling curtain onto the web. The die has a plurality of transversely spaced inlets leading into the manifold to define transversely spaced application zones across the web. The suspended starch and water are applied from the manifolds through control valves into the inlets by means of which the consistency or concentration of the starch may be varied at positions representing the application zones across the web to provide a desired strength profile to the dried web.

Abstract: Apparatus for influencing a cross-sectional profile of a headbox having an inner chamber and process for determining a width and position for the sections of the headbox. The apparatus includes a device for distributing fluid that extends across a machine width, at least one connection opening extending across the machine width between the fluid distribution device and the inner chamber of the headbox, and a plurality of elements being one of continuously and discretely adjustably positionable within the fluid distributing device to section the fluid distributing device across the machine width. The process includes measuring a profile of a selected characteristic of the pulp suspension in the headbox that is dependent on its position; forming intersecting points of the profile of the characteristic with a uniform sectioning of the size of the characteristic under consideration; and determining the position and width of the sections.

Abstract: Method and apparatus are presented for use in a papermaking process for determining permeability and/or compressibility characteristics of a pulp suspension within the process. The method/apparatus includes monitoring height of pulp suspension within one or more test columns as a function of time while allowing pulp suspension drainage from each test column. At least one parameter representative of permeability or compressibility of the pulp suspension is determined, via computer processing, using the monitored height as a function of time of the pulp suspension within the test column. The at least one parameter representative of permeability or compressibility can comprise specific surface area (S.sub.w), specific volume (v.sub.f) compressibility constant m or compressibility constant n for the pulp suspension.

Abstract: A roll sensing system for measuring the pressure distribution and nip width in a nip roll press. The sensing system comprises a strip having sensors thereon, the strip being placed in a nip press, for sensing the pressure at several locations therealong. At one end of the strip lies electronics associated with the sensors. The electronics communicate with an optional multiplexer and a bidirectional transmitter for signal transmission to an external signal conditioner and an external computer. The computer determines pressure values and nip width values at various locations along the strip, and communicates with a display which provides a visual, graphical and/or numerical data to the operator. Optionally, a control system can be in communication with the transmitter or the computer to initiate crown corrections in response to pressure or nip width readings.

Abstract: Apparatus and process for controlling the basis weight of paper produced in a papermaking machine are provided. In the papermaking process, a major portion of the paper stock flows through a first line that is controlled by a thick stock valve and a minor portion of the stock flow from the stuff box to the headbox is diverted through a second line that is regulated by a second valve (e.g., vernier valve). The thick stock valve is controlled by the dry end basis weight and the second valve responsive to measurements of the basis weight of the wet stock at the wire. The second line and control valve along with the wet end basis weight measurements form a fine control loop with fast response time whereas the first line and control valve that is responsive to dry end basis weight measurements form a course control loop. The dual control loops enable fast and actual basis weight control.

Abstract: The present invention is directed to a device for removing at least one of paper sheet remnants and a paper sheet from a belt. The device may include a blow device including at least one blow opening extending lateral to a travel direction of the belt and a compressor coupled to the blow device to supply compressed air to the at least one blow opening. The at least one blow opening may be directed toward the at least one of the paper sheet remnants and the paper sheet to be removed.

Abstract: A system and method that combine an array of fast under wire water weigh sensors with a scanning system provides an accurate measurement of the entire sheet down to 1 in. by 1 in. resolution. Because CD profiles are obtained instantaneously, MD and CD variations are completely decoupled, even if CD profiles are taken at longer intervals apart.

Abstract: The present invention is directed to a method for controlling and adjusting the permeability of a cigarette wrapping paper. Permeability is controlled in the paper by adding different sized filler particles in different proportionate amounts. Permeability of the paper is altered without having to change the total amount of filler in the paper. By selectively controlling the permeability of the paper, various characteristics and properties of a cigarette made with the paper can be likewise modified as desired. In one embodiment of the present invention, the permeability of a cigarette wrapper can be automatically maintained or adjusted as the paper is being made.

Abstract: A method for continuous overall regulation of a former of a paper or board machine or equivalent in which a physical fluid flow model of the drainage and the flow state of the pulp suspension flow is formed. The model is solved by making use of the data on the geometry of the former and initial and boundary conditions necessary for a solution to the model. The difference between the simulated state, which has been obtained as the solution of the physical flow model, and the state adopted as the target is determined as the cost function, wherein the target state is determined by means of the quality requirements of the paper and possibly by means of the costs of operation and the runnability of the paper machine. The cost function is optimized and, thus, optimal regulation values and set values are obtained for the regulation devices and/or actuators of the former in view of the given cost function.

Abstract: A system for control and monitoring of the circulation lubrication of the bearings of the revolving cylinders and rolls in a paper machine or equivalent in which lubrication oil is fed from an oil-lubrication center or centers through a system of pipes into lubrication points. From these lubrication points, the lubrication oil is passed back through a system of return pipes into the oil-lubrication center or centers. The system includes actuator panels placed and grouped in the vicinity of the lubrication points primarily above the floor level of the paper machine hall or equivalent. From the actuator panels, lubricant feed pipes are passed to several lubrication points placed in the vicinity. The actuator panels have a feed-back connected regulation loop for lubricant flow quantity provided for each lubrication point, which regulation loop includes an oil-flow regulation valve, an actuator motor for same, as well as an oil-flow measurement device and a regulation circuit.

Abstract: A method for the continuous overall regulation of a single-layer or multi-layer headbox of a paper, board or pulp-draining machine. A physical fluid flow model of a pulp suspension flow discharged from the headbox to be regulated is formed and solved to obtain a simulated flow state based, e.g., on data on the geometry of the headbox and initial and boundary conditions related to the headbox. A target flow state based on the quality requirements of the paper produced from the pulp suspension flow and the costs of operation and runnability of the machine is obtained and a difference between the simulated flow state obtained as the solution of the flow model and the target flow state is determined. This difference constitutes a cost function which is optimized to determine optimal regulation values and set values for instrumentation devices and actuators of the headbox which affect the pulp suspension flow.

Abstract: A papermaking vacuum apparatus having a web-facing surface adapted to support a papermaking belt and comprising a head, a body and at least one vacuum slot disposed in the head and defining an aperture on the web-facing surface. The vacuum slot is in fluid communication with the web-facing surface and extends from the web-facing surface to the body which is in further fluid communication with a vacuum source. The web-facing surface comprises a leading surface and a trailing surface. The leading surface has a transitional area juxtaposed with the aperture created by the vacuum slot. This transitional area has a predetermined Z-directional spacing from the papermaking belt, which Z-spacing continuously and gradually increases in the machine direction whereby the amount of vacuum pressure applied through the vacuum slot to the paper web gradually increases as the paper web travels in the machine direction over the slot.

Abstract: An endless loop of fabric of the type used in papermaking is provided with a row of optically detectable marks aligned in the direction of motion of the fabric. A beam of light pulses from a strobe light is directed to a position on the fabric through which the row of marks passes and the position of the marks as illuminated by the strobe light is observed. When the observed marks are stationary, the speed of the fabric can be determined based on the frequency of the light pulses from the strobe light and the spacing between the marks on the fabric. The speed of the fabric can be controlled to a desired speed by setting the strobe pulse frequency and adjusting a variable speed drive for the motor driven rollers driving the fabric until the marks as illuminated by the strobe light appear stationary. Variations in the speed of the fabric result in variations of the position of the marks as illuminated by the strobe light, allowing equipment problems causing the speed variations to be diagnosed.

Abstract: The invention is directed to a paper machine including a headbox having an inlet and an outlet. A fluid conduit is connected to the inlet of the headbox. A sensor is disposed in communication with an interior of the headbox. The sensor senses a pressure of the fiber suspension within the headbox and provides a signal corresponding thereto. A first pump is connected to the fluid conduit and supplies a fiber suspension to the headbox through the fluid conduit. A second pump is connected to the fluid conduit between the first pump and the headbox, and further is connected to the sensor. The second pump is a substantially pulseless pump, and transports the fiber suspension away from the fluid conduit, dependent upon the sensed signal.

Abstract: A method and device in the regulation of a headbox. The headbox includes a pulp inlet header, after the pulp inlet header, seen in the pulp flow direction, a distributor manifold whose pipes are opened into an intermediate chamber. The headbox comprises an attenuation chamber placed in connection with the intermediate chamber and, after the intermediate chamber, a turbulence generator having tubes which are opened, at their outlet end, into a discharge duct and, at their inlet end, into the intermediate chamber. In the method, into different positions along the width of the headbox, a pulp suspension flow is introduced, the concentration of this flow is adjustable by combining two component flows. In the method, in the regulation of the concentration of the flow passed into the pulp suspension, two component flows are combined by into the pulp suspension flow introducing an additional flow. The mixing ratio of the combined flow is regulated by adjusting the additional component flow.

Abstract: A method and apparatus for processing a longitudinally traveling web of material using a sheet treating device positioned in a transverse direction relative to the web. The sheet treating device having a plurality of individually controllable zones for controlling a target parameter of the web, for example, the thickness, bulk, dampness, smoothness or sheen of the web. In conjunction with the sheetmaking device, a measuring instrument for measuring an actual value of the target parameter is placed downstream of the sheet treating device. An actual profile that is determined by the actual values is compared with a desired profile, and the zones of the sheet treating device are adjusted such that the discrepancies between the two profiles are minimized. To improve the matching of the actual profile to the desired profile even further, the web and/or the sheet treating device are shifted relative to the other in the transverse direction to minimize the discrepancies between the two profiles.

Abstract: A method in the regulation of a pulp suspension flow through the headbox of a paper machine/board machine wherein an additional flow is introduced into the pulp suspension at different points across the width of the headbox. The concentration of the additional flow is regulated by a mixer unit which includes a displaceable distributor part such that when the mixing ratio is being regulated, the flow resistances of the component flows, of the additional flow, entering into the mixer unit are adjusted by displacing the distributor part of the mixer unit in a chamber of the mixer unit.

Abstract: An apparatus for controlling the degree of fiber variations in paper sheet has a formation meter for receiving an image of transmitted light on one side of an area of paper from a light source located on the other side of the area of paper, an image processing computing element for introducing the image from said formation meter for image processing and a fuzzy control unit for calculating and outputting optimum J/W ratio, optimum foil angle, and optimum deflector pushing degree and angle on the basis of results of image processing from said image processing computing element.

Abstract: The invention is directed to a continuous belt edge detector system for use in a paper making machine having a continuous belt guide device. The edge detector system comprises a continuous belt having an edge dope with metallic particles therein and an inductive sensor connected to the guide device and adjacent the edge dope. The inductive sensor sends a signal to the guide device indicative of a location of the continuous belt. The guide device moves the continuous belt, e.g., transversely relative to the running direction of the belt within the machine, dependent on the inductive sensor signal.

Abstract: A screen aperture blinding prevention and liquid overflow prevention and level control apparatus for a knot drainer senses liquid level within the knot drainer and compares the sensed level to a setpoint level. Differences in the two levels generate control signals of appropriate magnitude and direction, and those control signals are transmitted to a valve whose degree of responsiveness and openness is adjusted to change the outflow rate of accepts liquor from the accepts chamber of the rejects separator. In addition, passive level control is provided in the discharge line for establishing accept flooded screen apertures regardless of variations of inflow and outflow rates during operation while active level control to create accept flow rate greater than, less than, or equal to inlet flow rate is provided by the combination of siphonic loop, barometric leg and control values for accepts outflow and for backwash nozzle flow.

Abstract: An apparatus and method for monitoring the de-watering performance of a forming section of a papermaking machine is disclosed which includes a laser instrument having a laser displacement meter laterally spaced and supported above an upper run of a paper forming fabric having a paper stock deposited thereon. A head box deposits paper stock consisting of a water/fiber mixture on top of the upper run. An adjustable C-shaped carrier stand has an upper leg that supports the laser instrument above the upper run of the forming fabric. The carrier stand has a lower leg to support a baseline contact device below the upper run of the forming fabric. The laser displacement meter is disposed at a laser reference position above the forming fabric so that a laser beam is reflected off of the paper stock which is deposited on top of the forming fabric.

Abstract: An edge tracking apparatus for maintaining a continuous circulating papermaking fabric in an aligned position as it moves through a papermaking machine. The edge tracking apparatus includes a pivotally mounted guide roll and a laser scanner. The laser scanner, which produces a laser screen, is positioned relative to an edge of the papermaking fabric so that the edge bisects the laser screen. A controller is connected with the laser scanner. The controller acts to receive signals from the laser scanner in response to transverse movement of the edge of the papermaking fabric and to convert those signals into control signals which activate a drive in the steering apparatus. The drive shifts the longitudinal position of the guide roll causing it to steer the papermaking fabric back into its aligned position. A recording unit is also connected with the controller and is controlled to plot the position of the edge during operation of the papermaking machine.

Abstract: A method, device, and arrangement in a paper machine for regulating the control of the transverse profile or profiles of properties of a paper web produced therein. Water is removed from the paper web under compression between two forming wires by making use of dewatering and/or forming ribs. The deflection of the dewatering and/or forming ribs in the transverse direction of the web is regulated thereby affecting the retention profile of the paper web in the cross direction. By regulating the deflection of the dewatering and/or forming ribs, the transverse fiber-orientation profile and/or the filler profile of the paper web is influenced through the control of the transverse retention profile of the web.

Abstract: A digester temperature distribution control system comprises an optical fiber type temperature measuring unit utilizing the Raman scattering effect, reference temperature measuring unit, reference point temperature setting unit, measured temperature distribution calculating unit, target temperature distribution calculating unit and control unit. The optical fiber type temperature measuring unit is provided in that digester charged with chips and equipped with control valves for controlling steam for heating the charged chip mass in the digester and is adapted to detect temperature at a plurality of points in a length thereof including a given reference point in the digester.

Abstract: A method and device in the regulation of a headbox. The headbox includes a pulp inlet header, after the pulp inlet header, seen in the pulp flow direction, a distributor manifold whose pipes are opened into an intermediate chamber. The headbox comprises an attenuation chamber placed in connection with the intermediate chamber and, after the intermediate chamber, a turbulence generator having tubes which are opened, at their outlet end, into a discharge duct and, at their inlet end, into the intermediate chamber. In the method, into different positions along the width of the headbox, a pulp suspension flow is introduced, the concentration of this flow is adjustable by combining two component flows. In the method, in the regulation of the concentration of the flow passed into the pulp suspension, two component flows are combined by into the pulp suspension flow introducing an additional flow. The mixing ratio of the combined flow is regulated by adjusting the additional component flow.

Abstract: A process and apparatus for controlling and/or regulating a solids-liquid separation process, such as in a dewatering or drying device includes at least two photodetectors, each associated with a light source, a detector to detect light of the associated light source reflected from the surface of the solids-liquid mass, a controller generating an output signal as a function of the detected light and converting and processing the output signals of the photodetectors into correcting variables for controlling and/or regulating at least one process parameter of the separation process. At least one of the photodetectors is associated with at least one second photodetector for detecting light reflected into the photodetector at an angle, preferably an angle of 30.degree. to the main direction of reflection. The output signals of the photodetectors are advantageously processed into correcting variables for the step-wise adjustment of the at least one process parameter to optimize the separation process.

Abstract: A plurality of spaced knock-off shower nozzles are located adjacent to an edge of a paper web forming wire to provide knock-off sprays which will remove trim strips from the wire. A control is provided to separately and independently control the spray nozzles so that the operator can adjust the number of nozzles being sprayed in accordance with the width of the trim strip.

Abstract: A doctor cooperates with the peripheral surface of a Yankee dryer for peeling the tissue away from the peripheral surface such that when the tissue is peeled from the surface, a series of microfolds are generated in the resultant tissue. An adjusting mechanism is connected to the doctor for adjusting an angle defined between the doctor and the peripheral surface. The arrangement is such that when the angle is adjusted, the physical dimensions of the microfolds change. A sensor is disposed downstream relative to the doctor for sensing the physical dimensions of the microfolds. A control circuit is electrically connected to the sensor and responsive to the sensor. The control circuit is electrically connected to the adjusting mechanism for varying the angle of the doctor so that the physical dimensions of the microfolds are optimized.

Abstract: A method of treating the edges of a fiber web is provided wherein a pressing device device conveys and presses a fiber web through a pressing gap of a pressing station of the device. The station includes a pressing roll and a counter roll. The pressing roll has a roll shell. A pressing shoe is disposed within the roll shell and pressing units are disposed substantially along a width of the pressing shoe transverse to the direction of movement of a fiber web through the pressing station. The pressing units press against the pressing shoe which in turn presses a pressing surface of the shoe against an inner surface of the roll shell in a series of zones. The pressing units including pressing/pressure relief elements. The pressing force of the pressing/pressure relief elements is reduced in a step-wise fashion, zone-by-zone, from a normal operating level to a lower level in a region that includes the fiber web edges and the pressing shoe ends.

Abstract: The system effects an automatic observation of the dry line on wire of the Fourdrinier paper machine and the control actions based on it. In order to produce an image of the dry line range on wire this is illuminated by means of a large, diffusely illuminating surface (20) of even luminosity. The material on moving wire (10) is imaged by an optoelectric camera (40) on a detector whereby the pulp surface preceding the dry line and being specularly reflecting is found homogeneous and bright while the web surface following it and being diffusely reflecting is found homogeneous but matter and darker. The electric image signal delivered by the detector is conducted to a computer (50) in which the dry line is identified as the borderline of said surfaces of different brightness.

Abstract: The invention relates to a method of firing black liquor in recovery boilers where the intention is to obtain fumes having a low content of nitrogen oxides (NO.sub.x). A part of the combustion air is added as a last portion at a very high level so that a reducing atmosphere will exist in a very great part of the boiler for a long time period, e.g. at least 3-5 seconds.

Abstract: The instant device is a forming board position control system. A forming board fitted with the instant invention is positioned at various distances from and with virtually perfect constant parallelarity to the lie of the frontal plane of a headbox in apposition to the forming board. A computer controlled motor causes a parallelwise positioned pair of worm gear jacks mounted to the board, to move the board longitudinally to and fro through a distance from the frontal plane of the headbox as is determined with reference to manually manipulated computerized settings until the system stops perforce of a signal to such effect received by a controller computer as the result of interaction as between a magnet affixed to the base of one of two mounting plates to which the board is also mounted and a transducer closely positioned thereto and connected directly to the computer.

Abstract: System in a press section of a paper machine for monitoring and control of the running of the press felts (10,20,30). The press felts (10,20,30) are guided by means of rolls (13,14,15; 23,24,25; 33,34, 35), whose axial directions are altered by means of an actuator (18a, 18b) so as to control the running of the press felts (10,20,30). The system includes detector devices (16,26,36), by whose means the alignment stripe (K) on the felt or felts (10,20,30) is detected, as well as oscillation detectors (17,27,37), by whose means oscillations of the press rolls (10, 20,30) are detected. Into the computer part (50) included in the system, the monitoring signals (a,b) are fed from said detectors (16,26,36, 17,27,37). The computer (50) analyzes the detector data in order to detect any felt-induced oscillations.

Abstract: A control system regulating the transverse profile of properties of a web in a paper or board machine is disclosed. The control system comprises a plurality of actuators and a corresponding plurality of actuator controllers. The actuators are arranged to be effective across the width of the web whose profile is to be regulated. Further included is a process controller and a feedback network connected to the process controller and provided with an arrangement for measuring the web profile to be regulated. The actuators are provided with intelligent actuator controllers. A data bus common to the actuator controllers is provided, along which occur data communications in a control hierarchy between a higher control device and said actuator controllers.

Abstract: A direct monitoring and control method is provided for on-line measurement of effective alkali, carbonate, sulfate and thiosulfate concentrations in process liquors for the production of kraft pulp. The control method eliminates frequent sampling, and the need for frequent equipment maintenance. The method includes the steps of withdrawing samples of a liquor from the kraft manufacturing process, subjecting the samples to infrared spectrophotometry at predetermined wave numbers to produce peak-absorbance measurements relative to a background spectrum of water, determining peak absorbance for different alkali concentrations, correlating relationships between the peak-absorbance measurements of samples with the peak absorbance for different alkali concentrations to determine optimum effective alkali in the samples, and controlling at least one process parameter to obtain effective alkali of the liquor.

Abstract: A method and apparatus for generation of electricity by pressurized gasification of black liquor in a combined power plant. The gases produced in the gasification of black liquor are purified and introduced into a gas turbine for generating electricity. From the turbine, the gases are conducted to a waste heat boiler. High pressure steam generated in the waste heat boiler and or auxiliary boiler is introduced into a steam turbine to such an extent that the exhaust steam from the steam turbine covers the steam and heat demands of the pulp mill. The excess steam is introduced into the gas turbine or the combustor thereof for increasing the generation of electricity.

Abstract: A direct monitoring and control method is provided for on-line measurement of effective alkali, carbonate, sulfate and thiosulfate concentrations in process liquors for the production of kraft pulp. The control method eliminates frequent sampling, and the need for frequent equipment maintenance. The method includes the steps of withdrawing samples of a liquor from the kraft manufacturing process, subjecting the samples to infrared spectrophotometry at predetermined wave numbers to produce peak-absorbance measurements relative to a background spectrum of water, determining peak absorbance for different alkali concentrations, correlating relationships between the peak-absorbance measurements of samples with the peak absorbance for different alkali concentrations to determine optimum effective alkali in the samples, and controlling at least one process parameter to obtain effective alkali of the liquor.

Abstract: Tank level and flow control systems wherein the presence of materials or solutions of known viscosity ranges in a tank or flow stream is detected by using viscosity detection devices. Automatic control devices are also incorporated into these systems to react to one or more signals from the viscosity detection devices and to control the operation of a pump and appropriate valves. One embodiment of the tank level and control system includes a viscosity detection system using a vertical three probe arrangement to report relative viscosities of materials in a storage tank, at predetermined levels in the tank, to the control device.

Abstract: In minimizing effluents from a cellulose pulp mill, liquid effluents from a bleach plant are concentrated, and then incinerated to produce a residue including sodium, sulfate, and sodium chloride. This residue is distilled with sulfuric acid to produce gaseous hydrogen chloride and remaining residue, the HCl being used in chloride dioxide production for the bleach plant, while the remaining residue is passed to the recovery loop (e.g. recovery boiler). Sulfur containing gases from the non-condensible gas system may be combusted to produce gaseous sulfur dioxide, which is then converted to sulfuric acid, to distill the residue. Where a non-chlorine bleach plant is provided, the liquid effluents may be concentrated in evaporators and then passed directly to the recovery boiler. The liquid streams in the mill are managed by a cascade principle to reserve the cleanest water for only those processes where it is needed while minimizing its use where it is not necessary.

Abstract: A web rewet moisture actuator in which a plurality of air atomizing nozzles at spaced locations along a boom extending across the web are supplied with air under pressure by an air manifold on the boom and are supplied with water from a water manifold on the boom through respective proportional valve assemblies which permit flows therethrough in proportion to the magnitudes of control signals applied to the assemblies. A unit located downstream of the boom obtains a moisture profile across the web from which location and control signals are derived and fed to the valve assemblies to control the liquid flow through the valve assemblies in proportion to the magnitudes of the control signals.

Abstract: A method and system are provided for controlling the feed of comminuted cellulosic fibrous material (e.g. wood chips) to a continuous digester utilizing a chips meter of variable speed. A quality of the chips related to mass flow--preferably density--is continuously determined, preferably while the material is in free fall, not immersed in liquid. The speed of the material meter is controlled in response to the quality determined to provide a target mass flow of material from the meter to the digester. A nuclear type density gauge may be utilized having a source and a detector mounted on opposite sides of a chip chute, and above the level of liquid in a chip chute so that density is determined during free fall of the chips, not immersed in liquid. A level sensor may also be associated with the chip chute with a shield between the nuclear source and the level sensor. The chip meter speed is controlled in the range of about 0-16 rpm.

Abstract: A method and apparatus in the press section of a paper machine for regulating the axial linear-load profiles in its nip or nips (N.sub.1,N.sub.2,N.sub.3). The axial temperature profile(s) of the outer mantle(s) of a press roll or rolls (11, 13, 16, 17) is/are regulated. Thereby, the distribution of the diameter of the press roll in the axial direction is controlled on the basis of thermal expansion. Also thereby, the distribution in the transverse direction of the machine of the linear load in the press nip or nips (N.sub.1,N.sub.2,N.sub.3) formed by the press roll or rolls (11, 13, 16, 17) is affected. The temperature profile of the outer mantle(s) (11', 13',17') of the press roll or rolls (11, 13, 17) is regulated by a press felt or felts (10, 14, 18) running through the press nip or nips (N.sub.

Abstract: The invention provides an improvement in the quality and quantity of cellulosic fibers recovered in recycling wastepaper contained in waste material packaged in compressed bale form by sufficiently wetting the baled waste material with a liquid that wastepaper cellulosic fibers will soften and swell prior to the waste material being subjected to the recycling pulping operation.

Abstract: In a method and apparatus for making a dry sheet-like sample of solid particles from a suspension, a part of the suspension is sampled by a sampling unit as it flows through a pipe or while it is retained in a storage tank, then the sampled suspension is stirred by supplying a compressed air and then dewatered by filtration with vacuum, thereby forming a wet sheet-like intermediate sample of solid particles deposited on a filter, subsequently, the filter and the intermediate sample deposited thereon are conveyed by an overturning conveyor unit to a drying station while being turned upside down, thereafter intermediate sample is removed from the filter by a sample removing unit, and finally, the wet sheet-like intermediate sample is dried with heat and pressure whereby a dry sheet-like final sample is obtained.

Abstract: Method and system for applying steam to a paper forming web for the purpose of heating the web to improve the quality of the paper, and withdrawing steam through the use of a vacuum opposite the steam shower, by the simultaneously controlled removal of steam at equally spaced increments by the use of a computer based control system. The computer based control system includes a selectively actuable stepper motor, to effectuate the simultaneous opening of both the steam valve and opposing withdrawal means valve. The system includes a coanda nozzle to cause steam to travel between the sheet and the adjacent surface of the apparatus in a direction opposite to the direction of travel of the sheet and also includes steam impingement nozzles. The apparatus includes devices for creating, housing and providing a supply of steam and a supply of vacuum.