Honeywell-Measurex Corporation

Honeywell International Inc.

Claud Hagart-Alexander

John D Goss

Lee M Chase

Hung-Tzaw Hu

David Watson

John G Preston

Graham V Walford

E Michael Heaven

John David Watson

Martin G Clarke

Raymond Yu

Laslo Dudas

A sensor apparatus and electrode configuration within the sensor apparatus for measuring electrical characteristics of an aqueous fibrous composition. The electrode configuration includes an elongated ground electrode and at least one segmented electrode to form an array of measurement electrode cells. The electrode configuration further includes an array of reference electrode cells formed by a plurality of reference electrodes built into the array of measurement electrode cells. The measurement electrode cells and reference electrode cells have a different sensitivity to water weight of the aqueous fibrous composition and the same sensitivity to conductivity of the aqueous fibrous composition. The measurement apparatus obtains simultaneous resistive measurements from both measurement and reference cells and determines the ratio of the measurements such that the affects from conductivity is canceled out of the measurement ratio. The determined measurement ratio is used to obtain a measurement of the water weight of the aqueous fibrous composition by using previously determined characterization data of the water weight vs. a range of measurement ratios.

Means of correcting a measurement of a property of a material with a sensor that is affected by a second property of the material

A system of providing fast machine direction (MD) and cross direction (CD) basis weight adjustments using a simultaneous multi-point water weight sensor which provides independent MD and CD measurements is described. The water weight sensor is placed under the wire of the sheetmaking machine and provides fast wet end water weight measurements which are converted into predicted dry end basis weight information and used to control operating variables of machine elements in the sheetmaking machine to compensate for high frequency process variations. MD wet end measurements are used to control operating variables of machine elements that influence the MD dry end basis weight and CD wet end measurements are used to control operating variables of machine elements that influence CD dry end basis weight.

Fast CD and MD control in a sheetmaking machine

A system and method of providing on-line turbulence measurements in a sheetmaking machine and using these measurements to perform on-line adjustments to turbulence-inducing and adjusting elements in the sheetmaking machine to optimize final sheet product quality. Turbulence measurements are obtained using water weight sensors in the wet-end of the sheetmaking machine and specifically under wire water weight measurements. Water weight readings are correlated to turbulence intensity levels by correlating ranges of water weights to intensity level intervals. A turbulence processing sensor sorts accumulated water weight measurement readings into intensity level intervals to obtain turbulence measurements or a turbulence profile. The turbulence measurements or profile is provided to a machine element controller which uses the measured turbulence information and target turbulence information to generate control signals. The water weight sensors can obtain independent machine direction (MD) and cross direction (CD) water weight measurements and consequently independent turbulence measurements can be determined so that turbulence can be controlled in both directions. Machine elements are controlled so that turbulence remains uniform across the CD and so that the MD turbulence profile is optimized to resemble a target profile.

Underwire water weight turbulence sensor

System and method for producing paper are provided. The system controls formation of wet stock comprising fibers on a moving water permeable wire of a de-watering machine that has a refiner that is subject to a variable load and a headbox having at least one slice, wherein each slice has an aperture through which wet stock is discharged at a stock jet speed onto the wire that is moving at a wire speed. A sheet of wet stock moving a speed develops on the wire. The system includes: a) at least two water weight sensors that are positioned adjacent to the wire wherein the at least two sensors are positioned at different locations in the direction of movement of the wire and upstream from a dry line which develops during operation of the machine and the sensors generate signals indicative of a water weight profile made up of a multiplicity of water weight measurements; and b) means for adjusting at least one of the stock jet speed, sheet speed, wire speed, or refiner load to cause the water weight profile to match a preselected or optimal water weight profile. Techniques for predicting the dry stock weight of wet stock on the wire can be employed to assess the effect of adjusting the operating parameters. In addition, employing two sensors placed in the machine direction, the sheet speed can be determined by measuring the water weigh profile of a segment of the sheet and the time required for the segment to travel from one sensor to the next.

Paper stock shear and formation control

System and method for producing paper are provided. The system controls formation of wet stock comprising fibers on a moving water permeable wire of a de-watering machine that has means for supplying the amount of pulp from at least one source, means for adding an amount of non-fibrous additives to the wet stock, a refiner that is subject to a variable load and a headbox having at least one slice, wherein each slice has an aperture through which wet stock is discharged onto the wire. The system includes: (a) at least two water weight sensors that are positioned adjacent to the wire wherein the at least two sensors are positioned at different locations in the direction of movement of the wire and upstream from a dry line which develops during operation of the machine and the sensors generate signals indicative of a water weight profile made up of a multiplicity of water weight measurements; and (b) means for adjusting at least one of the motor load controller, the amount of non-fibrous additives added to the wet stock or amount of pulp supplied from the at least one source to cause the water weight profile to match a preselected or optimal water weight profile.

Wet end control for papermaking machine

A system and method of providing fast machine direction (MD) and cross direction (CD) basis weight adjustments using a simultaneous multi-point water weight sensor which provides independent MD and CD measurements is described. The water weight sensor is placed under the wire of the sheetmaking machine and provides fast wet end water weight measurements which are converted into predicted dry end basis weight information and used to control operating variables of machine elements in the sheetmaking machine to compensate for high frequency process variations. MD wet end measurements are used to control operating variables of machine elements that influence the MD dry end basis weight and CD wet end measurements are used to control operating variables of machine elements that influence CD dry end basis weight. The fast control information provided by the non-scanned water weight sensor can be used in a fast control loop which provides feedback information to wetstock source, headbox and forming elements and which can be used with a slower response control loop including a dry end sensor which provides a slower basis weight measurement and which controls system variables to compensate for larger basis weight fluctuations.

System and method for producing paper are provided. The system controls formation of wet stock comprising fibers on a moving water permeable wire of a de-watering machine that has a refiner that is subject to a variable load and a headbox having at least one slice, wherein each slice has an aperture through which wet stock is discharged at a certain stock jet speed onto the wire that is moving at a certain wire speed. The system includes: a) at least two water weight sensors that are positioned adjacent to the wire wherein the at least two sensors are positioned at different locations in the direction of movement of the wire and upstream from a dry line which develops during operation of the machine and the sensors generate signals indicative of a water weight profile made up of a multiplicity of water weight measurements; and b) means for adjusting at least one of the stock jet speed, wire speed, or to cause the water weight profile to match a preselected or optimal water weight profile.

System and method for producing paper that employ an apparatus for measuring electrical characteristics of a fibrous composition. The apparatus comprises a plurality of conductivity (or resistance) detectors each comprising a sensor that is sensitive to the conductivity (or resistance) and the proximity of the material (e.g., fibrous composition) to the sensor. Measurements from the apparatus relate to the zeta potential of the fibrous materials in the composition. The zeta potential profiles corresponding optimized configurations of the sheetmaking process can be employed to monitor and control the process.

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Vancouver, Canada

Claud Hagart-Alexander