The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform

Martine Rueff - One of the best experts on this subject based on the ideXlab platform.

  • characterization of the fiber water separation process through a suction box of a single wire pilot paper machine
    Separation and Purification Technology, 2012
    Co-Authors: Jeanclaude Roux, Martine Rueff
    Abstract:

    Abstract During paper forming on a single-wire paper machine, i.e. a Fourdrinier or a hybrid paper machine, the pulp suspension is dewatered on a moving wire mainly through vacuum assisted devices (suction boxes). The dewatering process is supposed to occur by dead-end filtration under constant pressure as long as the fiber mat (filter cake) remains fully saturated with water. A physical model was written based on the kinetics of deposition of a compressible fiber mat and a drainage model for the filtrate. After some mathematical arrangements, a model similar to Hermans and Bredee’s formulation [1] was obtained. It states that, at a constant suction pressure, the amount of filtrate per unit surface area is proportional to the square root of suction time. Our approach also yields an equation that is similar to the empirical drainage model used in the paper industry, which links the drained flow rate to a power law of the suction pressure and of the dwell time. By identification of the values of the coefficients, it is then possible to analyze the compressibility of the fibrous mat. For purpose of validation, experimental investigations were performed on one slotted suction box of a Fourdrinier pilot paper machine. The suction pressure was varied from 0.5 to 3.0 kPa and the dwell time was changed by successively increasing the number of slots from 1 to 6 slots. The flow rate of filtrate was measured in each case in order to determine the corresponding specific amount of filtrate. Result analysis confirmed that the specific volume of filtrate varies as the square root of the dwell time. In addition, we could calculate the basis weight of the mat deposited on the wire upstream of the suction box and on the suction box itself, the average specific filtration resistance which was 10 10  m kg −1 for the studied case. The methodology developed in this study can be transposed to other dead-end filtration processes.

James S. Goddard - One of the best experts on this subject based on the ideXlab platform.

  • FOUR-DIMENSIONAL CHARACTERIZATION OF PAPER WEB AT THE WET END Final Report for
    2015
    Co-Authors: James S. Goddard
    Abstract:

    This report presents a detailed description of a vision system whose purpose is to detect and to localize the nonuniformities that appear on the paper slurry (wood fiber and water mixture) at the wet end of a paper machine. Specifically, the system is capable of monitoring the paper slurry upon its exit from the headbox and alerting the operators of any event (e.g., streaks) that disrupts the otherwise homogeneous background. Such events are thought to affect crucial product properties such as formation, which if poor, results in thick and thin spots on the sheet and impacts its strength and printability. This report describes the vision system in terms of its hardware modules, as well as the image processing algorithms that it utilizes to perform its function. Basically, the system acquires both intensity and topographic information from the scene and uses texture-based features for the detection, and facet-based descriptors for the localization of the nonuniformities. In addition to being tested in a laboratory environment, a prototype of this system was constructed and deployed to a paper mill, where its performance was evaluated under realistic conditions. Installed on a fourdrinier paper machine, running at 480 m/min and producing linerboard material, the vision system was able to monitor an approximately 1-meter-wide area and to successfully detect an

Js Goddard - One of the best experts on this subject based on the ideXlab platform.

  • Four-Dimensional Characterization of Paper Web at the Wet End
    Oak Ridge National Laboratory, 2001
    Co-Authors: Js Goddard
    Abstract:

    This report presents a detailed description of a vision system whose purpose is to detect and to localize the nonuniformities that appear on the paper slurry (wood fiber and water mixture) at the wet end of a paper machine. Specifically, the system is capable of monitoring the paper slurry upon its exit from the headbox and alerting the operators of any event (e.g., streaks) that disrupts the otherwise homogeneous background. Such events are thought to affect crucial product properties such as formation, which if poor, results in thick and thin spots on the sheet and impacts its strength and printability. This report describes the vision system in terms of its hardware modules, as well as the image processing algorithms that it utilizes to perform its function. Basically, the system acquires both intensity and topographic information from the scene and uses texture-based features for the detection, and facet-based descriptors for the localization of the nonuniformities. In addition to being tested in a laboratory environment, a prototype of this system was constructed and deployed to a paper mill, where its performance was evaluated under realistic conditions. Installed on a fourdrinier paper machine, running at 480 m/min and producing linerboard material, the vision system was able to monitor an approximately 1-meter-wide area and to successfully detect and localize slurry streaks

Jeanclaude Roux - One of the best experts on this subject based on the ideXlab platform.

  • characterization of the fiber water separation process through a suction box of a single wire pilot paper machine
    Separation and Purification Technology, 2012
    Co-Authors: Jeanclaude Roux, Martine Rueff
    Abstract:

    Abstract During paper forming on a single-wire paper machine, i.e. a Fourdrinier or a hybrid paper machine, the pulp suspension is dewatered on a moving wire mainly through vacuum assisted devices (suction boxes). The dewatering process is supposed to occur by dead-end filtration under constant pressure as long as the fiber mat (filter cake) remains fully saturated with water. A physical model was written based on the kinetics of deposition of a compressible fiber mat and a drainage model for the filtrate. After some mathematical arrangements, a model similar to Hermans and Bredee’s formulation [1] was obtained. It states that, at a constant suction pressure, the amount of filtrate per unit surface area is proportional to the square root of suction time. Our approach also yields an equation that is similar to the empirical drainage model used in the paper industry, which links the drained flow rate to a power law of the suction pressure and of the dwell time. By identification of the values of the coefficients, it is then possible to analyze the compressibility of the fibrous mat. For purpose of validation, experimental investigations were performed on one slotted suction box of a Fourdrinier pilot paper machine. The suction pressure was varied from 0.5 to 3.0 kPa and the dwell time was changed by successively increasing the number of slots from 1 to 6 slots. The flow rate of filtrate was measured in each case in order to determine the corresponding specific amount of filtrate. Result analysis confirmed that the specific volume of filtrate varies as the square root of the dwell time. In addition, we could calculate the basis weight of the mat deposited on the wire upstream of the suction box and on the suction box itself, the average specific filtration resistance which was 10 10  m kg −1 for the studied case. The methodology developed in this study can be transposed to other dead-end filtration processes.

Y U Zhangsh - One of the best experts on this subject based on the ideXlab platform.