摘要:
The invention relates to a device for detecting properties of a moving web of paper, more specifically for production control in the paper making process, with an infrared lighting device suited for illuminating the web of paper with infrared light and provided with a light exit portion, with a detector device for detecting infrared light reflected or transmitted by the web of paper which is provided with a light input portion and with a housing a) which is arranged in immediate proximity to the paper web, b) which is provided with a front face facing the web of paper and c) which accommodates the light exit portion and/or the light input portion provided with optical fibers. A plurality of n spherical lenses is arranged in a sealed manner in the front face, said spherical lenses being each optically coupled to an allocated optical fiber within the housing, said spherical lenses constituting, together with the corresponding optical fibers, the light exit portion and/or the light input portion.
摘要:
An infrared detector device for a device for detecting properties of a moving web of paper, more specifically for a device for controlling production in the paper making process, the detector device being provided, on the one side, with a polychromator that receives, on its receiving side, light coming from the web of paper and, on the other side, with an infrared detector with a matrix of infrared sensitive photoconductors, an evaluation electronic unit with one memory assigned to a respective one of the photoconductors of the matrix being connected downstream thereof. An additional source of light that can be controllably switched on and off between a first light intensity and a second light intensity which is greater than the first one uniformly illuminates the infrared detector for deriving correction values for correcting the signals from each of the photoconductors during a measurement.
摘要:
A device for heating a roll in a paper or paperboard machine or in a finishing machine for paper or paperboard the device including a profiling induction heater (5) which is arranged to heat the roll (3) with a power dependent on the location of the point to be heated in the axial direction of the roll, and a non-profiling induction heater (4) which, to provide basic heating, is arranged to heat the same roll (3) with a heating power which is substantially even over the width of the roll (3). The profiling induction heater (5) and the non-profiling induction heater (4) are placed in the same support structure (1) outside the roll (3). The roll (3) is a calender roll.
摘要:
A method for blowing steam against a paper web, whereby the steam is blown by a steam box having several profiling chambers in the cross direction of a paper machine. The cross-profile of the paper web is controlled by means of the steam supplied by the profiling chambers. A gas flow is provided between the profiling chambers to prevent the steam blown by a profiling chamber from affecting the effective area of the steam blown by the adjacent profiling chamber. Further, a steam box for implementing the method is disclosed.
摘要:
A method and an apparatus for adjusting a chemical dosage of a pulp processing stage. The method comprises measuring a change in a variable in dependence on the chemical dosage and the chemical dosage to be added, and determining a model describing the change in the variable as a function of the chemical dosage. A performance index is determined for the new model to be compared with the performance index of certain previously determined models. The model that produced the best performance index is put to use.
摘要:
The measuring device is arranged to measure at least one property of a moving web. The measuring device includes at least one measuring head with at least one measuring element arranged in a flexible membrane that surrounds the measuring element and is arranged in connection with the measuring head such that the measuring element is movable by means of the flexible membrane perpendicularly to the moving web. The turning effect, which is caused by the pressure of the air conveyed with the moving web, and directed in the travel direction of the web at least in front of the measuring element on the web side of the flexible membrane, and turns the measuring element, is prevented by at least partly changing the amount and/or flow direction of the air conveyed with the web moving to the measuring element.
摘要:
The invention relates to a method and an apparatus according to the method. A sample is illuminated by a band of optical radiation the illumination state of which is variable as a function of time. Reference measurements of the spectrum of the optical band illuminating the sample are made at least at three separate instants of time. A spectrum of a band of the optical radiation that has interacted with the sample is measured at the corresponding separate instants of time as the reference measurement, and the radiance transfer factor matrix of the sample is estimated from the set of reference measurements and the set of sample measurements.
摘要:
The measuring device comprises at least one measuring head having a reference part, which comprises a reference surface against which the moving web is supported. The reference surface comprises a measuring area in the inside of which the property of the web is measured. The reference part is arranged in connection with the measuring head in such a way that below the reference part, there is a substantially open air space. The measuring head comprises means for generating negative pressure in the air space below the reference part, and the reference part comprises holes formed through it, in such a way that the negative pressure generated in the air space affects through the reference part the space between the reference surface and the moving web in such a way that the web is supported against the reference surface substantially over the whole area of the measuring area.
摘要:
A device for detecting properties of a moving web of paper, more specifically for production control in the paper making process, comprising an infrared lighting device suited for illuminating the web of paper with infrared light and a detector device for detecting light reflected or transmitted by the web of paper which is provided with a light input portion. The infrared lighting device is provided with a light source in the form of a long, rod-shaped infrared emitter, the light source being accommodated in a housing having a front plate facing the web of paper. An exit window, through which the light from the light source passes to impinge upon the web of paper, is tight-fittingly received in an aperture in the front plate.
摘要:
An arrangement for measuring properties of a moving paper web. The arrangement comprises measuring means for measuring paper properties, in connection with which a plane-like support surface is arranged. The plane-like support surface supports the paper web and extends substantially over the whole width of the paper web in the cross-direction relative to the direction of travel of the paper web. An opening arrangement formed by at least one opening is arranged on the support surface for measuring properties of the paper web.