Abstract:
A web is passed over a surface (11) which is at least partly curved in the running direction of the web, which extends across the web in the cross direction, and which is placed at a distance from the web, in which connection an air cushion is formed between the moving web and the curved surface. The temperature and moisture of the web are measured indirectly by measuring the temperature and moisture of the air cushion by several detectors (41) which are in communication with openings (40) formed in the curved surface in spaced relationship with one another in the cross direction of the web.
Abstract:
A drying unit in a dryer section of a paper or board machine including a drying wire guided in a loop, a large-diameter impingement-drying and/or through-drying cylinder arranged inside the drying-wire loop and smaller diameter smooth-faced heated contact-drying cylinders arranged on top of the large cylinder and/or in the vicinity thereof and at both sides thereof. The impingement-drying and/or through-drying cylinder is placed in a space below the floor level of the paper machine hall and provided with an openable and closable blow hood so that the removal of broke out of connection with the hood takes place substantially by the force of gravity. The central axes of the contact-drying cylinders placed in the vicinity of the large cylinder are placed in the vicinity of, or above, the floor level of the paper machine hall. A curve sector of the paper web on the outer face of the drying wire over the large cylinder greater than about 180.degree..
Abstract:
The invention relates to a method in the process of manufacturing and/or finishing a fibre web, in which method said continuous and moving web, and/or a moving means related to the processing of the web, is monitored by at least one optical spectrum separating measurement device to determine at least one quality variable of said object for the purpose of controlling the quality or condition. According to the invention, spectral data is collected in synchronization with the movement from the object which is being examined and is in a progressive and/or rotating movement, by measuring electromagnetic radiation, which has been transmitted, reflected, or otherwise emitted by the object, in a temporally and spatially resolved manner. On the basis of this spectral data, a two-dimensional quality variable chart is formed, which is substantially continuous in the direction of movement of the object and presents at least one quality variable of the object, and in order to determine the characteristics of the object and/or to detect defects in the object from said continuous quality variable chart, local deviations and/or discontinuities are detected in said continuous quality variable chart, especially in the direction of movement. The cause of these deviations and/or discontinuities is identified on the basis of the periodicity of said phenomena in the direction of movement.
Abstract:
An arrangement for removing condensate from an interior of a drying cylinder in a paper machine and a method for regulating the removal of such condensate. The arrangement includes a steam pipe through which steam is passed into the space in the interior of the drying cylinder, and a condensate pipe and fluidly connected syphon pipe through which condensate is removed from the interior of the drying cylinder. The steam pipe and the condensate pipe are passed through a revolving axle journal of the drying cylinder. The arrangement also includes a syphon support attached in the interior of the drying cylinder to revolve along with the drying cylinder and support the syphon. A support bearing is arranged to attach to the syphon support and the syphon support is connected with the construction of condensate and steam pipes.
Abstract:
The invention concerns an equipment in a paper/board machine for regulation of the difference of draw. In the solution in accordance with the invention, the difference of draw in the web is regulated on the basis of the measured tension of the web. Preferably, the regulation of the difference of draw takes place by regulating the drives at the inlet and/or outlet of a web run not supported by a wire.
Abstract:
An arrangement in connection with the press and dryer section of a web-forming machine includes first and second devices for transporting the web. The second device includes a dryer wire and a roll arranged to support it. In the arrangement there is an open gap between the first and second devices, across which the web is arranged to be transferred, so that the web and the dryer wire form a closing throat. The arrangement further includes a deflector before the open gap in the direction of travel of the dryer wire, which is arranged close to the dryer wire, in order to restrict the air layer travelling with the dryer wire, and thus to prevent the formation of an excess pressure in the closing throat.
Abstract:
A method of controlling the quality and/or condition of a fibre web in a process for manufacturing and/or finishing the fibre web, which includes, monitoring the fibre web with at least one optical spectrum separating measurement device, determining a quality variable of the fibre web, measuring electromagnetic radiation reflected from the fibre web using an optical spectrum separating measurement device synchronously with a movement of the fibre web, and measurements in the form of spectral data, generating a continuous quality variable chart, dividing the continuous quality variable chart into successive matched partial charts having a cycle length, detecting deviations and/or discontinuities of the quality variable from the successive matched partial charts, and detecting malfunctioning of a rotating/moving means using the detected deviations and/or discontinuities of the quality variable.