Abstract: The invention relates to a filtering device for taking a filtrate sample from liquid matter containing solid particles. The filtering device comprises two filter parts and at least one filtering slot between the filter parts. The filter parts are adapted to move in relation to each other in such a manner that the width of the filtering slot changes when the filter parts move in relation to each other. When taking a sample from a process, the filtering slot between the filter parts is at its smallest, and it is adapted to filter the sample while the liquid matter being measured flows from the process to the measurement. When rinsing the filtering device against the sampling direction, the filter parts are adapted to move away from each other, whereby the filtering slot widens.

Abstract: 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.

Abstract: In a paper machine which comprises process elements and a measuring beam, the measuring beam is arranged at least at one paper machine process element so that a measuring device for measuring quality properties of a paper web is arrangeable in the measuring beam. The paper machine process element is e.g. a blow box, which is arrangeable in a dryer unit of the paper machine between drying cylinders to blow air via at least one blow air channel provided in the blow box to guide the moving paper web and/or to assist drying.

Abstract: A method and arrangement for controlling short circulation in a paper machine, in which the control of at least one property of the diluted fiber-containing pulp conducted to the headbox is based on consistency measurement or determination in high-consistency fiber-containing pulp, diluted pulp and/or white water. The amount of fiber-based fines in high-consistency fiber-based pulp, diluted fiber-based pulp and/or white water is determined, and the result obtained is used for controlling at least one property of the fiber-containing pulp to be conveyed to the headbox.

Abstract: The invention relates to a method for synchronizing information produced by imaging optical measuring devices (1-N) which monitor the manufacturing and/or finishing process of a fibre web, in relation to the movement of the fibre web in the machine direction, which method comprises the steps of monitoring the moving fibre web and/or a moving means involved in its processing in the machine direction by means of imaging measuring devices (1-N) placed in successive measuring positions in the machine direction, and searching the information recorded by imaging at different measuring positions, for images, or the like, relating to the same local area of the fibre web, for their analysis and/or storage.

Abstract: The invention relates to a method and a system for determining hysteresis of a process device in a process environment. The process comprises collecting (50) second-level sample data ys and us from control and measurement signals u and y of a control circuit. Minute mean values y(min) and u(min), which are stored in a database (52), are calculated from these second-level measurement values. The pairs suitable for hysteresis calculation are selected from the minute-level sample pairs um and ym according to a certain procedure. The pairs are also divided into two groups. Unsuitable pairs are rejected (57). Two characteristic curves (54) are calculated from the selected pairs (um, ym) for hysteresis calculation (55). The calculation (55) also includes a routine which evaluates the reliability of the identified hysteresis.

Abstract: The invention relates to a method in the control of the quality or the condition of a fibre web (21) on the basis of optical imaging diagnostics, wherein the fibre web (21) under examination and/or means (22, 23) relating to the processing of the fibre web are monitored with at least one optical imaging measuring device (1 to N). According to the method, the scale of the observation area of said at least one imaging measuring device (1 to N) is calibrated, when said measuring device is taken into use, by means of one or more calibration objects placed in the observation area of the measuring device, to correct the perspective error caused by the position between said measuring device and the object (21, 22, 23) observed by it.

Abstract: The present invention relates to a system comprising: a process control network (3) having process equipment (2) connected thereto for receiving, through the process control network, control commands and for transmitting messages. To enable a high-security-level system to be achieved, wherein the state of a process can be established from an external communication network, the process control network (3) is connected to an external communication network (5) via a one-way data transfer device (12). The external communication network has storage equipment (6 to 8, 13) connected thereto, configured to store at least some of the information contained in the messages to be transmitted from the process control network (3) to the external communication network (5).

Abstract: The invention relates to a condition monitoring system for machines equipped with a machine control system (12) and including rotating machine elements. The condition monitoring system is based on the measurement and monitoring of various variables during the operation of the machines. The condition monitoring system includes sensing elements (10) for the measurement of desires variables as well as processing equipment (25) and storing and analyzing equipment (28) for the creation and storage of the machine's condition information. The storing and analyzing equipment (28) is separately arranged in connection with each machine as a module (13) separate from the machine control system (12).

Abstract: The present invention relates to an induction heating coil comprising a litz cable which is wound into a spiral to form a bobbin, and means for cooling said cable indirectly. The litz cable is arranged to be cooled by means of an indirect cooling system that comprises a tube which is wound in an intermeshed fashion with the windings of the litz cable. The present invention relates also to a method on a paper or board machine or on a paper finishing machine, in which method at least one induction heating coil comprising a wound litz cable is used for heating a component, and said coil is cooled indirectly by a cooling medium.

Abstract: A method and an apparatus for measuring the amount (CW) of a coating (2) on a paper web (1). The amount (CA) of at least one component in the coating (2) on the paper web (1) is measured and the composition (CC) of the coating (2) to be transferred to the paper web (1) is determined. The amount (CW) of the coating (2) on the paper web (1) is determined on the basis of the amount (CA) of at least one component in the coating (2) on the paper web (1) and the composition (CC) of the coating (2) to be transferred to the paper web (1).

Abstract: The invention relates to a method and an apparatus for arranging redundancy in a process control system comprising at least one client device, at least one data source and at least one server device providing data transfer between the client device and the data source. The method comprises arranging, for the client device, at least two parallel logical connections for transferring substantially the same data between at least one data source and the client device. At the client device, property information on data units transferred via different logical connections is checked, the client device being provided with predetermined order criteria for the property information. At the client device, property information on parallel data units transferred via different logical connections is compared. Data units delivered via the logical connection having, according to the predetermined order criteria, the best property information are selected for the use of one or more applications processing the data units.

Abstract: A method and apparatus for determining the retention of a wire section in a paper machine. The mass flow of a paper web on the wire section is determined by means of web properties measured after the wire section. In addition, the mass flow of a headbox and/or white water is determined. The retention of the wire section is determined on the basis of the mass flows of the paper web and the headbox and/or the mass flow of the white water.

Abstract: 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.

Abstract: A method and an apparatus for controlling a moisture profile of a paper web, in which the moisture profile of the paper web prior to drying is measured. The measurement is carried out with a measuring device, which measures a cross-direction profile of the web substantially simultaneously. On the basis of the measurement, the moisture profile of the paper web is controlled prior to drying the paper web.

Abstract: The present invention relates to a diaphragm actuator for control valves, wherein the gear rack is arranged so that the points of contact of the gear rack/gear wheel system are situated on the straight line connecting the centers of the movable walls of the pressure spaces effecting the movement. Thereby, no torsion forces act on the diaphragm backing plates or on the diaphragms, but the forces effecting the movement of the reciprocating elements are substantially parallel with the path of motion and symmetrical. Additionally, the clearance between the gear rack and the gear wheel is substantially eliminated by means of a support roll with bearings. According to the invention, a lightly movable actuator is provided, in which the delays caused by clearances or wall friction of the cylinder-piston arrangement are substantially eliminated. The actuator can be implemented either as double-acting or single-acting.

Abstract: A method and equipment for measuring the tension of a moving web. The tension of the moving web is measured by means of a measuring element provided with a guide surface which the moving web is guided to pass such that the web forms an air cushion of the air it carries between the web and the guide surface. Measuring devices are arranged at a distance from one another in connection with the measuring element in the cross direction of the web for measuring a variable representing the tension of the moving web. The measuring element is moved back and forth in the cross direction of the web such that the tension profile of the web is measured at least on a part of the web width by means of the measuring devices arranged in connection with the measuring element.

Abstract: A method of blowing drying gas against a paper web, and an impingement dryer of a paper machine. Drying gas is blown with an impingement dryer comprising several profiling chambers in the cross-direction of a paper machine, the cross-profile of the paper web being controlled with the drying gas blown from the profiling chambers. Each profiling chamber blows drying gas to its own effect range. The impingement dryer further comprises a return air chamber and return air ducts such that drying gas blown against the paper web from the profiling chambers is returned into the return air chamber through the return air ducts in such a way that some of the effect of the drying gas blown from the profiling chamber is at least partly prevented from reaching the effective area of the adjacent profiling chamber.

Abstract: The invention relates to a method and arrangement for measuring optical properties from paper or board that constitutes a target to be measured and comprises two planar surfaces. In the arrangement, one surface of the target to be measured is illuminated by an optical power source, and the illuminated area on the opposite side of the illuminated surface comprises at least one backing with known optical properties. A detector detects the illuminated surface in the area of the backing, and at least one optical property of the target to be measured is determined by means of spectral information obtained at the backing.

Abstract: A method and apparatus for sootblowing a recovery boiler. Sootblowers of the recovery boiler are divided into sootblowing groups, and a sootblowing interval is determined for the sootblowers. A fouling index is produced for each sootblowing group of the recovery boiler, and relative frequency values are calculated.