摘要:
The invention concerns a method for detecting a contamination and damaging of a face (10) that runs through a nip or nips (N1 . . . N10) in a calendar for paper. In the method vibrations occurring in connection with the constructions (18, 100) of a calendar are detected and processed. The vibrations are detected by at least one vibration detector (40; 41 . . . 46; 41a. . . 46a, 41b. . . 46b) fitted in connection with the bearing supports of calendar rolls (11 . . . 16) or in connection with constructions (18, 100) related to said bearing supports. By the way of these vibration detectors the calendar roll(s) (11 . . . 16) is/are identified from which the vibration derives. In the method , it is possible to observe the rotation of all of the rolls to be monitored and to measure vibration from any suitable point whatsoever, for example from the frame (100) of the machine, by employing at least one vibration detector (40), the time (Tr) of the cycle of the vibration signal obtained from said detector(s) being compared with the numbers of revolutions of the rolls to be monitored. In this way, the source of the disturbance is determined, and action is taken in order to eliminate the disturbance.
摘要:
In a measurement method in the manufacture of paper or paperboard, different forces prevailing in a nip between a roll and a counter roll of an apparatus conveying a paper or paperboard web are measured. In the method there are several measurement points implemented with one or more film sensors (3) placed in the roll (1) in the transverse direction of the paper or paperboard web. The measurement information obtained from the measurement points by means of the sensor or sensors (3) is utilized to determine the pressure distribution of the nip. The film sensor (3) is a piezo- and pyroluminescent sensor from which the measurement information can be received optically at least in the initial stage, or a sensor comprising an electromechanical film (EMFi). The sensors (3) placed in the calender roll (1) can be utilized to measure the pressure distribution of the calender nip (N).
摘要:
The invention relates to a method by means of which the machine-direction moisture of a web being coated can be controlled in an optimal manner that takes into account moisture content changes along the entire path of the coating and drying process. Advantageously, all the dryers the coater section are controlled in an integrated manner in order to obtain a controlledly processed product which is optimized in regard to energy consumption and product quality. Each process section and unit contributing to the drying of the web is identified by means of a mathematical submodel describing the specific evaporation rate in the respective process section/unit and, by chaining these submodels, a composite model is compiled for the entire process, whereby the composite model makes it possible to manage the drying operation in the process so that the individual units are controlled as a portion of the overall process.
摘要:
The surface of a web is monitored by a fault detection system (20), a machine condition monitoring system, a quality measurement system, a web moisture measurement and/or a web temperature measurement and the soiled part of the surface of the roll is detected and localized by means of a soiling monitoring apparatus (31, 35; 60). A control system (41) controls a cleaning device (40) to remove the detected soiling. As a web (W) travels in a paper or board production or finishing process or in finishing machinery the web and/or the surface of the roll is monitored and after a detected deviation the surface thereof is momentarily spread with a liquid while machinery is running at the same time as the web (W) travels over said roll surface.
摘要:
The invention concerns a method for conditioning of a roll, in particular of a roll (10) in a paper machine or in a paper finishing device. In the method the face/coating on the roll of the paper machine is cleaned and/or ground. In the method, the cleanliness and/or condition of the roll (10) is/are measured continuously during operation and, based on the measurement results, the roll face/coating is cleaned and/or ground so that the roll (10) remains constantly in good condition and the level of quality of the paper remains at the desired level. The invention also concerns a device for conditioning of a roll, in particular of a roll in a paper machine and/or in a paper finishing device, which device (20) comprises means for cleaning and/or grinding the roll. The device (20) consist of an assembly (20) of devices which comprises a cleaning/conditioning unit (24, 23, 29), a control unit (33), and measurement units (30, 31, 32), and the device operates continuously and can be operated during running.
摘要:
A method and a system to control a reeling profile of a material web reel (30), when, in the forming of a material web reel (30), a web is reeled around a reeling core and when in an adjustment of CD-directional profiles of the web reel, profiling devices (8) have been applied. For adjusting quality profiles and reeling profiles of the web, profiling devices are managed with the help of profile measurings of the roller nip and/or of the profile measurings of the reel (30), which are obtained from the reel-up (2). A measuring device (40) for a measuring of a CD-directional hardness profile of the fiber web reel includes a measuring head (43), which is connected with a loading means (41, 42), which loads the measuring head against the fiber web reel. The motion course of the measuring head is linear.
摘要:
The invention relates to a method for controlling a surface quality variable (300) in one or more fiber webs (3) in a shoe calender (1) comprising one or more calender nips. In each calender nip of the shoe calender, the overall loading pressure of the shoe element (8) and the loading pressure difference between the leading edge (8′) and the trailing edge (8″) of the shoe element are controlled so as to achieve minimum difference between the determined values (300″) for the surface quality variables of the fiber web and the set values (300′) for the same quality variables after the shoe calender.
摘要:
A method and arrangement for computing and regulating distribution of linear load in a multi-nip calender. A material web is passed through the nips in a set of rolls including a variable-crown upper roll, a variable-crown lower roll and intermediate rolls positioned between the upper and lower rolls. The rolls in the set of rolls are supported so that, when the nips are closed, the bending lines of the rolls are curved downwards. When computing and regulating the linear loads, one or more of the physical properties affecting the bending of each intermediate roll under load, such as bending rigidity, mass, shape, and material properties, are taken into account. The ratio of the linear loads applied to the intermediate rolls, the weight of the rolls per se, and/or the support forces applied to the rolls are regulated so that the set of rolls is in a state of equilibrium and a predetermined state of deflection.