摘要:
Headbox for a machine and process for forming the same. The headbox includes a plurality of channels arranged in rows that extend across a width of the machine and in columns substantially perpendicular to the rows, at least one lamella positioned between adjacent rows, a fixing point for the at least one lamella, and lamellar supports positioned after the fixing point, relative to a headbox flow. This includes arranging a plurality of headbox channels into rows and columns, positioning a lamella between adjacent rows, fixing an end of the lamella at a fixing point, and arranging lamellar supports downstream of, relative to a headbox flow direction, the fixing point.
摘要:
Process of forming a headbox for a machine, which includes arranging a plurality of headbox channels into rows and columns, positioning a lamella between adjacent rows, fixing an end of the lamella at a fixing point, and arranging lamellar supports downstream of, relative to a headbox flow direction, the fixing point.
摘要:
Process for a metered addition of a fluid medium into a material suspension stream of a headbox, including feeding the material suspension in a main flow direction through at least one turbulence-producing conduit to a headbox nozzle, the at least one turbulence-producing conduit having an entrance, a graduated pressure loss area, and an exit. A total pressure loss &Dgr;Ptotal is caused in the at least one turbulence-producing conduit such that the total pressure loss &Dgr;Ptotal includes at least one intake pressure loss &Dgr;Pintake formed at the entrance and a graduated pressure loss &Dgr;Pgrad formed at the graduated pressure loss area. A metered addition of a fluid medium is also provided in a region between the entrance and the exit. The headbox for one of a paper and cardboard machine includes at least one material suspension supply running a width of the machine, at least one turbulence producer having at least one conduit through which a material suspension flows, at least one metered suspension supply running a width of the machine, at least one turbulence producer having at least one conduit through which a material suspension flows, at least one metered addition point located in the conduit for introducing a fluid medium, and a headbox nozzle located downstream from the at least one turbulence producer for delivering the material suspension. A portion of a flow resistance located downstream of the metered addition point is at least approximately 50% of a total flow resistance of the at least one conduit.
摘要:
Paper or cardboard machine and method for regulating a basis weight of a paper or cardboard web in the manufacturing process. The paper or cardboard machine includes at least one headbox that extends across a machine width. The at least one headbox is adapted to provide a machine-wide distribution of a material suspension onto one of a screen and between two screens. The machine also includes at least one material suspension supply coupled to the at least one headbox and adapted to supply a material suspension to the at least one headbox. The at least one material suspension supply has at least one concentration. At least one first control loop is provided that includes at least one actuator being adapted to adjust the at least one concentration of the at least one material suspension supply, at least one detector for determining a basis weight of a finished web, at least one supply being adapted to modify the at least one concentration of the at least one material suspension supply, and at least one device that adjusts the at least one actuator. In this manner, the at least one concentration of the at least one material suspension supply is adjusted. At least one second control loop is provided that is adapted to regulate the concentration of the material suspension supply. The method includes determining a basis weight at an end of the manufacturing process, calculating a deviation of the determined basis weight from a predetermined target value, adjusting a concentration of a material suspension supplied to a headbox via a first control loop such that the calculated deviation is corrected, one of directly and indirectly measuring a basis weight of a resulting web in a region upstream, with regard to a web travel direction, a drying section, and supplying a signal related to the measured basis weight to a second control loop.
摘要:
Process and a device for detecting a change in the fiber orientation cross-direction profile of a paper or cardboard web in the manufacturing process on a paper or cardboard machine. It is recognized that a change in the fiber orientation cross-direction profile in the web is inferred or determined by way of a characteristic change in the basis weight cross-direction profile or at least one measurement quantity that correlates to it, and/or by way of a characteristic change in the basis weight in the travel direction of the web or at least one measurement quantity that correlates to it. The device includes an arrangement for detecting a change in the basis weight cross-direction profile and/or a characteristic chronological course of the change in the basis weight, which is characteristic for a change in the fiber orientation.
摘要:
Method for regulating a basis weight of a paper or cardboard web in the manufacturing process. The method includes determining a basis weight at an end of the manufacturing process, calculating a deviation of the determined basis weight from a predetermined target value, adjusting a concentration of a material suspension supplied to a headbox via a first control loop such that the calculated deviation is corrected, one of directly and indirectly measuring a basis weight of a resulting web in a region upstream, with regard to a web travel direction, a drying section, and supplying a signal related to the measured basis weight to a second control loop.
摘要:
A headbox for passing fiber suspension from a headbox entrance to a headbox outlet. A microturbulence insert with a plurality of flow channels inside the headbox. The channels are defined by channel forming elements having upstream ends. The headbox has an antechamber upstream of the turbulence insert. Respective individually adjustable additional feeds for feeding at least one second liquid into the antechamber upstream of the upstream ends of the channel forming elements of the turbulence insert. The feeds are preferably directed counter to the direction of the main flow of suspension into the channels of the turbulence insert. Vanes direct the main flow of suspension through the antechamber to the channels creating a respective sectioned flow to each channel. The additional liquid feeds are positioned to feed their additional liquid into the respective sectional flows after the main flow of suspension has already been diverted to a sectional flow. A method of use of such a headbox wherein each feed of additional liquid into the main flow of suspension is deflected in the direction of the nearest channel of the turbulence insert by the main flow of suspension and by the vanes which guide the main suspension flow toward the channels and which prevent the additional liquid feed from one sectional flow entering another sectional flow.
摘要:
Headbox for one of a paper and cardboard machine includes at least one material suspension supply running a width of the machine. At least one turbulence producer has at least one conduit through which a material suspension flows. At least one metered addition point is located in the conduit for introducing a fluid medium. A headbox nozzle is located downstream from the at least one turbulence producer for delivering the material suspension. A portion of a flow resistance located downstream of the metered addition point is at least approximately 50% of a total flow resistance of the at least one conduit.
摘要:
Process and a device for detecting a change in the fiber orientation cross-direction profile of a paper or cardboard web in the manufacturing process on a paper or cardboard machine. It is recognized that a change in the fiber orientation cross-direction profile in the web is inferred or determined by way of a characteristic change in the basis weight cross-direction profile or at least one measurement quantity that correlates to it, and/or by way of a characteristic change in the basis weight in the travel direction of the web or at least one measurement quantity that correlates to it. The device includes an arrangement for detecting a change in the basis weight cross-direction profile and/or a characteristic chronological course of the change in the basis weight, which is characteristic for a change in the fiber orientation.
摘要:
An apparatus and a process for controlling or regulating a web property profile of a paper or cardboard web produced in the manufacturing process of a paper or cardboard machine is disclosed. The apparatus incorporates information regarding the position of one or more devices of a plurality of adjustable devices for sectionally manipulating at least one web property for regulating or controlling the devices to manipulate at least one web property across the width of the machine. The process includes combing the regulating process or a regulator device for adjusting individual actuators that only act on a certain section of conventional systems with the adjustment of an actuator acting across the entire web width for achieving a certain web property, so that the sectionally-operating actuators are not located in an end-position, so that these sectional actuators continue to be able to adjust the web property.