摘要:
A method and a device for stabilizing the web run in a paper machine or the like having a blow suction module (12) mounted above and/or below the web. The blow suction module comprises a blow nozzle unit (14) extending across the web, through which gas, such as air or combustion gas, is blown against the web (10) from the blow nozzle unit, and a first air discharge unit (18) arranged on the front side of the blow nozzle unit, and a second air discharge unit (22) arranged on the back side of the blow nozzle unit, which remove air or gas from between the web and the blow suction module. The blow suction module is asymmetric regarding the first and second air discharge units, so that more air or gas is discharged via the first air discharge unit than via the second air discharge unit.
摘要:
A nozzle arrangement in an airborne web-drying apparatus for drying a coated paper web (10) or the like. The nozzle arrangement comprises at least one overpressure nozzle (14), which is arranged to blow drying air both in the web's travel direction and against the web's travel direction. The nozzle arrangement comprises further a direct impingement nozzle (16) combined with the exit side and/or the entrance side (26) of the overpressure nozzle, in which direct impingement nozzle a plurality of nozzle slots or nozzle orifices (17) are formed in order to blow drying air mainly perpendicularly toward the web. The perpendicular distance (a1) from the nozzle surface (30) of the direct impingement nozzle (16) to the web is larger than the perpendicular distance (a2) from the supporting surface (32) of the overpressure nozzle (14) to the web.
摘要:
The object of the invention is an end part (1) of an air dryer, the air dryer being applicable for drying a pulp web, such as a cellulose web or the like. The end part comprises a fan tower (11), and a roll tower in which a number of turn roll (27, 37) are arranged mainly on top of each other in order to turn the travelling direction of the pulp web in the air dryer, the longitudinal axis of the roll. towers being parallel, and a fan tower arranged at a distance from the roll tower, adjacent to it, comprising a number of fans arranged on top of each other, a single fan being arranged to blow heated air as drying air to a dryer group. The end part further comprises one or more centrifugal fans (14) arranged in the direct vicinity or the roll tower, and a number of end drying means (13) arranged between the roll tower and the dryer group of—the fan of the fan tower, to which end drying means drying air is supplied with said centrifugal fan or fans. A further object of the invention is also a method in the end part of an air dryer, an air dryer and use of a centrifugal fan.
摘要:
At the end of the twin wire zone of a paper machine former, a suction box (17) inside the upper wire loop (11) has a curved lid (17′) opposite a roll (18) within the lower wire loop (10). The lid is curved in a run situation so the tension of the upper wire (11) reduces the normal force between the wire (11) and the lid (17′) caused by the underpressure of the suction box. The underpressure keeps the web mainly off from the roll (18) and the lower wire (10) while being adhered to the underside of the upper wire (11) and conforming to the curved shape of the lids. Members (17a, 18′) are provided for making the web follow the lower wire (10) in a break situation for conducting it to the broke handling system.
摘要:
A pulp drying line which comprises a pulp press for pre-drying the pulp and a defibrator for shredding the pre-dried pulp into a loose pulp. The drying line further comprises a web forming section and a pulp dryer section. The loose pulp coming from the defibrator is spread in the web forming section in a layer on an air-permeable forming base, from which the air-permeable pulp web thus formed is taken through the dryer section supported by an air-permeable support fabric, such as a wire. The pulp is not formed into a pulp web during pre-drying.
摘要:
A method in a paper machine for transferring a paper web from a wet wire in a former section to a pick-up fabric or an equivalent transfer fabric of a press section, including the steps of forming a pick-up point on the wet wire and separating an edge strip from at least one edge of the web prior to the pick-up point by means of at least one cutting device. The method further includes separating the web from the wet wire and passing the web onto the pick-up fabric at the pick-up point. The method also includes applying a pressure difference to the at least one edge strip through the wet wire or the pick-up fabric at or after the pick-up point to cause the at least one edge strip to either follow the wet wire or become separated from the pick-up fabric after the pick-up point and to be placed in a broke system arranged beneath the paper machine.
摘要:
A method in a paper machine for transferring a paper web from a wet wire in a former section to a pick-up fabric or an equivalent transfer fabric of a press section, including the steps of forming a pick-up point on the wet wire and separating an edge strip from at least one edge of the web prior to the pick-up point by means of at least one cutting device. The method further includes separating the web from the wet wire and passing the web onto the pick-up fabric at the pick-up point. The method also includes applying a pressure difference to the at least one edge strip through the wet wire or the pick-up fabric at or after the pick-up point to cause the at least one edge strip to either follow the wet wire or become separated from the pick-up fabric after the pick-up point and to be placed in a broke system arranged beneath the paper machine.