摘要:
The invention is directed to a drying section of a paper machine for drying a fiber web. The drying section includes a plurality of drying groups, with each drying group having a plurality of heatable drying cylinders and a continuous hold-down belt. The hold-down belt has a longitudinal tension which biases the fiber web against the drying cylinders. The plurality of drying groups include at least one high-pressure group comprising a single-row drying group having one row of drying cylinders and one row of corresponding deflection rolls. The high-pressure group has a corresponding hold-down belt with a longitudinal tension which is at least 10 kN/m.
摘要:
The press section of a paper machine for thin papers has the following characteristics: a pressing gap is formed by a rotary, smooth surface (1) in contact with the paper and by a felted pressing roll (3); the smooth surface (1) transfers the paper web downstream of the pressing gap to a heatable roll (4) without free pulling of the paper web. The invention is characterized in that the smooth surface (1) is the outer surface of a tubular roll with dimensionally stiff roll sleeve.
摘要:
A paper machine forming section with two twin-wire sections for forming a multilayer paper web. Each twin wire web-forming unit consisting of a headbox, two wire loops arranged to define a common wire path for molding the web being formed in sandwich-like manner and drainage elements for each of the wire loops. The common wire path of each web-forming unit has a first section including a curved suction drainage element or roll in the first lower wire loop; a second section including opposing drainage ledges, wherein the drainage ledges are stationary on the upper side and the drainage ledges are developed resiliently pressable on the bottom side; the drainage ledges of the upper and lower sides are arranged staggered with respect to each other in the direction of travel of the wire, and at least the ledges of the upper side are developed with suction; and a third section which has at least one suction wire separating element on one side. The twin-wire forming units are so arranged that the same drainage elements are associated in each case with what will be the inner and outer sides respectively of the respective layer of the multilayer paper web.
摘要:
Headbox for paper machines, provided with an output channel in the form of a nozzle, with an output slot for producing a strip of pulp having the width of the machine. The output channel is delimited by two flow guide walls converging toward one another and as a rule by a rear wall. It is divided up into a number of channel sections (32), preferably autonomous, by subdivision of the flow guide walls into wall sections (30, 31) and preferably by subdivision of the rear wall into rear wall sections (37). Each channel section may have at least one input line (40) of its own, as well as (for adjusting the opening of the output slot) a section of part of the mobile wall (35) and an associated regulating system (38, 39).
摘要:
A twin-wire former for making a web of paper (9) having two endless loop travelling screens (11, 12) which travel over respective breast rolls (13, 14) and form a wedge-shaped feed gap of a twin-wire region. In the twin wire region the two travelling screens pass first over a curved stationary supporting device (15), then over a forming roll (16) which lies in the same screen loop (11) as the curved supporting device (15), and finally over a screen suction roll (18) which lies in the other screen loop (18). In order to form a large storage volume for water, an additional lattice-like outer shell (27) surrounded by a coarse-mesh textile filter envelope (28) is arranged on the body (16a) of the forming roll. Approximately half the periphery of the screen suction roll (18) is wrapped by the two screens (11, 12). At the end of the said wrapping zone, the one screen (11) runs off from the screen suction roll (18) followed by the other screen (12) together with the web of paper (9).
摘要:
A twin-wire former for the production of a web of paper from a fiber suspension. An upper endless loop of wire belt having a lower horizontal run and a lower endless loop wire belt having an upper horizontal run. Guide rolls support the wire belts to define a twin-wire zone. The upstream inlet wedge of the twin-wire zone is disposed at the outlet from a head box. The initial part of the path of the twin-wire zone has a gradual curvature convexly with respect to the lower wire belt, and in that initial portion are positioned guide tables, suction boxes and dewatering elements. This curved initial part is followed by a forming roll within the loop of the upper wire belt. The twin-wires wrap an arcuate sector of the lower region of the forming roll. A support roll follows the forming roll. The support roll is upraised sufficiently to wrap the twin-wires around the bottom of the forming roll and over an arcuate sector at the top of the support roll. Following the support roll, the upper wire separates from the lower wire. In the continuing generally horizontal, slightly descending path of the lower wire with the web on it are disposed a plurality of suction boxes and a lower wire suction roll to define a final dewatering path after the twin-wire zone.
摘要:
A press section of a paper machine is of the type having two extended press nips (27, 37) disposed one behind the other, which are each formed by a press roll (21, 31) and by a flexible rotating press member (28) which can be pressed against the press rolls by means of a press shoe (27, 37). The paper web which is to be dewatered passes through the first extended press nip between two endless felt belts (11, 13).In accordance with the invention, the paper web runs through the second extended press nip together with only one (11 or 13) of the two felt belts. As a result the paper web (9) comes into contact with the smooth outer surface of the second press roll. Because of this arrangement the flexible press member can have a rough outer surface formed, for example, by the joggles of a reinforcing fabric.
摘要:
An air guide box for the dryer section of a paper making machine is arranged as generally between two succeeding drying cylinders and along a continuous support band or belt which supports the associated paper web to be dried; the air guide box has an end of generally wedge-like configuration which extends at least some distance into the gore-like space as exists in the region where the support band or belt runs onto the next drying cylinder; a first gap exists generally between a first wall of the guide box and the running support band or belt while a second gap exists as between a second wall of the guide box and the juxtaposed surface of such next drying cylinder. In order to guide the paper web along the support band or belt in order to assure proper contact: (a) on the inflow side, an air wipe-off or barrier apparatus is provided as at the guide box; (b) the first gap preferably diverges from the first wall as the first gap more nearly approaches the gore-like space; (c) the guide box is connected to a blast air supply which, preferably, is directed through an opening and into the second gap as to have a flow direction generally opposite to the direction of rotation of such next drying cylinder; and (d) preferably the first and second gaps are interconnected by a passage with such interconnecting passage being situated as to occur before the air blast opening when viewed or considered in the direction of rotation of such next drying cylinder.
摘要:
A manifold-like chamber is shown having a plurality of distribution conduits in communication therewith for evenly and uniformly distributing fluid pulp stock for subsequent paper forming operations; alternate ones of such conduits communicate with the chamber as at a relatively low elevation thereof while intermediate alternate ones of such conduits communicate with the chamber at a relatively higher elevation; the distribution conduits are formed as with two straight sections joined by an intermediate single curved or bent portion to further enhance turbulence therein; the distribution conduits are further situated as have the discharge therefrom generally parallel, at least as viewed from above; edge-forming means is provided within the chamber as to thereby obtain desired flow patterns within the fluid pulp in the chamber.
摘要:
Measurement system and process for measuring a cross-direction profile of specific properties of at least one of a material web and a coating on the material web. The system includes at least one stationary cross-direction profile measurement device having at least one radiation source adapted to irradiate the at least one of the material web and the coating on the material web in a plurality of defined and different wavelength ranges, and at least one sensor adapted to measure the intensity of radiation affected by the at least one of the material web and the coating on the material web. The system also includes at least one measurement and/or evaluation electronics system. Each sensor detects only one of the defined different wavelength ranges of the radiation at a specific point in time. The process includes irradiating the at least one of the material web and the coating on the material web with a plurality of defined and different wavelength ranges via at least one radiation source, and measuring an intensity of radiation affected by the at least one of the material web and the coating on the material web with at least one sensor. Only one of the defined different wavelength ranges of the radiation is measured by each sensor at a specific point in time.