摘要:
A former for a paper machine: The paper machine includes a perforated forming cylinder and a suction device for drawing water inward through the perforations. An inner and an outer belt are wrapped around the forming cylinder. The outer belt meets the inner belt at the peripheral surface of the forming cylinder in a generally wedge-shaped inlet slot located at and upstream of the bottom of the forming cylinder. A pulp fiber suspension nozzle of a width that covers the axial length of the forming cylinder injects pulp into the inlet slot. A supporting device is provided at the inlet slot and includes a convexly curved surface, convexly curved around an axis generally parallel to the cylinder axis. The supporting device includes a concavely curved surface that follows the convexly curved surface downstream of the flow of pulp. A suction device communicates with the concavely curved surface beneath the outer belt. The outer belt rides over the convexly curved surface and down onto the concavely curved surface. The inner belt is a wire mesh. The outer belt is a felt strip.
摘要:
Stock distribution means for delivering an aqueous slurry in a papermaking machine has a tapering passage which delivers stock to a nozzle by way of several rows of channels whose inlets are in communication with the passage. The passage, the entire channels and/or the inlets of the channels are configurated and dimensioned in such a way that the resistance which the inlets nearer to the intake end of the passage offer to the inflow of stock is more pronounced than the resistance of inlets which are more distant from such intake end. This insures uniformity or substantial uniformity of the volume of stock flow in each channel in spite of the fact that the channels of neighboring rows are at least partially inclined with respect to each other and that the inlets of channels in successive rows are located downstream of each other, as considered in the direction of stock flow in the passage.
摘要:
Pressing section of paper machine including first and a second pressing stations, a common lower felt arranged to run through first and the second pressing stations, and an first upper felt and a second upper felt arranged to run through first and second pressing stations. Second pressing station includes shoe press roll located above a lower roll, and pressing plane of second pressing station is oriented essentially vertically or inclined at an angle &bgr;, which is a maximum of about 20° to vertical. The common lower felt is sufficiently dense to be essentially air impermeable even in its new state after moistening, and is sufficiently open to allow water through at pressures greater than about 5 bar. First and second upper felts are sufficiently open to allow air through in their moistened, uncompressed state, and pressing plane of first pressing station is oriented at an angle greater than angle &bgr;.
摘要:
A machine for manufacturing a fibrous pulp web, in particular a tissue or hygienic paper web with a main press, including a contact shoe press unit and a drying cylinder, and a shoe pre-press. The main press is so designed that the pressure profile which is built up in its press opening along the length of the opening exhibits increasing pressure, which starts at the beginning of the opening and extends along at least one third, preferably a minimum of one half the length of the opening. The length of the main press is shorter (1/3 to 2/3) than the length of of the pre-press, the linear force of the pre-press is greater than the linear force of the main press, and the maximum pressure of the main press is greater than the maximum pressure of the pre-press.
摘要:
An apparatus and a method are indicated for a paper-making machine, for delivering liquid from a first level in a first space, through a line into a second space on a second, higher level, under the action of a difference in the gas pressures over the liquid in the first space and in the second space. A throttle valve in the line is controlled, to regulate the fluid flow, in such a way that the throttle valve is at least partly closed when the gas flow through the line rises, and is opened when there is little gas flow through the line. This guarantees continuous delivery of liquid, stable flow conditions prevail, and a delivery that is largely free of pulsation is achieved with a low proportion of gas (FIG. 2).
摘要:
A press roll for treating a material web in a nip formed with an opposing surface is provided. A press shoe extends along the nip and guides a press jacket. Several adjacent force elements disposed along the direction of the roll axis are supported on a stationary carrier. The force elements are preferably each fluid-actuated cylinder/piston units which can bias the press shoe with their movable pistons. The piston of at least one force element and/or an opposing region of the press shoe concentrate support forces in piston edge regions that are disposed opposite one another on different ends of a central piston plane perpendicular to the roll axis.
摘要:
The invention is directed to a dryer section for an apparatus to produce a continuous material layer, such as paper, carton or cardboard. At least one dryer group has a plurality of dryer cylinders and guiding rollers. The dryer cylinders and guiding rollers carry the material layer along a meandering path, with each dryer cylinder and each guiding roller having a first side disposed on a same side of the dryer section. At least one mechanical drive mechanism is provided, with each drive mechanism being coupled with the first side of a dryer cylinder and/or guiding roller. A plurality of supply tubes are each connected with the first side of a corresponding dryer cylinder and/or guiding roller.
摘要:
A method and apparatus for temporarily separating a web from one of the two wire belts in a twin wire zone in a paper making machine. In the twin wire zone, the negative pressure from a suction box is applied to the first wire belt for temporarily deflecting and separating the first wire belt and the web from the second wire belt and the wire belts then returning to contact the web following the suction box. The wire belts are then successively separated from the web by an appropriate guide and take up device. The take up device may comprise a press which includes a press nip defined by one of a suction roll over which the second wire in the web is passing or another type of roll or a flexible support device like a rotating press jacket. A smooth surface, such as that of a roll, forms a press nip with the support device for the second wire belt and after that press nip, the web adheres to the smooth surface to be transported further through the machine.
摘要:
The twin-wire former serves for the production of a web of paper or board. Two wire belts (endless wire loops 11 and 12) form a twin-wire zone with each other. Within the twin-wire zone, the one wire belt (12) travels over rigid ledges (28', 28) which are arranged spaced apart from each other on a water-removal box (18). Within the twin-wire zone, furthermore, the other wire belt (11) travels over several ledges (27) which lie opposite the rigid ledges (28), are supported by means of resilient elements (springs 24, pneumatic pressure cushions, or the like), and can be pressed with a selectable force against the other wire belt. Within one of the wire loops (for instance 11), bridging at least two of the ledges (27) present there, a closed wire support surface (9) is provided. A secondary headbox (10') can be arranged in front of the closed wire support surface (9).
摘要:
A wire or felt forming section of a paper-making machine has breast rollers for guiding a respective one of two forming wires. The two rollers are disposed with a pulp gap formed between the two rollers and the wires are disposed just downstream of a pulp suspension ejecting nozzle of a headbox. Each roller is supported against the respective taut forming wire by a hydrostatic bearing. The hydrostatic bearing has two circumferentially separated resiliency chambers provided in a combined region of resiliency disposed over an arc of the circumference of the roller. A sealing strip after the region of resiliency prevents fluid from contacting the wire.