Abstract:
An apparatus for controlling the consistency of a flow of stock solution in a papermaking machine comprises a generator (10) of ultrasonic waves (12-14) and an ultrasound absorber (24) arranged in such a way that the flow of the stock solution flows for deviating the fiber particles (18-20) suspended within the stock solution are deviated from the flow direction for the control of the cross machine direction stock solution consistency profile.
Abstract:
The invention relates to a method for the production of a fibre web, in particular, a SC-A or SC-B paper web, from a fibre suspension provided by a headbox (10), whereby the fibre web is then introduced into a forming unit (12), in particular, a pressing section (14), a drying section (16), a calander (18), in particular, an on-line calander and a roller (20). A raw material is used which at least partly comprises DIP (deinked paper, recycled paper) and/or similar materials. A corresponding device for production of the fibre web is also disclosed.
Abstract:
The present invention provides a method making stratified paper by redistributing the pulp suspension inside the headbox nozzle using acoustic radiation waves. Acoustic radiation forces fractionate fibers based on fiber radius. The acoustic radiation waves separate the fibers by pushing the coarse and longer fibers to the inner area while fines and smaller fibers remain in the outer area. This has a similar effect of multi-layer stratification headbox, and provides paper with a smoother surface.
Abstract:
The present invention provides a method making stratified paper by redistributing the pulp suspension inside the headbox nozzle using acoustic radiation waves. Acoustic radiation forces fractionate fibers based on fiber radius. The acoustic radiation waves separate the fibers by pushing the coarse and longer fibers to the inner area while fines and smaller fibers remain in the outer area. This has a similar effect of multi-layer stratification headbox, and provides paper with a smoother surface.
Abstract:
In a head box for a paper machine, there is provided a tube bank structure which, by a simple and low-cost means, is capable of improving the flow regulating action on a flow of raw paper material in a tube bank and preventing the turbulence in the flow and concentration irregularity of the raw paper material in the flow area immediately below the outlet end, thereby realizing the speedup of the paper machine: and a flow tube producing method. A tube bank structure for a paper machine head box consisting of a plurality of flow tubes arranged side by side is characterized in that each flow tube comprises a small diameter tube portion which is circular in section on the inlet side, a large diameter tube portion connected to the small diameter tube portion, a rectangular tube portion which is rectangular in section on the outlet side, and a taper tube portion interconnecting the large diameter tube portion and rectangular tube portion and spread toward the downstream side, wherein the taper tube portion has its sectional shape smoothly spread from a circular shape to a rectangular shape so that the upstream end is circular and the downstream end is rectangular.
Abstract:
A headbox for delivering a jet of stock to a forming zone in a former for wet-forming a fiber web, comprising at least one vane (21), arranged in the slice chamber (12) of the headbox, and an arrangement for mounting the vane to the turbulence generator (7) of the headbox, said arrangement comprising an engagement member (26) connected to the vane at its upstream end portion (25), and an elongate structural element (27) with a longitudinal groove (28; 34) for receipt of the upstream end portion and its engagement member for securing the vane in the machine direction. In accordance with the invention the engagement member comprises oblong engagement bodies (40; 51) and the upstream end portion is provided with oblong recesses (41; 50) arranged at predetermined distance from each other, extend parallel with the upstream edge (42) of the vane at a distance therefrom and receive at least one engagement body for detachable mounting the engagement body in the upstream end portion of the vane. The invention also relates to such a mounting arrangement.
Abstract:
There is disclosed a high consistency extrusion forming unit for laying fibrous material on a moving forming fabric such as for example a wire screen, a fabric screen or a felt. The forming unit includes a headbox (12) having an exit slice (24) through which a high consistency liquid suspension of pulp (26) is expelled at a first speed (Vj). The headbox includes an upper lip (50) that extends downstream of and is curved slightly inclined from the slice opening so that the pulp travels along and is supported by this lip. The forming fabric (28) travels below the slice opening and along a path of travel adjacent to the upper lip to support the pulp. The speed of the forming fabric (Vw) is greater than that of the speed of the pulp expelled from the slice opening so that theforming fabric stretches or extrudes the pulp to the desired weight or grammage.
Abstract:
The invention relates to a headbox for a paper machine, comprising a plurality of turbulence channels (1, 2) extending between a pulp suspension feeder and a stock flow nozzle, which are fitted with rotating walls contacting the suspension and guiding a pulp suspension flow containing fibers towards the stock flow nozzle in the direction of the main flow along their longitudinal axis. The invention is characterized in that at least one medium (4, 6) for reducing or eliminating the rotational flow components is located in at least one turbulence channel (1, 2) in the vicinity of the direction of the main flow.
Abstract:
A headbox for discharging a jet consisting of one or more stock layers to a forming zone in a former comprising at least one separator vane (23) separating two stock channels in order to keep the stocks on each side of the separator vane separated from each other and having engagement dowels (43) arranged in a row for detachable mounting on a turbulence channel group (7) via an engagement part (31) with a through-running groove (34) to receive the upstream end portion (42) of the separator vane (23) and its engagement dowels (43) to secure the separator vane (23) in machine direction, said groove (34) having two longitudinally extending recesses (40, 41) with support and guide walls (54, 55) facing the free engagement end portions (50, 51) of the engagement dowels (43). According to the invention the engagement dowels are yieldingly arranged in the separator vane to be displaced laterally in relation to an unaffected starting position when influenced by forces occurring at the support and guide walls, or to be inclined when the separator vane is pushed aside from its normal position to equalize a pressure difference between the two stock channels.