MXPA00001701A - Apparatus and method of generating stock turbulence in a fourdrinier forming section - Google Patents

Abstract

A method and apparatus for generating turbulence in stock to deflocculate the stock in an open surface forming section of a paper making machine comprises a dewatering box (2) providing vacuum assisted drainage and which has a set of dewatering elements that impart turbulence into relatively thick stock layers carried at machine operating speeds of equal up to about 400 m/min, for the production of paper products having a basis weight generally in excess of about 160 gsm. Each set of elements includes a lead-in element (5), at least one intermediate element (6, 7), and a trailing element (8). The path of the forming fabric (13) is deflected downwardly as it passes over the intermediate elements, which are inclined at an angle of from about 0°to about 10°from a plane defined by forming fabric supporting surfaces on the lead-in and riser elements. This vertical movement initiates turbulence and agitation in the stock, which acts both to deflocculate the stock and to diminish the possibility of sheet sealing. The apparatus is useable in combination with other known formation and drainage devices which are located either upstream or downstream to augment their performance with thicker, slower moving stock layers.

Description

APPARATUS AND METHOD FOR GENERATING A TURBULENCE IN THE WOODEN PASTE TO MANUFACTURE PAPER IN A SECTION OF CONFORMATION FOURDRINIER FIELD OF THE INVENTION This invention relates to an apparatus and method for generating turbulence in wood pulp to make paper in the forming section of an open surface papermaking machine. More specifically, this invention relates to an apparatus and method for generating sufficient turbulence in the pulp layer contained in an open surface shaping section of a papermaking machine, as an aid in the formation of a colloidal solution of a relatively thick layer of pulp transported on a shaping cloth that moves relatively slowly. This invention thus finds application in the manufacture of relatively heavy paper, as well as pulp and cardboard products. In addition, it is possible to adjust the apparatus to be able to control and optimize the amount of turbulence imparted on the pulp layer, to adapt to the quality of the product to be manufactured.

BACKGROUND OF THE INVENTION In a conventional open surface shaping section, a wood pulp for making paper in water, containing both papermaking fibers and other solids used in papermaking, in amounts of about 0.1% to about 1.5 % by weight, is fed from the opening of gates on a shaping cloth with horizontal movement. In this forming section, once the paste is received from the opening of the gates, the moving shaping cloth is supported by a shaping table, followed by a series of drainage boxes. Drain boxes generally include drainage devices such as blades and metal strips mounted on the drainage box in contact with the side of the forming cloth that is next to the machine. In some modern slow-speed machines, rollers or laminators are also used as devices to eliminate water and generate turbulence. The shaping section may also include other devices that have the purpose of generating at least some turbulence within the pulp, such as shaping showers. As the paper pulp on the open surface shaping cloth is moved through the shaping section, the water is removed from the pulp until an incipient paper web containing approximately 75% is formed. and 85% water. The remaining water is removed in subsequent parts of the papermaking machine. The thickness of the pulp layer deposited from the opening of the gates on the shaping cloth is determined by the speed of the machine, the water content of the pulp fed from the gates and the base weight of the product. of paper or cardboard that is being manufactured. Products of a heavier kind, such as coated paperboard, pleated media, commercial grade pulps and paperboard, require a higher initial pulp thickness than lighter-class products, such as paper. for newspapers. In order to obtain an acceptable paper product, it is important that the solid products necessary for the manufacture of the paper, including the fibers, are mixed and dispersed conscientiously and in the most random way possible within the pulp fed by the opening of the gates . In practice, this is almost impossible to achieve: a portion of the fibers for papermaking tend to flocculate in the pulp and these lumps are deposited on the shaping cloth. Flocculation will continue to be generated in the pulp on the shaping cloth unless the necessary steps are taken to create turbulence within the pulp. Once an incipient paper network has been formed, it is practically impossible to disperse any remaining lumps. In this way, what happens in the pulp deposited on the shaping cloth to convert it from a diluted or diluted solution of fibers and other solids to a woven network of incipient paper, is of vital importance to the paper manufacturer. Various methods have been proposed to homogenize the fiber distribution in the pulp fed to the forming section. Most of these methods include the creation of a certain level of turbulence within the paste to disperse the lumps. For example, a rapid, transverse, vibratory movement can be imparted on the forming sheet adjacent to the gates to apply a cutting force that destroys the lumps so that the papermaking fibers are evenly distributed again. Shaping showers, rollers and various air and water jets, located either above or below the forming cloth, are also used to create turbulence in the pulp layer. The amount of energy necessary to impart the desired level of turbulence in the pulp is directly proportional to the thickness of the pulp layer, to the speed of the machine and to the type of materials present in the pulp. A common method for creating turbulence within the pulp on an open-surface moving shaping cloth is to place drainage elements (such as metal tapes, stirring blades and the like) on which the face side is supported and contacted. to the conformation cloth machine in motion. Devices of this nature have been described by Wrist, in E.U.A. 2,928,456; Sepall, E.U.A. 3,573,159; Johnson, E.U.A. 3,874,998; Saad, E.U.A. 4,420,370; Kallmes, E.U.A. 4,687,549 and E.U.A. 4,838,996; and Fuchs, E.U.A. 4,789,433. The metal ribbons have a leading edge that passes over the forming cloth and removes the liquid; the hanging portion is tilted down at an angle of between 1 ° and 8 °, and serves to provide a suction effect that separates the liquid from the paste and causes the cloth to deviate sufficiently to induce at least some turbulence within of the pulp. The agitator blades are positioned vertically so that part of the water is removed and subsequently changes its direction and moves backwards through the forming cloth and penetrating the liquid layer of pulp. To achieve this, a carefully shaped steering channel is placed on the surface of the blade along the machine; in this way, the water changes direction moving backwards along the shaping cloth and creating a turbulence in the pulp that is on the cloth, and this has a deflocculating effect and serves to distribute the solids homogeneously in the pasta. Another means of inducing agitation is described by Johnson, E.U.A. 4,140,573. In this device, at least one of the drainage elements on a low vacuum drainage box is placed slightly below the elements that are on either side so that, as the cloth passes over the formation of elements , this is slightly pulled down by the vacuum of the drain box and then released, thus causing some turbulence inside the pulp. An alternative means to induce turbulence in pulp is described by Cabrera and López Caram, E.U.A. 5,830,322. In this device, a pair of elements supporting the cloth is used, a primary element with an inclined surface together with a hanging element with a horizontal surface. The drainage of water from the paste is controlled by restricting the size of a directional drain opening along the machine between the two elements. The inclined surface of the primary element is configured to impart turbulence in the pulp over the drain opening, without deflecting the shaping cloth towards the drain opening, using vertical blades substantially similar to those described by Fuchs, E.U.A. 4,789,433 and Kallmes, E.U.A. 4,838,996. The apparatus depends on the inward flow of fluid from the drainage opening, as well as the shape of the inclined surface of the primary element into the drainage opening, to cause turbulence inside the pulp once the fluid has been returned through the forming cloth and any incipient paper edge formed thereon, towards the pulp. Other devices for stirring the pulp describe them Cowan, E.U.A 3,922,190; Marx, Jr., E.U.A. 4,999,086; Hansen et al., E.U.A. 5,011, 577; Hansen, E.U.A. 5,089,090 and Neun, E.U.A. 5,681, 430.

However, in situations where the paper product being manufactured requires the shaping cloth to move at a relatively slow speed and transport a relatively thick layer of pulp, for example in the production of products with a basis weight heavy, it is more difficult to generate the desired levels of turbulence within the paste. As the speed of the machine decreases and the thickness of the paste increases, in the manufacture of high base weight products, it becomes more and more difficult to create an effective amount of turbulence within the pulp and thus improve the conformation. For this reason, it is estimated that for open-surface forming sections in which the shaping cloth moves at speeds lower than 400 m / min, it transports pulp layers whose initial thickness is greater than about 2.0 cm in the opening of the composite, and which produces a heavier-class paper product with base weights exceeding 160 gsm, there remains a need for a device capable of generating an effective level of turbulence within the pulp, sufficient to cause at least certain deflocculation inside the pasta. It would also be a considerable advantage if that device could be adjusted at will, so that the level of turbulence can be determined according to the needs of the paper manufacturer. An additional problem occurs with pulp compositions using materials with a high content of relatively short fibers or recycled materials. In these pastes, an almost impenetrable mat can be formed on the side facing the paper of the surface of the shaping cloth, able to completely seal the cloth and prevent the paste from draining properly; This phenomenon is generally known as "leaf sealing". There is therefore a need for a water removal device capable of correcting the drainage problems that arise due to this phenomenon.

BRIEF DESCRIPTION OF THE INVENTION The object of this invention is to provide an apparatus and method for generating turbulence in the pulp sufficient to cause at least some deflocculation, and to improve the shaping in the forming section of an open-surface papermaking machine, in which the layer of paste is relatively thick, and in which the shaping cloth moves at a relatively low speed. This invention thus seeks to improve the shaping in open surface papermaking machines that are used to make products with a heavy basis weight such as paperboard and the like. This invention also aims to mitigate, if not eliminate, the sheet seal, by generating enough turbulence within the paste to redistribute the fiber mat forming a more or less impenetrable layer on the side facing the paper of the cloth of conformation. This invention consequently implies a particular applicability in the use of compositions of pastes containing a significant amount of relatively short fibers or recycled materials. Furthermore, in a particular embodiment, this invention has as an object to provide an adjustable apparatus for generating a controllable level of turbulence in the papermaking pulp, sufficient to cause at least some deflocculation inside the pulp and improve the conformation in the forming section of an open-surface papermaking machine in which the pulp layer is relatively thick, and in which the shaping cloth is moved at a relatively slow speed. In the context of this invention, a "relatively slow speed" refers to an open surface shaping cloth that travels along the shaping section at a linear speed of less than about 400 m / min; a "product with relatively heavier base weight", and a "relatively thick pulp layer", refer respectively to an open surface shaping cloth of a machine that is used to manufacture a product with a finished basis weight about 160 gsm, which commonly requires a layer of pulp more than 2.0 cm thick adjacent to the opening of the gates. It should also be noted that although this invention is concerned with the manufacture of products with a relatively high basis weight, it is not so limited and under certain circumstances it is advantageous with lighter products and with higher machine speeds. In accordance with a first aspect of this invention, an apparatus for generating turbulence in the dough is provided on a shaping cloth in an open surface shaping section of a papermaking machine, and the shaping section includes a cloth of conformation that moves at a relatively slow speed with one side facing the paper and another side facing the machine, a relatively thick layer of pulp on the side facing the paper of the shaping cloth, a drain box located underneath the shaping cloth, connected to a controlled and operable vacuum to create a reduced pressure inside the drainage box, and various support elements for drainage in the shaping cloth carried by the drainage box and which essentially comprise of : (i) .- A drain outlet element with a surface that holds the cloth and that includes, in order of succession: a bor of electroplating attack); an intermediate surface substantially horizontal; and a hanging inclined surface; (ii) An ascending element of drainage with a surface that holds the cloth and that includes, in order of succession: a galvanoplastic attack edge; a sloping surface; an exit surface; and a portion comprising the splicing of the inclined and outlet surfaces; and (iii) .- At least one intermediate drainage element located between the drainage outlet element and the ascending element and separated from each additional drainage element by an opening, and the or each intermediate element has a surface that holds the cloth and comprising, in order of succession: a galvanoplastic leading edge; a sloping surface; and a hanging edge; wherein: (a) the part of the ascending element located at the junction of the inclined and outlet surfaces is chosen from a vertex at the junction of the inclined surface and the exit surface, a short and substantially horizontal surface joining the inclined surface with the exit surface, and a curved surface that joins the inclined surface with the exit surface; (b) the intermediate surface of the drainage outlet element, and the portion of the ascending element comprising the junction of the inclined and outlet surfaces defines a first plane; (c) the inclined sloping surface of the drainage outlet member and the inclined surface of the or each intermediate drainage element defines a second inclined plane at a predetermined hanging angle inclined downward with respect to the first plane; and (d) the galvanoplastic leading edge of the rising element is located above the hanging edge of the adjacent intermediate drainage element, so that the movement of the forming cloth from the hanging edge of the adjacent intermediate drainage element to the leading edge The electroplating of the ascending element results in a vertical movement of the shaping cloth, as well as the incipient web of paper and the pulp transported on the cloth. Preferably, the intermediate drainage element (at least one) located between the drainage outlet element and the ascending element and separated from each additional drainage element by an opening, is fastened in an adjustable manner to the drainage box, allowing placing the or each inclined surface thereof in the second desired plane, and allowing the movement to a different desired second plane. In this embodiment, as indicated below in greater detail, the included angle between the first and second planes, instead of being determined by the angle toward which the inclined surface of the intermediate element is cut, is determined by the placement of the Adjustable gasket to the drain box. In this embodiment, because the pick-up element is not mounted in an adjustable manner, it is preferred that its inclined hanging surface be arched.

In a preferred alternative embodiment, the apparatus further includes a drainage restriction element, interposed between the rising element and the adjacent intermediate element, with a surface that holds the cloth and which comprises, in order of succession: a galvanoplastic leading edge; and a surface inclined upwards; where the joint of the drainage restriction element to the drainage box is positioned and arranged so that it locates the surface inclined upwards at an angle with respect to the second plane so that they form between them a shallow "V" shaped angle that matches the inclined surface of the rising element. In this embodiment, the seal of the drainage restriction element to the drainage box can be chosen from a group consisting of a fixed joint, an adjustable joint and a second adjustable joint incorporated in the first adjustable joint for the intermediate elements. Preferably, all the support elements of the intermediate cloth are of the same width in the machine direction. Alternatively, all the support elements of the intermediate cloth are not of the same width in the machine direction. Preferably, the or each support element of the intermediate cloth has a substantially flat inclined surface. Alternatively, at least one intermediate element has a vertical stirring blade.

In an alternative aspect, this invention aims to provide a method for creating a desired level of turbulence in the pulp layer on a shaping cloth in an open surface shaping section of a papermaking machine, and consists essentially of in moving the shaping cloth that transports the paste on at least one drainage box that has a variety of elements that hold the cloth underneath and have a support contact with it, and apply a controlled vacuum to create a pressure Reduced control in the drainage box, and the drainage elements that hold the cloth essentially consist of: (i) a drainage outlet element with a supporting surface for the cloth comprising, in order of succession: a galvanoplastic leading edge; an intermediate surface substantially horizontal; and a hanging inclined surface; (ii) an ascending drainage element with a supporting surface of the cloth comprising, in order of succession: a galvanoplastic leading edge; a sloping surface; an exit surface; and a portion comprising the splicing of the inclined and outlet surfaces; and (iii) at least one intermediate drainage element located between the drainage outlet element and the ascending element and separated from the rest of the drainage elements by an opening, the or each intermediate element having a supporting surface of the drape that comprises, in order of succession: a galvanoplastic leading edge; a sloping surface; and a hanging edge; wherein: a) the portion of the ascending element located at the junction of the inclined and outlet surfaces is chosen from a vertex at the junction of the inclined surface and the exit surface, with a substantially horizontal short surface joining the surface inclined and the exit surface, and a curved surface that joins the inclined surface and the exit surface; b) the intermediate surface of the drain outlet element, and the portion of the rising element comprising the junction of the inclined and outlet surfaces defines a first plane; c) the inclined sloping surface of the drainage outlet element and the inclined surface of the or each intermediate drainage element defines a second inclined plane at a predetermined downward hanging angle with respect to the first plane; and d) the galvanoplastic leading edge of the rising element is located on the hanging edge of the adjacent intermediate drainage element, so that the movement of the forming cloth from the hanging edge of the adjacent intermediate drainage element towards the electroplating edge of the element Ascending results in a vertical movement of the shaping cloth and the incipient paper web and pulp conveyed thereon. Preferably, the desired level of turbulence is created and controlled by at least one adjustable intermediate drainage element located between the drainage outlet member and the ascending element which is adjustably attached to the drainage box allowing the placement of the of each inclined surface thereof in the second plane; and the level of turbulence is controlled by adjusting the adjustable intermediate support element to a desired second-plane position. More preferably, the desired level of turbulence is created by an apparatus that also includes a drainage restriction element, which is placed between the ascending element and the adjacent intermediate element, with a supporting surface of the cloth comprising in order of succession. : a galvanoplastic leading edge; a surface inclined upwards; wherein the joint of the drainage restriction element to the drainage box has been placed and arranged so that the surface inclined upwards is at an angle with respect to the second plane in the form of a shallow "V" between them in conformity with the inclined surface of the rising element. In the most preferred embodiment, the desired level of turbulence is created and controlled by: (i) at least one adjustable intermediate drainage element located between the drainage outlet element and the ascending element which is adjustably attached to the box of drainage, allowing the placement of or each inclined surface thereof in the second plane; and (ii) a drainage restriction element, positioned between the rising element and the adjacent intermediate element, with a supporting surface of the cloth comprising, in order of succession: a galvanoplastic leading edge; and an adjustable upward inclined surface; wherein the level of turbulence is controlled by: a) adjusting the adjustable intermediate support element by placing it in the desired second plane; or b) adjust the drainage restriction element, changing it from location; or c) adjusting both the adjustable intermediate support element, placing it in a desired second plane, and the drainage restriction element, placing it in a different place. Preferably, the angle between the first and second planes is between more than 0 ° to about 10 °.

One advantage that has been discovered with the apparatus of this invention is that with relatively thick pulp layers, once the desired level of turbulence has been reached, it is easier to retain the desired level of turbulence along the section of conformation. Consequently, although known devices can not always generate an acceptable level of turbulence, they are sufficient to maintain that level of turbulence once it has been generated. Thus, this invention can be used to optimize the performance of these prior technical devices. As a consequence of this, the shape of the exit surface on the rising blade will be determined by the element that is placed after the drainage device of this invention in the forming section. For example, if immediately afterwards there is a second group of similar elements, so that the ascending element is both the last element of a group and the first element of the next group, the output surface of the ascending knife will have the same shape as the of the corresponding part of a pick-up element, so as to have a substantially horizontal intermediate surface and a hanging inclined surface in the same second plane as the following elements. Alternatively, if it is followed by a non-drained opening or by a drainage box equipped with metal belts, the output surface of the ascending knife will generally have the shape of a metal belt knife with an angle between 0.5 ° and 5 ° , as usual.

BRIEF DESCRIPTION OF THE DRAWINGS This invention will now be described with reference to the appended figures, in which: Figure 1 schematically shows a cross-section in the machine direction of a turbulence generating unit in the pulp according to a first embodiment of this invention; Figures 2, 3 and 4 show cross sections of the cloth support elements used in Figure 1; Figures 5 and 6 show arrangements of the elements other than those illustrated in the figure, Figure 7 schematically shows a cross section in the machine direction of a turbulence generating unit in the pulp that incorporates two groups of elements of cloth support; Figure 8 illustrates in schematic form an intermediate element including a vertical stirring blade; Figures 9 and 10 illustrate schematically a partial section of a turbulence generating unit in the pulp according to a second embodiment of this invention; Figures 11 and 12 illustrate details of the pivot and adjustment device used in Figures 10 and 11; Figure 13 schematically illustrates a cross-section of the unit of Figures 9 to 12; Fig. 14 schematically illustrates a cross-section in the machine direction of a turbulence generating unit in the pulp according to a third embodiment of this invention; Figure 15 illustrates a cross section of the drainage restriction element shown in Figure 14; and Figure 16 illustrates alternative arrangements of the intermediate elements applicable to Figures 1, 7 and 14, including vertical agitator blades for the intermediate elements.

DETAILED DESCRIPTION OF THE INVENTION In the context of this invention, the relevant terms have the meanings defined below: "machine direction" means a direction along the machine substantially parallel to the direction in which the forming cloth is moved; "cross machine direction" means a direction substantially perpendicular to the machine direction, generally parallel to the plane of the forming cloth; "upstream" means a position closer to the gates from a given point in the machine direction; "downstream" means a position beyond the gates in the machine direction; "attack" means an edge of an upstream element; "pendant" means a surface or edge of an element downstream; "side facing the paper" means the face of the shaping cloth on which the pulp is deposited, and where the paper web is formed; and "side facing the machine" means the side of the forming cloth in contact with the supporting elements of the cloth, and therefore it is the face opposite the side facing the paper. In all the schematic cross sections of the drainage box shown in the figures, the cloth supporting elements extend in the direction transverse to the machine over the entire width of the forming cloth. In addition, all the angles illustrated have been increased for clarity. In Figure 1 a first embodiment of this invention is illustrated. Both in this figure and in later figures, most of the conventional parts of a shaping section are not illustrated, such as the gates, the opening of the gates, the anterior cylinder, a shaping table (if any), a shower or Shaping showers and any other drainage or shaping device. The turbulence generating device in the pulp 1 includes a drain box 2, which comes with a hydraulically sealed drain 3 to the bottom, through which the water 3A is drained from the exhaust valves of the pulp. The drain box 2 is connected via line 4 to a suction source which provides a controlled reduced pressure with an amplitude ranging from the ambient pressure to 7.5 kPa below the ambient pressure. The desired level of turbulence is generated in the pulp by a group of cloth supporting elements 5, 6, 7 and 8, which are mounted on the upper rail of the drain box 2 by a conventional T-bar, as illustrated in 9A, 9B and 9C. In combination, the space between the T-bars and the widths of the elements determines the drainage openings 10, 11 and 12. These openings are sealed at their side edges with beard edges (not shown). In the illustrated embodiment, the openings 10 and 11 are of the same width and the opening 12 is wider. Subsequently, the factors that determine the choice of the amplitude of these openings will be discussed. The elements 5, 6, 7 and 8 can be made of high density polyethylene, with inserted wear surfaces of ceramic material or of any other material relevant for forming abutment surfaces. Within the group of cloth elements illustrated, the element 5 is the picking blade, the element 8 is the ascending knife and the elements 6 and 7 are the intermediate knives. The shaping cloth 13 moves in the direction of the arrow A with its side facing the machine in contact with the support elements 5 to 8. On the opening 12, the shaping cloth 13 rises from the last intermediate element 7 towards the ascending element 8. This vertical movement of the shaping cloth, as well as the network of incipient paper and pulp that it transports, induces a turbulence within the pulp adjacent to, and downstream of, the exit surface of the element. ascending 8. The cross section of the intake member 5 is illustrated in Figure 2. This includes a galvanoplastic leading edge 14, a flat intermediate surface 15 and a sloping pendant surface 16. In this embodiment, the hanging surface is substantially planar and it is at an angle of inclination a, relative to the surface 15. The element is mounted to a bar T 9A so that the surface 15 is in substantially position horizontal The galvanoplastic leading edge 14 removes at least part of the water that has been drained through the forming cloth upstream of the intake member. The cross section of the ascending element 8 is illustrated in Figure 3. It includes a galvanoplastic leading edge 17, an inclined surface 18, an outlet surface 19 and a portion 20 comprising the junction between the inclined and outlet surfaces. As illustrated, portion 20 is the vertex at the junction of the two surfaces 18 and 19 on both sides; The alternative forms are a short horizontal surface and a curved surface. The fundamental requirement for the portion 20 of the rising element is that it provides a continuous support to the shaping cloth that is displaced and bent over it, and that together with the substantially horizontal surface 15 of the pickup element defines the first plane, under the which the cloth is deflected during its passage over the intermediate elements. The exact shape of the portion 20 is determined based on the materials used for its construction and the desired lengths of the inclined surface 18 and of the outlet surface 19. The inclined surface 18 is at an angle β, which is measured between the inclined surface and the first plane defined by the surface 15 in the intake member, and the portion 20 of the ascending member. The shape of the exit surface 19 is described below. In Figure 1, two intermediate elements 6 and 7 appear, which are generally the same. Its cross sections are generally the same, and in Figure 4 the cross section of the intermediate element 6 is illustrated. This includes a galvanoplastic leading edge 21, an inclined surface 22 and a hanging edge 23. The group of three elements that includes the element and the two intermediate elements supported by the bars T 9C are separated so that the surface 16 and the two surfaces 22 occupy the same second plane at an angle a with respect to the first plane. In the apparatus of this embodiment of this invention, as illustrated in Figure 1, as the cloth 13 moves over the drainage box 2, the side facing the machine of the cloth 13 first occupies the edge of the drawer. Attack 14 of the pick-up element 5 that removes liquid from the side facing the cloth machine 13. The shaping cloth 13 continues to move downstream and passes, in order of succession, on the inclined surface 16, the opening 10, the surface inclined 22 and hanging edge 23 of intermediate element 6, opening 11, inclined surface 22 and hanging edge 23 of intermediate element 7, opening 12 and finally leading edge 17 and surfaces 18, 20 and 19 (in that order) of the rising element 8. The cloth is pulled down on the surface 16 and the two surfaces 22 in order of succession by the low vacuum controlled in the drain box to form a seal of the fluid on these surfaces. Finally, the shaping cloth rises above the opening 12 and the surfaces of the rising element 8. This upward movement generates turbulence in the pulp surrounding the rising element 8. In this embodiment, the value assigned for the angle α is determined by the characteristics of the machine, which include the total separation of the intake and rising elements, the number of existing intermediate elements, the speed of the machine, the thickness of the pulp layer and the level of turbulence desired in the product that It is being manufactured. Accordingly, the value determines the vertical distance that the forming cloth must pass through from the point where it loses contact with the last intermediate element, which is on or near the hanging edge 23 of this element, up to the leading edge Galvanoplastic 17 of the rising element. In general, it is between 0.25 ° and 10 °. For almost all objects, it has been determined that a is less than 6 ° and is often between about 2 ° and about 4 °. The widths of the openings between each of the elements that make up a group, in combination with the vacuum applied and the properties of the pulp and the materials used in it also affect both the amount of drainage that occurs and the amount of turbulence generated. The level of vacuum applied in combination with the widths of the openings should be sufficient to ensure that the forming cloth is in hydraulic contact with the supporting surfaces of the cloth of all the elements. The actual value of the vacuum applied also influences the level of turbulence, since it affects the transition of the shaping cloth from the last intermediate element to the rising element. At this point, the shaping cloth has a shallow "V" shape, which becomes sharper or flatter depending at least in part on the vacuum applied. The actual values assigned to a and for the other variables identified will be determined by the amount of turbulence desired in the pulp at that point in the shaping section; it may be necessary to perform certain tests to determine the optimal values for a given set of papermaking conditions. The shape of the outlet surface 19 of the rising element depends to a large extent on the subsequent element downstream in the forming section, for which there are several options. The rising element can be succeeded, for example, by another turbulence generating unit in the identical pulp, by an uncontrolled drainage opening, by a group of metal belts or by a drainage unit Isoflo (registered trademark). When the next drainage unit is another unit identical to a greater or lesser extent adjacent to, or even mounted in, the same drainage box as the preceding unit, the ascending element is shared by both units. The output surface of the rising element then acts as if it were an intake element, so that it equals the designated value of a for the next unit, which may not be equal to the preceding unit. When the rising element is followed by an opening, or a unit of metal tapes, it seems to be sufficient to use an exit surface either substantially horizontal or sloping down to more or less the same angle as that used for a conventional metal belt blade , that is, up to around 5 °, without intervening a short horizontal surface. The inclined surface of a rising element, such as 18 in FIG. 3, generally has a fairly steep upward angle, since it defines the upward trajectory of the shaping cloth as illustrated in FIG. 1. The angle ß illustrated in figure 3 it is usually located between 0 ° and 30 °. In practice, an angle between about 10 ° and about 20 ° is normally sufficient. The value of the angle β is determined by the vertical displacement of the shaping cloth as it rises from the inclined surface 22 of the last intermediate element to the surface 20 of the rising element. The value of ß should be determined in such a way as to minimize the deflection of the cloth with a low vacuum level. If the deviation of the cloth is or becomes greater when operating the machine, it has been seen that the forming cloth remains on and follows the shape of this surface. However, it may be necessary to perform certain tests to determine the optimal value of ß for a given set of machine conditions. It has also been found that once the desired level of turbulence in the pulp is achieved by the apparatus of this invention, it is easier to induce turbulence in the pulp which is downstream in the shaping section, which in turn facilitates the use of subsequent turbulence generating devices. This also improves the operation of the subsequent conventional deflocculation and drainage devices and aids in a better conformation of the manufactured product. In the same way, it has been observed that the apparatus of this invention increases the lower level of turbulence created in the pulp by an upstream device, such as a shaping shower. Although the above-described embodiment is applicable when the speed of the cloth is 400 m / min or less and the paste is relatively thick, for example, 2.0 cm or more, adjacent to the opening of the gates, for the manufacture of paper products whose base weight is 160 gsm or greater, it is expected that this invention will also provide advantages in other circumstances, such as a higher speed of the cloth and / or thinner pulp layers. Unexpectedly, it has been discovered that, once the cloth 13 is traveling at the speed of the machine on the drainage box 1 under an applied vacuum, it will commonly remain in the path defined by the support elements 5, 6, 7. and 8 even when the vacuum is reduced. This allows a reduction in the amount of drainage on the drainage box 2. This has the additional benefit of reducing any tendency of sheet sealing. In the embodiment illustrated in figure 1, the unit shown has two intermediate drainage elements 6 and 7. Depending on the characteristics of the machine and the manufactured product, it is possible to use other configurations. Figure 5 illustrates an intermediate drainage element 6 between a take-up element 5 and a rising element 8 and figure 6 illustrates a configuration in which 5 intermediate elements 24, 25, 26, 27 and 28 are used, all arranged in the second flat and with a common angle a with respect to the first plane. Figure 6 also shows that it is not necessary that the intermediate elements all have the same width. It is also possible to use this invention with two drainage units side by side, with the ascending element of the first unit also serving as a pick-up element for the second unit. This arrangement is illustrated in Figure 7. The first group of elements includes a take-up element 5, and two intermediate elements 29 and 30. The second group of elements again includes two intermediate elements 32 and 33, and an ascending element 8. The central element 31 functions as an ascending element for the first group and an element for the second group. Its inclined surface 18 is arranged so that it can adapt to the rising element, and its sloping surface hanging downstream is arranged so that it can be adapted to a pick-up element. This arrangement can also be made in two different ways: (i) it is possible to use a single drainage box 2, with a single vacuum 4, as indicated in essence in Figure 1; or (ii) a drainage box with two hydraulically independent compartments 2A and 2B, separated by a wall 34, each with its own vacuum cleaner 4A and 4B, as illustrated in figure 7. In this last provision, it is not necessary that the vacuum applied to the two compartments is of the same intensity. It is also possible that the angles a-i and a2, which are measured relative to the first plane as illustrated in figure 7, are not the same, depending on the level of turbulence desired in each unit. In the illustrated embodiments, the intermediate elements have a resting surface of the essentially planar shaping cloth. Under certain circumstances, depending on the characteristics of the machine as well as the pulp and the product to be manufactured, it has been found convenient to cause more turbulence in the pulp than that caused by the use of conformal cloth support surfaces. flat on the intermediate elements of the second plane. As illustrated in Figure 8, an intermediate element with a vertical stirring blade with a single channel 35 can be used to induce additional turbulence. Agitator blades having this vertical surface are described, for example, by Johnson in the U.S.A. do not. 3,874,998; other vertical blades are known and used. Apparently, a vertical stirring blade can increase the turbulence effects created by the turbulence generating unit of this invention. In the same way, it is possible to contemplate in this invention that the drainage device shares the same drainage box with a different drainage device, such as the Isoflo (registered trademark), the stirring blades or a group of metal strip blades.

Experimental test In an experimental test, a turbulence generating unit in the pulp according to this invention was placed downstream of a shaping shower in an open surface shaping section of a papermaking machine. The unit used was the one illustrated in figure 7, but without the dividing internal wall 34, and with a vacuum only. Two suction boxes were placed with covers substantially the same as those described by Johnson in the U.S. patent. No. 4,140,573 immediately downstream next to the unit. The machine speed of the forming section was about 320 m / min, and the cardboard product had a basis weight of about 299 gsm. The intake element was 38.1 mm wide, with an inclined surface of 8.5 mm. The two intermediate elements were identical in each pair, and had an inclined surface of 150.9 mm wide. The drainage opening between each element was 9.5 mm, except for the downstream opening of each of the intermediate elements, which was 12.7 mm. In both groups of elements, the value of a was 2 °. The drainage element, which functioned as an intake element and ascending element shared to the middle of the group, had an inclined surface of 9.5 mm in width, and the value of the angle ß was 5 °. The output surface downstream of this shared element was substantially flat, and sloped down to 2 °, thus equaling the value of a. The exit surface of the second ascending blade was horizontal. All the widths of the elements and the separation openings between the elements were measured in the direction of the machine. During the test, the vacuum level applied by the suction box varied from the ambient pressure to around 5 kPa below the ambient pressure. It was found that when the shaping shower located upstream was turned off, the visual appearance of the pulp passing over the turbulence generating unit did not indicate any increase in the activity inside it. However, it was observed that the drainage of the incipient leaf and the quality of the resulting paper product, as demonstrated by its conformation and softness, improved in comparison with its quality before the unit was installed. This indicated that the unit effectively generated turbulence within the pulp and avoided sheet sealing, despite the fact that the shaping shower had been turned off.

When the shaping shower was activated, the visual appearance of the pulp as it passed over the turbulence generating unit of the pulp changed dramatically, indicating an increased level of activity therein. This demonstrates that the turbulence generating unit in the pulp of this invention is effective both to impart turbulence in the pulp and to improve the shaping and to avoid sheet sealing, and to improve the performance of other devices generating turbulence and drainage. In the above-described embodiment, the location of the intermediate elements is determined by fixed structures, and the cross-sectional profile of the intermediate elements determines the value of a. Since the value of never is very large, this structure requires a precision machining and installation of the intermediate elements to be able to count on a group of surfaces located with accuracy in the second plane. In a second embodiment of this invention, instead of mounting each intermediate element directly on the structure of the drainage box, each intermediate element is adjustably mounted to the structure of the drainage box. In this way, it is feasible to control the value of a by moving the entire intermediate element to obtain an inclined angle pertinent to the inclined surface, by adjusting the adjustable assembly instead of constructing the element so that it has the required fixed inclined angle. In this configurationWhen more than one intermediate element is used, it is preferable that all the intermediate elements are assembled in a single assembly adjustable to the desired separation in the machine direction with their surfaces of the shaping cloth support in a shared plane. The desired value of a is then obtained by adjusting the assembly, or assemblies, as required. In addition to greatly simplifying the construction of the turbulence generating unit, since all the intermediate elements can be manufactured with essentially the same dimensions, this configuration has the additional advantage that the value of a can be changed at will to alter the level of turbulence generated. This may be necessary for several reasons, such as a change in the product, a change in materials for the same product, and a defective mix in the gates that can cause problems on the forming cloth. Thus, in addition to providing a means to generate turbulence within the pulp on the shaping cloth, this embodiment of this invention provides a means through which it is possible to control the level of turbulence created, and either increase or decrease it. as required by the specific conditions of paper manufacture. This embodiment of this invention is illustrated in Figures 9 to 13. In Figures 9 to 12, the forming cloth is omitted for clarity. Referring first to FIGS. 9 and 10, which illustrate three-quarter views with partial cuts of the unit, the unit includes a single drain box 2 that supports a pick-up element 5, three intermediate elements 35, 36 and 37 of which the middle 36 is narrower than the other two, and an ascending element 8. The intake element 5 and the rising element 8 are supported by bar structures T 9A and 9B, both directly supported by the frame 38 in the upper part of the drain box 2. The three intermediate elements are supported by similar T-bar structures 9C, each of which is mounted on an adjustable support frame 40. At its upstream end, adjacent to the takes 5, the adjustable frame 40 is supported by a pivot mount 41. At its downstream end, the adjustable frame 40 has a vertical adjustment assembly 42, which in turn is controlled by the adjuster bar. 43 that moves in the directions illustrated by the arrow B using the handle 44. The adjustment bar 43 is supported by suitable support surfaces (not shown) on the beam 45 that carries the support frame of the upper part of the beam. the drainage box illustrated generally as 46. The pivot that is upstream is illustrated in more detail in Figure 11. The frame 40 is swung through a small arc (which provides sufficient angular movement to obtain any desirable value for a) on the rod 47 which is supported by the wall of the drainage box 2, which is illustrated with the number 50. The frame 40 is attached to the rod 47 by the adjustable carrying frame 48 supported by a bracket 49. carrier frame is held in place by the lock latch 51 passing through the slot 52. This joining shape allows to finely control the location of the surface of the element 35 relative to the surface inclination of the socket element 5. Figure 12 illustrates a single pivot mount only; in practice there will be at least two, and often more, so that the upstream end of the frame 40 is properly supported throughout the length of the forming section. The downstream vertical adjustment assembly is illustrated in more detail in Figure 12. The vertical adjustment assembly 42 is attached to the downstream face of the frame 40 by bolts 53 and 54 which are in the openings 53A and 54A. The assembly 42 also includes an angled groove 55, inside which a captive pin 56 is placed. The outer end of the pin 56 is embedded in the opening 57 in the adjustment bar 43. As a result, the horizontal movement of the bar 43 in the directions of the arrow B causes a vertical movement of the frame 40 in the direction of the arrow C. The grooves 53A and 54A allow fine adjustment of the assembly 42 relative to the frame 40 in order to obtain the same value of aa throughout the conformation section. If desired, the bar 43 can be adjusted in a particular arrangement by the use of any pertinent lock mechanism. Figure 12 illustrates a single adjustment assembly; in practice there will be at least two, and often more, so that the downstream end of the frame 40 is properly supported throughout the length of the forming section. The use of other means of vertical adjustment has also been contemplated: for example, the adjustment bar 43 can be replaced by a screw thread system, which is operated by motor, and the entire adjustment means can be replaced by a hydraulic system. or tire. In order for the vertical adjustment system to operate freely, the fact that it is placed in an environment where it can be clogged due to the accumulation of solids from the pulp must be taken into account. The cross section of the unit of FIGS. 9 through 12 is illustrated schematically in FIG. 13. The up and down elements 5 and 8 are supported by their respective bars T 9A and 9B directly connected to the drain box 38. three intermediate elements 35, 36 and 37 are each supported by the bars T 9C mounted to the sub-frame 40. The sub-frame 40 is in turn supported at its upstream end by the rod 47, on which it rotates to provide the required value . At its downstream end it is supported by the adjustment assembly 42, controlled by the adjustment rod 43. The actual value for a is determined by the position of the adjustment rod 43 relative to the vertical adjustment assembly 42. In this arrangement , although the intermediate elements are adjustable to any desired value for a, the intake element remains fixed and is not adjustable, so that its inclined and hanging surface maintains a constant angle. In some circumstances, it has been observed that this may result in the deflection of the forming cloth over the hanging edge of the pick-up element, which is not convenient for several reasons. Therefore, it is preferable that in this arrangement, as illustrated at 70 (see also figure 10), the pick-up element has an arched hanging edge. It can then be seen that in this preferred embodiment, instead of adjusting each intermediate element to obtain the desired value of a, which would imply either a precision installation machining or precise individual vertical and angular adjustments, the intermediate elements are all of the same dimensions and are mounted on the sub-frame so that all its supporting surfaces of the forming cloth meet in a common plane, which is conveniently substantially parallel to the frame itself. When the frame is installed, after making any necessary adjustment using bolts 51, 53 and 54, the desired value is obtained for a by moving the bar 43 and placing it in the required position, which tilts the surfaces of the intermediate elements to the desired position that determines the second plane. In another modality more, a fourth drainage restriction element is included in the drainage device, located in the opening between the ascending element and the immediately preceding intermediate element upstream. In certain configurations, in particular when the spaces chosen between the elements are relatively wide, or the value of a combined with the length of the unit in the machine direction provides a relatively high vertical distance between the last intermediate element and the leading edge As the galvanisaplastic of the ascending element, an important part of the forming cloth can be exposed to the drainage assisted by the application of vacuum between the point where the side facing the machine of the forming cloth loses contact with the last intermediate element adjacent to its hanging edge , and the galvanoplastic leading edge of the ascending element. This allows the removal of excess water from the pulp at this point. This can be controlled by inserting a fourth drainage restriction element in this opening, with a cloth supporting surface having an upward angle to maintain the contact contact with the forming cloth, so that the supporting surfaces of the intermediate element and the support surface of the drainage restriction element form a shallow "V", which supports the side facing the machine of the shaping cloth and which limits the area of the side facing the machine of the exposed shaping cloth to vacuum-assisted drainage at this point. There are several options for the construction of the additional drainage restriction element; for example: (a) it can be mounted in a non-adjustable manner, more or less in the manner described above for the other elements; or (b) can be mounted in adjustable form; or (c) can be mounted in an adjustable manner to a sub-frame that supports a group of intermediate elements. For the same reasons stipulated above with respect to the intermediate elements, it is preferable that the additional drainage restriction element be mounted in an adjustable manner. It is further preferable that a sub-frame assembly more or less similar to that described for the intermediate elements is used to mount the additional drainage restriction element. A schematic cross-section showing a drainage restriction element is illustrated in Figure 14. The take and up elements 5 and 8 are supported by their respective T bars 9A and 9B. The three intermediate elements 35, 36 and 37 are supported respectively by the bars T 9C supported by the first sub-frame 40. The first sub-frame 40 is in turn supported at its upstream end by the rod 47, on which it rotates to provide the value for. At its downstream end it is supported by the adjusting assembly 42 and the adjustment bar 43. The actual value for a is determined by the position of the adjusting rod 43 relative to the vertical adjustment assembly 42. The restriction element of Drain 55 is supported by the T-bar 9D supported by a second sub-body 56, supported rotatably at its downstream end (much like the first sub-frame 40) by the rod 57. The angular position of the drainage restriction element, indicated by the angle Y between the surface 61 and the first plane, is controlled by the vertical adjustment assembly located upstream 58 for the second sub-frame 56. Conveniently, an arrangement similar to that described for the first sub-frame is used. In most cases, the ß and Y angles will be more or less equivalent.

The cross section of the drainage restriction element is illustrated in Figure 15. The upstream face 59 includes a galvanoplastic leading edge 60, followed by a rising inclined surface 61, ending in a hanging edge 62. The element is properly supported by a bar T, as illustrated in 9D. The value of the angle d is determined to assign a value to the angle Y which allows a smooth transition of the shaping cloth in motion from the point where it loses contact with the last intermediate element 37 to the inclined surface of the ascending element 8. Depending on the the shape of the assembly used for the drainage restriction element, the angle d can be very small, and even reach 0, so that the rising inclined surface is substantially perpendicular to the face 59 located upstream. As indicated above, the point at which the forming cloth loses contact with the element 37 depends, among other things, on the level of vacuum applied to the drainage box. Figure 16 schematically illustrates profiles of intermediate elements alternative to those illustrated in Figures 1, 7 and 14. Figure 16 shows a group of seven elements. The first group of elements includes a take-up element 5, and two intermediate elements 63 and 64 each with a vertical stirring blade. The central element 31 is at the same time an ascending element for the first group and a taking element for the second group. The second group includes two intermediate elements 65 and 66, followed by an ascending element 8. The elements 65 and 66 have a substantially planar surface. As illustrated, the two groups are placed on a divided drainage box 2 with independent drainage spaces 2A and 2B on which it is possible to apply the same level of vacuum or a different one in each space. Also, it is possible that the elements 63 and 64 form the second group, and that the elements 65 and 66 form the first group. In this way, it can be observed that it is possible to use different combinations of elements to generate the desired level of turbulence within the pulp. The present invention has several advantages over the prior art. The turbulence generation unit in pulp can be used with advantage to remove water and deflocculate heavy and / or heavy-class pulps while applying a low vacuum pressure or, under certain circumstances, a minimum vacuum once that the section is operating. The ability to decrease the level of vacuum applied significantly reduces drainage and sheet sealing during the movement of the pulp over the unit. The turbulence generated throughout the thickness of the pulp can be exploited to achieve a deflocculation of the pulp more uniformly and efficiently using other agitation devices located both upstream and downstream of the unit.

Claims (50)

NOVELTY OF THE INVENTION CLAIMS

1. - Apparatus for generating turbulence in the papermaking pulp on a shaping cloth in an open surface shaping section of a papermaking machine, and the shaping section includes a shaping cloth moving at a relatively slow speed , with one side facing the paper and one side facing the machine, with a layer of relatively thick paste on the side facing the paper, a drainage box located under the forming cloth and connected to a vacuum cleaner controlled to create a low vacuum within the drainage box, and a variety of drainage elements with support surfaces of the forming cloth contained in the drainage box and which essentially consist of: (i) a drainage outlet element with a supporting surface of the cloth comprising, in order of succession: a galvanoplastic leading edge; an intermediate surface substantially horizontal; and a hanging inclined surface; (ii) an ascending drainage element with a supporting surface of the cloth comprising, in order of succession: a galvanoplastic leading edge; a sloping surface; an exit surface; and a portion comprising the splicing of the inclined and outlet surfaces; and (iii) at least one intermediate drainage element located between the drainage outlet member and the ascending element and separated from each additional drainage element by an opening, and the or each intermediate element has a supporting surface of the drape comprising in order of succession: a galvanoplastic leading edge; a sloping surface; and a hanging edge; wherein: (a) the portion of the ascending element located at the junction of the inclined and outlet surfaces is chosen from a vertex at the junction of the inclined surface and the exit surface, a substantially horizontal short surface linking the surface inclined and the exit surface, and a curved surface that links the inclined surface and the exit surface; (b) the intermediate surface of the drainage outlet element, and the portion of the ascending element comprising the junction of the inclined and outlet surfaces defines a first plane; (c) the inclined sloping surface of the drainage outlet member and the inclined surface of the or each intermediate drainage element defines a second plane inclined at a predetermined angle hanging downward with respect to the first plane; and (d) the galvanoplastic leading edge of the rising element is located on the hanging edge of the adjacent intermediate drainage element, so that the movement of the forming cloth from the hanging edge of the adjacent intermediate drainage element towards the electroplating leading edge of the ascending element results in a vertical movement of the shaping cloth, and of the incipient paper web and the pulp transported thereon.

2. - The apparatus according to claim 1, further characterized in that at least one intermediate drainage element located between the drainage outlet element and rising element and separated from each additional drainage element by an opening, is attached in an adjustable manner to the drain box, allowing the placement of or of each inclined surface of the same in the second desired plane and allowing the movement to a different desired second plane.

3. The apparatus according to claim 2, which includes a variety of intermediate elements attached to a first sub-frame adjustably attached to the drainage box.

4. The apparatus according to claim 1, further characterized in that it includes a drainage restriction element, interposed between the ascending element and the adjacent intermediate element, with a supporting surface of the cloth comprising, in order of succession: an edge of galvanoplastic attack; and an ascending inclined surface; wherein the junction of the drainage restriction element to the drainage box is positioned and arranged to locate the inclined surface ascending at an angle with respect to the second plane so that a shallow angle "V" is created between them in accordance with the inclined surface of the rising element.

5. The apparatus according to claim 2, further characterized in that it includes a drainage restriction element, interposed between the rising element and the adjacent intermediate element, with a supporting surface of the cloth comprising, in order of succession: an edge of galvanoplastic attack; and an ascending inclined surface; wherein the junction of the drainage restriction element with the drainage box is positioned and arranged to locate the inclined surface ascending at an angle with respect to the second plane so as to establish a shallow "V" angle therebetween in accordance with the inclined surface of the rising element.

6. The apparatus according to claim 3, further characterized in that it includes a drainage restriction element, interposed between the rising element and the adjacent intermediate element, with a supporting surface of the cloth comprising, in order of succession: an edge of galvanoplastic attack; an ascending inclined surface; wherein the junction of the drainage restriction element with the drainage box is positioned and arranged to locate the surface inclined at an angle with respect to the second plane so as to create a shallow angle "V" therebetween in accordance with the inclined surface of the rising element.

7. The apparatus according to claim 4, further characterized in that the junction of the drainage restriction element with the drainage box is chosen from the group consisting of a fixed splice and an adjustable splice.

8. The apparatus according to claim 5, further characterized in that the junction of the drainage restriction element with the drainage box is chosen from a group consisting of a fixed splice and an adjustable splice.

9. The apparatus according to claim 6, further characterized in that the junction of the drainage restriction element with the drainage box is chosen from a group consisting of a fixed splice, an adjustable splice and a second adjustable splice incorporated in the first adjustable splice for the intermediate elements.

10. The apparatus according to claim 1, further characterized in that all the intermediate cloth support elements are of the same width in the machine direction.

11. The apparatus according to claim 1, further characterized in that all the intermediate cloth support elements are not of the same width in the machine direction.

12. The apparatus according to claim 2, further characterized in that all the intermediate cloth support elements are of the same width in the machine direction.

13. The apparatus according to claim 2, further characterized in that all the intermediate cloth support elements are not of the same width in the machine direction.

14. The apparatus according to claim 4, further characterized in that all the intermediate cloth support elements are of the same width in the machine direction.

15. - The apparatus according to claim 4, further characterized in that all the elements of the intermediate cloth support are not of the same width in the machine direction.

16. The apparatus according to claim 1, further characterized in that the or each support element of the intermediate cloth has a substantially flat inclined surface.

17. The apparatus according to claim 1, further characterized in that at least one intermediate element has a vertical stirring blade.

18. The apparatus according to claim 2, further characterized in that the or each support element of the intermediate cloth has a substantially flat inclined surface.

19. The apparatus according to claim 2, further characterized in that at least one intermediate element has a vertical stirring blade.

20. The apparatus according to claim 3, further characterized in that the or each support element of the intermediate cloth has a substantially flat inclined surface.

21. The apparatus according to claim 3, further characterized in that at least one intermediate element has a vertical stirring blade.

22. - The apparatus according to claim 1, further characterized in that the hanging angle down between the first and the second plane is around 0.25 ° to about 10 °.

23. The apparatus according to claim 2, further characterized in that the hanging angle down between the first and second plane is around 0.25 ° to about 10 °.

24. The apparatus according to claim 3, further characterized in that the hanging angle down between the first and second plane is around 0.25 ° to about 10 °.

25. The apparatus according to claim 1, further characterized in that the hanging angle down between the first and second plane is less than about 6 °.

26. The apparatus according to claim 2, further characterized in that the hanging angle down between the first and second plane is less than about 6 °.

27. The apparatus according to claim 3, further characterized in that the hanging angle down between the first and second plane is less than about 6 °.

28. The apparatus according to claim 1, further characterized in that the hanging angle down between the first and second plane is from about 2 ° to about 4 °.

29. - The apparatus according to claim 2, further characterized in that the hanging angle down between the first and second plane is from about 2 ° to about 4 °.

30. The apparatus according to claim 3, further characterized in that the hanging angle down between the first and second planes is from about 2 ° to about 4 °.

31. The apparatus according to claim 1, including the first and second turbulence generating apparatus in successive order, with the exit surface of the rising element of the first apparatus providing the hanging surface of the intake element of the second apparatus.

32. The apparatus according to claim 31, including a single drainage box supporting both turbulence generating apparatuses.

33. The apparatus according to claim 31, including a drainage box with first and second hydraulically independent compartments, each with its own vacuum cleaner, and each with its own turbulence generating apparatus.

34. The apparatus according to claim 31, further characterized in that the angle between the first and second planes in the first turbulence generating apparatus is equal to the angle between the first and second planes of the second turbulence generating apparatus.

35. The apparatus according to claim 31, further characterized in that the angle between the first and second planes in the first turbulence generating apparatus is not equal to the angle between the first and second planes in the second turbulence generating apparatus.

36.- An apparatus according to claim 1, further characterized in that the forming cloth is moved to less than about 400 m / min.

37.- An apparatus according to claim 2, further characterized in that the shaping cloth moves at less than about 400 m / min.

38.- An apparatus according to claim 3, further characterized in that the shaping cloth is moved to less than about 400 m / min.

39.- An apparatus according to claim 1, including an intermediate element.

40.- An apparatus according to claim 1, including at least two intermediate elements.

41.- An apparatus according to claim 2, including an intermediate element.

42.- An apparatus according to claim 2, including at least two intermediate elements.

43.- An apparatus according to claim 3, including at least two intermediate elements.

44. - A method for creating the desired level of turbulence in a layer of pulp transported on a shaping cloth in an open surface shaping section of a papermaking machine, consisting essentially of moving the shaping cloth carrying the pulp paper bin on at least one drainage box that holds a variety of cloth support elements underneath, and in contact with, the forming cloth, and apply a vacuum to create a controlled vacuum in the drainage box, and The support elements of the drainage cloth consist essentially of: i) a drainage outlet element with a supporting surface of the cloth comprising, in order of succession: a galvanoplastic leading edge; an intermediate surface substantially horizontal; and a hanging inclined surface; ii) an ascending drainage element with a supporting surface of the cloth comprising, in order of succession: a galvanoplastic leading edge; a sloping surface; an exit surface; and a portion comprising the splicing of the inclined and outlet surfaces; and iii) at least one intermediate drainage element located between the drainage outlet element and the rising element and separated from each additional drainage element by an opening, and the or each intermediate element has a supporting surface of the drape comprising order of succession: a galvanoplastic leading edge; a sloping surface; and a hanging edge; wherein: a) the portion of the ascending element located at the junction of the inclined and outlet surfaces is determined from a vertex at the junction of the inclined surface and the exit surface, a substantially horizontal short surface joining the inclined surface and the exit surface, and a curved surface joining the inclined surface and the exit surface; b) the intermediate surface of the drain outlet element, and the portion of the rising element comprising the junction of the inclined and outlet surfaces defines a first plane; c) the inclined sloping surface of the drainage element and the inclined surface of the or each intermediate drainage element define a second plane inclined at a predetermined downward angle with respect to the first plane; and d) the galvanoplastic leading edge of the rising element is located on the hanging edge of the adjacent intermediate drainage element, so that the movement of the shaping cloth from the hanging edge of the adjacent intermediate drainage element to the electroplating edge of the element ascending results in a vertical movement of the shaping cloth and the incipient paper web and the pulp transported thereon.

45. A method according to claim 44, further characterized in that the desired level of turbulence is created and controlled by at least one intermediate adjustable drain element located between the drain intake element and the rising element which is connected in a manner adjustable to the drainage box allowing the placement of or of each inclined surface thereof in the second plane; and the turbulence level is controlled by adjusting the adjustable intermediate support element to a desired background location.

46.- A method according to claim 45, further characterized in that the apparatus further includes a drainage restriction element, interposed between the ascending element and the adjacent intermediate element, with a supporting surface of the cloth comprising in order of succession : a galvanoplastic leading edge, and a surface inclined upwards; wherein the junction of the drainage restriction element to the drainage box is positioned and arranged to locate the inclined surface ascending at an angle with respect to the second plane to create a shallow "V" shaped angle therebetween in accordance with the inclined surface of the rising element.

47.- A method according to claim 46, further characterized in that the desired level of turbulence is created and controlled by: i) at least one intermediate adjustable drain element located between the drainage outlet element and the ascending element adjustably attached to the drainage box allowing the placement of or of each incunabula surface of the same in the second plane; and ii) a drainage restriction element, interposed between the rising element and the adjacent intermediate element, with a supporting surface of the cloth comprising, in order of succession: a galvanoplastic leading edge; and an adjustable upward inclined surface; wherein the level of turbulence is controlled by: a) adjusting the adjustable intermediate support element to a desired background location; or b) adjust the drainage restriction element to a different location; or c) adjusting both the adjustable intermediate support element to a desired second location, and the draining restriction element to a different location.

48. The method according to claim 44, further characterized in that the cloth is moved at a speed equivalent to or less than about 400 m / min. 49.- The method of compliance, with claim 45, further characterized in that the cloth is moved at a speed equivalent to or less than about 400 m / min. 50.- The method according to claim 46, further characterized in that the cloth is moved at a speed equivalent to or less than about 400 m / min.