Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F1/00—Wet end of machines for making continuous webs of paper
  • D21F1/02—Head boxes of Fourdrinier machines
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F1/00—Wet end of machines for making continuous webs of paper
  • D21F1/02—Head boxes of Fourdrinier machines
  • D21F1/026—Details of the turbulence section
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F1/00—Wet end of machines for making continuous webs of paper
  • D21F1/02—Head boxes of Fourdrinier machines
  • D21F1/028—Details of the nozzle section
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F9/00—Complete machines for making continuous webs of paper
  • D21F9/003—Complete machines for making continuous webs of paper of the twin-wire type
  • D21F9/006—Complete machines for making continuous webs of paper of the twin-wire type paper or board consisting of two or more layers

Definitions

• the present invention concerns in a paper machine or equivalent, a headbox having two or more pulp stock flow passages comprising turbulence generators, and through which paper suspension of one or several kinds is supplied by a lip slice (or slices) onto web forming means.
• Ganged headboxes are used e.g. in the manufacturing of cardboards and of tissue paper.
• the web is composed of two or several pulp grades, which are supplied by means of a ganged headbox, or by separate headboxes, to the forming section of the paper machine.
• headbox constituting the subject of the present invention is mainly intended for the making of webs built up of a plurality of different pulp grades, of which the stock jet forming the web is assembled, it should be emphasized that such headboxes also are within the scope of the invention in which one single pulp grade is used, but which is distributed (at the initial end of the flow path at least) to travel by two different paths, with aims which will become apparent later on.
• the Finnish Patent No. 27191 shall be cited as an example.
• a headbox construction presenting within the lip cone a separator tongue dividing the lip cone into two parts.
• the said two parts communicate with supply passages carrying different pulp grades.
• the turbulence generator for a headbox in a paper machine or equivalent, having a plurality of flow passes in parallel, causing turbulence in the pulp stock flowing through these passes.
• the turbulence generator consists of a plurality of parallel, and preferably mutually identical, partial elements which. have been disposed between the walls of the headbox, said partial elements being shaped so that in their interstices and/or partially at least within them are formed parallel flow passes for the pulp stock.
• the turbulence generator of said Finnish patent application is utilized in a way enabling new, practically important advantages to be gained.
• the object of the present invention is to provide a ganged headbox which is easily and rapidly modifiable to fit the desired production grade and/or adjustable to be optimized in various characteristics. It is a further object of the invention, to provide a'ganged headbox allowing the number of pulp courses to be varied, that is to increase or reduce their number as required in each instance. It is an additional object of the invention, to provide a headbox modifiable in its essential parts, also regarding its turbulence generators, so that the construction of the headbox is rapidly, and with compara ⁇ tively minor cost, adjustable accurately enough to fit each pro-
• the invention is mainly characterized in that the distri-
• ' bution header of the headbox is of segmentary design, consisting of two or more pulp stock suspension supply segments; that said supply segments communicate each with its own turbulence generator, these generators consisting of a plurality of partial elements defining between and/or within themselves flow passes running in parallel and disposed between the walls of the headbox and/or its partial segments; and that the number, construction and/or the turbulence generators of the partial segments are exchangable as required by different output grades.
• a ganged headbox provided with turbulence generator and with separate segment distribution header and wherein symmetrical oppositeness of the segmented distribution header with respect to flow has been imple- mented up to the lip cone, whereby the disturbances of flow affecting the transversal profile in the header are compensated in part.
• the headbox design can be made in ⁇ expensive because, in principle, for instance merely a partition sheet with one thinned-down end divides the single (not ganged) headbox into two parts.
• the cassette-resembling, readily modifiable construction of the invention is adaptable to fit any desired flow velocity, con ⁇ sistency, pulp grade and desired level of turbulence. It is possible to provide more numerous or fewer turbulence generator cassettes or to exchange them in . case of a substantial change in output grade. By the expedients mentioned, new one, two, three-gang etc. headboxes can be modified, consistent with the intended use in each case.
• the upper and lower frame halves of the turbulence generator cassette have been di ⁇ mensioned to be fully symmetrical, whereby they can be used to compose any desired number of generator cassettes with completely equal securing and mating faces, independent of the height of flow cross section of each cassette.
• Fig. 1 presents, in elevational view, a twin-gang headbox according to the invention, intended in the first place to serve as headbox in a tissue paper machine.
• Fig. 2 presents, in like manner as Fig. 1, a triple gang headbox, but in which number of gang members may be varied with comparative freedom.
• Fig. 3 presents a twin-gang headbox design according to the invention in a manner equivalent to Figs 1 and 2.
• Fig. 4 shows the section along the line IV-IV in Fig. 1.
• Fig. 5 shows a structural design for the turbulence generator, and at the same time Fig. 5 is the section along line V-V in Fig. 2.
• Fig. 6 presents a structural design of the turbulence generator, and at the same time Fig. 6 is the section along line VI-VI in Fig. 3.
• Fig. 7 is the section along line VII-VII in Fig. 3.
• the lip slice L of the headbox has been disposed adjacent to the supply throat G defined in contiguity with the breast rolls 10 and 13. This throat G is defined between the wires 11 and 14, or
• the headbox of the invention is used to supply the pulp stock, or various different stocks, in between the wires 11 and 14, where the forming of the web W takes place in a manner known in itself in the art through twin-wire formers.
• twin-wire formers Although in the following the invention is described with reference to such embodiment examples in which a twin-wire former is employed, it should be understood that the head ⁇ box of the invention may in certain instances also be applied in single-wire formers or in those formers which have a single-wire initial portion (most usually fairly short) with a twin-wire forming region following thereafter.
• the lower lip beam 20 of the headbox structure is carried by the pivot axle 17 and 18 on the supporting beams 15.
• the lower lip structure 20 has an upper wall 20' participating in defining the stock suspension flow passage.
• the lower lip structure 20 is ad ⁇ justable of its position. To this purpose there has been provided in conjunction with the pivot axle 17, a slide 16 moving on guides 17' and which is displaced by means of a screw and a gear box 16' .
• the lower lip structure is supported at its lower end by a supporting lug 18', which has been attached over a guide 19 to the end face of the lower lip structure 20. Between the supporting lug 18' and the lower lip structure 20 has been inserted a screw driven by the gear box 19'.
• the supporting lug 18' has been attached by the pivot axle 18.to structures which are supported by the guide 17' from the headbox carrying beam 15.
• the means just described may be used to displace the lower lip structure ' 20 in the direction of arrows A and B, and thereby an expedient and proper positioning of the lower lip structure 20 and of its upper wall 20' is obtained in each instance.
• the headbox comprises an upper wall structure 32,33, consisting of a beam 33 to which the upper lip beam 32 attaches by the pivot 31.
• the socket of the pivot 31 is defined between the bodies 29 and 30.
• the body 29 has been affixed to the end flange 28 of the beam 23 constituting the upper wall of the headbox.
• the lip plate 36 is adjustable by means of a plurality of parallel screws 35, which are rotated by the hand wheels 37, by mediation of arms 34'.. It is in this manner that the fine adjustment of the lip slice L is accomplished in a manner known in itself in prior art.
• the upper lip structure 32,33 is swivelled about its pivot 31 by the aid of screws operated by the gear boxes 38. Said screws and gear boxes 38 have been connected by cardan shafts 39 and 39' between the beam 33 and the top cover structures of the headbox.
• the distribution header of the headbox consists of a plurality of segments one upon the other. As depicted in Figs 1 and 4, there are two such segments on top of each other, that is, the segments 21 and 22, and which are separated by the partition 24. Within the segments 21 and 22 are confined the flow passages K_. and K tone of the distribution headers, their directions of flow F_. and F architectural opposing each other.
• the entry of pulp stock into the flow passage K_ has been indicated by the arrow F_.. r & 1 J lm and its exit, by the arrowF. .
• An essential feature in the twin-gang headbox of Figs 1 and 4 is the above-described segmented distribution header 21,22, consisting of symmetrically opposed segments having separate input and bypass flows.
• segmented distribution header 21,22 consisting of symmetrically opposed segments having separate input and bypass flows.
• One important structural component in Figs 1 and 4 is also the set of turbulence generators 40a and 40b, twisting flow passes S.. having been established in these units, providing in periodically expanding configuration counter-surfaces changing the direction of flow and causing turbulence.
• tail vanes 71a directed symmetrically in opposition to the vanes 71b of the other segment.
• the turbulence generators 40a and 40b consist e.g. of partial elements 71 die-cast of plastic, of which only one type is required.
• the said cross-flows are achieved by placing the partial elements in the mutually superimposed turbulence generators 40a,40b with different sides up.
• the partial elements 71 have been provided with wide holes, through which the partial elements have been braced by bolts 70 between the walls 20' and 23 of the headbox.
• the segments 21 and 22 are supported by the structures 25 and 26, between which at the point 27 the partition 24 between segments has been affixed.
• the partition 24 has a tapering tip portion 24', whereafter follows the tapering lip cone part S,, which terminates in the lip aperture L.
• the headbox comprises, disposed between the walls 20' and 55, three separate supply segments 121,122 and 123, ⁇ communicating each with its own turbulence generator 41,42,43. After these turbulence generators 41,42,43 follow, separated by the vanes 56,57, flow passages S-., which terminate at the sharp edges 56' ,57' of the vanes 56 tapering down in the direction of flow, and where- after immediately then does follow the lip cone part.
• the turbulence generators 41,42,43 consist of mutually separate entities, so-called cassettes, of which one may assemble turbulence operating in single, twin, triple etc. gang arrangement with the greatest conceivable variety of entity and gang grouping dependent on velocity, pulp stock grade, basis weight and other factors influencing the output grade and quality. It is specifically essential in this construction that it is possible with certain definite basic unit components to obtain by their assembly a variety of operational units for production purposes within an immenseliy wide range; this implies that in the case of a radical change of output grade or brand there is no need to procure a whole new headbox. This is nowadays a major problem in such cases where an exceptional grade is being produced during a limited period of time only.
• OMPI PO is readable from Fig. 2, consist ' of upper and lower parts 20',51;52, 53 and 54,55, between which is mounted a turbulence component like that shown in Fig. 5, for instance.
• the lowermost turbulence generator cassette 41 in Fig. 2 has its lower part formed by the lower lip wall 20' , with which the upper part connects by securing shoulders 61 and 64 in front and in the rear.
• the front shoulders 64 provide, on the side of force binding, a fixing shoulder for the socket of the joint 58 of the lip plate 56, its dimensioning being such that the shoulder projections of any one of the alternatives are precisely secured in each and any joint socket.
• the mode of fixing of the centremost generator cassette 42 is similar to the foregoing. It is specifically significant in the design, as regards the control of forces, that the number of generator cassettes 41,42,43 may be increased or reduced, while the joint socket 58 and the rear shoulders 61,62,63 operate as an accurate and precise locking in each and every alternative.
• the upper lip supporting beam 23 With socket for the joint 31 of 'the upper lip 32 and with displacing gear box base. It is a characteristi feature of this design that the securing shoulder 66, in front, of the supporting beam 23 is exactly equivalent to the dimension of one half of the joint socket, whereby the supporting beam 23 with its upper lip 32 can be conveniently secured to the shoulder locking means of any alternative, no matter whether this is a single, twin, triple or multiple gang alternative. In the rear, the equivalent shoulder locking 63 is with reference to the supporting beam 23 by the locking rail 63' .
• the intermediate lip plates 56,57 located in the lip cone are pivotally carried by journal pins 58 projecting through the side
• Fig. 3 shows a multiple gang headbox, its construction having as an essential feature, as in Fig. 2, turbulence generators 141,143 and 142,144 operating in gang 1,2,3 etc. cassettes having for flow guidance and turbulence elements"; for instance, turbulence vanes 73, 74 like those in Figs 6 and 7.
• a deviation from the preceding is in the embodiment of Fig. 3 the circumstance that the flow formation periods are the same as in the SYM-NOZZLE (Trademark) headboxes presently used by the same applicant, and also the circumstance that, if desired, one may in this design apply flow forming elements with a similar principle of operation (such as e.g.
• the set of turbulence vanes 72 shown in Fig. 5 is mainly used in the turbulence generator 41,42,43 of Fig. 2.
• the set of flow passes S terme of Fig. 5 is formed in a flow directing part starting on the distribution header side and serving the task of directing the transversal distribution header flow to parallel the machine direction.
• S termed Fig. 5 is formed in a flow directing part starting on the distribution header side and serving the task of directing the transversal distribution header flow to parallel the machine direction.
• the final direction of flow is stabilized, and the actual turbulence level required for paper formation and its configuration become determined at the vertical and horizontal level tail vanes at the ultimate end.
• the set of flow guiding vanes 73 of Fig. 6 is more straight-lined and simple of its construction because its main task is to direct the distribution header flow of Fig. 3 to parallel the machine direction, by the aid of its set of passes S ".
• the set of turbulence vanes 74 depicted in Fig. 7 consists of vertica and horizontal projections narrowing after the bumping surface adjacent to the equalizing chamber, stepwise, and terminating in the so-called tail vane part. It is essential in view of structures dis ⁇ closed in prior art, that the flow pattern on the equalizing chamber side contains horizontal projections disposed crosswise with regard to the vertical and by the breadth dimensioning of which it is easy to obtain an open flow cross section conforming to the dimensioned optimum velocity, and the best possible spacing of turbulence vanes.
• the flow resistance of the bumping surface efficiently damps the flow disturbances in the equalizing chamber.
• stepwise expandin set of flow passes S ' successive vortex zones are formed, which in the ultimate tail vane part attain a finely distributed and short- period microturbulence level, which renders possible a uniform paper base formation.
• Figs 4,5,6 and 7 have only been shown some structural examples of the partial elements of the rubulence generator. It should be understood that within the scope of protection of the invention the design of these partial elements may greatly differ from that which has been shown in the said figures. One may for instance employ all those partial elements which have been disclosed in the same appli ⁇ cant's Finnish patent application No. 800018, or any other partial elements which may be appropriate to the purpose of application in hand.
• the superimposed headbox segments in cassette construction 121,41;122, 42;123,43 constitute parallel flow passages for the pulp stock, the principal directions of flow in these being radial with reference to each other in such a way that the planes of the principal flow directions intersect substantially at the lip slice L.
• the headbox of the invention may also be applied in other equivalent machines, in cardboard machines for instance.

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Cited By (8)

Citations (5)

• 1980
  • 1980-04-11 FI FI801167A patent/FI69664C/fi not_active IP Right Cessation
• 1981
  • 1981-04-03 EP EP81900825A patent/EP0049254A1/en not_active Withdrawn
  • 1981-04-03 BR BR8108308A patent/BR8108308A/pt unknown
  • 1981-04-03 WO PCT/FI1981/000027 patent/WO1981002903A1/en not_active Application Discontinuation
  • 1981-04-03 JP JP56501038A patent/JPS57500515A/ja active Pending
  • 1981-04-09 CA CA000375121A patent/CA1157303A/en not_active Expired
  • 1981-04-10 IT IT21066/81A patent/IT1194781B/it active
  • 1981-04-10 ES ES501265A patent/ES501265A0/es active Granted
  • 1981-12-10 SU SU813366702A patent/SU1218929A3/ru active

Patent Citations (5)

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