DE2000660A1 - Improved Apparatus for Making Paper - Google Patents

Description

BEM) IT COHFORATION
Beloit, Wisconsin 535H
United States

INCREASED DEVICE FOR INCREASING PAPER

Priority »USA-798,887
Patent application dated February 13, 1969

The present invention relates to the manufacture of fibrous paper webs and, more particularly, to an improved one Machine and an improved process for the production of \ fibrous paper webs from a dilute, aqueous suspension ™ sion of these fibers.

In recent years papermaking has made a number of significant advances in the area of paper web formation in which two opposing wire webs are used to form the paper webs between these wire webs, in contrast to the previously common Fourdrinier type paper machines which used only a single forming wire . Downwardly inclined and / or substantially aligned in sakrechter direction of paper web forming devices that use two faced forming wires, are still more recent and present particular problems in the formation of an acceptable paper web, slightly nevertheless allow these vertically W aligned paper web forming devices in theory the use of a much smaller floor area and higher speeds in the work process and in this way make such devices appear economically powerful. While these twin wire vertical forming machines have had limited commercial success, they are still in the process of improvement and in some respects the operation and paper quality achieved may leave some things to be desired, at least in certain specific cases. For example, when the speed of the machine is increased, operational difficulties are often associated with it

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premature wear and tear on certain devices. The difficulties that arise are not limited to that mere avoidance of the wear and tear of the running surfaces of such devices, but also understand construction problems, the technical adequacy of structural and / or functional Parts, the fabrication of such parts, and so on. The present invention essentially provides a new, unique one Device for the formation of paper webs that as well as increased speeds of the paper machines Quality of the paper produced in this way.

It is therefore an important object of the present invention, to provide a new apparatus and method which effectively improves papermaking at high levels Allow speeds. Another object of this invention is to provide a paper machine of improved quality Construction and a method for a vertical Paper web forming device with double wire and another object of the invention is the realization of a vertical one Paper web forming machine that reduces construction difficulties to a minimum.

Other further objects, features, and advantages of the present invention will become apparent to those skilled in the art can be clearly understood from the following detailed specification and accompanying drawings.

Figure 1 is essentially a diagrammatic elevation of the forming section a paper machine embodying the principles of the present invention; and

Fig. 2 is essentially an enlarged elevational view of a portion the forming section of this invention which illustrates certain additional details.

Figure 1 is a substantially diagrammatic view of the forming section 10 of the paper machine. A headbox en 11 is in suitable communication with a paper stock container he PS that the headboxes 11 in the usual wines feeds continuously with a dilute, aqueous suspension of fibers. The headbox 11 is in communication with

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a damming device 12 which is equipped inside with devices lcia which increase the dispersion of the fibers within the aqueous suspension and at the same time reduce the vortex movement thereof; the additional details of a preferred one! Forms of such devices are described in the Hill et al patent application (US Serial do. 698,635), which is incorporated herein by reference. It will be understood, however, that any conventional headboxes and stowage devices may be used in place of the preferred headboxes and stowage devices. The damming device Id directs the dilute, aqueous suspension of the Fasexm moving together downstream

as a jet stream of high velocity, which is essentially flows in one direction and is very thin as a building, j η the formation gap G, which expands in the vertical direction.

Two breast rolls 15 and 14, which are rotatably mounted and whose direction of rotation is indicated by the curved arrows, take up the jet stream along a horizontal plane between them. The breast rolls 13 and 14 are separated by a horizontal space in order to form the space G between them, which extends in the vertical direction and is wider than the thin paper stock EtrahJLstrom which passes through the damming device Id . Rollers Y'j and 14 are provided with scrapers on their downstream sides:. ·. '. Directions 13a and 14a. or provided in order to clean their surfaces from foreign matter adhering to e tv / ν Igen. Although the rollers 13 and 14 are essentially shown as closed Bruetwalzeri, it should be noted that open brush rollers, be it one or two, can also be used.

A first 'Formsieb Fl is on the brush IJ (d_u as first brussels are denoted :; can) and then over several, essentially smooth, curved surfaces Ip guided the are staggered below the intermediate space G in a downstream direction one behind the other and opposite one another to a generally vertically oriented, serpentine-like one To form a career whose direction generally corresponds to the direction of the Scr-.Iilsnroms matches. The first sieve Fj. runs

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BATH ORIGINAL

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we'tür, -. ¹ UVJaI ¹ IiS to Siebrückleitwslze l ^r /, deviates from the downward direction and returns over several guide rollers 15b to the upper part of the formation section 10. The guide rollers 15b can be provided with tensioning devices T1 in order to ensure the desired tension within the running screen web. For practical reasons, reference is made to both the first forming screen and the first forming screen web with the reference number Fl. The second forming screen F2 is passed over the breast roll 14 (referred to as the second breast roll) and then in a similar manner over several curved surfaces 15 in a vertically aligned, serpentine-like pathway to the cable pulley 18 (which has a suction couch 18a) then ex from the downward direction to return to the upper part of the forming section via a plurality of guide rollers 14b. The guide rolls 14b are also provided with tensioning devices T, j in order to ensure the desired tension in the second form Leb. For practical reasons, both the second screen and the second screen web have the reference symbol Fc. '. It must be noted that the guide rollers 15b and 14b are provided on their downstream sides with discharge devices 15b ¹ and 14b ^1, respectively, in order to remove any foreign matter.

The forming wires Fl and Fk are uctwalzen B on 15 and 14 by an intermediate space, which is initially very closely guided to the gap G to L dor the Paρ: yrstoffStrahlstrom take between calibration. Immediately afterwards the sieves converge

in a general parallelism in order to be curved over a multitude Areas 15, which are staggered oppositeiiegoudiri distances sjndj to run. When the paper stock jet stream enters the ' initially narrow space between güu foraisieten occurs Drainage and / or water purification directly through the appropriate peripheral surfaces of the forming screens on the downstream sides of the breast rolls 15 and 14 as a result of the Gravity and tension take place within the image trajectories. Such removal of water, which continues through the entire formation zone, enables drainage 'through both sides of the sandwich-like (sub- pap ie bahii sieve)

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BATH ORIGINAL

mm ^ i mm

Arrangement takes place therethrough ;. The Pe piers braille: brom sohl eats from the damming IJ as an im ν; ο ii borrowed continuous, very thin L-jet bromine with jet speed, that is? O m and more per minute. The jet stream strikes essentially tangentially against the peripheral surfaces of the rollers 13 and 14, so that pressure is generated in the zone of convergence. The ge; jw.Lndigke.lt of the jet stream is essentially converted into hydraulic pressure when the jet stream touches the forms Lebe Fl and F ^, while the dehydration process discussed above increases; will.

On the immediately downstream sides of the breast rolls 1: 'and 14, a first dewatering zone Al is created, where the water is removed from the paper web that is being formed in essentially opposite directions. At this stage, the sides F1 and FI: exert little, if any, real pressure on the jet stream. In other words, there is a "light" pressure in the initially narrow space between the forming screens. This slight pressure merely holds the fibers together between the moving sieves, which enables a suitable distribution of the fibers of various sizes within the cross-section of the paper web being formed and at the same time enables the water to be drained from these fibers. Such a uniform fiber distribution within the cross-section significantly promotes the production of a first-class paper web with the most desirable properties. During this stage of slight pressure water along beidex · sides of the forming paper web will continue to entfex ⁿ nt, which allows the formation of a substantially uniform one-side paper sheet.

The running sieves Fl and F ^, which the newly forming Paper web pass between themxi, converge together into one general parallelism as soon as they begin have left and run across the work surfaces of a multitude of opposing staggered curved surfaces - the distributed from the intermediate space downstream one behind the other in the space are in order to form a generally perpendicular, serpentine runway between them, the direction of which generally coincides with the direction of the jet stream

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BATH

- ο -

true ;, d: u; he eats downward. The AuSr ¹ KLA "general parallel. <: ^Ωΐο: referenced don Ln this patent ν / ί :: · <1, beze'.ehnei: IUJ dynamic relationship of the screens zue> the rider who Matching Caps * Ln same direction. laui'en, separated from each other by the Pa ₁ e υ in between lines, and the si.ch constant and ailiaähi 'cn ι.α dem Hasse to move auiixnander,: no de ;; water from de: 3i_ch forming Pap.L. erb; üm removed. r: l and wenLgeL · Pap _L e .: z to ff separates the running screens.

The ge writhing L Lu AbI e never voiv lines \ j> are vurzugswei so WLE thief Ln of FigUL · 1 is shown, compact rollers have a small diameter. Nevertheless, the rollers and ^one must cht di'cau: luid köm.en in certain arrangements also statLonä .. · be. Auen can have the rollers of a üfl'euoi- round, Ln more similar to W-ise v / ie the open breast roller, o \ ^r : vcj; · - has been described. In any case, the warts Ip are provided with adjusting devices F1 in order to be able to move them in the directions of the do | /: el: fe line. As explained above; became, dLe V /; ιIzon Ip rotatable · so moutic.vt, d ^; ; .us si.e sLch more curved in the direction dor. ' Move arrows to avoid frictional wear. the running sieve webs Fl and Fi-., ci'.e run over the rana surfaces of these rollers, to be limited to a minimum size. Each of these .. · rollers (or in //J.rkl.Lcli.koil; their corresponding surfaces) guides the sieve webs, which lead in the middle of the pa. ^ Ier-buhn, through one; Curve hindux'ch Ln a direction that / or. the previous one:;! Bahri.'Lentungen differs, whereby additional water masses are removed from the paper web by centrifugal force and gravity, of course, further drainage takes place through the simple exit wateri.aingsvorg- .. ⁽ .ng, - 'referred to above was, along stttt the opposite surfaces of the paper web. the curved surfaces 1 ■ (which are shown here as rollers) guided ode .. · urge the current sieves along a serpentine-like track η it more alternately entgegegesetzten curvatures in aligemeinen from the direction of the jet stream These bends or bends in the walkway are sufficient to alternately drive water through the opposing sieves and drain it away from them

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BATH

. Water, dr. ·: * G I did along the inner surfaces of the ent unreellen the Siebbahnen yi ^ e ^ amm -It. In other words, the curved surfaces so 1_ occur in calming the Sj ebbahiren, doss, - .. ie a deviation from the vorhex'igen Balin in a yevhältnismäfHLg jähoii deviation amount cause the genügt- dei water through the opposite sides ¹ Siebbuimen to ür ~ -iben and to derive νυη from them. Dei · turn degree may resent uerden changed .... cli, but he must at least about ^, (from the previous Laui'bohn) vorzugswei.'je Upper longer bet hunt, so that the procured distraction is enough (to water you Cii gravity and Zentr 'fug & lkr- · It) to drive through the free beings of the Siebbahneix and from him; derive. In this ί-ϊ in eicht it is to be noted that a ^ · if ^ around B ..! There is an extreme curved,. · Surface I ^ 'comes into contact with the converging Siebb-inner ;, ss jn reality only The first form sieve Fl touches this in parallelism against the fact that z \ veite forms.'eb F ^ di 'extends, v / elclies in this zone of contact with the first curved surface 1-y is free of holding devices. This a.- tint is everywhere in the multitude of Walsenvcrrichtungen 1, the same - that hüisat in the zone, \ <o one of the roller connections eji single rubbed against the other sieve is d! eseszv; ei-ce sieve in the zone of this particular roller free from nutrients m ^; Haitcvorx'ichtunge: .. In this way, there is essentially an equal additional drainage along the · ·, i. oppositely staggered zones of the forming paper-Üm instead. Of course, further drainage is constantly taking place along both lakes; on the paper web.

One can see that vienn all the running S "ebb ^ iinon Fl and F2, which carry the moist Paj. Ierbahii between them, would be diverted from their direction of the path, transferred iJuntrifugelkx-aft of the total mass, but especially the existing V / ascer v;: ird, because it is free of movement. This Zci, \: v .fug &lkx'aft causes the water in the paper web to be thrown through the free side of the forming wire and from it Example on the roller arrangement I ^ 'through the second forming wire F ^ -, but by successively alternating sides of the sandwichaitijci arrangement). In this way several dewatering structures are formed. A ^, Ai Uxid a4 with each deflection the path of the Fo. m-lucu. a ^ naturally also the force of gravity acts on the jesamt-

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BATH ORIGINAL

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mass and thus promotes drainage. The squeezed out water «? ; J is collected in a suitable collecting device S in order to. ^ to derive it from the education section. If the curved r , { surfaces II? "Are rotating rollers, scraping devices 1 ^ a can be attached to remove any adhering water droplets, foreign matter and so on. In addition to centrifugal force and gravity, the acting on the calibrating paper web, the wire tension exerts a kind of inevitable, pulsating pressure on the paper web when the wires pass the multitude of curved devices, whereby additional water is squeezed out in the zone of these curved surfaces. Drainage also takes place in the zones remote from the curved surfaces along the free inner surfaces of the respective screen webs F1 and F2. In this way the considerable amounts of water inside the inserted paper stock are removed along both sides of the paper web being formed, which results in an uneven fiber distribution in the paper web Water is continuously everywhere in the formation zone along both sieves areas are removed and additional amounts of water are drained away in the deflection zones.

It must be noted that the forming screen paths F1 and F2, after having completed their serpentine-like path along the last curved devices Ii? have finished, continue downhill and pass another drainage device 16. The drainage device 16 is illustrated in the drawing in gestelt a plurality of suction box, the Cn of the inner surface of the mold screen F2 are engaged. When the paper web runs past the dewatering device, it has a tendency to adhere to the forming wire F2 and deviate from the forming wire F1. The forming screen F1 continues downward until it touches the surface of the screen backing roller 17, which it from the downward leading direction in the reverse direction to the guide rollers IiJb and to the upper one. Part of the education section IO directs. The wire F <2, which carries the newly formed paper container W on its outside, continues downward until it comes into contact with the sieve return roll 18 (which works here couch roll), like the new one

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♦ formed paper web V and its carrier wire F2 from the education sec-

* lead away. The roller 18 is provided with a suction cup 18a equipped to ensure that the newly formed paper web does not deviate from the forming wire F2 in the zone of curvature. The mold sieve F2 tr ^ g; the newly formed paper web V upwards and brings it into contact with a removal felt PF, dex 'kills a little Valze is wrapped. This removal felt PF is guided over a large number of guide rollers (not shown) and thus forms a felt running in a loop path, who touches the newly formed paper web in order to transfer it from the education section to another department, like a first press section, for the purpose of desired additional processing. Drive devices M1 and M2 are useful with the Poi-msieben Fl and F2 connected to drive them synchronized with jet velocities. The · driving devices and connected to rollers IJb and 14b in the drawing; however, it must be noted that the drive devices can also be connected to other rollers if so desired is. The guide rollers 13b and 14b can also be equipped with tensioning devices T2 and T 3 can be provided to the desired Ensure the degree of tension in the corresponding sieve webs. Stoffanger S are in working connection below each drainage zone set up to remove the water from the educational section.

The forming section of the paper machine of the present invention is provided with two breast rolls attached to a frame (not shown) which supports along a horizontal plane the breast rolls separated by a narrow space to form a vertically extending space. Two screen rollers, which are connected to each dex chest roller, can be attached to this frame, separated in the vertical direction by a space below the breast rollers from the corresponding breast rolls to the wire return rolls. Devices are provided to loop the screens around the corresponding screen return rollers

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lead and branch off from each other in order to return them to the corresponding breast rolls. A headbox that attached to the frame above the breast rolls sends stock down through the space between the breast rolls, to feed the downward flowing paper stock stream between the wires. A variety of curved surfaces that separated from each other in the vertical direction, in the loop of each of the two sieves staggered opposite and in a downward direction from the corresponding sieves are separated, each of the wires urge away from the raceway, thus driving water out of the stock along the raceway between the sieves to cause the formation of a sheet of paper, devices being provided to circulate this water to remove from the loops of the corresponding sieves. Devices are also provided to accommodate the sheet of paper and lead it away from the wire return rollers. Each arrangement of the curved surfaces causes at least one deviation from about J? from the original career, v / as is sufficient to drive water through the free side of the sieve webs and divert it from it.

FIG. 2, to which reference is now made, shows an enlarged illustration of one of the curved surfaces 21. As the illustration shows, the fo mscreens F1 and F2, which carry the paper web that is being formed in their center, run in a general parallelism, to come into contact with the peripheral curved surface 22 of the curved device 21. The peripheral surface 22 directs the current wires from their original path direction to i_nem to e degrees from, de;. · Is sufficient water through the free side of the screen in Fl dex · zone k'y to treitm and lead away from it. Han will recognize that the ongoing screens Fl and F2 are curious and resistant ^"1 aufeinandex werdon to crowded, so they exert a constant pressure on the paper web and pressing water from 'lossen both sides Such aung & ridged water naturally has the tendency 3I to. collect or flow along the inner surface of the sieve webs and when these sieve webs touch a deflection surface, such as the curved device 21, the water along the free side of the sieve web of the centrifugal

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BAD OBIGJNAL

- 11 - 'subjected to force and thrown away from the free side.

The sieves ι as explained above, then continue to come into contact on the opposite side with another deflection device, so that water is thrown away from an opposite side of the sandwich-like arrangement (sieve- paper web-ball ). In this way, by means of a simple dewatering process, dewatering takes place everywhere in the formation zone; an additional dewatered ι eerung (caused by pulsatile pressure, though. the Siebbahnen 'on the curved devices run) along finds the deflection zones instead, so that considerable amounts of water from the paper web are removed and a paper web is Λ is formed, the cohesion has Uxl has a good fiber distribution ™ .

The curved surface 22 of the device 21 abuts the oncoming side of the running wires and deviates from the wires on the downstream side. Because of their flexibility, the screens will actually lay over a portion of the work surface 22 to form a contact surface over the deflection surface. The surface is preferably solid and deviates from the raceway of the sieves on the downstream side at an angle of approximately 5. This deflection angle can vary somewhat, but still has to be such that it prevents the pumping of water towards the device 21. The pump is avoided when -W is taken care for sufficiently large deviation between the solid surface and the ongoing screening, ao that no vacuum forming (or partial vacuum) in the deflection zone \ and may enter the air quickly, dec pumping Waasex * is prevented on the immediately downstream side of the curved devices. It should be noted that the pumping leaves streaking and undesirable marks in the paper web as it forms.

The curved device 21 is set up in working connection with the sieve webs and along the same to in the original Career dei * sieve -: to cause a distraction, di.e. is enough, the Wuücer in Iiui ^ m the newly formed paper ^ -bahi.

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"'MJ *

joo.oeio-1

to transmit sufficient centrifugal force so that it is flung through the free side of the screen webs and away from them. A planned adjustment T5 helps to bring the curved devices 21 la their work together with the current seven in the right location and ermb'g- 'light, the movement of these curved devices in the direction of the double arrows. The working surface 22 of the curved device 21 is provided with a solid high gloss overhang 23. Only a limited part (i.e. the working surface) of the curved device 21 is provided with a cover which preferably consists of tungsten carbide, titanium carbide or a ceramic-crystalline refractory metal oxide such as aluminum oxide and is polished to a high gloss. The ceramic coating 23 will form a thin monolithic layer over the work surface 22 and when it is polished to a high gloss, it provides an essentially frictionless running surface for the forming sieves Pl and F2 Charles WE Walker (US Ser. No. 150,917) is provided and may be used in accordance with the principles of the specification which are incorporated herein by reference. It has been found that a significant unexpected reduction in scuffing and wear on the screens as well as on the work surface of the apparatus 21 is achieved when such a high gloss coating is used. It should be pointed out that such a coating can also be applied to the roller devices 15 (as shown in FIG. 1).

It will be seen that the present invention is a unique, Realized an improved forming section of a paper machine incorporating a plurality of curved surfaces is that the forming sieves over a serpentine-like career guide in order to bring about effective and rapid drainage duxOh the two sides of the newly formed paper web. the The device shown, which is easy to maintain and economical to install, also enables an external

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usually quick and efficient formation of first class paper webs. Since the device shown has a long service life and its power requirement is not excessively high, it increases the economy of the paper machine. The method according to the invention consists in the fact that two opposite screen webs are passed through a narrow space extending in the vertical direction and there take up the paper stock between them. "Immediately afterwards the dewatering of the jet stream takes place in essentially opposite directions in the immediate vicinity of the narrow space, mainly by a dewatering process without the application of significant pressure on the paper stock and converge into a general parallelism, through a serpentine-like raceway with successively staggered, substantially opposed curvature surfaces which urge one wire path against an opposite zone of the other wire, which in the turns dex ¹ serpentine-like raceway is not in contact with holding devices in order to effective way to drive water out of the alternating opposite sides of the screen webs and to throw it away from them.

It goes without saying that the invention does not apply to the specific implementations shown and described here limited, but can also be evaluated in other ways and without deviating from the claims.

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Claims (1)

-IA- PATENT CLAIMS A device for producing a fibrous paper web from a dilute aqueous suspension of felted, common moving fibers, which essentially function as a continuous, rectified, ribbon-thin jet stream flowing down the valley step out of a lath - (12), with a first and second rust roller (13, 14) which is rotatably mounted along a horizontal plane and separated by a gap (Gh) are, a first and an opposing second screen web (Fl, F2) which are essentially at jet speed Run over the first or second breast roll (13 »14) through the gap (G) to put the stream between them immediately afterwards, in a general parallelism with the fibrous one sandwiched at its center wet paper web converging through a formation zone and in which parallelism the wire webs (Fl, F2) are held when they run together downstream, characterized in that from the gap (Gö on downstream one behind the other at intervals a multitude of curved surfaces (15, 21) set up and generally opposite one another are staggered around a generally serpentine-like To form a career between them, the direction of which generally coincides with the beam current direction, and that each of the curved surfaces (15, 21) has a smooth surface, that of one of the screen webs (Fl, F2) has a curved surface Working surface (22) offers, which this sieve web in such parallelism against the opposite zone of the other, no holding device touching screen web pushes and the one screen web in parallelism through a curve with relatively deflects the sudden degree of deviation from the jet flow direction in order to drive water through the other screen web and to remove from her. 2. A device according to claim 1, characterized in that that each of the curved surfaces (15, 21) has one of the S ebbahnen (Fl, F2) touching running surface (22), which is covered with a hochgianzpo.V arten solid ceramic coating (23). 009836/0121 'J. A device according to Claim 2, characterized in that each of the curved surfaces (15, 21) produces a curve which "does" lead more than approximately 5 ° from the previous direction of the track. 4. Hin · Device according to claim 2, characterized in that each of the running surfaces (22) of the curved surfaces (15, 21 ) touches one of the Itaufaiebe (Fl, F2) and deflects it from the running track . the one sieve deviates to a degree that is sufficiently large to prevent pumping. 5 »Sine device according to claim 2, characterized in that the curved surfaces (15, 21) essentially form friction- lined guiding surfaces for the running sieve tracks (F1, F2). 6. Sine «device according to claim 2, characterized in that the essentially frictionless guide surfaces consist of rotating orphans (15) with a relatively small diameter . 7 »Sine device according to claim 2, characterized in that the essentially frictionless guide surfaces have stationary, curved drainage devices (21). 8. Sine device according to claim 2, characterized in that each of the curved surfaces (15, 21) is provided with an adjusting device (T5) for the purpose of selective movement of these surfaces with respect to the raceway of the screen webs (Fl, F2). 9. Am process eur production of a paper web from a dilute, aqueous suspension of matted fibers moving together, which emerge vertically downward from the baffle (12) as a substantially traversed, ribbon-thin jet stream, with the following phases) guiding two opposing screen webs ( Fl, F2) through an initially narrow space (G) extending in the vertical direction in order to accommodate the jet flow there between them, immediately thereafter draining the jet flow along its essentially opposite surfaces in the immediate vicinity of the one extending in the vertical direction Space (G) to " 009836/0121 OC- ¹ I ulc formation e ".. η er Γ: aerigeii, nc Gd en paper web, without introducing beating pressure cut qlü jet stream, characterized by the immediately following conducting da ¹ paper webs (Fl, F «-) which in an e-ligeme i.nen parallelism with the fibrous, luminous Puj ^; _erbj.hn in i.lirer Jiittt iconvergiu_-en, by an ■» e ... t: .kr 1 ~ ί: ^ .'penvinenäiniliche LauT-Bahn with a .. · V '.. elz:; hl from α'-ΐ / οι ... and staggered in the opposite direction:., divides “n curved surfaces (i>, ^ 1 to the 3Lldung of curves in the L ';uibi.'ii: i, the one of the Siebbahiien (Fl ₁ F ..) gai J ..e gugenüberxi .g ^ nde zone dti · andei-e:.,: η the curve: , the Laui'b; -h: i don't push hard before the Lchtung beriüu'ciiden Siebbaim, un i: zu entiej:. ^ !.