CN1043178A

CN1043178A - The forming method of paper or board web and device

Info

Publication number: CN1043178A
Application number: CN 89109038
Authority: CN
Inventors: 约尔马·胡雅拉
Original assignee: Valmet Paper Machinery Inc
Current assignee: Valmet Technologies Oy
Priority date: 1988-12-01
Filing date: 1989-12-01
Publication date: 1990-06-20
Also published as: FI84637B; CA2004174A1; EP0373133A2; FI885608A0; FI885608A; EP0373133A3; FI84637C

Abstract

The forming method of fibrous paper or cardboard and device in the paper machine have the off line loop and relevant online loop of level when initial.Fibrage initially dewaters the back by the direct supporting system that extends at single net drying zone, and this district can prevent that the gravity effect is by off line dehydration.When producing high grammes per square metre papery, paper web is delivered to the dual-network dehydration district again.This district comprises opposed with it suction and case panel assembly in supporting system and the online, by the online dehydration.When producing papery, suction and case panel assembly separate with paper, only off linely contact with paper.The dual-network dehydration section is followed in the back, is finished by the short fan-shaped section that format roll makes progress.Led by the long radius profiled sheeting and be bent downwardly in two subsequently net shapings district.

Description

The forming method of paper or board web and device

The present invention relates to a kind of is the paper of raw material or the manufacturing process of board web with the fiber.This method is used on the wet end of paper machine or similar devices.This wet end is made up of an off line loop and online loop.Off line loop and the associated working of off line loop.In the method, will deliver to the start-up portion of off line loop up stroke from the fiber suspension of System of Paper Machine Head Box, this start-up portion has constituted first single net drying zone.Then make the fibrage of partial dehydration deliver to second drying zone.In this district, make the fibrage of the topped above-mentioned partial dehydration in online loop, this fibrage is continued in the dehydration of second drying zone, separate with the fibrage of shaping in the loop of then surfing the Net, and this fibrage is along with the stroke in off line loop continues to move.

The invention still further relates to implementing the Web forming apparatus of the inventive method.It comprises that one has and is the off line loop of up stroke of level and one basically with above-mentioned off line loop associated working and is provided with the Internet device in online loop, and flow box.Flow box is used for the fiber suspension jet flow is delivered to single net start-up portion of off line loop up stroke.The associating stroke of off line and online between also be formed with a two net shapings district thereafter.Be provided with and place the various parts that play dehydration in off line loop and the online loop in this pair net district that is shaped.

In the manufacturing process of the most ancient paper or board web, paper web is to be shaped on the wet end of the so-called fourdriner forming device of a level, fiber suspension on the wet end total length only in a direction-promptly dewater downwards.Top and the following quality of the paper of producing like this differs from one another, and is smooth below the top ratio of paper, the vestige that is produced by forming net clearly more or less arranged, promptly so-called net mark below it.Aspect fibr tissue, paper top and followingly also differ from one another, the short glass fibre that comprises above and the filler of paper are more much more than following, and this is because at folk prescription during to dehydration, following most of thin finely caused to washing off.To printing, it is important making the two sides quality try one's best identical.Difference is called as " unequal-side degree " (unequal-sidedness) between the paper two sides.

In the prior art, more known paper machines can be used to reduce the unequal-side of paper.These machines can be divided into two big classes, i.e. Zhuan Yong twin wire former and so-called hybrid shaping device (hybridformer).In the former of special use, the shaping of paper web is all to carry out from start to finish between two nets.In the hybrid shaping device, paper web then allows this partially-formed paper web by between two nets, with the mutual alignment of final curing fiber at first online a shaping.

One of advantage of hybrid shaping device is, the wet end of available existing fourdriner forming device is by relatively simply converting, and, loads onto an online loop with off line up stroke associated working in off line up stroke mid portion or decline that is.Except that the quality that has improved the paper of producing, can also strengthen the dehydration of carrying out, thereby improve the speed of production of paper machine at wet end.Introduced a kind of hybrid shaping device in No. 820742, applicant's Finnish patent application, it is mainly used in the printing of producing news printing paper and similar quality, and its speed of production is about 900 meters/minute or higher.

Usually, the hybrid shaping device of prior art all is unsuitable for producing ground paper and cardboard, because follow beginning part in two mesh portions of first single net drying zone back, net and the fibrolaminar stroke that places between two nets part to become paper web are led immediately relatively suddenly, and are being bent revolving roll on a segment length the distance or bending on the static surface that is referred to as formed mat.Crooked shaping makes paper web produce a kind of interior shearing effect, and when the thickness of paper increased, it is more severe that this effect can become.Therefore apply a quite high dewatering pressure to the fiber between two nets, just this is inversely proportional to the radius of curvature of relevant spigot surface in the stretching of outer net to this pressure.

Because space problem and other structural factor, in existing hybrid shaping device, introduce as No. 75375 (being equivalent to United States Patent (USP) No. 4614566) of Finnish patent, the radius of curvature that changes the member of net direction is so little, if so that utilized this former to produce thick relatively paper and plate, the instantaneous relatively pinch effect that is added on the paper web that is shaped in this stage would be just too big.Therefore, excessive compression can damage fibrage, reduces the quality of finished product, has particularly reduced its intensity, thereby has also reduced printing quality.In the worst case, excessive compression can cause the what is called " cracked " of paper web, causes to produce to interrupt.

About prior art situation of the present invention, the please the applicant's who further submits to the Finnish patent application and the Finnish patent application of Messrs.Valmet-Ahlstrom Inc company with reference to No. 4769111, the United States Patent (USP) of Messrs.A.Ahlstrom company with the application.

Main purpose of the present invention provides a kind of former of many performances, utilizes it can obtain the product of the speed of production and the wide region grammes per square metre of wide region, and therefore, the grammes per square metre scope of utilizing same former can make paper and cardboard can reach 30 gram/rice ²To 500 gram/rice ², the speed of production scope can reach 100 meters/assign to 1200 meters/minute.

One of starting point of the present invention is the applicant's " Sym-Former R " (TM) No. 75375, folded formula twin wire former Finnish patent of Sym type), have found that in use it works preferably under less grammes per square metre and high-speed case.Therefore, the objective of the invention is further to improve " Sym-Former R " former of the applicant, its scope of application can be enlarged, can comprise ground paper and cardboard, and can adopt low speed.

When attempting to reach the production of higher grammes per square metre paper, noticed that the shaping uniformity and the smoothness of the quality, particularly paper of the paper that its is produced all has been subjected to influence with this " Sym-Former " former.The objective of the invention is also will to avoid this shortcoming and shaping uniformity that can production paper delivery under all very wide situation of speed of production and grammes per square metre scope and paper and the cardboard that symmetry all has good quality.

Another purpose of this is that a kind of former will be provided, and its some embodiment is specially adapted to the wet end of existing fourdriner forming device is reequiped.

Another object of the present invention is that a kind of method and former will be provided, and wherein, can be added on this paper web improving the shaping of paper and the micro-turbulence of smoothness in the suitable stage of dehydration.

The former that the purpose of this invention is to provide a kind of many performances, it can avoid the excessive dewatering pressure that stretch to occur because of paper web at the initial part of sheet forming at least, and after the level (Couching) that paper goes to reach suitable if having time, the final stage that is shaped at paper just applies this pressure.

Subsidiary purpose of the present invention provides a kind of so multiduty method and sheet forming device, and wherein the dual-network dehydration district is not less than down the horizontal plane on netting twine plane.This is in the shaping of paper and can utilize under the situation of repacking and advantage is all arranged aspect the framework knot of existing fourdriner forming device wet end.

Another subsidiary purpose of the present invention provides a kind of like this method and many performances former, and this former can adopt second flow box where necessary, utilizes it the paper pulp of second kind of quality or the paper pulp of equal in quality can be delivered on the fibrage that is being shaped.

Be the purpose that achieves the above object and occur later on, the principal character of the inventive method is:

After initially dewatering by off line single net drying zone, the fibrage that is being shaped is by an off line supporting system that constitutes the direct extension of above-mentioned single net drying zone.In this supporting system zone, can prevent the dehydration that causes by the gravity effect by off line to a great extent.

Select the mode of sheet forming according to the grammes per square metre of the paper that will produce, when producing the paper of big grammes per square metre, paper web is passed through after single net drying zone, arrive the start-up portion in dual-network dehydration district.This start-up portion is to be determined by the supporting system that places inboard, off line loop and suction and chopping board (foil) device.This suction and case panel assembly place example in the online loop, and relative with supporting system.Dehydration is mainly undertaken by online in this start-up portion.In second kind of alternative sheet forming mode, when producing thin paper web, above-mentioned suction with facing to the off line of it does not contact with the case panel assembly;

After stage, a dual-network dehydration part is arranged at above-mentioned sheet forming, this part places forming rolls or the like guiding of online in the loop by one, and upwards crooked in short fan-shaped section.So, be directed to and be bent downwardly by two net shapings district of forming board or corresponding part guiding.This forming board has bigger radius of curvature.Behind the district that is shaped by two nets, paper web is along with a wherein net motion, preferably along with off line motion.

On the other hand, the principal character of apparatus of the present invention is: at its suitable and long start-up portion, its two nets second drying zone is smooth, and has constituted the direct straight line extension of single net start-up portion.And two barriers are by placing in the online loop, and have the hollow lining face forming rolls a short fan-shaped section guiding and be bent upwards.Afterwards, a forming board is housed in off line loop.The spigot surface of forming board is bent downwardly two barriers guiding.The spigot surface of forming board is preferably with floor and has bigger radius of curvature.Surfing the Net the initial of the inner, loop, be equipped with suction and case panel assembly.When this building mortion be transferred to be used for producing thin papery (usually 30 to 120g/m ²The grammes per square metre scope in) time, can utilize actuator will absorb water with the case panel assembly from be used to produce ground paper matter below the position of operating position above being raised to.

In high running speed and low grammes per square metre scope (usually at 120g/m ²Below) in, can be used as the hybrid shaping device of Sym type former according to building mortion of the present invention, the suction of its Internet device and case panel assembly are raised up to top position.Therefore, its running speed is in 800 to 1200m/min the scope usually.

Under the situation of using same paper machine, as needs production thicker papery or cardboard, for example 100-500g/m ²Even higher grammes per square metre scope, and when adopting lower running speed again, can be adjusted according to the running of building mortion of the present invention, the suction of Internet device and case panel assembly can be rotated on the self-regulated nodal section that is positioned at one group of inboard backbar of off line device.Through after single net start-up portion, can mainly utilize suction and case panel assembly with the dehydration direction conversely, undertaken by online.And utilize be positioned at off line below and with one group of backbar of suction and case panel assembly positioned opposite, can prevent by off line dehydration basically.So after most of moisture content was removed, last dehydration was to utilize " Sym former " suitably crooked two mesh portions to carry out.Arrange two mesh portions of this bending, the paper that makes thicker part keep flat (Couched) is not subjected to the influence of the shearing force that excessively acutely or for a long time changes or produce because of this variation on the direction.

In the present invention, behind the initial drying zone of single net, need its dehydration of control, its dehydration is mainly undertaken by the online loop.In this connection, it can utilize and place the dewater unit of online in the loop, for example the dewater unit as being introduced in No. 8703468, the applicant's the Swedish patent application.This device comprises that combination has helping suction or scraping the water cutter of corresponding collecting chamber.It is very easily that collecting chamber connects with suction source.In addition, this dewater unit comprises a collecting chamber at least, and this chamber is made up of several chopping boards and is communicated with suction source.In addition, in off line loop, the dewater unit in the face of in the online loop is equipped with a series of net backbars.These supporting beam actions are minimizings or prevent from basically to dewater by off line.On the one hand, apply an enhancing upward to the suitable pulsation of pressure and this pressure of dehydration in this zone, for partially-formed paper below the online.The shaping of the paper that is being shaped on the other hand, is also because of having utilized this pressure and pulsation to improve.Each root beam of these net backbars all fills the compression air hose as utilization off line loop is loaded.Therefore, the compression that applies paper feeding is self-regulating.

In case of necessity, can adopt one or several second flow box in the present invention.Utilize these flow boxs, before two nets are shaped the district, can be to the paper that is being shaped with the paper pulp streaming of same quality or different quality, therefore, can control the overall process that paper is shaped, in case of necessity, can be used to produce different laminated construction, when for example being used to produce cardboard.

Utilize a networking backbar, promptly web plate used according to the present invention produces micro-turbulence.These net backbars place in the off line loop, and as the direct straight line extension of single net drying zone.Micro-turbulence has improved the shaping and the smoothness of paper web.And self-regulating interstitial area is to produce at the initiating terminal of two mesh portions.This self-regulation interstitial area also brings advantage at aspect the sensitivity of dehydration and paper shaping aspect, and the pressure that the stretching because of net is produced is not added on the paper web, and the interstitial area between the net can very freely be regulated and is shaped according to the situation of discharge water decision.

Below, the some embodiments of the present invention shown in each figure in reference to the accompanying drawings are described in detail the present invention.The present invention shows no sign of the details that is confined to these embodiment.

Fig. 1 shows the first embodiment of the present invention, and it is adjusted to the working method of " Sym type former ", utilizes this former high-speed production to hang down the paper or the cardboard of grammes per square metre.

Fig. 2 shows same former shown in Figure 1, is adjusted to working method, even can produce the paper or the cardboard of high grammes per square metre under low speed.

Fig. 3 shows the second embodiment of the present invention, is adjusted to the working method of producing higher grammes per square metre product.

Fig. 4 shows the working method of third embodiment of the invention, wherein, uses two chopping boards and or suction box thereon in the net arrangement.

Fig. 5 represents the fourth embodiment of the present invention, and it adopts one second flow box, utilizes it can make thicker cardboard.

Fig. 6 is according to a cover chopping board and a suction box of the present invention and places in the off line loop also facing to the net supporting of chopping board and suction box and the vertical sectional view of supporting (blocking) device.

Paper former shown in Fig. 1-5 comprises a flow box 19 and an off line loop 20.The stroke in off line loop is basically by breast roll 21, wite roll 22, forming board 26, couch roll 28 with drive net roller 29 guiding.In addition, in 20 inboards, off line loop, in the first drying zone 20a, one group of dewatering element 23 is arranged.At second drying zone net supporting arrangement 30 and suction box 27 are arranged.These suction boxs are placed in forming board 26 and roller 25(Fig. 3) and couch roll 28 between off line 20 stroke on.

Fig. 1 also comprises an online loop 10 by

deflector roll

11,11a and 11b guiding to paper former shown in Figure 5, the off line loop in its topped dual-network dehydration section.In addition, in online 10 inboards, loop, a dewater unit 40 is arranged, it illustrates more specifically in Fig. 6.As first parts, device 40 comprises the dehydration scraper of an auto-slice type, and it and suction chamber are linked.Dewater unit 40 also comprises two three water legs, and the bottom of groove is made up of chopping board (foil), and it is put and leans against in the online 10.

Below, just Fig. 1 is a little narrated to differing from one another of various formers shown in Figure 5.

Fig. 1 and Fig. 2 illustrate two kinds of different working methods of same former.In the working method of Fig. 1 " Sym former ",, be about 30 usually to 120g/m with the thin papery of high-speed production ²Fig. 2 illustrates a kind of working method of same former, usually with the papery thicker than low speed production, is about 120 to 500g/m ²

As depicted in figs. 1 and 2, in two nets are shaped the district, have hollow lining face 16 ' forming rolls 16 back, have one have floor 26 ' forming board 26, this floor has bigger radius of curvature R, logical R=5 to 9m still.Some suction flat boxs 27 are arranged after the forming board 26.In Fig. 1, two barriers stop to line B from the start line A1 of the fan-shaped part of roller 16.In Fig. 2, two barriers stop to line B from the line Ao towards deflector roll 11a.

In Fig. 3, the forming board 26 shown in Fig. 1 and Fig. 2 is replaced by short forming board 26A and a forming rolls subsequently 25.Forming rolls preferably has smooth hard lining face.The radius of forming rolls 25 is significantly smaller than the radius of curvature R A of the floor 26A ' of forming board 26A.Usually in the scope of RA=0.8 to 1.5m, the structure of others is similar to above-mentioned structure illustrated in figures 1 and 2 to this radius of curvature.

Structure shown in Figure 4, except be furnished with above the forming board 26 suction and case panel assembly 40A, other all with structural similarity illustrated in figures 1 and 2.This device 40A except that the profile of the chopping board system that limits its downside have a floor 26 corresponding to forming board 26 ' the curve form this point have the difference, its structure and operation all are similar to above-mentioned dewater unit 40.Forming board 26 back are with a suction flat box 27a who places 20 inboards, off line loop is arranged.In above-mentioned suction flat box 27a back one second forming rolls 16a is arranged, it places online 10 inboards, loop, and smooth and hard lining face is preferably arranged.

Structure shown in Figure 5 is similar to structure illustrated in figures 1 and 2, and its difference is to have used among Fig. 5 one second flow box 60.By its cutter awl 61, the second paper pulp jet flow J1 is shaped before the district on the fibrage that is shaped on the wet end 20a of single net fourdriner forming device delivering to two nets.The pulp quality of the main jet stream J and the second jet flow J1 can be identical also can differing from one another.For example, under latter event, be the cardboard that is used to produce laminated construction.

For ground paper matter (120g/m ²To 500g/m ²) production, Fig. 2 is as follows to the working condition of sheet forming device shown in Figure 5.Flow box 19 is delivered to paper pulp jet flow J on the horizontal start-up portion 20a in off line loop 20, promptly deliver on first drying zone, in this drying zone, dehydration work is only slowly carried out downwards by off line 20, also utilize suitable dewatering element 23, come (foilbox) suitably to strengthen dehydration as the chopping board case.The fibrage that is shaped on 20 surfaces, off line loop continues its stroke and moves on to second drying zone, when online loop 10 with a little angle d(Fig. 6) when being directed near off line loop 20, just formed this drying zone.Optimal angle d is 2 to 5 °, and can be by device 18(Fig. 1) adjust online loop 10 aligning roller 11a and regulate in the position of vertical direction.

In Fig. 2 to Fig. 5, second dual-network dehydration is divided into several segments.Place the dewater unit 40 of online 10 inboards, loop and place off line loop 20 inboard and formed first section of second drying zone with the net supporting arrangement 30 of dewater unit 40 associated working.The first long section of the first drying zone 20a and second drying zone all had been on the same horizontal plane before forming rolls 16.Forming rolls 16 rotates, and makes the stroke of net 10 and 20 form a little angle that makes progress.This angle equals the size of sector shape a.On this fan-shaped section a, net 10 and 20 associating stroke contact with forming rolls 16.This fan-shaped section a forms second section in dual-network dehydration district.Pressure between the net 10 and 20 (P=T/R) is removed more water from the paper web W that is shaped.These water conservancies are thrown into water leg 13 with action of centrifugal force.

Online 10 utilizes deflector roll 11b to break away from placing off line 20 lip-deep paper web W, and above-mentioned paper web continues to move to roller 14.Suction box 27 can guarantee that paper web W does not follow net 10 and moves, and net 10 turns back to roller 11a.Near couch roll 28, the paper carrying roll 14 that has suction zones 14a is put together with separating woollen blanket 15, utilizes woollen blanket 15 that paper web W is sent to the press section (not shown) from wet end.

Former shown in Figure 1 adjusted to be used to produce common grammes per square metre and be about 30 to 120g/m working method than papery.In this case, dewater unit 30 is as the direct straight line extension of single net start-up portion 20a, and utilize the micro-turbulence of groove 35 generations between dewater unit and its backbar (Fig. 6) to finish the dehydration work that takes place by off line 20, and paper is played the shaping effect.

The start-up portion 20a of substantially horizontal single net drying zone is the following net arrangement that belongs to shown in Figure 1, and its back then has from the two mesh portions between the line A1 to B, and wherein paper web W moves along with off line 20.For example, following mesh portions is the wet end of the fourdriner forming device that has a morning that has a frame structure 100.It is early existing, with specific Internet device 70 of the present invention be combined to it above be combined into new equipment.

For example, the dewater unit from existing fourdriner forming device wet end is arranged on single net start-up portion 20, such as chopping board and/or suction box and at the suction box 27 of two mesh portions ends.

Internet device 70 comprises a framework, and it has level and vertical beam 71,72, and various parts are fixed on the framework.The stroke in online loop 10 be utilize hollow lining face 16 is arranged ' vent roll 16 and forming board subsequently 26, begin to lead from the starting point A1 of two mesh portions.Forming board 26 have a radius of curvature be R floor 26 '.The dual-network dehydration district terminates in the zone of last suction box 27.

According to Fig. 1, Internet device 70 comprises a framework 75.This framework 75 rotates around pivoting in vertical plane, and the sharp screw 17a and 17b or similarity piece of adjusting attaches it on the horizontal beam 71.The first wite roll 11a of online 10 is installed on the framework 75.In Fig. 1, display frame 75 and be installed in dewater unit 40 on its support ' and the 1st deflector roll 11a all be positioned at the rotating position that makes progress, when the papery that will produce changed, it can turn back to position shown in Figure 2 from this position, on one position, back,

device

30 and 40 associated working relative to one another.

Start-up portion 20a at single net drying zone, the dewatering element 23 of utilization between the device 30 of the discharge port of flow box 19 and for example forming board and chopping board and so on dewaters, at single net start-up portion 20a, be dewatered to a certain degree to water by off line 20, the remainder that makes enough ratios is as dehydration upward.Through behind the line A1, net 10 and 20 associating stroke are bent upwards a=10 ° to 35 ° preferably a=15 ° to 25 ° of this angle with the angle of short fan-shaped part a.

Utilize one group of groove 35(Fig. 6 that beam is interior in the net supporting arrangement 30) produce micro-turbulence, thus can before beginning, two barriers finish and improve the shaping of paper web W.

After fan-shaped section a, the Direct Travel of one section very short net 10 and 20 is arranged, in forming board 26 zones, utilize the compression between net 10 and 20 and utilize action of centrifugal force, 10 dewater by surfing the Net to the side.After forming board 26 trailing edges, the straight associating stroke of one

section net

10 and 20 is arranged.

In the working method of Fig. 1, former of the present invention is to produce than papery according to the mode of hybrid twin wire former as mentioned above.About its concrete structure and operation, please refer to the applicant's No. 75375, above-mentioned Finnish patent.

Fig. 6 shown and belonged to Fig. 1 to the dewater unit 40 of the wet end of Fig. 5 and its most important CONSTRUCTED SPECIFICATION, and with the off line support system of above-mentioned dewater unit 40 associated working.

Dewater unit 40 is assemblys, generally includes 2 to 4 (being 3 among the figure) suction and collecting

chamber

46,47,48.Each chamber is separated each other by dividing plate 47b and 48b.Every

chamber

46,47 and 48 all has gas port (not shown) and the drainpipe 49 that is connected to suction source.The collector pipe 46a that belongs to first suction chamber 46 forms between 46b and the guide plate 46c setting a roof beam in place of dewater unit 40.There are a horizontal chopping board scraper 51 and the wedge 52 that can utilize regulating shaft 53 to adjust in lower end at pipe 46a.This scraper and wedge form the gap E that the part is adjustable.Gap E is across the width of former, and the water that pushes out from the fibrage between net 10 and 20 flows into first Room 46 by groove E.

After the chopping board scraper 51 of device 40 shown in Figure 6, have some similar chopping board scrapers 51 ' and 51 ", their bottom surface all is in same level.The water that chopping board scraper 51 ' gathering is separated from the fibre structure under first suction-chamber 46.These water are directed in the suction chamber 47 by pipe 47a, and pipe 47a forms between dividing plate 47b and guide plate 47c." water of assembling is directed in the 3rd suction chamber 48 by pipe 48a, and pipe 48a forms between the rear wall 48d of dewater unit and guide plate 48c equally, by the following scraper 51 in step.

Pipe 46a shown in Figure 6 is with relevant chopping board scraper 51 and adjust Sucking-assisting type dewatering element of wedge 52 formation.When utilizing this former during than ground paper and millboard, preferably to utilize vacuum dehydration to help the automatic scraper system works with low speed production.Optimal vacuum is 6-8kpa(kPa).At the dehydrating amount (partly also being vacuum amplitude) that this stage carries out upward, can utilize the gap E that regulates between wedge 52 and the chopping board scraper 51 highly to change.

Among Fig. 6, the dehydrating effect of the Sucking-assisting type dewatering element and relevant first suction chamber 46 is local, is limited near the tip of the first chopping board scraper 51.The drying zone broad of second suction chamber 47, be by chopping board scraper 51 ' quantity decision, in Fig. 6, be expressed as 7, be an object lesson.Chopping board scraper 51 ' effect be based on its associated working with the net supporting arrangement 30 that places off line loop 20 inboards.The principal character of supporting arrangement 30 and its work is, utilizes it, can be in the zone of dewater unit 40, in desired mode, increase continuously the compression that imposes on the shaping paper web by off line 20.Utilize this compression, the dehydration of paper web W is mainly undertaken by online loop 10, water enters suction pipe 47a, and enters suction chamber 47 by suction pipe 47a.The operation class of the 3rd suction chamber 48 is similar to the work of second suction chamber 47.

The second and the

3rd Room

47 and 48 negative pressure that present shown in Figure 6 preferably will be much higher than first Room, and promptly Room 47 are about 10 to 20kpa, and Room 48 are about 15 to 30kpa, and its concrete numerical value depends on the material of the paper of producing.

The suction chamber of placing before and after captation 40A shown in Fig. 4 comprises two.Place two wedges below two suction chambers to contact with net 10.These two wedges are with its suction pipe at the mouth rear side device for limiting 40A of the direction of motion of net 10.

About Fig. 4, principal character of the present invention should be further clear and definite, in some embodiments of the invention, particularly in those embodiment that are suitable for most fourdriner forming device wet end is transformed, the district that is shaped does not need to reach fully below the definite T-T plane of single net start-up portion 20a.According to Fig. 4, after forming rolls 16a, in off line loop 20, there are two barriers of suction box 27 to turn back to determined horizontal plane T-T again by single net start-up portion 20a.This list net start-up portion 20a is level preferably.

With regard to device shown in Figure 6, when with Fig. 2 when the former of Fig. 5 is produced thick matter paper, its dehydration is as follows.At the first drying zone 20a of former, the fibrage that divide to be shaped in 20 upper surfaces, off line loop enters the space between

net

10 and 20, and its clearance angle d is by the determining positions of deflector roll 11a.Deflector roll 11a leads to net 10, but the position use device 18 of roller is adjusted.Fibroreticulate surface contacts with online 10 in wedge 52 fronts.In this position, net supporting arrangement 30 parts that support off line loop 20 also begin, and utilize its effect, and fibrolaminar dehydration begins and mainly takes place upward.

The beam 31 of device 30 shown in Figure 6 utilizes the mid portion that is filled with compressed-air actuated rubber tube 32 to be bearing on the longitudinal supporting beam 33.Backbar 33 is again by 34 supportings of horizontal box-girder.The pressure effect of rubber tube 32 can be regulated, make act on off line 20 and the load of fiber web member can on the direction of motion of net 10,20, increase successively.In rubber tube 32, use pressure than paper, as 10 to 50cmH ₂The O(centimeter water column), apply a very appropriate compression for the paper web W of shaping stage with this.Dewatering pressure is self-regulating.The component surface of device 30 is provided with the transverse groove 35 that traverses net 20 whole width.These grooves also have some dehydrations by off line 20.Utilize these grooves to produce micro-turbulence, to improve the shaping of width of cloth W.

Among Fig. 6, dehydration is proceeded in the contact wire of paper web W upper surface and the zone between the wedge 52.Wherein, the inner face in online 10 is formed with water layer.This water layer is collected at wedge shape space between net 10 and the wedge 52 and the gap E between wedge thereafter 52 and the chopping board.By this gap, utilize its kinetic energy effect and/or the vacuum action of vacuum chamber, make water be pressed into first Room 46 of dewater unit by pipe 46a.Wedge 52 can utilize adjusting device 53 vertically to adjust, and can regulate the water yield that enters conduit 46a with this, and the while is the adjustable air amount also.Nature, the adjusting of inclination angle d between the net 10 and 20, the adjustment that enters pipe 46a gap, and the paper or the cardboard that all depend on production by the adjusting of supporting system applied pressure.

In some cases, utilize adjusting wedge shown in Figure 6 52 can replace with another kind of structure for the Sucking-assisting type system on basis.In this structure, regulate wedge 52 and replaced by a roller, the rotating speed of roller and its height and position, promptly the distance of it and net 10 is adjustable.

To provide claim of the present invention below, nationality is borrowed these claims, and various details of the present invention can change in the scope of the invention thought of these claims regulations, and is different from above-mentioned those embodiment that only introduce as an example.

Claims

1, with the fibrous material is the paper of raw material or the manufacturing process of board web (W), this method is used for the wet end of paper machine or similar devices, wet end is made up of off line loop (20) and online loop (10), this off line loop initiating terminal of stroke at least thereon is level basically, this online loop and this off line loop associated working, in the method, to deliver on the start-up portion (20a) of up stroke in off line loop (20) from the fiber suspension jet flow (J) of System of Paper Machine Head Box (19), this start-up portion has constituted first single net drying zone, to deliver to second drying zone through the fibrage of partial dehydration then, in this second drying zone, make the fibrage of topped this process partial dehydration in online loop (10), make this fibrage in the second dehydration section, continue dehydration, online loop (10) and the fibrous web (W) that is shaped are broken away from, make fibrous paper along with the stroke of off line loop (20) continues to move paper web (W) is carried out back operation processing, the inventive method is characterised in that:

After single net drying zone (20a) initially dewaters by off line (20), the fibrage (W) that is shaped is passed through the supporting system (30) of off line (20), system (30) constituted should list barrier (20a) direct extension, in the section of this supporting system (30), can prevent the dehydration that causes because of the gravity effect by off line (20) to a great extent

Select the mode of sheet forming according to the papery grammes per square metre of producing, when producing the papery of higher grammes per square metre, after through single net drying zone (20a), paper web (W) is delivered to the start-up portion in dual-network dehydration district, this start-up portion be by place the inboard above-mentioned supporting system (30) in off line loop (20) with by placing inboard suction relative in online loop (10) and case panel assembly (40) to determine with supporting system (30), dehydration is mainly undertaken by online (10) in this start-up portion, in second kind of alternative paper forming mode, when the thin paper of production papery, to absorb water and case panel assembly (40) with disengage facing to its off line (20), and

Passing through above-mentioned sheet forming after the stage, follow a dual-network dehydration section, this section is by a forming rolls (16) or a corresponding part guiding that places in the online loop (10), and it is upwards crooked in fan-shaped section (a) scope of lacking, by forming board (26) or corresponding part two nets are shaped subsequently and distinguish guiding, make it to be bent downwardly, forming board (26) has a bigger radius of curvature (R), after two net shapings district, paper web (W) is directed to and follows wherein a net and move, preferably make it follow off line (20) and move together.

2, the method for claim 1, it is characterized in that, the section later at single initial drying zone of net (20a) of off line up stroke is smooth at its long start-up portion, and having constituted the direct straight line extension of the off line initial stroke of former (20a), groove (35) or the corresponding structure of utilizing net supporting member (31) to be provided with at this start-up portion produce micro-turbulence in paper web (W).

3, method as claimed in claim 1 or 2 is characterized in that: be generally 30 to 120g/m when former is adjusted to be used for producing ²When hanging down the paper of grammes per square metre, to place suction and dewatering box (40) group in the online loop (10) to be raised to a upper position (40 ') with online (10) top deflector roll (11a) at least, make two net sheet forming districts place in the online loop (10) have hollow lining face (16) ' the fan-shaped part of weak point (a) of forming rolls (16) locate beginning, when production is generally 120 to 500g/m ²Than ground paper matter the time, the parts of Internet device (75) are transferred to lower position, make the net supporting arrangement (30) that is positioned at off line loop (20) and place suction that online loop and having changeed gets off and case panel assembly (40) dewaters as the start-up portion in dual-network dehydration district, main here by surfing the Net and by means of described suction and case panel assembly (40).

4, as each described method in the claim 1 to 3, it is characterized in that; Two barriers are bent upwards a short fan-shaped section (a) on the forming rolls (16) that is positioned at the online loop, the angle of fan-shaped section is selected in a=10 ° to 45 ° scope, optimal angular range is a=15 ° to 25 °, and two barriers are reclinate on the static forming board member (26) of bending, and the radius of curvature (R) of member (26) is more much bigger than the radius of this forming rolls (16).

5, method according to any one of claims 1 to 4, it is characterized in that, after the section (a) that passes through the forming rolls (16) that is positioned at the online loop and hollow lining face (16 ') are arranged, two barriers are reclinate on a forming board (26A) of lacking, forming board (26A) has bigger radius of curvature (RA), a steeper district that is bent downwardly is then arranged, this buckled zone is to utilize second forming rolls (25) that is positioned at off line loop (20) to lead, so two barrier is positioned at the suction flat box (27) of off line loop (20) by one or several or quite installs.

6, as method as described in each in the claim 1 to 5, it is characterized in that, in the method, the district's forming rolls (16) that are shaped through two nets go up occur be bent upwards the district after, in the dehydration of being undertaken by online (10), adopted the captation of installing facing to forming board (26) (40A)

7, as in each described method in the claim 1 to 6, it is characterized in that, when producing, before two nets are shaped district's beginning, will deliver to above-mentioned single net drying zone (20a) from second paper pulp (J1) of second flow box (60) than ground paper matter.

8, implement the Web forming apparatus of each described method in the claim 1 to 7, it comprises an off line loop (20), an Internet device (70) and following flow box, and off line loop (20) have substantially horizontal up stroke; Internet device (70) and off line loop (20) associated working, and is furnished with online loop (10), the flow box of settling (19) is used for fiber suspension jet flow (J) is delivered on single net start-up portion (20a) of off line loop up stroke, thereafter, be provided with two net shapings district, it is formed between the associating stroke of off line (20) and online (10), in this pair net is shaped the district, have and place various members and the member group that in off line loop (20) and the online loop (10) dehydration is worked, the invention is characterized in: basically and long start-up portion at it, the second dual-network dehydration district is smooth, and constitute the direct straight line extension of single net start-up portion (20a), and two barriers of being led by a short fan section (a) of forming rolls (16) are directed to and are bent upwards, forming rolls (16) is fixed in the online loop and has hollow lining face (16 '), the back, forming board (26) is housed in off line loop (20), the spigot surface of formed mat (26) is bent downwardly two barriers guiding, spigot surface is preferably with a floor (26 '), and a bigger radius of curvature (R) arranged, initiating terminal in online loop (10) is equipped with suction and case panel assembly (40), is generally 30 to 120g/m when the shaping device is adjusted to produce ²Grammes per square metre than papery the time, can utilize actuator (17a, 17b), make described device (40) from be used to produce ground paper matter below the position (40 ') of operating position above being raised to.

9, device as claimed in claim 8, it is characterized in that, on the straight preliminary sectors in dual-network dehydration district, one forming board (30) is installed, it comprises off line self-adjusting backbar (31), forming board (30) places in the off line loop (20), and is equipped with they parts as the device that prevents to dewater, and is mounted with a suction and case panel assembly (40) facing to forming board (30) in the online loop.

10, install as claimed in claim 8 or 9, it is characterized in that, place the forming board in the off line loop (20) to form by self-regulating crossbeam (31), crossbeam 31 supports and extends through facing to two or three suction chambers and its case panel assembly (51 by the flexible pipe (32) or the corresponding part of pressurising, 51 ', 51 " zone), the online (10) of case panel assembly guiding dewater unit, and staggered relatively with crossbeam (31).

11, as any one described device in the claim 8 to 10, it is characterized in that, be placed on suction in online loop (10) and case panel assembly (40) and have two, preferably the case group and the suction chamber thereafter (46 of three casees at least by one group, 47,48) and the case panel assembly (51 that places this case group bottom, 51 ' 51 ") form described device (40) be used for leading dual-network dehydration district and as the direct straight line extension of single net start-up portion (20a).

12, as any one described device in the claim 8 to 11, it is characterized in that, the suction and case panel assembly (40) before, a Sucking-assisting type device is arranged, its acclivitous pipe (46a) communicates with first suction chamber (46), and the mouth of this pipe (46a) has one with respect to online (10) adjustable shaping piece (52).