CN1009213B

CN1009213B - Headbox trailing element

Info

Publication number: CN1009213B
Application number: CN 85103870
Authority: CN
Inventors: 约遮·约安·安东尼·罗德; 杰美·雷罗·艾华
Original assignee: Beloit Corp
Current assignee: Beloit Corp
Priority date: 1985-05-10
Filing date: 1985-05-10
Publication date: 1990-08-15
Also published as: CN85103870A

Abstract

The present invention relates to a trailing element for a paper machine, which is arranged in a layering chamber of a paper pulp box. The trailing element is composed of stacked materials, wherein a transverse beam (used for fixing the element in the layering chamber) at the upstream end of the trailing element is composed of stacked fibers. The fibers on the external surfaces extend along a direction of a machine, and the fibers in the transverse beam extend along a direction of the cross section of the machine. As a result, the upstream end of the element has larger rigidity along the direction of the machine. The element is tapered and becomes thinner along a direction toward the downstream end to a downstream thin tip end part. The downstream end is composed of all layers containing the fibers which extend along a direction of the cross section of the machine so as to enhance the rigidity and reduce the instability of the element.

Description

Headbox trailing element

The invention relates to and improve the paper machine head box, especially improve head box layering chamber and improve trailing element, an end that is positioned at the upstream of this element is fixed, the other end can freely extend to the layering opening part, and the paper pulp raw material that layering chamber opening part could be located and remain on to this element automatically has small turbulence.

The invention relates to relevant the awaiting the reply simultaneously the application case application number 555158(applying date 1983,11,25 that we once proposed and disclosed) further improvement invention, its disclosed content appendix is in this, for your guidance.

Design about the trailing element (layering that is positioned at head box is indoor) of automatic location that can be free movable at first is disclosed in United States Patent (USP) 3939037(Xi Er).People such as U.S. Patent application RE28269(Xi Er are arranged again later on), so the technology of trailing element just progressively spreads.When these trailing elements are crossed layering chamber opening when paper pulp stream, can produce and keep small turbulence.The advantage of this design of patent and function all can be used on the paper machine in the past, made multi-ply paper, were about to raw material of different nature and were fed into opposite both sides (these elements are arranged side by side) of each trailing element in the layering chamber.

But the head box by the characteristics of above-mentioned patent design also has shortcoming, and the device size that promptly produces turbulence (so that with fiber diffusion) in fibrous suspension is sizable.Adopt this kind device, the way with increasing turbulence intensity just may produce little turbulence.Therefore, this turbulence energy is to carry naturally from big to small, and intensity is big more, and then the energy transmitting speed is also big more.Therefore, can keep less turbulence.But the large-scale turbulence of this high strength meeting produces disadvantageous result, has promptly produced Free Surface disturbance and big fluctuation on the net platform.Therefore, the rule that the head box performance is general is to spray the diffusion of fluid and the degree of turbulence is closely-related in head box, i.e. turbulence is high more, diffusion good more.Under the condition defined in this, when selecting the structure of head box for use, a kind of extreme mode of essential selection perhaps considers to produce a high turbulence, so that the diffusion of injection fluid is better, perhaps considers generation one low turbulence, makes the diffusion of spraying fluid relatively poor.Because no matter be to adopt very high turbulence or adopt very low turbulence (this can cause spreading very poor) all in the paper of fourdrinier machine is shaped, to produce defective.The head box designing technique includes selected scheme of taking into account between two extreme cases.This scheme is exactly the original purpose to the design of so far head box, be developed into a kind of element of automatic location, this element can produce turbulence to a certain degree, and this turbulence is high enough to the fiber diffusion, is enough to avoid produce defective at Free Surface but hang down also to working as at shaping.Will be understood that the best scheme of taking into account is that the speed of machine and other are chosen different schemes by the structure of different paper making equipments, pulp thickness, fourdrinier wire platform, the structure of machine.Also have because these take into account scheme and always damage its preferably possible diffusion and/or the preferably possible flow pattern on fourdrinier wire, so we think, the time up to now, possibility still is significantly improved in the head box design.When considering when being shaped on fourdrinier wire, people will be appreciated that advantage when the present invention is applied to twin-wire former and original technology are applied to the shortcoming on the twin former.

The uniqueness of the element in the above-mentioned patent and the combination of novelty have guaranteed to have the fiber of a high diffusion and lower turbulence in nozzle when the stream slurry is ejected into the profiled surface of paper machine.Produce small fiber diffusion with this understanding, the turbulence that this is small can be not poorer than being diffused as with the common turbulence that headbox structure produced.It is found that it does not have big turbulence.(because the flocculation phenomenon mainly is that this big tubulence energy prevents to produce the thick flocculation again of fiber, must make it that big turbulence is arranged owing to the result of less turbulence decay.) diffusion that keeps the fluid on fourdrinier wire, spray, shaping operation is improved.

This method (is finished above-mentioned purpose with this method, produce small turbulence in other words and do not produce big eddy current) be fibrous suspension to be flowed through one become transversal parallel fluid channels system with machine, this runner is for even and undersized, but the aperture area percentage is bigger.Above-mentioned this two condition is that the big aperture area percentage of even and undersized runner and discharge mouth is essential.Therefore, the fluid in runner is to produce big turbulence in the large scale part, when the height of single runner hour, will cause turbulence to become very little.Need the big aperture area percentage of discharge mouth, to prevent producing large-scale turbulence in the discharge zone.Big entire area between each runner discharge mouth can cause producing big turbulence on these areas in other words.

Therefore, runner must carry out the transition to little outlet size from big inlet size.The variation of this kind size should make on certain distance and reduce to the little turbulence that required from import department with big Hydrodynamic turbulence within a certain period of time.Area size between each runner must equal the size of the port of export.This design of shrinking simultaneously is that important design is gone up in design.This design application (referring to top described) before us is used, and adopts a trailing element, this element to have the advantages that more improve.

Under certain operating condition, (it is used to obtain the turbulence of tiny scale this trailing element, does not need stability, and the transverse machine instantaneous pressure makes trailing element along the transverse machine bending, and can cause the uniformity of paper is changed.When paper pulp flows through wafing during sheet edge at trailing element with average rate, along machine direction on trailing element length because the ability of resistance to deformation is arranged, so it slightly is offset, under certain operation condition, static(al) and dynamic instability all may take place, according to the fluid power characteristic, resonant frequency also may reach.It is found that inertia and fluid dynamic force coupling all can be destroyed by the quality of suitable distribution, certain quality distributes and the chip architecture of wafing of stiffness distribution so have, and it is very important need having the elasticity this point.

Therefore, a purpose of invention provides an improved trailing element structure, and it can prevent the above-mentioned shortcoming that produces in existing structure.Its purpose particularly provides a trailing element, and this element has different deflection physical characteristics from the upstream extremity to the downstream, and method is to take laminated construction to reach.As adopting among the present invention, the noun of Cai Yonging is here: the direction with machine is the direction that pulp liquor stream flows through head box, with cross machine direction is and the rectangular direction of machine direction.So-called homogeneous is meant that in all directions identical character is all arranged, and so-called heterogeneous body is meant that in all directions all be not homogeneous, in other words, when when test the axis of variant direction, presents different character.

According to principle of the present invention, the target of design reaches by an automatic location trailing element is provided, and this element is positioned at its upstream extremity or installation end place in machine direction, has the bigger rigidity of structure; And on cross machine direction, be positioned at its downstream or the sheet end that wafts has the bigger rigidity of structure.In a reference coupon, this element is made by heterogeneous material, and preferably gather into folds mutually and make by each independent layer, since material property, direction, and the difference of size or number is so it also has different rigidity and flexible.Perhaps can adopt the different weaving directions of different braid methods or needle-like material, or adopt the different quality of controlling party tropism rigidity or the filament of size or quantity to make.Yet, preferably adopt fiber to obtain this different character.At the upstream extremity place, this fiber is arranged along machine direction, makes along having bigger rigidity on the machine direction; At this fiber of downstream is to have bigger rigidity along arranging on the cross machine direction, making on cross machine direction.Another characteristics are to have big intensity at the bearing cross beam place of upstream, can prevent that this place is bonding not firm, can also remove the jockey that disappears, to avoid producing the cleaning problem.Filler is filled in single wedge shape space, and not firm to prevent attaching, the fiber of cross machine direction is positioned at this interior volume, to reduce the thermal expansion in cross machine direction.On downstream direction, the skin place that is positioned at dividing plate of this trailing element downstream part mainly is the fiber that has along on the cross machine direction, and it has strengthened the rigidity on the cross machine direction so that reduce its warpage.Mainly the quite thin size at the fiber on the cross machine direction and the sheet edge that wafts on this outer surface, all strengthen the rigidity on the cross machine direction and reduced the rigidity on the machine direction, so that most advanced and sophisticated place can adapt to the streamline shape that produces minimal disturbances in fluid, the thin tip that on machine direction, has minimum rigidity and intensity, but on the machine cross-directional, has maximum rigidity, this can strengthen the stability of this section shape on cross machine direction, disturbance when flowing, thereby the generation of minimizing eddy current with reduction liquid stream.Similarly, can use the longest dividing plate,, reduce the generation of eddy current to increase its crystallized ability and to reduce turbulence with minimum gap, place, tip, and can adapt to streamline, adopt the dividing plate of multilayer to allow that minimum disturbance is arranged when being shaped (it helps the purity of layering) at this place.

Other purposes, advantage and characteristics will be disclosed with optimum implementation in this specification, claims and accompanying drawing, and the principle of the invention is given clearer introduction, introduce accompanying drawing below:

Fig. 1 is the diagrammatic cross-sectional view of the head box layering chamber of a certain band trailing element, in this layering chamber the paper pulp raw material of multilayer is transported in the shaped portion of paper machine;

Fig. 2 is the detailed construction by the trailing element of principle of the invention design and work, is the vertical cutaway view Amplified image of this trailing element shown in the figure;

Fig. 3 is the vertical cutaway view Amplified image by the another kind of trailing element of constructing of the present invention.

The explanation of optimum implementation:

As shown in Figure 1, head box 10 has a layering chamber 12, and aliunde pulp liquor stream is accepted in this chamber, and some trailing elements 11 of location automatically are housed in the layering chamber, this trailing element preferably extends from a side to opposite side ground, and is contained in its end that is positioned at the upstream on the wallboard 16 of band through hole.Raw material ejects through each aperture that is positioned on the wallboard from this head box, and pass through aperture 15 places of the layering chamber of this taper to layering, and (this part is made of the gap between the form metal silk screen 13 and 14 that moves of a pair of convergence to the forming section office.) Fig. 2 and Fig. 3 represented the detailed construction by the trailing element 11 of the optimum shape of principle design and use of the present invention.

In principle, the device of being introduced among Fig. 2 and Fig. 3 all is equipped with and adopts the non-trailing element that all claims structure, as disclosed in the relevant application case application number 555158 that awaits the reply simultaneously.Here, each part of dividing plate has been optimized in this design, and method is to utilize the oriented arrangement and the different thickness that utilizes material of layers of material, with different machinery and the fluid power performance that obtains different parts in dividing plate.Because the outermost portion of this structure is most important to its intensity and rigidity, so the performance of the thickness at this position and material and direction cooperate application, will obtain the best performance of dividing plate.In the layout as Fig. 2,18 places, end in the upstream of dividing plate or element 11 are the structure of interlayer at the skin 20 and 21 and similarly outer 22 and 23 of this element.These layers are preferably made (this fiber stretches along the paper machine direction) by the graphite that for example has fiber (or other material).As shown in FIG., there is the fiber of some layers to extend along transversal paper machine direction, shown in the little garden circle among the figure, each end of its expression fiber; With each layer that has the fiber that stretches along the paper machine direction, can clearly express the fiber that stretches along the paper machine direction.Two skins that fiber is arranged along machine direction, its internal layer is more longer than skin, that is to say, and layer 20 and 22 is bigger than layer 21 and 23 length.This will make the upstream portion of dividing plate or the thickness maximum of start-up portion, that is to say on skin, it mainly is fiber along the paper machine direction, with to greatest extent with its reinforcement, enable to sustain at one of the multilayer head box indoor closing force and pressure and descend, and still remain on pressure in one or several other the chamber, help to strengthen its rigidity, so that big turbulent flow is lowered.

To the inside, dividing plate among Fig. 2 is three layers, promptly is positioned at 24,25 and 26 and be positioned at 27,28 and 29 of downside of upside, fiber in this layer becomes cross-directional to stretch with machine, equally, innermost layer 24 and 27 is the longest, and it stretches on total length, tip 19 to element, the second layer 25 and 28 is vice-minister, and band becomes the outermost layer in each layer of transversal fiber with machine, and promptly 26 and 29 is the shortest one decks of length.Being positioned at and most advanced and sophisticated 19 adjoining location of this structure becoming on the cross-directional with machine, and it has bigger rigidity, makes becoming with machine on the transversal direction, because the unstability that the shortage rigidity causes can reduce.That is to say, the most advanced place in the downstream part of this dividing plate, having at the outermost layer of dividing plate mainly is the fiber that becomes cross-directional with machine.This fiber has been strengthened the rigidity that machine becomes cross-directional, has reduced the warpage of this direction.Mainly be transverse fiber and make its advantage that less thickness is arranged be in the outside of dividing plate: reduced in the machine direction rigidity (so that most advanced and sophisticated place adapts to the streamline shape that produces small turbulence in pulp liquor), strengthened the rigidity of cross machine direction.

Innermost layer partly is the length that 30 and 31 its length equal whole dividing plate, and its machine direction is arranged along machine direction.Though place, tip that should be thin reduces along the rigidity of machine direction, in that it has bigger rigidity along cross machine direction, to strengthen its horizontal stability and can reduce disturbance when mobile, with the generation of minimizing eddy current.This can make the dividing plate of maximum length or the tip-clearance of element be minimum, so that have maximum crystallized ability and minimum turbulent flow, produce minimum eddy current and have the ability that adapts to streamline and the disturbance that the dividing plate of multilayer is had minimum, help the purifying of each layer.

The thickness optimum range at the dividing plate tip shown in size 34 is 0.010 to 0.020 inch (0.254 to 0.508 millimeter), the thickness the best that is illustrated in its upstream end as size 33 is that it is also more relevant with the length of element certainly in 0.080 to 0.100 inch (2.032 to 2.54 millimeters) scope.

At these 18 places, end, upstream, this dividing plate is installed in the wallboard 16 with the header portion of its expansion.This header portion be with several layer materials expanded and filling form with filler 32.Added filler is done wedgewise to prevent damage, and this filler preferably is made of the material of band transverse fiber, to reduce horizontal thermal expansion.

Above-mentioned principle is applied on the structure among Fig. 3, in Fig. 3, the upper surface outermost layer 35 of dividing plate and 36 and the aligning method of the outermost layer 37 of lower surface and 38 and Fig. 2 shown in similar, its outermost layer 36 and 38 length slightly are shorter than the length of sublevel 35 and 37, and these layers all have the fiber that stretches along machine direction.The machine direction of sublevel 39 becomes cross-directional with machine, is sublevel 39 at the upper surface place, is sublevel 40 at the lower surface place, but these sublevels are what to stretch until most advanced and sophisticated 48 places on the total length of this dividing plate in this structure.

Shown in Figure 41 and 42, is short in the inside of this sublevel structure, and its fiber stretches along machine direction.This sublevel again to the structure of the inside be 43 and 44(be positioned at the upper part of dividing plate) and 45 and 46(be positioned at the following position of dividing plate), innermost layer 43 and 45 almost stretches to the tip, outer 44 and 46 near this innermost layer 43 and 45, and slightly short than this nexine, these layers all have the fiber with the machine cross-directional.

The innermost core of this dividing plate is made of individual layer 47, and fiber wherein stretches along machine direction, and this layer equally also stretches on the total length of dividing plate.

Each course of head end of dividing plate 49 extended out out and fuse 50 is packed in it, the machine direction of this fuse becomes transversal with machine.

In operation, in the layering chamber of head box, single dividing plate can be housed, also a plurality of dividing plates can be housed, paper pulp raw material will flow through the layering chamber, because layered arrangement, promptly more and each layer also has the fiber that stretches along machine direction in the number of plies of updrift side, so the intensity of the upstream portion of element 11 is maximum.Progressively during downstream end, element 11 is bigger in the rigidity of machine cross-directional, and its thickness reduces gradually, and has big pliability on machine direction.Therefore, clearly we propose the improved trailing element structure that paper machine is used, it can satisfy above-mentioned purpose and have a lot of above-mentioned advantages, and provides the turbulent flow of improving when paper pulp raw material flows and control is flowed to improve the forming technology of paper machine shaped portion.

Claims

1, it is indoor and across head box that a kind of trailing element that is used for the paper machine head box, said elements are positioned at layering, thereby said elements swims thereon that the end place is fixed its downstream be free end to the masterpiece that is applied to it counter go out should,

It is characterized in that:

Said elements has at its upstream end in structural strength and the rigidity of suitable machine direction greater than cross machine direction, and has in cross machine direction greater than the rigidity of structure along machine direction, to reduce unstability in its downstream.

2, a kind of head box trailing element as claimed in claim 1 is characterized in that, the structure of said elements comprises that lamination puts into the fiber of this element, and the fiber in the end, upstream stretches along machine direction, stretches along cross machine direction at the fiber of downstream end.

3, a kind of head box trailing element as claimed in claim 2 is characterized in that said elements is made of laminated material, and above-mentioned fiber is on the outer surface of said elements.

4, a kind of head box trailing element as claimed in claim 1 is characterized in that, the tapered attenuate of said elements is until thin downstream end.

5, a kind of head box trailing element as claimed in claim 4 is characterized in that, the thickness range of its downstream end of said elements is 0.010 to 0.020 inch (0.254 to 0.508 millimeter).

6, a kind of stream as claimed in claim 4 is characterized in that the case trailing element, and the thickness range of its end, upstream of said elements is at least between 0.080 to 0.100 inch (2.032 to 2.54 millimeters).

7, a kind of head box trailing element as claimed in claim 1 is characterized in that said elements is made of material laminate, has the fiber that stretches along cross machine direction at its upstream end as nexine, to reduce the thermal expansion along cross machine direction.

8, a kind of head box trailing element as claimed in claim 1, it is characterized in that, it is indoor that said elements has a crossbeam that said elements is fixed in layering at its upstream end, this crossbeam is formed by a plurality of laminations, wherein be filled with filler, the fiber that includes cross machine direction is to reduce the thermal expansion of cross machine direction.

9, a kind of head box trailing element as claimed in claim 8 is characterized in that, its lip-deep fiber of said elements stretches along machine direction, so that strengthen its strength and stiffness to lower big turbulent flow.

10, a kind of head box trailing element as claimed in claim 1, it is characterized in that, said elements is superimposed mutually and constitute by the material of multilayer different length, be that each all layers all comes across said elements upstream extremity place substantially, and the less number of plies comes across downstream;

Be positioned at each layer on the said elements outer surface, its length is shorter;

The skin of said elements has the fiber that extends along machine direction, layer then has the fiber that extends along cross machine direction from inwards some of skin;

The innermost layer of said elements has the fiber that extends along machine direction, and some outside layers then have the fiber that extends along cross machine direction from the innermost layer;

The outermost layer of said elements has the fiber that extends along machine direction.