US2928464A - Adjustable slice for flow box - Google Patents

Description

March 1960 A. w. WESTERN ETAL 2,928,464

ADJUSTABLE SLICE FOR FLOW BOX 3 Sheets-Sheet 1 Filed Dec. 24, 1957 iibihi i O O I o Qua/9.;

rllllllll 611%! Gardner Attorneys March 15, 1960 A. w. WESTERN ET AL 2, 2

ADJUSTABLE SLICE FOR FLOW BOX 3 Sheets-Sheet 2 Filed Dec. 24, 1957 dim/ll gm-lea V y m Attorneys March 15, 1960 A. w. WESTERN ET AL 2,928,464

ADJUSTABLE s LIcE FOR FLOW BOX 5 Sheets-Sheet 3 Filed Dec. 24, 1957 .Q..; I J 5 22 6 A// w w v Q United Sta Patmtl O ADJUSTABLE SLICE FOR FLOW BOX Arthur William Western and Roland C. Gardner, Aylesford, near Maidstone, England, assignors to Albert E. Reed and Company Limited, London, England, a British company Application December 24, 1957, Serial No. 704,967

Claims priority, application Great Britain January 1, 1957 Claims. (Cl. 162-347) This invention is concerned withimprovements in or relating to the manufacture of paper, board or like fibrous products and more particularly with machines and parts thereof for the manufacture of paper, board or like fibrous products.

' It is usual in paper or board machines to have mechanical means whereby the top slice lip of the flow box can be deformed across its width in order to vary the size of the aperture at different parts of its length so as to control the quantity or density of the stuff flowing out of the flow box onto the wire. Such control is required not only to counteract the sag which occurs across the width of the top slice lip in a large machine, but also to take account of eddies and non-uniform flow within the flow box. It is furthermore often desired to vary the flow of stuff onto the wire across its width to take into account the non uniform shrinkage of the web ondrying.

Deformation of the top slice lip'is effected in known machines by mechanical means which include a plurality of rods connected to the top lip and provided with threaded adjusting means by which selected rods can be raised or lowered to change the profile of the top lip. There are various disadvantages to this means of varying the profile of the top slice lip. The space required to mount and manipulate the threaded adjusting means, which are usually handwheels, places a limit on how close together the rods can be located and therefore on the amount of control which is exercisable. The connection of a rod to the lip means that tension or pressure is exerted substantially at a point with a consequent tendency to produce abrupt changes in the profile of the lip. A superstructure has to be provided on the front of the flow box to carry the adjusting means, and in large machines a runway is required to enable a machine man to have access to the handwheels to make any necessary adjustments. Variations in the profile of the top lip couldonly be effected remotely from the machine by means of a very complex and cumbersome linkage which would be quite impracticable. Furthermore with any threaded mechanism subjected to the working conditions of a paper or board machine backlash in the transmission again reduces the degree of control.

In addition where a paper or board machine is used having a top wire in addition to the normal wire, it may .be desirable that the slice shall feed the stuff as nearly as possible into the nip between the two wires. Mechanical control of the above mentioned kind is impossible if that is to be achieved since the closer to the nip the slice is disposed, the less space is there for the top lip adjusting mechanism.

' It is one object of this invention to provide improved means for varying the profile of the slice of a flow box in a paper or board machine, which overcomes the above mentioned disadvantages and enables the slice to be easily controlled if desired remotely from the machine without the need for cumbersome mechanical transmissrons.

According to. the invention we provide a slice for the flow box of a paper or board machine in which the top and/or bottom lip is provided with one. or a plurality of flexible, fluid impervious bags, capsules, or equivalent closed chamber devices extending across its length and bearing directly or indirectly uponit, said bag(s) or capsulets) being adapted to be filled with fluid and means for varying the fluid pressure in said bag or capsule or any of them in order to vary the profile of thelip.

Whilst we may employ a single bag or capsule extending wholly or partially across the lip, we prefer to provide a plurality of small .bags or capsules disposed close to one another across the slice lip sincebyvarying the fluid pressure in the individual bags across the slice lip a finer control on its profile can be exercised than is the case with a single bag.

The bags or capsules may be of, rubber, polyethylene, polyvinyl chloride or any other suitable substance which is flexible so as to transmit fluid. pressure and impervious to the fluid to be used. In general we prefer to use a liquid in the bags or capsules such as oilfor water, although with appropriate means for pressure control a gas could be used. V

The bags or capsules may be of any desired shape. In general we have found it convenient to have them of generally rectangular shape and of the same size across the slice lip. If, however, it is desired to be able to exercise greater pressures and thus larger deformations at any part of the slice 'lip, we may have bags orcapsules of appropriate shapes and sizes, since it will be understood that by increasing the area of contact of the bag with the slice lip at any part thereof greater pressure will be exerted on that part of the lip for a given increase inthe fluid pressure and hence a greater deformation will be effected. If desired individual bags or capsules may be made of varying widths over their length so,that varying applications of pressuremay be obtained. Similarly the wall thicknesses of the bags or capsules may be varied if desired.

In order to localise or concentrate the application of pressure within the bags to the slice lip, we prefer to provide the bags or capsules with side walls which are thicker than their pressure applying surfaces or alternatively to provide pockets or seatings within the slice lip structure, which pockets or seatings receive the bags snugly side of the slice lip arestaggered with respect to each other.

Each bag or capsule or other closed chamber device is connected to means such as a bellows or pump whereby the fluid pressure in it can be varied as required, we may however, provide a further bellows or pump so connected to the closed fluid systems of the individual bags as to enable a common pressure variation to be imposed upon them all.

The lip of the slice to be deformed is formed of any suitable resilient material, for instance stainless steel-of a suitable degree of flexibility or spring steel suitably coated to resist corrosion and is so mounted in a support that it will be constrained to bear against the support thus giving a'precise starting'position from which it can be deformed as required. This may be achieved by gripping the slice lip between two rigid supporting plates, .one of Patented Mar. 15, 1960 slice hp 5.

disposed with their pressureapplying surfaces between the. suppor tingplate and the slice lip so that pressure'variaa tions appli'ed to the fluid will be directly trans'ng ittedr'to the lip to cause its deformation.

' s ms as. will be. seen from Fig. 2 the, pipes24. leading. the capsules 25 in the'top'supporting plate 7 are grouped together and led'along the frontwall of the flow box 4.

' They are retained in position by securing straps 28 and at In order that the invention may bewell understood,

one preferred; embodiment only thereof by way of ex ample will be described in furtherdetail with reference to the accompanying drawings in which:

Figure l is a'diagrammatic side view of the wet end of a paper making machine showing the wire and a flowbox having top andbottom slice lips according to the invention,

Figure 2 s a front view of a part only of the flow box one side of the flow bo rare led oif to a control panel 29 which carries one pressure controlling bellows 27 for each capsule. Thefiuid inlet pipes for the bottom slice lip which are not [shown are similarly grouped together and each lead to a pressure controlling bellows inrthe control panel 29. a v

The control panel 29 which is disposed at anyl cation convenient to an operatorhouses all the bellows units 27 of Figure-l with the cover plate removed and'showing '1' henceithe PICSSUIG'QfflEh} fluid therein can be closely the arrangement ofpipesfroht the capsules-tothe control panel, "1 a .1 a a Figure 3 is-an e'nlargedside sectional View of the top and bottom slice lips of Figure'l, Figure 4 is a section onthe line Figure 5; is an underneath plan view of the supporting;

plate of the top slice lipof Figure l, and a Figure 6 is a sectional view on the line VI'VI of Fig 2 and shows one of the pressure'applyingunits in the control panel. v Referring to Figure 1 there is shown diagrammatically part of the'we t endfof a' Fourdrinieri-paper making; machine. v a a The wire 1 passes around a breast roll 2 and table. rollers 3 and beneath a flow box 4, from which stock is supplied to the wire for the production of paper in a generally known manner.

The flow'box 4 has a top slice lip 5 and a bottom slice lip 6 which extend across the whole width of theflow box. The top slice lip 5 is carried, by a' supporting plate 7 which is rigidly secured to the front wall 8 ,of the flow box." This front wall 8 is -so mounted to-the flow bok'that it can be raised or lowered with respect .to the remainder of the flow box by means of bevel gears 9 and hand wheel'10' in order controlled. I

Each unit consisting, of a capsule its inlet piper24 required there being one such bellows 28 for'each capsule 25 provided on the topand bottom slice lips. As will seen from Figure 6the bellows 27 is a closed compressible bellows unit known perse having a hand wheel .by

which the compression or expansion of the bellows and e and associated bellows 27 constitutes a closed system and; is filled with a suitablefluid, e. g. oil or water. It isthuat, possible selectively to vary the pressure of each capsule along the length of either slice lip 5 or 6.

Itwill be appreciatedthat when it is desired to vary the? ;.profile of either slice lip during'operation of the paper on board machine it is merely necessary to raise or lower the pressure in one or more ofthe bags or capsules 25in to vary the space *betwenthetop and bottomslice lips. The bottom slice lip 6 is carried by a supporting plate I 11 is substantially identical. j a a a As will be seen from Figures 1- and 3 the supporting plates 7 and 11 each have a flange12 by which they are secured respectively toflanges, 1 3, and Hon the front of the flo'w'box. The slice dipsS and 6 are made ofrstainless steel and are secured to the web-15 of their respectivesupporting plates by means ofbolts 16 and acarrier block 11 and the construction of the two supporting platesfl and a slice lip itself and against which the slice-lip bears lfirmly due to its inherent resilience; p l H Referring to Figures 3, 4 and15" it will be seen that the supporting plate 7 has a plurality 'of pockets 19 formed and, extending overits whole length. Ea ch of'these orderto change the curvature of the lip. Since the flex iblebags or capsulesZS .will be smoothly curved'over the length of their pressureapplying surfaces a distributed pressure is applied to the, slice lip whichwill therefore; be deformed in smooth curves across its length. By hav ing an appropriately large number of small bags for the length of slice lip a muchimproved control'of the. profile of the lip alongits length can be achieved.

In Figure 4 which shows a part only of the top and bottom slice] lips 5 and 6 itgwill be noted'that one capsule 25 in-the bottom slicellip .6 have been. subjected to increased pressure withthe result' that the slice lips 5' and are smoothly curved to produce a reduced spacing from each other in the region of those two'capsules'. i

Since with slices according to this invention no me; chanical means of the kind hithertoused are required for deforming the lip, it .will 'be appreciated that theflow'box' .can be disposed so that the slice feeds straight into the .17. 'Along the inner surface at' the front edge of each supporting plate is a rib 18 which is directed towards the l In each pocket 19 thereis disposed a polyethylene bagf; or capsule 25 offlat rectangular form each such capsule being connected to its fluid inlet pipe 24 centrally of the rear wall of the capsule. The bags or capsules 25 are so 'clisposed in thepockets 19 that their larger r,ectangular surfacesabut respectively against the inner surface of the supporting ing 9 ate 11 for the, bottom slice lip 6 is similar.

1 4 Each fluid. inlet pipe 24 passes via a connector 26 see plate 7 and theouter surface of the actual The arrangement of capsules in; the supportnip; of the top two 'wires. v

' Furthermore since the control of the lip profile is effected by pressure variation of the fluid in the bags,this can be carried out at any desired point remote from the flow boxto which the fiuidlines'can be run. Thus the and bottom wires of machines which use cumbersome-V mechanical lip deforming mechanism on known flow boxes can be dispensed with altogether. It; is

alsopossible to provide an. automatic control of the pro,- file of the slice lip by arranging for the signals from a substance gauging. device eg. of the beta ray type or from any otherjdetecting device which directly or indirectly measures the thickness or substance of the paper, board" or other fibrous-material toefiectf the appropriate corresting pressure variations in the bags across the "slice.

It will be understood that we have only described indei tail one preferred embodiment by way of example of the invention and'that variations and modifications may made therein-without departing from itsscope. Thus for example-we may incorporate a pressure gauge in the fluid line :01 each "bag, which'will enablethe pressure applied 7 to the lip atdifferent par-ts of, itslength to be noted;

cure'diin thei body of the supporting plate and is individu ally nn ted ea m asure c trdll ns lzel q 's 2.7 (Eis- It will-furtherrnore, be understood thatitis within zthe scope of this invention, to provide machines for making paper, board, forother fibrous products having a single wire only or a top and. bottomewire and. incorporating, a

1. w qx. ha n w se a abqvesst c tli We c i i 1. A slice forthe flow box of apaper or board in which said slice is provided with a top lip and a bottom lip, one of said lips being'provided with at least one flexible, fluid impervious closed chamber device extending across its length and arranged to exert pressure on said lip, said closed chamber device being adapted to be filled with fluid, and means for varying the fluid pressure in said closed chamber device in order to vary the profile of the lip. T

2. A slice as claimed in claim 1 inwhich said one lip has a single flexible fluid impervious bag extending a substantial distance thereacross, said bag being of varying width over its length so that varying pressures can be applied to the lip over the length of the bag.

3. A slice as claimed in claim 1 in which said one lip is provided with a plurality of said closed chamber devices of substantially the same shape and size extending there across.

4. A slice as claimed in claim 1 in which said closed chamber device comprises a bag having side walls, one of which engages said lip, the remaining walls being thicker than said one side wall.

5. A slice as claimed in claim 1 in which said closed chamber device is a bag of rectangular shape.

6. A slice as claimed in claim 1 including a plurality of said closed chamber devices, each of said devices being connected to a separate source of fluid pressure to form): the pressure of fluid in a closed system therewith whereby each device can be individually adjusted.

7. A slice as claimed in claim 6 including means for I applying a common pressure variation to all of the said closed systems.

8. A slice as claimed in claim 6 in which said devices are filled with a liquid.

9. A slice as claimed in claim 1 including a fixed supporting plate adjacent said one lip, a pocket in said plate facing said lip, said closed chamber device being disposed in said pocket. 7

10. -A slice as claimed in claim 9 in which the forward edge of said suporting plate has a rib which normally bears on said lip.

References Cited in the file of this patent UNITED STATES PATENTS l,632,760

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