US2205693A - Paper-making machine - Google Patents

Description

June 25, 1940. s NHLNE l 2,205,693

PAPER-MAKING MACHINE Filed March 22, 1937 3 Sheets-Sheet lv IE7/a7@ @m-SA S. MILNE PAPER -MAKING MACHINE 5 Sheets-Sheet 2 Filed March 22, 1937 June 25, 1940. S, M|LNE 2,205,693

PAPER-MAKING MACHINE Filed March 22, 1937 3 Sheets-Sheet 3 r-l "im un Hab'.

[IWL-dauw t; .By his Attorney. fm)

.latented June 25, 1

rarnnsamuel Mime, nemen, scotland Application March 22, 1937, Serial No. 132,311 ln Great Britain March 2l, i936 e claims. ,(oi. exa-lt) This invention relates to paper-making mazhines, and in particular to the breast boxes or low boxes of wire machines, such as those of the Fourdrinier type, and of cylinder mould mazhines, by which boxes the prepared Vpulp from ;he strainers, etc., is delivered to the wire or nould.

The object of the invention isv to provide im- `Droved constructions of flow box by which the vate of flow of pulp may be made more even it all points in the width of the box. Hitherto, several proposals have been made for the obaaining of this desired end, but without the reiuired success. The chief diculty experienced s due to the fact that the various points in the width of the box are not equally distant from ',he point or points where the pulp enters the box, 1nd since the pulp tends always to take the :ourse of' least resistance, which so far has been she shortest course, -there has always been a ;endency for the pulp to flow onl to the wire or nould at a faster rate at the centre than at the ands of the box. The present invention aims at complete avoidance of this dimculty.

According to the invention, the flow box is so :onstructed interiorly, that between the point of entry of the pulp and any point in the width of the ocx at the final outlet, the pulp is constrained to flow through one or more apertures, produced by bales inthe box, the apertures being so shaped and positioned and of such a size that there is an equal resistance to ilow to all parts of the wire, and a uniform rate of ow results.

The preferred embodiments ofthe invention are characterised by a plurality of bafiie plates within. the box to divide and sub-divide the pulp into separate streams, either for the whole distance between the inlet and outlet, or for a part only of that distance.

In other embodiments, however, the box is provided interiorly with a baille or bales, preferably adjustable in position, and of a shape such as to leave an aperture ofv Varying width such that where the pulp would normally tend to flow faster (were the aperture of uniform width) the said Similarly, where the pulp aperture is smaller. would normally tend to flow slowly, the said aperture is wider. In consequence, the resistance voffered by the baille counter-acts the normal differences of flow, in the opposite ratio, so as to produce or permit a uniform rate of flow at all points in the width of the box.

In still other cases, the two above features may be combined in a single box.

According to a further and optional feature of the invention, means'is provided in the ow box or adjacent thereto for varying the velocity of the pulp'flowing into the space orv pool before the slice, to suit the velocity of the pulp flowing under the slice, and` thus avoid turbulence, and irregularity in the said space. Such means comprises amovable wall to the passage through which the cording to the rSt-mentioned example, with'the front wall removed so as to show the interior construction, wherein the pulp stream is divided and sub-divided within the box;

Fig. 2 is a cross-sectional elevation on the line 2--2 of Fig. 1;

Fig. 3 is anelevational view partly in section,

but of a flow box in which the sub-division is carried out in a somewhat different manner; two types of box are illustrated, one in each half of the view, as hereinafter explained;

Fig. 4 is a cross-sectional elevation on the line tl-fl of Fig. 3;

Fig. 5 is a plan of the low box shown in Fig. 3;

Fig. 6 is a cross-sectional elevation'of a flow box made according to the second-mentioned example, wherein an adjustable baille of varying shape controls the rate of ilow of the pulp, and

also incorporating means to vary the velocity of the pulp` flowing into the space or pool before the slice; and Figs. 7a and 7b are sectional views on the lines 'lala vand lb-lbrespectively of Fig. 6.

Referring to Figs. l and 2, the flow box a is provided interiorly with a number of horizontal baflies b extending from wall to wall and from end lto end, and'each having perforations croutlets. In order to exclude the lower corners c of the box, where no substantial flow would take place, and to avoid theconsequent lodgment of pul`p` in those parts, the'sloping walls d are provided. If desired, the external form of the flow box may be such as to eliminate the corners which are shown out oi by the'sloping walls.

There is a single pulp inlet e in thiscase, arranged central to the width o-f the box (and therefore central to the width of the wire) and in the first (lowest) baille b are two large openings f, arranged equi-distant from the inlet e, and spaced. from each other a distance equal to one half the width of the wire. As will be seen, the space above the centre of the rst baffle is closed off by the short sloping walls g. The next baille b has four openings f1 all equally spaced, two of them being equi-distant from one of the openings in the rst baille, andthe other two being equidistant from the Iother opening in the 'iirst tionship to those in the baille next below, and

the perforations in .each case being of smaller size than those in the baiiie next below. Further, as the number of openings increases, the baflles are arranged nearer together.

At the top of the box is a non-perforated baille or shelf h spaced away from the front wall of the box so as to leave a long narrow opening i across the full width of the box, which opening serves as the nal outlet. The pulp may emerge from the slot i directly into the space or pool before the slice, or, as described later, into a preliminary box or passage of adjustable width leading thereto. There may be a second slot i, below that shown, but at the otherside of the box.

As will be seen from Fig. 1, the distance from the pulp inlet e to any of the final openings, along thefdirection of flow is equal. 'I'his is demonstrated by the broken lines There may be other numbers of bales than those shown, and the short sloping walls g may be repeated between each point of subdivision, thereby providing a series of isolated passages of equal length to each pair of nal out- The bailles b and their sloping walls g (if used) may be adapted for withdrawal e'ndwise for cleaning purposes, or, if the walls g are not used, the baiiles may be hingedly carried by one of the walls of the box and be capable of turning up against that wall for cleaning purposes. Hand holes or the like, with removable covers may be provided in the wall of the box to facilitate cleaning out.A The baiiies maybe of copper or bronze or other suitable metal, or be of wood, or rubber, or any suitable combinations of material.

To assist in preventing settling of the pulp, on the baffles, an agitator may be provided between each pair of bailes, which may take the form of a rotating plate or'paddle, longitudinally of the box, its ends projecting through the end walls of the box and the plates being driven by means on such ends outside the box.

The openings f may be of any useful shape in plan, the shape being selected according 'to it's best mixing properties for the usual consistency of pulp to be dealt with in any particular case.

Referring now to Figs. 3 and 4, several modications are illustrated. In this construction, there are two pulp inlets e in the box, separated by a distance equal to one half the width of the wire, and disposed equidistant from the centre of the wire. Instead of the continuous bailies b, the box is provided with shaped filling members 1' forming passages between them, those of the lling members which extend to the top, having knife edges at the top to give a practically continuous nal outlet. The iilling members y' are of a shape such that each divides into two branches a stream of pulp issuing through an outlet below it, and such that collectively they provide passages of equal length from an inlet to any one of the outlets supplied by that inlet. 'I'he number and position of the elements 7' will vary according to the number of final loutlets it is desired to have. In Fig. 3, two forms of filling members :i are shown, in the right and left hand parts of the view respectively. In the left hand part of the view, the members 7' provide parallels iled passages, each succeeding passage being of smaller cross section than its predecessor. In the right hand part \of the view, however, the

passages areeach of varying width so as to vary the rate of ow of ,.the.- pulp andjmprove the mixing of the pulp. -These members a may be of wood, cut across the grain.'

The two inlets e will preferably be fed by two branches of a single pipe from the pulp supply, the branching taking place outside the ow box as shown in Fig. 3, but if desired they may be fed by two independent supplies.

As will be seen from Fig. 4, the improved iiow box is of less width towards the top. A removable distance piece l is inserted in the top of the box, leaving a parallel-sided outlet, but by removing such distance piece, the outlet may be widened. The :front'wall of the box extends upwards to form the wall of the usual pool before the slice, the bread-board m extending from the top edge of the shorter wall of the box.

Instead of the pulp inlets e being in a vertical wall of the box, they may be in the bottom. This applies also to the form shown in Figs. 1 and 2L Referring now to Figs; 6, 7a. and 7b, instead of there being a number of iixed apertured bafes b, there is a single baiie n with a shaped edge such that'between itself and the walls of the box there are apertures of varying width. The shape of the baille is such that pulp will iiow through the apertures at a uniform rate at all points. As will be seen, the apertures are smaller at the centre of the box where the distance from inlet to outlet is least, and they gradually widen as the distance to the outlets increases, being of the maximum width at the ends of the box. The

baffle n is adjustably carried on trunnions n1.

journaled in the box ends, and is positioned by the hand lever n2 and locking lever n3.

If desired, more than one such baffle may be provided in the same box. Also, a baii'ie of this description might be incorporated in a box emthe baille diminishing in width away from each f" inlet.

Instead of the baille 11. being pivoted centrally of the box and providing two shaped apertures, as shown, it may be pivoted along one of its edges to one wall of the box, and provide only one shaped aperture.

The ow box has a fixed baffle o near the top extending from one side and leaving a long narrow slot p across the box, equivalent to the slot i in the construction shown in Figs. 1 and 2. Cleaning doors q are provided where necessary, and a sluice gate or valve r.

Figs. 6, la and '7b also illustrate a further feature of the invention, which is also applicable to the forms shown in Figs. 1 and 2 or 3 and 4. This consists oi' the lhinged wall s which extends from the top of the ow box upwards and also forms the back wall of the space or pool before the slice. This'wall is carried by a hinge-plate s1 oi copper or the like and has a rubber angle element t at each end to make a joint with the side walls of the pool. 4

By varying the angular position of the wall s, .the cross-sectional area of the box at the level of the breast-board is varied, and consequently the velocity (as distinct from the volu. metric rate of flow) varies. Such velocity may thus be varied when that of the pulp owing under the slice is varied, but not necessarily to the same extent. I

The flow box with its adjustable baffles, and

the channel withpivoted wall, may be vertically one above the other, as shown, forming together bili aaoaeea a complete ow box; or that part which has the adjustable baffles may be horizontal; whilst the channel with the pivoted wall is vertical, rising from the wire-ward-end of the horizontal part. In both cases, at the junction between the two parts there will usually be a long narrow opening as above described, to assist in making the ow of pulp uniform.

What I claim is:

1. A unitary breast box construction for a paper making machine comprising in combination, a box having front, rear.' bottom and side walls and provided with an inlet in the lower portion thereof, parallel sided ballles extending between said front and rear walls having their upper ends terminating in substantially the same plane providing' substantially rectangular outlets spaced apart between the side walls of the box, certain of said bames having enlarged lower portions disposed below lower portions of adjacent bames, certain other of said bames extending downwardly past the enlarged lower portions of said certain baes havinglenlarged lower portions disposed below the enlarged lower portion thereof, all adapted and arranged whereby rectangular passageways to said outlets are provided with a passageway successively reduced in size by said baes from wide to relatively narrow passageways. l

21A unitary breast box construction for a paper making machine comprising in combination, a box having front, rear, .bottom and side wallsI and provided with an inlet in the lower portion thereof, parallel sided baflies extending between said front and rear walls having their' upper ends terminating in substantially the same plane providing substantially rectangular outlets spaced apart between the side walls of the box, certain of said bailles having enlarged lower portions disposed below lower portions of adjacent baffles, certain other of said baiiies extending downwardly past the enlarged lower portions of said certain bales having enlarged lower portions disposed below the enlarged lower portion thereof, the said front` and rear walls inclining towards one another from said inlet, all adapted and arranged whereby generally tapering rectangular passageways to said outlets from said inlet are provided that are successively reduced 1n size by said baffles from wide to relatively narrow passageways.

3. A unitary breast box construction for a paper making machine comprising in combination, a box, having front, rear, bottom and side walls and provided with an inlet in the lower l portion thereof, upper, intermediate and lowerE providing sets of parallel sided bames extending between said front and rear walls having their upper portions terminating in substantial alignment substantially rectangular outlets spaced apart between said side walls, the baiiies of the intermediate set thereof having relatively f Wide lower portions spaced from and disposed below'the lower portions of the baffles of the upper'set, and the baffles ofthe lower set having intermediate portions spaced from the lower portions of the intermediate baihes and lower portions spaced from and disposed below said lower portions, all adapted and arranged whereby rectangular passageways from said inlet to vsaid outlets are provided that are divided and reduced in size successively by the bales of the sets from wide to relatively narrow passageways.

4. A unitary breast box construction for a paper making machine comprising in combination, a box having front, rear, bottom and side walls and provided with an inlet in the lower portipn thereof, upper, intermediate and lower sets ofparallel sided' baies extending between said front and jrear walls having their upper portions terminating in substantial alignment providing substantially rectangular of the intermediate set thereof having relatively wide lower portions spaced from and dis-v posed below the lower portions of the baiiles of the uper set, and the bales of the lower set havling intermediate portions spacedfrom the lower vwalls and provided with an Vinlet in the lower portion thereof, parallel-sided baiiles extending between said front and rear walls having upper portions in substantial alignment and cooperating' with said walls and forming rectangular passageways leading upwardly from said inlet and terminating in rectangular outlets spaced apart between the side walls of said box, certain of said baffles having relatively wide lower portions spaced from and disposed below bales adjacent thereto, and other certain baffles having outlets v spaced apart between saidside walls, the baffles intermediate portions spaced from and disposed between the wide portions of the certain baies and provided with relatively wider lower portions spaced from and disposed below the wide portions of said certain bales, the said lower portions of the balles in conjunction with adjacent bailles dividing a passageway thereunder into separate passageways at opposite sides thereof.

6. A unitary breast box construction for a paper making machine comprising in combination,a box having front, rear, bottom and side walls and provided with an inlet in the lower portion thereof, a set of baliles extending between said front and rear walls having lower portions above said inlet and sides tapering generally upwardly therefrom, a secondv set of baffles extending between said front and rear walls having lower portions spaced from and disposed above the" lower portions of the bailies of the first named row, a third set of baffles extending between said front and rear walls spaced from and disposed between adjacent bames of said first and second named sets of baffles, the upper portions of the baffles of said sets terminating in successively into adjacent passageways by the po

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