US2546376A - Pulp beater - Google Patents

Description

March 1951 w. N. SHERWOOD PULP BEATER 2 Sheeis-Sheec 1 Filed Oct. 20, 1945 Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE PULP BEATER Walter N. Sherwood, Eagle Bridge, -N. Y. Application October 20, 1945, Serial No. 623.474

.6 .Claims.

Myinvention relate s to papermaking and-more particularly to an improved pulp beater of the type disclosed in my Patent No. 2,078,030granted April 20, 1937.

One of the objects of my invention is'to .provide a vat or tub of an improved shape whereby the flow of stockfrom the rear to the front of the roll is greatlyfacilitated. Another object is toprovide-a newand improved type of bed plate which cooperates directly with the roll throughout adistance-approximating the diameter of. the roll and in which no bed plate boxesarenecessary. Anotherobject is-to provide animproved type otguide.plateattherear of the bed plate in.-which theupperv surface. thereof conformsapproximately to the trajectory of the vstoclrand servesto guide the thrown stock upand rearwardly,- while the lower surface thereof, in cooperationwith the:bridge which supportsthebed plate, offers asmooth', streamlined guide for. confining, atzthe top thereof, the mass ofstock moving toward the front of the .beater. Another objectis to'provide, invconnectionswith thellast mentioned object, -a tub having the :inside surfaces ofthe ,ends and bottom thereof so .correlatedrasrto form :asubstantially smoothly curved or streamlined path orpassageway for the mass of stock movingaf-rom the rearto the front of the ;-roll, .-whereby continuous movement of .the entire'stock' mass is assured under the potential head-built up by the action of the roll in. the rear end of thetub. ;Ano ther objectisto provide a heater of such design thatthe stock,;before it flowstcothe 011, issubiecte toasur ing, r011- ingandtumb1ing actionby passing it over a am avin anadiu tabl cre t wh reby atheru git tion an .mi th r-eo i a tain r o h ob ect i t provid m ns-fo tr pp nso en n n o n a the ockat th rea o h t a d i j fro o rrc an more particularly toprovide a means whereby theaction'of the roll will induce afiow of cooling air around the front .of the roll, and means whereby cooling air wi-llbe entrapped between theloop ofst c throw up l h th o an the mass of stock therebelow in the tub.

other objectis to provide a; lighter beam having me n f ra i tin th s meatea h en thereof. whereby the surface-of the rollmay .be. made precisely. concentricwith the bed plate. ,Another object is .to provide a roll .and. bed plate combination. in which the stock is admitted. between the roll. and the bed plate .and .is -.discharged from-between the roll and the :bed .plate at substantially .sthe same .elevation, and .preferably, approximately half way between the roll axis and the bottom center of .the roll surface. Another object is to provide .a target against which the stock will be thrown fromthe rolland which will further facilitate the'hydra'tion .thereof and the breaking up of bundles of fiber there,- in. Another object is to provide such an arrange'ment of fiylbars in the roll and bars in the bed plate as will effect analternatebrushirig and combing of the fibers. A further object is to provide a heater having .aIbeater roll of ..comparativelyismall diameter which may be operated at comparatively high speed and which is so correlated with the bed plate .thatIthe number of inch .euts per minute may very wellvbelof an order in excess of halfabillion.

With these objects in view my invention includes the .novel elementsand thecombinations and arrangements thereof described below .and

illustrated in the accompanying drawings ,in

which- Fig. 1 is a moreor less diagrammatic sectional elevationview of .my-beater;

Fig. 2 is .aperspective view of .a flexiblegate or dam regulating the depth of stock which'is fed toa second gate immediatelyin front ofthe' roll;

Fig. -3.is anelevation viewpartiallyinsection with portions broken awayshowing a lighter beam of my beater with ameans for adjusting each end thereof;

Fig. 4 is a section of Fig. 3 in-the planeATA;

Fig. 5 is .a.-fragmentary.end elevation viewof a portion of the periphery of the beater roll;

Fig. 6 is an .end elevation viewof oneof the sections of thebed plate;

Fig. 'Tis a ,diagrammaticoend .view ofthe .bed plate for the purpose of describing thepreferred arrangement of the bars. therein; and

Fig.8 is a fragmentary section of Fig.1 in the plane 8--'8.

Referring, first to Figs. 1 and -2 My beater comprises .atub Lhavinga bottom 2 and downwardly and inwardly inclined ends 3 and .4 whichare designedtofacilitate theiiow of stock from. the. rear end to the front end of thetub. Suspended in the. central portion of the tub and extending from side topside thereof is a bridge 5 composed of metalnplates '6 and timbers]. Both the upper suriaceand the lower surface of the bridge are smooth, cylinders; the upper surface supporting the bedplate :1 directly thereon, and the undersurface ,of the bridge being,spacedsubstantially from. the bottom of the, tubtoprovidefor the flow -of...stock 3 therebelow. 8 is the roll of a length which is understood to extend from side to side of the tub and to which are secured a plurality of fly bars 9 shown in detail in Fig. 5. At the rear of the roll is a guide In, functioning as a backfall, which extends from side to side of the tub and the upper surface of which is slightly convex, as shown, to form a guide for the stock thrown from the roll. The upper surface of the guide In is made convex to conform approximately to the trajectory or natural curvature of the bottom of the stream of stock as it is thrown from the roll, and hence the curvature will depend somewhat on the speed at which the roll is designed to operate. In the top rear portion of the tub and with at least the upper portion thereof disposed in the path of the stock thrown by the roll is a screen lining ll formed of angularly disposed sections designed to form a target against which the stock is directed and which facilitates the hydration thereof and promotes the disintegration of small bundles of fiber as they impinge against it. Preferably these screens vary from coarse at the top to fine at the bottom. The bottom portion l2 of the stock guide at the rear of the roll is preferably of sheet metal forming a substantially plane surface which is disposed tangent, at [3, to the bottom of the bridge 5, and which forms a means cooperating with the interior surfaces of the tub end and sides at the rear of the roll, and with said bridge, to form a stock passage of approximately uniform cross section throughout this position of the tub and within which the lateral flow of stock is restricted so that it must flow substantially downwardly. I4 is a truss or brace which extends from side to side of the tub. I5 is an air opening in the side of the tub and it is to be understood that there is an oppositely disposed opening IS in the other side of the tub. Extending between the bottoms of these openings is a guard I6. Thus, air will be induced by the stock which is projected from the roll at high velocity beneath the guard I6 to flow into the tub through the openings l5 as shown by the arrow I1. jacent the screens l l and in the upper rear sides of the tub are oppositely disposed air openings l8 which, however, are positioned below the path of the stock projected from the rear of the roll so that cooling air may flow freely into the tub just underneath the loop of projected stock.

The sides of the tub, above the roll, are provided with a plurality of air openings I9, and disposed between these openings and the top of the roll are a number of curved baflles which extend from side to side of the tub. The adjacent ends of these baffles overlie each other to form nozzle-like passages 2| and 22 through which air is induced to flow, by the action of the roll, downwardly into the zone where the stock meets the roll at the front thereof.

23 is a suspended platform which extends from side to side of the tub and which forms the bottom of a trough or channel through which stock flows down grade directly to the roll. 24 is an adjustable gate which is disposed to regulate the depth of the stock in a zone immediately adjacent the front of the roll and 24 is a spatter board pivotally mounted at 62, and which may be rotated and set in any position by means of the crank 63. Where the stock flows on to the platform 23 I provide a flexible metal gate or dam 25, shown in detail in Fig. 2, and which comprises a pipe 26 at the free end of the gate and around which the metal is wrapped, as

shown. This gate slides under a strap 2! overlying the platform 23, and the cover 23 of the tub which overhangs the crest of the dam 25 is hinged at 29, whereby to provide a hand hole for adjusting the position of the gate or dam 25 to control the stock flowing thereover. In order to secure the gate 25 in adjusted position the opposite sides of the tub may be provided with a plurality of small holes (not shown) through which a bolt or pin 54, or the like, may be thrust into the adjacent ends of the pipe 26, as shown in Fig. 8. 3B is a manhole, while 3| represents in a purely diagrammatic way, a washer which may be lowered into the path of the stock flowing to the roll in order to regulate the concentration thereof.

Due to the comparatively narrow bed plates ordinarily used in beaters, or to the positions in which they are disposed with respect to the bottom center of the cooperating roll, the usual lighter beams upon which the bearings for the roll are supported are pivoted at one end only and are provided with means at the other end for moving the beams about their pivotal mountings to regulate the distance between the roll and the bed plate.

Due to the width of my bed plate, which preferably approximates the diameter of the roll, this would be an undesirable arrangement in my beater and I, therefore, provide means whereby both ends of the lighter beams upon which the roll bearings are supported may be adjusted so that the roll may be maintained approximately concentric with the bed plate at least when the surface of the roll is not far above the bed plate. Thus, in Figs. 3 and 4, 32 is a lighter beam carrying the bearing 33 for the roll shaft 34. Secured to the side of the tub I adjacent one end of each lighter beam is a stud 35. Mounted to turn on the stud 35 is a sleeve 36 which is secured in place against a shoulder 31 on the stud by means of the nut 38. The lighter beam 32 is provided with a cut-out portion 39 through which the stud 35 projects, and directly above and below the cutout portion 39 the beam is threaded to receive the screws 40 and 4| which have end portions of reduced diameter, as shown at 42, which are received in diametrically disposed openings in the sleeve 36. The entire load of the lighter beam at this end is carried by the upper screw 40, and by turning down on this screw, or by letting off on it, this end ofthe lighter beam may be raised or lowered, respectively. The lower screw 4! is merely for holding the end of the lighter beam firmly in adjusted position. At the other end, the lighter beam is provided with a threaded passage adapted to receive the adjusting screw 43, the lower end 44 of which is received in the cuplike recess 45 in the fixed support 46. Screw 43 is provided with a hand wheel 41 and hand grip 48 by which it may be turned.

There is considerable diversity of opinion among beater manufacturers as to the proper type, size and arrangement of the bars both in the roll and in the bed plate in order to attain the best results.

While I do not wish to limit myself to any particular size of roll I have found in actual practice that, with a 48 roll and a 48" bed plate, made according to my invention, the stock can be broken down into individual fibers without damaging the fibers and thereby without reducing the strength of the paper by arranging the bars about as described below. Thus, instead of hav-. ing only one type of bar in the roll the results. are

very i'nuch better if comparatively thick bars are alternated with comparatively thin bars, as shown in Fig. 5. By so arranging the bars the fibers are -subje'cted alternately to a combing and brushing action. I prefer to use composite bars comprising stub bars 49,- whieh are secured to the roll in the usual manner by means of the ring 50, and which are capped by working bars secured thereto by rivets or bolts 5| so that renewal of the working bars, when worn, is facilitated.

My preferred bar arrangement for a 48" roll would consist of 62 stub roll bars 49. All of the caps or working edges of the stub bars would comprise two outside bars 52 between which the other working bars are secured by means of rivets 53. Everyother one of the caps would comprise three bars 54 1%? in thickness and spaced from each other and from the side of the bars '52 by 1% wood fillers 55. The stub bars alternating with the bars just described have caps or working edges comprising, in addition to the side bars 52, asin- 'gle bar 56 which is 1- 5" in thickness and which is spaced from the side bars 52 by 1 5'" fillers 51. Thus every other bar of the rollfunctions as a comb, and the other bars as brushes.

I prefer to form my bed plate in twelve separate sections shown diagrammatically in l ig. 7. Since for a 48 roll the width of the bed plate, according to my invention, should preferably approximate the diameter of the roll, each of the sections in the bed plate would have a thickness, measured circumferentially of the face thereof, of approximately 4". The width or de th of the bars may be only from 1 to Binches, depending somewhat on the diameter of the roll; the greater depth or width being used with the larger rolls.

In the following table 1 have set forth my preferred size and arrangement of the bars in the bed plate; the sections being as indicated in Fig.

The first bar 58 and the last bar 59 in each section should be thick enough to permit the heads of the rivets Bil which secure the bars together to be countersunk.

Squeezing and bruising the fibers is the best means for softening and loosening the outer fiber layers Without damaging them and my roll and bed plate are designed to subject the fibers precisely to this treatment. Furthermore, a bed plate approximating in width the diameter of the roll in accordance with my invention permits the use of a wider gap between the roll and the plate than is the case in other beaters. Because of this fact cutting of the fibers is not only prevented but a great saving in power is also effected.

By using a multiplicity of comparatively thin bars with very thin fillers between them the fibers cannot refuse to take treatment by slip= ping and sliding into the wide spaces which 6 exist in heaters where only a comparatively few bed plate bars are employed.

By utilizing the space between the bed plate and the bottom of the tub as a stock return passage the mid-feather is entirely eliminated and a considerable saving in fio'or space is effected because the tub can be made narrower but higher than the present common type of beater.

By inducing a flow of air into the stock both in front of the roll and at the rear of the roll the stock is maintained cool and overheating is prevented.

In the specific embodiment of my invention described above in connection with a 48" roll it is possible to operate the roll at comparatively high speed. That is to say, between 200 and 300 R. P. M. (preferably about 250 R. P. M.). This projects the stock from the roll towards the target at high velocity with a comparatively fiat trajectory so that the impact with the screen target is particularly effective in facilitating the hydration of the stock and the breaking up of small bundles of fiber therein.

It will be noted that the shape of my beater is such, and the means forming the top and bottom of the stock passage in that portion thereof at the rear of the roll, are so correlated that lateral spreading or flowing of the stock in the zone where it is projected from the roll is restricted and flow thereof is substantially downward. Thus, a very substantial head of stock can be built up in that portion of the tub behind the roll which functions to drive or force the stock underneath the bed plate bridge, towards the front end of the tub and upwardly over the adjustable dam 25. In other words, the cross-sectional area of that portion of the stock passage extending from the top of the guide In to the bottom of the bridge 5 is restricted and approximately constant so that it functions in a manner quite analogous to a standpipe which is maintained substantially full at all times by the roll action, and thus provides a substantial and constant head or pressure on the stock in the tub which creates not only a rapid, horizontal flow of stock through the tub but also upwardly at the opposite end thereof.

Since the top of the tub at the front end thereof substantially overhangs the edge or crest of the adjustable dam 25, a passage of limited but variable cross-sectional area is here provided through which the stock must pass on its way to the roll. By adjusting the height of the dam crest the velocity and action of the stock can be controlled at this point either to cause the stock merely to surge over the darn or to roll and tumble 'thereover in a manner to provide a very thorough mixing thereof.

Furthermore, it will be apparent from Fig. 1, that the cross section of the stock passage between the platform '23 and the inclined end 4 of the tub is gradually and quite smoothly reduced in size as itapproaches the gate 25 so that a substantially uniform flow of stock is maintained throughout each cross section of the passage in this zone. In other words, there are no portions of the stock passage in this zone, or, for that matter, in any other zone thereof, in which a mass of stock can become lodged or settled and refuse to circulate. Moreover, this gradual reduction in cross section of the stock passage as it approaches the restricted passage at the gate 24', makes the passage through the gate 25 function as a sort of nozzle through which stock surges under pressure of the head thereon.v

It is well known that a vertical pipe of small cross-sectional area connected to a closed container and filled with liquid or other flowable material produces just as much head or pressure on the material in the container as a very large pipe under the same conditions. It is this principle which I employ in providing a driving head or force for the stock in my beater. r

While I have described my invention in its preferred embodiment it is to be understood that the words which I have used are words of description rather than of limitation and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of my invention.

What I claim is:

1. In a pulp beater, the combination with a tub, of a bed plate extending from side to side of said tub and suspended above the bottom thereof to provide a passage for the fiow of stock through said tub below said plate, a roll adapted to be rotated at comparatively high speed cooperating with said bed plate throughout a distance approximating its diameter; said bed plate being approximately symmetrically disposed with respect to a vertical plane through the axis of said roll, whereby stock will be projected from said roll at high velocity, at a substantial angle to the horizontal, and to a substantial height to maintain a high level of stock in said tub behind said roll; a platform fixedly suspended above the bottom of said tub and forming with the sides thereof a trough having its bottom extending from a zone closely adjacent both the end and top of said tub in front of said roll downwardly to said bed plate for the flow of stock therethrough to the descending side of said roll; a cover on said tub extending from the end thereof in front of said roll to a zone closely adjacent but above the level of the bottom of said trough at the entrance thereto and forming with the sides and end of said tub and the bottom of said trough a completely laterally enclosed passage of restricted cross-sectional area for the flow of stock therethrough under pressure into said trough; whereby a rolling and tumbling thereof will take place as it is discharged into said trough, and a thorough mixing thereof Will be facilitated.

2. In a pulp beater, the combination with a tub, of a bed plate extending from side to side of said tub and suspended above the bottom thereof to provide a passage for the flow of stock through said tub below said plate, a roll adapted to be rotated at comparatively high speed cooperating with said bed plate throughout a distance approximating its diameter; said bed plate being approximately symmetrically disposed with respect to a vertical plane through the axis of said roll, whereby stock will be projected from said roll at high velocity, at a substantial angle to the horizontal, and to a substantial height to maintain a high level of stock in said tub behind said roll; a platform fixedly suspended above the bottom of said tub and forming with the sides thereof a trough having its bottom extending from a zone closely adjacent the end of said tub in front of said roll downwardly to said bed plate on the descending side of said roll for the flow of stock to said roll, a gate slidably mounted on the bottom of said trough at the entrance thereto and adapted to be drawn out towards the adjacent end of said tub to form an extension of said bottom and, with the end and sides of said tub, a restricted passage of adjustable cross-sectional area for the flow of stock therethrough under pressure into said trough.

3. A pulp beater comprising an elongated tub having side walls, end walls and a bottom; said end walls and said bottom merging substantially smoothly into each other; a roll of a length substantially equal to the width of said tub rotatably mounted therein; a bed plate cooperating with said roll throughout a distance approximating the diameter of said roll, whereby stock will be initially projected from said roll at a substantial angle to the horizontal and to a comparatively high elevation in said tub behind said roll; means above the bottom of said tub for the free flow of stock therebetween for supporting said bed plate; a backfall extending upwardly from said bed plate and said bed plate supporting means and having the bottom thereof above and substantially spaced from the bottom of said tub;

\ a platform fixedly suspended above the bottom of said tub and forming with the sides of said tub a downwardly inclined trough extending from a zone closely adjacent the end of said tub in front of said roll at an elevation only slightly above the end of said bed plate on the descending side of said roll to said bed plate; a cover on said tub merging comparatively smoothly with the end wall of said tub in front of said roll and extending to a zone closely adjacent but above the adjacent end of said trough and forming with said platform and the sides of said tub an entrance to said trough of restricted cross-sectional area for the flow of stock therethrough under pressure, and to effect a rolling, tumbling and mixing of said stock as it enters said trough; the bottoms of said backfall, said bed plate supporting means, and said platform forming with the sides, bottom and ends of said tub a substantially streamlined stock passage throughout, and of substantially uniform cross-sectional area throughout, except in the zone approaching the entrance to said trough, where the cross-sectional area of said passage is gradually and substantially uniformly reduced to a minimum at said entrance.

4. A pulp beater comprising a tub, a bed plate extending from side to side of said tub and sus pended above the bottom thereof to provide for the flow of stock through said tub therebelow, a roll cooperating with said bed plate throughout a distance approximating the diameter of said roll and adapted to be rotated at comparatively high peripheral speed, whereby stock will be projected by said roll, as it leaves said bed plate, at substantial velocity and at a substantial angle to the horizontal to maintain stock in said tub at a comparatively high elevation behind said roll; means, including the sides of said tub, forming a fixed, elongated, downwardly inclined trough extending from a zone closely adjacent the end and top of said tub in front of said roll to said bed plate on the descending side of said roll; and a cover on said tub extending from the end thereof to a zone closely adjacent but above the level of the bottom of said trough at the entrance thereto for guiding and maintaining said stock under pressure substantially until it is discharged into said trough; whereby a rolling and tumbling of said stock is produced as it is discharged into said trough, and a thorough mixing thereof takes place.

5. A pulp beater comprising a tub, a bed plate extending from side to side of said tub and suspended above the bottom thereof to provide for the flow of stock through said tub therebelow, a roll cooperating with said bed plate throughout a distance approximating the diameter of said roll and adapted to be rotated at comparatively high peripheral speed, whereby stock will be projected by said roll, as it leaves said bed plate, at substantial velocity and at a substantial angle to the horizontal to maintain stock in said tub at a comparatively high elevation behind said roll; means, including the sides of said tub, forming a fixed, elongated, downwardly inclined trough extending from a zone closely adjacent the end and top of said tub in front of said roll to said bed plate on the descending side of said roll; a cover on said tub extending from the end thereof to a zone closely adjacent but above the level of the bottom of said trough at the entrance thereto for guiding and maintaining said stock under pressure substantially until it is discharged into said trough; whereby a rolling and tumbling of said stock is produced as it is discharged into said trough, and a thorough mixing thereof takes place; a gate, and a slidable mounting therefor at the entrance to said trough adapting said gate to be pulled out to form an extension of the bottom of said trough cooperating with the sides,

end, and cover of said tub to form an adjustable the elevation of the extended bottom of said trough at the entrance thereto and the crosssectional area of the stock passage at said entrance; together with means for securing said gate in flexed condition.

WALTER N. SHERWOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 662,726 Jones Nov. 27, 1900 1,144,666 North June 29, 1915 1,185,926 North June 6, 1916 1,679,056 Shlick July 31, 1928 1,716,407 Wood June 11, 1929 1,838,875 Shartle Dec. 29, 1931 1,863,808 Sherwood June 21, 1932 2,078,030 Sherwood Apr. 20, 1937 2,148,448 Edwards Feb. 28, 1939 FOREIGN PATENTS Number Country Date 17,483 7 Great Britain 1890 209,693 Great Britain June 17, 1924 355,635 Great Britain Aug. 27, 1931 632,521 France Apr. 7, 1927

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