US2550776A - Papermaking machine flow box - Google Patents

Description

May 1, 1951 E. W. CLEM PAPERMAKING MACHINE FLOW BOX Filed March 3, 1947 3 Sheets-Sheet l Patented May 1, 19 51 I PEWAKIN M HINE ww 39X v m 0.1m .sm Mass s 1mr m Bic Ba on o p mtion, W Ic g, Q

1 NEW; -451? e, present invenpion relates t0 the manufac: tributi n oi the pulp fibfir i 11mm 15? WK? Wi l P5? ture r paper apd to jolge apparatus used the effected S 191; an 1 W? 1 manufacture of panen. More specifically, this qv rcom th fect in prqfilll Q-Pfifil @PQYQ $9. p e nt i ve tion relat es to a Eourdrinier type the, xe aon. hat 91:9? m9 1. 3 1 11%. 1 P1? 9 of papssr makin machineandmeans which ma 5 up n th wire t e wate is draw; of th 2 9 be applied to such a ma hine for -.efiseclbimn n and. a on e ngn any rfiqi yribptio f improved me hodof manufacturing paper- 7 pulp fiblfifi with ut 6 ,49 lqgn fit 03 me wig; @143:

pap r makin ma hi es of the Equrdxin er tion s $1Xt 1 0 mxeo ibl y e her is prqyide ar e tank. or flow 10.0.2; t; tg xa ifi; pr; Vary 01 E 99; l nrfisfim into wh ch he. pulp sl ry is. p mpeq at to .37 10, inygnh ip .to 9 :9 W nqvslm ih si 93131191; pe qent cqnq ntrat on or pulp. Fr m this flow a ulp sl rry rhe fymg: 41 9 w b po D92 the pu p s urry Rams ove n. apmn board n a llqmq i n S i Q 1 99?} @R l? whi h is u ia n all th samewkith as. tbs: 9i $I1e." IQ J t QR .-P $2??? 353% Wir o the ma h By m ant. ms: 19m h J endl ss w re be tin up w ic a pulp w b iq m .sl the w r i advan dl The. pul as e Qver is @9291; bqard ir n; 19w hz 0 be d sited ,t q endl s .,.11.0V1. g f n h c i ..s r :a1 wan yhy wwlex twxq liqe and hus qpma nuqus w b .Q 14mm,. 20 n. WWW? with E N invfinbion a apprp a e y m rw dth ltn a,. 9 h m g q sl i P b Wit ual iqmqd- Thgzwe thg -.Wb zn S #9 11 W 'fii l i fl 25 Q @ry @A of the mwhixw Whih 11% a 9f @9 wayh stllm ih P I M prqq r9115 .whi l? IfiIQQX? WW aQQ P$ Mqq a5 F u i fl w 1503i "BY the w he w b @t sin 9 Y-n m er o b .1 2: Q E -P Y fimilmwa'ves at i yli sier 9 9W1; in qlaap and to fli thl umber ut r l fi s 29 calend We Fpurq iiai i 12 K7 ?as,v

I fil l fi makin n nqr in tni manwr w at the ,de aq s wh h a a ww rw rs vsxilt B l s o 21 1?" ll w t wire of the magpinge am; gg th e s licg: mecpadnisxp whnot quml hrfi k. "P1 1? on Haiw r 1S- he paper sheet will 5 @11- lq m d h .7 v

i h s v u m han ca Q Vi ha e v egn provided withiifth now bchg fgr agithjgigg jihepulp slurry in an gfiortltb obtaip an I en distributipn of e .pulp Within meme ,.s61i1 "n.

Fig. 3 represents an enlarged sectional view of an electrical vibratory mechanism.

Fig. 4 is a wiring diagram representing the electrical means whereby the vibratory means disclosed in Fig. 3 is energized.

Fig. represents an enlarged sectional view of a pneumatic vibratory means.

Fig. 6 is a diagrammatic illustration showing the various steps required in the manufacturing of paper by the Fourdrinier process.

Fig. 7 represents a fragmentary top plan view of a Fourdrinier flow box illustrating the manner in which the pulp fibers separate out from the slurry thereby to form pulp fiber balls.

Fig. 8 represents a fragmentary vertical sectional view of a Fourdrinier fiow box illustrating the manner in which the laminar flow of the pulp slurry causes the pulp fibers to separate from the slurry thereby to form pulp balls.

A Referring particularly to Figs. 1 and 2, there is illustrated a flow box comprising a bottom wall in havingvertical side walls II and I2 and back and front walls l3 and I4 all projecting upwardly therefrom in the usual manner. The upper front portion of the flow box is partially blocked off by means of a slice or gate l4. Referring particularly to Fig. 1, the forward portions of the side walls H and I2 are each provided with tongues l5 and I6 which function as guides in which the slice I4 is slidablymounted. A screw jack Il may be attached to the top portion of the slice M for the purpose of increasing or decreasing the opening between the lower portion of the slice and an apron board 23 which projects forwardly from wall l4. If desired, the entire flow box may be mounted upon leg members l8, l8 only two of which are disclosed here- Extending crosswise within the flow box are a pair of upper bafile plates l9 and each of which is spaced slightly from the base Ill of the box. Between the plates l9 and 20 is provided a third baflie plate 2! which projects upwardly from the base 10 and which terminates at a point below the top of the flow box. The rear wall l3 of the flow box is provided with one or more conduits 22 which function as a means whereby pulp solutions may be admitted into the flow box.

thus described the present fiow box is subs'tantially of a design used for many years in conjunction with Fourdrinier type paper making machines. In the operation of such a Fourdrinier type machine the pulp fibers are mixed a solution of water and then this fiber and water solution, which is usually called a slurry,

is admitted into the fiow box by way of the conduit-22. Referring particularly to Fig. 2, it is to be understood that this slurry will find its way through the flow box in a tortuous path as defined by the baflle plates I9, 20, and 2|. By means of these baflle plates the slurry is given a thorough mixing before it reaches the forward portion of the flow box. After passing about these bafile plates the slurry is ejected from the flow box in a thin stream the thickness of which is initially determined by the height of the slice I4 above an apron board portion 23 of the wall member I4. After being delivered under the slice l4 the slurry will be deposited upon the usual Fourdrinier wire 24. V

Referring particularly to Figs. 1, 2, and 6, the Fourdrinier wire 24 comprises an endless belt which is trained over spaced rolls which are generally designated as a breast roll 25 and a lower couch roll 26. Power is supplied to these rolls so preferably power driven, so that the felt can carry the pulp web through a plurality of pairs of additional oppositely disposed press rolls, not shown, for the purpose of removing more water from the web. After passing through one or more press roll stations the web is trained over a pluralityv of steam-heated drying cylinders 33,

33, which, by means of heat and pressure, will remove any water which is left in the pulp Web.

When the pulp web finally emerges from the steam-heated drying clyinders it is usually calendered by means of oppositely disposed calendering rolls 34, 34, which function to produce a proper finish on the paper surfaces.

As noted above, the above described process of making paper has a glaring defect in that the usual Fourdrinier flow box is not effective to deposit a pulp web upon the wire in a manner such that the web will have the pulp fibers uniformly disposed therein. Referring particularly to Figs. 7 and 8, it is to be understood that as the pulp slurry is admitted into the box through the conduit 22 small vortices of pulp fibers will be formed as at points 35, 35. It has been found that as the slurry is passed through such fiow boxes concentrations of pulp fibers will be formed wherever a vortex would normally occur in the solution contained within the box. Furthermore, no matter how the flow box is designed the slurry will be subjected to the characteristic laminar fiow effects with the result that those portions of the slurry which are adjacent the sides of the flow box will be slowed down relative to the main current of slurry passing through the box. .As these portions of the slurry are slowed down it has been found that the fiber particles of the pulp will accumulate in small balls with the result that a homogeneous distribution of the fibers within the water solution is impossible. Although, in the past, various mechanical means have been provided within the flow box for the purpose of breaking up these pulp concentrations no adequate method has heretofore been devised which will prevent some pulp balls from passing from the flow box and onto the wire. As hereinabove noted, these small concentrated fiber deposits will show up in the paper as defects.

In order to obviate these difiiculties the present invention contemplates the provision of means whereby compression waves may be passed through the pulp slurry as the same passes through the fiow box. It has been found that by so subjecting the slurry to these compression waves the slurry is rendered substantially free of any pulp concentrations. Apparently these compression waves are effective to break up any concentrations of pulp fibers within the slurry with the result that the fibers are distributed uniformly throughout the water solution. Furthermore, it appears that those fibers which would normally tend to cling to the sides of the flow box and thus' concentrate together in the form of balls, are driven away from the flow box sides thus to reenter the moving stream of slurry. In order to produce these compression waves assume within the slurry various means maybe applied to the flow box; For example, referring particularly to Figs. 1, 2, 3, and 5, the flow box may have attached to the side wall l I thereof a plurality of vibratory means each of which will set up vibrations or impulses which may be transferred directly to the iiuid contained within the fiow box. Such vibratory means may be effective to impart their impulses directly to the side wall I l which will in turn transfer these impulses directly to the fluid or, if desired, the flow box may be provided with a plurality of diaphragms which may be set in movement by the vibratory means to the end that these diaphragms will impart their impulses directly to the solution. This latter method is particularly illustrated in Figs. 3 and 5 of the present drawings. v

A typical form of pneumatic vibrator is illustrated in Fig. 5. In order to apply this pneumatic vibratory device to a flow box the wall portion H is formed with a substantially circular aperture 36 over which is secured a circular diaphragm 37 This diaphragm may be welded'or otherwise secured to the wall H as at points 38 and-'39. Mounted directly upon the diaphragm 37 is a pneumatic vibrator comprising a substantially cylindrical housing 40 which is provided with a hollow cylinder 4| therein. A vibratory piston 42 is slidably mounted within the cylinder 4| which is provided with intake ports 43 and s4 and exhaust ports 45 and 45. The intake ports 43 and 44 are connected together asat '4'! to a common air hose 48. Provided within the lower portion of the cylinder 4! is a coil compression spring 49 which is adapted to bias the piston 42 upwardly. This pneumatic vibrator is of a usual design and it is adapted tohave the piston 42 thereof reciprocate back and forth within the cylinder under the impetus of air which is directed into the cylinder by means of the hose 48.- Referring particularly to Fig. 5, it will be understood that as the air is delivered to the hose 48 it will enter both of the intake ports 43 and 44 but since the piston 42 is in its upper position the inlet port 44 will communicate directly with the outlet port 46 with the result that the air in the upper portion of the cylinder will be effective to force the piston downwardly within the cylinder against the action of the spring. It

will be clear that when the pistonreaches a lower position within the cylinder the exhaust port 46 will be closed by the piston 42 and the exhaust port 45 will be placed in communication with the inlet port 43 so that the air entering the inlet port 44 will be effective to bias the piston upwardly. The spring 49 will, of course, function to prevent the piston from being air-locked in a central position within the cylinder 4i. This pneumatic vibrator may be suitably secured as by a rivet 50 to the center portion of the diaphragm 31 and, therefore, it is to be understood that as the piston 42 vibrates back and forth within the cylinder 4! impulses will be set up within the diaphragm 31. Since this diaphragm is exposed to the fluid within the flow box it will be effective to impart compressional waves directly to the fluid contained within the box. The amplitude and frequency of these compressional waves may be varied by adjusting the pressure of the air as the same enters the hose 48. If desired, a valve 5! may be provided in the air-line so that the pressure of the air supplied to the pneumatic vibrator may be readily varied.

In order to protect the pneumatic vibrator from damage either from the presence of liquid or from mechanical blows,v the present unit is provided with a substantially circular ring 52 which is secured directly to the outside portion of the wall II by means of a plurality ofbolts 53. A substantially cylindrical cap 54 may be removably secured over the ring 52 by means of a plurality of screws 55. Thus, this cap 54 will prevent the pneumatic vibrator from being exposed to any liquid which may spill over the outside of the flow box. Of course, it is to be understood that the herein above described pneumatic vibrator may be attached directly upon the outside wall of the flow box thus obviating entirely the use of a diaphragm member 31. In this latter case, the walls of the flow box will function as diaphragms thereby to transmit the impulses from the pneumatic vibrator directly to the pump slurry.

. Figs. 3 and 4 illustrate still another form of vibratory device which is electrically powered and V which may be used in conjunction with the pres-- ent apparatus. To install this second form of vibratory device the side wall Il may again be provided with a circular aperture 36 which is covered by means of a diaphragm 31. This electrical vibrator comprises a substantially circular ring 55 which is secured directly to the side wall H by means of a plurality of bolts 51. Projecting outwardly from the ring 56 are a pair of arms 58 and 59 which are connected together by means of a yoke member Ell. Extending across the base portions of the- arms 58 and 59 is a member 6| the central portion of which is adapted to have slid-' ingly received therein a non-magnetic armature shaft 62 of which one end portion is secured directly to the center of the diaphragm 37 by means of a rivet 53. The other end of this armature shaft has mounted thereon a circular armature 64 which is spaced from a stator member 65 the upper portion of which is mounted directly in non-magnetic core holders 66, 66 which in turn are mounted upon the yoke 60 by means of bolts 67, 61. Surrounding the mid portion of the stator 55 is an energizing coil 68 having the usual lead wires 69 extending therefrom. This entire electrical vibrator is adapted to be enclosed completely by means of a cylindrical cap 54 which may be snapped over the ring 56 and secured thereto by means of a plurality of screws 55.

Referring particularly to Fig. 4, the coil 68 is adapted to be connected by means of wires 69 to an alternating current generator 79 which is driven by variable speed direct current motor ll. Arheostat T2 is provided in the motor leads so that the speed of the motor may be varied to the end that the frequency or cycle of the generator may also be varied. Motor leads 13 extend from the motor to a proper source of electrical energy. Thus, by means of the rheostat 12 the impulse frequency of the armature 64, and consequently that of the diaphragm 37, may be varied at will. Under the impulses set up by the electrical vibrator the diaphragm 31 will be effective to transmit compression waves directly to the pulp slurry. It is also to be understood that this electrical vibrator may have its armature mounted in a manner such that it will transmit its impulses directly to the side wall H of the flow box rather than to a diaphragm 31. Referring particularly to Figs. 1 and 2, in one form of the present invention the flow box may be provided with a plurality of vibrating devices designated generally by the numerals I4, 14. These devices 14 may be disposed in a manner such that they will be effective to set up compressional waves between the baflie plates I9, 20 and 2|.

As thus disposed, these vibratory devices will propagate compressional waves in a direction substantially transverse to the direction of flow of the pump slurry through the the flow box. However, the present invention is not to be limited to this particular disposition of vibratory devices for such vibratory units may be disposed upon the flow box in a manner which best meets the needs of the particular design of the fiow box; it being understood that various installations of Fourdrinier paper making machines require various types of flow box designs. It has also been found that if a vibratory device is applied to the apron board portion 23 of the fiow box it will be efiective to set up compressional waves within the pulp slurry as the same passes beneath the slice l4 and over the forward portion of the apron board. By so subjecting the pulp slurry to these compressional waves at this particular point in its progress, it has been found that the pulp fibers are set into motion to the end that When the slurry is deposited upon the wire 24 these pulp fibers will be homogeneously arranged throughout the pulp web but at the same time a great percentage of the fibers will be disposed with their longitudinal axes vertically arranged as opposed to the usual condition in which most all of the fibers are horizontally disposed. In other words, these compressional waves will set the pulp fibers in motion so that the flow of the pulp slurry onto the wire will not cause all of the fibers to be disposed with their axes in one direction. Thus, by sending compressional waves up through the slurry as it flows onto the wire there is efiected a stronger pulp web for the reason that the fibers of the pulp will be interlaced in all directions.

Fig. 1 illustrates one form of the present nivention in which the various vibratory devices 14, 74 are energized from either a single electrical or pneumatic source of energy by way of the main conduits 75, 75 and the distributing conduits 76, 76. It is to be understood that such vibratory devices may also be associated with the flow box side wall l2 or bottom thereby to provide such devices on each side of the box. However, as shown in Fig. l, the vibratory devices are associated with the wall ll only, and in such an installation it has been found that the compression waves will be sent out from the wall H to pass through the slurry and strike against the opposite wall l2 which will deflect the wavesand reverse the direction thereof. Thus the entire con- 8 tents of the flow box will be agitated by the passage of compression waves therethrough. It is to be understood that, in effect, the opposite side walls II and I2 of the flow box function as dia- I phragms between which the compression waves travel with the result that all of the pulp fibers are subjected to the agitating action of these waves.

Pneumatic oscillatory units such as disclosed in Fig. 5 of the drawings are best capable of producing from about 500 to 6000 vibrations a minute whereas the electrical oscillatory unit disclosed in Fig. 3 is best capable of producing from 6000 to over 12,000 vibrations a minute.

I claim:

In a paper making machine, the combination of a travelling forming wire, a flow box having horizontal walls and upstanding walls over and between which a stream of pulp and water slurry is adapted to be passed, means disposed at one end of said fiow box for receiving a stream of the slurry, means disposed at the other end of said flow box for depositing a thin stream of the slurry upon said forming wire, a plurality of relatively thin diaphragms connected to said horizontal and upstanding walls as constituent parts thereof, said diaphragms being thereby exposed to the slurry stream passing through said box and said diaphragms being spaced apart along said boxs length in the direction of slurry stream flow, and means for imparting high frequency vibrations to each diaphragm so as to propagate compression waves back and forth within the slurry as it passes through said flow box and in a direction transverse to the direction of slurry flow thereby to effect a homogeneous suspension of the pulp fibers throughout the slurry.

EVERETT W. CLEM.

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

UNITED STATES PATENTS Number Name Date 1,623,157 Berry Apr. 5, 1927 1,669,307 Sall May 8, 1928 1,682,460 Aldrich Aug. 28, 1928 1,841,702 Berry Jan. 19, 1932 1,846,406 Sweeney Feb. 23, 1932 2,076,991 Holgersson Apr. 13, 1937 2,216,817 Kufier a. Oct. 8, 1940 2,369,608 Salvaneschi Feb. 13, 1945

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