US1692602A - Beating engine - Google Patents

Description

Nov. 20, 1928. 1,692,602

G. S. WITHAM, JR

BEATING ENGINE Filed Deo. 13, 1926 1 1 l f I I l I 24 25 l /lvvE/vroR *.25 is provided behind the roll.

Patented Nav'- 2o, 192s.

UNIT-EDfsrArEs EEATING GEORGE srANEoEnwIcrHaMr, JE., OE HUDSON FALLS, 'NEW YORK. A

ENGINE. t

Appiication iea December 1a, 192e.A seriai No. 154,508. v

My invention relates to paper making and particularly toan improved device for breaking ,up and hydrating the stock preparatory to forming a web therefrom.

The present type of beating engine comprises an elongated, comparatively shallow, open tank having semi-cylindrical ends, and provided with a centrally disposed partition, called a midfeatheg'. This partition terminates somewhat short of the ends of thel tank so that stock-'may be circulated horizontally about it. l

On one side of the midfeather is the beater roll having a diameter of about twice the l5 depth of the tank, and long enough to eX- tend between the midfeather and the side of the tank so that `any substantial iow of stockV n y past the ends Of the roll is prevented. The cylindrical surface of the roll is provided plate beneath to cutcomb, draw out or break up the pulp into v`its elemental fibers.

In the presentY type of,machine,a compara-f tively high, dam-like Wall, called a backfall,

This wall extends from the bottom of the tank upwardly to about the middle of the roll, or quite close to the top of the tank. The movement 0f the roll reduces the normal, static depth of the stock in front of the roll by drawing stock from this part of the tank, passing it between y the roll and bedl plate and projecting it over \`the top ofthe backfall into the tank at the rear of the roll-'where the normal static depth vof .sto'cljsfincreased. In this'way a considerablegdiiference in depth, or head fis es.- tablished which creates a gravitational flow a ,of stock fromthe rearfto the front of the` roll. On accountof the backfall; very little circa- 4o lation is caused by the direct, 'impelli'ng action of the roll, and the rate 'is'almost -wholly dependeI'i-upon the consistency of the stock 'and the. `head or difference. in depth of the stock stream at the backfall and at the front of thef-,rolL The consistency of the stock cannot increased to the point lwhere `it will not flowsutliciently fast to feed the roll at the 'front,`and under actual working conditions theheadwhich can be establishedl is other- .'O wisematerially limited by thefact that some appreciable depth of stockmu st be maintainedimmediately in front ofthe roll. The present practice is to have the 'degree of concentration such that the-'difference in elevation bem tween the surface Of the sluggis'hlymoving stock lstream at the rearofthe rolland the -20 with plates and knives which coact with a bed surface at the end of the stream ust in front of the roll is considerable. v In other words, the tank is, substantially full of stock at the backfall where the utilization of its capacity level of theV` stock stream is far below the top of the tank and the percentage capacity uti-l lization between vthe backfall andthe front of the roll decreases aboutuniformly, and the average percentage probably does not exceed 65%. Y

T he efficiency of a beating engine-may be very greatly increased `by increasing the degree of concentration of the stock and increas- -is about 100%',` but in front of the ro ll,thel

ing its rate of'circulation.v The hydration of the lstock may be improved, and hence the efficiency of the engine increased, by maintaining a greater depth of stock in front of the `roll than is now possible, thus avoiding the whipping of air into the stock which in terferes with the hydration thereof. Furthermore, the charge capacity of the present type of machines may be very greatly increasedv without increasing the floor space occupied, by providing Ymeans whereby the stock may be circulated at a greatly increased depth through chine.

Theobjects of to 'provide- 1st. A beating engin my invention, therefore, are

e in which ay stock sol out substantially the whole mamass h ving a higher degree of concentration than heretofore may be circulated.

2nd. A machine which will circulatepa,

highly conceiitrated stock more rapidly than is possible with the present types. f

\ `3rd. A .machine occupyingl substantially the same floor space as thel present typebut capable of containing and operating upon aA greatly increased volume of stock.

4th. A machine in which'a greater depth of stock may be maintained in front o'f the roll to avoid the whippin of airinto the stock, 1

thereby completely llingthat. section between the beater bars anda-ttaining full eiciency as the stock passes between "the roll and the bed plate. t f

I propose to accomplish these objects by forcing the stock lmass away fromI the rear of the beater roll by means of a-screwpropeller and driving it under pressure, so to speaks, towards the front of the roll where the pressure is relieved and the comparatively thick mass owsldownwardly toward the beater roll partly by gravity and partly -by the driving force of the stock behind. By

' y and color may be fed into the machine, and

forcing the stockabout inthe beater and thus reducing the length of the gravitational flow, I am able to use a morehighly concentrated stock, to maintain the surface of the stock at -a hi h elevation throughout the machine,

there y vutilizing its full capacity, and to circulate this highly concentrated stock mass more rapidl than it is possible to circulate a diluted stoc 'in the present type of machine. Referring to the accompanying drawings- Fig. 1 is a plan view of my beating engine f with a portion of thecover broken aivay Fig. 2 is a section of Fig. 1 inthe broken planes 2 2;

Fig. 3 is a sect-ion of Fig. 1 in the plane 3--3;

Fig; 4 is asection of Fig. 1 in the plane L1--4; and

Fig. 5 is a typical, developed profile of the stock stream from the backfall to the front of the roll at about one-half the scale of the other figures.

In `the drawings 1 represents the floor or foundation upon which the tank, 2, is erected.

. The tank is provided with the cylindrical ends, 3, and the central partition or midfeather, 4. Between one side of the tank and the midfeather is the beater roll, 5, mounted upon the spindle or shaft, 6, and provided with suitable bearings not shown. Upon thel L bottom of the tank,

further that stock can be taken out from' time to time for test purposes.

Behind the roll, I provide the pro eller, 11,

which is mounted upon shaft, 12, driven by 14. e shaft, 12, is supported by the caring, 15, within the tank, and by a suitable bearing and packing gland, 16, where it 'passes through the end of the tank.

In order that the propeller may ioperate eiiiciently, the cover plates, 9, are semi-cylinf` drical inform and the angles formed between the sides and bottom of the tank are illeted or huilt up as shown at, 17, so that, about the perlphery of the propeller, and preferably throughout the covered portion of the tank behind the propeller, the tank is substantially than the propeller.

circular in section and but` slightly larger At the roll, the transverse, halfscction of the tank is rectangular in form, and this section is gradually changed to a circular section in the plane ofthe propeller by the transition surfaces 18. From the front of the bed plate motolr, through suitable reduction earing,

to the covered portion of the tank, the transl'verse half section is gradually changed from rectangular to circular by the transit-ion surfaces, 19. l

In the usual form of beating engine, a backfall, 20', extendsupwardly around the rear portion of the roll to about the center thereof, ut Where a propeller is used for drawing the stock awa from the' roll, the backfall may be eliminate altogether or be reduced to about the form shown at 20 in Fig. 1, so that the impelling action of the roll upon the stock is utilized to the fullest extent.

The usual doctor,'21, consisting of a heavy board with a `cast iron edge just clearing the roll, may be provided to prevent stock being carried around the roll, but it is not a necessary feature in this im roved type of beater.

AsA previously pointeld out, the surface level -of the stock in the open form of beating engine, which depends essentially upon gravit-y as a circulating force, is considerably higher behind the roll than it is in front of the roll. For this reason, while the tank is substantially filled behind the roll it is only partially filled-1 in front, and thus, a great deal of space within the tank is not utilized. Furthermore, in the Qld form of tank, the useful depth cannot greatly exceed about one-half the diameter of the roll. In my closed form of en ine, the depth of the tank is increased to a out the diameter of the rolland practically the entire volume is utilized. This great increase in volumetric capacity is diagrammatically illustrated in Figure 5 which is a small scale, `developed rofile of the ystock stream. Re-

y ferring to t is figure, ythe heavy line 22, represents the elevation ofthe bottom of the tank,

and the inclined dotted line, 23, represents the inclined surface of the stock stream in the present type of beater as it flows from the backfall around tothe front of the roll. The

ldotted line, 24, reprents the approximate,

lln

III.

Where the major'portion 'of the passage is rectangular, as in the old type, the sectioned area, 25, approximately represents the increased volumetric capacity.

Byproviding a driving means for the stock it is possible not only to increase the concentration but also to increase the rate of circulation so tliat with the increased volumetric capacity, it is possible to prepare nearly three tinfes:y the quantityof stock in i one-half to three-fourths the time formerly necessary. In other words, with my improved beating engine the circulation rate is increased from'200% to 300%; the capacity, due to increased concentration and volume, is increased aboutI 250% by weight; and the time required 4to prepare this charge is only 50% to 75% of the time required to prepare a charge in the present type of engine. This greatly increased efficiency is not wholly attributable to increased concentration,I increased rate of circulation, and increased volumetric capacity, but is partly attributable to improved hydration of the stock as it passes under the roll. In the present type of engine with thestock'riding low at the point where itis fed under the roll, a large volume of air is unavoidably carried in with the "stock, thus preventing complete hydraltion. In my improved type, the increased depth of stock in front of the roll completely fills the section between the beater bars, therevolume of air-that is whipped into the stock and results in a complete hydration.

If'desired, a second propeller, 11,`may be provided, supported by bearings, 15 and 16', and having a driving' shaft, 12', reduction gearing, 14', and a motor, 13', all similar to like numbered elements associated with the propeller, 11.`

While I have illustrated and described but one form of my invention, it is to be understood that the illustrations are merely typical, that the words which I have `vused in describing this form are words of description rather than words 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 inits broadest aspects.

What I claim is- 1. In a beating engine, the combination with a roll, of means forming an enclosed, substantially horizontal stock passage from the rear of the roll around to a point near the front thereof, and means within said passage for forcing the stock therethrough.

2. In a beating engine, the combination with a roll, of means forming an enclosed stock passage from the rear of the roll around. to a point near the front thereof, and a lscrew propeller adapted to revolve in said passage for forcing the stock therethrough.

3. In abeating engine', the combination `with a roll and tank, of means forming an enclosed, substantially horizontal stock pas- ,safre from the rear of the roll throughout a su .stantial portion of the length of said tank, and a plurality of screw propellers adapted to revolve in said passage for withdrawing the stock from behind said roll and forcing it through said passage.

4. In a beating engine, thecombination 6. In a beating engine, the combination` with a roll, of means forming an enclosed stock passage of a depth substantially greater than the radius of the roll and adapted to convey stock horizontally from the rear of the roll to a point near the front thereof, and a propeller within said passage in proximity to Vthe rear of the roll for circulating stock under moderate pressure in said passage.

7. A beating engine comprising a roll, a

tank providing a passage through which the 'stock is circulated horizontally from the rear by -eliminating or greatly reducing the extending rearwardly from said roll and ento the front of the roll, a cover for said tank closing a major portion of said passage, and a screw propeller within said enclosed portion of the passage for-driving the stock therethrou h. 8. beating engineof the horizontal circulating type comprising means forming a continuous, stock-circulating passage, a roll, and means independent of the roll for forcing a circulation of comparatively concentrated stock in said passage; the stock circulating passage. being enclosed and adapted to carry the stock under 4moderate pressure throughout a substantial portion thereof, but being o en and of increased cross sectional area at t e front of the roll; whereby the level of the stock stream adjacent the roll is materially lowered.

9. I n a beating engine of the horizontal circulating ty a roll, means forming an enclosed, stockcirculating passage of a width and depth approximating the length and dilllfi ameter, respectively, of the roll and extending i from the rear of the roll-aroundto a point near the front thereof, and means independent of the roll for forcibly circulating the stock in said passage.V

10. In a beating engine of the horizontal circulating type, the combination with a roll, of a tiib having a cross section thereof nearer the rear than the front of the roll forming a substantially circular 'stock passage, and a screw piopeller adapted to revolvevin said passage for forcing the stock therethrough.

11. In a beating engine of the horizontal circulating type, the combination with a roll, of a tub providing a passage through which the stock is circulated from the rear to the frontfof the roll, said passage having a restriction therein comparatively near the rear of the roll, and a' screw propeller adapted to revolve in 'said restriction for withdrawing the stoc'kfrom the rear ofthe roll and'forcing it towards the front thereof. I

l2. In a beatin engine of the horizontal 5 circulating type, t e combination with a roll, y

of a tub `providing a` assage through Lwhich the stock is circulate from the rear to the front ofthe roll, -a portion ofthe passage

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