US2035994A - Fiber refining and refiner - Google Patents

Description

Mardl 1936- D. M. SUTHERLAND, JR 2,035,994

FIBER REFINING AND REFINER 5 Sheets-Sheet 1 Filed Oct. 5, 1934 N QNLN MN g March 31, 1936- D. M. SUTHERLAND, JR v 2,035,994

FIBER REFINING AND REFINER Filed Oct. 5, 1934 5 Sheets-Sheet 2 INVENTOR: Daniel 717mm fidherlanifi TORNEYS.

' March 31, 1936- D. M. SUTHERLAND, JR 9 FIBER REFINING AND REFINER Filed Oct. 5, 1954 S SheetsL-Sheet 3 FIG; m

WITNESSES: W 1 IN VEN TOR:

27 Daniel Mans/m Sifiherlazzifir, /wZaf w 18y I t Qlm TTORNEYS.

March 5- D. M. SUTHERLAND, JR

, FIBER REFINING AND HEFI IZNER Filed Oct. 3, 1954 5 Sheets-Sheet 4 F161 XF I N V EN TOR:

71a 70a flazzzlel Mwmffikerlamlfi, j BY M }2& v

I A TTORNEYS.

March 31, 1936- V D. M. SUTHERLAND, JR 2,035,994

FIBER REFINING -AND REFINER WITNESSES: .95 nymvron:

ORNEYS.

-?atented Mar. 3i, l36

PATENT OFFICE 38 Claims.

.My invention relates to the reduction and refining of fibrous materials, such as wood, leather, or cork, and especially to thetreatment of fiber pulp, consisting of fibrous particles in association with liquid, generally water. With suiiicient water or the like, the aggregate or suspension itself behaves as a liquid, and can thus be more easily fed and handled. For wood pulps, it is generally satisfactory to use from three to six parts fiber and ninety-seven to ninety-four parts of water, although other proportions may be used, if preferred for any reason. Materials may be treated dry, provided they can in that condition be fed without clogging between the relatively moving refining surfaces or members by whose coaction the fiber particles are reduced.

The machines generally used, heretofore, for reducing and refining fiber pulp stock for paper or for fiber board are of two broad types, represented by heaters and Jordans. They are used complementarily, for successive treatment of the same pulp stock, rather than alternatively. The beater has a rotor with a series of peripheral knives or bars separated by axially extending "gutters, and coacting with a stationary (segmental) bed-plate in the bottom of a tank containing the fiber pulp to be treated, which bedplate may have similar gutters. The "Jordan has a conical shell in which revolvesa conical core, and the fiber pulp flows in an axial direction through the conical pass between these mated members, which may have longitudinally extending bars separated by gutters. The beater is used to draw and brush out fibers so as to maintain high tear strength in paper made from the refined product, while the Jordan is used to cut and shorten the fibers and close up the sheet, and also tends to reduce the 'freeness of the product. In both heaters and Jordans, only the plain "peripheral surfaces of the beater bars and bed, or of the Jordan shell and plug,and the corners of the gutters or any other openings in or amongst the parts,--are really eifectivein working or refining the fibrous material: 1. e., the openings or gutters themselves serve only as clearances, or for the circulation of'the pulp.

The beater operates on a batch basis, with acycle of hour to 18 hours per batch, according to the kind of fibrous material used and the grade of paper to be made. Previously beaten" stock is passed continuously through a Jordan, and usually only once,-although sometimes the resultant product is recirculated one or more times.

valves, chests, etc., which increase the operating cost and add to the risk of trouble from dirt, rust, .etc., getting into the pulp; Beaters and Jordans also require skill and experience on the part of the operators, to obtain the necessary quality and 5 uniformity of pulp for any particular kind of paper or board; and even with great skill, variations of the refined fibers occur which result in variations in the resulting paper or fiber board.

Attrition mills," sometimes used for refining l0 fiber pulp, haverelatively revolving abrasive discs between which the pulp stock fiows radially outward. The mating abrasive disc faces are generally recessed or groovedr-either in such wise that all the pulp has to pass between the plain 15 surfaces of the discs, or else so that the material can travel outward unrestrained through the grooves, without proper refining. In either case, very much as in beaters and Jordans, only the plain facial surfaces amongst the disc openings 20 or grooves (and their comers) are effectively used for working or refining the fibrous materials; so that the actual working surface area of a grooved or recessed disc is considerably less than if it were entirely plain. Also, regulation of the degree of refining has to be eifected by varying the fine gap or working clearance between the disc faces-insofar, that is, as any such regulation is really possible. And when all the pulp must pass between the plain surfaces of the discs, very considerable pressure is produced on them.

Attrition mills heretofore used require a high power consumption for a relatively slight degree of refining, and will notin a single pass of the stock between the discs, at any rate-produce a refined pulp equal in quality to that produced by the successive action of heater and Jordan. The metal or stone disc faces used in attrition mills wear rapidly, and do not give uniform results. Sometimes the refining discs are held together by 40 spring pressure, so as to yield and separate temporarily if extra large or hard fibrous particles come between the discs,-thus allowing any and all other particles to pass with little or no reduction in size, until the extra large particle gets through. Generally, the gap or working clearance between the discs is purposely varied as a means of controlling the amount or degree of refining and the particle size in the refined product; but this is very unsatisfactory, because a large gap gives very poor efllciency, and also changes the capacity or throughput of the refiner. This is less detrimental than might be expected, however, owing to the peculiar method of pulp infeed to anattrition mill: by means of a mechanical feeding de- 5 vice, separately driven and regulated, without any a nice regard to the capacity to receive the pulp beof refined particles, so that it has usually beennecessary to screen it'to eliminate oversize par,- ticles and secure a.- reasonably uniform product. Even then, such pulp may contain anexces'sive proportion of very fine short particles or "filour,

'88 it is called.

My invention affords a means of refiningfiber stock rapidly; economically, with low power consumption in proportion to the refining accomplished: and'to reasonably uniform and readily controlled particle fineness, fraying, and degree of hydration of fiber. At a single pass ofthe stock through it, and in a few seconds, a refiner emmy invention can be made to produce bodyins stuff properties that would require hours in a beater, and could not be obtained at all in a, Jordan. My refiner affords a readily controlled brushing and rubbing of the fiber particles, as in a beater, and concurrently produces all necessary cutting of the fibers to give satisfactory sheet formation, as in a Jordan. It also permits of varying the deg'reepf refining and the capacity or throughput independently of one another,toa

considerable d fied-and without altering the gapor working clearance between the refining surfaces. As compared-with beaters, Jordans,

and attrition mills hitherto used, my invention can be made to produce a superior pulp, characterized by longer average length of fibers, by the development of more flbrilla: on the ultimate. fibers, by a'freeness the same as that of similar pulp produced by the heaters and Jordans, and

by greater strength of the paper made from the pulp. A

For the purposes of my invention, I employ relatively revolving refining members with parallel-moving mated or mutually corresponding main'rubbin'g or abrasive surfaces, which may be fiat, conical,- or even; radiallylcurved in profile, and may revolve substantially coaxially relative t'o one'another,- -either in'o'pposite directions, or

in the same directionuat "'difi'erentspeeds, or.

merely relatively! i. e., only'on may revolve, while the other is stationary. Hence in speaking of the refining members as "rotary", and of their as paralleL-moving, I refer only to. the character of their relative movement,

without any implication as to whether both mem-' hers actually move, or only one of them. The

vworking faces of these members are traversed by the stock or pulp transversely of the direction of their relative rotary movement! and these faces preferably enlarge circumferentially in the' direction ofstock or pulp fiow, so that centrifugal force tends to produce 'or maintain the flow of the stock. The members may be of stone, steel, iron, bronse, or other materials, or combinations of materials. My invention is concerned both with "time process or mode of coaction'by which the desired results areproduced by the mating re-' fining' members, and with certain important facial features of the members. 7

In the practice of my invention. I maintain the plain rubbing orabrasivesurfaizes of the relatively members at a close v clearance,-which may preferably be as fine,

ordinarily, as about one or two thousandths of an inch, since a much-larger gap or clearance (such as ten thousandths of an inch) does not usually give sufiicient refining action or reduction in particle size for most papers of good quality. I provide the mating surfaces with radially extending flow grooves that permit continuous passage therethrough'cif much of the stock'or pulp, in-

cluding the larger fiber particles or bundles to be reduced. These fiow grooves may extend circumferentially as well as radially,e. g., spirally,or if the mating surfaces are conical or of curved profile, the grooves may extend both axially and radially or spirally. Hence in speaking I of the grooves as "radially extending" I refer only to the fact that their direction has a radial component, without meaning either to exclude or to imply a diagonal direction, with a circumferential or an axial component,-or even both. with the gap or clearance between the main rubbing sur-- I faces so fine that, in general, the greater part of the stock or pulp treated passes through the fiow grooves behind" these main surfaces, so to speak, high pressure on the refining members is avoided, and the power required to operate the refiner is minimized. At the same time, with the grooves sufiicientlyshallow and of suitable depth and conformation, great reduction and working of the fibrous particles in the'grooves can be effected, sincemany of the larger particles (at, least)-- are forced outward to protrude slightly 'abovethei main surface of the member in "whose grooves they are travelling-so as to be squeezed and crushed, torn, or frayed by the interaction of particles in the grooves of the two members, or

rubbed or brushed against the plain, rubbing sur' face of the other member, or hit by the corners of the BI'QQ es in said other member, etc. with suitable grooving of this character, the entire surface of each disc becomes effective in working" or refining the fibrous material: i. e., its total working area equals the plain surface area amongst the grooves plus' the developed inter v nal surface area of the grooves themselves. g

- To assuresufiicient reduction or working of the fibrous particles in the flow grooves, as well as of such particles as pass between the plain surfaces of the refining members, I retard the movement of the stock, by limitation orv diminution of the' eflective area and widthof passage for the stock and its fibrous particles; 'Thus I control the dwell of the stock in the refiner and the maximum fibrous particle'size in the refined product. For

this purpose, the refining members may have coacting outer flow-control zones, with only limited" effective area and'width of passage between them;

or the flow grooves may be reduced in cross-sec- 6 tion anddepth, gradually or at intervals; or both these means of fiow control maybe combined:

In addition, 1 preferably supply the stock or pulp to the refiner under such definite, constant (but regulable) pressure orhead and in such ample quantity as to assure that the refiner will always operate with the refining pass between'the refining members (including their grooves) fullof pulp, thus obviating any variation or irregularity of the workdone on the .pulp due to partial and variable emptiness of grooves from time to time. 'I'hislcan be done by supplying the pulpfrom a constant-head head-box, such as known in the art for other purposes. Instead of controlling and varying the amount of work done'on the stock and the capacity or throughput of the refiner by varying the gap or clearance between the mating surfaces of the refining members, as has heretofore been the practice in. Jordans and attrition mills, I hold this gap substantially constant, and effect the desired control by varying and adjusting other influential factors: viz., the width of the working faces in the-direction of pulp fiow, and their facial features (grooving) the effective area and width of passage for the pulp and its fibrous particles afforded by the fiow grooves and the outer control zones; the inlet head or pressure under which the stock is fed to the refiner; and the speed of rotation of one or both refining members. The maximum particle size can be controlled especially by the depth of the grooves and the effective width of passage or gap between the control zones,--one or both,-while the capacity and output can be controlled by the crosssection and number of flow grooves, by the inlet pressure or head, and by the speed. Even after the groove depth and control-zone width of passage have been fixed, the throughput can still be more or less independently adjusted by varying the inlet pressure and the speed,although these factors may also influence the average particle size, since if the speed of rotation and the flow of stock through the flow grooves are very low, the average reduction of particle size in the grooves may materially exceed what would, sufiice to let the particles through. In some cases, a slight variation of the gap or clearance between the main surfaces may be resorted to, in order to control and adjust the freeness of the refined fiber as desired consistently with the desired capacity. This, however, is in the nature of a last fine adjustment, since any very material increase of the gap or clearance above the limits already indicated will give poorer and less economical refining.

While variation of either inlet pressure or speed of rotation of one or both refining members affects the throughput of the refiner, the effects are not by any means identical. Increase of the pressure under which the stock is fed to the refinertends to increase the throughput and reduce the dwell of the stock in the refiner without any compensatory increase or intensification of the work done on the stock Hence such increase of inlet pressure tends to become less and less effective in increasing throughput of stock containing any quantity of large fibrous particles: e. g., if the inlet pressure is doubled or quadrupled, twice or four times as much stock will not go through, because the large particles can not be sufiiciently reduced in one-half or onefourth the time. On the other hand, any increase in the speed of rotation of either refining member which also increases the rate of relative rotation of the members does tend-to be selfcompensatory; because the work done on the stock and the reduction of its particles naturally increases according, to (and almost pari passu with) the relative rotation of the coacting mating surfaces of the members.--and vice versa. In general, therefore, speed variation may be preferred to inlet pressure variation as a means of controlling output.

Various other features and advantages of my invention will appear from the following description of species thereof, and from the drawings.

In the drawings, Fig. I shows a vertical'axial 7 section through a fiat-faced rotary disc or attrition mill type of refiner conveniently adapted for the purposes of the invention.

Fig. II is an end elevation of the machine and its pulp-feeding provisions, certain parts being in vertical section; and Fig. III shows 'a horizontal section through part of the pulp-feeding means, taken as indicated by the line and arrows III-III in Fig. II. I

Fig. IV is a plan or facial view of a segment of one of the refiner discs shown in Fig. I, on a larger scale.

Fig. V is a sectional and edge view with the refiner disc in radial section, as indicated by the line and arrows VV in Fig. IV. v

Fig. VI is a fragmentary inner edge view,-and Fig. VII a similar outer edge view, taken as indicated by the lines and arrows VI-VI and VII-VII in Fig. V, respectively.

Fig. VIII is a fragmentary outer edge view similar to Fig. VII, but with a part removed.

Fig. IX shows an axial section through part of a coacting pair of refined disc faces different from those shown in Figs. I and IV-VIII, on a larger scale than Figs. I and IV.

Fig. X is a plan or facial view of a segment of one of the refiner discs shown in Fig. IX.

Figs. XI and X11 show fragmentary radial sec- .ions of one of the discs, taken as indicated by the lines and arrows XII-XI and XII-XII in Fig. X, respectively,-on a larger scale than Figs. IX and X.

Figs. XIII, XIV, XV, XVI, and XVII show fragmentary circumferential sections of one of the discs, taken as indicated by the correspondingly numbered lines and arrows in Fig X, respectively.

Fig. XVIII shows a radial section through cooperating grooves of the discs shown in Figs. I, IV. and V, with fiber pulp passing through them; and Fig. XIX shows a cross-section through these grooves as indicated by the line and arrows XIXXIX in Fig. XVIII.

Fig. XX shows an axial section through part of a refiner disc generally similar to that of Figs. IX to XVII, but with a facing of sectional construotion.

Fig. XXI shows a fragmentary plan or facial view of the disc and facing shown in Fig. 29!; and,

Fig. XXII shows a fragmentary facial view of the disc of Figs. XX and XXI with its facing secions reversed. v

To assure a clearer understanding of my invention, I will first briefly explain the general construction of the refiner in which it is here shown.

The refiner shown in Fig. I comprises oppositely rotating coacting refining members or rotor discs l0, ll enclosed in a housing l2 and driven by separate (electric) motors l3. l4 mounted directly on the disc or rotor shafts l5, I6. One or both of the motors l3, M are preferably variable speed motors. lhe shafts l5, l6 are mounted in inner anti-friction (thrust and journal) bearings l1, IS in pedestal supports 2'0, 2! located closely adjacent the rotors l0, H and forming part of the housing structure l2, and in outer (journal) bearings in other pedestals 22, 22 at the outer sides of the motors l3, Hi. The pedestals 20. 2! are rigidly tied together (and united to the housing I?) by longitudinal webs below the shafts I5, l6, and all of these and other parts are mounted on a common rigid base 23. This construction obviates deflection and untruing of the rotor discs l3, ll under the working thrust between them. The base 23 has therein an opening with a depending inward-sloping apron or fiange Zl that forms a downward extension of theihousing l2 and a downward mm roithe pulp refined between the rotors II, II. The

mtors il, H are keyed fast on the shafts ll, I2

ing pass" between the faces-21, 21. .Pulp is ail-- mitted to the cavity '28 through the rotor II, which has an annular intake passage 22 in its central hub portion around its inner hub 2| in which the shaft- IE is keyed and secured, The inner hub 3| is connected to the outer hub by vanes 32 between which the pulp can pass freely. The pulp is supplied through a passage 23 inthe pedestal 20 (below the shaft bearing H), which" passage extends up around the hub 2| and opens into the annular intake 29. The box 24 of the thrust bearing I8 in the pedestal 2| is movable lengthwise in the pedestal, but is kept from turning therein by a groove and feather engagement at 35, and is extern'ally threaded to take a worm wheel nut 36 that can turn between abutment shoulders in the pedestal. Th'e nut 28 can be turned 'either way by a subjacent worm 31 on a transverse shaft 38 mounted in hearings in the pedestal 2|. v 4

. By turning the shaft 22 and the nut 22 one way or the other, the rotor canxbe shifted toward the rotor '|0,-into efi'ective refining proximity thereto; or away from the rotor It, so as to afford a large interval between the faces 21, 21.

Also, the gap or clearancebetween-the faces 21,

-21 canbe adjusted to just the number of tenthousandths of an inchdesired, according to the character. of the pulp being treated and the maximum fineness of flber desired in the product.

When thus adiusted, the machine operates with its faces 21, 21 dead set at-the desired working clearancez gi. ,e., the clearance is positively and,

unyielding'ly fixed and'held until and unless adjusted. For many kinds ofpulp, 900 R. P. M. of the rotors IO, U is a favorable speed: but wide variation is admissible, e. g. speeds of 300 to 900 R. F. M. can readily be used.

As shown in Fig. 11, the stock orpulp to be ,"refined may be supplied to the passage 22 through 'a feed pipe connection from a regulable, constant-head head-box 40-01 any suitable type and construction, located at a height above the machine corresponding to the inlet head or pressure desired. The stock or pulp is delivered to the head-box 40 through a supply pipe 4| by a (centrifugal) pump 42 drawing from the usuaL"stufl'- chest 43, with agitator 44; and any excess returns to the chest 42 through an overflow pipe 45. As shown in Figs. II and III, the'head-box '40 is divided by a partition 46 into an outlet chamber 41 and-another (larger) chamber, which latter is divided by aligned transverse dams 42, 49 and a longitudinal dam iii into'an inlet chamber ii to which the supply pipe- 4| delivers; a constant head chamber i2; and an overflow chamber 53 into which opens the overflow pipe 45 There is avariableopening or 52 through the partition 46 to the chamber 41, controlled by any suitable regulating means, such as a gate valve 55. As shown, the dam 48 for the inlet chamber 5| is about an inch lower than the dams 48, 50 around the overflow chamber 62, so

I that the pulp first overflows from inlet chamber 5| over dam 48 into constant head chamber 52,

from the chamber and only overflows dams 4. and it into overflow chamber I2 when not carried oil by feed pipe 89 as fast as supplied through,p|pe 4|. Ordinarily, pump 42 will be operated to deliver an excessive supply to the head-box 42, so that there would be some overflow into chamber 52 even with valve 55 wide open. By adjusting valve 55, the height of the pulp in outlet chamber 41 can be regulated. and the pressure head and throughput of pulp correspondingly varied.

The annular refining disc facings 21, 21 are mounted on metal supporting plates 60, 0| which are. secured to the rotors in, II by bolts 62 extending through the rotors and taking intothe plates 6|), 6|. The plates 62, II are centered on the rotors III, II by engagement of annular grooves in the plates over annular ridges 82, 63 on the rotors. The center ofr'the plate 80 is open at 64 around the nut 25 that holds the rotor ill on its shaft IS, t admit the pulp from the intake 29 between the plates 80, 6|. The center of the plate -6| is closed, thus. excluding the pulp from the nut 26 that holds the rotor H on its shaft it; but it is annularly recessed or dished to an arcuate profile at 65, to spread the axial pulp stream from intake opening 64 into an annular outflow into the annular refining pass between the facings 21, 21. The disc facings 21, 21 are secured to the supporting plates 60, 6| by bolts 66 extending through the plates 80, 6| and taking into the facings 21, '21.

. .66, are'accommodated in seat recesses .1 countersunk in the plates 60. 6|.

The general operating. and structural features oi the particular refiner here illustrated have been thus described for the sake of clearness and as a background for the explanation of my present invention, new presently to follow; The refiner and head-box. construction can be widely 21, 21 has in its main plain, rubbing surface 10- that mates and coacts with'the other face 21 a plurality of radially extending flow grooves 1|, similar to one another and equally spaced. Thirty-two such grooves 1| to the total circumference are indicated in Fig. IV, althoughamuch less or much greater number mightbe usedl Each groove 1| extends across the flat surface 10 from the inside facing-bevel 12 substantially or nearly to the outer facing periphery, and has its bottom rounded transversely: l. e., circumferentialiy of the face 21. In the present instance, the grooves 1| gradually or progressively diminish inxipth from their inner to their outer ends, and their bottoms gradually "flatten" with a diminishing (arcuatei' curvatureand an increasing radius.-

The heads of the bolts varied, or even radically changed, since its'fea-' As shown, the grooves 1| also gradually widen a little outward across the face 21, though not somuch as wouldv correspond, to the flattening of their bottom curvature; for their edges for at least part of their length are much steeper thanwould correspond to the general curvature of their bottoms. The annular corner between each flat main working surface 10 and the inner bevel 12 is eased or rounded at 14, and the walls of the grooves 1|-at their inner ends merge into the bevel 12 with like rounding 1i.

Besides the'control of the outflow through the grooves 1| by their outward-diminishing depth and cross-section, an outer flow-controlling facialfzone 16 is preferably provided adjacent the periphery of the face 2'7, aifording more limited cross-section and width of passage thereacross for the stock and its fibrous particles than the grooved facial refining areas or working zone depth of the deepest outflow grooves in the zone it of either face 27, 2?. As shown in Figs. I, IV, V, and VII, provision is made for adjustablyvariable flow-control grooving across the zone it. One way of doing this is to provide the outer edge or margin of each facing 21 with recesses or notches ll, preferably in line. with the grooves H, and of a-depth equal to the full width of zone l8,-with inset (brass) blocks 8!! adjustable therein in the direction of the thickness of the facing 21. For this purpose, bolts 8! are shown extending with suitable clearance through holes or slots 82 in the blocks 80 and taking into the edge of the facing 21. By loosening the bolts 8| and shifting the blocks 80, any desired number of these blocks can be set either flush with the surface 10 or at distances below it affording shallow grooves of just the desired depth and cross-sectional area across the zone 18. In this way, various grooves H can be made to deliver fibers of various different sizes, and the proportions of such fibers in the pulp thus varied and controlled pretty much as desired. As shown, the notches H are narrower than the outer ends of the grooves l i, and the later have rounded corners 83 just inside of the notches I1.

To illustrate suitable proportions for one of the working faces 2'! and its various features for certain uses, it may be of 30 in. outside diameter, 19%in. minimum inside diameter, 20% in. inside diameter to the intersection of -the inner bevel 12 with the surface ML-disregarding the rounding way of their corner at UL-and 2 in. thick. The grooves H may be I; in. deep at their inner ends and rounded to a /8 in. radius, and at their outer ends it in. deep and rounded to a 3% in.

radius-with a minimum depth of 5 in. at the roots of the bevels 13 just inside the rounded corners 83. The width of the plain surface 10 between adjacent grooves H may be /8 in. at the inner ends of the grooves. The notches 11 may be 1 /4 in. wide and /2 in. deep, and the blocks 80 may have like dimensions and a length of' lit in.

A fair practical range of adjustment for the blocks 88 would be 3/64 below the surface 10 as a maximum, and 1/64 in. below as a minimum. The bolts 8| may be /2 in. bolts.

Working faces 21 with grooving, etc., of the their ultimate fibers. For example, spruce or other chips may be cooked with steam or hot water; or they may be digested in any usual way with an aqueous liquor'of calcium bisulphlte (C8.(HSO3)2) at a temperature gradually rising to about 135 C.,--usually with about 11 hours total treatment of the chips inthe digester. Pulp resulting from treatment of these partially di== gested chips in a refiner with the working faces 21,. 21 of Figs. IV-r-VIII may be screened through a pulp screen of '50 to 60 meshes per sq. in. to remove oversize particles, and then mixed with with: i. e., the facing discs 27a, 2112 may be mounted and secured directly on the rotors in, l l of Fig. I, just as the plates 60, 6| are mounted and secured. Accordingly, the disc 21a is shown with a pulp intake opening 64a at its center like the plate 60; while the center of the disc 21b is closed and annularly recessed or dished-at a, like the plate 6| The mating annular main surfaces l0, 18 of the facing discs 21a, 21b, around the opening 64a and recess 65a, may be just alike. In Figs. IX-XVII, various parts and features are marked with the same reference numerals as in Figs. I-VIII, (with an added letter, where such distinction appears desirable), as a means of dispensing with repetitive description.

On the working faces 21a, 21b, several distinct annular working zones A, B, C may be distinguished. These zones A, B, C are preferably separated from one another and from the circumjacent flow control zone 1611 by shallow annular redistributing grooves 84, 85, 86. (Figs. IX- XLI)- Three such distinct refining zones A, B, C are here shown, but obviously any desired number of them (from one up) might be provided.

As these zones A, B, C are successively traversed by the outfiowing stock or pulp under the influence of progressively increasing centrifugal force, their main fiow grooves Ha, lib, 'Hc are of successively or progressively diminishing crosssection and depth (Figs. IX, X, and mlI-XVI). The inner, intake ends of the grooves H0 in the initial zone A are .fiaringly enlarged and rounded (Figs. X, XVI), to facilitate entrance into them of the large fibrous particles in the raw stock or pulp as it enters the refiner; and their depth is shown as diminishing progressively outward (Fig. IX), with a view to assuring prompt reduction of the large fibrous particles, and also in view of the rapid increase of centrifugal force in the grooves Ha. The first distributing groove 88 is shown shallower than the outer ends of the main fiow grooves H a. The grooves Ha may end in a "bead 87 short of the middle of groove 84, or on a taper 88 to the outer side of the groove 86 I in Figs. IX and-X, both of theseforms are embodied.

In addition to the main flow grooves Ha, lib, lic, some or all of the zones A, B, C may be provided with radially extending intermediate, secondary flow grooves 8|, .shown as narrower and shallower than said main flow grooves, to receive such smaller fibrous particles as may be alternate with main fiow grooves lid in zone A (Figs. XV and XVI), and are twice as numerous as grooves lib in zone B (Fig. XV) ,-where the number of grooves lib indicated is the same as that of grooves lid in zone A. In zone C (Fig. XVI) the difference of width and depth between main and secondary fiow grooves lie and Si is not very great, and they are arranged in alternation; but their aggregate number much exceeds that of grooves ill) and Si in zone B, being about double, in fact.

Besides their function of reducing particles too large to enter the smaller or secondary" flow grooves 9i,when and if such very large particles exist in the stock or pulp,the main flow grooves lia, lib also serve as feeder or bye- -pass channels to the circumferentially more extensive outer zones B and C: i. e., they supply these zones B and C with more stock than could reach them through such number of narrow, shallow grooves 9i as the less extensive inner zones- A and B would properly afford room for.

As I shall point out more fully hereinafter, a certain amount of ungrooved plain surface Illa is needed amongst .the grooves of each zone A, B, C, in order that each zone may do its work on the stock properly. Unless, therefore, some such provision as the deep grooves Ila, -'lib were made for supplying stock to the outer zones B and C,

the efliciency of the refiner would'necessarily be impaired: either by underworking of the more extensive outer zones B and C through failure to supply enough stock to them, or by over-grooving of the less extensive inner zones A and B in order to supply stock to the outer zones 3 and C. In addition to flow grooves lia, lib, lie, and Si, some or all of the working zones A, B, C may have d ad, or non-flow working grooves, to assist in reducing the fibrous particles (as hereinafter described) without affecting the pulp flow. As shown in Fig. X, zone A has radially extending dead working grooves 94 in alternation with its grooves lid and ti, and zone Bhas a radial "dead working groove 95 between each pair of itsgrooves 9i. In both of zones A and B, the dead grooves 94 and 95 open into the distributing groove 84 between said zones,althoug h this is not broadly essential.

Preferably, the outer ends of main fiow grooves lid in zone A are not oppositemain or secondary flow grooves lib or ii in zone B, in order that the redistribution of stock or pulp in groove 84 may be more thorough. This redistribution is not interfered with, however, by having grooves lie in zone A opposite grooves 95 in zone 3.0: by hav+ ing grooves9i in zone A opposite grooves lib in zone B, as shown in Fig. X.v For similar reasons, alignment of grooves lib and lie in'zones B and C is preferably avoided, although grooves ii in zone 6 may come Opposite grooves lib in zone B without objection.

The type of adJustably-varlablo flow and outlet-control grooving here shown for-the outer+ most zone "a comprises a series of inset (bronze) blocks "a in'recesses in said zonella outside the distributing groove l5, fiush with the main surface Ilia, and secured by pairs of screws Ila.

' Any desired number of the insets-Ilia may have be.- The depth of the grooves 06 will determine the maximum particle size in the refined accuses pulp, and'the total area of grooves mail the blocks a will determine the refiner capacity or throughput for given intake pressures and disc speeds of revolution. The maximum refined particle size and the capacity may be changed whenever desired by replacing one set of blocks "a with others. I t I To illustrate suitable proportions for the facings 21a, 21b and their various features, they and the grooves 84 and 85 may have theircorners rounded to radii equal to their depths. The grooves i is may be in wide, and vary in depth from in. at their inner ends to V in. at their outer ends; and their corners may be rounded to about $4; in. radius,or more at their widened inner ends. The grooves lib may be V4 in. wide and 54; in. deep, and semi-circularly rounded;

, and the grooves He may be? in. wide, in.

deep, and semi-circularly rounded. All of the grooves 9i and 94 may be M; in. wide, in.deep,

and semi-circularly rounded. The grooves 95 may be 1; in. wide, 3 5111. deep, and semi-circularly rounded. The insets 80a may have one groove 96 apiece; it may be in. wide and a; in. deep;

and there may be 12 of the blocks "a, at 30 intervals on centers. In zone A, there may be some 48 to 50 each of grooves lid and Si, and 96 to 100 grooves 94; in zone B, there may be 48 to 50 each of grooves lib and 95, and 96 to 100 grooves 95; in zone 0, there may be about 128 each of grooves lie and SI.

In the operation of a refiner with working faces such as 2 l, 21 in Figs'.IV-VI1I, or 21a, Ilb in Figs. IX-XVII, the stock is fed in axially at 28 or 64a under constant (head-box) pressure, and fiows outward through the refining pass between ,the discs-including the'fiow grooves II or lia,

lib, lie and Bi. In the refining pass, the stock is also impelled outward very powerfully by the centrifugal force due to the high speed of rotation,-which force increases outward from the axis. Owing to the mall gap or clearance of .001 or .OQ2 in. between the disc surfaces 10,10, the

' greater part of the fibrous particles (and of the liquid too) passes through the flow grooves. In

"these grooves, the fibrous particles are spun around, squeezed, and disintegrated very rapidly,-undergoing a variety of actions that tend to reduce their size, to fray or roughen them. and to hydrate the ultimate fibers.

The coaction of the grooved working faces to produce these efiects is promoted by the crosssection of the grooves, with their transversely curved bottoms and sharp, approximately rightangled top edges or corners, as well as by the gradually or successively depths of the grooves 1i and lid, lib, and lie. The rounded groove bottomis only one of manypossible forms: the important points-arethat the depth of the groove should decrease toward its side',

and that at and just below the surface ll, the groove side should be perpendicular to the surface l0,or at least sufiiciently steep to give a fairly sharp corner-angle. However, the "arcuai character of a groove-by whichI mean its diminution in depth toward the side-is so much minimum of cutting ofthe fibrous material. It

is not necessary to machine or otherwise out the internal groove surfaces: on the contrary, the grooves may be cast in a-cast-iron facing, without any subsequent work being done on it except to grind its plain surface (intermediate the grooves) and its ba'.k, as .already mentioned.

The sides of the grooves that count most are their ,trailing or following sides,speaking with reference to the direction of rotation of the discs. By reversing the rotation of the discs after the corners at their trailing sides have worn round, the relatively, unwom, sharp leading corners will become the trailing corners, and so the necessity of regrinding the working faces 21, 21 (and perhaps recutting their grooves) will thus be deferred.

Main reductive influences on fibrous particles in the grooves of each disc facing 21, 21 or 21a, 21b are squeezing, crushing, and fraying by the interaction of particles in the grooves of the two facings; the abrasive friction with the plain surface III of the coacting facing; and the impacts against the trailing corners of the grooves in the coacting facing; These influences tend to detach small fibrous particles (or even ultimate fibers of the material) from the-larger particles. The squeezing and the impacts especially tend to crush, mash, tear, and even shear the fibrous particles, both along the natural cleavages amongst their ultimate fibers, and across the ultimate fibers,thus shortening them. As the fibrous particles are reduced, they are continually forced outward to undergo further crushing, abrasion, and impact, by the diminution in depth of the grooves, both transversely toward their sides and longitudinally in the direction of pulp,

flow. -Such fibrous particles and fibers as get into the dead grooves 94, 95 are, swept through and out by the flow between the plain surfaces 10, I0.

How fibrous particles may be reduced by the interaction of material in arcual grooves of cooperating discs is illustrated by Figs. XVII and XIX, and especially in the latter. 'Here large fibrous particles A and B are shown in a groove ll of disc 21a, and other'large particles C and D in a groove 1| of disc 21!), opposite groove ll of disc 21a. Smaller fibrousparticles and ultimate fibers are also shown in each of these grooves 'I I, I l Another large fibrous particle E is shown in the midst of the particles A, B, C, D, being squeezed between particles A and D in the opposite grooves H, H. Obviously, this must result in crushing and splitting, tearing, or fraying one or more of these particles A, D, and E. Of course,

this is only one of the waysinwhich the squeezing and reduction of particles may result from interaction of material in grooves 1|, H as they pass.

Such ultimate fibers as become wholly detached and independent may to a certain extent work in between the plain surfaces 10, I0, and

there be further rubbed, brushed, frayed, andhydrated. When the gap or clearance is as much as '.002 in. or a little more, some of the smaller j'fiber bundles (composed of some two, three, four' or five ultimate fibers, for example) may work in between the surfaces I0, I0, and be there torn apart, wholly or partially.

As rubbing against the abrasive plain surfaces 10, '70 and impacts against groove edges are both important reductive influences, it follows that adequacy of plain, rubbing surface is important, as well as sufiicient total length of groove edges. On the working faces 21, 21 and 21a, 21b here shown, the plain area approximates the depressed or grooved area, including dead grooves 94, 95 as well as fiow grooves: on the faces 21a, 21b, indeed, the aggregate plain area very considerably exceeds the aggregate depressed area, the ratio beingroughly about 2 to 1. On the other hand, the recessed or grooved surfaces heretofore employed in refiners have had considerably greater depressed area than plain area: i. e., they have relied too much on edge impacts, and have not really utilized the distinctive fiber-working possibilities of abrasive plain surfaces. Neither have the internal groove surfaces been utilized effectively.

Broadly regarded, therefore, my invention involves a recognition and effective utilization of plain, rubbing surfaces to abrade the fibrous particles in combination with fiow grooves to hold them and permit their travel while being reduced. Also novel is the recognition and utilization of the internal groove surfaces to cause squeezing and consequent reduction of the fibrous particles as explained in connection with Figs. XVIII and XIX. Important to the eflicient utilization of these principles is the retardation or control of the stock-fiow through the refining pass to give time for adequate abrasive and impact working of the fibrousmaterial. Likewise helpful are the comparative shallowness'of the grooves; their transverse'reduction in depth, especially toward the trailing side, so as to force particles outwardamount of work on the fibrous material, they may, nevertheless eflect some reduction or working of the particles.

When steel refining discs are employed, their plain, rubbing surfaces 10, 10 will preferably be finished true and fiat by grinding, which leaves them with slight abrasive roughness or tooth. Their back sides will preferably be also ground true and parallel with their surfaces 10, 10. For

greater abrasive roughness or tooth of the plain, rubbing surfaces l0, 10, natural or artificial stone discs may be employed. Artificial stones of grit with a binder (e. g., alundum or carborundum, with a silicious binder) permit a considerable range of roughness and hardness,such as Norton grades 40-250 of roughness, and grades M--Z of hardness. Abrasive plain, rubbing surfaces of cast iron or bronze alloys with carborundum or other grit cast in may also be used.

In the design of the refiningflmembers, their area and width in the direction of stool: flow are proportioned to the material to be treated and to the work to be done on it, and so likewise their flow and "dead grooving. Approximate corre spondence-between the refiner throughput and the demand" of the paper (or fiber board) machine from time to time is secured by suitably adjusting the head or pressure under which the stock is supplied to the refiner and the grooving a in its outer'fiow-control zone.due regard being ofoburse had forthe fact that the depth .ofthe flow-control grooving determines the maximum particle sizein the refined pulp. Final and] accurate adjustment of the refiner capacity to the regarded as normal speed, one or both members may be droppedaslow as'l5il R.P. M. or raised as high as 1050 R. P. M.,-by methods of motor --speed control well understood by electricians.- k'without very materially altering the degree of fining members having parallel-movingmating flag a difierent ring refining and the quality of the refined pulp. Final adjustment of the freeness ofithe refined fiber may be made by varying the gap or clearance between the refining members a few tenthousandths-of an inch, as already mentioned.

Figs. xx to XXII illustrate a sectional construction of a disc '01 facing that permits of easily changing the outermost fiow and outlet control zone 16a, and also makes it easy to change the working zone or zones. The particular disc here illustrated resembles-that oi? Figs. Ill-XVII in having three distinct working zones A, B, however. the construction is adaptable to a disc with any desired smaller or larger number of zones. l

' Asshown, the outermost flow control zone Il av consists of a metal ring separate from the rest of the active dlscface, and detachably secured to a backing or supporting plate I like that of l'ig. I by bolts 68'. By unscrewing the bolts'tl the ring Ito shown can be'removed, and with another affording greater or less crosssectional area or width ofoutfiow passage. in the present instance, each of the working zones A, B, C is also a separate ring, secured to the backing 6| by bolts 68', and having therein the desired flow and dead" working grooves ,lla', lib, lie, and 94', 95',-etc., and also having in lts'edge a rabbet 84', I, 88' which cooperates with the adjacentring to form an annular redistributing groove. By unscrewing the proper 'bolts ii', any one or more of the working rings A, B, Ccan be removed. and replaced with a similar one difi'erently grooved. Thus the disc facing can be changed to vary its action on the fibrous material: e. g., it can be given a greater or less total length of grooving in proportion to its plain facial surface. so as to cut the fibrous material more or less in proportion to the abrasive work done on it. As indicated in Figs. x and XXII, opposite sides of each ring A, B, C,

i may be difi'erently-grooved, so that by reversing one or more of therings, the efiect of substitutwill be realized, as shown 4 In Figs. xx to XXII, various Part and features are marked with-the same reference characters as inFlgsLIX and x,asameansof with repetitive descriptiom-with distinguishing fprime marks where such distinction appears necessary. Y

.Having thus described my invention, I claim:

1. An improvementin refining fiber stock between coacting coaxial relatively revolving replain, rubbing working faces' with extending flow grooves therein permitting con- Itinuous passage across said taces of fibrous particles to be reduced: whichimprovement comprises maintaining the at such close clearance, and feeding in the stock to'the refining pass between the members in such quanacting members and thereby controlling the throughput and the maximum fibrous particle size in the product,

2.4m improvement in refining fiber stock between coacting coaxial relatively revolving refining members having parallel-moving mating plain, rubbing working faces with radially extending flow grooves-therein permitting continuous passage across said faces of fibrous particles to be reduced; which improvement comprises maintaining the coacting surfaces at such close clearance, and feeding in the stock centrally to the refining pass between the members in such quantity, that the major portion of the stock goes through the grooves, and only a small portion passes between the plain surfaces; peripherally restricting the effective width of passagev and the outflow from between said coacting memhers and thereby approximately determining the throughput and the maximum fibrous particle size in the product; and varying the speed of revolution of a refining member according to the exact throughput desired.

3. A method of'controlllng the maximum size of refined fiber from stock fed between coacting relatively revolving refining members with parallel-moving mating working faces having therein radially extending grooves permitting continuous passage therethrough, across said faces, of fibrous particles to-be reduced, and also having peripheral outlet controi zones affording limited width of passage for the reduced fibrous particles: which method comprises maintaining a substantially constant gap or clearance between said relatively moving working faces, and varying the efiective width of passage afforded by said outlet-control zones according to the desired maximum particle size in the product. i

4. A method of controlling the. output and maximum size of refined fiber from stock fed between coacting relatively revolvingrefining members with parallel-moving mating working faces having therein radially extending grooves per- 'mitting continuous passage therethroilg across .5. An improved method of refining fiberstock ly revolving refining members parallelmoving mating plain-surfaced working i'aces;

which method comprises causing the major portion of the stock to pass continuously across said faces through continuous fiow grooves in said plain surfaces, andforcing fibrous particles thus travelling and held in such fiowgroov'es of each member outward toward the other member, thus abrading and reducing such fibrous particles against the plain surfaces of the members, besides crushing,- reducing. and fraying the particles by by passage thereof between cooperating relative- I interaction of grooves in said members and by coaction of their plain surfaces.

6. An improved method of refining fiber stock by passage thereof between cooperating relatively revolving refining members having parallelmoving mating plain-surfaced working faces; which method comprises causing the major portion of the stock to pass continuously across said faces through continuous flow grooves in said plain surfaces, and forcing fibrous particles thus I travelling and held in such flow grooves of each member outward toward the other member, thus abrading and reducing such fibrous particles against the plain surfaces of the members, besides crushing, reducing and fraying the particles by interaction of grooves in said members and by coaction of their plain surfaces; and restricting and retarding the outflow of stock from between said members and itspassage through their said flow grooves, so as to give time for adequate working and reduction of larger particles in the grooves.

7. A refiner of the character described comprising coacting coaxial refining members having parallel-moving mating plain, rubbing working faces with radially extending flow and working grooves therein permitting continuous passage across said faces of fibrous particles to hereduced, said members revolving relative to one another with such close clearance that the major portion of the stock entering the refining pass between the members goes through the grooves, and only a small portion passes between the plain surfaces, and being provided with means at the peripheries .of their working faces for restricting the outflow from the members and controlling the dwell of fibrous particles in the refining pass.

8. A refiner of the character described comprising coacting coaxial refining members having parallel-moving mating plain, rubbing working faces with radially extending'fiow grooves therein permitting continuous passage across said faces of fibrous particles to be reduced, and revolving relative to one another with such close clearance that the major portion of the stock entering the refining pass between the members goes through the grooves, and only a small portion passes between the plain surfaces, the depths and bottom configurations of said grooves being such as to wedge fibrous particles in the grooves of one member toward the other member.

9. A refiner of the character described comprising coacting coaxial relatively revolving refining members having parallel-moving mating plain, rubbing working faces with radially-extending sloping-sided flow and rubbing grooves therein permitting continuous passage across said faces of fibrous particles to be reduced but so shallow that substantially the entire internal groove surfaces are active in working the fibrous particles, as well as the plain surfaces amongst the grooves and the corners of the latter, said members revolving relative to one another with such close clearance that the major portion of the stock entering the refining pass between. the members goes through the grooves, and only a small portion passes between the plain surfaces, and being provided with means at their peripheries for restri'ct-.

ing the outflow from between them and controlling the dwell of fibrous particles in the grooves.

10. A refiner of the character described comprising coacting coaxial refining members having parallel-moving mating plain, rubbing working faces with radially extending flow grooves therein permitting continuous passage across said faces of fibrous particles to be reduced, and revolving relative to one another with such close clearance that the major portion of the stock entering the refining pass between the members goes through the grooves, and only a small portion passes between the plain surfaces, said grooves diminishing in depth in the direction of flow therein.

11. In a refiner of the character described, the combination of coacting coaxial relatively revolving refining members with parallel-moving mating plain, rubbing working faces having radially extending working grooves therein permitting continuous passage therethrough across said faces of fibrous particles to be reduced, and also having coacting peripheral flow-control zones affording more limited area and width of passage flow control zones, with flow grooves thereacross in at least one of the members, affording more limited area and width of passage for the stock and its reduced fibrous particles, and coacting to control the dwell of the stock in the refining pass between the members and the maximum particle size in the refined product.

13. In a refiner of the character described, the

.in at least one of the members, affording more limited area and width of passage for the stock and its reduced fibrous particles, and coacting to control the dwell of the stock in the refining pass between the members and the maximum particle size in the refined product.

14. In a refiner of the character described, the combination of coacting coaxial relatively revolvlng refining members with parallel-moving mating plain, rubbing working faces having roundbottomed grooves therein permitting continuous passage therethrough across said faces of fibrous particles to be reduced, and also having outer facial outflow control zones, with fiow grooves thereacross in at least one of the members, afiording more limited area and width of passage for the stock and its reduced fibrous particles, and coacting to control the dwell of the stock in the refining pass between the members and the maximum particle size in the refined product.

15. In a refiner of the character described, the combination of coacting coaxial relatively revolving refining members with parallel-moving mating plain, rubbing working faces having grooves therein permitting continuous passage therethrough across said faces of fibrous particles to be reduced, said grooves diminishing in depth toward either side and also diminishing in depth in the direction of fiow therein, and further having outer facial outflow control zones, with flow grooves thereacross in at least one of the members,'afiording more limitedarea and width of passage for the stock and its reduced fibrous particles, and coacting to control the dwell of the flow-control zones affording limited efiectivearea working clearance between said refining members.

and the maximum particle size in the refined product. a

P 16. In a refiner of the character described, the

. combination of coacting coaxial relatively revolving refining members with parallel-moving mating plain, rubbing working faces having radially extending grooves therein permitting continuous passage therethrough across said faces of fibrous particles to be reduced, and also having coacting and width of passage for the stock and its reduced fibrous particles-and provided with means for adjusting and varying said effective area and widthof passage independently of the gap or 1'1. A refiner of the characterdescribed comprising coacting coaxial refining members .having parallel-moving mating plain, rubbing .working .faceswith radially extending flow grooves therein, permitting continuous passage across said faces of fibrous particles to be reduced; said members revolving relative to one another with such close clearance that the major portion of the .stock entering the refining pass between the members-408s through the grooves, and only a small. portion passes between the plain surfaces, and being provided with means at their peripheriesfor restricting and varying the outflow from 1 another with such close clearance that the major portion of the stock entering the refining pass between the members goes through the grooves, and

. between them independently of the gap or working clearance between said refining members 18.A' refiner of the character described comprising coacting'coaxial refining members havingparallel-moving mating plain, rubbing .work- .ing faces with radially extending fiow and work- 'ing grooves therein permitting continuous passage across said faces of fibrous particles to be reduced, said members revolving relative to one only a small portion passes between theplain zones, and also having coacting zones at the pe-.

surfaces, and ,having circumferentially extending dividing the working faces into annular .nones and permitting redistribution of fibrous particles amongst the fiow grooves in successive 'lpheries of their working faces for restricting the outflow from between the members and controlling the dwell of fibrous particles to be reduced in the refining pass.

' clearance that the major portion-of the stock entering the refining pass between the members goes through thegrooves, and only a small portion between the plain surfaces, and having circumferentially extending grooves dividing the working faces into annular zones and permitting redistribution of fibrous particles amongst the ficw grooves in successive zones, and also having intermediate working grooves amongst said flow grooves each opening into one circumferential roove only.

prising coacting coaxial refining members having 20. A refiner of the character described comparallel-moving mating plain, rubbing working faces with radially extending fiow grooves therein permitting continuous outward across 75 said faces of fibrous particles to be reduced, said 1,085,994.. stock in the refining pass between the members members; revolving relative to one another with such close clearance that the major portion of the stock entering the refining pass between the members goesthrough the grooves, and only a small portion passes between the plain surfaces, and having by-pass channel means for passing stock behind the inner portions of the faces of said members to the outer. portions thereof and thus substantially compensating for the greater circumferential extent of the outer portions-and utilizing the areas of the inner and outer portions substantially alike in working the stock, and

being further provided with means at the periph-' cries of their working faces for restricting the outflow from the members and controlling the dwell of fibrous particles in the refining pass.

21. A refiner of the character described comprising coacting coaxial refining members having parallel-moving mating plain, rubbing working faces with radially extending flow grooves therein permitting continuous outward passage across said faces of fibrous particles to be reduced, said members revolving relative to one another with such close clearance that the major portion of the stock entering the refining pass between the members-goes'through the grooves. and only a small portion passes between the, plain surfaces, and having by-pass channel means for passage of stock behind the inner portions of the faces of said members to the outer portions thereof, and also having outer facial outflow-control zones affording limited area and width of outflow passage,

so as to restrict the rate of flow through said grooves and channels and the maximum fibrous particle size in the product.

22. In a refiner of the character described, the" combination of coacting coaxial relatively revolving refining members having parallel-moving mated plain, rubbing working faces that are trav ersed transversely of the direction of their relative movement by the stock being treated, and that: enlarge circumferentially in the direction of stock fiow, so that centrifugal force maintains the fiowf' the said plain, rubbing working faces of said.

membershaving therein radially extending working grooves permitting continuous outward passage therethrough of fibrous particles to be reduced, and also having coacting outer zones receivlng the flow from the grooved facial areasbut afiording more limited efiective area and width of passage for the stock and its fibrous particles, so as to control the dwell of the stock in the refiner and the maximum fibrous particle size in the refined product; I

23. In a refiner of the character described, the combination of coacting coaxial 1 relatively revolving refining members having parallel-moving mated plain, rubbing workingfaces that are traversed transversely of the direction of their relative movement by the-stock being treated, and that enlarge circumferentially in the direction of stock flow, so that centrifugal force maintains the flow; the said plain, rubbing working faces of said members having therein grooves of progressively decreasing depth permitting continuous outward passage therethrough of fibrous particles to be reduced, but forcing the particles in the grooves of each member more and more to its surface as they travel outward.

24. In a refiner of the character described, the

- combination of coacting coaxial relatively revolving refining members having parallel-moving mated plain, rubbing working faces that are traversed transversely of the direction of their relative movement by the stock being treated, and 76 that enlarge circumferentially in the direction of stock flow, so that centrifugal force maintains the flow; the said plain, rubbing working faces of said members having therein radially extending grooves permitting continuous outward passage therethrough of fibrous particles to be reduced, but so shallow, and with their bottoms so inclined transversely of the direction of movement of the fibers, that the groove bottoms of each member coact with the other member in the working of the fibrous particles, and also having coacting outer zones'receiving the fiow from the grooved facial areas but affording more limited effective area and width of passage for the stock and its fibrous particles, so as'to control the dwell of the stock in the refiner and the maximum fibrous particle size in the refined product.

25. A rotary-refiner member having a plain, rubbing working face, for coaction with the relatively revolving parallel-moving mating working face of a corresponding rotary-refiner member, and having in its said plain, rubbing working face radially extending grooves for permitting continuous outward passage therethrough, across said face, of fibrous particles to be reduced, the depths and bottom configurations of said grooves being such as to wedge fibrous particles in the grooves outward against said coacting member.

26. A rotary-refiner member having a plain, rubbing working face, for coaction with the'relatively revolving parallel-moving mating working face of a corresponding rotary-refiner member, and having in its said plain, rubbing working face radially extending arcual fiow grooves permitting continuous passage therethrough across said face of fibrous'pa'rticles'to be reduced and working and reducing fibrous particles by interaction of fibrous material in them with such material in the grooves of the coacting member.

2'7. A rotary-refiner member having a plain,

- rubbing working face, for coaction with therelatively revolving parallel-moving mating working face of a; corresponding rotary-refiner member, and having in its said plain, rubbing working face radially extending grooves for permitting continuous outward passage therethrough, across said face, of fibrous particles to be reduced, said grooves diminishing in depth outward so that' fibrous particles travelling therein shall be forced more and more against said coacting member as :aid particles are reduced during their outward rave 28. A rotary-refiner member having a plain, rubbing working face, for coaction with the relatively revolving parallel-moving mating working face of a corresponding rotary-refiner member, and having in its said plain, rubbing working face radially extending grooves for permitting continuous outward passage therethrough, across said face, of fibrous particles to be reduced, said grooves having their bottoms rounded transversely so as to force fibrous particles travelling therein against said coacting member, and also diminishing in depth .outward so as to force the particles more and more against said coacting member as said particles travel outward.

29. A rotary-refiner member having a plain,

- ing face radially extending working grooves for and the maximum particle size in the refined stock.

30. A rotary-refiner member having a plain, rubbing working face, for coaction with the relatively revolving parallel-moving mating workin face of a corresponding rotary-refinermember. and having in its said plain, rubbing working f ce radially extending grooves for permitting continuous outward passage therethrough, across said face, of fibrous particles to be reduced, and also having an outer facial outflowcontrol zone with outflow grooves therein affording more limited area and width of pass ge for the stock and its reduc'ed fibrous particles.

31. A rotary-refiner member havinga plain, rubbing working face, for coaction with the relatively revolving parallel-moving mating working face of a corresponding refiner member, and having in its said plain. rubbing working face arcual fiow grooves permitting continuous passage therethrough across said-face of fibrous particles to be reduced, and working and reducing fibrou particles by interaction of fibrous material in them with such material in the grooves of the coacting member, and also having an outer facial outflow control zone. with fiow grooves thereacross affording more limited area and width of passage for the stock and its reduced fibrous particles, for coacting-with said co 'cting member 'to control the dwell of the stock in the refining pass between the members and the maximum particle size in the .refined product.

32. A rotary-refiner member having a plain, rubbing working face, for coaction with the relatively revolving parallel-moving mating working face of a corresponding rotary refiner member, and having in its said plain, rubbing working face grooves for permitting continuous outward passage therethrough, across said face. of fibrous particles to be reduced, said grooves diminishing in depth toward either side, and also having an outer facial outflow control zone, with flow grooves thereacross affording more limited area and width of passage for the stock and its reduced fibrous particles, for coacting with said coacting member to control the dwell of the stock in the refining pass between the members and the maximum particle size in the refined product.

33. A rotary-refiner member having a plain, rubbing working face, for coaction with the relatively revolving parallel-moving mating working face of a corresponding refiner member, and having in its said plain, rubbing working face grooves for permitting continuous outward passage therethrough. across said face, of fibrous particles to be reduced, said grooves diminishing in depth toward either side so as to force fibrous particles traveling therein against said coacting member and also diminishing in depth outward so as to force the particles more and more against said coacting member as said particles travel outward, and' further having an outer facial outflow control zone, with flow grooves thereacross affording more limited area and width of passage for the stock and its reduced fibrous particles, for coacting with said coacting member to control the dwell of the stock in the refining pass between the members and the maximum particle size in the refined product.

as. A rotary-refiner member having a plain,

rubbing working face, for coaction with the rela-' tively revolving parallel-moving mating working face of a corresponding refiner member, and having in its said plain, rubbing .-working face flow and working grooves for permitting continuous outward passage therethrough, across said face, of fibrous particles to be reduced, and a removable ring detachably secured to said memberaffording an outflow control zone at the.

periphery of its working face, for coacting with said other member to restrict the outflow from the members and control the dwell of fibrous particles in therefining pass between them, said ring having flow grooves across its face provid' ing more limited area and width of passage than the grooves in the working face of the member.

35. A rotary-refiner member having a plain,

rubbing working face, for coaction with the relatively revolving parallel-moving mating working face of a corresponding rotary-refiner member, and having mus said plain, rubbing work ing face radially extending grooves for permitting continuous passage therethrough, across said face, of fibrous particles to be reduced, and also having a facial flow-control zone for coacting with said coacting member to control the dwell of the stock in the refining pass between the coacting members and the maximum particle size in the refined stock, and provided with means for adjusting and varying said area and width of passage independently of the gap or working clearance between said refining members.

36. A rotary-refiner member having a plain, rubbing working face, for coaction with the relatively revolving parallel-moving matingworking face ofa corresponding rotary-refiner member, and having in its said plain, rubbing working face radially extending grooves for permitting continuous outward passage therethrough, across said face, of fibrous particles to be reduced, and also having an outer facial outflowcontrol zone for coacting with said coacting mem- .ber to control the dwell of the stock in the refining pass between the coacting members and the maximum particle size in the refined stock, and provided with replaceable means for adjusting and varying said area and width of passage.

87. A rotary-refiner member having a plain, rubbing working face, forcoaction with the relatively revolving parallel-moving mating working face of a corresponding rotary-refiner member,

and, having in its said plain, rubbingworking face radially extending flow and working grooves for permittingcontinuous passage therethrough, across said face, offibrous particles to be reduced and also circumferentially extending redistributing grooves dividing said working face into annular zones and permitting redistribution of fibrous particles amongstthe fiow grooves of successive zones, and being provided with anoutflow control zone at the periphery of its working face, for coacting with said other member to restrict the outflow from the members and congreater circumferential extent of the outer zoneandutilizingthe areas of the inner and. outer zones substantially alike in working the stock,

and being further provided with an outfiow control zone at the periphery of its working face, for coacting with said other member to restrict the outflow from the members and control the dwell of fibrous particles in the refining pass between them. a

' DANIEL MANSON SU'I'HERLAND, JR.-

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