US2156320A - Fiber pulp refiner - Google Patents

Description

y 1939. D. M. SUTHERLAND, JR ,320

FIBER PULP REFINER Filed April 1, .1936 4 Sheets-Sheet l FIG; I

n WITNESSES: 53 M 4 Danid mm Sutherlamfi {g m BY TTORNEYS.

y 1939- D. M. SUTHER'LAND. JR 2,156,320

FIBER PULP REFINER Filed April 1 1936 4 Sheets-Sheet 2 WITNESSES:

Habi 5 1% INVENTOR: Danwl Mansm SuZIwrZam$ I if/ ORNEYS.

y 3 D. M. SUTHERLAND, JR 2,156,320

FIBER PULP REFINER Filed April 1, 1936 4 Sheets-Sheet s WITNESSES: INVENTOR:

Danid Mmson .SuZizcrMnQJ;

ATTORNEYS.

y 1939- n. M. SUTHERLAND, JR I 2,156,320

FIBER PLEJLP REFINER Filed April 1, 1956 4 Sheets-Sheet 4 HG W H F'JG 1.2L

f l ll I INVENTOR: Damd Mhnsun Suihzriand flg TTORNEYS.

Patented May 2, 1939 UNITED STATES FIBER PULP REFINER Daniel Manson Sutherland, Jr., Morrlsville, Pa,

assignor to Lionel M. Sutherland,

. Trenton,

N. J., and Douglas 'G.-Sutherland, Morrisville,

Application April 1, 1936, Serial No. 72,082

- 9 Claims.

My invention relates to the reduction and refining of fibrousmaterials, such as wood, leather, or cork, and especially to the treatment of fiber pulp, consisting of fibrous particules in association with liquid, generally water. With sufficient water or the like, the aggregate or suspension itself behaves as a liquid, and can thus be more easily fed. between the relatively moving refining surfaces or members by whose coaction the fiber particles are reduced. In using relatively rotating discs as the refining members, both of them may actually revolve, either in opposite directions or in the same direction at different speeds; or only one may actually move, While the other remains stationary.

In refining fibrous materials or pulp between I relatively moving refining members, an important factor is the pressure between the acting surfaces. Comparatively little is known about this factor; nor has it been controlled or gaged satisfactorily in practice. Some attrition mill refiners are operated with a fixed, dead-set working clearance or gap between the relatively rotating disc members, as illustrated in U. S. Letters' Patent No. 1,984,869, December 18, 1934,

Farley and Brown; other refiners. have the refining members held together by spring pressure, so as to yield and separate if extra large or hard fibrous particles come between the discs. Attempts have been made to determine the pressures between the discs by calculation from a spring in compression at the end of one disc shaft; but this is not entirely equivalent to a direct pressure reading.

My invention allows of directly measuring and controlling the pressure between the refining surfaces, and of accurately gaging and regulating it according to the degree of refining of the fiber required for any particular paper or fiber board. By such regulation, also, overload protection against damage to bearingsor other parts of the refiner can be provided. A definite clearance for the refining action required can be readily set, maintained, and reproduced, so as to ensure uniformity in refined pulp produced over an extended period of operation-or even on different occasions, between which the machine may have been used to produce an altogether different pulp. The refiner can be constructed, operated, and maintained at relatively low cost.

Various other features and advantages of the invention will appear from the following description of species or forms of embodiment, and from the drawings. So far as novel, indeed, all features shown or described are of my invention.

In the drawings, Fig. I is a side view of a refiner conveniently adapted for the purposes of my invention, certain parts being broken away and omitted, and some parts" being shown in yer tical longitudinal section.

Fig. II is a plan view of therefiner, with certain parts removed or in horizontal section.

Fig. III is an end view from the right of Figs. I and II, with certain parts in cross-section as indicated by the line and arrows III--III in Fig. E.

Fig. IV is a viewfrom the left of Figs. I and II, with certain parts in cross-section as indicated by the line and arrows IV-IV in Fig. II.

Fig. V is a fragmentary diagrammatic longitudinal vertical section through a pressure cylinder, such as shown in Fig. I, with certain added accessories.

Fig. V1 is a fragmentary view similar to the corresponding portion-of Fig. I, but showing a difierent revolving refining member.

Fig. VII shows a section taken as indicated by the line and arrows VII--VII in Fig. VI.

Fig. VIII is a view similar to' Fig. VI, illustrating another modification; and, V

Fig. IX is a view similar to Figs. VI and VII, illustrating a modification of the stationary refining member.

As illustrated in Figs. I and II, the general arrangement of the refiner resembles that illustrated in the above-mentioned Patent No. 1,984,869, but differs therefrom in particulars that make a brief general description desirable.

The refiner shown has coacting coaxially arranged refining members or discs H, I2 enclosed in a housing l3 whose lower portion forms part of the main rigid (cast metal) base and frame structure M of the machine, while its upper portion may consist of a removable semi-cylindrical (sheet metal) cover l5. Preferably only one refining member I l rotates, while the other member l2 remains stationary. Many methods of applying fiuid pressure to the members II, I2 (or their acting faces) and recording any increased pressure due to pulp passing between the refining surfaces may be employed; but for purposes of illustration, the fluid pressure is here shown as applied to the stationary member, while the rotating disc is unyieldingly sustained by bearings carried by the machine frame. As shown, the rotating refining member ll may be mounted on the end of a shaft I6 which revolves in suitable (anti-friction) thrust and journal bearings I! in pedestal supports l8, I8 upstanding part of the base structure 14,

2 to prevent it from turning while allowing it to shift (in an axial direction) toward or from the revolving member ll, relative to said structure HL As shown, the stationary member i2 is mounted on the end of a (hollow) shaft 22 iongitudinally slidable in guide supports 23, 24 carried by the machine frame Hi. The shaft 22 is anti-turningly engaged with the frame structure M, as by means of keyway and feather arrangements 25 atone (at least) of the guide supports. The working faces 21, 21 of the refining members l I, I2 may be formed by separate detachable and renewable facings of natural or artificial stone, or of metal such as bronze, iron, or (stainless) steel-or even in some cases of elastic material like rubber. Their facial features may be of any suitable character; although I prefer acting faces such as disclosed in my pending application Serial No. 746,646, filed October 3, 1934, now Patent No. 2,035,994, granted March 31, 1936. The fiber .pulp may be supplied to the refining pass between the members H, 12 via the tubular shaft 22, which opens centrally through the facing 21 of the stationary member H, by means of any suitable sliding connection (not shown) to the left-hand end of the tube 22. The pulp is preferably supplied under substantially constant pressure, as by the means described in my said application, or in the aforesaid Patent No 1,984,869.

For the purposes of present invention, fluid (and venting it from the opposite side), .the'

member l2 can be moved toward or from the member ll. sq. in. on piston 30, urging the members H, 82 together, the working pressure per sq. in. between them will be inversely proportional to the effective area of piston 30 and the coacting areas of said members I I, I2. In general, a liquid such as Water or oil is preferable as a pressure medium. As shown in Fig. I, the guide supports 23, 24 have clamp straps 33, 33 which can be tightened to grip the shaft 22 fast and immovable, thus fixing or setting the clearance between the members H, l2.

As shown in Fig. I, ,a pressure gage or indicator 35 is connected into the cylinder 3| at the left-hand side of the piston 30, to show the closing pressure. This gage 35 may either be graduated to show pressures per sq. in. on piston 30, or to show corresponding working pressures per sq. in. between the refiningmembers ii, 12. In addition, an indicator 36 may be operatively connected to the shaft 22 to show the gap or clearance between the acting faces of the members H, l2: it may begraduated in any convenient units of measurementsuch as thousandths or ten-thousandths of an inch, for example. Such an indicator-36 may be mounted on a bracket 31 carried by the clamp 34 of guide support 24, and may be actuated by an actuator screw 38 adjustable in a bracket arm on a clamp collar 39 fast on the shaft 22. By adjustment of the screw 38, the indicator may be set to read zero when the members ll, [2 are in actual contact under a suitable closing pressure on the For a given closing" pressure per between the members piston 30: e. g., a pressure corresponding to about 10 lbs. per sq. in. on the areas of memhers I I, I2 which coact in working the fiber pulp. This zero setting is of course made when neither pulp nor any other fluid is being admitted between the working faces of members ll, l2.

If desired, the pressure and clearance indicators 35, 36 may be of continuously recording types, so as to furnish complete records of mutually corresponding pressures and clearances throughout the operation of the refiner.

A mode of operation of the refiner is as follows:

When the refiner is to be started up, water under pressure suflicient to separate the mem bersll, I2 to a clearance of about .01 in. (as shown by the indicator 3B) ispassed through the refiner via the shaft 22,.while a convenient closing pressure is maintained on the piston 30. Ordinarily, the machine operates without any disc-separating pressure on piston 30. The motor i9 is started, and the rotor II is brought up to normal running speed-such as 50 to 350 R. P. IVL, for example, according .to the design of the refiner and the character of the stock to be treated. Normal speed of the rotor II having been attained, the pulp or stock to be refined is started through the refiner under a suitable constant operating head or infeed pressure, and the water shut off. The closing pressure in cylinder M .is modified as necessary to give a deslred working clearance of from about .001 in. to .005 in. between the members I I, I2, as shown by the indicator 36.

The. normal running speed and the pulp-feed or infeed pressure are determined according to the desired throughput and degree of refining,

and upon the following principles:

When the refiner is operating with the clam 33, 3d loose, with a constant infeed pressure on the stock, and with a definite closing pressure on the piston 30, the unitary rigid structure consisting of piston 30, shaft 22, and refining member i2 automatically assumes a position of. equilibrium in which the total closing pressurethrust on piston 30 balances the opposing total pulp-pressure thrust produced on the member l2 by the stock in the refining pass. In this stock ll, l2, the centrifugal force and the initial infeed pressure produce kinetic energy which is used up in friction with the members H, l2, as wellas pressure on the members ll, l2 tending to separate them. The closer the members ll, l2, the greater the friction,-and vice-versa; and the greater the frictio'n, the less the velocity and flow through the refining 'pass, and the greater the separating pressure, and vice versa. For given facial fea-' tures of the refining members 'I l, l2, the degree of refining of the stock put through the refiner depends on the clearance or gap between the members, while the throughput and capacity of the refiner depend on the speed of rotation and the infeed pressure. The speed and the infeed pressure, as already mentioned, also influence the pressure in the stock between the members, and hence the clearance or gap for equilibrium. In the preferred practice of my invention, the closing fiuid pressure and the pulp thrust are balanced with a clearance or gap corresponding to the desired refinement of the pulp, and with a pulp-feed pressure and speed of rotation giving be tightened on the shaft 22 to lock and hold the member |2 fixed during subsequent operation. Thus'the movable member I2 is in secured, to the frame structure I4; and so both the members |2 are now engaged by parts associated with said structure l4 and. are sustained thereby at the clearance or gap previously established, as already described-quite independently of any closing fluid pressure on the piston opposing the pulp thrust, and even in the absence of any such pressure. This setting of the working clearance or gap need not be disturbed until or unless the essentialconditions are changed for some reason-such as a change of the stock to be treated, of the desired degree of refining, of the infeed pressure, of the relative speed of rotation of the members I, I2, or of the gap or clearance between the members |2- which last naturally changes with wear on the facings 21, 21. Ths correctness of the setting may be checked from time to time by bringing the closing pressure in cylinder 3| to the value determined-at the previous setting, and loosening the clamps 33, 34 and noticing whether this freeing of the parts I2, 22, 3|! results in any change of the clearance or gap as shown by the indicator 36. When such change occurs, the gap as thus corrected may be reset by retightening 7 the clamps 33, 34. When thus resetting the gap,

the zero of indicator 36 may be readjusted as already described; or the reading of this indicator afterresetting the gay may be taken, for reference when next rechecking. Ordinarily, the refiner may be expected to run about a week at a time before resetting becomes necessary.

Of course the refiner may if desired be operated with the clamps 33, 34 loose and a standard closing pressure on piston 30, thus automatically compensating for wear on the members l2 as it occurs and maintaining a constant working clearance or gap between them.

In order to obtain a low freeness or a large .amount of, refining action at a single passage of the stock through the refiner, a close clearance between the members l2 (about .002 in.) is necessary. Very small variations of the gap or clearance between the members l2 materially afiect the properties of the refined product. A change of .001 in. in this gap is suflicient to give a wide range of properties. Further refining accuracy may be obtained by closely regulating and controlling the pressure between the refining surfaces. Slight changes in the degree of refining may be produced by slightly changing the infeed pressure. with the clamps 33, 34 loose as above described. J

If with a closingpressure of lbs. per sq. in. on piston 30 (for example) and the clamps 33, 34 loose, the gap registers .002 in. on indicator 36 when sufiicient water is passing through the refiner to keep the temperatures of the members l2 down to about F., and if escape of liquid from the closing side of piston 30 is cut off, the closing pressure on piston 33 willrise when pulp is turned into the refiner instead of water-according to the consistency of the pulp and the volume of it passing. .This increased pressure will be shown on the indicator 35,\ and any slight concomitant increase in the clearance will be shown on indicator 36. Such increase in the reading of indicator 35 for operation with pulp over operation with water accurately indicates the pressure required by reason of work done on the fiber.

Fig. V is a fragmentary diagrammatic view [about the same way as above of a cylinder 3| with shaft 22 and piston 30, showing various pressure arrangements and connections. To permit equalization of pressure or transfer of fluid between the two sides of'piston 30 (and yielding of the latter to the separating thrust between the members l2), there is a by-pass connection 40 with a control and regulating valve 4|. For supplying fluid under pressure at either side of line 42 with control and regulating valves 43, 44. For venting fluid either side of the piston 30, there are pipes 45, 46 with control and regulating valves 41, 48. The pipe 42 has branches, with 'control and regulating valves 49, 50, to opposite sides of the piston 30. The pipe 42 is connected to the pressure side of a (gear) pump 5| supplied with oil or other liquid through a pipe 52, and also to a source of gas under pressure, such as a reservoir 53. Yet another branch of pipe 42,leads to a cylinder 54 with a piston operable by a screw to force liquid into cylinder 3| or vent it therefrom. There are also cylinders 55, 56 with screw-operated pistons (similar to the cylinder 54) connected through control and regulating valves 51, 58 to opposite ends of cylinder 3|, affording another means of forcing liquid under pressure into the cylinder, or venting piston 30, there is a pipe it therefrom, to move the piston 30 either Way.

clearance or gap is dead-set, just as if the clamps 33, 34 had been tightened. How the various instrumentalities of Fig. V can be operated to move the piston 30 as desired, or hold it stationary, will readily be apparent to those skilled in such mechanisms.

Fig. VI illustrates a different construction of the stationary refining member l2a, and another way of applying fluid pressure in connection with this member. As here shown, the acting face 21a of this member |2a consists of a flat (metal) ring axially movable in an annular cavity in the member, which also contains a fluid-tight flexible or elastic-walled annular pressure cell 60,

more or less like the inner tube of an automobile.

tire. Thus the member |2a forms a cylinder, the ring 21a itself constitutes a piston: and the cell 60 serves as packing to prevent leakage of pressure fluid past the piston. The cell 60 (as well as the facing 21a) may-be anti-turningly engaged with the inner and outer peripheries of the cavity in the member |2a, one mode of such engagement being illustrated in Fig. VII. .Pressure fluid (either liquid or gas) is introduced into the cell 60 and vented therefrom through a tubular connection 6|, to which a pressure indicator or .gage 35d may be connected for the same purpose as the indicator 35 in Fig. I. In this way, the clearance or gap and the working pressure between the acting faces of the refining members |2a can be varied and adjusted in described in connection with Figs; I-IV.

Fig. VIII illustrates a construction similar to that of Figs. v1 and v11 wherein the facing 21b is flexible or elastic and forms part of the wall of the pressure cell 60b, though much thicker than the rest of its wall. This pressure cell 60b may be of rubber construction like a single tube bicycle tire, with fabric'reinforcement (like that of an automobile tire casing or of a disc for a flexible disc joint) in the'facing 21b.

Fig. IX illustrates a similar construction applied to a revolving refining member He. Here the pressure connection extends (axially) through the revolving shaft, including a tube/Blownnected to a pressure indicator or gage 35c and to a supply of pressure fiuid in a reservoir 64,

. with a control and regulating valve 65 interposed in the connection. In the refining member He, the pressure connection includes a bent tube 66 in a central cavity 61 that is normally closed off from access of pulp by a removable cover 68.

In Figs. V-DI, various parts and features are marked with the same reference characters as in Figs. .I-IV-with an added letter where such distinction appears desirableas a vmeans of dispensing with repetitive description.

Having thus described my invention, I claim:

1. A method of gauging and setting the refining gap or working clearance between relatively revolving refining disc members which are mounted on a frame and between which ,fiber pulp is introduced under constant pressure; which workingclearance or gap corresponding to they "desired refinement of the fiber pulp; allowing relative positions of equilibrium of the members to be attained under these opposing forces; and

thereafter securing said axially movable member to the frame, and thus sustaining it therefrom, at the clearance or gap thus established, against pressure responsive separation from the other member, even in .the absence of any closing fiuid' pressure opposing the pulp thrust.

2. In a refiner of the character described, the combination of coacting axially acting refining disc members revolving relative to one another and free for relative movement in the axial direction, with an associated structure relative to which the members revolve and move as aforesaid, and means for supplying and introducing fiber pulp between the-disc faces under constant pressure; means for eexrting on at least one of said members a definite closing fluid pressure that balances the pulp thrust tending to separate the faces; and means engaging said members and sustained by said structure to maintain the members at the clearance or gap thus established. everr in the absence of any closing fiuid pressure opposing the pulp thrust.

tending to separate the disc faces; and meansengaging said stationary refining member and sustained by said frame to maintain disc faces at a clearance thus established, independently of any closing fiuid pressure on the piston.

4. In refiner of the character described, the combination of a frame and coacting axially acting refining disc' members, one revolving and one stationary, carried ,by said frame, the stationary member being free for movement toward and from the revolving member; means for supplying and introducing fiber pulp between the acting disc faces of said members under constant pressure; means for exerting on said stationary member a definite closing fluid pressure balancing the pulp thrust between said faces tending to separate the members; and clamp means carried by the frame for clamping said stationary member and holding it fixed in a position thus established, thereby preventing pressure-responsive fiber pulp between the acting disc faces of said members under constant pressure; cylinder and piston means associated with said shaft for exerting on said stationary member a constant closing fluid pressure balancing the pulp thrust between said faces tending toseparate the members; and clamp means around said shaft for clampingcsaid stationary member and holding-it fixed in a position thus established, thereby preventing pressure-responsive movement thereof.

6. A fiber pulp refiner comprising relatively revolving coaxialrefining members with opposed coacting working faces substantially parallel and enlarging outward around their axes, and traversed transversely of the circumferential direction of the relative movement of their said faces-by the fiber stock being treated, at least one of said refining members having its working face movable in the axial direction toward and from the other member, and including means for applying sustaining fluid pressure behind said face to maintain it in effective coaction with said other member.

7. A fiber pulp refiner comprising relatively revolving coaxial refining members with opposed coacting working faces substantially parallel and traversed transversely of the circumferential direction of the relative movement of theirsaid faces by the fiber stock being treated, at least one of said refining members having its working face movable in the axial direction toward and from the other member, and containing a fluid pressure cell for exerting behind said working face a pressure to maintain it in effective coaction with said other member. 7

8. A refiner of the character described comprising coacting relatively revolving axially act-- ing refining disc members, one, at least, of said members having a substantially rigid acting face movable in the axial direction, and means for supplying elastic pressure fluid to said member behind its said movable face, to sustain the latter in coaction with theother member.

9. 'A refiner of the character described com- DANIEL MANSON SUTHERLAND, JR.

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