US2674928A - Machine for treating wood pulp - Google Patents

Description

April 13, 1954 J. T. COGHILL 1 2,674,928

MACHINE FOR TREATING woon PULP Filed Dec. 30, 1948 4 Sheets-Sheet l or /o A 109 l' w 95 ja7 8 3; l & AS 1 I 110 m, s I l 108 74 l 1/3 7s 28\ U /L I a! 2 x 1 l 24 I?) i Q INVENTOR. JAMES 7. GOGHILL ATTORNEY April 1954 J. T. COGHILL 2,674,928

MACHINE FOR TREATING woon PULP Filed Dec. 30, 1948 4 Sheets-Sheet 2 WT \I v INVENTOR. JAMES I GOGH/LL ATTORNEY April 13, 1954 J. T. COGHILL 2, 74, 8

MACHINE FOR TREATING WOOD PULP Filed Dec. 30, 1948 Q 4 Sheets-Sheet 5 INVENTOR. JAMES 7. GOG/ ILL ATTORNEY April 3, 1954 J. T. COGHILL MACHINE FOR TREATING woon PULP 4 Sheets-Sheet 4 Filed Dec. 30, 1948 INVENTOR. JAMES 7.' GOGHILL ATTORNEY Patented Apr. 13, 1,954

UNITED STATES PATENT OFFICE MACHINE FOR TREATING WOOD PULP James T. Coghill, Fairport, N. Y., assignor, by mesne assignments, to Curlator Corporation, Rochester, N. Y., a corporation of New York Application December 30, 1948, Serial No. 68,207

9 Claims.

The present invention relates to machines for processing fibrous material and particularly to machines "for processing wood pulp for making paper. More particularly, the present invention relates to machines for mechanically processing wood pulp according to the method disclosed in the Hill and Edwards U. S. patent application Serial No. 565,128, filed November 25, 1944, now Patent No. 2,516,38 i, granted July 25, 1950. In a still more specific aspect it is the purpose of the present "invention to provide an improvement upon the machine of my pending U. S. patent application Serial No. 773,012, filed September 9, 1947, now Patent'No'. 2,622,490, granted December 23, 1952.

In the machine of my prior application mentioned, the pulp, which is to be treated, is fed through a central inlet onto a drainage plate where it is thickened and is picked up by sweep arms and moved onto a stationary lower working surface which surrounds the drainage plate. The thickened pulp is rolled between a gyrating upper working surface and the lower working surface under pressure. Periodically, the upper working surface may be moved toward and from the lower working surface to control the traverse of the material, which is being treated, between and over the working surfaces from the entry zone to a discharge zone around the periphery of the lower working surface. The movement of the upper working surface toward and from the lower working surface is eifec'ted hydraulically under control of cams. At the discharge zone the pulp falls into a trough which has a helical bottom, and it may be sluiced down this trough to a discharge outlet.

A principal object of the present invention is to provide a machine which Will be more efficient in operation and of simpler construction than the machine of my prior application above mentioned.

Another object of the invention is to provide a machine in which separate means for moving the upper working surface toward and from the lower working surface is eliminated, and in which the gyratory motion of the upper working surface in itself causes variation in the distance between the upper and lower working surfaces, thereby alternately increasing and decreasing pressure on the pulp being treated and controlling the traverse of the material over and between the working surfaces.

Another object of the invention is to provide in amachi'ne of the character described improved means for carrying off-the treated pulp from the discharge zone of the machine.

Still another object of the invention is to provides. machine of the character described which isequipped with means for heating the pulp or other material being treated so as to improve its workability.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims.

In the drawings:

Fig. l is a fragmentary view, partly in side elevation and partly in vertical section, of a machine built according to a preferred embodiment of this invention;

Fig. 2 is a fragmentary vertical sectional view on an enlarged scale showing in greater detail the sweep mechanism, the upper and lower working surfaces, the turn table for carrying off the treated pulp, etc;

Fig. 3 is a fragmentary sectional view on a still further enlarged scale showing in detail one of the steam jets for heating the pulp, and its mounting;

Fig. 4 is a fragmentary plan View, with parts broken away, showing further details of the dewatering area, sweep arms, lower working surface, turn table, and stock outlet;

Fig. 5 is a fragmentary plan view, with parts broken away and on a reduced scale, showing details of the mechanism for insuring parallel bodily movement of the upper working surface;

Figs. '6 and 7 are diagrammatic views illustrating the motion and action of the working surface of the machine;

Fig. 8 is a fragmentary sectional view on a greatly enlarged scale of portions of the working surfaces of the machine and Fig. 9 is a fragmentary plan view of one of these working surfaces.

The machine illustrated in the drawings, like the machine of my prior application, has a centrally disposed de-watering area in which the consistency of the stock is raised and in which the stock is nodulated, a lower working surface, which is stationary and which surrounds the dewatering area, and an upper working surface which is given a continuous gyratory or orbital motion during operation of the machine and which extends over both the de-watering area and the lower working surface.

The pulp, which is to be treated, as in the machine of my prior application mentioned, enters the de-Watering area of the machine from below through a continuously rotating hollow shaft and fans out over an internal conical perforated de-watering plate which surrounds this shaft. A sweep head having a plurality of lateral- 1y extending arms which extend over the dewatering surface, is secured to this shaft; and as the shaft rotates, the sweep arms gather the stock from the surface of the de-watering plate and press it up against the gyrating upper plate while at the same time urging it radially outward.

In th machine of the present invention, the upper working surface is dished upwardly, that is, it is an internal conical surface above the sweep arms and above the portion of the lower working surface which surrounds the drainage area. As the upper working surface gyrates, then, the nodules of stock are rolled between the concave portion of the upper Working surface and th opposed surfaces of the sweep arms and of the lowering working surface. During half of a revolution of the upper working surface, then, there is a reduction in clearance between the upper working surface and the sweep arms and the lower working surface, which increases the compression of the pulp and tends to cause slippage of the nodules on the upper plate. This causes the nodules to traverse the upper plate and leaves them a little farther out than they would be if this slippage did not occur. On the other half of the revolution of the upper plate the clearance increases and the nodules roll without slippage. The net result is an outward traverse of the nodules and a periodic variation in the clearance between the working surfaces.

Both upper and lower working surfaces are knurled, and in the inner portions of these surfaces, at least, the knurls or protuberances are inclined and directed outwardly so as to help the traverse of the material over the surfaces toward the discharge zone. When the pulp reaches the edge of the lower working surface, it drops onto a turntable which extends around the lower working surface and which rotates continuously. It is carried around by this turntable to a doctor or arm which overlies the turntable and which directs it into a discharge outlet. The white Water, which has been extracted from the stock in the de-watering zone, may be carried to this outlet to sluice the stock away. If desired, this white water may restore the stock to approximately the same fluid state in which it entered the machine so that it can be carried easily for further treatment. A simple flap valve, governed by a weight, is provided to control the flow of white water into the discharge outlet. By adjustment of this valve a back-pressure can be applied to regulate the rate of feed of the stock through the machine.

As the thickened stock moves onto the lower working surface it may b heated by steam jets located in the lower working surface around the de-watering area. It has been found that stock will roll and traverse more readily when heated and that greater pressure can be applied thereto without danger of setting up shear planes in the stock. In some cases this heating is necessary in order to obtain curling of the stock and prevent smearing of the stock on and between the working surfaces. The stock is heated after it is de- Watered because this reduces the amount of heat (steam) required and enables the heat (steam) to be employed most effectively.

Referring now to the drawings by numerals of reference, it denotes the :base or bed of the machine. Journaled in this base or bed in any suitable manner is a hollow'shaft 24- (Figs. 1 and 2) which is internally'threaded at its upper end to receive and engag the externally threaded portion of a rotary sweep head 25. The sweep head is provided with a plurality of radially extending .4 sweep arms 28 that extend outwardly from the head and are of longitudinally spiral shape (Fig. 4). These arms are generally similar to the sweep arms 28 of the machine of my prior application above mentioned. The front faces of these arms may be convex but they differ from the sweep arms of my prior application in that they have upper surfaces 38 which lie in an external conical surface coaxial with the axis 32 of the shaft 26 and sweep head 25. The front and upper surfaces of the sweep arms may be smooth, although they can also b roughened or knurled if desired.

The shaft 24 may be driven from a motor (not shown) through the bevel gears 33 and 34 (Fig. 1), the shaft 3?, the spur pinion 38 and spur gear 39. Gear 34 is keyed or otherwise secured to shaft 31 and pinion 33 is integral with that shaft. Gear 39 is fastened in any suitable manner to shaft 24.

As the sweep head rotates, its arms 28 travel over a perforated internal conical drainag or de-watering plate 3i (Figs. 2 and 4) which is concentric with sweep head 25. This plat has a plurality of spaced, fiat straps 2i secured to its upper face. These straps are fastened so that they extend obliquely across the drainage surface, being tangent to a circle concentric with the drainage surface; and they are arranged preferably as shown, so that they are disposed about the aXis of the drainage surface to have the opposite hand of inclination from the hand of spiral of the sweep arms 28. The straps 2! are narrow and relatively thin.

The under surfaces '29 of the sweep arms have the same general cone angle as the conical upper surface of the drainage plate. The clearance between the bottom surfaces 29 of the sweep arms and the upper surface of the drainage plate may be determined by axial adjustment of the sweep head 25 in the shaft 25; and is so adjusted that the sweep arms readily clear the straps 21. As the sweep head rotates, then, the sweep arms sweep pulp up off the drainage plate. The skew straps 2i prevent the stock from sliding around on the drainage surface, if the stock is slippery; and they help cause the stock to progress outwardly as the sweep arms pass over them.

The de-watering plate is secured :by riveting or in any other suitable manner to a casting 35 that has a conical upper surface and that is fastened by screws 35 to the base 29 of the machine. The casting 35'has holes .35 in it beneath drainage plate 31! so that the white water expressed from the pulp may flow from the drainage plate into a conduit as will be described further hereinafter. The aqueous slurry of pulp, which is to be treated, is supplied to the machine through a pipe 55 (Fig. l which communicates and registers with the bore of the shaft 24.

Surrounding the de-watering area and coaxial therewith is the lower working surface of the machine which is designated as a whole at L. This is circular and comprises a plurality of sectoral knurled plates lil, which are riveted to a supporting shoe 4! that in turn is secured by screws 42 to the base 29, and a plurality of sec toral knurled plates 44, that are riveted to a plate 45 which in turn is riveted to a plurality of sectors forming a ring 56. The sectors of ring 46 are clamped against one wall of an outer shoe 48 by clamping screws 4! that adjustably 48 is secured by screws 43 to the base 20.'

gamete plate 45, which supports the plates '44, is adapted to engage under the plates 40 and is held in that position by the clamping screw 41.

The plates 48 and 44 are shown, like drainage surface 3|, only fragmentarily in Fig. 4. It is to be understood, however, that drainage surface 31 fully overlies casting 35, and that plates 40 and '44 together constitute a full circular working surface coaxial with the sweep head and drainage surface.

Mounted above the sweep arms 28 and the lower working plates 40 and 44 and in opposed relation thereto is the circular upper working surface of the machine which is denoted as a whole at U. This comprises a plurality of sectoral knurled plates 50 and 54 (Fig. 2) which are riveted to plates 5| and 52, respectively. The plates 5| are riveted at their outer ends to "a plurality of sectors constituting a ring 53, which are clamped against a rib 55 of the driving plate 56 by clamping screws 51. At their inner ends, the plates 5i are held to the driving plate 56 by a gib plate 58 which is riveted to a plate 59 that in turn is riveted to a plurality of sectors forming a ring 50. These are secured by screws 61 to the driving plate 55.

The plate 52 is held against the driving plate by the overlapping working surfaces 59 at one end. The plate 52 is also riveted to a plurality of sectors constituting a ring 53 which are held against a rib 64 of the driving plate 55 by clamping screws 65. The under surface of the portion of the driving plate 56, which lies above the lower working plates 44-, is in a plane parallel to the plane of the lower working plates and as a result, the working surfaces of the upper plates 54 are parallel to the working surfaces of the lower working plates '45. The portion of the under surface of the driving plate 5-6 around the hub of that plate is, however, upwardly dished and the working plates 50 are secured to this portion of the driving plate so as to follow this upward or inward dish. Thus the working plates 50 form a concave conical working surface. The cone angle of this surface is preferably made to be within four or five degrees of the cone angle of the upper surfaces 35 of the sweep arms 28.

The hub of the driving plate 56 is secured by screws 7b to the journal or sleeve H which is mounted within a bearing 12. This bearing 12 has convex spherical surfaces which seat within concave spherical surfaces formed in blocks 1-4 and i5, respectively. Block has a counterweig'ht 16 secured to it. Block 14 is fastened by bolts 18 and nuts 19 to the head or flange '80 of a crank shaft 8|. The axis 34 of the driving plate 56 is, therefore, offset from the axis '82 of shaft ill; and the shaft imparts to the driving plate an eccentric motion. The shaft 81 is adapted to be driven from a motor (not shown) through the shaft 85 (Fig. 1) and the spiral bevel gears 85 and 81, the hub of the latter gear being keyed or otherwise secured to the shaft 81.

During operation of the machine, a predetermined pressure is applied to the upper working surface to apply a predetermined load to the pulp being treated. The load is applied by hydraulic pressure so that the upper working surface is free to float toward and from the lower working surface. The hydraulic pressure is applied to the upper ends of a pair of pistons 90 (Figs. 1 and -'5) which are housed in cylinders 9:] that lie at diametrically opposite sides of crankshaft :8l. The cylinders 91 are secured by bolts 92 to blocks as which "are in *secured by bolts 94 to the upper framework 95 of the machine. Each piston '90 has a hole extending diametrically through it which is adapted to receive the rounded inner ends of two aligned arms 96 that are secured by bolts 91 to rocker members N10. The rocker members I00 are mounted at opposite sides of crank shaft 8| to rock on trunnions l 01 that are secured by screws I02 to the framework 95. Mounted in each of the rocker members I00 are two heads I05 that are secured to the rocker members by bolts I06. These four heads L05 are connected by Garden joints or gimbals I01 with four rods I08, each of which extendsthrough aligned openings 109 and I It) in a rocker member and the frame work 95. At their lower end, the four rods I58 are connected by other Card'an joints or gimbals H2 with four plates H3 (Figs. -1 and 2) that are bolted at equi-spaced points to the drive plate 55.

The rods 1 0'8 constrain the upper working surface so that as crank shaft 8! rotates all points in the upper working surface will travel in cirl per and lower working surfaces of the machine.

Through use of a fluid medium for application of pressure, the upper working surface may float under predetermined load within the permissible limits of movement of pistons 90. The rocker members I00 and arms 95 insure uniform application of this load all over the upper working surface. They also insure that the upper working surface U moves parallel to itself as it moves up or down, and cannot tilt.

In the machine of my prior U. S. patent application Serial No. 773,012, means is provided for moving the upper surface cyclically toward and from the lower working surface. in the machine of the present invention this cyclical movement is ac-ccmplished without any separate mechanism but sharply by the gyratory motion of the upper surface itself because of the internal conical construction of that surface. This is illustrated diagrammatically in Figs. '6 and 2'.

.As the axis fi l of the upper working surface U rotates about the axis 52 of crank shaft 8i, axis 3 will travel in a circle l l5 (Fig. 6) concentric to axis '32 (Fig. 6). The position of the upper Working surfac is indicated diagrammatically in full lines at A in Fig. 7 when the axis Si of the gyra't'ory plate 55 is at 84 (Fig. 6). 3 denotes diagrammatically the position of the upper working surface when the axis 8d of the upper working surface has rotated through an angle of about the axis 52 of the crank shaft to the position 84" 6 The effect of the gyratory motion of the upper working surface and of its concave conical shape is alternately to squeeze and release the nodules N of pulp between the upper and lower working surfaces and between the upper working surface and the sweep arms 28. When the motion of the upper working surface is from A to B, a nodule N is squeezed down and rolled to the position N.

The reduction in clearance between the upper ing plate.

the nodule rolls without slippage on the lower working surface L. The net result of the gymtory motion is an alternate increase and decrease in pressure and a traverse outward of the nodule.

To increase the outward travel, the knurls or protuberances of the upper and lower working surfaces are preferably made directional at least in the cupped zone of the upper working surface. In other words, the plate 50 and the plates 48 are provided with inclined projections or protuberances I and IEI, respectively, that lean outwardly toward the discharge zone of the machine. Such knurls or protuberances are less resistant to slippage of the rotatable pulp units in the direction in which they lean.

In order to permit rollwise traverse of the pulp nodules or of rotatable units thereof over and between the Working surfaces, the pointed protrusions should be spaced adjacent to one another a distance of from two to three times their height. If the spacing is too close, the cavities between the points may fill up with stagnant pulp and the surfaces will not be self-cleaning which is a necessary condition in obtaining the required rollwise traverse. If the pointed protrusions are spaced too far apart, the gripping action on the nodules or on rotatable units thereof i diminished and the required rollwise traverse can not be achieved at as high a speed Or under as high compression. The directional working surfaces may be made as described in my earlier application Serial No. 773,012 above mentioned.

Through traverse of the pulp over the lower working surface, the nodules are carried on to the discharge zone at the periphery of the lower Working surface. The treated stock drops off of the lower working surface at this point onto a rotary turntable I which is mounted on the machine to be below the lower working surface, but to surround the lower working surface, as shown in Fig. 2. The turntable I25 is adapted to be driven from a motor (not, shown) through the shaft I29, bevel gears I27 and I28, shaft I29, spur pinion Etc and spur gear I3I. The pinion I and bevel gear I28 are secured to shaft I29 adjacent opposite ends thereof. The spur gear I3i is secured to or integral with the turntable.

Mounted at one side of the machine is a hopper I (Figs. 2 and 4). Secured to this hopper by a bolt I3; is a bracket I36 and mounted upon this bracket is a doctor or arm I38 which extends over the turntable. This doctor is adapted to deflect stock carried around by the turntable into the hopper 535. This hopper has a discharge opening 2% at bottom through which the pulp may drop into a container or onto a conveyor.

The white water expressed from the pulp in the de-watering area of the machine may be used to slush the treated pulp out of the hopper I35. For this purpose an annular chamber I45 (Fig. 2) may be secured beneath the de-watering area of the machine, and a conduit I i! may be provided to connect this chamber I55 with the hopper I35. A damper I53 may be provided at the mouth of the conduit Hi? to control flow of the white water out of the conduit and thereby exert a back-pressure on the white water to control to a degree the traverse of the pulp through the machine. The damper restricts the flow of white water from the pulp and thereby aids in regulating the through-put of the machine.

The damper I59 is integral with an arm I 5I that is fastened to a shaft I52. This shaft is 75 this point, the nodules are gripped and vigor- On theoutward stroke of the upper plate from B to A the clearance increases and.

journaled in bearings formed at opposite sides of the hopper I35. It has secured to it at one end an arm I56 on which is adjustably mounted a weight I55. By adjusting this weight along the arm IE4, the back-pressure exerted by the damper can be controlled.

An apron I56 is secured by screws I57 to one side of the turntable, and an apron I58 is secured by screws I59 to a bracket or ring member I68 which surrounds the turntable and which is suitably mounted on the base of the machine. These aprons serve to prevent the stock from falling off of the turntable until it reaches the doctor I 38. The apron I58 has an opening in it, of

course, opposite the hopper I35, as shown in Fig.

3 through which the pulp may flow into the hopper. There is a plate It! secured to the hopper I35 parallel to the doctor I38 so that the stock is guided into the hopper.

It has been found in the cases of some stocks that if the stock is too cold, it will not form into nodules and it will tend.to shear, instead of to roll, under normal pressure. Means has been provided in the present machine, for heating the stock to raise its temperature sufficiently for it to curl. This means comprmes a steam manifold I65 (Fig. 2) which is mounted beneath the lower working plates 45]. Nozzles IS? are threaded into this manifold at angularly spaced points. These nozzles register with openings I68 in the working plates 49. Steam is supplied to the manifold Itfi from a pipe I59, and is directed by the nozzles IB'I at the de-watered pulp swept onto the plates 10. This steam heats up the dewatered pulp and per'mits it to be worked by the machine.

In the operation of the machine, it will be seen that the stock, which is of low density, enters the working area of the machine through the pipe 55, the bore 2? of the shaft 24, the bore 26 of th sweep head 25 and the spaces between the sweep arms 28. It fans out over the dewatering plate 3i and up against the gyrating upper working plates 58. As it spreads out over the de-watering plate 3i, the white water drains from the pulp through holes in the drainage plate and through the holes 35 in the casting 35 into the chamber I45 whence it flows through theconductor I l! to the hopper I35. As the sweep head rotates, the sweep arms clear the thickening stock from the surface of the de- Watering plate 3I while at the same time squeezing portions of the stock between the upper surfaces 36 of the sweep arms and the opposed upper working plates 55. The rotating sweep arms, aided by th straps 2i, also urge the thickening stock radially outwardly over the de-watering surface onto the lower working plates 46. There it may be heated by steam from the nozzles I61. The upper working surface U is, of course, moving in an orbital path under the actuation of the crank shaft SI. Hence, as the stock is carried between the sweep arms and the upper working surface and between the lower working surface and the upper working surface, it is alternately squeezed and released and it is rolled traversingly in different tangential directions in tractive contact with these surfaces. Thus, it is formed into small, discrete nodules of pulp in which the fibres are curled and twisted upon one another. By the time the stock has reached the limit of the de-watering zone, it has been thickened to a consistency of 10 to 20% or more and is substantially completely nodulated. From ously rolled between th upper and lower working surfaces while they are caused to progress outwardly toward the periphery of the lower working surface. In their outward travel, the nodules are grouped and re-grouped into units which are rolled traversingly tangentially in different directions in tractive contact with and between the working surfaces and ar continuously reoriented with reference to the direction of applied pressure.

When the pulp reaches the edge of the lower working surface it falls onto the turntable I which is continuously rotating. It is moist and may be sticky but when it is carried around by the turntable to the doctor I38, the doctor forces it off mechanically into the hopper 55. 'It drops through the opening in the bottom of the hopper into containers or onto a conveyor by means of which it may be carried on for further treatment. The white water flowing through the conductor it! will sluice the pulp down to the discharge outlet Mt. This water may at the same time help convert the nodulated pulp to a dis- 'persed fibre suspension state in which it can readily be handled for further processing if desired. Th damper 59 serves to control the back pressure, and is one of the controls on the rate of feed of the pulp through the working surfaces.

While the invention has been described in connection with a machine for treating raw wood pulp, it will be understood that it may be used as is or with modifications known to the art for treating fibrous material in other forms. Thus it may be used in de-inking and reclaiming waste printed stock according to the process of the joint application of Harold S, Hill and myself, Serial No. 681,918, filed July 8, 1946, now Patent No. 2,641,164, granted June 9, 1953. In such case, both upper and lower working surfaces will preferably be perforated for flow of water or other liquid into and out of the stock being treated as described in application, Serial No. 681,918.

In general, it may be said that while the invention has been described in connection with a particular embodiment thereof, it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth and as fall within the scope of the invention or the limits of the appended claims.

Having thus described my invention, what I claim is: 1. In a machine for processing papermaking pulp, a pair of working plates having opposed working surfaces disposed to form between them a thin working space and which are roughened to provide traction for nodules of pulp without obstructing rolling traverse of the nodules on the working surfaces, means for pressing one plate toward the other to compress the pulp between the opposed working surfaces, and means for imparting a translator-y gyratory motion to one of said plates about an axis extending in the direction of compression, th working surface of the gyratory plate having a central portion which is internally dished away from the opposed working surface of the other plate, and the area of the working surface of said other plate which is opposed to said internally dished portion of the gyratory plate being inclined'to said internally dished portion at an angle no greater than the angle between said internally dished portion and a plane perpendicular to said axis, whereby th clearance between opposed portions of the working surfaces is periodically varied as the gyrating plate gyrates about its axis so that the nodules of pulp between said internally dished portion and said opposed area are alternately compressed and released and are traversed outwardly toward the peripheries of said working surfaces as said gyratory plate gyrates about its axis.

2. In a machine for processing papermaking pulp, a pair of working plates having opposed working surfaces disposed to form between them a thin working space, both said working surfaces having tiny, spaced protuberances formed thereon projecting into the working space to provide traction for nodules of pulp without obstructing rolling traverse of the nodules on the working surfaces, fluid-pressure operated means" for pressing one plate toward the other to compress the pulp between the working surfaces, means for imparting a translatory, gyratory movement to one of said plates about an axis extending in the direction of compression, the working surface of the gyratory plate having an internally dished conical portion and the other working surface having a plane area opposed to said dished portion which is perpendicular to the axis of gyration, whereby the clearance between the working surfaces is periodically varied as the gyratory plate gyrates about its axis and the nodules of pulp are traversed outwardly toward the periphcries of the working surfaces as said gyratory plate gyrates about its axis.

3. In a machine for processing papermaking pulp, a perforated drainage plate, an inlet disposed centrally of said drainage plate through which an aqueous slurry of pulp may be delivered to said drainage plate, a sweep arm rotatable about an axis coaxial with said inlet for sweeping the thickenin stock up off said drainage plate, a lower working member having a working surface surrounding said drainage plate, an upper working member overlying both said sweep arm and said lower working member and cooperating with both, said upper working member having a working surface opposed to the working surface of the lower working member which has. an internally dished central portion overlying both said sweep arm and the adjacent'surrounding part of the working surface of said lower working member, the area of the working surface of said lower member which is opposed to said internally dished portion bein inclined tosaid internally dished portion at an angle no greater than the angle between said internally dished portion and a plane perpendicular to said axis, both said working surfaces being formed with tiny, spaced protuberances thereon to provide traction for nodules of pulp without obstructing rolling traverse of the nodules on the working surfaces, means for pressing one of said working members toward the other to compress pulp between them, and means for imparting a translatory gyratory motion to said upper working member about an axis extending in the direction 'of compression and perpendicular to said plane.

4. In a machine for processing paperrnaking pulp, a perforated drainage plate, an inlet disposed centrally of said drainage plate through which an aqueous slurry of pulp may be delivered to said drainage plate, a sweep arm rotatable about an axis coaxial with said inlet for sweeping the thickening stock up off said drainage plate, a lower working member having a working surface surrounding said drainage plate, an upper working member having a working surface overlying both said sweep arm and the working surface of said lower working member and cooperating with both, the upper surface of said sweep arm being an external conical surface coaxial with said sweep arm and the portion of the working surface of the upper working member, which overlies the sweep arm and the part of the lower working member that is adjacent the drainage plate, being an internal conical surface whose axis is parallel to the axis of said sweep arm, said part of the working surface of the lower working member that is adjacent the drainage plate being a plane surface perpendicular to the axis of the sweep arm, both of said working surfaces having tiny, spaced protuberances formed thereon to provide traction for nodules of pulp without obstructing rolling traverse of the nodules on the working surfaces, means for pressing one of said working members toward the other to compress the pulp between them, means for rotating the sweep arm, and means for imparting a gyratory movement to the upper working member about an axis extending in the direction of the axis of the sweep arm.

5. In a machine for processing papermaking pulp, a perforated drainage plate, an inlet disposed centrally of said drainage plate through which an aqueous slurry of pulp may be delivered to said drainage plate, a lower workin member having a working surface surrounding said drainage plate, an upper working member having a working surface overlying the working surface of the lower working member and having opposed relation thereto, both said working members having their opposed working surfaces roughened to provide traction for nodules of pulp without obstructing rolling traverse of the nodules on said opposed faces, sweep means for moving thickened pulp from said drainage plate onto the WOIkiIlg' surface of the lower working member, means for pressing one of said working members toward the other to compress the pulp between them, means for imparting a translatory gyratory motion to said upper working member about an axis extending in the direction of compression to roll nodules of pulp traversingly on the working surfaces from the place of entry of the pulp onto the lower working member to a discharge zone around the periphery of the lower working member, a rotary turntable surrounding the lower working member to receive the discharged pulp, means for rotating the turntable, a hopper, means for sweeping pulp on the turntable into the hopper, and a conduit for conducting liquid. which is expressed from the pulp through the drainage plate, into the hopper to wash the processed pulp out of the hopper.

6. In a machine for processing papermaking pulp, a perforated drainage plate, an inlet disposed centrally of said drainage plate through which an aqueous slurry of pulp may be delivered to said drainage plate, a lower working member having a working surface surrounding said drainage plate, an upper working member having a working surface overlying the lower working member and having opposed relation thereto, both said working members having their opposed working surfaces roughened to provide traction for nodules of pulp without obstructing rolling traverse of the nodules on said opposed faces, sweep means for moving thickened pulp from said drainage plate onto the-working surface of the lower working member, means for pressing one of said working members toward the other to compress the pulp between them, means for imparting a translatory gyratory motion to said upper working member about an axis extending in the direction of compression to roll nodules of pulp traversingly on the working surfaces from the place of entry of the pulp onto the lower working surface to a discharge zone around the periphery of the lower working member, a rotary turntable surrounding the lower working member to receive the discharged pulp, means for rotating the turntable, a hopper, means for sweeping pulp off the turntable into the hopper, and a conduit for conducting liquid, which is expressed from the pulp through the drainage plate, into the hopper to wash the processed pulp out of the hopper, and a valve for controlling the flow of liquid out of the conduit into the hopper, said valve being adjustable to control by back-pressure the movement of pulp through the machine.

7. In a machine for processing papermaking pulp, a pair of opposed working members ar-- ranged to form therebetween a working space, both said working members having tiny, spaced protuberances on their opposed faces which proiect into said working space less than half the depth of said working space so as to provide traction for nodules of the pulp without obstructing rolling traverse of the nodules on the working members, means for pressing said members toward one another to compress pulp between their opposed faces, means for imparting a translatory, gyratory motion to one of said working members about an axis extending in the direction of compression, the working face of said one working member having a central portion internally dished away from the opposed working face of the other working member, the opposed area of the other working member being inclined to said internally dished portion at an angle no greater than the angle between said internally dished portion and a plane perpendicular to said axis, and an inlet disposed centrally of one working member for delivering pulp between the opposed faces of said working members, the protuberances on the dished portion of the gyratory working member and on the opposed portion of the other working member being inclined away from said inlet to direct the pulp from said inlet toward a discharge zone around the periphery of said other working memher.

8. In a machine for processing papermaking pulp, a perforated drainage plate, an inlet disposed centrally of said drainage plate through which an aqueous slurry of pulp may be delivered onto said drainage plate, a lower working member having a working surface surrounding said drainage plate, an upper working member having a working surface overlying the working surface of the lower working member and arranged in opposed relation thereto, a sweep arm rotatable about an axis coaxial with said inlet for sweeping thickening stock up off said drainage plate and moving it onto the working surface of the lower working member, a plurality of nozzles disposed around said drainage plate for injecting steam into thickened pulp delivered onto the working surface of the lower working member, means for pressing one of said working members toward the other to compress pulp between li fiir working surfaces, and means for imparting a translatory gyratory movement to the upper working member about an axis extending in the direction of compression to roll pulp on and over the working members.

9. In a machine for processing papermaking pulp, a perforated drainage plate, an inlet disposed centrally of said drainage plate through which an aqueous slurry of pulp may be delivered onto said drainage plate, a plurality of straps secured obliquely on said drainage plate with their leading edges tangent to a circle concentric with said inlet, a lower working member surrounding said drainage plate, a sweep arm rotatable about an axis coaxial with said inlet for sweeping thickening pulp up 011 said drainage plate and moving it onto the lower working member, said sweep arm being spirally curved about said axis in the opposite direction to the direction of inclination about said axis of said straps, an upper working member overlying the lower working member and disposed in opposed relation to both the sweep arm and the lower working member and cooperating with both, means for pressing the upper working member toward the lower working member and the sweep arm to compress pulp between them, and means for imparting a translatory, gyratory motion to the upper working member about an axis extending in the direction of compression.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 47,425 Jones Apr. 25, 1865 657,206 Terrell Sept. 4, 1900 1,065,332 Newhouse June 17, 1913 1,226,275 Symons May 15, 1917 7 1,256,843 Symons Feb. 19, 1918 1,616,240 Symons Feb. 1, 1927 1,795,603 Hussey Mar. 10, 1931 1,847,159 Adams Mar. 1, 1932 2,121,275 Zober et a1. June 21, 1938 2,156,321 Sutherland May 2, 1939 2,180,080 Cowles Nov. 14, 1939 2,226,429 Hall Dec. 24, 1940 2,254,455 Sorenson Sept. 2, 1941 2,470,140 Castner May 17, 1949 2,516,384 Hill et al July 25, 1950 2,561,013 Coghill et al July 17, 1951 2,573,709 Hill et a1. Nov. 6, 1951

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