US2938580A - Continuous cellulose pulp digester - Google Patents

Description

May 31, 1960 J. DE LA ROZA, SR. ET AL 2,938,580

commuous CELLULOSE PULP DIGESTER Filed April 2, 1953 12 Sheets-Sheet 2 INVENTORS. .6424

May 31, 1960 J. DE LA ROZA, sR., l-rrAL 2,938,580

coNTINUous CELLULOSE PULP DIGESTER 12 Sheets-Sheet 3 Filed April 2, 1953 H 5% [lg INVENTORS.

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May 31, 1960 J. DE LA ROZA, SR., ETAL CONTINUOUS CELLULOSE PULP DIGESTER 12 Sheets-Sheet 4 Filed April 2, 1953 INVENTORS. AXG'Q JQ. ma r.

May 31, 1960 J. DE LA ROZA, SR, ET AL 2,938,580

CONTINUOUS CELLULOSE PULP DIGESTER l2 Sheets-Sheet 5 Filed April 2, 1953 JNVENTORS. M W.

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May 31, 1960 J. DE LA ROZA, sR., ET AL 2,938,580

cou'rmucus CELLULOSE; PULP DIGESTER Filed April 2, 1953 12 Sheets-Sheet a 1 1 I V 9 a k 3 May 31, 1960 J. DE LA ROZA, SR, ETAL 2,938,580

CONTINUOUS CELLULOSE. PULP DIGESTER Filed April 2, 1953 12 Sheets-Sheet '7 IN V EN TORS.

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ATYLRNEY? y 31, 1960 J. DE LA ROZA, SR, ETAL 7 2,938,580

CONTINUGUS CELLULOSE PULP DIGESTER Filed April 2. 1953 12 Sheets-Sheet 8 I N V EN TORS.

May 31, 1960 J. DE LA ROZA, sR., ETAL commucus CELLULOSE PULP DIGESTER 12 Sheets-Sheet 9 Filed April 2, 1953 INVENTORS.

ATTORJEYS May 31, 1960 J. DE LA ROZA, SR, ETAL 2,938,580

CONTINUOUS CELLULOSE PULP DIGESTER Filed April 2, 1953 12 Sheets-Sheet 11 May 31, 1960 J. DE LA ROZA, SR., ETAL 2,938,580

commuous CELLULOSE PULP DIGESTER Filed April 2, 1953 12 Sheets-Sheet 12 INVENTORS.

MAJ'Z'ORNEYS CONTINUOUS CELLULOSE PULP DIGESTER Joaquin de la Roza, Sr., White Plains, and Joaquin de la Roza, Jr., New York, N'.Y.; said Joaquin de la Roza, In, assignor, by mesne assignments, to said Joaquin de la Roza, Sr.

Filed Apr. 2, 1953, Ser. No. 346,368

20 Claims. (Cl. 162-244) This invention relates to apparatus for the continuous digestion of cellulose bearing material to produce a cellulose pulp of any degree of purification suited for use in the manufacture of board, paper and a multitude of products having cellulose as their base or as an important component.

An object is to produce such an apparatus which is designed and adapted for digesting treatments of extended duration and in large volume, under appropriate conditions with relation to pressure, temperature, and chemical action; the apparatus eliminating the restrictions, inconvenience, and lack of uniformity of batch treatment, as well as the small output and structural and mechanical defects or drawbacks that have attended previous efforts in the direction of continuous treatment, while avoiding excessive construction cost and complication and attaining such a degree of automaticity, reliability and uniformity in functioning as sharply to reduce supervisory expense and maintenance.

Another object is to produce such an apparatus which embodies combined material feeding and impregnating means and mechanism that serve to form a pressure resisting cork for the digesting chamber inlet, provide for effective removal of excess treating liquid and other fluids or gases from the material as it forms the cork, and permit ready forward movement and ejection of the cork from the inlet into the digesting chamber regardless of the density or hardness of the cork.

Another object is to produce such an apparatus of which the inlet is fitted with novel means for restricting its cross sectional area in order to impede to a predetermined extent the forward motion of the material and thereby form a cork of desired density, the restricting member being activated in its closing movement by fluid pressure thereupon and being restrained as to the extent of its opening movement by an adjustable element.

Another object is to produce such an apparatus that has a hopper, or the like, for supplying the material to the feeding means, and in which there is associated with the hopper an arrangement for wetting and at least partially impregnating the material with treating fluid.

Another object is to produce such an apparatus which comprises inner and outer cylindrical chambers, the inner constituting the digesting chamber and the outer serving to establish a heating jacket surrounding the inner; together with means for simultaneously rotating both chambers to facilitate thorough and uniform admixture and impregnation of the material with treating liquid, uniform exposure to temperature and pressure conditions, and travel of the material through the apparatus.

Another object is to produce such an apparatus as described in the preceding paragraph which also includes provisions to allow for relative longitudinal expansion of the cylindrical chambers while resisting relative torque thereof.

Another object is to provide such an apparatus with improved connections between the fixed inlet and discharge structures and the rotating digesting chamber,

United States Extent chamber and re WC whereby a yielding, adjustable seal is established, and the ends of the apparatus are fitted with means to resist longitudinal thrust due to pressure.

Another object is to produce such an apparatus which includes means connecting or tying together the fixed inlet and discharge structures so as effectively to withstand the longitudinal thrust generated by pressure within the digesting chamber.

Another object is to fit such an apparatus near one or both ends with constantly effective safety and relief devices for air, gas and liquid, to prevent injury to the apparatus; said devices preferably being equipped with suitable instruments for indicating and/or recording and enabling control of such factors as pressure, temperature, material level, as well as others normally incident to the treatment involved.

-Another object is to provide improved means for rotatably supporting and driving the digesting chamber without in any way disturbing its operative relationship with stationary pants.

Another object is to include in such apparatus improved rneans for the supply of heating steam, and for removal of condensate; the latter involving valves, or the like, peripherally positioned on the digesting chamber and complementary means for coacting with a valve when it approaches a low point in the cycle of rotation of the chamber, together, preferably, with means for controlling the functioning of the said valve.

' Another object is to associate with such an apparatus a control system, preferably electric, for discontinuing the motor drive of the digesting chamber and bringing the apparatus to rest if the longitudinal movement of the chamber exceeds desired operational Another object is to construct such an apparatus with improved features at the discharge end whereby efliciency in operation is attained and maintenance reduced.

Another object is to provide the interior of the digesting chamber with an helix, worm, screw, or the equivalent, for causing the material being treated to.travel a longer path during treatment without increasing the length of the apparatus; provision also being made for the escape of air, gas and vapor past the helix, worm or screw and the venting thereof promptly after liberation or forming through an appropriate relief device.

Another object is to produce such an apparatus which is admirably suited to arrangement and interconnection with one or more similar units, coupled with appropriate and suitable intermediate elements, for the purpose of plural step digestion, such, for instance, as a first treatment, with or without the addition of chemical, and a second treatment with the addition of alkali.

A further object is to provide certain improvements in the form, construction and arrangement of the several parts of the apparatus whereby the above named objects and others inherent in the invention may be effectively attained.

The subject matter of this invention, generally considered', comprises a rotatable digesting chamber, either jacketed or not, with improved and novel means for performing the following functions: feeding the material to be digested, usually wet with chemical solution, into the chamber; removing excess liquid, air, and other fluids and gases from the material as it is fed; regulating the feeding opening to form the material into a cork of desired density; providing for longitudinal expansion of the chamber while maintaining proper alignment of the jacket; supporting and rotating the chamber and jacket; supplying steam to the jacket space or steam, Water and chemical to the interior of the chamber; automatically removing condensate; yieldingly and adjustably sealing the contacting end portions of the rotatable digesting chamber and the fixed inlet and dis-.

assessocharge structures of the apparatus, and preserving the seal in spite of circular wobbling motion of the chamber with respect to the fixed structures due to departure of the chamber axis from precise alignment with theaxis or either or both said fixed structures; causing the material to follow either a straight or elongated spiral path through the chamber while permitting escape "of air and gases; automatically stopping the drive of the chamber in the event of longitudinal movement beyond a predetermined" limit; and discharging the treated material from the chamber.

. The various elements of the apparatus just summarized, together with their functions, will be explained at length and their novelty'and improved characteristics will be more clearly presented in conection with the detailed description to follow the identification of the figures of the drawings which exhibit a plurality of embodiments of the invention, and in which Figs. 1, 1a and 1b represent collectively a broken side elevation, partly in section," of the form of the invention which embodies a jacketed digesting chamber for the purpose of suplying heat to'the exterior of, the chamber;

Fig. 2 represents an end elevation of Fig. 1b, looking from right to left I i Fig. 3 represents an enlarged detail transverse section taken in the plane of the line III of Fig. 1b, looking in either direction; I

Figs. 4, 4a and 4b represent collectively a view similar to Figs. 1, 1a and 1b but showing a modified form of the invention embodying an unjacketed digesting chamber to the interior of which heat is supplied;

Fig. 5 represents an enlargeddetail, vertical, longitudinal, central section, partly in elevation, of the right hand end portion of Fig. 1b;

Fig. 6 represents an enlarged transverse section taken 1 partly .ing in the direction of the arrows, and showing the distion, showing an helix, worm or screw which may be in the plane of the line VI-VI of the Fig. In, looking in either'direction;

Fig.7 represents an enlarged detail transverse section taken in the plane of the line VII of Fig. 1a, looking in either direction;

Fig. 8 represents a detail section taken in the plane of the line VIII-VIII of Fig. 7, looking in either direction;

Fig. 9represents a view similar to Fig. 7, but somewhat more complete, showing a modified form of structure; 1

Fig. 10'representsa view similar to Fig. 8, but showing the modified structure of Fig. 9;

Fig. 11 represents an enlarged detail section, partly in elevation, taken in the plane of the line XI of Fig. lb, looking in the direction of the arrows;

Fig. '12 represents an enlarged detail, vertical, central sectiompartly in elevation, of the material supplying hopper and crankoperated piston. shown in Fig. 1;

Fig. 13 represents an enlarged detail, vertical, central section partly in elevation, of the adjustable check or iqonstrictor-for the digesting chamber inlet shown in Fig. 14 represents an enlarged detail section of the pivotal mounting and gasket for the said check or con strictor;

Fig. 15 represents a transverse section taken in the plane of the line XVXV of Fig. 13, looking in the direction of the arrows;

Fig. 16 represents an enlarged detail, vertical, longitudinal, central section, partly in elevation, of the sealing construction, thrust resisting construction and pressure releasing dome at the inlet end of the apparatus;

Fig. 17 represents a transverse section, partly in elevation, taken in the plane of the line XVII-XVII of Fig. 16, looking in the direction of the arrows; 7

Fig. 18 represents an enlarged detail longitudinal section throughthe upper part of the bellows and'adjacent parts shownin Fig. 16;

Fig. 19 represents an enlarged, vertical, transverse sec tion, taken in the plane of-the line XIX-oi Fig. 1b, lookmounted within the digesting chamber for causing the material being treated to travel a longer path;

Figs. 25 and 25a represent collectively a broken, detail, side elevation of the form of the invention which embodiesan' unjacketed digesting chamber, with a modification directed to the provision of external means for connecting or tying together the fixed inlet and discharge structures for the purpose of withstanding longitudinal thrust generated by pressure within the digesting chamber;

Fig. 26 represents a transverse section, partly broken away, taken in the plane of the line XXVIXXVI of Fig. 25, looking in the direction of the arrows;

Fig. 27 represents a detail perspective view of the central support for the external connecting or tying'means;

Fig. 28 represents a detail sectional view, partly in elevation, of the form of the invention which embodies an unjacketed digesting chamber and includes an helix, worm or screw, as also illustrated in Fig. 24, the said Fig. 28 exhibiting a further modification directed to the provision of internal axial means for connecting or tying togethe the fixed inlet and discharge structures; and

Fig. 29 represents a detail section taken in the plane of the line XXIXXXIX of Fig. 28, looking in the direction of the arrows.

Proceeding now to a detailed description of the invention, and considering all the figures of the drawings, with the exception of Figs. 4, 4a, 4b, 24 to 28, which exhibit the modified forms; the apparatus includes a feeding inlet 1 (Figs. 1 and 12), that is generally cylindrical inform but is provided with flanges 2, 3, at the lower portion of each side thereof for firmly securing the inletby cap screws 4 to the top 5 of a sturdy, rigid base 6, which; may desirably be of steel and concrete construction. Formed in the top of the inlet is a flanged opening7 to which is bolted a material supply hopper 8, that has an open top into which may be dumped, as by traveling belt or the like, the cellulose bearing material, e.g., bagasse, wood or other analogous substances. The upper edge of the hopper is surrounded by a pipe 9 which is fitted with suitable connections for receiving fluid and has perforations along its inner periphery coinciding with holes through the wall of the hopper so that any desired fluid, such for instance as water, chemical solution, or steam, may be sprayed upon the incoming material.

The side of the inlet 1 away from the digesting chamber (to the left in Figs. *1 and 12), is bored, as indicated at 10, slidably to receive a charging piston 11 which is fastened by cap screws, one of which is shown and marked 12, to a crank'head 13, that is connected by a pitman 14, toappropriate rotary-reciprocating .mech anisrn, denoted generally by 15, that is mounted on the base 6 and powered by a motor 16, with the provisionof suitable variable speed. reduction intermediate driving connections that are illustrated in Fig. 1, but will not be described in detail as they; per se, constitute no part of the present invention. The crank head 13 has gibs, one being shown and marked -17, screwed to its lower side edges, which ride in undercut rails (one of which is shown and marked 18) on the top of base 6, to guide the reciprocation of the crank head.

bore of; the inlet 1, sufiicientto permit the passage of liquid, and the said bore is surrounded by an annular rim 19 which is cut away to constitute a small chamber 20, which communicates at its bottom with a pipe 21 that may lead to a disposal point or to a connection for reuse or recovery. The chamber 20 is sealed around the piston 11 by a gland 22 which is adjustably secured to rim 19, and is itself rendered fluid tight by a stufling 23, clamped in place by another gland 24, which is adjustably fastened to gland 22. The construction just explained is of notable value in that it provides for the automatic removal of excess fluid from the material being treated as the latter is compressed by the piston, and hence permits the use of a maximum amount of fluid for mixing with the material as it enters the hopper 8, thus tending to insure complete impregnation. At the same time, the clearance between the piston and the hopper bore in which it lies is not sufilcient to permit passage of solids and, in effect, serves as a strainer which never clogs.

As the impregnated material falls downwardly through the hopper into the inlet 1, it is compressed by the reciprocating piston and forms a cork in the inlet which resists the pressure generated in the digesting chamber during operation, the said cork composed of the material being continuously forced through the inlet and into the digesting chamber for treatment therein; and being likewise continuously renewed; so that there is a constant ingress of the material for digestion and the maintenance of a cork or plug to withstand the back pressure from the digesting chamber. In this connection, an important feature relative to the form of the inlet 1 resides in the fact that the diameter, or cross sectional area, of the interior thereof increases in the direction from the hopper 8 toward the digesting chamber, thereby obviating a serious previously existing drawback attendant upon the use of an inlet of opposite form, i.e., one that tapered rather than flared in the direction toward the digesting chamber. It has heretofore been regarded as necessary to employ such a taper in order to insure the formation of the above mentioned cork, but the result has been the frequent formation of a cork of such density or hardness that it could not be forced through the inlet, and required stoppage of operations and hours, or even days, devoted to breaking up and removing the cork. We have determined that the flaring or increasing cross-sectional form of our inlet eliminates this previous trouble, and we insure the establishment of a satisfactory cork of predeterminable density by the provision of a properly adjustable constriction throat which intervenes between the inlet 1 and the digesting chamber, and will now be described.

Referring to Figs. 1 and 13-15, the constriction throat is denoted generally by 25. Its body is quadrangular in cross section, but its ends are in the form of circular flanges 26, 27, which are fastened by stud bolts (some of which are shown and marked 28, 29) to mating flanges 30, 31, on the inlet 1 and the neck of the digesting chamber. A central external flange 32, and connecting external web shown in the drawings but which it is not deemed necessary to number, serve to strengthen the throat, and the lower part of flange 27 is projected in the form of a foot 33 to rest upon a suitable base support A constrictor 35, which is tapered longitudinally and rectangular in cross section, is pivoted in a curved socket recess 36 at its small end within the throat 25 so as to swing upwardly and downwardly therein, as indicated by the full and broken lines in Fig. 13; while a stop 37 is threaded in the upper wall of the throat at 38, and housed within a sleeve 39 projecting upwardly therefrom, adjustably to limit the upward swing of the constrictor. The protruding upper end of the stop is shaped for the application of an adjusting tool. The constrictor may thus be held in proper contact with the material passing through the throat 25 and resist its movement to insure the formation of a satisfactory cork by, in effect, reducing the cross section of the interior of the throat. To continuously urge the constrictor 35 downwardly, any appropriate fluid, e.g., or steam, under regulatable pressure from a suitable source, is injected through a pipe 40 which enters an orifice in flange 31. This pressure will serve to move the constrictor 35 all the way down and close the throat 25 in the event the material cork is dissipated, as by chemical action, thereby preventing material under pressure in the chamber from returning to the inlet 1. A sealing gasket 41 is fitted in a groove surrounding the lower part of the constrictor; and a packing gland, denoted generally by 42, prevents leakage around the stop 37. Removable plugs 43, 43, are preferably provided for cleaning the space in the throat that houses the constrictor.

'The neck of the digesting chamber to which the throat 25 is fastened as just described, and with which it communicates, is composed of two parts 44 and 45, which are rigidly secured together by flanges 46, 47, and bolts 48 (Fig. 16). The bore of the neck is somewhat greater in cross section than that of throat 25, so that, as the material being treated passes from the latter to the former, a certain amount of expansion is permitted which eases and facilitates the flow. In the. top of part 44 of the neck is fitted a pipe 49 adapted for connection with a conduit 50 that leads from asource (not shown) of treating fluid, e.g., chemical, so that a regulated amount thereof may be added to the material at this juncture if desired. Any approved form of valve control may be provided for regulation. The part 45 of the neck is formed at the upper portion into a collar 51 designed for communication with a relief dome 52, the parts being connected by flanges 53, 54, and bolts 55; and the dome is surmounted by a rupture diaphragm unit, indicated generally by 56, which may be of any appropriate form and construction calling for no further illustration or description because well known to engineers, the unit being secured in position on the dome by flanges 57, 58, and bolts 59. A vent is also provided at one side of the dome near its top. In the drawings the dome is shown in broken view with respect to its height and it should be stated that the exact height is not a matter of importance provided it is suflicient to permit a level of contents at least as high as (preferably higher than) the highest level of the contents of the digesting chamber. The lower portion of the part 45 is likewise formed with a collar 61 which extends downwardly and is fitted with a removable bolted cover 62 for drainage and cleaning purposes. The dome 52 is equipped at or near its top with instruments of any standard or suitable form (not shown) for indicating, measuring and/or control-ling digesting chamber pressure, temperature, material level, relief, and other desired factors, which are of value not only for management of the digesting treatment but also for safety. It will thus be seen that the dome 52 and its accessories are designed as automatic safety means and also as means for operational control. To the forward end of part 45 of the neck is fast, preferably integrally or by welding, a sturdy annular frame 63, the lower portion of which finds support on a well braced foot 64 that rests upon a foundation base at 65, thus cooperating with the parts 6 and 33-34 in sustaining the elements or members of the apparatus heretofore described in fixed, rigid alignment.

An important aspect of the invention is the structure that unites these fixed parts with the rotating digesting chamber While maintaining a substantially perfect seal, which structure will now be described, with reference to Figs. 1048.

A cylindrical cover 66 is fixed to the forward (right in Fig. 16) peripheral face of frame 63 by 'an annular 7 and secured together by bolts, some of which are marked 68. .Within-thejcover and in contact with its inner "surf race is an annular 'discl69, the perimeter of which is'groovedt receive anti-frictioninserts 70 that are cemented or otherwise suitably fixed therein and arrang'ed in sets of three at the top and'bottom'of'the disc; while the side portions of the disc are notched to receive keys 71, 72, which are bolted to the cover 66 and serve to preventlmovement' of the disc in -a rotary direction while permitting .sliding motion. The disc 69 is also formed with 'a circular series of holes. in which are tightlymounte'dhollow studs, some of which are marked 73, that are surrounded by expansion coil springs '74.

A ring 75 is fitted over the extremities of the studs, and

the ring isbacked by a series of adjusting rods 76 which are threaded through the frame. 63 and, have their protr'uding ends formed for the application of an adjusting tool. Flanged collars 77 and 78, fastened by cap screws 8 s free relative motions while automaticallymaintaining an a'deguateseal 'againstj'leakage conformable to the demandsjof process conditions. It should'be added that the springs 74 may be used asthe'rnain source of pressure while thebellows acts chiefly as a flexible connection.

Turning now to the digesting chamber structure and operation, and referring particularly to Figs. 1, 1a and 1b, it willj be observed that, generally speaking, it-takes the form of 'a greatly elongated cylinder that is composed of several sections for construction purposes and also .tojprovide for longitudinal expansion and contracthan under temperature changes. The first section 88 which, as above described, is'fianged at its intake end and bolted to annulus 85 (Fig. 16), is of plain cylindrical form and is also'provided with a flange 91 at its opposite end that "is fixed by. cap'screws to a flange 92 or the like to the forward face of frame 63 and to the opposing face of disc.69, serve to clamp to the said frame and died the extremities of an expansionand-contraction bellows 79, with the intervention of suitable gaskets, e.g., asbestos. p

The forward face of disc .69 is provided with a circularflange 82 (Fig. .18) to which is aflixed by screws, or the like, a sealing ring 83 composed of material well adapted to resist chemical action and offer a minimum of friction to mechanical contact movement such, for instance, as a graphite compound, several of which are well known to engineers. smooth surfaced'metallic ring 84, preferably composed of stainless steel, that is aifixed, with the interpositioningo'f a suitable gasket, e.g. asbestos, by stud bolts,

This sealing ring mates with a a foundation base 98.

or the like, to a heavy, flat annulus 85, which is firmly secured by a large number of bolts, some of which are marked 86, to a flange 87 on the first or intake section 88 of the digesting chamber; a substantial gasket, preferably asbestos, being interposed. A tube 89 is formed integrally with, or properly secured to, the annulus 85, I

and projects rearwardly (to the left in Figs. '16 and 18) to a point just below the safety and control dome 52; said tube serving to lead the material being treatedinto the main body of the digesting chamber, and also to subject theequipment associated with the dome 52 to the conditions prevailing within the digesting chamber.

From the foregoing description it will be evident that rotation of. the digesting chamber 88 is permitted by the sealing surface contact of the sealing rings 83 and 84; and that the pressure within thedigesting chamber will force the said rings together by acting upon the inner faces ofthe corrugations of the bellows 79, which are subject to suchpressure because there is space between the bellows and the tube 89. This pressure will, of course, tend to expand the bellows and, as the frame '63 is rigid, the expansion of the bellowswill slide disc 69 to the right in Figs.'l6 and 18, and force ring 83 against ring 84. This effect is augmented by the springs 74 which are adjustable with respect to their power. The pressure with which these parts are forced together should'be greater than, say by a few pounds, the pressure within the digesting chamber, to prevent leakage; and the extent of movement imparted by the bellows 79 and springs 74 is limited by contact of annulus '85 with "an inwardly projecting'flange 90 on cover 66. Endwise thrust is resisted by the rigid base 6, at the inlet end of 1 the apparatus, and by structure at the discharge end of the apparatus which will be described later on. The fleXibilit-y'o'f the bellows'79 allows the digesting chamber to, withoutbreaking theseal at 83, 84, partake of what maybe described as a circular 'wobbling motion re sultantfrom-factors such, .for instance, as the length the digesting chamber.

on one end ofthe second orcentral section 93. The intermediate portion of section 88 is fitted with an ex.- ternaltire 94, whichmay, be composed of. metal or rubber; and rides upon a pair ofsupporting rollers (see also Fig. 2, which shows a duplication of this structure), one beingvisible in Fig. 1a and marked 95, suitably journaled in two bearings, one being visible in Fig. 1a and marked '96, adjustably. mounted on rails 97, 97, on Wedges, some of which are marked 99, serve to hold the tire in place; and access to the interior of the section may be had through removably covered ' ports 100, 101. The-central section 93-of the digesting chamber is of extended length (being shown broken in Figs. la and 1b), "and its other or forward end (to the right of Fig. lb) is formed with a flange 102 which is .united bygcap screws with a flange 103 on the adjacent end of the third or discharge section 1040f Surrounding the central section 93 is a spaced jacket or outer shell, which is also shown as broken in the drawings," and consists of three members 105,106, 107, fastened'end to end by bolted flanges 108, 109, and 110, 111. The rearward (to the left'in 'Fig. 1a) endof jacket member 195 has a flange 112, while the forward (:to the right in Fig. end of jacket member 107 has a similar flange 113; andbctween said flanges and :flange91 on digesting chamber section 88, and flange 103 on digesting chamber section 104, are positioned two like expansion and contraction joints 114 and 115,-each .of said joints being formed with a pair 'of flanges 116, 117, and 118, 119, that are bolted to flanges 91, 112, and 113, 103, respectively. This provisionallows forlongitudinal expansion and contraction of the: jacket with respect to the digesting chamber under the influence of variations in temperature. To prevent relative torque or twist thereof, two circumferential series of'longitudinally slotted blocks 12!), 121 (see also Fig. 6), arewelded or otherwise suitably fixed to the exterior of. the central section 93 of the digesting chamber, one series 'being located near each end; and two corresponding series of pins 1'22, 123, are threaded through members 105 and 107 of the jacket to ride in the slots of'the said blocks and thus, as already indicated, allow relative longitudinal movement while preventing relative torque of'the jacket and digesting chamber. Finally, the central member 106 of the'jacket is fastened at its'middle to the .middle of the central section 93 of the digesting chamber (see also Figs. ,7 and 8) by a ring 124 that is welded, or otherwise fixed, to both parts. The said ring is provided with a large number of perforations 125 to-permit flow of heating steam therethrough "as -will'be later-explained. If "deemed'necessary or desirable this fastening means may be repeatedat another point or other points. An alternative form of fastening means'is illustrated in Figs.

9 and 10, in which a non-perforated" ring 126 is" welded toboth parts'andi through the digesting cham'ber'wall,

19 valves 129, 130, may be fitted in the said pipes'to control the flow.

The tire unit 9498 hereinabove described as associated with section 38 of the digesting chamber is repeated in association with section 104, where the tire is marked '131; the supporting rollers (see Fig. 2) 132, 132; the bearings 133, 133; the rails 134, 134; and the foundation base 135. A generally similar, but somewhat different, unit is also associated with the central member 106 of the jacket, Where the tire 136 has beveled edges and rides on horizontally disposed discs 137, 137, which are mounted on bearings 138, 138, carried by rails 139, 139, on a foundation base 140.

As previously indicated, the digesting chamber is rotatable, and driving means for rotating the same, together with its jacket, during the digesting treatment, consists (see Fig. la) of an appropriate variable speed electric motor 141, mountedon a stand 142, and connected by a belt 143, or the like, and cooperating pulleys, with a shaft 144 that is journaled-in bearings 145, 146, and has fast thereon a pinion 147, which meshes with a ring gear 148 that surrounds jacket member 105 and is securely fastened thereto in any proper manner, as by a standard kiln gear drive connection which is Well known to engineers. The stand 142 and bearings 145, 146, are supported by a common base 149.

For the purpose of heating thematerial being treated within the digesting chambenthereis provided a main steam inlet pipe 150 (see Figs 1b and which is axially disposed with respect to the chamber and'extends from the forward part of section 93 through section 104 and the discharge portion of the apparatus; bearing supports for the said pipe being-embodied in structure to be hereafter described. The inner end of pipe 150'is closed and four branch pipes, two of which are shown and marked 151, 152, radiate therefrom and pierce the wall isection 93 to establish communication with the spacebetween the digesting chamber and its jacket. To remove the condensate which collects in the lower portion of the steam space, four stud pipes, two of which are shown and marked 153, 154, pierce and project from jacket member 107, and are coupled to four longitudinally extending exterior pipes, two of which are shown and marked 155,

' 156. Said last named pipes are coupled to four poppet valves, two of which are shown and marked 157,158, which valves, in turn, are coupled to four radially disposed pipes, two of which are shown and marked 159, 160, that pass through the wall of digesting chamber section 104, and enter a sleeve pipe 161, which iss'omewhat larger than and concentrically surrounds steam inlet pipe 150, and leads to a drainage outlet 162 for the condensate that may be connected to a steam trap, dump, or other desired form of receiver, not shown. The inner end of sleeve pipe 161 has a leak proof contact with steam inlet pipe 150 to prevent emission of the condensate into the digesting chamber, and the said sleeve pipe has bearing supports which will be identified later on. The poppet valves 157, 158, and the two like ones which are not shown, are normally held closed by springs embodied therein, and a device is provided for momentarily opening each valve as it approaches its lowest point in the rotation of the digesting chamber and its jacket. The said device consists of a shoe 163 having a curved upper surface (see Fig. 11) which is adjustably mounted on foundation base 135, and adapted for contact with a roller 164 carried by each valve, the said contact serving to compress the valve spring and hold the valve open while shoe and roller are in contact. By this arrangement, loss of steam through the other valves is obviated because they are held closed by their springs. It will be evident that the discharge of the condensate can be regulated by' variations in the size of pipes and valves, the length and shape of the shoe 163, and the rotative speed of the digesting chamber; such regulation being apt to be called for by difiering operative conditions-relating particularly to the tempera ture and duration of treatment.

The hereinabove described means for uniting the fixed parts at theintake end of the apparatus with the rotating digesting chamber, while maintaining asubstantially perfect seal, is duplicated for uniting the chamber with the fixed discharge parts, and, as the said means which is enclosed within the cover 66 has been explained in detail, it is deemed sufiicient merely to identify the cover at the discharge end which corresponds to cover 66 by the reference numeral 165, and note that it houses -a structure like that within cover 66;

Similarly, the discharge end of the apparatus embodies a relief and control dome 166, that is like dome 52, and correspondingly'equipped; its vent 167- and rupture diaphragm 168 being shown. This dome 166 is flanged at its lower end and bolted to a flanged collar 169, that uprises from a discharge chamber 170,- which is welded to or formed integrally with an annular frame 171, that is bolted to' cover 165, andalso stands upon a sturdy support 172, resting'on a foundation 173. The dome 166, like dome 52, is shown broken as to its height, and it should be noted that the relative heights of these two domes may vary in conformity with conditions of the particular process for which the apparatus is being installed. They may be of equal height or either one may be higher than the other. J

:The discharge chamber 170 has a co-axial extension 174 bolted thereto, as-indicated at 175; the said extension being formed with an annular wall 176 reinforced by webs, two of which are shown and marked 177, 178. Longitudinal thrust resisting beams 179, 180, are rigidly bolted to the said wall 176, the beams being of I shape in vertical section, as shown in Fig. 5, and having a wide lateral extent, as shown in Fig. 2, whereby their ends may be embedded in rigid building walls, e,g., masonry. This structure is very effective in withstanding the thrust generated by pressure within the digesting chamber, and complements the rigid base construction at the intake end of the apparatus which has hereinabove been explained. an added precaution, the apparatus is equipped with electric set-upfor automatically stopping the drive motor 141 in case the longitudinal thrust results in movement exceeding the designed limit at either end ofthedigesting chamber. This set-up is represented in the wiring diagram of Fig. 23 with appropriate inscriptions; and it will be seen that a limit switch connected was to break the electric current to the drive motor will be activated by the fiange87 on section 88 of the digesting chamber and/or by the corresponding flange (not shown) on section 104, in the event of more than designed longitudinal move ment by either or both sections.

The condensate drainage outlet 162 is formed ina cast ing 181 that is fastened by cap screws to a centrally apertured square plate 182 bolted to beams 179, 180. The casting 181 has a horizontal bore surrounded by a flange 183 to which is bolted a flangedbracket 184 that is likewise formed with a bore and is developed at its extremity into an inlet 185 for live steam, which inlet is provided with a flange to assist in coupling a source of steam supply (not shown) thereto. The open end of the main steam inlet pipe 159 is adjacent inlet 185, and the said pipe finds packed bearings 1-86, 187, in the bores of bracket 1'84 and casting 181; while the condensate discharge sleeve pipe 161 has similar bearings 18%, 1 89, in the inner peripheral edge of casting 181 and in the wall 176 of discharge chamber extension 174. A tube 199 surrounds pipe 161 within the said discharge chamber, having its ends supported by the said wall 176 and an annular partition 191 within the discharge chamber 170.

The discharge portion of the apparatus is shown as to its general arrangement at the right side of Fig. 1b, and in Fig. 2, while its construction is set forth in Figs.l9-2 2, and will now be described. V

The discharge chamber 170 is formed in'its lower por presser 220, which is highly. desirable.

' erable shut oif valve 197 may, if desired, be fitted in'the duct 194 in order to close the same and isolate the discharge valve for the purpose of maintenance and adjustment. Thebottom of the funnel also a flange198 that is fixed by stud bolts or cap'screw's'to the annular cover 199 ofthe discharge valveunit The discharge valve proper 200 is of the volumetric type and provided with the usual peripheral series of buckets 201. 'It is keyed, or otherwise suitably fixed, to a shaft 202, the ends of which aremounted in ball bearings 203, 204, that are fitted in journal boxes-205, 206,1having removablecovers2'07, 208; the said'boxes' being secured by cap screws, four of which are shown and marked 209, to the valve housing 210 and its side cover 211 that is,

in turn, fixed to the housing bycap screws, two of which arelsho'wn and marked 2121 The end of 'the shaft sup portedby bearing 204 protrudes from bearing box 206 through cover 8and has a sprocket 213 first thereon which meshes with a chain 214 that also meshes with a smaller sprocket 215 (Fig. 2)which is gear driven from a variable speed electric motor 216. The housing 210 is flanged at its top and securely-fastened to cover 199 Mountedfor' vertical slidablemovement within the housingis a saddle 218 which rests upon the volumetric valve 200 and is eurved to conform thereto. The saddle,

is formed with'a downwardly tapered opening the lower arethreaded through the'cover 199 and have their lower ends fittedin a presser 2 20 which rests-on the top of saddle 218. Expansion coilv springs 221 surround the rods 219-and are'confined between the presser 220 andcolla'rs 222 formed integrally with or fixed, asby pins, to the rods. The upper ends of the rods are squared for the application ofan adjusting tool, and they are enclosed within caps. 223 that uprise' from the cover 199, being cast therewith or aflixed thereto, and are fitted at their tops with sealing screw 'plugs 2.24. It will be evident that, by removing the plugs and turning the rods' 219, the pressure of springs 221 can be varied, while the replacement of the plugs will seal the parts against leak: age of pressure from the housing 210. A bellows 225 is positioned between the cover 199'and the presser 220,

and held in place by a pair of containing rings 226, 227, which are fastened by bolts or screws to the cover 199 and presser 220, respectively, and clamp the extremities of the bellows therebetween. the bellows constitutes a connectionbetween the funnel 196 and the saddle 218 for the passage of the treated material which is being discharged,,and that the pressure from the digesting chamber that exists the bellows will tend to expand the latter and thereby unite with the springs 221 in forcing the saddle against the volumetric valve 200. The bellows also provides flexibility'in' the connection between the cover 199 and .the

' To improve the sliding contact between the valve and the saddle by relieving the friction engendered by the force of the bellows and springs, the saddle is preferably provided with an anti-friction facing 228, that may be composed of, for instance, graphite or graphitic carbon; or the facing may consist of an inert low friction plastic, orlthe like. The vertical movement of the saddle may likewise be bettered by making it in the form of an iron while-the housing 210 is of steel, with or without the'interpositioning of a'lining 229 composed of some Uta ' by a large number of bolts, some of which aremarked,

It will thus be clear that 12 material suchasstainless steel. The precise nature of the materials employed will naturally be dictated by the factors of chemicals, temperatures, and pressures involved in the treating-process for which the apparatus is designed.v s f It will be evident, that the cooperation of the valve 200 and saddle 218 enables each bucket of the valve to receive and carry along its capacity of treated material as the valve is rotated, and"that, when each bucket reaches the lowermost point'of. its travel, its contents will be, dumpedinto the' outlet 230 of housing 210, for finishing treatment'or further-digesting treatment as desired, which need not be described for an understanding of this invention. Thus, with the cubical size of the valve buckets being known, the valve'may be rotated at such speed as definitely to control the rate of discharge of the *material. For'the purpose of inspection and cleaning, an opening in the. housing 210 having a cover plate 231 is provided, and additional openings may be positioned at other .points if desired.

The modified form of the invention exhibited in Figs. 4, 4a and 4b, difie rs' from the form already described mainly in that there is no heating jacket surrounding the digesting chamber, which, of course, requires certain changes with respect to the sup plyingof heating steam to the materialbeingtreated. is preferably'accomplished by entirelyeliminating' the steam supply piping with its supports, 'of theiacketed form, and merely injecting steam through the vents and 167 of the domes 52 and 166, respectively, ,it being advantageous to use steam of a higher temperature at'the vent 'l67 owing to the desirability of greater .heat in the later stage of the process. The means for removing condensate is also omitted from this modified form, because the condensate "with the material under treatment and is dis charged-therewith. The absence of the steam supply and condensate removal pipes obviates the necessity for a large part of the structure at the discharge end of the apparatus, and permits the forward '(to] the right in Fig. 4b) end'of the discharge chamber 170 to be connected by bolted flanges 232 to a curved duct 233 of gradually reducing cross-section that is flanged and bolted" directly to the cover 199 of thedischarge valve unit which is the same as that of the'jacketed form of theinvention. :A thrust resisting beam 234 is integral with duct 233, and the lower part of the discharge chamber 170 is formed with a'drainage and cleaning'collar 235 and cover 236 like theparts 61 and 62 of the other form. This unjacketed embodiment is less expensive to construct but it lacks the desiderata of eliminating the dilution and con tamination of the material being treated bythe injection of steam thereinto; and of being'able to 'use heating steam at lower pressure than that within the digesting chamber; as well as others inherent in the characteristics of the jacketed structure. 7

With reference to both forms of the invention, the digesting chamber may, if desired or it is'deemed advisable, be reinforced against distortion in the direction of either collapse or expansion by the provision ofbands welded, or otherwise properly alfixed, to the exterior thereof, such as the bands shown in dotted lines 'and marked 237 inFigs. la and lb.

, Again referring to both the jacketed and unjacketed forms of the invention, it should be pointed out that, although not shown in the drawings, the apparatus is usually so mounted and arranged that the digesting chamber declines at'a' slight angle from the intake end to the discharge end, a drop of one-sixteenth to one-quarter of an inch per foot of length having been found 'to be satisfactory; the purpose being to facilitate movement or" the material being treated through the apparatus, and also .to aid in evacuation of the steam condensate in the case of the jacketed chamber. However, the characteristics or conditions of some procedures may dictate a horizontal or even slightly inclined arrangement of the 13 chamber, and the apparatus is equally suitable to such positioning.

In Fig. 24 is represented an added feature which may be adopted in the construction of either or both embodiments of the invention. It consists in a helix, screw or worm that may be installed within the central section 93 of the digesting chamber in order to compel the material undergoing treatment to travel a winding or spiral course or path, thereby notably lengthening the travel without requiring elongation of the chamber. In this figure of the drawings the central section 93 of the digesting chamber is so marked, while the helix, screw or worm is indicated by 238. It winds around and is secured, as by welding, to a hollow core 239, and its spiral peripheral edge or rim is likewise attached to the inner wall of the chamber at the inlet end or throughout all or part of its length, as desired, so that the screw or worm rotates therewith. The flights or individual spirals are formed with notches 240, which are of value in permitting escape of air and gases by venting through either or both domes 52 and 166. These notches will naturally allow some of the solid material to travel along the chamber without following the spiral path, but this will be small in amount and will practically cease as soon as the chamber is filled.

A further modification of the invention is illustrated in Figs. 25-27, where the unjacketed digesting chamber form of the apparatus is fitted with connecting means for tying together the inlet and discharge structures to augment their ability to withstand the powerful longitudinal thrust generated during operation by the pressure within the digesting chamber. As these figures repeat to a large extent the showings of Figs. 4-4b, the repeated parts will neither be described nor numbered except as they are involved with this modification of the invention. The connecting means comprises a suitable number, three being shown, of tubular tie rods 241, 242, 243, which are longitudinally disposed at 120 intervals around the exterior of the digesting chamber, and preferably in the path of an imaginary circle concentric with the axis thereof. The said tie rods are provided at their ends with flanges, welded or otherwise properly secured thereto, which flanges are bolted to mating flanges as indicated in part at 244, 245, 246, 247 and 248; which mating flanges are likewise secured to butts, some of which are shown and marked 249, 250, 251 and 252, that are welded or otherwise suitably fixed to pairs of anchor lugs, some of which appear and are marked 253, 254, 255, 256 and 257; the said anchor lugs being, in turn, fast, as by welding, to the rigid covers 66 and 165 that constitute parts of the inlet and discharge structures respectively. The butts on the anchor lugs are spaced equal radial distances from the longitudinal axis of the digesting chamber, so that they may be said to be, as a group, ccncentric with the chamber. It will be clear that the tie rods will tensionally resist thrust stresses occasioned by operational pressures within the digesting chamber and thereby maintain the end structures of the apparatus in operating position.

As the tie rods 241, 242, 243, are of considerable length, intermediate portions thereof find support in two triangular trusses, which are denoted generally in Figs. 25 and 25a by 258 and 259, and are based on solid foundations, e.g., concrete, 260 and 261. Fig. 27 shows the detail of one truss and, as they are alike, it is deemed sulficient to describe that disclosure in which the truss comprises three members united at their ends in triangular form by webs. Each of the said members consists of a pair of angle iron or steel elements denoted by 262262, 263-263, 264-264, and they are riveted or otherwise properly fastened to the webs 265, 266, 267, that are interposed between the pairs of elements, which latter are also secured to each other by rivets, or the like, and washers, some of which are indicated by 268. The webs are formed with openings that snugly receive en ages the tie rods, as clearly shown in Fig. 27; and it will be seen that these trusses which surround the digesting chamber of the apparatus and are mounted on their own foundations constitute means for rigidly supporting the tie rods intermediate the ends of the latter.

It should be noted that, while this tie rod construction has been described in connection with the unjacketed form of the apparatus, it is equally applicable to the jacketed form.

Figs. 28 and 29 illustrate a second kind of means for connecting or tying together the inlet and discharge ends of the apparatus which means is particularly adapted to the form of the invention in which the digesting chamber is not jacketed and is provided with an internal helix,.worm or screw as is also represented in Fig. 24. The portions of the inlet structure of the apparatus shown in Figs. 28 and 29 are the same as those shown in Fig. 4 and previously described, so they will not be redescribed or numbered; but it may be desirable to note that the digesting chamber partially appearing in Fig. 28 is marked 88, and a part of its inlet neck 45, as in. Fig. 4, while the helix, worm or screw, which difiers somewhat from that shown in Fig. 24, is marked 269, and its hollow core or axis 27 0.

The tying means in this modified form of the invention comprises a single tubular tie rod 271 that lies within and passes entirely through the core 270, from which the ends of the tie rod protrude and are made fast to the inlet and discharge structures of the apparatus, as depicted in Figs. 28 and 29, which are directed to the inlet end. The means for making the tie rod fast at the discharge end is the same, and so calls for neither addi tional illustration nor description.

The said means for making the tie rod fast consists of a very strong spider having three radial arms 272, 273, 274, and a hub 275 that is traversed by the end of the tie rod. The hub is welded, or otherwise properly fastened, to the arms, and the latter are likewise firmly afiixed to the inner wall of the inlet neck part 45 previously described in connection with Figs. 1 and 4. A large nut 276 is threaded on the end of the tie rod and, when screwed tight, bears firmly against the hub 275. A conical tip 277 is amxed, as by welding, to the extremity of the tie rod in order to close the rod to the ingress of the material under treatment and also to facilitate the passage of the material thereby.

This form of end structure tying or connecting means requires no supports for the tie rod 271 intermediate its ends because the rod lies within the hollow core 270 of the helix, worm or screw 269 and the said'core is well supported by the flights or spirals of the latter. It should also be observed that the tying means, though positioned within the digesting chamber, does not at all impede the movement of the material being treated because the tie rod is within the core of the helix, worm or screw; while the ends of the rod are so attached to the inlet and discharge structures, and are so formed, as not materially or noticeably to hamper material flow. Finally, the resistance of the tie rod to longitudinal stresses generated by pressure within the digesting chamber is very efieetive due to its axial positioning; and the tying structure is simple and inexpensive.

In the foregoing description occasional mention has been made of the presence of gaskets or the like; and it should be noted that, whether mentioned or not, such are employed in connection with all joints or connections where leakage is to be avoided and their use is practical. Similarly, flexible piping may be adopted when called for.

While we have described this apparatus as being used singly, it should be emphasized that it is extremely well suited to tandem arrangement with a second similar apparatus, appropriate connecting structure being interposed, as set forth, for instance, in U.-S. Patent to De la Roza, Sr., No. 2,542,801, dated February 20, 1951, whereby the treatment may be continued in two stages,

e.g., aqueous treatment, with or without added acid, followed by alkaline treatment. Indeed, if contemplated procedure should so dictate, more than two of the apparatus may be hooked up to accomplish treatment consisting of more than two stages, e.g., neutral, acid and alkali.

As the functioning of the several parts, and subassemblies of parts, has been set forth in connection with their mechanical description, and as the invention is directed to apparatus rather than process, and as it is adapted to use in various forms of digesting procedures, there is thought to be no call for a general summary of the operation of the apparatus. However, it may be of some importance to observe that this invention is especially well fitted for digestion treatments which minimize the degradation of the cellulose, particularly at elevated temperature, while preserving the purity, strength and other desired characteristics of the final product, and maintaining a high yield.

We desire it to be understood that various changes may be resorted to in the form, construction, arrangement and material of the parts of the apparatus without departing from the spirit orscope of the invention; and hence, we do not intend to be limited to details herein shown or described except as they may be included in the claims or be required by disclosures of the prior art.

What we claim is:

l. Apparatus designed and adapted for continuous procedure in the digesting treatment of cellulose bearing material for the separation from the cellulose of foreign substances associated therewith comprising, a digesting chamber, a spaced jacket surrounding at least part of the chamber, means for supplying a heating medium to material for the separation from the cellulose of foreign substances associated therewith comprising, a digesting chamber, a spaced jacket surrounding at least part of the sides of the chamber, means for supplying a heating medium to space between the chamber and the jacket, means rotatably supporting the jacket, and means for rotating both'the chamber and the jacket around their longitudinal axes, said means for supplying a heating medium'to space between the chamber and the jacket including pipes axially and radially disposed with respect to the digesting chamber.

4. Apparatus as defined in' claim 3, which also includes means for removing condensate of the heating medium'from space between the chamber and the jacket embodying pipes axially and radially disposed with respect to the digesting chamber, the axial pipe of the condensate removing means surroundingthe axial pipe of the means for supplying heating" medium.

5. Apparatus as defined in claim 4, in which the means for removing condensatealsoembodies pipes carried by the jacket exteriorly thereof and connecting spacebetween the chamber and the jacket with the radially disposed pipes of-the means for removing condensate.

16. Apparatus as defined in claim 5, which also includes normally closedvalves positioned in the said pipes carried by the jacket exteriorly thereof. '7. Apparatus as defined in claim 6, which also includes fixed means in the path of rotation of said valves for temporarily pening them seriatin'i. a

8. Apparatus as defined in claim 7, which also includes 1 1b means for varying the duration-of theopen valve periods.

9. In apparatus designed and adapted for continuous procedure in the digesting treatment of cellulose bearing material for the separation from the cellulose of foreign substances associated therewith and having a rotary digesting chamber, fixed means for the passage of the material into the chamber and fixed means for receiving treated material from the chamber, means connecting at least one of said fixed means with the chamber to permit relative rotary motion thereof and circular wobbling of the chamber while maintaining a seal against leakage therebetween, said connecting means including the combination of a complementary pair of sealing elements, one being fixed and the other rotatable, and a device subject to pressure within the digesting chamber forpressing said sealing elements together.

l6. Apparatus designed and adapted for continuous procedure in the digesting treatment of cellulose bearing material for the separation from the cellulose of foreign substances associated therewith comprising, an elongated rotary digesting chamber, a hollow core located centrally therewithin and extending lengthwise of the chamber, and spiral means secured to the outer wall of said core and the inner wall of said chamber. adapted to compel material being treated to travel an elongated spiral course through the chamber between the core and the inner wall of the chamber, the said spiral means being provided with openings at its outer circumference to form spaces which permit the passage of gas but not solids in a direction toward either end of the chamber.

11. Apparatus designed and adapted for continuous procedure in the digesting treatment of cellulose bearing material for the separation from the cellulose of foreign substances associated therewith comprising, a digesting chamber, a spaced jacket surrounding at least part of the chamber, means for supplying a heating medium to space between the chamber and the jacket, means rotatably sup porting the jacket, means for simultaneously rotating both the chamber and the jacket, means interconnecting the chamber and jacket which fixes them against relative rotary movement while providing for limited relative axial movement, and automatic means for removing from space between the chamber and jacket condensate of the heating medium collected therein, said last named means comprising a fixed contactor having an elongated contact surface and a spring biased valve carried by the jacket and constructed for coaction with the said contactor to open the valve and briefly hold it'open;

12. In apparaus designed and adapted for continuous procedure in the digesting treatment of cellulose bearing material for the separation from the cellulose of foreign substances associated therewith and having a rotary digesting chamber, fixed means for the passage of the material into the chamber andfixed means for receiving treated material from the chamber, means connecting at least one of said fixed means with the chamber to permit relative rotary motion thereof and circular wobbling of the chamber while maintaining a seal against leakage therebetween,

, said connecting means including the combination of a complementary pair of sealingelements, one being fixed and the other rotatable, and a device subject to pressure within the digesting chamber for pressing said sealing elements together, the said means for the passage of the material into the chamber comprising, an inlet leading toward the chamber and provided with an opening for the ingress of the material and a heroin its wall, and a piston mounted to reciprocate within the bore for urging the incoming material through the inlet, the bore being slightly larger in circumference than the circumference of the piston to permit the pass-age through .therebetween of liquid squeezed from the material by the piston while preventing the passage through of solids therebetween;

13. Apparatus as defined in claim 12, in which the cross sectional area of the said material inlet increases in size between the said ingress opening and the chamber.

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