US2103896A - Machine for disintegrating, screening, and pumping fibrous or paper making stocks - Google Patents

Description

1 w. T. DOYLE ETAL MACHINE R DISIN ATING, SCREENING, AND

PAPER MAKING STOCKS 12,1935

PUMPING FIBROUS 2 Sheets-Sheet 1 Fil ed Dec Dec. 28, 1937. w. T. DOYLE ET AL MACHINE FOR DISINTEGRATING, SCREENING, AND

PUMPING FIBROUS OR P MAKING STOCKS 1935 2 Sheets-Sheet 2 APER Filed Dec.

. Patented Dec. 28, 1937 v UNITED STATES PATENT OFFICE MACHINE FOR DISINTEGRATING, SCREEN- ING, AND PUMPING FIBROUS OR PAPER MAKING STOCKS tion of Massachusetts Application December 12,1935, Serial No. 54,054

9 Claims.

This invention relates to a machine for effecting a combined disintegrating, screening, and pumping action on fibrous stocks such as are to be usedfor papermaking and allied purposes.

The machine of the present invention fits nicely into one or more stages of stock preparation, being a pted, for example, for installation in the took-preparing system immediately before the stock is delivered to a beater or Jordan engine or in combination with a beater or Jordan engine. There are various kinds of raw fibrous stocks lending themselves readily to at least partial defiberization or fiber-individualization without the expenditure of. the comparatively large amount of energy that must be put into the operation of such stock-preparing machines as beaters, Jordans, and kollergangs. Thus, it is well known that chemically pulped straw and various kinds of wood pulp in bulk, lap, or sheet form may be 20 largely deflberized without intensive manipulation, but the practice has been to put such stock through such comparatively large, expensive, and power-consuming machines as have been mentioned for the purpose of transforming the stock as a whole to the desired papermaking condition. In accordance with the present invention, we provide a small and relatively inexpensive machine which is operable with low power consumption and which, although partaking of the character of a centrifugal pump, is equipped with stockprop elling blades designed to disintegrate or deflberize the stock as it is being progressively fed into and discharged fromthe machine and also with an impedance at its discharge sector in 35 the form of a slotted or perforated plate designed to permit only a properly disintegrated or deflberized portion of the stock to be discharged,

the discharge being had under suillcient residual pressure to permit transfer of the disintegrated 40 stock to an overhead beater or to any other destination so located relative to the machine as to requirepositive or pumping pressure. Whereas the ordinary beater is of low emciency even insofar as concerns disintegrating easily disintegrable 45 stock y virtue of the fact that much of the power nsumedthereby is dissipated in repeated recirculation of water containing a progressively increasing traction of properly disintegrated stock, the machine of the present invention is of 50 high efllciency in that such portion-oi the stock as has undergone proper disintegration therein need make-only one pass therethrough excepting in those instances when it is desired that such machine operate conjunctively with a beater to 5 eifectcomplete conditioning of the stock for papermaking. It might be remarked that besides serving to disintegrate the stock, the machine ot the present invention tends to develop or hydrate the stock to some degree, the particular degree of stock development produced depending, for instance, on whether stock has passed once or repeatedly throughthe machine and on the particular conditions under which the machine is operated.

With the foregoing and other features and obl0 jects in view, the present invention will now be described in greater detail with reference to the accompanying drawings wherein,-

Figure 1 is a vertical transverse section through a machine embodying the present invention on '15 the line |l of Figure 2. v (I Figure 2 is a vertical longitudinal section on the line 2-2 of Figure-l. 1

Figure 3 represents a front face of the bladecarrying rotor' of the machine- Figure 4 is a section on the line 4-4 of Figure 3.

Figure-5 shows the front face of a modifl form of rotor.

Figure 6 is a section on the line 6- of Figure 5;

Figure 7 is a. vertical longitudinal section through a modified form of machine equipped with two sectors or zones of stock discharge.

Figure 8 illustrates the machine of Figures'l and 2 installed as part of a system for handling raw stock.

. As best seen in Figure 1, the machine illustrated includes a front casing plate ll having a large central inlet opening ll defined by an outwardly projecting flanged duct l2 forming part of such plate and serving to feed the stock axially into the centrifugal chamber of the machine as the disintegrated stock is being discharged radially under pressure from such chamber, as will hereinafter appear. The back casing plate I3 also has a central opening through which the shaft ll 40 for the rotor the shaftterminating short of the plate II. The casing portion I! sur-.' rounding the shaft is provided with an annular recess, at the innermost region of which recess is shown a grooved lubricating ring I. to which suitable lubricant, such as oil or grease. may be supplied by way of a channel I I normally'cloled,

as by a headed oil or grease'nipple II. The channel I I may extend upwardly and angularly outwardly from an upper portion of the ring II to so the exterior of the plate I! so that lubricant putinto the channel can to the external groove of the ring and thence work through tiny openings ll in the ring to the shaft. Adjacent to the outer'edge of the ring about the shaft ll be described, and has at an upper end portion is suitable packing material forming part of a stufiing box completed by the usual outer compression element 2|. The shaft portion extending beyond the stuffing box may-be iournaled in a suitable bearing (not shown) and be driven at the desired speed by an electric motor or other suitable prime mover.

The machine includes between its front and back plates l0 and I3 a casting 22 which serves to retain in place lining and discharge sectors of cylindrical curvature for defining the disintegrating and pumping chamber, as will presently thereof adjacent to the discharge sector a discharge opening 23 formed as a continuation of a compartment 24 arranged on one side of the lining and discharge sectors, such compartment being defined at its lower end portion by a flanged duct 25 normally closed by a cover 28 which may be readily removed when it is desired to clean or flush out 'the contents of the machine. The end plates l0 and I3 are secured as by bolts 21 to the casting 22, which is lined on one side with cylindrically-shaped imperforate sectors 23 and partioned oil! on the other side to define the compartment 24 by an imperforate sector 28- and by a discharge sector 23, which latter sectors abut at their side edge portions against the inner edges ill of that portion of the casting 22 bounding the compartment 24. The discharge sector 23 is shown provided with a plurality of discharge openings in the form of transverse slots 30, but the discharge openings may take the form of round or otherwise shaped holes. The discharge sector 23 illustrated occupies approximately 90". It is obvious, however, that such sector may be of greater or smaller compass, as desired. Indeed, the compartment 24 is shown as occupying substantially 180 for the very purpose of permitting a comparably large sector of discharge to be installed. In order to retain the various sectors in place to afford a substantially cylindrical internal wall for the distintegrating and pumping chamber, a wedge-shaped bar 3| may be disposed in between cooperating bars 32, one of which bars is located adjacent to the upper edgeof the discharge sector 23 and the other of which bars is located adjacent to the upper edge of the upper imperforate section 23. The wedge surfaces of the bar 3| are designed to clamp the various cylindrical sections into tight cylindrical form upon being drawn upwardly, to which latter and a pair of bolts 33 may be in threaded engagevantageous in that it enables ready removal and replacement of the various sectors, including the discharge sector, as operation may require or as may be desirable.

The rotor of the machine, as depicted in Figure 3, comprises a disk-shaped portion 34 beyond whose front face is a hub 35 from which project radially a plurality of, say, three, propelling and disintegrating blades 36. Beyond the back face the'internal surfaces of the sectors 28 and 29. are preferably notched peripherally at lateral intervals, as best shown in Figure 1, to afford a plurality of tooth-like elements 38 which move through the ring of stock constantly maintained in the machine during its operation and exercise the desired disrupting or disintegrating action on the stock. At this stage, it might be noted that the imperforate sectors 28, rather than being smooth faced on their internal surfaces as shown, might present transverse ribs and pockets therebetween in which the stock can lodge and thus set up a distintegrating resistance against the peripheral propulsion of the stock by the toothed blades. While the blades 36 might assume any suitable configuration and be toothless at their outer extremities, yet there are advantages in' toothed blades of the particular configuration shown, according to which configuration, the front faces J of the blades (considered from the aspect of their direction of rotation) are slightly concave so as to entrain and propel the stock more positively than would be the case with fiatties of the blades are toothless, it may be desirable to provide one or more openings through the peripheral width or thickness of each blade for the purpose of reducing the frictional resistance encountered by the blades. The rotor may be keyed to the shaft l4; and in order to ensure axial fixation of the rotor to the shaft, the end portion of the shaft may be tapered to fit into the hub 35 and be fastened against backward axial movement to the hub by a bolt 39 headed tightly over and outwardly cupped washer 40 engaging the front face of the hub, as appears in Figure 1.

The modified form of rotor shown in Figure 5 comprises a disk-shaped portion 4| beyond whose front face are a plurality of radially extending blade elements 42 whose-chief function, besides that of disintegrating the stock, is to direct the stock entering into the machine radially through the discharge openings. Such a rotor includes a large axial opening 43 communicating with a radial discharge opening 44 of progressively diminishing width outwardly in each of the blades 4!, wherefore, stock entering the machine axially of the rotor is directed outwardly or-radially of the rotor through its blade elements 42 tothe interior wall of the machine with minimum loss of centrifugal force at the discharge zone while the ring of stock maintained next to the interior wall of the machine is undergoing the desired disintegrating action. Such form of rotor is of value when the stock. is to be discharged with considerable residual or pumping pressure, although it does not conduce to the best screening or selecting action on the stock. As appears in Figure 6, such form of rotor may also be equipped with a hub 46 projecting part way into the opening 43 and to which the driving shaft may be keyed and, if desired, additionally secured against axial movement.

Another form of machine illustrated in Figure 7 is distinguished from that of Figures 1 and 2 essentially in that it is provided with discharge sectors 41 and 48 on opposite sides of the machine, each of which sectors leads to an independent discharge opening 49 and a related discharge compartment 50 having a lower endportion defined by a normally closed clean-out duct The discharge sector" preferably contains discharge slots of a size permitting only properly disintegrated stock to escape therethrough, whereas the discharge sector 48 preferably contains discharge slots large enough to permit remaining coarse stock to be emitted freely therethrough, thereby enabling substantially all of the stock fed into the machine at.predetermined rate to be discharged therefrom at a corresponding rate and. accordingly, a large amount of stock to be handled 4 by the machine. The incompletely disintegrated stock portion emitted through the discharge sector l5 and thence. through the correspondingadditionally a screw conveyor, or feeder 52 operating within a cylindrical chamber 58 into which thick raw stock of appropriate character may be fed as by a hopper 54, the screw feeder being driven by suitable means (not shown) to effect the appropriate rate of feed of stock into the particular form of the machine of I lgures 1 and 2 designated. in the system generally by the numeral 55. In order to enable the diiution of the stock being fed into the machine 55 and its recirculation through the, machine, if desired,

there is shown between the exit of the feeder 52 and the machine intake opening H a duct section 56, into which section water in desired volume may be delivered as from a valved water pipe 51 and into which section stock already passed through the machine and accumulated in a storage tank or accumulator 58 may be delivered for reworking. In operating the system, the disintegrated stock discharged from the machine 55 through the discharge pipe 59 may be passed through a valved pipe 50 to a heater, Jordan or other desired destination; or it may be passed through a valved p113 6i to the tank 50 wherein it may be kept until its reworking is to be effected.

The tank 58 has at its bottom a sliding gate valve 52 which, when reworking of the stock is to be effected, is opened so as to permit the stock to re enter the machine 55; and the stock may be recirculated a. number of times through the tank 58 and the machine 55 until it has been reduced and/or developed to the desired degree, whereupon the valve 6] may be closed and the valved pipe 60 opened to permit the stock to be pumped to the desired destination. While recirculation of stock through the tank 58 and the machine 55- "is taking place, the feeder 52, which serves merely as'a pressure-feed for fresh or other stock which cannot otherwise be conveniently introduced into the system, does not run; and its dis-'- charge end is kept closed at such time from the rest of the system as by a sliding gate valve BI.

Should there be available in'a mill fresh stock of such consistency as to require no pressure-feeding,

such stock may be fed into the tank" by a pipe 55 and be delivered directly through the valve 52 and the section 55 into the machine 55. It might be noted that the system might be one inclusive of-a heater in lieu of the tank 58, in which case the machine 55 can be made to work conjunctively with the heater in disintegrating anddeveloping the stock. The machine 55 serves in such case chine 55 located therebelow and the machine in tum return the stock to the beater immediately in front of the beater roll.

In operating the machine 55, it has been obtherein, which action evidently prevents the discharge sector or screen from clogging. It has been further observed that with high tip speed at the blade tips, say, a speed of 2000 to 4000 feet per minute, it is possible to realize excellent selective or screening action on the stock at the discharge openings even when such openings are served that a strong pulsating-action is caused slots or round openings of as great as 0.125" in .width or dia'meten- While we are unable to account precisely for this selective or screening action on the stock, it is apparently the case. that asthe stock is fed into the machine, it is given a strong whirling centrifugal motion and thus transformed into a whirling ring of stock moving at such highspeed tangentially to the dissmall particle size tends to change its course or direction and be carried out by the water through the discharge openings, the coarse stock being under sufllcient tangential momentum to sweep past the discharge openings. Irrespective of whether our analysis of the action taking place on the stock is accurate,'it is a fact that the higher the speed of whirl imparted to the stock, that is. the higher the blade tip speed, the more' selective or finer is the stock discharged through a given size of discharge opening. The pulsating action, which evidently obviates clogging of the discharge or screening zone, may arise from a condition of higher pressure in the stock immediately adjacent to the front or leading edge of a blade than the sudden release and dissipation of this pressure differential accompanied by vibration or .surge at a zone of stock discharge, but it is possithat at the back or weight edge of the blade and charge zone and in clearing such zone sufliciently to permit substantially unimpaired discharge of properly disintegrated stock. In any event, the

' discharge zone is maintained in unclogged condition despite the fact that a large fraction of the stock present in the machine at any time is too coarse for discharge and might beexpected to clog the discharge openings. When the machine is operated with extremely rapid blade tip speed, for instance, a speed in the order of magnitude of 7500 to 10,000 feet perminute, not only is excellent selectivity of discharge or screening action on the stock realized, but the stock is developed or hydrated to a noteworthy degree, thereby re-" ducing the energy expenditure necessary in the further development of the stock for papermak ing. The machine of the present invention ac; com'plishes its various actionsonthe stock while vidualized fibers are discharged from the machine,

under which conditions such stock portion as is improperly disintegrated at any time and moves l past the discharge openings remains in the machine and undergoes recirculation therein until it attains such reduced state that it, too, is discharged. With blade tip speeds such as we have investigated, namely, tip speeds ranging from, say, about 2000 to 10,000 feet per minute, and afiording practical conditions of operation, we

' have found that slots or round openings varying from 0.02 to 0.125 in width or diameter conducenot only to the desired selectivity of stock discharge but also to the desired residual pumping pressure in the discharged stock, for instance, a pressure of about ten pounds or even greater, the particular residual pressure depending upon various factors, one of which is the consistency of the stock fed into the machine. While the machine of the present invention is capable of working upon stock of any pumpable consistency, for instance, stock of a consistency as high as about 5 to 6%, yet, from the standpoint of realiz ing maximum capacity in a machine of given size, it is preferable to work with stock at as low a consistency as comports with the particular system in which the machine is being used. Thus, when the stock passed through the machine of the present invention is to undergo an afterbeating or jordaning treatment, consistencies of about zfi, to 5% are considered preferable, since it is desirable to operate heaters and Jordans at as high a stock consistency as possible. Theoretically, however, the machine of the present invention may operate to advantage at lower consistencies, since the presence of more water in the stock means that there is a greater volume of liquid carrier tending to promote the discharge or removal of perfect stock fromthe sphere of action of the machine. The particu- .must under practical conditions of operation handle a 3% to 5% stock, as when the machine is to be combined with a beater, it may be preferred with a gi'ven'blade tip speed to usedischarge openings of a size approaching the upper end of the range hereinbefore given, whereas, on the present invention is to beioperated ahead of a Jordan or other machine through which stock of a more dilute consistency, say, 2% to 3%, can be advantageously passed, discharge openings of a .size approaching the lower end of therange tiallymylindrical internal wall defining a disintegrating and pumping chamber and comprising a substantially imperforate sector and at least two "peripherally successive but separate discharge sectors each containing discharge openings and each leading into an independent discharge compartment, the openings in one sector being larger than those in the other, a bladecarrying rotor within said chamber capable of developing under rotation pumping pressure on stock fed into said chamber and of causing an emission of a relatively fine stock fraction radially through said discharge sector containing the smaller openings and a relatively coarse stock fraction radially through said discharge sector containing the larger openings, said discharge sectors constituting only a portion of said cylindrical internal wall and the remainder of said wall being substantially imperforate and occupying at least about 120, and means for feeding said stock; into said chamber substantially axially thereof.

2. In a machine for disintegrating, screening, and pumping aqueous fibrous stock, a substantially cylindrical'internal wall defining a disintegrating and pumping chamber and comprising a substantially imperforate sector and at least two peripherally successive but separate discharge sectors each containing discharge openings, the openings in one sector being larger than those in the other and the openings in each of said sectors leading to a discharge compart- -ment immediately outside of each sector, each discharge compartment being bounded by the corresponding discharge sector, by an exterior. wall spaced therefrom, and by a member extending outwardly from said cylindrical internal wall to said exterior walLend closures for said cylindrical wall, a rotor within said chamber, and a shaft for said rotor passing through one of said end closures, the other of said end closures containing a stock-inlet opening leading to said chamber, said rotor including a plurality of radially extending blades capable upon rotation of acting upon stock to disintegrate it and to emit a relatively fine stock fraction through said discharge sector containing the smaller openings and a relatively coarse stock fraction through said discharge sector containing the larger openings and said discharge sectors constituting only a portion of said cylindrical internal wall and the remainder of said wall being substantially imperforate and occupying at least about 120.

3. A centrifugal pump for effecting disintegrating and screening action on aqueous fibrous stock fed thereinto, comprising a substantially cylindrical internal wall which defines a disintegrating and pumping chamber, a cylindrical sector of said wall containing discharge openings and a substantial sector of said wail corresponding to at least about 120 being substantially lmperforate, closures at the ends of said wall, a blade-carrying rotor within said chamber. capable of developing substantial pumpother hand, assuming thatthe machine of the ing pressure on stock fed into said chamber and of causing an emission of disintegrated stock under residual pressure radially of said chamber through said openings upon being rotated at such speed as to promote the formation of a peripherally movingringof stock next to said internal wall, and a shaft for said rotor passing through one of said closures but terminating short of said other closure, said other closure having a stock-inlet opening leading into said chamber in an axial direction.

4. A centrifugal pump for effecting disintegrating and screening action on aqueous fibrous stock fedtherelnto, comprising a substantially cylindricai'iinternal wall which defines a disintegrating and pumping chamber, a cylindrical sector of 'gjsaid wall containing discharge openings and a substantial sector of said wall corresponding to at least about 120] being substantially imperforate, closures at the ends of said wall, a rotor carrying a plurality of blades arranged within said chamber and capable of developing substantial pumping pressure on stock fed into said chamber and of causing an emission of disintegrated stock under residual pressure radially of said chamber through said 1o openings upon being rotated'at such speed as to promote the formation of a peripherally moving ring of stock next to said internal wall, and a shaft for said rotor passing through one of said closures but terminating short of said other closure, said other closure having a stock-inlet opening leading into said chamber in an axial direction and said blades projecting radially from said rotor and having tooth-like elements at their outer extremities. only slightly clearing said internal wall.

5. A centrifugal pump for effecting disintegrating and screening action on aqueous flbrous stock fed thereinto, comprising a substantially cylindrical internal wall which defines a disintegrating and pumping chamber, a cylindrical sector of said wall containing discharge openings and a substantial sector of said wall corresponding to at least about 120 being substantially imperforate,. closures at the ends of aid wall, a rotor carrying a plurality of blades arranged within said chamber and capable of developing substantial pumping pressure on stock fed into said chamber and of causing an emission of disintegrated stock under residual pressure radially of said chamber through said openings upon being rotated at such speed as to promote the formation of a peripherally moving ring of stock next to said internal wall, and a shaft for said rotor passing through one of said clo- 40 sures but terminating short of said other closure,

said other closure having a stock-inlet opening leading into said chamber in an axial direction and said blades projecting radially from said rotor and having=concave faces leading in the direction of rotation.

0 disintegrating and pumping chamber, a cylindrical sector of said wall containing discharge openings and a substantial sector of said wall corresponding to at least about 120 being substantially imperforate, closures at the ends of said wall, a rotor carrying a plurality of blades arranged within said chamber and capable of developing substantial pumping pressure on stock fed into said chamber and of causing an emission of disintegrated stock under residual pressure radially .01 said chamber through saidopenings upon being rotated at such speed as to promote the ,formation of a peripherally moving ring of stock next to said internal wall,- and a shaft for said rotor passing through one of said closures but terminating short of said other closure, said other closure having a stock-inlet opening leading into said chamber in an axial direction and said bladesprolecting radially from said rotor and having concave faces leading in the direction of rotation and tooth-like elements at their outer extremities slightly clearing said internal wall.

7, In a machine for disintegrating, screening and pumping aqueous fibrous stock, a substantially cylindrical internal wall which defines a disintegrating and pumping chamber, a sector of said wall containing discharge openings and a substantial sector of said wall corresponding to at least 120 being substantially imperforate, end closures for said wall, a rotor within said chamber, a shaft for said rotor passing through one of said end closures but terminating short of said other closure, said end closure through which said shaft passes containing a stuffing box about said shaft and said other end closure containing a' stock-inlet opening leading to said chamber in an axial direction,-said rotor including a plurality of rigid radially extending blades slightly clearing said internal wall and capable of acting upon stock to disintegrate it and to force disintegrated stock under substantial pressure radially of said chamber through said discharge openings upon being rotated at a rate such that stock is caused to form a peripherally moving ring next to said internal wall.

8. In a machine for-disintegrating, screening, and pumping aqueous fibrous stock, a substantially cylindrical internal wall. which defines a disintegrating and pumping chamber, a sector of said wall containing discharge openings leading to a discharge compartment immediatelyoutside of said sector and a substantial sector of said wall corresponding to at least 120 being substantially imperforate, said discharge compartment being bounded at least in part by said discharge sector and by a wall spaced therefrom, 7

end closures for said cylindrical wall, a rotor Within said chamber, and a shaft for said rotor passing through one of said end closures but terminating short of said other closure, the other of said end closures containing a stock-in1et opening leading to said chamber in an axial distock fed thereinto, comprising a substantially cylindrical irfternal wall which defines a disintegrating and pumping chamber, a cylindrical sector of said wall containing discharge openings and a substantial sector of said wall corresponding to at least about 120 being substantially imperforate, closures at the ends of said wall, a blade-carrying rotor within said chamber capable of developing substantial pumping pressure on stock fed into said chamber and of causing an emission of distintegrated stock under residual pressure radially of said. chamber through said openings upon being rotated at such speed as to promote the formation of a peripherally moving ring of stock next to said internal wall, means for feeding stock at least through one of said closures in an axial direction'into said chamber,

and a shaft for said rotor passing through at N least one of said closures.

THOMAS J. STUR'I'EVANT.

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