US2911334A - Apparatus and method for disintegrating fibrous material - Google Patents

Description

H. D. STUCK Nov. '3, 1959 A APPARATUS AND METHOD FOR DISINTEGRATING FIBROUS MATERIAL Filed Nov. 18, 1955 3 Sheets-Sheet 1 nnnnnnunnnnnnnnpnunnn INVENTOR HAROLD D. srucK.

ATTORNEYS.

H. D. STUCK Nov. 3, 1959 APPARATUS AND METHOD FOR DISINTEGRATING FIBROUS MATERIAL Filed Nov. 18, 1955 3 Sheets-Sheet 2 INVENTOR. IVA/FOLD fl. STUCK.

PQM

ATTORNEYS.

Nov. 3, 1959 H. D. STUCK 2,911,334

APPARATUS AND METHOD FOR DISINTEGRATING FIBROUS MATERIAL Filed Nov. 18, 1955 3 Sheets-Sheet- 3 HVVEN TOR,

HAROLD ,0. 6706K.

Pia/1AM EM ATTORNEYS.

United States Patent APPARATUS AND METHOD FOR DISINTEGRAT- IN G FIBROUS MATERIAL Harold D. Stuck, Andover, Mass., assiguor to John W. Bolton & Sons, Inc., Lawrence, Mass., a corporation of Massachusetts Application November 18, 1955, Serial No. 547,670 14 Claims. (Cl. 162-17) This invention relates to a machine and method for disintegrating fibrous material for use in the manufacture of paper.

The invention relates particularly to the disintegration and separation of fibers by agitation by churning in a tank rather than to disintegration and separation of fibres between the rotors and stators of such machines as beaters, Jordans and similar refiners.

It has heretofore been proposed to provide a single nonpressurized tank with a rotating impellor blade therein for agitating fibrous material fed thereinto. Usually the tank is charged, the charge agitated in the tank for a predetermined time and the charge is then entirely drawn ofi, with the vat remaining empty until the next charge is supplied thereto. In some such devices, instead of a batch operation, a small portion of the charge is continuously extracted through a screen below liquid level and additional charge is continuously fed to the vat to produce a continuous process.

The principal object of this invention is to provide a machine and method which treats continuously supplied fibrous material, successively and continuously in batches with the successive batches being discharged at a regular rate, fully and uniformly treated.

An important object of the invention is to provide a device for loosening the pith portion of the stalk, as well as scrubbing off the wax on the rind surface, of vegetable fibrous material as bagasse, bamboo, ramie, jute and kenaf or straw to separate out long fibres, and bundles of such fibres of uniform cross section, free from damage. A major portion of this objective is accomplished bythe pieces hitting against each other while thoroughly wet and at high temperature.

Another object of the invention is to provide a machine and method for disintegrating fibrous material in which all of the material receives a preliminary disintegration 2,911,334 Patented Nov. 3, 1959 ice the next succeeding tank until finally passing through all the tanks in the series.

A continuous flow of softened fibrous material introduced into the apparatus is thus converted into a uniform intermittent discharge from the exit end whereby the apparatus operates continuously at a regulated flow.

It should be noted that movement of the fibrous mixture through the mixing tanks of this invention is not the result of a siphon action, nor is there any rotary device such as a roll, brush or the like tending to direct the mixture from one tank into the next. In this invention the impellers create a churning action in each tank causing periodic upward surges and the mixture moves from one tank to the next only when its level is raised by surging sufiiciently to be ejected or vomited into the next tank or compartment of a tank.

In the drawings:

I Fig. l is a side elevation in section on line 1-1 of Fig. 2 of apparatus according to this invention. I Fig. 2 is a plan view, in section on line 22 of Fig. 1.

Fig. 3 is an end View in section on line 33 of Fig. 1 with the bafile plate broken away.

Fig. 4 is an end view in section on line 4-4 of Fig. l. Fig. 5 is an enlarged plan view of a vaned impeller.

Fig. 6 is an enlarged side elevation of the impeller shown in Fig. 5.

Fig. 7 is a diagrammatic illustration of typical fibrous pieces, such as bagasse, as fed to the apparatus of this invention, and a Fig. 8 is a diagrammatic illustration of the long fibres, or fibre bundles, screened out at the exit end of the apparatus.

and only material already-preliminarily treated is passed is to provide outlet In the embodiment selected for illustration of the apparatus: and method of this invention, a hollow casing 20 is provided which preferably is formed by two substantially identical shells 21 and 22. Each shell 21 or 22 includes an outturned conduit 23 or 24 at one end and includes an opening 25 or 26 at the opposite end encircled by an outwardlyprojecting flange-27 or 28. The. shells 21 and 22 are elongated and'the longitudinally extending interior walls thereof,- are formed into at least two, and preferably three concave lobes such as at 30, 31 and 32 in shell 21 and 33, 34 and 35 in shell 22.

The shells 21 and 22 are joined, open end to open end, by suitable bolts 36 through the flanges 27 and 28, but shell 22 is upside down relative to shell 21. In addition, a laterally extending partition 37 is provided between the shells together with suitable gaskets such as 38. The casing 20 is supported generally horizontally whereby the outturned conduit 23 is upturned to serve as an inlet-to the casing and the outturned conduit 24 is downturned to serve as an outlet to the casing. A laterally extending ;Still another object of the invention is to provide .a

novel cooperation between .a rotary vaned-impeller and a lobular-side walled tank whereby a liquid fibrous mix ture therein is rotated by the impeller, caused to surge upwardly and downwardly and continually directed back inttithepath of the impeller, thereby loosening the fibres from thematerial in an unusually efficient manner. A'still further object of the invention to provide a series of tanks in which a fibrous mixtureis subjected to churning agitation and caused to surge and swirl with porend wall member 40' is provided just in advance of the downturned outlet conduit 24 and a series of two tanks 41 and 42 are thus formed within casing 20.

Because of the inversion of one shell relative to the other, the concave lobes 30 and 32 of shell'21 meet along the bottom centre thereof and the shell is wider at the bottom than at the top formed by lobe 31. On the other hand in shell 22 the concave lobes 33 and 34 meet along the top centre of the shell and the shell is wider at the top than at-the bottom formed bylobe 35. The intermediate side of thelongitudinal centre line of the casing as shown in Fig. 3. The top of the end wall member 40 is spaced.

' from'the top of shell 22 to form an exit tibns'ofth'e' mixture in each tank erupting or vomiting into passage or aperture 44 into the outlet conduit 24. a The first tank ill and its succeeding tank 42 are thus arranged to contain a liquid fibrous mixture up to a predetermined level, that level being determined by the height of the passages 43 and 44 above the bottom of the tanks;

The flanges 27 and'28 are not of uniform width throughout their circumference and when shell 22 is inverted relative to shell 21 it will be noted that the tank 42 is on a slightly lower level than tank 41. Tank 42 is thus deeper, narrower and of less length longitudinally than tank 41. Preferably the casing 20 is supported by an adjustable thrust screw 45 with its longitudinal axis on an inclined plane whereby the tank 42 may be raised with relation to tank 41. This causes the end wall member 4%) to present a higher barrier above the liquid level and below the passage 44 for increasing dwell of the liquid mixture in the second or last tank 42, as well as in the first tank 41.

In tank 41 an impeller 47 is provided, rotatable around the shaft 48 as an axis of rotation, the shaft 48 being driven by a motor 49 mounted on top of shell 21. A suitable bearing 59 for the lower end 46 of shaft 48 is provided in the bottom of shell 21. The impeller 47, as shown in Fig. and Fig. 6 consists of four vanes in the form of a cross, two opposite vanes 51 and 52 being right triangle shaped and flat while the other two opposite vanes 53 and 54 are upturned and downturned at 55 and 56 respectively. The impeller 47 rotates in a plane extending generally in the direction of the lobes of the tank rather than in a plane generally at right angles to the lobes as in certain pulping devices of the prior art. Similarly the axis of rotation of the impeller instead of running parallel to the lobes is more nearly at right angles thereto. It is preferred that the shaft 48 of the impeller 47 in the first tank 41 be inclined toward the outlet passage 43 in partition 37 to urge the mixture in the direction of the passa e while agitating, churning, surging and swirl ing the same. The edges of the vaned impeller 47 are beveled but blunt rather than sharp, in order to segregate the fibres without cutting, shearing, abrading or otherwise changing the nature of the fibres.

The upturned and downturned vane tips 55 and 56,

when revolved at high speed, tend to throw the lower central portion of the fibrous mixture in tank 41 outwardly to swirl peripherally in the tank and at the same time tend to surge the peripherally revolving portion of the mixture upwardly and downwardly in the tank. At the same time, the concave lobes 3t) and 32 tend to guide the peripherally moving mixture back into the centre of the tank into the path of the impeller 47, thereby giving the mixture a thorough, preliminary, segregation-treatrnent. At a predetermined time of dwell in tank 41, a portion of the upper outer peripherally moving fibrous mixture surges, erupts or vomits over intermediate partition 37 through the partition passage 43 and into tank 42. This continually occurring successive ejection of individual batches of the mixture is compensated by the continuous introduction of untreated fibrous material through the inlet conduit 23, or by some other desirable means, so that the predetermined liquid level in the tank remains substantially constant.

Preferably hot water, or other desirable liquid, is continuously introduced through inlet 23'from a'suitable sourceof supply such as pipe 58 along with-a continuous supply of softened fibrous material. The liquid is preferably at about 150 F. and since the tank is not pressurized, no appreciable digestion action occurs. The hot water acts as a vehicle or carrier in assisting in the segregation of the fibre from the fibrous material so that effective separation takes place and the hot water continuously drips out the outlet 24 in the same quantity as it is introduced into the inlet 23, except immediately. after an eruption. The fibrous material and liquid introduced together and uniformly into'inlet 23, is immediately caught.

up in the swirl created by impeller 47 and lobes 31 and and drawn inwardly and downwardly in the manner of a churn despite the surging of the mixture mentioned above.

In tank 42 an impeller 60 is provided, rotatable around the shaft 61 as an axis of rotation, the shaft 61 being power driven by a motor 62. A suitable bearing 63 is provided at the bottom of tank 42 for the lower tip of shaft 61. Impeller 6%) is identical with impeller 47 and rotates in a plane generally in the direction of the lobes 33, 34, of the tank, but the plane of rotation is angled away from outlet passage 44 and toward the passage 43 in partition 37. Thus the axes of rotation of impellers 47 and 60, formed by shafts 48 and 61 are in the central longitudinal vertical plane of casing 20, but are inclined toward each other in that plane with an imaginary meeting point above the casing. While impeller 47 urges mixture toward its outlet passage 43, impeller 60 is inclined to urge mixture away from its outlet passage 44 in order that the dwell in the second tank will be longer than the dwell in the first tank. The ejection operation is the same, however, in the second tank, even though consuming more time.

The portions of fibrous mixture ejected through passage 43 are received into the surging mixture created by im- ;peller 69 and lobes 33, 34 and 35 and are immediately submerged and further treated in the lower central portion of the mixture as well as in the lower outer portion thereof. After prolonged swirling and surging in tank 42, upper, outer portions of the mixture eventua ly surge to the point that they are ejected over the end wall member through passage 44 and out of outlet 24 in the form of successive individual batches of desegregated fibrous material.

Preferably a screen 64 is mounted below outlet 24 to pass the liquid in the mixture together with the soluble separated material such as pith, wax and the like. The segregated fibres are caught by the screen 64 and may be removed for further treatment in any convenient manner.

Preferably a laterally extending bafiie' plate 65 is pro vided just in advance of the outlet passage 43 in partition 37. The bafiie plate 65 is imperforate and extends from the top of tank 41 downwardly to a line below the level of the passage 43 and below the predetermined liquid level in the tank. Plate 65 functions to prevent back surge or back flow from the tank 42 through passage 43 and into tank 41 but does not adversely affect the ejection operation of the tank 4'1. In addition, the plate 65 not only assures that a new supply of fibrous material cannot pass immediately through passage 43, if by remote chance it escapes the churning action, but also tends to hold'back the mixture in tank 41 except for the portions thereof surging upwardly and outwardly in rear of the plate.

As shown in Fig. 1 and Fig. 2, the partition 37 is not merely a vertical wall but preferably is provided with a convexed forward and rear face 66 and 67 arcuately curved both in plan and in elevation to guide the mixture most efficiently and to prevent the creation of dead space or pockets. The end wall member 40 also includes a convexed rear face68 but the forward face 69 is concave, lobular and closely spaced to the path of the impeller 60 at its lateral centre point. This lobular forward face 69 increases the tendency of the mixture to be retained in the second or final tank 42 until it has been thoroughly and completely disintegrated.

In operation, the casing 20 is arranged horizontally at the desired angle of tilt, such as that shown of 57 in Fig. 1, to create a predetermined liquid level in the series 7 of tanks 41 and 42 therein'and to control the dwell in each tank. Hot water at about 150 F. is supplied from pipe 58 into inlet conduit 23 until the tanks 41 and 42 are up to the predetermined level and the water com mences to drip out the, outlet 24 in the same amount as is being supplied. The motors 49 and 62 are then started causing the blunt edged impellers 47 and 60 to swirl and surge the contents of their respective tanks. A continuous supply of the fibrous material, for example bagasse in mash form or the like, is introduced byhand or mechanically into the inlet conduit 23 whereupon it is pre tion of the impeller47 and the lobular interior walls of the tank; Portionsoi the mixture are periodically ejected through passage 43 into tank 42 and are again surged, swirled and agitated by the churning action created by impeller 60 and the'lobular walls of the tank. After a longer dwell. for treatment in tank 42, portions of the fibrous mixture are erupted, vomited or ejected out of passage 44 into outlet 24. The thoroughly desegregated mixture, ejected from, outlet 24 in successive batches, passes through the, screen 64 except the fibres therein which are caught by the screen and the fibres may be removed therefrom in any desirable manner. (See Fig.8.) I

In the case of,bagasse, the sections of stalk received from sugar canevfactories in-pieces about two inches long and one halfinch wide are first subjected to an enzyme solution for a period such as ten to seventeen minutes, to enable the enzymesto' consume the proteins, pentosans and sugars in' the ba gasse. The mash 75 of enzyme treated bagassestill includes both desirable fibre and undesirablepith (see Fig. 7) but when passed through the method and apparatus of this invention, the pith and fibre are separated and the fibre 76 may be screened out, as explained above, and the enzymes recovered.

, -It has been found that placing the impellers high in the tanks causes'the surging and churning action to be too pronounced and it is, therefore, preferred that the impellers be close to the tank bottom as shown, to secure a longer dwell. I do not. desireto be limited to the structure of the particular embodiment illustrated herein as it will be apparent that various changes may be made therein within thescope of the invention. For example, aseries of more than two tanks may be provided, each tank I having substantially "horizontally extending lobular side walls, a;vaned.impeller rotating in a substantially horizontal plane, and an outlet above the normal liquid level, and the tanks may be created in a one piece casing rather than by the use of a plurality of shells. Similarly the height of the lateral partitions and outlets may be adjustable to' further control dwell in the tanks and the height-of the impellers on their shafts may be adjustable for a similar purpose. I "f The soft'ened, enzyme treated, mash 75, which may be bag'asse,1is diagrammatically illustrated in Fig. 7. The product; of the method-and apparatus described herein is-diagrammatically illustrated in Fig. 8. It should be I noted that the pith, -wax and other undesirable, soluble,

materials have been separated out leaving long single fibres such as 76 or long fibre bundles of substantially uniform cross sectionas at 77. a

-"I :laim:"-

1. Apparatus for continuously disintegrating successive batches of fibrous material, said apparatus comprising a tank adapted to contain a fibrous liquid mixture, said tank having laterally extending end Walls, one of said end walls having an outlet aperture in the upper portion thereof, said tank having longitudinally extending bottom and side walls interiorly formed, below the level of said outlet aperture, into at least two longitudinally extending -ofrotation is inclined, whereby the fibres in the lower portion of the mixture are continuously segregated and urged upwardly'into the outer, upper portion of said mixture and said outer, upper portion periodically surges up to the level of said outlet aperture to emit successive batches of segregated fibres through said outlet aperture.

2. Apparatus for continuously disintegrating successive batches of fibrous material, said apparatus comprising a series of tanks each succeeding the other and successively connected by passages connecting the upper portions thereof, the first tank in the series having an inlet and the last .tank in the series having an outlet; rotary impeller churning means within each tank operable below the level of saidpassages, inlet and outlet and adapted to impart a rotary, fibre-submerging movement, around an upstanding inclined axis of rotation, to a liquid mix ture therein, and eruption means, including substantially horizontal, concave, lobes in the bottom and side walls of each said tank, cooperable with said churning means, to periodically eject a portion of the rotating mixture in each tank upwardly into the next successive tank through the passage therebetween and to periodically eject a portion of the rotating mixture in the last tank upwardly into said outlet whereby a fibrous mixture continuously fed to said first tank is successively submerged, swirled and dis-- integrated in, and batches thereof erupted from, each tank of the series and finally erupted from said last tank with the fibrous material disintegrated.

3. Apparatus for continuously disintegrating successive batches of fibrous material, said apparatus comprising a longitudinally extending casing divided by at least one lateral partition into at least two longitudinally extending tanks, each tank I being adapted to contain a fibrous liquid mixture and having longitudinally extending bottom and side walls interiorly formed in the lower portion thereof into at least two longitudinally extending, concave, lobes, the'first said tank having an inlet for receiving a continuous supply of liquid and a continuous supply of said fibrous material, each partition between said tanks having a connecting passage in the upper portion thereof, and the last said tank having an outlet in the upper portion of a wall thereof, and a rotary impeller in each said tank, below the level of said passages and outlet, each said impeller being revoluble on an axis of rotation inclined from the vertical in a longitudinal direction and being adapted in cooperation with said lobes to disintegrate fibres in'the lower portion of its tank while urging the mixture therein upwardly and outwardly in thedirection in which its axis of rotation is inclined, whereby the upper outer portion of the mixture in each tank is periodically ejected upwardly and outwardly through a passage into the next succeeding tank andfinally out of the outlet of, the last tank in said casing.

4. A combination as specified in claim 3 wherein said casing includes means for adjusting the central longitudinal axis thereof at predetermined angles to control the. dwell of mixture therein. i

5. A combination asspecified in claim 3 wherein the axis of rotation of the impeller in one tank is inclined toward the outlet passage of that tank to decrease dwell and the axis of rotation of the impeller in anothertank is inclined away from the outlet passage thereof to increase dwell of the mixture therein.

6. A combination as specified in claim 3 wherein the impellers in said tanks are eachtonned with four blunt edged vanes in the form of a cross, at least two opposite vanes being of triangular outline with one said vane being upturned at its free end and the other said vane being downturned at its free end.

7. A combination as specified in claim 3 wherein each tank includes three longitudinally extending concave lobes in its interior walls, said lobes being uniformly spaced from the longitudinal axis of the rmpective tanks, but the three lobes of one tank being at a different angular position around said axis from the lobes of another tank whereby one tank is wide at the bottom and narrow at the top and another tank is wide at the top and narrow at the bottom.

8. A combination as specified in claim 3 plus a baflle plate extending laterally across at least one said tank at a spaced distance in advance of the outlet of said tank, said plate depending downwardly from the top of the tank to below the level of said outlet and adapted to prevent 7 back flow and back surge from the next succeeding tank through said outlet.

9. Apparatus for treating fibrous material, said apparatus comprising a pair of substantially identical, elongated, hollow casings, each having one end formed with an outturned conduit at one end and an opening at the opposite end and each having longitudinally extending interior walls in the form of three concave lobes uniformly spaced from the longitudinal axis thereof, said casings having outturned flanges around said open end and being connected to each other by said flanges with one casing inverted relative to the other whereby one outturned conduit forms an upt u'ned inlet at one end of the tank formed by said casings and the other outturned conduit form a downturned outlet at the other end of said tank, a

. laterally extending partition, having a connecting passage in the upper portion thereof at the flanged joint of said casings dividing said tank into first and second compartments; a laterally extending end wall member, within the second compartment just in advance of the downturned outlet thereof, the top of said member being spaced from the top of said compartment to form an outlet passage therefor; a motor driven vaned impeller in the first compartment revoluble on an axis of rotation obliqued from the vertical in the direction of the outlet passage of said compartment and a motor driven vaned impeller in the second compartment revoluble on an axis of rotation obliqued from the vertical in a direction away from the outlet passage of said compartment, the impeller and lobes of the first compartment cooperably segregating fibres therein and ejecting a portion thereof periodically through said outlet passage into the second compartment and the impeller and lobes of the second compartment cooperably segregating fibres therein, with a longer dwell then in the first compartment, and ejecting a'portion thereof periodically over said end wall member and out said downturned outlet.

10. A combination as specified in claim 9 wherein the flanges of said casings are adapted to connect said casings at slightly different levels with the level of the second compartment below the level of the first compartment.

11. A combination as specified in claim 9 wherein the tank formed by said casings includes means for supportingthe same with its longitudinal axis inclined slightly from the horizontal, upwardly from the inlet end to the outlet end. v

12. A combination as specified in claim 9 wherein the plane of the top of the end wall member of the second compartment is higher than the bottom of the passage through said intermediate partition and a bafile plate is mounted across said first compartmentin advance ofthe passage through said intermediate partition adapted to prevent back flow. v

13. Apparatus for continuously disintegrating successive batches of fibrous material, said apparatus comprising an elongated tank having an inlet and an outlet 0ppositely disposed in the upper portion of the end walls thereof; horizontally extending lobe means in the side walls and bottom of said tank and power driven rotary impeller means in said tank, proximate the bottom thereof, said impeller being revoluble on an upstanding axis of rotation inclined toward one of said end walls, said lobe means and said impeller means being below the level of said inlet and outlet for co-operatively submerging fibrous material received through said inlet and disintegrating the same in said tank while periodically erupting successive batches thereof upwardly into said outlet.

14. A continuous method of treating and disintegrating fibrous material which comprises the steps of continuously feeding fibrous material, accompanied by liquid at a temperature of about E, into a first rotary mixing and churning operation for preliminary segregation of fibres the-rein; then drawing said fibrous material inwardly and downwardly into said mixing and churning operation to completely submerge the same; then periodically erupting successive batches of fibrous material and said liquid upwardly out of said first rotary mixing and churning operation and into succeeding similar rotary submerging, mixing and churning operations for complete segregation of fibres therein and finally, periodically erupting successive batches of fibrous material and said liquid upwardly out of the last said rotary, submerging, mixing and churning operation into a screening operation for separation of said fibrous material from said liquid.

References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

1. APPARATUS FOR CONTINUOUSLY DISINTEGRATING SUCCESSIVE BATCHES OF FIBROUS MATERIAL, SAID APPARATUS COMPRISING A TANK ADAPTED TO CONTAIN A FIBROUS LIQUID MIXTURE, SAID TANKL HAVING LATERALLY EXTENDING END WALLS, ONE OF SAID END WALLS HAVING AN OUTLET APERTURE IN THE UPPER PORTION THEREOF, SAID TANK HAVING LONGITUDINALLY EXTENDING BOTTOM OF SIDE WALLS INTERIORLY FORMED, BELOW THE LEVEL OF SAID OUTLET APERTURE, INTO AT LEAST TWO LONGITUDINALLY EXTENDING CONCAVE LOBES AND SAID TANK HAVING TANK INLET MEANS FOR RECEIVING A CONTINUOUS SUPPLY OF LIQUID AND A CONTINUOUS SUPPLY OF SAID FIBROUS MATERIAL AND A ROTARY IMPELLER IN SAID TANK BELOW SAID OUTLET APERTURE, SAID IMPELLER BEING REVOLUBLE ON AN AXIS OF ROTATION INCLINES FROM THE VERTICAL

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