US1542939A - Process and apparatus for treating liquid material - Google Patents

Description

l June 23, 1925.

E. HOPKINSON PROCESS AND APPARATUS FOR TREATING LIQUID MATERIAL Filed oct. 27, 1922 4 Sheets-Sheet 1 June'zs, 1925. 1,542,935)

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lE. HOPKINSON PROCESS AND APPARATUS FOR TREATING LIQUID MATERIAL 4 Sheets-Sheet l4:

Filed Oct. 27, 1923 Patented June 23, 1925.

UNITED STATES PATENT oFFlcE.

ERNEST HOPKINSOIL OF NEW YORK, N. Y., ASSIGNOR T GENERAL RUBBER COM- PANY, OF NEW YORK, N. Y., A CORPORATION 0F NEW JERSEY.

PROCESS AND APPAIQAJJUSJ FOR TREATING LIQUID MATERIAL.

Application filed October 27, 1923. Serial N'o. 671,127.

To all 'whom t may concern:

Be it known that I, ERNEST HoPKINsoN, -a citizen of the United States, residing at New York city, county of New York, and State of New York, have invented a certain new and useful Process and Apparatus-for Treating Liquid Material, of which the following is a full, clear, 4and exact description. l

This invention relates to a process and apparatus for treating liquid material, particularly latices containing rubber, balata, or gutta perclia.

The invention contemplates broadly a new and novel method and apparatus for finely dividing or atomizing liquid material in general, but particularly liquids containing solid matter. or'a liquid fuel. It aims to reduce the ,cost of recovering solid matter, such as rubber, from latex, both the cost of theoperation and the equipment necessary to carry it on. Itl also aims to provide a type of construction that is readily accessible for repair or replacement. Still further, it aims to provide a construction capable of assemblage with the crudest of facilitiesV and labor, hence meeting the need of growers, and a method and apparatus capable of increased yield and operation with a comparatively low pressure. i

With the illustrated embodiments of the invention in mind as applied to the treatment of rubber latex and without intention to limit its scope more than isrequired by the prior art, the discovery may be briefly stated to consist inthe filming of latex and the dispersion of the filmed latex into Ja `finely divided spray, the comminuted particles of .which are preferably dried in a gaseous medium', such as hot air. The filming of the latex is preferably effected by 4 drawing a foraminous surface or support through g bath, the films being pneumatlcally shattered and dividedinto minute liquid particles in a -condition adapting them for subsequent treatment.

Preferred embodiments of the invention are diagrammatically illustrated in the accompanying drawings in Which:' Figure 1 is a vertical longitudinal section through anl apparatus suitable for drying in suspenslon, like latex 4 4, Figure 3, with the adjacent parts of y the feeding system appearing in elevation;

Figure 5 is a plan view of a furnace suitable for heating hot air to besupplied to the latex drying apparatus, a modified form offilming and spraying apparatus being shown as applied thereto 'for burning liquid fuel;

Figure 6 is a front elevation of the furnace shown in Figure 5;

Figure 7 is 'an' enlarged detail of a floatfeed controlling mechanism suitable for liquid fuels;

And Figure 8 illustrates diagrammatically a safety switch desirable for burner installations. l

According to the invention, the liquid material is filmed and the films Shattered with -a concentrated stream of air or gas so as to form a mist or spray which may be variously utilized or treated.- Many forms of construction involving the underlying principles of the invention may be utilized.

Apparatus that may be employed for obf taining rubber in solid form from latex will now be detailed and the process explained -in connection therewith.

Latex may be supplied from a. tank 1, Figures 1 and 4, connected'by hose 2d with a. pan 3, the level of the liquid within which is preferably, but not necessarily, maintainedsubstantially constant by anyY Suitable means. One such means is illustrated in the drawings, comprising a float 4 loosely articulated to a lever 5 which is fulcrumed intermediatelyat 6, its remote end having fixed thereto a depending rod 7, with a cross-arm 8 adapted to be pressed down upon the pipe 2, which is preferably of rubber and constrictable. vThe size'of the passage therein may thereby be varied and the Supply of the latex to the pan regulated. This type of feed control does not clog, being self-cleaning, and is particularlyadvantageous for controlling the supply of latex, or liquids containing solid matter in suspension. If it is desired to mingle other liquid substances with the latex, similar supply tanks, connections and float controls, may be provided, but these are omitted from the drawings for the sake of clearness.

While the latex or mixture may be applied to a film-forming device variously to suit the characteristics of the liquid material, the construction of the hlm-forming device, and the subsequent treatment or use to be made of the atomized spray, it is preferred to film latex (which ordinarily consists of around 30% rubber and 7 0% water, and small percentages ofy other matter) on a perforated drum dipping intothe bath. This preferred construction, as illustrated, comprises a cylindrical woven wire surface 9 of, preferably, fine meshsay 40 to the inch, but wide variation in the size of the mesh is permissible-stretched taut between Hanges 10 and 11, see Figure 3, which are integral with or secured to sleeves 12, rotating on a stationary hollow tube 13, that is closed at one end, as at 14. To move the foraminous surface 9, the sleeves 12 may be equipped with a gear 15 rotated by a pinion 16 on a shaft 17 turned with a hand-crank or by a motor 18. @f course, the perforated surface 9 may be otherwise variously supported and rotated. The tube 13,

preferably extends only a short distance beyond the pillow-blocks 19, which may be split, as at 19, so that their upper halves may be swung about the hinges 20, Figure 4, to permit quick removal of the film-forming device and substitution of another in its place.

The tube 13 is provided with a nozzle 21 in communication with its bore, the tip of the nozzle being located close to the inner surface of the wire, the closer the better. The nozzle discharges preferably through a very narrow slit extending approximately the full width of the film-forming wire surface 9. rllhe nozzle may be .directed any way desired, vertically, horizontally, or at an inclination, butis preferably located for spraying latex into a horizontal chamber so as to direct the spray at a slight downward inclination to the horizontal, substantially as shown. Ti/l/'hile a multitude of individual nozzles may be employed, it is preferred to shape single nozzle so as to direct huid under pressure through the wire, or other foraminous construction, such as perforated sheet metal, that be employed, in confined or concentrated stream, blade-like. The nozzle may be united `ntegrally with the hollow shaft or the shaft be slitted and the nozzle suitably secured thereabout, as desired. I

The tube 13 may supplied with any suitable duid under pressure, from any suitable source, through a connection with its open end 22, preferably made through a flexible hose 23, provided with a quick attachable band-clamp or' connection 24 to facilitate operations incident to removal or replacement of the entire filming and spraying unit for repair, cleaning, or other purposes, without long interruption of the process. A scraper 8 of rubber or other suitable material may be mounted to wipe the sides of the flanges 10 clean, as shown in Figure 3. v

The latex is continuously filmed on the screen 9, probably by capillary adhesion to the metal defining the apertures, with its opposite surfaces free and unsupported in a condition idealfor their blasting or shattering by a stream of air under moderate pressure, which is projected through the screen, preferably radially or at a substantial angle to the extent of the films. To obtain rubber from latex, the spray of finely divided or dispersed comminuted particles is preferably directed at a slight downward inclination from the horizontal into a drying chamber, indicated generally at 25, see Figures 1 and 2. This chamber may be variously proportioned and shaped to meet the production requirements of a small or large plantation, or of a regional factory. For commercial production on a large scale, however, the chamber or room 25 may be made about twice as long as high and about as wide as high, and preferably with all or most of its side walls sloped or flared outwardly and downwardly, as illustrated, so as not to allow the particles to impinge or collect thereon. In general, the cross-section of the chamberwill increase towards the outlet end. And, in general, the arrangement should be such as to avoid the particles of liquid, or partly dried, latex from contacting with any of the surfaces of the chambert,` or each other, until they have been substantially or completely dried, or at least sufiiciently dried so as not to coalesce together on impingement one with another. To these ends, the chamber 25 is iared lengthwise and downward, as indicated in the drawings. To dry the dispersed liquid particles of latex,van inert gas, such as C02, may be employed, but the preferred drying medium, preferred because of its low cost, is heated air mingled with the products of combustion from a furnace, which products are conducted to the chamber through an expanding duct 2G, reducing the vri 't i of movement. The delivery end of the expanding duct is preferably equipped with horizontal baffles 28 spaced closer the top than at the bottomV to insure the drying medium passin;0A down the chamber in a more or less un form manner and to avoid the setting up of eddies, or other likely to carry the particles the hot air downl as much as possible an of the chamber Warm.

The heated air is exhausted from the far end of the chamber through a duct or ducts 29, which are desirably in communication with some form of baffled box or passage for collecting dried particles that have not previously been deposited on the bottom of the chamber. A suitable form of such collector is illustrated in the'drawings as comprising four ducts 29, each equipped with a counter-balanced, or otherwise conveniently operated, blast-gate 30, and each communieating with an upright iue 31, containing a large number of boards or trays 32, which are staggered, or overlapped, as shown, to compel the escaping air to follow a tortuous path. These boards or trays are preferably supported on slides 33 for convenient removal through a hinged door, or doors, 31',

. at the accessible side of the lue 31. Any one of the four ducts 29 may be closed with the blast-gate 30, the door of the flue in communication therewith opened, the trays removed, the particles cleaned therefrom and collected, and returned to place while the other three iues are in operation; the capacity of three being sufficient in such case to permitthe movement and escape of the heated air at a suitable ratethrough the drying chamber 25. Above the flues 31, a header' or outlet 32 into the atmosphere is provided.

While the dried particles which settle at the bottom of the chamber may be allowed to pile up and the operation halted at intervals to allow laborers to enter the chamber and remove the rubber, it is obviously more desirable to provide for continuous operation. To this end, it` is preferred to mount platforms 35 on wheels 36, or other movable agency, and advance them step by ste the length of the chamber 25. These plat orms 35 `are preferably madeof a length sufficient to span the inside walls of the chamber at the bottom thereof, and of a width practicaly to manipulate. The end wall 25' of the chamber, where the platforms are introduced, is brought down so as to barely clear the same, ifnecessary a skirt of flexible material being provided to brush against the tops thereof. The end wall of the chamber, under which the platforms carrying the dried material pass from the chamber, is preferably equipped with a vertically movablepanel 38, adapted to be raised or ad` justed above the deposit of rubber when the trays are moved andto be lowered sealingly down upon the rubber after the trays have been stepped forward.

The drying medium, gas or air, may be supplied to the entering duct 26 of the chamber 25 in any suitable manner a d from any suitable source.- Generally, he

products of combustion will be led from the furnace and Vcooled down to a temperature around or below 600 F., with air from the outside atmosphere admitted through a dam er controlled intake into the flue from the urnace, the necessary draft being af- 'forded by a blower or any other suitable means. It is desirable to keep the temperature of the dried particles of latex or rubber down around 212 F., or lower. These parts are all old and well known and need no detailed illustration or description.

While any suitable form of furnace may be employed, it is preferred to utilize a burner therewith, employing the broad filmforming and spraying principle of this invention to atomize liquid fuel. An illustration of one suitable form of s ray burner is disclosed in Figures 5 and 6 o the drawings. Therein, the furnace is indicated at 40, with an opening 41, -towards which `a stationary flat nozzle 42, with a long narrow discharge slit 42 is directed, the Anozzle -being in communication with a blower or a fan 43, operated by a motor 44. Between the nozzle 42' and the furnace opening 41, is rotated a disk 45 provided with a fine wire mesh 46, or minute perforations, the disk being rotatably supported on a standard 47 and operated by a worm-gear 48 from a motor 49, or other suitable means. The perforations 46 or the mesh or plate are preferably provided in an annular area o the disk of a width approximating that of the furnace opening and, upon rotation of the disk, are successively presented to the stationary nozzle. The disk, as in the reviously described rotor type of constructlon, preferably dips in liquid fuel contained ina pan 50 having an enlarged portion 51 for accommodating a float 52. The floatI 52, see Fi ure 7, is loosely articulated to a lever 53, ulcrumed intermediately at 54 and carrying a plunger 55, for closing or opening the port 56 in a pipe 57, which is connected to a fuel tank 58, the port 57 opening into a pass 59 which is in communication with the enlargement 51 of the pan. By this means, or any other of themany devices adaptable for the purpose, the liquid fuel may be-maintained in the pan 50 at a level sulicient to cover theperforated area of the disk 45, the level being preferably maintained substantially constant. The furnace may be of any suitable construction for carrying on the combustion, being preferably made of fire-brick and provided with` the necessary air inlets, as usual. As currentsome times fails by reason of a shut-down or accidents at the generating station remote from the furnace, yit is desirable to provide against resumption of the operation of the blower'and disk until anl attendant or householder arrives to properly startor resume combustion.` Any sultable mechanical means may be provided to -prevent operation of the motors after failure of the current and cessation of combustion, but it is preferred to employ an electrical switch of the no-voltage release type, one such being illustrated diagrammatically in Figure 8 of the drawings mounted in one side of the line. It comprises a manually operable switch-arm 60, fulcrumed at 61, and normally urged in a counter-clockwise direction by the spring 62, which connects the bent end 63 of the switch-arm 60 with one arm of a latch 64, which is adapted to hold the switch in contacting position, and which is fulcrumed at 65 to the laminated U-shaped metallic core 66, one leg of which is surrounded by a plurality of windings constituting a coil 67. One end of the co1l 67 is connected by the wire 68 to the positive side, say, of the main supply leads, and the other end of the coil is connected by the wire 69 to the contact 70. A. second contact 71 is connected with the positive side of the line. The circuit through the two contacts and 71 -is completed when the shoe 72 pivoted on the end of the arm 60 is manually moved into contact therewith. At 73 is indicated a shunt connection for temporarily cutting out the circuit through the coil 67 at the time the switch 61 is manually closed to start the operation of the motor. The contacts 70 and 71 are mounted on yielding arms to permit the shoe 72 to make temporary engagement with the pin 74 when the switch is manually operated, but while the motor is running and the switch-arm 60 stands in the position shown in solid lines in Figure 8, the shoe 72 is not in contact with the post 74. In this type of switch, assuming the motor to be running, failure of the current does not ychange the position of the parts. These remain as illustrated in solid lines in Figure 8. But, should the current fail and then be resumed through the night, or when there is no one in attendance, the initial surge'of a comparatively heavy current through the line, called for to start the motor, energizes the magnetic core 66 sufficiently to pull down upon the adjacent end of the latch 64 and release the switch-arm 60 to the action of the tension spring 62 which, of course, throws the switch-arm 60 from the solid line to the dotted line position and opens the circuit. During the normal operation of the motor when the switch-arm 60 is closed, as shown in full lines, the strength of the current flowing through the coil 67 is not sufficient tooperate the latch 64 against the force of the spring 62.

It is not\intended to limit the invention to this type of switch, it being detailed merely for the sake of completeness, any suitable form of mechanical or electrical contrivance being usable for the purpose of preventing operation ofthe spray disk and blower when no one is present to start combustion.

The operation of the apparatus and the process have been set forth fully and completely in the' detailed description above, rendering unnecessary further description. It will be seen that the invention in its broadest aspects comprehends the filming and dispersion of any liquidmaterial whether it contains solid matter or not, the filming and spraying of the materiallbeiug the same in broad principle in both cases and in both, the spray is projected into a heating chamber.

It is to be understood that various changes may be madein the process and apparatus without departing from the underlying principle of spraying or atomizing in two stages, (l) filming the liquid material, followed by (2) blasting or shattering the filmed liquid with air or other gas under pressure, preferably moderate, around eightpounds. Of course, however, the pneumatic pressure at the nozzle may be varied to suit the viscosity of the liquid film to be dispersed. The perforated carrier may be made of wire, or punched sheet metal, or of any other suitable materials, the size of the perforations or mesh being preferably small, but variable, as before stated, to suit the character of the liquid material. The liquid may be applied to the perforated carrier, whether it be in the form of a cylinder or an endless belt, by dipping preferably, but also in any other manner convenient and satisfactory for the formation of the films. The perforated carrier may just barely dip into the bath, as shown in the drawings, or it may be almost completely submerged therein if the character of the liquid material treated requires in order to prevent clogging of the perforations. These and all other mechanical variations that may be made in the apparatus and procedure are comprehended. For a full understanding of the breadth and scope of the invention, reference sho'uld be made to the appended claims.

Having thus described my invention, what I claim and desire to protect by Letters Patent is 1. A process of drying latex or, similar materials which consists in, filming the latex with opposite free surfaces, dispersing the film into liquid particles, and substantially drying the particles while dispersed.

2.'A process of drying latex or similar materials which consists in, filming the latex with opposite free surfaces, dispersing the film into liquid particles, substantially drying the particles while dispersed, and amassing the dried particles.

3. A process of drying latex or similar materials which consists in, continuously filming the latex with opposite free surfaces, dispersing the film into liquid particles, and substantially drying the particles while dispersed.

. 4.v A process 'of drying latex or similar materials which consists in, filming the latex with opposite free surfaces, pneumatically dispersing the film into liquid particles, and substantially drying the particles While dispersed.

5. A process of drying latex or similar materials which consists in, filming the latex with opposite free surfaces, dis/persing the film into liquid particles, and subjecting the particles while dispersed to a heated gaseous drying medium.

6. A process of drying latex or similar materials which consists in, filming the latex With opposite free surfaces, dispersing the film into liquid articles with a concentrated stream vof aeri orm fluid directed on the film, and substantially drying the particles While dispersed.

7. A process of drying latex or similar materials Which consist in, filming the latex with opposite free surfaces, dispersing the film into liquid particles With a concentrated stream of air under pressure directed through the film, and substantially drying the particles While dispersed.

8. A process of drying latex` or similar materials which consists in, continuously filming the latex with opposite free sur,- faces, dispersing the film into liquid particles, substantially drying the particles While dispersed, and amassing the dried particles.

9. A process of drying latex or similar materialswhich consists in, filming the latex with o posite free. surfaces, pneumatically dispersmg the film into liquid particles, substantially drying the particles while dispersed, and amassing the dried particles.

. 10. A process of drying latex or similar materials which consists in, filming the latex with opposite free surfaces, dispersing the film into liquid particles, subjecting the particles While dispersedto a heated gaseous drying medium, and amassing the dried particles.

11. A process of drying latex or similar materialswhich consists in, filming the latex with opposite free surfaces, dispersing the lm into liquid particles with a concentrated stream of aeriform fluid directed on the film, substantially drying the particles whlile dispersed, and amassing the dried par'- tic es. A A

v12. A process -of drying latex or similar materials Which consists in, filming the latex with opposite free' surfaces, dispersing the film into liquid particles with a concentrated stream of air under pressure directed through the film, substantially drying the particles While dispersed, and amassing the dried particles.

faces, pneumatically dispersing the film into liquid particles, and substantially drying the particles While dispersed.

14. A process of drying latex or similar materials which conslsts in, filming the latex with opposite free surfaces, dispersing the film into liquidvparticles, and subjecting the particles while dispersed to a heated gaseous drying medium.

15. A process of dry materials which consists in, continuously filming the latex with op osite free surfaces, dis rsing the film into liquid particles wit a concentrated stream of aeriform fluid directed on the film, and substantially drying the particles While dispersed.

16. A process of drying latex or similar materials which conslsts in, continuously filming the latex with opposite free Surfaces, dispersing the film into liquid particles with a concentrated stream of-air under pressure directed through the film, Vand substantially dryingy the particles while dispersed. l

17. A process of drying materials which consists in, with opposite freesurfaces, pneumatically dispersing the film intoliquid particles, land subjecting the particles While dispersed to a heated gaseous drying medium.

18. A process of materials which consists in, filming thelatex with opposite free surfaces,fpneumatically dispersmg the film into liquid particles with a concentrated stream of aeriform fl-uid directed on the film, and substantially drying the particles while dispersed.

19. A process of drying latex or similar materials which consists in, filming the latex with opposite yfree surfaces, pneumatically dispersingthe film into liquid particles with a concentrated stream of air under pressure directed through the film, and substantially drying the particles while dispersed.

20. A process of drying latex or similar materials which consists in, filming the latex with opposite free surfaces, dispersing the film into liquid particles with a concentrated stream ofk aeriform fluid directed on the film, and substantially drying the particles while dispersed in a heated gaseous medium.

21. A process vof dryingA materials which consists in, filming the latex with opposite free surfaces,-.dispersing the film into liquid articles Witha concen` trated stream of air. under pressure directed through the film, and substantially drying the particles while dispersed in a heated gaseous medium. f 1 f G 22. -A processof drying latex or similar latex or similar vlatex or similar continuously g ing latex or similar W filming the latex drying latex or similar materials which consists in, filming the latex with opposite free surfaces, spraymg the film, and drying the particles of the spray.

23. A process of drying latex or similar materials which consists in, capillarily drawing films of latex from a pool thereof, spraying the films, and substantially drying the particles dispersed.

24. A process of drying latex or slmllar materials which consists in, capillarily drawing films of latex, from a pool thereof, spraying the films, substantially drying the dispersed particles, and amassing the dried particles.

25. A process of drying latex or simllar materials which consists in, continuously and capillarily drawing films of latex from a pool thereof, spraying the films; and substantially drying the dispersed particles.

26. A process of drying latex or similar materials which consists in, maintaining a pool of latex -at a substantially constant level, capillarily drawing films of latex from the pool, spraying the films, and substantially drying the particles while dispersed.

27. A process of drying latex or similar materials which consists in, maintaining a pool of latex at a substantially constant level, capillarily drawing films of latex from the pool, spraying the films, substantially drying the dispersed particles, and amassing the dried particles.

28. A process of drying latex or similar materials which consists in, maintaining a pool of latex at a substantially constant level, capillarily drawing films of latex from the pool, spraying the films into a heated gaseous drying medium, and substantially drying the particles.

v29. A process of drying latex or similar materials which consists in,- maintaining a pool ofl latex at a substantially constant level, capillarily drawing films of latex from the pool, spraying the films into a heated gaseous drying medium, substantially drying the particles. 30. A process of drying latex or similar materials which consists in, filming latex on a moving perforated carrier, spraying the films therefrom, and substantially drying the sprayed particles.

31. A process of drying latex or similar materials which consists in, filming latex on a moving perforated carrier, pneumatically spraying the films therefrom, and substantially drying the sprayed particles. 32. A process of drying latex or similar materials which consists in, filming latex on a moving perforated carrier, spraying the films therefrom into a gaseous drying medium, drying the sprayed particles, and collecting the particles.

33. A process of drying latex or materials which consists in, filming l particles, and amassing the dried imilar tex on a moving perforated carrier, pneumatically spraying the films therefrom 1nto a gaseous drying medium, drying the spray, and amassing the particles.

34. A process of drying latex or similar materials which consists in, filming latex on a moving perforated carrier, blowing the filmed latex therefrom and dispersing it, and drying the particles of the spray.

35. A process of drying latex or similar materials which'consists in, filming latex on a lmoving perforated carrier, blowing the filmed latex therefrom and dispersing it, drying the particles of the spray, and finally amassing the dried particles.

36. A process of drying latex or similar materials which consists in, continuously filming the latex on al moving perforated carrier, blowing the entire width of the latex filmed on the carrier therefrom and materials which consists in, continuously filming the latex on a moving perforated carrier, blowing the entire width of the latex filmed on the carrier therefrom 'and dispersing it to forma spray of comminuted particles, drying the particles while dispersed, and finally amassing the dried particles.

38. A process of drying latex or similar materials which consists in, filming the latex on a moving perforated carrier, blowing substantially the entire width of the filmed latex therefrom and dispersing it to form a spray of comminuted particles, and substantially drying the particles in a heated gaseous medium. i

39. A process of drying latex or similar materials which consists in, continuously filming the latex on a moving perforated carrier, blowing substantially the entire width of the filmed latex therefrom and dispersing it in a slowly moving current of heated gas, drying the dispersed latex, and amassing the dried particles.

40. A process of drying latex or similar materials which consists in, filming the latex from a pool thereof at one portion of the path of a moving perforated carrier, blowing substantially the entire width of the filmed latex from the carrier at another portion in its path and into a heated gaseous drying 12d medium, and drying and amassing the disj persed particles.

41. In an apparatus for drying latex and similar material, a drying chamber, means for dispersing latex therein, means for supous drying medium through said flues, and

42. In an apparatus for drying latex andl similar material, a dryin chamber, means for dispersing latex therein, means for supplying a gaseous drying medium to the chamber, means for exhausting the gaseous medium from the chamber, said last-named means including a plurality of lues, means for governingthe passage of the` gaseous dryin medium throughl said ues, and a plurality of shiftable trays arranged in each of said flues so as to compel the escaping 15 gaseous medium to follow a tortuous path, each of said iues being provided with a movable Wall portion to permit bodily removal of the trays from the flues.

vSigned at New -York city, county of New 20 York, and State of New York, this 25th day of October, 1923.

-- ERNEST HOPKpINSON.

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