US2558408A - Outlet valve mechanism for solvent extraction plants - Google Patents

Description

June 26, 1951 c. w. zlEs 2,558,408

OUTLET VALVE MECHANISM FOR SOLVENT EXTRACTION PLANTS Filed 001;. 28, 1946 3' Sheets-Sheet 1 INVENTOR CARL W Z/E-S A TTORNEYS June 26, 1951 A c. w. z|Es 2,558,408

OUTLET VALVE MECHANISM FOR SOLVENT EXTRACTION PLANTS Filed Oct. 28, 1946 3 Sheets-Sheet 2 CARL W. Z/Es ATTORNEYS June 26, 1951 c. w. ZIES 2,553,403

OUTLET VALVE MECHANISM FOR SOLVENT EXTRACTION PLANTS Filed Oct. 28, 1946 3 Sheets-Sheet 5 m/va/vror? CARL W Z156 Patented June 26, 1951 OUTLET ALVE. MECHANISM F QR S OLVENT EXTRACTION -PLAN TS a corporation of Qhio Application October 28, 1946, SerialNo; 706,221

1 claim. 1

'This invention relates to extraction towers,

such asare used for-solvent extraction of oil from seed or other oil bearing vegetableoranimal materials. 'The invention has more particular relation to the means or mechanism by whichthe liquid solvent is supplied and the solid residue, after extraction is completed, is released, withdrawn or discharged from the tower.

One object of the invention is to provide improved discharge mechanism for-the solid mate- .rial which not only is efiicient'and of'high capacity, but also produces satisfactory dischargewith- :out. loss or escape of solvent liquid.

,Another object is to provide improved discharge mechanism which forms and maintains a uniformly dense plug of solid material at the outlet, thus preventing-escape and loss of liquid.

Still'another objectis to provide improved discharge mechanism embodying rotatable screw means equipped with the necessary instrumentalities to advance the solid materialtowardxthe outlet as the screwrotates, thus preventing rotationwith the screw of a mass of the xsolidzmaterial, such as might open a channel to perm-it liquid to escape, or prevent the forward movement of the material.

"Another object is to improve the relation between the inlet for solvent liquid and the outlet "for solid ,material, to insure maximum exposure -f--s01id'.to, liquid, and increase the quantity ,of oil extracted.

Another object is to provide a simple and improved arrangement of the solventxsupply channels with respect to the passages for discharge ,of solid material, and of both with respect to the agitating shaft, not only for easeofassembly, inspection and repair, but also to avoid ,caking or collection of solid material "around or-near the lower end of the shaft.

Finally, the invention aims to generally improve themechanism so thatitoperates satisfactorilyover long periods of time without special attention, but, nevertheless; is of generally-simple form with all parts readilyaccessible;fonrepair, replacement or-the like.

Further advantages ofthe'invention in part wareobvious and'inpart will appear morein detail hereinafter.

In, the draWin S, Fig. 1 represents an elevation,

2 the lower portion of the apparatus, on the line 5'3-3,;Fig. 1;

Fig. 4isya sectionalelevation, on the lined-Al, i

Fig. 5 is a sectional elevation, on the line 5-5, Fig.6, showing the driving mechanism, certain parts being omitted; and

Fig. 6 isasectional plan view on the line 6-:6, Fig.4.

While the invention'is capable of ,useinany form of solvent-extraction lant, for the purpose of supplying solvent liquid and discharging or ejecting the settled solid material, it has been shown in the drawings, solely for purposes of illustration and in no sense of limitation, in a form suitable for use with the same general type of extraction tower and fines separator illustrated in an application for Method and Apparatus for Separating Prepared Oil-Bearing Seed Oil and Solvent, Mixture, serial No. 551,244, filed August 25, 1944, by Louis E. Langhurst, and. now abandoned, to which reference may be hadif desirable or necessary.

In the drawings, ll] represents the tall cylindrical extraction tower provided with a central vertically extending rotatable agitating shaft ll having arms [2 which sweep over stationary horizontal disc form plates or shelves [3 having openings I4, staggeredor out of line on successive plates, through which the solid material finds a path in its course from the uppersupply channel Him the bottom outletby way of the valvegmech- ,anism to, be described. The solvent liquid, such as hexane, is supplied to thebottom of the tower, as will, appear later in detail, and, rises through the descending solid material, then through a ,fines separator, marked generally I6, and is discharged from an upperoutlet I l, the counter cur- ,rent manner of operation insuring high solvent extraction of oil from thesolid material.

,The extracted :solid material moving down- .wardly in the tower becomesa more or less compact mass nearits bottom, but cannot be per- --mitted tor-flowfreely out of the chamber, as-by gravity, without ,loss of solvent liquid. Consequently, 'I employ ,forthe purpose outlet valve mechanism including ,one or morerotatable conveyorscrews and a choke arranged to buildqup the pressure against which the solid matteris advanced and thus forma definitepluggorstopper ,forqthe outlet. A single screw may be employed but thedr-aw-ings show two-for the purpose.

:As illustrated the extraction chamber -18 is provided with and. is supported by a fiat bottom or floonyplate: t9 made of heavy, sheetsteeland resting upon beams 20. In said floor plate are two generally rectangular slots or openings 2| to which the collected solid material is fed by the lowermost arm I2 which sweeps around over the floor. Each opening 2| leads to a feed chamber 22 in a depending housing 23 in which rotates a feed screw or worm 24 mounted upon a shaft 25.

. That portion of the worm beneath the opening is is to break up the mass of solid material being advanced by the screw and to compel it to move forward without bodily rotation with the screw around the shaft axis. For the same purpose I may also provide the barrel, internally beyond the screw flights, with longitudinal ribs or vanes Beyond vanes 29, the channel within the barrel and around the shaft communicates with a discharge chamber 30, the opening to which is controlled by a more or less conical nonrotatable choke member 3! slidable on shaft 25 and connected to a sleeve 32 provided with pins 33 engaged by arms 34 on a shaft 35 extending out through the wall of housing 36, where said shaft supports one or more long arms 31 on which asuitable counterweight 38 is mounted. Rotation of sleeve 32 is prevented by an arm 39 attached thereto and sliding along a guide member on the casing wall.

A single discharge chamber may receive the solid material from both screws or, as shown, a vertical wall 4| may divide the space within housing 35 into two chambers. In either case the floor 42 of the discharge chamber slopes to an outlet opening 43 through which the finished solid material falls into a suitable vessel, such as a bin or cart (not shown) Inspection windows 44 in the top and side walls of casing 36 enable the operator to see how the solid material is behaving.

The drive end of shaft 25 is usually provided -with an adjustable packing 45 and bearing 43,

beyond which it is provided with suitable operating means. As shown, the two shafts 25 are each provided with a sprocket wheel 4? to receive a driving chain 48 passing over a sprocket "49 on shaft 55, which may be driven by any suitable variable speed driving mechanism, such as electric motor 50a, the speed of rotation of which may be varied in any suitable manner. 51 represents a chain tightening device.

Referring to Fig. 3, it will be observed that the lower end of vertical shaft II is reduced at 52, the reduced portion turning in a bearing ring 53 mounted in floor member IS. The weight of the shaft, it will be understood, is supported from a suitable bearing (not shown) at its upper end. Bearing ring 53 is in the roof or upper wall of a chamber 54 lying between the opposed parallel vertical side walls 23a of housings 23, depending end walls 55 (Fig. 3) and a bottom member 56, from which depends a. large diameter tube 51 having a flange 58 to which may be removably secured a plate 59 provided with suitable means for attachment thereto of the liquid supply conduit 60, such as a coupling 6|. In

'4 the side walls of housing 23' are openings 62 partially blocked by funnel or hopper members 63 welded to said walls and opening at their upper ends to chamber 54.

The extraction tower described is utilized in the customary manner for the extraction of any desirable value from solid material by the use of an extracting solvent. The solid matter, rolled, crushed, macerated or otherwise comminuted, and either wet or dry, is supplied continuously at the top of the tower through the channel [5, moving slowly downwardly toward the bottom through the staggered openings M as the result of slow rotation of the agitating shaft. During its downward motion the solid material at all times is in leaching relation or contact with the solvent liquid introduced at the bottom of the tower and flowing upwardly therein. The product, miscella in the specific instance being described, consisting of a mixture of oil and hexane or other suitable solvent fluid for the oil, passes through the fines separator I6 and is discharged continuously through the outlet [1. Solutions ,or mixtures of other materials than oil in other fluids than hexane, either gas or liquid, such as water, of course may be treated in the same manner.

As the solid material arrives in the region of the bottom of the solvent chamber l8, it becomes more and more dense or compact. The lower agitating blade l2 sweeps it across the floor formed by plate l9, so that it falls through the openings 2| into the receiving chambers in which the feeding worms 24 rotate. Each worm,

" therefore, begins to advance the material lengthwise of the shaft and to introduce it into the tubular barrel 28, where it is further advanced by the interrupted screw flights 24a, 24b. Discharge of the solid material from the barrel 28, however, is impeded by the choke 3! in an amount depending to a great extent upon the load imposed by the counterweight 38, according to its position. As the'result of the resistance to discharge, the advancing solid material becomes more and more dense and, indeed, in the region of the choke becomes a dense solid plug which substantially completely blocks or prevents any escape of liquid pastthe choke. The knives or stops 2'! serve to preyent rotation, bodily, of the solid material with the screw, while the interrupted screw flights, whose leading edges are beveled off or sharpened to knige edge form, as shown at 64, Fig. 4, cut the solid material, to facilitate their entrance into it, and cause it to move forward without rotation, rotation being further prevented, beyond the last screw flight, by the longitudinal ribs 29 before referred to.

The net result of the screw mechanism described, is to provide continual discharge of solid material from the barrel of each screw, past its choke, into the discharge chamber or chambers 30 and thence to the outlet 43, without any possibility of loss or escape of solvent liquid.

In addition, it will be observed that the solvent liquid is supplied, by way of the supply pipe 60, the channel in tube 58, chamber 54 andopening 62, to the supply chamber in which rotates the screw 24. Thus, the solvent liquid is supplied to and mixed with the solid material as close to the final outlet for the solid material as is possible, insuring maximum leaching contact of liquid with solid and insuring high eificiency in extraction. Further, the shielded or guarded openings 62, of which any number may be employed for each screw, together with the hopper-shaped guards 63 adjacent thereto, serve as traps to collect and deliver to the chambers 22 any solid material which otherwise might escape into chamber 54. Of course, liquid flow through chamber 54 and around the lower end of shaft 25 assists materially in maintaining its bearing surfaces clean and free from deposits of solid material thereon.

By removing plate 59 open access is provided to chamber 54 noto'nly for cleaning it out, but also for purposes of inspection of the lower end of the shaft and the bearing in which it rotates, if that is desirable.

The construction described is of relatively simple form but is durable and efiicient in op eration.

Other advantages of the invention will be apparent to those skilled in the art.

WhatIclaim is:

Extraction apparatus of the character described comprising an extracting tower having a bottom floor provided with a pair of parallel elongated openings spaced from each other, a trough-shaped feed casing below each opening and having a chamber communicating therewith, an imperforate cylindrical barrel communicating with the chamber of each feed casing, a shaft extending through each casin and barrel and pro vided with a multiple flight feed screw having a plurality of spaced worm flights thereon within said barrel, stop means in the barrel extending into the space between said flights, a yieldable choke device for each screw at the outlet end of its barrel, means for simultaneously rotating said shafts, a series of peripherally spaced, parallel ribs extending longitudinally of the inner wall of the barrel between said outlet end and the nearest said screw flight, each said rib projecting radially inwardly part way towards the barrel axis, the space between said trough-shaped feed casings being enclosed by means of a bottom transverse partition to provide a solvent liquid distributing chamber, the adjacent walls of the two feed casings being each provided with an opening constituting a liquid inlet port to a respective feed casing, liquid supply connecting means in said transverse partition whereby solvent liquid may be introduced to said distributing chamber and thence through a respective port to each said feed easing, said outlet ports being each in registry with a screw-flight-containing portion of a respective casing whereby liquid entering through each said port passes through settled solid material being discharged through said casings by said screw flights, a vertical shaft :in said tower having a lower end rotatably supported in the aforesaid bottom wall of said tower and having a part extending into said distributin chamber, shielding means for the said inlet ports consisting of a wall portion inclined inwardly and upwardly from the bottom edge of each said port whereby to direct the incoming liquid upwardly against the bottom end of said shaft portion before said liquid leaves said distributing chamber through each said port, means for simultaneously rotating each said shaft, said distributing chamber having a wall portion removable to afiord access to the interior of said chamber.

CARL WILLIAM ZIES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,685,534 Drahn Sept. 25, 1928 1,971,632 Anderson Aug. 28, 1934 2,184,248 Bonotto Dec. 19, 1939 2,203,666 Bonotto June 11, 1940 FOREIGN PATENTS Number Country Date 157,155 Great Britain Nov. 3, 1921

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