US3297043A

US3297043A - Continuous flow counter-current liquid and solids contact apparatus

Info

Publication number: US3297043A
Application number: US422943A
Authority: US
Inventors: Robert E Adams
Original assignee: GIFFORD WOOD Inc
Current assignee: GIFFORD WOOD Inc
Priority date: 1965-01-04
Filing date: 1965-01-04
Publication date: 1967-01-10
Anticipated expiration: 1984-01-10
Also published as: CH443222A; DE1519799A1

Description

Jan. 10, 1967 R. E. ADAMS CONTINUOUS FLOW COUNTER-CURRENT LIQUID AND SOLIDS CONTACT APPARATUS 4 Sheets-Sheet 1 Filed Jan. 4, 1965 INVENTOR ROBERT E. ADAMS ATTORNEY Jan. 10, 1967 R. E. ADAMS CONTINUOUS FLOW COUNTER'CURRENT LIQUID AND SOLIDS CONTACT APPARATUS 4 Sheets-Sheet 2 Filed Jan. 4, 1965 INVENTOR ROBERT E ADAMS R. E. ADAMS CONTINUOUS FLOW COUNTER-CURRENT LIQUID Jan. 10, 1967 AND SOLIDS CONTACT APPARATUS 4 Sheets-Sheet :5

Filed Jan. 4, 1965 Jan. 10, 1967 R. E. ADAMS CONTINUOUS FLOW COUNTER-CURRENT LIQUID AND SOLIDS CONTACT APPARATUS 4 Sheets-Sheet Filed Jan. 4, 1965 INVENTOR ROBERT E. ADAMS [sf 1W.

ATTORNEY 3,297,043 CQNTINUUUS FLUW C(IUNTER-CURRENT LIQ- UID AND SGLIIIS CUNTAET APPARATUS Robert E. Adams, Hudson, NXL, assignor to Gifford- Wood, Inc., Newton, Mass, a corporation of Massachusetts Filed Jan. 4, 1965, er. No. 422,943 Claims. (tCl. I34-6tl) This invention relates to counter-current liquid and solids continuous contact apparatus, commonly called a counter-current contactor.

An object of the invention is to provide a horizontal counter-current contactor which provides continuous, uniform liquid-solid contact for extracting, leaching, ion exchange, decoloring, deodorizing, crystallizing, washing, flotation processes and the like.

An important feature of the invention resides in the provision of adjustable paddles arranged to form an interrupted helix, the paddles slowly lifting the solid material from a trough, tumbling it gently and advancing it upstream continuously counter to the direction of liquid flow.

A further object and feature of the invention resides in the provision of novel and simplified means for transferring solid material from one trough to the next trough of the apparatus or to any appropriate vessel or conveyor.

Another object is to provide an apparatus of the mentioned character which may be constructed in units and which units may be arranged in a variety of ways to accommodate a number of related processes.

Some of the operating advantages of the apparatus are the following: it allows continuous operation without down time for repacking columns, flushing, or regenerating; continuous counter-current flow also eliminates startof-run and end-of-run differences, allows controlled uniform efi'luent; samples or side streams of liquid or solid material or both may be removed or introduced at selected points; gentle lubricated tumbling of solids minimzes or eliminates attrition of valuable solids such as ion exchange resin beads; the contactor may be jacketed for heat transfer, if desired; troughs can be rubber-lined, if desired; for certain applications wipers may be added to the paddles to provide a continuous self-cleaning action.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this application and in which like numerals are employed to designate like parts throughout the same,

FIGURE 1 is a plan view of a basic unit of the apparatus embodying the invention;

FIGURE 2 is an enlarged transverse vertical section taken on line 22 of FIGURE 1;

FIGURE 3 is a fragmentary vertical section taken'on line 3--3 of FIGURE 2;

FIGURE 4 is a perspective view of a solid material transfer scoop;

FIGURE 5 is an enlarged transverse vertical section taken on line 5-5 of FIGURE 1;

FIGURE 6 is a fragmentary sectional view similar to FIGURE 5 and illustrating a different operating position of a transfer scoop and associated elements;

FIGURE 7 is a perspective view of a modified form of transfer scoop;

FIGURE 8 is an enlarged fragmentary side elevation of a rotary shaft and adjustable paddles forming a feature of the invention;

FIGURE 9 is an enlarged fragmentary vertical section taken on line 9-9 of FIGURE 8;

FIGURE 10 is a flow diagram for the basic unit shown in FIGURE 1; and

3,297,943 Patented Jan. IQ, 1%67 FIGURE 11 is a partly diagrammatic plan view of a system utilizing a plurality of the basic units shown in FIGURE 1.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of the invention, attention is directed first to FIGURES 1 through 10 of the drawings, pertaining to a single basic unit of the invention apparatus. In these figures, the numeral 20 designates a single independent unit of a counter-current contactor in its entirety. The unit 2t may be supported at the desired elevation on a suitable supporting framework or leg structure, not shown, and forming no part of the present invention.

The unit 2@ consists basically of three parallel

elongated U-shaped troughs

21, 22 and 23 which are of equal length and which extend substantially for the entire length of the unit Zii. The vertical side walls 24- of the three troughs are all of the same height and the two

outermost troughs

21 and 23 have outer side walls: 25 which extend above the tops of the side walls 24-, FIGURE 2. The outermost side walls 25 are strengthened by a series of crossbraces 26 interconnected with longitudinal bars or braces 27. Any alternate structure may be employed to render the shell of the unit 25) sufiiciently rigid, the shell being formed of sheet metal. The unit 20 may also embody an underlying casing or housing 28 below the bottoms of the

several troughs

21, 22 and 23.

Within each

trough

21, 22 and 233 and extending lengthwise and centrally therein for the entire length thereof is a rotary shaft having secured thereto adjustably a plurality of radial paddles 34], which collectively form an interrupted helix. As will be fully explained, the paddles 3t) lift solid material from the bottom of the trough, tumble it gently and advance it upstream counter to the flow of liquid through the trough, the liquid moving by hydraulic gradient and not requiring a pressure feed.

Each paddle 30 is a fiat plate element having diverging side edges SI and a circularly curved peripheral edge 32. The paddle is rigidly anchored to an adjusting rod 33 which in turn is connected with the rotary shaft 2? by means of adjustable screw-threaded part 34, or the like, as shown in FIGURE 9. Other forms of connections 'between the paddles 3th and shaft 29 may be employed. In any event, each paddle 3% may have its pitch or angle changed with reference to the shaft 29 as depicted in broken lines at the left-hand portion of FIGURE 8. The adjustability of the paddles enables them to be accurately set to elevate various solids from the bottom of the trough. Some solids behave differently from others and the adjustability feature is therefore necessary. The paddles 30 are also set to overlap longitudinally of the shaft 29 so that the solids are gently tumbled from one paddle to the next while in maximum contact with the counter flowing liquid. The arrangement of the several base paddles to form an interrupted helix is basic in allowing the liquid to flow by gravity reversely to the advancement of the solids through the liquid stream. Intimate contact of the solids with the liquid is obtained without restricting liquid flow.

The end portions of the three shafts 29 are supported exteriorly of the end walls 35' and 36 of the multiple trough structure, FIGURE 1, by means of sturdy bearings 3 which may be bracketed to the end walls or suitably tied in to the underlying supporting frame structure, not shown. This outboard arrangement of bearings relieves the sheet metal trough structure from the direct support of the shafts 29'.

As shown in FIGURE 1, the three shafts are geared together at 38 and 39 to turn in unison and in the same direction as shown by the arrows in FIGURES 2 and 5. One shaft may be powered by suitable gearing 4t driven by an underlying variable speed drive not shown in the drawings. The unit 2ft may be of any practical length and the mechanical details of construction beyond those enumerated above are not important to the present invention.

The diagram in FIGURE shows the essential paths of solids and liquids through the basic unit an of the apparatus. The path of the solids is indicated by the solid line 41 and the path of the liquid by the broken line 42. The diagram clearly shows the counter flow of the liquids and solids through the three

troughs

21, 22 and 23. With continued reference to FIGURE 10, there is shown diagrammatically a solids outlet 43 at one end of the trough 21 and at this outlet there will be no liquid flow because the liquid is introduced into the trough 2i slightly downstream from the outlet 43. At the remote end of the trough 23, there is a liquid outlet 34 and solids are introduced into the system slightly upstream from the outlet 44. There are two additional points in the unit 20, FIG- URE 10, indicated at 45 and 46, where solids are transferred from one trough to the next without interfering with the counter flow of liquid. The structures shown particularly in FIGURES 2 through 7 of the drawings provide for these transfers of solids and/ or liquid from trough-to-trough or from unit-to-unit of the invention.

FIGURE 2 shows the three

troughs

21, 22 and 23 and 1 associated elements in cross section adjacent the liquid outlet 44 previously referred to in FIGURE 10. At the liquid outlet 44, a discharge receptacle 4'7 or the like is provided upon the outer side of the trough 23 at one end thereof, FIGURE 1. A vertically adjustable weir 48 is provided to regulate the outflow of liquid from the trough 23 into the receptacle 47, and this Weir also controls the liquid level in the entire system or in the three troughs of the unit 2t), It may be observed in FIGURE 2 that the paddles 30 in each

trough

21, 22 and 23 are properly pitched to cause advancing of the solids in the direction of flow indicated in FIGURE 10 by the solid line in that figure when the several shafts 29 are turning in the direction indicated in FIGURE 2. The liquid in the system of course flows in the opposite direction as previously explained.

The previously mentioned transfer point 45 for solids and liquid between the

troughs

21 and 22 is also shown in FIGURE 2. Means are provided at this point to transfer solids from the trough 22 to the trough 21, without interrupting the counter flow of liquid from the trough 21 to the trough 22. This means comprises, in FIGURES 2-4, a scoop device 49 for solids having a tubular hub 50 cross-bolted rigidly to the shaft 29 as at 51. The scoop device 49 therefore turns with the shaft 29 in trough 22. The scoop device comprises diametrically opposed reversely curved scoop blades 52 whose tips 53 pass close to the wall of the trough 22, as shown. The scoop device also has side wall pontions 54 integral therewith, in turn having outwardly flared terminal straight edge portions 55 for close contact with a coacting scavenger plate or scraper 56. The scavenger plate 56 has its upper end pivoted at 57 between a pair of the transverse braces 26 and has a bottom transverse lip 58 which rests upon the scoop blades 52 to scrape and transfer solids therefrom into the trough 21 during rotation of the shaft in the trough 22. The scavenger plate 56 is freely suspended under the influence of gravity and merely rises and falls by the camming influence of the rotating 'blades 52, FIG- URE 2.

To effect the actual transfer of solids and liquid between the

troughs

22 and 21, the adjacent side walls 24 are notched as at 59, FIGURE 3. This forms a horizontal edge 60 of reduced height over which the liquid can flow readily from the trough 21 to the trough 22 and this edge is well below the top edge of the liquid outlet weir 48. The rotating scoop device 49, FIGURE 2, coacting with the scavenger plate 56 elevates and smoothly transfers solids from the trough 22 to the trough 21 and over the edge of in the reverse direction to liquid flow. The scavenger plate 56 with the lip 58 continuously scrapes the solids from the two sections of the scoop device and forces them through the notch between the two troughs and into the trough 21.

With reference to FIGURE 5, the previously-mentioned transfer point i6 for solids and liquids is shown. Solids must be transferred from the trough 23 into the trough 22 while liquids flow freely in the reverse direction from the trough 22 into the trough 23, corresponding to the diagram in FIGURE 10. The adjacent trough side walls are again notched at 61, FIGURE 5, to provide a horizontal lip 62 identical to the previouslydescribed lip or edge 6%). The rotating scoop device 63 for solids at the transfer point 46 and the coacting scavenger plate 64 are identical in construction and operation to the previously-described

elements

49 and 56 and this structure and mode of operation need not be repeated herein. The arrangement, FIGURE 5, enables the counter passage of solids from the trough 23 to the trough 22 and liquid from the trough 22 to the trough 23 exactly as described previously in connection with the transfer point 45.

FIGURES 5 to 7 also depict a somewhat modified scoop and scavenger plate means for use at the solids outlet 43. The outlet 43 must discharge the solids from the trough 21 at a higher elevation than the transfer points 45 and 46 because at this point or outlet 43, no liquid is discharged from the unit 20. This feature becomes particularly important where multiple units 20 are employed in a more elaborate system employing multiple liquids, such as the system of FIGURE 11 to be described hereinafter.

In FIGURES 5-7, a scoop device 64 is shown including essentially flat parallel opposed scoop blades 65 whose tips operate close to the curved wall of trough 21. The blades 65 are connected by right angular extensions 66 to a hub 67 which is cross-bolted at 68 to the adjacent rotary shaft 29. The scoop blades 65 may be braced by diagonal braces 69 as shown. A somewhat modified scavenger plate or scraper 70 is pivotally suspended as at 71 from the brace bars 26 and a stop element 72 is provided on bar 26, FIGURE 5, to limit downward swinging of scavenger plate 70 as shown in FIGURE 6.

The outer side wall portion 73 of trough 21 is somewhat elevated relative to the edges 6% and 62 to assure that no liquid will be discharged at the solids outlet 43 and there is therefore a relatively high elevation discharge of solids from the unit 20 as is desirable. A suitable chute 74 or conveyor means or receptacle is provided at the solids outlet of the unit 20, FIGURE 5. The general operation of the modified scoop device 64 is similar to that of the scoop device 49. The scoop blades 65 and their side wall portions 75 scoop and elevate the solids from the trough 21 and the coacting scavenger plate 70 scrapes the solid material from the two sections of the scoop and transfers it to the outlet chute 74 without allowing any liquid outlet at this point. The basic difference in the apparatus at this point is the elevation of the outlet 43 and the scoop means has simply been modified for this reason. In other respects, the apparatus is essentially the same as previously described.

It should now be apparent with regard to the single apparatus unit 20 that the counter-current or flow pattern for solids and liquid depicted in FIGURE 10 is fully attainable in a controlled manner and in such a way as to allow continuous uninterrupted and uniform liquidsolid contact for a variety of processes.

FIGURE 11 of the drawings is a partly diagrammatic showing of four of the basic units 20 connected up in such a manner that several different liquids may be employed for contact with solids, without allowing intermixing of the liquids while still allowing ready transfer of solids from unit-to-unit of the system and from troughto-trough within a particular unit. The same counter flow of liquid within a particular unit of the system is also attained as in the prior basic form of the invention utilizing a single unit 20. Various systems can be devised with the apparatus unit 20 including systems involving series or parallel connected units. FIGURE 11 is illustrative of such a system.

The several units 20 in FIGURE 11 are basically the same as the unit described in detail previously, FIGURES 1-10, and will not be further described in detail. The system shown in FIGURE 11 provides for example an arrangement whereby several distinct liquids may be caused to contact a given solid, without any intermingling of the liquids and while the solids are transferred from unit-to-unit of the apparatus containing the various treatment liquids. There may be an ion exchange treatment in the unit 2t) at the bottom of FIGURE 11 followed by a first washing of the solids, a regenerative treatment at the top of FIGURE 11 and a second washing, as shown.

In FIGURE 11, the continuous path of solids from unit 20 to unit 26 of the system is shown by the solid line arrows 76. The counter flow of the particular liquid in each unit 20 is designated by the broken line arrows 77. From an inspection of these full line and broken line arrows in FIGURE 11, it is readily apparent that the particular liquid in each unit 20 remains in that unit and is not transferred to a next adjacent unit 20 and therefore does not commingle or mix with any other treatment liquid in the entire system. The solids, on the other hand indicated by the full line arrows, are trans ferred from unit-to-unit through the entire system to receive a separate treatment by a separate liquid flowing counter thereto in each unit 20. Various like systems can be devised with the basic unit 20 and FIGURE 11 is illustrative.

More particularly in FIGURE 11, solids enter a first wash unit 20 at 78 from an ion exchange unit of the system indicated at 79. There is a solids transfer means 80 at this point having one of the high level transfer scoops 64 and associated elements, previously described. The first wash liquid enters the first wash unit 20 as at 81 and flows counter to the solids in this particular unit. The solids are transferred at $2 to the next unit 2-8 at the top of FIGURE 11 by another one of the previouslydescri bed typical high level transfer means which prevents the transfer of liquid while effecting the transfer of solids. The first wash liquid discharges at 83 to a common sump 84 or the like, centrally located in the system.

The solids transferred at 82 discharge onto a short solids conveyor 85 carrying the same into a regenerant unit 2d at 86. Regenerant liquid flowing oppositely to the solids enters at 87 and is discharged at 88 in FIGURE 11. The solids are again transferred by transfer means 89 to a second wash unit 26 of the apparatus designated 90 in FIGURE 11. The second wash liquid enters this unit at 91 and is discharged at 92 to the common sump 8 after flowing counter to the solids in the three troughs of the particular unit. After the second wash of the solids, they are transferred at 93 to a conveyor 94 which carries the solids to the ion exchange unit 79. The ion exchange liquid enters this unit at 95 and discharges therefrom at 96. Each discharged liquid at a particular unit 20 of the system is controlled by one of the weirs 48 previously described, FIGURE 2. Each unit 20 has within it the previously described low level transfer points or means 45 and 46, see FIGURE 10, to allow transfer in the opposite direction of both solids and liquid within a particular unit 20 of the total system shown in FIG- URE 11. As stated, the several liquids of the entire system cannot and do not mix because of the high level transfer means for solids only between the several units 20.

It is thought that the versatility of the apparatus, its simplicity and its efiiciency of operation for a variety of processes will now be fully understood in view of the above description of the basic unit 20* and the typical system in FIGURE 11 employing a plurality of such units, it being understood that FIGURE 11 is in part diagrammatic.

It is to be understood that the form of the invention herewith shown and described may be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.

Having thus described my invention, I claim:

ll. A liquid and solids continuous contact counter flow apparatus comprising a body portion including a plurality of sideby-side substantially coextensive troughs, a rotary shaft extending longitudinally through each trough, a plurality of spaced generally radial paddles on each shaft collectively forming an interrupted helical flight on each shaft, screw-threaded means adjustably connecting each paddle with each shaft independently so that the pitch of each paddle along each shaft may be adjusted, poweroperated gearing connected with the shafts to turn the same in unison and in the same direction in said troughs, low level solids transfer rotary scoops on said shafts in certain adjacent troughs of said apparatus for transferring solids from trough-to-trough and allowing liquid to flow in the opposite direction from trough-to-troug-h, and a high level rotary transfer scoop on at least one shaft of one trough to lift and transfer solids therefrom and preventing liquid from passing out of the last-named trough.

2. A counter-current contactor for liquid and solids comprising a plurality of side-by-side elongated generally U-shaped substantially level troughs, a shaft extending rotatably and lengthwise through each trough, adjust-able pitch paddles on each shaft collectively forming an interruped helix on each shaft for advancing solids in one direction in each trough while permitting counter flow of liquid therein, means to drive said shafts in unison and in the same direction, low level transfer rotary scoops rigidly connected with certain of said shafts and driven thereby to transfer solids from one trough to another trough in said contactor and permitting counter flow of liquid between said troughs, a higher level solids discharge rotary scoop rigidly connected with another shaft of said contactor and driven thereby to lift and discharge solids from the contactor and retaining liquid therein, and a vertically adjustable weir on one side of the contactor to regulate the outlet of liquid from one of said troughs and also regulating the level of liquid in all of said troughs of the contactor.

3. The invention as defined by claim 2 and support bearings for each shaft spaced substantial distances outwardly of the ends of said troughs and relieving the troughs of the weight of said shafts, said shafts extending entirely through the troughs and beyond the ends thereof.

4. A counter-current contactor for liquids and solids comprising a plurality of side-by-side elongated generally U-shaped substantially level troughs, a shaft extending rotatably and lengthwise through each trough, adjustable paddles on each shaft collectively forming an interrupted helix on each shaft for advancing solids in one direction in each trough while permitting counter flow of liquid therein, each of said paddles being a substantially flat plate having an arcuate peripheral edge for close fitting engagement with one of said troughs, a rod carrying each plate and extending radially of one of said shafts, connector means between the rod and shaft allowing the rod to be turned on its radial axis to adjust the pitch of the plate relative to the shaft, means to drive said shafts in unison and in the same direction, low level transfer means connected with certain of said shafts and driven thereby to transfer solids from one trough to another trough in said contactor and permitting counter flow of liquid between said troughs, a higher level solids discharge means connected with another shaft of said contactor and driven thereby to lift and discharge solids from the contactor and retaining liquid therein, and an adjustable liquid outlet on one side of the contactor to regulate the outlet of liquid from one of said troughs and also regulating the level of liquid in all of said troughs of the contactor.

5. In a continuous flow liquid and solids contact apparatus, a substantially level trough adapted to have liquid flow therethrough continuously in one direction, a rotary shaft extending longitudinally Within said trough, an interrupted helical flight on said shaft turning there- With to advance solids through the trough opposite to the direction of liquid flow therein, a rotary scoop device on said shaft near one end thereof to elevate solids within the trough, said scoop device comprising a tubular hub engaging telescopically over said shaft, and a pair of diametrically opposed arcuate scoop sections on the hub and turning therewith and conforming to the cross sectional shape of the trough, each scoop section having a curved scoop blade and side wall portions, and a coacting scavenger plate suspended above the scoop device and serving to remove solids from the scoop device during rotation thereof, said scavenger plate operating freely between the side wall portions and having a scraper lip engageable with said scoop blade, said trough having a side opening near the scoop device for the discharge of the solids elevated by the scoop device and removed therefrom by the scavenger plate.

References Cited by the Examiner UNITED STATES PATENTS Re. 23,887 10/1954 Balluteen 134-132 X 2,074,788 3/1937 Holloman et al. 13460 2,548,996 4/1951 Morton 13465 X 2,576,183 11/1951 Irvine et al. 134132 X 2,857,878 10 /1958 Matson et al. 134104 X 3,054,230 9/1962 Logue 13460 X CHARLES A. WILLMUTH, Primary Examiner.

R. L. BLEUTGE, Assistant Examiner.

Claims

2. A COUNTER-CURRENT CONTACTOR FOR LIQUID AND SOLIDS COMPRISING A PLURALITY OF SIDE-BY-SIDE ELONGATED GENERALLY U-SHAPED SUBSTANTIALLY LEVEL TROUGHS, A SHAFT EXTENDING ROTATABLY AND LENGTHWISE THROUGH EACH TROUGH, ADJUSTABLE PITCH PADDLES ON EACH SHAFT COLLECTIVELY FORMING AN INTERRUPED HELIX ON EACH SHAFT FOR ADVANCING SOLIDS IN ONE DIRECTION IN EACH TROUGH WHILE PERMITTING COUNTER FLOW OF LIQUID THEREIN, MEANS TO DRIVE SAID SHAFTS IN UNISON AND IN THE SAME DIRECTION, LOW LEVEL TRANSFER ROTARY SCOOPS RIGIDLY CONNECTED WITH CERTAIN OF SAID SHAFTS AND DRIVEN THEREBY TO TRANSFER SOLIDS FROM ONE TROUGH TO ANOTHER TROUGH IN SAID CONTACTOR AND PERMITTING COUNTER FLOW OF LIQUID BETWEEN SAID TROUGHS, A HIGHER LEVEL SOLIDS DISCHARGE ROTARY SCOOP RIGIDLY CONNECTED WITH ANOTHER SHAFT OF SAID CONTACTOR AND DRIVEN THEREBY TO LIFT AND DISCHARGE SOLIDS FROM THE CONTACTOR AND RETAINING LIQUID THEREIN, AND A VERTICALLY ADJUSTABLE WEIR ON ONE SIDE OF THE CONTACTOR TO REGULATE THE OUTLET OF LIQUID FROM ONE OF SAID TROUGHS AND ALSO REGULATING THE LEVEL OF LIQUID IN ALL OF SAID TROUGHS OF THE CONTACTOR.