US3080065A

US3080065A - Insoluble separator

Info

Publication number: US3080065A
Application number: US828664A
Authority: US
Inventors: Arthur J Hunt
Original assignee: NA Douglas Mfg Inc
Current assignee: NA Douglas Mfg Inc
Priority date: 1959-07-21
Filing date: 1959-07-21
Publication date: 1963-03-05
Anticipated expiration: 1980-03-05
Also published as: GB909310A

Description

March 5, 1963 A. J. HUNT INSOLUBLE SEPARATOR v.

2 Sheets-Sheet 1 Filed July 21, 1959 fiNVENTOR. ARTHUR U, l/UA/T FIG] ATTORNEY March 5, 1963 A. J. HUNT INSOLUBLE SEPARATOR [C3 2 Sheets-Sheet 2 Filed July 21, 1959 INVENTOR. 4R7'HUE a. HU/VT 3,@,%5 Patented Mar. 5, 1953 3,080,965 INSOLUBLE SEPARATGR Arthur J. Hunt, flrraond Beach, Fla, assignor, by niesne assignments, to N. A. Douglas Mfg, lno, Brmond Beach, Fla, a corporation of Florida Filed July 21, 1959, Ser. No. 828,664 3 (Ilairns. (Cl. 210-414) This invention relates to means of separating insolubles from liquid solutions, and more particularly to a screw extractor for such and other purposes.

Numerous industrial processes are hampered by the problem of removing insolubles from liquid solutions. A typical example is in bottle washing and like processes where insoluble foreign substances are rapidly accumulated in the washing tanks and seriously reduce the effectiveness of the washing solution and cause contamination of the washing tanks.

In bottle washing facilities, a caustic neutralizing solution is generally used to carry solubles into solution and to serve as a so-aker for bottle labels and the like. The caustic solution is maintained in large tanks through which the bottles are carried on some form of conveyor system. In the course of soaking the bottles to remove labels and the like, a great deal of other foreign debris also collects in the tanks. The labels and other debris collect on heater lines, the sides and bottom or" the tanks, on the conveyor means, etc., and generally disrupts th bottle washing operation. Such debris also contaminates the caustic solution and materially reduces its effectiveness within a relatively short time. An undue build-up of such foreign matter in a washing tank will even raise the liquid cleaning solution to the overflow level and soon cause a material reduction in the effectiveness thereof.

All previous attempts to remove insoluble impurities from bottle washing and similar cleaning solutions have failed in one respect or another. Accordingly, it is common practice in bottle washing facilities to either have appreciable down-time for tank cleaning purposes, or to have a separate and distinct stand-by unit ready 'to be placed in operation.

Aside from the expense of down-time and rejuvenation of a washing tank, large quantities of caustic compound are required to be used in attempting to maintain a standard of cleanliness during washing operations and are unfortunately lost as a result of tank flushing and cleaning operations.

It is an object of this invention to disclose a simple and effective means of extracting insolubles irorn liquid solutions.

It is also an object of this invention to disclose means of continuously extracting insolubles from liquid solution to prevent the build-up of solution contaminating substances therein.

Another object of this invention is to disclose a complete system for continuous rejuvenation of cleaning and like solutions without frequent recharging or down-time.

Still another object of this invention is to disclose an extractor particularly suited for separating insolubles from liquid solutions, and without diminishing the effectiveness of such solutions when used for cleaning purposes.

A further object of this invention is to disclose and teach the use of an extractor screw and suitable fluid agitation for the most effective use thereof.

Still further among the objects of this invention is to disclose and teach the use of a vertically disposed extractor of insolubles from liquid solutions in combination with a scraper-strainer for more eficient and efiective operation thereof.

Yet another object of this invention is to arrange the extractor of insolubles in a vertically disposed position such that the discharge for the pulp mass is elevated in relation to the level of the solution washing tank and is arranged in a circulating system on the suction side of the pumping means, whereby there is no syphon effect produced upon shut-down of the system; and as a further feature it is an object to return the fluid after separation from the pulp mass to the washing tank and to direct the flow in such manner that force of the pumping means serves to cause the agitation of insolubles in the washing tank and movement thereof toward the exterior.

Even further among the objects of this invention is to disclose a means of extracting insolubles from liquid solutions in a dry pulp mass for easier handling and conservation of the strength and effectiveness of the liquid solutions.

The apparatus disclosed by this invention is readily adapted for use with new and older equipment and accordingly enables a quick field change for improved operational efiiciency.

The aforementioned and numerous other objects and advantages in the practice of this invention will be more apparent upon a reading and study of the following description of a working embodiment of the principals involved, and with particular reference to the accompanying drawings.

in the drawings:

FIG. 1 is a pictorial illustration of the disclosed xtractor unit and filter system for use with bottle washing equipment.

FIGURE 2 is an enlarged cut-away and cross-sectioned view of the disclosed screw extractor and scraper-strainer sleeve assembly.

FIGURE 3 is a diagrammatic top plan view of a bottle washing tank with the disclosed system incorporated for use therewith.

FIGURE 4 isv a diagrammatic side plan view of the disclosed system in use with bottle washing equipment.

The principal components of the disclosed invention, as used to rejuvenate bottle washing solutions, include a l9, strainer and extractor unit 26, a fluid flow pump on, and a filter unit 70.

The bottle washing tank It is such as any reservoir tank having a prescribed level of a caustic bottle washing solution 12 maintained therein. A conveyor system 14 passes through the tank lid and carries bottles 16 to be washed through the caustic solution.

A certain liquid level and caustic consistency is required to be maintained in the cleaning tank 10. Accordin ly, as previously mentioned, prior practice has required frequent additions of caustic compounds to the washing solution and periodic shut-downs to enable cleaning the tanks of debris that collects therein.

A planned system of circulating the weakened and ineifective caustic washing solution is provided by this invention to remove impurities and regain the required l vel of causticity without requiring the use of additional large quantities of expensive caustic compounds.

An outlet connection 18 is provided between the tank 39 and the strainer and extractor unit 2%. The outlet connection, at the tank It is made near the bottom and at one side of the tank. Such connection is preferably made as straight as possible to avoid elbow connections and the like where debris from the tank lit might collect.

The strainer and extractor unit 25 include an elongated and tubular housing member 22 having the outle connection 18 from the tank it connected near one end thereof. The housing 22 is intended for a vertically and slightly inclined disposition, as shown by FIGURE 1. A fluid outlet fiow connection 24 is provided in spaced ver tical relation to the tank outlet connection 18; which serves as the inlet to the housing member. I

Within the tubular housing 22 is concentrically disposed a strainer sleeve 26. This screen-like or perforated member is spaced from the end of the housing 22 to provide a collecting chamber 28 at the bottom thereof for the incoming solution and insolubles from the tank 10. A tapered neck 36 is secured to the end of the strainer 26 to provide a graduated entrance to the strainer part. The strainer sleeve 26 extends past the housing outlet 24 and substantially the full length of the housing member.

A smaller diameter extension part 32 is secured to the end of the housing 22 by means of

complementary flanges

34 and 36 on the respective parts. Extension part 32 extends to an elevation in relation to tank 16 (FIG. 4) such that the solution level is below the outlet end so that there is no syphon effect created or drainage and loss of solution when the apparatus is shut down. The strainer sleeve 26 is engaged and centered by the extension part 32 at its upper end; as shown by FIGURE 2.

A11 extractor screw 38 is disposed centrally within the housing 22 and through the strainer 26. The screw 38 includes a shaft 40 with a full bladed helix feed screw 42 provided thereon. The feed screw blades extend from within the chamber area 28 to and just beyond the end of the strainer 26. The screw is intended to wipe the inner surface of the strainer. 26 and to feed any substances collected thereon towards the open upper end of the housing.

One or more wiper blades 44 may be provided peripherally of the screw blades 42 and within the tapered neck 39 at the lower end of the separator sleeve 26. These afiord additional wiping in such areas and prevent a buildup of debris that might causev binding of the screw in this vicinity. It WTll be appreciated that fluid flow is from the collecting chamber 28, centrally into the strainer 26, and through the perforated or otherwise ventilated side walls thereof. The annular space 46, between the strainer and housing walls, above the outlet fluid flow connection 24, enables a fluid head to be maintained in the housing which adequately covers the fluid outlet 24 and enables drainage through the strainer thereover. Neck 30 serve to separate chamber 28 from space 46 and comprises means for resisting the passage of insolubles from the inlet chamber 28 into the space 46, and in the illustrated embodiment, the neck is screen like or perforated in the manner of the sleeve.

More particularly in view of the showing in FIGS. 2 and 4, the system of tank 10, extractor 22, and the connecting conduit means 18, 24, 62, 64 and 68 is arranged to have a static condition, with the pump 66 non-operative, such that the level of cleansing solution in the tank 19 is substantially the same in the bore of perforated separator sleeve 26 and in the annular space 46 in housing 22. The extension part 32 is always open to atmosphere so that there is no plug condition to prevent the space 46 from being at atmospheric pressure just as is tank Upon start-up pump 60 the fluid to be reclaimed and returned to tank 10 for reuse is first drawn from the column in the space 46 above the elevation of outlet 24, which draw-down causes a static head diflerential between the level in the sleeve 26 and space 46. The differential head permits free fluid to pass outwardly to the space 46 whereby a static head differential is caused between the level in sleeve 26 and tank 10. The higher tank level thereby tends to feed the sleeve 26 to restore the equilibrium, but the pump 61) keeps the differential head between space 46 and sleeve 26 so that the flow from tahk 10 continues by the difierential level condition. In this system, therefore, the pump 60 draws fluid from the space 46 and not from the tank 10, and the level of fluid in the space 46 tends to rise or fall as the flow of fluid burdened with insolubles varies in its density of the insolubles. The less insolubles in the flow over from tank 10 means that there is less resistance to fluid flow and the level in the sleeve 26 rises which also raises the level in space 46. More insolubles in the flow, as when a slug of the same is entrained, increases the resistance so that the pump 4. drawn-down in space 46 lowers the level to increase the difierential head between the tank 10 and sleeve 26 which responds by increased flow from the tank 10. Thus the system tends to correct itself and reach an equilibrium condition because the tank and extractor are both Working at atmospheric pressure.

The feed screw 38 is suitably journalled within the lower end cover 48 of the housing 22. The shaft 40 is engaged by a tapered pin 50 to a coupling shaft 52 which extends through a Water tight gland in the cover 48. The coupling shaft 52 is engaged to the out-put shaft 54 of a suitable reduction gear unit 56 driven by a motor 58. The motor and reduction gear assembly are mounted on a stand 59 which also serves to support the tubular housing 22. It will be appreciated that the

flow connections

18 and 24 afford intermediate support for the housing, adequate for the slight inclination required (and which is some.- what exaggerated in FIGURE 1).

A fluid circulating pump 60 is connected to the outlet 24 from the housing 22. the debris laden washing solution into the strainer 26 and extracts the cleaner solution therethrough. The insolubles are left on the upstream side of the strainer 26 and are extracted by the feed screw 38 through the open upper end of the housing member.

The circulating pump 60 passes the cleaner washing solution directly into a return flow line 62. The return line 62 is divided into

separate flow lines

64 and 66 which enter the side of the tank 1! and extend towards the opposite side thereof. The return flow may be directed against the opposite tank wall. However, best fluid. agitation and circulation is obtained in the use of a reverse nozzle arrangement 68 at the end of each of the

return lines

64 and 66. By directing the return flow back towards the tank outlet 18, a more direct and positive circulation is obtained. The positive circulation from nozzles 63 is toward the suction line 18 so that insolubles collecting at the tank bottom are agitated toward the line 18 and the tank is thus constantly being flushed so that contaminating substances do not remain in the tank for any extended periods. 7

A filter unit 70 is connected into the return flow line 62 by a connecting flow line 72. The filter unit 70 is of the conventional type used to remove soluble impurities and minute particles from fluid passing therethrough. Fluid flow from line 72 is directed into the top of the filter unit 79 and returns from the bottom. The return line 74 from filter 70 is directed to the top of the tank 10 and is preferably disposed directly over the conveyor 14 to flush any labels or the like collected thereon.

A fresh water line 76 (FIG. 1) is connected to the filter unit 70, for back washing purposes, and a back wash drain line 78 is provided. The fresh water line 76 connects through flow line 80 to the filter feed line 72 and through conduit 82 to the bottom of the tank for other flushing purposes.

Suitable control valves

84 and 36 are in the fresh water lines 8%) and 82, a pressure gauge 88 and valve 9t) is in the filter feed line 72, and

valves

92 and 94 are in the pump line 62 and drain line 78, respectively.

It will be appreciated, though not illustrated, that other control valves may be incorporated into the disclosed system for better flow control. For example, the

tank lines

64 and 66 may include valves which enable one or the other to receive full return flow for periodically reversing the circulating flow pattern in the tank.

An upright funnel 96 is shown by FIGURE I mounted on a stand 98 and having its funnel end 10! disposed under the upper end of housing 22. This accessory item is principally to enable collecting the paperand other pulp extruded from the strainer-extractor unit 20 in the course of its operation. The funnel shank 162 is hollow and open at its lower end to enable collection; of'the pulp mass in a bucket which can be placed under the supporting stand.

Accordingly, the pump draws Operation and Use The disclosed fluid circulating and cleaning system is extremely efficicnt for removing bottle labels and other debris, and as a washing compound filtering unit. The disclosed equipment is intended to operate continuously with the bottle Washing machine. It may also be left in operation after the bottle washing equipment operations are concluded for the day. It is intended to change the Washing solution in the washing tank very rapidly and many times per hour. In this manner it draws all floating labels and heavier foreign matter away before they can settle. The extractor screw 38 handles all labels, small pieces of glass and miscellaneous items which collect in the tank it in the course of bottle washing operations.

The combination strainer and extractor unit is preferably installed near one side or end of the tank it to be treated. Valves and fittings complementary to the inlet connection 18 to the sludge removing extractor unit are used and the tank connection is made as near the tank bottom as is possible. The extractor unit 20 is then tilted up until its end 32 is above the operational water line in the tank 14?. This assures against overflow through the housing 22 during normal cleaning operations.

After the pump 6 is connected to the outlet line 24 from the extractor unit 20, its rotation should be checked to assure that it will draw water from the extractor and return it to the tank it).

The return line 64, and more particularly lines 66 and 68, from the pump 64? are cut into the tank 143 at the far side or end from the outlet 13. This assures a good sweeping movement in the fl w of fluid through the tank and back for recirculation through the cleaning units.

. The flow lines to the filter 7d are more or less conventional, as mentioned. However, it is preferable to have the filter lines of smaller size than the separator lines to enable more frequent circulation through the separator unit 26 than through the filter 7%. Only a part of the fluid flow need pass through the filter 7t) during the fluid circulation due to the large quantity of fluid being moved.

, In cases where the washing tank I includes a dividing plate across its bottom, it is advisable to cut moderate size holes through the divider wall and to pipe the

return lines

66 and 68 on opposite sides thereof. This enables labels and other debris to move from one section of the tank to the other and control as regards forcing labels from side or the other by closing off one of the flow lines 65 or 63.

Although the disclosed system will remove accumulated labels as Well dirty caustic solutions, it is preferable to start with a clean machine.

Upon the opening of the proper valve to the separator and extractor housing 22, the water level will rise to that in the tank it Operation of the pump as will reduce the liquid head slightly but not enough to uncover the outlet 24. Accordingly, the pump 69 is always primed and ready for operation.

Operation of the pump 6b and of the drive motor 58 are initiated together, in most instances. The pump begins to draw caustic washing solution from the tank 19 and through line 13 into the separator housing 22. The liquid solution with its labels and other foreign matter is drawn into the strainer sleeve 26, but only the liquid is drawn through the perforated or otherwise ventilated sleeve member. The size of the openings in the separator sleeve to a large extent determine the degree of cleanliness obtained.

As the bottle labels and other foreign matter collects on the inside of the separator 26, the feed screw 38 is turning and its helical blades scrape the strainer clean and carry the debris upward. The paper and lighter substances swirl and wrap about heavier particles and both are carried to the height of the liquid head in the separator housing 22. As this mass builds up, the substances collect on the blades 42 and build up until the pitch space is filled. Continued action causes a compression and wringing of the pulp mass along with movement out of the fluid and towards the open end of the housing. The surplus liquid wrung from the extruded pulp mass falls through the separator screen 26 and into the annular space 44 from whence it is returned to the tank 10.

The cleaner fluid, with the labels and other debris separated out, flows through the pump 60. A part of the return flow passes through the filter unit 70 where other smaller impurities and certain soluble substances maybe extracted and removed from the caustic washing solution. The filter acts independently of the rest of the unit and at a slower rate. It is separated from the separator unit to enable a faster displacement of the bottle washingcompound and greater assurance of capturing labels in suspension and on the tank bottom by rapid and uninterrupted flow through the separator.

A faster flow through the filter is obtainable by proper manipulation of the correct shut-off valves. However, it must be remembered that any appreciable restriction in the flow of the caustic washing solution through the major flow lines may seriously affect the movement of labels and other insolubles in the tank 10.

The filter is readily shut-off from the rest of the installation and back-Washed whenever considered necessary. Periodic inspection of the filter output is advisable to avoid undue restriction of flow through the filter system.

Although this application has been directed principally to the use of the disclosed system in bottle washing operations, it will be appreciated that the system is equally applicable for use in any system or process requiring the separations of insolubles from a liquid fluid solution. This applies equally as well to systems in which the fluids or the insolub es are the necessary end product.

Although only one embodiment of this invention has been disclosed, it will be appreciated that certain modifications and improvements may be made for use in other and similar systems. Accordingly, the hereafter appended claims are intended to be inclusive of such other forms of this invention unless expressly denied by the language thereof.

1 claim:

1. A device for extracting insolubles from a liquid, said device comprising an elongated casing having one end higher than the other end and being provided with an inlet opening adjacent the lower end, the higher end providing a discharge opening, said casing having a body of cleaned liquid therein of which the surface level is spacedly above said inlet opening, a sleeve having an upper end portion engaging with said discharge opening and having a perforate portion extendin downwardly from said discharge opening spacedly within said casing and entering said body of cleaned liquid, said perforate portion of said sleeve terminating in a lower end located below said liquid level, means resistant to passage of insolubles joined to said sleeve lower end and extending outwardly therefrom and meeting said casing above said inlet opening, said means defining an inlet chamber communicating with the interior of said sleeve through its said lower end, a conveyor operatively mounted in said sleeve and having a lower portion Within said inlet chamber and an upper portion in said upper end portion of said sleeve and an intermediate portion contacting interiorly a part of said perforate portion of said sleeve which lies below said liquid level, said casing being provided with an outlet opening communicating with the space therein outwardly of said sleeve and above said means, and other means including said inlet and outlet openings for supplying liquid burdened with insolubles into said inlet chamber and for removing cleaned liquid from said space, said other means being operative to maintain said liquid level above a lower part of said perforate portion of said sleeve which is contacted by said conveyor, said conveyor being operative to raise insolubles through said lower part of said perforate portion of said sleeve which is under the level of liquid in said casing and progressively increasing the concentration of insolubles so raised toward the liquid level and thereafter to raise the insolubles into the perforate portion of the sleeve above the liquid level to drain liquid therefrom and finally to discharge the insolubles from the upper end of the sleeve.

2. A device for extracting insolubles from a liquid, said device comprising an elongated casing having one end higher than the other end and being provided with an inlet opening adjacent the lower end, the higher end providing a discharge opening, a sleeve having an upper end portion engaging with said discharge opening and having a perforate portion extending downwardly from said discharge opening spacedly within said casing and terminating in a lower end, means resistant to passage of insolubles joined to said lower end of said sleeve and extending outwardly therefrom and meeting said casing above said inlet opening, and means defining an inlet chamber communicating with the interior of said sleeve through its said lower end, a conveyor operatively mounted in said sleeve and having a lower portion within said inlet chamber and an upper portion in said upper end portion of said sleeve and an intermediate portion contacting interiorly said perforate portion of said sleeve, said casing being provided with an outlet opening communicating with the space therein outwardly of 'said sleeve and above said means, said outlet opening being located spacedly above said lower end of said sleeve, and other means including said inlet and outlet openings for supplying liquid burdened with insolubles into said inlet chamber and for removing cleanedliquid from said space, said other means being operative to maintain said liquid level above a lower part of said perforate portion of said sleeve which is contacted by said conveyor, said conveyor being operative to raise insolubles through said lower part of said perforate portion of said sleeve which is under the cleaned liquid level and progressively increasing the concentration of insolubles so raised toward said liquid level and thereafter to raise the insolubles into the perforate portion of the sleeve above the liquid level to drain liquid therefrom and finally to discharge the insolubles from the upper end of the sleeve.

3. A device for extracting insolubles from a liquid,

said device comprising-an elongated casing having one end higher than the other end and being provided with an inlet opening adjacent the lower end, the higher end providing a discharge opening, said casing having a body of cleaned liquid therein of which the surface level is spacedly above said inlet opening, a sleeve having an upper end portion engaging with said discharge opening and having a perforate portion extending downwardly from said discharge opening spacedly Within said casing and enterihg said body of cleaned liquid, said perforate portion of said sleeve being of constant size and terminating in a lower end located below said liquid level, means resistant to passage of insolubles joined to said sleeve lower end and extending outwardly therefrom and meeting said casing above said inlet opening, said means defining an inlet chamber communicating with the interior of said sleeve through its said lower end, a screw conveyor operatively mounted in said sleeve and having a lower portion within said inlet chamber andan upper portion in said upper end portion of said sleeve and an intermediate portion contacting interiorly a part of said perforate portion of said sleeve which lies below said liquid level, said casing being provided with an outlet opening communicating with the space therein outwardly of said sleeve and above said means, and other means including said inlet and outlet openings for supplying liquid burdened with insolubles into said inlet chamber and for removing cleaned liquid from said space, said other means being operative to maintain said liquid level above a lower part of said perforate portion of said sleeve which is contacted by said conveyor, said conveyor being operative to raise insolubles through said lower part of said perforate portion of said sleeve which is under the level of liquid in said casing and progressively increasing the concentration of insolubles so raised toward the liquid level and thereafter to raise the insolubles into the perforate portion of the sleeve above the liquid level to drain liquid therefrom and finally to discharge the insolubles from the upper end of the sleeve.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

1. A DEVICE FOR EXTRACTING INSOLUBLES FROM A LIQUID, SAID DEVICE COMPRISING AN ELONGATED CASING HAVING ONE END HIGHER THAN THE OTHER END AND BEING PROVIDED WITH AN INLET OPENING ADJACENT THE LOWER END, THE HIGHER END PROVIDING A DISCHARGE OPENING, SAID CASING HAVING A BODY OF CLEANED LIQUID THEREIN OF WHICH THE SURFACE LEVEL IS SPACEDLY ABOVE SAID INLET OPENING, A SLEEVE HAVING AN UPPER END PORTION ENGAGING WITH SAID DISCHARGE OPENING AND HAVING A PERFORATE PORTION EXTENDING DOWNWARDLY FROM SAID DISCHARGE OPENING SPACEDLY WITHIN SAID CASING AND ENTERING SAID BODY OF CLEANED LIQUID, SAID PERFORATE PORTION OF SAID SLEEVE TERMINATING IN A LOWER END LOCATED BELOW SAID LIQUID LEVEL, MEANS RESISTANT TO PASSAGE OF INSOLUBLES JOINED TO SAID SLEEVE LOWER END AND EXTENDING OUTWARDLY THEREFROM AND MEETING SAID CASING ABOVE SAID INLET OPENING, SAID MEANS DEFINING AN INLET CHAMBER COMMUNICATING WITH THE INTERIOR OF SAID SLEEVE THROUGH ITS SAID LOWER END, A CONVEYOR OPERATIVELY MOUNTED IN SAID SLEEVE AND HAVING A LOWER PORTION WITHIN SAID INLET CHAMBER AND AN UPPER PORTION IN SAID UPPER END PORTION OF SAID SLEEVE AND AN INTERMEDIATE PORTION CONTACTING INTERIORLY A PART OF SAID PERFORATE PORTION OF SAID SLEEVE WHICH LIES BELOW SAID LIQUID LEVEL, SAID CASING BEING PROVIDED WITH AN OUTLET OPENING COMMUNICATING WITH THE SPACE THEREIN OUTWARDLY OF SAID SLEEVE AND ABOVE SAID MEANS, AND OTHER MEANS INCLUDING SAID INLET AND OUTLET OPENINGS FOR SUPPLYING LIQUID BURDENED WITH INSOLUBLES INTO SAID INLET CHAMBER AND FOR REMOVING CLEANED LIQUID FROM SAID SPACE, SAID OTHER MEANS BEING OPERATIVE TO MAINTAIN SAID LIQUID LEVEL ABOVE A LOWER PART OF SAID PERFORATE PORTION OF SAID SLEEVE WHICH IS CONTACTED BY SAID CONVEYOR, SAID CONVEYOR BEING OPERATIVE TO RAISE INSOLUBLES THROUGH SAID LOWER PART OF SAID PERFORATE PORTION OF SAID SLEEVE WHICH IS UNDER THE LEVEL OF LIQUID IN SAID CASING AND PROGRESSIVELY INCREASING THE CONCENTRATION OF INSOLUBLES SO RAISED TOWARD THE LIQUID LEVEL AND THEREAFTER TO RAISE THE INSOLUBLES INTO THE PERFORATE PORTION OF THE SLEEVE ABOVE THE LIQUID LEVEL TO DRAIN LIQUID THEREFROM AND FINALLY TO DISCHARGE THE INSOLUBLES FROM THE UPPER END OF THE SLEEVE.