US2513836A - Liquid separating apparatus - Google Patents

Description

July 4, 1950 G. A. AUER 2,513,836

LIQUID SEPARATING APPARATUS July 4, 195o G. A. AUER 2,513,836

LIQUID SEPARATING APPARATUS Filed Aug. 6, 1945 2 Sheecs--Shee'kl 2 Patented July 4, 1950 UNITED STATES PATENT OFFICE 3 Claims.

This invention is concerned with. a hydraulic streamcurrent apparatus for Separating materials.

The termstreamcurrent-has been dened in Patents Nos. 2,386,419, 2,391,858 and 2,464,418. It refers to the control of a fluid or liquid body in motion for the purpose of producing rational hydraulically substantially stable agitation in the presence of which solid and fluid particles will exhibit a predictable behavior, as distinguished from unpredictable behavior of particles in a liquid or fluid medium which is agitated in a manner that produces irrational turbulence.

irrational turbulence is produced, e. g., by the operation, in a fluid mass, of mechanical elements, rotating paddles, stirrer arms and the like, whether they are driven directly orby hydraulic reaction. Such turbulence is characterized by meandering vortices and eddies, dead pockets, migrating variable fields of stagnation. It is ununiform, unpredictable, not subject to rational analysis. The separation of solid particles in and from such irrationally agitated turbulent mass, as heretofore practiced, is likewise un-uniform, unpredictable, therefore irrational.

Rational agitation is produced by streamcurrent control of a fluid medium as broadly dened above. materials, the term specifically means a rational hydraulic displacement of the body of a fluid separating medium which proceeds upwardly and laterally symmetrically outwardly with upwardly diminishing-` magnitude or upward velocity, and substantially without creating irrational turbulence therein.

The above noted co-pending patents may be consulted for antecedents, general principles and theoretical considerations which apply in the present case especially with regard to observations relating to the prior art and to the behavior oi' solids in liquids.

Some of the principal objects and features of the present invention may be briefly summarized as follows:

@ne object is to provide a separator equipped with feed means for supplying the raw material in adjustable, measured, uniform amounts, which are released either intermittently or consecutively in adjustable measured increments forming a steady uniform stream.

Another object is to provide a turbulence chamber containing a normally quiescent body oi liquid for receiving the raw material from the feed means intimated in the preceding paragraph and for subjecting the raw material in such liquid Applied to the hydraulic separation ofy body to irrational turbulence for the purpose of wetting the particles, breaking up. agglomerates, preventing packing, and generally for the purpose of thoroughly dispersing the particles in and intermiXi-ng them with the liquid.

A further object is to provide a separator having a separating chamber equipped with means for supplying liquid to its base, means for supplying liquid in upwardly decreasing lamounts centrally axially of the chamber, and a plurality of serially related ow control members forming a generally vertically extending now-distributing wall forming a series of vertically spaced, peripherally or circumferentially unobstructed outlets or discharge ports which permit selective withdrawal of liquid in upwardly increasing amounts fromV corresponding vertically spaced levels of the liquid body in the chamber.

Still another obj ect is to provide means forming settling chambers which communicate hydraulically With the body of liquid in the streamourrent chamber at vertically spaced levels thereof, and means for selectively withdrawing adjustable amounts of liquid from `said settling chambers and returning such withdrawn liquid to the inlet means for the purpose of creating in the separating chamber the streamcurrent displacement of the fluid body contained therein which proceeds upwardly and laterally outward ly, with upwardly diminishing'` magnitude or upwardly diminishing upward velocity, and substantially Without creating irrational turbulence therein.

The turbulently agitated, wetted and highly mobile raw material particles are discharged from the turbulence chamber downwardly in a steady stream directly and immediately into the path yof the upwardly directed streamcurrent flow, axially centrally thereof, and the particles can now orient themselves rationally in accordance with their specific gravities. rlhe lightest particles move laterally directly for discharge at the top of the separatingchamber, progressively heavier particles move downwardly and laterally outwardly for discharge through outlet ports disposed at vertical-ly downwardly successive levels of the liquid body in the separating chamber, and the heaviest particles gravitate downwardly to a bottom discharge port where they are Withdrawn. rIhere is no lost motion and no confusion. The separation is direct and begins instantly at the moment the particles enter the liquid separating medium which is subjected to the streameu-rrent displacement.

The invention also provides bleeder means extending from the turbulence chamber into the streamcurrent separating chamber for the purpose of draining fluid containing accumulated nes downwardly to avoid undesirable increase of the density of the liquid in the turbulence chamber.

Other objects relate to the provision of a secondary streamcurrent separator or sump for receiving the underflow from de-watering screens and for separating from such underflow valuable j fines, refuse lines, and returning residual liquid to the primary streamcurrent separator.

l These and additional objects and features are described below in detail with reference to the accompanying drawings, wherein scale; they are intended for illustrative and descriptive purposes only. Like parts are indicated by like reference numerals. Known elements will j be referred to only to the extent required for an understanding of the invention.

Referring now to Fig. l, the primary streamcurrent separator comprises a vertically disposed tank having an upper cylindrical section II and a lower inverted conical section I2. Inside of section I2 are provided inserts or baies I3-I'l. These bailles, in the embodiment shown, are cir- I2 settling and discharge chambers 21--3IL The upper end of the insert I'I extends in parallel with the cylindrical section II of the tank 'and forms the settling chamber therewith.

The material discharged through the outlet ports 2I-2U--|9--I8, respectively, flows into the chambers 27-28-29-30, respectively, and may be drawn 01T from the bottom of these chambers through the valve controlled outlets 3I--34, respectively. These outlets are schematically shown in the form of pipes. They may receive different form, e. g., the form of conduits terminating in conveyer or elevator casings, and slide valves of the type diagrammatically shown in Fig. 2 at ID3, in connection with the refuse discharge |02 may be used for regulating the flow of material from the outlets.

The inlet chamber 26 underneath the spillway 22, which spaces the baile I3 from the tank wall I2, is connected with an inlet controlled by the valve 35. Circular rows of slots, as indicated at 36, are provided at the bottom of the baille I3 for dilusing liquid injected into the chamber 26 through the inlet controlled by valve 35. These rows of slots may be replaced by an open port such as ports 2I-2Il-I3I*8, and the latter in turn may be replaced by slots Ias shown at '36. Either cular and each extends substantially in parallel with the outer tank wall. Each baiile may be supported in its position by suitable brackets which are not shown in the drawing. Upwardly successive inserts or ballles recede radially outwardly toward the outer tank wall. In other words, the bale I3 is spaced rwidest from the tank wall I2; the bafes Ill-I6 are progressively closer to the tank wall I 2; and the downwardly and inwardly directed lower end of baille I'I is closest to "the tank wall. The top edge of baile I3 accordingly overlaps the bottom edge of the baffle I 4 the top edge of baffle I4 overlaps thet bottom edge of baffle I5; the top edge of baffle I5 overlaps the bottom edge of baille I6; and the top edge of bale IIE overlaps the bottom edge of baille I'I.

This overlapping relationship of the baillesminimizes and substantially prevents theoccurrence of undesired irrational turbulence of uprising currents peripherally within the separating chamber.,

The baliles I3-I1 are vertically spaced as kshown in the drawing, to provide peripherally or circumferentially unobstructed po-rts or openings 1 I-8-2I for the symmetric withdrawal or discharge of material from the separating chamber. An

insert 22 is provided in back of the bottom bale structure provides a peripherally or circumferentially unobstructed communication with the liquid body in the separating chamber.

Arranged in parallel with the inlet controlled by valve 35 is an inlet controlled by the valve 31, and both in turn are connected with valve 38 which is part of the conduit coming from the pressure side of the pump 33. The inlet :controlled by valve 3l is connected with a pipe `lll eX- tending upward centrally axially of the separating chamber, as shown. The pipe "40 is provided with a series of vertically spaced outlets of upwardly progressively diminishing size. Therefore, liquid injected through the valve 31 enters the interior of the structure in upwardly decreasing amounts, as generally indicated by the relative prominence of the ilow lines. The openings in the pipe 40 may be circumferentially contiguous slots, as shown, e. g., at 216. The inlet pipe may be a structure assembled of pipe sections joined by tubular peripherally perforated sections forming outlet ports at each level where liquid is to be injected. Outlets which may be formed in a top closure operating as a spray-head are also provided at the upper end of pipe 40.

Liquid injected through the valve 35 into the inlet chamber 2B and through valve `3'I into the inlet pipe 40 diffuses through the slots 36 and through the ports in the pipe 40 and floods the interior of the separating chamber, moving upwardly and laterally outwardly with upwardly diminishing magnitude and velocity, as generally indicated by the relative prominence of the flow lines.

The discharge chambers 2'I-3B extend upwardly from the associated discharge conduits. They may be of considerable size, depending upon the ton-hour capacity of the separator, and function as settling chambers. The capacity of these chambers may be increased by making the outer tank cylindrical, as disclosed in the prior Patent No. 2,386,419 and Patent No. 2,464,418. The chambers are ilooded by liquid from the separating chamber and solids settle therein for removal through the discharge conduits, leaving clarified liquid on top. Valve controlled pipes 21a, 28a, 29a, 30a connect the [corresponding settling chambers with the conduit 1I, which feeds liquid to the pump 39 by-wayofthepipe1f5- Adjusted amounts of liquid can thus be iwithdraw-n from the settlingc'hambers, that is, from the various levels of' the liquid body inthe separatingchamber and symmetrically peripherally thereof. Suction pipes such asI Shown at 19. and 'L3 may. be provided, in. the settling chambers.

The flow of= liquid within the separatingv chamber is thus controlled:` by thenow-distributing wall formed by thel inserts or bafflesI l3--If1; by; the. manner of injecting liquid at the bottom through the inlet chamber 26- and the pipe 4Q, respectively; and by the amounts of liquid withdrawn in a controlled manner through the valve controlled outlets 28d-30a. The resulting displacement of the liquid body within the. separating chamber is the streamcu-rrent displacement previously referred to.

The` tank may be provided with a lid or cover 45. The cover forms centrally thereof a circular downwardly and inwardly dependingy flange 4B. A tubular open-ended feed conduit havingan inverted con-ical portion'li'l and an upper cylindric-al portion 48 is provided with brackets 49-50 which support it centrally of the cover 45, the inverted conical portion 41 depending downwardly centrally axially into the streamc-urrent sep-.. arating chamber. The ilange 4S depending from the cover also supports the conduit 41 and centers it in properposition with respect to the streamcurrent chamber. The open-ended bottorn of the feed conduit is disposed somewhat below the top discharge portl I'8. l

A hood 5| extends upwardly from the cylindrical portion 48 of4 the feed conduit and is provided with a chute 52 which connects with the discharge end of a hopper 53;.

At the lower end of the feed conduit 41- is provided a bearing 54, carried byl a s-uitable bracket, for journalli'ng the lower end of a shaft 55 which is journalled at its upper end in a bearing 56. A suitable driving mechanism, which may include bevelgears 51--58, is provided for rotating the shaft 55. The shaft also carries stirrer arms orpaddles 59-63.

The structure including the tubular feed conduit 41, with its shaft and stirrer arms, constitutes a feed passage for the r-awmaterial and the turbulence chamber of the. separatori The rawmate-rial drops from the hopper 53 through the chute 52= into the. liquid contained in thev feed conduit t1-4 and is subjected therein toirrational turbulence by the operation of the. paddles or stirrer arms attached to the shaft 5.5.

Secured to the tankcover 45- and depending therefrom is a peripheral; baiileor insert 655 forming a peripheral topy settling chambert. An, other insert or baille 611 is secured to the cover centrally thereof, forming with the wall of the auxiliary tank 4.1 an annular` axially. extendingv settling chamber 58.. Liquid drawn into. these chambers through the inlets atA the bottom. of` the inserts 65 and (ily is subjected to quiescentconditions, and solid material can therefore set-.1. tle downwardly inV these` chambers. Near and at the top of these chambers. there. will bei substantially clearliquid.

Disposed in the upper strata of the settling chamber 66` is a circular pipe 'l0 connected with the conduit 'l|- by way of the valve 12. A pipe. I3 is similarly disposed in the. settling chamber (i8` which. connects with the conduit ll; by way of the valve 1'4. Clear liquid withdrawn from the settlingl chambers. and (i8` can thus be pumped back and can be. injected by way of valves 35 and 3.1i into the inlet chamber 25., and into. the centrally disposed inlet pipe 40. The two settling chambers 6 6 and 618. form additional means for controlling the streamcurrent dis.- placement in the separating chamber by witha, drawal of liquid therefrom and reinjection ofthe liquid through the-inlet means- The mechanism for controlling the feeding of the rawv material from the hopper 5.3 into the apparatusk constitutes an improvement on the. structure disclosed in U. S. Patent No. 2,334,337: It, comprises a shield which extends. transversely across the hopper, being rotatably mounted at 8l on a shaft which is journalled in the sideV walls of the. hopper. This shield can thus be placed into the dotted line position, as shown in Fig. 1', or into the cross-hatched central position, or into a position opposite from that shown in dotted lines. Chute baffles 82-.8'3 are disposed within the hopper, as shown, for directing the raw'material downwardly and laterally inwardly against the shield 80:. When the shield 80 is disposed in the central cross-.hatched position, material flows downwardly on either side thereof.

.l When the shield is tilted to the left, into the dotted line position, material flows downwardly only` on the right side thereof, through the opening between the shield and the baffle 831; and when the shield is tilted to the right intov a position opposite to that in which itv isA shown in dotted lines, material flows downwardly only on the left side through the space, between the shield and the baiile 82. The shieldI 811 functions in this manner in the nature of a valve for directing the raw material downwardly alongv one or the other oralong both of its side walls.

Below the shield 8d and spaced therefrom is. disposed a tray having two tray members 8.5 and 85 which extend transversely across the hoppen just. as the shield 8i), in a plane perpendicularto the plane of the drawing Fig. 1 The tray members are separated by a central opening 81", as shown. This tray with its two members 85- 86, is mounted on opposite sides of the hopper by flanges such as 8,8.

An arcuate scraper having two Segmentashaped mounting members 8.9 is pivotally mounted on a shaft 99- disposed just below the pivot point 8| of the shield 8.0;. Stub. shafts may be used, one with eac-h of the segment-.shaped end plates 89. The scraper is provided with twoI scraper mem-. bers 9 l--S'Z depending downwardly in close proximity to the upper surface of the. tray members 85,-86. The shaft St of the scraper extends outside of the hopper housing 53 in back of the side wall thereof, as shown in Fig. l., and attached to the shaft is a rocher arm shown in dotted lines and indicated by the numeral 9.5.. This rocker arm coacts with a connecting rod 95 which extends from an eccentric operable by a shaft;

93. It will thus be clear that rotation of the shaft 98 causes rotation of the eccentric 9T and reciprocation of the connecting rod with consequent rocking motion of the lever or arm 95 and rocking motion of the Scrapers Slm-52 with respectto the tray members 851-36.

TheI tray and its members Sii-86, and also the tray-like memberI carrying the Scrapers Slm-92; are sov shaped and dimensioned that raw.Y material dropped downwardly normally assumes an angle of repose which inhibits the free downward flow thereof. if the shield tu is disposed; centrally, as shown in cross-section, material; flows downwardly on1 either side thereof and piles up on the tray members (i5-86. Reciprocation `various points along the arm 95.

` material.

\ may likewise be provided as desired.

of the scraper by the varm 95, responsive to rotation of the eccentric Sl, results `in ejection of consecutive increments of material alternately from the left and right of the tray members 854-86. The stroke with which the arm 95 is reciprocated may be regulated by placing the lower end of the connecting rod 56 adjustable at For this purpose the arm 95 may be provided with a series `of holes for variably attaching the connecting rod S6.

It will be seen from the above description of the feeding device that raw material may be fed from the hopper downwardly into the separator in adjustable measured amounts, either intermittently or in a steady stream composed of consecutively released measured increments of The amounts or increments released in'either case are adjustable by the stroke of the rocker arm 95 and the frequency of release of material is adjustable by the speed of operation ofthe eccentric 9T. The feed mechanism prevents erratic and haphazard supply of raw material to the separator, thereby preventing overloading or underfeeding of the liquid separating medium. The optimum feed can be easily determined for any given raw material which is to be subjected to separation.

The operation of the separator may be described with reference to both Figs. 1 and 2. For the `sake of convenience, it will be assumed that the raw material is coal within a size range from about 1/4" to 0".

The machine is first filled with water which l is obtained from the makeup water conduit lllll, `being pumped into the separator by the pump 39 through the valves 38, 35 and 131. Valves l2 and M, and also the valves in the pipes 21a, 28a, 29a and 30a, are closed during the initial lling z operation. The valve IUI (Fig. 2) in the return f `water line from the sump is likewise closed.

Suitable vent valves'inay be provided wherever desired or necessary so as to allow the escape of air from the various chambers. A level gage Water rises within the separator up to a predetermined level near the cover of the machine. If desired, a float may be provided for controlling the initial lling operation and for automatically maintaining a constant level in the separator during the operation thereof. It is, of course, understood that the cover may be dispensed with and suitable means may be provided for supporting the various baffles and inserts and also the feed conduit 41. The upper cylindrical portion Il of the separator tank may for this purpose be extended upwardly as may be necessary. It should be observed that water also rises within the feed conduit 41, providing the normally quiescent body of liquid for receiving the stream of raw material.

The drive mechanism, including the gears 551-58, may then be started to rotate the paddles 59--63 to provide turbulence within the feed conduit 41. Streamcurrent circulation is started in the separating chamber by openingthe valves 12 and 'M and the valves in the pipes Zia- 30a to circulate water from the various settling chambers downwardly for reinjection through the inlet chamber 26 and the centrally axially extending pipe 40. Upward streamcurrent displacement of the body of water within the separating chamber in accordance with the flow lines upwardly and laterally outwardly is th initiated.

The magnitude of the streamcurrent displacement is, of course, dilerent for any given raw material and is adjusted in accordance with the specific gravity of the particles and/or particle sizes which it is desired to save and to reject, respectively. For example, the upward terminal velocity of the streamcurrent flow at the top discharge level I8 must be different in case of coal of 1.35 specic gravity and a size range from 1A to 0 than in case of heavier coal within a different size range. Material containing a great amount of ines may require different treatment than material which is relatively free of nes. In the latter case, which is assumedfin the drawings, it may be decided to discharge the lightest components at the top port I8 through the discharge conduit 34, and in the former case, it may be preferable to remove only or mainly the lines at the top level and to discharge -relatively line-free lightest particles through the port 9 and dischargel conduit 33. These examples are given for convenience of description and do not indicate any inherent limitations as to the precise procedure which may be called for in any actual operation. The structure presents many operating possibilities for creating practically any desired uprising current condition.

The streamcurrent flow which is adjusted must also be` correlated with the amount of material fed into the machine for separation therein, and with the amounts of material, separated products as well as water, which are withdrawn in operation from the bottoms of the various discharge and settling chambers 21-3. It is, of course, possible to leave the proper valve settings to the operator in the field, as it is being done with previously known separators, who simply starts the machine as described and then starts feeding raw material thereto, samples the various discharged products, and makes corrections, as may be required, by setting the various valves and adjusting the raw material feed so as to obtain the desired separation.

The present invention furnishes the possibility of calibrating the various adjustments, raw material feed, speed of rotation of theshaft and paddles inthe turbulence chamber formed by the feed conduit, and settings of the various valves, in accordance with the needs of any-given raw material. This is done by operating the machine through a number of test runs, under supervision of the factory, using materials whose analysis is known, and Calibrating index means provided with such adjustments in terms of particle size and/or specific 'gravities Water meters may be used for such calibrating or preadjustment in connection with the various valves so as to permit calculation of the upward displacement within the separator from the amounts of liquid which is displaced at each level of the liquid body. With such calibration, the operator in the eld merely has to know the analysis of the raw material which he wants to treat and sets the adjustments' accordingly, as specied by the factory.

The separator being lled with water, and streamcurrent displacement as well as turbulence in the turbulence chamber being in operation, as previously described, the machine is now ready to receive the stream of raw material particles, which is also adjusted to anoptimum, and to perform the pre-treatment in the feed conduit and the `separation in the separating chamber.

The raw material is fed into the hopper 53'by '9 a suitable feeder, and rotation is imparted to the shaft 98, at a rdesiredfspeed, so as to actuate the eccentric 91 `for 'the purpose of reciprocating the Scrapers 9| and 92. Assuming that the feed device is inthe vlposition 'shown in Fig. 1, we will have a continuous now of material downwardly through the vfunnel A52 into the machine. The amount of material thus supplied in a-continuous regulated stream may be variable vfrom Va minimum to a maximum .by adjustment of the connecting rod 96 with respect to the rocking lever 95 and adjustment vof the speed of the eccentric 91. The material drops down into the turbulence chamber formed by the feed conduit 41 and is subjected therein to irrational turbulence provided by the rotating paddles 59-63.

The purpose of subjecting the material to irrational agitation will be clear from what has been said before. Agglomerates are broken up and the raw material .particles are distributed or dispersed in the liquid body within the feed conduit. It should be observed that the paddles 59-63 are successively tilted in valternate directions. The purpose is to vprovide for maximum agitation by imparting to the mass in the feed conduit not lonly La rotary beating and churning force but also alternate izones in which the mass receives upward and downward thrusts, respectively. Stationary ba'iiles projecting from the inner wall of the feed conduit may be provided, if desired, to aid in `imparting turbulence ,and to break the rotary motion` of the turbulent mass which it otherwise would assume. Rotary motion imparted tothe mass by the bottom paddles 63 is lbroken by the stationary bracket which secures the bearing 54; Any practically desired degree of turbulence may thus be produced.

The agitation .and the turbulence produced within the feed conduit is wholly irrational, in the sense explained before. it furnishes the desired dispersion of the raw material in the liquid and imparts to the .particles the mobility which is required for motion through the liquid ,separating medium. The wetting of 'the particles is believed to be important because occluded air or a surface nlm of gas surrounding a particle changes its apparent specific gravity in the separating medium vand 'creates confused conditions. The airis removed in the present case and the particles are wetted, that is, they are surrounded by a lrn of liquid of the dispersion medium and therefore offer no resistance to movement through the separating liquid. They are mechanically mobile and therefore respond instantly to the 'streamcurrent flow upon ejection from the turbulence chamber downwardly directly into the path of the streamcurrent flow in the separating chamber. It should be observed that the particles 4do not plunge into the liquid in the streamcurrent chamber but are eased into it from above. The irrational mixing and wetting operation may require a considerable degree of irrational turbulence which under orthodox operations would make separation quite impossible. In the present case, the irrational turbulence accomplishes its purpose without affecting rational separation.

The lightest particles, 'or fines., depending upon conditions previously mentioned, travel directly upwardly and laterally outwardly with the similarly directed currents in the streamcurrent chamber; the heavier particles move directly downwardly through the upwardly directed streanicurrent flow and successively laterally outwardly to the respective outflow discharge levels vin accordance with their speciiiogravities; and the heaviest `.particles 'move Adirectly downwardly `for discharge through the discharge neck m|02 which may lbe provided 'with a slide valve |103;

1t will be :seen from the lforegoing that we have vin the .present lcase settling of the particles without any inter-ference by mechanical elements "or by irrational turbulence or cross-"currents, 'in a liquid body which is rationally upwardly ldisplaced in a rstreamcurrent flow as vdefined before. The -particlescan therefore actually settle in accordance with well known laws. It is believed that this is the nrst instance -of an industrial -uprising curren-t separator which is capable vof accomplishing this result.

The heaviest components of the raw material which rmove into the discharge neck -or spout |02 are taken up vby a suitable encased elevator or conveyer -o-f known structure and are moved to the vdta-watering screen |94 shown in Fig. 2. The elevator may be of the bucket type enclosed in a suitable housing and rising lfrom the discharge neck |92 ina manner well known in the a-rt. In the case of coal the heaviest particles are, Aoi course, refuse, vand the flow of the refuse is indicated in Fig. 2 in dash lines. The material discharged through the conduits Sli-33 may also be refuse and may be joined with the material flowing to the refuse -de-wateringscreen IM. The conduits 43i|33 may :likewise terminate in elevator casings similar to the vone which removes the ref-use from the'discha-rge neck |92. One of `the products, for example, that removed through the conduit 93, may contain valuable material yand :in that case it may be .recirculated as middlings through the dot-dash line conduit |05 for `:reinjecti'on into the separator. The clean `coal is drawn oli" by means of a similar encased conveying -or elevator device, and takes the dotted course shown in Fig. 2 to the cle-watering screen `I-lll.

The separated products vare removed, with a minimum of water, from the bottoms of the respective 'discharge and settling chambers, while clear water is 'recirculated from such chambers to maintain the -streamcurrent flow. The arrangement contributes to the 'economy :of operation.

'Ih'e "de-watering screens discharge the undernow downwardly through the conduits HI into the inflow control tank H2. This tank may be provided with a 'suitable device, e. g., a simple float valve, indicated in dotted iines, which regulatesthe flow down into the sump by maintaining a substantially constant level. The float, if centrally disposed, as indicated in Fig; 2, may be protected by an umbrella-like shield which dev fleets the dow 4of liquid 'downwardly and radially outwardly around the -iioat bulb.

The Isump labeled in Fig. 2 as S.C.Sump, meaning stre'amcurrent sump, is, `oi course, Aa separator taking care of separating the valuable lines, which may be contained in the underflow from the `de-watering screens, from 4the refuse, and also for recovering water which is returned to the primary `strear'nc-urrent separator. 'The sump may be of the same general structure las the streaincurrent separator shown in Fig. 1,?01', for example, of the same vgeneral structures as the machines disclosed in Patent No. 2,386,419 and Patent No. 2,464,418, with certain improvements which are illustrated in'Fig. v3.

Referring now to Figs. 2 and v3, the inflow pipe H3 coming from the constant `level sump inflow control tank l| I2 terminates near the bottom of the structure and the under-flow mass iS vdischarged downwardly onto the deilector H4, which is verticallyadjustable by means of an adjusting member, e. g.,.a hand-wheel H5, or its equivalent. The ow-deecting member H4 directsthe current incoming from the inflow pipe `upv'v'a'rdly and laterally -outwardly and protects 'the discharge ports |20 against undesired turbulence which might otherwise occur at the bottorn of the separating chamber. The heaviest particles go over the edge of the deflector H4 and gravitate without interference downwardly for withdrawal through Vthe ports |20. Numeral -I I6y is a stationary water-tight bushing through which projects the threaded shaft of the baffle H4.

used for the sump is of the streamcurrent type similar to the one shown in Fig. 1, We have again a number of upwardly extending baflles or insert members, as indicated at ||`I and H8 in Fig. 3, which are arranged in staggered or overlapping relation, as previously discussed, forming peripherally or circumferentially unobstructed outflow ports just as in Fig. 1. It should be observed, however, that in the case of Fig. 3, all the ports in the flow-distributing wall are outiiow or discharge ports, the inlet being provided by the pipe H3. The outflow port between the inserts or baffles II'I--H is indicated at H9.

' At the bottom of the baille HI are the outow H9 discharges into the chamber |23 for Withdrawal through the conduit |24.

The upow within the sump separator is again a streamcurrent flow, as previously described and as indicated in the ilow lines in Fig. 3. The heaviest components of the underiiow from the de-watering screens |04 and H0 are directed over` the edge of the deflector H4 and gravitate downwardly for discharge through the ports by way of the chamber |2| and conduit |22. successively lighter components seek upwardly vertically successively disposed discharge levels for discharge from the apparatus. The lightest components, which may be coal fines, are discharged at the highest level. In Fig. 2, it is as- Vsurned that'the material discharged from the four bottom levels is refuse, and in that case it is joined withA the refuse coming from the dewatering screen |04. The coal fines discharged from the highest level may be joined with the clean coal from the de-watering screen I I0. The

' products discharged from all of the levels of the :sump may be refuse, and all of them are then disposed with the refuse. Alternatively, the two highest levels may contain valuable fines and the separator shown in Fig. 1.

Some water is lost and discharged from the primaryA separator together with the clean coal and together with the refuse. The amount of -'water which is lost is replaced by makeup water y The flow coming from the sump iniow` fcontrol device H2, and therefore the streamcurrent flow within the separating chamber, may thus be regulated. Assuming that the separator from the conduit |00. Water may, however, be sprayed on the de-watering screenstofacilitate the handling of material, andthe total'waterA injected into the sump' and clear water available from it, may exceed the' amount lost in Vthel primary separator. The excess water is made available for vuse by way ofthe valve-controlled outlet shown in Fig. 2. The makeup water, excess water and return water valves may be regulated by a simple constant level float control in the primary separator, as mentioned before.

The separator shown in Fig. 1, so far as described, is operated as an uprising current separator. In present-day separators of this general class, which usually furnish only two separated products, fines accumulate within an intermediate level of the liquid separating medium', remain therein, and change the characteristics of the uprising current separator into a heavy density separator, with consequent loss of lvaluable material, contamination of the desired discharged products, and need for constant supervision which increases labor costs. The same troubles also arise in the operation of orthodox-heavy density separators, including those which use -a so-called stable iiuid separating medium. The density gradually increases beyond that which is desired for any given operation. Such alteration of the characteristics of the separator cannot occur in the present case, simply due to the fact that there is a constant exchangey and withdrawal of liquid and material from vertically successively placed levels of the body of the liquid separating medium which prevents accumulation and retention of lines in any level thereof. The invention thus removes one of the prominent drawbacks of previous separators, which is particularly pronounced when it is attempted to useY such separators for the treatment of raw material of relatively small particle size or material containing large amounts of nes.

It may be desired, however, to modify the operation of the new separator, withdrawingonly two separated products, one at the bottom and one at the top level, and to use as a separating medium either water or a heavy density medium. Fines could accumulate in the liquid and could change the characteristics of the system, under such condition, as indicated in the foregoing paragraph. In order to avoid trouble in such operation, it is desirable to provide for control of the relative density of the separating medium so 'as to maintain it` substantially constant. The circular suction pipes I0 and 13 within the settling chambers 66 land 68 are for this purpose provided at an intermediate or at s, lower level,

` as indicated in dotted 4lines in Fig. 1, so as to withdraw and to ycirculate vliquid containing heavy density particles back to the inlets of the separator. A similarly placed vcircular suction pipe may be provided at an intermediate levelin the chamber 30 for withdrawing heavy density liquid from the port I8. The suction applied to the pipes in chambers 30, 66,' 68 is such that only liquid is withdrawn containing substantially only those particles which tend to increase its specific density. The withdrawn material may then be circulated through a density control device shown diagrammatically in dotted lines in Fig. 1 and indicated by numeral |30, which device may be constructed and controlled generally along the lines disclosed in co-pending application Ser. No. 697,982. Thesettling and clarifying function of thev chambers 30, 6B and 68 are in this case ignored, andheavy density liquid is drawn directly from these chambers into the pipe 1I. The settling and clarifying function of the discharge chambers 21--29 is, however, retained. The density control device |30 may also be provided in a by-pass conduit disposed in parallel with the pipe 1I and drawing only heavy density liquid from all or some of the chambers 60, 68, 30, for controlling, checking and correcting purposes, and for re-injection into the separator.

The accumulation of fines Within the wetting and turbulence chamber formed by the feed conduit 41 is theoretically possible but practically will have no detrimental effect, if it arises, because, whether or not the dispersion, wetting and the required mobility are imparted to the particles in Water or in a heavy density medium is substantially immaterial. All the solids of the raw material, including fines, ultimately work down from the wetting and turbulence chamber into the streamcurrent separating chamber. Bleeder conduits such as the one shown in Fig. 1 at |3| may, however, be provided. Several such bleeder conduits may be used and angularly spaced for symmetric downward discharge into the relatively low density and relatively quiescent top level of the streamcurrent chamber. Fines accumulating in the turbulence chamber, tending to change the liquid therein to a heavy density liquid, beyond a desired point, thus bleed automatically downwardly into the streamcurrent chamber, and the heavy density particles discharged by such bleeding are subjected to the streamcurrent flow and separation as previously discussed.

The separator may also be used as a classifier for separating materials of given specific gravities in accordance with the sizes of the particles thereof. For example, a material composed of particles of a substantially uniform specific gravity, but varying in size from 3" to 0", or any other suitable size range, may be fed into the machine, and the streamcurrent displacement may be adjusted so as to deliver the fines on top, successively larger, from pea to nut size particles at vertically downwardly successive levels, and to discharge the largest lump-sized particles at the bottom.

Structural modifications are likewise possible. For example, the discharge or outflow ports in the flow-'distributing wall may be of varying width to provide a relatively narrow top discharge port for the fines, and downwardly progressively wider discharge ports for the discharge of successively larger particles. It is understood, of course, that the width of the ports exceeds in any case the size of the largest particles which are discharged therethrough. The re1ative amounts of fluid removed from each port are not aifected by its width, being controlled by the operation of the pump and the relative setting of the corresponding valve in the streamcurrent circuit. The separator structure is shown to be circular and the flow-distributing wall of generally inverted cone shape. The structure may be made of angular conguration; for example, it may be square on top and the flow-distributing wall may be of the shape of an inverted pyramid.

It may be remarked, in conclusion, that the separator may be made for any practically desired ton-hour capacity and for treating materials other than coals and within size and specific gravity ranges other than mentioned in the foregoing description. Some of the features of the invention will be found useful in apparatus and systems other than relating to the separation of materials, and particularly in basic processes and machinery such as noted in the previously mentioned patents. The invention is structurally as well as functionally versatile and adaptable, and presents new possibilities which will be apparent to those skilled in the art.

What is believed to be new and desired to have protected by Letters Patent is defined in the appended claims.

I claim:

1. A hydraulic separator comprising an upright tank, inlet means disposed centrally axially of said tank for injecting liquid thereinto radially outwardly in a plurality of levels thereof, means for withdrawing liquid centrally annularly upwardly from an upper stratum of the liquid body in said tank, means for feeding a stream of material particles centrally axially downwardly into the upper stratum of the liquid in the tank, and means for withdrawing adjusted amounts of liquid and material particles peripherally symmetrically from a plurality of vertically spaced levels of the liquid in said tank.

2. The structure and combination dened in claim 1, together with a tubular holder extending into the liquid in said tank downwardly centrally axially thereof for receiving the raw material particles for passage therethrough into the liquid body in said tank.

3. The structure and combination defined in claim 1, together with a tubular holder extending into the liquid in said tank downwardly centrally axially thereof for receiving the raw material particles for passage therethrough into the liquid body in said tank, and means for irrationally agitating the liquid in said holder for the threefold purpose of dispersing and wetting the raw material particles passing therethrough and of imparting mobility to such particles prior to feeding the particles into the liquid in said tank.

GEORGE A. AUER.

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

UNITED STATES PATENTS Number Name- Date 252,731 Butzel Jan. 24, 1882 975,971 Malchus Nov. 15, 1910 982,583 Flood Jan. 24, 1911 1,294,759 Blcmfield Feb. 18, 1919 1,449,603 Hokanson Mar. 27, 1923 1,459,921 Nagel June 26, 1923 1,465,143 Mullen Aug. 14, 1923 1,511,643 Trent Oct. 14, 1923 1,748,569 Hibbard Feb. 25, 1930 1,792,179 McLean Feb. 10, 1931 1,990,129 Menzies Feb. 5, 1935 2,071,617 Daman Feb. 23, 1937 2,139,047 Tromp Dec. 6, 1938 2,286,979 Samuel June 16, 1942 2,293,398 Meesook Aug. 1'8, 1942 2,365,734 Tromp Dec. 26, 1944 FOREIGN PATENTS Number Country Date 16,443 Great Britain of 1910 245,608 Great Britain Jan. 14, 1926

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