US2377875A

US2377875A - Compound clarifier

Info

Publication number: US2377875A
Application number: US421171A
Authority: US
Inventors: William E Geissler
Original assignee: Dorr Co
Current assignee: Dorr Co
Priority date: 1941-12-01
Filing date: 1941-12-01
Publication date: 1945-06-12
Anticipated expiration: 1962-06-12

Description

June 12, 1945. w. E. GEISSLER COMPOUND CLARIFIEB.

Filed Dec.

1, 1941 3 Sheets-Sheet l INVENTOR VV/lL/fl/ E. 65/554 5/? H. 8W

ATTORNEY AwWw-i v a June 12, 1945. w. a'caElssLER COMPOUND CLARIFIER.

3 Sheets-Sheet 2 Filed Dec. 1; 1941 INVENTOR V/LL/HM E. 65755151? E ATTORNEY Paramecium 12, 1945 UNITED sTAres PATENT OFFICE COMPOUND cmarr'mn William E. Geissler, Osslnlng, N. Y., asslgnor to The Dorr Company, New York, N. Y., a corporation of Delaware 7 Application December 1, 1941, Serial No. 421,171

14 Claims.

The general object of the present invention is to provide improved apparatus for use in the continuous clarification of liquids by sedimentation and decantation, and particularly for use in the compound clarification of two liquids received from different sources and having different char acteristics in a single multitray clarifier structure.

More specifically, the object of the invention is to provide a single multitray clarifying machine adapted for use in the compound clarification of the primary juice and secondary juice extracted from sugar cane in initial and subsequent portions, respectively, of a sugar cane milling train or circuit of the usual type, such secondary juice has a lower sugarcontent and is of lower purity and ordinarily is more difiicult to clarify though smaller-in volume than the simultaneously produced primary juice.

Now, and in recent years, the clarification method, commonly called "compound clarification which is disclosed and claimed in the Petree Patent No. 1,625,680, granted April 19, 1927, has been in extensive, widespread and successful use in clarifying sugar cane juice; and generally regarded as the most efficient and desirable method practically available for the purpose. That method comprises two separate continuous clarifying actions in each of which clarified liquid is separated from mud, which includes the solids separated My improved multitray clarifiei y comprises a plurality of superposed clarifying compartments and two receiving chambers respectively above and connected to upper and lower groups of said compartments, 'to thereby form two separate clarifying units, each including one of said chambers and the clarifier compartment or compartments connected thereto, and also comprises mud rakes working in the different compartments of the two units and carried by and forming a part of .a common rotating structure including a vertical column centrally disposed in the clarifier said rotating structure preferably includes agitat ing elements in the receiving chambers of the two units which serve to flocculate the liquid therein prior to its flow into the corresponding clarifying compartments. 1

My improved clarifier may include various arrangementsof the tworeceiving chambers and associated clarifying compartments, and of the conduit or flow path provisions for the passage of from the clarified liquid subjected to the clarifying action. Furthermore, 'the liquid subjected to one of the two clarifying actions is a mixture including the clarified liquid product 'of the other action and the relatively rich primary juice sepa rated from the sugar cane in an initial portion of the milling circuit, and the liquid subjected to the other clarifying action includes the relatively weak juice extracted from the sugar cane in a secondary portion of the milling circuit, and also ineludes the mud produced in the clarification of the-mixture including the primary juice. In compound clarification as heretofore practiced, the two clarifying actions have been effected in separate clarifiers, each of which is customarily a multitray clarifier. By the use of a single clarifier constructed in accordance with the present invention, in lieu of the two separate clarifiers heretoforerequired for compound clarification. I simplifythe clarifying operation, and reduce the construction, operation and maintenance costs of the. apparatus required for the clarification ofa given .amount of cane sugar Juice, and also reduce the floor and housing space required;

liquid from each receiving chamber into the associated clarifying compartments.

In a. preferred form of the present invention for I use in clarifying sugar cane juice, the secondary juice receiving chamber is located in the upper portion of the clarifier, and is of a diameter less than the clarifier diameter, and the primary juice receiving chamber comprises a central portion beneath the secondary receiving chamber and an annular portion surrounding the secondary chamber. This preferred arrangement of the two receiving chambers contributes to and facilitates the provision of means oi. desirable form for the removal 01' scum from the two receiving cham-' vantageously include provisions for independently raising and lowering the discharge and of the connection, such as are customarily employed in regulating the relative overflows of clarified juice from different clarifying compartments of an ordinary multitray clarifier. Such clarified juice overflow connections serve the special tpurposein m impr ed clarifler, of insuring that in normal operation, approximately the same hydrostatic pressures in the two clarifying units will exist at every liquid level common to the .two units. The maintenance of such common hydrostatic pressures in the two units eliminates the possibility that in normal operation a part1,-

tion separating adjacent compartments of the two units will be subjected to the harmful mechanical stresses to which it might be subjected if relative liquid levels in the two units varied substantially. The maintenance of such common pressures also minimizes the tendency to flow from one unit into the other through a joint space between the center column of the rotating structure and the margin of the central opening in a partition separating adjacent compartments included in different units.

Advantageously I provide a joint seal between the rotating structure and the partition separating the lower compartment of one unit from a subjacent compartment of the other unit, which is normally effective to prevent flow from one compartment into the other, but which operates like a safety valve to permit such flow on the development of an abnormal differential pressure, such as may occur in filling or emptying the clarifier at the beginning or end of a grinding season, or in the course of a clarifier cleaning or repair operation.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however. its advantages and specific objects attained with its use, reference should be had' to the accompanying drawings and descriptive matter in which I have illustrated and described preferredembodiments of the invention.

Of the drawings:

Fig. 1 is a flow sheet diagrammatically illustrating the use of a preferred form of my improved clarifier in association with a sugar cane mill of conventional type;

Fig. 2 is a plan view of the clarifier shown diagrammatically in Fig. 1;

after leaving the rolls A. The liquid expressed from the cane by the rolls A and primary mill A passes into the primary juice collection box B. The juice passes from the box B through a pipe I to juice treating apparatus C in which the juice is heated and limed in the customary manner. and from which the juice passes through a pipe 2 to the primary juice receiving chamber D of a multitray clarifler E. The juice expressed from the cane by the secondary mill A, is collected in a juice ,box 18 from which juice passes through a pipe 3 to a secondary juice heating and liming Fig. 3 is an elevationof the clarifler shown in V ciated with said central column;

Fig. 6 is a partial section on the line 6-8 of Fig. 3;

Fig. 7 is a somewhat diagrammatic sectional elevation, and Fig. 8 is a plan, of a modified form of clarifier; and

Fig. 9 is a somewhat diagrammatic sectional elevation of a third form of a clarifler.

In Fig. 1 I have illustrated diagrammatically the use of a preferred form of the present invention in connection with a sugar cane mill'which is of conventional type, and which is associated with my improved clarifier and with juice heating apparatus and a source of maceration water, by piping of the character commonly used in associating a sugar cane mill with apparatus for the compound clarification of sugar juice.

As shown in Fig. 1 the sugar cane mill circuit includes a pair of disintegrating rolls A, and four three roll grinding mills, A, A A and A through which the sugar cane passes successively device CA from which the juice passes through a pipe 4 to the secondary juice receiving chamber d of the clarifler E. Juice expressed from the cane by the mill A is collected in a juice receiving box B and passes from the latter through a pipe 5 back to the mill circuit where it is discharged as maceration liquid on to the cane passing from the primary mill A to the secondary mill A. Juice expressed from the cane by the mill A is collected in the juice receiving box 3*, and is returned to the mill circuit for use as maceration liquid by a pipe 8, which discharges onto the cane passing from the secondary mill A to the third mill A Maceration water is discharged by a pipe I onto the 'cane passing from the third mill A to the fourth mill A.

As shown in Fig. 1, secondary juice clarified as hereinafter described, passes from the clarifler E through a pipe 8 into the juice box B, so that the pipe I carries a mixture of unclarifled primary juice and clarified secondary juice away from the juice box B. The primary mud removed from the primary clarifying unit of the clarlfler E as hereinafter described, is passed through a pipe 9 into the secondary juice receiving box B, and the pipe 3 thus carries away from the secondary juice box 2B a mixture of unclariiled secondary juice received from the mill .A with the mud separated from the primary juice in the clarifier E.

As shown best in Fig. 3, the secondary juice chamber 11 is separated from the receiving space D by a pan-shaped partition member 1 smaller in diameter than and axially disposed in the shell or tank of the clarifler E. The partition I has a dished bottom and an uprising rim or peripheral portion f, and is carried by truss-like supports 1 which extend radially inward from the peripheral wall of the clarifler E into engagement with rim 1', and thus do not interfere with the hereinafter mentioned mud rakes and scum removing means. A dished partition F generally parallel to and spaced downwardly from the bottom wall of the partition f, forms the bottom wall of the receiving chamber D. The partition F extends to and is welded or otherwise attached at its periphery to the cylindrical wall of the tank E. The primary juice receiving chamber D thus includes a portion directly beneath chamber d. and an annular portion surrounding the chamber 11 and extending between its vertical wall I and the surrounding wall of the tank E.

A series of dished partitions F, FEE and F generally similar in form to the partition F and each attached at its periphery to the tank shell, divides the portion of the tank space beneath the chamber D into three superposed primary juice clarifying compartments G, G G and two secondary juice clarifying compartments g and 9 The compartment G is directly beneath the re ceiving chamber D, and the compartment g is directly above the. conical bottom wall of the tank. The partition F separates the bottom 2,877,875 compartment (3- of the primary juice clarifying I settled sludge or mud towards the center ofthe receiving chamberor clarifying compartment in which it works. The rotating structure also includes mud rake arms H working mud accumulating in the bottom compartment 9 toward the central mud outlet E in the bottom wall of the The shaft H also supports and rotates floccu-' lating panels or grids H" and H in the receiving chambers d and D, respectively, and scum removing sweeps H and H at the inner and outer sides of the upper edge of the uprising rim portion f of the wall of the receiving chamber (1.

The sweeps H' and H are adapted to work scum into outer and inner portions of a common scum channel or trough I, which extends from the tank periphery inward across the annular outer portion of the chamber D and across an outer portionof the chamber d. Curved arms H carried by the shaft H in the chamber d, and just short enough to clear the inner end of the cum channel I, work scum from the central portion of the chamber 11 into the path of the sweeps H The rotating structure including the shaft H is rotated at a suitably low speed by mechanism H" above the tank E, which may be of the type customarily employed to rotate the mud raking structure of the multitray clarifier of conventional type, and hence need not be further described herein.

In the preferred clarifierconstruction illustrated. juice is fed from the receiving chambers D and d to the corresponding subjacent clarifying compartments by separate feed channels within and extending longitudinally of the tubular shaft H. Thus, as shown in Figs. 3 and 6, vertically extending partitions J in the upper portion of the hollow shaft H separate two primary juice distribution channels K at opposite sidesof the shaft, from a central secondary juice channel L.

Iii. Big. 5 Ihave illustrated sealing provisions which may be employed to prevent'leakage flow between the receiving chambers D and d through the joint between shaft H and the margin of the central opening in the partition element f. The sealing provisions shown in- Fig. 5 comprises a flexible washer or gasket member N of cup leather form, mounted in an annular support N carried by thepartition element 1 and having a flexible edge bearing against the periphery of a metallic bearing ring N welded on the shaft H. The

character of the sealing provision just described is relatively unimportant, since the pressure differential tending to produce leakage between the two receiving chambers will never be large andsome small leakage between the chambers will do no real harm.

It is definitely advantageous, however, to prevent leakage under normal conditions, and to permit leakage under abnormal. conditions through the joint between the shaft H and the partition F and for this purpose. I advantageously make use of sealing provisions of the type illustrated in Fig. 4, Those provisions comprise a cylindrical member 0 attached to and forming a hollow uprising projection from the partition 1"", and which surrounds the shaft H from which it is separated by an annular space. As shown, the member 0 comprises an out-turned flange portion 0' at its lower end, which has its peripheral edge welded to a cylindrical boot F secured to and depending from the partition F at the margin of the central opening therein. The upper endlof the member 0 extends into an air pocket (1 open at its lower end and closed at its upper end, between the-shaft H and a cylindrical hood member 0 The latter is spaced outwardly awayfrom the porticn of the member O which it overlaps, and has an upper end portion of reduced diameter; which is welded to the shaft H.

The wall of the shaft H is cut away to form inlet ports K, one opening into the upper end of each channel K from the portion of' the receiving chamber D between the walls 1. and F. Each channel K is also provided with an outlet port K opening to the clarifying compartment G, and with a second outlet port K opening to the compartment G As shown, the ports K are simple openings'or windows in the cylindrical wall ofthe pipe H. Each port K however, is in register with a corresponding pipe section K rectangular in' cross section which is welded to and extends radially away from the pipe H, The

pipes K extend through and support a cylindrical member M coaxial with the pipe H and unit'- ing with the latter to form an annular channel through which mud passes from the compartment G'- into the lowerwportion of the compartment Gfias hereinafter explained. The pipe H is formed with inlet port openings L' through which secondary juice passes into the channel L from the secondary juice receiving chamber d, and with outlet ports L which open from the channel into the compartment g.

Under normal operatingconditions. liquid flow over the top of the member 0 in either direction between the chambers'cl and g is. prevented by air supplied to the air pocket 0 by a pipe 0 at a suitably low pressure which is limited by bleed ports 0' formed in the wall of the pipe H at a level below the top of the member 0 and above the bottom of the member 0 Air bleeding through the ports 0 into the feed channel fier at the end" of such a period, there is a possibility that liquid will be passed into or withdrawn from one of the two clarifying units much more rapidly than into or from the other. This might result, for example in making the pressure in the compartment g'- much higher than the pressure in the compartment G and thereby subject the Partition F to destructive stresses, if no means were provided for limiting the maximum value of the diflerential of said pressures. I

, The sealing provisions shown in. Fig. 4 are adapted to suitably limit the maximum of value ofsaid differential. As will be apparent, as soon as the pressure in one of-the two compartments exceeds that in the other by an amount corresponding to a liquid head equal to the distance between the upper edge of the member and the lower edge of the member 0", liquid will begin to new through the space 0 from one compartment into the other, and if the flow capacity of the flow path including said space, is suflicient for the purpose, as it may well be, it will act like a safety valve to prevent further increase in the pressure differential between the two compartdown into the compartment 9'. Mud separated from the primary juice in the chamber D is also relatively small in amount and may be worked by the mud rakes H either through the ports K into the feed channels K and thence into the compartments (3 and (3 through the ports K and K or directly into the compartment G through the joint space between the'partition F and shaft H. As shown, the member H is surrounded by a bearing ring or collar P immediately above the ports K, which is engaged by guide means P secured to the dished partition F and centering the shaft H. The guide provisions P need not be of a character to interfere with the passage of mud through the joint between the partition' F and the member H.

Mud worked toward the center of the compartment G by the mud rakes H passes downward into the compartment G through the annular gamers into the center of that compartment by the mud rakes H, passes downward into the compartment 0' through the annular channel between the shaft H and the depending center boot portion of the partition F The mud thus entering the compartment 9, along with the mud settling in that compartment, and the mud passing downward space between the shaft H and a depending-boot portion of the partition member F surrounding the central opening in the latter. As shown, the last mentioned boot extends downward into the annular space surrounded by the previously mentioned member M. The latter guides the descending mud into the lower portion of the compartment G, and in conjunction with the tubes K keeps the Juice entering the compartment (3: from the feed channels K away from the mud entering the compartment from the compartment G. Mud passing down through the member M, and mud worked into the center of the compartment by the mud rakes H pass into the compartment G through the annular channel between the shaft H and the boot depending from the partition F at the margin of the central opening in the latter.

The mud rakes H work the mud received from the compartment G and mud settling in the compartment G into an annular mud trough Q collectively formed by the member 0 and boot F which is of appreciably greater diameter than the shaft H, and is connected to the flange portion 0' of the member 0 at a distance appreciably below the partition F The mod thus received in the trough Q passes away from the clarifier through an overflow connection comprising a horizontal pipe section Q extending from the trough Q outwardly through the shell of the clariiier E and an external uprising pipe section Q through the upper end of which mud overflows into a mud box Q at a level but little below the liquid level in the chamber D. The overflow level in the mud box Q may be adjusted by the vertical adjust ment of a sleeve Q in telescopic relation with the u" per end of the pipe section Q Mud settling in the compartment a and moved through the shaft H, is worked to the central outlet E in the bottom wall of the clarifler E by the mud rakes H", and passes away from the clarifler through a mud draw-oil. pipe R, which discharges into a mud tank 3 The latter forms part of secondary mud handling apparatus of known type, which as shown in Fig. 1, comprises a rotary filter R to which mud is moved from the tank R by a pump R and from which a pump R withdraws relatively clear filtrate and passes it into admixture with the secondary juice flowing through the pipe 3 from the juice box 13 to the secondary juice treating apparatus CA.

In the arrangement shown in Fig. 3, the juice clarified in each of the compartments G and 0' passes into the compartment along with the mud from the compartment immediately above, though each of the clarifying compartments shown in Fig. 3 might have a separate feed inlet as do each of the clarifying compartments of the clarifiers shown in Figs. '7 and 8.

Clarified juice is withdrawn from the primary juice clarifying compartments G, G and 6 through overflow pipe connections S, El and S respectively, each of which includes an uprising portion external to the clarifler E, discharging at its upper end into a primary juice overflow box S. The discharge levels of each of said connections may be vertically adjusted in a known manner by an adjustment of the sleeve S in telescopic association with, and, in effect, forming the upper end of the corresponding overflow connection. .The clarified juice passed into the juice box S, is withdrawn from the latter through a pipe S for transmission to the evaporating pans (not shown). Similarly, clarified juice is separately withdrawn from the secondary juice clarifying compartments 9 and g through overflow connections T and T including uprising portions which discharge at their upper ends into a secondary juice overflow box T. The discharge level of each of the overflow connections T' and I may be adjusted by vertical adjustments of a 'sleeve T forming the upper end of the overflow connection. The clarified secondary juice passed into overflow box T passes from the latter through the previously mentioned pipe 8 to the juice box B which receives primary juice from the rolls A and primary mill A. Each of the overflow connections S, S S T and 'I' may receive juice through the usual circularly extending perforated pipe located in the upper peripheral portion of the corresponding clarifying compartment.

The intended operation of the apparatus collectively illustrated by Figs. 1 to 6 will be readily apparent from the foregoing statements anc explanations. .As those skilled in the art will understand, with the apparatus illustrated in Figs. 1 to 6 the compound clarification method can be practiced in the same manner and to the same advantages, as it has heretofore been practiced with apparatus including separate primary juice and secondary juice multitray clarifier. The use of the single clarifler which I have devised in lieu of the two separate clarifiers heretofore required for compound clarification, gives a number of practically important advantages includ-- ing:

In general, the inherent cost or construction will be lower for my clarifier; than for the'separate primary and secondary clarifiers of the same aggregate clarifying capacity, in respect to each In general, also, the use of a single clarifier constructed in accordance with the present invention, in lieu of the two clarifiers heretofore requiredffor compound clarification, should reduce the operation and maintenance costs by reducing the heat loss from the clarifying apparatus, by reducing the power consumption of the mud raking machinery, and by reducing the exclariiying compartments gaLand ga respectively. Juice passes from the primary juice receiving chamber DAtc the clarifying compartments GA and GA, through feed conduits KA in the shaft HA as in the construction first described. The feed conduits KA have their lower ends extended and provided with outlet ports KA for the passage of primary Juice from the chamber DA directly into the lowermost primary clarifying compartment GA t Mud passes from the receiving chamber DA and from the clarifying compartments GA and GA. of the clarifier EA through a mud channel U, which comprises all of the bore of'the horizontal shaft HA not occupied by the feed conduits KA. Mud enters the mud channel U from the chamber DA through inlet ports U, and en- ,ters said'channel from the compartments GA and GA through ports U and U respectively,

pense for labor and material necessary to maintain the clarifying apparatus in operation.

While I regard the apparatus shown in Figs. 1 to 6 as embodying the best form of my invention now known to me for practical use under ordinary conditions, it will be apparent that'the general principles of the present invention-may be used and the major'advantages thereof may-be obtained, with clarifying apparatus quite different from that illustrated in Figs. 1 to 6, and in Figs. 7 and 8 I have illustrated one clarifier, and in Fig; 9 a second clarifier, which differ in a number of respects from one another and from the clarifier shown in Figs. Ito 6.

and passes out of the channel U into the compartinentGA through ports U The shaft HA comprises an upper hollow section and a lower rod-like section HA. The latter passes through -a central opening in the bottom wall of a conical mud pocket QA having its .Wall formed by a depressed central portion of the. partition FA Primary mud passes from the pocket QA through a pipe QA' to a mud pump V The clarifier EA shown in Figs. '7 and 8 comprises many parts which are similar, or analogous to parts or the clarifier first described, and which are designated so far as appears necessary in Figs. 7 and 8, by reference symbols diil'ering from those used in Figs. 1"to 6 to describe corresponding parts, only by the inclusion of a secand reference letter, -A or a. The clarifier EA- shown in Figs. 7 and 8 differs from the clarifier E first described principally in the ,form and disposition of its receiving chambers DA and do; in the manner in which the secondary juice "is passed from its receiving chamber da into the associated secondary juice clarifying compartsions, and in details of its scum removing provisions.

The secondary: Juice receiving chamber do or the clarifier EA isannular in form extending between the cylindrical wall of the clarifier EA and which is external to the clarifier EA and discharges the mud through an uprising pipe QA into a hopper QA above and opening into the pipe 4A in which it mixes with the secondary Juice passing into the receiving chamber da.

Mud passes from the clarifying campartment ya into the compartment go through a central depending boot portion FA of the. intervening partition member FA depending from the latter at the margin of its central opening.

In Figs: 7 and 8, the scum trough IA extends into the clarifier EA from the cylindrical shell thereof for a radial distance less than the radial extent of the chamber da. Scum is worked over the uprising portions fa of the partition member fa from the primary receiving chamber DA,

and along the upper portion of the secondary receiving chamber da at the inner side of the scum trough IA, into the path of movement of ments 0a and ya, in its mud handling provi-,

the uprising portion fa of a partition member fa, which is,oi angle-bar cross section and has its bottom. portion extending intc,engagement with, and welded, or otherwise secured, to the cylindrical shell of the clarifier EA. The chamber DA separated from the 'chamberda by the partition .fa, comprises a central cylindrical por-' tion at the inner side of the partition Ia and an annular portion underlying the partition fa.

Secondary Juice passes from the chamber do to the clarifying compartment ya and ya through piping LA and shown as. comprising a vertical conduit external to the shell of the clarifier EA which .receives juice from the chamber da through a connection LA, and is provided adJathe scum sweeps HA by curved scum sweep arms HA". The joint between the shaft rod portionf HA and the margin of the opening'in the partition FA through which said portion passes, is sealed by sealing provisions" NA which may be similar iniorm and .type to those illustrated in "Fig.5.

\ Except in respect to vdilferences mentioned above, theclarifier EA may be similar in construction and operation to the clarifier EA first described.

- The clariflerEB shown in Fig. 9 comprises many features similar to corresponding features of the clarifier shown in Figs; 7 and 8. The clarifier EB diifers primarily from theqclarifiers previously described, in that its secondary juice receiving chamber db is located below the partition FIE;

- separating the lowermost primary juice clarifying compartment GB from the upper secondary juice clarifying compartment 9 As shown, the chamber db isisurroundedby a cylindrical wall coaxial with the tank or shellof the clarifier EB, but of much masher-diameter.

2). The lower seccelves Juice to-be clarified as Well as mud, from .the compartment ob through the boot FA de- The chamber db opens at ts lower end directly into an underlying portion 1 the compartment ondary clarifying compartment obi of Fig. 9 repending from the partition FA separating the two compartments.

Primary juice passing from the feed chamber DB, which occupies the entire'horizontal cross section of the clarifler EB, tank or shell above the partition F3, is distributed to the sublacent clarifying compartments GB, GB and GB, and

mud is passed from the chamber DB and from which forms a mud pocket QB having its outer wall formed by a corresponding portion of the shell of the clarifier EB. Primary mud passes from the mud pocket QB through a pipe QB into a mud tank QB from which the mud is moved,

by a pump VB and its discharge pipe QB into the feed pipe 43 through which'secondary juice admixed with the primary mud, is passed into the secondary juice receiving chamber db.

The pressures in the portions of the primary and secondary juice clarifying units adjacent but at opposite sides of the partition F3, are adapted to be substantially equalized in normal operation, by the clarified juice overflow provisions QA which may be identical in principle with those shown in Fig. 1, and in Figs. 7 and 8.

Scum rising to thetop of the liquid in the chamber DB of Fig. 9 is moved into a scum pocket within and adjacent the shell of the clarifier EB by curved sweepers hb. A valved scum draw oif pipe W opens into the uppermost portion of the receiving chamber db, through which scum may be periodically removed from aid chamber.

The three clarifier forms shown in sectional elevation in Figs. 3, '7 and 9 are generically alike in that each discloses a multitray clarifier including two clarifying units adapted for use in carrying out compound clarification, and each comprising a receiving chamber and a plurality. of associated clarifying compartments.

Each of the three forms permits of the attainment of all of the general advantages obtainable by use of a single clarifier structure in lieu of the two separate clarifiers heretofore required for compound clarification including in particular the advantage of a single mud movtion of the liquid in the receiving chamber D to which movements relative to the supports f are given the liquid by the scum sweeps H above the supports 1* and the mud rake arms H and flocculation arms 1-! which move through the zone beneath thebrackets f.

The three forms of apparatus shown in Figs. 3,? and 9 diifer specifically in respect to the manner in which juice to be clarified is fed into the clarifying-compartments. Thus, inFig. 7 juice to be clarified is fed to each of the clarifying compartments GA', GA, on and an along a new path separate from the flow paths through which each of those compartments receive settled solids from the compartment above it. In the form shown in Fig. 3 the lowermost compartments G and g of the two units each rerelatively low density, their volume may exceed the aggregate volume of properly thickened mud and properly clarified juice which can be withdrawn from the compartment GA through its mud outlet QA and clarifying juice outlet 8A In such a case, therewill be back flow from the compartment GA through the feed inlet port KA, with the result of some disturbance or upset in the clarifying performance of the compartment GA Such back flow from the compartment G and resultant disturbance in, the operation of compartment G will not occur in the operation of the clarifier shown in Fig. 3 under similar operating conditions. With different conditions tending to lhigher density and lower volume of the solids separating from the clarified liquid in the compartments G and G of Fig. 3, the clarifying capacity of the compart- 'ment G- may be somewhat less than it would be if mud to be thickened and juice to be clarified entered the compartment G through separate inlets such as those provided for in the compartment GA of Fig. '7.

In respect to the features just discussed, the arrangement shown in Fig. 9 is like the arrangement shown in Fig. 7 insofar as the primary juice clarifying unit is concerned, and is like the form of Fig. 3 in respect tothe operation of the secondary juice clarifying unit.

While in accordance with the provisions of the statutes, I have illustrated and described the best forms of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit of my invention, as set forth in the appended claims and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire to secure by Letters' Patent is:

1. Apparatus for the compound clarification of liquids having diiferent characteristics, comprising a multitray clarifier including a tank. and a plurality of superposed clarifying compartments and two receiving chambers within the tank, said chambers being, respectively above and associated with upper and lower groups of said compartments, each of said groups comprising one or more of said compartments, and means connecting each group and the associated chamber into a separate sedimentation and decantation unit including a fiow path for the down flow of liquid from the chamber into the compartment or compartments of the unit. means for separately withdrawing clarified liquid from the two units, means for separately withdrawing mud from the two units, means for passing mud withdrawn from one unit and one or the first mentioned liquids into the receiving chamber of the other unit, means for passing the clarified liquid withdrawn from the last mentioned unit and the second of the first mentioned liquids into the receiving chamber of said ione unit, and a common mud compacting and moving means for the two units comprising a rotatable, vertical column centrally disposed in i the tank and mud rake arms carried by said column and extending into the diiferent clarifying compartments.

2. A multi-tray clarifier for effecting compound clarification of two liquids having diflerent characteristics, comprising in combination a tank and partitions therein subdividing the tank interior into two receiving chambers and a plurality of superposed clarifying compartments iorming two separate sedimentation and decantation units each of which comprises one of said receiving chambers andone or more clarifying compartments, chambers and compartments for passing one of said liquids into the receiving chamber of one of said unitsand for withdrawing clarified liquid from the second of said units and passing it into the last mentioned receiving chamber and for passing into the receiving chamber of the second or said units the second of said liquids and also for passing solids settled out of the liquid-treated in the first mentioned unit into the last mentioned receiving chamber, and conduit connections for withdrawing clarified liquid from the first mentioned unit and discharging it from the clarifier and for withdrawing from the second of said units solids settled out,oi' the liquid treated therein and for passing those solids from the clarifier. v

3. A multi-tray clarifier as specified in claim 2, comprising common mechanism for moving solids accumulating in the lower portion of each unit to the said conduit connection through which solids are passed from the unit.

4. Apparatus for the compound clarification of liquids having difiererit characteristics, comprising a multitray clarifier including a, tank and a plurality of superposed clarifying compartments I and two receiving chambers within said tank, said receiving chambers being both above said compartments and respectively associated with upper and lower groups of said compartments, .each of said groups comprising one or more of said compartments. and means connecting each group and the associated chamber into a separate sedimentation and decantation unit including a flow. path for the downfiow of liquid from the champrising a multitray clariifier including a tank and a pluraity of superposed clarifying compartments and two receiving chambers within said tank,

said receiving chambers being respectively above g and associated with upper and lower groups of said compartments, each of said groups comprising one or more of said compartments, and means connecting each group and the associated chamber into a separate sedimentation and decantetion unit including a flow path for the downflow of liquid from the chamber into the compartmentor compartments oi. the unit, means for separately withdrawing clarified liquid from the two units, uprising overflow pipe connections having their discharge ends at approximately the same level whereby said connections insure that in normal operation approximately the same hydro-static pressures will exist in the two clarified units at every liquid level common to the two units, means for separately withdrawing mud from the two units, means for passing mud withdrawn from one unit and one of the first menconduit connections to said tioned liquids into the receiving chamber of the other unit, means for passing the clarified liquid withdrawn from the last mentioned unitand the second oi-the first mentioned liquids into the receiving chamber of said one unit, and a common mud compacting and moving means for the two units comprising a rotatable vertical column centrally disposed in' the tank and mud rake arms carried by said column and extending into the different clarifying compartments.

6. Apparatus. for the. compound clarification of liquids having difierent characteristics, comprising a, multitray clarifier including a tank and a plurality'ot superposedclarifying compartments and two receiving chambers within said tank, said chambersbeing both above said compartments and respectively associated with upper and lower groups'of said compartments, one of said chambers extending circularly about each ofsaid groups-comprising one or more of said compartments, and means connecting eachgroup and the associated chamber into a separate sedimentation and decantation unit including a flow path for the downfiow of liquid from the chamber into the compartment or compartments of the unit, means for separately withdrawing clarified liquid from the two units, means for separately withdrawing mud from the two units, means for passing mud withdrawn from one unit and one of the firstcmentioned liquids into the receiving chamber of the other-unit, means'i'or passing the ber into the compartment or compartments oi the'unit, means for separately withdrawing clarified liquid from the two units, means for separately withdrawing mud from the two units means for passing mud withdrawn from one unit and one or the first mentioned liquids into the receiving chamber of the other unit, means forpassing the clarified liquid withdrawn from the last mentioned unit and the-second of the firstv mentioned liquids into the receiving chamber of said one-unit, and a common mud compacting and moving means for the two'units comprising a rotatable vertical column centrally disposed in the tank and mud rake arms carried by 'said column and extending into the difierent clarifying compartments.

5. Apparatus for the compound clarification .of liquids having differentrcharacteristics. com-.

clarified liquid withdrawn from the last mentioned unit and the second of the first mentioned liquids into the receiving chamber of said one unit, a common mud compacting and moving means for the two units comprising a rotatable vertical column centrally disposed in-the tank and mud rake arms carried by said column and extending into the diflerent clarifying compartments, and scum removing means includi a common scum channel extending above each of said chambers and scum sweeping devices carried and moved by said column and extending into said chambers and moving scum collectingtherein. into said channel. 1 v

7. Apparatus for the compound clarification of liquids having difierent characteristics, comprising almutlitray clarifier including a tank and a plurality of superposed clarifying compartments and two receiving chambers within said tank, said chambers being respectively above and associated with 'upper and lower groups of said compartments, each oi said groups comprising one necting each group and the associated chamber into a separate sedimentation and decantation unit including a flow path for the downfiow of 1iquid from the chamber into the compartment or compartments oi the unit, means for separately withdrawing clarified liquid from the two units, means for separately withdrawing mud from the two units, means for passing mud withdrawn from one unit and one of the first mentioned liquids into the receiving chamber of the other unit, means for passingthe clarified liquid withdrawn from the last mentioned unit and the second of the first mentioned liquids into the receiving chamber of said one unit, a common mud compacting and moving means for the two units comprising a rotatable vertical column centrally disposed in the tank and mud rake arms carried by said column and extending into the different clarifying compartments, and flocculation arms carried by said column and extending into said receiving chambers.

8. Apparatus for the compound clarification of liquids havingdiiferent characteristics, comprising a multitray clarifier tank structure enclosing a plurality of superposed clarifying compartments and two receiving chambers, respectively above and associated with upper and lower groups of said compartments, each of said groups comprising one or more of said compartments, said structure including superposed partitions form ing the bottom walls of said chambers and compartments except the lowermost compartment, and means connecting each group and the associated chamber into a separate sedimentation and decantation unit including a flow path for the downfiow of liquid from the chamber into the compartment or compartments of the unit, means for separately withdrawing clarified liquid from the two units, means for separately withdrawing mud from the two units, means for passing mud withdrawn from one unit and oneof 1 the first mentioned liquids into the receiving chamber of the other unit, means for passing the clarified liquid withdrawn from the last mentioned unit and the second of the first mentioned liquids into the receiving chamber of said one unit, a common mud compacting and moving means for the two units comprising a rotatable vertical column. centrally disposed in.the tank and mud rake arms carried by said column and opening in the corresponding partition.

9. Apparatus for the compound clarification of liquids having different characteristics, comprising a multitray clarifier including a tank and a plurality of superposed clarifying compartments and two receiving chambers within said tank, said receiving chambers being respectively above and associated with upper and lower groups of said compartments, one of said receiving chambers being coaxial withthe tank and of a diameterless than the tank diameter, and the other of said'chambers' comprising a lower portion of the full diameter of the tank and extending under the firstmentioned chamber and also comprising an uprising portion extending circularly about as'ms'rs or more of said compartmentaand means conthe first mentioned chamber, each of said groups comprising one or more of said compartments, and means connecting eachgroup and the associated chamber into a separate sedimentation and decantation unit including a flow path for the downfiow of liquid from the chamber into the compartment or compartments of the'unit, means for separately'withdrawing clarified liquid from the two units, means for separately withdrawing mud from the two units, means for passing mud withdrawn from one unit and one of the first mentioned liquids into the receiving chamber of the other unit, means for passing the clarified liquid withdrawn from the last mentioned unit and the second of the first mentioned liquids into the receiving chamber of said one unit, and a common mud compacting and moving means for the two units comprising a rotatable vertical column centrallydisposed in the tank and mud rake arms carried by said column and extending into the different clarifying compartments, said vertical column being formed with channels which are included in the connecting means through which liquid flows from the two chambers into the clarifying compartments of the respective-units.

10. Apparatus for the compound clarification of liquids having different characteristics, comprising a multitray clarifler tank structure enclosing a plurality of superposed clarifying com partments, two receiving chambers, respectively above and associated with upper and lower groups of said compartments, each of said groups comprising one Or more of said compartments, said structure including superposed partitions forming the bottom walls of said chambers and of each of said compartments except the lowermost compartment, and means connecting each group and the associated chamber into a separate sedimentation and decantation unit including a flow path for the downflow of liquid from the chamber into the compartment or compartments of the unit, means for separately withdrawing clarified liquid from the two units, means for separately withdrawing mud from the two units, means for passing mud withdrawn from one unit and one of the first mentioned liquids into the receiving chamber of the other unit, means for passing the clarified liquid withdrawn from the last mentioned unit and the second of the first mentioned liquids into the receiving chamber of said one unit, a common mud compacting and moving means for the two units comprising a rotatable vertical column centrally disposed in the tank and mud rake arms carried by said column and extending into the different clarifying compartments, and means forming a seal between said column and the partition forming the, bottom wall of the lowermost compartment of said upper group of compartments operative to substantiall prevent flow between the last mentioned compartment and the subjacent tank structure space through the central opening in the last mentioned partition when the difierence between the pressure in the last mentioned compartment and the pressure in said space is that prevailing in normal operation, and to permit such fiow -when said difference in pressures exceeds that latter to form an inverted trough extending circularly about said column, and the other of which comprises a cylindrical flange extending outwardly into said trough, and means for passing air under pressure into said trough.

12. A multitray clarifier for compound clarification of liquids having different characteristics, comprising a tank and internal partitions dividing the tank space into a plurality of sections and comprising a plurality of horizontally extending partition members located at different levels and each separating two of said sections in superposed relation with one another, said sections being combined to form two separate sedimentation and decantation units, each of which comprises a clarifying portion comprising one or more of said sections and a receiving chamber, formed by another of said sections, which is above said clari-' fying portion and is connected to the latter to provide a flow path for the downflow of liquid into the clarifying portion from said receiving chamber, one of said receiving chambers having a peripheral wall extending about the tank axis and spaced inwardly from the peripheral wall of the tank and supported by connectlonsbetween said walls, and the other of said chambers comprising a lower portion of the full diameter of the tank and extending under the first mentioned chamber and comprising an uprising portion extending circularly above the first mentioned portion between upper and lower levels respectively above the upper edge and below the lower edge of said connections, and conduit connections to said sec.- tions'comprising means for separatelywithdrawing clarified liquid from each of the sections included in said clarifying portions, means for separately withdrawing mud from the lower portionof each unit, means for passing mud'withdrawn from one unit and one of the first mentioned liquids into the receiving chamber of the other unit, and means for passing the clarified liquid withdrawn from the last mentioned unit and the second of the first mentioned liquids into the receiving chamber of said one. unit, said means cooperating to normally maintain said tank space filled with liquid below a liquid level adjacent the upper end of the tank with the hydrostatic pressure of the liquid at any lower level substantially proportional to the distance between the two levels whereby the liquid pressures acting against the upper and lower sidesof each of said partition members, substantially balance one another.

13. Apparatus for the compound clarification oi liquids having difierent characteristics, comprising a multitray clarifier including a plurality of superposed claril'yin compartments, two receiving chambers, respectively above and associated with upper and lower groups of said com- Dflrtments, one of said receiving chambers having a peripheral wall extending about the tank axis and spaced inwardly from the peripheral wall or the tank and supported by connections between said walls and the other of said chambers comprising a lower portion of the full diameter of the .tank and extending under the first mentioned chamber and comprising an uprising portion extending circularly above the first mentioned portion between upper and lower levels respectively above the upper edge and below the lower edge of said connection, each of said groups comprising one or more of said compartments, and means connecting each group and the associated chamberinto a separate sedimentation and decantation unit including a flow path for the downflow of liquid from the chamber into the compartment or comprising a rotatable vertical column centrally disposed in the tank, mud rake arms carried by said column and extending into the different clarifying compartments, and scum removing means carried by said column and respectively extending over and under said connections.

14. A inultitray clarifier for compound clarification of'liquids having different characteristics, comprising a tank and internal partitions dividing the tank space into a plurality of sections and comprising a plurality of horizontally extending partition members located at different levels and each separating two of said sections in superposed relation with one another, said sections being combined to form two separate sedimentation and decantation units, each of which comprises a clarifying portion comprising one or more of said sections and a receiving chamber formed by another of said sections which is above-said clarii'ying portion and is connected to the latter to provide a flow path for the downflow of liquid into the clarifying portion from said receiving chamber, and conduit connections to said sections comprising means for separately withdrawing clarified liquid from each of the sections included in said clarifying portions, means for separately withdrawing mud from the lower portion of each unit, means for passing mud withdrawn from one unit and one of the first mentioned liquids into the receiving chamber of the other unit, means for passing the clarified liquid withdrawn from the last mentioned unit and the second of the first mentioned liquids into the receiving chamber of said one unit-said means cooperating to normally maintain said tank space filled with liquid below a liquid level adjacent the upper end center column extending through said partition members and formed with vertically extending channels separately connecting the receiving chambers of the two to the clarifying portions thereof and thereby providing the said flow path of each unit.

- WILLIAM E. GEISSLER.