‘Sept. 10, 1946. ‘ ' H. A. TEALE 2,407,303 APPARATUS FOR REDUCING THE FLUID CONTENT OF FLUID-SOLID INTERMIXTURES ' A Filed Aug. 15, 1943‘ 3 Sheets-Sheet 1 - ' _ IN VEN TOR. Harald ?. Era/e BY v ' Sept. 10, 1946.v _ , _ ~ H_ A, TEALE Y 2,407,303 APPARATUS FOR REDUCING THE FLUID CONTENT OF FLUID-SOLID INTERMIXTURES Filed Aug. 13, 1943 i0 v M I 3 Sheets-Sheeti I 65' a” r j i" .i/ a? A16 446 1m ',"H v _ did 140,445 mun" __ _____ 2,407,303 Patented ‘Sept. 10, 1946 ‘UNITED STATES PATENT OFFICE 2,407,303 I APPARATUS FOR REDUCING THE FLUID CONTENT OF A FLUID-SOLID INTERMIX TUBE Harold A. Teale, Brooklyn, N. Y., assignor to Filter Media Corporation, Irvington - on - Hudson, N. Y., a corporation of New York Application August 13, 1943, Serial No. 498,520 4 Claims. (01. 210-188)‘ 1 2 The invention relates to slurry separators, continuously removed from the slurry, thereby continuously increasing the proportion ofsolids thickeners, clari?ers or the like and more particu larly to a new and useful apparatus for continu ously decreasing the ?uid content of a solid and ?uid intermixture. Objects and advantages of the invention will be set forth in part hereinafter and in part will be remaining in the slurry which may be recircu lated or passed several times through the appa ratus, as required, to bring about the desired pro portion of solids-to-fluid therein. The inven tion is of general application to practically any obvious herefrom, or may be learned by practice and all such slurries or intermixtures but is par with the invention, the same being realized and ticularly useful in cases where thickening of the attained by means of the instrumentalities and 10 interm'ixture is impracticable or inefficient by combinations pointed out in the appended claims. The invention consists in the novel parts, con usual means such as settling and decanting. Hence the invention is applicable to the thicken ing of many slurries where solids are very ?ne or in a state of colloidal suspension, which cannot structions, arrangements, combinations and im provements herein shown and described. The accompanying drawings, referred to herein be thickened by settling or gravity action. Many of the novel principles of the invention are broadly and generally applicable to the sepa and constituting a part hereof, illustrate one em bodiment of the invention, and together with the description, serve to explain the principles of the ration or clari?cation orthickening of ?uids con invention. taining intermixed solids, including gas and solid . . Of the drawings: Fig. 1 is perspective view of an apparatus em 20 intermixtures. ~ In the succeeding _ bodying the invention; Fig. 2 is an enlarged fragmentary vertical sec tion, in expanded relation, of a plurality of typi cal elements comprising the thickener apparatus shown in Fig. 1; ‘ description, however, particular reference will be made to the treatment of liquid-solid intermixtures and for convenience of reference the action of the appa ratus will be referred to as thickening and the . ‘ Fig. 3 is an enlarged fragmentary section of the elements of Fig. 2 in assembled relation; Fig. 4 is a fragmentary top plan view of a thickener plate taken on line 4--4 of Fig. 2; Fig. 5 is a fragmentary bottom plan view of a ?lter plate taken on line 5—5 of Fig. 2; and ' Fig. 6 is a fragmentary vertical section through apparatus itself as a thickener. . The invention employs exceedingly simple and inexpensive~means, but by means of novel princi ples, is enabled to produce very superior results in relatively short time and at a low expenditure of power and labor. ' The thickening or liquid-removing action of the invention depends upon the movement of the slurry over or across the surface of a ?lter me— one element of the assembled apparatus, dia dium while under pressure su?icient to force liq grammatically illustrating the nature of the 123 (it uid through said nledium, maintaining a state of slurry ?ow therethrough; and motion in the slurry travelling over said medium Fig. '7 is an enlarged perspective view of a sec such that no substantial amount of solid is de tion of a plate ll showing the transverse nodes posited out of the slurry to form as cake on Said 44' and the transverse valleys 45 on one side and medium. In accordance‘with the invention the the longitudinal grooves 25 as Well as their adja 40 state of motion induced in the slurry to effect this cent lands 26; / desired action is brought about by exceedingly Fig.‘ 8 is an enlarged partial view similar to Fig. 6 but taken along the line 8-—8 in Fig. 7, but with the ?lter medium 50 in place thereon, and this ?gure illustrates what seems to happen to the 45 simple stationary means without the interposition of any mechanical agitation or pulsation from slurry particles in the channel 40; slurry over the ?lter medium and the mainte nance of desired pressures and velocities therein are all effected by static and exceedingly simple Fig. 9 is a plan view of a portion of a channel 40 and shows a modi?ed form of node; and Fig. 10 is a partial perspective view of the modi— applied mechanical means or forces. In other words, the required motion and movement of the devices within the chambers where the ?ltering ?ed arrangement of Fig. 9. , 50 action takes place. The invention is directed to providing novel and One object of the invention is to prevent the useful apparatus for reducing the ?uid content deposition of solid particles onto the ?lter medium of a ?uid-solid intermixture (hereinafter called by maintaining a substantial continuous turbu a slurry) by virtually continuous ?ltering or lence throughout the slurry as it travels in rela straining action wherein a clear fluid product is 55 tively high velocity streams across the surface of 2,407,303 3 4 the ?lter medium thereby producing a substantial scouring action of the liquid against the surface of the ?lter cloth or other medium which prevents the formation of any substantial amount of cake or solid matter thereon. The invention also pro desired'liquid-solid ratio. With many products, vides for recurrently actively forcing or urging the slurry against and into contact with the ?lter however, a single pass of the slurry through the unit It may be suf?cient to bring about the de sired thickener action or on the other hand, the slurry delivered by the pipe I8 may be passed through a second unit similar to unit I 0 in series or tandem therewith so that sequential thicken ing actions on the progressively thickened slurry medium as it travels thereover, thus providing frequent surges or impulses in the slurry which - may thus be effected, cause the liquid in same to be driven against and 10 Referring super?cially to the construction of through the medium. unit Hi, same comprises a plurality of superposed Another principle employed in the invention, rectangular plate members or elements I l which either as a concomitant of the foregoing or inde are relatively long and narrow and which are pendently thereof, is the maintenance of a sub stantially constant velocity in the stream of Slurry passing over a length of ?lter cloth, This func mounted to colliectively form a rectangular stack tion is preferably e?ected by causing the slurry of inter-communicating elements or plates one above the other, as shown, A bottom support ing plate l2 and an overlying top plate l3 are to travel through channels of decreasing cross provided, same being somewhat greater in area vsection so that, as the amount of liquid therein than the element plates II, and the entire stack decreases by the ?ltration effect, the loss in vol 20 is bound together by a plurality of vertical rods ume of the stream of slurry is compensated for by l'l. pairs of which at either side of the stack are decrease in the size of the conduit, thereby ef tied by top and bottom cross-members I‘! and fectively maintaining a generally continuous ve drawn together by nuts l9 at the threaded ends locity which facilitates the maintenance of the of the rods. Any other suitable means for com flow of slurry over the ?lter medium, counter 25 pressing or drawing together the several super acting the tendency of the solid particles to set posed plates or elements of the unit Ill may be provided, it being understood that the hydraulic tle out on the ?lter cloth, and, when used in combination with the turbulence-creating means pressure for the thickening of most products is above referred to, enhances the scouring and relatively low compared with that used in a typi anti-precipitating action as well, 30 cal ?lter press. Pressures of the order of about One feature of the invention which greatly 15 lbs. per square inch have been used success facilitates the successful operation thereof is the fully and therefore an expensive and heavy duty maintenance of a proper balance of forces and clamping or pressure-maintaining means is not ?uid movements so as to build up and maintain ordinarily required. However, for certain pur a relatively thin deposit or “skin” of solid matter poses and with some mixtures considerably higher on the face of the ?lter medium. This skin of pressures may be used and are sometimes desir cake is established at the beginning of the opera able and in such cases the clamping or pressure tion and, is maintained substantially constant maintaining means may be adapted to the higher throughout the continuous recirculation of the pressure operations without interfering with or slurry through the apparatus. The maintenance changing the basic design of the apparatus nor of said skin of cake is effective in providing a its internal functioning. clear solid-free liquid product delivered through The detailed constructionv of the several plates the ?lter medium and the forces employed are so making up the unit l0 will be seen in Figs. 2-5. regulated and balanced as to prevent the build _ As shown, the top plate or head stock I3 is pro ing up of said skin of cake beyond a predeter vided near one end with the vertical port 20 for mined very low maximum thickness, yet to estab the reception of the inlet pipe 6, the lower por lish and maintain same throughout the operation tion of said port being counter-bored at 2|. The and in spite of a continuously increasing propor port 2ll—2l is alined with a similar port 22 in tion of solid content in the slurry. the ?rst or head plate 23 of the unit Ill, said head It will be understood that the foregoing gen plate being smooth and flush on its top face to eral description and the following detailed de match with the bottom surface of the overlying scription as well are exemplary and explanatory head stock 13. The underface of head plate 23, but are not restrictive of the invention. Referring however, is provided with a plurality of longi now in detail to the present preferred embodi tudinal grooves 25 and lands 26 which serve as ' channels for the filtrate after same has ?ltered ment of the invention, illustrated by way of ex ample in the accompanying drawings, a general through the ?lter medium 50 overlying said lands view of an apparatus embodying a preferred form and grooves. As shown, each groove 25 begins adjacent the inlet slurry port 22, and terminates of the invention is shown in Fig. 1. Same com prises in general a tank 8 for containing the at 28 in a recessed cross-conduit 29. Said cross supply of slurry which is drawn preferably from 60 conduit thus communicates with all the dis charge ends of the clearate grooves (Fig. 5) and near the bottom thereof by conduit 2 on the in in turn communicates with an upwardly in take side of a motor driven pump 3 and forced thereby through pipe 4 past pressure gauge 5 into clined central duct 30 which directs the ?ltrate into a discharge channel which, in the head plate, the top of the thickening unit Ill by means of inlet begins with the enlarged socket portion 3| which pipe 6. The solid-free ?ltration product of the is alined with similar capacity ports in the other thickening unit l0, hereafter conveniently called ?ltrate, is delivered therefrom at one or more plates just below. The next plate or element II is typical of all points by delivery pipes I5 into a suitable recep tacle l6, while the thickened slurry, constituting those for making up the unit It], except for the the mixture which has passed through the unit 70 head plate 23 and the tail plate 35 hereinafter described. That is, a plurality of said plates ll Ill, is delivered therefrom by one or more outlet similar in construction thereto, will all be super pipes l8 which, as shown, feed back into the tank posed to make up the unit It] and in practice a In for re-mixture with the original batch and typical unit may include thirty of ' such plates re-circulation through the unit ID as many times as may be required to reduce the slurry to the 75 combined as shown in Fig. l. 2,407,303‘ 5 i . In the preferred construction, as shown, each.‘ 6 and by itself ‘in preventing settling out all the of the element plates l l is provided on its upper solid material ‘ and consequent choking and blinding of the channels. The same is true to surface (as disposedin the unit ID) with a plu rality of channels or conduits for the travel of an even greater extent of the other features of the slurry therealong while in contact with the the invention previously described, i. e. the pro ?lter medium 50 lying against the lands of the vision of Wavy surfaces in the slurry channels to ?lter grooves 25 of the plate just above. Prefer promote turbulence or ripples in said flow. That ably, in a unit of the general shape and dimen is, each of said features can be used independ sions shown, the plate will be provided with three ently of the other and when so independently parallel channels 40, the inlet ends of which 10 used will improve the thickening action and ef communicate with the slurry ‘port 22 of the ?ciency of the unit. However, I prefer that plate just above. Each of said channels 40 ex they be used together, the combination of the two features contributing to the improved opera tends from said inlet end to communicate with a down port 4| near the opposite end of the tion of the unit. Of the two such features, how plate H so that liquid reaching said end travels 15 ever, I regard the provision of the ripple or turbu downwardly through the port M to the next lence-creating elevations and depressions in the plate below. As will be apparent from Fig. 4 the conduit as being more important and, with some three channels 4!] of the plate are separated by materials, capable of efficient independent use, partitions or lands 43 which extend parallel for in which case the slurry channels 40 may be of the length of said channels 40. ' 20 uniform depth and width (except for the nodes and valleys) throughout their length. In accordance with the invention the course of the slurry travelling along a conduit 40 it con In the preferred construction shown it will be tinuously disrupted and changed in velocity so noted that the slurry is caused to travel through as to impart a disrupting turbulence therewithin as the liquid travels along said channel. For this purpose the bottom surface of the channel is preferably formed as a wavy surface compris ing successive nodes 44 and valleys 45 which, as illustrated diagrammatically in Fig. 6, cause a constant turbulence and scouring activity within the stream of slurry ?owing along said channel. The number, depth and spacing of the valleys 45 and nodes 44 do not appear to be especially critical although it is important to‘ make frequent changes in the depth of the chan- nel to thereby cause the slurry to be forced up wardly through narrow passages close to the overlying ?lter medium 5!] (Fig. 6) and then to quickly expand into zones of greater volume in the valley portions 45. For example, in plates ll of the general shape shown, having an overall length of about 5' with relatively long and narrow passages 48 with rever sals of ?ow direction at the end of each pass. The relatively sharp and. sudden reversals of direction have been found to contribute bene?cially to the prevention of solid precipitation, in that said changes in direction assist in breaking up the continuity of ?ow and the maintenance of turbu lence in the streams of slurry. The invention is not limited to use of relatively long passes of slurry in each compartment or section of the unit as, if desired, the pnitmay instead comprise a larger number of relatively short sections whereby the reversals of direction of slurry ?ow occur very frequently and thereby contribute of themselves in a relatively greater extent to the turbulence creating action desired. One important feature of the invention is to so regulate the turbulent or rippling flow of the slurry that a relatively thin skin or layer of solid grooves All of 4.8" in length, the approximate matter is formed promptly on the adjacent sur length from node to node is preferably about 4". face of the ?lter cloth and thereafter no increase However, it will be understood that the invention 45 in the thickness thereof takes place. In practice, is not limited to any particular shape or number it has been found that with many substances a of elevations or depressions in the slurry guid skin or cake thickness of about 1/2;" is the op ing channels and that same may vary with dif timum, said skin acting as a “?lter-aid” to in ferent types of materials, with different hy crease the clarity of the ?ltrate while being suffi draulic pressures and other factors. It will be 50 ciently thin as not to interfere with the prompt found by practice with the invention that cer passage of liquid through the ?lter medium at a tain optimum arrangements of the general de relatively high and constant rate. In this con signs hereinbefore disclosed will obtain‘ with nection it has been found that the construction various materials and mixtures of slurries but and shape of the nodes 44 is of importance in that a wide latitude may be had in the arrange 55 creating a recurrent upward surging of the slurry ment and number of the elevations and depres ‘or its bombardment against the overhead canopy sions in the grooves without departing from the of ?lter medium and its adherent skin of solid essential principles of the invention. particles. That is, the upwardly-directed kinetic impact of the slurry passing over each rise or node Another feature which has been found helpful in facilitating the desired continuous thickening 60 in the channel imparts recurrent dashings of the and prevention of solid precipitation, is the con slurry against the ?lter medium and thereby materially contributes to forcing liquid through struction of the slurry flow channels 49 in such manner that they decrease in capacity or vol the skin and the ?lter medium. ume in the direction of flow of the slurry there Such kinetic impact of particles of the slurry along, thereby to maintain substantially constant against the ?lter medium is illustrated in Fig. 8 of the general velocity of flow of the slurry in said the drawings, wherein the horizontal arrows at channels and thus oppose any slowing down of the right hand of the ?gure indicate the in?owing the slurry ?ow which in t?rn would promote slurry, while the V-shaped bent arrows indicate a settling action of the solid particles. As shown de?ective path taken by a slurry particle as it in Fig. 2, for example, the channels 4|] in plate strikes a rise or node 44 in the channel 40. The I l are of maximum depth at the in?ow or right A-shaped bent arrows indicate a de?ective path hand end and taper to a relatively shallow depth taken by a slurry particle as it strikes the ?lter at the delivery or left-hand end thereof. medium 50 and bounds away therefrom. The cir This feature of narrowing or tapering of the cular arrows indicate eddies and other disturb slurry channels has been found to be helpful in 75 ances created or set-up in the flowing slurry due 2,407,303 7 8 to these: bounds and rebounds indicated by the filter medium and constituting therewith a con bent arrows. This seems to be an explanation of duit for the flow of slurry therethrough, said con the scouring action of the flowing slurry that duit having an undulating bottom surface pre keeps down the thickness of the ?lter cake 5| on the ?lter medium 50 from growing thicker than that at which the cake normally stabilizes itself to the conditions of ?ow and kinetic impact. senting nodes and valleys for imparting turbu lence to a stream of slurry passing through said conduit, and also having outlet means for passing slurry from said conduit. The nodes or elevations 44 in the channels ea may be modi?ed as shown in Fig. 9, which differs 2. In a slurry thickener comprising a stack of elements, a plate element, having on its lower side from the arrangement of Figs. 4 and 7, for in 10 a downwardly open recess for the reception and stance. In those ?gures, the. crest or ridge of each flow therethrough of ?ltrate, a ?ltrate outlet pas node extends continuously transversely of the sage, and having on the upper side a channel for channel 40, whereas in the. arrangement of Fig. 9, the passage therethrough of slurry, said channel having an undulating bottom face presenting ity of individual nodes culminating in crests 44a, 15 nodes and valleys, and slurry outlet means at the Mb, 44c, 44d and so on, respectively, with these end of said channel. each general node 44 maybe made up of a plural crests forming a broken or irregular line more or In a slurry thickener a stack of plate ele less transversely on the channel 40. These irre ments, each plate element having on its lower side gular crests create further scouring eddies or tur a downwardly open recess for the reception of ?l bulence as indicated by the curved arrows shown 20 trate, and on the upper side a channel for the in Fig. 9. Fig. 10 shows how these irregular crests passage therethrough of slurry, said channel hav appear. ing an undulating bottom face presenting nodes For most purposes it will be found that wood is a and valleys, a ?lter medium interposed between suitable material for construction of the units adjoining faces of any two such plate elements, especially because the pressures of operation are and passage means in said plate elements whereby ordinarily not high or critical. However, the ele slurry passes from the end of a channel in one ments of the thickener unit may be made of plate element into a corresponding channel of the molded or laminated “Bakelite” or other similar next lower element and whereby the direction of material, and such plastics are especially effective flow of the slurry is reversed, a slurry inlet pas where. chemicals corrosive to wood, metal or other sage for the: ?rst channel of said stack of plate ele materials are present, in the slurry to be thickened. ments, a slurry outlet passage for the last conduit Metal or any other available material may, of of said stack of plate elements, and means for re course, be used where called for. moving the ?ltrate from said recesses. The invention in its broader aspects is not lim 4. A slurry thickener including in combination ited to the speci?c mechanisms shown and de a ?lter medium, ?ow conducting means constitut scribed but departures may be made therefrom ing with the underside of said ?lter medium a con within the scope of the accompanying claims duit for passing therethrough a stream of slurry without departing from the principles of the in along and past said underside, said conduit hav vention and without sacri?cing its chief advan ing an undulating bottom surface presenting tages. nodes and valleys for imparting turbulence to said stream passing through said conduit, inlet means for passing slurry into said conduit, outlet means plate having recesses on the lower side, means for for passing thickened slurry from said conduit, removing ?ltrate from said recesses, a ?lter med and conduit means for removing ?ltrate passing ium under said recesses and constituting there 45 upwardly through said ?lter medium. What I claim is: 1. In a slurry thickener in combination a ?lter with ?ltrate conduit means, and a slurry flow di~ recting plate adjacent to the underside of said HAROLD A. TEALE.