Патент USA US2410633код для вставки
NOV- 5» 1946- T. B. COUNSELMAN 2,410,633 TREATING RUBBER SUSPENSIONS Filed Nov. 4, 1943 2 Sheets-Sheet 1 <5 u. N4’ (\i c5 'u. uvmvmx ’ ‘THEODORE acouusemm, BY _ , _ WW ATTORNEY Patented Nov. 5, 1946 2,410,633 UNITED STATES PATENT’ OFFICE 2,410,633 TREATING RUBBER SUSPENSIONS Theodore B. Counselman, Evanston, Ill., assignor to The Dorr Company, New York, N. Y., a cor poration of Delaware Application November 4, 1943, Serial No. 508,920 11 Claims. (Cl. 260-865) 1 2 In the manufacture of synthetic or arti?cial rubber there is produced, for example from buta diene and styrene as basic materials, that which is known as synthetic or arti?cial latex and which is therefore often referred to as latex because of this having a milky appearance resembling nat ural latex. In the process of producing synthetic words, while by known methods one may assem ble and separate from the coagulum the coarser ’ of the synthetic rubber particles; nevertheless dif iiculty is experienced when one attempts to re cover the synthetic ?nes of that character where- ~ by they tend to continue in suspension in the serum and resist removal therefrom. For effecting a method of removing said co rubber such synthetic latex is co-polymerized whereby thereis produced a liquid-solids mix polymer ?nes, some of which may approach col ture or suspension, herein referred to as-coagulum 10 loidal conditions or which because of the physical and which comprises serum or brine as a major form or condition thereof refuse to respond by liquid component thereof and synthetic rubber known process to effective separation from the solids, crumbs or curds, of varying sizes and here liquid bearing the same, special treatments are in collectively referred to as synthetic or arti?cial required or are preferably resorted to. In order rubber crumbs or which are more de?nitely re 15 to overcome this di?lculty or apathy respecting ferred to herein as butadiene styrene co-poly these ?nes and to assure the effective separation mers or crumbs. This coagulum therefore com thereof from the liquid bearing the same, this prises that which may be viewed as a liquid frac invention includes the employment of a process tion of mother liquor on the one hand and a mass wherein there is realized a ?otation of the ?nes of such suspended synthetic rubber crumbs on the 20 by exposing the surface of a liquid-solids mixture other which have occasioned and developed in bearing the same, as for example the coagulum, the mother liquor during a suitable reaction to an overlying gaseous medium maintained at treatment carried out for realizing the sought for pressures substantially lower than that of the out synthetic latex. Some of these crumbs are rela side atmosphere. Under the in?uence or effect tively large but there is a certain quantity thereof 25 of the vacuum or sub-atmospheric pressure con which is extremely small or ?ne ranging down to ditions of the overlying gaseous medium the ?nes quasi-colloidal or colloidal size particles. will rise to the surface of the liquid in a manner The larger sizes of the crumbs resemble curds favorable to their ready removal from the surface of cottage cheese and are of a size up to one-half of the liquid bearing the same, to wit, as ?oated inch in diameter. When the coagulum in which 30 material or scum. ‘ said crumbs exist is exposed to normal atmos In the mother liquor or briny serum, there is pheric pressure and is relatively quiescent, the ‘ larger co-polymer crumbs rise to the upper por tions of the serum or mother liquor in which they were developed, this because the speci?c gravity ‘ thereof is less than that of the brine or serum often contained soap or fatty matter of a char acter,that tends to adhere to and continue~w~ith the yielded solids, as for example, upon the crumbs even after they have been separated from the mother liquor. Another aspect of this inven of the mother liquor in which they are thus tion is the devising of an effective and efficient found, but under the indicated state of facts the manner for separating the synthetic rubber from smaller size particles or synthetic rubber ?nes or the liquid fraction or serum of the coagulum and co-polymers do not readily and quickly rise with 40 it is particularly concerned with the effective in the serum or mother liquor, neither do they separation of synthetic rubber crumbs from a readily and quickly settle within the mother liquid fraction in which they are yielded or in liquor in which they are yielded. In fact, much which they are found. of said ?nes rather than tending to either rise A main feature and aspect of the invention re or settle within the serum tend to remain as rel volves about a process and system for effecting‘ atively dormant suspensions in the liquid after an efficient and ready separation of the synthet the manner of colloidal particles suspended in ically produced rubber solids and particularly of the liquid and which continue to remain in sus such co-polymer crumbs from their mother pension therein. liquor. In fact, the ?ner synthetic rubber particles or ?ner co-polymer grains have a decided tendency The invention has in view the obtaining of such synthetically produced solids and particularly to continue in suspension, to wit, in a manner according to which they may be referred to as. such solids as are in the form of crumbs in washed condition, as for example, in condition in which they have been freed (a) of substance such as In other 55 soap Q1: fatty acids and which tend to adhere solids more or less in colloidal suspension, or as solids in quasi-colloidal suspension. ' 2,410,838 3 4 thereto or remain therewith, or (b) of some of the process liquor or brine which would otherwise remain in the interstices of or on the surface of objectionable mass it the wash water were other the crumbs. wise passed directly to the waste. They would also constitute a substantial loss in quantity of synthetic rubber if not recovered and an impor tant aspect of this invention revolves about the obtaining, recovering or collecting of the lines ‘ ‘The invention hereof is illustrated and de scribed in connection with the subjecting to a 1 passing with the eiiiuent leaving the separated solids-removal treatment of a liquid having sus out larger rubber crumbs. Another aspect of the invention revolves about the passing of the rubber ?nes recovered from the e?luent liquid either back to a preceding portion pended therein synthetic rubber solids or crumbs, which suspension or mixture‘containing said syn thetic rubber crumbs has been realized in a proc ess according to which such crumbs are produced from co-polyinerization of certain starting ma of the process or even to a subsequent portion of terial that comprehends butadiene and styrene the process wherein they are made available for increasing the e?iciency of the rubber yield of as basic products therefor. It will be pointed out that the invention hereof 15 the plant. It has been ascertained that when a body of is directed to or revolves about the removing of liquid containing synthetic rubber curds sus curds, crumbs, or ?nes referred to as co-poly- , mers developed or realized in and by a butadiene pended therein is placed under vacuum there styrene process from the manufacture of that is realized a prompt rising of the curds, not only which is referred to as synthetic rubber and which 20 a prompter rising of the larger size crumbs but also a prompt rising of the rubber ?nes to the surface of the liquid whereat they can be col lected as ?oating material or scum which when in many respects is available as a substitute for rubber products produced from the sap or gum obtained from the rubber plants or trees. The invention hereof is applicable for employment in handled in the proper manner can be removed any such process wherein there is realized a 25 from the liquid along one path while clari?ed liquid-solids mixture embodying such curds, crumbs, or ?nes synthetically produced by poly eiiiuent freed of suspended rubber solids can be passed along another. merization and'which are to be separated from The steps just referred to are best carried out the liquid fraction of the mixture in which they (a) by establishing and maintaining a body of were developed or realized. / In order to separate the resulting polymerized synthetically ‘produced rubber solids from such liquid-solids mixture, there have been proposed or employed devices such as vacuum filters or shaking screening mechanisms. Where a vac uum ?lter is used the solids are collected as a layer or sheet on the ?ltering medium. The ?l tering medium may be a. woven wire mesh or screen or a ?lter cloth, or the equivalent on the 30 liquid within a- con?ning tank so that the surface of the liquid is constantly exposed to subatmos pheric pressure conditions of overlying air or gas; (1)) by continually feeding to such established body a liquid-rubber mixture containing syn 35 thetic rubber curds in suspension therein; (0) by continually collecting and removing as ?oat material from the surface of said body the rub ber solids rising to the surface thereof and de livering the collected solids from the tank or peripheral portion of a rotating drum. 40 container along one path at the same time avoid The ?ltrate or eilluent leaving the layer or sheet ' ing entrance of outside air into the tank; (11) by and passing through such medium or screen con passing clari?ed liquid from a lower portion of the body, namely, liquid freed of the rubber solids tains to some extent ?nes which continue with and which is delivered along a pathway leading the ?ltrate or eilluent passing from the left-be from the tank while at the same time avoiding hind or separated-out rubber crumbs. This ?l trate if derived from a coagulum is that liquid entrance of air into the tank; and (e) by remov ing, according to operative requirements, air or fraction which has heretofore been referred to gaseous medium tending to collect within the as serum, it may be relatively strong or rich in tank above the body whereby proper sub-atmos certain desired chemical content and it will con pheric conditions at the surface of the body will tain some rubber ?nes which pass therewith from be constantly maintained. left-behind rubber crumbs. This ?ltrate or serum There are diagrammatically illustrated in the which may be undiluted or‘ which may be only a minor dilution may be passed to a preceding portion of the process whereat the serum with accompanying drawings systems for removing or re-treatment in the process. Where one desires to obtain crumbs which had synthetic rubber solids from a liquid-solids mix ture containing the same. In one of said systems there is employed a vacuum type of apparatus for separating rubber been washed it is advisable to pass the already crumbs of varying sizes from a coagulum or other separated-out and substantially debrined crumbs liquid suspension of synthetic-rubber solids. the ?nes therein are made available for re-use ' In another of said systems, the large rubber derived from the coaglum for a further or wash 60 solids are ?rst separated from the liquor of the ' ing operation and for a dewatering of the washed process. which is recovered as non-diluted proc solids. Filters, screens or other suitable appa ess liquor or as process liquor only slightly di ratus may be employed for this purpose and here luted, to wit, as brine or serum herein identi?ed again the liquid or e?luent passing from the ?l ters, screen or other separating medium con 65 as a serum containing effluent of minor dilution. tains ?nes washed out from the larger rubber crumbs and which pass with the eilluent leaving the crumbs. This wash water eiliuent contains some of the much diluted brine and some washed out solids and may be identi?ed as an eilluent of major dilution. The rubber crumbs or ?nes re moved in this manner may seem in quantity rela tively small; however, in the aggregate they con Afterwards these initially separated larger rubber solids are washed and separated from the wash water, the latter of ‘which may be identi?ed as a serum containing eiiluent of major dilution. The serum containing eiiluent of minor dilution may be passed along one path leading to a prior portion of the process, or it maybe conducted along another path leading to a vacuum type of stitute a considerable amount—a quantity of such separation apparatus. extent that they might ultimately collect as an minor dilution carries rubber solids therewith as This - serum e?luent of 5 2,410,688 ' suspended matter and the treatment in this vac uum‘separator is to recover the ?ner solids as ?oated material passable from the apparatus along the one path while leaving behind a clari?ed serum or brine which can be passed as e?iuent from the apparatus along another path as for re use or employment in the process as may be deemed advisable. The washing operation dilutes brine in the in terstices of and remaining on the surface of the relatively de-brined mass of solids of the initial separation process, and the wash water e?luent from this mass has therein a quantity of brine 6 Fig. 3 diagrammatically illustrates such a unit inione type of environment. Reference is now made to the drawings in de tail. Therefrom in connection with the descrip tion herein set forth, there will be readily appre ciated and understood the importance and ad vantageous employment of certain steps or op erations realizable in and by the vacuum type of . apparatus referred to in and for the separation of synthetic rubber crumbs from a liquid fraction bearing the same and particularly of the smaller ?nes thereof from a liquid fraction bearing the same in suspension. or serum and also as suspensions therein a cer In these ?gures of the drawings there is illus tain quantity of ?ner synthetic rubber solids. 15 trated a unit adaptable for employment in a syn thetic rubber producing plant, namely, a unit The wash water or serum containing e?luent of embodying a feed-receiving basin I adapted to major dilution is conducted to a vacuum type of separation apparatus which particularly func hold a body of coagulum and a closed top vacuum tank 2 with associated parts. This vacuum tank tions to accomplish a ?oating of the suspended polymerized synthetic rubber solids that are 001 20 2 has a draft tube or feed pipe~3 with a low intake, section leading from the receiving basin I and an lectable and removable from the apparatus along upper delivery section terminating within the one path while leaving behind a weak but rela tank at elevation substantially above that of the tively clari?ed eilluen't which may be passed along bottom of the tank but lower than that of the another path for such use or disposition thereof as may be deemed advisable. ' 25 upper interior portion of the tank. In this tank there is held and maintained a‘ The ?nes recovered both from the serum con continuously changing body of liquid undergoing taining e?iuent of minor dilution and from the treatment, the surface level of which is normally serum containing eiliuent of major dilution can maintained up to an elevation substantially_a_bove be passed either to a preceding portion of the process or to a subsequent portion of the rubber 30 that in the bottom of the tank but somewhat lower than that of the upper interior portion of producing process as may be deemed advisable the tank and there is also maintained within the having in view the particular requirements of the upper interior portion of the tank, air or other particular synthetic rubber producing process em gaseous medium directly overlying said ever ployed. ' The fundamental features of the apparatus for 35 changing body of liquid and to which the surface of the ever changing body of liquid is constantly performing the separation of the synthetic rub exposed. The tank has means as will hereinafter ber solids-either largeuor ?ne solids—-from the appear for sucking the air or gaseous medium liquid in which they are suspended are diagram maticaliy illustrated in each of the systems re 40 from the interior of the tank whereby the air or gaseous medium in the tank will be main ferred to and constitute an important instrumen tained under vacuum as it is sometimes referred tality thereof. For convenience said apparatus ‘ to, or as otherwise expressed, whereby the air or may be referred to as a vacuum type of crumb gaseous medium will be maintained at pressures separating apparatus. substantially below that of the air outside of the The vacuum'type of crumb separation appara tank. The sub-atmospheric pressure of this gas tus has been adopted for the separating from a eous medium is such as will be indicated by not liquid-solids mixture bearing the same of syn less than substantially 9 inches of mercury. thetic rubber ?nes because the latter are not I have ascertained that a vacuum or sub-atmos readily settleable from the liquid because the pheric pressure type of ?otation operation can colloidal characteristics thereof tend to cause said ‘be advantageously employed to effect quick rising ?nes to continue as colloidal or quasi-colloidal and ready removal of the synthetic rubber ?nes suspensions. The same process and apparatus which is well adapted for removing of the dif?cultly settleable ?nes from a liquid is e?’ective for removing the larger size of rubber crumbs and therefore it becomes logical to employ this apparatus not only for removing the ?nes, but also at the same time for removing the coarser solids, and in this man ner avoid the necessity of employing separate and quite dissimilar types of machines for the separat ing-out operation. In said drawings which constitute a part of from a coagulum or liquid fraction bearing the same and I have adopted as a practical form of apparatus for accomplishing this quick and ready removal of the small ?nes a type of apparatus possessing the fundamental features of operation embodied in and by the vacuum type of apparatus illustrated in and by Figs. 1 and 2. In the unit or apparatus of Figs. 1 and 2 gas bearing mother liquid having polymerized syn thetic rubber crumbs which were yielded therein is fed as a liquid suspension of polymerized syn thetic rubber solids which is delivered to the basin I through a supply tube or conduit 4. The basin Figure 1 diagrammatically illustrates a vacuum 65 has an over?ow partition 5 rising from the bot type of separation unit functionable in a synthetic tom thereof whereby the interior of the basin is rubber plant for separating synthetic rubber divided into a relatively large receiving and stor crumbs from a process liquid fraction, or brine ing section 6 and a small section ‘I for receiving and according to which unit the separated-out overflowed liquid and solids at the ?ow delivery synthetic rubber crumbs are deliverable along side of the partition. I one path ‘while the liquid fraction is deliverable This partition is made up of removable and re along another path. placeable boards 8 and collectively constitutes a Fig. 2 is a horizontal sectional view taken on structure providing an adjustable height dam the plane indicated by the broken line 2—2 of the upper edge 9 of which constitutes an over?ow Fig. 1 and looking in the direction of the arrows. 75 weir at the top of the partition. The adjustment this specification: 2,410,638 7 8 of the height of this dam is according to the quan tity of the liquid-solids mixture to be retained in In the construction shown there is an auxiliary con?ning structure 23 which may be viewed as part of the launder and which embodies a wall the large section of the basin but it can be em ployed to release into the smaller section a con member or‘ portion 24, a cap member or top por tion 25 and a lower member or bottom portion 28 for providing therein a control chamber 21. In treated. The unit is designed so that there is this chamber there is disposed an adjustable suc constantly contained in the smaller section ‘I suf tion nozzle means 28 constituting an intake end ?cient of the over?owed liquid-solids mixture to of a pumping means 29 provided for withdrawing insure the maintaining of the intake end ill of the 10 gas or air from the upper interior portion of the .__draft tube 3 in submergence. trolled out?ow of liquid-solids mixture to be The crumb separating tank as shown, embodies an upright marginal wall H, cylindrical in plan, the’ upper horizontally-extending edge l2 of tank. ignated as I3. The tank has a bottom member or 28 and an upper horizontal tubular section 32 This pumping means 28 embodies an air suc tion pump P having a suction pipe line 30 leading thereto from the interior portion of the height which provides that which may be called a. clari ?ed-liquid over?ow weir edge that determines the 15 control chamber 21. This suction pipe line 38 includes the adjustable nozzle means 28 at and normal operative level of the ever changing body of liquid which is normally maintained within the for the intake end thereof, a rising tubular sec tion 3| leading upwardly from the nozzle means tank. This ever changing body of liquid is des ?oor portion l4 sloping downwardly and vinwardly 20 leading from the rising section 3| and connected to the pump P at the suction side thereof. from the lower edge portion of the marginal wall. The tank also has a launder structure providing an The nozzle means 28 is pivotally mounted so that it can be adjusted whereby the intake tip portion 33 thereof can be positioned as to the embodies a lower annular member l5 extending 25 height or elevation. This adjustment is attained through the medium of a shaft 34 connected to outwardly from the marginal wall, to wit, from an and extending laterally from the nozzle means elevation thereof slightly lower than that of the and providing a horizontally extending support upper or over?ow weir edge 12. The launder ing axis therefor and a handle 35 which is dis structure also embodies a rising outer wall portion l5 extending upwardly from the outer edge of the 30 posed outside of the structure providing the enclosed launder for receiving liquid overflowed from the upper edge l2. The launder structure member l5 and an upper annular member or height control chamber. , The pumping means 29 is also preferably equipped with a vacuum controlling means 36 over?ow weir edge I2 and extending inwardly that is connected to the suction pipe line 30 by a from the rising outer wall portion 18. The upper portion of the tank is completed by 35 pipe connection 31. The vacuum controlled means 36 is provided with an outwardly spring a top member or cap portion l8 rising from the pressed relief valve 38 which yields to allow an inner edge portion of the upper annular member out?ow of outside air into the suction line only IT. This top or cap member I8 is relied upon to after liquid hasbeei sucked into and upwardly complete with the launder structure a relatively gas-tight upper portion for the tank. Within the 40 within the rising section and for a substantial portion thereof but which valve opens before the interior of the tank there is provided a cylindrical liquid within the rising pipe section 3| reaches baiile member l9 that is circular in plan and which the upper horizontal section 32. In this way extends upwardly from a lower interior portion of there is assured continuation of conditions the tank, namely, from an elevation lower than that of the over?ow weir edge l2 to an elevation 45 whereby the pump P will never have to receive and deliver water and whereby the pump can higher than that of the over?ow weir edge l2. continue to operate to receive and deliver only This baf?e member [9 is carried from the cylin air or other gaseous medium supplied thereto drical marginal wall H through the medium of through the horizontal top section 32 of the suc spacing and supporting brackets 20. The cylin drical ba?ie l9 and the marginal wall II function 50 tion line 38. When the reduced pressure conditions within to provide between them an up?ow conduit 2| the top portion of the tank change whereby the leading from a lower interior‘ portion of the tank liquid within the rising section can drop or fall towards the over?ow weir edge l2. from the rising section 3| and from the nozzle This up?ow conduit 2| is annular in plan and section l1 at elevation higher than that of the affords means whereby there can be realized a 55 means 28 thereof, the pumping means can then function to withdraw some of the gaseous me dium from within the upper interior portion of the tank whereby to continue and maintain the and over the weir edge l2. The region within relatively uniform up?ow of clari?ed liquid from the lower interior portion of the tank towards required sub-atmospheric pressure conditions this baiiie member l9 occupies a relatively large portion of the horizontal cross-sectional area of 60 therein for satisfactory operation of the appara tus or unit. the tank and also a substantial portion of the depth of the liquid-holding portion of the tank. As previously indicated the normal operative surface level of the liquid undergoing treatment There is provided therein that which may be in the tank 2 is determined by the elevation of referred to as a zone wherein incoming liquid syn thetic rubber-solids mixture is received for treat 65 the over?ow weir i2 and above this body of liquid there is constantly maintained in zone 46 the ment and wherein the ever changing liquid body heretofore mentioned overlying body of air or I3 is held during the vacuum treatment thereof other gaseous medium which is continued at within the tank. pressures substantially sub-atmospheric because . The enclosed launder provided by the upper portion of the marginal wall H, the lower an 70 of the operation of ‘the pumping means 29. The general structure of the tank and associated parts nular ring IS, the rising outer wall portion l6 and are such that during the normal operation and the upper annular ring I‘! is designated as 22 and functioning thereof there is avoided any short is referred to as a clari?ed liquid-receiving laun circuiting entrance of air into the tank from the der because of its receiving the liquid over?ow~ ing thereinto from the weir edge I2. 75 exterior thereof either through the feeding 9 2,410,688 means leading to the tank or through the means by which clarified liquid is released and passed from the tank, or through the means by which ?oated and collected rubber crumbs are passed from the tank as scum. . From that which has preceded and also from an inspection of Figs. 1 and 2 it will be manifest that the gaseous medium which is within the upper portion of the tank occupies the entire re , gion therein which is at elevation higher than that of the over?ow weir edge I2. It will also be noted that this sub-atmospheric pressure gaseous medium extends across not only the full upper portion of the tank within the area de?ned by ._ receiving trough "there is provided ?oat-sweep ing means comprising a vertical shaft 10 extend ing from the exterior of the tank through a sealing packing ‘II at the top of the tank. This ' shaft is supported from suitable bearing means ‘I2 provided at the top of the tank. A motor actuated means ‘I3 is also provided for turning the shaft. The shaft carries outwardly extending arms 14 having resilient sweeping members 13 extending downwardly therefrom and dipping into the liquid body within the con?nes of the cylindrical ba?ie I9. As this shaft turns about its vertically extending axis the arms with resilient sweeping members depending therefrom the over?ow weir edge I2 but also so as to overlie 15 serve to engage and impel the ?oating rubber all of the liquid within the over?owed liquid receiving launder, including the liquid within the crumbs up the ramp past the overpass transfer edge into the receiving hopper or trough 50 from control chamber 23 of the latter. In other words which they pass from the downwardly extending passage area for the gaseous medium is provided tubular member 53. at 33 and 39 between the uppermost interior por 20 In connection with the foregoing, it will be tion of the top or cap portion of the tank on the noted that the depending or tubular members one hand and the upper interior portions of the 40 and 53 in effect constitute depending baro launder structure, including the upper portion of metric legs the lower ends of which constantly the control chamber 26 thereof on the other dip into sealing liquid and by which the par hand. 25 ticular clari?ed liquid is conveyed or the collected Referring now to the clari?ed liquid release rubber crumbs are conveyed and delivered to means. This includes the structure providing the exterior of the vacuum tank and in a manner the annular up?ow conduit 2I leading from a whereby there is minimized or avoided entrance lower interior portion of the vacuum tank, the of outside air into the interior of the tank in over?ow weir I2, the structure providing the en 30 cident to such transfer. closed over?ow receiving launder 22 and the con As to the draft tube, in the construction shown trol chamber 26 thereof, a clari?ed-liquid re the draft tube 3 is provided at the upper terminal ceiving and release box 42, a pipe or tubular portion thereof with a ?aring portion 83 the upper member 40 extending downwardly from the lower edge 34 of which is disposed at elevation proxi portion of the control chamber 26 into a body of mate but somewhat lower than that of the over sealing liquid 4I maintained within the receiv ?ow weir edge I2. There also extends outwardly ing box 42 up to an elevation 43 determined by from the upper edge 84 an annular plate 35, spaced an over?ow weir or darn 44 within the box 42. radial brackets 83 carried by and extending in This box 42 is also sometimes referred to as a wardly from the cylindrical baiile member aiford~ clari?ed-liquid release box. The clari?ed liquid ing support for the annular plate 85 and through which is released from the tank passes down the medium of the latter for the ?aring portion wardly from the over?ow launder 22 through this at the rising terminal of the draft tube 3. pipe 40 into the body of liquid 4I whereby the A sump 90 is provided in the bottom of the sealing liquid is continued and from which any tank for receiving any sedimented material that excess accumulations of clari?ed-liquid over?ow may pass or be passed thereto. A valve controlled the upper edge of the dam 44 and are passed pipe 9| leads from this sump and terminates in from the release box 42 as through the pipe 45. a box 92 when a body of sealing liquid 93 can be As to the means for receiving collected ?oating maintained. This valve controlled pipe can be rubber crumbs and for passing the scum of col employed to discharge sediment or liquid from the lected rubber crumbs from the interior to the ex 50 bottom of the tank while at the same time the terior' of the vacuum tank this comprises an open sealing liquid 93 can be relied upon to minimize top trough or ?oat-receiving hopper 50 provided or avoid entrance or back?ow of outside air into within the tank, a receiving box 55 and a pipe or the tank. tubular section 53 extending downwardly from The system of Fig. 3 has in view the‘ receiving the trough thence outwardly through the tank 55 and treating of coagulum, that is, a serum with structure and into a body of sealing liquid 54 rubber crumbs mixture suspended therein, such maintained within the receiving box 55 up to an as has been obtained from a co-polymerization of elevation determined by an over?ow weir or dam synthetic latex derived in the performing of a 56 within the box 55. Any ?oating material pass synthetic rubber producing process. ing downwardly from the trough through the leg 60 According to this system, the coagulum which is 53 is received in this liquid-holding section of sometimes described as a liquid-solids mixture, the box 55. As it accumulates it over?ows the of which the liquid fraction is brine while the weir 55 and can be released from the box 55 solids are rubber crumbs of varying sizes in the through the valve-controlled pipe 58. As to the brine solution or serum, is supplied along a path open top trough or ?oat-receiving hopper 50 this way It" into a de-brining tank or initial liquid has an overpass edge 5| with ramp 52 leading solids separating instrumentality I02 having a upwardly thereto. This overpass edge 5| is at screening or ?ltering medium I03 on which the elevation preferably slightly higher than that of rubber crumbs lodge as a layer or mass I04 the over?ow weir edge I2 and the trough is dis and from which the brine leaves as a serum posed so as to receive ?oating material passed or 70 containing eiiiuent of minor dilution collecting passing thereto as it rises to and collects at the within the lower portion I 05 of the tank I02. upper surface of the body of liquid within the This eiiluent brine carries therewith a certain tank. amount of the ?ner rubber crumbs, herein re In order to insure a positive transfer of the ferred to as ?nes which continue as solids sus ' ?oating rubber crumbs to and into the ?oat 75 pension therein. The eiliuent bearing the ?nes 2,41o,ess 12 therein passes from the tank I02 into and along a pathway or valve controlled pipe line I06. The rubber crumbs of the initially separated layer or mass I 04 are sometimes referred to as de bearing the same according to the disclosure re specting the apparatus or unit of Figs. 1 and 2. As to the wash water e?luent from pipe line I26, this can be passed by a valve-controlled connec~ brined crumbs but it will be noted that a certain in tion I2'I to the pipe line II8 leading to the re quantity of brine continues in the layer or mass ceiving basin 30I. I04. The crumbs constituting this mass are con For convenience the vacuum type of crumb ducted or conveyed as along chute or conduit separation apparatus or unit that embodies the I I I into an initial washing tank or instrumentality brine receiving basin 20l has been herein identi I I2 having a screening or ?ltering medium I I3 on ?ed as brine crumb separation unit BCU, while which the rubber crumbs lodge-and are supported the apparatus or unit embodying the basin 30I as a mass or layer II4 while being supplied and has been herein identi?ed as the' wash water washed with water delivered thereto along the crumb separating unit WWU. pathway or valve-controlled water supply line In Fig. 3 the parts of the brine crumb separa H0. The wash water thus applied washes out tion unit BCU which correspond to like parts in the remaining brine and also carries therewith unit of Fig. 1 bear reference characters which certain of the ?ner grains from the layer H4 are 200 greater than that of the corresponding and the water leaving the layer collects as wash reference characters of Fig. 1. Likewise with water eiliuent in the lower portion I I5 of the tank respect to the parts of the wash water crumb I I 2. This wash water eiliuent bearing some brine 20 separation unit WWU they bear reference char and also quantities of the washed out synthetic acters which are 300 greater than of the refer rubber ?nes suspended therein, which is some ence characters of unit of Fig. 1. As the units times referred to as a serum bearing e?iuent of ECU and WWU and the functioning parts there major dilution, is pased from the washing tank of correspond to and function according to the I I2 into and along a pathway or valve-controlled disclosure respecting the corresponding parts of pipe line II 6. , ' the apparatus or unit of Fig. 1 extended com ments in regard to the construction and operation washed mass II4 are conducted or conveyed as of the apparatus or units ECU and WWU are un along a chute or conduit I 2I into a second or necessary at this time. subsequent washing tank or instrumentality I22 30 In connection with the operation of the brine having a screen ?ltering medium I23 on which crumb separation unit BCU, it will be noted that the thus transferred crumbs lodge or are sup the brine eiliuent bearing ?nes supplied to the ported as a mass or layer I24 while being sup feed-receiving basin 20I passes from the latter From the washing tank H2 the crumbs of the plied and washed with water delivered thereto from a valve-controlled line I20. through the draft tube 203., and is delivered from The eiliuent 35 the ?aring top 283 of the latter into the ever of this subsequent washing operation also carries changing body of liquid 2I3 within the closed a certain quantity of further washed out ?nes which continue with it. The secondary wash water e?luent is passed from the lower portion top vacuum tank 202. The ?nes rise and are collected by the resilient member 218 at the outer ends of the horizontal tuming arms 214 I25 of the secondary washing tank I22 along the 40 whereby they are swept towards and beyond the pathway or pipe line I26. over-pass edge 25I of the receiving hopper 250. The de-brined and the twice washed and de From this hopper the fines are delivered through watered rubber crumbs constituting the coarser or the tubular section or barometric leg 253 into the sealing liquid 254 within the receiving box 255 from which the accumulated portion thereof 'is released as over?ow through the pipe 256. The processing as may be desired and in order. clari?ed liquid, to wit, the serum freed of ?nes, It is feasible to pass the brine effluent of the leaves from a lower portion of the tank 202', to ?rst tank I02 from the brine e?luent line I06 wit, through the up?ow conduit 22I which is an leading therefrom by pumping the brine through 50 nular in plan, over?ows the weir edge 2I2 and the valve-controlled pipe line I01 to a preceding enters the enclosed launder 222 and flows there portion of the‘ process or by passing the brine from downwardly into and through the baro from the line I06 into a valve-controlled branch metric leg by the tubular member 240 which line I08 connected to a feed or pipe line I09 constantly dips into sealing liquid 24I in the leading to and delivering into a brine receiving , receiving box 242 and from which the accumu-v basin 20I constituting a feed-receiving basin for lating brine or serum is released as over?ow a vacuum type of crumb separation apparatus through the pipe 245. Suitable vacuum condi identi?ed as BCU, namely a vacuum type of tions are maintained in this unit through the crumb separation apparatus embodying the medium of the pumping mechanism collectively features of construction and functioning to sepa 60 indicated as 229.v rate synthetic rubber ?nes from the brine or liquid In like manner the wash water effluent bear fraction bearing the same according to construc ing ?nes which has been delivered through pipe tion and method of operation already described in line H6 into the feed-receiving basin 30I is connection with the synthetic crumb separation ‘ ‘passed from the latter through the draft tube apparatus or unitof Figs. 1 and 2. 65 303' into the ever changing body of liquid main As to the wash water e?luent from pipe line tained in the closed top vacuum tank 302 where II6, this can be optionally passed at will by a in a liquid-solids separation takes place whereby valve-controlled branch II'I“ to the feed line or the ?nes ?oat. These ?oating ?nes are passed pipe I03 leading to the aforementioned receiving into the open top trough or hopper 350 from basin 20l or by a valve-controlled branch I I'Ib to 70 which they pass downwardly and into the baro a feed line or pipe I I6 leading to a receiving basin metric leg 353 into the ?nes-receiving tank or 30I of a second crumb separating unit identi?ed box 355 from which they pass as over?owed dis as WWU and which like BCU embodies the fea charge through the pipe 358 while the clari?ed tures of construction and function to separate liquid or wash water freed of ?nes passes up synthetic rubber ?nes from a liquid fraction 75 wardly from a lower portion of the tank through larger synthetic rubber crumbs derived from the coagulum are conveyed from the last washing tank I22 along the pathway I31 for such further 2,410,888 » 13 . the annular up?ow conduit portion 32i past the 14 um liberated from, directly overlying and engag ing the surface portion of such ever-changing body; maintaining such medium at pressures vsubstantially sub-atmospheric by applying sue tion thereto; continually feeding such suspension from a locality outside of said ever-changing body and delivering the same to the body proximate the surface thereof and whereat the thus-deliv over?ow edge 3l2 into the enclosed launder and whereby clari?ed wash water eilluent ultimately passes into and downwardly through the baro metric leg 340 into the receiving basin or release box 3“ from which there is a release of clari ?ed liquid to discharge along the line 345. If the synthetic rubber ?nes thus recovered from the crumb separation units are to be in ered suspension comes under the direct influence corporated with the already washed out larger 10 of the overlying gaseous medium thereby further crumbs in the pathway I31, this can be accom ing a liberating of certain quantities of said gases plished by passing the recovered ?nes alonga and furthering the ?oating of ?ne polymer sus pathway or pipe line that comprises the pipe pended particles to said exposed surface portion line sections 60, 6| and 62 leading to I31. If a of said body; continually collecting ?oating poly valve 59 is closed, then it is feasible to pass the 15 mer particles and removing them from said body ?nes from the wash water crumb separating unit from the region whereat they are exposed to said WWU to the pathway I31 while the crumbs from overlying gaseous medium to a locality outside of the brine crumb separation unit BCU can be said region; and continually removing liquid frac passed as along the pathway or pipe line 63, as suming the valve at 64 is open to a preceding 20 tion from a lower portion of said ever-changing body to a locality outside of said body. portion of the process. } . 2. In a butadiene styrene co-polymer process Respecting the serum or brine which is sepa for the manufacture of arti?cial rubber wherein rated out by the brine crumb separation unit there is involved the obtaining of co-polymer BCU this can be taken care of ?rst as by passing the brine from box 242 through pipe 245 into a 25 crumbs from gas-bearing and gas-releasing briny suspensions provided by a coagulum comprising box or basin 65 from which the brine can be such crumbs as a solids fraction thereof and passed as by pump 66 and pipe line 61 to any serum as a liquid fraction thereof and bearing preceding portion of the process where the brine therein gases liberatable from the suspension can be used. From that which has preceded, it will be mani 30 when the surface of the suspension is exposed to overlying gaseous medium whose pressure is less fest that the crumb separation apparatus which than that which the suspension was previously is described in connection with the unit or ap subjected to, the method comprising establish paratus of Figs. 1 and 2 can be employed to ing an ever-changing body of said suspension separate out the rubber crumbs of varying sizes from the liquid fraction in which they are found 35 and maintaining the surface thereof directly exposed to a gaseous medium liberated from and while according to the system of Fig. 3 one can remove the larger crumbs as by screening or ?ltering and can remove ?ner crumbs from brine bearing the same and can also remove ?ner overlying the ever-changing body, continually supplying suction to the gaseous medium over lying said ever-changing body to maintain pres crumbs from wash water e?luent bearing the .40 sure thereof substantially below that to which the suspension was previously exposed and all same. of this while the following operations are carried Whereas the foregoing describes the treatment out, namely, while continually supplying quan of synthetic rubber suspensions to recover the titles of said coagulum and delivering it as feed rubber particles, this invention is equally ap and towards the surface level of the plicable to reclaim natural rubber solids that 45 proximate body, while removing co-polymer crumbs ?oating are in suspension phase as a result of practicing at the surface of said body and delivering the processes for the recovery or reclaiming of such removed crumbs to a region outside of said body, rubber. This is especially true where rubber and while passing liquid relatively free of said ?nes are dif?cult to separate from suspension crumbs from a lower region of said body to a and would otherwise be lost by passing into the 50 locality outside of the same. ' sewage with the waste water-—where such rubber 3. In a butadiene styrene process for the pro ?nes are detrimental to subsequent sewage treat duction of basic crude products usable in or for ment processs. the production of synthetic rubber and in which It will be manifest that according to the dis process there is the obtaining of co-polymer closure hereof one can readily adopt the method 55 crumbs from a briny serum-crumb mixture real hereof to any part of a synthetic rubber produc ized in the process, wherein the co-polymer ing process wherein it is desired to remove ,rub crumbs are of varying sizes ranging from coarse ber crumbs from a liquid wherein the same was particles to and including small particles sus yielded or exists. The invention can be particu pended in the liquid fraction provided by serum larly employed where one desires to eliminate or and wherein there are in the serum gases which collect from the liquid bearing the same syn are liberatable when the serum-crumb mixture thetic rubber ?nes which may be in colloidal ‘or is subsequently exposed to an overlying gaseous quasi-colloidal condition. medium of pressure less than that to which the I claim: . i serum mixture is exposed; a continuous method 1. In a butadiene styrene co-polymer process 65 including establishing and maintaining an ever for the manufacture of arti?cial rubber and the changing body of liquid provided by such serum recovering of ?ne co-polymer particles from the crumb mixture, constantly exposing the surface briny suspensions thereof wherein there are gases of said ever-changing body to an overlying con liberatable from such suspensions when the lat ?ning body of gaseous medium liberated from ter are exposed to subsequent sub-atmospheric 70 said serum-crumb mixture, applying suction to pressure conditions; the method comprising es said con?ned gaseous medium to maintain pres tablishing an ever-changing body provided by sures thereupon substantially less than that of such suspension and maintaining the surface level the serum-crumb mixture supplied thereto, con thereof up to an operative elevation; exposing a stantly supplying serum-crumb mixture from a surface portion of such body to a gaseous medi 76 region outside of the ever-changing body and i -15 2,410,033 l6 delivering the serum-crumb mixture thus sup- .5 suspensions therein thereby obtaining asecondary plied into said ever-changing body within the brine-bearing ei‘iluent of major dilution and in reach of the suction in?uence of said overlying suring the existence in said secondary eilluent of gaseous medium, removing ?oating crumbs from gases when the secondary eiiluent is subsequently the surface of said ever-changing body and de exposed to pressures less than that at which the livering the removed crumbs outside of said ever washing operation was carried out, establishing changing body and also outside of said gaseous and maintaining an ever-changing liquid body, medium while at the same time substantially exposing an upper portion of said liquid body di avoiding entrance of air into said overlying gasrectly to the suction effect of a gaseous medium . eous medium, and passing clari?ed serum from 10 overlying the same, sucking gases from said over-' a lower portion of said ever-changing body to a lying gaseous medium for maintaining the pres region outside of the same while at the same sure thereof lower than that existing when said time substantially avoiding entrance of outside secondary eiliuent was obtained, passing quanti air into said overlying gaseous medium. ties of said secondary e?luent as feed material into 4. In the production and obtaining of buta said body and delivering the same at elevation diene styrene co-polymer crumbs from a briny proximate that of the surface of said body, col coagulum containing such crumbs as a sus lecting ?ne solids which assemble as ?oating ma pended solid fraction thereof and process liquid terial on the surface of said liquid body and as a liquid fraction thereof, the method compris within the region overlain by said gaseous med ing establishing and con?ning the ever-changing 20 ium, transferring collected ?oated material as body of said process liquor and maintaining the recovered ?ne solids to a locality outside of said surface thereof up to an operative level, expos region, which transfer of ?ne solids is in a man ing the upper surface portion of said body to an ner for avoiding any substantial leakage of air overlying gaseous medium derived from said into said overlying gaseous medium. passing briny coagulurn and applying suction thereto 25 clarified liquid from a lower portion of said body whereby to maintain the same at pressures sub whereat the suction e?ect of the overlying gas stantially sub-atmospheric, passing said agitated eous medium is substantially less than that at suspension into and delivering it within said the overlain surface of said body, delivering the con?ned body at elevation proximate that of the - thus passed clari?ed liquid to a locality outside operative surface level of the body whereby the of said body and in a manner for avoiding any coagulum thus delivered within said ever-chang substantial leakage of air into said body, and ing body is under the direct in?uence of said passing the recovered ?ne solids to a portion of overlying sub-atmospheric pressure gaseous me the synthetic rubber producing process. dium, collecting such crumbs assembling as ?oat 7. In the production of synthetic rubber ac material at the surface of said body, transferring 35 cording to a butadiene styrene process in which along one path said collected ?oating material there is realized a liquid-solids mixture compris from within the overlying gaseous medium and ing process liquor that includes brine and co transferring the same to a locality outside of polymers as solids of varying sizes, the method said gaseous medium while avoiding any sub comprising separating large solids from the pro stantial leakage of outside air into said atmos 40 cess liquor; passing separated large solids along pheric pressure gaseous medium incident to said one path, passing along another path process li transfer, passing process liquid from along an quor bearing ?ne solids and from which the large other path from a lower region of said body while solids have been separated; washing the sepa avoiding any substantial leakage of outside air rated large solids while exposing to atmospheric into said body incident to said passing of liquid pressure whereby to further remove entrained therefrom, and passing the collected transferred portions of liquor; passing along a third path the crumbs for further treatment. wash water e?luent hearing some of the washed 5. A method according to claim 4, wherein out process liquor and also carrying as suspen the overlying gaseous medium is maintained at sub-atmospheric pressures substantially not 50 sions therein washed out ?ne solids derived from the separated large solids; insuring the existence higher than that realized by a suction pull re in said wash water eiiluent of gases employable in the performing of the method, which are releasa whereby the surface level of the column is not ble and which rise to an overlying gaseous med less than ‘7 inches above that of the surface level ium of such gases at sub-atmospheric pressures of body of mercury exposed to the atmosphere 55 when a body of such wash water eiliuent is di and from which the elevated column was lifted, rectly exposed to such sub-atmospheric pressure agitating such briny coagulum to be treated while gaseous medium; establishing an ever-changing exposed to atmospheric pressure air. liquid body; exposing an upper surface portion of 6. In the production of synthetic rubber ac said liquid body to a gaseous medium of such cording to a butadiene styrene process in which 80 gases liberated from liquid supplied for providing co-polymers in the form of solids of varying sizes such body and directly overlying such body; feed are produced and developed under conditions ing such wash water ei?uent with such gases wherein they are eidstent in the liquid-solids mix therein and delivering such fed eiiluent proximate ture of which the liquid fraction comprises process the upper surface of said liquid body; sucking liquor that includes brine and of which the solids gases from said overlying gaseous medium for fraction includes said solids, the method com maintaining pressures thereof substantially sub quired to lift a con?ned column of mercury prising initially separating from such mixture atmospheric whereby~ to e?'ect the liberating of large solids removable along a solids discharge quantities of gases in the wash water e?iuent thus pathway, collecting process liquor from said ini fed and delivered whereby to further the ?oating tially separated operation as a primary brine 70 to the surface portion of said liquid body ?ne bearing e?iuent of minor dilution and conducting solids suspended in the wash water eiiiuent fed the same along a liquid ?ow-path leading from and delivered proximate the surface of the liquid said initially separated solids, supplying wash body; collecting ?ne solids ?oating within the water to the initially separated solids, collecting region overlain by the sub-atmospheric pressure the wash water with fine co-polymer solids as 76 gaseous medium; removing the thus collected ?ue 2,41o,ess l8 solids and delivering the same to a locality‘ \ according to a butadlene styrene process in which whereat they are discharged outside of the region whereat they were collected; and passing clari ?ed liquid'from a lower portion of the ever v there is obtained a liquid-solids mixture compris ing as a solids fraction butadiene styrene-co polymers and has a liquid fraction process liquor changing body and delivering said transferred 5 that includes brine and releasable gases, the liquid to a locality o'utside of said body. separating of such solids from said liquid frac 8. In the production of synthetic rubber accord tion by a method comprising establishing from ing to claim 7, the aerating of wash water e?iuent such liquid-solids mixture an ever-changing li before feeding it to the ever-changing body. quid body having a surface portion overlain and 9.- In the production of synthetic rubber accord 10 directly exposed to a gaseous medium provided by ing to claim 7, the passing of the collected and gases released from such process liquor, sucking gases from the overlying gaseous medium whereby removed ?ne solids to a, portion of the butadiene styrene ‘process for employment therein. » ll). In the treating of a briny suspension bear to maintain the same at pressures substantially , sub-atmospheric, maintaining the surface of ing, as solids therein, butadiene styrene co 15 said body up to an elevation providing an opera‘ polymers and also bearing gas releasable when .tive surface level, passing such liquid solids mix exposed to an overlying gaseous medium derived ture as feed into said ever-changing body and from said suspension‘ when at lesser pressures delivering it at elevation approximately that of than that at which suspensions were previously the operative surface level of said body whereby subjected, the method comprising exposing a body 20 the liquid solids mixture as thus delivered comes of such suspension to an overlying gaseous med under the effective in?uence of said overlying ium obtained as gaseous medium released under . gaseous medium, collecting at the surface of said said lesser pressures and maintaining such lesser body and within the region overlain by said gas pressures to effect releasing of quantities of gases eous medium co-polymer solids assembled as rising within said body and thereby furthering ?oating material within said region, removing the ?otation of solids of such suspension to the the thus collected solids from said region and dis surface of said body andv of which rising gases charging them to a locality outside of said region some pass directly into the‘ overlying gaseous while at the same time substantially avoiding the medium, collecting from the surface of said body entrance of air into the overlying gaseous medium and within the region overlain by said gaseous ' 30 at said region and which might otherwise take medium solids ?oating upon said body and re place incident to said removal and discharge, and moving the thus collected solids from a region ' withdrawing clari?ed liquid derived from a por where collected to a locality of the region over- , tion of the ever-changing body that is at elevation lain by said gaseous medium while maintaining lower than that of the‘inwardly passed liquid the required lesser pressure conditions for said solids mixture as delivered into the body and overlying gaseous medium, and passing from a transferring it for discharge to a locality outside lower portion of said body of liquid substantially of said body and away from the in?uence of said freed of said solids and delivering it as a clari?ed overlying gaseous medium and during such trans liquid fraction to a locality outside of said body ferring of the clari?ed liquid substantially avoid while at the same time ‘maintaining the required 40 ing entrance of air into said body and thus into lesser pressure conditions for said gaseous medium _ the region overlain by said gas incident to said overlying the body. transferring and discharge of said clari?ed liquid. 11. In the art of producing synthetic rubber THEODORE B. COUNSELMAN.