claim: 1. A process which comprises formin.- a substantially helically traveling sheath of hot combustion gas, introducing a reactant hydrocarbon into the interior of said sheath, heating said hydrocarbon to a carbon black forming temperature by virtue of heat directly imparted by said combustion -as, dividin.a a resulting mixture into two portions, one portion encompassed within the other, pasSiDg said one portion along the inner part of a substantially tubular radiant surface, passing said other part along the exterior of said substantially tubular radiant surface, whereby carbon black is formed by pyrolysis of said hydrocarbon, and recovering said carbon black. 2. A process which comprises introducing a combusLible mixtlre of fuel and oxygen containing gas tangentially into a substantiary cylindrical combustion zone; substantially completely reacting said mixture by combustion in a peripheral part of said combustion zone, passing thus formed combustion gas along an inward spiral path within said combustion zone; directing said gas longitudinally in a heucal path along the periphery of a substantially cylindrical reaction zone having. a smaller diameter than said combustion zone; axially introducing a reactant hydrocarbon into said combustion zone and subsequently into said reaction zone, whereby heat is directly transferred from said combustion gas to said hydrocarbon and said hydrocarbon is heated to a carbon black formin.- temperatlire; dividing a resulting mixture into two portions, one encompassed within the ,other; passing said one portion along the interior of a stibstantiauy cylindrical radiant surface; p@assing said other portion along the exterior of said substantially cylindrical radiant siirface; recovering an effluent from said reaction zone; and recovering carbon black from said effluent. 3. in a carbon black production reactor, comprising A 's-6b@taiatially cylindiical tea7ctibn ch@altbdr, inlet 'nieans siibstahti@illy t@Lhgejiti'ally po@itidjjtd with resj@e@t to an inner waH of said rektor and in op@n cbbfttriliniciitidh Vvith said 6hamber, substantially -axin:l inlet hic@tns iii 6@en comraunication wifh said chanibet at one eiid of s-@tid reactbr and outlet means in ccimmumcation @vith said reactor at fhe Opl)bsite ftd thereof, the impkdveiiient e which comprises, in combin;@ti6n, a stibsta@hiidlly iiib@ular r@fr,@ctory member lohgitli&n@illy pos.iti6iied Nvithin 16 said reaction ch@amber and spaoed frbm thd -,vafl@ thereof, said member having 6poti @nds, the 6nd jaeatest s@4id taiigenfial ii@ldt inea'ns beihg l(ifigitudinally reiadti@, in the direction oj' sa'id oiitlet ineans, irom said tarigeiitial ifilet means. 15 4. A carbon black production reactor comprising, in coribination, a substantiafly cylindrical combustion chamber coaxially positioned adjacent and in open communication ivith a substantiary cylindrical reaction chamber havina a smaller diameter fnan said combustion 20 chamber; i'nlet means tangentially positioned with respect to the interior surface of said combustion chamber; substantially axially positioned inlet means in said combustion chamber at the end thereof opposite said reaction chamber; a substantially cylindrical refractory tube positioned 25 within said reaction chamber and spaced apart from the waus thereof, the end of said ttibe rearest said inlet means being longitudinally remote f.-om the inlet end of said reaction chamber; and carbon black recovery m.-a-ris in commtinication with said reaction chamber at the end 30 thereof opposite said combustion chamber. 5. A reactor according to claim 4 wherein said tube ispositioned coaxiahy with respect to the corrmon axis of said combustion chamber and said reaction chamber. 6. A reactor according to claim 4, wherein the di3,5 amete, of said reaction chamber is less than 6 inc'ries and wherein the sum of the surface areas of the reaction chamber and of said tube is from 1.25 to 1.50 times the volume of said reaction chamber per foot of length thereof. 40 7. A reactor according to claim 4 Nvherein the intemal diameter of said reaction chamber is at least 6 inches and the sum of the surface areas of the reaction chamber and of said refractory tube is from 0.8 to 1.0 times the volume of said reaction chamber per foot of length 45 thereof. 8. A reactor according to claim 4 wherein said ttibe div-.des the cross-section of said reaction chamber into an annular portion and a central portion, the ratio of the area of said annular portion to the area of said central 50 portion is in the ran.-e 0.5: 1 to 3: 1. 9. A reactor according to claim 4 wherein the distance froni the inlet end of said reaction chamber to the nearest end of said tube is from 3 to 10% of the total length of said reaction chamber. 5.5 10. A process which comdrises introducing an oxygencontaining gas tangentially into a cylindrical reaction zone, axially introdi-icin.- into said zone a reactant hydrocarbon, contacting said oxygen-containing gas with said reactant hydrocaeoon at an elevated temperature, 60 thus forming -a swirling mass of combustion gas which heats a part of said hydrocarbon to a carbon black fo@iming temperature, dividing the resulting mixture into tnvo strearns, one within the other, pass,.ng said one stream along the interior of a cylindrical radiant surface, 65 passing the other stream along the exterior of said surface, recombining said streams, and recovering carbon black from the resulting mixture. 11. A process according to claim 2 wherein said reactant hydrocarbon is an aromatic recycle gas oil. i- t) 12. A process vi@ierein a iiydrocarbon feed is converted to carbon black by pyrolysis, the improvement Nvhich comprises dividing a hydrocarbon gas, heated to a carbon black forming temperature, into two parts, one part being encompassed within the other part, passin.- 75 said one part along the interior of a substantially tubular

7 radiant surface, passing said other part along an exterior of a radiant surface corresponding to said interior, and recovenng carbon black thus formed. 13. In a carbon bla6k production reactor compnsing a substantially cylindrical combustion chamber coaxially posidoned adjacent and in open communication with a substantially cylindrical reactio-,i chamber having a smaher diameter than said combustion chamber, said combu@tion chamber having at lea st one tangential inlet and an axial inlet and said reaction chamber havin.- an outlet the improvement comprising, in combination, a substantially nonobstructing and intemally unobstruc ied cylindrical refractory tube positioned coaxially within 2,785,053 .8 said reaction chamber,-downstream from said tangential inlet, and having open ends which are spaced from the ends of said reacdon chamber a@nd a periphery spaced from the periphery of said reaction chamber. 5 References Cited in the file of this patent UNITED STATES PATENTS 1,980,827 Reed ----------------- Nov. 13, 1934 10 21188,133 Hepbum -------------- Jan. 23, 1940 2,375,795 Krejci ---------------- May 15, 1945 2,556,196 ci ---------------- ne 12, 191 2,564,700 Krejci --------------- Aug. 21, 1951

T T 21785@053 unitec"t States Patent Office 2,785,053 PP,CCESS AND APPAP@ATUS FOR PRODUCTION OF CA-RBON B'F-ACK 5 Harolf-I A. Lm-@son and Wilson H. Rushford, Bor-er, Tex., assignars to Phillaips Petroleum Cornpnn:y, a@co@Par--tion of D@-laware AppL@ea-.-@on November 13, 1953, SerW No. 391,965 10 13 Claims. (Cl. 23-209.4) This invention Telates to, a novel method for the pro15 duction of carbon black in high yield In another aspect, it @-ela'Les to a novel apparatls for the prcdtiction of carbon black, said apparatus having an :inc,reased radiant surface area. In aiaother aspect, the invention relates to a melhod and an apparatus for inc-reas'LTIC the yield of 20 high q@dai.;Ly carbon black. In another aspect, the inventio-,i -eiates @c a no--/el cart)on biack i)roduction - apparatus -oro,iidin-, increased radiant surface area without an -un@esirably high pressure drop. ii another ast)ect, the invelition relates to an apparat.tis for the production of 25 caroon black, said apparatus hav;ng a cylindrical refractory member placed ivithin the reaction section. '@ has becti fwdnd in the prier art that high-grade, carbon black can be ptoduced by in@rodlcing a - rea-.tant I,-ydrocarbon, preferably in vapor forrn, into the interior 30 r--; a heli-.ally movin-. sheath, of hot cojp-bustion gas, and by 0-irectly transferri-mg heat from said combiistion gas to su,,t r,-,actant @@ydrocafoon and thus heating said hydrocari)on to a carbon b'@ack foriridg temperature. Examples of s-Lich processes and apparatus pertaining thereto 35 are described in TCrejci Patents U. S. 2,564,700 (1951), 2,375,795, 2,375,796, 2,375,797 and 2,375,798 (1945). The type of process described in 'hese patents has enjoyed great commercial success because of its capacity to produce high-quality carbon black in high yields. Efforts 40 are constantl-y b-.ing made, however. to improve the yields from this and other types of carbon black prqcesses. This invention provides a prqcess and an apparatus v,!hereby th@- yield of carbon black from a process of the type described in the above-cited patents is substan45 tially incr--ased and ',he quality of the carbon black is maintained. According to this invention, a reactant hydrocarbon, h,-ated to a carbon black forniing 'LempLrature by direct c-3ntact with n, h--'@ically travelin- sheath of hot combusr3o tion @as, is divided L-ito tivo portions, cqe portion enco@npassin- the other; one of the pdrtions is passed along the exterior of a stibsta.-,tially t-,ibular radiant surfac@e. and the other is pass-,d alon-- the irterior of a substantiany tubLIar radiant sur.Lace, carb,,n blaci-, being thereby 55 formed; and carbou black is. recovered from the - resi-ilting mixture. wurth-,r, accord@ng to this invention, thl-re is provided rs a carcon black product-Ion reactor comp ' ing a substant-l'ally axially dis,,oosed at one end of said reactor, inlet m,-ans srbstantially tangentially , positio.ned with respect to an inner wall of said reactor in open communication with said reaction chamber, carbo-n black recovery means i,a open communication with said reactor at the end 65 there@of p_t)pcsite the at-ially positioned inlet means, and a substantially tubular re.Lractory member positioned in said reaction charaber at a point donvnstream from said tan.-entially positioned inlet means. Thus,, according to one modification of this invention, there is provided, in 70 a reactor of the tangential:ftame type, a substantiary eylindric-al refractory tube positioned within the reaction P a t e n t e d M a r . 1 2 , 1 9 6 7 2 chamber of said reactor, whereby increased radiant surface area is provided. According to one modification of the invention, there is provided, in a carbon black reactor comprising a substantially cylindrical combustion @chamber positioned coaxially and in open communication with an adjacent substantially cylindrical reaction chamber having a smaller diarriet,-r than said combustion chamber, a substantially cylindrical refractory member longitudinally positioned within said reaction chamber. This type of reactor, which is also provided with tangential inlets for fuel and oxidizin- gas, is described in Krejci Patent 2,564,700 (1951). One enabodiment of the invention in connection with a carbon black reactor oj' the precombusiion type is dia.-rammatically illustrated in the drawings. Figure I is a sectional side elevation of a reactgr according to this invention. Figure 2 ;s a cross-sectional view taken through Hne 2-2 of Figure 1. Figure 3 is a self-explanatory flow sheet of a process according to this invention. As sho'@vn in Figures 1 and 2,. the reactor comprises an outer shell 3 provided with a refractory lining 4. Also provided is a cylindrical combustion chamber 5 pi7ovided with one or more inlets 8 which are tan.-entiafly positioned with respect to the interior surface of char@iber 5. 'vVitWR inlet 8 is positioned an orifive-tipped burner means 9. Hydrocarbon inlet 7 is positioned to extend through. the end wall of chamber 5 and is substantially coaxial with, r,espect to chamber S. Reaction chamber 6 is pos@:tioned, adjacent and in open communication with chamber 5 and has a smaller dia-meter than chamber S. Combustion chamber 5 preferably has a, diameter g@reater than its length, and reaction chamber 6 preferably has a 1--ngth greater than its diameter, In the operation (see Figure 3) qf a furnace or reactor of the type described, a combustible mixture of the fuel and an oxidizing c.as, such as oxy,-en or air, is directed into bumer 9 at a high velocity. Combustio-n of the fuel takes place within inlet 8 and/or within the periphery of chamber 5, the combustion gas so produced moving iri a spl-al path toward the axis of chamber 5. Combustion of the fuel is substantiary complete viithin the peripheral part of chamber 5 or within inlet 8. The temperature in combustion zone 5 is ordinaffly about 3000' F. Combustion gas from chamber 5 passes into reaction chamber 6 and moves longitudinally in a helical path along the walls of chamber 6. A preheatedreactant hydrocarbon is introduced through inlet 7 and passes into the interior of the helical shea'@h of combustion gas traveling throu.- h reaction chamber 6. Heat is transferred from the hot combustion gas directly to the vaporized hydrocarbon. The reactant hydrocarbon is thus rapidly heated to a carbon black- forming temperature, e. g. 2600' F., and is:converted to carbon black inreaction chamber 6. A mixture of combustion gas and suspended carbon black is withdrawn from chariber 6 throiigh pipe 14 and passes to carbon black recovery effitient mixture is cooled in pipe 14 to below reaction temperature, c. g. beliow 1000' F., by water quench !L8 and/or indirect or at-mospheric cooling of pipe 14. Separation means 15 can include one or more cyclone separatorsi electrostatic precipitators, and/or Mters. Off-gas is withdrawn through outlet 16 and product carbon black through outlet 17. According to, this invention, there is positioned Ion tudinally within reaction chamber 6 a refractory cylindrical tube 10 which is open at both ends and ivhich is supported in spaced relationship with respect to the wafls of chamber 6 by means of supports 11 (Figures I and 2) tially cyhndrical reaction charrber, inlet- means substan6o means 15, of any suitable type knov.,n in the art. The

2,785,053 3 which can be positioned in any desired arrangement. Supports 11 ca-@i be of any suitable refractory material such as alumina, zirconia, etc. The supports 11 can be of the same niaterial.as tube.10 or a different refractory maierial. 5 Tube 10 is heated to incandescence by contact with the helically moving blanket of combustion gases in reAction chamber 6, thus providing increased radiant surface v@hich transfers a-dditional heat to the reactant hydrocarbon. - The reactant hydrocarbon flows tl-trou@,h the 10 inten'or and along the@exterior of -tube 10. Cylindrical tube 10 can be of any desired cross-sectional shape, such as elliptical or circular. It is preferred that the cross-section be of substantially the same shave as the cross-section of reaction chamber 6 and that -th-, crcss- 15 section of both reaction ehamber 6 and tube 10 be stibstantially circular. It is further preferred that tube 10 be.positioned so as fo be coa-aal with reartion chamber 6 and combustion chamber 5; however, tube 10 can be ; laterally displaced so that the cross-section tbereof is 20 slightly eccentric with respect to the cross-section of chamber_ 6,, but it is preferred that the axis of tube 10 be parallel or coincident with the axis of chamber 6. It is flirther preferred that tube 10 and chamber 6 be substantially coaxial. 25 The upstream end of tube 10 should be remote from the inlet end of reaction chamber 6, i. e. -the upstream end of tlbe 10-shotild be displaced in a downstream direction 1 from the inlet end of chamber 6 so that @direct contact between the heecally moving combustion -as and the 30 axia'ffy introduced reactant hydrocarbon can take place before the hydrocar,bon reaches tube 10. It is preferred that the upstream end of tube 10 be positioned downstream fr6m the inlet end of chamber 6 by from 3 to 10% of the length of chamber 6. The downstream end of tube 35 10 can extend to the downstream end of chamber 6 if desired; however, in most cases, it is unnecessary that tube 10 extend that far. It is preferred, when the internal diameter of chamber 6 is less than 6 inches, that the total inside and outside 40 surface area of tube 10 plus the inside surface area of recation cha.-,iber 6 be from 1.25 to 1.50 times the volume of chamber 6 per foot of length thereol When the int6rnal diameter of chamber 6 is 6 inches or greater, it is preferred that the total internal and external surface 45 area of tube 10 plus the inside surface area of 6harr@ber 6 be from 0.8 to 1.0 times the voliime of chamber 6 per foot of length thereof. . Ftom Figur6 2, it is seen -that tube 10 divides the crosssection of chamber 6 into an annular zone 12 and a central 50 zone 13. It is preferred that the ratio of the crosssectional 4 area of the annulus 12 to the cross-sectioiial a of central portion 13 be in the range 0.5:1 to 3:1 ' This invention can also be practiced in connection with a carbon black fumace of the tangential ff ame *,Ype having no enlarged precombustion sectio-Ti (see Patent 2,375,795). EXAMPLE A reactor of the type shown in Figure I was constructed utilizing a cylindrical radiant member according to this iwietitio-n. The combustion chamber of this reactor was 3 3 iii,-hes in diameter and 12 inches in length and was pron,ided w:itb two tangential inlets spaced 180' apart. Th-- reaction section of the reactor was 12 inches in intemal diamoter and 11 feet in length. Positioned within ',he reaction section was a cylindrical Carbofrax (trade name) tube having an ext ernal diameter of 81/2 inches, an internal diameter of 6'h inches and a length of 21 inches. The upstream end of this tube was posifioned 6 inches downstream from the inlet of @the reaction section. The tube tvas positioned coaxiafly with respect to the common axis of, the combustion chamber and the reaction chamber. A fuel gas, compnsmg principahy methane, and air was passed into the combustion chamber through the tangential inlets,.the fuel being substantiary completely burned at the periphery of the combustion chamber. A highly aromatic recycle gas oil having a Bureau of Mine's correlation index of 88 was passed axiary into the combustion chamber and subsequently into the reaction chamber. The effluent from the reaction chamber was quenched -.vith water and the product carbon black was collected. The oil was charged to the reactor at a rate of 193 gaeons per.hour. Air was supplied to the tangential inlets at a. rate of 120,000 standard cubic feet per hour. Fuel gas was supplied at a rate of 8,200 standard cubic feet per hour. The yield of carbon black per gahon of oil charged was 4.15 pounds. In a second run in which the same type of furnace is used, but without a cylindrical refractory tube according to this invention and in which the same oil is used as a reactant under substantially the same conditions, the yield of carbon black is 3.84 pounds per gaeon of oil. From the foregoing, it is evident that the process and apparatus of this invention produced an increase in the yield of carbon black of 8%. Samples of the carbon black prepared according to this invention and samples prepared viitho-ut the use of the refrac-tory cylindrical member without the use o'L this invention were compounded with butadiene-styrene synthetic rubber and the compounded r-abber ivas evaluated. The results are shown in Tables I and H below. Table I RUBBER (IONTAINING CARBON BLACK PREPARED ACCORDING TO THIS DIVISION Abrasion Loss, Minutes 300% Tensile, Elon@a- Resillgrains 00-PlesComCure at Modulus, p. s. i. tion, 5er- ence, perI;in s@@t, ponnded 3 071 F. p. s. 1. c ent cent p ercent Ms-iH' orig. a ged 20 -- ----- 1,110 2,740 635 5 8.7 -------- -------- 31.1 3 1.5 so 1 220 2,800 615 5 9.8 9.41 7. 10 17.3 -- -------- 45 -- -- 1:220 2,770 506 5 9.4 -------- -------- 9.8 -- -------- Table If RTJBBER CONTAINING CARBON BLACK PREPARED WITHOUT THE RMFRACTORY CYLINDER OF THIS INVENTION Abrasion Loss, Minutes Cure at Tmsile, ElongaResiH- Shore grams CompresCom300 3071 P. Md3.@, p. s. 1. tion, per- ence, perHardness sion Set, pounded P. S. i. cent cent percent MS-IM. orig- aged 20 ----------------- 1,130 2, 825 560 57.5 5 2 -------- -- ------ 31.3 32 30 ----------------- 1,320 3. 270 590 59. I 53 9.99 7. 37 17.3 ---------- 45 ----------------- 1,300 sl oso 530 58.9 5 4 9. 8 ---------- 7 --------

5 The above-hientioned riitib;er saitl@le@ wer@, Vrepared trom the foII6*ing redi@6: RECIPF, Gt&-jLO,60 Ingredient: Parts by weight Rubb-er 100 Carbon black -------- I -------- ---- 40 Zinc oxide ----------------------------- 3 Sulfut -------------------------------- 1.75 BRT #1 1 -------------------- 6 Santo(@ur&, 2 @'a-C-Cele@l;afat) .0.8 ................. 'A refl3ied tar with a high free-carbron 'content@ Sp. gr. 1.20-1.25. 2 N-eyelohexyl-2-benzothiozolesulfenamide. The foregoing data show that the properties of rubber cow-pounded with carbon black prepared according to this invention compare favorably with those of rubber compounded with carbon black prepared by a prior art process. Variation and modification are possible within the scop-- of the disclosure and the claims to this invention, the essence of which is that there has been provided an improved carbon black production process wherein hydrocarbon gases heated to a carbon black forming temperature are divided into two parts, one part encompassed within the other, said one part being passed along the interior of a radiant tubular surface, the other part being passed along the exterior of a radiant tubular surface, and the carbon black so forined is recovered; and that there has been provided a reactor for the production of carbon black comprising a tangential flame type carbon black reactor, in the reaction section of which is substantially longitudinally positioned a substantially tubular refractory member. Thus, the cross-section of the tubular member can be circular, elliptical, rectangular, or triangular. NVhile certain process steps, structures, and examples have been described for purposes of Hlustration, the invention is clearly not limited thereto. We