US1924602A - Method and apparatus for distillation of hydrocarbons - Google Patents

Description

C. D. GARD Aug. 29, 1933.

METHOD AND APPARATUS FOR DISTILLATION OF HYDROCARBONS Filed May 30, 1930 INVENTOR. 34 %are .0. Gard BY /2 Mad M11 TTORNE Y.

Patented Aug. 29, 1933' N ED LTM' E'S v v 11,324,602 1 METHOD AND APPARATUS FOR DISTILLA- a 5 TION or HLYDROCARBONS C larerDa Gard, Los Angeles', Calif assignor to Union Oil Companyof California, Los Angeles,

Calif a corporation of California Application may 30,4193). Serial No. 457,656 7 5 Clain sQ (01.196585) 4' This invention relates to distillation method and apparatusandis. directed more particularly to steam distillation of oil in which the steam is directly introduced into the oil and the oil is.

' agitated thereby.

'I have found that while operating either at constant or increasing temperatures it .is ;high-' 1y. advantageous to keep the oil and the steam -in:constant and adequate contact in order to vaporize the-maximum. percentage of oil vapor- ;iz'able under the-conditions.employed;

.iA. difficulty] is. ordinarily I encountered 'inithe ].distillation of oil due to .the' fact that thelighter vapors volatilized from the oil body carry over 1011 fractions heavier thanthose desired .inthat' .pai'ticular c'ut." Also, the unvolatilized oil re- -maining in the still may yet contain lighter oil fractions" which desirably; should be xxdistilled .overlwith the other vapors. .Ihave found that by refluxing .imdesirable heavy oils back into the oil body and by contacting the oil bottoms. with ,j

the steam .employed' as adistillation aid, either at a constanttemperature or at increasing'temperatures. An. additional .object is 'tocpro'vid'e means for the return offreflux and the circula- :tion ofstill' bottoms. All 'ofz these objectspare for the purpose of distilling oil to obtain vapors free :from undesirable heavy fractions' and to "insurextotal vaporization of a all fractions "dc- I c In eitherevent; it-must be'given aconformation sired in the vapor state without-the danger of *local overheating.

. More specifically stated/the invention comprises "a distilling apparatus including an. oil still concentric steam pipes wound verticallyto form baflles which act to direct the course of oil currents produced by steam which isinjected into withir'itthe annular space between ,;the {inner 'apparatus in. which reflux condensate obtained 1 from the vapors rising froni the oil bodyand/or unvolatilized oil obtained from the oil bottoms .may causedgtjo re enter intotlie oil 7 heating coil and theouter heating'coil-L The in -Q; fvention further comprises a steam distillation middle area of i the cylindrical" space foutlined f maintained in circulation b means of the; afore- 3 1 said baflles and steam. 1 The invention-also comprises the method of distillation wherein our.

rents. within the oil body rare induced, lay-"flow of steam therethrough and wherein the sa'id' E currents arechanged indirection; by a second fstream of steam,the .oilmeanwhilebeing-heated h by contact'with internal heating means.

- nth acco anyin d aw n her n -",'85 ferred embodiment of the invention isldisclosed "byway of illustration: I

Fig. l isa vertical section showing anoiljdis-f tillation column constructed according to; the

present invention; and. i

, 0 'Figs. 2 and 3 arecross-sections through the distillation ,1 column: and are taken respectively sents a shell ,of a rvertical still connected -with oil conducting pipe .2' 'Whi0hbranches into inlet pipe 3 controlled byvalve;4'andinlet'pipe 5 con-.

trolled by valve ;Still 1 is further provided with vaporoutlet ilcontrolled by valve. 10 and residuum I outlet ll controlled .by' valve 12.: Below the nor-,

\ing "steam inletl? controlled ibyzva-lve -1'8 and out- 35 'let.;l9 controlled, by valve 203' comprisesa pipe vertically; coiled to form a baflle which. acts v.to direct the course of, oil-currentsproduced by steamenteringthrough jet 30 to be described be low. Coil 116 may be ,tightly; woundin order'to Q forma substantially solid cylindricalqwalL-oritauj may notbe necessary to windit as tight as this. I

sufiicientto forma baflie' for the'purpose of directing oil currents in the body ofoil' in a manner .to ibe describedbelow.

adapted to hold a body of oil and containing 'two V pipe 24 controlled by valve 25 and outlet 26 con- The outer heating coil 21 comprises steam inlet I trolled by valve 27.' Heating coil" 21 may be more loosely gwound than coil I6 in order to allowat least a partial flow of oil between the coils. Steam= jet 30 in its preferredform-islshown in detailin Fig.1i3. It comprisesitwo c'oncentr-ic'pipes' Bland 32 connected bypipesf33fsteam in1et ;-3 4controlled by valve 35 connects with thejinner pip'e32 which is p'erforatedon'its'uppr s e.'; Outerpipe 31*is li ewis perrcrageq;. 71; periorati onsfon the inner .je't ar'e, so arranged that steam jettingfrom them will pass through "approximately the no 7 or other heating fluid is passed through heating 7 pipes 31 and 32 respectively can be individually controlled. If additionally desired, either one of these streams of steam may be totaliyishut, off

depending upon the exigencies in the distillation of any particular oil.. I a V The upper portion of still 1 comprises a reflux section containing reflux plates provided with bubble caps 41 and overflow pipes 42 disposed in therusual manner. may extend to a point above oil level A--A or it may depend into the oil body'in the manner as I V :of inner heating coils 16, thereby aiding'in' the circulation of the-oil body as previously a de shown. Deflector 44 is provided in orderto give the desired directional flow to the incoming oil. For circulating the -oil:bottoms, pipe is provided, connected with still 1 near the bottom thereof and also' with the refluxing section thereof. In order to circulatethe'oil from the bottom of the still through line 50 back into the still,

thereis provided steam or oil inlet 51 terminating valve 52. V I

In employing this system 'for the distillation of oil, still 1 is filled withoil to the level A-A, maintained during the course of the operation. The

steam ejected from'the, perforationsin the upper oil may enter from .a source not shown through pipes 2, 3and 5, valves 4 and-6 being open. 'Steam coils l6 and-21, the steam enteringthrough inlets 1'7 and 24, respectively and leaving the coils through outlets 19 and 26, respectively. Steam is 30.- The steam which isjetted through the perfof-ration's in pipe 32,'si tuated in approximately the heating means. This downward flowing current of oilwithin the oil body then causes the oil to.

flowbelow coil 16. The ascending'current-of part'of outer steam pipe 31 which-is situated so thatthe steam flows-between the inner heating coils 16 and the outer heating coils 21 assists-in drawing the oil :from the inner chamber into the annular .chamber between coils 16 and 21. The etting action last mentioned thereby reverses the flow of the oil in the oil body and causes an up- :ward circulation which forces .the oil between the any particular oil. Due to the prolonged, andintimate contact between the oil, the steam and theheating coils auniformity of temperature .ma y be "maintained within. the oil body-and a' maximum -of-.,products desired in the vapor state may 'be'volatilized therefrom without danger of local overheating. e 7

As the .oil is 'volatilizedg the vapors pass upwardly through'the bubble-caps 4 situated on The bottom 1 overflow pipe 43 'vided without departing from also introduced directly into the oil through jet the reflux plates 40 in the usual manner. Fresh oil may becontinuously introduced into still 1- caused to enter upon either or both of the reflux plates 40 above which these inlets are directly situated, depending upon the degree of refluxing desired. The fresh oil and reflux condensed from the vapors flow downwardly from the reflux plates '40 through overflow pipes 42 in counter-current with ascending vapors in the usual manner. The oil on the lowest reflux plate 40 is then directed downwardly through overflow pipe 43. If the latter does not depend into the body of oil, the oil descending therethrough merelydropsiupon the.

scribed- Other types of deflectorsx-may b'eprothe spirit of the invention. y

The 011 bottoms may still contain some lighterfractions which it is desired should be vaporized. In order to accomplish the total vaporization of these lighter fractions, the bottoms are recirback into the refluxing-' section of the. still. 'In

order to forceithe oil from the bottomof the still upwardly through pipe 50 back into the 1 still, steam or the like may be injected into vertical pipe S'O'through injector 53 connected withsteamtfio supply pipe 51 controlled by valve :52. In place 'of steam, a portion of the oil charge'may be fed into the still 1 through line5l', andinjector 53 The same result is thereby producedyi". e.

1 lifting the oil bottoms through pipe .50 for recirculation.

Due to the scrubbing *action .onthe vapors heavy undesirable constituentswill be removed within the refluxing zone previously described, Y

from the vapors and will be refluxed into the oil;

body. Due to the recirculation of the oil 'bot- 7 toms and-totheconstant and adequate contact of the oilysteam, and heating coils, as previously described, substantially-all of the products desired in the vapor state willbe volatilized from w the'oil. Vapors from the still pass'through pipe 9 controlled by valve 10 into suitable condensers or the like, notshown. 'Residuum from still '1 exits through pipe 11 controllediby valve 12 .to suitable storage or the like,not shown.

The pressures and temperatures. employed this devicev depend entirely upon the character ofsthe oil stock introduced into the still and the boiling points of the fractions which are to I be separated by the distillation. The. amount of g} refluxing is'likewise dependent upon. these conditions.

It is tobe understood that the above disclosures are considered merely as illustrative and not as tiliation chamber and additionally functioning as .a-cu'rrent directing baffle, asecond heating coil, spaced fromand disposed around said first mentioned coil, and means to induce circulation of the oil undergoingdistillation in 'suchamanner that oil Within the distillation chamber 'iscaused .1 9 W downwardly along the inner periphery apparatus, a vertically dis-' r of the closely wound coil and thence upwardly between the two coils.

-2. In distillation apparatus, a vertically disposed, closely woundheating coil defining a distillation chamber and additionally functioning as a current directing baffle, a second heating coil,

spaced from and disposed around said first mentioned coil, and means for injecting steam into the distillation chamber so that the oil undergoing distillation is caused to flow downwardly along the inner periphery of the closely wound coil and thence upwardly. between the two coils.

3. In distillation apparatus, a vertically disposed, closely wound heating coil defining a distillation chamber and additionally functioning as a current directingbafile, a second heatingcoil, spaced from and disposed around said first mentioned coil, and means for injecting steaminto the space between the two coils so that the oil undergoing distillation is caused 'to flow down-' wardly along the inner periphery of the closely wound coil and thence upwardly between the two coils.

4. In distillation apparatus, a vertically disposed, closelywound heating coil defining'a'distillation chamber and additionally. functioning as a current directing baflle, a secondheating coil,"

spaced from and disposed around said first mentioned coil, means for injecting steaminto the distillation chamber and means for injecting steam intothe space between the two coils so that the oil undergoing distillation is caused to flow downwardly along the inner periphery of the closely wound coil and thence upwardly between'the'two coils.

5. A method of steam distilling oilwithout substantial cracking thereof comprising inducing a down-flowing current of oil along the periphery of a heating coiland within a body of oil by an ascending stream of steam, deflecting the direction of said down-flowing current by a second, ascending stream of steam so that the oil is

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