US1563818A - Oil-cracking and carbon-removing method and apparatus - Google Patents

Description

Dec. 1 1925; 1,563,818

1 L. D. WY ANT OIL- CRADKING AND CARBQN REMOVING METHOD AND APPARATUS Filed March 20. "1922 2 Sheets-Sheet 1 L. D. WYANT OIL CRACKING AND CARBON REMOVING METHOD AND APPARATUS File March 20. 1922 2' Sheets-Sheet 2 a citizen of tlie-UnitedStates, residing at- .ll atented Dec; ll, i925.

LYNTON D.

W WYAh TT, or runsa, canal-roam.

oiit-cnacxme Ann CARBON-REMOVING n'rnon awn arraaa'rus.

- Application filed March 20, 1922. Serial No. 545,275.

To all whom it may concern: I

Be 1t known that I,- Lr roN D. WYANT,

Tulsa, in the county of'Tulsa and State of Oklahoma, have, invented. new and useful Improvements in Oil-Cracking and Carbon-Removing Methods and Apparatus, of which the following is a specification.

i This invention relates to a method of and apparatus for cracking hydrocarbon oils and removing coke or carbon therefrom during the cracking operation.

'Theprocess of heating heavy hydrocarbon oils to high temperatures, thus causing the decomposition of heavy molecules into molecules having lower bo ling po nts than the original heavy-oils, is generally called.

cracking.

This cracking operation is carried on by various processes; all of which are faced by the same general problem of the elimination of the carbon which is precipitated orwhich remains in the distillation system when" heavy hydrocarbons are cracked to yield lighter oils.

'VVhen a large volume of oil is heated to high temperatures, say 600 F. to 800 F, under pressure of from 75 lbs. to 150 lbs. per square inch, there is a considerable v danger hzlzard, vThese temperatures are so high as to render the tensile strength of the metal of which the stillis composed verymuch reduced] This trouble is, very much increased because of the free carbon depos-.

ited in the "still. Divers means are now employed to keep this free carbon, .which is a good non-conductor of heat, from'de positing on the still bottom. Of these .devices there are many now in use, such as chain drags, double bottoms, helicoidal.

scrapers, etc., but with these separate or combined devices. the amount of oil that can be distilled or cracked is limited to from 40% to of the still capacity. Many of the devices suggested are not practical because they are-too complicated to be operated in the still at such high temperatures. But with the best means that are at present employed only .a maximum of about 60% of the still capacity can be distilled or cracked before the still has to be taken down or shut down and the car-.

bondeposited therein be removed therefrom before the process can be resumed or continued.

One object of this invention is to pro- .1

vide a simple and practical method of and ing,- and by means of dragsand scrapers now in use, will not prevent such an amount of carbon from being deposited on the still bottom as to insulate the oil from the heat and materially interfere with the heat transmission from the still shell to the body of shell to become red and rendering any further operation of the still dangerous un-,

til the carbon deposits are removed.

oil, thereby causing vthe metal of the still A further object of the invention is to I provide a simple, reliable and eflicient method ofand means for removing the free carbon from the oil whereby, in addition to the time period of cracking being mate rially lengthened, the incrustation of care bon upon the stillbottom will be materially reduced, thus enabling the still to be cleansed when necessary with greater ease and with a considerable saving of time, and

thus reducing the shutdown periods between successive cracking operations.

In the accompanying drawings illustrating the invention,

Figure 1 is a vertical longitudinal section through a cracking still embodying the invention, and f Figure 2 is a vertical transverse section through the still.-

Referring to the drawings,

struction, whichstill is provided with the usual vapor collecting-dome 2, from which the vapor flows through the vapor line 8 to the. knock-back tower 4, and thence through a pipe or conductor 5 containing a pressure relief valve 6 to'the condenser (not shown). 7 is the return line for the return of any oil separated in the tower from the vapors, for the flow of said" oil back to the still, and 8 is a pressure gage of any suitable type-or construction. The still may be iniv 1 designates a horizontally d sposed still, which in general may be-of anyordinary-form, size and conlow, 12 indicating the back -,line of the furnace so that tially charged from a source of supply by gravity or through the action of a pump, an

a pump or other suitable supply connections may be employed for replenishing the still at intervals during the cracking period. Also any suitable means may be employed for emptying the still of any residuum oil when run is completed. I have 'not deemed it necessary to show any type of oil supplying or residuum discharging connections, as such specificallyconstitute no part of the present invention, and as any of the devices in common use for these'purposes may be em-- ployed,

In accordance with my invention, the lower portion of the tank is sub-divided by a vertical transverse partition 9 to form a heating and agitating chamber 10 and a settling chamber 11, the former being of materially greaterlength than the latter. The chamber 10 is designed to be heated at its bottom from a suitable type of furnace befire wall of the furnace, which is arranged substantially in vertical alinemen't with the partition, the chamber 11 thus being arranged beyond the the contents thereof will not be directly heated therefrom. 13 indicates a thermometer well communicating with the bottom of the chamber 10 and leading to any suitable type of ther mometer or heat indicating device, whereby the temperature of the oilin the bottom of said chamber may be determined at any time, and 1% designates the outlet leading from the bottom of the chamber '11 for the discharge ofthe gathered coke or carbon therefrom. This outlet 1% is preferably funnel-shaped or diametrically contracted toward its discharge end and is provided with a, discharge nozzle 15 having a controlling valve 16 which may be opened whenever it is desired to effect the discharge of the gathered carbon.

In practice the still is .charged with oil in the usual manner-to a suitable level above the maximum oil level indicated in Figure 2, the excess of oil being such that when "of the oil being cracked is distilled out of the still the remaining 80% will fall below the level of the line ;cm, the oil being, maintained, during the cracking process, between the said maximum level-w ar and the minimum level g y, also indicated in Figure 2. The supply ,of oil is replenished from time-to time, by pumping in fresh charges as the vapors are taken olf through the vapor line 3, so as to generally maintain the higher level noted. The oil in the still after 20% has been cracked con-, tains all the free carbon produced bythe cracking of the said 20% and this free carbon is suspended in the oil because of the upward agitation of the oil caused by the applied heat and also because of the agita- I customarily 1n use.

settling chamber 11.

tion produced by the mechanical agitators In order to collect and carry off this free carbon and the carbon which is thereafter liberated during the cracking process, I provide a novel type of separating and collecting means and means for keeping the oil in the bottom of the chamber 10 agitated to maintain the carbon, as far as possible, in suspension and to prevent the deposit of any material amount on the bottom of said chamber.

Extending longitudinally and horizontally within the still is a shaft 17 having affixed thereto and depending therefroman agitator carrying frame comprising a series of inverted substantiallyV-shaped brackets 18, the arms of which project beyond opposite sides of vthe line of the shaft and are connected and reinforced by braces 18. Se-

cured to the lower ends of these arms is an arcuate or segmental, approximately quadrantal, open work or screen agitator 19, composed of chains, iron bars or mesh work material, the convex lower face of which agitator is arranged in close" proximity to the bottom of the chamber 10. The shaft 17 is journaled at its rear end in a suitable bearing'QO and extends at its forward end outwardly through a stuffing-box 21, and this outer end of the shaft may be coupled to any suitable means for rocking the shaft for oscillating the agitator l9 laterally back and forth in the chamber 10, the screen thus causing the liberated carbon particles to be kept in motion and in suspension and acting as a scraper or sweeper to keep the bottom of the still chamber as far as possible clear of deposits. At suitable intervals along its length the shaft 17 is also journaled in fixed bearings 22 supported by hanger rods 23 from the still body, and said bearings and hangers also assist in supporting the weight of the agitator, as will be readily under"- stood.

Arranged also supported by the shaft 17 bearings and hangers 23, is a collecting trough it. which may be suitably secured at its forward end to the forward end or head of the still. as indicated at 25. 'lhislrough is arranged slightly above the maximum oil level line w-asand is provided at its rear end with a discharge opening 26 comnmnicatiug with Disposed at opposite sides of the trough and depending therefrom are carbon collecting pipes or tubes 27, which communicate at their upper ent longitudinally in the still and a w ls with the trough and at their lower ends are provided with enlarged portions or collecting funnels 28, said funnels having their lower open ends arranged on opposite sides of the normal medial line of and close to the top surface of the agitator 0r scraper. 19. The said pipes and funnels serve in the nature of jet devices or suction collectors, for draw ing the free carbon settling in the-chamber andconveying the same to the trough 24 orto the settling chamber nqn'wnree f understoodthat-the oil gravity .seekslin the pipes QZandtunneIsQS'the level-true" oil outside the pipes and funnels. The funnels'28 collectthe gas, which is evolved be,

cause 'ofthe heat, applied'to the still bottom beneath the funnels, over an area consider- I ably in excess-of the area of the pipes '27..

This; gas thus entrapped seeks the surface of the liquid by the natural upward course which forces it into' and through pipes 27, andthese rising and expanding gases-impregnate and make the oil within the pipes 'lighteifithan the oil outside the pipes, which is not so highly impregnated with gases, thus causing j the entrapped gases to eject an amount-of oil into the trough 24, portions of the oil thus being constantly drawn into the pipes and ejected therefrom by pressure, difference in Weight, velocity and suction into the trough. This action-is constant 'dur--- :ing 'the cracking process because the oil inside the funnels continues to rise in the pipes to the level of the oil outside the tunnels;

The liquid thus carried over into the trough 24' is higher than the natural level of the oilinthe'still and carries with it its rela tive amount of free carbon and this oil flows along the trough to the outlet 26 and thence intothe settling chamber 11, carrying with it the suspended free carbon which it contains. 4 v

As hereinbefo're stated. the settling chamber 11 is separated from. the heatingbnd bon deposits contained therein settle by: gravity into the outlet 14, from which thecarbon collected may be discharged whenever desiredby opening the valvelG. To further assist in making the flow of oil .as quiet as possible in the chamber 11 a vertically diposed battle plate 29 is disposed therein substantially on a vertical line between the partition!) and the axial center of the outlet 14, said baliie plate extending to a point somewhat above the maximum liquid level line This partition plate prevents a directback-current or flow of the oil over the partition 9 and any'movement of the oil in the chamber 11 tending to disturb its comparative degree of stillness. As the carbon accumulates in the outlet 14 and chamber 1 1, however, thebodv of oil contained therein jfrom which-the'carbon has been precipitated, will. rise. and flow back underi"and.or around the bailie29 and over partition!) into the chamber 10, so that such oil-will be subjected to the intense heat required'in. the latter named chamber for the cracking action.

It-will' be understood from the foregoing description that through the agitation otgthe oil contained in the chamber-10 from the heat, andthe movement of the agitator 19, substantially.all or a greater proportion of the liberated carbon-(in such chamber will be kept in suspension, which action, will be further promoted by the additional agitation offtliev jetting of theoil and carbon through the pipesf'27 into tliegtrough 24 and the constant' relie'f of heavy deposits from, the body of oil insaid chamber by the'dra'wing oil of the carbon depo sitsjtherefrom.

By this means a considerableiproportion of. the carbon will not only be removed and. discharged from the body of. oil, but the deposit of the carbon on the surface of the bbttom 'ot' the chamber 10 will be retarded I and to a large extent prevented, thus "keeping't'he-heated bottom portion of the still period with the result that "the cracking operation may be carried on for a much longer PBIIOd Of time. This opei'ationjalso reduces the depth, thickness and degree ofhardness of the carbon deposits 'on the botf tom, withthe result that, when it is necesi sary to shut down the. stillfor cleaning- .free from carbon deposits-feral longer;

purposes, the carbon may be renioved with greater ease and facility "and within a less period of time, thus shortening to a considerable extent the shutting "down period.- EX- perience has demonstrated that a still of this character embodying my improvements may;

be operated-at a workingpressure of from to 150 lbs. per square inch, and under a temperatureof from GOO'to 850 F., with much greater safety than stills of ordinary construction, owingtothe fact that from to 125% of the. still volume can be run without danger of. red spots. I Having thus fully described my invention, I claim; v 1

1. The process of cracl'ring oil and separating carbon therefrom which consists in heating the oil under a pressure ot"70 topounds per squareinch to cracking temperature,'.agi-tating the heated oil to maintain the liberated carbon more or less in suspension within the oil, and contmually segregating and discharging streams of this oil imp'regi nated with carbon froi'nthe heated portion of the still under the direct actionof gas pressures generated in the still and then dis charging such carbon impregnated oil to a place within the still where such carbon 1 can be settled out and removed.

2. The process of cracking oil and removing carbon therefrom, which consists in heatcarbon from the body of heated oil through pressure directly generated through the gases present in and as-evolvcd from the body of oil and then separating the charges of carbon from the oil within the still and discharging the carbon so collected.

3. The process of cracking oil and removing carbon therefrom, which consists in heating a body of oil, mechanically agitating the same to maintain more or less of the liberated carbon in suspension, collecting streams of the evolved gases as evolved in the body of oil, causing said streams of gases to segregate and eject from the body of oil portions of oil containing portions of the suspended carbon, and then separating and discharging the carbon.

4. The process 01 cracking oil and separating carbon therefrom, which consists in heating and agitating a body otoil, ejecting by pressure produced by evolved gases from.

the body of oil as evolved portions of oil carrying portions of the carbon, and then collecting and dischargingthe carbon. I

5. The process of cracking oil and removing carbon therefrom, which consists in directly heating and agitating a portion of a body of oil, while maintaining separate therefrom a relatively quieter portion of oil of the same body, producing jets from the heated portion of the body of oil under pressure ot the evolved gases as evolved and causing said jets to eject from said heated portion of the body of oil streams of'oil carrying portions of carbon with them, collecting and conducting the ejected streams of oil and carbon carried thereby to the relatively quieter portion of the. body of oil, allowing the carbon to settle in said relatively quieter portion ofthe body of oil, and then discharging the collected carbon.

6. The process of cracking or distilling oil and collecting and separating carbon therefrom, which consists in providing a still having a heatin: and agitating chamber and a settling chamber, heating and agitating the oil in the heating and agitating chamber while allowing the oil inthe settling cha1nher to remain in a comparatively quiescent state, collecting .coluinns ot-evolve'd. gases from the bottom ofthe heatinggand agitating chamber, causing said columns of gases to draw and eject. from the body of oil in the heating and agitating chamber to alevel above said body of oil streams of such oil with particles of free carbon, collecting and conducting the ejected oil and particles of carbon to the settling chamber, causing the carbon so collected to be precipitated in the remote from the source of heat and in a comparatively quiet state, collecting gases evolved from the heated and agitated portion of the oil and under the pressure thereof causing .jets orstreams of oil to be ejected from the said heated and agitated portion of the oil together with portions of carbon carried thereby, collecting and conducting the ejected streams of oil and carbon earried thereby to the relatively quieter portion of the body of oil, allowing the carbon to settle in said rela ively quieter portion of the body of oil, and then discharging the collected carbon. v

8; The process'ot cracking oil and removR ing carbon therefrom, which consists in heatmg and mechanically agitating a portion of a body of oil, under a pressure of to pounds per square inch, to a teinperature'of from 00 F. to 800 F., while maintaining saidportion of saidbody of oil separated from a relatively quieter portion of oil also under the same pressure conditions and of the same body, producing jets from the gases evolved from the heatedand agitated portion of the body 01": oil and causing said jets to eject fromsaiddieated and agitated portion of the body of oil streams of oil carrying portio-ns of carbon with them, collecting and conducting the ejected streams of oil and carbon carried thereby to the relatively quieter portion of the body of oil, allowing the carbon to settle out in said relatively quieter portion of the body of oil, and then discharging the collected carbon.

9. The process of cracking oil and removing carbon therefrom, which consists in maintaining two portions of the'same body of oil separate while permitting flow of oil from one portion to the other when the oil of either portion rises above a predetermined level, heating and mechanically agitating one portion of the body of oil while maintaining theother portion of the body 01 oil in 'a comparatlvely quiet state. producing streams of gases from the gases evolved from and in the heated and agitated portion of-the body of oil, causing said streams of.

gases to force segregated streams of oil from the heated'and agitated portion of the body of oil to a level above the normal level 01' such portion of the bodyof oil, such streams otgases and oil carrying with them their proportions of the carbon contained in the heated and agitated portion of the body of oil, collecting the ejected oil streams and carbon above the level of the heated and lllf) agitated portion of the body of oil and conveying the same to the relatively quiet portion of the body of oil, permitting precipitation of .the carbon in the comparatively quiet portion .of the body of oil, and then discharging the collected carbon therefrom.

10. The process of removing carbon from' the oil during distillation, which consists in heatingfthe oil to cracking temperature and pressure while mechanically agitating the same to keep the free carbon moreor less in suspension therein, collecting from the oil evolved gases and causing the same to travel upwardly in segregated streams through the body of oil, causing said streams of gases to carry with them portions of the oil in the form of streams carryin with them entrained'portions of carbon an discharging, the same at a point-above the level of the body of oil, and then collecting the streams of oil and discharging the carbon therefrom. V

11. An oil cracking still having a heating andagitating chamber and a settling chamber for jointly containing abody of oil, means for separating portions of the'body of oil-in the. heating and agitating chamber and the settlingchamber from each other,

while permitting oil-to flow from one to the otherwhen the oil in either chamber rises above a predeterminedlevel, means for heating and mechanically agitating the portion of the. body of oil in said agitating and heating chamber, conductors submerged in the portion of the bod of oil -contained .in the heating and agitating. chamber for collecting evolved gases and causing, under the pressure of .said gases, the segregation of streams of oil from said portion of the body of oil, together with the carbon carried thereby, to a level above the level of such portion of the b0 y of oil, a collector arranged toreceive t e streams of oil and car;

bon carried thereby and convey the'same to the oil contained in. the settling chamber,

and means for discharging the carbon from the settling chamber.

12. An oil cracking still having a heating and agitating chamber, means for agitating the heated oil in said chamber, means for producing gas forces from the gases evolved from the heated oil, means for directing and causing said gas forces to eject streams-of oil from the body of oil in the chamber With portions of carbon carried thereby, andmeans for separating the carbon from theejected streams of oil and discharging such carbon from the still.

13. An oil cracking still having a heating and agitating chamber, means for agitating the body of oil in said chamber, a collector arranged above the level of the oil, conductors depending into the body of oil for the collection of evolved gases and upfiow theretlnough into said collector of portions of operating .in said chamber, a collecting trough arranged above the normal level of the oil, conductors depending into the body of oil and communicating at their upper ends with the trough for the collection of evolved gases-and the u flow of portions of oil and portions of car on into the'trough from the body of heated oil under. pressure of said gases, and means for separating the carbon from the oil and discharging the same from the still; 4 V 15. An oil cracking still having a heating chamber and a settling chamber, a partition separating said chambers, means for heating the heating and agitating chamber separate from the settling chamber, a discharge outlet from the settling chamber, a collecting trough arranged above the normal level of the oil and having an outlet for discharge into the settling chamber, and pipes com municatin'gat their upper ends with the trough and having enlarged portions at their lower ends depending into the body of oil -in the heating and agitating chamber at a point near the bottom ofsaid chamber, for collecting streams of evolved gases'and' under the action thereof forcing portions of the oil and particles of carbon into the trough.

16. A cracking still having a heating and agitating chamber and a settling chamber, agitating means. in sai'dheating and agitating chamber, means for producing gas forces from the gases evolved from the heated oil, means for directing and causing said gas forces to eject streams of oil from the body of oil in said heating and agitating chamber with portions of carbon carried thereby, conducting the ejected streams of oil and the carbon carried thereby to said settling cham- 1 her, and means for discharging the collected carbon from the settling chamber;

for agitating the oil in the agitating chamber 'to keep the liberated carbon in suspension,

means acting under pressure generated in said chamber for jetting portions of the liquid,

'. 17. An oil-cracking'still having an agitating chamber and a settling chamber, means from the agitatingchamber and conveying the same to the settling chamber, and means for discharging the collected carbon from the settling chamber.

18. In an apparatus for cracking hydrocarbon oil and removing carbon therefrom,

means for heating a body of oil, means for mechanically agitating the same to maintain the carbon more or less in suspension, meansacting under pressure of the gases evolved in the cracking operation to force streams of 011, carrying with them proportions of carbon, from the body of oil, and means for collecting and discharging the carbon so sep-'.

arated from the body of oil.

19. A cracking still having a .heating and agitating chamber and a. settling chamber,

' said chambers being adapted to contain portions of a body of oil contained in the still,

i oil contained in said heating and agitating chamber, upwardly extending conductors in said heating and agitating chamber for col lecting gases evolved l'romthe portion of the body of oil therein and causing streams of such gases to pass upwardly therethrough and to carry with them streams of oil and proportions of carbon carried thereby, and a collector arranged above the level of the body of oil to receive said streams of oil and carbon and convey the same to the settling chamber.

20. An oil cracking still having a heating and "agitating chamber and a settling chamber, said chambers being adapted to contain portions of the same body of oil, means for separating the portions of the body o'toil contained in said chambers while permitting oil to overflow from one chamber to the through the portion of the body of oil in the heating and agitating chamber and extending above the level thereof, said conductors having enlarged lower ends forlcollecting evolved gases and causing uptlow to a level above the top of the said portion ot the body at oil, a collector for receiving the ejected streams of oil and carbon and conveying the same to the settling chamber, a vertically disposed battle plate in the settling chamber extending upwardly to a point slightly above the level of the partition, and a valved discharge outlet from said chamber.

21. In 'an apparatus for cracking hydrocarbon oil and removing carbon therefrom, a still, means for heating a body of oil contained therein, means tor mechanically agitating the oil to maintain the carbon more or less in suspension, means for collecting evolved gases trom the bod of oil and under the pressure thereof, segregating and ejecting streams from the oil carrying with them portions of the suspended carbon, and means for collecting the carbon carried by the streams of oil and discharging the same from the still. I

In testimony whereof I afiix my signature.

LYNTON D. l-VYAN'I.

till

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