US1828398A - Process for treating oils - Google Patents

Description

Oct. 20, 1931. c.,P. DUBBS I PROCESS FOR TREATING' OILS Filed Feb. 17, 1921 dfbohdzub' @ZMA/MM. Wi

Patented Oct. 20, 1931 e UNITED STATES PATENT OFFICE GABBON P. DUBBS, OF lWlLME'III'JE, ILLINOIS, ASSIGNOR T0 UNIVERSAL OIL .PRODUCTS COMPANY, F CHICAGO, ELIN'OIS, A CORPORATION 0F SOUTH DAKOTA PROCS FOR TBEATING- OILS Application led February 17, 1921. Serial No, 445,670.

This invention relates to improvements in process :tor treating oils and refers more particularly to a means for bringing an oil process on stream more quickly and more eiiiciently than the usual method-generally em loyed.

ong the salient objects of the invention are to provide a pro'cess which may be more readily brought on stream due to the act that less oil is introduced to the stream in the initial stages oi the operation of the apparatus; to provide a process in which by producing a local circulation between the heating zone and vaporizing zones the oil in that localized portion ci the apparatus may be more readily heated with less fuel coneumption and in a less period of time than is usually employed to bring an apparatus et like capacity on stream; to provide a process in which, due t0 the circulation of the oil through the heating zone and expansion chamber, the carbon deposited from the oil during the heating operation is prevented from Aaccumulating in the heating tubes and kept in suspension with the circulating iiuid whereby dimculties from hot spots and carhon accumulation in both the heatingand expansion zone are materially lessened; to provide a process which is simple in operation and necessitates very little additional aipparatus; to provide an apparatus for t e carrying out of the described process and, in general, to provide a process and apparatus of the character referred to.

Ylhe single gure isa diagrammatic side elevation partly in section with parts broken away to permit a more complete showing ci the apparatus.

Referring to the drawing-the apparatus can be more simply described by following the course. of the oil in its progress during treatment through the system. The oil is introduced from any convenient source of supply (not shown) to the line 1 controlled by a throttle valve 2 and is charged by a pressure'pump 3 through a line 4 into the top of the dephlegmator 5. Theoil travels down through the dephlegmator` in an opposed direction to the course of the oil vapors which rise therein, the raw oil comved to a crackin ing in intimate contact with the oil vapors serving as a dephlegmating medium, condensing out the higher boiling point `fractions and when combined with them is drawn oil from the bottom oi the dephlegmator through a line 6 through which it is directed to the inlet line 7 of the heating coil 7'. A valve 8 is interposed in the line 6 and a valve 9 in the line 7. The oil is charged in this man- 1 ner in startin the process until it stands at the desired helght in the expansion chamber at which time the heating coils are completely filled, the valve 8 in the line 6 opened and the valve 9 and valve 10 opened while the valve l1 in the residuuin draw-ofi' pipe 12 is closed. When the desired quantity of oil has been 'charged into the system, the

charging lvalve (not shown) above the dephlegmator is closed. rllhe fires are then lighted in the furnace i3 which is preferably heated by means or" gas burners 14 and the oil heattemperature. During the heating of the oi the pump 15 is kept in operation which keeps the oil circulating th rough the heating tubes into the expansion chamber, out through the residuum draw-oil' line and back to the heating tubes through the inlet pipe 7, As previously mentioned, the valve 11 is closed until the oil in the heating tubes 7 and expansion chamber 16 has been raised to a temperature at which a substantial conversion is commencing to take place. At this juncture in the roces's, oil is gradually admitted to thevinlet ine 7 by opening slightly the charging valve (not shown)` above the dephlegmator and as conversion continues the pump 15 may be slowly cut out of the system by closing the valves 9 and 10. lt will be necessary at this time to draw od the heavy residuum and direct the same to storage through the line 12 by opening the valve 11. The oil vapors released in the expansion chamber rise through the vapor line 17 controlled by a valve 18 and after being relieved of their higher boiling point fractions by the raw oil in the rectifier or dephlegmator 5, the vapors ass out through the line 19 to a water con enser 20 where, after passing through the coiled pipe 21 they are collected as distillate in the receiver- 22. A valve 93 is interposed in the line connecting the condenser and receiver. The receiver is fitted with liquid level gauge 24, pressure relief pipe 25, controlled by a valve 26 and a liquid draw-off line 27 regulated by a valve 28.

During the initial stagesl of the process it may be advisable to keep the throttle valve 18 in the vapor line closed in order to decrease the amount of free carbon separation in the heating and expansion zone.

An illustrative run on Mid-continent gas oil would be operated approximately under the following conditions :-by introducing' a gas oil of approximately 31 B. gravity and heating the same by a continuous local circulation from the residuum draw-off line in tbe expansion chamber back to the heating :zone in the initial stages of the process and raising the oil to approximately 750 F. and at the same time maintaining a pressure of i rom 50-200 pounds upon the system, then gradually, as the conditions of pressure and temperature become somewhat stable, introducing additional raw oil and simultaneously therewith cutting out the local circulation and directing the heavier ends taken from the expansion chamber to storage, I have been able to bring an apparatus much more readily on stream by expanding much less fuel and thereafter proceeding with the process as in operating any other continuous cracking apparatus, recovering a distillate having a Baume gravity of approximately 51 and comprising 50 to 60 percent ofthe original oil charge.

I claim as my invention:

1. In the art of cracking hydrocarbons, a proces. 'hich comprises the initial steps of supplying charging oil to a heating coil and expansion chamber, heating the heating coil and pumping the charge of oil from said chamber to the coil and bart` into said chamber. controlling the discharge of vapors evolved from the oil from said chamber. to gradually increase thek pressure in the system to the desired operating pressure. continuing the pumping operation to and'from said expansion chamber. to gradually increase the temperature of the charge. then proceeding with the normal operations of the process. which include prerciting the scape of liquid from said expansion 'chamber to .said pump,`

pumping a stream of hydrocarbon liquid fromv a source of supply and forcing the hydrocarbon liquid through said heatingr coil and into said expansion chamber, passing the vapors through a refiux condenser to a nal condenser, continuously permitting refiux condensate to commingle with the hydrocarbon liquid comingfrom the source of supply, to be forced therewith through said heating coil and into said expansion chamber, regulating the admission of the charging oil from 5 said source of supply and removing carbonaceous residue as it accumulates in said expansion chamber.

2. In the art of cracking hydrocarbons, the process which comprises the initial steps of supplying charging stock to a heating coil and expansion chamber, heating the oil in the coil and pumping the charge from said cham ber to the coil and back into said chamber, controlling the discharge of vapors from said chamber through a reflux condenser and into a final condenser, to gradually increase the pressure in the system to the desired operating pressure, and continuing` the pumping operation to and from said separating chamber, to gradually increase the temperature of the charge, then proceeding with the normal operations, which include preventing escape of liquid from said separating chamber to the pump, conducting a stream of hydrocarbon liquid from a source of supply to said reflux condenser, permitting a substantial volume of such hydrocarbon liquid and reiux condensate, separated from the vapors, to accumulate` passing vapors from said separating chamber through said reflux condenser to said nal condenser, continuously forcing a mixture of reflux condensate and said liquid hydrocarbon from said accumulated volume through said heating coil and into said expansion chamber, regulating the supply of liquid hydrocarbon from said source of supply, and removing carbonaceous residue as it accumulates in said expansion chamber.

3. A process of cracking oil, consisting in charging a heating coil and an enlarged reaction chamber with a predetermined quantity of hydrocarbon oil, in heating the coil while initially repeatedly circulating the oil through the` coil and the reaction chamber to raise the oil to a cracking temperature, in controlling the escape of generated vapors to create in the reaction chamber superatmospheric vapor pressure, in proceeding with a normal operation when cracking conditions of temperature and pressure have been attained by discontinuingthe cyclic circulation of the oil body through the heating coil and reaction chamber, and in continuously supplying fresh charging oil to the process to e converted continuously subjecting vapors evolved from the oil to reiux condensation, returning the reflux condensate thus formed to said heating coil for conversion with the oil supplied to the process while continuously removing unvaporized residue from the re action chamber without permitting the return thereof to the heating coil.

- CARBON P. DUBBS.

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