US1766331A - Process and apparatus for cracking oil - Google Patents

Description

June 24, 1930. EGLOFF PROCESS AND APPARATUS FOR CRACKING OIL Original Filed Dec. 6. 1920 Patented June 24, 1930 UNITED; STATES PATENT oF lca eus'rav Esters, orcnIcAeo, ILLINOIS, ASSIGNOR 'ro UNIVERSAL OIL rnonuc'rs COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or sou'rn naxo'ra rnocnss Ann APPARA'I US FOR CRACKING OIL Application'filed'neeniber 6, 1920, Serial No. 428,787. Renewed Mai; 25, 1929'.

This invention relates to improvements in a process and apparatus for cracking oil, and

refers more particularly to the conversion of such petroleum constituents as fuel oil and heavyasphaltic crudes'intolighter hydrocarbons, such as'gasolene, kerosene, gas oil and the like, although in its broadest aspects the invention relates to the conversion of heavy to lighter hydrocarbons. In the cracking of petroleum oil, certain of the generated vapors are iiisufliciently converted, and it is desirable tofreturn them to the system for further treat- Inent. The heavier vapors so returned are known as reflux condensate forthe reason that they are the result of reflux condensation in one form or another. This reflux condensate is of a different character than the 'raw oil from which it originally came, and

in many types of oils, should be, if possible,

subjected to diflerent conditions of cracking,

particularly as to temperature and pressure, than should the raw oil itself." At the same time, it is desirable to treat the oil in an economical and simple apparatus, as the cost of construction and maintenance of apparatus for cracking oilis an item of such moment as to frequently make the process, however desirablein itself, commercially not feasible.

. The present invention overcomesthis objecvided with the oil or gas burners and 6,,and the furnace is provided with a stack 7. In the" lower chamber is mounted the raw oil heating coil 8, which may take the form of several hundred feet of four-inch pipe,"the inlet side of whichis-connected by feed line 9 to raw oil pump 10, provided with throttle valve 11. This raw oil pump is connected to any suitable source of raw oil sup-;

ply. The upper end ofthe coil 8 isprovided. .tengperature and, pressure to which the raw &

with a discharge line 12, in turn connected .to the main transfer line 13, leading to the expansion chamber'14 located outside of the fire zone. -A throttle valve is inter osed in the line 13. In the transfer line 12 1s interposed a pump 16, provided on either side with valves 17 and 18. The 'pump may be bypassed through bypass line 19, having throttle valve 20. The arrangement is such that the oil may be delivered from the coil 8 to the I expansion chamber either at the same pressure as in the 001]. or at a reduced pressure or at an Increased pressure relative to the 0011.

The lower end of the expansion chamber is provided with a residue draw off line 21,

having throttle valve 22. It is also provided fles 26. The upper end of the dephlegmator is provided with vapor outlet pipe 27, having throttle valve 28, and leading to the .con; denser coil 29, seated in condenser box 30.

Thelower end of the coil 29' is connected by pipe .31, having throttle valve 32, to the upper end of the receiver 33. This receiver 33 has a liquid draw ofl pipe- 34, controlled by throttle valve 35, gas outlet pipe 36, controlled by throttle valve 37. It is also p'rovided with liquid level gauge 38.

The reflux condensate is drawn off fr omthe bottom of the dephlegmator through reflux line 39, having throttle valve 40, and leading to the inlet side of feed pump '41.

The discharge-side of the pump 40 is connected by means of feed line 42, having throttle valve 43; to the lower end of a heating coil 44,,seated in the combustion chamber 3. This coil 44 may be of the same length and size as thecoilS, or it may be of in-- creased diameter or increased length of pipe, particularly if there is more reflux condensate to be treated than raw material. In the cracking of certain petroleums this will be the case, the amuont of reflux, of course, depending also upon the temperature and size of the dephlegmator, the desired end point product to be obtained, as well as uponthe sion chamber.

oil is subjected. In other words, all factors must be taken into consideration in regulating the size of the coils relative to each other. From extended practical experience in the 5 cracking of petroleum oil, it is impossible to definitely give figures for all oils, but anyone skilled in the art will have no difliculty in regulating these features.

The other end of the coil 44 is connected by pipe 45 to the main transfer line 13. A pump 46, having at either side valves 47 and 48, is interposed in the line 45. The pump may be bypassed by meanS of the bypass pipe 49, in which is interposed throttle valve 50. The arrangement is such that the reheated reflux condensate may be delivered from the coil 44 tothe expansion chamber under the same, increased or decreased pressure relative to the pressure in the heating 20 coil. 4

Suitable pressure gauges 51 are provided 1 in various parts of the system as shown.

In carrying out the'process, raw oil, as for example Kansas or Oklahoma gas oil of 31 35 degrees Baum gravity, may be continuously fed through the first heating coil, and there subjected toa temperature of say 750 de- "grees F., care being taken to deliver it in substantially liquid condition to the expan- The reflux condensate may be heated to a temperature varying between 600 and 8OQ degrees F. A uniform pressure, if desired, may be maintained on the entire system clear through to thereceiver, as for 35 example, pounds. A process may be carried out with'this apparatus in which the? pressure on the raw oil coil may be say pounds, 200 pounds on the reflux condensate coil, and 100 pounds on the expansion chamber, dephlegmato'r and condenser. One pro-. nounced advantage of the present invention is the ability to subject the reflux condensate in the same apparatus and in the same .furnace to independently regulated conditions oftemperature and pressure relative'to that .to which the raw oil is first subjected.

I claim as my invention: 1. A process for converting oil, comprising passing a stream of charging oil through a ture sufficient to vaporize a substantial part thereof, in introducing the heated hydrocarbons under a pressure, in excess of that maintained on the charging oil during passage through the heating zone, to an enlarged expansion chamber where vaporization occurs, in subjecting the vapors to dephlegmation, in heating the reflux condensate in a separate stream to a cracking temperture, in passing the heated reflux condensate under pressure to said'expansion chamber, and in Withdrawing the unvaporized residual oil from the expansion chamber.

2. A process for converting oil, comprising passing a stream of charging oil through heating zone to be subjected to a tempera-- I a heating zone to be subjected to a temperastream to a cracking temperature while maintamed under a pressure 1n excess of the pressure on the charging oil passing through the heating zone, in passing the heated reflux condensate to said expansion chamber, in withdrawing the unvaporized residual oil from the expansionchamber, and in maintaining a superatmospheric pressure on the oil' undergoing conversion.

3. A process for cracking hydrocarbon oil, comprising the simultaneous and independent subjection of a relatively low boiling point hydrocarbon oil and a relatively high boiling point hydrocarbon oil to higher and lower cracking conditions of temperature and pressure respectively, thereafter commingling the heated oils in a common zone maintained under a pressure higher than the pressure to which said relatively high boiling point hydrocarbon oil was previously subjected.

4. A continuous process for cracking hydrocarbonf oils, comprising simultaneously advancing in independent streams a relativee ly high ,boil ing point hydrocarbon oil and a relatively low boiling point hydrocarbon oil through a heating zone, subjecting the stream of relatively low boiling point hydrocarbon 011 to higher conditionsof temperature and pressure than maintained on the stream of relatively high boiling point bydrocarbonoil, delivering the heated oil from said independent streams to an enlarged zone,'mai-ntaining a pressure in said enlarged zone in excess of the pressure maintained on said stream of relatively high boiling point hydrocarbon oil, and subgeicting vapors evolved from the oil to dep egmation and condensation.

5. A process of. oil conversion, comprismg maintaining. a body of heated hydrocarbons in an enlarged zone, where substantial vaporization-- occurs, subjecting vapors togefiux condensation, tov condense the heavier vapors, passing the reflux condensate resulting from the condensation of the heavier vapors in an advancing stream through a heatingzone, where it is subjected to cracking conditions of temperature and pressure, delivering the heated condensate to said enlarged zone, simultaneously heating an ndependent stream of charging oil, for delivery to said enlarged zone, to a temperature sufiicient to cause a substantial vaporization thereof in said enlarged zone, introducing said heated charging oil to the enlarged zone,

under a pressure in excess of the pressure maintained on said independent stream of charging oil during the heat treatment there- 6. An apparatus for cracking hydrocarbon oil, comprising a plurality of heating coils, an enlarged expansion chamber, means connecting each of said coils to said enlarged expansion chamber, means for supplying oil to each of said coils, means for maintaining independently controlled pressures on the oil in each of said coils, means, associated with the means connecting -each coil to said expansion chamber, for introducing oil from the associated coil to the expansion chamber, at a pressure in excess of the pressure maintained on the oil in such associated coil.

7. A process for cracking hydrocarbon oil, comprising the simultaneous and independent subjection of a relatively low boiling point hydrocarbon oil and a relatively high boiling point hydrocarbon oil to higher and lower cracking conditions of temperature and pressure respectively, thereafter commingling the heated oils in a common zone maintained under a pressure higher than the pressure to which said relatively low boiling point hydrocarbon oil was previously subjected.

GUSTAV EGLOFF.

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