US1821746A - Process and apparatus for cracking oil - Google Patents

Description

Sept. 1, 1931; G. EGLOFF PROCESS AND APPARATUS FOR CRACKING OIL Original Filed Dec.

Patented Sept. 1, 1931 UNITED STATES PATENT OFFICE GUSTAV EGLOFF, OF INDEPENDENCE, KANSAS, ASSIGNOR 'I'O UNIVERSAL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA PROCESS AND APPARATUS FOR CRACKING OIL- Application filed December 6, 1920, Serial No. 428,788. Renewed February 7, 1930.

This invention relates to improvements in process and apparatus for cracking 011, and

refers more particularly and has among its' vention also relates to the cracking of fuel oil in one heating chamber and gas oil or fuel oil in another heating chamber, while the reflux condensate may be diverted to either chamber or carried elsewhere fontreatment. In any event, the oil in theseparate chambers may be subjected to different conditions of heat and pressure. It is well known to those skilled in the art that different cuts of petroleum oil are desirably cracked under different conditions of heat and pressure. It is also well. known that most ofthe cracked gasolene now in the market is a blended material. This blending is done afterthe pressure distillate has been produced, as for example, by mixing the gasolene obtained from the pressure distillate with casinghead gasolene or,

gasolene obtained from fractional distilla I tion of crude or both. In the present inven tion, this blending is accomplished as part of the cracking operation. thus being able to obtain a much more effective and cheaper blend than might otherwise be possible.

i i In the drawing, the single figure designates a view partly in vertical section and partly in side elevation of my improved apparatus.

Referring to the drawing, 1 designates a.

furnace, provided with upper and lower combustion chambers 2 and 3, and corresponding burners 4 and 4, the combustion chambers being separated by a foraminated bridge wall 5. The furnace is, of course, equipped with the usual stack 6. In the combustion chamber 2 is seated a heating cham-' ber 7, which may take the form of a contina uous coil of four inch pi'p'e, say 200 to 600 feet long. In the lower chamber 3 is mounted a similar pipe 8 which may be of the same diameter and length. The diameter and length of the pipes will be determined somewhat by how much oil is to be fed into one heating chamber relative to the other. The heating coili7 is provided with feedline 9, having throttle valve 10, connected to the delivery side of pump 11, which pump 11 is connected at its inlet side by line 12, having throttle valve 13, to any suitable source of raw oil supply, as for example, gas oil or kerosene. The inlet sideof the coil 8 is connected by feed line 14, having throttle valve 15, to charging pump'16T This pump 16 is connected at its inlet side to the raw oil line 17, having throttle valve 18, which line 17 may be connected to supply offuel oil or such heavy oils as asphaltic, Mexican or California asphaltic crudes or mid-continent heavy crudes or heavy fuel oils. The delivery sides of the coils 7and 8 are connected by transfer lines 19 and 20, having throttle valves 21 and 22, to a main transfer line 23, having throttle valve 24. .The line 23 connects .to a large shell-like expansion chamber 24, which chamber 24 is provided with I residue draw off pipe 25, having. throttle valve 26. To the upper part. of the chamber 24 is connected a vapor outlet pipe 27 having throttle valve 28, which pipe 27 leads to a dephlegmator 29. This dephlegmator 29.

is provided with suitable bafile members 30, K

' with liquid level gauge 38, liquid draw ofi pipe 39, having throttle valve 40. It also has gas outlet pipe 41, having throttle valve 42 and extension 41', leadin to vacuum pump 43'. A branch pipe aving throttle valve 45, is also provided. The arrangement is such that a vacuum ma be mamtained on the condensing part 0 the appa-.

ratus, or by shutting the valve 42 and regu- .lating the valve 45, a pressure may be maintained-on the condensing part of the s stem.

The heavier vapors which are con ensedv in the dephlegmator are drawn off from the lower end of the latter through the reflux pipe 46. This pipe 46 is provided with a branch 47, having throttle valve 48, which branch 47 is connected to the pump 11. It

.also has a branch 49, having throttle valve 50, which branch 49 leads to the inlet side of the pump 16. It is also provided with still another branch 51, having throttle valve 52, leading to any suitable receptacle (not shown). The arrangement is such that the reflux condensate may be returned to either of the heating coils or may be diverted elsewhere. The system is provided with suitable pyrometers (not shown), and with a plurality of pressure gauges 53.

A process may be carried out in this apparatus as follows: Fuel oil of a more or less. asphaltic nature of say 26 degrees Baum may be fed continuously to the heating coil 8, and there heated to a temperature of say 675 degrees F., and

subjected to a pressure of say 100 pounds. It is delivered into expansion chamber 24, preferably in substantially liquid phase so as to prevent precipitation of carbon in the coil. At the same time gas oil of say 32 degrees Baummay be'fed continuously through the second heating coil 7 and there subjected to a temperature of say 750 degrees F. and a pressure of say 150 pounds. It also is delivered in substantially liquid condition for the same reason to the expansion chamber. Here vaporization of the mixture takes place, and

thevapors pass to the dephlegmator. The

heavier or incompletely converted portions thereof will be condensed and drawn off through the reflux line." If this reflux condensate is particularly refractory, or of a gravity of substantially the same as the gas oil, it should be returned to the heating coil 7. On the other hand, if it more nearly approaches the character of the fuel oil, it

should be returned to the lower coil 8. In.

certain cases, it may be desirable to divert this reflux condensate elsewhere and sepainto pressure distillate of say 53 degrees.

Baumgravity, containing some to of 400 end point gasolene based on the raw oil charge;

A process may be carried out in this apparatus, in which the raw oil in the lower coil may be fuel oil or a mixture of fuel oil and gas oil, and the raw oil in the upper part kerosene or a mixture of kerosene and gas oil, and the reflux condensate may be carried through any oneof the three branches heretofore de scribed. In any event, the process will be so operated as to secure in the final product a gasolene or other like oil content containing the relative proportions of the various end point cuts. For example, in cracking the fuel oil, the gasolene produced therefrom may be say 56 degrees Btlllll'l gravity, while the gasolene produced from cracking the kerosene or gas oil might be 58 degrees Baum gravity. By suitably regulating the amount obtained from each raw oil, it will be seen that a blend of the desired character may be obtained. For example, it might be desirable to contain in the blend some so-called wild gasolene, which may be obtained by cracking in the upper coil kerosene to form very light cuts, for example, those having an end point of to 100 F.

I claim as my invention:

1. An apparatus for cracking oil, the combination of a furnace provided with two superimposed interconnected combustion chambers, a coil seated in one chamber for receiving an oil of predetermined gravity, a coil seated in the other chamber for receiving an oil of a different gravity and an expansion chamber to which both coils are connected,- a reflux condenser connected with the vapor space of the expansion chamber, and connections between the lower part of the reflux condenser and each of the coils.

2. In an apparatus for cracking oil, the combination with a plurality of heating chambers, of a heating coilpositioned in each of said heating chambers, means for su plying oils from separate sources to the di erent coils, an enlarged expansion chamber to which said plurality of coils are connected, a reflux condenser connected with the expansion chamber, means for returning reflux condensate from the reflux condenser selectively to any one of said plurality of coils, and means for removing the reflux condensate from the apparatus in the event that it is not desired to return the reflux condensate to any one of said coils.

3. A method of cracking a mineral oil which comprises: heating a'stream of a heattransferring medium while out of contact with said mineral oil to a temperature above GUSTAV EGLOFF.

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