US1865172A - Process and apparatus for cracking hydrocarbon oils - Google Patents

Description

June 28, 1932- c, COOK 1,865,172

PROCESS AND APPARATUS FOR CRACKING HYDROCARBON OILS Filed Jan. 9, 1928 Patented June 28, 1932 UNITED STATES PATENT OFFICE RALPH C. COOK, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNIVERSAL OIL PRODUCTS COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA PROCESS AND APPARATUS FOR CRACKING HYDROCARIBON OILS Application filed January 9, 1928. Serial No. 245,387.

I11 the cracking of hydrocarbon oils, as for example, in the well known type of heat and pressure process in which the oil may be fed through a suitable heating coil thence to an enlarged expansion chamber and the vapor removed from said chamber and subjected to dephlegmation, difliculty has been experi enced in obtaining satisfactory separation of the sufliciently cracked from the insufliciently cracked vapors. In various types of packed towers or dephlegmators, there has been, in many cases, a pronounced tendency for the vapors to channel, thus preventing proper fractionation. Also in these types of dephlegmators, difiiculty is frequently experienced in entrainment. The object of the invention is to prevent suchchanneling and entrainment, and to accomplish it in a practical manner which can be utilized by an oil refiner.

Inasmuch asthe type of apparatus in which these dephlegmators are used is well known,- it will not be necessary to show them in drawing, but only to show the type of dephlegmator utilized in such process and apparatus. In the drawing, Fig. 1 is a vertical sectional view of the dephleginator used in my apparatus and process. Fig. 2 is a fragmentary, horizontal, sectional View of the same.

In carrying out the process, the oil may be passed through a suitable heating coil, where it may be heated to a transfer temperature of 800 F., or more, and thence passed to the usual expansion chamber. Here vaporization takes place, the residue may be drawn off and the vapors passed to the dephlegmator. The temperature of the dephlegmator may be suitably controlled so that only the gasolene constituents, for example, will remain uncondensed and will pass out through the invention, the dephlegmator may consist of an outer cylindrical shell 1, divided by means of perforated plates 2 forming a plurality of superimposed compartments 3. Between the plates 2 are mounted a series of nested vapor pipes, or conduits 4, which I have shown as hexagonal in cross section, but they may be of any desired cross section contour. The lowermost plate 5 is supported on suitable lugs or brackets 6, and the superimposed plates may rest on the top of corresponding internested pipes 4.

Spaced away from the top of the uppermost pipes 4 is a plate of the well known bubble tray type 7, provided with risers 8 and spaced caps 9 and open ended reflux return pipes 10. By means of the bubble trays 7 the cooling medium, which may be the raw oil, is uniformly distributed into the pipes 4. The oil may be fed through the inlet line 11,

as shown. Each of the pipe sections 4 is preferably packed throughout a portion of its height with suitable packing 12, as for example, Raschig rings, or other suitable packing material. The reflux condensate is collected in the bottom chamber 13,and thence is drawn out through the reflux return pipe 14. The vapors may enter the bottom of the dephlegmator through the vapor inlet pipe 15, the various pipes 11, 14 and 15 being controlled by' suitable throttle valves.

As the vapors enter the lower end of the dephlegmator, they will pass through the perforated plate 5, up through the adjacent set of the vertical conduits 4, through the packing up through the superimposed plates 2 and through the corresponding sets. of vapor pipes, as shown. It will be noted that the upper portion of the various pipes 4 do not have any packing. This permits any liquid which is carried into such open space by the ascending vapors to drop out and flow back into the packing. The-arrangement is such that in each compartment there is obtained a fractionation or separation of the lighter from the heavier fractions within relatively narrow limits.

It will also be noted that the relatively small cross section of each pipe 4 in relation with the diameter of the cylindrical shell will prevent channeling of the vapors in their passage through the dephlegmator.

I claim as my invention- 1. A process of treating hydrocarbon oil vapors to separate insufficiently cracked constituents from sufliciently cracked vapors, which consists in passing the vapors to be treated upward in a plurality of parallel in dependent streams, causing the vapors in each of said streams to pass through packing material, subsequently causing the vapors to bubble through a pool of refluxing liquid, causing liquid from said pool to flow downwardly in contact with and countercurrent to the rising vapors, and thereafter withdrawing said vapors for condensation as the product of the process.

2. A process of treating hydrocarbon oil vapors to separate insufficiently cracked constituents from sufiiciently cracked vapors, which consists in passing the vapors to be treated to the lower portion of a treating zone, maintaining a pool of refluxing liquid at the upper portion thereof, causing the vapors to ascend and liquid from said pool to descend through packing material, subsequently causing the vapors to bubble through said pool of refluxing liquid, and thereafter withdrawing said vapors for condensation as the product of the process.

4 3. A process of treating hydrocarbon oil vapors to separate higher boiling point constituents from the vapors of lower boiling point constituents, which consists in introducing the vapors to be treated at the lower portion of the treating zone, introducing a condensing liquid at the upper portion of the treating zone, maintaining a pool of said liquid near the point of liquid introduction and causingthe ascending vapors to bubble therethrough, dividing the vapors introduced at the lower portion of said zone into a plurality of upwardly directed independent streams, causing the vapors in each stream to pass through granular packing material, conducting the overflow from said pool to a region above said packing material and discharging it thereover to permit it to descend therethrough and pass over the surfaces of said packing material in contact with the ascending vapors, and withdrawing the con densing liquid after contacting with the vapors, from the lower portion of the treating zone.

4. A device for use in heat treating process for hydrocarbon oils in which oil vapors are evolved, comprising in combination,.a chamber, means for introducing heated oil vapors at the lower portion of said chamber, means for introducing a condensing liquid at the upper portion thereof, vertical partitions dividin the intermediate portion of said chamber into a plurality of vertical passages, I a transverse partition for supporting a quantity of packing material in each passage, said partitions being perforated to permit ascendlng vapors to pass through said material, a transverse partition above said vertical partitions adapted to retain a pool of condensing liquid, means for causing the vapors passing from said packing material to bubble through said 001 of liquid, and means for collecting t e vapors after bubbling through said pool for condensation as the'product of the process.

5. A dephlegmator comprising a shell, a vapor inlet adjacent the lower portion of said shell and a vapor outlet adjacent the upper portion thereof, a perforated partition within said shell, a plurality of vertical vapor conduits supported at their lower ends on said partition, means for retaining a pool of liquid in the upper portion of said shell, means for supplying liquid from said pool to said vapor conduits, and means for passing vapors from said conduits through said pool.

6. A dephlegmator comprising a shell, a vapor inlet adjacent the lower portion of said shell and a vapor outlet adjacent the upper portion thereof, a perforated partition within said shell, a plurality of vertical vapor conduits supported at their lower ends on said partition, and packing material in the lower portions of said conduits, means for retaining a pool of liquid in the upper portion of said shell, means for supplying liquid from said pool to said vapor conduits, and means for passing vapors from said conduits through said pool.

RALPH O. COOK.

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