US1839030A - Dephlegmator - Google Patents

Description

DEPHLEGMATOR original Filed not.' 4, 1'922 APR LINE Patented Dec'. 29, 1931 UNITED STATES PATENT oFFIcE LYMAN C. HUFF, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNIVERSAL OIL PRODUCTS COMPANY, F CHICAGO, ILLINOIS, A CORPORATION 0F SOUTH DAKOTA DEPHLEGMAT OR Application iled October 4, 1922, Serial No. 592,194. Renewed December 26, 1928.

` This invention relates to improvements in dephlegmator fractionating columns or reflux condensers and refers more particularly to a vertical heat interchanger and partial vapor or reflux condenser, which is adapted for use particularly in the art of cracking hydro-` carbon oils to produce maximum yields of light hydrocarbon products suitable for gasoline andthe like.

Among the objects of the invention are to provide a dephlegmator divided into two parts,"in the lower portion of which are placed a series of vertically extending baffles, so constructed that the rounded end of one l5 baflie will overlap the rounded end of the next bafHe in'a vertical plane; to provide a construction in which the arrangement just described permits of a maximum vaporizing surface within the shell; to provide a construction in the upper part of which is positioned a spiral coil extending downwardly through which distillateof a predetermined gravity may be forced; to provide a construction of the character described in which a series of fins, placed one over the other, are

positioned above and within the spiral coil` heretofore described; to provide a dephlegmator which has inlet and outlet vapor pipes,

distillate and raw oil inlets so controlled that to predetermined quantities vcan be forced to the dephlegmator; to provide a construction of the character described, which permits of a continuous thin film of oil flowing. downwardly over the vertical baffles, obviating the bubbling commonly produced in a dephlegmator in which the vaporization zone is limited, and in general to provide improvements of the character referred to.

The single gure inthe drawing is a view of a dephlegmator, equipped with my invention, partly in side elevation, and partly in vertical cross section.

Referring in detail to the drawing, 1 designates the dephlegmator as a whole, which may take the form of a vertical steel shell, This vertical'shell may be constructed in one piece having-a top portion 2, bottom portion 3, and sidewall 4, or it may be constructed as shown in the drawing in such a manner as to 50 provide a top piece 5, bolted as shown at 6.

In the bottom portion of the shell are posil tioned a series of vertically extending baflies 7, which may be constructed of sheet metal,

aluminum, etc. These baflles are preferably staggered in form as shown having rounded ends 8, the roundedfend of one baile overlapping the rounded end of a similar baffle in a vertical plane. These bailies are supported in the dephlegmator by means of the lugs 9, and bottom cross members 10, tied together by bolts and spacers 10a, extending through the baffles. 11 designates a raw oil inlet pipe, from any extraneous source of supply, which pipe is preferably circular in form, conforming to the inner periphery of the shell. It is provided with a series of nozzles 12, by means of which the oil` is caused to be forced out of the pipe in a uniform spray. 14 designatesa distillate inlet line, which 'terminates in a downwardly extending continuous helical pipe in the form of a coil 15, terminating in an upturned pipe 16. The pipe 16 leads upward and terminates in the outlet 18. A cap 19 is provided over the outlet 18, held in place by suitable lugs (not shown). li provide a series of projecting fins 19a extending around the pipe 16, which in the present instance, are practically oval-shaped in cross section.

In the cracking of hydrocarbon oils, under heat and pressure, the dephlegmator performs a double function which is well known and need not be explained in detail. The I staggered baffles 7. Being under.pressure,

4substantially at a conversion temperature. Upon release therefrom, the lighter fractions 55 of the baes.

will vaporize, while the residue will dow in a thin even dlm continuously vaporizing. y These dns may consist of plain or corrugated surfaces, which slope on an angle so as to retard the dow of liquid over them and retain the heated liquid in this zone for a maximum period of time in contact with the surrounding hot vapors.

v Raw oil may be introduced into the system through the inlet pipe 11 and sprayed over the bales where it will be preheated by the vapors and will mix with the redux or condensate from the condensed vapors and may be drawn od from the bottom connection and conveyed to the heating tubes for further treatment. Vapors are withdrawn from the dephlegmator through the vapor outlet-pipe 21 leading to any suitable condensing and collecting means. Thevapors which condense in their upward passage through the dephlegmator will fall back as redux condensate and will dow downwardly on the surfaces of the badles 7.

As one of the features of my invention, l

25 wish to point out that the condensate or raw oil dowing down over the surface of the bame )plates in a thin even dlm, will be retarded and allowed a maximum period of time for y the lighter ends to vaporize. The vapors dowing upwardly are continuously badied against the sloping surfaces of the vertical badie plates, which are covered with a descending film of redux, causing a scrubbing action of the vapors. Any moisture or glob- 355 ules of oil carried in suspension in the vapors will be deposited with the redux condensate on the surface of the plates and intimately mixed therewith. A fter the redux condensate has been subjected for a maximum i0 period of time to the action of the incoming heated vapors, the still unvaporized portion will be drawn od through the drawod pipe 22 to any suitable storage or returned for retreatment in the same system.

The entire outer wall of the dephlegmator may be lagged to prevent the radiation of heat or it may be desirable to only lag part of the side wall, for instance, the bottom half.

The surface of the bame plates may be corruy 59 gated or rigid, if desired, to further retard vthe dow of liquid thereon. The bades are so spaced that any condensate from the vapers or redux will fall but a short distance efore coming in contact with some portion v It will be understood that the temperature of the vapors leaving the de,- phle ator through the outlet 21 can be readily controlled `and regulated by the amount of cooling liquid introduced through @0* the pipe 14.

I do not wish to restrict m. self to the use of my invention for the crac g of hydrocarbon oils. lt may be used with slight modifications as a distilling apparatus for dis- @5 tlling alcohol. lin addition, with slight down the sides of the fins 19a,

aaeaoae modifications, it may be used as a topping still for the purpose of fractionating and recoverin the light fractions of oil, commonly cal ed topping in the art. For instance, a vertical still can be equipped with my vertically extending staggered badies positioned therein. The crude oil may be ntroduced at the top of the still or at a point above the bames, and allowed to dow down over the zig zag surfaces of said baffles. Steam under pressure may be forced upward continuously from the bottom of the still, and when this steam meets the descending film of oil, some of its heat will be transferred thereto and part of the light constituents of the oil will vaporize, which together with the steam which does not condense, may be drawn off to a suitable condensing and separating means. The unvaporized portion will dow downwardly and may be withdrawn.

Further, the crude oil may .be heated and partially vaporized in the usual way, and the vapors introduced into the still below the vertically extending staggered badies and the vapors forced upward as explained. The unvaporized portion of the heated crude oil can be separated from the vapors in a separate still or tank interposed between the heating means and still and drawn off while the vapors only are made to enter the still below the staggered badies.

lt will be seen from the foregoing description that the staggered badies allow of maximum cross sectional vapor space through the dephlegmator, insuring slow velocity of vapors and permitting the use of small diameter dephlegmator. Also these staggered bafdes are self-cleaning and cannot become clogged with foreign matter, as there are no dat surfaces on which foreign matter can collect. By heating distillate in a closed coil as explained and discharging it in the upper part of dephlegmator, and allowing it to dow over the series of fins where it is exposed in a thin film to the hot vapors, it readil absorbs its heat of vaporization and vaporizes, thus cooling the surrounding vapers, and passes out of the dephlegmator with vapors which have been cooled by reason of the vaporization.

lit is obvious that the coil and dns in the upper portion of the dephlegmator or still may be replaced with a series of vertically extending baffles similar in constructior to those in the lower part of the apparatus and ythat the cooling distillate may be introduced by means of a spray on thetop of baies where it will be heated and vaporized by the ascending vapors as it dcws downward in a thin film over the badies.

l claim `as my invention:

1. A n apparatus of the character described, comprising an elongated vertical shell, means for introducing vapors into the lill?) lower portion of said shell, a plurality of staggeredly disposed bailes positioned within the lower portion of said shell to initially retard the flow of vapors' therethrough,

means for conveying a cooling medium downwardly through a substantial portion of said shell in indirect contact with the vapors, means for returning such cooling medium to the upper portion of said shell and l means for then causing such cooling medium -to llow downwardly through the shellin direct contact with the vapors'and means for tslrilng` 0E uncondensed vapors from saidv s el l l5 2. An apparatus of the character described comprising an elongated vertical shell, means for introducing vapors into the lower portion of said shell, means for conveying a cooling medium downwardly 2o through a substantial portion of said .shell in indirect Contact with the vapors, means within the shell for returning such cooling medium to the upper portion of said shell and means for then causing such cooling 'medium to How downwardly lthrough the shell indirect contact with the vaporsand Y means for taking off uncondensed vapors from said shell.

' LYMAN C. HUFF. t

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