US1615779A - Method of cracking oil - Google Patents

Description

2 1927. Jan 5 F. E; WELLMAN METHOD OF CRACKING OIL Filed July 10, 2 Sheets-Sheet -l FFW/wf W22 lll Patented Jan. 25,l 1927.

UNITED STATES l`15A-TENT oFFicE."

FRANK E. WELLMA-N, 0F KANSAS CITY, KANSAS, ASSIGNOR TO TEE KANSAS CITY GASOLlNE COMPANY., KANSAS ClllTY, KANSAS, lA CORPORATION OF KANSAS.

METHOD or cnAoKiNe orL..

lAppncation inea July 1o, 1922. serial No. 574,941.

riod Vto, des'tructively affect the container,A

while .at the Same timea high temperature is employed at the point of application of the source, for eiiiciency'in driving in the heatl energy and causing it to penetrate the oil for` cracking purposes. cracking zone is found within a limited area ofl penetration, and it is therefore important to include within it as large a percent- 'age' of the whole body of oil under treat@ ment as possible, by increasing the heating surface.

lin my prior copending application, Serial Number 565,633, filed June 3, 1922, .I 'have disclosed an apparatus in which the heating surface is largely increased proportionate ly to the mass of oilunder treatment, by using a circular series of pipes as containers, with headers and expansion tanks to prevent foaming, and a rotating burner system in which a trailing flame is applied periodically to each pipe. The cracking zone is thus largely increased, and it is evident that the method of heating involved might be practiced with various forms of apparatus, not

necessarily .included within the claims of said application, Serial Number 565,633.

Hence the purpose of the present application 1- lis to present the method above referred Loand claim the same Without limitation to caseis a continuation in part thereof.

vBriefly stated, my improved process con- Y of its volume lies within the cracking zone ofv direct heat" penetration; the extension being in some symmert'ical of other ligure such that a high temperature source may be The active 'my present invention p .of Fig. 2; any particularapparatus- As said method l is disclosed in the foregoing application, vthis applied or a high temperature' created, over, 1n or through one .circumscribed portion afteranother of the extended body with the result thatcrackingenerg'y is driven in und er most favorableconditions, atY high eiiiciency, without' destructive action on the container or containers of whatever nature they may be. f i

Forms of apparatus, both as to the still and as to the heating means, may be varied quite widely without departing from this process. I have cliosen'and shall describe herein the circular pipe still and therotating burner of my prior copending application, Serial'No. 565,633, as the best form known to me at the present time, but contemplate modifications thereof including circulating coils leading from the upper part of a main sill to the lower part thereof and with their turns Varranged in any figure that per. mits a flame or other source of heat to be applied to them in rotation periodically.' It

rotation. Many other modifications in both the' form of container and the specific heatingmeans will occur toi those skilled in the art; and all of these are within the sco e of though notspeciliczally claimed herein.

The preferred form of apparatus for practicing my invention is illustrated in the accompanying drawings, in which:

'9 k\li4`ig. l is a vertical section on the line l--l Fig. 2 is a transverse section on the line 2&2 of Fig, l; and

Fig. 3 is a detail` sectional View on an enlarged scale of the burner, its supporting shelf and associated parts.

--.Referring to the drawings, 1 designates a series 'of vertical still pipes, which may be for example 7 inches in diameter and approximately 40 feet in length. These are arranged in a circle, being supported preferably at 'their upper ends. 3 is an inner wall or liner of refractory material, in the form of Ia frustrum of an inverted cone. t

is the outer furnace Wal-l of the same imaterial in the form of the frustrumofan up-` right cone. It is to be observed that in cross section at any pointthese inner and outer Walls are circular as shown inA Fig. 2. At their lower ends, the still pipes 1 are all securedto a ring manifold 5, from which draW-oif pipes 6 are led Vout through the furnace Walls 4. At their upperv ends the still pipes are closed by flanged and bolted .but a very small su'rface'for the yielding up of vapor, it is necessary to provide means for preventing foaming, which I do in the formiof tanks 8th-8. Qlhese tanksare connected to the'still pipes by radial tubes 9-10, the former lying below the normal liquid level and the latter lying above it. In

addition4 to these connections, the tanks@il and 8, are connected by pipes 11 containing expansion joints 12 With the central equalizing and feeding tank 13. Below the liquid level this is connected to all of the still pipes by radial tubes 14. A gauge glass or other convenient form of indicator 15 is provided to show the liquid level in the tank 13.

lhe usual vapor line and make-Yup or feed pipe connections are shown 'at 16v and-17, connected to the tank 13, from which the feed of fresh material is equalized' to all of th-)still pipes' andthe liquid level maintained the saine throughout the system.

The fuel feed and burner mechanism is mai'fked 18, 19, 20, 21, vand 34. The pipe lengths-18, 19 and 21 are double, that is to Say an oil pipe is secured concentrically Within the steam pipe, so that at the burner 34 oil and steam are both supplied as determined by suitable valves connected `to the supply pipe 18. Centralized v'vithrespect to the still is a swivel joint 23, the outer section of which is connected to the pipe 19 and is rotated by means of a crown tooth gear 22 and gear 24 driven by shaft 25 carrying a sprocket Wheel 26. The pipe section 21 drops through an annular slot in the guard plate 20, closing the annular opening 20L in the top of the furnace.- The lower end of the pipe 21 (see'Fig. 4), passes through an opening lin the rotating shelf 27 Where a bend is produced to form a trailing burner arm 28, (see Figs.l 2 and 3), which carries a burner composed of a lpair of feeder arms 33 and 35, one carrying oil and the other steam, and a burner head34.

ferai/7e i The arms 33 and 35 are connected to thev inner and the outer pipes, respectively, of the concentric pair 18--19--21 The burner arm 28 lies beneath the shelf 27, its' end passingnp through an opening therein and carrying a T-fitting 32k toA which the 'arms' 33 and 35 are secured. The shelf 27 is annular, pierced With a'ir openings 27a, adjacent the burner, and has depending annular flanges 29 each dipping into liquid 31 in an annular trough '30, constituting the top member of an liermetically sealed enclosure 39, which communicates with the outer air through piper40, (see'Figs. 1 and 2)v the volume of air supply being-regulated bj1-,means such as the damper 41, controlled ashy an operating rod 42 from thel outside. The chamber 3 9 is of such "size and shape that Workmen may enter it through a suit-- able manhole for adjustment of the burners. When the still is in operation the air chamber and surrounding parts are cool, even the, brick' Work in Walls 3' and 4 remaining dark and at a low temperature compared with that of cracking stills as ordinarily fired.l

The burner system, including the shelf 27, isrotated lat a regular rate of speed by to and bottom gears. At the top, gear 24 1s vcarried on shaft 25, fitted With sprocket 26.

At the bottom the gear 36 meshes with crown teeth around the outer edge of shelf 27, and is driven through the shaft 37 by motor 50, which also vdrives the upper shafts 25 through sprocket chain 38 or yequivalent means. By suitably relating the Worm sprockets, gears and motor, the entire system is rotated at a uniform speed and Without racking or strain, the top guard plate sliding around the top of the furnace and pivoting at the joint 23. The shelf 27 may of course be given additional bearing support in or out of the troughs 30, and the dov`vn pipe 21 may be duplicated at 180 around the shelf to give a hanging frame, if desired. The specific arrangement of 'the burner system is immaterial so long .as it performs the functions described. rllue burner throws its flameacross the inner sides of the still pipes 1, around which it isrotated at such a rate of speed that any given spot in lany still pipe is Within the directly heated -area during each cycle vof rotation, for a period less than that in which destructive heating would occur. Since the air supply to the .annular'combustion space is only by Wayl of openings 27, there is no admixture of atmospheric air With the products of coinbustion, and the. furnace temperature and operatingconditions therein, are therefore both uniform and eicient. This effects a substantial saving in fuel, and also produces a more uniform output.

lHaving thus described means for practicingf my invention, the advantage gained b this method of subdivision when combined with rotary or other periodic heating, is apparent. rl`he active zone in which suficient heat energy for cracking penetrates the oil extends inward a limited distance from the heated shell of the still or retort. Assuming this to be say two inches, and that a six inch pipe be employed, the cross sectional area of the zone eiiiciently penetrated is greater than the Varea of the central unpenetrated zone. To heat efficiently, a high temperature source must be employed, and to prevent destructive effects as Well a's to uniformly distribute the heat, periodic interruptions of the heating and cyclicapplications thereof must be produced. IWish'it distinctly understood, however, that the present invention is in no Way limited to the specific apparatus described, but that it inay be practiced with any form of apparatus, and with any source of heat, which satisfies the requirements hereinbefore laid dolvn.

In this connection it should be noted that Wherea pipe still or the equivalent is employed, the pipe arrangement or figure adopted must be such in any case that periodic application of .heat can be made over the surface of the oil in each pipe in succession. This symmetrical arrangement of units may be for example, in a straight `line with 'an oscillating Haine, in a vertical cylinder with aninwardly pointing radial or tangential Haine, (either the cylinder or.

the fiame rotating), or as in my' prior appli- -cation hereinbeforereferred to, in acircle loil which consists in dividing the main body of oil under treatment into a plurality of connected bodies whereby the area available for the external applicationof heat is proportionately increased, intermittently and individually heating said separated bodies in periodic rotation whereby a degree of heat greater than coul; "e withstood if continuously applied may be employed Without destructive action, and dravvlng off the resultant vapors from all the bodies in common While maintaining a common liquid level with extended surface vto in the individual bodies.

In testimony whereof I hereunto aiix my signature.

FRANK E. WELLMAN.

prevent foaming

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