US1678728A - Treating hydrocarbon oils - Google Patents

Description

July 31, 1928; 1,678,728

. W. S. HADAWAY, JR

TREATING HYDROCARBON OILS Filed Sept. 15, 1925 Syvum/woz SMM 5, MB1

Patentecl July 3l, 1928.

UNITED STATES PATENT OFFICE.

'WLLIAM S. HADAWAY, JR., OF NEW ROCHELLE, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE TEXAS COMPANY, F NEW YORK, N. Y., A CORPORATION or DELAWARE.

TREATING- HYDROCARBON OILS.

Application led September 15, 1923. Serial No. 662,821.

This invention relates to improvements 1n carrying on the conversion o f high boiling hydrocarbon into lower` boiling. ones, such as gasoline and other similar products.

5 The invention has special reference to a method of cracking in which the bulk of" the heat required for the cracking operation is ap lied to theoil lin a heating zone separate to a degree at least, from the main cracking zone. If all of the heat required for cracking be applied to the vessels in which the cracking operation is taking place, it is difficult to prevent the formation of injurious deposits of carbon on the walls 16 of the vessel.

far as possible, the application of material heat to the walls of the cracking chamber itself and the problem presentedis to inain tain the cracking temperatures in this ves- 20 sel Without the application thereto of high external heat.

The primary objectof the 'present inventionis to provide a rocess and apparatus by which it is possib e to maintain the required cracking temperature in the cracking vessel without the application of high internal heat thereto.

For the purpose of describing the invention in detail, reference is had to the accompanying drawings, wherein Fig. 1 is a diagrammatic elevation partially in section of an apparatus constructed `in accordance with the invention constituting an embodiment thereof Fig. 2 is an enlarged section taken on the line 2-2 of Figure -1.v

Fig. 3 is an enlarged section taken on the line 3 3 of Figure 1.

` Fig. 4 ,is an enlarged section taken on the .40 line 4 4 of Figure 1.

Referring nowto the drawings it will be seen that the apparatus thus illustrated einbodies a heating coil 10 and a cracking still or converter 11. lThe coil 10 is positioned in a furnace adapted to heat the oil passing through the coil to the temperature desired and may, for example, be an oil or gas fired furnace.' The outlet 13 of the coil communi- Cates with the crackingvessel 11 which is preferably provided with insulation 14 but may, if desired, be positioned in a furnace or chamber by which it may be subJected to It i's desirable to avoid, sok

comparatively moderate heating. Thus for example, the cracking chamber may be arranged to be heated by means of waste gases from the furnace 12. The oil to be treated 4 is drawn by a pump 15 from a suitable source of supply and charged through the pipe 16 to the heating coil A10. If desired, the oil may, before being introduced to the coil 10, be passed through such exchangers, economizers, preheaters, and the like, as may be desired, the use of which structures is well known in the art and need not be described in detail herein.; I If distillation be carried on during the cracking operation, the vapors may be removed b means of a vaporline 17 which may lea Ato preliminary fractioning or condensing means 18, such as bubble towers, air condensers or the like, by which the products of heavier boiling point than that desired may be condensed. These heavier products may be passed into a line 19 and by means of a pump 20 or other suitable means re- 75 turned to the pipe 16 and thus discharged into the heating coil 10. -A vapor line 21 extends from the separator 18 to a condensing coil 22. The outlet of the condenser leads to a receiving drum 23 wherein the 80 condensate may be collected. The cracking vessel may be equipped with a pipe 24 for removing residue.

In the apparatus thus illustrated, a single converter 11 is shown. It is to be under- 85 stood, however, that a' plurality of converters may be employed, if desired, and in fact it is generally preferable to use two or more converters. The apparatus shown is adapted for carrying on the conversion process Wit-h simultaneous distillation. If desired, however, the cracking may be carried on in a closed type of converter Without distillation, the synthetic crude oil bein drawn off for subsequent distillation of the light products formed.

A. charging line 13 communicates with a multi-tubular conduit 25 which is in heat exchange relation with the contents of the stillor converter 11. As illustrated the pipe 13 enters the bottom of the vessel 11 and terminates in an annularheader 26. A plurality of tubular members extend from the header 26 thus forming a ring of pipes concentric with the vessel 22. As illustrated the pipes are preferably positioned adjacentv ner as is desired. In the apparatus illustrated the tubular members are shown as being arranged in multiple but they may, if desired, be in series, or in several sections comprising tubular members in series, or various other modilications may be made.

The converter is preferably provided with agitating means, such as i's'disclosed in a copending application of mine filed on even date with the present application. Thus the vessel may be provided with a shaft 27 carrying a plurality of propellers or stirrers '28. The shaft may be rotated by any convenient means. It is shown as being turbine operated, a turbine 29 being arranged in a turbinev casing 30 to which an impelling fluid is supplied by a pipe 31 and removed by a pipe 32. If desired, the stirring or agitating mechanism may be arranged to impart heat to the contents of the vconverter as is disclosed in my co-pending application previously mentioned.

In practicing the invention with the apparatus illustrated, the oil to be treated is brought to the desired temperature in the coil 10, and is then discharged through the pipe 13 into the heat exchanger conduit 25. The passage of the heated oil through the coil 25 tends to maintain the required temperature in the converter. It is generally preferable to have the coil adjacent the wall of the converter so that the heated oil may be passed through the Zone that is most exposed .to loss of heat through radiation. The heated oil after passage through the tubular exchanger is discharged into the converter. By agitating the contents of the converter, the heat diffusion is increased, thus assisting in maintaining the required temperature in the converter and at the same time the carbon formed is held in a state of suspension in the coil so that it may be readily drawn off with the liquid when so desired. 4

In operating the process the apparatus is preferably maintained under pressure or at least the coil 10 and cracking chamber 11 are held under superatmospheric pressure.

It is preferable to so heat the oil as it passes through the coil 10, that as it is discharged into the heat exchange conduit it is at a somewhat higher temperature than that desired to be maintained in the body of the liquid within the converter, in thisway obviating the necessity of having to apply high temperature external heat to the wall of the converter. By carrying a temperature in the outlet of the pipe13 of, for exam le, 25, 50 or 100 F. or more in excess of t at desired in the cracking vessel 11, the required temperature therein may be readily maintained. Thus, for example, the temperature of the oil passing through the pipe 13 may be held at say about 800 to '850 F. in order to maintain a temperature of say about 750 to 775 F. in the cracking still. The temperaturedifl'erential between the coil 10 I5` and the converter 11 will vary considerabl with thedilerent factors of operation suc for example, as the size of the apparatus used, whether the converter be insulated or be subjected to moderate heating, and other variable elements.

It may be noted that by carefully regulating the passage of the oil throng the coil 10 and the application of heat thereto, the oil may be brought to a high cracking temperature in the coil outlet but discharged into the coil 25 or the converter 11 before any material decomposition has taken place, and a temperature thus maintained in the converter which, while more or less below that of thev coil o utlet, is nevertheless adequate for a rapid rate of decomposition.

In this way, the application of heat to the metallic walls of the vessel in which the cracking operation is taking place is obviated, thus preventing the deposition `of carbon on the walls of the converter.

If agitation be carried on in the converter either 'by mechanical means of by the discharge of fluid thereinto, the carbon formed in the process will be maintained in suspension and may readily be removed from the system by being drawn olf from the converter through the discharge pipe 24.

. Obviously, various modifications of the invention may b e effected without departing from the spirit and scope of the invention. The true scope of the invention is defined in the appended claims.

What I claim is:

1. Apparatus for converting higher boiling hydrocarbons into lower boiling ones comprising a vertical cracking chamber, a multi-tubular exchanger disposed longitudinally within the cracking chamber and formed with outlets at the upper end thereof, means for introducing oil into the bottom of the exchanger, mechanical means for agi-4 tating the contents of the cracking chamber and means for drawing ofi' liquid from the 120 bottom of the cracking chamber.

2. Apparatus for converting vhigher boiling hydrocarbons into lower boiling ones comprising a vertical cracking' chamber, a

heating coil, a multi-tubular exchanger disposed longitudinally within the cracking chamber and formed at the top with outlets adapted to discharge fluid intoA the upper portion of the cracking chamber, means interconnecting the heatmg coil with the bottom of the multi-tubular exchanger so that heated fluid may be passed'fromthe coil into the exchanger, mechanical means for agitating the contents of the cracking chamber and means for drawing off liquid from the bottom of the cracking chamber.

3. Apparatus for converting higher boiling hydrocarbons into lower boiling ones comprising a vertical cracking chamber, an exchanger formed of a plurality of tubes extending longitudinally within the cracking chamber adjacent the periphery thereof and formed with outlets at the upper ends thereof, means for' introducin exchanger, mechanical means or agitating the contents of the cracking chamber and means for drawing off liquid from thev bottom of the cracking chamber. v

In witness whereof I have hereunto set my hand this 12th day of September, 1923.

WILLIAM S. HADAWAY, JR.

oil to the-

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