US1873037A - Art of cracking hydrocarbons - Google Patents

Description

Aug. 23 1932. H. RINGGENBERG ART OF CRACKING HYDROCARBONS 2 Sheets-Sheet Filed Aug. '15, 1931 INVENTOR Herman I, F/flyyenbery ATTORNEYS Aug. 23, 1932. H. 1. RINGGENBERG ART OF CRACKING HYDROCARBQNS Filed Aug. 15, 1931 2 Sheets-Sheet 2 w??? (a V 5 Ar 6 W m .w a F r m m m H 00 0 9 Z 1 ,M I m l 7 INVENTOR Mfr/77w) Z, 502 1900 bay A M /AAA,

ATTORNEYS Patented Aug. 23, 1932 UNITED STATES PATENT OFFICE HERMAN I. BINGGENBERG, OF HAMMOND, INDIANA, ASSIGNOR TO SIIICLAIR BEFININ COMPANY, OF NEW YORK, N. Y., A CORPORATION OF MAINE ART OF ORACKHTG HYDROCARBONS Application filed August 15, 1931.- serial No. 557,271.

This invention relates to improvements in apparatus for cracking higher boiling oils such as gas oil and topped crude oil to produce lower boiling oils such as gasoline. The

invention relates particularly to improvements in oil cracking apparatus comprising a heater in which oil is heated to a cracking temperature under superatmospheric pressure, an evaporator in'which the hot oil products discharged from the heater are separated into a vaporlzed fraction and a residual fraction under a lower pressure, and means for introducing relatively cool oil into the evaporator to limit continued cracking in the evaporator of the hot oil products discharged 1 from the heater.

Limitation of further cracking in the evaporator of the hot oil products discharged from the heater is sometimes designated quench- .9? ing. This operation may or may not involve cracking, in the evaporator, of the oil introduced for this purpose, depending upon the character of this oil and the conditions prevailing in the evaporator.

. The reduction of the pressure on the hot oil products discharged from the heater into the evaporator involves a number of difliculties peculiar to cracking operations carried out in this type of apparatus, particularly where the oil is heated to a high cracking temperature, upwards of 900 F., for example, in the heater. The expansion of the hot oil products, upon pressure reduction, involves a tendency toward the formation of solid or semisolid carbonaceous aggregates immediately in the region of expansion. These aggregates deposit and accumulate on the low pressure side of conventional reducing valves, or in the connections between conventional reducing valves and the evaporator, with a consequent tendency to choke the apparatus at this point rendering the operation irregular and uncertain and frequently compelling termination of the operation. These and related difiiculties are largely eliminated in theimproved apparatus of the present invention. The improved apparatus of the present invention comprises, in combination with such oil cracking apparatus, a short vertically arm ranged conduit in the lower part Of the evaporator, a discharge conduit connected to the heater and extending horizontally 'into the evaporator and joining this vertically arranged conduit at an intermediate point, the inner end of this dischar e conduit forming a valve seat at the junctlon of the two conduits, a valve plug positioned with respect to this valve seat by an operatingextension extending through the wall of the evaporator at a point across from the point of entry of the discharge conduit, and means for supplymg relatively cool oil to one end 'of this vertically arranged conduit, the other end of the vertically arranged conduit opening directly into the evaporator. Means for spraying the hot oil mixture formed in the vertically arranged conduit may with advantage be ar ranged at the end of this conduit opening into the evaporator.

In operating the apparatus of the inventlon, a flow of relatively cool oil is maintained through the vertically arranged conduit through the region of expansion immediately adjacent the junction of the discharge conduit with the vertically arranged conduit, the valve plug and valve seat controlling the expansion being arranged at this point. This flow of oil through the region of expansion minimizes any tendency toward deposition of solid or semi-solid carbonaceous aggregates in the vertically arranged conduit. From the vertically arranged conduit, the hot oil mixture formed therein is discharged into the evaporator where suflicient volume to accommodate any solid or semi-solid carbonaceous aggregates formed in any reasonable period of operation is easily provided. Con- 1 nections external to the evaporator on the low pressure side of the expansioncontrolling valve plug and valve seat are eliminated. The operating parts of the expansion controlling valve plug and valve seat within the evaporator are arranged entirely within the region of lower pressure.

The apparatus of the invention will be further described in connection with the accompanying drawings which illustrate, diagrammatically and conventionally, two embodiments of the invention. In the accompanying drawings, Fig. 1 is a fragmentary 3 is an elevation, partly in section and with parts broken away, of an apparatus embodyin the invention.

11 the apparatus illustrated in Fig. 3, charging oil is forced, by means of pump 4,

1 through the heater 5, in the heater 5 this oil is heated to a cracking temperature, 900-97 5 F. for example, and the hot oil products are discharged through connection 6 under a superatmospheric pressure, 400-800 pounds per square inch for example, into the evaporator 7 in which a lower pressure is maintained, 10-50 pounds per square inch for example, relatively cool oil, at a temperature as high as GOO-650 F., or higher for example, is introduced into the evaporator through connection 8, the vaporized fraction separated in the evaporator 7 is discharged through connection 9, to a fractionating system for example, and residual oil is discharged through connection 10. The charging oil ma comprise raw oil or one or more higher boiling fractions separated in suchv fractionating system or a mixture of raw oil and one or more such higher boiling fractions. The relatively cool oil, introduced through v connection 8, may comprise raw oil, particularly raw oil including residual constituents undesirable in charging oil to be supplied to the heater. The reduction in the pressure on the oil between the heater 5 and the evaporator 7 in this system illustrates the reduction an expansion controlling valve.

of pressure involving the difl'ieulties to which reference has been made. In the apparatus of this invention these difiiculties are largely eliminated- In the apparatus of this invention, the heater discharge is conducted into the evaporator 7 through a discharge conduit 11 extending horizontally into the evaporator to a short vertically arranged conduit 12 which itjoins at an intermediate point. The inner end of the discharge conduit 11 forms a valve seat 13 cooperating with the valve plug 14 to form The valve plug 14 is positioned with respect to the valve seat 13 by an operating extension 15 extending through the wall of the evaporator 7 at a point across from the point of entry of the discharge conduit 11. The valve plug 14 itself is thefirst and only obstruction the heater discharge meets prior to expansion. The operating extension 15 carrying the valve plug 14 slides through a plurality of supporting blocks 16 carried by a frame 17 arranged within the evaporator 7. The operating extension 15 extends through a stufling box 18 to an appropriate mechanism, corresponding for example to the mechanism for operating a geared gate valve, operated by the hand wheel 19 and accurately positioning and fixing the position of the valve plug 14 with respect to the valve seat 13. Relatlvely cool oil is supplied to one end of the vertically arranged conduit 12 through connections 8 and 20. A spray plate 21 is advantageously positioned at the other end of the vertically arranged conduit 12 to spray the hot oil mixture formed in this vertical conduit into the evaporator rather than to permit its discharge into the evaporator as a more or less solid stream.

In the foregoing description the same reference numerals apply to the same or correspondlng parts in the apparatus illustrated in Figs. 1 and 3 and to the modified apparatus illustrated in Fig. 2.

It will be apparent that, in the apparatus of this invention, any solid or semi-solid carbonaceous aggregates formed or separated as a result of the ex ansion of the hot oil products discharged rom the heater as they pass between the valve seat and the valve plug are afforded no opportunity to deposit in the region adjacent cooperating parts of the valve. At the same time, the relatively cool oil supplied to limit cracking in the evaporator is brought into intimate contact and li rect heat exchange with the hot oil products discharged from the heater under conditions which can be maintained reasonably unier are discharged into the evaporator with".

the composite hot oil mixture discharged from the short vertically arranged conduit through which the relatively cool oil is supplied and into which the hot oil products discharged from the heater are expanded. Such aggregates may deposit in the lower end of the evaporator but since adequate volume is easily providedat this point to accommodate such material this is at 'most of but minor consequence. I The several features of the apparatus cooperate to make possible uniform operation over long periods of time.

I claim:

1. In combination in oil cracking apparatus comprising a heater in which oil is heated to a cracking temperature under superatmospheric pressure and an evaporator in which the hot oil products discharged from the heater are separated into a vaporized fraction and a residual fraction under lower pressure, a short vertically arranged conduit in the lower part of the evaporator, a discharge conduit connected to the heater and extending horizontally into the evaporator and joining said vertically arranged conduit at an intermediate point, the inner end of said discharge conduit forming a valve seat, a valve plug positioned with respect to said valve seat by an operating extension extending through the wall of the evaporator at a point across from the point of entr of said discharge conduit, and .means or supplying relativel cool oil to one end of said vertically arrange conduit, the other end of said vertically arranged conduit opening into the evaporator.

2. In combination in oil cracking apparatus comprising a. heater in which oil is heated to a cracking temperature under superatmospheric pressure and an evaporator in which .the hot oil products discharged from the heater are separated into a vaporized fraction and a residual fraction under lower pressure, a short vertically arranged conduit in the lower part of the evaporator, a discharge conduit connected to the heater and extending horizontally into the evaporator and joining said vertically arranged conduit at an intermediare polnt, the inner end of said discharge conduit forming a valve seat, a valve plug positioned with respect to said valve seat by an operating extension extending through the wall of the evaporator at a point across from the point of entry of said discharge conduit, means for supplying relatively cool oil to one end of said vertically arranged conduit, and means arranged at the other end of said vertically arranged conduit for spraying the hot oil mixture formed therein into the evaporator.

In testimonylwhereof I afiix my si ature.

HER AN I. RINGGENB RG.

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