US1924520A - Distilling pressure converted products by contained heat - Google Patents

Description

1933. E. J. SHAEFFER ET AL 1,9 4,520

DISTILLING PRES SURE CONVERTED PRODUCTS BY CONTAINED HEAT Filed April 10, 1925 Patented Aug. 29, 1933 DISTILLING PRESSURE CONVERTED PROD- UCTS BY CONTAINED HEAT 1 Edward J. Shaefier, George W.

Watts, and

Eugene P. Brown, Whiting, Ind., and Robert E.

Wilson, Chicago, 1

'assignors to Standard Oil Company, Whiting, Ind., a corporation of Indiana Application April 10, 1926. Serial No. 101,103

Claims. (Cl. 196-43) The prevent invention relates to improvements in the handling of pressure-conversion oil products such as the tar or residuum from pressure stills or converters in which pyrolitic conversion of hydrocarbon oils into gasoline and like products takes place. It is more particularly intended for use in connection with systems in which there is a continuous withdrawal of heated tar or residuum from the pressure system. It may also employed in connection with a system in which there are a plurality of units in which pressure distillation takes place, the withdrawal of tar or residuum from any one of such units being intermittent, but so timed with respect to the others as to give a roughly continuous supply of heated pressure tar to be operated upon. It will be fully understood from Referring more particularly to the drawing,

the numeral 5 designates a pipe receiving pressure tar or residuum or hot conversion products from a system in which pressure conversion or distillation takes place. The temperature of the conversion products thus received will usually approximate the temperature of that part of the conversion system from which it is derived; that is, it will be at least approximately the minimum conversion temperature. Thus the temperature of the conversion products received by the pipe 5 may be 600 to 750 F. or higher. The pressure upon the conversion products within the pipe 5 will be about the same or somewhat less than that prevailing in the pressure distillation or conversion system with which it is connected, in which the pressure may be 4 atmospheres upward.

The hot conversion products, such as pressure tar or residuum, entering the system through the pipe 5 pass through the pressure reducing and control valves 6, in which there is some reduction in pressure. The products passwith somewhat smoother flow through the pipe 7 and enter a chamber 8, preferably formed as a compartment in the upper portion of a tower 9. As a result of the reduction in pressure upon the conversion products after leaving the conversion system, a substantial portion thereof is vaporized, and the-vaporized portions pass out through the pipe 10 for further treatment as hereinafter more fully set forth. The unvaporized portions collect in the lower part. of the compartment 3, the maximum liquid level maintainable therein being determined by an overflow pipe 11. The partition 12 separating the compartment 8 from the lower portion of the tower 9 is preferably sloped, this slope of the partition preventing accumulations of tarry deposits and facilitating cleaning. In general, liquid does not discharge through the overflow pipe 11, but is caused to pass through a valved pipe 13 into the lower compartment 14 of the tower 9. Where the supply of conversion products to the compartment 8 is not constant, or is intermittent or in slugs the level of the liquid body of unvaporized oil in the base of the compartment 8 varies (up to the maximum determined by the overflow. pipe), taking care of such fluctuation. An approximately uniform flow to compartment 14 may thus be maintained. The compartment 14 is suitably provided with a number of baflle plates 15, which are illustrated as 01' the doughnut and disk type, although other types 01' ha!- fle plates may be employed, ii desired. The pipe 13 discharges unvaporized liquid from the com- "partment 8 at a point above the bane plates in the compartment 14, although, if desired, baifle plates may also be provided above the point of discharge of the pipe 13. A- body of liquid collects in the lower portion of the compartment 14, and a coil 16 is provided therein to which steam or other suitable inert gas, such as flue gas, carbon dioxide, hydrocarbon gas or the like may be supplied through the pipe 17 it the tar is larger in amount or lighter in quality than is desired. The steam or other inert gas thus supplied may be superheated, if desired. Ordinarily it is not superheated, and merely aids in driving oil lighter portions of'the unvaporized liquid derived from the compartment 8. lhe steam and vapors carried by it ascend the compartment 14 in countercurrent to thedescending liquid, thus effectively stripping the latter of its lighter constituents. The steam and vapors from the compartment 14 pass out through the pipe 18, which'joins the pipe 10 carrying the vapors separated in the com partment 8.

The vapors derived from the compartments 8 and 14 and passing through the pipe 10 enter a separating device 19, in which they are given. a rapid helical movement, for example, by the vanes 20, resulting in a substantial separation 01 entrained particles 01' unvaporized oil preferably without any substantial reduction in velocity o! the flow 01' the vapors and preferably with an increase therein. The separated 1mvaporized oil out of the separator 19 through a slot 21 into a smallchamber 22, from which it is withdrawn by trapped pipe 23 and returned to the upper portion of the compartment 14 where it-descends the column in the same manner'as does the unvaporized liquid supplied from the compartment 8.

desired, additional cooling may be supplied'within the tower by any desired nieans. For example,a cooling medium, preferably a hydrocarbon oil having the characteristics of the oil collected as condensate in the base of the tower may be pumped into the lower portion of the tower through pipe 2'7. The supply of such oil may becontrolled by a pressure operated valve 27", which is in turn controlled (e. g. through control line 32) by the pressure or temperature in compartment 8, so that any substantial increase in pressure and consequent increase in .fiow of vapors .to tower 25 or an increase in temvupper portion of the tower 25 through the line 29 into a condenser 30, from which the condensed liquids. pass out through the line 31.

.0 parts of the apparatus described up to the dephlegmating tower 25 are preferably well lagged with any suitable thermal insulation.

In a specific operation, pressure tar or residuiun derived from the pressure distillation of an oilof the character of naphtha bottoms was received in the pipe 5 at a temperature of about 750 F. and a pressure of about 400 pounds. 0n reduction of pressure to about 10 pounds, a substantial temperature reduction took place, the temperature in the pipe 7 being approximately 650 F. From 5 to 25% remains unvaporized and separates in the-chamber8, the vaporized portion out -.through...the line. 10. body of unvaporired oil is maintained in the base of compartment 8, its uppermost level being controlled by overflow 11. This body of oil serves as a reservoir from which a fairly smooth or constant supply of oil may be provided into compartment 14. The unvaporized portion into the tower chamber 14 and about 5 to"10% additional (based upon the original residuum supplied) may be removed in the compartment 14 by, the stripping action of the steam the compartment 14. It is of the character of an asphalt or fiuxing or road oil, and may be used, such, according to its characteristics.

The combined vapors pass through' the separator 19, anv entrained oil carried thereby being in this tower, and drawn ofif through the line 28,

this condensate having a gravity of about 23 to-25" A. P. I. This fraction is suitable for use as a cracking stock in pressure stills of other conversion devices, either alone or in conjunction with other stocks, as desired. The distillate fraction passing out of the dephlegmating tower through the vapor line 29 is condensed in the condenser 30, and may be rerun in any desired manner for the removal of its gasoline content. Inthe specific example herein set forth, the proportion of the conversion products collected as a residuum from the tower 14. amount to about 14%; those collected as an intermediate distillate from the dephlegmating tower 25 amount to about 70 to 16% and those collected as a. light distillate, consisting largely of gasoline fractions,

amount to about 10 to 15% of the original liquid conversion products delivered to the line 5.

Although a particular set of conditions have been specifically set forth herein, it is of course apparent that these should not be regarded as limitations upon the scope of the invention, as they merely illustrate a suitable set of operating conditions. They may be varied in accordance with the nature of the products which it is desired to collect; for instance, if a lighter fuel oil is desired, the temperature conditions prevailing in line 5 and in the separating compartment 8 and the stripping compartment 14 of the tower 9 may be correspondingly controlled; or,if a greater proportion of intermediate distillate product is desired, the corresponding temperature conditions. may be maintained in the We claim: V

1. The method of distilling hot products derived from a pressure conversion system by contained heat which comprises dischargingsuch products into a chamber in which a pressure below that 01' the conversion system is maintained, thereby vaporizing substantialportlons of such conversion products, removing the vaporized portions thereof, maintaining a reservoir of unvaliquid in said chamber, dischargingfrom a point below the level of said liquid separated unvaporized liquid.at a regulated rate of flow into a second chamber, contacting it with an inert gaseous materialin said second chamber, thereby removing lighter constituents therefrom, and separately conducting excess liquid from above the normal liquid level in the first mentioned chamber into the second chamber.

2. The method of distilling hot products 'derived from, a pressure conversion system by contained heat which comprises discharging such products into a chamber in which a pressure below that of the conversion system is maintained, thereby vaporizing substantial portions of such conversion products, removing the vaporized portions thereof, maintaining a reservoir of unvaporized liquid in said chamber, dis- 15o charging unvaporized liquid from said reservoir at a regulated rate of flow into a second chamber, contacting it with an inert gaseous material in said second chamber, thereby removing as vapors lighter constituents therefrom, and mixing the vapors thus removed with the vaporized portions removed from the first chamber.

3'. In apparatus for the distillation of hot hydrocarbon oils by contained heat, a tower, a partition providing a compartment in the upper portion of said tower, a conduit for hot oil leading into said compartment, means for retaining a body of unvaporized oil therein, bailie plates in said tower below said partition, means for supplying an inert gaseous medium below said bafile plates, means for supplying unvaporized oil from the upper compartment in said tower to a point in said tower below the partition, and means for sealing the upper compartment against ingress of vapors from below said partition.

4. In apparatus for the distillation of pressure conversion products by contained heat, a chamber at reduced pressure, means for supplying hot conversion products thereto whereby vaporization takes place therein, means for maintaining a body of liquid oil therein, means second chamber and adapted to carry vapors therefrom, said conduit discharging said vapors into the means for withdrawing vapors from' the first mentioned chamber.

5. In apparatus for effecting distillation of pressure converted products by contained heat, a chamber at reduced pressure, means for sup: plying hot conversion products thereto, whereby vaporization is eifected by reduction in pressure therein, a vapor conduit for removing vaporized products from the said chamber, means for maintaining .a body of liquid oil in said chamber, a second chamber provided with distilling plates, means for supplying an inert gaseous medium below said distilling plates-means for supplying unvaporized liquid from the first chamber to the second chamber above said distilling plates, a vapor conduit leading from the upper portion of the second chamber and joining the vapor conduit leading from the first chamber, means for separating entrained liquid from ,the vapors issuing from the two chambers, and means for returning separated liquid to the second chamber.

6. In apparatus for eifecting distillation of lower compartment, means for supplying an inert,

gaseous medium into the lower portion thereof, a valved conduit leading from the lower portion of the upper compartment into the lower compartment above the distilling plates therein and adapted to supply a controlled flow of unvaporretaining a liquid body, means for supplying an 1 ized liquid to the second compartment, and means for withdrawing vapor from each of said compartments. 1

7. The method of distilling hotproducts derived from a pressure conversion system-by contained heat, which comprises discharging such products in an irregular stream into achamber in-which a pressure below that of the conversion system ,is maintained, thereby vaporizing substantial portions of such conversion products, removing the vaporized portions thereof, maintaining a reservoir of unvaporized liquid in said chamber, discharging unvaporized liquid from said reservoir at a regulated rate of fiow into a second chamber, causing it to flow downwardly therethrough in thin layers in countercurrent to ascending steam, thereby removing as vapors lighter constituentstherefrom, mixing the vapors thus removed with the vaporized portions removed from the first chamber, extracting entrainment from said vapors, and returning it to the second chamber.

8. In apparatus for distilling pressure converted products by their contained heat, a reduced pressure chamber, means for supplying the hot conversion products thereto,'means for withdrawing vaporized portions of the conversion products therefrom, means for maintaining a body 'of liquid in said chamber, a second cham-{ ber, means for supplying an inert gas in said second chamber, means for causing a regulated, flow of liquid from the liquid body in the first chamber into the second chamber, and a liquid sealed overflow for conveying excess liquid from the first chamber into the second chamber.

9. In apparatus for the distillation of pressure conversion products by their contained heat, a chamber at reduced pressure, means for supplying hot conversion products thereto, whereby vaporization takes place therein, means for separately removing vaporized products therefrom, means for maintaining a liquid body therein, a stripping column having a chamber therein for inert gas in said liquid body, a conduit connecting the first chamber with the upper portion of said column and adapted to permit the fiow of unvaporized oil from the first chamber, means for regulating the fiow of .oil. through said conduit, and a liquid sealed overflow for conveying excess liquid from the first chamber into the second chamber. I

10. In apparatus for the distillation of pressure converted products by contained heat, said products being derived from the conversion of hydrocarbon oils by heat underv pressure for the formation of gasoline, an unheated separating chamber, means for conducting such residuum from 'a converting means to 'theseparating chamber, and for reducingpressure thereon before entering the latter, a fractionatingcolumn, means for discharging vapors from the separating chamber into the fractionating column, means for introducing an oil containing gasoline constitutents into the upper part of said column to effect cooling therein, means operated by pressure conditions in the separating chamber for introducing additional cooling oil into a lower point in the column, and means for with drawing vapors containing gasoline constituents from said column.

11. The method of distilling hot products'derived from a pressure conversion system by contained heat, which comprises discharging such 150 products in an irre ular stream into a chamber in which a pressure below that of' the conversion systemis maintained, thereby vaporizing substantial portions of such conversion products, removing the vaporized portions thereof, maintaining a body of unvaporized liquid in said chamber, withdrawing liquid from said body of unvaporlzed liquid at a substantially uniiorm rate of flow and discharging such withdrawn liquid into a second chamber, contacting it with inert gaseous material in said second chamber. thereby removing lighter constituents therefrom, and separate- 1y conducting excess liquid from said body of unvaporized liquid and above its normal liquid level into said second chamber.

12. The method of distilling hot products derived from a pressure conversion system by contained heat, which comprises discharging such products in an irregular stream into a chamber in which a pressure below that of the conversion system is maintained, thereby vaporizingsubstantial portions of such conversion products, removing the vaporized portions thereof, maintaining a reservoir of unvaporized liquid in said chamber, discharging unvaporized liquid from apoint below the level of said reservoir .at a regulated rate of flow into a' second chamber, causing it to flow downwardly therethrough in countercurrent to ascending steam and thereby removing lighter constituents of said liquid, and separately conducting excess liquid from above the normal liquid level of said reservoir of unvaporized liquid into said second chamber.

13. In apparatus for the distillation of hot hydrocarbon oils by contained heat, a tower, a partition providing a compartment in the upper portion of said tower, a conduit for hot oil leading into said compartment, means for retaining a body of unvaporized oil therein, bailie plates in said tower below said partition, means for supplying an inert gaseous medium below said bame plates, means for supplying a regulatable flow of unvaporized oil from the upper compartment in said tower .to a point in the tower below the partition, and a separate, vapor-sealed overflow pipe extending through said partition for determining the maximum liquid level in the compartment in the upper portion thereof.

14. In apparatus for the distillation of pressure converted products by contained heat, said products being derived from the conversion of hydrocarbon oils by heat under pressure for the formation of gasoline, an unheated separating chamber, means for conducting such residuum from a converting means tothe separating chamber and for reducing pressurethereon before entering the latter, a fractionating column, means for discharging vapors from the separating chamber into the fractionating column, means for introducing cooling 011 containing gasoline constituents into the upper part of said column, means for introducing additional coolsure on said products before entering said chamher, a fractionating device, means for conveying separated vapors from said chamber to said fraetionating device, a strlwlna column. means for supplying liquid fromsaid unheated cham- -ber to saidstripping column, means for supplying stripped vapors from said stripping colto said fractionating device, means for supon said products before entering said chamber.

a fractionating device, means for conveying separated vapors-from said chamber to said fractionating device, a stripping column, means for supplying liquid from said unheated chamber to said stripping column, means for supplying stripped vapors from said stripping column to said fractionating device, means for supplying a cooling medium in said fractionating device, and means operated by pressure conditions in the vapor space in the separating chamber and the stripping column for controlling the supply 190 of said cooling medium.

17. In the art of converting higher boiling hydrocarbons into lower boiling ones wherein the oil is subjected to regulated conditions of pressure and temperature in a conversion none to produce a residuum and .a lighter fraction, the improvement which comprises discharging the heated residuum in irregular quantities into a chamber in which a presure below that of the conversion system is maintained, thereby vaporizing a portion of said residuum, maintaining a reservoir of unvaporized residuum in said chamber, discharging unvaporized residuum from said reservoir at a regulated rate of flow into a second chamber wherein it is contacted with an inert gaseous material and a portion of said liquid is vaporized and withdrawing the vapors from each of said chambers and passing them to tem is maintained, thereby vaporizing substantial portions of such conversion products, maintaining a reservoir of unvaporised liquid in said chamber, normally withdrawing nonporised liquid from a point below the level of the-liquid and passing it to a second chamber and distilling the said liquid therein, separately withdrawing additional liquid from the first-chamber only when the liquid level of the reservoir of liquid therein exceeds a predetermined point and the liquid'so withdrawn to said second chamber for distillation therein. 19. The method of distilling hot products derived from a pressure conversion system bycontained heat, which comprises discharging such conversion products in irregular quantities into a chamber in which a pressure substantially below that of the conversion system is maintained, thereby vaporizing a portion of such conversion products and producing vapors in said chamber in varyin amounts, separately discharging the liquid portion of said products from said chamber in a regular flow into a secondchamber wherein it is distilled and a portion of said liquid is vaporized, separately with- I drawing the vapors from each of said chambers and passing them to a common iractionating Patent No. 1,924,520.

YCERTIFICATE or CORRECTION.

the liquid portion of such products from said chamber in a regular flow into a second chamber wherein light constituents are stripped from said liquid by an inert gas, separately withdrawing the vapors from each of said chambers and passing them to a common fractionating means, and controlling the conditions of operation in said fractionating means to compens'ate for the irregular supply of vapors thereto from said first-named vaporizing chamber, thereby securing a fractionated product of substantially uniform characteristics ROBERT E. WILSON.

EDWARD J. SHAEFFER.

GEORGE W. WATTS. EUGENE P. BROWN.

August 19, 1933.

EDWARD J. SHAEFFER, ET AL.

It'is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: 1 Page 1-, line 1, for i "prevent" read present; page 3, line 16, claim 3 ,(after "supplying" insert the words a regulable flow of; line 66. claim 6, after "compartment" second occurrence insert a comma;

and lines 67,

68 and 69, strike out the words "unized liquid to the second compartment, and partment" and insert instead unvaporized liquid maintained in the upper compartment; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

'Signed and sealed this 21st day of November. A. D. 1933.

(Seal) -F. hi. Hopkins Acting Commissioner of Patents.

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