US1561758A - Apparatus for distilling oil - Google Patents

Description

G. W. WALLACE Filed May 20, 1922 4 Sheets-$heet l iiil G lwtyToR 1 20/99 a ace 7-..

1,561,758 G. W. WALLACE APPARATUS FOR DISTILLING OIL Filed May 20I 1922 4 Sheets-Sheet 2 BY 4068/ A HT TORNEYS Nov. 17, 1925. 1,561,758

G. W. WALLACE APPARATUS FOR DISTILLING OIL Filed May 20, 1922 4 Sheets-Sheet 3 [NVENTUFF' George W W0//0ce ATTORNEYS Nov. 17, 1925. 1,561,758

G. W. WALLACE APPARATUS FOR DISTILLING OIL Filed May 0, 1922 4 Sheets-Sheet INVENTOF? George W waflace ATTORNEYS I Patented Nov. 17, 1925.,-

UNITED STATES PATENT OFFICE.

- GEORGE w. WALLACE, or nnsr s'r.. LOUIS, ILLINOIS.

APPARATUS FQR DISTILLING OIL.

Application filed May 20, 1922. Serial no! 562,500.

To all whom it may concern:

Be it known that I, GEORGE IV. W'ALLAcE, a citizen of the United'States, residing at East St. Louis, Illinois, have invented a certain new and useful Improvement in Apparatus for Distilling Oil, of which the following is a full, clear, and exact description, such as will enable others skilled in the art 'to which it appertains to make and use the same.

This invention relates to an apparatus for cracking oils.

An object of this invention is to provide a pressure still for cracking oils that is more eflicient than the oil cracking stills now in general use, easier to control and also safer. Another object is to.provide-a pressure still for cracking oil that is equipped with' an etlicient means of novel construction for continuously removing carbon from the heated surfaces of, the still when the still is in operation, thus making it particularly adapted for cracking shale oil, owing to the "fact that considerable quantities of carbon are formed in cracking shale oil.

And still another object is to provide an oil cracking still which is ofsuchconstruction that the carbon produced by the cracking operation is recovered in the form of a soft, flocculent precipitate known commericially as carbon black. Other objects and desirable features of my invention will be hereinafter pointed out.

To this end I have devised a process, which, briefly stated, consists in distilling oil in a still under a pressure sufiicient to keep the oil in a. liquid state, causing the light hydrocarbons produced by said distilling operation to pass through a dcphlegmator or fractionating column which is maintained under approximately thesame pressure as the still and when'so arranged, conducting the light hydrocarbons from the dephlegmator through a condenser which is maintalned under approximately the same pressure as the deph egmator and still, and subjectin the heavy hydrocarbons separated from the light hydrocarbons in the dephleging conducted from the dephlegmator to a condenser and the heavier hydrocarbons be- 1ng conducted from the dephlcgmator back to the still or to a separate still in which they are subjected to a further cracking operation. I am aware of the fact that it is old to crack or-destructively distill oil under pressure in a still also that it is old to then pass the light hydrocarbons thus formed through a condenser that is maintained at substantially the same pressure as the still, and conduct the light hydrocarbons produced by the cracking operation through a dephlegmator and then through a condenser, either or both of which are maintained at substantially the same pressure as the still, and causing the heavy hydrocarbons that are separated from the light hydrocarbons in the dephlegmator to be the still the heavy hydrocarbons separated in the dephlegmator while said heavy hydrocarbons are in a heated state.

Various kinds of apparatus may be used in practicing my process, but I refer to use an apparatus composed of a sti l of such design that the quantity of oil in the still at any given time per square foot of still heating surface is materially less than the amount of oil in the conventional oil cracking still, and provided with means for preventing carbon from cakmg on the heatmg surfaces of the still, a dephlegmator or fractionating column of any suitable type or kind connected with the still in such a mantion from the liquid oils condensed in the condenser.

Figure 1 of the drawings is a diagram matic view, illustrating an apparatus constructed in accordance with my invention for practicing my process. t

Figure 1 is a diagrammatic view, illustrating a slight change that can be made in said apparatus.

. Figure 2 is a vertical longitudinal sectional view of the still and the furnace thatis used for heating same.

Figure 3 1s a front elevatlonal view of the still proper.

' Figure 4 is a detail vertical sectional view,

illustrating a portion of one'type of dephlegmator that may be used.

Figures 4 and 4" are similar views, 11-

lustrating other types of dephlegmators that may be used; and

Figure 5 is a perspective view, illustrating one type of-condenser that may be used.

Referring to the drawings which illustrate the preferredform of my invention, A in Fi ure 1 designates an oil cracking still, B designates a dephlegmator or fractionating column, C designates a condenser and D. designates a gas'and liquid separatingdevice connected with the outlet of said condenser. The oil that is to be cracked is preferably fed into the lower end of the still A through an oil supply pipe 1 and the gases and vapors that are evolved in thestill are conducted from the upper end of the still through a'pipe 2 that leads to the lower end of the dephlegmator B. The light hydrocarbons that are separated from the heavy hydrocarbons in the dephlegmator are conducted from the upper end of. the dephlegmator through a pipe 3 that leads to'the condenser C and the heavy hydrocarbons are conducted from the dephlegmator through a pipe 4 that leads from the lower end of the dephlegmator. The fixed gases produced in the cracking operation and the liquid oilthat is condensed in the condenser pas. from the condenser through a pipe 5 into a suitable separating device D, wherein the gases are separated from the liquids, the gases escaping through a discharge pipe 6 leading from the upper end of the separating device D and the liquids escaping through a liquid discharge pipe. 6 leadin from the low er end of. said device. A va vs 7 is provided for dephlegmator and condenser are to be main tained at a pressure different from the stillpressure, the valve '7 ma be arranged at any suitable place to pro uce-the result.

I Still. a The still A is preferably of the construc-.

-tion illustrated in Figures 2 and 3 and consists of two banks of tubes 8 and 9 arranged preferably in parallel relation, and preferably vertically disposed with one-bank positioned in front of the other, an upper header 10 consisting of a transversely-dis posed drum connected to the upper ends of bothof said banks of tubes and a lower header 11 consisting of a transversely-dis posed drum connectedto the lower ends of both of said banks of tubesfthe tubes constituting each bank being spaced apart, as

shown in Figure 8. -Any suitable means can be used for heating the tubes 8 and 9, but I prefer to arrange said tubes in a passageway 12 through which products of com bustion travel'from the combustion chamber 13 of a furnace, said passageway 12 being connected'at its upper end to an uptake flue 14 that leads from the combustion chamber of the furnace and being connected at its lower end to a stack flue 15, as shown in Figure 2. The passageway 12 and the fiues 1 1 and 15 with which said passageway communicaTtesare preferably formed in masonry, and the u per and lower headers 10 and 11 of the still path of travel of the products of combustion. Fuel oil, gas or any other suitable means can be used to heat the still, and while I are arranged outside of the prefer toliave the products of combustion enter the upper end of the passageway 12 and circulate downwardly through. same longitudinally of the tubes 8 and 9 of the still, as indicated bythe arrows in Figure 2, I do not wish it to beunderstood thatit is essential-that the still be heated in this particular manner, although this is the preferably way of heatingthe still, as it produces a still in which the rate of heat transfer is materially higher than in the conventional oil cracking still, due to the fact that the hot gases first come in contact with. the upper part of the still where the gases are. most efficient for cracking the oil.

The oil to be-cracked is preferablyintro duced into one end of the bottom header 11 of the stillthrough the oil supply pipe 1. and whenvthe still is in operation, the oil circulates rapidly through same and is maintained at vsubstantially the level indicated by the dotted line a: in Figure 2. Due to the fact that the oil circulates rapidly through the tubes of the still, it comes in contact with walls that are always maintained in a highly heated condition, thus insuring rapid-heating of the oil, uniform mixtirre of the oil, and consequently, securing a uniform thermal reaction. As the 1 upper header is only partially filled with liquid oil, the upper portion of said header forms a vapor chamber wherein the products resulting from the cracking reaction are liberated and from which said products escape through the pipe 2 that leads to the dephlegmator. If the apparatus comprises a battery of stills, it is preferable to provide the apor discharge pipe 2 of each still with an automatic safety check valve 16 that closesautomatically when the pressure in a particular still becomes less than the pressure in the other stills and which opens automatically when the pressure in said still thereafter returns to normal. The upper header 10 of the still is also provided with a safety valve 17 that discharges into a reservoir or container (not shown) and which is of sufiicient size to instantly relieve excessive pressure in the still. Ifdesired, valves 18 and 19 can. be arranged in the -vapor discharge pipe 2 of the still on opposite sides of the automatic check valve 16, so as to enable repairs to be made on said automatic valve when the still is in operation.

- In order to prevent carbon from caking on the interior of the tubes 8 and t) and thus causing the tubes to burn out, means is provided for scrapingolf the carbon that collects on the interior of said tubes so that said carbon will fall downwardly to a point where it can be easily removed. on herein illustrated the means that is used l'or this purpose consists of endless chains 22 arranged in oppositely-disposed tubes of the front and rear banks of tubes 8 and t), ,as shown in Figure 2, horizontally-disposed shafts 23 and 2-1 in the upper and lower headers 10 and 1.1. respectively, equipped "'9 with sheaves or other suitable wheels 25 around which the chains :22 travel, means such as a belt 26 for rotating one of said shafts, so as to cause the chains 22 totravel upwardly through the tubes of one bank and downwardly through the tubes of the other bank, and thus scrape Qfi" any carbon that deposits on the interior of said tubes and cause said carbon to fall downwardly into a collection chamber 2-7 that extends longitudinally of the bottom header 11 at the underside of same. If desired, the chains 22. can be operated in such a manner that the direction of movement of same is reversed automatically at stated intervals; lVhile I prefer to provide the still In the form of my inven-.

wheels, such as illustrated in' Figure 2, that co-operate with endless chains which travel through pairs of tubes that are spaced close together and provided with larger sheaves or wheels that co-operate with endless chains which travel through pairs of tubes that are spaced farther apart. A hoe or other scraping device 28 that is arranged inside of the carbon collect-ion chamber 27 is connected to an operating rod 29 that, projects outwardly through a stufiing box 30 in one end of the carbon collection chamber 27, as shown in Figure 3, thereby permitting the carbon that drops downwardly into said chamber to be moved longitudinally of the chamber into a discharge pipe 31 that leads from one end of same, said carbon discharge pipe being preferably provided with a valve 32 that is normally closed. If desired, the drums that are used to form the upper and lower headers of the still may be provided in their end walls with manholes normally closed by covers (not shown), so as to facilitatc the cleaning of the interior of, the drums, and the soot that collects on the exterior of the tubes 8 and 9 can be removed from same by means of soot blowers or other devices that are commonly used for removing soot from the exterior of the tubes of a water tube boiler.

In a still. of'the construction above described the quantity of oil in the still at any given time per square foot of still heating surface is a small fraction of the amount of oil in an ordinary oil cracking still, thus materially reducing the fire hazard. An other thing that contributes to the safety of the still is the arrangement of the upper and lower headers 10 and ll outs ideof the path of travel of the products of combustion used to heat the still and the arrangement of the tubes 8 and 9- in a passageway that communicates directly with the stack flue through which the products of combustion escape from the combustion chamber of the furnace. For example, even if one of the tubes materially reduces the fire hazard, as said means is of such design that it is a simple matter to keep the interior of the tubes clean and free from carbon deposits. Moreover, as the carbon, that is removed from the tubes falls down into a carbon collection chamber that is equipped with a hoe or other scraping device which can beoperated from the exterior of said chamber, it is not necessary to shut down the still at stated intervals so as to remove the carbon from same, as is. necessary with the .oil cracking stills now The chains "that travel in general use. through the tubes of the still insure a rapid circulation of the oil through the still in the direction in Which the chains travel, and as,

said chains travel continuously through the tubes and. rub against the interior of the tubes, it is practically impossible for carbon to cake on the interior of the tubes; The result is that the carbon which is recovered I from the collection chamber 27 is in tl e form of a soft, fiocculent precipitate that is commercially known as carbon black.

Dephlegmator.

Various types of dephlegmators can be used for separating the light hydrocarbons from the heavy hydrocarbons so as to cause only that fraction of the cracked oil which enters into the finished product to be'supplied to the condenser. and for causing the fractions which have not been sufficiently decomposed to be returned to the still or to a Separate recracking still. In Figure 4 of the drawings .1 have illustrated one type of 'dephlegmator that may be used which is composed of a vertically-disposed, cylindrical shell 34 provided with a funnel-shaped lower portion 35 and having a number of i horizontally-disposed trays t arranged inside of same, one above the other. Arranged in.-

side of each of the trays t is a substantiallyinverted, cup shaped bafiie b that is provided with adependingtube'd which projects downwardly through the bottom of the tray, said tube having ,orific'es a at the. upperend of same and said bafiie having a serrated or saw-toothed ed e flange "of that is normally submerged in the liquid oil in the tray.

When the apparatus is in n rm'al operation,

the trays t will-be filled witi liquid oil that has been'condensejd from the vapors-passing from the still intothe lower end of the dephl'egmator.- The vapor that enters the dephlegmator travels upwardly through the i tube (Z on the baflie in the bottom tray, and

I upon reaching the upper end of said tube;

escapes through the orifices o in same and, thence'downward-ly through the liquid oil inthe tray, the unconden'sed'vapors escaping hnder' the serrated flange on the bafile, and

finally, escaping-upwardly through'the' oil in I the tray. After escaping from thebottom tray the uncondensed vapors pass successively through the various other trays of the dephlegmator, thereby ensuring a very complete separation of the light hydrocarbons from" the heavy hydrocarbons. The light hydrocarbons pass from the upper end of the dephlegmator into the condenser, and the heavy liquidhydrocarbons that collect inthe trays t escape therefrom through the orifices oiin'the tubes 03 and drain down to the heavy hydrocarbon return pipe leading from the lower end of the dephlegmator.

also comprises a vertically-disposed shell 35 having numerous horizontally-disposed wooden trays t arranged inside of ,same,

one above the other and spaced apart so as- The dephlegmator illustrated in Figure F1 of a vertically-disposed shell 35" filled with o small pieces of porcelain, fire brick, coke or any other suitable friction producing mate-i rial up through which the vapors circulate.

Irrespective of the particular type or kind of dephlegniator that'is used, the dephlegmator will be provided at its lower end with a vapor inlet through which the vapors can enter from the vapor discharge pipe 2 of the still, a return pipe 4 through which the heavy hydrocarbons can be returned'to the point where they are subjected to a further 3 cracking'operation, and an outlet pipe 3' leading from the upperlend of same to the condenser. While I have herein illustrated the return pipe 4 as being connected to the oil supply of the still, th s is not essential,

for if desired, said return pipe could lead to the upper end of the still or to a'separatc. re-cracking still, or through a suitably heat exchange device.

I I Condenser. 'lhepai 'ticular type or kind of condenser that 1s used 1s also, nnmaterial, the condenser shown in Figure 5 consisting of a container 40' filled with water and equipped. with it pipe coil 41 having its inlet end connected to the discharge pipe 3 leading from the dephlegniator and its discharge end connected to the discharge pipe 5-which leads to the liquid and gas separating device.- D.

, Operation.

To start the apparatus the still is filled with pi]; up to the approximate oil level indicated by the dotted line a in Figure 2 and a fire isstarted in the furnace that is com- "bined with the still. When the pressure of the oil and the pressure in the still reaches the desired point, the vapor in the vapor space in the upper header of the still will escape from the still through the vapor pipe 2 to the. dephlegmator: Until the dephlegmatoris thoroughly warmed, practically all of the vapor entering same will be returned to the'still or to the re-cracking still through the heavy hydrocarbon .return pipe 4 that leads from the lower end of the dephlegmatorl When the apparatus is thoroughly warmed up, liquid oil will-begin to discharge from the condenser, the vapor and gases lib erated in the still passing into the dephle gmator, wherein the light hydrocarbons are separated from the heavy hydrocarbons, and said light hydrocarbons thereafter admitted to. the condenser and said heavy hydrocarbons thereafter returned to the point where they are subjected to further cracking. The

valve '7, which may either be in the discharge pipe 5 leading from the condenser or the fixed gas discharge pipe 6 leading from the device D is adjusted so as to maintain the desired pressure in the various elements of the apparatus through which the vapors pass. As the light hydrocarbons are eifectively separated from the heavy hydrocarbons in the dephleg'mator, the liquid oil that is obtained in the condenser is a clean product that requires less chemical treatment to convert it into motor fuel than the product of the conventional oil cracking apparatus. Moreover, the heavy hydrocarbons that are recovered in the dephle gmator are returned for re-cracking while they are in a heated condition." From the foregoing it will be seen that my process insures a'high yield of a clean product th-atcan be refined. into -motor fuels with minimum trouble and expense,"

and the apparatus that I have devised for practicing my process is easy to control and is safer than the conventional oil. cracking apparatus.

Having thus describedmy inventiom'what I claim as new and desire to secure by Letters Patent is:

1. A still for cracking oil, comprising a plurality of banks of tubes arranged in'parallel relation and adapted to containoil that is tobe cracked, means foiexternally heating said tubes, headers communicating with the opposite ends of said tubes, endless car- "bon removing devices arranged 1n oppositely-disposed tubes of the respective banks, andmeans for moving said devices longit dinally of the tubes.

A 2. A still for cracking oil, comprising a plurality of banks of tubes arranged in parallel relation and adapted to contain oil that is to. be cracked, means for externally heating said tubes, headers communicating with the opposite ends'of said tubes, endless carbon removing devices arranged in oppositely-disposed tubes of the respective banks,

and shafts arranged longitudinally of said headers and provided with wheels around which sa d carbon removing devices travel.

1 A still for cracking-oil, comprising aplurality of banks of tubes adapted to contain oil that is to be cracked, transverselydisposed headers at the ends of said tubes communicating with the tubes of the respective bhnks, a passageway in which said tubes are arranged, means for causing products of combustion to circulate through said passageway longitudinally of said tubes, endless chains arranged in oppositely-disposed tubes of the respective banks, sheaves or the likein said headers around which said chains travel, and means for actuating said chainsso as to remove carbon that collects on the interior of said tubes.

4. A still for cracking oil, comprising 'a plurality of banks of tubes adapted to contain oil that is to be cracked, transversel disposed headers at the ends of said tubes communicating with the tubes of the respective banks, a passageway in which said tubes are arranged, means for causing products of combustion to circulate through said passageway longitudinally of said tubes, endless chains arranged in oppositely-disposed tubes of the respective banks, sheaves or the like in said headers around which saidchains travel, means for actuating said chains so as to remove carbon that. collects .ly of said tubes.

'6. Astill for cracking oil, .comprising aplurality of "banks of tubes in which the oil is to be cracked, means for externally heating said tubes, headers communicating with the opposite ends, of said tubes, endless devices mo'vab le longitudinally thru said tubes to dislodge carbon from the inner surfaces thereof'and convey the carbon from the tubesyf .GEORGE w. WALLACE. I

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