US1418713A - Process of and apparatus for cracking oils - Google Patents

Description

e. L. HOXIE. PROCESS OF AND APPARATUS FOR CRACKING OILS,

APPLICATION FILED AUG .9, I918.

Patent-ed June a, 1922.

2 SHEETSSHEET I.

n Co/wE/vsms flux/marry STILL G. L. HOXIE.

PROCESS OF AND APPARATUS FOR CRACKING (ms.

APPLICATION FILED AUG-9. I918.

1,418,718. PatentedJune 6, 1922.,

2 SHEETS-SHEET 2.

To all 'wlwm'it may concerh:

' GEQB-G-E I. HOXIE, OF UPPER MONTGLAIR, NEW J PRQCESS OF AND lAIEPARATU S FOR dRACKING: OILS,

i mi Be it known that I, GEORGE L. HoxIE, a citizen of the United States, and a. resident of U per Montclair, in the county of Essex and fate of New Jersey, have invented certain new and useful Improvements in Processes of and Apparatus for Cracking Oils, of which the following is-a full, clear, concise, and exact description, such as will enable others skilled inthe art to which the invention relates to make and use the same, reference being made therein to the accom panying drawings, which form a part of this specification.-

My invention relates to v the treatment of liquid hydrocarbons such, for example, as petroleum in the crude form in which it is obtained from the earth, or after a part of the more volatile'constituents thereof have been removed therefrom by fractional dis; tillation; the object of said treatment or process being to increase; the amount of sirable liquid hydrocarbons, such for examlighter and more volatile'hydrocarbons obtained from a given quantity of crude or partially refined petroleum or crude oil. In processesv of the class to which my invention relates the liquid hydrocarbon is heated to a comparatively high temperature, which results in the decomposition or breaking up of some of the. constituents of the hydrocarbon-being treated,.after which the volatile products thus produced are collected and condensed; such processes being commonly referred to as cracking? processes, the purpose of which is to'increase the'yield of the more volatile products, such as gasolene and similar light hydrocarbons, obtainable from a given quantity of crude petroleum'orsimilarliquid hydrocarbon.

, The -object s of my inyention are toprovide an improved processor method of treatment, and an improvedapparatus or devic suitablefor performing the said proc' ess, whereby, the quantity of light 'liquid; hydrocarbons, that is, those boilmg below to,

fixed boiling pointa'ssu-med as the" maxi-mum boiling point desirable, obtainable from a given quantity of. crude oil is materially in-- creased; to provide an improved method and I Specification ofLetters B'atent. Patented June 6, 1922; Application filed August 9, 1918, Serial no. 249,077.

for storage or convenientuse on the other,

is reduced toa minimum; to provide an imapparatus in which the production of un'd'e-I ple as those boiling at a temperature the high for eficient use [in an internal combusproved process and means for working the same which may be operated continuously, which may be readily controlled, and one in which the product produced will be of uniform quality so long as the operation of the process is continued; to provide a process which may be readily and cheaply carried out, and an apparatus for convenientlyand' with facility performing the process; and to provide other improvements in and relating to the processes commonly known and referred to as cracking processes for increasing the yield of the lighter liquid hydrocarbonsmbtainable from a given quantity of crude petroleum. 1 In cracking processes heretofore in use the usual practice has been to heat the entire mass of liquid hydrocarbon being operated upon to a high temperature, that is to a temperature which, from experience, has been found to increase the yield, of liquid hydrocarbons which boil at a comparatively low temperature, as in the case of gasolene, and then separate the light or more volatile hydrocarbons fr 0m. the mass ofhydrocarbon thus treated,

As distinguished above outlined, my improved process contemplates the heating to a temperature sufficient to accomplish the cracking of the liquid hydrocarbon operated upon of a small volume of said liquid, and-then adding said small quantity of heated and more or lesscomple'tely cracked hydrocarbon to a muchlarger volume of'comparatively cool liquid hydrocarbon and mixing the same,- there with; whereby the heated liquid is suddenly cooled, the cracking action'is entirely or for the most part'arrested, and the small volume of liquid hydrocarbon subjected to the ac- "tion ofthe 'lreat together with such volatile products as may have resulted from such heating-are rapidly: dispersed throughout a largefmass of similar liquid at a much lower temperature.

-,The temperature of the larger volume of liquid hydrocarbon is kept substantially lower than' the temperature best suited for cracking the liquid being operated upon;

and the said larger massfin the carrying-out from the old processes a of my process in its preferred form, and by means of the preferred form of apparatus provided for that purpose, and after the process is in operation; is made up of fresh untreated liquid hydrocarbon, of liquid hydrocarbon which has been subjected to a cracking temperature but the volatile products thus produced not separated therefrom, and of heavier liquid hydrocarbon the residue left after drivin off the more volatile constituents from previously heated liquid, and which residue is being continually worked over.

It therefore follows that in the carrying out of my improved process small quantities of liquid hydrocarbon are being continually heated to a cracking temperature and that said small quantities are immediately, and without attempting to separate the more volatile products thus produced therefrom, added to and mixed with and more or less dispersed throughout a much larger volume of liquid hydrocarbon maintained at'a much lower temperature; there being no attempt to separate the light or volatile hydrocar bons produced by the heating from the identical volume of liquid subjected to the cracking temperature as by distilling them off at or substantially at the cracking temau perature, and under such conditions as to pressure as'may be necessary in order to accomplish the distillation of such light hydro- .carbons at the inordinately high temperature required for the most eifective cracka at ing of the liquid being operated upon.

The particular mass of liquid subjected to the cracking temperature, or rather continual succession of small masses so treated has just previously been heated to such a temperature such that it vwas being cracked or decomposed into more volatile products arrests the cracking operation, and the uncrackedportion of the liquid in question as well as the lighter or cracked products produced by the heating become merged with and dispersed throughout the larger mass of cooler hydrocarbon while the lighter products are in a nascent state or condition,

as it were, and before they have separated, to as vapors or otherwise, from the heated liquid from which they were formed. After this cooling and'mixingstep or operation the said light and volatile products are driven oil or distilled from the total volume 5 or liquid hydrocarbon produced by mixing This sudden cooling of the liquid which a above the boiling point of the lighter hydrocarbons produced in carrying out the process, whereupon they will obviously pass off from the mixture in the form of a vapor which may be condensed by any suitable condenser. I prefer, however, to withdraw the mixture produced as above from the mixing receptacle and subject the same to a dis tillation process in a separate still; in which case the cracking of the liquid hydrocarbon and mixing the same with a large volume of cooler similar liquid, and the separation of the lighter hydrocarbons from the mixture thus produced, are separate and distinct steps, and are carried out by separate and distinct parts of the apparatus provided for the performance of my process. In either case the process is a continuous one, for the highly heated and cracked constituent is being continuously added to the larger mass of cooler liquid hydrocarbon, thus producing a mixture which contains, and from which the lighter and more volatile hydrocarbons may be separated. The actual separation of such light products by a distillation process is or may be continuous in the case where such process is carried out in the receptacle in which the mixing occurs, and by the inherent heat which the mixture attains when the process has been in operation for a while; and the distillation step is or may likewise be made continuousif the mixed liquid is withdrawn from the mixing receptacle and distilled in a separate distilling apparatus.

Various particular forms of apparatus may be employed in performing my im proved process, some of which are illustrated in the drawings accompanying and forming a part of this specification; althoughit will be appreciated ithat forms of apparatus other than those illustrated may be employed, so long as they are suitable for use in performing the various steps or operations in which my improved process consists.

In the said drawings Figure 1 is a view showing in a conventional manner an apparatus in which the heating of the relatively small quantity of liquid hydrocarbon is accomplished by means of a plurality of gas heated heating devices located within the receptacle containing the relatively large volume of liquid hydrocarbon, this view being a section taken upon a plane'indicated by the line 1- -1,'

Figure 2;

Figure 2 is a View showing a sectlon taken upon a plane indicated by the line 2-2, Fi ure 1;

igure 3 is a view showing a-conventional form of'apparatus in which the heating of the relatively small volume of liquid hydrocarbon to crack the same is provided for by the use of a furnace located outside the receptacle containin the relatively large volume of liquid by rocarbon;

Figure 4 is a view illustrating a form of apparatus in which the heating of the por tion of the liquid hydrocarbon which is cracked is accomplished by the use of an inductive electrical heating-device; v

Figure 5 is a View similar to Figure 3, but showing a modified form of heating means;

Figure 6 is a'view showing in a conventional manner an apparatus in which the heating is accomplished by an electrically heated resistance element located within the receptacle containing the larger volume of liquid hydrocarbon with which the heated liqluid hydrocarbon is mixed; and,

igure 7 is a view showing a conventional form of apparatus inwhich the liquid hydrocarbon being heated, as well as that with which the heated portion is mixed is in the form of a spray, the heating being accom-' plished by an electrically heated resistance element.

Referring now to the drawings, and first to the form of my invention illustrated in Figures 1 and 2 thereof, the reference numeral 10 designates a suitable receptacle or container of any desired form; the same being designed to contain the liquid hydrocar bon operated upon in the performance of my process, and of large capacity as compared with the amount or volume of liquid hydrocarbon being heated at any given time to a cracking temperature.

Located within the'receptacle or container 10 is a plurality of heating members, each designated as a whole by the reference numeral 11, whereby the small portion of the liquid hydrocarbon which is heated to such a temperature as to crack it in performing my process is heated to a comparatively high temperature, to thereby crack the liquid thus 7 heated, and decompose the same into liquid hydrocarbons having a lower-boiling point thanthat of the original liquidhydrocarbon subjected to my process. lt will be obvious, however, that a greater or less number of vheating elements than the number illustrated may be employed, as my invention is in no way concerned with a particular number of heating devices employed in a given apgaratus.

ach of the heating devices above referred to is shown as made up of a metallic tube 12 arranged in an inclined positionand extend- ,as will be appreciated.

ing from one side to the other of the receptacle 10, within which tube a heating ele ment in the form of a gaseous fuel'burner 13 is located, to thereby heat the tube, as will a v be appreciated, a suitable outlet flue or chimney 14 being provided at the upper end-of each tubular member through which the products of combustion may pass. Sur-.

rounding, the tubes 12 are tubes 15 made, preferably, of non-conducting material, such as porcelain, fire clay, or similar material; which outer tubes are spaced apart somewhat from the metallic tubes 12 to thereby provide an annular heating space 16 between the two tubes. Provision is made for the flow of a stream-of liquid hydrocarbon from, the main body of liquid contained in, the receptacle l0'into the annular space be tween the two tubes, along or through said space, and out therefrom and into the main body of'liquid hydrocarbon; so that a'continuous circulation of the liquid being thus heated to a cracking temperature will be form of my invention illustrated by openings 17 provided in the outer tube and located, adjacent the lower end thereof, and through which the cool liquidmay flow into the annular space, and other openings 18 located adjacent the'upper end of the tube and through which" the heated liquid may flow from the said space and return to the main body of liquid within the receptacle 10.

It will therefore be appreciated that when the device is in operation and the tube 12 is being heatednas above explained, a continuous flow of that porti on of the liquid hydrocarbon being treated which at any particular instant is being heated to a cracking temperature, will flow from the main body or mass of liquid contained in the receptacle 1O lnto the annular space between the tubes 'maintained; this being provided for in the 12 and 15, upwardly through and along the passage between said tubes, and out from between said tubes at the upper ends thereof; whereupon the liquid whichis thusheatQ ed returns to the main body of liquid and.

will be such as to produce the largest pos- A sible quantity of the particularly light hydrocarbons which it is desired to produce,

The portion of the liquid flowing through the annular space 16 which is actually cracked by the heating action to which it is subjected in the performance of my process, as well also as the portion of the said liquid which in practice is notactually cracked, re

turn to and mix with the main body of the liquid hydrocarbon in the receptacle 10, the

posed to radiation, and to which a fresh supply of cool liquid is commonly being supplled continuously or frequently; (and the use of the outer tube 15 of non-conducting material whereby the heat generated within and conducted to the exterior of the metallic tube 12, and to the liquid hydrocarbon flowing through the annular space 16, is not communicated or conducted to the main body of liquid, obviously contributes to the keeping of the main body of liquid at a comparatively low temperature; The main body of liquid within the chamber 10, may, if found necessary, be cooled and its temperatur thereby more positively regulated and kept materially below the temperature of the portion of the liquid which is being heated by the heating devices, by the use of separate and independent cooling means provided for that purpose; as it is obvious that the continuous mixing of the liquid which is heated to the cracking temperature with that in the receptacle. 10 will cause the temperature of the latter to rise, and that such temperature might, if uncontrolled, rise to too high a point.

It therefore follows that the cracked products produced by the heating members are carried away from the zone at which heating and cracking occurs by the stream of heated liquid, and that the uncracked portion of the heated liquid as well as the portion thereof which is cracked by the heat to which it is subjected are immediately mixed with the main body of cooler liquid within the chamber 10 while the cracked products are in a nascent state, and before they have hadtime to vaporize and become free of or to separate from the uncracked portion of the heated liquid with which they are associated; the said products being thus condensed, dissolved in, reabsorbed into, or otherwise incorporated with and dispersed throughout the much larger body of relatively cool hydrocarbon into which the heated liquid enters and with which it mixes. 1

This mixing of the heated constituent of the liquid operated upon with the cooler main portion thereof, and the consequent cooling of the said heated portion to a temperature below the cracking temperature to which it was subjected, arrests the cracking action and prevents decomposition of the cracked products, or over cracking, or the continuation of the cracking action after it may be desirable to terminate the same. The cracking action is thus controllable in my process, and may be regulated and varied in such a way as to secure uniformity in the product obtained to a greater extent than has heretofore been the case; furthermore, the process may be regulated with reference to and in such away as to produce cracked products having definite and predetermined characteristics, for the properties of the cracked roducts depend upon the temperature emp oyed', the duration of the heating action or rate of flow of the stream of liquid being heated, and other circumstances all of which are under the control of the operator.

The main body of liquid hydrocarbon within the receptacle 10 obviously becomes more or less heated after the rocess has been in operation for a time, alt ough as stated the temperature of said liquid is always materially below the temperature to which the small portion of liquid separated or differentiated from the main body thereof is heated to thereby crack the same. This heating of the main body of liquid will obviously result in the vaporization of some of the lighter and more volatile'hydrocarbons produced, which action, however, will rapidly build up a pressure within the receptacle 10 above the liquid therein, which will arrest such action and prevent the further vaporization of the cracked products produced.

In certain cases I find it desirable to subject the liquid within the receptacle 10 to a gas pressure other than that due to the vaporization of cracked products produced, and reater than the vapor tension of the liquid containedtherein at the temperature of the said liquid, to which end I have illustrated a tube 19 leading, from a reservoir 20 containing .a liquefied gas or a gas compressed to a high pressure, to the receptacle 10 and discharging thereinto above the surface of the liquid, whereby the liquid hydrocarbon within the receptacle 10 may be sub-' jected, to a as under pressure derived from the recepta e 20; the gas employed preferably being nitrogen, carbon di-oxide, hydrorovides also 1,418,713 Y I r other characteristics ofthe said products are in the container to gas pressure as above at the wbeginningof the process, after which and when the body or liquid within the receptacle has become heated, the supply of gas from the container 20 may be disco-ntinued', the pressure to prevent the vaporlzation of the cracked products being there-- after maintained by the vaporization of a small portion of the lighter and more volatile v as 'hereinbefore -jecting the same to a -which process may be carried'on iicts produced in the operation ofmy procp be. conducted in the receptacle of the said products.

It will be appreciated that after my improved process has been in operation for a time the body of liquid hydrocarbon within. the receptacle 10 will contain the cracked products which have been thus far produced, explained, the amount of such products withinthe mass of liquid being obviously dependent upon the length of I time the process has been in operation, and the temperature to which the liquid flowing past the heated device hasbeen heated; or,

as otherwisestated, upon the degree or extent'of cracking produced by the heating means. These light or volatile products will be removed from themass of liquid by subdistillation process, either in the receptacle 1001- in a still separate and distinct from the said receptacle. The distillation may be fractional whereby cracked products having different boiling points are separated from one another, or all said products boiling above a predetermined temperature may be collected as a single liquid.

In case the distillation of the volatile prodess is to I 10, such distillation will preferably be ,ac-

' complished bythe heat of the mass of liquid process and which are-contained in the. said I Ordinarily I I I I cracked liquid products-from the condenser,

containedwithin the receptacle; it being'ob- I jvious that the said mass of liquid will, after .the process haslbeen in operation for a time, have become'heated to-a thecracke-d hydrocar temperature above the boilin point of bons pro ucd in the performance of the liquid; In distilling in accordance withthis scheme it is only;necessary to provide. an outlet conduit" 21' 1 leading from the receptacle 10, which conduit .is cooled by a con- I denser-QQyWhereb-y the vapors of the cracked hydrocarbons driven off from the main body of'diquid are condensed and a liquid cracked product thereby secured,'said condu1t 21 be-' .ing preferably provided with'a valve 221 for controlling the flow therethrongh and regu lating the pressure within thereceptacle" 10. "the discharge-' of condensed or the flow of vaporfrom the receptacle -io,

will be regulated and restrained by means of a suitable ressure regulating valve; in

f orderto there y increase the back pressure leading to a still 24 of any suitable form and construction, and within whichthe liquid is distilled;'the lighter hydrocarbons passing from the still through a conduit'25 controlled at itsoutlet end by a valve 251, and the sameloeing condensed by a cooler 26 as in ordinary distilling and condensingop- I erations. As a matter of racti-ce I prefer to use both methods of distillation at one and the same time, as it is more convenient and in other respects advantageous to con-. duct such of the cracked products as are vaporized under the temperature and pressure conditions present in the receptacle 10 therefrom through a conduit controlled by a pressure regulating valve to thereby control the pressure within the said receptacle, and condense the said'products by means of a cooler like the cooler 22; while at the same time providing for the removal of liquid from the receptacle 10, which liquid obviously contains. cracked products which are not vap rized under the temperature, conditions existing in the said receptacle, into a separate still like the still 24 wherein they may be subjected to a different temperature than that of the main'body of liquid within the receptacle 10, 1

Itwill be appreciated ,thatmy improved process is a continuous one in that cracked roducts are being continuously produced by the heating memberor device, and continuously added to the main body of liquid within the receptacle 10, thus "providing a mass or' body of liquid containing cracked covered. i a I The cracked" products may in whole or in ipart be permitted to flow as vapors and continuously from the receptacle 10 through the.

v products and from which they may berei which case it follows that the; cracking of a massv of liquid introvduced' into the container may'be continued or carried on until the residue isof such a character that it may no longer be cracked; because of the fact that the residue ori-uncracked part ferentiated portion of the liquid flowing through the annular space 16 ata givenin- "stant ma jaga1n flow8thro gh said. space as been" returned' -to andm'ixed after it with the'main body of'liquid, andafter the cracked products'produced in the said po tion-havefbeen separated therefrom. 3

of any particular dif- I prefer, however, to provide for the supply of fresh and untreated liquid hydrocarbon to the receptacle 10, to which end asupply pipe 27 leads thereinto through which fresh liquid hydrocarbon. may be supplied; and, in order to insure that the liquid will be effectively subjected to the action of each of the several heating devices, I preferably provide baffle plates 28 within the receptacle 10 for causing the liquid to flow past the several heaters 11 in succession. When operating with a constant or substantially constant supply of fresh and untreated liquid hydrocarbon, as will usually be the case, the process and apparatus will be so regulated that the residue from the still 24 will-be a heavy hydrocarbon having a high boiling point, and one which it is not desirable to subject anew to a cracking process.

In the form of apparatus illustrated in Figure 3, a receptacle 28 similar to the receptacle 10- is provided for containing the. mass of liquid hydrocarbon operated upon. Communicating with this receptacle is a heating loop made up of metallic pipes 29, 30, 31 whereby a circulation of liquid hydrocarbon from the receptacle 28 through said pipes and back to the said receptacle, is maintained; which pipes pass through and are heated by a suitable furnace 32 so that the heating is accomplished by heating means located outside of the receptacle which contains the liquid being operated upon. In this form. of apparatus the liquid hydrocarbon is supplied to the receptacle through a conduit 33 which communicates with an equalizing chamber 34 to which liquid hydrocarbon is suplied by a pump 35, and into which chamber a conduit 36 leading from a source of gas under pressure discharges; and by means of which =devioe liquid hydrocarbon may be supplied under pressure to the said receptacle 28. The

heating tubes preferably contain deflectors.

37made of non-conducting material, such as porcelain, the purpose of whlch is to cause the liquid being heated to-flow adjacent the wall of the tubes whereby the liquid is more effectively heated.

Figure 4 shows a form of apparatus in which the heating of the portion of liquid hydrocarbon subjected to the cracking operation is accomplished by means of a loop 38 made of hollow piping and the ends of which communicates with, a receptacle 39 containing the liquid hydrocarbon being treated, and the ends of which loop are also preferably connected by an independent conductor 40 whereby the loop and conductor form a secondary coil, madeup of a single turn, of a transformer; the iron core of which is indicated at 40 andtheprimary coil of which is shown at 41. .It therefore follows that upon passing an alternating current through the primary 41, the secondary made up of the pipe 38 will be heated to a high temperature by induction, thus providing for the cracking ofthe liquid hydrocarbon flowing through the said tube. Figure 5 shows a form of apparatus in which the heating of the liquid hydrocarbon subjected to the cracking temperature is accomplished by means of a gas heated furnace 42 in which a loop 43 is located,'and the ends of which loop communicate with the receptacle 44 which contains the main body of liquid hydrocarbon being treated.

Figure v6 shows a form of apparatus in which the heating of the liquid is accomplished by means of an electrical heater 45 located within the receptacle 46, said heater being shown as made up of an outer tube 47, an inner core 48 and a tubular resistance member 49 spaced apart from both said last mentioned members whereby annular passages are provided; and which resistance member is heated electrically by a current of electricity conveyed thereto through an insulated terminal 50 and a second terminal 51 connected with the wall of the receptacle, one end of the heating element 49 being connected with the wall .of the receptacle as shown at 52. The members 47 and 48 are made of insulating material inorder to prevent short circuiting, and to also. provide heat insulation whereby the heating of the liquid within the receptacle 46, except by the mixture therewith of the portion of theliquid csubjected t0 the cracking temperature, is avoided. t

Figure 7 shows a form of apparatus in .which the liquid hydrocarbon is in a finely divided. form during the heating of the portion thereof which. is subjected to the cracking temperature, and when the heated and cracked products thus produced are mixed with the larger volume of unheated liquid. In the apparatus there illustrated the hydrocarbon being subjected to my process passes from a chamber 53 through an outlet conduit 54 having a nozzle or rose at its lower end, whereby the liquid is finely divided and a spray produced, said rose being located in a closed chamber 56. Located be low the nozzle 55 is a heater 57 which may be in various forms, but which is here shown as an electric heater, the said heater being in the path of the finely divided or sprayed liquid issuing from the nozzle or rose 55. Such being the case it will be obvious that the portion of the sprayed liquid closely adjacent the heater 57 will beheated to a high temperature and cracked, while the portion thereof more remote from the heater will not be subjected to such heating and era cking operation. Both the heated and cracked, and the unheated liquid pass downward through the chamber 56 and become mixed with one another at the lower portion there? 30 heating-device; and that the liquid hydroof where they accumulate, and from which chamber they pass through conduit 58 into a receiving receptacle 59. The a product which collects in this last mentioned receptacle is obviously madeup of a small volume of liquid hydrocarbon which has been highly heated and a portion of which has been cracked, together with a larger volume of liquid hydrocarbon which has not been subjected to the cracking temperature, the

' same as in the case of the receptacles in the.

various forms of apparatus heretofore de-; scribed, and the temperature of which mix- .ture is obviously low as compared with the tem erature to which the smaller portion of the iquid hydrocarbon is heated during the cracking step. This mixed liquid hydrocarbon is withdrawn from. the receptacle 59 through a conduit- 60 and treated to a distillation process in any suitable-still, as hereinbefore explained.

In view of the premises it will be appreciated that in the working of my improved process the entire mass or body of liquid hydrocarbon with which the process is concerned at any given time may properly be regarded as made up of two parts, the

' greater of which within the receptacle 10 is many times'the volume of the lesser part being heated to a cracking temperature by the I -assume that state, because of the high temimme iatelly 55.

perature employed for cracking the liquid;

but no attempt is made to separate them from "such liquid as may not be cracked .while they are in the nascent state in which the must necessarily exist at or immediate y after the instant that they.are produced. On the contrary, the said gaseous or incipiently gaseous products are pre vented from separating, physically, from theli uid from which they are produced by discharging both the cracked. and uncrac ed heated liquid into'the greatly excess volume of cooler liquid, whereby the cracked products are, before they have had an o portunity to separate as aigas or vapor, con ensed and absorbed into and become; dispersed throughout the greater mass ofcomparatively coolliquid; the cracked volas tile products being subsequently recovered performed upon the entire mass thereof, as

'from the large volume. of liquid in which they are absorbed by a distillation process distinguished from keeping or attempting to keep the cracked products inthe gaseous or vaporousform in which they are produced,

collecting them in that state and finally condensingthe vapor.

The pressure to which the liquid hydrocarbon operated upon is preferably subjected prevents the cracked and volatile products from separating from the liquid from which. they are produced until the mix ing of said liquid with the larger body of liquidhas been consummated, restrains the vaporization of the cracked products and determinesthe temperature at which they will be driven ofl from the mass'of liquid throughout which they are dispersed, and

determines the character of the cracked products resulting from the heating action as the properties of the said products depend upon the temperature and concomitant pressure conditions present at the place where the cracking occurs. The process may therefore be controlled and regulated both as to the purely physical phenomena associated therewith and as to the character or properties of the cracked products produced by regulating'the pressure to which the liquid hydrocarbon operated upon is subiected;

The temperature to which the small volume of liquid which is being continuous heated while it is separated from the main mass of liquid is heated will be a temperature suflicient to accomplish the cracking of 7 i the hydrocarbon being treated, and will vary'both with the character of the liquid being treated and the character'or boiling point of the product desired. As a general average a temperature of 650 degrees Fah renheit .or upward will accomplish the cracking. of most hydrocarbons, and will produce a product sufiiciently volatile to. take the place .of or be used with ordinary gasdlene.

It will be appreciated, however, that the temperature of the main body of liquid never rises to the cracking temperature. Its

volume is large as compared with that of the liquidbeing hracked, and the liquid being cracked -.is heated under c0nd1t1ons designed to minimize'the direct commumca .tion of heat to the main mass of liquid.

The main body of liquid is to be sure heated by the small volume of cracked hydrocarbonf dischargedthereinto to accomplish the sudden cooling of the cracked p'or'-.

'tion, but as hereinbefore pointed out the temperature of the main volume is kept substantially lowerthan the temperature best {suited for cracking the hydrocarbon operated upon. "A- temperature of 650 F. or above will ordinarily be used to accomplish to the cracking tem-peraturytthe tempera- ---ture of the main mass should be kept as l'ow,

' the cracking of the small volume subjected as possible, as the process is the more effective the more sudden the cooling of the cracked portion discharged into the main mass of liquid undergoing treatment; and thetemperature of the main mass of hydro- 1 carbon ought to be kept at least 250 or 300 degrees Fahrenheit below the cracking temperature. i

It will be appreciated that whereas a high temperature is commonly necessary to accomplish the cracking of a liquid hydrocarbon, the temperature at which the resulting product vaporizes is very much lower, in fact several hundred degrees lower in most cases. My process takes advantage of this fact and avoids, and in fact prevents to as great an extent as possible, the heating of the entire mass of liquid being treated up to the cracking temperature, as has heretofore commonly been the case; thus providing a process wherein the cracking is accomplished \by the heating of a small isolated and continuously renewed mass of liquid, which' to be sure is heated to the cracking temperature, but in which the main body or mass of liquid being treated is kept at a temperature several hundred degrees below the cracking temperature. I

Having thus described and explained my invention, I claim and desire to secure by Letters Patent:

1. In a device for cracking liquid hydrocarbons, a closed receptacle of relatively large capacity adapted to contain a liquid hydrocarbon; heating means located within said receptacle; means for causing a stream of liquid hydrocarbon of relatively small volume as compared with the volume of liq,-

uid contained within said receptacle to flow from the body of liquid contained therein past said heating means, and backinto the relatively large mass of liquid contained within said receptacle; a source of gas under pressure; a conduit leading from said source and discharging into said receptacle to thereby create a gas pressure therein, and control the vaporization of the cracked products present in the liquid within said receptacle; and means whereby the liquid hydrocarbon not heated as aforesaid is maintained in a relatively cooled condition.

2. The carbon which consists in heating a relatively small quantity of liquid hydrocarbon to a temperature sufficient to crack the same;

mixing said heated liquid immediately, and without separation of the lighter products produced by such heating therefrom, with a relatively large quantity of liquid hydrocarbon the temperature of which is maintained throughout such heating operation at a tem-v perature substantially below the temperature to which the small quantityof liquid hydrocarbon is subjected; and removing the rocess of treating liquid hydro tively large volume of liquid hydrocarbon;

isolating a'relatively small quantity of said liquid hydrocarbon; heating the small volume of liquid hydrocarbon thus isolated to a temperature sufiiciently high to crack the same; discharging the said heated liquid into the large body of liquid aforesaid below the surface thereof immediately, and without separation of the lighter products produced by such heating therefrom; maintaining the temperature of said large body of liquid'materially below the temperature to which said smallvolume of liquid hydro carbon is heated; and removing the lighter products from the mixture .thus produced by distilling thesaid mixture.

4. The process of treating liquid hydrocarbpn which consists in providing a relatively large volume of liquid hydrocarbon; continuously removing relatively small uantities of said liquid hydrocarbon from t e main body thereof; continuously heatin the liquid hydrocarbon thus removed an while it is isolated from ,the main body of liquid hydrocarbon to a temperature sufliciently high to crack the same; continuously Rreturning' the heated'liquid hydrocarbon to the main body of liquid hydrocarbon at a point below the surface thereof; maintaining the temperature of said large body of liquid materially below the temperatureto which said small quantities ofliquid hydrocarbon are heated; and subjecting the said mixture to a distilling ."pro c ess to thereby separate the lighter hydrocarbons produced liquid hydrocarbon to a temperature suih- I 'ciently high to crack the same; continuuously returning the heated liquid hydrocarbon at a-point below the surface thereof; keeping said small quantities of liquid are'heated; and subjecting the said mixture to a distilling process to thereby separate the lighter hydrocarbons produced by the heating step aforesaid therefrom. q

6. The process which consists in providcarbon to the main body of liquid hydro-W the temperature ofsaid mixture substantially below thetemperature to which ing a relatively large mass of liquid hydrocarbon; isolating a relatively small' uantity of said mass of liquid hydrocarbon eating mass of liquid hydrocarbon not heated as aforesaid at a temperature substantially lower than the temperature to which said small quantity of liquid hydrocarbon is heated.

7. The process which consists in providing a relatively large mass of liquid hydrocarbon; isolating a relatively small quantity of said mass of liquid hydrocarbon and heating the same to a cracking temperature; discharging the heated liquid into the large mass of liquid aforesaid below the surface thereof immediately, and without separation of the lighter products produced by said heating action therefrom; continuously replacing the liquid heated as aforesaid by liquid derived from said relatively large mass of liquid; and maintaining said relatively large mass of liquid at a temperature below that to which said relatively small mass is heated.

8. The process which consists in providing a relatively large mass of liquid hydrocarbon; isolating a relatively small quantity of said mass of liquid hydrocarbon and heating the same to a cracking temperature; permitting a movement of the heated liquid into the large mass of liquid aforesaid below the surface thereof immediately, and without separation of the lighter products produced by said heating action therefrom; continuously replacing the liquid heated as aforesaid by liquid derived from said relatively large mass of liquid; maintaining said relatively large mass of liquid at a temperature below that to which said relatively small mass is heated; and subjecting said large mass of liquid to a gas under pressure to thereby restrain the evaporation of volatile products therefrom.

9. The process which consists in providing a relatively large mass of liquid hydrocarbon; isolating a relativelysmall quantity of said mass of liquid hydrocarbon and heating the same to a cracking temperature; discharging the heated liquid into the large mass of liquid aforesaid below the surface thereof immediately, and without separation of the lighter products produced by said heating action therefrom; continuously replacing the liquid heated as aforesald by liquid derived from said relatively large mass of liquid; maintaining sa1d relatively large mass of liquid at a temperature below that to which said relatively small mass is heated; subjecting said larger mass of liquid to a gas under pressure; and subjecting the mixture produced by the continual discharge of the heated liquid containing cracked products into the larger mass of liquid to a distilling operation, to thereby separate the, lighter products from the said mixture.

10. The process which consists in providing a relatively large mass of liquid hydrocarbon; isolating a relatively small quantity of said mass-of liquid hydrocarbon and heating the same to a cracking temperature: discharging the heated liquid into the large mass of liquid aforesaid below the surface thereof immediately, and without separation of the lighter products produced by said heating action therefrom; continuously re. placing the liquid heated as aforesaid by liquid derived from said relatively large mass of liquid; maintaining said relatively large mass of liquid at a temperature below that to which said relatively small mass is heated; and distilling the mixture produced by the continual discharge of the heated liquid containing cracked products into the larger mass of liquid by means of the heat thus acquired by said larger mass, to thereby separate the lighter products from said mixture.

11. The process which consists in providing 'a relatively large mass of liquid hydrocarbon; isolating a relatively small quantity of said mass of liquid hydrocarbon and heating the same to a cracking temperature; discharging the heated liquid into the large massof liquid aforesaid below the surface thereof immediately, and without separation of the lighter products produced by said heating action therefrom; continuously re- 1M5 placing the liquid heated as aforesaid by liquid derived from said relatively large mass of liquid; maintaining said relatively large mass of liquid at a temperature below that to which said relatively small mass is we heated; subjecting said larger mass of liquid to a gas under pressure; and distilling the mixture produced by the continual discharge of the heated liquid containing cracked products into the larger mass of no liquid by means of the heat thus acquired by said larger mass, to thereby separate the lighter products from said mixture.

In testimony whereof, I have signed my name to this specification this 7th day of 11st August, 1918. l

GEORGE L. HOXIE.

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