US1568016A - adams - Google Patents

Description

Dec. 29

.L--l-i.A ADAMS PROCESS 0F' GONVERTINGQHYDROCARBON OILS Original Filed Dec. 5, 1917 4 Sheets-Sheet 1 i Y Y ed,

. 19a o o aan@ Dec.. 29

J H. ADAMS PROCESS 0F CONVERTING HYDROCARBON oILs original Filed Deo. 5, 1917 4 sheets-'sheet 2 Dec. 29, E925.

PROCESS-0F GONVERTING HYDROCARHON OILS Original Filed Dec. 5, 1917 4 Sheets-Sheet 3 Dec. 2599,*11925755;

J. H. ADAMS PROCESS 0F CONVERTING HYDROCARBON OILS 4 sheets-sheet d original Filed Dec. 5, 1917 mvamtoz Patented Mec, 29, 1.925,a

ld it "FFQEO JOSEPH E. ADAMS, 0F BROOKLYN, NEW YORK.

PROCESS OF. GONVERTENG HYDROCARBON OIL".

Original application led December 5, 1917, Serial No. 265,527.

Divided and. this application filed October 12, 1922.. Serial N0. 593,953.

T0 all whom t may concern:

Be it known that l, Josnri-r H. ADAMS, a citizen of the United States of America, and a resident of Brooklyn, county of Kings, and State of N ew York, have invented certain new and useful Improvements in Processes of Converting Hydrocarbon Oils, of which the :following is a specification, reference being had to the accompanying` drawings, forming a part thereof.

My invention relates to a process of cracking oil and particularly to a thermal and vapor pressure method of converting more or less refined mineral hydrocarbon oils, such as gas oil into more volatile products, such as gasoline.

rFhe apparatus illustrated and hereinafter described, as adapted for use in carrying out the present process, was invented by me but is not herein claimed since it is a part of the subject matter claimed in my Patent No. 1,320,354 granted Oct. 28th, i919 on an application filed Dec. 1st, 190).

The present application is a' continuation in part of the aforesaid patent, since it is a division of my copending application 205,527, as it was originally filed on Deceniber 5, 1917, and which itself was a continuation in part of the aforesaid patent at the time of its Vfiling but which during its prosecution became a true division of the aforesaid patent and matured as such into Patent ingame on October 24, i922.

One object of my invention is to provide a. cracking process for the purpose above indicated whereby the oil or mixture of oils is subjected to the powerful influence of an internally applied decomposing temperature, while holding the oil anal its vapors under super-atmospheric pressure.

Another-object of my invention is to pro-- vide a process which shall combine the advantages from the use of pressure, and avoid the disadvantages incident to the application of heat to the exterior walls of the cracking chamber in which oil under pressure is contained, thus obviating the baking or hardening of the carbon on the interior walls of the cracking chamber and avoiding great loss of heat resulting` from the incrustations on the interior surface, and the great danger of burning and weakening the walls which are subjected to tremendous strain by ,reason of the pressure within.

Accordingly this invention contemplates cracking oii under super-atmospheric pressure which may be self-imposed by the generation of vapors during the cracking operation, through the direct application of cracking temperatures to the body of oil under treatment through the agency of a suitable internal heating device, that is immersed within the oil and in direct contact therewith, whereby the cracking heat is effectively and locally applied to the oil. Preferably, the heating device takes the form of an electric resistor of carbon, or other suitable heat enduring material, which is submerged in a body of oil that is advantageously retained within a receptacle of restricted cross-section so that the oil therein, or passing therethrough, is necessarily in intimate contact with the heater. The heavier constituents of the evolved vapors are separated by condensation from those of desired lighter volatility and are returned or back-trapped to the cracking Zone so that they are again subjected to cracking heat, whereby further conversion thereof takes place. The vapors of desired volatility are passed on and subsequently condensed and collected. Substantially the same superatmospheric pressure self-imposed by the generated vapors is maintained throughout the separation, and cyclic back-trapping, as well as the condensation and collection of the final distillate.

Other objects of the invention and features by means of which they are attained will become apparent from the following description of the process as exemplified in the accompanying drawings.

Referring to the drawings:

Figure l is an elevation of a cracking apparatus adapted for practicing the process# f of my invention.

Figure 2 is a sectional elevation of a converter which constitutes one of the elements of the apparatus of Figure l.

Figure 3 is a sectional plan view, taken on the line lll-lll of Figure 2.

Figure l is a view corresponding to Figure l of modified apparatus which is also suitable for carrying out the process of my invent-ion.

Figure 5 is a view corresponding to Figure 2 of another modified form of converter that may be employed,

Cil

Figures G and 'i' are respectively an elevation `andL a plan view of the electricheater utilized in the converters of Figures 2, el, and drawn to a larger scale.

Figure S is a sectional plan'vie'w taken on the line VIII-VIII of Figure 6, and

Figure 9 is a partiallysectional elevation ot' the heater of Figure 6.

In Figure l the containing vessel l, of" the supply apparatus A may be sonie'what elevated with respect to the adjacent converter C, so that the gravitating tendency of the oil may A augment its `flow into the converter under the influence ot the compressed air maintained over the surface ot oil contained within the tank l, to cause its delivery into the system against a super-atmospheric Avapor pressure maintainedover the surface of oil and inthe vapors while undergoing` conversion and condensation in the converter and condenser.

A suitable traine 2 oit woodormetal may be utilized as a support tor the tank.

The Afluid oil may be admitted into the containing vessel or tank l, by means oi one or more suitable supply pipes indicated by 3, and controlled by valve d, and when admitting oil the displaced air may escape through pipe 5, controlled by valve (i. This tank is provided with glass sight gages 7, so that the oill level therein may be constantly under observation.

A. pipe 9 connects the supply tankand converter C, in any desired manner and in order to control the delivery oi oil into the con-- verter the valve 'l0 is provided in the pipe line 9 tor this purpose,

Ars meansot (ilcawingv ott oil Vtroni the tank, the pipe ll'cont-rolled by valve l?, is provided below the `pipe fitting under the tank, and in order to sumly compressed air to tank l., pipe 8, leading out from a T 'fitting in'pipe 3, land controlled by valve S, leads to a compressor or suitable supply ot compressed air, so that compression may be employed overthe surface oit oil in tank l, to

cause its delivery into the converter against a. super-atmospheric vapor pressure mainH tained therein.

The converters C proiiosed for use in this invention nnty'assunie diverse terms, certain oit which are shown in the drawings, without undergoing :1n-essential dilliercnce incharacterA ordeparting Ytrom the spirit of the in vention.

The coiivci'tei'sliown in Figures l, 2 and 3 comprises a retort or fheating section 13, provided with a glass sightgage 14, and surmounted by kva cylindrical crown or dome l5, also provided with a glass sight gage 16.

`Preteiably, but not necessarily, thesupply pipe 9 in this form connecting trom the supply tank l, will lead-'into the upper part bt t `rettili-t or section "i3, which section forms the lower part ol the converter C.

"which may havev accumulated therein, and

the heavy residual oil may be withdrawn 'tromi time to` time during the operation of the system.

The crown cylin'deril, is'se'cured tothe retort 13,' by means of suitable interposed iange members 20, which are screw threaded onto the respective parts and are bolted to each other.

Inasmuchjas the vapors rising into and tilling'the crown or dome l5 exert high pressures, I have arranged a' cap 21, in close litting relationwith the upper end ol" the cylinder crown or dome and have utilized4 as a` means tor securely retaining the ca'p'in positi'on a' lnumber otstrong `steel bolts which hold this cap securely tothe top ot the dome. The lower section or' retort may be connected with the overlying dome by means ot a gage coiumn 22, on whiclrglass sight gages "23 are arranged :.o that thc condition and disposition ot' the contents oil. the converter C, may always be the more readily apparent andbe susceptible oil an intell'igei'it variz'ttion.

A l'eature of importance is the means loi internally applying li'eat to the oil contained in the retort while held under a self-imposed super-atmospherie vaporlpressure ttor the purpose ot bringing about a conversion oilE such oil.

Pret'el'ably this feature is electrically operated and embodies an electric heat-er 30 comprising one or morev resistance. rods, or resistors of carbon or other suitable material,

which are adapted to be maintained at a the resistance rods maybe varied to con- Yform to the voltage ot the source ot sup-Y ply, I have illustrated a series coiniection,

which is suitable for ordinary working con ditions.

The electric energy is supplied to the heater by means 'of a metallic conductor rod 2li which passes through the cap 2i at the sunnnitof the dome 15, and in order to `Yprevent groin'iding or short circuit of the current, an insulating bushing and grand .olf suitable, material, sueltas soapstoneoil long fibre asbestos composition, will be interposed in a tight iitting relation between the cap and the leading in conductor rod 2i.

So also, a leading out conductor rod may similarly pass through the bottom of the retort section 13, and the current for operation will be supplied from the mains 27 and 2S.

The conductors 2d and 26 project into the heating section 18 and their adjacent ends are spaced apart to form a gap which, if desired, may be bridged or lilled in by a suitable insulating or non-conducting interponent 29, as shown in Figs. 6, 8 and 9.

While a variety of materials are available from which this insulating interponent may be made, I prefer that it shall be formet of a comparatively hard and unyielding insulating material, such for example as soapstone or porcelain, so that the interponent may form a rigid connection between the conductors 24 and 26 in order to prevent or obvia-te any undesirable looseness and lateral movements of the heater and lend stability and strength to the structure.

lVhile this non-conducting interponent 29 may be connected to the spaced terminals 2d and 26 in different ways, that shown in Fig. 9 will be found simple and serviceable. This connection comprises an internally threaded collar 29 in screw-threaded en `gagement with the end of the adjacent terminal and the corresponding` end of the insulating interponent.

ln my preferred form of grid or electric heater, the current passes into the lirst resistance rod, that indi lated by (Fig. 9) through a link 3l, which is tightly secured to the terminal of the conductor 2l by means of a clamp nut 32. The upper end of the resistance rod 30 is screw threaded to provide an engagement for the complementary clamp nuts and The current thus passes down through the, resistance rod 3W, then across the link 35 (Fig. (i) up through the adjacent rod 36, across link 37 and down the next resist-ance rod 38, until linally it passes out through the last link 9 and into the leading out conductor 26, to which the last mentioned link is electrically connected by lock nut 32 in a similar manner to that of the first link 3l.

By this arrangement, each of the rods 30, and 38, etc. will carry the same current and, as they are constructed of material having like resistanees, they will be evenly and equally heated. By suitable current regulating devices (not shown), these rods may be maintained at any predetermined temperature, even though submerged in the oil.

This internal electric heater or resistor constitutes a feature of considerable importance in my invention by reason of the fact that in operating upon certain classes of oil it is desirable to localize the application of internal heat, thereby tending to eliminate the evaporation of undue quantities of oil prior to their conversion by the aetion of the submerged electric heater.

To this end, l have provided a heat-insulating shell l0, as shown in Figs. 2 and 3, which shell provides a relatively restricted center channel or passage for the upward flow of the oil towards the electric heater SO. rlhis heat-insulating shell l0 rises above the level of the oil, as indicated in Fig. 2, and preferably has its upper end ll in interlitting relation with the overlying eylin drical crown or dome l5. lts lower end, however, is either provided with apertures 4:2 for the inlow of the oil or it may be carried upon a suitable perforated support rising from the bottom of the retort.

WYith this construction, it will be under stood that whenever the oil to be converted is admitted into the retort and brought to the proper level indicated by the ll, 16 and 23, it will assume the same level on the outside of the insulating shell l0 as it will on the inside thereof. ln this manner the electric heater 30 will be maintained in predetermined submerged relation and the oil lost by evaporation in the overlying dome will be constantly and uniformly replaced by fresh quantities of oil to be converted. The heater, therefore, will always be completely submerged and a constant oil level maintained above it.

ln order to insure that the electric heater brings about a local application of a very considerable degree of heat, it is in many cases desirable to prevent the dissipation or spread of heat through a large body ol` oil, inasmuch as such action would result in undue evaporation or distillation of oil without any appreciable alteration of its character. The insulating shell il), being preferably constructed of a cellular and laminated heat-insulating material, admirably serves as a. barrier to localize the heat where it is especially effective for the purpose intended.

As the operation of the process proceeds, new quant-ities of original or fresh oil constantly tiow into the converter and rise past the heater to compensate for that removed in the form of evolved vapors and xed gases. By meansvof the glass sight gage on the converter and gages column, the surface level of the oil may be under constant observation and may thus be held at a predetermined height. With the electric heater 30 in operation, oil will be constantly flowing toward and into intimate contact with the highly heated resistor, thereby becoming cracked and changed into lighter or more volatile products.

It will be understood .that during the operation, the raw 0 1 .lincnverted .oils will llO vpipe 113, and thence-through pipe i be relieved of more or-less of the carbon of ywhich they are in part composed. This of course alters their chemical character and converts them from one or more of the products of the hydrocarbon series into others of an essentially different character. The carbon which is removed in this manner will be .in part deposited on the highly heated resistor and in part precipitated in the ad jacent oil, being` to some extent heid in suspension and to some extent gravitated through the oil toward the bottom of the converter. The heavy residual oil, containing this gravitated carbon, may be with drawn as desired tl'irough the pipe 'i7 and valve 1S.

Inasmuch as the precise degree of temperature at which the electric heater should be maintained in .practice `largely depends upon and varies with partit cin'alitions, suoli as the composition of the raw oil to be converted, I may state that' the temperature will in practice ordinarily vary so that the resistor will have a high black temperature or anincandescence from a low cherry red to a white'heat, according to the oil being' treal ed.

l/Vhen operating in this manner, it has been observed that apparently only a part of the oil comes in direct contact with the resistor for the reasonthat the conduction of heat is sufficient to evaporate a certain portion at a lower temperature than is requisite forthe cracking operation. Accordingly,the-vapors passing into the dome will be composed not only of the oil which has been converted by the breaking up of its molecules during its exposure to the high heat, but also will contain a certain proportion of the volatili/red and uncracked original oil.

The mixed vapors of the original and the cracked oil are evolved very rapidly, mving to the intense heat of the resistor' and consequently care should be exercised to -keep the oil level at the proper height and not permit it to fall below or approach the top of the electric heater, for the resistorswould protrude above thelevel of the oil and uneven heat would result, the `upper or exposed. part of the resistors becoming hottest whereV there is the greatest resistance tothe radiation 'of heat.

The'mixed vapors pass from the dome or crown cylinder' l5 into a vapor d' ...harge suitable condenser'll, of which cooline coils 445 are contained within a 'tank and mounted ona suitable support Ai6, i.. desired.

Since some of the vaporized originaloil imay tendto condense before reaching the condensing apparatus 131,;1 prefer to conneet the vapor dischargelnpe e3 with the "bottom of the retort 13 by means of the gage roluiimv 22 `and in. `this manner utilize the 'when gage column to enable the preliminarily condensed unconverted oil to `be readily passed through the retort again for further treatment.

I also prefer to provide a safety pop valve 17 mounted above the condenser `E and inan elbow of the pipe 44, so as to relieve any sudden or excessive pressure above the predetermined vapor pressure at which the process is operating. I may also place in the vapor line 425-44, a thermometer or pyrometer -iS so thatthe temperature of the converted vapors passing over to the condenser may be observed.

After passing through the coil condensin apparatusl, the oil passes through pipe 5l) into a tank 1l-9 of a reservoir F. The upper part of this reservoir is provided with a gas vent pipe 51 controlled by a needle valve and the lower partv provided with a liquid drauholl pipe 53, controlled by valve fili. y

A sight gage 55 is located on the tank 1l-t) so that the surface level of the oil may be noted and a pressure gage 56 is provided at the upper part of the tank so that the vapor pressures -within the system can be under constant observationl in order to make it possible for the operator to be informed to lower fthe built up pressure by opening the needle valve 52 of pipe 5l. A draw-oil" tap 57 is at the foot of the condenser E for the purpose of taking samples of distillate from time to time during the operation of the process. Y

The use of the gas vent pipe 5l and valve 52, in conjunction `with the other features of my invention is of great importance, for tl'iereby I am Venabled to regulate the prede termined vapor pressure in the apparatus and promote uniformity and certainty in the operation of the entire system from the source of supply through to the end of or beyond. the condenser.

As a means of regulating the temperature of the condenser coil 45 ofthe condenserE, I have provided a cold water inlet pipe 5S and an overflow pipe 59 for the discharge of the heated water ywhich acciunulates at the top of the condenser tank, and as a means of observing the pressure in the supply `tank 1,'I have provided a pressure gage G0 at the top thereof. A pressure gage 6l is also employed at the top of the crown or drum l5 so that the pressure in the converter may be known, as well as at the discharge end in the tank F. When the apparatus is working under sz'itisfactory conditions, both gages :36 and (il should register the same uniform pressure throughout the system from the valve l0 in pipe 9, through the condenser and :in the collecting apparatus F.

The above specifically described apparatus was employed. by me in connection with the conversion of light oils, as kerosene, into napthas and gasolenes at high or cracking temperatures While the oil undergoing treatment and the vapors being condensed were held at superatmospheric pressure,

Another and more commercially practical apparatus is shown in Fig. 4. This system comprises the various co-related parts shown and described With respect to Fig. 1, but in place of the use of con'ipressed air maintained over the surface of the oil in supply tank 1, a pump 62 is provided to withdraw oil therefrom and force it into a'converter C through a preheater B against a back vapor pressure maintained in the preheater B, converter C and running tank F. lnasmuch as it is desired to conserve heat energy in this apparatus, the comparatively cold oil flowing through the pipe 9 is preferably caused to pass through the oil preheater B and thus be raised in temperature before passing into the oil converting receptacle. This preheater may be of any suitable type but preferably embodies a continuously rising coil 63 connected with the outlet pipe 64 i which is located at the top so that any air bubbles may readily escape and not 'form air locks therein. The source of heat for said preheater may be the oil returning from the converter and hot oil receivers at the opposite end of' the apparatus, or it may consist oli' any other suitable heat supplying means.

The converter in this type of apparatus comprises retort 13, an over-lying dome 15 and an under-lying chamber 65 for receiving the heavy bottoms, carbon and other residues, such chamber being provided with a detachable plate 19. The residuuml may be drawn off through pipe 17 and valve l18.

The means for admitting oil to the converting receptacle is shown as pipe 66 controlled by valve 67, and pipe 68 controlled by valve 69, and by this means oil may be delivered into the upper or lower part of the converter as desired. This converting receptacle is conveniently supported by suitable legs or supports 70 and, like the converter of Fig. 1, preferably comprises a number of sections bolted together to form fluid-tight connections. The heavy bottoms chamber 65 is formed by a pipe-like section having a bottom plate 19 provided With an insulated bushing 71 tightly itted in central aperture therein. This bushing like bushing 25 at the upperl end of the retort, tightly encircles the conductor rod 26 and insulates the same from the metal of the receptacle.

A suitable thermometer or pyrometer 7 2 may be arranged in permanent relation With the retort 13 and another one 73 With dome 15 so that the temperature of the oil contained therein may be kept under constant observation.

As has been stated the branch line feed pipes 66 and 68 may enter the converter as shovvn at the top and bottom, and also a branch line pipe 74 having a valve 7 5 may connect such converter With a returnpipe 76 to enable a 'flow to take place as will be hereinafter described.

The vapor dome 15 comprises a drum like section having one inlet at 66 for the oil coming Jfrom the supply tank 1 to the coil 63 of the preheater B and pipe 64, and an outlet pipe 77 controlled by valve 78 for overflow unconverted hot oil.

Since the process of conversion depends on subjecting oil or oily vapors to very high temperatures considerably above their vapor-ization points, and since this evidently cannot be done Without volatilizing in unconverted form large quantities of such oil, it will be necessary to maintain high selfgenerated vapor pressures Within the system and to re-treat such fractions as have escaped cracking by the heat of the submerged heater 30.

By arranging the electric heater in the manner described it is possible to materially reduce the escape of unconverted oils, but it has been i'ound that considerable quantities pass through the receptacle Without hav- 'ing been atiected. Such oils, being comparatively heavy, may be readily condensed or caught by properly arranged baille plates, and to this end this invention 'proposes a structure or system of parts intervening between the converter and condenser for the converted fractions and the unconverted oils which are to be collected and returned for retreatment.

In the embodiment shown in Fig. 4, a vapor trap 7 9 having a baille plate 8() intercepts the vapors escaping from the upper part of dome 15 and any heavy parts, not light enough to go through and out through pipe 44, are led back into the converter through pipe 76.

The oily vapors and particles ot heavy oil from the converter pass out through pipe 43 and are projected against the plate 80 and this action, as in the steam trap, collects the heavy particles, condenses and throws them down in liquid form. Such vapors as have escaped condensation in the trap 7 9 pass through pipe l44 to a suitable condenser E, capable of condensing all products which may have a liquid form at ordinary temperatures.

The pop release valve 47 is provided in this form of apparatus and is located over the condenser E in the pipe 44 to insure safety in case the pressure should exceed a pre-determined number of pounds to the square inch, under which the apparatus is working normally.

This apparatus may be operated with the oil flow either `upwardly or downwardly past `the electric heater as desired. Thus, when operating with aV downward ilowy of oil, valve 69 in pipe. 68 is closed, as well as valve 78 in pipe 77. The incoming oil will then flow through pipe 66 and valve G7 into the dome 15 and passing down through the retort 13 past the electric heater, is led out through pipe 74e and valve 75 and then rises through pipe 76 and lrom thence into tank 82 through pipe 81.

The hot oil overliow tank 82 is provided with a glass sight gage. 83 so that the height of the oil therein may be known in order to indicate when the valve S5 in pipe 84 should be opened to draw oil' the hot oil into the collectingapparatusl), oi which tank 3G is provided with glass sight gages 87. The oil may bei withdrawn from this collec"ing apparatus D bymeans of pipe 8S and pump 89, which latter will force oil through pipe 90 pastcheck valve 91 and into supply Vtank 1 for retreatment with new oil. The converted vapors will pass through the trap 79 and other partsfas described, the d'istillates and gases being` caught in the running tank F located beyond the condenser.

In'caseit is desired to have the lilow upwardly. past the electric heater, valve 67 in )i ie. G6 andvalve 75 in ai 3e 74 will be closed, while the valve 69 in pipe GS and valve 78 in pipe 7,7,will lbe. opened. In this manner oilflowingthrough pipe 68 and up-l wardly through retort 13, will overl'low through pipe V77 vinto tank 82 from which it is drawn into collecting apparatus D and returned to supplyQ tank l by means of pump 89, as described. The vapors passing oli' through pipe 43, trap 79 and condensing coils 45 are reduced-to distillates and col* lected as set forth.

InFig. 5 is illustrated another modified.

formof converter of very simple 'structure which differs somewhat from those already described. This type of converter` is not providedwith aheavy bottoms or residue chamber, and the electric heater 30 'is located in the lower part .of the retort 13 and is positioned opposite a sight glass 102, adjacent the lowerend ot' the converter. The lowcrinletpipe 68 isdisposed adjacent and directly opposite the electric heater so that.

the incoming oil is projected` into contact with the heater; An outlet 77 is provided in .the dome 15 so to carry oil any overthrough the condensers and the running trap tanks located beyond the condenser-s.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

l. The process of converting hydrocarbon oils that comprises subjecting oil to direct contact with an electric resistor, immersed therein and heated electrically to a cracking temperature, and maintaining a super-atmospheric pressure upon the oil under treatment.

2. The process of cracking hydrocarbon oils that comprises subjecting the oil to direct contact with a carbon resistor immersed in the oil and heated electrically to a crackin temperature, while maintaining the oil under super-atmospheric self-imposed vapor pressure, and condensing the evolved' vapors.

3. The process of [converting j hydrocarbon oils that comprises subjecting the oil to dircct contact with an electric resistor immersed therein and heated to. a cracking temperature by the passage of 'an electric current, maintaining a regulated` super-atmospheric pressure upon said oil,and condensing the evolved vapors under substantially the same super-atmospheric pressure.

4l. The process of converting liquid hydrocarbon oils that comprises maintaining a carbon resistor immersed in. the oil at a cracking temperature by the. passage of an electric current, while maintaininga regulated super-atmospheric self-imposed vapor pressure, and condensing the evolved vapors under substantially the same super-atmospheric self-imposed vapor pressure.

5. The. process of converting hydrocarbon oils that comprises subjectingthe oilin a conlined receptacle of restricted cross-section to a cracking temperature developedv by an electric resistor immersed in the oil and heated electricallyy by the passage of an electric current, while maintaining upon the oil sufficient superatmospheric vapor pressure to hold'it in liquid form during thc conversion process, removing the evolved vapors from the cracking. Zone, and eifectinga condensation thereof while maintaining substantially the same superatmospheric vapor' pressure thereon.

6. Tlieprocess of converting hydrocarbon oils that comprises subjecting the oil locally to a cracking temperature developed-by an electrically heated resistor immersed in the oil, while maintaining superatmospheric seli` imposed vapor pressure upon the., oil 'during conversion, removing the. evolved vapors, condensing the heavier constituents thereof and returning them to the action of the electric resistor for further treatment, removing and condensing the lighter. constituents of the evolved vapors, and maintaiir ing substantially the same self-imposed vapor pressure throughout the entire operation.

7. The process of converting hydrocarbon oils that comprises flowing a stream ot liquid oil through a restricted passage and past an electrically heated resistor disposed therein and immersed in the oil whereby said oil is raised in transit to a cracking temperature by the local application ot cracking heat thereto, and maintaining a regulated superatmospherie self-imposed vapor pressure upon the oil during the conversion process.

8. rThe process oit converting' hydrocarbon oils that comprises flowing` liquid oil through a restricted pa. tainingI an electricallyT heated resistor maiutained at a cracking temperature, and thence into an enlarged chamber where the evolution of vapors takes place, removing` the evolved vapors, selectively separating` the heavier from the lighter constituents thereo1, returningthe heavier constituents in cyclic passage through the cracking zone, condensing,` and collecting the lighter constituents, and maintaining a superatmospherie self-imposed vapor pressure upon the oil throughout the entire process.

9. The process of converting` liquid hydrocarbon oils that comprises continuously flowing a stream or" liquid oil in a single passage through a cracking` Zone ot restricted crosssection and past an electrically heated resistor disposed therein whereby the oil in transit is locally cracked in Contact with said resistor, delivering the oil into an enlarged chamber where vaporization takes place, separately removing` evolved vapors and liquid oil from said chamber, and maintaining superatmospheric vapor pressure upon the oil throughout its treatment.

In witness whereof I have hereunto set my hand and seal this 9th day of October, 1,922.

JOSEPH H. ADAlVlS.

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