US1732805A

US1732805A - Method of heat treating hydrocarbon oil

Info

Publication number: US1732805A
Application number: US316947A
Authority: US
Inventors: Yarmett Edward C D
Original assignee: FRACTIONATOR Co
Current assignee: FRACTIONATOR Co
Priority date: 1928-11-03
Filing date: 1928-11-03
Publication date: 1929-10-22
Anticipated expiration: 1946-10-22

Description

Oct. 22, 1929. E. c. DYARMETT 1,732,805

METHOD OF HEAT TREATING HYDROCARBON OIL Filed Nov. 1928 5 Sheets-Sheet 1 EN TOR.

. fi/ma/l ATTORNEY Oct. 22, 1929. E. c. D'YARMETT METHOD OF HEAT TREATING HYDROCARBQN OIL Filed Nov. 1928" 3 Sheets-Sheet 2 w w r Q11 i w a n M W "m .0 0/ Z Z I 6/ W #1 M, y w 2 w w w. 7 a 0 0 9 v y r4. M I m rm 6 im 1 Z Z x h- 5 m a m U U w MM INVENTOR. fad firms/f A TTORNEY Oct. 22, 1929. E. c. DYARMETT 1,732,805

METHOD OF HEAT TREATING HYDROCARBON OIL IN V EN TOR.

ATTORNEY Patented Oct. '22, 1929 UNITED STATES PATENT OFFICE EDWARD G. DYARMETT, OF KANSAS CITY, MISSOURI, ASSIGNOR TO THE FRACTION- .ATOR COMPANY, OF KANSAS CITY, MISSOURI, A CORPORATION OF MISSOURI METHOD OF HEAT TREATING HYDR OCARBON OIL Application filed November 3, 1928. Serial No. 316,947.

My invention relates to a method of heat treating hydrocarbon oils to change their characteristics, the pressure application being a continuation in part of my applications Serial Nos. 246,533 and 251,063.

Crude oil, being composed of a mixture of various hydrocarbon liquids of different boiling points and solids in suspension, may be separated into fractions by vaporizing "he oil and fractionally condensing the vaporized product of the oil. y

Crude oil is a poor conductor of heat and resists convection. Consequently in treating crude oil for the recovery of a desired product with heat transferred through the wall of the vessel containing the oil, the part of the oil in contact with the heating surface will acquire a higher temperature than the body of the oil; the difference in temperature been Eng dependent upon the rapidity of the heat transfer through the wall of the vessel and unavoidably resulting in vaporization of components heavier than those desired for re covery and in some undesired change in the characteristicsof the oil. For example, if crude petroleum is being treated for. recovery of its gasoline content, overheating will crack other components of the oil, resulting in dilution of the desired product with unsaturated constituents. Such overheating also produces an excess of vapors of heavier fractions. which must be removed from the recovered gasoline.

If the treatment is for cracking the oil, then overheating will result in formation of free carbon, which will settle on the wall of the container, interfering with heat transfer and necessitating cleaning thus limiting the yield.

Vapors driven from crude oil by heat of necessity contain a portion of all the various volatile components of the crude oil and, being of varying density, will comingle in a vapor space, so that recovery of only ighter fractions necessitates removal of the heavier components. by fractional condensation, or the vapors may be stratified by centrifugal force and the heavier vapors separated for independent treatment.

In cracking crude oil to increase its gasoline yield, molecules of the original oil are broken into smaller molecules, some of which include carbon and hydrogen in proper proportions while others lack in hydrogen content butcan be saturated with hydrogen supplied from gases or vapors introduced from an extraneous source.

It is, therefore, the principal object of my invention to provide a method and apparatus for treating hydrocarbon oil for recovery ofa maximum quantity of a desired product free from undesirable constituents, and without injury to other components of the oil or to the converting apparatus.

More particularly my invention consists in passing the oil rapidly over a heated surface in the form of a thin film for promoting rapid vaporization without overheating and in centrifuging evolved vapors so that heavier and lighter vapors may be removed separately at the end of the treatment.

A particular feature of my invention includes the introduction of a gas rich in hydrogen, such as methane having a molecular constru ction denoted by the formula 0H,, into the vapor space surrounded by the film of oil within the heating chamber, where it may be bombarded by molecules freshly formed by cracking, the oil,to promote combination ofl light and heavy molecules of the. gas and 01 Apparatus embodying my invention, including all of the elements required for the recovery of a maximum quantity of gasoline from hydrocarbon oil, and adapted for selective use for recovery of any'desired frac tion, or for the combining of gas or vapors with molecules of the oil, is illustrated in the accompanying drawing, wherein:

Fig. 1 is a perspective view of a battery 90 of assembled fractionating, cracking and combining stills.

Fig. 2 is a central vertical section of a still for preliminary treatment of oil, particularly adapted for use in separation of low boiling point fractions of an 'oil, without cracking.

Fig. 3 Fig. 2.

Fig. 4 is an enlarged section in perspective 100 is a cross section on the line 33,

of the lower portion of the heating chamber of the still.

Fig. 5 is a central vertical section of a cracking and combining still,-'ineluding a fractionating tower.

Fig. 6 is a detail perspective view partly in section of parts of the fractionating tower. Fig. 7 is a cross section on the line 7-7,

Fig. 5.

Referring more in detail to the drawings: A, B, G and D (Fig. 1) designate stills arranged inv series and adapted for conjoint or selective use according to the product it is desired to recover from the oil under treatment the several stills corresponding generally in detail construction and diflering only in that gases leaving the still units, and H a compressor employed for delivering gases rich in hydrogen to certain of the units for saturating lean components of a cracked liquid. Other mechanical and structural elements will be identified in the more detailed description of the apparatus.

Referring first to the initial still or unit of the apparatus designated A in the assemv bly, 1 Figs. 2, 3 and 4) designates a shell refera 1y cylindrical and supported on a ase plate 2, preferably of cast metal and ineluding a liquid receiving chamber 3 having an opening to the bottom of the shell through a throat 4, having a beveled edge 5. Supported on the base 2 is a drum 7 spaced from the shell to provide an annular chamber 8 having inlet and outlet Ports 9 and 10 at the top and bottom, and within which a spiral partition 11 extends about the shell from the inlet port 9 to the outlet port 10. Supported on the drum 7 and enclosing the upper portion of the shell 1 between the drum and the top of the shell is a housing 12 having an outwardlydirected, V-shaped flange 13 at its upper edge provided with a rim 14, forming the trough 15. Extending in convolutions through the flange 13 and the body of the housing is a channel 16, terminating in an outlet port 17.

Mounted on the rim 14 of flange 13 is a tower 18A, preferably cylindrical and provided with a cover 19' including an upwardlyinclined body portion terminating in a vapor dome 20 and having an extension 21 depending into the drum 18A. The top of the dome is provided with a central aperture 22 containing a shaft bearing '23 and with a stufiing box 24 for a shaft presently described a nip 1 ple 25 being mounted on the dome pose presently mentioned. A port 26 opens laterally for a purfrom the-dome and a gas line 27 extends through an opening 28 'Which gases or vapors may be delivered into in the side of the dome and into a collar 29 located centrally within the dome and surrounding the shaft presently described.

Suspended from the base 2 is a box 30 provided with a bearing 31. J ournaled in the bearing 31 and extending through a stufiing box 32 on the chamber 3 is a shaft 33 operatively connected with a motor 34 through a beveled gear wheel 35 on the shaft, a pinion 36 on a transverse shaft 37, a belt wheel 38 on the shaft 37, a belt 39 and a wheel 40 on the motor shaft 41.

Fixed to the shaft 33 in the bottom of the shell 1 is an impeller 42 for forcing oil' passing through the throat 4 radially within the shell, and preferably consisting of a lower ring 43 having a lip 44 extended into the throat 4 in the base 2, the upper ring 45 and ribs 46' connecting the rings and forming discharge openings 47. Mounted on the impeller 42 to rotate therewith and extending through the shell, the fractionating tower 18A and the vapor dome 20, and journaled in the bearing 23 at the top of the dome is a tubular shaft 48, hav- 'ing ports 49 in its lower portion through the bottom of the shell.

Fixed to the tubular shaft 48 are blades 50 preferably radial and extending from the bottom of the shell to slightlyabove the top 95 thereof and to near the inner surface of the shell 1.

Fixed to the shaft within the fractionating tower are spaced disks 51 of slightly less diameter than that of the tower to provide space for travel of vapors through the tower without restriction of the vapors, and provided on their upper faces with radial ribs 52 for a purpose presently described, the disks being spaced by collars 53 sleeved on the shaft 48.

Fixed to the wall of the tower and extending downwardly-and inwardly between the disks are drip plates or rings 54 for re-, turning condensed liquid, with any reflux liquid that may be employed, from the wall of the tower onto the disks. Located in the bottom of the tower is an annular trough 55 for receiving liquid flowing down the wall of the tower below the bottom disk, and opening from the trough 55 is a line 56 for conducting said liquid back to the receiving chamber 3 through a port 57 when the liquid is to be recirculated with fresh stock as illustrated in the present drawings.

58A (Fig. 1) designates a line leading from the trough 15 of the heating drum for conducting residue of the treated oil from i the trough 15 to storage, here shown to consist of the tank 59A.

' 60 designates a pipe surrounding the downward extension 21 of the vapor dome within the fractionating tower through which redisk 51 in the tower.

The preheater or heat exchanger E may be of any suitable construction, but preferably comprises avertical shell to which raw stock may be delivered through a line 63 and removed through a pipe (34, the structure here shown being of a type adapted for utilizing hot liquids from other units of the system for heating the raw stock and preferably comprising a plurality of heating chambers to which hot liquid may be supplied through pipes 65 and 66 and removed through pipes 67 and-68. Vapors from the prehcater may be conducted through a line 69 to the nipple 25 on the vapor dome 20 of the still A for passage through the tubular shaft 48 into the shell 1 where they may comingle with vapors generated in the still A for treatment therewith.

70A designates a pump for drawing oil through line G4- from the preheater and delivering same through a line 71A to the receiving chamber 3 of still A. a

The still or unit A just above described is adapted for use individually for fractionating oil without cracking and when so used will operate as follows:

Assuming that hot liquids are in delivery through the pipes 65 and 66 into the heating chamber of the preheater and raw stock in delivery to the preheater through line 63 and from the preheater through line 64 and that the pump 70A is in operation, oil from the preheater at a temperature produced by the exchange of heat fromthe hot liquid is delivered to the receiving chamber 3 and forced upwardly through the shell 1 of the still A by the pump 70A. When the oil enters the shell 1 it is thrown outwardly to the wall of the shell by the impeller 42 and,

' rising in the shell under the force of supply,

, the inner surface of the shell. 5t)

passes into the zone of tlie'blades 50, which,

rotating at a peripheral speed of seven feet 'or more per second, drive the oil outwardly to contact with the shell rotating the oil and thereby forming a thin film thereof on The oil, being continuously supplied to the bottom of the shell under the pumping force and rotated by the blades, rises through the shell in the form of a film and overflows into the trough 15 at the top of the heating collar.

Heat supplied to the drums 7 and housing 12 by hot liquid and vapors passing through the channel 16 and through the spiral path in the drum 7, raises the temperature of the film of oil during its travel through the shell 1, generating vapors which leave the inner face of the film and enter the space surrounded by the film, Vapors leaving the oil, although of different fractions and conse- 'quently of different densities comingle within the space within the film and rise through the space between the blades 50, into the fractionating tower. When the vapors enter the tower they pass beneath the lower disk 51 into the space between the periphery of the disk and the wall of the tower and are, by the bottom drip plate 54, deflected back over the disk into contact with the blades 52 on the top of the disk and then upwardly in a tortuous path about, over and beneath successive disks and drip plates to the top of the tower. tating at a peripheral speed greater than that of the blades in the heating shell, impart sutlicient centrifugal force to the comin'gled vapors to separate same according to their respective densities, the gases and lighter vapors being retained in the innermost zone adjacent the shaft and the relatively heavier vapors being thrown back and toward the wall of the tower. 4

While heat is applied to'the bottom of the tower through the flange 13, the wall of the tower is unheated. Consequently when the vapors contact the wall they condense and flow back down the wall to the collecting trough 55. As the gases and uncondensed vapors rise in the tower and pass back and forth beneath the successive drip plates and over successive disks, liquid from progressive condensation in the upper portions of the tower flows back overthe platesand drips through the oncoming vapors so that light,

rising vapors vaporize and carry ofl' lighter fractions in the downflowing condensates, while the heavier fractions are, by the disks, impelled to the wall of the tower.

As a result of such action vapors of the predetermined desired fraction reach the top of the tower uncondensed, collect in the dome 20 and may be conducted through a line 72 to a condenser 73, having a liquid line 74 leading to storage. The reflux line may constitute a branch of the liquid line 74. Any noncondensible gases present in the material, being lighter than the vapors, will rise in the innermost zone of the tower next to the shaft 48 and collect in the trap 29 through which they are conducted through the line 27 for suitable disposal. Any steam content of the material may be separated from the oil vapors with the gas and disposed of through the trap. If gases separated in the tower are of a nature to render them unfit for use, they may be wasted through the outlet line, or if such gases are rich in hydrogen, they may be employed in other stills for the purpose presently described.

If the denuded product constituting residue from the still A is to be further treated for the recovery of naptha, kerosene and other light distillate, but without cracking for the formation of additional gasoline, the residue is run from the tank 59A to the still B through a pump B and line 71B.

The disks 51 and blades 52 ro- As the still Bis identical with the still A except in the respects presently mentioned I will employ the same numerals of references for like parts in description of the still B, differentiating by use of the index identifying the'part with the still B.

- As tempefatures higher than those employed for'driying off the light gasoline vapors must be employed in still B, I substitute for the heating drum 7 and housing 12 a heatin chamber 75 (Fig.5) surrounding the shell 1 and comprising non-conductive material 7 6 lying within metal plates 77 and 78 and provlde the fractionating tower 18B with a bottom member13B, also forming a cover for the heating chamber 7 5 and integral with the shell 1B, the upper surface "of the member 13B being provided with a relatively wide trough 15B adapted to overflow into an outer trough 80 ha-vin an outlet channel 81 connected with a ine 58B through which unvaporized liquid leaving the still is conducted to a tank 59B or other storage. r

As more fractions are to be separated in the tower of the still B than in the tower of the still A, a (greater number of centrifuging disks 51B an drop plates 54B arevpro vided in the tower of the still B, and in order to draw 0 the condensate of these diflerent fractions I provide some of the drip plates with troughs 82 adjacent the wall of the tower, having ports 83 through which the condensed liquid is passed to receiving cups 84 of ofi-take lines 85. i

In the accompanying drawings I have illustrated three fractional off-take lines from the tower 18B, although any desired number may be provided, and I have shown each outlet line 85 providedwith'a double fitting 86 (Fig. 1), one branch 87 of which may be em- 'ployed'for conducting the liquid to separate storage, and the other line 88 of which con= nects with a manifold 89; each branch being provided with a valve 90 or 91 for controlling flow therethrough. The manifold 89' coni the stack G.

nects-with'a line 92 through which the condensed liquid may be conducted through the line to the preheater E, or through a line 93 to storage under control of the valves- Vapors from the vapor dome 20B may be conducted through the line 96 to the port 9 of the heating drum 7 for exchange of their heat through the shell 1 to the liquid assing covery of more gasoline, the liquid residue from tank 59B is conducted to the bottom of the still C through a pump C and line 710.

The still C is of a construction identical with that of still B except that fewer centrifuging disks are employed in the fractionating tower and no fractionated liquid outlet is provided in the tower, and in that it is of heavier construction to permit operation under higher pressure. There is a further difference in the operation of still C in that the material delivered through the hollow shaft to the bottom of the heating shell is of a nature to enrich the unsaturated components of the oil cracked in the still instead of merely constituting a light fraction of the oil treated under relatively low temperature, For this latter purpose I connect to the nipple 30C on'the top of the vapor dome 200, a line 103' leading from a source" of supply of a gas rich in hydrogen, here shown to be the line 106 leading through a fitting 105 to the compressor H, which receives its supply of gas from condensers in the system through a line 107, or from a source of independent supply through line 108. The line 106 connects through a fitting 105 with the line 103 and also with the line 109 leading to a further still presently mentioned, the lines 103 and 109 being provided with valves 110 and 111 for controlling the respective lines 103 and 109.

The vapor line 112 leading from the dome 20C connects with a condenser 730 through a stepdown valve 113 whereby pressure may be reduced between the still and the condenser. lhe condenser 730 is here shown to connect with the line 107 to the compressor through a line 114, and the condenser 73 C is provided with an outlet line 7 1C leading tothrough the chamber under the same conditions heretofore described with reference to the stills A and B, and with the further condition of an application of pressure to the film of oil sufficient to retain the oil in liquid phase until sufficient heat has been absorbed to crack the oil; the pressure in the vapor,

space of the still C being supplied by the gases injected into the heatmg chamber through the compressor H, supplemented with that self-imposed b the vapors generated from the oil after the cracking has taken place, and the centrifugal force applied by the filmingblades.

The hydrogen rich gas not only provides desired pressure, but further supplies to the cracked-vapors a material, the molecules of which will combine with the unsaturated components of the cracked product to form fully saturated molecules therefrom, thereby converting into a valuable product an element of the oil which would otherwise constitute a detriment and increasing recovery to the extent of the added gas molecules.

Condensate collected in the tower 180 may be conducted backto the intake end of the still through a line 56C for recirculation with fresh stock delivered'through line 710.

Residue from the still G is drawn off through the line 58C to a tank 59C through a pump D for further treatment in the still The residue of the cracked oil contains only such elements as did not crack in still C under the heat and pressure treatment there involved, and which will crack under higher temperature without substantial pressure. Consequently the still D may correspond exactly with still B except that it is preferably of stronger material than employed in still B for the reason that under some conditions the still D may be used for cracking under high pressure as well as under high temperature.

It is the hot residue from still'D that is employed for heating still A, the residue being conducted through the lines 115 from the still D to the pipes 116 leading to the channel 16 in the housing 12 of still A. The line 115 extends to storage through an extension 117 connected with the outlet line 118 from the heater channel 16 of still A and valves l1\9-120 are placed in the

lines

115 and 116 to control flow throu h the heater of still A or direct to storage. ot liquid condensed in the tower 18D of still D passes to the preheater E heating the charging stock for still A., The line 121 has an extension 122 leading to storage and the lines 121 and 66 have valves 123-124 controlling flow through the lines.

The vapor line 112D leads through a regulating valve 113D to a condenser 73D from which gases are drawn through the line 107 to the compressor for delivery to stills C and D or either of them. The reflux line 60D including the pump 61D ma conduit liquid from the condenser 73D back to the fractlonating tower 18D for treatment of the vapors in said tower 7 While I prefer to connect the furnace with the stills B, G and D through the manifold 99 and individual ducts 125-126 controlled by dampers 100, 100C and 100D and to draw off the spent gases through individual flues 101B, 101C and 101D to the common stack G and have shown other specific details of structure and arrangement, such has been principally for convenience of illustration of an operative system without intention of limitation to such details, as other methods of applying heat and conducting vapors and liquids may be employed without departing from the spirit of the invention.

Assuming that the apparatus disclosed is employed for treating crude oil which, for

example, may be oil from the Cushing through lines 121 and 66 for Oklahoma Field, having a specific gravity of about 0.824 (40.2 B.), the operation of the apparatus and practice of the method is as follows:

The pump 70B is connected with the source of supply of oil to be treated through a line 127 by opening valve 128 in said line and closing valve 129 in line130 leading from tank 59A. The dampers 100C and 100D are closed and gases from the furnace passed to the heating chamber of the still B. Oil is delivered from supply line 127 through the pump 70B to the receiving chamber of the still B,,through which it is forced into the heating shell 1B. The motor 34B rotates the impeller in the bottom of the heating shell of the still B, throwing the supplied oil to the side of the heating shell and the oil rising through the shell is maintained in a thin film and rotated rapidly over the wall of the shell by the action of the radial blades on the center shaft. The heat is so regulated as to avoid excessively high temperatures and the vapors driven from the oil film are only the lighter fractions and uncracked. These vapors passing up through the fractionating tower of the still B are separated, the heavier vapors condensing and the condensate passing out through the line 58B for recirculation, the non-condensible and water vapors passing oif through the line 27B and the lighter vapors finding outlet through the line 96 to the heating chamber 7 of the still A.

While I have described use of my method and apparatus for recovery of certain prod nets and as operating under certain pressures, it is apparent that the treatment may be effected under vacuum in the stills, and that the steps recited may be supplemented or varied, as by introduction of steam 1nto still B for recovery of lubricating cuts, and that oil and water emulsions may be treated with my apparatus without generation of excessive pressure.

When the preheater is in operation oil is pumped therethrou'gh to the receiving chamber of the still A, fIOIl'YWlllCll it is passed to the heating shell and there impelled to the wall of the shell and rotated to cause it to travel to a thin "film. over the wall of the shell to the fractionating tower 18A, vapors generated in the preheater being passed through the hollow shaft of still A to mix with the vapors generated insaid still and pass with them into the fractionating tower. Vapors passing through the tower are centrifuged for separation of heavier and lighter fractions, the condensed liquid drawn oil and returned to the receiving chamber 3 for recirculation, the noncondensible gases and steam being drawn off through the line 27A and the vapors of the desired fraction conducted through the line 7 2 to the condenser 73.

The heat employed in this operation is only suflicient to drive off the very light fractions and may be of relatively low temperature because of the rapid absorption of the heat by the thin film of oil.

Residue of oil collected in the trough 15 at the top of the heating housing is collected in the tank 59A.

When the system is first placed in operation the oil incoming to still B is heated to a maximum of about 430 degrees F. The vapors will leave the \fractionating tower 18B at a temperature of about 300 degrees F. and the fractionated liquid will pass from the tower to the preheater at about 400 degrees F. Consequently the oil passing through the still A will be heated to only about 250 degrees F. and only very light fractions will be driven off and the residue will contain a considerable quantity of gasoline.

When sufficient liquid has accumulated in the tank 59A,-the valve 128 is closed and the valve 129 opened, cutting off supply through the line 127 and admitting supply from the tank 59A. Liquid from. the tank is then pumped into the receiving chamber of still B and passed through the heating shell thereof Where it is treated in the same manner as was the original stock in still A.

The hot oil from tank 59A passing through the still B will be heated to a temperature of approximately 550 F., which is suflioient to drive off naptha and kerosene vapors without cracking the oil, the vapors leaving the vapor dome of the still B and entering the heating chamber of the still A. at about 47 5 E, which is sufficient to drive off the lighter gasoline vapors from the oil passing through still A, but not suflicient for removal of all of the light vapors, some of which pass into still B during the preliminary operation of the system.

' When the fractionated liquid is drawn off from still B through the manifold 89 to the preheater, it is at approximately 500 F., which is sufficient to heat raw stock passing through the preheater to the still A to about 550 F. Residue leaves the still B at about 550 F., and when drawn immediately from the tank 59B enters the still C at about 525 F. The still C is heated to approximately 750 F., and held under a pressure ranging from 50 to 300 pounds per square inch according to the heat applied and whether or not the pressure is only that-self imposed by vapors generated in the still plus that generated by the rotating blades or such pressure plus that of the gases supplied through line )103.

Residue from the still. C when passed immediately through tank 59C enters the still C at approximately. 7009 F., and is there heated toabout 1100 F., but, owing to the nature of the material, no added pressure .is necessarily required, supply of gases from line 109 being only for the purpose of furnishing hydrogen to saturate some of the molecules of the residue cracked in this still. Liquid leaves the fractionating tower of still D and enters the preheater at about 600 F., thereby raising the temperature of the raw stock passed through the preheater to the still A. Residue leaves the still D and enters the heater 12 of still A at about 1000 R, which, with the heat of vapors from still B, is sufficient to effect vaporization of substantially all of the gasoline vapors from the oil passing through the still A.

Consequently as soon as the last unit of the system is in operation suflicient heat is supplied from the higher temperature stills for raising the temperature of the raw stock and of the oil in still A by heat exchange. v

While I have shown a complete system for recovery of a maximum gasoline content from raw oil, and have recited certain definite temperatures and pressures, I Wish it to be understood that the invention'is not limited to the complete combination, as a number of the units less than the whole or even the individual units alone may be employed according to the nature of the product acted upon and the material to be recovered and pressures and temperatures may var according to the grade of the raw stock an the product to be recovered, the principal features of the invention being the filming of the oil and treatment of the vapors to avoid loss and injury to the treated stock and secure a maximum and uniform product of condensation.

What I claim and desire to secure by Letters Patent is:

1. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of extending surface area, rotating the oil at a speed suflicient to maintain the oil in the form of a continuous film on the inner surface of the vessel, heating the vessel, transferring heat from the vessel to the film of oil, and collecting vapors evolved from the oil within the space surrounded b said film.

2. The method of heat treating hydrocarbon oil including delivering the oil into a stationary vessel having circular cross-section, rotating the oil within the vessel with sufficient Velocity for the centrifugal force generated by its rotation to cause the oil to pass over the inner surface of the vessel in the form of a continuous film, heating the oil through the wall of the vessel, and collecting vapors evolved from the oil within the space surrounded by the film.

3. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of extended surface area, rotating the oil at a speed suflicient to maintain the oil in the form of a'continuous film on the inner surface of the vessel, heating the vessel, trans ferring heat from the vessel to the film of oil, collecting vapors evolved from the oil Within the space surrounded by said film, and removing the vapors from said space.

4. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of extended surface area, rotating the oil at a speed sufficient to maintain the oil in the form of a continuous film on the inner surface of the vessel, heating the vessel, transferring heat from the vessel to the film of oil, collecting vapors evolved from the oil Within the space surrounded by said film, and removing said vapors and remaining oil separately from the vessel.

5. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of ext-ended surface area, moving the oil through the vessel by force of its delivery to the vessel, rotating-the oil at a speed suliicient to maintain the oil in the form of a continuous-film on the inner surface of the vessel,

' heating the vessel, transferring heat from the vessel to the film of oil, and collecting vapors evolved from the oil Within the space surrounded by said film.

6. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of extended surface area, impelhng the oil toward the Wall of the vessel as the oil enters the vessel, continuously rotating the oil during its travel through the vessel at a speed sufficient to maintain the oil in the form of a continuous film on the inner surface of the vessel, heating the vessel, transferring heat from the vessel to the film of oil, and collecting vapors evolved from the oil Within the space surrounded by said film.

7. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of extended surface area, rotating the oil at a speed sufficient to maintain the 011 in the form of a continuous film on the inner surface of the vessel While the oil is'travelling toward a receiving zone, heating the vessel, transferring 'heat from the vessel to the film of oil, collecting vapors evolved from the oil Within the space surrounded by said film, receiving said vapors and remaining liquid in said zone, and removing the vapors and liquid separately from said zone.

8. The method of heat treating hydrocarbon oil including delivering the oil upwardly into the lower end of a sta ionary vessel having circular cross-section, rotatin the oil within the vessel with suificient ve ooity for the centrifugal force generated by its rotation to cause the oil to pass over the inner surface of the vessel in the form of a continuous film, heating the oil through the Wall of the vessel, collecting vapors evolved from the oil Within the space surrounded by the film, and conducting the vapors and remaining liquid separately from the top of the vessel.

9. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of extended surface area, rotating the oil at a speedsufiicient to maintain the oil in the form of a continuous film on the inner'surface of the vessel, heating the vessel, transferring heat from the vessel to the film of oil, collecting vapors evolved from the oil Within the space surrounded by said film, conductin vapors and gases from said space to a seconc vessel, continuously rotating the vapors and gases during the travel thereof through said second vessel, returning condensate of said vapors across the path of vapors and gases in travel through the second vessel, and conducting lighter vapors and gases from the second vessel.

10. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of extended surface area, rotating the oil, at a speed sufficient to maintain the 011 in the form of a continuous film on the inner surface of the vessel, heating the vessel, transferring heat from the vessel to the film of oil,

collecting vapors evolved from the oil within the space surrounded by said film, conducting vapors and gases from said space to a second vessel, continuously rotating the vapors and gases during travel thereof through said second vessel, condensing heavier vapors on the Wall of the second vessel, returning condensate of said vapors across the path of vapors and gases in travel through the second vessel, and conducting lighter vapors "and gases from the second vessel.

11. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of extended surface area, rotatino the oil at a speed sufficient to maintain the 011 in the form of a continuous film on the inner surface of the vessel, heating the vessel, transferring heat from the vessel to the film of oil, collecting vapors evolved from the oil Within the space surrounded by said film, conducting vapors and gases from said space to a second vessel, continuously rotating the vapors and gases during travel thereof through said second vessel, returning condensate of said vapors across the path of vapors and gases in travel through the second vessel at spaced points in the second vessel, and conducting lighter vapors and gases from the second vessel.

12. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in crosssection and of extended surface area, rotating the oil at a speed suflicient .to maintain the oil in the form of a continuous film on the inner surface of the vessel, heating the vessel, transferring heat from the vessel tothe film of oil, collecting, vapors evolved from the oil within the space surrounded by said film, conducting vapors and gases from said space to a second vessel, continuously rotating the vapors and gases during travel thereof-through said second vessel, returning condensate of said vapors across the path of vapors ,in travel through the second vessel, .impelling said condensates toward the wall of said second vessel across the path of said vapors and gases at spacedpoints in said second vessel, "and conducting lighter vapors and gases from the second vessel.

13. p The methodof heat treating hydrocarbon oil including admitting a stream'of oil to a confining vessel, circular in cross-see tion and of extended surface area, rotating the oil at a speed sufficient to maintain the oil in the form of a continuous film on the inner surface of the vessel, heating the yessel, transferring heat from the vessel to the film of oil, collecting vapors evolved from the oil within the space surrounded by said film, conducting vapors and ases vfrom said space to a second vessel, cont uously rotating the vapors and gases'during travel there ofthrough' said second vessel, returning condensate of said vapors across the path of vapors and gases in travel through the second vessel, and drawing ofl said vapors and gases and said condensed liquid separately from the second vessel.

14. The method of heat treating hydrocarbon oil including admitting a stream of oil to a confining vessel, circular in cross-section and of extended surface area, rotating the oil at a speed suflicient to maintain the oil in the form of a continuous filmon the inner surface of the vessel, heating the vessel, transferring heat from the vessel to the film of oil, collecting vapors evolved from the oil within the space surrounded by said film, conducting vapors and gases froin said space to a second vessel, continuously rotating the vapors and gases during travel thereof through said second vessel, returning condensate of said vaporsacross the path of vapors and gases in travel through the second vessel, conducting lighter vapors and gases from the second vessel, drawing quid at spaced points in the second vessel, and drawingl ofi vapors and gases from said second vesse In testimony whereof I afiix m si ature.

EDWARD C. DY'Afi TT.