US1533839A - Process and apparatus for cracking hydrocarbons - Google Patents

Description

' April 14,1925.

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April 14, 1925.

R. EGELAND PROCESS AND APPARATUS FOR CRACKING HYDROCARBONS Filed om. 17,' 1921 2 Sheets-Sheet 2 Patented Apr. 14, 1925.

UNITED STATES rV y1,153,3,8319 j NT oFF-ion.

PATE

RECTOR EGELAND, or cuidado, ILLTNoIs. l

raocnss AND APPARATUS ronfcnncx'me HYDRooARBons.

Application med october 17,1921. serialm. 508,286.

i To ally whom z't may concern:

Be it known that I, RECTOR EonLANn, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Processes and Apparatus for Cracking Hydrocarbons, of which `the following is a full, clear, concise, and

exactdescription, reference being hadl 'tothe accompanying drawings, forming a part ot this specification.-

paratus for 'cracking hydrocarbons of a heavy character, 'such as`p etroleum,and the extraction or separation therefrome of lighter-hydrocarbons, such as gasolene.

The .invention-has' among its various objects the construction of an apparatus and the provision of a process in'which crude oil to be cracked is continuously fed under pressure to the apparatus and lighterhydr carboneI are continuously4 extractedtherev from.

and tempera-tures varying from -600 to1,000 degrees will pressure and with this degree of temperature employed, it has also been Jt'oundthat' the percentage of olenesin the distillate produced from petroleum .of the paralin series is reduced. This is an. objectionable Aingredient in thedistillate, although a. small percentage is allowable. It isiaii object of the invention .to provide an apparatus and a process which'will efficiently operate with the proper pressures and temperatures vto extract and yield the greatest amount of the 2lighter .hydrocarbons at a maximum rate consistent withlgoodquality, 'for the longest period of continuous operation.

Another object of thei-nvention 'is' to continuously feed.' tothe apparatus a non-con? densablegas, preferably a-co'ld gas, or a' non-superheated gas, sueltas methane gas, at a temperature of l5() degrees to 150 degrees Fahrenheit.. The non-condensable gas which is a'productof the cracking operation of the invention isone of the` gases which .may be used. It may beled from thereceiving tank or other-'contalner of the system, or it may be Vpiped from any other source of supply. This'4 gas is 'introduced lhe invention relates toa process and ap It has been found by many eXperimentersl in the art of cracking hydrocarbons thata pressure of 60 to. `150 pounds in the system produce the' greatest yield of 1 lighter hydrocarbons. [With this amount of.

lby 'the inclusion flames possible to produce.

junction with other features of the nven info the .supply-ef' @rude ou before the crude,

oil reaches an ejector which is included 'in the Pipe line leadingv to the .heater ofthe apparatus, which ejector is provided with restricted passages for the flow and propul-4 sion of theiluids; l It is a further object of the invention to f cause the crude o'il which is` to bedistilled and gas, both of which are underv pressure,l

to enterthe ejector and 'be ejected thereby into the heatmg area of the apparatusand` to mix prior to their entry into the ejector,

' continue .under pressure into other'parts of the system.A In the'hfeater thevv high-temperatures obtained, combined with vthe motion, agitationand ebul'liency of the miX'.-. ture ofxthe volatile fluid .and the rapidly the newly .created gas 'i in the yheat area'A formed by the admixture of Athe heated' I' expandmf.; nonsuperheated 'and non-.coni I 'densable gas of the :temperature named fed through the ejector andalso the impulse `of cof.

creased velocity 4and'action of the liquid and resultingvapors inrtlie heater area andbe'- yond in the apparatus, but of coke on theheating surfaces is reduced toa minimum and the time of operation ofl the entire apparatus is-eXtended'. y

It' isanpbjecto the invention tolessen f as much as'possible the deposition of cokeg' on the heating surfaces. ,Coke forming on the heating'surfaces presents one'- ofthe greatest dangers in cracking processes, -bef cause it', weakens the steel' at the heating lthe deposition .i

surface'sby combination, `frequently causing a local overheating andV bursting. -'Il1eheatl ed gases will thereupon4 escape and produce one of thefmoslt` intense Yand l destructive It isjanoth-er object-of the invention to l employ vertical oil `heating surfaces, in conf` A further object of the invention is to provide means whereby the crude oil and the non-condensable andvw non-superheated gas, such as methane gas, may be separately' introduced into the system or only one may be introduced.

In addition to the usual recautions taken in systemslike the herein escribed, it is an object to provide the system with an auxiliary safety device which is operable to relieve the system in any emergency, as when the maximum operating pressure is exceeded, should this occur at any time, and thus minimizing .one of the great dangers that is encountered in the practice of a process such/as is herein described. c

In the particular embodiment of the invention illustrated in the drawings, the use of an ejector is contemplated. A number of pipes or pipe lines are connected to the ejector. One of these pipes is in communication with 'a source of crude oil supply. Another pipe leads from a source of gas supply to the ejector, the gas being preferabl of a non-condensable character, such as Ahy rogen gas, and preferably not under heat, or superheated, and at a temperature.

of 50 degrees to 150 degrees Fahrenheit.

This gasmay be methane gas found in the receiver used in the system. These two pipe connections, that is, the crude oil supply and the gas supply, are 'connected together so that they will preferably simultaneously and under pressure, feed through the ejector an admixture of oil and gas to the system during the entire operation of the system.

Another crude oil pipe is also connectedthe ejector,and this provides a means for `initially-charging the system with the hydrocarbons to be cracked. Twoadditional pipes or branches are connected to the ejector, one of whichleads to the bottom of the still, affording a passage for the unvaporized oil which is to: be returnedto the ejectonand thence to the system, and the other of which leads to -vertically arranged heater pipes through which the admixture of crude oil and gas is passed, and Asubjected to heat. This application of heat causes the gas to expand and the necessary additional pressure to be supplied to change a portion of this mixture into vapors. different gas, or newly created gas, is formed by the .'combination of the heated oil and the non-con-L densable gas. The vapors and the unvaporized heavy oil pass lfrom the heater to a still, from which the vapors escape into a dephlegmator. A portion of the residue passes through' the pipe extending from the the crude oil which is introduced into the dephlegmator and the unvaporized distillates to be passed back into the still. From the still the crude oil from the dephlegmator and thev partially refined distillates are passed through the pipe connection between the still and the ejector, at which time this uncracked portion of the oil is again mixed with fresh crude oil and gas, which is again passed throu h the heater, still and dephlegmator. he vapors which pass from the still into the dephleg'mator are, as before stated, separated in the dephlegmator. Those containing the constituents of the Ilighter' hydrocarbons pass into a condenser, which transforms the vapor into a liquid which passes into a receiver, from which the gasolene or lighter hydrocarbons may be drawn for storage or use.

Another connection is provided to draw off the tar and less valuable distillates which find their way into and settle to the bottom of the still after portions of the crude oil have been cracked and separated. The still is prlovided with a blow-olf valve to insure safety of operation, and in addition an added safety device is provided in the form of a blow-out plug which, when an excessive pressure exists in the system, operates to rcleve it and thereby prevents an explosion. A pressure indicator is employed and preferably associated withl the receivin lows: The system y/is initially charged with.

`crude oil, which fills the heater pipes and partially fills the still and the pipe leading from the `'still to theejector. This source of supply is then turned ofi'. When the system is thus filled, heat is applied to the heater pipes and at the proper time the admixture of gas and the const-ant supply of crude oilis fed through the ejector to the system, giving impulse to the liquid of the initial charge. This liquid, under impulse, upon reaching the heater, gains in velocity and the mixture gains in volume as it is heated, adding to the motion, which serves the-dual purpose of adding impetus to the liquid and increasing the volume of the gases, including the newly created gas, which expands and creates "pressure, which carries the-vapors into-the still and other 130 elements of the system, whereby the lightery l and more readily lunderstood when read in conjunction with the accompanyingdrawings, which illustrate one embodiment of the invention, it being obvious, however, that changes and modifications may-be employed without departing'irom the spirit of the appended claims -forming la partv hereof.

ln the drawings,

Figure 1 is a central section cfa heater having the various elements entering into the invention associated for cooperation therewith;

Fig. 2` is a shownl in Fig. 1;

Fig. 3 isa sectional view of one type or ejector which may be employed in the structure? Fig. 4. is a sectional View of a fragment of the piping system showing a pressure relief element employed; and

Fig. 5 Ais a front elevati-on ofthe elefment employed in Fig. 4.

.The ejecto-r hereinbefore referred to is indicated atl() and clearly shown in Fi 3, and has provision for the connection or an initial crude oil supplypipe 11 through which the entire system is initially filled or charged with vthe hydrocarbons to be separated or cracked.. This pipe 1'1'is provided with a valve 12 for controlling the flow of oil to and from the s stem. The ejector casing has a horizontally arranged pipe 13 connected to it. 'lhe opposite end of this pipe 13 is connected to a lower manifold 141-,

"to which are connected a plurality of headers 15, which carry the vertical risers or pipes 16, which terminate at their upper ends in a connection with headers 17, which in turn connect with the upper manifold 1S. A pipe connection 19 leads from the upper manifold 18 to the tank orstill 2201.

j A vertically arranged pipe 21 extends into the still 20 and between the still 2O and the casin of the ejector 10 and provides a passage etween the `still and the ejector. 'l'hus it can readily been seen that when the valve 12 is opened, the ciroulatorysystem, includ# ing the pi 13, lower manifold 14, headers 15, vertica pipes 1.6, headers 17, upper manifold 18, pipe 19, still 20 and pipe 21 will be illed to the desired capacity, and, after the valve 12 isclosed and heatapplied, the

vaporization of the oil will eau ,the initial charge of oil to be circulated through the various elements named. The still is filled to such a level that there is provided suiiiplan view of the\structure nished. This level of the liquid in the still is approximately maintained by replenishments of fresh crude oil during subsequent operation of the system.

After the initial charge of crude oil is introducedr into the system, non-condensable unheated or non-superheated gas, such as menthane gas, with a temperature of '5(1 .degrees to 150l .degreesFahrenheiu under pressure, which is secured from a suitable source of supp-ly, is also introduced into the system. Heat is then applied to the riser tubes or pipes 16 by means of the ignition of the gas emitted from the plurality of burners 22, vwhich direct the flames toward these pipes. Solid fuel may be used instead of gas. Grate bars are shown at 23 and an ash pit with an opening at 2A. The temperature in the heater is brought up to. and maintained at from 600\degrees to 1,500 degrees Fahrenheit. Flame deflecting plates 25, 26 and 2? are employed to cause the circulation of -the products of combustion around these heater pipes before the products of combustion are permitted to .escape through the passage 28 and lout through the smokestack 29. The various sets of heater -pipes 16 are supportedl at their upper ends by means of the transversely arranged rods or pipes 30, which are arranged between the vertical pipes and below the headers 17 and rest upon the walls of. the furnace 31. The passage 28y is controlled' by means of the valve or damper 32. Each of the headers 15 and 17 are provided with apertures whichv are in'aliginnent with the various pipes 16 and are closed by means oi screwLthreaded plugs designa 33 and 34, respectively, which are removable to allow these Vpipes to". be cleaned. A cleaning pit 35 with .an opening 36 is shown beneath the manifolds and heater risers. A pipe 37 is connected to thelower manifold 1li, but the passage of oil, etc., therefrom is prevented by means of the dislr38 which is" provided with an annular recess 39. The material of this recess As before stated, the ejector 10 is prol vided with a combined gas and crude oil inlet 'passage indicated at 4&1, whereby a mixture of gas and crude' oil is constantly .fed to the system during its operati-on, at from 60 lbs. toy 250' lbs. pressure. r'The gas -suppipe 41 between the gas regulating valve 43 .plying pipe for the inlet passage indicatedat 42 and is providedwith a regulating and control valve 43;4 The cru e oil supply pipe 44 having the regulating and control valve 45, is connected to the inlet and the ejector 10, and thus the oil and gas will thoroughly commingle and mix before it enters the pipe 13 through the combined inlet passage 41 and the ejector 10. The gas passage 42 may receive its supply from the passage control valves48 and 49. rlhe valve 1 pressure 49 is placed in an additional pipe line 5() through which 'any excess supply of gas from the receiver 46 may flow. Another gaspipe line 51, provided with a control' valve 52, is connected to the pipe 42 between the control valves 43 and 48. The gas pipe line 42 is connected with the pump 53 to furnish the requisite pressure for the gas which is continuously fed to the system. A pump (not shown) is also included in the crude oil ipe line 44 to supply the requisite or the crude oil which is fed to the system. The outlet of the combined gas and crude oil passage 41, or its connection with the. ejector 10, is preferably in alignment with the' apertured nipple 54 and the restricted paages or Venturi tubes and 56 of the ejector, so that the velocity of the oil and gas entering therethrough wll be increased. e f

From the foregoing description of the structure it is evident that after the introduction of the initial charge of ,crude oil,

and gas into the system a'nd the application of from 600 to 1,500 degrees Fahrenheit of temperature thereto inthe heater, that this oil and gas will become heated and will circulate, under a pressure of from 60 lbs. to

150 lbs., through the system, and by the gas' and oil connections with the ejector, that fresh undistilled crude and uncracked oil,

'and gas will be continuously fed'thereto.

the pipe connection .59. The addition of The vapors and unvaporized heavy oil of .this heated adniixture of gas and crude oil' 'is passed from the heaters through the pipe 19 to the still 20 and the vapor-will thence pass therefrom through the pipe connection 57 rinto the dephleginatoi 58 to which is supplied `a quantity of fresh crude oil through crude oil to the vapor entering the dephlegj' inator condenses lthe heavy hydrocarbons` 00 through the pipe connections 60 to the 'conallowing the lighter hydrocarbons to escape denser 61.. Pipe connections 62, which may be'extended to a point below the liquid level in the still 20 and the opening and closing of which may be regulated by a suitable valve, and which may be ofa size foundmingle with the fresh crude oil and gas con-v tinuously fed `to the ejector, to have -any values contained therein removed therefrom. The heavy hydrocarbons, tar, waste matter and other substances'which have had the lighter hydrocarbons extracted there-l from, remain in the still and may be drawn oli' through the pipe connection 63, which is.

controlled by the yalve 64. The condensei" 61 provided with the cooling fluid inlet connectign 65 and the cooling fluid outlet connectii 66, is connected at 67 to the receiver 46, into which the distillate or lighter condensed hydrocarbons flow and are stored, and may be drawn oif as occasion demands, through the outlet pipe 68 controlled by 'a valve 69. A high pressure gas relief line l 70, with a relief valve 71 and apressuiegage 72, is also connected to the receiver 46. The

still is provided with the usual Safety blow` off valve 73.

Having thus described the invention, what I claim and .desire to secure by Letters Patent is 1. The process of cracking hydrocarbons consisting of circulating hydrocarbons, supplying a gas to said hydrocarbons during circulation, subjecting the hydrocarbons and gas to heat, passin application of heat to said hydrocarbons and gas to a still and'supplying additional gas and hydrocarbons through an ejector to the unvaporized `hydrocarbons and again subj ecting the unvaporized hydrocarbons, added gas and added hydrocarbons to heat. I

the vaporized and unvaporized hydrocar ons resulting from the' 2. The process of cracking hydrocarbons I consisting of circulating hydrocarbons, supp lying a gas to said hydrocarbons during circulation, subjecting the hydrocarbons and 4gas to heat, passing the vaporized and unvaporized hydrocarbons resulting froin the application of heat to said hydrocarbons and gas to a still, passing said vapor` to a dephlegmator and to a condenser, and supplying additional gas and hydrocarbons/througlpv an ejector to the unvaporized hydrocarbons and a ain subjecting the unvaporized hydrocar ons, added gas and added hydrocarbons to heat. a

3. The process of crackin hydrocarbons consisting ofhcirculatin hy rocarbons, sup-- plying a non-condensib e gas to said hydrocarbons during circulation, subjecting the hydrocarbons and gas to heat, passing thel v :liporizedand unvaporized hydrocarbons res ting from the applicationof heat to said vhydrocarbons andgas to a still, and supplying additional gas and hydrocarbons through an ejector tothe unvaporized hydrocarbons- 1130 through a heater,

and again subjecting the unvaporized hydrocarbons, added gas and added hydrocarbons to heat. j f

v1..The process of cracking hydrocarbons consisting of circulating hydrocarbons supplying a non-condensible gas under pressure to said hydrocarbons by means of an ejector at the point Where circulation is started through the heater,

subjec-tingthe hydrocarbons and gas to heat, passing the vaporized and unvaporized hydrocarbons resulting from the application of heat to said hydrocarbons and gas to a still and supplying additional gas and' hydrocarbons through the ejector to the unvaporized hydrocarbons, and again subjecting the unvaporized hydrocarbons, added gas and added hydrocarbons to heat.

5. In an apparatus for cracking hydrocarbons, the combination of a heatin element and an ejector, said ejector having a passage-way therethrough for the flow in a continuous path of hydrocarbons and gas, said passage-way having a Venturi tube, passages from the ejector to the heating element and from the heating element to the ejector through Which the hydrocarbons may circulate, a gas connection into the ejector whereby gas mayv be fed to the hydrocarbons to be cracked during the circulation through said passages.

6. In an apparatus for cracking hydrocarbons, the combination of a heating element and an ejector, said ejector having a passage-Way for the flow in a continuous path of hydrocarbons and gas, said passageway having a plurality of Venturi tubes therein in axial alignment with each other,

passages from the ejector to the heating element and from the heating element to the ejector through which the hydrocarbons may circulate, a gas connection into the ejector whereby gas may be fed to the hydrocarbons to be cracked during the circulation through said passages.L

In witness whereof, I hereuntosubscribe myname thisvllth day of October A. D., 1921.

RECTOR EGELAND.

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