US1335771A - Apparatus for cracking hydrocarbons - Google Patents

Description

F. E. WELLMAN.

APPARATUS FOR CRACKING HYD'ROCARBONS.

APPLICATION FILED 1AN.15,1917.

1,335,771 Patented Apr. 6, 1920.

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i F. E. WELL.MAN. APPARATUS FOR CRACKING HYDROGARBONS.

APPLICATION FILED JAN. 15,-1917.

Patented Apr. 6, 1920.

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Ghini/Meg' F. E. WELLMAN. APPARATUS FOR )RACKING HYDROCARBONS.v

APPLICATION FILED )AIN-15, 1.917.

" Patented Apr. 6, 1920.

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sw w l@ F. E. WELLMAN.

` APPARATUSIFOR cRAcKxNG HYDRocARBoNs.

APPLICATION FILED IAN. I5, 1911.

Patented Apr. 6, 1920.

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F. E. WELLMAN. APPARATUS FOR CRACKING HYDROCARBONS.

APPLICATION FILED IAN. I5. I9I1. I 1,335,771 Patented Apr. 6, 1920.

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` iin eine FRANK n. WnLLiuaiv, or Kansas ciw, Kansas, Assisnonro rnnimnsnsfcrrr essonne company', or Kansas CITY, Kansas, A1 oonronarrionor Kansas.-

APPARATUS FOR CRACKING HYDROCARBOIS. f

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Application filed January l5, 1317,

To all 'whom t may concern Be it known that l, FRANK E. VELLMAN, a citizen of the UnitedStates, residing at Kansas City, in the county vof Wyandotte and State of Kansas, have invented certain new and useful lmprovements in Apparatus for Cracking Hydrocarbons, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention relates to apparatus for the treatment of hydrocarbons, and particularly to mixed series of hydrocarbons found in petroleum. It has for its object the production of apparatus which shall be more elficient, simpler, and safer than those heretofore'in use. p

The specific object of the presentinvention is to crack heavy oils so as to produce,

lighter oils, that is to say, to crack the heavy petroleum products so as to. produce gasolene' and similar mixtures of, lower lspecific gravity. The essential principle involvedv in this as in previoussystems of'myl invention, is that" of heating the oil while underl pressure, or' compressing it while heing heated, until a desired critical point `is reached in both temperature and pressure, at which-the `desired conversion takes place,

This much is known in the art, being com^- monly referred to as the heat and pressure process. Various forms of apparatus have been designed for carrying the general proc- J ess into effect, and many specific modifica# tions have been proposed with respect to the several steps involved, theirl duration, etc.

All of these, however, so far as I -ain aware," have had to do with continuously operating systems, -using tins term, of course, in a vloroad sense, since in all systems it is necessary `to interrupt the 'operation at stated intervals for vpurposes of cleaning, allowing the retorts or stills to cool down, and for general inspection Iand repairs. There isa class ofr continuously operating systemsl in whichI intermittent steps4 are l erformed, such asf that vdisclosed in United tates Patents Numbers 342,5,64 and 342,565, granted May 25, 1886, to L. Benton. The purpose in-that-caSe, however, is different from my present-purpose, as will sumciently appear hereinafter.' Y f The distinguishing feature of the present invention lies in fthe fact that it 1s essentially and as to its main operation', intermit-tent,V An v`ancillary but also very imporspecication of Lenersratern.

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tant feature is that the 'system is automatic inoperation, although, like other systems, it

can be operated manually/When necessary or desirable. Briefly stated, the apparatus comprises a retort or stilladapted to resist, high temperatures and high pressures, with means for heating the same; a supplyl tank and a measuring tank in which the charge manner, as /for example through the agency controlling valves and pipe connectionsso `is placed underl .pressure in any suitable l of compressed 'airga' connection from'themeasuring tank to one end of the retort and,1

a connection from the otherend of the retort to condensingv and receivingl devices and,

adjusted that the method may, he practisedl as follows :l vFirst, a charge, preferably of preheated oil,.is admitted tot e measuring tank and there placed under pressure. rlllie discharge'valve of the retort lacingv closed, lthis charge is forced into the retort, in which it is retained against hack pressure by check lvalves,.-bet.veen which is interposed a protective device., The charge is heated in thereto'rt, andv the temperature and pressure rise until the critical poi1it"is reacl ied' at which additional` thermal energy -is constan'tly taken up and transformed into work done in cracking or breaking down the molecular structureand arrangement of the oil. Beyond this point thepressure increases, but the temperature remains 'fairly stationary and will'so remain until the er1-' tire charge is cracked. Any increase 1ntemperat'ure beyond this point means that theldesired step-of cracking is completed Atthis critical point therefore l remove-the enl converted hydrocarbon from the retort, and E in'order to'do this with the greatest eiii-r' vciency, and produce amaxiniuin effect, I- provide forwhat'l Vmay call an.l automatic explosion. lThe pressure in the' retort, isl

caused to operatesJ series 'of valves controllingathel inlet andv discharge ports v of the' retort, aswell ,as ,the admission of a fresh charge, to the measuring` tank, and various details.4 When the "pressurain the retort has 'risen to the critical point referred toV the discharge valve is. suddenly pened and i latched, and the entire contents' of theretort are permittedto 'forcibly blow out, carrying .i

with themnotonl i the converted hydrocarbons in bulk-.butin so whatl would ordinai'rily be regarded as residual carhondeposits, tar

andthe` like, Which` otherwisewould form lhas .taken place,

sionjof the balance of the coky deposits on the walls of the retort. This blowing out not only cleans the retort,

ywhich may be regarded as an Y incidental series with more or less adinixture of very heavy residuum unconvertible without further treatment, and diiiicult to vaporize except at very high temperatures. This mass is blown out and "conversion is not only accelerated, but, so far as the convertible constituents are concerned, seem to be com- .employ the pleted by the sudden shock. v

As will sufiiciently appear hereinafter, l usual condensing and receiving apparatus, and T may employ also -any suitable type of fractionating means or dephlegmator. l have not heretofore found it necessary to blow out into an'expansion chamber, but it is tothe understood that l may do soshoaildV l findv it to be necessary or dei s'irable, without departing in the slightest degree from the principles of my invention. A very important 'matter' l have found'in upon which the success or failure of any given operation may depend, is the amount of oil placed in the retort at any given time. Tn 'operating the old type coils or stills it has been'observed thatz'- First, with conditions 4 apparently .right for cracking," only a small conversion into gasolene was made; second, under the same conditionsl ofpressure and ltemperature as before a large conversion was made; thi d, under apparently the same conditions a large amount of fixed i duced, accompanied only by a small coni'rersion of poor gasolene. These observed facts were not understood until studied in the light of the present invention. In the irstcase the coil was too full of oil, so that' while the temperature and lpressure were right, jthere was not enough vapor space;

in the second ease there was just enough oll inthe retort and the proper space above 1t,-

that is to sa conditions were correct; while in the thir case there was too little oil in the coil. Thus it will be seen there is a specific relation between the volume of the the space above in order to make a' ood rate of conversion. Attempts to determine the temperature and pressure `relations, as hereinbefore stated,

possible to pump into Cracking have been .made with fair success, but sofar as l am aware it has not heretofore been possible to perfectly control the space relation, because of the continuing nature of the processes, and` the `more or lessl continuous supply used in all the systems. On the other hand, in my present intermittent system, the spaced relation is controlled with more ease and certainty, so that a higher ratio of con# version may be attained. It is of course the retort or coil continuously, and discharge thecracked products intermittently through a pressure re lease valve; but this valve would discharge variable amounts 4and would leave variable amounts in the cracking still, 'so that .the spaced relation would be variable and uncontrolled.

My experiments up to this time indicate that the oil should ill about one-fourth of the total space in the coil or retort in order to crack distillate at the'temperature and pressure which T consider the most desirable. As an example of the conditions and results attained, the following recent trial may be cited: The operation involves a charge of distillate at 38 B., which it will he apparent to those skilled in the art is vextremely difficult to crackinto gasolen'e.

The retort employed was a ipe still in several tiers, in a furnace carefu ly regulated to give approximate `distributed and uniform temperature throughout. The pressure reached was the comparativel low pressure of six hundred pounds. his is much lower than has been used vin previous successful operations, and my present theory is that it wasV due to the cracked vapors rising to the upper convolutions of the pipe, into a comparatively cooler zone. By maintaining constant temperature and therefore a high pressure in the upper as well as the lower tiers ofrpipe, at least a forty percent. conversion .can be made by thisintermittent operation", but from purely commercialconsiderations, and character of the materials to be treated, itwould seem tobe more economical and more eiiicient to operate on the basis of the 4following chart, which represents the particular operation referred to. The temperatures and pressures given are those occurring in the processing of a batch, the 'temperature and pressure varying with the following simultaneous values and order oftime. y

First sample 25% gasolene of 62.2 B.

Last sample 35% gasolene"of64.2 B.

Average 32% gasolene of 63.7 B. l

Temperature. Pressure. 806 100 85o 20ov l 875 300 875 400 ne feature of the invention to be herein risers act more or less as fractionators, and a gasolene of a very good gravity may be secured directly thereby. The cracking and 'expansion being coincident, natural separation by gravity willI take place as the lighter molecules attain their maximum vibratory speed. What may be calledvnatural fractionation will therefore ensue by -merely drawing off from the tops fof the risers or expansion tubes into a suitable cooling coil or condenser. In this case, a valve for dis,- turbing the e uilibrium and drawing off the gasolene is p aced between the tops of -therisers and the cooling coil. By slightly, opening this valve inoperation, a very good gravity of gasolene can be drawn off, and by so removing the gasolene vapors, the pressure `-may be maintained uniform. Assuming a definite pressure, the production -of more gasolene would increase this pressure, but by removing the excess gasolene from time to time, the pressure is never permitted to rise vbeyond a predeter-mined'limit. When the required amount of gasolene is secured, the valve is closed and the residue,

allowedto be blown out through a suitable conduit connected at the bottom of theretort. l

I shallherein describe and illustrate several specific forms of my invention. I wish it distinctly understood, however, that these are not thus described and shown for purposes of limitation, butonly for clarity of definition. Inaddition to the suggestions hereinbefore made, many others will readily occur to those skilled in the art after. reading this description and all such 'non-essential anodications or changes as are fairlywithin the scope 'of the appended claims are con? templated by me and are intended t0 be made use of in practising this invention. For example, I may use various known types of apparatus elements, such as`may be obtained in the open market, in place of those shown hereinv and capable .of subserving the required functions.

My invention is illustrated inthe faccompanying drawings in which,l\

Figure l is a diagrammatic lView of a simplified form of my invention.

Fig. 2 is a diagrammatic view of a modification, making use of a pneumatic. relay system.

Figs. 3 and 4 vconstitute la diagram of a further elaboration of the system. Fig. 5 is a detail view of the leak or bypass valve used in my system.

Fig. 6 is a diagram`4 showing expansion tubes. Y

Fig. 7 is-a'detai'l view indicating a preferred arrangement of an*ggzhzpansioli` tank' when used with the apparatul'lof Fig; 1.

Referring in detail to theiidrawing's, and part-icularlyto Fig. 1, 1 indicates a ysupply- 'tank for the lhydrocarbon to be Itreated',

which tank is equipped withfpa pop valve 2 and a vacuum valve 3'. This .supply tank is also provided with suitable means 4 for preheating the contents to a predetermined point which, o course, is below its boiling point. 'A .pipe 5 leads from the supply tank. to a pump 6 discharging into the supply line 7 which leads throughv a'diaphragm valve 8, Acheokxvalve 9,- and float valve 10 "into the interior of the measuring tank '11. `The various diaphragm valves are here shown ih .mmed pressure, which devices are classic in the art. The, float valve 10 is controlled by a suitable float 12 and so arranged-as to bewopen Iwhen 'the oat is down and closed when the floatis up. The pump A6 is M ranged to'maxintairi the pressure in the sup-l ply line 7 at a constant predetermined point 1n a manner well known in the art. By the xterm ldiaphragm valve I indicate a' valve` in which the valve stem is connected 't a diaphragm operated by fluid pressure, andi although I havey shown this type of valv .throughput the diagrams, itis to be underT stood that other types capa'ble of perform# inga similar .function may be used in their place, such as a pistonoperated valve, or in fact any form of Huid relay.

A gage glass 13 is provided for the meas`vl uring tank 11 and also an air reservoir 14 connected therewith through a pipe 15 for` a purpose to be hereinafter explained.

Press re in the reservoir v14is kept at a constant predetermined point, below that maintained in the supply' line 7, by means of a suitable constant pressure pump 16. The measuring tank 11 discharges at its. lower end, and is there provided -with a ball float valve 17 Whose function is to tra-p the air in the tank after the oil passes out o-f the same and thus prevent the air from entering other vparts of thesystem. The liquid discharged from the ,tank passes through the charging pipe line 18 into the cracking tube or retort 19. This-tube is constructed so as to resist the cracking temperature and pressure, both of/which relatively high. The charging pipe liney 18 contains .a manually 'operated valve 20, a

1n this system are;

normally open diaphragm valve '21, and f check valves .22 and 23, interposed in the line of travel of the oil in the order named.

Between the check valves 22 and 23 and between the check valve 23 and the 'cracking operates I find in practice that .thecracking tube 19` most efliciently when lled to approximately one-fourth of its capacity, and for this reason the measuring tank 11 is so proportioned, and the iioat 12 so regulated that the tank will automatically till to an amount equaling approximately one-fourth ofthe capacity of the tube 19 before the valve 10 operates to shut olf the supply. By the term normally open di-a-phragm valve'l indicate a valve in which the parts are so arranged that the passage controlled thereby will remain open whenthe pressure on the diaphragm is z ero or below a predetermined actufating pressure, and in which the passage will be closed upon the application of the predetermined actuating pressure on the diaphragm.

The discharge of the cracking tube 19 is provided with a b'all'float valveI 26 for the purpose of retaining some gas pressure in the tube after discharge of the liquid, and, to take off excess gas pressure after closure of the float valve, a leak or bleed duct 27 is connected directly with the cracking tube 19 and lwith the discharge line 28 -which is in communication with the discharge end-of the cracking tube through the iioat valve 26. A pop valve 29 is included in the discharge line 28, and so arranged and 1 adjusted as toopen upon a predetermined pressure, which is the pressure reached at the time of the completion of the cracking ofa given charge in 4the crackingtube. The discharge line 28 leads into a condenser 30, from whence the condensed product is led through a pipe `31 into a suitable receiving tank 32. If desirable the discharge pipe 28 may be connected to an expansion chamber as indicated in Fig. 7. In order to hold the pop valve 29 unseated during the dise charge of the cracking tube,-1 providethe diaphragm operated'trigger 33- arranged to 'be normally out of the path of a catch on the stem of the pop Valve 29,' but to be moved into the path thereof upon the application of a predetermined operating pressure on its operating diaphragm 34. This diaphragm 34` as well as the diaphragms of the valves 8 and 21 are connected to a common operating pipe line35 which is connected with` the cool through the charging line 18. valve 36 is interposed line 35 between the cracking tube and the various operating diaphragms heretofore which controlling valve is of the diaphragm operated type and hasits operating diaphragm connected through` a tube 37 to the operating line' between the valve 36l and the cracking tube: The cracking coil 19 is mounted in a suitable oven or suitable heating means, burner such las 39. The level of the liquid end of the crackingtube A control in the operating pipe furnace 38 and supplied with heat byl preferably an oil` v in the tanks 11 and 58 andretorts 19fand 48, and' the positions of the various'float.

valves during the treatment of a batchv of material, are indicated in dotted lines lin Fi s. 1 and 2.

he operation of the system shown in Fig. 1 is as4 follows:

At, the outset with no heat applied to the cracking coil 19, there would be no pressure'4 pass 40, indicated in dotted lines.` As'v-fthe air supplied to the measuringtank 11 from the reservoir 14 is at a lower pressure than that maintained in the supply line- 7 the preheated hydrocarbon from the supply tank 1 is, through thel automatic action of the pump 6, forced through the check valve 9 and float valve 10 into the measuring tank 11. When the measuring tank receives the predetermined volume of oil for the batch to be treated, the float. valve lO-is closed and the supply pump G automatically stopped. The presence of a full measured batch in the measuring tank is indicated in the gage 13,

and the valve 2O may now be opened and the oil burner 39 started, from-which point on the opera-tion becomes automatic. Under force of the compressed air from reservoir 14 the charge of oil in the 4measuring tank 11 is forced down through'the charging line 18 into the cracking tube 19passing through valves 21, and-23, the check valves 22 and 23 being arranged t'o pass the fluid only in the direction indicated by the arrows thereon. As the tube 19 lills the pressure therein rises gradually. After the charge has passed out of the measuring tank, it rises to a point slightly above that in the reservoir 14 due to the heating up of the cracking tube, the charging line being closed against back pressure by 'thecheck valve 23. This increase of pressure actingthroughthe operating line-35 causes the valve 21A to "close, cutting ofi' the supply tank, after which, the /pressure continuing torise to the predetermined point -to which the diaphragm valve 8 is set to operate, causes this valve to open, whereupon -the measuring tank is again -filled with the preheated hydrocarbon from the supply tank -in the manner before described. Upon a further increase of pressure in the cracking tube'the diaphragm 3i is acted upon through the operating line 35 to move the trigger 33 into the path of the catch on the stem of pop Vvalve 29..

When the. pressure yrises a little above this last predetermined point, the diaphragm 13( valve 36 is actuated to cut off the operating line- 35 from the -cracking tube soas top rotect the low pressure diaphragms from the subsequentincrease in pressure' in the crackin tube 19.

continues to heat up, the pressure increasing, until cracking begins-when the temperature ofthe hydrocarbon becomes substantially constant while lthe pressure continues to rise. When the pressure finallyl reaches the predetermined point to which the pop valve 29 is set, the pressure exerted thereon through the cracking'tube .end of-the discharge line 28, the oat valve 26 being at this time oli' its seat, causes the pop valve 29 to open and to beheld open by the engagement of the triggerl 33 with the catch on `the valve stem, Immediately upon opening of the pop valve the contents of the cracking tubeare forcibly discharged out through the chamber of the float valve 26 and the discharge liney'into the condenser. This forcible discharge carries with it any -carbon or other relieved through the leak or bleed tube 27.

When the 1 pressure Vin `the cracking tube drops to the predetermined. point for which the diaphragm valve 36 is set, this valve opens again connecting the operating line ,'35

with the cool end of the cracking tube, and

the pressure dropping farther to the points to which the diaphragm valves 21 and 8 and the operating ldiaphragm 34 are set, thetrigger 33 is retracted, permitting the :pop valve 29 to close, the valve 8 closed andthe valve 21 is opened. Immediately-upon the opening .of thev'alve 21 the cracking tube is recharge from the measuring tank 11, and the cycle of operation is automatically repeated.`

The purpose of the check valve 22 is to trap any leakage through the check valve 23 until the pressure between the two risessufd ficiently to operate the relief or pop valve 24.

The pop valve l25v is connectedwith the chargingline 18 between the diaphragm of the valve 36 and the cracking coil to protect the said diaphragm from excessive pressure.

. Referring now to Fig. 2, this-shows a system similar in all respects to'that shown in Fig. l, except that the valves 41- and 42 controlling, respectively, the charge and discharge of the crackin tube are operated through a pneumatic re ay in the form of a diaphragm operated valvev 43. The valve 43.

is the same as that shown in Fig. 5, that is, it

he hydrocarbonin the cracking tube then is provided with a waste or bleed duct 44 arranged to be brought into communication with thefex'it chamber 45 of the valve, npon j-t'he closure'thereof, throughl a duct 46 in the valve stem to relieve-pressure at -the .dis- 7.0

chargeend of the valve and parts connected thereto. As used in the systemof Fig. 2, the valve 43 is connected to be operated through the operating pipe line 47 in response to a rising of pressure in the cracking tube 48 to 75 the predetermined point 'at which thevalve is set, and to control the connection through the pipe 49 between the air 'reservoir 50 and the air line l. The valve 43 is also arrangedto be normallyclosed, and to open only upon t the application of a'predetennined pressure' to its operating diaphragm, operating yupon s closure to open the bleed duct 44 to relieve l pressure inthe air line 51.`

The operation of the arrangement of 2 is as folows: Assuming that the measuring tank 5 has been filled with therequired charge, and that the pressure in the --cracking tube is below that `required for the operation of the air valve 43, compressed air 90 f will be supplied to the air line 51 from they reservoir 50 at a constant predetermined pressure maintained in a manner as that-de- Y' scribed for the reservoir 14 of F ig..1, and

this pressure inthe line 51 causes the nor- 95 mally'closed diaphragm valve 41, to be held open an'd'a't thesame time operates the diaphragm I52 to hold the trigger stud 23 `out of engagement with the valve stemof the' discharge pop valve 42. This condition ob- 10"@ taining, the handv operated valve l3-is opened permitting the charge of hydrdcarbon from the measuring tank to be ,forced into thev cracking' @be 48 in the same manner as that described-in F ig. 1. pressure therein increases and consequently the pressure in the operating line 47 until the pressure reached is a little abovel that in the reservoir 50, whereupon thejdiaphragm valve 43 is actuated to disconnect the air 1,10 line 51 from the reservoir and to permit the air therein to escape, thus reducing the pres-- sure and allowing the trigger 23 to move back into the path o f the valve -stem of the valve 42 and`also permitting the valve ,l il@ i -to close. When the pressure `in the tube' '48 reaches the point to which the normally closed diaphragm valve 53 is set, thisvalveI is caused to open, permitting a recharge of the measuring tank 58 with preheated hyv120 drocarbon from the supply tank 54. Upon furtherl increase of pressure the valve 56 is closed to protect thevalves 43 and 53 from the subsequent rise in pressure as the crack ing tube heats up. `The temperatureof the 125 contents ofthe cracking tube then continues to rise, and also the pressure, until cracking takes place, after which the'further rise in 'pressure to the point to whichthe pop valve 42 is set causes this valve t9 operateand per-y 130 Asuthe tube ills the l l nectsA the mit a'discharge of the'contents of the cracking tube in the samemanner as that described for ,Fig. 1l As the tube 48 discharges, and.\ the, pressure decreases, the valve 56 irst opens to reconnect the operating line 47 with the cool end of the cracking tube, after which valve 53 closes and'after-1t valve 43 opens. Closure of.. the valve 53 disconnects the measuring tank from the source. The opening of valve 43 again con-` air line 51 with the reservoir 50 which opens the diaphragm valve 41 and actuates the diaphragm 52 to y,push the trigger stud out of engagement with the catch on the stem of the pop valve 42, permitting the valve to close. The measured batch in the measuring tank is now driven through the charge line into the cracking tube by the pressure of the air supplied from reservoir through pipe 59, completing the cycle o'f operation which `will be automatically re- 'peated In Figs. 3 and'4 elaboration of my system in which a positively actuated discharge valve is' used instead of the discharge pop valve of Figs. 1 or 2, and a diaphragm relief valve is used in place of the leak valve shown in Fig. 5. e

eferring in detail to the arrangement of the apparatus of Figs. 3 and 4, 60 is the preheater which leads through the pipe 61 to the automatic constant pressure pump 62, discharging through the pipe 63 into the measuring tank 64 through a diaphragm valve 65 and a float valve 66. The constant pressure pump is arranged to maintain a constant pressure in the pipe line 63 through operation of the pressure controlled valve 100 controlling the shpply of steam through the pip`e 102 inresponse to variations in pressure in the pipe 63, all in a manner well known to those skilled in the art.V The measuring tank 64 is provided with a gage glass 65', constant pressure air reservoir 66 connected through pipe 67 with theV interior thereof, and a lower float valve 68. Pressure is maintained in the reservir 66 by means of a steam pump 69 supplied with steam through the pipe 70 and controlled in response to a change of pressure in the reservoir 66 bymeans of the diaphragm valve 71. A charglngpipe line 72 leads from the exit end of the float valve 68 to the cracking tube 73 through the diaphragm valve 74 and 'i check valve 75. The portion of the charging pipe line '72`lbetween the valves 74 and 7 5:is connected with a relief or pop valve 76 to relieve any pressure that might accumulate between the valve 75 and the valves 74 and 68. A ioat valve 77 which is like that shown at 26 4in Fig. 1, and bleed duct 78 are provided at thedischarge end of the cracking tube 73 and connected with a discharge p1pe line 79 containing a diaphragm valve 80 and from the exit side of which it leads is shown alstill further through a condenseror cooler 81 to a receiving tank 82. An operating pipe line 83 connects directly with-the cracking tube 73 and connects in common with the diaphragms of the diaphragm valves 65, 80, 84 and 85.` The ivalve 84 is a normally open valve and con- The diaphragm valve 85 is a normally closed valve and operates as a relief'valve for the air line 86. u with the diaphragme. of the valves 74 and 92'. Valve 92 is a normally closed valve and controls` a by-pass around the check valve 93.

The operation of the system shown in Figs. 3 and 4 is as follows: i

The preheater 60 is supplied with thehydrocarbon to be treated and heated up to the predetermined temperature below that ofv its boiling point, which temperature is to be maintained during the operation of the devices, and upon this temperature beingA reached power is supplied to thev pump 62 which starts operating to vfill the measuring tank 64, the valve 65 being temporarily blocked up through the use of any suitable means capable of holding the valve stem in its open position, orl it may be shu'nted through a-by-pass such as 44. When the `measuring tank is filled the valve 88 is opened to connect the air line 86 with the reservoir 87 Air under pressure now passes through the normally open valve 84 into the air line causing valves 74 and 92 to open. The opening of valve 92 at this point in the cycle has no effect, but the opening of valve 74 permits the measured charge in the tank 64 to be driven under pressure of the air from reservoir 66. through the charging line 72' into the cracking tube. When the measuring tank 64 empties to within a short distance of the inlet end of the fioat valve 68, this valve is closed by the downward movement of its operating float, thus p reventing the entrance of air from the measuring tank into thel system. The tire is now started in the oven or furnace 95, land as the temperature in the cracking tube rises the pressure also risesandl when the latter reaches a point a little higher than -that in the air reservoir66. this pressure, transmitted through the operating line 83, operates the diaphragm valves 84, 85 and 65, in the order named, the time element being obtained by' setting the valves to operate on l slightly var y'fing pressures. The closure of val-ve 84 disconnects the air line 86 from the reservoir 87, the opening` of valve 85 re- The air line 86 is connected y to those skilled -i'nthe art. A. Among the advantagesof'th'e system disl leases the compressed air from the air line,

- the valve 'controlling the discharge of the and the opening of valve permits. the'- measuring tank 64 to vbe again charged by the automatic pump 62. The temperature and pressure lin the cracking tube now continue tov rise until cracking begins, when the temperature becomes approximately .constant, and] 'the pressure continues, to rise until it reaches the predetermined point, at

which the Valve 80 is set. When this point is reached, pressure transmitted through the branch83 of the operating line 83 tothe operating diaphragm, of the valve 80 causes this valveto open, permitting the discharge of the contents of the cracking tube through the discharge line and receiving tank 82. At the moment this 79 to the condenser 8l discharge begins, the pressure in the crack-v ing tube will, of course, begin to fall, and

check'valvej93v prevents the'release of pressure. from the diaphragm of the valve` 80.

back into the cracking tube, until the preslsion is materially lessened yantage as a more superior'gasolene can be obtained whereythe hydrocarbons being 8ov v treated are kept largely in a liquid state and l the pressure necessary to keep them down in a liquid state underfavorablef cracking con.

sure has dropped to the predetermined point at which -the IValve 84 is set,"where upon this valveis' opened, again connectlng the airline 86 with the reservoir 87. Immediately-after the openingA of valve l84 the` relief valve-85 is closed, and immediately 'after this, valve 65 is closed. Closure of the relief valve 85 ,permits the air pressure to rise in the air line 86th'us opening vvalves 92 and'74. Immediately upon the opening of valve 92 the of valve is released, causing this valve to close. The opening of valve 7 4 permits the cracking tube to be recharged from the measuring tank'G-l, after which the cycle of operation is repeated automatically p While lI `have here shown the operation of pressure on the diaphragmf my system entirely automatic, it will'be ob-l vious that part or all of the vcycle of operationsmay be controlled by hand. 'It is also obvious that various parts maybe made adjustable to compensate for variations in working conditions and thequalities -of hydrocarbons to be treatedv For example, the' measuring tank may be made j adjustable to `varythe size .o f the batch to be treated and `the diaphragm valves, .or other pneumatic relays that might be used, may be made adjustable to operate on temperaing tubebut'. may make u'se of any Aform of cracked retort. Also, other-measuringde-l vices may be substituted for the measuringtank, such as a vmeasuring pump,"a meter in the charging line arranged to control a valve in the charging line, 'oi-any other automatic measuring device that would readily occur '-`clos'ed are, that a certain amount of oil -is put into the crackingtubeeach time and as:

.l high temperature is disturbance of the equilibrium which acts ers 605 referred to` ditions is extremely high; the. sudden relief of pressure on the hydrocarbon while at'y a found to bring about 'a to increase the percentage of conversion; the retentionv of some of the fixed gases inl the tube after each dischargev enables, 4 sure to,be builtI up for recharge, by the com,- pression of the gas retained and at/the same time lessens the amount of Afree gas generl ated and the amount of heat required. g

6'shows the 'expansion' tubes or ris- 1n the preliminary or l the presgeneral lstatement of the invention, The

charging and discharging pipes are" indicated by` shorty broken sections only. With the arrangements for distributing the equiljbrium which If have `'shown in this figure,

there'isl no reason why the yield ycould not be forced to fort -ve perpent. It willb'e noted I have shown a valve 606 at the'top of the cooling u water, and thus I amable toeifect condensation, with orwithout pressure. Another ad-V vantage is that-the operationof the valve 606 at the'top vof the cooling coil as also shown in' Fig.` 6,

space in the-'cracking coilor--retort 'will be i filled with uncracked vapor when -the presl differentpressures sov as to effect variations in time and ture. A-gain, inv practice, the system is 'not e limited tothe use of a single straight cracksure is built 'up onthe next reaction, .and

u A 1015l coil 607 immersed in' 11o will leave the coil empty' 'WhenQI have finished' drawing off, and the" thus the'coolingcoil 60T will be filled with the uncracked.' material `or the "natural fapors'. x `I have'this cooling coil contain j ust enough space? to fholdthe amount that I wantv to'. draw ofl".` I can thusclose the top valve; build up conditions. in theretort suitable 'A for cracking, allowing the cooling coil to condense fully and thus literally trap ofl". gasolene. ,.(The top valve being 'closed before I blow the 'resid-uethen open the\top valve,

from out the retort, the'contentsof 'the cool-1 -f ing coil will not be expanded Aback into .the

retort when-the. release takes place: I-.cafnA also employ with the ap aratus-of Fig. 6,v a fractionator such-as in icatcd at 60.0, concept when it is end of the retort in librium is suddenly -necting said fractionator at the top of the risers, instead of piping off directly from them. To make this connection the normally open valve 601 is closed andthepnormally closed valves 602, 603 and 604 are open. vThis, however, is not required eX- found that the-risers do not provide suiiicient fractionation in themselves'. I- prefer to blow out through the the same manner and by the same means indicated in the other' may be retained, consequently when the new'- as stated, is`

charge is inserted, the pressure,

` built up with the compression of the gas re v tained; Assuming thatl I blow 3ol j highv boiling-point fractions, .i holds -gas atv olf until the gage registers only 100 pounds, the container'is then/free fromliquid hydrocarbons -with the possible4 eXcep but it Still a Vpressure of 100' pounds. may now insert one-third capacity of'oil, which would raise thev pressure to 133Y pounds; and this is the pressure with which I startl operating; obviouslymuch nearer a poi-nt of equilibrium than the low or zero are, less free gas-generated, a lower pressures heretofore available.V *The results temperaturerequired, a higher conversion, and better^gasolene. i'

tion of VV'a few very One advantagewhich "is" of the greatest importance in practice is theremoval of the carbon with each batch of the cracked material." 'It has been assumed tobe impossible to crack' oil into gasolene wlthout having the-.precipitated carbon collect on the walls of 'the' container m which the cracking is' done. Based on calculations madey in connection with my apparatus, it has been der termined that a uniform film of carbon .005 inch will cut downY the efficiency of operation to five per cent., of normal. In other words, this thin film will require twenty times the normal amount .of heat to be used for the same operation, to maintain any efliciency at;all,-^the pipe must be overheated, and is ultimatelydestroyed in whole or in part, From personal experience, I believe that the coil approaches the danger line when .the soot is 116 inch in thickness, but its usefulness is. greatly reduced long before that limit isreached.

in substantially its entirety by attained.

. leaving The deposit of soot or carbon is prevented the use of my present method. At the pressures employed, largely over 700 pounds to the square inch, when the pop valveor release valve opens, there is an instantaneous violent explosion, and the jar of this explosion removes al1 of the-adherent carbon and throws it out in the stream of oil. v i

It will be observed that I attain automatic control vof thepressure by means of the blow-off valve, and automatic control of the space'relation in the retort between the oil and the gasor vapor therein, by means of the measuringtank. With respect tothe temperature, it may be said that" this remains constant, with proper control, after a cracking degree of temperature is once Additional increments of heat energy arev taken u continuously in the work of disintegratlng or breaking down the `molecular' ystructure and Aarrangement of the heavy hydrocarbons. The normal. pointA for each kind of oil treated will soort be found, and afterfa certain period of heatf ing,1 if the actual temperature of the oil rises, it will bean indication that molecular equilibrium has been established and crack-v ing, com leted and at a standstill, all added heat. units thereafter going to raise the actual temperature of the entire mass in the retort.- As this means to increase the elastic u forces or tendency to expand, it indicates a rise inl pressure which would be dangerous y automatic valves which 10o were it not for the check the pressure by emptying the retort preferably, as I have heretofore explained,

the fixed gases under a certain pressure, which will'form the initial pressure for the next succeeding charge of '011. existence of this-initial pressure does not of course save any energy, but it does economize time in` raising the charge to cracking heat and.pressure.

The' '105.

A` commerciallyldesirable feature which I`have'n'ot specifically; described herein, because in itself `t forms no part of the present invention, but which is mentioned here as an example of refinements in the use of the invention, is tionator, connected to lreceive the cracked' products from the retort and'to fractionally with the result that in order conde/rise the same and deliver them either to receiving tanks direct, or Vif further cooling be required, to ordinary condenser-s or 120 of this general type is coolers. Apparatus illustrated and described in my priorl applications Serial No. 32,704, filed June 7, 1915; Serial No. 50,775, /iled Sept. 15 1915; Serial No. 69,499,

No. 69,500, filed Dec. 30, 1915; Serial No.

110,795,1filed July 22, 1916; and Serial No.

126,971,61ed oct. 21, 1916.., Anyl ofthe foregoingA apparatus can be la-pplied in the present -case either in place -o'f the conv130` a' dephlegrnator or frac- 115 filed Dec. 30, 1915;`Serial denser or between the 'condenser and the pressure retaining Valvejat the discharge end of the retort. If a fractional vevaporator be em loyed such as described tion 'sgml No. 126,971, filed' Oct. 21, 1916,- no other expansion chamber would. probably be needed, and the same `might be true with a dephlegmator having a cylindrical chamber of large dimensions; but-with any of the remaining types, involving `the use of coils of pipe orthe like .of relatively small diameter, it will probably-be necessary Ito interposean expansion chamber between the discharge end of the retort and the fractionator. This expansion chamber may take the form of a vertical cylinder of some height,.or anyother desired form provided that its capacity is sutlicient to permit a multiple expansion of the oil and vapors blown out of thevretort so as to substantially reduce the pressure' before it encounters the resistance of the small bore pipes. If the discharge end ofthe fracltionat'ing andcondensin system be opened to the atmosphere the e great, and if' all. piping be made strong enough to withstand the discharge pressure,

then the expansion chamber may be reduced in size or eliminated. n l

-Having thus described my invention what I claim and desire to secure by Letters Patent is: I

1. Apparatus for treating hydrocarbons .comprising the followinginstruinentalities,4

a retort having charging and discharging ports, valves for said ports,-:means for heating the retort and an erated relay valvel connected on its controlled side tothe retrt and connected on its controlling side to said discharge valve, `to operate the latter at any pressure for which the relay may -be set.

f 2'.' Apparatus for treating hydrocarbons comprising the following instrumentalitiesz'- a retort having charging and discharging ports, valves for said ports, -means for heating the retort, and an automatic pressure op-A erated relay valve -cnnected on its controlled side to the retort and connected on its controllingside to the discharge valve, to Y pres-g er witha latch for open the latter at any ,predetermined sure in the retort, -toget l in applicavtrolling side to both Avalve is opened and vice versa.v

ect would not be so l .a retort LAhaving automatic pressure opinitial pressure su nection for said latch of said relay.

the following instriimental'ities: a 'retort having charging and discharging ports, valves for-said ports, means for heatingthe retort, and an automatic'p'ressure operated relay valve 'connected on its controlled side to the retont'and connected on-its con# the charging and diS- charging valves, saidvalves being Aset "for opposite conditions, whereby the charging valve will be yclosed when the 4. Apparatus .for treating 'hydrocarbons'.

' discharging j `said discharge valve and a controlling con-y to the controlling side l '55v 3. Apparatus Ifor treating hydrocarbons -comprising comprising the following instrumentalitiesi' a retort having charging and `discharging ports, Valves for saidports,- means for heating the retort, and an.- automaticpressure operatedrelay valve connected on its contrlled side to the retort and connected on vits controlling side lto vboth-Vthe charging anddischarging valves, said valvesv discharging valve is together with means said relay valve, and

ing set for opposite conditions, whereby the charging valve-will be closed when the' opened and vice versa,

meansoperably to force said charge'into .thel

retort w ,5. Ap comprising en the charging valve is opened.

ports, means for heatports, valves for said automatic pressure opin'g the retort, and an side to the retort and co ected on its controlling side to both the ar charging" valves, said valves ing set for opposite conditions,\ whereby-the charging valve will be closedwhen the;dis char valve is opened and, vice versa, together witg Imeans lfor measuring a c h trolled Iby said relay valve, .and means for forcing' said char e ii'ntoA theretort under ual pressure of FRANK WELLMAN.

gases -left .i

the retort aften aratu's l for l treating hydrocarbons l the following instrumentalities:vv charging and discharging.

arge, also concient to overcome resid-`

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