US1591428A - Process and apparatus for treating hydrocarbon oils - Google Patents

Description

July 6 1926.

C. MATLOCK PROCESS AND APPARATUS FOR TREATING HYDROCARBON OILS Filed Sept. 27, 1920 2 Sheets-Sheet 1 H MMMM Ava KNQQQM QW aftozmg July 6, 1926. 1,591,428

c. MATLOCK PROCESS AND APPARATUS FOR TREATING HYDROCARBON OILS Filed Sept. 2'7, 1920 2 she ets-sheet' 2 52 glwwhtqo r refie UNITE-D1 or m'zwromt, N; 1", conrona'rron .01: DELAWARE. j a

irnocnss Ann arrmrus FOR TREATEtIGHDROCARBb1IOIiSQ- Application filed September 27, 1920. Serial No 413,020.

' This invention relates to a process and 31). paratus for treating hydrocarbon oils and more particularly toa process and apparatus for treating the products obtained 1n con- 5 tinuous processesof cracking heavy hydrocarbon oils for the production of lighterhy drocarbons. 3

-In crackin processes of the continuous type, in whic the oil undergoing treatment.

is passed in a continuous stream through a heating coil or otherv heating means and s heated to, and maintained at, a temperature suflicie t to crack a substantial Txportion of said oil, a variety of hydrocarbon products is formed which range from light permanent gases, which do not condense at ordinary tem peratures, to heavy products which do not readily vaporize at very high temperatures. If the product thus obtalned is condensed, a

' mixture of hydrocarbons-resembling crude Y etroleum in boiling'point range and iany other physical characteristics is obtained. The mixture of hydrocarbons obtained-in this manner may be fractionally distilled in the same manner as natural crude petroleum to separate it into the desired fractions. In condensing and redistilling the products, however, a comparatively large quantity of cooling'water and heat 1s used and moreover a large amount of equipment is necessary for carrying on the varioiis distillations;

' ,An object of, the present invention is to provide a process, by which the products. ob

tained .in cracking hydrocarbons, may be separated directly into a number of fractions of .difierent boiling point limits.

Another object ofithe invention is to provide an apparatus by which the products-obtained in the continuous cracking of hydrocarbon oils may be continuously separated in a single operationinto fractions of differentboiling point limits.

Of the heavier hydrocarbons resulting from the cracking operation remainin after the separation of the lighter pro ucts suitable for gasoline, those-products having a boiling point next above-the gasoline fraction and corresponding in bolling point range to the material originally used, may be resubjected to the crackingoperation for the production of additional quantities of gas-- oline. The. heavy hydrocarbons condensing "onl at temperatures above intermediate cracking, since they contain a very highcar vof the process is substantially the same as} described in the. Greens'treet- Patent', No. 3

1,110,924 the steam serving. to prevenfithe" fraction are, however, not, suitable. forre bon content and :upon' cracking cause trouble from the excessive formation ofcarbon. o It] is, therefore, more profitable tosell this heavy fraction as .fuel'oil or other type of heavy hydrocarbon product. A- further objectof the invention: to]

provide a process and an apparatus for;

treating hydrocarbon oils to produce lighter hydrocarbons in which those products suitable for rerunning are continuously sepa rated from the heavier'and lighter hy drocar-- bons and are returned to the crackingoper ation. With these and other objects in view, the invention conslsts in the process and'a-ppa ratus described in the following specification k and defined in the-claims. v The various features of the invention are. lllhustfi-ated in the accompanying'drawings, in w1c Fig. 1 is a diagrammatic sectional leleva-i 9 I tion of an oil cracking plant and dephlegmator embodying the preferred form of the in vention, and 5 1 r Fig. 2 is a sectional elevation of the de-;. phlegmatoi' shown in Figure 1.

the Preferred Q f hQi Ees:

ent' invention, the oil to be cracked or transformed into light hydrocarboni liquids mixed with a small quantity of steam and 'j I passed in a rapid, continuousstreamthrogh coils of pipe heated in a -furnace to a crack mg temperature. The operation-of this partdeposition of carbon on the inner walls of the coil. The cracked vapors pass fromthe heated coils directly intoa cooling header" or chamber into which afnu'mberfof jetsof water or coolin fluid are injected andlthe vapors are .rapi ly chilled-by evaporation of the'jets of water to ateniperature'at which further cracking of' the vapors" ceases. 'The 1 vapors pass from the cooling. header-through;

a pressure release valve into, the lower part of a dephlegmator whichserves to ar'ate thevapors into a number-of sharply efined fractions. .5 As the vapors. enter thelower part of the dephle'gmator, they arefurther-chill'ed.

by a spray of water whichis' injectedfintof j v cot.

the vapors in suflicient amount to bring the vapors nniformlyto a definite temperature.

A mist of condensed particles containing substantially all hydrocarbons having a boiling point aboye the temperature maintained in the lower'partbf the dephlegmator is immediately formed. As the vapors pass upwardly through .the dephlegmator the condensed particles are separated from the vapors by a number of bafiie plates. The vapors freed from the mist of condensate pass upwardly through the dephlegmator,

end point of thefilight distillate desiredor of an intermediate fractlon as may be the case. The mist formed by' this second chilling contains those vapors which condense between the temperature limits established by the first and second cooling jet mentioned above. The suspended particles forming this mist. are maintained in-suspension in the gases at a fixed zone by a balance 1 between the force of gravity and the frictional resistance between the gases and particlesof condensate. A small quantity of gasis continuously withdrawn from the dephlegmator adjacent the zone in which the particles are suspended and carries with it the accumulation of condensate formed during the process. The gases passing upwardly through the dephlegmator are freed from any particles of condensate which might be carried upwardly and may be again subjected to' a cooling spray or may leave the dephlegmator and enter a condenser.

Referring to Figure 1 of the accompanying drawings, a supply of oil or other hydrocarbon to be treated is drawn from a supply tank, not shown, through a supply pipe 10 and forced by means of a pump 12 through a delivery'pipe 14 leading to the cracking coils. The oil delivered to the pipe 14 is distributed to a number of coils through branch'pipes 16, the quantity of oil passing to each coil being measured by means of meters 18 and controlled by means of valves 20 in the pipes 16. Before entering the cracking coils, the" oil ismixed with a quantity of steam supplied from a header 22 throu 'h branch i es 24 and controllin valves 26. .The mixture of steam and oil under pressure passes through pipes 28 to cracking coils 30 maintained at a cracking temperature in a furnace 32. The oil is vaporized and cracked in passing through the coils 30, and the cracked vapors are conducted from the coils 30 through connecting pipes 34 to a cooling header 36 in which they are immediately chilled by the evaporation of jets of cooling water or other liquid injected through inlet pipes 37 into direct contact with the'vapors. The chilled vapors pass ,from the cooling header 36 through a delivery pipe 38 and a pressure valve 40 to the lower part of a dephlegmator' column or chamber 42 shown in detail in Fig. 2 of the drawings.

The partly chilled vapors entering the dephlegmator 42 through the pipe 38 are received in a chamber 44, Fig. 2 in the lower partof the dephlegmator. In the chamber 44 the vapors are further cooled by a jet' of water entering the chamber through a pipe 46 and sprayed into the vapors through a nozzle 47. The water is divided by the nozzle 47 into a very-large number of very small drops or particles which are dispersed.

uniformly throughout the upwardly passticles, which accordingly evaporate substantially instantaneously into the vapors. This evaporation absorbs a large quantity of heat and chills thevapors throughout to a definite temperature. The temperature of the vapors is measured by means of a pyrometer 48 and the quantity of water injected is adjusted to bring thetemperature to a definite point. vapors the heavier hydrocarbons are condensed throughout the-vapors and form a mist or suspension, the formation of the mist being apparently facilitated by the presence of the small drops of water, which appear to form nuclei for the building up oi the condensed particles and favor the formation of substantially uniform drops or particles of condensate throughout the vapors.

From the chamber 44'the vapors pass upwardly through an opening 50 in the center of. a bafile 52 which extends across the dephlegmator and flow outwardly to the edge of a second battle plate 54 and up qwardly through a passage 56 between. the

In the sudden chilling of theover the baffle plate 54 and upwardly through an opening 60in a higher baflle plate 62 into a chamber 64. In passing back and forth between the bafiles 52, 56 and 62, the suspended particles of condensate impinge on the walls of the baflles and the inner wall 58 of the dephlegmator and are separated from the upwardly passing vapors and gases. From the chamber 64', the gases and vapors pass upwardly through the baffles 66. 6 8, and 70 arrangedsimilarly to the baflles .52. 56, and 62 in which any further particles of liquid condensates are separated from the gases and vapors.

After passing through the baflle 70the gases are received into a chamber 72 into which a second supply of coolingiwater is .injected through an inlet pipe 74 and The temperature of the gasesand vapors in the chamber 72 is measured by means of a after leaving the condensing zone. This bal,-' ance between the lifting and lowering forces pyrometer 76, and the quantity of water entering the pipe 74 is adjusted by means of a valve 7 8 to maintain a definite temperature in the chamber 72. The temperature in the chamber 72 is maintained at approximately the temperature of the upper end point of the light hydrocarbon liquid to be produced in the process. Those hydrocarbons-having boiling points higher than the temperature maintained in the chamber 72 and lower than that maintained in the chamber 44, are therefore condensed. and form a mist of condensed particles in the chamber 72.

The velocity of passage of the gases upwardly through the chamber 72 is so controlled as to obtain a balance between the force of gravity tending to cause the particles of condensates to fall and the lifting force of the upwardly passing gases, and to' thereby hold the suspended particles substantially stationary in the zone or chamber '72. .The tendency'of the particles to rise may be further lessened through the decrease in volume of the gases due to the condensation of the hydrocarbons, and the consequent decrease in velocity ofthe gases on the condensed particles causes the suspend-ed particles to accumulate. in the chamber 72. The accumulation of suspended particles is continuously removed from the chamber by withdrawing a small quantity of the upwardly passing gases through an outlet opening 80, in the. side of the deplilegmator. The proportion ofgases withdrawn through the opening 80 is comparatively small as compared with the volume passing upwardly through the dephlegmator, since a much greater velocity must be maintained in an upward direction to sustain the particles against the force of gravity than to draw them through the opening80 in which their passage is not opposed by any force.

To prevent any of the suspended .particles from being carried upwardly with the gas, the gas is passed through a number of battles s2, 84., 86,88, 90, 92, 94, 96 and 9s arranged similarly to the baffles 52 to 70.

- 10-1 to a condenser After passlng through the uppermost bafiie 98, the vapors free from the condensates and containing only the vapors condensable below the temperature maintained in the chamber '72, together with steam and incondensable gases. are received in.an uppermost chamber 100. The. gases and vapors are withdrawn from the chamber 100 through an outlet pipe 102 and pass through a vapor pipe 7 106, in which the light vapors are condensed.

The heavy condensates which are caught on the baflies. 52 and flow downwardlythrough a number of overflow pipes 108,

fold 126 by tackle blocks or through overflow pipes 122 to the baflle. TO.

As these condensates, however, flow downwardly over the bafiies 70, 68, 66, 56, and 52, they are reevaporated. and carried upwardly with the upwardly passing vapors and agaln brought 'into' 7 the chamber 72 and recondensed.

The mixture of suspended condensate and gases withdrawn through the 'outletpipe passes into a condenser or separator in which the'condensed particlesare collected and removed to a run down tank or to the oil supplytank. This condensate is similar in boil-, ing point range and composition to the by drocarbons which are supplied-to the process through the pipe 10 and may, therefore, be returned, together with additional supplies of oils to the cracking process. y In the description of the process given above, water has been indicated as the cooling fluid, in the different temperature zones.

The invention is not, however, limited to the use of water as a cooling fluid and any fluid capable of maintaining the desired temperature maybe substituted for water. In some cases it may be desirable to use certain types of crude petroleum or petroleum distillates,

necting a number of draw-off pipes, similar to pipe 80, to the chamber 64 and to the spaces between baffles 86 and 88 and 92 and 94.

The dephlegmator is provided with adraw-oft' pipe 122 at its lower end, and with a removable cover 124 through which access may be had to the upper. part of the tower, for purposes of cleaning and repair. derrick or angle 126 is provided at the top of the dephlegmator for removing the baffles 52 to 98- in cleaning and repairing the apparatus. Each of the baflies 68, 84. 90 and "96 is provided with rings 128, 130, 132 "gaged by a hook suspended from the scafpulleys or other suitable hoisting means. The baffles are connected in sets of three so that upon lift- 134. 136 respectively, which may be e11 ing the baflies 54, 68, 84, 90 and 96 the baffies immediately above and below are lifted at the'same time. i

, While the invention has been described in connection With a particular type of oil cracking process it will be understood that it may be applied to other processes and to products than those described above.

Having described the invention what is;- claimed as new is:

1. A method-of fractionating mixtures of vapors of varying boiling points, which com-v prises condensing and removingthe highest boiling fraction from said vapors, passing the remaining vapors upwardly,'inject ing a' cooling fluid into said upwardly passing va-' -pors in amount sufficient to condense an intermediate fraction and form a'suspension of said fraction in said vapors, maintaining the velocity of said gases at such a rate as to hold the suspension within a fixed zone, withdrawing said suspension and'a portion of said gases from said zone, removing any suspended particles carried upwar ly from said zone, returning said particles to the vapors below-said zone, and removing and. condensing the vapors separated from said intermediate condensate.

2. A method of fractionating vapors of different boiling points, which comprises injecting a cooling fluid into, and forming a suspension of high boiling condensates in, said vapors, separating said suspended condensate, passing said vapors upwardly, injecting a liquid spray into said vapors and condensing an intermediate fraction to form a suspension of said fraction in said va or's, maintaining the suspension of interme iate fraction in a fixed zone, withdrawing a portion of the gases and suspended particles from said zone, removing particles of suspended condensate from gases leaving said zone, and removing and condensing said residual vapors.

3. In a method of frac'tionating vapors of different boiling points, the step which comprises injecting a spray of cooling liquid into a moving streamof said vapors, and diverting a mixture of condensed particles and vapors from said stream in a direction different from the general direction of. movement of said vapors.

4. In a method of fractionating vapors of differentboiling points, the step which comprises suddenly chilling said vapors to a substantially uniform temperature within temperature limits, forming a suspension of condensed vapors within said temperature limits, and diverting said suspension of condensed vapors. r

, 5. A method of fracti-onating vapors of different boiling points which comprises condensing and removing from said vapors constituents having boiling points above a throughout to a lower temperature and,

forming a suspension of intermediate condensates in said vapors, maintaining the velocity ofsaid vapors at a rate to maintain said suspension within a definite zone, with'- drawing a portion of sald vapors and sald suspension from said zone, freeing said upwardly passing vapors from said suspension, and condensing said vapors.

6. Ina method of. fractionating vapors of different boiling points, the steps of sprayingliquid into an upwardly moving stream of vapors, maintaining the velocity of the an upright column, means for spraying a cooling liquid into the lower part of said column, bafliing means above said sprayin means, means for spraying a cooling liquid into said column above said bafiiing means, an outlet from said column adjacent said last mentioned spraying-means, additional baflii-ng means above said outlet, means for returning liquid-from said bafiling means to the lower part of said column, and an outlet from the upper part of said column.

8, In an apparatus for treating hydrocarbon oils the combination of a furnace, pipes in said furnace, means for supplying fluids to said pipes, a cooling header connected to the outlet ends of said pipes,'means for ln ecting liquid into said header, an upright chamber, connected near its lower end to said header, means for spraying liquid into said chamber at different heights, outlet pipes adjacent said liquid spraying means, and baflies positioned between said liquid spraying means.

9. In'an apparatus for treating hydrocarbon oils the combination of a furnace, a number of pipes in said furnace, means for supplying fluids to said pipes, a cooling header connected to the outlet end of said pipes, means for spraying liquid into said cooling header, a dephlegmator connected to said cooling headerand a pressure release valve between said cooling header'and said dephlegmator. v

' 10. In an apparatus for treating hydrolos carbon oils the combination of a furnace, a

number of treating pipes in said furnace,

means for supplying fluids to said pipes, a

header connected to the outlet ends of said pipes, a means for injecting liquid into said header, andmeans for, fractioniating the vapors thus cooled.

11. An apparatus of the class described comprising means for cracking hydrocarbon oils, means for condensing the heavy fraction from the'resulting mixture of hot vatemperature limit, chilling said vapors pors, means for forming a mist consisting of condensed partieles of an intermediate fraction su nded inuncondensed vapors, means for d verting a ortion of said mist, means for condensing t e intermediate fraction from the diverted rtion of said mist and returning said con ensate to the cracking means for rerunning, means for separat-' ing the intermediate fraction from thatportion ofthe mist which is not diverted, and means for revaporizing such condensate and returning it to said mist, and'means for removing the uncondensed gases and concondensed vapors having boiling points be-- low that of the intermediate fraction 'for further condensation and separation.

- 12. An apparatus of the type described comprising means for crackinghydrocarbon oils, a fractlonatmg column into -which the resulting mixture of hot vapors is directed,

means in the' lower partof said column for condensing the heavy fraction from said mixture of hot vapors, means in said column for forming and maintaining a mist consisting of condensed particles of an intermediate fraction suspended in uncondensed vapors, means for diverting a portion of said mist, means for separating thecondensed intermediate fraction from those portions of the mist passing into the upper part of said column, means for returning such condensate to the lower part of the column, and means for carrying ofii'the uncondensed vapors having a boiling point below that of the intermediate fraction for further condensation and separation.

In testimony whereof, I aflix my signature.

- CHAUNCEY MATLQCK.

Images