US1757596A - Method and apparatus for processing heavy oils - Google Patents

Description

May 6, 1930.

\,. A-. J. sLAG'rER METHOD AND APPARATUS FOR P'OCESSING HEAVY OILS Filed March 28, 1924 2 Sheets-Sheet 1l H U (tkl NN MM.

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May 6, 19.30. A. J. sl- AGTER METHOD AND APPARATUSKOR PROCESSING HEAVY OILS Filed March 28, 1924 2 Sheets-Sheet 2 /N v-EAN Tae Patented May 6, V1930 UNITED .STATES- ABTHUR J'. SLAGTR, OF MUSKOGEE, OKLAHOMA, ASSIGNOR TO TRANSCONTINENTAL i PATENT l OFFICE OIL COMPANY, -OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OIF DELAWARE METHOD AND 4APPARATUS FOR PROCSSING HEAVY OILS Application led March 28, 1924'. Serial No. 702,565.

This inventionrelates to a method of pro'- cessing heavy oils, such as gas oil and to new and improved :pparatus for carrying forward the metho An object of the invention is to produce a method of processing such heavy oils whereb a greater yield of high volatile fractions is o tained and in which the quality of such fractions is better than has heretofore been obtained by'methods now in use and known to me.

A further object is to produce an improved method such-that a greater volume of distillate may be effectively processed in a unit of 15 'time without materially increasing the expense of the apparatus employed or without increasing the slze of such apparatus.

A further object is to produce a method of l ing heavy hydro-carbons, such as fuel oilsv and heavy natural crudes, in which an improved quality and-increased quantity of the volatile fractions is obtained and in which the process may be continuously carried forward for relativel long periods as compared to present methode employed in oil cracking or distillation processes.

These and other objects which will be made more apparent throughout the further description of the invention are attained by means of the methods herein set forth and the apparatus herein illustrated and described.

In the drawings accompanying and forming apart hereof, Figure l is a more or less diagrammatic view of apparatus embodying my invention. Fig. 2 is a front elevation of a portion of the apparatus shown in Fig. -1.

Fig. 3 is a front elevation of a portion of the apparatus shown in Fig. 1, which may be employed as an auxiliary to the apparatus disclosed in Fig. 2. Fig. 4- is a detail of a -porv tion of the apparatus disclosed in Figs. 2 and 3. Fig. 5 is a modified form of apparatus for for carrying forward a modification of the method of processing employed in connection with t'ie apparatus illustrated in Figs. 1 and 3. Fig. 6 is a diagrammatic detail of view of a p: rtion of the apparatus shown in Fig. 5; ann Fig. 7 is a further modified form of apparatus which may be employed in carr ing forward a substantiallycontinuous method of processing heavy hydro-carbons or disl tillates.

The inventions -herein set forth are particularly applicable to oil-cracking operations, which distinguished from the usual and well-known distillation processes in that the molecular character of the high volatile fractions resulting froln the method of processing 7o isl modified by the application of heat under the conditions encountered.

In the present invention, 'I employ a still., slmilar in general characteristics to the stills employed in ordinary distillation and 0il cracking rocesses. For example, the 'still 8 disclose in Fig. 1 may be of the ordinary. type which is. heated by a furnace 8a located l below it. The method of processing employed by me, however, distinguishes from the ordinary distill'tion process in that the distillate is maintained under a pressure approximately eighty pounds above atmosphere, and theproducts given ofi1 by the still are maintained under this pressure while being sprayed with raw distillate, which is subsequt --tly delivered to the still, and while being further cooled to a predetermined temperature by a gradual reduction of the heat carried by them.

' As illustrated, in Fig. 1, the high volatile4 5';

fractions, or the gaseous products resulting from the method of processi-ng, 'are withdrawn from the still through a pipe or passage 9 which communicates with a header 10 forming a art of apparatus which may be termed a dephlegmator. At least two risers or pipes communicate with the header l0 and extend vertically to a second header 12. These pipes are preferably exposed to atmospheric temperatures and are ,of such diameter as to provide a large cooling surface per unit of volume of the gaseous product passing through them. For example, in apparatus employed by me, the pipes 11 are of 10-inch diameter throughout the major portion of their length but are reduced to approximately 6 inches in diameter atthe junction with the header 12 for the purpose ofy directing the flow of gaseous products issuing from them and insuring an intimate mixture of these products with raw distillate delivered to the header l2 in the form of spray.

As shown in Fig. 4, a spray pipe 13 extends longitudinally throughout the length of the header 12 and is provided with spray nozzles or orifices 14 which are spaced along the spray pipe to correspond with the spacing of the pipes 11. In order to provide a uniform delivery of raw distillate spray to each of the risersll, the orifices 14 are reduced in diameter from the inlet end of the spray pipe so that the orifice of largest diameter is most remote from the inlet end ofthe spray pipe. In practice, I have. found `that 'satisfactory results are obtained with the spray-delivery orifice immediately adjacent to the inlet end of the spray pipe 35 in diameter and with each successive orifice increased by 912 in diameter. Each orifice is located immediately above the delivery end of a riser 11, and the orifices are directed downwardly, and are of such size, relatively to the outlets of the risers 11, that the entire cross sectional area of the outlet of each riser is completely filled with spray; I have also obtained satisfactory results by delivering the raw distillate to the supply pipe under a pressure varying from 125 to 150 pounds above atmosphere where the ressure within the header 12, and commumcating passages, is maintained at eighty pounds above atmosphere.

With the arrangement of apparatus employed, the gaseous products delivered from vthe .still are intimately mixed with the spray issuing from the spray pipe 13 and are further subjected to the expansion of the raw fractions occasioned by the reduction in presthe processing o eration and the quality oftions combine or unite with t sure and the increase in temperature to which they are subjected on being sprayed within the header 12. This intimate mixture of the hot gaseous products with the raw fractions occasions a reaction within the header 10, pipes 11 and header 12, which improves both the material resu tin from this operation.

It appears that t e intimate mixture of these products and the raw fractions, occasions a chemical` reaction between the high volatile fractions of the raw distillate, which are liberated by the expansion and the heat to which they. are subjected in the header 12,

j volatile frace high volatile fractions resulting both, from the distillaand pipe 11, and that thesehih tioneand cracking process. In addition to lThis proportion may,

occasions a carrying back of the lower volatile fractions, which may be liberated from the distillatein the still, and consequently these fractions are at least partially condensed and entrained by the raw -distillate and returned to the still.

This operation also appears to improve the quality of the products of the processing operation over that which would be obtained if this condensate or low volatile material were returned to the stillindependently of the raw distillate. In addition to this, the continuous delivery of the raw distillate to the still during the method of processing, improves the operation of the method, since it tends to reduce the deposition of carbon within the still and, of course, continues the operation for a longer period and increases the amount of distillate which is acted upon during a single run. In practice, I preferably deliver raw distillate during the processing operation in amounts equal to about one-third of the products given-ofi. however, be varied by varying the temperature conditions and italso may be varied for different qualities of the raw distillate employed.

A second series of vertical pipes or passages communicates with and extends above the header 12. In `Fig. 1, these pipes are indicated by the reference numeral 15 and they vcommunicate at. their upper ends with a header-16. The header 16 is provided with an outlet pipe or passage 17 which may conimunicate directly with a water-cooled condenser 18, but which -is provided with a relief valve 19 for controlling the delivery to the condenser 'and incidentallyl for controlling the pressures maintained Within the still 8, the headers 10, 12 and 16 and the communicating passages. It will, of course, be apparent that this valve, when opened more or less, will maintain the pressure within the communicating passages only by reason ofthe application of heat to the-still 8 and the resultant fiow of gaseous products from the still. Under operating conditions, the gaseous'. roducts traversing the passage 17 lwill be elivered directly to the condenser 18 if their temperature isapproximately 400 degrees F. I-f this temperature is exceeded' an appreciable amount, I employ a secondary reaction chamber similar to the apparatus described in connection withthe headers 10, 12 and 16 and illustrated in Fig. 3 of the drawin s. l

As il ustrated, this' secondary apparatus consists of a header 20 which is provided with risers or pipes 21 corresponding in lo cation and function to` the risers 11. These risers are reduced in diameter at their upper ends and communicate witha header 22 pipes 13 and 23 is controlled by the valves` 31 and 32, respectively. The delivery pipe 17 is also in communication with the header 20 through one or more pipes 33 which are provided with a valve 34. As shown,'the pipes 33 communicate with eachA of the risers 21,.but a single connection may be made .between` the pipe 17 and the header 20 if desired.

Under conditions such as above outlined, i. e., where the temperature of the gaseous products in the pipes 17 are materially in` excess of 400 degrees F., vthe valve -29 is partially opened and the valve 19 isfully closed after the valve 34 .has been fully opened. The valve 32 is also opened, it being understood that the valve 31 is open, and a valve 35, in a return 36 from the header 20 to the outlet pipe 9, is open. This return is also provided with a check valve 37 which is adapted to permit a free flow of liquid from the header 20 to the pipe 9 but to prevent a flow in the opposite direction.

Under conditions above set forth, the gaseous products issuing from the head-er 16 will pass through the piping 17 and 3 3 to the secondary apparatus where it ,is delivered to the risers or pipes 21 and is therefore subjected to a continuation of the slow cooling process to which it was subjected in traversing the risers 15 and the pipe 17. In addi-A tion, these gases delivered to the risers 2l are also subjected to a spray of raw distillate delivered into the outlet of each, of the -risers 21. As has been said these risers 2l are reduced in diameter at their upper ends for-the'purpose of directing the flow of gasecus products issuing from them and for insuring an intimate mixture of these products with the spray issuing from the spray pipe 23. v

`It will be apparent that the same reaction takes place in therisers 21 and the header 20 as took place yin the headers 10 and risers 11, although the activity of this reaction may differ in degree from that of the former action, due to the fact that the temperatures are somewhat reduced. If, however, the temperatures encountered in the secondary apparatus are substantially the *same as those encountered in the primary apparatus, viz: headers 10, 12 and 16 'and communicating passages, then the reaction occurring in the secondary apparatus will-be substantially the same as that in the primary apparatus and the gaseous products will becooled by their contact-with the raw distillate, their chemical or atomic characteristic will also be modified by the chemical reaction between them and the high volatile fractions liberated bythe instantaneous reduction in pressure and the high temperature to which the raw distillate is subjected, andV also by the carrying-back operation occasionedby the counter-current How of'this distillate s ray in movingl downwardly through the risers 21 and the header 20. 4

If the rate of the operation of the still,

and other conditions are such that theitemperature of the gaseous products issuing from the `header 26 is still materially above ythe desired temperature of 400 degrees F., I- i may employ additional apparatus corresponding to that illustrated in Fig. 3,. since the most satisfactory results are obtained where the process is operated under such conditions that the gaseous products are delivered to the water-cooled condenser 18 at about- 400 degrees F.

The primaryand secondary dephlegma'tors and any additional dephlegmators which may 4 be employed are all exposed to atmospheric temperatures and consequently the operation of the processV may have to be slightly varied to compensate for varying atmospheric conditions. .In other words, in extremely cold weather, I have found that it is desirable to heat the raw 'distillate introduced in thev form of spray to a temperature not to exceed degrees'. Other conditions maylbe maintained substantially ,normal even under wide variations in temperature conditions by varying the heat applied to the still andby manipulation of the amount of spray delivered.

In Fig. 1, I have illustrated an emergency relief valve 38 in a passage between the outlet pipev9 and the intake to the condenser 18.

The valve is only opened under emergencyv Aconditions and for the purpose of preventing `waste of lproducts through a safety valve 39 with which the header 10 is equipped.

In Fig. 2, ,I have shown the outlet pipe 9 stills and is accomplished by proy-iding a T- connection in the `outlet passages immediately adjacent to the outlet port of the still and 'then employing two sets of similar piping .between this connection and the header 10.

the header 20 eachpipe will preferably comv municate with one branch pipe 9.'

In Figures 5 and 6 I have illustrated a modified form of the still employed'in connection with the apparatus heretofore dev as having two branches. This corresponds to a. well known practice inconnection with livered to the outl scribed. This modification of the apparatus to some extent modifies the method of'processing described and materiallyimproves the quality of the product. As illustrated the still is provided With means for maintaining .v a rapid and forced circulation of the disvelocity to the hottest portion of the still.

As illustrated I employ a pump, shown as acentrifugal pump 40', Within the still. The intake or suction of this pump communicates with a trap 4l located in the top of the still and surrounding the outlet port 91 through which the aseous products are dee? pipe 9. This trap receives the raw distillate as it fiows in through the inlet` port from the header 10 or the secondary header 20- of Fig. l. As shown a pipe 42 connects the bottom of the trap with the suction of the pump and this pipe is provided With an additional inlet opening which communicates with the interior of the still and receives oil from a predetermined level within the still. opening consists of a short section of pipe 43 which extends upwardly Well above the bottom ofthe still to the desired level Within the Well. The function of this pipe is to supply sufiicient liquid to the intake of the pump to satisfyV the-demand of the tions with the oil contained in the still and to maintain-a uniform mixture throughout all portions of the still. This uniformity of mixture Within the still assures themaintenance of a uniform temperature throughout Vthe mass of oil in the still. The outlet of the pump communicates with a distribution passage 44, which is'preferably divided as shown in Fig. 6 and-Which extends longitudinally of the still near its bottom. This .passage is shown as formed of piping and is'yprovided with delivery apertures Which are equally spaced along the passage and are so posii tioned with relation thereto that they deliver theliquid pumped through them downwardly and'againstthe bottom of the still.

augmented by the forced circulation occasioned by the operation of the pump, and, in addition, the ow from the pump occasions a As shown this additional i pump. Its further, and most important function is to insure a thorough mixing of the incoming raw fracdirectly connected to. the

Washing or scouring action over the hottest portions of the still and therefore effectively and efficiently carries away the heat occasioned by the furnace. This scouring action also minimizes the deposition of carbon With in the still .and in th1s respect maintains the heat transfer lmore or less uniform during the entire ru'n. Another function of the pump and the distributing passage employed 1n connection With it, is that the high rate of dischargefrom this passage maintains a more or less turbulent circulation Within the still and therefore prevents local` excess heating. This prevents-some portions of the still be-v ing more active in the evolution of the gaseous products than others and therefore insures uniformity ofthe gaseous products delivered from the still. A

In Figure 7 I have illustrated a still further modification of the apparatus employed for carrying out my improved process and this modified form of apparatus also, to some extent varies, the process. As there illustrated the apparatus consists o-fa heating chamber 45', Which`is equipped with coils-'46 through which the oil is circulated during the processing operation. Any means may be em`- ploy'ed for delivering heatto this chamber and I have diagrammatically shown an oil burner 47 for this purpose.

Asillus'trated both lthe inlet and the outlet of the coil 46 communicate w' h an expansion chamber 48 from which the lighter fractions are delivered and to which the raw distillate is also delivered. 1 Fundamentally this apparatus functions on the Asame principal as the apparatus illustrated in Figures 1 and 5 and is adapted to be'employed in connection with a reaction chambersuch as described in connection With the.

headerslO, 12 and 16 of Figure l. For this reason I have illustratedthe expansion chamber provided with an outlet port 9b, which communicates with an outlet piping 9 having the same functions'as' the outlet piping 9 of Fig. 1,'in that it delivers the hot gaseous products to a header chamber 10 Which communicates with the risers 1 1 having the same -functions as the risers 11 of Fig. 1. Thesey risers also .communicate Wlth a header 1.2 equipped with a spray pipe as illustrated in Fig. 4 and also provided with risers 15 which correspond in function to the risers 15 of Fig. 1. The header 16.* of this apparatus is shown intake of a Water cooled condenser 18 by a relief pipe 17 having a relief valve 19. It will also be apparent that the secondary apparatus disclosed in connection with Fig. 1 maybe employed in connection with the apparatus just described.

The port 9b is equipped with a trap 41 corresponding in function to the trap 41 of Figure 5 in that it for the gaseous products and at the same time receives the raw fractions entering through provides\an adequate outlet 49, which is adapted to maintain a rapid' and the piping 9. 'Asillust-rated the expansion chamber is provided with a circula-ting pump vWhich extends upwardly tothe desired level within'the expansion chamber. -With this arrangement the ,fractions entering the trap 41 are combined with oil contained in the upi per part of the expansion chamber on being delivered to the pump and are notonly thoroughly mixed with this'oil but are -delivered at a high velocity through th coils 46 and then to the upper portion ofthe expansion chamber. i

This arrangement of apparatus while insuring an intimate mixture of the raw distill-` ate with the oil in the expansion chamber,

' promotes temperature stratification within the expansion chamber, since the hot oil issuingfrom .the heating. coils 46 is not mixed with thel incomingcold or cooler raw distillate. This is of-'inateiial advantage, since the evolution of the lighter fractions and the cracking of these fractions is not impeded or affected in any way by a reduction in temperature occasioned by the incoming' raw distillate. As a further result of this arrangement of apparatus the evolution of the lighter fractions takes place in the upper portion of the chamber 48 and the heavier residuum settles to the bottom of the chamber from which it may be Withdrawn through either the branch pipe 52 or a branch pipe 53 which is located at a higher level in the chamber.

From the foregoing it will be apparent that.

raw fractions may be continiially introduced into the expansion chamber and that the v heavy residuum may also be continually withdrawn throughout the operation of the process. Where this is accomplished I deliver heat .'in such quantities to the coils-46 that the raw fractions of raw distillate may beintroduced to the reaction-chamber in such-quantities as to replace the oil taken out as distillate or residuum.;

' It will also be apparent that the bottom portion of the expansion chamber is practically unaffected by the currents set upby ythe pump 49 and that therefore the settling operation is accomplishedunder ideal conditions. In addition to this the high velocity of travel ofthe oil passing through the coils 46, increases the heat transferthrough these coils by the scouring action, and this in turn,

prevents or at least lminimizes the deposition f of carbon within the coils, with theresult that the process can be continued for indefinite periods without the necessity `of shutting down for the purpose of'cleaning the coils.

are well adapted for The forced and positive circulation through .the coils '46 also make it possible to process heavier residu'um or'heavier natural crudes than could be processed successfully in appailar distillates is particularly adapted for heavier oils, such as fuel oils and heavy natural crudes. As a matter of factl such elaborate apparatus is not necessary for the satisfactory treatment of any distillates except those heavy residuuins to which I-have referred. The `apparatus of Fig. 7 is also particularly adapted for use where exceedingly high pressures are employed, such as pressures employed'in the cracking of kerosene and like distillates. It is apparent that the various chambers may be reduced 'to a minimum size because of the continual withdrawal of the residuum and the continual delivery of the raw distillate. Then too, the portion of the apparatus subjected to the greatest temperature-is formed of piped coils which high pressures and high temperatures. v

What I claim is 1. A. method of treating petroleum oil which consists in heating a body .of oil to a cracking temperature while subjecting it to i pressure materially above atmospheric pressure,l continuously withdrawing vaporous productsresulting from said heating and slightly cooling the saine while maintaining said pressure, continuously mixing said products with fresh oil and returning the liquid, products of said mixing back to-thebody of oil forcing said liquid products to the hottest part of the body, a-nd subjecting the vaporous products to gradual cooling while maintaining said pressure andfurther cooling said iioA ing it in the form of spray into separately directed streams of said slightly cooled vaporous products, delivering the residue oil from 1 said spray to said batch in a continuous and unobstructed flow `in'intimate contact with body the hot vaporousproducts withdrawn therefrom, and delivering such liquid products to a hotter portion of the batch, and then condensing the vaporous products after said treatment with fresh oil.

3. A process of treating heavy oil to produce oils having a lower boiling point, which consists in heating a batch of heavy oil to a cracking temperature in a still while maintaining it under pressure, continuously Withdrawing lighter fractions from the still while maintainin the pressure, mixing the lighter fractions wile hot and while under pressure With a finely divided spray of fresh oil, continuously delivering the Aliquid products of the mixture to the still in contact with the lighter fractions being withdrawn therefrom and positively forcing said liquid products to the hottest part of the still by a positive circulating means, gradually cooling the vaporous products of the mixing while maintaining said pressure and then condensing said vaporous products after expanding them to a lower pressure.

4. The process for treating heavy oil to produce `fractions `of lower boiling point,

which consists in maintaining a body of heavy oil under pressure while circulating it at a high velocity and subjecting it to a cracking temperature, withdrawin vaporous products resulting from said ieating, directing said vaporous products in Well defined streams, subjecting all portions of each stream to a finely divided spray of fresh oil, delivering the residue of the oil from the spray to said body below the surface thereof and positively forcing it to the hottest portion of the body, Gradually cooling said vaporous products a ter subjecting them to said spray and then expanding said products `to atmosphericl pressure and subjecting them to a condensing temperature.

5. The process of treating oils of high boiling point to produce lighter fractions having low oiling point, which consists in heating a of oil in a still to a cracking temperature While maintaining it under pressure substantially above atmosphericl pressure, maintainlng a fgrced circulation of the oil within the still ttljlproduce a scouring action on the heatedportion of the still, and withdrawing vaporous products resulting from said heatmcg, subjecting said products to a finely. divi ed spray of fresh oil and deliverin residue of the oil from said spray to said bod the surface-thereof and positively directing such fresh oil so delivered to the hottest portion of the still. V

6. In an apparatus for processin oil, a receptacle for oil having a vapor elivery y below having its inlet submerged below the surface of the oil contained therein, a heating coil communicating with the outlet of said pump and with the top of said receptacle, and means for delivering fresh oil to said receptacle through said vapor delivery port and to the inlet of said pump.

7. An apparatus vfor processing oil comprising a still, a dephlegmator consisting of headers and risers for directing vaporous products passing therethrough into well defined streams, an yunobstructed liquid and iiuid passage from said still to said dephlegmator, and means for introducing a finely divided spray of fresh oil to each well defined stream of vaporous products traversing said dephlegmator and in counter current flow relation to said stream, and means for delivering the liquid products of said spray traversing said unobstructed passage tothe hottest portion of said still and for maintaining a foled circulation of the liquid within the sti 4 Y 8. An apparatus for processing oil comprising a container for oil having a vapor delivery port formed in the. top thereof, a dephlegmator communicating with said port, means for delivering oil sprays to the vapor pasi sages of said dephlegmator, a trap for receiving liquid delivered from said dephlegmator located within said container below said port, a circulating coil and a pump located within said container having its inlet communicating with the said trap and its outlet communicating with a circulating coil.

9. A method of treating petroleum oils, which consists in heating a quantity of oil in a still to a cracking temperature while main.

taining it under pressurematerilly above atmospheric pressure, withdrawing vaporous products resulting from such heating from the upper part of said still, while maintaining said products under pressure,. dividing the fiow of said products into separate streams in which they are gradually cooled while under pressure, delivering fresh oil in the form of spray to each of such streams and passing the liquid product of such mixture of oil andl hot vapors to said still in contact with vaporous products leaving said still.

In testimony whereof, I have hereunto subscribed my name this 25th day of February,

lARTHUR J. SLAGTER.

port formed in the top thereof, and a residuum delivery port formed in the bottom thereof,

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