US2493036A - Method of and apparatus for minimizing deposition of carbonaceous material - Google Patents

Description

METHOD OF AND APPARATUS FOR MINIMIZING Jan- 3, 1950 R. T. SAVAGE Er AL 2,493,036

DEPOSITION OF CARBONACEOUS MATERIAL Filed July l, 1948 2 Sheets-Sheet l g iN;

ATTORNEY Jan- 3, 1950 R.'T. SAVAGE T AL 2,493,036

METHOD 0F AND APPARATUS FOR MINIMIZING DEPOSITION OF CARBONCEOUS MATERLL .2 Sheets-Sheet 2 Filed July l, 1948 ATTORNEY vPatented Jan. 3, 1950 UNITED STATES PATENT OFFICE METHOD OF AND APPARATUS FOR MINI- MIZING DEPOSITION OF CARBONACEOUS MATERIAL poration of Delaware Application July 1, 1948, Serial No. 36,304

3 Claims.

Our invention relates to a hydrocarbon conversion system and has particular reference to a method of and apparatus for at least substantially preventing deposition of carbonaceous material on one or more mechanical parts extending into an atomizing zone forming a part of said system.

More particularly, our invention relates to a hydrocarbon conversion system wherein at least a substantial portion of the gravitating contact material is controlled for movement as a freely falling curtain or stream of contact material having tubular configuration. The atomizer is disposed in the lower area of a zone located within said tubular curtain and this zone is defined by a housing adapted to exclude atomized matev rial therefrom. In accordance with the invention, one or more annular streams of vapors is or are passed through said housing and directed downwardly in sweeping relation with respect thereto so as to substantially prevent deposition of migrating atomized material thereon.

Various other objects and advantages of our invention will become apparent from the following detailed description.

Our invention resides in the method of and apparatus for minimizing deposition of carbonaceous material in an atomizing zone, features. and arrangements of the character hereinafter described and claimed.

For an understanding of our invention and for an illustration of one form of apparatus with which the invention may be practiced, reference is to be had to the accompanying drawings, in which:

Fig. l is a vertical sectional View, partly in elevation, showing a conversion housing and associated apparatus as constructed in accordance with one form of the invention;

Fig. 2 is a vertical sectional View, partly in elevation, showing an atomizer;

Fig. 3 is a horizontal sectional View, partly in plan, taken on the line 3 3 of Fig. 2;

Fig. 4 is an enlarged vertical sectional View, partly in elevation, showing the apparatus of the invention; and

Fig. 5 is an inverted plan View looking from the line '5 5 of Fig. 4.

In an application of Reuben T. Savage, Serial No.y 766,714, filed August 6, 1947, there is disclosed a hydrocarbon conversion process utilization of an arrangement for engaging atomized liquid hydrocarbon material with a freelyfalling stream or curtain of contact material. For purposes of explanation as regards our involving 2 invention, we have included in this application a general disclosure of the subject matter illustrated and described in the aforesaid Savage application.

Thus, referring particularly to Fig. 1, we have shown a Vertical housing l which, in horizontal cross section, may be circular or of any other suitable configuration. The housing I defines a reaction zone wherein hydrocarbon material is cracked or otherwise converted in the presence of contact material C which moves downwardly therethrough under theinluence of gravity, the contact material C being introduced into said housing I in suitable manner, as by an inlet pipe 2 extending through the top housing wall at the center thereof.

A shallow receptacle-like member 3 may be suitably supported in the upper portion of the housing l, said member 3 having a central discharge pipe 4 opening therethrough and extending downwardly therefrom. If desired, the lower end of the pipe 4 may have a frusto-conical pipe 5 suitably secured thereto, as by a flange-andbolt connection 6. With an arrangement of this character, the lower end of the pipe 5 has diameter somewhat greater than that of the lower end of the pipe il. Obviously, the pipes i and 5 may be replaced by a single pipe having desired uniform diameter throughout the length thereof.

Disposed interiorly of said discharge pipe 5, immediately adjacent the lower end thereof, is a frusto-conical member l, the lower surface of which, preferably but not necessarily, is positioned in the same horizontal plane as the lower surface of the pipe 5, said conical member l being suitably supported in the position shown, as by a plurality of bars 8 secured thereto and to said pipe 5. The external diameter of the lower surface of the conical member l is suitably less than the internal diameter of the lower surface of the pipe 5 and, accordingly, these two surfaces define an annular passage 9 utilizable as hereinafter described. The pipe 5 and the conical member 1 should be symmetrically related to each other and, if so, the width of the annular passage 9 l is uniform throughout the circular length thereof.

Preferably, the arrangement is such that the exterior sloping surface of the conical member 1 forms with the interior sloping surface of the pipe 5 a path which diverges in a direction leading upwardly from the aforesaid annular passage 9.

A pipe I0, adapted to be traversed by hydrocarbon material, which is either partially or entirely in the liquid phase, extends from the exterior of the housing I to the interior thereof and, if desired, this pipe I may enter the aforesaid pipe at any suitable level and pass downwardly therethrough in coincidence with-the longitudinal axis thereof.l If so", the pipe I t) passes'- through' the aforesaid conical member 'I to which it is welded or otherwise suitably secured in sealed relation and terminates a suitable distance below said conical member 'I' where it communicates with and supports an atomizer' A' of any suitable type which, as herein illustrated, is of the general character disclosed in the pending application of James E. Evans, Serial No. 7560321ed Junef20,Y 1947, although, if desired, the atomizer A may be of the character disclosed in the pending application of Reuben T. Savage, Seriall No. 792,810, filed December 19, 1947. A pipe II adapted to be traversed by hydrocarbon vapors extends from the exterior of the housing I to the interior thereofand-preferably;thispipe' II is positioned at al higher level than the aforesaid pipe I0.

As shown, ther pipe 4, the pipe 5, the conical member I and the atomizer A should be sorelated to each other' that their respective longitudinal axes are in ceincidencelwitlieach other and. also with the lorigitudlinal3 axis of the housing I.

In operation, regenerated or other heated contact material G having! suitable reaction temperature passes continuously from the pipe 2' and, to suitable extent, fills therecept'acle 3 which? defines an upper zone of the housing I. From the receptacle the Contact material gravitates downwardly through: thepipe" Q, the pipe 5 and then through the annular passage 9A which, as hereinafter more fully described, has width su'chthat itY restricts or controls" the downward flow of contact material under the influence of gravity while moving along the described pathabove the plane of the annular passage 9; Below thepla-neA of saidy annular` passage 9, the contact material falls freely un'der' the inu'enceI of gravity as a tubular' curtain or stream S, which is not necessarily circular' in horizontal section, until it comes to' rest upon and' at least partly defines the upper surface of th'e bed B' of gravitatin'g contact material which defines the reaction zone proper, the bottom surface of' the bed of contact material engaging a tube sheet', not' shown, whichis horizontally'disposed inthe housing I' and suitably secured to the interior surface thereof. s the contact material falls freely below the plane f the annular passage 9, it is engaged by liquid hydrocarbon material after atomization thereof" by the aforesaid atomizer A which, shown iii 4, is supported interiorly of the tubular curtain {i} by the aforesaid pipe ID. m Y d `In view of the foregoing, it clearly appears that the atomizerA is disposed in a chamber Dv of the housing I, said chamber D being bounded, at its lower end, by the zone definedby the upper surface of the bed B and, at its upper end, by the aforesaid zone dened by the receptacle 3.

If desired, a plurality of pipes I2 may be spaced uniformly around the interior surface of the housing I. The upper ends of these pipes- I2 communicate with the chamber defined by the member 3, which may supportsaid pipes, and the lower ends thereof terminate at the upper surface of the aforesaid bed of contact material, said pipes I2 being adapted to be traversed by a portion, preferably a minor portiomas 20% more or lessof the total amount of contact material gravitatingthrough the housing I. The pipes I2, when utilized, contributes as regards maintenance of the surface of the bed B at a level approximately that of the lower ends of said pipes.

As stated, the bed B of contact material gravitates through the housing I. and any suitable known oiotlier' arrangement, not shown?. may be utilized for discharging the spent contact material from the housing I for passage through a discharge pipe I3. Likewise, any suitable known or other arrangement, not shown, may be provided fr'disengagingcracked or converted vapors from the contact material C so that they may pass through an outlet pipe I4.

Referring particularly to Figs. 2, 3 and 4, the atomizer A hereinb'ef'ore referred to should be one which produces fog, mist, spray or other liquid particles having suitable dimensions from the liquid hydrocarbon material admitted thereto. As shown, thev atomizer A comprises a casing I5 having a top wall I6 through which the lower end of the aforesaid pipe I0 opens and to which said pipeY is secured. The casing I5 has a lower wall I'I above which said casing I5 comprises vertical andfhorizontal circular plate portions Ilia and I5?)` related to ea'ch other in right-angle relation. In the form of atomizer herein shown, although not necessarily, a row of ports or passages I5c open through the respective casing portions I5a and I5b, these ports Ic being alined in sets. Hydrocarbon material admitted by the pipe Ill to the casing I5 passes to andthrough each of said ports I5c. The atomizer A is disposed interiorly of the tubular curtain S a suitable distance below the annular passage 9 and, preferably, said atomizer A is so positioned that its rows 0f ports I5c, or equivalent are concentrically related to the curtain S.

When hydrocarbon material is to be cracked in the housing I, the contact material C Ihereinbefore referred toshould be catalytic incharacter and. the temperature` thereof, upon admission to the housing I, should range betwen 800 F. and 1000 F. or higher vfor example, about 900 F. Any suitable kind of catalytic contact material may ,4 thus be utilized such, for example, as activated clay pellets, or syntheticsilica-alumina pellets or beads, etc. having suitable major dimensions such as between sie and 3%; of an inch. Other suitable catalysts for cracking include synthetic plural oxide composites, silicious or non-silicious in character and containing, for example, zirconia, alumina or beryllia. In lieu of a cracking operation, other types of conversion operations such, for' example, as one wherein hydrocarbon material of the character referred to below is desulphurizedA under known conditions with catalytic gas oil, naphtha or lighter hydrocarbons having suitable elevated temperature, as in a range from 850 F. to 950 F. are admitted continuously tothehousing I by way of the conduit II. Simultaneously, liquid hydrocarbon material such, for exam-ple, as a suitable residual stock, topped or reduced crude having temperature elevated into Ex suitable range as, for example, from 400 F. to 800 F. is charged continuously through the pipe I under superatmospheric pressure ranging, for example, yfrom 10 lbs. to 200 lbs. per square inch gauge or as otherwise may be required for causing the atomized liquid material from the atomizer A to engage and properly penetrate the contact material forming the hereinbefore described falling curtain S of contact material. The liquid hydrocarbon material thus traversing the pipe II0 passes through the atomizer casing I and the alined atomizer ports I5c of the respective sets thereof are traversed, respectively, by streams of hydrocarbon material which pass toward and engage each other to produce resultant streams yof atomized material which, as a mist or fog, `pass downwardly in inclined relation and penetrate the curtain S throughout a circumferentially complete inner area thereof, Fig. 4.

As stated, hydrocarbon vapors, which in connection with a cracking operation preferably have temperature substantially higher than that of the liquid hydrocarbon material admitted to the atomizer A, are admitted to the housing I by way of the pipe -I I. These vapors pass through the housing I, concurrently as regards the contact material C and in the presence thereof, are converted to cracked products. In so doing, the heat content of these vapors assists as regards vaporization of the liquid hydrocarbon material entering said housing I through the atomizer A and provides a desired control on the space velocity of the entire charge traversing the housing I. Simultaneously, in the manner described rabove, atomized liquid hydrocarbon material is engaged with the fallin-g curtain S of contact material with resultant vaporization of such atomized liquid material and formation of cracked products while passing through the housing I concurrently as regards the contact material C. As regards the total charge entering the housing I, the ratio of vapors to liquid material may be such as is suitable and desirable. Thus, for example, between and 30% of the charge may be in the liquid phase for passage to the atomizer A and the remainder in the vapor phase for passage through the pipe I I.

As particularly described in the aforesaid Savage application, Serial No. 766,714, the thickness of the curtain S and the density of the pieces of contact material forming said curtain are suiicient to entirely or at least substantially prevent passage therethrough of any of the atomized liquid material which is produced land directed into engagement therewith by the atomizer A. This curtain, then, positively prevents or almost entirely lminimizes migration of atomized liquid material to interior surfaces of the housing I and the pipes I2 in the event that the latter fare utilized. Consequently, formation of carbonaceous material on the metallic housing vand pipe surfaces is entirely or substantially prevented. This is highly desirable .by reason of the fact that, if there is any substantial formation of carbonaceous material in the locations stated, chunks thereof sep- Iarate from the main mas-s and -m-ove into and through the bed B of contact material with resultant partial or complete plugging of the outlets, not shown, at the bottom of the housing. Should this happen to any substantial extent, it is necessary for operation of the system to be discontinued for cleaning purposes and this, of' course, is undesirable.

In View of the foregoing, it will be understood that hydrocarbon material admitted to the housing I by way of the pipes I0 and II is converted in the presence of the contact material C and, as described inthe aforesaid Savage application, Serial No. 766,714, this hydrocarbon material passes through the housing I in concurrent relation as regards the gravitating contact material from which the cracked products are disengaged and passed to any suitable destination by way of the pipe I4. In known manner and by suitable means, not shown, a suitable gaseous medium such as steam is admitted to the lower portion of the lhousing I, below the pipe I4 and under pressure above that existing at the level thereof, to prevent passage of hydrocarbon vapors through the pipe I3. Simultaneously, spent contact material leaves the housing I by way of the pipe I3 and, after regeneration, is returned to the inlet pipe 2 for readmission to said housing I.

As stated above, it is a feature of the disclosed process that the curtain S, at least to substantial extent, yprevents migration of atomized liquid material into engagement with the interior surface of the housing I. said curtain S and as stated in the pending application of Raymond C. Lassiat, ASerial No. 776,202, filed Setpember 26, 1947, there maybe migration of atomized liquid material as causedV principally by the splashing effect which occurs when the atomized liquid material engages the interior curtain surface, such migration being undesired for the reasons hereinafter stated. Inv

accordance with the present invention, such undesired migration of atomized liquid material iseifectively controlled, the desired result being obtained in an improved manner compared with the procedure described in the, aforesaid Lassiat application.

Thus, as shown particularly in Fig. 4, a frustoconical member 20 has its larger, upper end welded or otherwise suitably secured, as at ZI, in sealed relation to the lower interior surface of the conical member 'I. Associated with the frusto-conical member 20 is a lower frusto-conical member 20a, the external diameter of the As shown, the extreme lower portion of the upper member 20 overlaps the extreme upper portion of the lower member 20a and, accordingly, the annular passage 22 faces downwardly more or less in a vertical direction. I

In accordance with our invention, frusto-con- Y ical members 20h, 20c and 20d are disposed, inv

the order named, below the frusto-conical member 20a. The relation between each pair of members 20a and 2Gb, 20h and 20c, 20c and 20dis the same as described above with respect to the members 20, 20a. Hence, in addition to the` described annular passage 22, the aforesaid pairs;

of frusto-conical members define successively lower annular passages 22 having progressively decreasing diameter.

Referring particularly to Fig. 4, the lowermost frusto-conical member 20d forms with the exterior surface of the atomizer casing I5 a lower annular passage 23 which, the same as the other annular passages 22, faces downwardly generally in a vertical direction.

In any suitable manner, the frusto- conical members 20a, 20h, 20c and 20d may be secured in the relation described above and as shown in Fig. 4. To this end, a plurality of spaced bars However, interiorly of.

arcanes l or' rods'. 2li may be welded.A boltedi or otherwise suitably secured to interior surfaces" of the reispective frusto-conic'al members to thereby forrm a.j unitary assembly.

As shown` inl Figs. 1 and. 4;. a pipey 25.' extends from the' exterior of the housing. I to' the interior thereof where the inner end. of` said pipe' 25 opens through the'` upper conical member' 1.. Inf view of! the previous description, it willv be understood that the assembly comprising the members. 1', 20,. 2021,2011, c and 20d constitute a housing which denes'the boundary of a zone'having the atomiz'er A. disposed in the lower areav thereof, this zone being sealed` except for thev passages 22,` 23-.

While` hydrocarbon material; is undergoing. conversion in the housing: t ashereinbefore dec--Y scribed, suitable vaporsl aref passed continuously by way of the: pipe 25 into' the aforesaid zone under pressurey exceeding that existing in the chamber D' ofv the housing l. 'Ihesei vapors may' be' off any suitable character` such, for example',v as' steam. which. may besuperheated to approxi= mately 600 F. or higher, or hydrocarbon vapors such asV those which are admitted to' thev housing l by way of theconduit ll.

Resulting` from the operation described im'-v mediately' above, circumferentially complete streams of.' vapors traverse the passages 22 and the passage 23 respectively', these passages be-- ing formed at different respective levels inv the lower boundary of the aforesaid zone. These' vapori streams are directed'downwardly inA gener-y ally' aA vertical directionl so that they sweep along. the portionbof4 the zone boundary below the mem*` ber 1 to thereby shield' therlatter fromy migrating atomized material as hereinafter morel particularly described.

As hereinbefore described, during a hydrocarbon conversion. operation; streams' of atomized liquid material pass downwardly in inclined re lationA and atV high velocity from'. the respective', sets of alined atomizer portsL I5c, substantially all of this. atomized liquid material engaging tl'lel tubular curtain S throughout a circumferem ti'ally complete inner area"` thereof. Particularly by reason'.A of this high velocity condition,y some of this atomized liquid materiali. either aloner or having nes o'f the contacty material entrainedi therein, migrates' or tends to migrate upwardly within the area enclosed by th'e upper portion of the tubular' curtain S. However, due to the presence of the housing or boundary dened by the membersA 2'0`, 20a, 2th,. 20c' and 20d, the atomized liquid material last named is prevented fromrnigrating into' the zone defined by said. members. In this manner, migrating atomized' material is prevented from reaching. the' atom-f izer casing and the vertical portiorr of the pipe l0? to thereby prevent formation thereon' of a carbonaceous deposit which would adversely aiect operation of the' system.

It will be understood, then', that in theabsenceof the aforesaid housing or .boundary arrange' ment comprising the" members 2B; 20a, 20h, 20c, and 28d', a part at least of any upwardly migrating atomized liquid material would be deposited on the upper portion of the atomizer casingv l5 and on the adjacent vertical. portion of the pipe I0 with resultant production ofcarbonaceous. material which, in the course of time, would form hanging or other adherent deposits of such carbonaceous materialI having suicientlengtheither to interfere. with proper operation of.v theatomizer or to break into chunks which would move into aruiiihifoughK the bed B of contact material with resultant development of a plugged condition at thef bottom` of the housing An operation of this' character,- of course, is undesired and is at least. substantially prevented, in accordance with the invention, by utilization of the described housing or boundary arrangement formed from the mem'bers- 20,- 20a, 20h, 20c and 20d which function in the manner described to prevent formation1 of` carbonaceous material on the metallic parts disposed-.Within the Zone dened thereby.

However, theY formation of a carbonaceous deposit on the members last named would be disadvantageous for the reasons hereinbeiore stated and, therefore, it is necessary to prevent or substantial-ly minimize formation of such a carbonaceous deposit thereon. It is for this reason that theherenbefore described annular passages 22, 23 are provided. As stated, the respective vapor .streams passing therefrom are directed downwardly ingenerally a vertical direction. They engage the arrangement comprising the members 20,. 2Da, 2gb' etc. at different respective levels where the vapor velocity is sufficient to eiect the desired7 shielding action. Thus, the vapor streams form a'barrier around and immediately adjacent the. described members which effectively prevents them from being engaged by migrating atomized material. Consequently, little or no cai-"conaceousl material is formed thereon.

Of significance as` regards the foregoing is the annular passage 23 which is so positioned that the stream of vapors iiowing downwardly therethrough sweep the adjacent vertical surface of the casing I5 to thereby substantially prevent deposition thereon of any atomized liquid material which tendsto migrate upwardly.

It shall` bev understood that the invention is not to be limited tothe particular' housing or boundary arrangement hereinbefore described. 'Il-hus, for example, the desired sweeping action may be elected under some circumstances by the provision of a single annular passage.

@bviously many modications and variations of theinvention as hereinbefore set forth may be made without departing from the spirit and scope thereof and therefore only such limitations should be imposed as are indicated in the appended claims.

We cla-im as our invention.:

l.` In the art of converting hydrocarbons in the presence of contact material having conversioni` tem-perature and adapted to gravitate through a chamber as a tubular curtain of freely falling contact material, the method which oomprisesE atomizing liquid hydrocarbon material in the lower area-of a` zone located within said curtain andv having a boundary adapt-ed to exclude atomized material therefrom, directing a circumferentially complete stream of the atomized material: into engagement withv the curtain contactmaterial, passing vaporsv through an annual passage. formed in the boundary of said zone, and directing. the annular stream ofV vapors downwardly in sweeping relation with respect to the boundary of said. zone to thereby substantially prevent deposition of migrating atomized material thereon.

2.- In. the art-ofconverting hydrocarbons in the -presence of contact material having conversion temperature and adapted to gravitate through a chamber as a tubular curtain of freely falling contact material, the method which comprises atomizing liquid hydrocarbon material therefrom, directing. a circumferentially complete stream` of 76 the atomi'zed material into eng-agement with the curtain contact material, passing vapors through annular passages formed in the boundary of said zone at dlierent respective levels and having, respectively, progressively decreasing diameter in a downwardly extending direction, and directing the annular streams of vapors downwardly in sweeping relation with respect to the boundary of said zone to thereby substantially prevent deposition of migrating atomized material thereon.

3. In apparatus of the character described, a conversion housing, means disposed interiorly thereof and comprising inner and outer members forming an annular metering passage adapted to cause gravitating contact material to form a tubular curtain of contact material freely falling below said metering passage, an atomizer supported interiorly of said curtain below said metering passage, means enclosing a portion of said atomizer and forming a chamber with said inner member, and means for passing vapors into said REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,944,483 Zieley Jan, 23, 1934 2,432,344 Sinclair Dec. 9, 1947 OTHER REFERENCES Houdry-Pioneer, vol. 2, No. 1, Oct. 1946, 8 pages.

Certicate o' Correction Patent No'. 2,493,036 January 3, 1956 REUBEN T. SAVAGE ET AL.

It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 75, for the word contributes" read contribute; column 4,'v line 58, for normal" read normally; column 8, line 61, for annual read annular;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oilice.

Signed and sealed this 16th day of May, A. D. 1950.

THOMAS F. MURPHY, l

Assistant 'ommz'm'oner of Patents.

Claims (1)

1. IN THE ART OF CONVERTING HYDROCARBONS IN THE PRESENCE OF CONTACT MATERIAL HAVING CONVERSION TEMPERATURE AND ADAPTED TO GRAVITATE THROUGH A CHAMBER AS A TUBULAR CURTAIN OF FREELY FALLING CONTACT MATERIAL, THE METHOD WHICH COMPRISES ATOMIZING LIQUID HYDROCARBON MATERIAL IN THE LOWER AREA OF A ZONE LOCATED WITHIN SAID CURTAIN AND HAVING A BOUNDARY ADAPTED TO EXCLUDE ATOMIZED MATERIAL THEREFROM, DIRECTING A CIRCUMFERENTIALLY COMPLETE STREAM OF THE ATOMIZED MATERIAL INTO ENGAGEMENT WITH THE CURTAIN CONTACT MATERIAL, PASSING VAPORS THROUGH AN ANNUAL PAS-

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