US2956008A

US2956008A - Method and apparatus for the supply of hydrocarbon charge to moving mass hydrocarbon conversion processes

Info

Publication number: US2956008A
Application number: US536974A
Authority: US
Inventors: Eric V Bergstrom; Jr Thomas C Cattrall; James H Haddad
Original assignee: Socony Mobil Oil Co Inc
Current assignee: ExxonMobil Oil Corp
Priority date: 1955-09-27
Filing date: 1955-09-27
Publication date: 1960-10-11
Anticipated expiration: 1977-10-11

Description

CHARGE Oct. 11, 1960 E. v. BERGSTROM ETAL METHOD AND APPARATUS FOR THE SUPPLY OF HYDROCARBON T0 MOVING MASS HYDROCARBON CONVERSION PROCESSES Filed Sept. 27, 1955 6 Sheets-Sheet 1 Illl mg PRODUCT 01/7 mA/mzr/wrimz 01/7 Oct. 11, 1960 E. v. BERGSTROM arm. 2,956,008

METHOD AND APPARATUS FOR THE SUPPLY OF HYDROCARBON CHARGE T0 MOVING MASS HYDRQCARBON CONVERSION PROCESSES Filed Sept. 27, 1955 6 Sheets-Sheet 2 INVENTORs [fr/a 1726111550110 Tim/mas 6 (Mira/Li:

AGENT 1960 av. BERGSTROM ETAL 2,956,008

METHOD AND APPARATUS FOR THE SUPPLY OF HYDROCARBON CHARGE TO MOVING MASS HYDROCARBON CONVERSION PROCESSES Filed Sept. 27, 1955 6 Sheets-Sheet 3 INVENTO RS [ht Vfler 55/0110 Tfiamas (.Za frail, J2 Jam's/l fladdad HGENT 1960 v. BERGSTROM ETAL 2,

memos AND APPARATUS FOR THE SUPPLY OF HYDROCARBON amass: T0 MOVING MASS HYDROCARBON couvsasxon PROCESSES Filed Sept. 27,, 1955 s Sheets-Sheet 4 in: Z fiqjJ/rwn/ mamas 6 Kali/all, fit James 17 fiadaa'af INVENTORS ATTORNEY Oct. 11, 1960 E. v. BERGSTROM ET AL 2,956,008

METHOD AND APPARATUS FOR THE SUPPLY OF HYDROCARBON CHARGE TO MOVING MASS HYDROCARBON CONVERSION PROCESSES Filed Sept. 27, 1955 6 Sheets-Sheet 5 [fit 7 Ber Ts/raw T/mmas 6 (aflra/Lfx Jinan flT f/addzui INVENTORS ATTORNEY BY 7 1" Wu METHOD AND- APEARATUS "FOR THE SUPPLY F HYDROCARBON CHARGE T0 MOVING MASS HYDROQARBON CQNVERSEON PROCESSES Eric V. Bergstrom, Short Hills, Thomas C. Cattrall, Jn,

Glassboro, and James H. Haddad, Fort Lee, N.J., assignors to Socony Mobil Oil Company, Inc., a corporation of New York Filed Sept. 27, 1955, Ser. No. 536,974

17 Claims. 01-. 203-166) This application is a continuation-in-part of copending application, Serial Number 446,598, filed July 29, 1954, now abandoned.

This invention has to do with a method and apparatus for the conversion of fluid hydrocarbons in the presence of a moving granular contact material mass which may or may not exhibit catalytic properties with respect to the conversion reaction. Particularly, this invention is concerned with a method and apparatus for the introduction of a hydrocarbon charge, at least partially in the liquid phase, to the conversion zone of processes wherein the granular contact material passes cyclically through successive zones or vessels, in the first of which it is contacted with a liquid or mixed phase charge to effect the conversion thereof, and. in the second of which the contact material is reconditioned for re-use in the first zone.

Typical of processes to which this invention may be applied is the catalytic conversion of. high boiling liquid or mixed phase hydrocarbons to lower boiling, gasoline-containing hydrocarbons, by contacting the hydrocarbon charge at temperatures of the order of 800 F. and upwards, with a moving bed of granular adsorbent catalytic material. Other exemplary processes include the catalytic dehydrogenation, polymerization, isomerization, alkylation, and, the like, of liquid or mixed phase hydrocarbons using an adsorbent catalytic solid and thethermal coking, cracking, visbreaking, and the like, ofliquid or mixed phase hydrocarbons in the presence of a granular inert material.

In such processes wherein the contact material is catalytic in nature, it may partake of the nature. of natural or treated clays, bauxite, activated alumina, or synthetic assoeia-tionsof silica, alumina or magnesia or combinations thereof, to which certain metals' or metallic oxides or sulfides maybe added in small amounts for specific purposes. When the contact material is inert in character, it may partake of the form of' refractory materials, such as zirkite, corhart material or'mullit'e or particles of quartz, fused alumina or coke, or itmay partake of the form of stones or metallic particles or balls. The contact material should be of palpable particulate form, as distinguished from finely divided powders, and may take the shape of pellets, tablets, spheres, capsules, and the like, or particles of irregular shape-such as are obtained from grinding and? screening operations. Generally, the contact material should be. within the size range about 1 inch to 100 mesh, and preferably 4 to 20 mesh by Tyler Standard. Screen Analysis; The term granular as used herein'in: describing and claiming; this invention should be understood. to includeany contactmaterial of the above forms and size, whether of regular or irregular shape.

In conversion systems of the aforementioned typesldt is frequently desired to. effect the conversion of a. hydrocarbon material, a substantialpart of which will not vaporize below itsv thermal decomposition temperature;

'nited States Patent I This makes it necessary to supply at least a part of the material to the conversion zone and the reaction bed of contact material therein, as a liquid rather than a vapor. The supply of hydrocarbon charge to the reactor in such cases presents a variety of interrelated problems which must be satisfactorily solved by any charge system.

First, the system must be physically operable. This includes a variety of process necessities such as requirements that the hydrocarbon feed system not be one requiring excessively high pressure drop which will in turn materially add to the height of seal leg necessary to feed contact material into the reactor, and that hydrocarbon feed system not" interfere with the smooth flow of contact material to the reaction bed through the internal contact material feed system.

Second, the liquid charge must be supplied in such a manner that contact between the liquid portion of the charge and hot metal parts in the conversion chamber is minimized. As previously stated, the liquid charge must be introduced at a temperature below its thermal decomposition temperature. However, the most desirable conversion temperature is normally above the thermal decomposition temperature; Therefore, the heat necessary toraise the temperature of the charge from the level of its introduction to the conversion temperature usually must be supplied by the fresh contact material. Thus, contact material will be supplied to the conversion chamber at temperatures well in excess of the thermal decomposition temperature of the liquid, and most metal parts of the conversion chamber will also be above the liquid decomposition temperature due to heat transfer from the contact material. If liquid charge contacts any of these hot metal parts, it immediately undergoes conversion to a vapor hydrocarbon and leaves a coke deposit on the metal surface. Unless this coke is continuously' scrubbed from these surfaces, it will build up and break off in large pieces which will plug up the restricted openings in the lower section of the conversion vessel and elsewhere in the cyclic system.

Third, the supply of the charge to the reaction bed must be accomplished in a manner which minimizes lateral temperature differentials across the reaction bed. These differentials, because they involve converting most of the charge at temperatures other than the optimum conversion temperature, severely decrease the revenue that can be obtained from sale of the products of any given charge stock, as explained hereinbelow. Two factors, principally, will produce these differentials; one, excessive cross-flow of cool vapor and hot contact material and, two, excessive concentration of the liquid or vapor portions of the charge at widely spaced points across the reaction bed;

Fourth, a satisfactory hydrocarbon charge system should not cause excessive attrition or breakage of the contact material particles. Excessive attrition obviously results in the need for heavy addition of make-up contact material and thereby increases the cost ofoperation.

Fifth, the feed system must be one that avoids excessive smoke plume. This plume consists of a quantity of hydrocarbon. vapors which is carried from the re actor tothe regenerator and there enters the flue gas and passes through the flue gas stock to the atmosphere to be thereby lost from the system. Substantial quantities of hydrocarbon may be lost in this fashion. Smoke plume generally results when excessive quantities of liquid are supplied to relatively small regions of the reaction bed, so that these regions are reduced below the temperature at which any conversion will take place before the liquid is all vaporized or converted. Contact material in these regions then carries the liquid into the regenerator where it vaporizes at the lower pressure therein.

There have been proposed a large variety of systems for supplying hydrocarbon charge in the extensive prior art in this field. However, none of the proposals dealt entirely adequately with the above problems.

Probably the most widely used systems, to date, have been those which fractionate the hydrocarbon charge into a large vapor fraction and a substantially smaller liquid fraction. The vapor fraction is passed into the substantially compact reaction bed from a plenum space thereabove, while the liquid is sprayed through a spray nozzle into a falling curtain of contact material which drops into the bed.

These systems, While most of them have been commercially operative, have certain well recognized limitations.

First of all, it has not been possible to supply the entire charge as a mixture of liquid and vapor to the spray nozzle without formation of excessive coke deposits on the walls of the reactor above the reaction bed. Thus, fractionation into liquid and vapor has been necessary, requiring the use of a heater and expensive fractionation equipment exterior to the reactor, frequently including both an atmospheric fractionation and a vacuum fractionation. A system which could supply the entire feed as one stream of mixed liquid and vapor would only require a heater exterior to the reactor to prepare the charge.

In addition, even when only liquid is sprayed into the falling curtain, the operation of such a system is not always entirely satisfactory. Frequently, as the amount of liquid so supplied increases, the coke formation on the walls of the reactor increases to a point where premature shutdown of the reactor may be required solely to clean the coke from the Walls.

Other systems proposed have suggested that the liquid fraction or all of the charge be injected into a compact flowing stream of contact material. However, these systems have usually resulted in such excessive temperature difierentials across the reaction bed that large losses in product revenue over that which could be obtained by conversion at the optimum conversion temperature have resulted. Further, many of these systems have not been commercially operable with charge stocks of the kind used in such processes as the catalytic cracking of hydrocarbon charge.

A major object of this invention is to provide a method and apparatus for the supply of fluid hydrocarbon charge to the conversion zone of processes employing a moving mass of granular contact material which overcomes the above described difiiculties and problems.

An other object of this invention is to provide a method and apparatus for supplying the total hydrocarbon charge to a substantially compact moving bed of contact material as an unfractionated stream of mixed liquid and vapor hydrocarbons.

Another object is to provide a method and apparatus which will supply fluid hydrocarbon charge, at least partially in the liquid phase, to a moving mass of granular contact material in a manner which avoids excessive temperature differentials across the reaction bed.

These and other objects of the invention will be apparent from the following discussion.

Broadly, in this invention, the contact material which is to supply the downwardly moving, substantially compact reaction bed of contact material, is passed as a stream into the conversion zone above the bed. This stream is then expanded and a substantially compact layer of contact material, which contains a major portion of the contact material supply to the reaction bed but has an area normal to the direction of contact material flow amounting to only a minor fraction of the horizontal cross-section of the bed, is formed. Into this layer is injected, at a plurality of points, the hydrocarbon charge which consists at least partially of liquid hydrocarbon ,4 which hydrocarbon charge is at a temperature substan tially below the contact material temperature. The points of injection are spaced apart in a horizontal direction transverse or normal to the contact material flow in the layer on a center-to-center spacing less than the spacing determined in the manner set out hereinbelow, which acts to minimize temperature differentials across the reaction bed. Hydrocarbon feed is supplied at these injection points at a mass velocity sufficient to form at each point a vapor bubble, in and around which liquid, vapor and contact material are mixed. Also, in the vicinity of these feed points, the layer is mechanically confined on its upper side for a sufficient area that no vapor will issue from an unconfined surface at a velocity sufiicient to substantially disrupt said surface.

Certain of the terms used in the above broad description, as well as elsewhere in the specification and claims, are advantageously defined here. When the specification and claims refer to points of injection of hydrocarbon feed, the mathematical concept of point is not used, but rather what is meant is an area or volume of hydrocarbon injection which is very minor compared to the crosssectional area or volume of the reactor and reaction bed. The term at a temperature sufiicient to effect the desired conversion, and like terms, are used herein to refer to contact material which carries sufficient heat to supply the heat of reaction, as well as suflicient heat to raise the temperature of the hydrocarbon feed from the temperature at which it is charged to the conversion temperature. The term liquid is used herein to refer to a material which is in the liquid phase at the particular conditions of temperature and pressure at which it exists, regardless of what may be its state at atmospheric conditions. The term boiling mass velocity is used herein to denote a mass velocity (unit weight per unit area per unit time) of the charge which will cause a pressure gradient (unit pressure per unit length) in the immediate vicinity of the feed injection point equal to the apparent density of the contact material in the compact layer. Apparent density here refers not to the true density of the contact material but rather to a density measured by weighing a given volume of contact material which exists packed to the degree that it is packed in the compact layer. Hence, if the apparent density of the contact material were 43 pounds per cubic foot, the boiling mass velocity would be that mass velocity of feed issuing from the injection feed pipe which would give a pressure gradient, immediately outside the vapor bubble, 43 pounds per square foot per foot of length.

Other terms which appear later in this description and in the claims include the terms annular, annularshaped, and like terms, which are used herein to refer to a stream or member which is of the shape of the space defined between two members of the same or different shapes but of different lateral dimensions, with the smaller member placed Within the larger, regardless of whether such space is ring-shaped or not, or whether the smaller member touches the larger over areas amounting to only a minor fraction of the total internal area of the larger member. The term calculated head of contact material is also used herein with reference to seal legs, and refers to the quotient of the weight of contact material in a seal leg above the point of seal gas injection divided by the cross-sectional area of the seal leg at the level of seal gas injection.

This invention will be best understood by referring to the attached drawings, of which Figure 1 is an elevational view, partially in section, showing the application of this invention to a typical hydrocarbon conversion reaction;

Figure 2 is a cross-sectional view along line 2-2 of Figure 1;

Figure 3 is an elevational view, partially in section, of the upper portion of a hydrocarbon conversion reactor employing a modified form of this invention;

Figure 4 is an elevational view, partially in section, of one-half of the upper portion of a hydrocarbon conversion reactor employing a further modified form .of this invention;

Figure 5 is an elevational view, partially in section, of a hydrocarbon conversion reactor employing a preferred form of this invention;

Figure 6 is an elevational sectional view of a hydro.- carbon conversion reactor employing a more preferred form of this invention;

Figure 7 is a graph of product revenue versus temperature of conversion for two typical charge stocks; and

Figure 8 is a graph illustrating the increase in product revenue possible at various spacings of hydrocarbon feed injection points.

All of thesev drawings are diagrammatic in form and like parts in all bear like numerals.

Turning now to Figures 1 and 2, which are best considered together, there is shown therein a reactor or conversion chamber 10 suitable for use in the catalytic cracking conversion of hydrocarbons and having a con.- tact material outlet conduit. The upper end of the inlet conduit is connected to a seal gas chamber 13, into the upper end of which extends the lower end of a seal leg 14 of conventional design.

Situated centrally within the upper section of chamber '10 is an open-topped receptacle 15, and the lower end of conduit 11 is positioned so that it will feed contact material to the receptacle. Extending downwardly centrally and vertically from the bottom of the receptacle is a seal leg conduit 16, which terminates in the upper end of chamber 10 so as to discharge contact material into a short chamber 17 of slightly greater lateral dimensions than conduit 16. Chamber 17 is closed on top but entirely. open on the bottom.

A solid confining member 18, shaped similar to a hollow frustum of a cone, extends across chamber 10. Member 18 is tightly connected on it upper end to the lower end of chamber 17, and on its lower end it, is connected to the walls of chamber 10 by means of spaced support legs or brackets 19, so that there is a space. 60 between member 18 and the walls of vessel 10.

A conical baffle member is situated beneath the lower end of chamber 17 and beneath confining member 18. This baflle consists of two parts, an upper part 21 and a lower section 22, vertically displaced from the upper part to allow a hydrocarbon feed manifold 25, described below, to protrude between the two parts. The sides of this baffle extend outwardly along lines roughly parallel to the sides of member 18.

A hydrocarbon feed manifold 25, consisting of an upper end 23 in the shape of an inverted cone, and a lower end 24, in the shape of an inverted frustum of a cone, is situated centrally beneath chamber 17 and member 21. The side walls of the manifold are formed by cylinder 26. Connecting centrally into the underside of manifold 25 is a hydrocarbon feed pipe 27, which extends from the feed preparation system (not shown) exterior to chamber 16.

Extending radially outwardly from the side walls 26 of manifold 25 are a plurality of uniformly spaced conduits 27. Each of these conduits has a connector 28 at its outer end. From each connector there extends four branch pipes 29, each of which connects with the interior of the connector. Branch pipes 29 terminate short of the outer edge of baflle member 22.

The operation of the apparatus of Figures 1 and 2 will be discussed in connection with the process of catalytic cracking of hydrocarbons. It is not intended thereby to limit the invention to this process, since it has wide applicability to many moving mass processes.

Within conversion chamber or housing 10 there is maintained a substantially compact reaction bed 31 of granular catalyst, which catalyst may be, for example, a synthetic silica-alumina catalyst. Used catalyst is congaseous tinuously removed from the lower end of bed 31 through passage 12, so that particles of catalyst move downwardly through the bed. Bed 31 consists of a main body, comprising that portion of the bed in which catalyst particles are flowing substantially unidirectionally vertically downwardly, and an upper portion in which most of the catalyst is flowing substantially laterally in one direction or another so as to be uniformly distributed across the bed. By far, the major fraction of the bed height will be taken up by the lower portion.

Fresh catalyst, at a temperature suitable for the desired conversion, for example, 1025 F., enters the upper end of housing 10 and is supplied to an accumulation of catalyst 32 maintained within receptacle 15. Catalyst gravitates as a substantially compact stream or seal leg from the lower section of accumulation 32 onto a restricted central area of the upper end of bed 31 through the passage formed by

members

16 and 17.

The upper end of bed 31 is confined by member 18 at an angle with the horizontal greater than the angle of repose of the catalyst, so that flowing catalyst continually scrubs the underside of member 18. The angle of repose varies with the particular contact material but will generally lie within the range about 2545 degrees. For most commercially used contact materials it is about 30 degrees.

Baflle

members

21 and 22 act to baffle the flow of contact material issuing from chamber 17, so that a transversely flowing, substantially compact layer 33 of catalyst is formed between member 18 and members 21 and '22.

The hydrocarbon charge, which might be a reduced crude, is supplied in its entirety to manifold 25 through passage 27. This charge is advantageously supplied as a mixture of liquid and vapor, for example, 30 percent of the charge by volume liquid and 70 percent vaporized, and will be at a temperature substantially below the temperature of contact material beng supplied through member 17, for example, about 825 F. The charge passes from the manifold through the passages formed by pipes 27, members 28 and branch pipes 29, to be injected into the catalyst layer 33 at a plurality of points which are spaced apart in a direction transverse to catalyst flow in the layer a center-to-center distance between adjacent conduits less the critical maximum spacing as determined in the manner explained below. In addition, pipes 29 should be spaced a distance apart less than 1}1 inches in a direction normal to contact material flow to minimize radial temperature differentials. In the design of Figures 1 and 2, the points of injection fall in two circular patterns when projected on a horizontal plane, the centers of which lie on the vertical center line of passage 16 and chamber 10'.

The mass velocity of the hydrocarbons issuing from pipes 29 should be maintained sufficiently high that there will be formed at each injection point a vapor bubble 34, in and around which vapor, liquid and catalyst are thoroughly mixed so that they will arrive'at a substantially uniform temperature before they have moved any substantial distance beyond the injection points. Of course, some of the hot catalyst will flow around or between bubble-s 34, and it is for this reason that the injection points should be spaced apart less than the critical maximum so that adjacent hot and cold areas will be sufficiently close together that the initial temperature differential set up, because only a part of the hot catalyst is contacted by the substantially cooler charge, will be .dissipated in the bed below the injection system.

The area between baflle member 22 and confining member 18, measured normal to the direction of contact material How in the layer 33, in the vicinity of injection points 34, should amount to only a minor fraction of the horizontal cross-sectional area of bed 31 and preferably should be less than 40 percent thereof. Thus, percent of the contact material will flow as a narrow high velocity band past the injection points, insuring maximum contact between hydrocarbon charge and contact material.

Hydrocarbon charge and catalyst pass from layer 33 into the main body ofreaction bed 31. The charge passes through the bed and is converted to the desired products, for example, a product containing high percentages of gasoline and fuel oil. These products disengage from bed 31 in conventional fashion and are removed through passage 35.

A further feature of the apparatus of Figure 1 is that passage 16 may be utilized as a short seal leg and thus take advantage of excess height in the upper end of the reactor, which may be available when the system of this invention is installed in existing units, to add additional seal leg height without extending the height of the unit. This is accomplished as follows: Inert seal gas, such as steam or flue gas, is supplied to the base of the seal leg in passage 16 through passage 36 at a pressure slightly in excess of the pressure at which hydrocarbons are injected through branch pipes 29 so that steam rather than hydrocarbon flows up the seal leg. There is a pressure gradient across the seal leg which causes the pressure within gas space 20 to be below that in contact material layer 33. Seal gas may then be supplied to chamber 13 at the base of the conventional seal leg 14 at a pressure only slightly in excess of the pressure in gas space 20, rather than at a pressure in excess of the pressure at which hydrocarbons are injected, as would be necessary in the usual prior art setup. Seal gas flows from space 20 into the reaction bed 31 through space 60 and pipes 61.

In a typical installation the pressure at the outlets of pipes 29 might be about 15.2 pounds per square inch. With seal leg 16 being 9 feet, 3 inches high, the pressure in gas space 20 might be about 13.2 pounds per square inch. Thus, seal gas could be supplied to chamber 13 at about 13.6 pounds per square inch, rather than in excess of 14.8 pounds per square inch.

Seal gas is supplied to chamber 13 through passage 37 equipped with a valve 38 operated by a diflierential pressure controller 39 to maintain the pressure of supply of seal gas at a fixed level above the pressure in gas space 20. This insures that no gaseous material will escape from chamber 10.

Turning now to Figure 3, which illustrates a modified form of this invention, hot contact material, at a temperature suitable to effect the desired conversion, is supplied to receptacle 15 through passage 11 and then gravitates from the receptacle downwardly through central vertical passage 16. Passage 16, in Figure 3, is not equipped to act as an internal seal leg, although this could be done, if desired, in the manner illustrated in Figure l. The compact stream in passage 16 feeds on to a central area of the upper surface of reaction bed 31. The upper surface of the reaction bed is confined by member 18 from the area to which the compact stream feeds, outwardly to a region adjacent the walls of conversion chamber 10.

In order to supply regions of bed 31, which are not directly beneath feed passage 16, the contact material must expand outwardly as a substantially compact transversely flowing layer with the direction of flow indicated by arrows 41. The lower edge of this layer will be generally as defined by lines 40, which denote conical shaped surfaces of flow between transversely flowing, fast moving contact material and vertically flowing, slower moving contact material. Below lines 40 the contact material moves substantially unidirectionally downwardly, except for that part which must flow around feed manifold 25. Contact material continuously passes from layer 33 into the main body of bed 31 so that, while the layer starts out with almost 100 percent of the contact material supply to the reaction bed, this is constantly diminishing as the layer moves outwardly. In this species of the invention the hydrocarbon feed is injected into this naturally occurring high velocity layer in the same manner that it 8 is injected into the layer 33 of Figure 1, formed by bafiling.

It is necessary here, however, to take care to make the injection at a region in the layer Where a major portion of the contact material supply to the reaction bed, and preferably percent of such supply, flows past the points of injection. In a cylindrical-shaped reactor this means that the points of injection should lie within a distance of the center line of the reactor not more than 50 percent of the radius of the reactor.

The system for supplying hydrocarbon charge to the injection points of Figure 3 is similar to that of Figure 1. However, in Figure 3 the manifold 25 is formed of up right

conical members

23 and 24 rather than inverted members, and hydrocarbon supply conduit 27 enters the top of the manifold rather than the bottom. Connected into the manifold are a plurality of T connections 42 spaced around the manifold. Feed pipes 43 extend from each branch of each T 42 and have horizontally directed outlet ends directed toward confining member 18. Those of pipes 43 lying in a lower plane will be longer than those lying in higher planes, so that the vapor bubbles 34, formed at the outer ends of all pipes, will lie in compact contact material layer 33. The two branch pipes from each T preferably do not lie vertically above each other since, if they did, the same contact material would pass through both bubbles. Preferably, a plane passing longitudinally through the center of the outlet ends of both of the pipes extending from any one T is at an angle with the horizontal so that different regions of hot contact material pass through all injection points. In the device of Figure 3, where the hydrocarbon feed pipes 43 are not directed along lines parallel to the direction of contact material fiow but are in horizontal planes and directed at confining member 18, in order to insure that the vapor bubbles formed at each injection point will lie within the high velocity layer, the ends of pipes 43 should be within about 15 inches of member 18. Preferably, these pipes should not be closer than 5 inches to member 18 to avoid excessive attrition.

It will be noted also that in Figure 3, as in Figure 1, confining member 18 does not extend completely out to the walls of the reactor. The confining member must extend, however, sufiiciently beyond the injection points that vapor cannot issue from an unconfined contact material surface at a mass velocity suflicient to disrupt the unconfined surface. The maximum average mass velocity across the unconfined surface that can be tolerated without substantial disruption of that surface is a function of the ratio of peripheral length of the confining member 18 to the area of the unconfined surface. In addition, the shape and size of the solids will be influential. Dependent on these factors, the maximum allowable average mass velocity through the unconfined surface may be considerably below or above the boiling mass velocity. Normally, for the type of installations used in this invention, the maximum allowable average velocity will be between 50 and percent of the boiling mass velocity. Of course, immediately adjacent the periphery of member 18, the local mass velocity may be considerably above boiling and the invention may be operated so that the unconfined surface builds up above the outer edge of member 18 if the solids are not allowed to be continually blown about by vapor issuing from the surface.

The boiling mass velocity will vary with the size and density of the particular contact material in use, the density of the vapor, and the temperature and pressure of the vapor. For a typical moving mass conversion system of the type in present day commercial use, a typical boiling mass velocity might be 1000 to 1500 pounds per hour per square foot.

Still another form of this invention is illustrated in Figure 4. Only one-half of the apparatus in the upper half of the reactor is shown in Figure 4, but the half not shown is identical with that shown and is a mirror image thereof. in this species contact material is expanded outwardly from receptacle through a passage defined between confining member 18 and a central balfle 59. The injectionof hydrocarbon charge is here accomplished after the contact material has. undergone this initial expansion, and occurs in a substantially vertically flowing layer which is, however, of cross-section amounting to only a minor cross-section of the bed 31 while carrying a major portion of the contact material supply to the reactor. Also, in Figure 4, confining member 13 is tightly connected to the wall of vessel so that there is no unconfined area at the upper end of the reaction bed.

In Figure 4, a hollow, frusto-conical baflie 53 is situated shortly beneath the lower ends of hydrocarbon feed injection pipes 51, which extend from manifold 52, and is sufiiciently larger than baffle 50 that a narrow contact material passage 54 is formed between the two directly beneath the points of liquid injection. Manifold 52 may be of the type described and claimed in U.S. patent application, Serial Number 353,745, filed May 8, 1953. A second hollow, frusto-conical shaped baffle 55 is situated at a level substantially below passage 54. The large diameter of baffle 55 is a major fraction of the diameter of the cylindrical conversion chamber 10, so that only a minor fraction of the total cross-section will lie be tween the bottom of 55 and the walls of 10. Preferably, this area should be less than 25 percent of the cross-section of vessel 10. Hence, the contact material which is needed to supply all of the rest of the bed, preferably over 75 percent, must pass through the interior of baffie 55. The smaller diameter of b aille 55 is such that a surface extending upwardly at the angle of internal flow of the contact material will intersect the inner Wall of baffle 53 adjacent its lower end. Such a surface is represented by line 56. The angle of internal flow for most granular materials is about 75 degrees. Thus, the major fraction of contact material flow which must pass through bafile 55 will all be drawn through passage 54, since material will not be drawn from outside the surface of internal flow. All of this material must then be drawn past injection points 34 as a narrow stream. The injection of the hydrocarbon charge is accomplished in the same manner previously described, at a plurality of points with center-to-center spacing less than that determined in the manner given below. A vapor bubble, in and around which, liquid, vapor and contact material are mixed, should be formed at each injection point.

A preferred form of this invention is illustrated in Figure 5. The apparatus setup there shown is similar to that of Figure 3, except that only a single level of radial pipes 60 extend from manifold 25. Liquid or mixed phase charge passes from pipes 6t) outwardly at a surficient mass velocity to form bubbles 34, which extend completely through the high speed layer 33 and mushroom out along confining member 18. Pipes 6d are sufficiently close together that the bubbles 34 join circumferentially and form a torus of vapor and liquid which extends completely through layer 33 and completely around the layer. In and around the torus formed by bubbles 34 contact material and vapor and liquid are uniformly mixed. Since bubbles 34 form a circumferentially complete torus and extend entirely through layer 33, none of the contact material in layer 33 can escape subjection to the hydrocarbon charge. Thus, the only contact material which will not contact the charge while it is still liquid will be that contact material which does not flow through layer 33, i.e., the contact material supplying the center region of reaction bed 31. In order to reduce the amount of this uncontacted material, a baffle 62 may be provided. Baflle 52 is in the shape of a hollow inverted frustum of a cone. The smaller end of baffle 62 should have an area which is a percentage of the total horizontal cross-sectional area of reaction bed 31 equal to the percentage of flow to which it is desired to reduce the contact material which is not subjected directly to the liquid or mixed phase charge. Baffle 62 is so positioned that a line, such as 51, drawn at the angle of internal flow will intersect the high speed layer 33 above bubble 34. This means that all of the contact material which supplies those regions of bed 31 not directly below the smaller end of baffle 62 must pass through, or immediately adjacent to, the torus formed by bubbles 34. The arrows shown on Figure 5 denote the course taken by various portions of the contact material flow in the upper region of bed 31.

Figure 6 illustrates a still more preferred modification of this invention. In the operation of the apparatus there shown, the liquid or mixed phase charge is injected completely through high speed contact material layer 33 and the bubbles 34, so formed, are joined circumferentially to form a torus. Contact material which does not pass through layers 33 is caused to enter an annular passage 63 situated immediately beyond and below the outer edge of the upper section of manifold 25 and formed between an upright frusto-conical member 64 and the lower section of manifold 25. Extending from manifold 25 is a second group of liquid or mixed phase feed pipes 65, which terminate adjacent conical member 64. Contact material, after entering opening 63, expands outwardly in a high velocity layer or band 68, formed in the same manner as layer 33. A bubble 69 is formed, in the manner described above, at the outer end of each of pipes 66. Bubbles 69 extend entirely through layers 68 and may or may not be joined circumferentially as desired. Preferably, however, the bubbles 69 are so joined and should in any case be spaced apart in the manner defined below. Pipes 65 should be so sized or manifold 25 so designed that the pipes will carry a percentage of the hydrocarbon feed equal to the percentage of the total contact material flow which passes through opening 63. A suitably designed manifold, illustrated in Figure 6, is the subject of claims in Us. patent application, Serial Number 553,864, filed December 19, 1955, now Patent No. 2,789,889.

In all forms of this invention it is necessary that at each injection point a vapor bubble be formed. To initially form such a bubble in a compact contact ma terial layer, it is always necessary that the mass velocity of the hydrocarbon feed injected exceed the boiling mass velocity. Further, in order to maintain the bubble once formed, it is necessary, if contact material flows over the top of the bubble, that the mass velocity of feed injection at each point continue at all times toexceed the boiling mass velocity. However, when no contact material flows over the top of the bubble, as when the upper side of the bubble is against confining member 18 (Figures 5 and 6), the mass velocity at which the hydrocarbon feed is injected, need only exceed V sine 0) to maintain the bubble. In this equation V denotes the boiling mass velocity while 0 denotes the angle with the horizontal made by the upper surface of the reaction bed and therefore by confining member 18. The lower value in the latter instance results from the fact that the bubble in this case need support no contact material.

Moreover, in all forms of this invention the spacing of the injection points must be such as to avoid excessive temperature gradients across the main body of the reaction bed. It has been determined that if cool hydrocarbon charge is supplied to hot catalyst through widely spaced injection points, there will be set up across the reaction bed widely spaced hot and cold contact material regions which are not dissipated as the contact material moves through the bed.

The importance of temperature differentials across the reaction bed is illustrated by Figure 7. Shown there are graphs of conversion temperature against product revenue for two typical charge stocks having the properties specified in the following table and catalytically cracked under the conditions given therein.

Curve A B Mid-Continent Charge Stock Source Mirando Crude.

Charge Gravity, API 22.2.

Charge Boiling Range, F 200-954 300-861.

Catalyst Typo Silieaitlumina Silica-Alumina Beads with Beads with 0.15% OM 0.15% CTgO Average Particle Diameter of 0.13 0.13.

Catalyst, Inches.

These two curves show graphically that each charge stock has a single optimum temperature at which the conversion should take place for the maximum in product revenue under a given set of conditions (about 863 F This optimum will lie, normally, above the temperature to which hydrocarbon charge may be conveniently heated without thermal conversion exterior to the reaction bed. Consequently, the charge will usually have to be supplied substantially below the optimum temperature and to compensate, the contact material will be supplied substantially above the optimum temperature. If a severe tempertaure gradient is set up across the bed, by crossfiow of cool vapor and hot catalyst or by maldistribution of the liquid or vapor part of the charge, and the gradient persists throughout the length of the bed, it is obvious that a large part of the charge will be reacted at temeratures below the optimum while another large part is reacted at temperatures above the optimum. Both of these conditions decrease product revenue. Thus, in Figure 7, where the distance between adjacent hot or cold regions of the bed is about 40 inches, conversion will occur at all points around each curve between the points marked 6-6. When the distance between adjacent hot or cold areas is reduced to 10 inches, conversion will only occur between the points H-H, giving an average product having an obviously higher value than in the former case.

In the method and apparatus of this invention there are two different directions in which temperature differentials will be set up. This will be discussed in connection with a cylindrical reactor although they will have obvious counterparts in any other shape of reactor. One of these is a temperature differential set up radially and the other is set up horizontally and circumferentially around the bed. Eliminating either of these tem perature differentials results in a substantially improved feed system. The radial temperature diiferential may be set up by contact material which, while contained in the high speed layer, nevertheless passes essentially vertically over or under the vapor bubble and its immediate vicinity at each injection point and then expands outwardly or inwardly radially across the bed while some other material from the high speed layer enters the bubble. In addition, when all of the contact material does not pass through the high speed layer as in the device of Figure 3, a radial temperature pattern will be set up unless some other step, such as that shown in Figure 6, is taken. In any installation, the radial temperature pattern may be minimized by causing each injection point to extend entirely through the high speed layer of contact material in a direction normal to the direction of contact material flow, as shown in Figures 5 and 6 and, where all the contact material is in this layer, causing the vapor bubbles to extend through the layer, will entirely eliminate the radial temperature differential. Also, where some contact material does not pass through the high speed layer, the use of an additional feed device to contact this material will minimize the radial temperature differential.

Even more troublesome in many applications is the circumferential temperature pattern. This temperature pattern is set up by the feed injection points being spaced apart too great a distance in a horizontal direction transverse to the direction of contact material flow as the contact material expands. In this invention it is critical that the feed injection points be spaced sufficiently close together that lines drawn through the centers of any adjacent feed points and having the direction of the flow of contact material in the expanding contact material stream, will intersect the wall of the reactor, which is the vertical plane in which the outer edge of the reaction bed lies, a horizontal distance less than 20 inches apart and preferably less than 10 inches apart, and still more preferably less than 7 inches apart. This will be more easily understood by referring again to Figure 2. There, lines L represent two lines drawn as specified above, which intersect the reactor wall 10 a distance M apart. This distance M is the one that must be less than 20 inches, preferably less than 10 inches, and still more preferably less than 7 inches. In most preferred forms the vapor bubbles touch to form a torus as explained in connection with Figures 5 and 6.

It should be noted that the directions that lines L take should be the direction of the expanding contact material. in the processes of Figures 1 and 3, the expanding contact material is the high speed layer into which the charge is injected. However, in Figure 4, this is not true and in this case, the lines L should take the direction of the expanding contact material rather than that of contact material flow in the layer.

When cylindrical reactors and reaction vessels are used, the above spacing requirement may be embodied in a formula which specifies the maximum spacing of the actual injection points rather than the spacing measured at the wall of the reactor. This would be the distance N in Figure 2. In this case the horizontal center-to-center distance between adjacent injection points should be less than inches and preferably less than inches, and still more preferably less than inches. In this formula 1' equals the radius of the circular pattern in which the injection points are arranged. If the injection points lie on more than one circular pattern, 1' is the average of the radii of all such patterns. R is the radius of the cylindrical reactor or reaction bed. Of course, 1' and R must be expressed in consistent units. When there is more than one circular pattern of injection points, the injection points should all be projected down the line of contact material flow onto a surface normal to the direction of contact material flow, as it expands, and the horizontal spacing measured in this single plane should be less than the amount given by the above formulae.

Figure 8 illustrates the criticality of the 20 inch spacing measured at the reactor wall in the manner set out above. In this graph a case in which the spacing was 40 inches (known to be unsatisfactory) was assumed as the base and the increase in product revenue as a percent of the increase that could be obtained if there were no circumferential temperature gradient, was measured as the spacing was brought closer and closer. it is apparent that there is no substantial change over the base case until the spacing is brought below 20 inches,

13 a at which point the curve breaks sharply upwardly, indicating that 20 inches is the critical spacing.

Where the high speed layer is between two metal surfaces, as in Figure 1, it is not desirable to use vapor bubbles which extend perpendicularly through the layer and touch each other circumferentially, as this may cause contact material hold-up. This mode of operation is desirable, however, when the underside of the high speed layer is open to other contact material (Figures and 6).

Where it is desired that the vapor bubbles touch circumferentially, the spacing of the hydrocarbon feed pipes required will depend on the mass velocity of the charge. To operate in this manner, generally the feed pipes should be not greater than 15 inches apart and preferably not greater than 10 inches apart. Also, where it is desired that the vapor bubble extend entirely through the high speed solids layer, the ends of the feed pipes should be within about inches of the solid surface which confines the layer.

In supplying hydrocarbon charge to the manifold of Figures 1 and 3, the charge pipe 27 should be substantially vertical when mixed feed is being charged, in order to insure that a uniform mixture of liquid and vapor will be supplied to each injection point. Further, for the same reasons, the vapor velocity in pipe 27 should always exceed 3O feet per second and preferably 50 to 100 feet per second.

it is also desirable that, even when the above spacing requirement may be met, the number of injection points should usually not be less than 50. It has been found that the contact material will normally flow past the injection points in intermittent fashion in slug flow. With a small number of injection points this inter-mittent flow will be reflected in the passages feeding contact material to the reaction bed and may cause a hold-up in flow therein. The system would then be physically inoperable and would have to be shut down to restore normal contact material flow. Generally, 50 to 300 injection points are desirable.

In addition, it is desirable to design the piping from the manifold 25 to the injection points to have a substantially greater pressure drop than that in the piping from the feed preparation system to the manifold and also greater than the pressure drop in the upper end of the reaction bed above the main body thereof. By this means, regardless of pressure fluctuation in layer 33 or in the feed preparation system, the amount of hydrocarbon feed charged to each injection point will remain substantially equal to the amount charged to all other points.

While the various species of this invention have been discussed in connection with equipment that was of cir- .cular shape so that the narrow layer of contact material into which the hydrocarbons were injected was of circular annular shape, as was the pattern or patterns on which the hydrocarbon feed injection points were set, within the scope of this invention the layer and injection point pattern could be any other desired shape within the broad definition of annular given above.

It is preferable that the total hydrocarbon feed be injected in mixed phase at the injection points, but within the broader scope of this invention only a part of the feed need be so injected and the remainder may be supplied in some other conventional fashion. For example, only liquid feed could be injected through the above described system, with vapor feed being supplied through distribution channels beneath the injection system. When only liquid is supplied to the injection points, it is desirable that it be accomplished by some inert gas, such as steam, to assist in forming the vapor bubbles.

In general, in order to avoid attrition of the contact material, it is desirable that the pipes which deliver the charge be no closer to a solid surface than 5 inches. This figure will, of course, vary with the velocity of 14 the charge as it issues from the pipe and for a suitably low velocity it may be as low as 1 inch.

As previously stated, the compact layer into which the hydrocarbon feed is injected should have a minor cross-sectional area, measured normal to the direction of contact material flow, compared with the horizontal cross-sectional area of the reaction bed. Preferably, the cross-sectional area of the layer should not exceed 40 percent of the bed cross-sectional area. The layer should, however, carry a major fraction of the contact material supplied to the reaction bed, preferably over 75 percent. The Velocity at which the hydrocarbon charge is injected preferably should not exceed feet per second, so that the bubbles will remain essentially spherical in shape where they do not impinge on a confining surface like member 18.

Thecontact material should be supplied to the conversion zone at a temperature suitable to supply the heat of reaction plus the heat required to elevate the temperature of the hydrocarbon charge to the desired conversion temperature without the contact material falling below the desired conversion temperature. Generally, for catalytic operations, temperatures within the range 800 to 1200 F. are required. For thermal cracking operations the contact material inlet temperature may range as high as 1700" F. Liquid and vaporized hydrocarbon charge should generally be heated before being supplied to the conversion zone to temperatures within the range about 600 to 900 F. The space velocity of the total hydrocarbon charge through the reaction bed should generally be within the range about 0.5 to 10 volumes of hydrocarbon charge (as 60 F. liquid) per volume of reaction bed per hour. The ratio of contact material to hydrocarbon charge should generally be with in the. range about 0.5 to 20 parts of contact material per part of charge by weight.

As previously stated, the confining member 18 should extend outwardly a sufficient distance to avoid vapor issuing from an unconfined contact material surface at a velocity which will disrupt such surface. In all cases the outer edge of member 18 should be at least one-half of the distance from the center line of the conversion chamber to its walls. Also, while member 18 is preferably solid, it may, Within the broader scope of this invention, be porous, such as a screen with openings sufficiently small to retain the contact material in the bed. Further, while only one passage 16 has been shown feeding the bed, within the broader scope of this invention a plurality of such passages may be used, each with a separate feed manifolding system and suitably arranged injection points.

Example I In one design of an apparatus according to this invention. utilizing a construction similar to that of Figure 1, the reactor had a diameter of 13 feet. An internal seal leg consisting of a 24 inch pipe, 9 feet 3 inches high was employed. Confining member 18 was of frustoconical shape, with sides at a 35 degree angle with the horizontal and with a base diameter of 12 feet 1 inch. The bafile beneath member 18 consisted of two parts, 21 and 22, as shown in Figure 1. These parts both were of circular cross-section and had sides at angles of 45 and 40 degrees with the horizontal, respectively. Member 22 had a base diameter of 7 feet 4 inches. The distance between members 118 and 22, measured perpendicular to member 18 at the points of feed injection, was about 20 inches. The reaction bed was 10 feet high as measured from the lower edge of member 22. There were 24 of pipes 27, having 3 inch diameters, extending from manifold '25 and each of these pipes branched into four 2 inch branch pipes 29, which were in vertically aligned pairs so that in a horizontal plane the ends of pipes 29 formed two circular patterns having an average radius of about 3 feet 8 inches. The distance between each vertically aligned pair of pipes 29 was 11 inches centerto-center. The circumferential distance between adjacent horizontally aligned pipes 29 was about inches, so that when lines were passed through the injection points in the direction of catalyst flow, they intersected the wall of the reactor about 10.2 inches apart. This unit was designed to be charged with a reduced crude at the rate of about 15,000 barrels per day as a mixed phase charge, and it was estimated that about one-third of the charge would be in the liquid phase when supplied to the injection points. The charge temperature was about 790 F. Silica-alumina catalyst was to circulate through the unit at the rate of about 275 tons per hour and was to enter the unit at about 1025 F.

Example II In another suitable design according to this invention for a catalytic conversion unit, the construction was similar to that of Figure 3. The reactor was cylindrical and 16 feet in diameter. Confining member 18 was 13 feet 3 /2 inches in diameter, while manifold 25 had an outside diameter of 4 feet. The upper row of pipe 33 employed horizontal pipes which were 4% inches long, while the lower row used horizontal pipes 9% inches long, so that the outer ends of pipes in both rows extended to within about 7 inches of member 18. There were 32 pipes in each row, and each T connection made an angle of 21 degrees so that there were 64 horizontally spaced injection points. The center-to-center spacing between adjacent injection points measured at the wall of the reactor in the manner outlined above, was about 9.42 inches. To this unit hydrocarbon charge was supplied at a rate of about 14,487 barrels per day, of which 3,573 barrels per day were liquid. The hydrocarbon charge temperature was about 800 F. Silica-alumina catalyst, of a size within the range about 4 to mesh, was supplied to this unit at a rate of 386 tons per hour and at a temperature of about 1000 F. In general, there was less than a 100 F. variation in temperature across the major portion of reaction bed.

Example 111 In another suitable design of a T.C.C. unit, similar to the apparatus shown in Figure 6, the reactor was 18 feet in diameter and the outside radius of manifold 25 was 16 inches. A first level of injection pipes 60 extended from this manifold. There were 28 of these pipes and each split into two outlets so that there were 56 injection points on this level. The outer ends of these pipes were on a 4 feet ll inches radius. Opening 63 was about 11 inches wide. Pipes 66 were constructed in a manner similar to pipes 60 to form 20 injection points. The ends of these pipes lay on a 22 inch radius.

Pipes

60 and 66 were 9% inches from members 18 and 64 respectively. This unit was designed to process 30,000 barrels per day of charge at a catalyst circulation rate of about 1,100 tons per hour. It was estimated that the charge would be about 50 percent liquid as it entered the bed.

This invention should be understood to cover all changes and modifications of the examples of the invention herein chosen for purposes of disclosure which do not constitute departures from the spirit and scope of this invention.

We claim:

1. In a continuous process for the conversion of fluid hydrocarbons in the presence of a downwardly moving, substantially compact reaction column of granular contact material maintained within a confined conversion zone, the improved method of supplying hydrocarbon charge to said column, which comprises: passing a stream of fresh hot contact material at a temperature suitable to eifect the desired conversion into the upper section of the conversion zone; expanding at least a part of the contact material from said stream outwardly across the upper end of the reaction column and forming from said expanding contact material a substantially compact, flowing layer of hot contact material which has a crosssectional area, normal to the direction of contact material flow, amounting to only a minor fraction of the horizontal cross-sectional area of the reaction column; injecting hydrocarbon charge, at least partially in the liquid phase and at a temperature below the fresh contact material temperature, into the layer at a plurality of points, laterally removed from the area of discharge of said stream, at a mass velocity sufficient to form a vapor bubble at each of said points in which bubble vapor, liquid and contact material are mixed, said layer carrying a suificient quantity of contact material that a major portion of the contact material supply to the column is carried by said layer as the contact material therein passes past said points of injection; spacing said injection points horizontally, in a direction transverse to the flow of contact material as it expands, suificiently close to each other that lines drawn through the centers of any adjacent injection points in the direction of flow of the expanding contact material outwardly to the edge of the bed will be horizontally a distance apart less than 20 inches as they intersect the edge of said bed; mechanically confining the upper side of said layer in the area adjacent the points of injection to an extent that no vapor can issue from an unconfined surface at a velocity sufiicient to substantially disrupt said surface.

2. In a continuous process for the conversion of fluid hydrocarbons, which must be charged partially as a liquid and partially as a vapor, in the presence of a downwardly moving, substantially compact reaction bed of contact material maintained within a confined conversion zone, the improved method of supplying hydrocarbon charge and contact material to the bed, which comprises: supplying hot contact material at a temperature suitable to effect the desired conversion to the upper surface of the reaction bed as a downwardly gravitating stream of contact material of substantially minor cross-section compared to said bed, whereby hot contact material will spread across the upper end of said bed as a transversely flowing layer to supply those areas of the reaction bed not directly beneath the feed stream, contact material passing from said layer into the main body of the reaction bed all along the length of the layer; injecting hydrocarbon charge at a temperature substantially below the contact material temperature into the transversely flowing layer at a plurality of points laterally removed from the area of discharge of said stream and horizontally spaced apart in a direction transverse to the direction of contact material flow in the layer an amount such that lines drawn through the centers of any adjacent points of injection outwardly to the edge of said bed are less than 10 inches apart as they intersect the vertical plane of the edge of said bed, said layer having a cross-sectional area transverse to the direction of contact material flow amounting to less than 40 percent of the horizontal cross-section of the bed but said layer carrying at least 75 percent of the contact material supply to the reaction bed past the points of hydrocarbon injection; confining the upper side of said layer from the area of supply of said stream to beyond the points of injection to an extent that any vapor which issues from an unconfined surface will be at a velocity insufiicient to substantially disrupt said surface; maintaining the mass velocity at which the hydrocarbon charge is injected greater than V (sine 6)- where V equals the boiling mass velocity and 0 equals the angle with the horizontal at which the upper side of said layer is confined, whereby a vapor bubble in which vapor, liquid and contact material are mixed, will be formed at each injection point; and passing hydrocarbons from said layer into said bed.

3. In a continuous process for the conversion of fluid hydrocarbons in the presence of a downwardly gravitating, substantially compact reaction bed of granular contact material maintained within a confined conversion -zone,'the improved method of supplying the hydrocarbon charge and contact material to the reaction bed, which comprises: passing hot contact material at a temperature suitable to effect the desired conversion into the upper section of the conversion zone, battling the flow of contact material so supplied to form a confined transversely flowing, annular-shaped, substantially compact stream above said bed and delivering contact material from the lower end of said stream to said bed, said annular-shaped stream having a cross-sectional area transverse to the direction of flow less than 40 percent of the horizontal cross-section of the reaction bed; injecting hydrocarbon charge as a mixture of liquid and vapor at a temperature substantially below the contact material temperature into said stream at a plurality of points laterally removed from the area of discharge of said stream and spaced apart around said annular-shaped stream on a center-tocenter spacing such that lines drawn through the centers of adjacent injection points in the direction of contact material flow in the layer will intersect the vertical plane of the edge of said bed at points spaced -a horizontal distance less than 10 inches; delivering the hydrocarbon charge to the reaction bed through the lower end of the annular-shaped stream; confining Said annular-shaped stream and the upper end of said bed by means of solid surfaces to a sufficient extent to prevent vapor issuing from an unconfined surface at a velocity suflicient to substantially disrupt said surface and maintain the mass velocity at which charge is injected at each of the injection points above V (sine where V equals the boiling mass velocity and 0 equals the angle which said vsolid surfaces make with the horizontal, whereby a vapor bubble in which liquid, vapor and contact material are mixed is formed at each injection point.

-, 4. In a continuous process for the conversion of fluid hydrocarbons by concurrently flowing the hydrocarbons through a cylindrical, downwardly moving, substantially compact reaction bed of granular contact material maintained within the lower section of an enclosed cylindrical housing, the improved method of supplying hydrocarbon charge and contact material to the reaction bed, which comprises: passing a single, confined, substantially ver- 'tical, substantially compact stream of contact material of substantially less cross-section than said bed and at a -temperature suitable to effect the desired conversion into the upper section of said housing and centrally onto the upper surface of said bed, whereby at least 75 percent of the contact material from said stream flows outwardly transversely over the upper surface of said bed as a frusto-conical shaped layer, from the underside of which contact material passes into the main body of the reaction bed; injecting the hydrocarbon charge as a mixture of liquid and vapor and at a temperature substantially W below the contact material temperature into said layer at Ia plurality of points, laterally removed from the area of jdischarge of said stream, said points being arranged inat least one circular pattern having as its center the vertical center line of said stream, said points being located (laterally sufliciently close to thelower end of said stream that at least 75 percent of the contact material supply to "the bed flows past said points and said points being spaced apart a center-to-center distance in inches measured in -the plane of the average radius of the circular patterns, between adjacent points less than the amount determined 'from the following equation:

: inches, where r equals the average radius of the circular patterns on which the injection points are arranged and i R equals the radius of the reaction bed in consistent unlts 11.18, ,formed at each of said points; confining the upper sideof said layer by said surfaces from the lower end of said passage to a region sufiiciently beyond the points of injection in the direction of contact material flow in the 5 layer that Vapor cannot issue from an unconfined surface at an average mass velocity above the boiling mass velocity. 5. In a continuous process for the conversion of fluid hydrocarbons by concurrently flowing the hydrocarbons through a downwardly moving, substantially compact reaction bed of granular contact material maintained within the lower section of a cylindrical enclosed housing, the improved method for supplying the hydrocarbon charge and the contact material to the bed, which comprises: passing a single confined substantially compact stream of contact material at a temperature suitable to effect the desired conversion vertically and centrally into the upper end of the housing and onto the upper surface of the bed, said stream having a horizontal cross-section amounting to only a minor fraction of the horizontal cross-section of said bed; confining the upper surface of said bed at an angle greater than the angle of repose of the contact material by means of solid surfaces extending from the area of supply of said stream to the walls of said housing; bafiling the flow of contact material as it issues from said stream so that the entire contact material flow fromjsaid stream passes outwardly across the upper end of the bed as a substantially compact layer shaped in the form of a hollow frustum of a cone; injecting hydrocarbon charge as a mixture of liquid and vapor at a temperature substantially below the contact material temperature into said layer at a plurality of points laterally removed from the area of discharge of said stream and arranged on at least one circular pattern within said 5 layer, the center of said patterns being the centerline of 'said streamand adjacent points of injection being spaced apartcenter-to-center a distance in inches in the plane of the average circular pattern of all of said circular patterns less than the amount determined by the follow- 40 ring equation:

inches, where r equals the average radius of all of the circular patterns and R equals the radius of the'housing in consistent units with r; maintaining the area of said layer transverse to the direction of contact material flow -in the vicinity of said points of injection less than 40 percent of the horizontal cross-section of said bed; maintaining the mass velocity of the hydrocarbons at the injection points above the boiling mass velocity, whereby a. bubble of fluid hydrocarbons is formed at each injection point in which vapor, liquid and contact materialare ,mixed; and passing hydrocarbons and contact material fromthe lower end of said layer to the main body of the reaction be'd.

6. A continuous process for the conversion of fluid hydrocarbons by flowing the hydrocarbons concurrently through a downwardly moving, substantially compact 0 reaction bed of granular contact material, which comprises: maintaining said bed within the lowersection of a confined cylindrical conversion housing with a gas space above the bed in the upper section of the housing; .maintaining an accumulation of fresh contact material at a temperature suitable to eifect the desired conversion within the gas space in said housing at a level substantially above said bed, said accumulation being less in 'lateral dimensions than said housing and being open on its upper end to said gas space; supplying fresh contact material at a temperature suitable to effect the desired conversion to the upper surface of said accumulation; :passing' a confined, elongated, substantially compact seal leg of contact material from the lower section of said accumulation centrally onto-the uppersurface of said 7 -5 bed; bafiling the flow of contact material as it issues from said seal leg so that the entire flow, after it issues from the seal leg, passes outwardly across the upper end of 'said bed as a substantially compact layer shaped in the form of a hollow frustum of a cone; injecting hydrocarbon charge as a mixture of liquid and vapor at a temlOr inches, where r equals the average radius of all of the circular patterns and R equals the radius of the housing in consistent units with r; maintaining the area of said layer transverse to the direction of contact material flow in the vicinity of said points of injection less than 40 percent of the horizontal cross-section of said bed; confining the upper surface of the bed at an angle greater than the angle of repose of the contact material by means of solid surfaces which extend outwardly beyond said injection points to a region sufficiently close to said housing walls that vapor does not issue from the unconfined bed surface at a velocity suflicient to disrupt the unconfined portion of the bed surface; maintaining the mass velocity of the hydrocarbon injection at the injection points above the boiling mass velocity, whereby a bubble of fluid hydrocarbons in which vapor, liquid and contact material are mixed, is formed at each injection point; passing hydrocarbons and contact material from the lower end of said layer to the main body of the reaction bed in which contact material particles pass substantially unidirectionally downwardly; injecting seal gas at a pressure slightly in excess of the pressure at said injection points into the lower end of said seal leg and maintaining the pressure in said gas space substantially below the pressure at which seal gas is supplied to said seal leg but sufliciently high that the pressure drop across said seal leg and said accumulation does not exceed the calculated head of contact material in the seal leg.

7. An apparatus for the conversion of fluid hydrocarbons in the presence of a moving mass of granular contact material, which comprises in combination: an enclosed conversion chamber, a contact material supply conduit extending substantially vertically into the upper end of said chamber and terminating in a downwardly facing open discharge end therein, means for supplying granular contact material to the upper end of said conduit, solid confining members adapted to confine the upper surface of Said mass extending outwardly in all directions at angles with the horizontal greater than 30 degrees from the lower end of said conduit to at least one-half the distance from the lower end of said conduit to the walls of said chamber, a hydrocarbon feed manifold situated centrally within said chamber at a level below the lower end of said conduit, means for supplying hydrocarbon feed as a mixture of liquid and vapor to said manifold, a plurality of hydrocarbon feed pipes extending radially outwardly and terminating on a plurality of spaced-apart points, all of which are vertically below said confining members, said pipes being so spaced that lines drawn through the centers of the outlet ends of any adjacent pipes and extending outwardly in the direction parallel to the confining members intersecting the walls of said chamber at points horizontally spaced apart less than 20 inches, means for removing contact material from the lower end of said chamber and means for removing hydrocarbon products of conversion from the chamber.

8. An apparatus for the conversion of fluid hydrocarbons in the presence of a moving mass of granular contact material, which comprises in combination: an enclosed cylindrical conversion chamber; a vertical contact material supply conduit extending centrally into the upper end of said chamber and terminating'in the upper section thereof on a downwardly facing open discharge end; a frusto-conical confining member having sides at angles with the horizonal greater than 30 degrees and connected on its upper end to the lower end of said conduit and on its lower end to the walls of said vessel; a hydrocarbon charge manifold situated centrally a spaced distance below said conduit; means for supplying hydrocarbon charge as a mixture of liquid and vapor to said manifold; a plurality of charge pipes extending radially from said manifold, each of said charge pipes delivering to a plurality of branch pipes which terminate beneath said confining members to form at least one circular pattern of discharge points, all of said branch pipes being spaced apart a center-to-center distance in inches between the discharge ends of adjacent pipes less than that determined by the following equation:

inches, where r equals the radius of the average of the circular pattern of the discharge ends of the branch pipes and R equals the radius of the conversion chamber in consistent units with r; an upwardly tapered contact material flow bafiie beneath said branch pipes with apex centrally beneath said conduit, the distance between said baliie and said confining members being such that the cross-sectional area between baffle and confining members measured normal to the baffle in the vicinity of the outer ends of said branch pipes being less than 40 percent of the horizontal cross-sectional area of the conversion chamber; means for removing products of conversion from said chamber at a level below said bafile and means for removing used contact material from said chamber at a level below said baffle.

9. An apparatus for the continuous conversion of fluid hydrocarbons in the presence of a downwardly gravitating, substantially compact column of granular contact material, which comprises in combination: a cy' lindrical conversion chamber adapted to confine said column of contact material, members defining a substantially vertical passageway for the supply of contact material extending vertically into the upper section of said chamber and terminating on a downwardly facing open discharge end within the upper section of said chamber, a solid confining member in the shape of a hollow frustum of a cone and having sides at angles with the horizontal greater than 30 degrees with upper end connected to the lower end of said passageway and lower end adjacent the walls of said chamber, a hydrocarbon charge manifold situated centrally a spaced distance below the lower end of said passageway, means for supplying a hydrocarbon charge as a mixture of liquid and vapor to said manifold members defining a plurality of spaced-apart hydrocarbon charge passageways extending outwardly to outer ends spaced away from said confining members but within 15 inches thereof, the outer ends of said hydro carbon supply passageways being a distance from the center line of said contact material passageway amount ing to less than 50 percent of the radial distance from the center line of said contact material passageway to .the walls of said chamber and the outer ends of said hydrocarbon supply passageways being spaced apart a center-to-center distance in inches between adjacent passageways less than that determined from the follow- 21 inches, where r equals the radius of the average of radii of all circular patterns which the outer ends of said passageways form and R equals the radius of the conversion chamber in consistent units with r, means for removing products of conversion from the lower section of said chamber and means for removing used contact material from the lower section of said chamber.

10. An apparatus for the conversion of fiuid hydrocarbons in the presence of a moving mass of granular contact material, which comprises in combination: an en- ;closed cylindrical conversion chamber adapted to confine said moving mass, an open-topped receptacle situated within the upper section of said chamber and having lateral dimensions substantially less than said chamber,

a fresh contact material supply conduit extending into said chamber from the exterior and adapted to deliver contact material into said receptacle, a substantially vertical seal leg extending downwardly from the lower end of said receptacle to a substantially lower level in said chamber, means for supplying inert seal gas to said seal leg adjacent its lower end, a hollow upright f-msto-conical shaped confining member with sides at angles with the horizontal greater than 30 degrees and upper end tightly connected to the lower end of said seal leg and lower end adjacent to but short of the walls of said chamber, a conical flow-deflecting baffle with apex a spaced distance beneath said seal leg and extending outwardly beneath said confining member but having a lower diameter substantially less than said chamber and substantially less than the lower diameter of the confining member, the distance between baffle and confining member being such that the area between the two at all points is less than 40 percent of the horizontal cross-section of said chamber, a hydrocarbon feed manifold situated centrally within said chamber, means for supplying hydrocarbon charge as a mixture of liquid and vapor vertically to said manifold, members defining a plurality of hydrocarbon charge passageways extending radially outwardly from said manifold to a plurality of spaced-apart points within the area between said confining members and said battle, the discharge ends of said hydrocarbon charge passageways being directed toward the walls of said vessel along lines generally parallel to the sides of said confining member so as to form at least one circular pattern and being spaced apart a center-to-center horizontal distance in inches between adacent passageways less than the amount determined from the following equation:

lOr T inches, where r equals the average radius of all of the circular patterns formed by discharge ends of said passageways and R equals the radius of the reactor in consistent units with r, means for removing products of conversion from the lower section of said chamber and means for removing used contact material from the lower section of said chamber.

111. In a continuous process for the conversion of fluid hydrocarbons in the presence of a downwardly moving, substantially compact reaction bed of granular contact material maintained within a confined conversion zone, the improved method of supplying hydrocarbon charge to said bed, which comprises: passing a stream of hot contact material at a temperature suitable to effect the desired conversion into the upper section of the conversion zone; expanding at least a portion of the contact material from said stream outwardly across the upper end of the reaction bed and forming from said expanding contact material a substantially compact flowing layer of hot contact material which has a cross-sectional area, normal to the direction of contact material flow, amounting to only a minor fraction of the horizontal crosssectional area of the reaction bed; injecting hydrocarbon charge, at least partially in the liquid phase at a temperature below the temperature at which contact material is supplied to the conversion zone, into said layer at a plurality of points laterally removed from the area of discharge of said stream, said injections being at a mass velocity sutficient to form a vapor bubble at each of said points which extends completely through said layer in the direction normal to the direction of contact material flow, said bubbles being of sufficient'size that they join at their outer edges to form a torus extending through said layer in both the direction normalto the contact material flow and the direction transverse to the contact material flow; causing said layer to carry a sufficient quantity of contact material that at least a major portion of the contact material supplied to the bed is carried by said layer as the contact material'therein passes said torus; confining the upper side of said layer in the area adjacent the points of charge injection to such an extent that no vapor can issue from an unconfined surface at a velocity sufficient to substantially disrupt said surface while maintaining the underside of said layer in substantially open communication with said bed in the region of said torus.

12. In a continuous process for the conversion of fluid hydrocarbons by concurrently flowing hydrocarbons through a downwardly moving, cylindrically-shaped, substantially compact reaction bed of granular contact material maintained within the lower section of an enclosed cylindrical housing, the improved method of supplying hydrocarbon charge and contact material to the reaction bed, which comprises: passing a substantially compact stream of contact material confined within a passage of substantially less cross-section than said bed and" at a temperature suitable to eflect the desired hydrocarbon conversion into the upper section of said housing and centrally into the upper surface of said bed, whereby at least 75 percent of the contact material from said stream flows outwardly laterally over the upper surface of said bed as a narrow, frnsto-conical shaped layer, from the underside of which contact material passes into the main body of the reaction bed through which it moves substantially vertically; injecting a major portion of the hydrocarbon charge as a mixture of liquid and vapor and at a temperature substantially below the contact material temperature into said layer at a plurality of points, said points being laterally removed from the area of discharge of said stream and arranged in a circular pattern having as its center the center line of said stream, said points being located laterally suificiently close to the lower end of said stream that at least 75 percent of the contact material supplied to said bed flows past said points; maintaining the mass velocity of hydrocarbon charge injection sufiicient to form at each of said points a vapor bubble which extends entirely through said layer, said vapor bubbles being suificiently large that each bubble touches adjacent bubbles so that there is formed within said layer a circular torus of vapor; confining the upper side of said layer by means of solid surfaces which extend from the lower end of said passage at an angle greater than the angle of repose of the contact material to a region sufficiently beyond the points of charge injection in the direction of contact material flow in the layer that vapor cannot issue from an unconfined surface at a mass velocity above the boiling mass velocity; battling the flow of contact material which does not pass through said layer to cause said contact material to flow as a narrow band at at least one point; and injecting a second quantity of hydrocarbon charge into said band at a plurality of points.

13. An apparatus for the continuous conversion of fluid hydrocarbons in the presence of a downwardly gravitating, substantially compact bed of granular contact material, which comprises incombination: a cylindrical conversion chamber adapted to confine said bed of contact material; members defining a substantially vertical passageway for the supply of contact material extending vertically into the upper section of said chamber and ter- -minating on a downwardly facing open discharge end within the upper section of said chamber; a solid confining hood in the shape of a hollow frustum of a cone having sides at angles with the horizontal greater than about 30 degrees and having its upper end connected to the lower end of said passageway; a hydrocarbon charge manifold situated centrally a spaced distance below the lower end of said passageway; means for supplying a hydrocarbon chargeas a mixture of liquid and vapor to said manifold; a plurality of spaced-apart hydrocarbon charge conduits extending radially outwardly to outer ends spaced away from said confining member but within 15 inches thereof, adjacent conduits being a circumferential distance less than 15 inches apart; solid members defining an annularshaped passageway with inlet immediately below the underside of said manifold and with outlet substantially greater in horizontal cross-section than said inlet; a plurality of hydrocarbon charge pipes extending from said manifold into said annular passageway and terminating therein on horizontally facing outlets adjacent the outermost of said solid member forming said annular passageway; and means for removing hydrocarbon products situated within said conversion chamber at a level beneath said hydrocarbon charge pipes and conduits.

14. A process for the supply of fluid hydrocarbons and granular contact material at different temperatures to a downwardly moving compact bed of contact material, in a manner that minimizes lateral temperature difierentials across the compact bed, which comprises: passing contact material onto the surface of the compact bed of contact material as at least one stream of substantially less horizontal cross-sectional area than said bed so that contact material from said stream expands laterally across the surface of said bed to the outer edge thereof; injecting fluid hydrocarbon reactant, at a temperature substantially different from the temperature of the contact material, into the expanding contact material at a plurality of points which are spaced apart so that lines drawn through adjacent injection points intersect a vertical surface passing '24 through the horizontal lirie where the contact material expansion ends at a distance apart less than 20 inches. 15. The process of claim 14 wherein the fluid hydrocarbons as they are injected are at a substantially lower temperature than the contact material temperature.

1.6: A process for the supply of fluid hydrocarbons and granular contact material at substantially different temperatures to a downwardly moving compact bed of contact material, which comprises: gravitating a single stream of contact material of substantially less horizontal cross-sectional area than said bed onto the upper surface of said bed whereby contact material from said stream will expand outwardly across the upper surface of the bed to the outer edge of said bed; injecting fiuid hydrocarbons at a substantially different temperature from the contact material temperature into the expanding contact material at a plurality of points which are so spaced that lines drawn through any adjacent points of injection which take the direction of the expanding contact material will intersect a vertical plane through the outer edge of the bed a distance less than 20 inches apart.

17. The process of claim 16 wherein the fluid hydrocarbons are supplied at a temperature substantially below the contact material temperature and said lines through adjacent injection points intersect the plane of the edge of the reaction bed less than 10 inches apart.

References Cited in the file of this patent UNITED STATES PATENTS 2,386,670 Evans Oct. 9, 1945 2,432,344 Sinclair Dec. 9, 1947 2,482,139 Schutte Sept. 20, 1949 2,593,495 Shimp Apr. 22, 1952 2,701,788 Schutte Feb. 8, 1955 2,703,936 Hut Mar. 15, 1955 2,770,582 Eastwood Nov. 13, 1956 2,842,430 Bishop July 8, 1958 2,846,370 Halik et a1 Aug. 5, 1958

Claims

1. IN A CONTINUOUS PROCESS FOR THE CONVERSION OF FLUID HYDROCARBONS IN THE PRESENCE OF A DOWNWARDLY MOVING, SUBSTANTIALLY COMPACT REACTION COLUMN OF GRANULAR CONTACT MATERIAL MAINTAINED WITHIN A CONFINED CONVERSION ZONE, THE IMPROVED METHOD OF SUPPLYING HYDROCARBON CHARGE TO SAID COLUMN, WHICH COMPRISES: PASSING A STREAM OF FRESH HOT CONTACT MATERIAL AT A TEMPERATURE SUITABLE TO EFFECT THE DESIRED CONVERSION INTO THE UPPER SECTION OF THE CONVERSION ZONE, EXPANDING AT LEAST A PART OF THE CONTACT MATERIAL FROM SAID STREAM OUTWARDLY ACROSS THE UPPER END OF THE REACTION COLUMN AND FORMING FROM SAID EXPANDING CONTACT MATERIAL A SUBSTANTIALLY COMPACT, FLOWING LAYER OF HOT CONTACT MATERIAL WHICH HAS A CROSSSECTIONAL AREA, NORMAL TO THE DIRECTION OF CONTACT MATERIAL FLOW, AMOUNTING TO ONLY A MINOR FRACTION OF THE HORIZONTAL CROSS-SECTIONAL AREA OF THE REACTION COLUMN, INJECTING HYDROCARBON CHARGE, AT LEAST PARTIALLY IN THE LIQUID PHASE AND AT A TEMPERATURE BELOW THE FRESH CONTACT MATERIAL TEMPERATURE, INTO THE LAYER AT A PLURALITY OF POINTS, LATERALLY REMOVED FROM THE AREA OF DISCHARGE OF SAID STREAM, AT A MASS VELOCITY SUFFICIENT TO FORM A VAPOR BUBBLE AT EACH OF SAID POINTS IN WHICH BUBBLE VAPOR, LIQUID AND CONTACT MATERIAL ARE MIXED, SAID LAYER CARRYING A SUFFICIENT QUANTITY OF CONTACT MATERIAL THAT A MAJOR PORTION OF THE CONTACT MATERIAL SUPPLY TO THE COLUMN IS CARRIED BY SAID LAYER AS THE CONTACT MATERIAL THEREIN PASSES PAST SAID POINTS OF INJECTION, SPACING SAID INJECTION POINTS HORIZONTALLY, IN A DIRECTION TRANSVERSE TO THE FLOW OF CONTACT MATERIAL AS IT EXPANDS, SUFFICIENTLY CLOSE TO EACH OTHER THAN LINES DRAWN THROUGH THE CENTERS OF ANY ADJACENT INJECTION POINTS IN THE DIRECTION OF FLOW OR THE EXPANDING CONTACT MATERIAL OUTWARDLY TO THE EDGE OF THE BED WILL BE HORIZONTALLY A DISTANCE APART LESS THAN 20 INCHES AS THEY INTERSECT THE EDGE OF SAID BED, MECHANICALLY CONFINING THE UPER SIDE OF SAID LAYER IN THE AREA ADJACENT THE POINTS OF INJECTION TO AN EXTENT THAT NO VAPOR CAN ISSUE FROM AN UNCONFINED SURFACE AT A VELOCITY SUFFICIENT TO SUBSTANTIALLY DISRUPT SAID SURFACE.