IE47100B1 - Hydrocarbon-feed distributor and method of injecting hydrocarbon feed - Google Patents

Description

The field of art to which this invention pertains is hydrocarbon processing with a fluidizable catalyst. More particularly, 1n one embodiment the present application relates to a hydrocarbon feed distributor and, in another embodiment, to a particular method of injec5 ting a hydrocarbon feed Into a catalytic conversion zone, both of which find particular utility 1n the fluidized catalytic cracking process.

The fluid catalytic cracking (FCC) process wherein the present invention finds particular applicability comprises mixing in a riser reaction zone a hydrocarbon feed, typically having a boiling range of fran about 260°C. to about 649°C. with a fluidizable catalyst and converting the hydrocarbon feed therein, at conversion conditions, into lighter, more valuable, products. Typically the temperature of the hydrocarbon feed is from about 177°C. to about 371°C. and the temperature of the regenerated catalyst is from about 621°C. to about 732°C. The two are mixed together to completely vaporize the hydrocarbon feed and to achieve a temperature within the con ‘ ·' ’ version zone of generally fran about 468°C. ta about 593°C. Conversion conditions 710 0 also typically include low pressures of from about atmospheric pressure to about 7.8 atm. and hydrocarbon residence times of from about 0.5 second to about 5 minutes. Catalyst is normally circulated through the riser reaction zone at a rate of from about 4 to about 20 kilograms of catalyst per kilogram of hydrocarbon feed. Ihe catalyzed reactions may be conducted entirely in a riser reaction zone, as in an all-riser FCC unit, or partially in a riser reaction zone with the mixture of catalyst, reaction products and unconverted feed, if any, then being discharged into a dense bed of fluidized catalyst for further conversion of the feed or of the heavier reaction products into lighter reaction products. The apparatus and method of this invention find utility in either case.

A variety of techniques have heretofore been employed to introduce a hydrocarbon feed into the riser reaction zone. U.S.

Patent No. 3,152,065 for example describes a method of injecting a hydrocarbon feedstock into a catalytic reaction zone which comprises passing the liquid hydrocarbon as an outer stream in a generally linear direction, imparting a centrifugal energy component to the outer stream, passing the outer stream having a centrifugal component through an annulus, and discharging the moving stream through a restricted passageway in contact with an inner stream of a vaporous material such as steam which operates to disperse the hydrocarbon stream into small droplets of liquid. Other vaporous or gaseous materials such as inert gases, nitrogen, natural gas, recycled catalytic cracking unit process gases, etc. can be used as the inner stream. Also disclosed in that same prior art reference is a nozzle for injecting a liquid hydrocarbon feed into contact with a catalyst which nozzle contains components for imparting a centrifugal energy component to material flowing through an outer shell of the nozzle. Both the method and the nozzle are for providing a high degree 4'< of atomization of the feedstock and good contacting of the hydrocarbon feedstock and the catalyst. This high degree of atomization is achieved by the use of means of imparting a centrifugal energy component to a liquid hydrocarbon stream and by using a vaporous mater5 ial which operates to disperse the hydrocarbon stream into small droplets. ll.S. Patent No. 3,654,140 describes an improved catalytic cracking process which comprises feeding a substantially liquid hydrocarbon oil feedstock to at least one feed injection zone of a fluidized catalytic cracking reaction zone, concurrently feeding steam to said injection zone in a volumetric ratio of steam to liquid hydrocarbon ranging from about 3 to about 75, thereby imparting to the resulting mixture an exit velocity relative to the fluidized catalyst of at least about30.5 meters per second, whereby the oil feedstock is essentially completely atomized forming droplets less than about 350 microns in diameter. The process of this reference relies on the use of steam and very high exit velocities of at least .5 m/sec to achieve a high degree of feedstock atomization characterized by droplet sizes of less than about 350 microns in diameter.

These prior art processes and apparatus and others have been primarily concerned with the initial contacting of the hydrocarbon feedstock and catalyst to achieve, at least initially, a uniform mixture of catalyst and hydrocarbon feed in the riser reaction zone to avoid excessive coking of the feedstock and attendant product loss. While the initial formation of a uniform catalyst and hydro25 carbon mixture is certainly important, it is equally important that the mixture uniformity be maintained as well as possible across a cross -seefeicn of the riser reaction zone at any elevation along the riser reaction zone. More specifically, it has been found that in spite of the use of methods and apparatus to achieve initial uniform contacting of a hydrocarbon feed and a cracking catalyst, wide variations of catalyst density and temperature can exist across crosssections of typical riser reaction zones, particularly across crosssections at lower elevations of riser reaction zones. With the use of radiation equipment and probes containing thermocouples,catalyst densities and temperatures In riser reaction zones at different elevations have been measured and catalyst density and temperature contours have been obtained. At lower-elevation cross sections of a riser reaction zone catalyst densities of about 961 kg/m3 have been found near the walls while catalyst densities of less than about48 kg/m3 were found on the same cross section but near the riser centerline. Temperature profiles have shown the same wide variation; at lowerelevation cross sections of a riser reaction zone temperatures of 649°C. and higher have been measured while temperatures near the centerline of the riser were about 343°C. Such high wall temperatures cause elongation of the riser reaction zone and in many instances exceed the design wall temperature and result in permanent deformation of the riser reaction zone. Additionally high wall temperatures cause overcracking of hydrocarbon feed in these regions of higher temperatures and result In increased yields of dry gas (Cg-)· Ihe present invention seeks to improve the distribution of hydrocarbon feed to reaction zones, particularly riser reaction ccnduits such as are used in fluidized catalytic cracking and to avoid excessive wall temperatures. 47l°° In one embodiment, the invention provides a hydrocarbon-feed distributor for injecting a hydrocarbon feed into contact with a fluidizable catalyst under conversion conditions in a lower end of a riser reactor conduit having a lower end, cylindrical inside and outside walls, a center portion, a hydrocarbon-feed inlet means entering said conduit at said lower end and a regenerated-catalyst inlet means passing through said walls at a distance downstream from said hydrocarbon-feed inlet means, said distributor comprising: a) a truncated cone having a small-diameter end, adapted to be connected to said hydrocarbon-feed inlet means, and a large-diameter end; b) a plate fitted into said largediameter end, said plate having one or more first holes and a plurality of second holes passing through said plate; and, c) one or more first nozzles each fitted into an individual first hole, each nozzle having a first inlet means and a first outlet means positioned to direct, in use of the distributor, hydrocarbon feed vertically upwards into said center portion of said conduit; and d) a plurality of second nozzles each fitted into an individual second hole, each nozzle having a second inlet means and a second outlet means positioned to direct, in use of the distributor, hydrocarbon feed into said conduit at an inclined angle to hydrocarbon feed exiting the first nozzle(s) and in a direction to impinge against said inside wall downstream of said second outlet means.

In another embodiment the invention provides a method of injecting a hydrocarbon feed into contact with a fluidizable catalyst in a catalytic conversion zone having a center portion and an inside wall which comprises: a) passing a first portion of said feed into said zone through one or more first nozzles having a first inlet means and a first outlet means, said nozzle being vertically positioned in said conversion zone whereby said first portion is directed from said first outlet means vertically up into said center portion; and b) passing a second portion of said feed into said zone through multiple second nozzles each having second inlet means and second outlet means and positioned in said conversion zone so that a centerline passing through a long axis of a second nozzle is inclined toward the inside wall of said conversion zone at an angle from a vertical centerline passing through the center of a second inlet means, whereby said second portion exits said second outlet means and impinges on said inside wall downstream of said second inlet means.

As compared to the above-mentioned prior art the distributor of the present invention, when in use as part of apparatus for carrying out a hydrocarbon conversion reaction, particularly a fluidized catalytic cracking, and the method of the present invention, when in use in a hydrocarbon conversion process, particularly fluidized catalytic cracking, generally reduce these high wall temperatures and the problems they cause. The apparatus and method, when in use, produce temperature profiles across a cross-section of a riser reaction zone which are more nearly flat thus reducing overcracking and the risk of damage to the riser reaction zone and also reducing yields of dry gas.

The accompanying drawings illustrate preferred embodiments of the invention but it is to be understood that it is not our intention to limit our invention to those embodiments but rather to include all alternatives, modifications and equivalents thereof as are within the scope of the claims appended hereto. It is also to be understood that the embodiments are only shown in such detail as is necessary for an understanding of the invention and that minor items have been omitted for the sake of simplicity. 47ΐυυ Figure 1 Is a side view of a fluid catalytic cracking apparatus In which the hydrocarbon feed distributor of this invention is incorporated as one component of the apparatus; Figure 2 is an enlarged side view of the lower end of the 5 cracking apparatus shown in Figure 1 and in particular of the lower end of a riser reactor conduit showing in more detail the positioning of the feed distributor 1n the riser conduit in relation to other components of the cracking apparatus; Figure 3 is a top view of one embodiment of a hydrocarbon 10 feed distributor while Figure 4 is a side sectional view of the same distributor; and Figure 5 is the top view of another embodiment of a hydrocarbon feed distributor while Figure 6 is a side view of the same distributor.

A particular environment wherein the present Invention finds its greatest utility is 1n a fluid catalytic cracking apparatus shown in Figure 1 and comprising a riser reactor conduit 1, a feed distributor 2, a hydrocarbon inlet means 3, a regenerated-catalyst inlet means 4, a reception vessel 6, a cyclone separation means 12, and a spentcatalyst outlet means 16. A hydrocarbon feed, for example, a virgin gas oil boiling within the range of from about 343°C. to about 649°C. , is introduced into the apparatus by way of hydrocarbon-feed inlet means 3. The hydrocarbon feed may be preheated by a fired heater (not shown) 25 or by a system of heat exchangers (not shown) before entering the unit and it is to be understood that recycle streams may also be charged in conjunction with the virgin feed into the unit. The hydrocarbon feed may be in vapor phase or in liquid phase or a mixture of the two but more typically in fluid catalytic cracking processes it will be in the 710 0 liquid phase. Hydrocarbon feed inlet means 3 is connected to hydrocarbon feed distributor 2 through which hydrocarbon feed passes and becomes mixed in the lower portion of conduit 1 with hot regenerated catalyst from a regeneration zone (not shown) which enters conduit 1 through regenerated catalyst inlet means 4 which has flow regulating means 5 located thereon to control the flow of regenerated catalyst. Essentially complete vaporization of the hydrocarbon feed occurs rapidly and conversion of the feed at conversion conditions, including the presence of regenerated catalyst, takes place as the mixture passes upward through conduit 1 which extends vertically upward through the bottom portion of reception vessel 6 into disengaging space 8 within reception vessel 6. Reaction products plus unconverted feed, if any, pass out of conduit 1 via opening 7 located at the upper end of conduit 1 Into disengaging space 8 within reception vessel 6. Some separation of hydrocarbon vapors and catalysts occurs within disengaging space 8 because of the decrease in velocity and the change in the direction of flow of the mixture of vapors and catalyst. Separated spent catalyst drops down into dense bed 10 which has an interface shown at 9. Hydrocarbon vapors and any inerts plus any entrained catalyst in disengaging space 8 enter cyclone separation means 12 through inlet 11 and catalyst and vapors are again separated with separated catalyst passing downward toward dense bed 10 through dip leg 13 and vapor passing out of cyclone separator device 12 and out of vessel 6 through vapor conduit 17. Although Figure 1 shows only one cyclone separation device 12, more than one such device could of course be employed in parallel or series flow arrangements as the volume and loading of the vapor stream and the desired degree of separation dictate. Catalyst in dense bed 10 flows in a downward direction and passes through a lower necked-down section of vessel 6 over baffles 14 and is stripped of adsorbed and interstitial hydrocarbons by a countercurrent stream of stripping medium, generally steam, which enters the lower portion of vessel 6 through stripping medium inlet means 15. Spent catalyst leaves vessel 6 through spent-catalyst conduit 16 and passes to a regeneration apparatus (not shown) wherein coke is oxidized from spent catalyst to produce regenerated catalyst.' Hydrocarbon feed distributor 2 is shown in more detail in Figure 2 which is an enlarged side view of a lower portion of the apparatus of Figure 1. Riser conduit 1 has inside wall IA, outside wall IB, center portion 1C, flange ID and necked-down portion IE. Distributor 2 is shown to have a cone-shaped component 2A having a smaller-dianEter end connected to hydrocarbon-feed inlet means 3 and having a larger-diameter end cn which are located nozzles 2C which have outlet means 2D. Hydrocarbon-feed inlet means 3 will typically be joined to riser conduit 1 by flange ID. Also shown in Figure 2 is the positioning of - distributor 2 so that outlet means 2D of nozzles 2C are below regenerated catalyst inlet means 4. It is believed that the possibility of plugging of one of nozzles 2C with coke, particularly of low hydrocarbon-feed velocities through nozzles 2C as might occur on reduced throughput operations, will be less when distributor 2 is thus positioned than if it were positioned such that outlet means 2D were above regenerated-catalyst inlet means 4. Figure 2 shows three nozzles 2D in side view; one center nozzle and two outer nozzles. The center nozzle is positioned to direct hydrocarbon feed exiting that nozzle vertically up into center portion 1C of riser conduit 1 and the outer nozzles are positioned so that hydrocarbon feed exiting from those nozzles will impinge on inside wall IA of conduit 1 downstream of outlet means 2D and preferably downstream of where regenerated-catalyst inlet means 4 enters conduit 1. More preferably the hydrocarbon feed will impinge on inside wall IA at a distance of 30.5 cm or more downstream of where regenerated-catalyst inlet means enters conduit 1. Hydrocarbon feed velocity through nozzles 2C Will generally be fron about 0.3 to about 15.2 m/sec and more preferably from aboui'® to about6.1 m/sec. Impinging hydrocarbon feed from these outer nozzles onto inside wall IA at these velocities breaks up the wall effect and reduces the wall temperatures so that temperatures at any point on a horizontal crosssectional plane through conduit 1 become more nearly the same. The beneficial consequences of reduced wall temperatures are reduced overcracking of the hydrocarbon feedstock and reduced yields of dry gas.

One preferred embodiment of feed distributor 2 is shown in more detail in Figures 3 and 4. Figure 4 shows truncated cone 2A having a smaller-diameter end and a larger-diameter end vhich is fitted with plate 2B. The diameter of the smaller-diameter end will be about the same as that of the hydrocarbon-feed inlet means to which the smallerdiameter end attaches and the diameter of the larger-diameter end will be such that it will pass through the flange connecting the riser conduit and the hydrocarbon-feed inlet means and also pass through the necked-down portion of the riser conduit. Plate 2B has a first circular hole passing through the center of the plate and has second circular holes passing through the plate and equally spaced around a circle described by a radius from the center of the plate 2B. cylindrical nozzles 2C have inlet means 2E which are inserted Into the first and second holes and have outlet means 2D through which hydrocarbon feed leaves nozzles 2C and distributor 2. A first nozzle 2C is located in the center of the plate and is positioned at a right angle with respect to plate 2B, that is, a vertical centerline will pass through the centers lOO of inlet means 2E and outlet means 2D of that center nozzle. Hydrocarbon feed is thus directed up through this center nozzle up into the center portion of the riser conduit. As illustrated in Figure 4, second nozzles 2C are arranged in the circle around the center nozzle and are positioned such that a centerline passing through the long axis of a second nozzle is inclined away from the center nozzle at an angle a from a vertical centerline passing through the center of an inlet means 2E of a second nozzle so that hydrocarbon feed passing through these nozzles will impinge on the inside wall of the riser conduit downstream from nozzle outlet means 2D and more preferably 12 inches (30.5 cm) ,or more downstream of where regenerated catalyst inlet means enters the riser conduit. Preferably angle a will be from about 10° to about 30°. Although eight· second nozzles are shown, there may be from 3 to about 30 second nbzzles so positioned on plate 2B. The nozzles will generally he sized in both total number and inside diameter to pass hydrocarbon feed at velocities of from about 0.3 to about-15.2 m/sec.and more preferably from about 1.5 to about 6.1 m/sec.

Another preferred embodiment of feed distributor 2 is shown in more detail in Figures 5 and 6. Like Figure 4, Figure 6 shows truncated cone 2A. hawing a sisaller-diameter end and a larger-diameter end viiich is fitted with plate 2B. In this embodiment however plate 2B has first circular holes passing through plate 2B and equally spaced around a first circle described by a first radius from the center of plate 26 and has second circular holes passing through plate 2B and equally spaced around a second circle, larger than the first circle, described by a second radius from the center of plate 2B. Cylindrical nozzles 2C have inlet means 2E which are inserted into the first and second holes and have outlet means 2D through which hydrocarbon feed leaves nozzles 2C and distributor 2. First nozzles 2C are located on the first circle on the 471! OO plate and are positioned at right angles with respect to plate 28, that is, a common vertical centerline will pass through the centers of inlet means 2E and outlet means 2D of each first nozzle 2C.

Hydrocarbon feed is thus directed through these first nozzles up into the center portion of the riser conduit. Second nozzles 2C are arranged around the second circle and are positioned such that a centerline passing through the long axis of a second nozzle is inclined away from the first nozzles at an angle a from a vertical centerline passing through the center of an inlet means 2E of a second nozzle so that hydrocarbon feed passing through these nozzles will impinge on the inside wall of the riser conduit downstream from nozzle outlet means 2D and more preferably 12 inches (30.5 cm) or more downstream of where the regenerated catalyst inlet means enters the riser conduit. Preferably angle a will be from about 10° to about 30°.

Although 5 first nozzles and 10 second nozzles are shown, there may be from 2 or 3 to about 10 first nozzles and from 3 to about 20 second nozzles. The nozzles will generally be sized in both total number and inside diameter to pass hydrocarbon feed at velocities of from about 0.3 to about 15.2m/seq.and more preferably from about 1.5 to about 6.1 m/sec.

Features common to the distributor in any of its main embodiments are that there be one or more first nozzles at right angles to plate 2B; that there be second nozzles positioned in plate 2B such that they are inclined away from a first nozzle and toward the inside wall of the riser conduit; and, that the second nozzles be equally spaced around a circle on plate 2B. First nozzles are positioned at right angles to plate 28 to avoid dead space or regions of slow flow in the center of the conduit. As previously explained, second nozzles are inclined toward the inside wall of the riser conduit so that hydrocarbon feed exiting the second nozzles will Impinge upon the inside wall ±7 4-°0 thus breaking up the stagnant boundary layers of hot catalyst near the inside wall of the conduit and reducing the wall temperature of the conduit. Second nozzles are equally spaced on a circle on plate 2B so that hydrocarbon feed from the second nozzles impinges evenly around the inside wall of the riser conduit thus avoiding localized high wall temperatures.

Suitable materials of construction for building the distributor are materials which are able to withstand the sustained abrasive, high-temperature conditions found in the lower section of a riser conduit. Specifically, metals such as carbon steel or stainless steel are contemplated. Typically nozzles 2C will be made out of schedule 80 to schedule 160 pipe and plate 2B and trun15 cated cone 2A will be made of 1.3 cm steel plate. The top surface of plate 2B will preferably be covered with 1.3 to 2.5 cm of refractory concrete to provide additional abrasion resistance. 471oq In one embodiment of the method of the invention the first portion of hydrocarbon feed will be passed through a single first nozzle; in another embodiment it will be passed through multiple first nozzles. The first and second portions of hydrocarbon feed will be passed through the first and second nozzles at velocities generally of from 0.3 to about 15.2 m/sec and more preferably at velocities from about 1.5 to about 6.1 m/sec. Preferably the second portion of the hydrocarbon feed will exit the second outlet means and impinge on the inside wall of the conversion zone at a distance of 30.5 cm or more downstream of the second inlet means. The hydrocarbon feed can be in liquid or vapor phase or in both liquid and vapor phase but preferably it will be in liquid phase at a temperature of from about 177°C. to about 371°C. Hydrocarbon feed will contact hot catalyst entering the conversion zone at a temperature generally of from about 621°C. to about 732°C. Other conversion conditions within the conversion zone will generally include a total pressure of from about atmospheric pressure to about 7.8 atm. and a hydrocarbon residence time of from about 0.5 seconds to 5 minutes and more preferably from about 0.5 seconds to about 2 minutes. Conversion conditions may also include the pressure of steam or other vaporous material to aid in fluidizing the catalyst and to reduce the hydrocarbon partial pressure which aids in the cracking reaction.

Claims (21)

1. I. A hydrocarbon-feed distributor for injecting a hydrocarbon feed into contact with a fluidizable catalyst under conversion conditions in a lower end of a riser 5 reactor conduit having a lower end, cylindrical inside and outside walls, a center portion, a hydrocarbon-feed inlet means entering said conduit at said lower end and a regenerated-catalyst inlet means passing through said walls at a distance downstream from said hydrocarbon-feed 10 inlet means, said distributor comprising: a. a truncated cone having a smaller-diameter end, adapted to be connected to the hydrocarbon-feed inlet means, and a larger-diameter end; b. a plate fitted into said larger-diameter end, 15 said plate having one or more first holes and a plurality of second holes passing through said plate; c. one or more first nozzles each fitted into an individual first hole, each nozzle having a first inlet means and a first outlet means positioned to direct, in 20 use of the distributor, hydrocarbon feed vertically upwards into said center portion of said conduit; and d. a plurality of second nozzles each fitted into an individual second hole, each nozzle having a second 25 inlet means and a second outlet means positioned to direct, in use of the distributor, hydrocarbon feed into said conduit at an inclined angle to hydrocarbon feed exiting the first nozzle(s) and in a direction to impinge against said inside wall downstream of said second outlet 30 means. -4-71 0 0

2. A distributor as claimed in claim 1 wherein said first nozzle or each of said first nozzles is positioned at a right angle to said plate and said second nozzles are positioned so that a centerline passing through a long axis of a second nozzle is inclined at an angle from a vertical centerline passing through the center of a second inlet means whereby hydrocarbon feed passing through a second nozzle exits a second outlet means and, in use of the distributor, impinges on an inside wall of said conduit downstream from said second outlet means.

3. A distributor as claimed in claim 2 wherein said angle is from 10 to 30°.

4. A distributor as claimed in any of claims 1 to 3 wherein: a. a single first hole is located in the center of said plate and a first nozzle is fitted into said hole; and, b. second holes are located on a circle described by a radius from the center of said plate and second nozzles are fitted into said holes.

5. A distributor as claimed in claim 4 wherein there are from 3 to 30 second nozzles.

6. A distributor as claimed in any of claims 1 to 3 wherein: a. first holes are equally spaced around a first circle described by a first radius from the center of said plate and first nozzles are fitted into said first holes; and, b. second nozzles are located on a second circle, larger than said first circle, described by a second radius from the center of said plate and second nozzles are fitted into said second holes.

7. A distributor as claimed in claim δ wherein there are from 3 to 10 first nozzles.

8. A distributor as claimed in claim 6 or 7 wherein there are from 3 to 20 second nozzles.

9. A distributor substantially as described with reference to or as illustrated in Figs. 3 and 4 or 5 and 6 of the accompanying drawings.

10. Apparatus for carrying out a fluidized catalytic cracking process comprising a riser reaction conduit having a lower end, cylindrical inside and outside walls, a center portion, a hydrocarbon-feed inlet means entering said conduit at said lower end and fitted with a distributor as claimed in any of claims 1 to 9, and a regenerated catalyst inlet means passing through said walls at a distance downstream from said hydrocarbon feed inlet means.

11. Apparatus as claimed in claim 10 wherein said distributor and conduit are so arranged that said hydrocarbon feed exiting said second outlet means impinges on said inside wall at a distance of 30.5 cm or more down19 >47100 stream of said regenerated catalyst inlet means.

12. Apparatus as claimed in claim 10 fitted with a distributor as claimed in any of claims 1 to 5 and substantially as hereinbefore described with reference to or as illustrated in Figs. 1 and 2 of the accompanying drawings.

13. A method of injecting a hydrocarbon feed into contact with a fluidizable catalyst in a catalytic conversion zone in a vertical riser reactor having a center portion and an inside wall which comprises: a. passing a first portion of said feed into said zone through one or more first nozzles having a first inlet means and a first outlet means, said nozzle being vertically positioned in said conversion zone whereby said first portion is directed from said first outlet means vertically up into said center portion; and b. passing a second portion of said feed into said zone through multiple second nozzles each having second inlet means and second outlet means and positioned in said conversion zone so that a centerline passing through a long axis of a second nozzle is inclined toward the inside wall of said conversion zone at an angle from a vertical centerline passing through the center of a second inlet means, whereby said second portion exits said second outlet means and impinges on said inside wall downstream of said second inlet means.

14. A method as claimed in claim 13 wherein said first portion of hydrocarbon feed is passed through a single first nozzle. 4-710°

15. A method as claimed in claim 13'wherein said first portion of hydrocarbon feed is passed through multiple first nozzles.

16. A method as claimed in any of claims 13 to 15 5 wherein said first and said second portions of hydrocarbon feed are passed through said first and said second nozzles, respectively, at hydrocarbon feed velocities of from 1.5 to 6.1 meters per second.

17. A method as claimed in any of claims 13 to 16 10 wherein said second portion of said feed exits said second outlet means and impinges on said inside wall at a distance of 30.5 cm or more downstream of said second outlet means.

18. A hydrocarbon conversion process wherein a hydro15 carbon feed is introduced into a catalytic conversion zone by a method as claimed in any of claims 13 to 17 and is contacted therein with a fluidized catalyst under hydrocarbon conversion conditions.

19. A process as claimed in claim 18 wherein the hydro20 carbon conversion is fluidized catalytic cracking conducted at least partially in a riser reaction conduit.

20. A process as claimed in claim 18 or 19 carried out in apparatus as claimed in any of claims 10 to 12 except insofar as the number of first nozzles specified in Α7ϊθο a process claim is incompatible with the number of first nozzles specified in an apparatus claim.

21. A hydrocarbon conversion product when obtained by a process as claimed in any of claims 18 to 20.