HK1140719B - Spray nozzle and method of maintaining a spray patter of fluid sprayed by the nozzle and inhibiting erosion of the nozzle - Google Patents

Description

Spray nozzle and method for maintaining spray pattern of spray fluid and inhibiting corrosion of spray nozzle

Cross Reference to Related Applications

This application claims priority from U.S. provisional application No.60/901,151 filed on 13/2/2007 and to U.S. application No.11/606,591 filed on 29/11/2006, which claims priority from U.S. provisional application No.60/741,022 filed on 29/11/2005, the entire contents of which are incorporated herein by reference as part of this disclosure.

Technical Field

The present invention relates to spray nozzles, and more particularly, to spray nozzles that discharge at least one fluid in an atomized spray, and more particularly, to spray nozzles that inhibit corrosion and maintain a consistent spray pattern when corrosion occurs.

Background

Fluid Catalytic Cracking (FCC) is one of the major refining processes used in the oil refining industry. The FCC process is used to crack feedstocks consisting primarily of petroleum-based hydrocarbons to produce products such as fuels for internal combustion engines and heating oils. The cracking process is typically carried out in a vertically oriented conduit or riser comprising a reactor vessel that forms part of an FCC system. In the process, hot catalyst particles in an aerated (fluidized) state are generally introduced into the bottom of the riser and are directed to flow upward. The hydrocarbon feed is mixed with steam to become partially fluidized and injected into the catalyst stream as the catalyst travels through the riser, which causes cracking reactions that break down the hydrocarbon feed into a simpler (lighter) molecular form.

The most suitable cracking conditions in an FCC process require that the catalyst and hydrocarbon feed be mixed substantially immediately and homogeneously. However, such mixing is difficult to achieve and stratified hot catalyst zones and cold hydrocarbon feed zones are often present in the catalyst-hydrocarbon stream. Over-cracking and thermal cracking of hydrocarbon molecules typically occur in the catalyst-rich region of the catalyst-hydrocarbon stream. In contrast, incomplete cracking of the hydrocarbon molecules often occurs in the hydrocarbon rich flow zone. These factors can significantly reduce the overall yield of the FCC process. In addition, over-cracking, thermal cracking, and incomplete cracking have undesirable side effects such as deactivation of the catalyst in the riser due to coke deposition, regeneration of the catalyst in the regenerator due to combustion of air and residual coke, and production of excess low boiling range gaseous reaction products such as propane and butane gases.

Therefore, an efficient method for mixing the catalyst and the hydrocarbon feed within the reactor vessel is very important for the cracking process, as proper mixing relies on maintaining a stable spray pattern of the hydrocarbon feed. This spray pattern is achieved by restricting flow through carefully shaped flow channels. If the shape of the channel changes, the length/diameter ratio (L/D) of the flow channel changes, which in turn changes the spray pattern. The most common cause of changes in geometry and L/D ratio is erosion of the nozzle material caused by the moving catalyst of the fluidized bed of the riser in which the nozzle is installed.

To ensure proper mixing, the spray nozzle is designed to introduce the hydrocarbon-vapor mixture into the upflowing catalyst; however, existing nozzles that can be used in FCC units have significant limitations. First, the nozzles can produce a non-uniform spray pattern that reduces liquid contact between the hydrocarbon-vapor mixture and the catalyst, which in turn prevents uniform mixing, resulting in over-cracking, thermal cracking, and/or incomplete cracking of the hydrocarbon molecules. Second, the nozzles are susceptible to erosion, which significantly alters the internal flow channels of the nozzles, resulting in a change in spray pattern, which in turn reduces the uniformity and overall production output of the FCC process. Similar limitations exist in other refining processes that use nozzles to introduce fluids into a mixing vessel, such as long residue conversion (RCC) processes.

For example, U.S. Pat. No.5,553,783 describes a feed distributor nozzle for a fluidized catalytic cracker. In strongly corrosive environments the outer surface will erode, and when the outer erodes, the erosion will extend into the interior of the hole (fig. 1A and 1B). When the holes change shape due to significant shortening, they no longer direct the spray as intended to maintain the desired spray pattern, which is typically a flat fan spray. As the depth of erosion increases, the flat fan spray becomes less sharp and eventually becomes an undesirable spray pattern, such as a narrow cone pattern, which significantly reduces the overall efficiency of the FCC and RCC processes.

To direct the spray pattern, the nozzle cap is designed to include an external protrusion (see FIGS. 2A-2C, 3A-3C, and 4A-4B); however, none of these configurations are designed to: when used in nozzle erosion applications (e.g., FCC and RCC applications), the minimum L/D deviation required to achieve a consistent spray pattern is maintained. For example, in the nozzle shown in fig. 2A-2C, the protrusions have varying L/D ratios designed to direct the spray pattern even with hole patterns skewed from the axis, however, varying L/D ratios make it impossible to maintain a consistent spray pattern in the event of nozzle erosion. Also, in the nozzles shown in fig. 3A-3B and 4A-4B, the protrusions comprise a "cat-eye" shaped configuration with flow channels having varying L/D ratios, which is designed to provide a single, small flat fan spray pattern of varying diameter, but as with the previous nozzle, a consistent spray pattern cannot be maintained if the nozzle erodes.

Accordingly, in order to increase the throughput of FCC and other refinery processes and reduce maintenance costs associated with frequent nozzle replacement, there is a need for spray nozzles that: it produces a consistent flat spray pattern to improve uniform mixing, reduces downstream low pressure zones and eddies to minimize catalyst erosion and maximize catalyst flow area, and is able to maintain the required minimum L/D ratio as the nozzle erodes to maintain the desired spray pattern for an extended period of time.

Disclosure of Invention

According to a first aspect, the present invention is directed to a spray nozzle for discharging at least one fluid in a spray pattern into a fluid stream in a vessel, wherein the nozzle alters the flow pattern of the fluid stream in the vicinity of the nozzle to inhibit nozzle erosion and maintain the spray pattern. The nozzle includes an inlet defining at least one inlet conduit and an outlet in fluid communication with the inlet and defining an outer surface. Further, the outlet defines a plurality of lobes angularly spaced relative to each other about an axis of the outlet, each lobe defining an outlet aperture in fluid communication with the at least one inlet conduit and an axially extending wall, wherein the axially extending wall extends outwardly a length (X) greater than about 1/8 inches relative to the exterior surface. The inlet conduit has a length (L) and a diameter (D), and L/D is at least about 1/2.

According to another aspect, the present invention is directed to a nozzle for discharging an atomized mixture of liquid and gas in at least one of a fluidized catalytic cracking vessel and an atmospheric resid conversion vessel. The nozzle includes an inlet defining at least one inlet conduit and an outlet in fluid communication with the inlet and defining an outer surface. In addition, the outlet includes a plurality of projections angularly spaced relative to each other about an axis of the outlet, each projection defining an outlet aperture in fluid communication with the at least one inlet conduit and an axially extending wall, wherein the axially extending wall extends outwardly a length (X) greater than about 1/8 inches relative to the exterior surface. The inlet conduit has a length (L) and a diameter (D), and L/D is at least about 1/2.

According to another aspect of the invention, substantially all of the flow axes of the outlet orifices are directed toward a target in the container for atomizing and directing the mixture of the first fluid and the second fluid in a spray pattern flowing in a direction through the target. In addition, the target lies substantially in a plane extending in the flow direction of the spray pattern.

According to another aspect, the present invention is directed to a nozzle for discharging an atomized mixture of liquid and gas in at least one of a fluidized catalytic cracking vessel and an atmospheric resid conversion vessel. The nozzle includes an inlet defining at least one inlet conduit and an outlet in fluid communication with the inlet and defining an outer surface. In addition, the outlet includes a plurality of boss members, each boss member fitting within a respective aperture and defining an outlet aperture having a length (L) and a diameter (D) and in fluid communication with the at least one inlet conduit and an axially extending wall, wherein the axially extending wall extends outwardly a length (X) greater than about 1/8 inches relative to the exterior surface, and L/D is at least about 1/2.

According to yet another aspect, the present invention is directed to a spray nozzle for discharging at least one fluid in a spray pattern into a fluid stream in a container. The nozzle includes first means for receiving at least one fluid, second means in fluid communication with the first means for ejecting the at least one fluid therefrom in a spray pattern, and third means in fluid communication with at least one of the first means and the second means for altering a flow pattern of a fluid stream proximate the nozzle to inhibit erosion of the nozzle and maintain the spray pattern. In such an embodiment, the first means is an inlet member defining at least one inlet conduit to receive at least one fluid, the second means is an outlet member in fluid communication with the inlet member, the outlet member defining an outer surface and a plurality of apertures angularly spaced relative to each other about an axis of the outlet, and the third means is a plurality of boss members, each boss member fitted in a respective aperture and defining an outlet aperture and an axially extending wall, the outlet aperture having a length (L) and a diameter (D), wherein the axially extending wall extends outwardly a length (X) greater than about 1/8 inches relative to the outer surface, and L/D is at least about 1/2.

According to yet another aspect, the present invention is directed to a spray nozzle for discharging at least one fluid in a spray pattern into a fluid stream in a vessel, wherein the nozzle alters the flow pattern of the fluid stream in the vicinity of the nozzle to inhibit erosion of the nozzle and maintain the spray pattern. The nozzle includes an inlet defining at least one inlet conduit and an outlet in fluid communication with the inlet and defining an outer surface and two wall members forming a single continuous protrusion about a central axis of the outlet. The continuous projection defines a plurality of outlet apertures having a length (L) and a diameter (D), angularly spaced relative to each other about a central axis of the outlet, and in fluid communication with the at least one inlet conduit. Additionally, the wall member extends outwardly a length (X) greater than about 1/8 inches relative to the outer surface and has an L/D of at least about 1/2.

According to yet another aspect, the present invention is directed to a method of maintaining a spray pattern of at least one fluid in a fluid stream injected into a vessel by a nozzle and inhibiting erosion of the nozzle when the nozzle erodes. The method includes the step of providing a spray nozzle for discharging at least one fluid in a spray pattern into the container, wherein the spray nozzle includes an inlet member defining at least one inlet conduit to receive the at least one fluid and an outlet member in fluid communication with the inlet member. The outlet member defines an outer surface and a plurality of apertures angularly spaced relative to each other about an axis of the outlet member. A fluid stream is introduced into the vessel. A plurality of boss members are provided, each boss member fitting within a respective aperture and defining an outlet aperture having a length (L) and a diameter (D) and being in fluid communication with the at least one inlet conduit and an axially extending wall, wherein the axially extending wall extends outwardly a length (X) greater than about 1/8 inches relative to the exterior surface, and L/D is at least about 1/2. Finally, as the nozzle erodes, the L/D ratio is maintained at about 1/2 for an extended period of time.

The advantage of the nozzle is that the inclusion of the angularly spaced projections alters the flow pattern of the catalyst in the FCC chamber adjacent the nozzle and makes the nozzle less prone to (inhibits) the adverse effects of corrosion that occur during FCC and the like, thereby extending the useful life of the nozzle as compared to prior art spray nozzles. Another advantage of the nozzle is that the raised configuration maintains a minimum L/D of at least about 1/2, which in turn allows the nozzle to discharge at least one fluid into the catalyst stream or fluid stream in the vessel in a consistent flat spray pattern to extend the life cycle in the event of corrosion. Yet another advantage of the nozzle is that by maintaining a flat spray pattern, the FCC process becomes more efficient because the fluid discharged from the nozzle interacts with the catalyst in a more consistent manner.

Other objects and advantages of the present invention will become more apparent in view of the following detailed description of the presently preferred embodiments and the accompanying drawings.

Drawings

FIG. 1A is a partial side cross-sectional view of a prior art nozzle without a bump, showing areas prone to erosion.

FIG. 1B is a top perspective view of the nozzle of FIG. 1A.

Fig. 2A is a top/side perspective view of a prior art nozzle in a skewed convex pattern.

Fig. 2B is a top view of the nozzle of fig. 2A.

Fig. 2C is a side view of the nozzle of fig. 2A.

Fig. 3A is a partial top view of a prior art nozzle having a "cat-eye" shaped boss configuration.

FIG. 3B is a partial side cross-sectional view of the nozzle of FIG. 3A taken along line A-A.

Fig. 4A is a top view of a prior art nozzle showing an alternative "cat-eye" shaped boss configuration.

FIG. 4B is a partial side sectional view of the nozzle of FIG. 3A taken along line B-B.

Fig. 5A is a top/side perspective view of the nozzle of the present invention.

Fig. 5B is a top view of the nozzle of fig. 5A.

Fig. 5C is a side view of the nozzle of fig. 5A.

FIG. 6A is a partial side cross-sectional view of an embodiment of a nozzle of the present invention.

Fig. 6B is a top view of the nozzle of fig. 6A.

FIG. 7 is a partial side cross-sectional view of an embodiment of a nozzle of the present invention.

Fig. 8A is a partial side cross-sectional view of an embodiment of a nozzle of the present invention.

Fig. 8B is a top view of the nozzle of fig. 8A.

Fig. 9A is a partial side cross-sectional view of an embodiment of a nozzle of the present invention.

Fig. 9B is a top view of the nozzle of fig. 9A.

FIG. 10 is a partial side cross-sectional view of a lobe embodiment of the present invention.

Detailed Description

In fig. 5 to 7 and 10, a first embodiment of the nozzle of the present invention is generally indicated by reference numeral 10. The nozzle 10 is used to discharge at least one fluid in a spray pattern into a fluid stream in a vessel (not shown) and to alter the flow pattern of the fluid stream in the vicinity of the nozzle to inhibit erosion of the nozzle and maintain the spray pattern. In one embodiment of the invention, the nozzle discharges an atomized mixture of the first fluid and the second fluid. In one example thereof, the first fluid is oil, the second fluid is gas or steam, and the vessel is a catalytic cracking vessel. However, as may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, the nozzles of the present invention are equally applicable to any of numerous different types of fluids associated with any of numerous different types of applications that are currently known, or that later become known.

The nozzle 10 includes an inlet portion 12, the inlet portion 12 defining at least one inlet conduit 14 to receive at least one fluid, and in one embodiment, a first fluid and a second fluid. The outlet portion 16 of the nozzle defines an outer surface 18 and a plurality of apertures 22, the apertures 22 extending through the outer surface 18 into fluid communication with the inlet portion 12 and being angularly spaced relative to each other about a central axis 24 of the outlet portion 16. In addition, the outlet portion includes a plurality of projections 26 or protrusions that are angularly spaced relative to one another about the axis of the outlet portion. Each projection defines an outlet aperture 28 therethrough and an axially extending wall 30, wherein the outlet aperture 28 is in fluid communication with at least one inlet conduit. In one embodiment, the axially extending wall 30 extends outwardly a length (X) greater than about 1/8 inches relative to the outer surface 18 and has a wall thickness of about 5 millimeters or about 3/16 inches. Typically, the boss 26 is generally cylindrical and the outlet aperture is generally circular. It should be noted, however, that many configurations of the projections 26 and outlet apertures 28 that are currently known, or that later become known, can be used without departing from the spirit and scope of the present invention; for example, as shown in fig. 9A-9B, a generally cylindrical protrusion defining a rectangular outlet aperture may be used. To ensure that the spray direction is along the axis of the orifice 22, the exit plane of the spray from each individual projection 26 is approximately perpendicular to the axis of the orifice 22 with which the projection is associated.

As shown in fig. 6A-6B, 7 and 10, each outlet orifice 28 of each projection 26 has a length (L) and a diameter (D). To maintain a consistent and accurate spray pattern as the nozzle erodes in FCC applications and the like, the L/D ratio is maintained at least around 1/2, which can be achieved by adding material to the lobes 26 as compared to a conventional nozzle without lobes. In the embodiment of fig. 7 and 10, a portion of the length (L) is located inside the outlet portion 16. The additional material added by the projection 26 allows more erosion to occur before the length L of the outlet orifice becomes too short, which in turn reduces the L/D ratio to below about 1/2, so that the desired flat fan jet becomes unclear; as the corrosion continues further, an undesirable narrow cone spray pattern occurs, which adversely affects FCC or RCC processes.

As shown in fig. 6A-6B, outlet portion 16 and boss 26 may be integrally formed as a single piece, or in an alternative embodiment (fig. 7), boss 26 may be a separate object that fits within aperture 22 of outlet portion 16 and is welded and/or mechanically fastened in place, or held in place by any other suitable fastening method now known or later become known, so long as the boss is able to be securely held in place. The latter embodiment provides such advantages: the individual projections 26 can be changed without having to replace the entire outlet portion 16 of the nozzle, and the projections 26 can be made of a different material than the nozzle outlet 16.

The outlet apertures 22 are preferably configured to form a generally flat fan spray pattern in accordance with the teachings of U.S. Pat. Nos. 5,553,783 and 5,692,682, both entitled "Flat Fan spray nozzle", each of which is assigned to the assignee of the present invention and the entire contents of which are hereby incorporated by reference as part of the present disclosure. According to the teachings of the above-mentioned patent, nearly all of the flow axes of the outlet orifices 22 are directed toward a target "T" (not shown) within the container for directing and atomizing a mixture of the first and second fluids in a spray pattern flowing in a direction across the target, and the target lies generally in a plane extending in the flow direction of the spray pattern. Furthermore, the flow axis of each outlet orifice 22 is directed to intersect a target "T" such that the outlet orifices 22 cooperate to define a spray pattern that is generally flat and fan-shaped, and the target "T" lies generally in a plane oriented at an acute angle relative to the vertical axis of the container. In one embodiment of the present invention, the target "T" is linear and generally intersects the central axis of the end face 18 of the outlet portion.

The nozzle 10 further includes a mixing chamber (not shown) in fluid communication between the inlet portion 12 and the outlet portion 16 for mixing at least one fluid therein. In one embodiment, the mixing chamber is formed within the outlet portion 16 immediately upstream of the outlet orifice 22.

In one embodiment, the nozzle 10 preferably further comprises at least one vane (not shown) located between the mixing chamber and the inlet portion 12 and extending transversely relative to the long axis of the inlet portion to receive a portion of the first and second fluids and create a swirling annular flow, and defining at least a portion of an orifice in an approximately central portion thereof to receive a portion of the first and second fluids and create a generally axial flow. The presently contemplated vanes and the manner of incorporating each such vane in the nozzle of the present invention are shown in the above commonly assigned patents incorporated by reference. In one such embodiment, each blade defines a generally convex lobe and a generally concave lobe. In this embodiment, each lobe is generally semi-circular, with the convex lobe being located upstream relative to the concave lobe. Preferably, the nozzle comprises two vanes, wherein each vane extends laterally across a respective generally semi-circular portion of the inlet portion 12. As further described in the above commonly assigned patents incorporated by reference, instead of vanes (vane sets), the nozzle may include an injection member (not shown) that extends helically in a direction from the inlet portion toward the outlet portion.

The nozzle 10 is particularly suitable for use as a feed distributor in a fluid catalytic cracking unit ("FCCU") and an atmospheric residue conversion unit ("RCCU"). FCCU and RCCU typically convert materials or recycled materials consisting essentially of petroleum-type hydrocarbons that are liquid at ambient or elevated temperatures and pressures to produce primarily automotive or other liquid fuels or naphthas having average molecular weights lower than the molecular weight of the feed, and by-products that are typically gaseous hydrocarbons. The conversion is generally carried out in such a way that:

a) at temperatures in excess of about 500 degrees fahrenheit; and is

b) The use of a solid catalyst which is present in the reaction zone, in particular in order to have an effect or influence on the reaction, and which thereby produces the result that: the yield, nature or reaction rate of the product is to a certain extent unequivocally different from what could be achieved with the same starting materials but otherwise identical without such catalyst.

Also typically in such units, (1) conversion and catalyst regeneration occur in separate zones as the catalyst is transferred between the zones, (2) the catalyst is maintained in the reaction zone in the form of a fluid mass consisting of finely divided solid catalyst dispersed in the hydrocarbon vapor undergoing conversion, and (3) the average residence time of the catalyst in the reaction zone is greater than the average residence time of the hydrocarbon vapor in the reaction zone.

In fig. 8A-8B, another embodiment of a nozzle of the present invention is indicated generally by the reference numeral 110. The nozzle 110 is similar in some respects to the nozzle 10 described above with reference to fig. 5-7 and 10, and therefore like reference numerals preceded by the numeral "1" are used to indicate like elements. Similar to nozzle 10, nozzle 110 is configured to discharge the first and second fluids into a container (not shown) in an atomized spray. The nozzle 110 includes an inlet 112 and an outlet 116. The outlet 112 further defines an outer surface 118 and two raised wall members 136, 138, the wall members 136 and 138 forming a continuous protrusion 126 around the central axis 124 of the outlet 116. The continuous protrusion 126 defines a plurality of outlet apertures 122 through which at least one fluid is discharged in a flat spray pattern, such as the flat fan spray pattern described above. The raised wall portion allows the projection to extend at least about 1/8 inches relative to the outer surface 118 of the outlet 116. Each outlet orifice has a length (L) and a diameter (D) such that the L/D ratio remains at least about 1/2 to maintain spray pattern integrity for a longer period of time as the nozzle 110 erodes due to the increased raised material relative to prior art nozzle configurations. This embodiment is particularly advantageous in applications where a larger diameter orifice is required, where the individual protrusions may interfere with each other.

One advantage of the nozzle 10, 110 is that the inclusion of the angularly spaced projections 26 alters the catalyst flow pattern in the FCC vessel in the vicinity of the nozzle and makes the nozzle less prone to (inhibits) the adverse effects of corrosion that occur during FCC and the like, thereby extending the useful life of the nozzle as compared to prior art spray nozzles. Another advantage of the nozzle 10, 110 is that the raised configuration maintains a minimum L/D ratio of at least about 1/2, which in turn allows the nozzle 10 to discharge at least one fluid into the catalyst or fluid stream in the vessel in a consistent flat spray pattern to extend the life cycle in the event of erosion. Yet another advantage of the nozzle 10 is that by maintaining a flat spray pattern, the FCC process becomes more efficient because the fluid discharged from the nozzle interacts with the catalyst in a more consistent manner. Yet another advantage of the nozzle 10, 110 is that the protrusions can be used to control the thickness of the flat fan or to change its shape. The spray jet thus produced is narrower and sharper using an L/D ratio of at least about 1/2 provided by the addition of the projections 26, 126. This property can be used, for example, to make the flat sectors thinner, which is advantageous in FCC or RCC processes because it ensures that the oil/catalyst contact is closer to instantaneous contact.

As may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, many changes and modifications may be made to the above-described and other embodiments of the nozzle of the present invention without departing from the spirit and scope of the invention as defined by the appended claims. For example, the nozzle boss and outlet orifice may have any number of shapes and configurations that are currently known, or that later become known. Furthermore, the orientation of the projection and the outlet orifice relative to the central axis of the outlet may be varied. Additionally, any of numerous different materials, outlet orifice configurations, spray pattern configurations, mixing chambers, mixing structures, and/or atomizers that are currently known, or that later become known, may be used in the different nozzles of the present invention. Accordingly, this detailed description of the presently preferred embodiments is to be taken in an illustrative, as opposed to a limiting sense.

Claims (35)

1. A spray nozzle for discharging at least one fluid in a spray pattern into a fluid stream in a vessel, wherein the nozzle alters the flow pattern of the fluid stream in the vicinity of the nozzle to inhibit erosion of the nozzle and maintain the spray pattern, the nozzle comprising:

an inlet defining at least one inlet conduit; and

an outlet in fluid communication with the inlet, the outlet defining an outer surface and a plurality of projections angularly spaced relative to each other about an axis of the outlet, each projection defining an outlet aperture having a first length (L) and a diameter (D) and in fluid communication with the at least one inlet conduit, and an axially extending wall, wherein the axially extending wall extends outwardly a second length (X) greater than 1/8 inches relative to the outer surface, and the first length/diameter ratio (L/D) is at least 1/2.

2. The nozzle of claim 1, wherein the inlet receives a first fluid and a second fluid, and each of the outlet orifices defines a flow axis to direct a mixture of the first and second fluids in an atomized spray through the outlet orifice in a direction along the respective flow axis.

3. A nozzle as claimed in claim 2, wherein all of the outlet apertures have flow axes directed at a target within the container for directing and atomising the mixture of the first and second fluids in a spray pattern flowing in a direction across the target, and the target lies substantially in a plane extending in the direction of flow of the spray pattern.

4. The nozzle of claim 1 wherein said axially extending wall has a wall thickness of 3/16 inches.

5. The nozzle of claim 3, wherein the vessel is at least one of a catalytic cracking vessel or an atmospheric resid conversion vessel, the first fluid is a liquid, and the second fluid is a gas.

6. The nozzle of claim 5, wherein the first fluid is oil and the second fluid is steam.

7. The nozzle of claim 1, further comprising a mixing chamber in fluid communication between the inlet and the outlet for mixing the first fluid and the second fluid in the mixing chamber.

8. The nozzle of claim 7 further comprising at least one vane positioned between the mixing chamber and the inlet and extending transversely relative to the long axis of the inlet to receive a portion of the first and second fluids and create a swirling annular flow, and defining at least a portion of an orifice at about a central portion of the at least one vane to receive a portion of the first and second fluids and create a generally axial flow.

9. The nozzle of claim 1 wherein each protrusion has sufficient material to maintain a first length/diameter ratio (L/D) of at least 1/2 until a predetermined amount of nozzle erosion occurs.

10. The nozzle of claim 1 wherein said outlet defines an interior and at least a portion of said first length (L) is located in said interior of said outlet.

11. A spray nozzle for discharging at least one fluid in a spray pattern into a fluid stream in a vessel, wherein the nozzle alters the flow pattern of the fluid stream in the vicinity of the nozzle to inhibit erosion of the nozzle and maintain the spray pattern, the nozzle comprising:

an inlet defining at least one inlet conduit;

an outlet in fluid communication with the inlet, the outlet defining an outer surface and a plurality of apertures angularly spaced relative to each other about an axis of the outlet; and

a plurality of boss members, each boss member fitting within a respective said aperture and defining an outlet aperture having a first length (L) and diameter (D) and in fluid communication with said at least one inlet conduit and an axially extending wall, wherein said axially extending wall extends outwardly a second length (X) greater than 1/8 inches relative to said outer surface and the first length/diameter ratio (L/D) is at least 1/2.

12. The nozzle of claim 11, wherein the inlet receives a first fluid and a second fluid, and each of the outlet orifices defines a flow axis to direct a mixture of the first fluid and the second fluid in an atomized spray through the outlet orifice in a direction along the respective flow axis.

13. A nozzle as defined in claim 12, wherein all of the outlet orifices have flow axes directed toward a target within the vessel for directing and atomizing the mixture of the first and second fluids in a spray pattern flowing in a direction across the target, and the target lies generally in a plane extending in the flow direction of the spray pattern.

14. The spray nozzle of claim 11 in which said axially extending wall has a wall thickness of 3/16 inches.

15. The nozzle of claim 13, wherein the vessel is at least one of a catalytic cracking vessel and an atmospheric resid conversion vessel, the first fluid is a liquid, and the second fluid is a gas.

16. The nozzle of claim 15, wherein the first fluid is oil and the second fluid is steam.

17. The nozzle of claim 11, further comprising a mixing chamber in fluid communication between a portion of the inlet and a portion of the outlet for mixing the first fluid and the second fluid in the mixing chamber.

18. The nozzle of claim 17 further comprising at least one vane positioned between the mixing chamber and the inlet and extending transversely relative to the long axis of the inlet to receive a portion of the first and second fluids and create a swirling annular flow, and defining at least a portion of an orifice at about a central portion of the at least one vane to receive a portion of the first and second fluids and create a generally axial flow.

19. The nozzle of claim 11, wherein each boss member is held in place within a respective orifice by welding, mechanical fastening, or any combination thereof.

20. The nozzle of claim 11 wherein at least one of the boss members is made of a material different from the material of the outlet.

21. The nozzle of claim 11 wherein each boss member has sufficient material to maintain a first length/diameter ratio (L/D) of at least 1/2 until a predetermined amount of nozzle erosion occurs.

22. The nozzle of claim 11 wherein said outlet defines an interior and at least a portion of said first length (L) is located in said interior of said outlet.

23. A spray nozzle for discharging at least one fluid in a spray pattern into a fluid stream in a container, the spray nozzle comprising:

a first device for receiving the at least one fluid;

a second device in fluid communication with the first device to eject the at least one fluid from the second device in a spray pattern; and

a third device in fluid communication with at least one of the first and second devices to alter a flow pattern of the fluid stream proximate the nozzle to inhibit erosion of the nozzle and maintain the spray pattern,

wherein the third device is a plurality of boss members, each boss member fitting within an aperture formed on the second device and defining an outlet aperture having a first length (L) and a diameter (D) and an axially extending wall, wherein the axially extending wall extends outwardly a second length (X) greater than 1/8 inches relative to an outer surface of the second device and the first length/diameter ratio (L/D) is at least 1/2.

24. The nozzle of claim 23 wherein said first means is an inlet member defining at least one inlet conduit to receive said at least one fluid, said second means is an outlet member in fluid communication with said inlet member, said outlet member defining an outer surface of said second means and a plurality of said apertures angularly spaced relative to each other about an axis of said outlet member.

25. The nozzle of claim 23 wherein each boss member has sufficient material to maintain a first length/diameter ratio (L/D) of at least 1/2 until a predetermined amount of nozzle erosion occurs.

26. The nozzle of claim 23 wherein said outlet member defines an interior and at least a portion of said first length (L) is located in said interior of said outlet member.

27. A method of maintaining a spray pattern of at least one fluid in a fluid stream ejected into a vessel by a nozzle and inhibiting corrosion of the nozzle, the method comprising the steps of:

providing a spray nozzle for discharging at least one fluid in a spray pattern into the container, wherein the spray nozzle comprises an inlet member defining at least one inlet conduit to receive at least one fluid and an outlet member in fluid communication with the inlet member, the outlet member defining an outer surface and a plurality of apertures angularly spaced relative to each other about an axis of the outlet member;

introducing a fluid stream into the vessel;

providing a plurality of boss members, each of the boss members fitting within a respective one of the apertures and defining an outlet aperture having a first length (L) and a diameter (D) and in fluid communication with the at least one inlet conduit and an axially extending wall, wherein the axially extending wall extends outwardly a second length (X) greater than 1/8 inches relative to the outer surface and has a first degree/diameter ratio (L/D) of at least 1/2.

28. The method of claim 27, wherein the vessel is at least one of a catalytic cracking vessel and an atmospheric resid conversion vessel.

29. The method of claim 27, wherein the fluid stream is a catalyst stream and the at least one fluid is an atomized mixture of oil and steam.

30. The method of claim 27, wherein the step of providing a plurality of raised members further comprises: each projection member is provided with sufficient material to maintain a first length/diameter ratio (L/D) of at least 1/2 until a predetermined amount of nozzle erosion occurs.

31. The method of claim 27, wherein the step of providing a spray nozzle further comprises: the outlet member defines an interior, and the step of providing a plurality of raised members further comprises: disposing at least a portion of the first length (L) in the interior of the outlet member.

32. The method of claim 27, further comprising: each projecting member is replaced when its first length/diameter ratio (L/D) is below 1/2.

33. A spray nozzle for discharging at least one fluid in a spray pattern into a fluid stream in a vessel, wherein the nozzle alters the flow pattern of the fluid stream in the vicinity of the nozzle to inhibit erosion of the nozzle and maintain the spray pattern, the nozzle comprising:

an inlet defining at least one inlet conduit; and

an outlet in fluid communication with the inlet, the outlet defining an outer surface and two wall members, the wall members forming a single continuous protrusion about a central axis of the outlet, the continuous protrusion defining a plurality of outlet apertures having a first length (L) and a diameter (D), angularly spaced relative to each other about the central axis of the outlet, and in fluid communication with the at least one inlet conduit, wherein the wall members extend outwardly a second length (X) greater than 1/8 inches relative to the outer surface, and the first length/diameter ratio (L/D) is at least 1/2.

34. The nozzle of claim 33 wherein said continuous protrusion has sufficient material to maintain a first length/diameter ratio (L/D) of at least 1/2 until a predetermined amount of nozzle erosion occurs.

35. The nozzle of claim 33 wherein said outlet defines an interior and at least a portion of said first length (L) is located in said interior of said outlet.