EP1835992A1

EP1835992A1 - Feed nozzle assembly and burner apparatus for gas/liquid reactions

Info

Publication number: EP1835992A1
Application number: EP05854080A
Authority: EP
Inventors: Charles Lipp
Original assignee: Dow Global Technologies LLC
Current assignee: Dow Global Technologies LLC
Priority date: 2005-01-06
Filing date: 2005-12-14
Publication date: 2007-09-26
Also published as: AU2005323240B2; AU2005323240A1; JP2008526490A; WO2006073713A1; CN101098750A; CN101098750B; CA2592775A1; MX2007008241A; BRPI0518090A; US20060147853A1

Abstract

A feed nozzle assembly suitable for use in synthesis and combustion reactions involving gas/liquid reaction systems comprises a plurality of nozzles positioned such that their sprays impinge upon one another to obtain improved, or maintain acceptable, drop size, measured as Sauter mean diameter, by suitably balancing impact destruction and coalescence of drops. This feed nozzle assembly can be incorporated into a burner apparatus combining annular areas with stepped extended barriers for feeding oxygen and moderator gas, e.g., steam, all preferably within an exterior annular cooling means such as a water jacket.

Description

FEED NOZZLE ASSEMBLY AND BURNER APPARATUS FOR GAS/LIQUID REACTIONS

This application claims the benefit of U.S. Application No. 11/030,925, filed January 6, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

(0001) This invention relates to feed nozzles, and more particularly to feed nozzles for a variety of gas/liquid reactions, including chemical synthesis reactions and also combustion and other oxidation reactions in which the feed nozzle is part of a burner apparatus.

2. Background of the Art

(0002) A variety of related industries employ reaction of a gas/liquid system to effect a desired end result. These include, for example, the waste-reduction industry, the chemical manufacturing industry, the gas manufacturing industry, and energy-related industries that rely upon combustion as the energy source. Each of these industries commonly effects this reaction by means of fine atomization of streams of one or more liquids, frequently within a zone of increased temperature, hi the case of gasification reactions, both the atomization and the higher temperature serve to promote the liquid-to- gas phase change that improves mixing at a molecular or near-molecular level, thereby promoting the desired final result. This mixing may be of one or more liquid compounds or compositions with a specific gas, such as air, oxygen, carbon dioxide, steam, an inert gas such as argon or nitrogen, or a combination thereof.

(0003) For each of the above types of reactions, the atomization generally takes place within a reactor vessel of some type. One common type of reactor vessel is the refractory-lined, generally cylindrical vessel used for "burning" liquid chemical waste, which is frequently a mixture of halogenated hydrocarbons. Because many of these are chlorinated compounds, the term "R-CIs" is often used to describe them. In essence the same type of combustion reaction is accomplished as in a simple internal combustion engine, for example, where the atomized liquid stream mixes with oxygen in a high temperature zone, and a desirably high conversion results in the final hydrogen, carbon dioxide and carbon monoxide products, with a minimum of residual carbon ("soot"). Other types of reactor vessels are used for a wide variety of chemical synthesis operations, according to the needs of the starting and desired final products.

(0004) The cited industries have geared much innovation toward developing appropriate feed nozzles to transport their specific starting liquid streams into the appropriate reactor vessels. They have recognized a number of factors that affect the conversion rates within the reactor, and feed nozzles have been designed to alter velocity, flow dynamics and spray patterns of the liquid. These design options are motivated by essentially one accepted concept: That the drop size of the liquid is an important factor in determining the ultimate outcome, i.e., the performance, of the process. Simply stated, if the drops are too large, the mixing of the liquid stream with a gaseous stream, such as oxygen, will be reduced. If the mixing is reduced (due to the decreased interface between molecules), the conversion of the liquid stream will be likewise reduced. If the conversion is decreased, the result will often be residual unreacted liquid feeds which may either form soot or leave the reactor, which may result in undesirable environmental consequences. This soot can foul equipment, resulting in expensive down-time. Thus, feed nozzle technology has consistently recognized that, to ensure that drop size remains appropriately small, the aperture of the feed nozzle must remain restricted, which limits the throughput of the nozzle. This inherent drop size limitation has heretofore limited the efficiency of operations and resulted in use of either multiple parallel reactor vessels, or single reactor vessels with multiple burner nozzles arranged such that the atomized streams do not converge. This is because those skilled in the art have accepted as common wisdom that convergence of atomized streams tends to result in increased drop size and, therefore, conversion rate losses.

(0005) It is important to note that the characteristics of a spray can be expressed in several ways. One common way is to use a spray's drop size average, such as the "Sauter mean diameter" (SMD). The SMD of a spray is the average drop size having the same surface to volume ratio as the overall spray. Alternatively, the spray can be characterized by its "volume median diameter" ("Dv"). This method describes a drop diameter which is greater than a given proportion of the spray. For example, if a spray is described as having a "Dv₉o" of a certain diameter, it means that approximately 90 percent of the spray volume is in drops smaller than that diameter. Similarly, a "Dv₅₀" of a certain diameter means that approximately 50 percent of the volume of liquid is in drops smaller than that diameter. Because drops follows what is called the "D squared Law" of drop evaporation, where the evaporation time is proportional to the square of the drop size, one of the best indicators of nozzle performance is the spray's Dγ₉0- Optimized nozzle systems also exhibit a directly proportional relationship between the spray's Dγ9o and the SMD of the drops, hi view of these relationships, then, the SMD can be used to provide a clear characterization of any spray.

(0006) Another problem is encountered where feed nozzles are used as components of so-called "burners", for example, in the waste-reduction industry. As used herein, the term "burner" refers to an apparatus that comprises both a feed means, such as a nozzle, and a means of mixing the liquid feed stream with a gas, such as oxygen, in a high temperature environment to promote combustion of the feed stream. The combination of the high temperature and the often corrosive nature of the environment surrounding the nozzle, i.e., of the mixture of atomized liquid feed and gases, tends to shorten burner life. This shortening is due to corrosion and/or thermal fatigue of the metals used to construct the burner and its included nozzle.

(0007) Still another problem, encountered by the waste reduction industry in particular, occurs when incompatible liquid feed streams are destined for a single reactor. An example of this is streams that contain small amounts of polymerizable monomers that may polymerize once the streams are mixed. Premixing may be impractical in these situations, because the formation of polymeric materials can foul equipment and, in the case of internal mixing burners, even shorten burner life where the polymer/gas reaction results in undesirable products.

(0008) In view of these problems, it is desired in the art to identify means to effectively introduce atomized liquid feed streams, having controlled drop size, into a reactor vessel for a variety of types of reactions. It is also desired, where such introduction is intended to accomplish burning of a waste feed stream, to control drop size and also to protect the burner, which includes the feed means, from environmental factors that tend to shorten burner life. SUMMARY OF THE INVENTION (0009) The invention is a feed means designed to ensure maintenance of appropriate drop size while increasing efficiency of a given operation within a single reactor vessel. In one embodiment it is an improvement in a feed means for a gas/liquid reaction system, in which a feed nozzle assembly includes a plurality of feed nozzles, suitable to atomize at least one liquid feed stream to form sprays, the feed nozzles being positioned such that the sprays impinge upon one another. The result of this impingement is that the Sauter mean diameter of the drops of the impinged sprays is substantially less than, or equal to, the Sauter mean diameter of the drops prior to impingement. The arrangement of the nozzles, which includes selection of an appropriate number of nozzles, can be optimized to ensure desired feed volume within a given time period without unacceptable sacrifice of conversion rate.

(0010) hi another embodiment the invention is a method for reaction of a gas/liquid reaction system wherein the described feed nozzle assembly is employed.

(0011) In still another embodiment the invention is an improvement in a burner apparatus for reaction of a gas/liquid reaction system comprising a feed nozzle assembly that is located along a central axis and employs a plurality of feed nozzles suitable to atomize at least one liquid feed stream to form sprays, the feed nozzles being positioned such that the sprays impinge upon one another such that the Sauter mean diameter of the drops of the impinged sprays is substantially the same as, or less than, the Sauter mean diameter of the drops prior to impingement. The inventive burner apparatus also includes a moderator gas feed area, an oxygen feed area, a mixed moderator gas/oxygene feed area, or a combination thereof, located annular to the feed nozzle assembly. An optional annular cooling area may also be included. These annular feed areas may be configured such that the exterior barrier of each annular feed area extends beyond the exterior barrier of the enclosed annular feed area, and the innermost annular area has an exterior barrier extending beyond the centrally-located feed nozzle assembly. This feature ensures that the sprays emitted by the feed nozzles pass first through a cap environment created by the innermost annular feed area.

(0012) Finally, in yet another embodiment the invention is a method of gasifying a liquid waste stream using the improved burner apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

(0013) Fig. 1 is a cross-section of a profile view of one embodiment of the burner apparatus, incorporating the inventive feed nozzle assembly, and shown as fed by a single liquid feed stream. (0014) Fig. 2 is a cross-section of another embodiment of a feed nozzle assembly, as incorporated into the inventive burner apparatus, wherein the feed nozzle assembly is fed by more than one liquid feed stream.

(0015) Fig. 3 is a schematic drawing of an end-on cross-section of an array of seven nozzles within a feed nozzle assembly housing.

DETAILED DESCRIPTION OF THE INVENTION

(0016) The inventive feed nozzle assembly is a simple but extremely effective means to circumvent the problems associated with use of just one feed nozzle, while surprisingly teaching away from the accepted wisdom that convergence of "sprays", i.e., atomized liquid feed streams, unacceptably and automatically increases drop size, thereby promoting poor conversion and overall process performance. It has now been found that, by appropriate adjustment of the number of feed nozzles and the positioning thereof relative to one another, and taking into account the characteristics of each feed nozzle as to maximum feed velocity, aperture configuration and resulting spray pattern, the sprays can be impinged in such a way so as to balance the impact destruction and coalescence of the drops, and thereby ensure desirable drop size for the given operation while at the same time maximizing potential feed stream input rate.

(0017) Impingement obviously requires at least two sprays which overlap at some point in their trajectories within the reactor vessel. For many purposes it is desirable to ensure that this overlap occurs as soon after entry into the reactor vessel as possible, in other words, as close to the feed nozzle apertures as possible. This maximizes the mixing of the liquid feed stream or streams (which may be the same or different) with at least one gaseous feed stream, such as oxygen, and also incidentally reduces the need for a larger reactor vessel. Thus, it is preferred in the present invention that the feed nozzles be located closely proximate or even in some direct contact with one another. Adjustment of the distance is a matter of routine design analysis, to determine the optimum balance of pressure and velocity against any gas phase turbulence which could tend to increase coalescence by increasing the incidence of low velocity collisions.

(0018) The relative positions of the feed nozzles can be used to increase or decrease the impingement area. For example, the feed nozzles can be angled toward one another, as in Fig. 1 , such that their apertures are closer together than are those nozzle portions distal to each corresponding aperture. Routinely employed engineering analysis and modeling will help to determine an optimal orientation, but where this angled orientation is selected, the nozzles' positioning can be at essentially any relative angle from about zero degrees (parallel nozzles) to about 90 degrees (directly facing one another). More preferred is an angle between about 30 degrees and 60 degrees, and most preferred is an angle of from about 40 degrees to 50 degrees. For the sake of simplicity and with deference to gravity, it is preferred that the angle be down- facing. Nonetheless, an upward angle can also be employed, and may increase the resulting ratio of impact destruction to coalescence by increasing the number of collisions per drop.

(0019) Those skilled in the art will appreciate that the orientation of the nozzles may, however, desirably take into account the spray pattern of any given nozzle.

Each nozzle, according to its aperture and the geometry of the flow conduit leading to the aperture, exhibits a characteristic (and in some cases, adjustable) spray pattern. Such pattern may be a so-called "hollow-cone" or "solid-cone" configuration, or may be described as forming a fan or flattened cone shape, or a hollow or solid cylindrical shape. Other configurations may also be employed. Nozzles may be of the pressure-swirl or other type. While the needs of a given liquid feed stream, including its purity, self-polymerization potential, and other characteristics, may dictate a preference for a particular configuration, a majority of commercially-available industrial pressure-swirl nozzles exhibit the "hollow- cone" pattern, and therefore such is preferred herein as a matter of convenience only. The "cone" diameter will vary according to distance from the feed nozzle, of course, but the angle of the cone at the aperture is, in many commercial models, approximately 80 degrees. Thus, for illustrative purposes only, such is shown in Fig. 1 and Fig. 2.

(0020) Those skilled in the art will automatically appreciate that selection of nozzles with cylindrical spray patterns, for example, will require at least some angling of the nozzles toward each other to ensure a desired level of impingement. Conversely, it will also be appreciated that nozzles having broad cone spray patterns may be capable of being positioned even at angles away from one another (i.e., with the aperture of the nozzles being farther apart than the nozzle portions distal to the corresponding apertures, as in Fig. 2), yet still obtain at least some impingement. It should be borne in mind that maximization of impingement, particularly where multiple (more than two) nozzles are being employed, is often equivalent to optimization of impingement, since the increase in the ratio of impact destruction to coalescence of drops tends to improve conversion and overall reaction efficiency. Preferably the drops of the pre-impingement sprays exhibit an SMD of less than or equal to about 500 microns, which implies that the SMD of the drops of the impinged sprays is substantially the same. As used herein, "substantially" means within a range of ± 5 percent. Thus, if the drops of a pre-impingement spray have an SMD of, for example, 300 microns, then the drops of the impinged spray would desirably fall in the range of less than or equal to 300 microns, plus or minus 15 microns. It is also desirable to take into account the surface tension of the liquid feed stream materials, since lower surface tension fluids tend to coalesce less, and therefore exhibit generally lower Sauter mean diameters both before and after impingement. (0021) It should be noted that impingement may alter the shape of the impinged spray area(s). For example, it has been found that impingement of a number of fan-shaped sprays, resulting from several nozzles that are annularly arrayed around a central nozzle, with the annular nozzles all angled generally toward the center line, may result in a dense spray having a cylindrical conformation. Thus, the initial shape of a single nozzle's spray pattern will be a factor in determining the initial SMD of the (non-impinged) drops, but may not be visually recognizable in the impinged sprays.

(0022) Where multiple feed nozzles are selected, space and overall design preferences will tend to prefer a cluster of nozzles that are closely positioned, enabling the "assembly" of nozzles (which as herein defined does not specifically require that the plurality of nozzles be attached to one another) to be constructed as an "assemblage"

(which as herein defined does require physical attachment of the nozzles themselves and/or of at least some of their supporting lines of fluid communication to a liquid feed stream source). Such a cluster is suggested in Fig. 3, which shows the maximized packing for seven nozzles, including six nozzles positioned as an array around a seventh central nozzle. Generally, it is preferred that the number of nozzles be from 2 to about 100, with 3 to 25 being more preferred for ease of manufacture. The skilled artisan can envision many variations on this theme, including, for example, an array of three or four nozzles around a central nozzle; three nozzles arranged in a triangular pattern; or a larger number of nozzles arrayed radially or in rows or columns. It is also possible to array the liquid stream feed nozzles annularly around a central gaseous stream feed. The present invention specifically requires neither symmetry nor asymmetry of the arrangement, but at least some impingement of at least two sprays. Where angling of nozzles toward one another is selected, an overall concave design, such as that illustrated in Fig. 1 , with the central nozzle recessed relative to the surrounding, annularly-arrayed nozzles, may be particularly effective.

(0023) It will be appreciated that the exigencies of interior nozzle design are beyond the scope of the invention and therefore need not be discussed in detail herein; however, one potential advantage of the present invention does suggest the basis for an interesting alteration of traditional nozzle design. Simply because the present invention employs a plurality of feed nozzles, which increase output rate and therefore efficiency, rather than the single feed nozzle heretorefore commonly employed for the types of reactions envisioned herein, it is possible to feed two, or more, chemically-different liquid streams into the reactor vessel at one time. Thus, two or more liquid reactants may be fed simultaneously into a synthesis vessel, to produce the desired product in reaction with a gas; or, alternatively, two or more liquid waste streams, that may technically be reactive, can be fed simultaneously into a waste-burner vessel, without encountering a prohibitive level of undesired reaction, if any. With this in mind, then, those skilled in the art will readily see that a single feed nozzle, defined herein to mean the pressure-producing housing containing at least one flow conduit connection that runs from the liquid feed stream source to the aperture, may, when fitted with more than one flow conduit connection and thus more than one aperture, accomplish the same goal. Such is further exemplified in Fig. 2, wherein it can be seen that one particular feedstream (R-Cl #1) supplies apertures 142 and 148, while a second, different feedstream (R-Cl #2) supplies only aperture 136. Variations of this nozzle design are also comprehended within the scope of the term "feed nozzle assembly" herein. Those skilled in the art will further appreciate that alterations in nozzle design, particularly those that tend to increase pressure and/or flow rate, may also be employed in the present invention to reduce initial drop size and, therefore, post-impingement drop size as well.

(0024) A particular advantage of the invention is that it may be employed where incompatible liquid feed streams are to be fed into a reactor. As used herein, "incompatible" refers to feed streams that react to produce an undesirable reaction product. An example of this is monomers that polymerize to form a polymer that may foul the equipment in an undesirable manner, or that may produce a product that has an undesirable environmental consequence. Thus, "compatible" refers to feed streams that, though they may react, do not produce a reaction product that is, for any reason, undesirable or that may, in fact, be a desirable reaction product.

(0025) A further advantage of the present invention relates to start-up problems. In many cases, conversion rates for single nozzle reactor systems are poor upon start-up because of changes in drop size relating to the necessary pressure ramp-up. As pressure is stabilized at operating levels, drop size likewise stabilizes, but during ramp-up, all of the problems associated with oversized drops, including poor gas/liquid reaction, poor conversion, fouling and the like, may occur. In the present invention, however, the nozzles may be started in a desired sequence, with the effect of the impingement to break up drops used to offset at least a portion of the poorer atomization within a single nozzle that occurs during the pressure ramp-up. In some cases it has been found that using an array of six nozzles surrounding a seventh, central nozzle, and starting the feed through the central nozzle first, followed shortly thereafter by additional feeding through the remaining nozzles, results in improved conversion. Routine engineering analysis and modeling will easily determine the sequencing and pressure ramping profile that will significantly improve performance during the start-up period.

(0026) The inventive feed nozzle assembly, described hereinabove, may be incorporated in an inventive burner apparatus. Such apparatuses are particularly suited to use in waste-burning, with the liquids that are destined for destruction being desirably mixed in their atomized, spray condition with one or more gases. Such gas may be air, oxygen, carbon dioxide, steam, an inert gas such as argon or nitrogen, or a combination thereof. The inventive burner apparatus provides a means to effectively accomplish this mixing, by including the inventive feed nozzle assembly in a location that forms a central axis, and with discrete gas feed areas arranged annular thereto. For example, in one embodiment the innermost annular area may be a moderator gas feed area. Such a moderator gas may be any of the above-identified gases, but is frequently steam which conveniently moderates the temperature under which the gasification may take place. In another embodiment there are two or more, outwardly successive annular feed areas, one of which is a moderator gas feed area and the other of which is an oxygen feed area. As the term is used herein, "oxygen feed area" refers to gaseous feeds that include any proportion of oxygen, and thus includes air feeds as well as those that contain generally from 1 to 100 weight percent oxygen. (0027) A particularly desirably feature of the inventive burner apparatus relates to the exterior barriers of the annular areas. As shown in Fig. 1 and Fig. 2, and as further discussed hereinbelow, the exterior barriers may be successively extended such that mixing of the liquid feeds with each gaseous feed is maximized and turbulent flow, that may interfere with mixing, is minimized. Significantly, the first exterior barrier is extended beyond the end of the feed nozzle assembly, such that the gas feed of the innermost annular feed area may tend to form a "cap environment", i.e., an area where primarily only the sprays from the feed nozzles and the gas being fed through the innermost annular area are mixed. Those skilled in the art will understand that the temperature and composition of this "cap environment" may be controlled in such a way as to afford some protection to, or otherwise benefit, the feed nozzle assembly and thereby potentially lengthen feed nozzle assembly, and therefore burner, life. For example, a consistent temperature may be maintained in this "cap environment", which reduces the thermal stresses on the metals that may be used to manufacture the feed nozzle assembly. (0028) Finally, in one embodiment some type of exterior cooling means may be employed to further reduce thermal stresses on the burner apparatus and/or on the reactor itself. For example, an annular cooling means, which may be disposed external to any or all of the annular feed areas, may provide desirable temperature control. Such may be, for example, a traditional water jacket, in which cool or cold water is fed into an open or closed loop-type jacketing on a continuous basis, with the water removing heat from the apparatus prior to its being routed away from the apparatus. Such a water jacket may form the final external "layer" of the burner apparatus.

(0029) A review of the drawings will assist the reader in understanding the overall concepts of the invention. However, the drawings are intended to be, and should be construed as being, merely illustrative and not indicative of either the scope of the invention or of the inventors' claims appended hereto.

(0030) Fig. 1 is a partial cross-section of a profile view of a burner apparatus of the present invention comprising the feed nozzle assembly of the present invention. In this drawing the feed nozzle assembly 12 is shown situated at essentially the center of an impliedly cylindrical burner apparatus 15. Looking first to the feed nozzle assembly, it is seen that three separate nozzles are shown, 18, 21 and 24. Each nozzle has a nozzle body 27, head 30 and aperture 33. The aperture 33 is in fluid communication with a feed stream conduit 36 via a nozzle conduit 39, which is in turn in fluid communication with a liquid feed stream source (not shown). External to the feed nozzle assembly's wall 42 is an annular area which constitutes a first moderator gas feed area 45. This annular moderator gas feed area 45 has a first moderator gas exterior barrier 48, which extends beyond the nozzle apertures 33. Moving from the center axis 51 of the feed nozzle assembly 12 toward the outer edge of the drawing, and therefore impliedly from the central interior toward the exterior of the burner apparatus, the next annular area is the oxygen feed area 54. Again, this is surrounded by its oxygen feed area barrier 57, which extends beyond the moderator gas feed area barrier 48. The next annulus is a second moderator gas feed area 60 with its second moderator gas feed area barrier 63 extending beyond the immediately precedent oxygen feed area barrier 57. Finally, the last annulus, at the exterior of the burner apparatus, is a cooling means barrier 66, which can be, for example, a water jacket. The reader will see that the effect of the progressive extension of the barriers of each annulus outward from the nozzle assembly results in a concave exit in what is essentially and preferably a cylindrical structure, i.e., the burner apparatus as a whole. Hollow-cone sprays 69, 72 and 75 have been drawn to indicate the extensive spray impingement accomplished by the angling of nozzles 18 and 24 inward toward central nozzle 21. Labeled arrows indicate the introduction of a liquid feed stream into the central feed conduit 36; of moderator gas into the moderator gas feed areas 45 and 60; of oxygen into oxygen feed area 54; and of water into the cooling means barrier 66. Also shown is a moderator gas cap environment 78 through which hollow-cone sprays 69, 72 and 75 must pass. This illustrates that the majority of gas/liquid mixing, which is aided by turbulence, will occur beyond moderator gas cap environment 78, thereby reducing exposure of nozzle heads 30 with either the oxygen (or other gas) alone or with the oxygen (or other gas) mixed with liquid.

(0031) Fig. 2 shows a variation on the embodiment of Fig 1. Again, it is a cross- section of the burner apparatus of the present invention, again incorporating a feed nozzle assembly 112, also of the present invention, but with some modification thereof. In Fig. 2, the nozzles are denoted as 118, 121 and 124. However, details of the interior of the feed nozzle assembly 112 are shown. The interior features include one central feed conduit 127 and one annular feed conduit 130. It will be noted that annular feed conduit 130 is in fluid communication, via channel 133, with nozzle 118 and its aperture 136, but that central feed conduit 127 is in fluid communication via central channel 139 with nozzle 121 and its aperture 142 and, via branch feed channel 145, also with nozzle 124 and its aperture 148. The schematically drawn spray patterns, impliedly hollow-cone, of each of the three nozzles, as well as the outward angling of nozzles 118 and 124 relative to one another, results in impingement areas 151, 153 and 154. Fig. 2 further indicates an annular moderator gas feed area 157 and its moderator gas feed area barrier 160; an annular oxygen feed area 163 and its oxygen feed area barrier 166; and, exterior thereto, an annular cooling means 169. Labeled arrows indicate the introduction of two different feeds, R-Cl #1 and R-Cl #2, into the central feed conduit 127 and annular feed conduit 130, respectively, as well as of moderator gas into the annular moderator gas feed area 157, oxygen into the annular oxygen feed area 163, and water into the annular cooling means 169. Sprays emitted at nozzle apertures 136, 142 and 148 must pass through moderator gas cap environment 173 before mixing with oxygen.

(0032) Fig. 3 is a simple schematic drawing of an end-on cross-section of an array of seven nozzles, such as could be employed within a feed nozzle assembly 201.

The smallest circles represent channels 204 within a nozzle, such as would correspond to 133 in Fig. 2. The larger circles represent the exterior cross section 207 of the nozzle heads themselves, and the largest, and encompassing, circle represents the exterior wall 213 of the feed nozzle assembly 201. (0033) The description, drawings and examples discussed hereinabove are intended to provide to the skilled practitioner the general concepts, means and methods necessary to understand the present invention and, when combined with a level of understanding typical of those skilled in the art, to practice it. It will therefore be understood that not all embodiments deemed to be within the scope of the invention are herein explicitly described, and that many variations of each embodiment, including but not limited to feed nozzle assembly and burner apparatus materials, orientations, constructions, arrangements and applications not described explicitly or in detail herein, will still fall within the general scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. In a feed means for a gas/liquid reaction system, an improvement comprising a feed nozzle assembly having a plurality of feed nozzles suitable to atomize at least one liquid feed stream to form sprays, the feed nozzles being positioned such that the sprays impinge upon one another, provided that the Sauter mean diameter of the drops of the impinged sprays is substantially less than, or equal to, the Sauter mean diameter of the drops prior to impingement.

2. The feed nozzle assembly of Claim 1 wherein the plurality is from 2 to about 100.

3. The feed nozzle assembly of Claim 2 wherein at least some of the feed nozzles are arrayed annularly around a central feed nozzle or a central gaseous stream.

4. The feed nozzle assembly of Claim 1 wherein the feed nozzles are angled toward or away from each other.

5. The feed nozzle assembly of Claim 1 wherein the Sauter mean diameter of the drops of the impinged sprays is less than or equal to about 500 microns.

6. In a method for reaction of a gas/liquid reaction system, an improvement comprising atomizing at least one liquid feed stream through a feed nozzle assembly having a plurality of feed nozzles to form sprays, the feed nozzles being positioned such that the sprays impinge upon one another within a reactor vessel, provided that the Sauter mean diameter of the drops of the impinged sprays is substantially less than, or equal to, the Sauter mean diameter of the drops prior to impingement.

7. The method of Claim 6 wherein the liquid feed stream is selected from the group consisting of halogenated and non-halogenated hydrocarbons.

8. The method of Claim 6 wherein the plurality is from 2 to about 100.

9. The method of Claim 6 wherein the sprays impinge upon on another to form drops having a Sauter mean diameter of less than or equal to about 500 microns.

10. The method of Claim 1 wherein there are at least two liquid feed streams and at least two of such streams are incompatible.

11. In a burner apparatus for reaction of a gas/liquid reaction system, an improvement comprising (1) a feed nozzle assembly located along a central axis, employing a plurality of feed nozzles suitable to atomize at least one liquid feed stream to form sprays, the feed nozzles being positioned such that the sprays impinge upon one another, provided that the Sauter mean diameter of the drops of the impinged sprays is substantially less than, or equal to, the Sauter mean diameter of the drops prior to impingement, wherein the feed nozzle assembly is centrally-located; (2) a moderator gas feed area, an oxygen feed area, a mixed moderator gas/oxygen feed area, or a combination thereof, located annular to the feed nozzle assembly, the exterior barrier of each annular feed area extending beyond the exterior barrier of the proximate enclosed annular area; provided that the innermost annular area has an exterior barrier extending beyond the centrally-located feed nozzle assembly.

12. The burner apparatus of Claim 11 further comprising one or more additional annular moderator gas feed or oxygen feed areas.

13. The burner apparatus of Claim 11 further comprising an annular cooling means exterior to all moderator gas feed areas, mixed moderator gas/oxygen feed areas and oxygen feed areas.

14. The burner apparatus of Claim 11 wherein the annular cooling means is a water jacket.

15. In a method to gasify a liquid waste stream, an improvement comprising feeding at least one liquid waste stream through a burner apparatus to atomize it in a feed nozzle assembly employing a plurality of feed nozzles to form sprays, the feed nozzles being positioned such that the sprays impinge upon one another, provided that the Sauter mean diameter of the drops of the impinged sprays is substantially less than, or equal to, the Sauter mean diameter of the drops prior to impingement; wherein the feed nozzle assembly is located along a central axis; and wherein are located, annular to the feed nozzle assembly, a moderator gas feed area, an oxygen feed area, a mixed moderator gas/oxygen feed area, or a combination thereof, provided that the exterior barrier of each annular feed area extends beyond the exterior barrier of the proximate enclosed annular area, and further provided that the innermost annular area has an exterior barrier extending beyond the centrally-located feed nozzle assembly, such that the sprays emitted by the feed nozzles pass first through a cap environment created by the innermost annular feed area.

16. The method of Claim 15 wherein the liquid waste stream is a halogenated or non- halogenated hydrocarbon.

17. The method of Claim 15 wherein the sprays impinge upon one another to form drops having a Sauter mean diameter of less than or equal to about 500 microns.

18. The method of Claim 15 wherein the moderator gas is steam or carbon dioxide.

19. The method of Claim 15 where there are at least two liquid feed streams and at least two of such streams are incompatible.