Inlet Nozzle Assembly

Abstract

An inlet nozzle assembly, an abatement apparatus, and a method are disclosed. The inlet nozzle assembly is for an abatement apparatus that processes an exhaust flow from a semiconductor processing tool, the inlet nozzle assembly comprising a delivery nozzle configured to deliver the exhaust flow into an abatement chamber, and a mount configured to couple with a housing that defines the abatement chamber, the mount further configured to receive the delivery nozzle that delivers the exhaust flow into the abatement chamber, the delivery nozzle configured to extend from the mount distal to the abatement chamber. In this way, instead of needing to change the height of the mount or the position of the abatement chamber for delivery nozzles of different lengths, the height of the mount and the position of the abatement chamber can remain fixed for delivery nozzles of different lengths, with different amounts of the delivery nozzle extending from the mount depending on the length of the nozzle. This helps reduce inventory of these different parts, as different mounts, housings, and other related parts are no longer needed for delivery nozzles of different lengths.

Description

[Technical Field]

[0001] The field of the invention relates to inlet nozzle assemblies, abatement devices and methods. [Background technology]

[0002] Abatement devices, such as radiant burners or other types of abatement devices, are known and are typically used to treat exhaust gas streams from manufacturing process tools used, for example, in the semiconductor or flat panel display manufacturing industries. During such manufacturing, residual perfluorinated compounds (PFCs) and other compounds are present in the exhaust gas streams pumped from the process tools. PFCs are difficult to remove from the exhaust gases, and their release into the environment is undesirable because they are known to have a relatively high greenhouse effect.

[0003] Known radiant burners, such as those described in European Patent Publication No. 0,694,735, use combustion to remove PFCs and other compounds from an exhaust gas stream. Typically, the exhaust gas stream is a nitrogen stream containing PFCs and other compounds. The exhaust gas stream is conveyed to a combustion chamber laterally surrounded by the exit face of a perforated gas burner. In some cases, a treatment material, such as a fuel gas, can be mixed with the exhaust gas stream before entering the combustion chamber. The fuel gas and air are simultaneously supplied to the perforated burner to affect combustion at the exit face. Combustion products from the perforated burner react with the exhaust stream mixture to combust the compounds in the exhaust stream. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Publication No. 0,694,735 Summary of the Invention [Problem to be solved by the invention]

[0005] Although abatement system configurations exist, each has its own drawbacks. It would therefore be desirable to provide an improved configuration for abatement systems. [Means for solving the problem]

[0006] According to a first aspect, there is provided an inlet nozzle assembly for an abatement apparatus for treating an exhaust stream from a semiconductor processing tool, the inlet nozzle assembly comprising: a feed nozzle configured to feed the exhaust stream into an abatement chamber; and a mounting base configured to couple to a housing defining the abatement chamber, the mounting base further configured to receive the feed nozzle that feeds the exhaust stream into the abatement chamber, the feed nozzle configured to extend from the mounting base distal to the abatement chamber.

[0007] The first aspect recognizes that a problem with abatement devices is that each combustion chamber must be carefully configured to match the flow rate and type of exhaust stream to ensure proper abatement. This means that various, often custom, parts must be manufactured to provide an abatement device suitable for operation under a variety of different conditions. For example, the length of a delivery nozzle that delivers the exhaust stream to the abatement chamber may vary depending on the exhaust stream and / or its flow rate. Having delivery nozzles of different lengths can be problematic because it can affect the size of the plate or mount that receives the delivery nozzle, as well as the location of the combustion chamber within the abatement device, which in turn affects the sizing of related parts or components. This can lead to the need for different height plates or mounts, different height housings for the combustion chambers and other related parts, which increases the parts inventory required to manufacture and maintain the abatement device.

[0008] Accordingly, an inlet nozzle assembly is provided. The inlet nozzle assembly can be for use in an abatement apparatus. The abatement apparatus can process an exhaust flow from a semiconductor processing tool. The inlet nozzle assembly can include a delivery nozzle. The delivery nozzle can deliver the exhaust flow into an abatement chamber. The inlet nozzle assembly can include a mounting base or plate. The mounting base can be configured to couple to, hold, or support the abatement chamber. The mounting base can be configured to receive the delivery nozzle for delivering the exhaust flow into the abatement chamber. The delivery nozzle can be configured to extend from the mounting base distal to or away from the abatement chamber. In this manner, rather than needing to change the height of the mounting base or the position of the abatement chamber for delivery nozzles of different lengths, the height of the mounting base and the position of the abatement chamber can remain fixed for delivery nozzles of different lengths, with different amounts of the delivery nozzle extending from the mounting base depending on the length of the nozzle. This helps reduce inventory of different mounts, housings and other related parts, as these different parts are no longer required for different length feed nozzles.

[0009] The mount may comprise at least a portion of the head plate.

[0010] The mount may define a receiving opening configured to receive the delivery nozzle such that the delivery nozzle can extend through the opening in the mount.

[0011] The delivery nozzle can be sized to extend from a surface of the mount distal from the abatement chamber, and thus can extend above an upstream surface of the mount facing outward from the abatement chamber.

[0012] The delivery nozzle may be sized to stand upright from the surface of the mounting base.

[0013] The mount can have a downstream surface that mates with or receives a housing that defines the abatement chamber, and the mount can have an upstream surface from which the delivery nozzle extends.

[0014] The delivery nozzle can include an upstream inlet portion defining an inlet chamber that receives the exhaust flow. The delivery nozzle can also include a downstream delivery portion defining a delivery chamber that delivers the exhaust flow into the abatement chamber. At least a portion or portions of the delivery portion can be dimensioned to extend from the mount.

[0015] The inlet portion may be configured to mate with or connect to a supply of exhaust stream. Thus, the inlet portion may include a coupling for coupling with a supply, such as a pipe, that provides the exhaust stream to the inlet portion.

[0016] The inlet section may be configured to transition from the cross-sectional shape of the discharge flow supply section to the cross-sectional shape of the feed section, which may be a lofted transition.

[0017] At least a part or portions of the feed portion may be dimensioned to upstand from the upstream surface.

[0018] The mount can be configured to receive a remaining portion or length of the feed portion therein, i.e., the portion of the feed portion that does not extend from the upstream surface is contained within the mount, and the remaining portion can extend at least partially from the mount into the abatement chamber.

[0019] The delivery portion may be sized to extend or protrude from the upstream side of the upstream surface into the abatement chamber.

[0020] The feed nozzle can include a divider. The divider can define an opening. The opening can couple the inlet chamber to the feed chamber. The feed nozzle can be dimensioned to position the divider upstream of the upstream surface of the mount.

[0021] The feed nozzle can include an upstream body. The upstream body can include the inlet portion and at least a portion of the feed portion. The feed nozzle can include a downstream body. The downstream body can include the remainder of the feed portion. Thus, the feed nozzle can be made from two bodies or components. The downstream body can be of a fixed length that extends through the mounting and into the abatement chamber. The upstream body can be of a variable length depending on the overall length required for the feed nozzle.

[0022] The downstream body can be sized to extend from the upstream surface. The downstream body can extend through the mounting base and housing to the abatement chamber. This allows the downstream body to be a standard length, which helps reduce parts inventory.

[0023] The upstream body can be sized to provide one of a number of different lengths for at least a portion of the delivery section, such that different lengths of the upstream body can be provided depending on the overall length required for the delivery nozzle.

[0024] The upstream body can be sized to provide a combined length of delivery portions that deliver a developed or selected flow profile of the exhaust flow into the abatement chamber, and the delivery nozzle is thus sized to have an overall length that provides a desired type of exhaust flow into the abatement chamber.

[0025] The upstream body can be sized to provide a combined length of delivery portion that avoids or prevents backflow of exhaust flow from the abatement chamber to the delivery nozzle.

[0026] The inlet nozzle can include a discontinuity shaped to separate the discharge flow into at least a pair of vortices, and the upstream body can be sized to provide a length of the feed portion that prevents the pair of vortices from extending into the abatement chamber. Thus, if the discharge flow is formed into at least a pair of vortices, typically by a discontinuity such as an annular plate, the combined length of the feed portions provided by the upstream and downstream bodies can be selected to be longer than the length of those vortices. If the vortices were allowed to extend into the combustion chamber, this could result in a lower pressure region that could cause gases from within the abatement chamber to be drawn back into the feed nozzle, which could lead to particulate matter accumulation in the feed nozzle and result in blockage. In other words, the combined length can be selected to prevent the vortices from extending from the feed nozzle. This leads to a higher velocity, split (swallow-tailed), turbulent discharge flow (described in GB Patent No. 2550382, the entire disclosure of which is incorporated herein by reference) entering the abatement chamber, which exhibits greater than a threshold amount of shear mixing as it enters the abatement chamber, which improves destruction rate efficiency.

[0027] The upstream body may be formed from a material that has a lower service temperature and / or lower oxidation resistance than the material forming the downstream body.

[0028] The upstream body can be formed of a material that is chemically compatible with the effluent stream flow, and the downstream body can be formed of a material that is chemically compatible with the abatement by-products. By providing separate upstream and downstream bodies, suitable materials can be used for both components.

[0029] The inlet nozzle may have an oval cross section.

[0030] The opening may have an oval cross section.

[0031] The openings may be positioned symmetrically within the inlet nozzle.

[0032] According to a second aspect, there is provided an abatement apparatus comprising at least one inlet nozzle assembly of the first aspect.

[0033] The abatement system may include multiple inlet nozzle assemblies, each having a different length.

[0034] The abatement device may include the inlet nozzle assembly features described above.

[0035] According to a third aspect, a method is provided that includes the steps of configuring a delivery nozzle to deliver an exhaust flow into an abatement chamber, coupling a mounting base to a housing that defines the abatement chamber, and receiving the delivery nozzle in the mounting base, the delivery nozzle extending from the mounting base distal to the abatement chamber.

[0036] The method can include providing a mount as at least part of a head plate.

[0037] The method may include receiving the delivery nozzle in a receiving opening in the mount.

[0038] The method may include sizing the delivery nozzle to extend from a surface of the mount distal from the abatement chamber.

[0039] The method may include sizing the delivery nozzle to stand upright from a surface of the mounting base.

[0040] The method may include coupling a housing to a downstream surface of the mount and extending a perforated sleeve from an upstream surface of the mount.

[0041] The method may include forming a delivery nozzle from an upstream inlet portion defining an inlet chamber for receiving the exhaust flow and a downstream delivery portion defining a delivery chamber for delivery of the exhaust flow into the abatement chamber, and dimensioning at least a portion of the delivery portion to extend from the mounting base.

[0042] The method may include coupling the inlet portion to a supply of exhaust flow.

[0043] The method may include dimensioning at least a portion of the feed portion to upstand from the upstream surface.

[0044] The method may include configuring the mount to receive at least a portion of the remaining portion of the delivery portion therein.

[0045] The method may include sizing the delivery portion to extend from upstream of the upstream surface to the abatement chamber.

[0046] The method may include providing a partition plate in the feed nozzle that defines an opening connecting the inlet chamber with the feed chamber, and dimensioning the feed nozzle to position the partition plate upstream of the upstream surface of the mounting base.

[0047] The method may include providing a feed nozzle with an upstream body comprising an inlet portion and at least a portion of the feed portion, and a downstream body comprising a remaining portion of the feed portion.

[0048] The method may include sizing the downstream body to extend from the upstream surface, through the mount and sleeve, and to the abatement chamber.

[0049] The method can include sizing the upstream body to provide one of a plurality of different lengths of at least a portion of the delivery section.

[0050] The method can include sizing the upstream body to provide a combined length of delivery portion that develops and delivers a selected flow profile of the exhaust flow into the abatement chamber.

[0051] The method may include sizing the upstream body to provide a combined length of the feed portion that avoids backflow of exhaust flow from the abatement chamber.

[0052] The method can include separating the discharge flow into a pair of vortices and dimensioning the upstream body to provide a length of the feed portion that prevents the pair of vortices from extending into the abatement chamber. Thus, if the discharge flow is formed into at least a pair of vortices, typically by a discontinuity such as an annular plate, the combined length of the feed portion provided by the upstream body and the downstream body can be selected to be longer than the length of those vortices. If the vortices were allowed to extend into the combustion chamber, this could result in a lower pressure region that could cause gas from inside the abatement chamber to be drawn back into the feed nozzle, leading to particulate matter accumulation in the feed nozzle and resulting in blockage. In other words, the combined length can be selected so that the vortices do not extend from the feed nozzle. This results in a higher velocity split discharge flow entering the abatement chamber, which exhibits greater than a threshold amount of shear mixing as it enters the abatement chamber, improving destruction efficiency.

[0053] The method may include forming the upstream body from a material having at least one of a lower use temperature and lower oxidation resistance than a material forming the downstream body.

[0054] The method can include forming the upstream body from a material that is chemically compatible with the effluent stream flow, and the downstream body from a material that is chemically compatible with the abatement by-products.

[0055] The method may include providing the inlet nozzle with an oval cross-section.

[0056] The method may include providing the opening with an oval cross-section.

[0057] The method may include positioning symmetrically arranged openings in the inlet nozzle.

[0058] The method may include providing a plurality of inlet nozzle assemblies and sizing each inlet nozzle to have a different length.

[0059] Further particular and preferred aspects are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with features of the independent claims as appropriate and in combinations other than those explicitly set out in the claims.

[0060] It should be understood that when features of an apparatus are described as being operable to provide a certain function, this includes features of an apparatus that provide that function or that are adapted or configured to provide that function.

[0061] Embodiments of the present invention will now be further described with reference to the accompanying drawings. [Brief explanation of the drawings]

[0062] [Figure 1] 1 is a cross-sectional view of an abatement apparatus showing an inlet assembly according to an embodiment. [Figure 2A] FIG. 1 is a view from the upstream side of the inlet assembly. [Figure 2B] FIG. 2 is a perspective view of the inlet assembly. [Figure 2C] FIG. 1 is a view from the downstream side of the inlet assembly. [Figure 3] The figure shows a view from the downstream side of the combustion chamber. DETAILED DESCRIPTION OF THE INVENTION

[0063] Before describing the embodiments in more detail, a brief overview will be provided. The embodiments provide a configuration that allows for the provision of different lengths of feed nozzles to accommodate different discharge flow conditions while avoiding unnecessary increases in the inventory of parts required to support different lengths of feed nozzles. Rather than having different height mounting bases to accommodate different lengths of feed nozzles and / or different length housings to allow the abatement chamber housing to be positioned correctly for different lengths of feed nozzles, along with other related components of different dimensions, a standard height mounting base and standard height housing are instead provided, with the different length feed nozzles projecting at different heights from the mounting base. In some embodiments, the feed nozzle is formed from two elements or components. In these embodiments, a standard height first element of the feed nozzle fits into the mounting base and extends into the abatement chamber. A variable height second element couples with the first element. This means that from a parts inventory standpoint, regardless of the length of the delivery nozzle, the housing for the enclosure defining the abatement chamber, the mounting base, and the first element of the delivery nozzle can all be standard size, with the only element that varies in size being the second element of the delivery nozzle, which significantly reduces inventory size and the complexity of assembling the abatement device.

[0064] inlet assembly FIG. 1 illustrates inlet assemblies 600A, 600B of an abatement apparatus 10 according to one embodiment. The abatement apparatus 10 includes a perforated sleeve 90 that defines a combustion chamber 120. In this example, the perforated sleeve 90 defines a tapered, cubical combustion chamber 120, as shown in FIG. 3, which illustrates a view from the downstream side of the combustion chamber 120. The perforated sleeve 90 has a planar upstream ceiling 200 from which depend four diverging walls 180 that terminate in rounded shoulders 140 at the discharge end of the combustion chamber 120. This forms the combustion chamber 120 with a generally trapezoidal configuration. The pilot module 20 has a downstream discharge face 130 that abuts the shoulders 140 of the perforated sleeve 90. However, it should be understood that other combustion chamber shapes and configurations are possible. Also, in this embodiment, the abatement device is a radiant burner abatement device, although it should be understood that other types of abatement devices are possible having different types of combustion chambers 120. Perforated sleeve 90 is retained within housing 610. A plenum 620 is defined between an inwardly facing surface of housing 610 and an outwardly facing surface of perforated sleeve 90.

[0065] The housing 610 and perforated sleeve 90 are held by a mount 50. In this embodiment, the mount 50 defines a plenum 630 that is in fluid communication with the plenum 620. However, it should be understood that other configurations are possible, and that the plenum 630 can be omitted if desired. If this is the case, the height of the mount 50 would be significantly reduced. Both the mount 50 and the ceiling of the perforated sleeve 90 include an opening 60 that is shaped to receive a portion of the inlet assembly 600, as described in more detail below.

[0066] Inlet assembly 600A includes a downstream body 640A and an upstream body 650A. Downstream body 640A extends between an upstream surface 660 of mount 50, through the ceiling of mount 50 and perforated sleeve 90, and into combustion chamber 120. Upstream body 650A extends from upstream surface 660 of mount 50 to a connecting inlet 670A that connects to a discharge flow supply (not shown).

[0067] As best seen in Figure 2, coupling 670A has a circular cross-section to match the shape of the discharge flow supply. Therefore, other shapes of coupling 670A are possible to match the shape of the supply. Downstream of coupling 670A is a divider 680A that defines an opening 690A.

[0068] The upstream body 650A defines an inlet portion 700A that transitions between a circular cross-section at the junction 670A and an oval cross-section at the divider 680A to fit the shape of the feed chamber 710A. Other shapes are possible to fit the shape of the feed chamber 710A. The upstream body 650A defines a portion 720A of the feed chamber 710A that extends downstream from the divider 680A. The downstream body 640A provides another portion 730A of the feed chamber 710A. By providing separate upstream and downstream bodies 650A and 640A, the range of materials from which the bodies can be formed is expanded because the conditions experienced by these bodies are different. During operation, the discharge flow through the opening 690A forms a pair of vortices that extend downstream of the divider 680A within the feed chamber 710A. Thus, the exhaust flow typically splits into a pair of slightly expanding, diverging streams that fan out downstream of the divider plate 680A within the feed chamber 710A and flow into the combustion chamber 120. Typically, the overall length of the inlet nozzle assembly is selected to ensure that any vortex flow is maintained within the length of the feed chamber. As noted above, if the vortex flow were allowed to extend into the combustion chamber 120, this could result in a lower-pressure region that could cause gases from within the combustion chamber 120 to be drawn back into the inlet nozzle, leading to particulate matter accumulation within the feed nozzle and resulting in blockages. The split streams entering the combustion chamber 120 have higher velocities than would not occur if the exhaust flow were not split by the action of the divider plate 680A. Therefore, these higher-velocity split exhaust streams exhibit greater than a threshold amount of shear mixing upon entering the abatement chamber, which improves destruction efficiency. However, it should be understood that other flow configurations are possible, with other inlet assembly configurations requiring different overall lengths.

[0069] As can be seen in FIG. 1, inlet nozzle assembly 600B has a longer overall length than inlet nozzle assembly 600A, but the additional length is accommodated by providing a longer portion 720B of feed chamber 710B provided by upstream body 650B.

[0070] It can thus be seen that whatever length of inlet nozzle assembly is needed to deliver an exhaust stream having the desired flow characteristics to the combustion chamber 120, this can be achieved without having to change the dimensions or configuration of the mounting base 50, the housing 610, the perforated sleeve 90 defining the combustion chamber 120, or any of the other associated components. Instead, different lengths can be achieved simply by changing the length of the inlet assembly, and in embodiments where it is formed from multiple pieces, by changing the length of one of those pieces, allowing a common downstream body 640A to be used. This simplifies the parts inventory for manufacturing and maintaining such an abatement device.

[0071] Some embodiments provide a method for configuring extreme flow (>1000 l / min) nozzles for abatement systems, allowing them to be deployed in a "mix and match" fashion with lower flow inlets of abatement systems built on modular burner mechanisms. So-called slot nozzles have been demonstrated to provide superior abatement performance at higher flow rates compared to traditional circular nozzles. One design optimized for flow rates of 200 to 600 l / min features an oval-shaped nozzle measuring 16 mm wide and 75 mm long on 50 mm centers. This inlet is suitable for semiconductor chemical vapor deposition processes, particularly high-deposition-rate processes such as those used in the fabrication of three-dimensional NOT-AND (3D NAND) memory devices. For even higher flow rates, such as those found in the flat-panel display industry, higher-capacity / larger-sized inlets are required. Computational fluid dynamics analysis predicts comparable flow behavior at flow rates of 1000 to 1200 l / min through a 75 x 24 mm oval nozzle compared to conventional flow rates (300 to 600 l / min through a 50 x 116 x 75 mm nozzle). A proportional increase in length from 75 mm to 113 mm is typically required to accommodate the vortex that forms below the slit opening as the flow develops into the nozzle. This vortex formation and flow division have been demonstrated to contribute to improved abatement performance for these high-flow inlets. The construction techniques detailed above accommodate a portion of the nozzle length within the inlet, achieving the required distance from the trailing edge of the slit opening to the nozzle discharge end while maintaining a common reference plane for the burner mount. This allows low-flow and high-flow modules to be deployed together. This allows for maximum flexibility and minimal inventory when building a modular system. It also allows for the configuration and reconfiguration of the modular system by changing a minimum number of components.

[0072] Although exemplary embodiments of the present invention have been disclosed in detail herein with reference to the accompanying drawings, it is understood that the present invention is not limited to the precise embodiments, and that various changes and modifications can be made by those skilled in the art without departing from the scope of the present invention as defined by the appended claims and their equivalents. [Explanation of symbols]

[0073] 10 Abatement equipment 20 Pilot Module 40 Housing 50 Mounting stand 90 Perforated Sleeve 120 Combustion chamber 130 Discharge surface 180 Wall 200 ceiling 600A; 600B Inlet Assembly 610 Housing 620;630 Plenum 640A downstream body 650A upstream body 660 Upstream surface 670A Combined Inlet 680A Partition Plate 690A aperture 700A entrance part 710A Feeding chamber 720A;730A part

Claims

1. 1. An inlet nozzle assembly for an abatement system for treating an exhaust stream from a semiconductor processing tool, comprising: a delivery nozzle configured to deliver the exhaust stream into an abatement chamber; a mount configured to couple to a housing defining the abatement chamber, the mount further configured to receive the delivery nozzle for delivery of the exhaust stream into the abatement chamber, the delivery nozzle configured to extend from the mount distal to the abatement chamber; Equipped with the delivery nozzle comprises an upstream inlet portion defining an inlet chamber for receiving the exhaust flow, and a downstream delivery portion defining a delivery chamber for delivery of the exhaust flow into the abatement chamber, at least a portion of the delivery portion being dimensioned to extend from the mounting base.

2. the delivery nozzle is sized to extend from a surface of the mount distal to the abatement chamber; The inlet nozzle assembly of claim 1 .

3. the delivery nozzle is sized to stand upright from the surface of the mount; The inlet nozzle assembly of claim 2 .

4. the mount has a downstream surface that mates with the housing that defines the abatement chamber, and an upstream surface from which the delivery nozzle extends; The inlet nozzle assembly of claim 1 .

5. At least a portion of the delivery portion is sized to upstand from the upstream surface.

5. The inlet nozzle assembly of claim 4.

6. the mount is configured to receive at least a portion of the remainder of the delivery portion therein; The inlet nozzle assembly of claim 1 .

7. the delivery portion is sized to extend from the upstream side of the upstream surface to the abatement chamber. The inlet nozzle assembly of claim 1 .

8. the feed nozzle includes a partition defining an opening connecting the inlet chamber with the feed chamber, the feed nozzle being dimensioned to position the partition upstream of the upstream surface of the mount; The inlet nozzle assembly of claim 1 .

9. the feed nozzle comprising an upstream body comprising the inlet portion and at least a portion of the feed portion, and a downstream body comprising a remaining portion of the feed portion; The inlet nozzle assembly of claim 1 .

10. the downstream body is sized to extend from the upstream surface through the mounting base and the housing to the abatement chamber; The inlet nozzle assembly of claim 9.

11. the upstream body being sized to provide one of a plurality of different lengths of the at least a portion of the delivery section; The inlet nozzle assembly of claim 9.

12. the upstream body is sized to provide a length of the delivery portion that delivers a selected flow profile of the exhaust flow to the abatement chamber; The inlet nozzle assembly of claim 9.

13. the upstream body is sized to provide a length of the delivery portion that avoids backflow of the exhaust flow from the abatement chamber; The inlet nozzle assembly of claim 9.

14. a discontinuity shaped to separate the discharge flow into at least a pair of vortices, the upstream body being sized to provide a length of the delivery portion that prevents the pair of vortices from extending into the abatement chamber; The inlet nozzle assembly of claim 9.

15. the upstream body is formed of a material having at least one of a lower service temperature and a lower oxidation resistance than a material forming the downstream body; The inlet nozzle assembly of claim 9.

16. An abatement system comprising at least one inlet nozzle assembly according to claim 1.

17. 17. The abatement apparatus of claim 16 comprising a plurality of said inlet nozzle assemblies, each having a different length.

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