Inlet assembly for an abatement assembly and method for conveying an exhaust stream to an abatement chamber - Patents.com

Abstract

An inlet assembly for an abatement apparatus is disclosed. The inlet assembly includes a discharge flow conduit configured to convey a discharge flow along a primary flow direction within the discharge flow conduit, an inlet nozzle fluidly connected to the discharge flow conduit and configured to convey the discharge flow received from the discharge flow conduit to an abatement chamber of the abatement apparatus, and a baffle disposed between the discharge flow conduit and the inlet nozzle, the baffle shaped and configured to redirect the flow of the discharge flow from the discharge flow conduit into the inlet nozzle by preventing the discharge flow from flowing along the primary flow direction into the inlet nozzle. In this manner, line-of-sight flow from the discharge flow conduit to the inlet nozzle is prevented by the baffle, and the discharge flow instead follows a non-line-of-sight or circuitous path from the discharge flow conduit to the inlet nozzle, which increases residence time within the inlet nozzle and helps provide better laminar flow to the abatement chamber, improving DRE.

Description

[Technical Field]

[0001] The field of the invention relates to inlet assemblies for abatement devices. [Background technology]

[0002] 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 exhaust gases and are known to have a relatively high greenhouse effect, making their release into the environment undesirable.

[0003] For this reason, known abatement devices utilize 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. A fuel gas is mixed with the exhaust gas stream, and the gas stream mixture is conveyed using an inlet assembly to an abatement chamber, such as a combustion chamber laterally bounded by the exit face of a perforated gas burner. The fuel gas and air are simultaneously supplied to the perforated burner to affect flameless combustion at the exit face, and the amount of air passing through the perforated burner is sufficient to consume not only the fuel gas supplied to the burner, but also all combustibles in the gas stream mixture injected into the combustion chamber. Summary of the Invention [Problem to be solved by the invention]

[0004] Although techniques for treating exhaust gas streams exist, each has its drawbacks. Therefore, it would be desirable to provide improved techniques for treating exhaust gas streams. [Means for solving the problem]

[0005] According to a first aspect, an inlet assembly for an abatement device is provided, the inlet assembly comprising: a discharge flow conduit configured to convey a discharge flow along a primary flow direction within the discharge flow conduit; an inlet nozzle fluidly connected to the discharge flow conduit and configured to convey the discharge flow received from the discharge flow conduit to an abatement chamber of the abatement device; and a baffle disposed between the discharge flow conduit and the inlet nozzle, the baffle shaped and configured to redirect the flow of the discharge flow from the discharge flow conduit into the inlet nozzle by preventing the discharge flow from flowing into the inlet nozzle along the primary flow direction.

[0006] The first aspect recognizes that a problem with existing inlet assemblies is that their performance may be lower than possible. In particular, destruction rate efficiency (DRE) using those inlet assemblies may not achieve a required level. This may be due to the exhaust flow passing through the inlet assembly and transitioning too quickly to the abatement chamber. Accordingly, an inlet assembly is provided. The inlet assembly may be an inlet assembly of an abatement device. The inlet assembly may include an exhaust flow conduit that carries or supplies the exhaust flow. The exhaust flow may proceed or move within the exhaust flow conduit generally along a flow direction. The inlet assembly may include an inlet nozzle. The inlet nozzle may be connected to the exhaust flow conduit. The inlet nozzle may carry or transfer the exhaust flow received from the exhaust flow conduit to the abatement chamber. The inlet assembly may include a baffle. The baffle may be interposed, disposed, or positioned between the exhaust flow conduit and the inlet nozzle. The baffle may be shaped, configured, disposed, or positioned to redirect or divert the flow of the exhaust flow from the exhaust flow conduit toward the inlet nozzle. Flow can be diverted by impeding, blocking, or preventing the exhaust flow from flowing along its primary flow direction to the inlet nozzle. In this manner, line-of-sight flow from the exhaust flow conduit to the inlet nozzle is obstructed by the baffle, and the exhaust flow instead follows a non-line-of-sight or circuitous path from the exhaust flow conduit to the inlet nozzle, which increases residence time within the inlet nozzle and helps provide better laminar flow to the abatement chamber, which can improve DRE and reduce fuel consumption.

[0007] The exhaust flow may exit the exhaust flow conduit along a primary flow direction. The baffles may be shaped and configured to redirect the discharge flow away from the main flow direction and into the inlet nozzle.

[0008] The baffles may be shaped and configured to promote turbulence in the discharge flow upstream of the inlet nozzle. Promoting turbulence may improve mixing of the discharge flow, which improves DRE. The baffles can be shaped and configured to promote laminar flow of the discharge flow into the inlet nozzle, thus helping to restore laminar or uniform flow of the discharge flow as it enters the nozzle, again improving DRE.

[0009] The baffles can be shaped and configured to promote a uniform axial flow velocity within the inlet nozzle. Providing a uniform axial flow velocity within the baffles improves laminar or uniform flow of the discharge flow, again improving DRE. The baffles can be shaped and configured to counteract an increase in axial flow velocity in the inlet nozzle proximate the discharge flow conduit and a decrease in axial flow velocity in the inlet nozzle distal to the discharge flow conduit to achieve a uniform axial flow velocity in the inlet nozzle. Thus, the baffles can reduce the axial flow velocity in the region closest to the discharge flow conduit and increase the axial flow velocity in the region farthest from the discharge flow conduit to help balance the flow and achieve a more uniform flow velocity in the nozzle to improve DRE.

[0010] The baffle may comprise a baffle conduit disposed within the plenum configured to receive the exhaust flow from the exhaust flow conduit, the baffle conduit defining at least one opening positioned for fluid communication between the plenum and the inlet nozzle. The baffle conduit may extend along an axial direction coaxially aligned with the inlet nozzle.

[0011] At least one opening may be located away from a position in the baffle duct that is aligned with the incoming discharge flow traveling along the primary flow direction. Thus, the opening may be offset from, located away from, not incident on, or not aligned with the primary direction of the discharge flow to reduce line-of-sight flow from the baffle duct to the inlet nozzle and improve DRE.

[0012] The at least one opening may be located towards at least one axial end of the baffle conduit. The inlet assembly may include a plurality of openings. At least some of the plurality of openings may be circumferentially located around the baffle conduit.

[0013] The cross-sectional area of ​​the openings proximate the discharge flow conduit can be smaller than the cross-sectional area of ​​the openings distal to the discharge flow conduit, which helps balance the flow within the baffle, improve uniform flow within the inlet nozzle, and reduce flow velocity nearest the discharge flow conduit and promote flow velocity distal to the discharge flow conduit to improve DRE.

[0014] The cross-sectional area of ​​the plurality of openings may match the cross-sectional area of ​​the baffle conduit. The baffle conduits may be shaped to redirect the flow of the discharge flow within the plenum transverse to the primary flow direction.

[0015] The openings may be shaped to redirect the flow of the exhaust flow to channel it radially into the baffle conduit. The baffle conduit may be shaped to redirect the flow of the discharge flow to channel the discharge flow axially along the baffle conduit into the inlet nozzle.

[0016] The exhaust flow conduit may be shaped and configured to deliver the exhaust flow along a primary flow direction transverse to the axial direction. The exhaust flow conduit may follow a curved path.

[0017] The baffle conduit and / or the inlet nozzle may comprise a helical structure configured to impart a circumferential rotational component to the discharge flow. The baffle conduit and / or inlet nozzle are positioned inside fuel A lance may be provided.

[0018] The helical structure may be configured to extend axially beyond the lance. The lance may not be able to extend axially beyond the opening of an inlet nozzle positionable within the abatement chamber.

[0019] The baffle conduit may extend axially for at least five times the inner diameter, which helps provide sufficient distance to restore laminar flow.

[0020] In a second aspect, there is provided an abatement apparatus comprising the inlet assembly of the first aspect and an abatement chamber.

[0021] In a third aspect, a method is provided, the method including the steps of conveying an exhaust flow in an exhaust flow conduit along a primary flow direction; connecting an inlet nozzle to the exhaust flow conduit to convey the exhaust flow received from the exhaust flow conduit to an abatement chamber of the abatement device; and diverting the flow of the exhaust flow from the exhaust flow conduit into the inlet nozzle by positioning a baffle between the exhaust flow conduit and the inlet nozzle to prevent the exhaust flow from flowing into the inlet nozzle along the primary flow direction.

[0022] The exhaust flow may exit the exhaust flow conduit along a primary flow direction. The method may include redirecting the flow of the discharge stream away from a primary flow direction and into an inlet nozzle.

[0023] The method may include promoting turbulence in the discharge flow upstream of the inlet nozzle. The method may include promoting laminar flow of the discharge flow into the inlet nozzle.

[0024] The method may include promoting a uniform axial flow velocity within the inlet nozzle. The method may include preventing an increase in axial flow velocity in an inlet nozzle proximate to the discharge flow conduit and preventing a decrease in axial flow velocity in an inlet nozzle distal to the discharge flow conduit to obtain a uniform axial flow velocity in the inlet nozzle.

[0025] The method may include positioning a baffle conduit of the baffle within a plenum configured to receive the exhaust flow from the exhaust flow conduit, the baffle conduit defining at least one opening positioned for fluid communication between the plenum and the inlet nozzle.

[0026] The baffle conduit may extend along an axial direction coaxially aligned with the inlet nozzle. The method can include positioning the at least one opening away from a location in the baffle conduit that is aligned with the incoming and outgoing flow moving along a primary flow direction.

[0027] The method can include disposing at least one opening toward at least one axial end of the baffle conduit. There may be multiple apertures.

[0028] The method may include circumferentially disposing at least some of the plurality of openings around the baffle conduit. The method may include reducing the cross-sectional area of ​​the opening proximal to the exhaust flow conduit relative to the cross-sectional area of ​​the opening distal to the exhaust flow conduit.

[0029] The method may include matching a cross-sectional area of ​​the plurality of openings to a cross-sectional area of ​​the baffle conduit. The method may include redirecting the flow of the exhaust stream within the plenum transverse to the primary flow direction.

[0030] The method may include redirecting the flow of the exhaust stream to convey the exhaust stream radially into the baffle conduit. The method may include redirecting the flow of the discharge flow to convey the discharge flow axially along the baffle conduit and into the inlet nozzle.

[0031] The method may include directing the exhaust flow along a primary flow direction transverse to the axial direction. The exhaust flow conduit may follow a curved path.

[0032] The method may include imparting a circumferential rotational component to the discharge flow. The method includes: fuel The method may include positioning the lance.

[0033] The method may include extending a helical structure axially beyond the lance. The method can include preventing the lance from extending axially beyond an opening in an inlet nozzle positionable within the abatement chamber. The method can include extending the baffle conduit axially for a distance of at least five times its inner diameter.

[0034] 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.

[0035] Where features of a device are described as operable to provide a certain function, this should be understood to include features of the device that provide that function or that are adapted or configured to provide that function. Embodiments of the present invention are described in detail below with reference to the accompanying drawings. [Brief explanation of the drawings]

[0036] [Figure 1]1 illustrates an inlet assembly for an abatement device according to one embodiment. [Figure 2] 1 is a computational fluid dynamics analysis showing the velocities occurring within the inlet assembly. [Figure 3A] 1 shows fuel mass fraction contours on a plane located downstream of the fuel lance. [Figure 3B] 1 shows fuel mass fraction contours on a plane located downstream of the fuel lance. [Figure 4] 1 is a graph showing the difference in DRE and NOx depending on whether or not a baffle is present. [Figure 5] 1 shows the performance of an abatement system having inlet assemblies 1, 2, and 6 feeding the abatement system. [Figure 6] 1 shows a baffle with orifices located at different positions. [Figure 7] Graph showing DRE, NOx, and CO generated as the orifice opening moves downward on the baffle. [Figure 8] The positions of the standard length fuel lance and the longest length fuel lance are shown. [Figure 9] 1 is a graph showing DRE, CO, and NOx performance with varying fuel lance length. [Figure 10] 10 is a graph showing the performance of DRE, CO, and NOx when the length of the spring is changed. [Figure 11] CFD comparison of inlet assemblies with and without baffles. [Figure 12] 1 illustrates an inlet assembly for an abatement device according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0037] Before describing the embodiments in more detail, an overview will first be provided. The embodiments provide a configuration that increases the residence time of the mixed gas and exhaust stream before entering the abatement chamber, which helps promote mixing between the gas (e.g., fuel, oxidizer, or another compound) and the exhaust stream, increasing DRE and reducing fuel consumption. This is achieved by preventing the exhaust stream from following a path that would limit the amount of mixing that occurs and reduce residence time, and instead forcing the exhaust stream to follow a path that promotes such mixing and increases residence time. Specifically, because reduced mixing and residence time causes reduced destruction rate efficiency (DRE), structures are positioned in the exhaust stream flow to prevent the exhaust stream from following a direct line-of-sight path from the exhaust stream conduit to the inlet nozzle, which reduces mixing and residence time. The exhaust stream is sometimes delivered to the inlet nozzle at an angle, which causes uneven flow of the exhaust stream within the inlet nozzle, resulting in greater flow and less mixing in the portion of the nozzle adjacent to the inlet that supplies the exhaust stream. This results in uneven mixing of the exhaust stream and gas and less optimal DRE. Although various configurations are possible, in a configuration in which an inlet nozzle is used to deliver the combined exhaust stream and gas to the abatement chamber, a baffle can be positioned to intersect the flow of the exhaust stream as it enters the inlet nozzle. The baffle can have one or more openings therein. The exhaust stream is then redirected by the baffle. The exhaust stream then flows through these openings into the inlet nozzle. The baffle can then restore a uniform flow of the exhaust stream within the nozzle for mixing with the fuel.

[0038] inlet assembly FIG. 1 illustrates an inlet assembly 10 for an abatement apparatus according to one embodiment. The inlet assembly 10 includes an inlet nozzle 20 comprised of an elongated cylindrical conduit with a coaxially disposed fuel lance 30 therein. A coaxially disposed helical spring 40 is located between the outer surface of the fuel lance 30 and the inner surface of the inlet nozzle 20. The fuel lance 30 may be provided in three different lengths, in this example, A, B, or C. An additional coaxially disposed lance 55 is provided to deliver a gas (such as a fuel or oxidizer) supplied to port 65. A baffle 50 is provided at the top of the inlet nozzle 20. The baffle 50 comprises a cylindrical tube having multiple openings 60 formed through its wall. The wall of the inlet nozzle 20 has an opening 70 that receives an exhaust flow conduit 80. The exhaust flow conduit includes an oxygen injector 90 positioned to inject oxygen into the exhaust flow conduit 80.

[0039] In operation, the exhaust flow 100 is conveyed into the exhaust flow conduit 80. When activated, the oxygen injector 90 delivers oxygen into the exhaust flow 100 as it passes through the exhaust flow conduit 80 toward the opening 70. The baffle 50 provides a cylindrical surface for the incoming exhaust flow 100 as it passes through the opening 70. The baffle 50 seals off the top of the inlet nozzle 20, so the only way the exhaust flow 100 can pass through the inlet nozzle 20 is through the opening 60. Thus, the exhaust flow 100 passes through the opening 70 and enters a plenum 110 defined by the outer surface of the baffle 50 and the inner surface of the top of the inlet nozzle 20. In this manner, the primary direction of flow of the exhaust flow is redirected toward the opening 60. This flow redirection creates turbulence that helps mix the oxygen into the exhaust flow 100. An annular chamber 120 is defined between the inner surface of the baffle 50 and the outer surface of the fuel lance 30. The annular chamber 120 redirects the flow of the outlet stream 100 along the elongated axis of the annular chamber 120. These flow redirections create turbulence that helps mix oxygen into the exhaust stream 100. As the exhaust stream 100 moves along the elongated axis of the annular chamber 120, a substantially laminar flow is restored. As the exhaust stream 100 passes the end of the fuel lance 30, it begins to mix with the fuel 130 delivered through the fuel lance 30. Mixing continues until the mixed fuel and exhaust stream 140 exit the inlet nozzle 20 into an abatement chamber (not shown) that is concentrically surrounded by gas delivered from the lance 55. To promote mixing and improve the stability of the mixed fuel and exhaust stream 140, the spring 40 imparts a rotational component to the mixed fuel and exhaust stream 140 as it passes along the annular chamber 120.

[0040] As can be seen from FIG. 1 , without the baffle 50, the exhaust flow 100 delivered through the opening 70 would enter the inlet nozzle 20 at an oblique angle and pass the end of the fuel lance 30 in a non-uniform manner when in position A, leading to non-uniform mixing and suboptimal DRE. In contrast, with the baffle 50 present, the exhaust flow 100 moves uniformly along the annular chamber 120, which allows for uniform distribution of fuel (typically by diffusion) to the annular column of the exhaust flow 100 passing through the annular chamber 120. The presence of a uniform distribution of fuel helps to improve DRE. As discussed above, the arrangement of the exhaust flow conduit, opening 70, and baffle 50 provides improved DRE primarily by eliminating line-of-sight gas flow to the inlet nozzle 20. This arrangement forces the main gas flow to be uniformly distributed around the lance fuel, resulting in stable, consistent, and repeatable DRE and NOx measurements.

[0041] speed FIG. 2 is a computational fluid dynamics analysis illustrating the flow velocities within the inlet assembly 10. FIG. 2A shows a configuration without a baffle 50, and FIG. 2B shows a configuration with a baffle 50. As shown, in the configuration of FIG. 2A, the velocity of the discharge flow is relatively low as it enters the inlet nozzle 20, and the flow is biased toward the lower portion of the opening 70 adjacent to the fuel lance 30. However, as can be seen in FIG. 2B, the baffle 50 helps provide a uniform distribution of the discharge flow 100 within the inlet nozzle 20, i.e., a smoother flow of the discharge flow through the inlet nozzle 20, and the longer residence time of the mixed fuel and discharge flow 140 before entering the abatement chamber promotes mixing of the fuel and discharge flow, thereby improving pre-reaction mixing. The presence of the baffle 50 imparts a high velocity to the discharge flow 100, which forces the discharge flow 100 over a smaller surface area, thus increasing its velocity, which can aid in mixing of the fuel 130 and the discharge flow 100.

[0042] mixture FIG. 3 shows fuel mass fraction contours on a plane located downstream of the fuel lance for position A. FIG. 3A shows the mass fraction without the baffle 50, and FIG. 3B shows the mass fraction with the baffle 50 present. As can be seen, fuel mixing is significantly improved in the configuration with the baffle 50 present. Specifically, in FIG. 3A, due to the angled entry of the flow from the discharge flow conduit 80 into the inlet nozzle 20, the maximum fuel flow rate is concentrated in the area below the circular region, resulting in a higher mass fraction at this location. In FIG. 3B, the flow is traveling straight downward, so the flow is distributed across the plane and the mass fraction is more uniform.

[0043] 4 is a graph showing the difference in DRE and NOx with increasing oxygen flow rates with the baffle 50 (line 1 showing DRE, line 3 showing NOx) and without the baffle 50 (line 2 showing DRE, line 4 showing NOx). As shown, the performance with the baffle 50 at 95% DRE produces 15 ppm NOx compared to the performance without the baffle, which produces 23 ppm NOx at 95% DRE.

[0044] 5 shows the performance of an abatement system having inlet assemblies 10 of 1, 2, and 6 feeding increasing oxygen flows into the abatement chamber. As can be seen, each achieves consistent performance.

[0045] FIG. 6 shows a baffle 50 having orifices located at different locations designated locations 1, 2, 3, 4 and 5.

[0046] As can be seen from FIG. 7, which is a graph showing the DRE, NOx, and CO produced when the orifice opening 70 is moved below the baffle 50 (at positions 1, 2, 3, 4, and 5 shown in FIG. 6), the CF4 DRE decreases, which is a result of the exhaust flow 100 entering the line-of-sight region of the inlet nozzle 20 from the exhaust flow conduit 80. As the opening 70 drops further, the exhaust flow 100 leaves this region and the CF4 DRE returns to its normal performance. Consequently, while it is important that the baffle 50 eliminates the line-of-sight gas flow from the exhaust flow conduit 80 to the inlet nozzle 20, any other variation of the baffle 50 causing the exhaust flow 100 to move around the baffle 50 into the plenum 110 and up or down into the annular chamber 120 significantly improves abatement performance.

[0047] 8A and 8B show the positions of a standard length fuel lance 30 (FIG. 8A) and a maximum length fuel lance 30 (FIG. 8B) with an appropriately sized spring 40, as mentioned in FIG. 1.

[0048] FIG. 9 is a graph showing DRE, CO, and NOx performance for varying fuel lance 30 lengths when operating with 9 SLM lance fuel, 2.5 SLM coaxial fuel, 15 SLM O2, and 26 LPM CDA. As can be seen from FIG. 9, there is a clear trend toward increased DRE with increasing fuel lance 30 length, making the incorporation of a shorter fuel lance 30 preferable. A shorter fuel lance 30 provides increased residence time for the fuel and the mixed fuel and exhaust stream 140 within the annular chamber 120, and the distance of the lance fuel from the coaxial flame is important for CF4 DRE. Furthermore, the analysis shown in FIG. 2 suggests that lance fuel velocity is highly disruptive, and the shortest fuel lance 30 allows the lance fuel to interact with the mixed fuel and exhaust stream 140 with the added benefit of residence time for flow smoothing, creating a more laminar flow to the coaxial flame.

[0049] Figure 10 is a graph showing DRE, CO and NOx performance with varying spring 40 length (using the shortest fuel lance 30) for 9 SLM lance fuel, 2.5 SLM coaxial fuel, 15 SLM O2, and 26 LPM CDA. From the data shown, it appears that as the spring 40 length increases, as shown in Figure 11, more turbulent gas flow interacts with the swirl effect in the annular chamber 120, resulting in increased mixing with available oxygen from the CDA, resulting in reduced NOx and CO emissions.

[0050] Also, FIG. 11 (which is a CFD comparison of the inlet assembly 10 with (FIG. 11B) and without (FIG. 11A) the baffle 50) shows that due to the increased inertia created by the baffle 50, the mixed fuel and exhaust flow 140 has increased swirl upon exiting the inlet nozzle 20.

[0051] It can thus be seen that the swept exhaust flow conduit 80 and baffle 50 control the gas path of the exhaust flow 100 to the abatement chamber. This configuration meets the need for improved CF4 DRE, and therefore the distribution of the exhaust flow around the fuel lance 30, thereby aiding in the mixing of the lance fuel with the incoming process gas (CF4, O2, and typically 50 slm of N2). The swept exhaust flow conduit 80 removes process stream gas bias, aiding in better mixing of the lance fuel with the incoming process gas, and allowing for a longer residence time of the resulting mixture before entering the coaxial flame.

[0052] FIG. 12 illustrates an inlet assembly 10' for an abatement apparatus according to one embodiment. This configuration is similar to that described with reference to FIG. 1, except that the exhaust flow 100' is delivered axially. The inlet assembly 10' includes an inlet nozzle 20' comprised of an elongated cylindrical conduit having a coaxially disposed fuel lance 30' therein. A coaxially disposed helical spring (not shown) may be located between the outer surface of the fuel lance 30' and the inner surface of the inlet nozzle 20'. The fuel lance 30' may be provided in different lengths, as described above. An additional coaxially disposed lance 55' is also provided for delivering a gas (such as fuel or oxidizer). A baffle 50' is provided at the top of the inlet nozzle 20'. The baffle 50' comprises a cylindrical tube having multiple openings 60' formed through its wall. An exhaust flow conduit 80' receives the exhaust flow 100' and is located upstream of a feed structure 150' disposed within the exhaust flow conduit 80'. The feed structure 150' has openings 75' that can convey fuel 130' to the fuel lance 30' and also convey the discharge flow 100' from the discharge flow conduit 80' to a plenum surrounding the baffle 50'.

[0053] In operation, the exhaust flow 100' is conveyed to the exhaust flow conduit 80'. When activated, an oxygen injector (not shown) delivers oxygen into the exhaust flow 100' toward the feed structure 150' as the exhaust flow 100' passes through the exhaust flow conduit 80'. The exhaust flow 100' passes through openings 75' and undergoes multiple turns because the only way the exhaust flow 100' can pass through the inlet nozzle 20' is through openings 60'. Thus, the primary flow direction of the exhaust flow 100' is redirected toward openings 60'. This flow redirection creates turbulence that helps mix the oxygen into the exhaust flow 100'. An annular chamber 120' is defined between the inner surface of the baffle 50' and the outer surface of the fuel lance 30'. The annular chamber 120' redirects the flow of the exhaust flow 100' along the elongated axis of the annular chamber 120'. These flow redirections create turbulence that helps mix the oxygen into the exhaust flow 100'. As the discharge flow 100' moves along the elongated axis of the annular chamber 120', a substantially laminar flow is restored. As the discharge flow 100' passes the end of the fuel lance 30', it begins to mix with the fuel 130' delivered through the fuel lance 30'. Mixing continues until the mixed fuel and discharge flow 140' exit the inlet nozzle 20' and into an abatement chamber (not shown) that is concentrically surrounded by gas delivered from the lance 55'. To enhance mixing and improve the stability of the mixed fuel and discharge flow 140', a spring can impart a rotational component to the mixed fuel and discharge flow 140' as it passes along the annular chamber 120'.

[0054] Although exemplary embodiments of the present invention are disclosed in detail herein with reference to the accompanying drawings, it should be understood that the present invention is not limited to the precise embodiments and that various changes and modifications can be made thereto 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]

[0055] 10, 10' inlet assembly 20, 20' inlet nozzle 30, 30' fuel lance 40 springs 50, 50' baffle 55, 55' Reims 60, 60', 70, 75' opening 65 ports 80, 80' exhaust flow conduit 90 Oxygen Injector 100, 100' discharge flow 110 Plenum 120, 120' annular chamber 130, 130' fuel 140, 140' mixed fuel and exhaust stream 150' supply structure

Claims

1. 1. An inlet assembly for an abatement device, comprising: a discharge flow conduit configured to convey a discharge flow along a primary flow direction within the discharge flow conduit; an inlet nozzle fluidly connected to the exhaust flow conduit and configured to convey the exhaust flow received from the exhaust flow conduit to an abatement chamber of the abatement device; a baffle disposed between the exhaust flow conduit and the inlet nozzle; Equipped with the baffle is shaped and configured to redirect the flow of the discharge flow from the discharge flow conduit into the inlet nozzle by preventing the discharge flow from flowing into the inlet nozzle along the primary flow direction; an outer surface of the baffle shaped and configured to cooperate with an inner surface of the upper portion of the inlet nozzle to redirect a primary flow direction of discharge flow passing through the opening; the baffle comprises a baffle conduit positioned within a plenum configured to receive the exhaust flow from the exhaust flow conduit, the baffle conduit defining at least one opening positioned for fluid communication between the plenum and the inlet nozzle; The at least one opening is positioned away from a location of the baffle conduit aligned with an incoming or outgoing flow moving along the primary flow direction.

2. The inlet assembly of claim 1 , wherein the baffle is shaped and configured to redirect the discharge flow away from the primary flow direction and into the inlet nozzle.

3. 3. The inlet assembly of claim 1, wherein an annular chamber defined between an inner surface of the baffle and an outer surface of a fuel lance disposed within the inlet nozzle is shaped and configured to have an elongated axis through which the discharge flow passes.

4. The inlet assembly of claim 1 , wherein the cylindrical surface of the baffle is disposed along an inner surface of the inlet nozzle.

5. The inlet assembly of claim 1 , wherein the at least one opening is located upstream of at least one axial end of the baffle conduit.

6. The inlet assembly of claim 1 , comprising a plurality of said openings.

7. The cross-sectional area of ​​the opening proximal to the discharge flow conduit is greater than the cross-sectional area of ​​the opening distal to the discharge flow conduit.

7. The inlet assembly of claim 1, wherein the product is less than 0.

05.

8. 8. The inlet assembly of claim 1, wherein the baffle conduit is shaped to redirect the discharge flow within the plenum transverse to the primary flow direction.

9. 9. The inlet assembly of claim 1, wherein the opening is shaped to redirect the flow of the exhaust flow to convey the exhaust flow radially into the baffle conduit.

10. 10. The inlet assembly of claim 1, wherein the baffle conduit is shaped to redirect the flow of the discharge flow to channel the discharge flow axially along the baffle conduit and into the inlet nozzle.

11. 11. The inlet assembly of claim 1, wherein the discharge flow conduit is shaped and configured to deliver the discharge flow along the primary flow direction transverse to the axial direction of the baffle conduit.

12. The inlet assembly of any preceding claim, wherein the exhaust flow conduit follows a curved path.

13. The inlet assembly of claim 1 , wherein at least one of the baffle conduit and the inlet nozzle includes a fuel lance positioned therein.

14. The inlet assembly of claim 13 , wherein a helical structure is configured to extend axially along the baffle conduit beyond the fuel lance.

15. 15. The inlet assembly of claim 1, wherein the baffle conduit extends axially over at least five times the inner diameter of the baffle conduit.

16. An abatement device comprising the inlet assembly of any one of claims 1 to 15 and the abatement chamber.

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