Abatement apparatus

Abstract

Abatement apparatus and methods are disclosed. An abatement apparatus is for abating an exhaust gas stream from a semiconductor processing tool and includes a combustion chamber formed by a perforated sleeve and a wetted sleeve fluidly coupled with the perforated sleeve, the perforated sleeve defining an upstream portion of the combustion chamber for processing the exhaust gas stream, the upstream portion of the combustion chamber having an inlet for receiving the exhaust gas stream, the wetted sleeve defining a downstream portion of the combustion chamber, wherein the perforated sleeve is configured to provide a perforated axial surface facing downstream toward the downstream portion of the combustion chamber. In this way, the perforated surface not only faces inward toward the upstream portion of the combustion chamber, but also faces downstream toward the downstream portion of the combustion chamber. This facilitates combustion on the surface of the perforated sleeve both toward the upstream portion of the combustion chamber and toward the downstream portion of the combustion chamber. This helps to maintain a temperature near the discharge region of the perforated sleeve, which helps to prevent condensation of particulate matter from occurring in that region, and helps to prevent accumulation of particles, powders, or condensate that can lead to bridging or plugging.

Description

Technical Field

[0001] The field of this invention relates to emission reduction equipment and methods. Background Technology

[0002] Emission reduction devices (e.g., radiant burners or other types of emission reduction devices) are known and commonly used to treat exhaust gases from manufacturing tools used in industries such as semiconductor or flat panel display manufacturing. During such manufacturing, residual perfluorinated compounds (PFCs) and other compounds are present in the exhaust gases pumped from the manufacturing tools. PFCs are difficult to remove from 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 use combustion to remove PFCs and other compounds from exhaust gas streams, such as the radiant burner described in EP 0 694735. Typically, the exhaust gas stream is a nitrogen stream containing PFCs and other compounds. The exhaust gas stream is conveyed into a combustion chamber laterally surrounded by the outlet surface of a perforated gas burner. In some cases, the treatment material (e.g., fuel gas) can be mixed with the exhaust gas stream before entering the combustion chamber. Fuel gas and air are simultaneously supplied to the perforated burner to influence combustion at the outlet surface. Combustion products from the perforated burner react with the exhaust gas stream mixture to burn off the compounds in the exhaust gas stream.

[0004] Although emission reduction equipment exists, each of it has its own drawbacks. Therefore, there is a need to provide an improved arrangement of emission reduction equipment. Summary of the Invention

[0005] According to a first aspect, an emission reduction device for reducing exhaust gas flow from semiconductor processing tools is provided, comprising: a combustion chamber formed by a perforated sleeve and a wetted sleeve fluidly connected to the perforated sleeve, the perforated sleeve defining an upstream portion of the combustion chamber for treating the exhaust gas flow, the upstream portion of the combustion chamber having an inlet for receiving the exhaust gas flow, the wetted sleeve defining a downstream portion of the combustion chamber, wherein the perforated sleeve is configured to provide a perforated axial surface facing downstream toward the downstream portion of the combustion chamber.

[0006] The first aspect recognizes the problems with existing combustion chambers with perforated sleeves, where particles, powder, or condensate can form or deposit, particularly at the interface between the perforated sleeve and the downstream wetting sleeve. This is because the wetting sleeve cools the surface of the discharge area of ​​the perforated sleeve, and furthermore, the fluid exiting the perforated sleeve (which helps prevent the accumulation of particles, powder, or condensate) occurs only radially, causing particles, powder, or condensate to accumulate in the treated exhaust gas stream at that discharge area, potentially leading to bridging or blockage by those accumulated materials. Moreover, it is difficult to place the wetting sleeve adjacent to the perforated sleeve to help avoid exposing the surface of the discharge area of ​​the perforated sleeve, as fluid from the wetting sleeve may undesirably be wicked into the perforated sleeve, or if a separation gasket is used, that gasket can similarly cause particles, powder, or condensate to accumulate thereon. Therefore, an emission reduction device is provided. This emission reduction device can be used to reduce the emissions of an exhaust gas stream. The exhaust gas stream may originate from a semiconductor processing tool. The emission reduction device may include a combustion chamber. The combustion chamber may be formed by a perforated sleeve and a wetting sleeve. A perforated sleeve defines an upstream portion of the combustion chamber for treating the exhaust gas flow. The upstream portion of the combustion chamber may have an inlet for receiving the exhaust gas flow. A wetting sleeve may be fluidly connected to the perforated sleeve. The wetting sleeve defines a downstream portion of the combustion chamber. The perforated sleeve may be configured, shaped, or arranged to provide a perforated axial surface facing downstream toward the downstream portion of the combustion chamber. In this way, the perforated surface faces not only inward toward the upstream portion of the combustion chamber but also downstream toward the downstream portion of the combustion chamber. This facilitates combustion on the surface of the perforated sleeve, both toward the upstream and downstream portions of the combustion chamber. This helps maintain the temperature near the exhaust zone of the perforated sleeve, providing fluid flow (which provides purging) in this zone and avoiding the need for adjacent perforated and wetting sleeves. This helps prevent particulate matter condensation in this zone and helps prevent the accumulation of particles, powder, or condensate that could lead to bridging or blockage.

[0007] The perforated axial surface can be orthogonal to or transverse to the wetting sleeve.

[0008] The perforated sleeve may have at least one inward-facing surface defining the upstream portion of the combustion chamber. The perforated axial surface may at least partially define the outlet of the upstream portion.

[0009] At least a portion of the axial surface with holes may be orthogonal to or transverse to the inward-facing surface.

[0010] The inward-facing surface can be oriented generally parallel to the main flow direction of the exhaust gas in or through the combustion chamber. At least a portion of the perforated axial surface can be oriented generally orthogonal to or transverse to the main flow direction of the exhaust gas.

[0011] The inward-facing surfaces and the perforated axial surfaces can have a lofted transition. This helps to reduce the presence of any discontinuities that would otherwise interfere with the flow of the exhaust gas and / or act as traps for particles, powders, or condensates.

[0012] The axial surface with holes can be planar and / or curved.

[0013] The combustion chamber can be tubular. It will be understood that this tubular combustion chamber does not need to be cylindrical, but can be other tubular shapes.

[0014] The combustion chamber can be cylindrical and perforated, and the axial surface can be annular.

[0015] The combustion chamber can be a cuboid. The perforated axial surface can be a ring-shaped quadrilateral.

[0016] The perforated sleeve may be at least partially housed within a radially outer sleeve that extends at least partially along the axial length of the perforated sleeve to define a pressure ventilation chamber (plenum) for conveying combustion material to be delivered or supplied through the perforated sleeve for combustion thereon.

[0017] The perforated sleeve can be configured to deliver combustible material to a perforated axial surface for combustion thereon. Therefore, the combustible material can burn on the perforated axial surface to maintain temperature and help prevent the accumulation of particles, powder, or condensate in that area.

[0018] The outer sleeve may not extend to the perforated axial surface to expose or reveal at least the radially outer edge of the perforated axial surface to support combustion thereon. Therefore, combustion can occur on the outer surface of the perforated sleeve facing the wetting sleeve, and this helps prevent the accumulation of particles, powder, or condensate in that area.

[0019] The wetting sleeve can be housed within a wetting sleeve housing. The perforated axial surface can be positioned at least flush with the upstream surface of the wetting sleeve housing. Therefore, the perforated axial surface can be positioned at the upstream or downstream surface of the wetting sleeve housing.

[0020] The upstream surface may have a deflection lip that is suspended or extends from the upstream surface. The perforated axial surface may be positioned at least flush with the edge of the deflection lip.

[0021] The perforated sleeve can be positioned to extend within the wetting sleeve to position the perforated axial surface below the upstream surface.

[0022] The wetting sleeve can concentrically surround at least a portion of the perforated sleeve.

[0023] Emission reduction equipment may include a purge duct configured or arranged to deliver or transmit purge gas to the exposed radially outer surface of a perforated sleeve extending within a wetting sleeve. Thus, that portion of the perforated sleeve extending within the wetting sleeve can be purged with purge gas to further help prevent the accumulation of particles, powder, or condensate in that area.

[0024] The emission reduction device may include multiple columns configured to extend at least to the perforated axial surface. This helps protect the perforated axial surface from damage during the assembly of the emission reduction device.

[0025] According to a second aspect, a method is provided, comprising: defining an upstream portion of a combustion chamber using a perforated sleeve for treating an exhaust gas flow; defining a downstream portion of the combustion chamber using a wetted sleeve fluidly connected to the perforated sleeve; and configuring the perforated sleeve to provide a perforated axial surface facing downstream toward the downstream portion of the combustion chamber.

[0026] The method may include orienting the perforated axial surface orthogonal to the wetting sleeve.

[0027] The method may include: forming a perforated sleeve having at least one inward-facing surface that defines an upstream portion of a combustion chamber; and using the perforated axial surface to at least partially define an outlet for the upstream portion.

[0028] The method may include orienting at least a portion of the axial surface with holes to be orthogonal to the inward surface.

[0029] The method may include: orienting an inward-facing surface substantially parallel to the main flow direction of the exhaust gas in the combustion chamber; and orienting at least a portion of a perforated axial surface substantially orthogonal to the main flow direction of the exhaust gas.

[0030] This method may include forming a high-arc spherical transition between the inward-facing surface and the perforated axial surface.

[0031] The method may include forming the perforated axial surface as at least one of a plane and a curve.

[0032] The method may include forming the combustion chamber into a tubular shape.

[0033] The method may include forming the combustion chamber into a cylindrical shape and forming the perforated axial surface into an annular shape.

[0034] The method may include forming the combustion chamber into a cuboid and forming the perforated axial surface into an annular quadrilateral.

[0035] The method may include at least partially housing a perforated sleeve within a radially outer sleeve that extends at least partially along the axial length of the perforated sleeve to define a pressure ventilation chamber for conveying combustible material to be passed through the perforated sleeve for combustion thereon.

[0036] The method may include configuring a perforated sleeve to deliver combustible material to a perforated axial surface for combustion thereon.

[0037] The method may include configuring an outer sleeve not to extend into the perforated axial surface to expose at least the radially outer edge of the perforated axial surface to support combustion thereon.

[0038] The method may include configuring an outer sleeve that does not extend to the perforated axial surface to expose a radial outer ring of the perforated axial surface to support combustion thereon.

[0039] The method may include accommodating a wetting sleeve within a wetting sleeve housing and positioning the perforated axial surface at least flush with the upstream surface of the wetting sleeve housing.

[0040] The method may include: forming an upstream surface with a deflection lip suspended from the upstream surface; and positioning a perforated axial surface at least flush with the edge of the deflection lip.

[0041] The method may include positioning a perforated sleeve to extend within a wetting sleeve to position the perforated axial surface below the upstream surface.

[0042] The method may include using a wetting sleeve to concentrically surround at least a portion of the perforated sleeve.

[0043] The method may include configuring a purge conduit to deliver purge gas to the exposed radial outer surface of a perforated sleeve extending within a wetting sleeve.

[0044] The method may include configuring multiple posts to extend at least to the perforated axial surface.

[0045] Further specific and preferred aspects are set forth in the appended independent and dependent claims. Features of the dependent claims may be suitably combined with features of the independent claims, and may be combined in combinations other than those expressly set forth in the claims.

[0046] When a device feature is described as operable to provide a function, it will be understood that this includes device features that provide that function or are adapted or configured to provide that function. Attached Figure Description

[0047] Embodiments of the invention will now be described further with reference to the accompanying drawings, in which: Figure 1A cross-sectional view of a portion of an emission reduction device according to one embodiment is shown.

[0048] Figure 2 A cross-sectional view of an emission reduction device according to one embodiment is shown. Figure 3 and Figure 4 A perforated sleeve according to one embodiment is shown. Detailed Implementation

[0049] Before discussing any embodiments in more detail, an overview will first be provided. Some embodiments provide a combustion chamber for an emissions reduction device, the combustion chamber being at least partially formed by a perforated sleeve having an inward-facing surface that supports the combustion of a combustor to heat the combustion chamber for treating the exhaust gas flow. In addition to the inward-facing surface, the perforated sleeve also has an axially oriented surface that also supports combustion thereon to provide heat and provide a purge flow near the axial exhaust region of the perforated sleeve. This prevents overcooling of the perforated sleeve in this region, reducing the accumulation of particles, powder, or condensate on the perforated sleeve (which could otherwise affect the performance of the emissions reduction device and / or cause bridging or blockage). In some embodiments, the perforated sleeve extends into a downstream wetting sleeve, and at least the portion of the radially outer surface of the perforated sleeve facing the wetting sleeve is exposed to support combustion thereon. This again helps to provide heat, preventing overcooling of the perforated sleeve in this region and preventing the accumulation of particles, powder, or condensate (which could otherwise bridge across the wetting sleeve, potentially causing blockage). In some embodiments, the inward-facing surface of the perforated sleeve transitions continuously to the downstream-facing axial surface in order to provide continuous heating in this region and avoid any sharp transition (which could otherwise promote the accumulation of particles, powder, or condensate).

[0050] Emission reduction equipment - first arrangement Figure 1 A portion of an emission reduction device 10 according to one embodiment is shown. For clarity, other components of the emission reduction device have been omitted. A combustion chamber module 30 is provided, comprising a housing 40 that accommodates a perforated sleeve 90 defining an upstream portion 120A of a combustion chamber 120. In this arrangement, the perforated sleeve 90 is a tapered cuboid, but other sleeve shapes are possible. An inlet nozzle 60 is disposed upstream of the combustion chamber 120, providing the exhaust gas stream to be treated. The inlet nozzle 60 extends through the upstream surface of the perforated sleeve 90 into the housing 40.

[0051] A wetting sleeve 1020, which forms a weir downstream of the perforated sleeve 90, defines the downstream portion 120B of the combustion chamber 120. The wetting sleeve 1020 is generally positioned downstream of and concentric with the perforated sleeve 90. Fluid, such as water, is supplied from the outer sheath 1040 and splashed onto the inward-facing surface of the wetting sleeve 1020 and flows downward along the inward-facing surface of the wetting sleeve 1020.

[0052] A pressure vent chamber 100 is defined between the outer surface of a perforated sleeve 90 and the inner surface of an outer sleeve 1050 housed within a housing 40. A combustion reagent inlet 50 is located upstream of the pressure vent chamber 100, which delivers the combustion reagent into the pressure vent chamber 100. The pressure vent chamber 100 supplies the combustion reagent through the perforated sleeve 90 for combustion on the inward-facing surface 1000 of the perforated sleeve 90, which defines the upper portion 120A of the combustion chamber 120. In addition to combustion occurring on the inward-facing surface 1000 of the perforated sleeve 900, combustion also occurs on the axial surface 1010 of the perforated sleeve, which faces downstream toward the downstream portion 120B of the combustion chamber 120 defined by the wetting sleeve 1020. Furthermore, a curved surface 1030 of the perforated sleeve 90 provides a transition between the inward-facing surface 1000 and the axial surface 1010, which also supports combustion thereon. Therefore, combustion occurs not only on the inward-facing surface 1000, but also on the axial surface 1010 and the curved surface 1030. This provides enhanced heating in the exhaust or discharge area of ​​the upstream portion 120A of the combustion chamber 120, which would otherwise be cooled by the wetting sleeve 1020 and would otherwise lead to the accumulation of particles, powder, or condensate in that area.

[0053] Additionally, the outer sleeve 1050 extends toward the axial face 1010 but stops before reaching it, exposing a radially outer surface 1060 that faces the wetting sleeve 1020 and supports the combustion of the burning agent thereon. Again, this helps prevent particles, powders, or condensates from accumulating on this surface (which would otherwise grow or bridge toward the wetting sleeve 1020).

[0054] A purge chamber 1070, supplied with purge gas, is provided between the housing 40 and the outer wall 1050. The purge gas exits through an annular purge gas outlet 1080 to cover the outward-facing surface of the exhaust end of the combustion chamber module 30, thereby also helping to prevent the accumulation of particles, powders or condensates on it.

[0055] Emission reduction equipment - second arrangement Figure 2 An emission reduction device 10A according to one embodiment is shown. This embodiment is similar to the one described above. Figure 1The embodiment described herein is similar, but the upstream portion 120A of the combustion chamber 120 is positioned further upstream of the wetting sleeve 1020, such that the perforated sleeve 90 is positioned entirely upstream of the wetting sleeve 1020. In this embodiment, the top plate of the outer sheath 1040 has a downwardly tapered protrusion 1090, which helps to deflect any fluid away from the perforated wall 90.

[0056] Perforated sleeve - second arrangement Figure 3 A perforated sleeve 90A according to one embodiment is shown. In this embodiment, the perforated sleeve 90A is cylindrical, rather than... Figure 1 The rectangular shape shown in Figure 2.

[0057] As in Figure 4 As can be seen, a pair of perforated sleeves 90A can be positioned together, and each has an axial surface 1010A oriented downstream toward its combustion chamber.

[0058] Therefore, some embodiments provide improved pressure vent chamber / weir or wetting sleeve constructions to address wetting and solids deposition issues in the lining or perforated sleeve at the burner base. Rectangular burner elements or perforated sleeves are constructed in a bell-shaped form, meaning that a discharge end supporting combustion porous material is formed around the rear edge to provide both radial and axial ignition surfaces. An elongated, high-speed pressure vent chamber minimizes the footprint. This elongated pressure vent chamber extends downwards to the weir or wetting wall section; with minimal radial clearance between the burner and the weir, the overflow water surface begins a significant distance upstream of the axial ignition surface. This area can be supplied with drip purging or air or nitrogen to avoid stagnation. The burner or perforated sleeve may have parallel walls. It may have tapered walls, preferably with the diameter increasing from the inlet to the outlet. The cone half-angle is preferably between 2 and 5 degrees, more preferably 3 to 3.5 degrees. The burner may be constructed as an unsintered deposit of metal and ceramic fibers cast against a perforated precursor. The burner lip extends into the weir section, effectively shielding the burner-weir interface from any powder emitted from the burner. This prevents solids from accumulating at the interface and subsequently damaging the liner as water flows across the deposits. Some embodiments feature a gas / air pressure vent chamber surrounded at the bottom by a porous material, eliminating the need for a lower sealing surface. These embodiments provide improved mean time between maintenance and reduced cost associated with burner liner replacement.

[0059] Some embodiments provide a surface burner or perforated sleeve with a substantially inward-facing wall, having a section at the burner outlet for transitioning the burner surface from the radial flow direction to the axial flow direction. This improves performance at the burner outlet section by eliminating non-purged surfaces such as gaskets and flanges. For multi-burner systems, this allows for reliable cross-ignition and increases packing density.

[0060] Some embodiments provide a cylindrical, inwardly ignited burner or a perforated sleeve. Fuel and air are introduced into the inlet and propagate through a cylindrical pressure vent chamber region. This pressure vent chamber is surrounded externally by impermeable burner walls and internally by permeable burner material. Fuel and air travel through the burner walls and burn within the combustion chamber region. The flow direction in this region will be radial. The top of the burner ensures that the burner gases exit only downwards. Further below the burner, burner sections transition the burner material from a substantially radial, inward-facing burner to an axially-facing burner. One burner section is entirely axially oriented. This causes the flow field in these combustion chamber regions to transition from a radial direction to an axial direction. Columns can be used to protect the outward-facing burner surfaces. These can be extensions of the burner walls, but are not necessary. The columns extend to the edges of the burner material. This protects the material from accidental contact during handling and allows it to be placed on a flat surface. The columns do not need to extend around the entire perimeter of the burner. Having areas without columns is advantageous. These areas can be covered by burner material (the edges of the burner surface). This reduces the unpurged area in the combustion zone, thereby reducing solids deposition and burner corrosion.

[0061] In some embodiments, process gas may be introduced into the inlet. The process gas will travel downwards, contacting the gas from the burner material. The transition region and axial flow region will ensure that the process gas remains in the center of the burner and prevent solid material from depositing on the burner surface.

[0062] In some embodiments, the same cylindrical burners described above are placed side-by-side with identical burners for use in multi-burner systems. These burners share a combustion space. The burner sections are directly adjacent to each other, allowing for immediate and reliable ignition from one burner to another. This helps reduce the number of igniters required in a multi-burner system. The axial surface also optimizes the interface between the two burners by removing the non-purged surface that would typically be needed at the interface. This reduces the accumulation of solid particles, improving burner life and efficiency.

[0063] Therefore, it can be seen that some embodiments help improve the performance at the burner outlet by removing non-purged surfaces such as gaskets and flanges; allow reliable ignition between different burner modules in a multi-burner system; increase the packing density of burner modules in a multi-burner system by removing gaskets and flanges from the burner outlet; and provide an axially oriented burner surface at the rear edge of the inwardly ignited burner.

[0064] It will be understood that the shape of the burner can be varied; a column can be included at the base of the burner to prevent damage to the outward-facing burner section; the shape and dimensions of the burner transition section can be varied; and the ratio of the radially facing burner surface to the axially facing burner surface can be varied.

[0065] Although illustrative embodiments of the invention have been disclosed in detail herein with reference to the accompanying drawings, it should be understood that the invention is not limited to the precise embodiments and various changes and modifications can be made therein by those skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

[0066] Figure Labels 10 emission reduction devices Combustion chamber module 30 40 housing Combustion reagent inlet 50 Inlet nozzle 60 Perforated sleeve 90; 90a Pressure ventilation chamber 100; Blow-up Room 1070 Combustion chamber 120 Upstream section 120a Downstream section 120b 1000 inward-facing surfaces Axial surface 1010 Wetting sleeve 1020 1030 curved surface Outer sheath 1040 External sleeve 1050 1060 outer surface 1080 purge gas outlet Protrusion 1090.

Claims

1. An emission reduction device for reducing exhaust gas from semiconductor processing tools, comprising: The combustion chamber is formed by the following: A perforated sleeve defining an upstream portion of the combustion chamber for treating the exhaust gas flow, the upstream portion of the combustion chamber having an inlet for receiving the exhaust gas flow; as well as A wetting sleeve fluidly connected to a perforated sleeve, the wetting sleeve defining a downstream portion of the combustion chamber, wherein the perforated sleeve is configured to provide a perforated axial surface facing downstream toward the downstream portion of the combustion chamber. The perforated sleeve is at least partially housed within a radially outer sleeve that extends at least partially along the axial length of the perforated sleeve to define a pressure ventilation chamber for conveying combustible material to be passed through the perforated sleeve for combustion thereon. The radial outer sleeve does not extend to the perforated axial surface to expose at least the radial outer edge of the perforated axial surface to support combustion thereon.

2. The emission reduction equipment according to claim 1, wherein, The perforated axial surface is orthogonal to the wetting sleeve.

3. The emission reduction equipment according to claim 1, wherein, The perforated sleeve has at least one inwardly facing surface defining the upstream portion of the combustion chamber, and the perforated axial surface at least partially defines the outlet of the upstream portion.

4. The emission reduction equipment according to claim 3, wherein, At least a portion of the perforated axial surface is orthogonal to the inward-facing surface.

5. The emission reduction equipment according to claim 3, wherein, The inward-facing surface is oriented generally parallel to the main flow direction of the exhaust gas in the combustion chamber, and at least a portion of the perforated axial surface is oriented generally orthogonal to the main flow direction of the exhaust gas.

6. The emission reduction equipment according to any one of claims 1 to 5, wherein, The perforated axial surface is at least one of planar and curved.

7. The emission reduction equipment according to any one of claims 1 to 5, wherein, The combustion chamber is tubular.

8. The emission reduction equipment according to any one of claims 1 to 5, wherein, The combustion chamber is either cylindrical or cuboid, and the perforated axial surface is either annular or annular quadrilateral.

9. The emission reduction equipment according to any one of claims 1 to 5, wherein, The radial outer sleeve does not extend to the perforated axial surface to expose the radial outer ring of the perforated axial surface to support combustion thereon.

10. The emission reduction equipment according to any one of claims 1 to 5, wherein, The wetting sleeve is housed within a wetting sleeve housing, and the perforated axial surface is positioned at least flush with the upstream surface of the wetting sleeve housing.

11. The emission reduction device according to claim 10, wherein, The upstream surface has a deflection lip suspended from the upstream surface, and the perforated axial surface is positioned at least flush with the edge of the deflection lip.

12. The emission reduction device according to claim 10, wherein, The perforated sleeve is positioned to extend within the wetting sleeve to position the perforated axial surface below the upstream surface.

13. The emission reduction device according to any one of claims 1 to 5, comprising a purge duct configured to deliver purge gas to an exposed radially outer surface of the perforated sleeve extending within the wetting sleeve.

14. The emission reduction device according to any one of claims 1 to 5, comprising a plurality of columns configured to extend at least to the perforated axial surface.

15. A method for forming an emission reduction device according to any one of claims 1 to 14, comprising: A perforated sleeve is used to define the upstream portion of the combustion chamber for treating the exhaust gas flow. A wetted sleeve fluidly connected to the perforated sleeve defines the downstream portion of the combustion chamber; as well as The perforated sleeve is configured to provide a perforated axial surface facing downstream toward the downstream portion of the combustion chamber.

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