Head plate and inlet head assembly

Abstract

A head plate 1 is suitable for an inlet head assembly (3, Fig. 3) of an abatement apparatus, and has a plurality of conduits 2 through the headplate, each conduit configured to receive an inlet nozzle

Description

Field The present invention provides a head plate for an inlet head assembly of an abatement apparatus. The present invention also provides an inlet head assembly for an abatement apparatus. The present invention also provides an abatement apparatus. The present invention also provides a method of treating an effluent gas stream. Background Abatement apparatus are known and are typically used for treating an effluent gas stream from a manufacturing process tool used in, for example, the semiconductor or flat panel display manufacturing industry. Hydrogen, chlorine, and other compounds may be present in the effluent gas stream pumped from such manufacturing process tools. Therefore, the effluent gas stream must be treated before being vented to the atmosphere to remove selected gases and solids therefrom. Known abatement apparatus use combustion to remove compounds from the effluent gas stream. A fuel gas is mixed with the effluent gas stream and that gas stream mixture is conveyed through an inlet head assembly into an abatement chamber for abatement therein. The treated gas stream exiting the abatement apparatus may then be vented to the atmosphere or may undergo further abatement steps. There is a desire to increase the number of process tool chambers that can be serviced by a single abatement apparatus. To allow this, additional inlet nozzles may be required at the inlet head assembly of the abatement apparatus. However, the dimensions of the inlet head assembly of the abatement apparatus are limited, and there is no more space for additional inlet nozzles to be added in the current arrangement. Furthermore, there is a desire to improve performance of the abatement apparatus. Summary In an aspect, the present invention provides a head plate for an inlet head assembly of an abatement apparatus. The head plate is configured to be arranged at an inlet of an abatement apparatus. The head plate defines a plurality of conduits through the head plate that are each configured to receive an inlet nozzle. The conduits are arranged about a central axis of the head plate. Each conduit is arranged such that a central axis of the conduit is angled with respect to the central axis of the head plate. In head plates of inlet head assemblies of the prior art, the central axes of the each of the respective inlet nozzles are arranged to be parallel with the central axis of the head plate. Such an arrangement is intended to reduce interaction between gas flowing from the inlet nozzles during use, as this interaction has been found to result in decreased abatement efficiency within the abatement apparatus. The present inventors have established that by angling the central axes of the conduits with respect to the central axis of the head plate, this may allow space for more inlet nozzles to fit on a single inlet head assembly and exhibit comparable performance. When arranged on a head plate, the inlet nozzles may have one or more conduits for conveying fluid, fuel injects, and / or further components arranged on an upstream side of the head plate. Therefore, the inlet nozzles may be bulky and difficult to fit on the inlet head assemblies. The present inventors have established that by angling the conduits of the head plate, and thereby angling the inlet nozzles, space for additional inlet nozzles (i.e., by providing additional conduits) can be made on the head plate. The head plate may be the head plate of an abatement chamber of the abatement apparatus. The abatement chamber may be a combustion chamber of the abatement apparatus. The head plate may be generally cylindrical. The diameter of the head plate may be from about 10 cm to about 30 cm. Preferably, the diameter of the head plate may be about 6 inches (i.e., 15.24 cm). Each conduit of the head plate is configured to receive an inlet nozzle. For the purposes of the present invention, an inlet nozzle may be any nozzle through which fluid flow (e.g., effluent gas flow and / or fuel) enters an abatement chamber of the abatement apparatus. Typically, an inlet nozzle may be configured to convey an effluent gas stream, and / or fuel into the abatement chamber. The angle of the conduit may determine the angle at which gas flowing through the inlet nozzle enters the abatement apparatus. Each conduit is configured to receive an inlet nozzle when in use. Preferably, each conduit may have substantially the same cross-sectional area and cross-sectional shape. Preferably, the conduit(s) may have a generally circular cross-section. The conduits being arranged about the central axis of the head plate may be defined as the conduits being arranged in a generally circular array about the central axis of the head plate. Alternatively, the conduits may be arranged as a plurality of concentric circular arrays about the central axis of the head plate. The central axis of each conduit may intersect with the central axis of the head plate. Said intersection may occur on a downstream side of the head plate. In other words, the conduits are each angled with respect to the central axis such that when an inlet nozzle is inserted into a conduit, the effluent gas stream from each inlet nozzle is directed towards the central axis of the head plate. Typically, the central axis of each conduit may be angled at between about 1 ° to about 45° with respect to the central axis of the head plate. Preferably, the central axis of each conduit may be angled at between about 1° to about 15° with respect to the central axis of the head plate. More preferably, the central axis of each conduit may be angled at between about 5° to about 15° with respect to the central axis of the head plate. For example, the central axis of each conduit may be angled at about 10° with respect to the central axis of the head plate. Advantageously, the present inventors have established that when a head plate according to the present invention is used in an abatement apparatus, it is possible to maintain a comparable destruction and removal efficiency (DRE) whilst providing space for additional inlet nozzle(s) in comparison to a head plate wherein the central axes of the conduits are parallel to the central axis of the head plate. Typically, the head plate may define more than 6 conduits. Preferably, the head plate may define an even number of conduits. Preferably, the head plate may define from about 8 to about 16 conduits. Typically, the conduits may be substantially evenly spaced about the central axis of the head plate. Preferably, the conduits may be substantially evenly spaced in a circular arrangement about the central axis of the head plate. The spacing may be determined by the number of conduits and the dimensions of the head plate. Advantageously, substantially evenly spacing the conduits about the central axis may reduce the disruptive interaction between the fluid flow from the inlet nozzles. Typically, the angle between the central axis of each conduit and the central axis of the head plate may be substantially the same for each conduit. In other words, all of the conduits may be angled at substantially the same angle with respect to the central axis of the head plate. In some embodiments, none of the conduits may be arranged such that their central axis is parallel with the central axis of the head plate. Typically, the central axis of each conduit is configured to intersect with the central axis of the head plate. Preferably, when the head plate is arranged at the inlet of an abatement apparatus, the intersection point of the central axis of each conduit with the central axis of the head plate may be located within or beyond the abatement chamber of the abatement apparatus in a downstream direction. Typically, the conduits may be substantially symmetrically arranged with respect to an imaginary plane that passes through the central axis of the head plate. In other words, when viewed directly along the central axis of the head plate, the conduits may be substantially symmetrically arranged about an imaginary plane. In another aspect, the present invention provides an inlet head assembly for an abatement apparatus. The inlet head assembly comprises a head plate according to any embodiment of the preceding aspect. The inlet head assembly further comprises a plurality of inlet nozzles, wherein the number of inlet nozzles corresponds to the number of conduits. Each conduit of the head plate receives an inlet nozzle. The inlet head assembly may be configured to be arranged at an inlet of an abatement chamber of the abatement apparatus. The abatement chamber may be a combustion chamber. The nozzles of the inlet head assembly may be configured to convey an effluent gas stream and / or fuel into the abatement chamber. Typically, all of the inlet nozzles are angled with respect to the central axis of the head plate. Preferably, all of the inlet nozzles are angled with respect to the central axis of the head plate by substantially the same angle. Preferably said angle is from about 10 to about 45°, preferably at between about 1° to about 15°, more preferably between about 5° to about 15°, for example about 10°. In a preferred embodiment wherein the angle between each inlet nozzle and the central axis of the head plate is about 10°, it has been found that 8 inlet nozzles may be arranged on an inlet head assembly that would only be able to fit 6 coaxially arranged inlet nozzles. In some embodiments, at least one inlet nozzle may be a first inlet nozzle. The or each first inlet nozzle may comprise an effluent gas conduit, and a fuel inject and / or an oxidant inject. Preferably, the first inlet nozzle may comprise an effluent gas conduit, a fuel inject, and an oxidant inject. At least one inlet nozzle may be a second inlet nozzle. The or each second inlet nozzle may comprise an effluent gas conduit without a fuel inject or an oxidant inject. For the avoidance of doubt, the second inlet nozzle(s) may comprise further features, such as temperature regulation devices, but the effluent gas conduit may be the sole fluid conveyance through the inlet nozzle. In contrast, the first inlet nozzle(s) may have multiple fluid conveyances (i.e., an effluent gas conduit, a fuel inject, and an oxidant inject). Preferably, there may be an equal number of first inlet nozzles and second inlet nozzles. The inlet head assembly may comprise third or further inlet nozzles having additional configurations. Alternatively, the inlet head assembly may comprise only first inlet nozzles and second inlet nozzles. The first inlet nozzle(s) may be configured for conveying effluent gas stream from epitaxy (EPI) process occurring in a process tool. The second inlet nozzle(s) may be configured for conveying an effluent gas stream for a chemical vapour deposition (CVD) process occurring in a process tool. For example, such an effluent gas stream may contain NF3 and / or F2. In other words, the inlet head assembly may be configured to be connected to a dual EPI / CVD abatement apparatus. The present inventors have established that when used as part of an abatement apparatus, the inlet head assembly provides comparable DRE performance to inlet head assemblies of the prior art. Specifically, it has been found that abatement of hydrogen may achieve <0.2% H2 emissions. Furthermore, it has been found that chlorine abatement may achieve ~99% DRE. Preferably, the inlet head assembly may comprise an equal number of first inlet nozzles and second inlet nozzles. Preferably, the inlet head assembly may comprise a plurality of first inlet nozzles and a plurality of second inlet nozzles. Preferably, the first inlet nozzles and the second inlet nozzles are alternately arranged in the conduits of the head plate about the central axis of the head plate. Advantageously, this may reduce the disruptive nozzle interaction between the effluent gas streams conveyed through the respective inlet nozzles. The first inlet nozzles and the second inlet nozzles may be alternately arranged in the conduits of the head plate about the central axis of the head plate. In an embodiment, the inlet head assembly may comprise four first inlet nozzles and four second inlet nozzles. Preferably, the first inlet nozzles may be spaced apart by about 90° or about 180° about the central axis of the head plate. In other words, when viewed along the central axis of the head plate, there may be a spacing of about 90° or about 180° between adjacent first nozzles of the inlet head assembly. Advantageously, this may reduce the disruptive nozzle interactions between the first inlet nozzles. Particularly, the hydrogen (H2) and carbon monoxide (CO) emissions from the abatement apparatus may be reduced in such arrangements. Comparison of emissions data between an inlet head assembly of the present invention and an inlet head assembly comprising a single nozzle showed that the nozzle interaction produced by the angling of the nozzles in the present invention was beneficial to performance. Specifically, an 89% reduction in CO emissions was achieved by providing a 90° separation between adjacent first inlet nozzles of the inlet head assembly of the present invention in comparison to a single inlet nozzle. Preferably, the inlet nozzles of the inlet head assembly may be swept inlet nozzles. Swept inlet nozzles may be defined as the inlet nozzles as set out in WO 2021 / 245371 A1, which is incorporated herein by reference. Each inlet nozzle may comprise an effluent stream conduit configured to convey an effluent gas stream along a major direction of flow within the effluent stream conduit. Each inlet nozzle may further comprise an inlet conduit fluidly coupled with the effluent stream conduit and configured to convey the effluent stream received from the effluent stream conduit to an abatement chamber of the abatement apparatus. When in use, the inlet conduit of the inlet nozzle may be coaxial with the central axis of the conduit of the head plate. The inlet nozzle may further comprise an inlet configured to inject gas (e.g., a fuel, an oxidant, or another compound) into the effluent stream in the effluent stream conduit. Each inlet nozzle may further comprise a baffle interposed between the effluent stream conduit and the inlet conduit. The baffle may be shaped and configured to redirect flow of the effluent stream from the effluent stream conduit into the inlet conduit by inhibiting effluent stream flow along the major direction of flow into the inlet conduit. In other words, the baffle may be positioned to prevent the effluent stream from following a direct, line of sight path from the effluent stream conduit into the inlet conduit. This may increase the mixing of the effluent stream with the injected gas and the residence time within the inlet nozzle. Advantageously, mixing of the effluent stream and the gas may improve the DRE performance of the abatement apparatus. In a further aspect, the present invention provides an abatement apparatus comprising an inlet head assembly according to any embodiment of the preceding aspect, and an abatement chamber. Each inlet nozzle of the inlet head assembly is configured to convey an effluent stream into the abatement chamber. The abatement apparatus may comprise an abatement chamber. The abatement chamber may be a combustion chamber. The abatement apparatus may be an Atlas as produced by Edwards limited. When the inlet nozzles are coaxially arranged as in the prior art, it may be possible to only fit 6 inlet nozzles on a standard Atlas abatement apparatus. However, advantageously, the present invention may enable the abatement apparatus to comprise 8 inlet nozzles. For example, the abatement apparatus may comprise 4 first inlet nozzles and 4 second inlet nozzles as described hereinbefore. In a further aspect, the present invention provides a method of treating an effluent stream in an abatement apparatus. The method comprises the steps of providing an abatement apparatus according to any preceding aspect or embodiment, directing the effluent gas stream through the inlet nozzles of the inlet head assembly into the abatement chamber, and treating the effluent stream in the abatement chamber. For the avoidance of doubt, aspects and embodiments may be combined, mutatis mutandis. Brief Description of Figures Preferred embodiments of the present invention will now be described, with reference to the following figures, in which: Figure 1 shows a view of a head plate in accordance with an embodiment of the present invention; Figure 2 shows a cross-sectional view of a head plate in accordance with an embodiment of the present invention; Figure 3 shows a view of an inlet head assembly in accordance with an embodiment of the present invention; and Figure 4 shows a cross-sectional view of part of an inlet head assembly in accordance with an embodiment of the present invention. Detailed Description of Figures Figure 1 illustrates a view of a head plate (1) in accordance with an embodiment of the present invention. The head plate (1) is for an inlet assembly of an inlet apparatus (not shown). The head plate (1) is viewed along the central axis of the head plate (1). The head plate (1) comprises a plurality of conduits (2). In this embodiment, the head plate (1) comprises eight conduits (2). The conduits (2) each extend through the head plate (1). Each conduit (2) is configured to receive an inlet nozzle (not shown) of the inlet assembly when in use. The conduits (2) are arranged about the central axis of the head plate (1). Each conduit (2) is arranged such that a central axis of the conduit is angled with respect to the central axis of the head plate (1). In this embodiment, the central axis of each conduit (2) is angled by about 10° with respect to the central axis of the head plate. Figure 2 shows a cross-sectional view of the head plate (1) of Figure 1, in accordance with an embodiment of the present invention. In this view, the central axis (X) of the head plate (1) can be seen. Two of the conduits (2) of the head plate (1) are visible. Each conduit (2) passes through the head plate (1). It can be seen that the conduits are each angled with respect to the central axis (X) of the head plate (1). The central axis (Y) of one of the conduits is shown. For the avoidance of doubt, the dimensions of the figure are for illustrative purposes only and are not to scale. Figure 3 illustrates an inlet head assembly (3) in accordance with an embodiment of the present invention. The inlet head assembly (3) comprises a head plate (1). The inlet head assembly (3) further comprises a plurality of inlet nozzles (4). Each nozzle (4) is arranged through a separate conduit (2) of the head plate (1). In this embodiment, the head plate (1) comprises eight conduits (2), and there are eight nozzles (4). All of the nozzles (4) are angled with respect to the central axis of the head plate (1). In this embodiment, four of the nozzles (4) are first inlet nozzles, and four of the nozzles (4) are second inlet nozzles. All of the nozzles (4) are swept inlet nozzles. The first inlet nozzles and second inlet nozzles alternate about the central axis of the head plate to reduce the disruptive nozzle interactions and thereby improve DRE performance of the abatement apparatus. Advantageously, due to the angling of the nozzles (4) with respect to the central axis of the head plate (1), it is possible to fit more nozzles (4) within the same diameter of head plate (1). Figure 4 illustrates a cross-sectional view of a portion of an inlet head assembly in accordance with an embodiment of the present invention. The inlet head assembly comprises a head plate (5). The head plate (5) may be as defined hereinbefore. The head plate (5) comprises a conduit (6). The head plate (5) comprises further conduits, which are not visible in this view. The central axis of the conduit (6) is angled with respect to the central axis of the head plate (5). The inlet head assembly further comprises an inlet nozzle (7). The inlet nozzle (7) comprises an effluent stream conduit (8). During operation, the effluent stream conduit (8) is configured to convey an effluent stream. The inlet nozzle (7) further comprises an inlet conduit (9). The inlet conduit (9) is fluidly connected to the effluent stream conduit (7) and is configured to convey the effluent stream received from the effluent stream conduit (8) into an abatement chamber of the abatement apparatus (not shown). The inlet conduit (9) is partly located within the conduit (6) of the head plate (5). Accordingly, the inlet conduit (9) is angled with respect to the central axis of the head plate (5). The primary direction of flow of the effluent flow through the inlet conduit (9) may be angled towards the central axis of the head plate (5). The inlet nozzle (7) further comprises a gas inlet (10) configured to inject gas into the effluent stream in the effluent stream conduit (8). The gas may be, for example, a fuel gas or an oxidant. The inlet nozzle further comprises a baffle (11). The baffle (11) is interposed between the effluent stream conduit (8) and the inlet conduit (9). The baffle (11) is shaped and configured redirect flow of the effluent stream from the effluent stream conduit (8) into the inlet conduit (9) by inhibiting effluent stream flow along the major direction of flow into the inlet conduit. The baffle (11) comprises one or more orifices (12) through which the effluent stream is conveyed into the inlet conduit (9). The inlet nozzle (7) further comprises a lance (13) through which fuel, an oxidant, or another compound may be injected into the effluent stream. The inlet nozzle (7) further comprises a cleaning spring (14) arranged within the inlet conduit (9) and configured to prevent build-up of solids within the inlet conduit (9). Reference Kev 1. Head plate 2. Conduit 3. Inlet head assembly 4. Inlet nozzle 5. Head plate 6. Conduit 7. Inlet nozzle 8. Effluent stream conduit 9. Inlet conduit 10. Gas inlet 11. Baffle 12. Orifice 13. Lance 14. Spring

Claims

1. A head plate (1,5) for an inlet head assembly of an abatement apparatus, the head plate (1,5) being configured to be arranged at an inlet of an abatement apparatus;wherein the head plate (1,5) defines a plurality of conduits (2,6) through the headplate that are each configured to receive an inlet nozzle, the conduits (2,6) being arranged about a central axis of the head plate; andwherein each conduit (2,6) is arranged such that a central axis of the conduit is angled with respect to the central axis of the head plate.

2. The head plate (1,5) according to claim 1, wherein the central axis of each conduit is angled at between about 1 ° to about 45° with respect to the central axis of the head plate, preferably at between about 1° to about 15°, more preferably between about 5° to about 15°, most preferably at about 10°.

3. The head plate (1,5) according to claim 1 or 2, wherein the head plate defines more than 6 conduits (2,6), preferably from about 8 to about 16 conduits (2,6).

4. The head plate (1,5) according to any preceding claim, wherein the conduits (2,6) are substantially evenly spaced about the central axis of the head plate.

5. The head plate (1,5) according to any preceding claim, wherein the angle between the central axis of each conduit and the central axis of the head plate is substantially the same for each conduit (2,6).

6. The head plate (1,5) according to any preceding claim, wherein the central axis of each conduit is configured to intersect with the central axis of the head plate.

7. An inlet head assembly (3) for an abatement apparatus comprising:a head plate (1,5) according to any preceding claim;a plurality of inlet nozzles (4,7), wherein the number of inlet nozzles (4,7) corresponds to the number of conduits (2,6); and wherein each conduit (2,6) receives an inlet nozzle (4,7).

8. The inlet head assembly (3) according to claim 7, wherein all of the inlet nozzles (4,7) are angled with respect to the central axis of the head plate.

9. The inlet head assembly (3) according to claim 7 or 8, wherein at least one inlet nozzle (7) is a first inlet nozzle comprising an effluent gas conduit (8) and a fuel inject and / or an oxidant inject (10); and wherein at least one inlet nozzle is a second inlet nozzle comprising an effluent gas conduit without a fuel inject or an oxidant inject; preferably wherein there are an equal number of first inlet nozzles (7) and second inlet nozzles.

10. The inlet head assembly (3) according to claim 9 comprising a plurality of first inlet nozzles (7) and a plurality of second inlet nozzles, wherein the first inlet nozzles (7) and the second inlet nozzles are alternately arranged in the conduits about the central axis of the head plate.

11. The inlet head assembly (3) according to claim 9 or 10, comprising four first inlet nozzles (7) and four second inlet nozzles.

12. The inlet head assembly (3) according to claim 11, wherein the first inlet nozzles (7) are spaced apart by about 45° or about 90° about the central axis of the head plate.

13. The inlet head assembly (3) according to any of claims 7 to 12, wherein the inlet nozzles (4,7) are swept inlet nozzles.

14. An abatement apparatus comprising an inlet head assembly (3) according to any of claims 7 to 13, and an abatement chamber, wherein each inlet nozzle (4,7) of the inlet head assembly is configured to convey an effluent stream into the abatement chamber.

15. A method of treating an effluent stream in an abatement apparatus, comprising the steps of providing an abatement apparatus according to claim 14, directing the effluent gas stream through the inlet nozzles (4,7) of the inlet head assembly (3) into the abatement chamber, and treating the effluent stream in the abatement chamber.Application No: GB2319507.6Examiner: Dr Rhys WilliamsClaims searched: 1-15Date of search: 8 May 2024Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X 1-8 &13- 15 GB 2609436 A (EDWARDS LTD) See Fig. 1, lines 8-31 of page 8. X 1-8 &13- 15 US 6261524 Bl (HERMAN et al.) See Fig.

1. X 1-8 &13- 15 US 7569193 B2 (FERRON et al.) See Fig.

1. v A 1-8 &13- 15 US 2007 / 0172399 Al (CLARK et al.) See Fig. 13, paragraph [0073], X 1-8 &13- 15 US 2005 / 0175521 Al (FENG) See Fig. 1.Categories:X Document indicating lack of novelty or inventive step A Document indicating technological background and / or state of the art. Y Document indicating lack of inventive step if p Document published on or after the declared priority date but combined with one or more other documents of same category. before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:Search of GB, EP. WO &US patent documents classified in the following areas of the UKCX :Worldwide search of patent documents classified in the following areas of the IPC____________BOID; F23D; F23G______________________________________________The following online and other databases have been used in the preparation of this search reportWPI, EPODOC, SEARCH-PATENTInternational Classification:Subclass Subgroup Valid From F23G 0007 / 06 01 / 01 / 2006 BOID 0053 / 70 01 / 01 / 2006 F23D 0014 / 02 01 / 01 / 2006

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