Head unit for abatement system

Abstract

The present invention provides a head unit for capping a combustion chamber of an abatement system The head unit comprises an outer face and inner face, which inner face, in use, provides an internal surface of the combustion chamber. A surface of the head unit defines at least one conduit configured to convey a fluid through the head unit during operation. The head unit is configured such that, during use, the head unit functions as a heat exchanger to transfer heat from the combustion chamber to the fluid within the conduit. The present invention also provides an abatement apparatus, and a method.

Description

[0001] Head Unit for Abatement System

[0002] Field

[0003] The present invention provides a head unit for capping a combustion chamber of an abatement system. The present invention also provides an abatement system, and methods of manufacturing a head unit.

[0004] Background

[0005] Abatement apparatuses are known and are typically used for treating an effluent gas flow from a manufacturing process tool used in, for example, the semiconductor, solar or flat panel display manufacturing industry. Harmful greenhouse gases and other toxic compounds may be present in the effluent gas flow pumped from such manufacturing process tools. Therefore, the effluent gas flow must be treated to remove selected gases and solids therefrom before being vented to the atmosphere.

[0006] Prior art abatement apparatus demonstrate excellent performance in destruction efficiency of harmful greenhouse gas emissions and other toxic compounds. There is a desire to improve the performance and serviceability of head units. There is also a desire to provide head units with simplified design.

[0007] The present invention aims to solve, at least in part, these and other problems associated with abatement apparatus of the prior art.

[0008] Summary

[0009] In a first aspect, the present invention provides a head unit for capping a combustion chamber of an abatement system. The head unit comprises an outer face and inner face, which inner face, in use, provides an internal surface of the combustion chamber. A surface of the head unit defines at least one conduit configured to convey a fluid through the head unit during operation. The head unit is configured such that, during use, the head unit functions as a heat exchanger to transfer heat from the combustion chamber to the fluid within the conduit.

[0010] The head unit may have a generally cylindrical body. The head unit may have a generally planar portion. The head unit may be a head plate. The head unit may provide the last stage of gas flow conditioning (e.g. mixing, redirecting, alignment, and / or temperature control) prior to the fluid conveyed through the conduit(s) reaching the combustion chamber of the abatement system. Typically, the head unit may be configured to align a plurality of fluid flows (e.g. effluent gas flows) such that they enter the combustion chamber in a generally coaxial flow direction. The flow direction may be substantially coaxial with a longitudinal axis of the head unit. The longitudinal axis of the head unit may be coaxially arranged with a central axis of the combustion chamber.

[0011] When arranged at an inlet of a combustion chamber of the abatement apparatus, the head unit provides a portion of the internal surface of the combustion chamber. The head unit may have an upstream side (i.e. the outer face) that faces generally away from the combustion chamber when in use, and a downstream side (i.e. the inner face) that faces towards the combustion chamber when in use. The inner face may provide an internal surface of the combustion chamber. Preferably, the inner face may be a surface of the generally planar portion of the head unit. For the purposes of the present invention, the terms “upstream” and “downstream” may refer to the relative positioning of components along the flow path of the effluent gas flow.

[0012] The head unit functioning as a heat exchanger may be defined as the head unit providing a physical body through which heat flows from the combustion chamber into a fluid within the conduit. In other words, the head unit provides both the surface that is being heated by the combustion chamber (i.e., the inner face that provides an internal surface of the combustion chamber), the physical body through which heat is conducted, and a surface that is heating a fluid (i.e. a surface of the head unit defining a conduit configured to convey a fluid through the head unit).

[0013] Preferably, the head unit may be configured to provide targeted heat exchange to the fluid flow as it passes through the head unit. Said fluid may comprise effluent gas flow and / or an inject gas flow, as defined elsewhere herein. The head unit may be configured to heat the fluid within the conduit. Specifically, the head unit may be configured to heat fluid within the conduit(s) using heat recycled (i.e. conducted) from the combustion chamber.

[0014] In embodiments wherein the fluid is a gas, the head unit may be configured to maintain the temperature of the gas above its condensation temperature. Advantageously, this may reduce the likelihood of deposition within the head unit. Controlling the temperature of the fluid flow through the conduit(s) may aid in providing efficient abatement. Preferably, the heat unit may be configured to have substantially uniform temperature during use.

[0015] In prior art head units, external heaters, such as heating jackets, are typically used to control the temperature of the fluid(s) entering the combustion chamber. Furthermore, an insulating layer, such as a ceramic insulating layer, may be present between the head unit and the combustion chamber to limit heat transfer to the head unit. Additionally, head units of the prior art do not define a conduit configured to convey fluid through the head unit, rather, head units of the prior art typically define a slot for the insertion of a nozzle, wherein the nozzle conveys fluid through the head unit. In other words, there is no direct contact between the fluid and the head unit of the prior art.

[0016] Advantageously, the head unit of the present invention may be operable without an external heating jacket around sensitive portions of the head unit. Using thermal energy from the combustion chamber to heat the head unit may reduce the overall energy used by the system. The head unit of the present invention may be configured to passively control the temperature of the fluid(s) passing therethrough. For the purposes of this invention, the passive temperature control may involve transferring heat produced in the combustion chamber to the fluid(s). Head units according to the present invention may also provide improved destruction or removal efficiency (DRE) performance in comparison to head units of the prior art.

[0017] During use, the combustion chamber may have a temperature of from about 600 °C to about 1500°C, for example about 1100 °C. It will be appreciated that this will vary depending on the specific abatement apparatus and process. In other words, the inner face of the head unit may be exposed to such temperatures when in use. The surface of the head unit defining one or more conduit(s) configured to convey a fluid through the head unit during operation may have a temperature of from about 25 °C to about 250 °C.

[0018] Typically, the head unit may be monolithic. For the purposes of the present invention, monolithic may be defined as the head unit being a single, unitary component. In other words, the monolithic head unit may be in the form of a single piece of material. The monolithic head unit may include components that are welded together, thereby effectively becoming a single, unitary component.

[0019] The monolithic head unit may be connected to further components of the abatement apparatus but said components do not form part of the monolithic head unit. For the purposes of the present invention, the monolithic head unit may not include any components that are removably attached thereto. For example, components that are fastened, bolted, screwed, or otherwise connected via removable fixing(s) may not be defined as forming part of the monolithic head unit. Furthermore, the monolithic head unit may not include components that are removably inserted within the monolithic head unit.

[0020] Advantageously, providing a monolithic head unit may improve the ease of installation and maintenance as there are fewer components and connections that must be attached and leak checked. Additionally, the monolithic head unit may improve the thermal conductivity within the head unit.

[0021] In some embodiments, the head unit may be a single-piece monolithic head unit. The head unit may be manufactured by an additive manufacturing technique.

[0022] In some embodiments, the head unit may comprise a main body and a plate. The main body may be fixedly connected to the plate (i.e. monolithic). Preferably, the main body and plate are welded together. Alternatively, the main body may be removably connected to the plate. For example, the main body may be bolted, screwed, or otherwise connected via removable fixing(s) to the plate.

[0023] The main body may be located on a generally upstream side of the head unit. The plate may be located on a generally downstream side of the head unit. The plate may define the inner face of the head unit which, in use, provides an internal surface of the combustion chamber. The main body may comprise a first material, for example, a metallic material. The plate may comprise a second material, for example, a ceramic material. The first material may be different to the second material.

[0024] The main body and plate may define therebetween at least a portion of the or each conduit. The main body and / or the plate may define one or more grooves which, when the main body and plate are connected, define at least a portion of one or more conduits through which fluid may be conveyed in use. When the main body and the plate are connected, they may provide at least one sealed flow path therebetween, i.e. , a conduit.

[0025] In embodiments, one or both of the main body and the plate may be manufactured via subtractive manufacturing techniques. For example, the main body and / or the plate may be manufactured via machining. Additionally, or alternatively, one or both of the main body and the plate may be manufactured via an additive manufacturing technique.

[0026] Typically, at least one conduit may be an effluent flow conduit configured to convey an effluent gas flow into the combustion chamber. Preferably, the head unit defines a plurality of effluent flow conduits. Preferably, the head unit may define from about 4 to about 8 effluent flow conduits. The head unit may be configured to passively control the temperature of the effluent gas flow within each of the effluent flow conduits.

[0027] The head unit may be configured to receive incoming effluent gas flows from one or more sources. For example, the effluent gas flow may be the exhaust flow from one or more process tools. The head unit may be configured to direct said gas flow(s) into the combustion chamber of the abatement apparatus.

[0028] The or each effluent flow conduit may have a conduit inlet through which the effluent gas flow enters the effluent flow conduit. The conduit inlet may be on an upstream side of the head unit. The or each effluent flow conduit may also have a conduit outlet through which the effluent gas flow exits the effluent flow conduit. The conduit outlet may be on a downstream side of the head unit. The conduit outlet may be configured to convey the effluent gas flow directly into the combustion chamber, or alternatively, into a further component, such as an inlet nozzle. The or each effluent flow conduit may define a non-linear flow path through the head unit.

[0029] Typically, the effluent flow conduit may have a circular or elliptical cross-section. Preferably, the surface defining the effluent flow conduit may be substantially free from angles or comers. Preferably, the or each effluent flow conduit may be defined by a single surface of the head unit.

[0030] For the avoidance of doubt, the surface of the head unit defining a conduit means that said surface directly contacts the fluid flow during use. Preferably, the surface of the head unit defining the conduit may be an internal surface of the head unit. In contrast, head units of prior art abatement apparatus typically have an aperture through which a nozzle is inserted, with the nozzle defining a flow path for the effluent gas flow rather than the head unit itself. In the present invention, the surface of the head unit defining the conduit may directly contact the fluid flow, enabling improved control of the temperature of the fluid flow.

[0031] The head unit may comprise one or more baffles arranged in the effluent flow conduit and configured to redirect the effluent gas flow passing therethrough. Preferably, the baffle(s) may comprise one or more louvers. Preferably, the head unit may comprise a plurality of louvers. Advantageously, the baffle(s) may improve mixing of the effluent gas flow as it passes through the head unit. This may improve the performance of the abatement apparatus.

[0032] The head unit may comprise one or more heating elements arranged within the effluent flow conduit. The heating elements may be configured to heat the effluent gas flow as it passes through the effluent flow conduit. In some embodiments, the heating element(s) may be arranged on, or integrated with, a baffle.

[0033] In some embodiments, the head unit may comprise one or more heating elements (e.g. fins) arranged within the conduit(s) and configured to transfer heat from the combustion chamber to the gas flowing through the conduit. This recycling of excess heat from the combustion chamber may reduce the energy required to heat the gas flowing through the conduit. The conduit may be, for example, an effluent flow conduit and / or an inject flow conduit.

[0034] Typically, at least one conduit may be an inject flow conduit configured to convey an inject flow fluid (e.g. an inject gas flow). Preferably, the head unit comprises a plurality of inject flow conduits. The inject flow conduit(s) may be substantially internally routed within the head unit.

[0035] For the purpose of the invention, inject flow may be fluid introduced into the head unit and / or combustion chamber and / or effluent flow which is not effluent fluid. Inject flow conduits do not channel effluent during use. One or more of the inject flow conduits may be reagent flow conduits, for conveying a reagent fluid flow towards the effluent gas flow. Additionally or alternatively, one or more of the inject flow conduits may be inert gas conduits for conveying a substantially inert gas towards the effluent gas flow. The substantially inert gas may be to maintain flow of the effluent gas flow towards the combustion chamber. Inject flow may be selected from the group comprising of fuel (e.g. methane or natural gas), oxygen, nitrogen, air (preferably compressed dry air), hydrogen, and / or ammonia.

[0036] The or each inject flow conduit may have an outer port at or adjacent the outer face of the head unit, and an inner port at or adjacent the inner face of the head unit, or at a surface of an effluent flow conduit. The outer port(s) may be configured to receive an inject fluid flow. Herein such outer port(s) may be referred to an inject flow outer port(s). Each may have a corresponding inject flow inner port and an inject flow conduit extending therebetween.

[0037] In embodiments, the or each inner port is an outlet of the conduit and / or the or each outer port is an inlet of the conduit. Accordingly, in use, fluid will flow from the or each outer port to the or each respective inner port via the or each respective conduit. Preferably, the or each outer port is configured to be coupled to a reversibly attachable external inject flow pipework for delivering inject flow to the outer port and, preferably, on through the conduit.

[0038] The inner port of one or more inject flow conduit may be fluidly connected to an effluent flow conduit within the head unit. Accordingly, said inject flow conduit(s) may be configured to direct the inject fluid flow into the effluent gas flow.

[0039] Additionally, or alternatively, the inner port of one or more inject flow conduits may be configured to such that the inject fluid flow exits the head unit substantially surrounding an effluent gas flow. In other words, said inject flow conduit may be configured to provide a sheath flow that substantially surrounds the effluent gas flow as it exits the head unit and enters the combustion chamber. The sheath flow may be, for example, nitrogen gas or another substantially inert gas. The sheath flow may be configured to cool the inject nozzle, as this region of the head unit may experience extremely high temperatures during operation. Thus, the sheath flow may reduce the likelihood of damage to the inject nozzle caused by overheating.

[0040] Typically, at least a portion of the or each inject flow conduit may extends through the head unit in a direction that is substantially parallel to the inner face. Preferably, the majority of the or each inject flow conduit may extend through the head unit in a direction that is substantially parallel to the inner face. For the avoidance of doubt, the inject flow conduit(s) may also extend in other directions. Advantageously, such an arrangement may enable the inject fluid flow(s) to be directed to wherever it may be needed while having the outer ports located in a convenient location for servicing. The inject flow conduit(s) may also include bends and / or turns and / or may include sections which extend parallel to the radial plane of the head unit. Again, this may provide flexibility in design, allowing outer ports to be located in a convenient location for servicing.

[0041] Furthermore, routing the inject flow conduit(s) internally within the head unit may enable improved thermal control of the head unit. The inject flow conduit(s) may be routed to enable appropriate heat exchange from the surface of the head unit defining the inject flow conduit(s) to the inject fluid flow conveyed therethrough. For example, the distance between an inject flow conduit and the inner face of the head unit, and / or the length of the inject flow conduit, and / or the length of the portion of the inject flow conduit that is substantially parallel to the inner face of the head unit, may be selected to control the heat transfer to the inject fluid flow when travelling through the head unit. It will be understood that further factors, such as the material of the head unit, the temperature of the combustion chamber at the inner face of the head unit, the temperature of the inject fluid flow entering the inject flow conduit(s), etc., may also affect this.

[0042] As explained in more detail in a further aspect herein, modelling may be performed to determine a preferred geometry of the head unit. Said modelling may account for parameters of the specific application in which the head unit will be used. Said modelling may be, for example, finite element modelling. For example, the positioning of the conduit(s) and / or the proximity thereof to the inner face may be designed, for example using finite element analysis, to provide preferred heat transfer characteristics to the fluid conveyed through the conduit(s) during use.

[0043] In embodiments wherein the head unit comprises a main body and a plate, the portion of the inject flow conduit(s) defined therebetween may be the portion of the or each inject flow conduit that extends through the head unit in a direction that is substantially parallel to the inner face. Preferably, the plate may define the inner face. The geometry of the plate and / or the position of the conduit(s) defined between the plate and the main body may be designed to provide desired thermal characteristics during use.

[0044] A further advantage of the head unit of the present invention may be a reduction in the number of connections and seals around the head unit. This may therefore provide more free space within the abatement apparatus. Such embodiments may reduce downtime during servicing as fewer leak checks may be required.

[0045] Preferably, the head unit may comprise and a plurality of effluent flow conduits and a plurality of inject flow conduits. The head unit may comprise a plurality of inject flow conduits that correspond to each effluent flow conduit. For example, each effluent flow conduit may have a corresponding inject flow conduits configured to covey a gas selected from the list comprising nitrogen, fuel, oxidant, and / or compressed dry air. It will be appreciated that appropriate inject flow conduits will depend on the configuration of the head unit and / or the effluent flow within the effluent flow conduits.

[0046] In some embodiments, the inject flow conduits may be concentrically arranged. For example, the portion of the inject flow conduits that extends substantially parallel to the inner face of the head unit may be arranged substantially concentrically. When viewed from above, the inject flow conduits may define a substantially circular or semicircular path through the head unit. Advantageously, this may enable the positions of the outer ports and respective outer ports of each inject flow conduits to be located in positions on the head unit that are convenient for access during use. This may enable easier maintenance of the head unit as described elsewhere herein. Said concentric arrangement may also enable improved heat transfer to the inject fluid flow during use.

[0047] In embodiments wherein the head unit comprises a main body connected to a plate, said concentrically arranged inject fluid flow conduits may be defined therebetween.

[0048] In embodiments, the outer face may comprise one or more topographical features (such as projections and / or depressions) configured to dissipate heat from the head unit. Preferably, said topographical features may comprise fins. Preferably, said topographical features may comprise a substantially hexagonal array of fins. The topographical features may extend from the outer face of the head unit. Advantageously, the topographical features may increase the surface area of the outer face of the head unit, thereby increasing the area for conduction of head from said outer face. A substantially hexagonal array of fins may be a honeycomb structure defined by the fins of outer face of the head unit. It will be appreciated that the array of fins may be alternatively viewed as an array of concavities within the outer face of the head unit.

[0049] The topographical features may be arranged to correspond to positions of one or more conduit(s) of the head unit. For example, in embodiments comprising concentrically arranged inject flow conduits, the outer face proximal the inject flow conduits may define one or more topographical features.

[0050] In embodiments, the dimensions and / or density of the topographical features may vary according to location on the head unit. For example, in embodiments wherein the topographical features comprise a substantially hexagonal array of fins, the height of the fins may vary according to location on the head unit. The array of fins may be configured to radiate heat generated in the combustion chamber away from the head unit during use.

[0051] Advantageously, the dimensions and / or density of the topographical features may be configured such that heat flux is preferentially distributed to specific areas of the head unit. The dimensions and / or density of the topographical features may be determined via simulation of heat transfer, gas flow, and / or thermal stresses within the head unit during use.

[0052] In some embodiments, the distance between the inner face of the head unit and the outermost portion of the outer face defined by each topographical feature may vary between the topographical features. In other words, the maximum thickness of the head unit at each topographical feature may vary between topographical features.

[0053] In some embodiments, the distance between the inner face of the head unit and the outermost portion of the outer face defined by a topographical feature may remain substantially uniform. In such embodiments, the dimensions of the topographical features may vary according to the depth of the “hollows” defined between or within the topographical features. For example, in embodiments wherein the topographical features comprise a substantially hexagonal array of fins, the height of the fins may be substantially uniform, whilst the depth of the hollows defined between the fins may vary. Additionally, or alternatively, the density of packing of the fins (i.e. the size of the hollows of the honeycomb structure) may vary according to the location on the head unit. The positioning and / or the geometry of the fins may be designed, for example using finite element analysis, to provide desired heat transfer characteristics of the head unit during use.

[0054] The skilled person will appreciate that, whilst a substantially hexagonal array of fins have been referred to herein, the invention is not limited only to this type of topographical feature.

[0055] In embodiments, the head unit may comprises a metallic material. Preferably, the head unit may comprise aluminium or an alloy thereof, and / or a stainless-steel alloy. Advantageously, a metallic head unit may provide the required balance between thermal conductivity and strength.

[0056] The head unit may comprise a ceramic material. Preferably, a portion of the head unit may comprise a ceramic material.

[0057] In some embodiments, the inner face of the head unit may comprise a ceramic material. The remainder of the head unit may comprise a metallic material. The ceramic material defining the inner face of the head unit may be a ceramic layer. The ceramic layer may be configured to provide a thermally insulating layer. The ceramic layer may have substantially uniform thickness. Alternatively, the thickness of the ceramic layer may be non-uniform. In some embodiments, the head unit may comprise a non-ceramic layer configured to provide a thermally insulating layer.

[0058] In a preferred embodiment, the thickness of the ceramic layer may be designed, for example using finite element modelling, to provide desired heat transfer characteristics to the fluid(s) conveyed through the conduit(s) during use. For example, it may be desired that the fluid conveyed through certain conduits is at a higher temperature than the fluid conveyed through other conduits. Accordingly, the ceramic layer may be designed to increase heat transfer to the higher temperature conduits, for example by having a reduced thickness proximal to said conduits, whilst reducing heat transfer to the lower temperature conduits.

[0059] In some embodiments the ceramic layer may be generally cylindrical. Preferably, the head unit may be at least partially produced via an additive manufacturing process. Preferably, the head unit may be substantially entirely produced by an additive manufacturing process.

[0060] Additionally, or alternatively, the head unit may be at least partially produced via a subtractive manufacturing process (e.g., machining).

[0061] In embodiments, the thickness of the head unit may be non-uniform.

[0062] In embodiments, the head unit may further comprise a coolant line passing through the head unit. The coolant line may be configured to convey a coolant to regulate the temperature of the head unit during use. The coolant line may be similar to an inject flow conduit, other than that the coolant line is not fluidly connected to the combustion chamber. The coolant line may be a closed loop. Other features of the coolant line may be as recited in relation to the inject flow conduit. The flow of coolant through the coolant line may be controlled via a valve, enabling variable cooling. The coolant fluid may be selected from the group consisting of nitrogen, dry air, water and purged gas.

[0063] In a further aspect, the present invention provides a method of manufacturing a head unit according to any preceding claim by additively manufacturing the head unit as a monolithic component. Advantages and further features thereof may be as described in relation to other aspects and embodiments herein.

[0064] In a further aspect, the present invention provides an abatement system comprising a combustion chamber with a head unit according to any embodiment of an aspect described herein capping said combustion chamber. The abatement system may be an iAtlas as produced by Edwards Limited. Advantages and further features thereof may be as described in relation to other aspects and embodiments herein.

[0065] In a further aspect, the present invention provides a method. The method comprises meshing a 3D model representation of a head unit according to any embodiment of an aspect described herein. The method further comprises defining the geometry of the head unit based on specified component characteristics to define an optimised finite element representation of said component. The method further comprises fabricating said component according to said optimised finite element representation.

[0066] The meshing may be based on, or performed in response to, specified or defined characteristics of the component. It will be appreciated that said characteristics may depend on the specific application. The meshing may define or create an optimised finite element or cellular representation of the component, based on the specified component characteristics. That is to say, the meshing of the 3D model representation may not only create a finite element representation of the component, but the finite element representation itself may be optimised based on the characteristics required of that component.

[0067] The method may comprise the step of fabricating the component from the optimised finite element representation. In this way, a 3D model of a head unit can be generated from which its performance can be modelled, and geometric adaptations can be made.

[0068] Particular characteristics of the component may be defined which affect the operation of the head unit. Those characteristics may then be used to generate the optimised finite element representation of the component which has those characteristics using meshing (i.e., the operation of representing a geometric object as a set of finite elements). The optimised finite element representation may then be fabricated, reliably producing a component having the required characteristics.

[0069] In one embodiment, the meshing comprises meshing with at least one finite element. Accordingly, the 3D model representation may be meshed with one or more finite elements. In one embodiment, the meshing comprises meshing with a plurality of finite elements. Accordingly, the 3D model representation may be meshed with more than one finite element.

[0070] The meshing may comprise fitting the finite elements to fill the 3D model representation. Accordingly, the finite elements may be fitted to fill the 3D model representation. It will be appreciated that the volume defining the one or more conduits may remain unfilled.

[0071] In embodiments, said specified component characteristics may define heat transfer from the inner face to the surface defining the conduit. In other words, the heat transfer from the combustion chamber to the fluid conveyed through the conduit(s) during use of the head unit.

[0072] In embodiments, said meshing comprises specifying geometry of the head unit to provide an optimised structure. Specifying the geometry of the head unit may include specifying the geometry and / or flow path of the conduit(s) according to the requirements of the head unit when in use. For example, conduits configured to convey fluid at a higher temperature may be arranged to pass closer to the inner face than conduits configured to convey fluid at a lower temperature.

[0073] Additionally, or alternatively, the specifying of the geometry of the head unit may include specifying the geometry of the topographical features of the outer face. Additionally, or alternatively, the specifying of the geometry of the head unit may include specifying the thickness of a ceramic layer.

[0074] For the avoidance of doubt, all aspects and embodiments described herein may be combined, mutatis mutandis. It is also to be understood that this invention is not limited to the embodiments and aspects set forth in the following detailed description or illustrated in the drawings. The invention may be implemented in various other embodiments and is capable of being implemented in alternative ways not expressly disclosed herein.

[0075] Brief Description of Figures

[0076] Preferred features of the present invention will now be described, by way of example, with reference to the accompanying figures, in which:

[0077] Figure 1 shows a perspective view of a head unit in accordance with an embodiment of the present invention;

[0078] Figure 2 shows a skeletonised perspective view of a head unit in accordance with an embodiment of the present invention;

[0079] Figure 3 shows a cross-section of part of a head unit in accordance with an embodiment of the present invention; and

[0080] Figure 4 shows a flow chart showing a method in accordance with an embodiment of the present invention.

[0081] Detailed Description of Figures

[0082] Figure 1 illustrates a head unit (1 ). The head unit (1 ) is for capping a combustion chamber of an abatement system (not shown). The head unit (1 ) comprises an outer face (2) and an inner face (not shown). The inner face (not shown), in use, provides an internal surface of the combustion chamber. In this embodiment, the head unit (1 ) is monolithic. Preferably, the head unit (1 ) consists of a single unitary piece of metal, for example aluminium or an alloy thereof. In some embodiments, the head unit (1 ) may comprise a thermally insulating layer on the inner face. Said thermally insulating layer may comprise a ceramic layer.

[0083] The head unit (1 ) shown in Figure 1 comprises six effluent flow conduits (3a-3f). Each effluent flow conduit (3a-3f) is defined by a surface of the head unit. The effluent flow conduits (3a-3f) are each configured to convey an effluent gas flow through the head unit and into the combustion chamber.

[0084] The head unit is configured such that, during use, the head unit (1 ) functions as a heat exchanger to transfer heat from the combustion chamber to the fluid within the effluent flow conduits (3a-3f) and the inject flow conduits (4a-4c).

[0085] The outer face (2) of the head unit (1 ) further comprises a plurality of topographical features (7) configured to dissipate heat from the head unit (1 ). In this embodiment, said topographical features (7) is a hexagonal array of fins. In some embodiments, the height of the fins may vary according to preferred heat dissipation characteristics in specific locations on the head unit. Further features of the topographical features are described in relation to Figure 3. The geometry of the head unit may be optimised via finite element modelling.

[0086] Figure 2 illustrates a skeletonised perspective view of the head unit of Figure 1 , thereby illustrating the flow paths of the conduits defined by the head unit (1 ).

[0087] As shown in Figure 2, the head unit (1 ) further comprises a plurality of inject flow conduits (4a-4c). For ease of understanding, only three of the eighteen inject flow conduits have been labelled in Figure 2. Each inject flow conduit (4a-4c) is configured to convey an inject flow fluid through the head unit during use. In this embodiment, the inject flow conduits (4a-4c) are internally routed within the head unit (1 ). Each inject flow conduit (4a-4c) terminates at an inject flow port (5a-5c).

[0088] The inject flow conduits (4a-4c) are each associated with an effluent flow conduit (3a- 3f). In the embodiment of Figure 1 , the inject flow conduits (4a-4c) terminating at inject flow ports (5a-5c) are associated with effluent flow conduit (3c). In this embodiment, each effluent flow conduit (3a-3f) has an associated inject flow conduit for conveying fuel (4a), oxygen (4b), and nitrogen (4c), respectively. Typically, the nitrogen inject flow is configured, in use, to maintain a forward flow of the effluent gas flow. It will be appreciated that the specific compositions of the inject fluid flows may depend on the application.

[0089] An inject flow port (5a-5c) associated with an effluent flow conduit may be located in a different sector of the head unit (1 ) to the corresponding effluent flow conduit when the head unit is viewed from above. For example, effluent flow conduit (3c) is located in a different minor sector of the head unit (1 ) to inject flow ports (5a-5c).

[0090] It can be seen in Figure 2 that each inject flow conduit (4a-4c) extends through the head unit (1 ) in a direction that is substantially parallel to the inner face. In other words, in use, an inject gas enters an inject flow conduit via an inject flow port and the inject gas is conveyed substantially laterally within the head unit towards a corresponding effluent flow conduit. This both allows for improved positioning of the inject flow ports, as well as improved heat transfer to the inject fluid flows conveyed through the inject flow conduits.

[0091] Several of the inject flow conduits (4a-4c) are arranged substantially concentrically within the head unit (1 ). This may enable the geometry of the head unit, for example the arrangement of the topographical features (7) of the outer face (2) of the head unit (1 ), to be specifically tailored to provide desired local thermal characteristics for different regions of the head unit. In some embodiments, it may be desired that certain inject fluid flows are heated to a different temperature to other inject fluid flows. This may be achieved by selecting the geometry head unit (1 ) of the present invention to provide the required heat transfer characteristics.

[0092] In the head unit (1 ) of Figures 1 and 2, each of the inject flow ports (5a-5c) is arranged as a bank (6) of inject flow ports. The bank (6) of inject flow ports (5a-5c) may enable the inject flow ports to be arranged on a proximal side of the head unit (1 ). The proximal side of the head unit may be configured to be adjacent an opening or door of a cabinet of the abatement system (not shown), said cabinet housing the combustion chamber. The internal routing of the inject flow conduits (4a-4c) enables the positioning of each inject flow port at the bank (6) thereof. Figure 3 illustrates a cross-section of part of a head unit (8) in accordance with an embodiment of the present invention. The head unit (8) has an inner face (9) which, in use, provides an internal surface of the combustion chamber of an abatement system (not shown). The head unit (8) has an outer face (10) that does not provide an internal surface of the combustion chamber.

[0093] The head unit (8) defines an inject flow conduit (11 ) configured to convey an inject flow through the head unit when in use. The portion of the inject flow conduit (11 ) shown extends through the head unit (8) in a direction that is substantially parallel to the inner face (9).

[0094] The outer face (10) comprises a plurality of topographical features. In this embodiment, the topographical features are an array of substantially hexagonal fins. The fins are monolithic with the head unit (8). It can be seen that some of the fins (12) of the array define relatively shallow concavities (13) within the outer face (10), and other fins (14) define relatively deep concavities (15) within the outer face (10). The fins (12) defining relatively shallow concavities (13) within the outer face (10) are proximal to the inject flow conduit (11 ). The fins (14) defining relatively deep concavities (15) within the outer face are distal from the inject flow conduit (11 ). Accordingly, the shape and size of the fins (12,14) are configured such that, during use, heat flux is preferentially distributed to specific areas of the head unit (8).

[0095] Figure 4 illustrates a flow chart showing a method in accordance with an embodiment of the present invention. The method comprises meshing a 3D model representation of a head unit according to any embodiment of an aspect described herein (16). The method further comprises defining the geometry of the head unit based on specified component characteristics to define an optimised finite element representation of said component (17). The method further comprises fabricating said component according to said optimised finite element representation (18).

[0096] The meshing may comprise meshing with at least one finite element. The meshing may comprise fitting the finite elements to fill the 3D model representation.

[0097] In embodiments, said specified component characteristics may define heat transfer from the inner face to the surface defining the conduit. In other words, the heat transfer from the combustion chamber to the fluid conveyed through the conduit(s) during use of the head unit. In embodiments, said meshing comprises specifying geometry of the head unit to provide an optimised structure. Specifying the geometry of the head unit may include specifying the geometry and / or flow path of the conduit(s) according to the requirements of the head unit when in use. For example, conduits configured to convey fluid at a higher temperature may be arranged to pass closer to the inner face than conduits configured to convey fluid at a lower temperature.

[0098] Additionally, or alternatively, the specifying of the geometry of the head unit may include specifying the geometry of the topographical features of the outer face. Additionally, or alternatively, the specifying of the geometry of the head unit may include specifying the thickness of a ceramic layer.

[0099] It will be appreciated that various modifications may be made to the embodiments shown without departing from the spirit and scope of the invention as defined by the accompanying claims as interpreted under patent law.

[0100] Reference Key

[0101] 1. Head unit

[0102] 2. Outer face

[0103] 3(a-f). Effluent flow conduit

[0104] 4(a-c). Inject flow conduit

[0105] 5(a-c). Inject flow port

[0106] 6. Bank

[0107] 7. Topographical features

[0108] 8. Head unit

[0109] 9. Inner face

[0110] 10. Outer face

[0111] 11. Inject flow conduit

[0112] 12. Fin

[0113] 13. Concavity

[0114] 14. Fin

[0115] 15. Concavity

[0116] 16. Method step

[0117] 17. Method step

[0118] 18. Method step

Claims

Claims1 . A head unit for capping a combustion chamber of an abatement system, the head unit comprising an outer face and inner face, which inner face, in use, provides an internal surface of the combustion chamber, a surface of the head unit defining at least one conduit configured to convey a fluid through the head unit during operation, wherein the head unit is configured such that, during use, the head unit functions as a heat exchanger to transfer heat from the combustion chamber to the fluid within the conduit.

2. The head unit according to claim 1 , wherein the head unit is monolithic.

3. The head unit according to claim 1 or 2, wherein at least one conduit is an effluent flow conduit configured to convey an effluent gas flow into the combustion chamber.

4. The head unit according to any preceding claim, wherein at least one conduit is an inject flow conduit configured to convey an inject gas flow.

5. The head unit according to claim 4, wherein at least a portion of the inject flow conduit extends through the head unit in a direction that is substantially parallel to the inner face.

6. The head unit according to claim 4 or 5, comprising a plurality of concentrically arranged inject flow conduits.

7. The head unit according to any preceding claim, wherein the outer face comprises one or more topographical features configured to dissipate heat from the head unit, preferably wherein said topographical features comprise fins, more preferably a substantially hexagonal array of fins.

8. The head unit according to any preceding claim, wherein the head unit comprises a metallic material, preferably aluminium or an alloy thereof.

9. The head unit according to any preceding claim comprising a main body and fixedly connected to a plate, preferably wherein the main body and the plate define therebetween at least a portion of the at least one conduit.

10. The head unit according to any preceding claim, further comprising a coolant line passing through the head unit and configured to convey a coolant to regulate the temperature of the head unit during use.

11. A method of manufacturing a head unit according to any preceding claim by additively manufacturing the head unit as a monolithic component.

12. An abatement system comprising a combustion chamber with a head unit according to any of claims 1 to 9 capping said combustion chamber.

13. A method comprising: meshing a 3D model representation of a head unit according to any of claims 1-9, defining the geometry of the head unit based on specified component characteristics to define an optimised finite element representation of said component; and fabricating said component according to said optimised finite element representation.

14. The method according to claim 12, wherein said meshing comprises meshing with at least one finite element, preferably wherein said meshing comprises fitting said finite elements to fill said 3D model representation.

15. The method according to claim 12 or 13, wherein said specified component characteristics define heat transfer from the inner surface to the surface defining the conduit, and said meshing comprises specifying geometry of the head unit to provide an optimised structure.

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