GB2540552A

GB2540552A - Radiant burner head assembly

Info

Publication number: GB2540552A
Application number: GB1512698.0A
Authority: GB
Inventors: David Stanton Gareth; Francis Kilgarriff Ian; Leslie Bidder John; Richard O'neill Mark
Original assignee: Edwards Ltd
Current assignee: Edwards Ltd
Priority date: 2015-07-20
Filing date: 2015-07-20
Publication date: 2017-01-25
Also published as: GB201512698D0

Abstract

A radiant burner head assembly comprising a housing, a nozzle conduit 100 located within the housing, the nozzle conduit having an inlet aperture and an outlet aperture for conveying an effluent gas, a nozzle conduit scraper 290A housed in a fixed position within the housing and within the nozzle conduit. An actuator is operable to rotate the nozzle conduit within the housing, around the nozzle conduit scraper, to reduce effluent gas stream deposits within the nozzle conduit. The actuator comprises a concentric gear wheel 160 mechanically engaged with the nozzle conduit, the gear wheel engages with an actuating gear wheel (170, fig 2) which is rotated to provide the rotation of the nozzle conduit. The nozzle conduit scraper is preferably a hollow cylindrical element having at least one aperture (300A-C, fig 6) which includes a cutting edge (310A-C, fig 6) for dislodging deposits.

Description

RADIANT BURNER HEAD ASSEMBLY

FIELD OF THE INVENTION

The present invention relates to a radiant burner head assembly and method. BACKGROUND

Radiant burners are known and are typically used for treating an effluent gas stream from a manufacturing processing tool used in, for example, the semiconductor or flat panel display manufacturing industry. During such manufacturing, residual perfluorinated compounds (PFCs) and other compounds exist in the effluent gas stream pumped from the process tool. PFCs are difficult to remove from the effluent gas and their release into the environment is undesirable because they are known to have relatively high greenhouse activity.

Known radiant burners use combustion to remove the PFCs and other compounds from the effluent gas stream, such as that described in EP 0 694 735. Typically, the effluent gas stream is a nitrogen stream containing PFCs and other compounds. A fuel gas is mixed with the effluent gas stream and that gas stream mixture is conveyed into a combustion chamber that is laterally surrounded by the exit surface of a foraminous gas burner. Fuel gas and air are simultaneously supplied to the foraminous burner to affect flameless combustion at the exit surface, with the amount of air passing through the foraminous burner being sufficient to consume not only the fuel gas supply to the burner, but also all the combustibles in the gas stream mixture injected into the combustion chamber.

Although techniques exist for processing the effluent gas stream, they each have their own shortcomings. Accordingly, it is desired to provide an improved technique for processing an effluent gas stream.

SUMMARY

According to a first aspect, there is provided a radiant burner head assembly for coupling with a combustion chamber, comprising: a housing; a nozzle conduit located within the housing, the nozzle conduit having an inlet aperture and an outlet aperture for conveying an effluent gas stream from an inlet assembly coupleable with the inlet aperture to the outlet aperture for delivery of the effluent gas stream to the combustion chamber for treatment therewithin; a nozzle conduit scraper housed in a fixed position within the housing, the nozzle conduit scraper being located within the nozzle conduit; and an actuator operable to rotate the nozzle conduit within the housing, around the nozzle conduit scraper, to reduce effluent gas stream deposits within the nozzle conduit.

The first aspect recognizes that a problem with existing arrangements for cleaning inlet nozzles is that they typically require a discontinuity or dog-leg in the gas path in order to provide a location to position a cleaning actuator which actuates a cleaning spring located within the nozzle. Not only is this existing cleaning arrangement mechanically complicated to provide, but it also suffers from residue deposits accumulating both on the actuator and within the dog-leg void, which can accumulate to prevent the cleaning spring from being actuated.

Accordingly, a radiant burner head assembly may be provided. The assembly may be coupleable or connectable to a combustion chamber. The assembly may comprise a housing or enclosure. A nozzle conduit may be located or retained within the housing. The nozzle conduit may have an inlet aperture and an outlet aperture. The nozzle conduit may convey or pass an effluent gas stream from the inlet aperture to the outlet aperture. The assembly may also comprise a nozzle conduit scraper. The nozzle conduit scraper may be housed or retained in a fixed or static position within the housing. The nozzle conduit scraper may also be at least partially located within the nozzle conduit. The assembly may also comprise an actuator. The actuator may be operable to rotate or turn the nozzle conduit within the housing. The actuator may also rotate or turn the nozzle conduit around the nozzle conduit scraper. The rotation may reduce deposits within the nozzle conduit. In this way, rather than needing to provide an actuating mechanism in order to move a spring within the nozzle conduit, instead the nozzle conduit is itself rotated around the conduit scraper, thereby avoiding the need to provide a discontinuity within the housing and avoiding problems caused by residue deposition on the actuating mechanism. Instead, a continuous gas path can be provided where the nozzle conduit has no discontinuities along its internal surface and instead a straight bore can be provided between the inlet and outlet apertures, with the actuating mechanism located outside the gas path. Furthermore, because the nozzle conduit scraper does not need to be activated axially within the nozzle conduit (instead, the nozzle conduit is rotated around the nozzle conduit scraper), the nozzle conduit scraper may extend along the full length of the nozzle conduit, may be located closer to the nozzle conduit and a greater actuating force can be applied when rotating the nozzle conduit in order to remove effluent gas stream deposits.

In one embodiment, the head assembly comprises the inlet assembly fixed to the housing and wherein the nozzle conduit scraper is connected with the inlet assembly which retains the nozzle conduit scraper in the fixed position within the housing. Accordingly, the inlet assembly may be used to retain the nozzle conduit scraper in the fixed or static position within the housing. This provides a simple mechanical arrangement for locating the nozzle scraper within the nozzle conduit and also facilitates its easy fitting and removal.

In one embodiment, the head assembly comprises a rotatable seal between the inlet assembly and the nozzle conduit. Providing a rotatable seal helps to prevent the escape of effluent gas stream during rotation of the conduit.

In one embodiment, the nozzle conduit scraper is hollow. Accordingly, the effluent gas stream may pass within the nozzle conduit scraper as it travels from the inlet aperture to the outlet aperture.

In one embodiment, the nozzle conduit scraper is cylindrical. Providing a cylindrical nozzle conduit scraper is advantageous, particularly when retained within a cylindrical nozzle conduit.

In one embodiment, the nozzle conduit scraper has a cutting edge for dislodging the effluent gas stream deposits as the nozzle conduit rotates. Accordingly, the nozzle conduit scraper may have a cutting edge dimensioned, adapted or configured to dislodge the deposits when the nozzle conduit rotates. Typically, such a cutting edge may have a knife or chisel configuration.

In one embodiment, the nozzle conduit scraper comprises at least one aperture which defines the cutting edge. Accordingly, an aperture or void may be provided by the nozzle conduit scraper which acts as the cutting edge.

In one embodiment, the cutting edge is shaped to direct the effluent gas stream deposits towards the outlet aperture. Accordingly, the cutting edge may be dimensioned, adapted or configured to urge the deposits towards the outlet aperture as they are dislodged.

In one embodiment, an external diameter of the nozzle conduit scraper corresponds with an internal diameter of the nozzle conduit. Accordingly, a close fit may be provided between the nozzle conduit and the nozzle conduit scraper to ensure maximal removal of deposits.

In one embodiment, the inlet assembly comprises a lance extending into the nozzle conduit for delivery of a gas stream. Accordingly, a typically coaxially co-located lance may be provided by the inlet assembly which extends into the nozzle conduit. Hence, the provision of the nozzle scraper is also possible in combination with a lance which provides additional gas flows.

In one embodiment, the actuator engages with the nozzle conduit within a void of the housing and the actuator comprises a conduit operable to convey a purge gas to the void. Accordingly, the actuator may engage, interact with or drive the nozzle conduit within a void within the housing. The actuator may have a conduit which conveys a purge gas to the void to provide a positive pressure to avoid the influx of effluent gas stream into the void and to reduce the likelihood of deposits within the void.

In one embodiment, the actuator engages with a plurality of the nozzle conduits, each having a corresponding nozzle conduit scraper housed therewithin, the actuator being operable to simultaneously rotate each nozzle conduit around the corresponding nozzle conduit scraper to reduce effluent gas stream deposits concurrently within each nozzle conduit. Accordingly, the single actuator may engage with more than one nozzle conduit in order to rotate each of them together around a corresponding nozzle conduit scraper. Hence, a single actuator may be utilized to clean multiple conduits.

In one embodiment, the head assembly comprises a scraper located outside the nozzle conduit, proximate the outlet aperture, the actuator being operable to rotate the scraper to reduce effluent gas stream deposits on the outlet aperture. Accordingly, a further or additional scraper may be provided outside of the nozzle conduit but near the outlet aperture. The actuator may also rotate this additional scraper in order to reduce deposits on the outlet aperture.

According to a second aspect, there is provided a method, comprising: providing a housing; locating a nozzle conduit within the housing, the nozzle conduit having an inlet aperture and an outlet aperture for conveying an effluent gas stream from an inlet assembly coupleable with the inlet aperture to the outlet aperture for delivery of the effluent gas stream to a combustion chamber for treatment therewithin; housing a nozzle conduit scraper in a fixed position within the housing, the nozzle conduit scraper being located within the nozzle conduit; and rotating the nozzle conduit within the housing, around the nozzle conduit scraper, with an actuator to reduce effluent gas stream deposits within the nozzle conduit.

In one embodiment, the method comprises fixing the inlet assembly to the housing and connecting the nozzle conduit scraper with the inlet assembly which retains the nozzle conduit scraper in the fixed position within the housing.

In one embodiment, the method comprises providing a rotatable seal between the inlet assembly and the nozzle conduit.

In one embodiment, the nozzle conduit scraper is hollow.

In one embodiment, the nozzle conduit scraper is cylindrical.

In one embodiment, the nozzle conduit scraper has a cutting edge for dislodging the effluent gas stream deposits as the nozzle conduit rotates.

In one embodiment, the nozzle conduit scraper comprises at least one aperture which defines the cutting edge.

In one embodiment, the method comprises shaping the cutting edge to direct the effluent gas stream deposits towards the outlet aperture.

In one embodiment, an external diameter of the nozzle conduit scraper corresponds with an internal diameter of the nozzle conduit.

In one embodiment, the inlet assembly comprises a lance extending into the nozzle conduit for delivery of a gas stream.

In one embodiment, the method comprises engaging the actuator with the nozzle conduit within a void of the housing and conveying a purge gas to the void using a conduit provided by the actuator.

In one embodiment, the method comprises engaging the actuator with a plurality of the nozzle conduits, each having a corresponding nozzle conduit scraper housed therewithin, and simultaneously rotating each nozzle conduit around the corresponding nozzle conduit scraper to reduce effluent gas stream deposits concurrently within each nozzle conduit.

In one embodiment, the method comprises providing a scraper located outside the nozzle conduit, proximate the outlet aperture, and rotating the scraper to reduce effluent gas stream deposits on the outlet aperture.

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

Where an apparatus feature is described as being operable to provide a function, it will be appreciated that this includes an apparatus feature which provides that function or which is adapted or configured to provide that function.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described further, with reference to the accompanying drawings, in which:

Figure 1 illustrates a head assembly housing for a radiant burner according to one embodiment;

Figure 2 illustrates a cleaning mechanism according to one embodiment; Figure 3 illustrates the internal configuration of the actuating gear wheel and actuation shaft in more detail;

Figure 4 illustrates an inlet assembly according to one embodiment;

Figure 5 illustrates the outlet portion according to one embodiment having a lance;

Figure 6 illustrates a nozzle scraper according to embodiments; and Figure 7 illustrates rotating the nozzle conduit around the nozzle scraper.

DESCRIPTION OF THE EMBODIMENTS

Before discussing the embodiments in any more detail, first an overview will be provided. Embodiments provide a radiant burner head assembly with cleanable inlet nozzles. The inlet nozzles, which provide the effluent gas stream to be treated to the combustion chamber of the radiant burner, are rotatable around a scraper which is fixed inside each of the rotatable inlet nozzles. The rotation of each inlet nozzle around its scraper causes any residues deposited within the inlet nozzle to be removed in order to prevent build-up of such residues within the inlet nozzle. Rotating the inlet nozzles around the scraper enables the inlet nozzle to have a straight bore with no discontinuities, which helps to reduce the build-up of residues in the first place. Also, providing a concentric scraper within the inlet nozzle enables the scraper to be positioned against the inner surface of the inlet nozzle, and so is effective in removing accumulated deposits. Furthermore, given that the inlet nozzle is rotated around the fixed scraper, the degree of force that can be applied is greater than existing arrangements, thereby removing particularly stubborn residues. A single actuator can be utilized to concurrently rotate multiple inlet nozzles, which reduces part count and simplifies the cleaning process. Also, the same actuator can be utilized to also operate a further scraper which is provided within the combustion chamber and which scrapes residues from the outlet apertures of the inlet nozzles. Furthermore, rotating the inlet nozzle enables the actuation mechanism to be placed outside the inlet nozzle gas flow.

Housing

Figure 1 illustrates a head assembly housing, generally 10, for a radiant burner according to one embodiment. The housing 10 comprises two main sets of components. The first is a metallic (typically steel) casing 20, which provides the necessary mechanical strength and configuration for coupling with the remainder of the radiant burner (not shown). The second is an insulator 30 which is provided within the casing 20 and which helps to reduce heat loss from within a combustion chamber (not shown) of the radiant burner, as well as to protect the casing 20 and items coupled thereto from heat generated within the combustion chamber.

Provided within the casing 20 and the insulator 30 is a series of inlet assembly apertures 40. The embodiment shown in Figure 1 has four inlet assembly apertures 40. However, it will be appreciated that any number of inlet assembly apertures 40 may be provided. An actuator aperture 50 is also provided. In addition, a sight glass 70 and a feed 75 for a pilot may be provided.

Rotatable Nozzle Conduit. Outlet Aperture Scraper and Actuation Mechanism Figure 2 illustrates a cleaning mechanism according to one embodiment. In this embodiment, four nozzle conduits 100 are provided, each of which is received within an inlet assembly aperture 40. The nozzle conduits 100 are cylindrical tubes having a bore extending from an inlet aperture 110 to an outlet aperture 120. In this embodiment, the inlet aperture 110 and outlet aperture 120 share a common axis so that they are coaxially located. Hence, the nozzle conduit 100 has no discontinuities on its internal surface.

The nozzle conduit 100 has an annular flange 130 (or shoulder) which abuts against an external surface 25 of the casing 20. The nozzle conduit 100 extends through the inlet assembly aperture 40, through both the casing 20 and the insulator 30. The outlet aperture 120 is provided generally flush with the surface of the insulator 30 within the combustion chamber.

The casing 20 and the insulator 30 together define a void (not shown) within which an actuating mechanism 140 is provided. The actuating mechanism 140 operates to rotate each nozzle conduit within the housing 10. The actuating mechanism 140 also operates to rotate an outlet aperture scraper 150 located within the combustion chamber, adjacent the outlet apertures 120.

Each of the nozzle conduits 100 is provided with a concentrically located gear wheel 160. Each gear wheel 160 mechanically engages with its nozzle conduit 100. Accordingly, rotation of the gearwheel 160 causes the nozzle conduit 100 to rotate. An actuating gear wheel 170 meshes with each gear wheel 160 and is located on an actuation shaft 180. The actuating gearwheel 170 is mechanically fixed to the actuation shaft 180 for rotation therewith. The actuation shaft 180 is connected to a pneumatic motor 190 which operates to rotate the actuation shaft 180. Accordingly, when the pneumatic motor 190 is activated, this causes rotation of the actuation shaft 180 and rotates the actuation gear wheel 170. The meshing between the actuation gearwheel 170 and each gear wheel 160 causes those gear wheels 160 to rotate, thereby rotating each of the nozzle conduits 100 simultaneously within the inlet assembly apertures 140.

The actuation shaft 180 extends into the combustion chamber and the outlet aperture scraper 150 is attached thereto. Accordingly, rotation of the actuation shaft 180 also causes the outlet aperture scraper 150 to rotate within the combustion chamber, passing in proximity to each outlet aperture 120. Rotation of the nozzle conduits 100 and the outlet aperture scraper 150 causes residue deposits to be removed.

Purge Gas Delivery

Figure 3 illustrates the internal configuration of the actuating gearwheel 170 and actuation shaft 180 in more detail. As can be seen, an internal conduit configuration 185 is used to convey a purge gas from outside of the casing 20 to the void within the housing 10 which houses the actuation mechanism 140. This helps to provide a positive pressure within the void to prevent backflow of gases into the void, and so reduces the likelihood of residues being deposited within the void.

Inlet Assembly

Figure 4 illustrates an inlet assembly, generally 200, according to one embodiment. The inlet assembly 200 comprises an inlet aperture 210 which receives the effluent gas stream from the processing tool, which is conveyed through the inlet assembly 200 to an outlet aperture 220. In this embodiment, the inlet assembly 200 is inclined so that the inlet aperture 210 is off-axis with respect to the outlet aperture 220, in order to provide for easier mechanical coupling to the inlet aperture 210.

The outlet aperture 220 is surrounded by an annular flange 230. The annular flange 230 is received over the annular flange 130 of the nozzle conduit 100.

The inlet assembly 200 comprises an outlet portion 240 which contains a lofted transition which changes the diameter from that provided by the inlet aperture 210 to that of the outlet aperture 220. In this example, the diameter reduces by way of a conical section.

Lance

Figure 5 shows the outlet portion 240A according to one embodiment having a lance 250. As can be seen, the lance 250 extends coaxially within the outlet aperture 220 and is fed by a lance inlet 260. The lance 250 extends through the inlet aperture 110 and into the nozzle conduit 100 for delivery of a gas provided via the lance inlet 260.

Scraper

Figure 6 shows the provision of a nozzle scraper 290A - 290C according to embodiments. Three different embodiments of nozzles scraper 290A - 290C are shown. The nozzle scraper 290A - 290C is retained by a mechanical fixing 270 on the outlet portion 240A. This holds the nozzle scraper 290A -290C within the inlet aperture 110, extending along the axial length of the nozzle conduit 100, in a coaxially and concentrically aligned position with respect to the outlet aperture 220. Hence, with the annular flange 230 fixed using fixings passing through the fixing aperture 235 into the casing 20, and with the nozzle scraper 290A - 290C fixed to the outlet portion 240A, the nozzle scraper 290A - 290C is retained in a fixed position on the housing 10.

As mentioned above, the outlet portion 240A covers the annular flange 130, the exposed surface of which bears against the O-ring 280 to provide a gas seal.

As can be seen in Figure 7, when the nozzle conduit 100 rotates, the fixed nozzle scraper 290A - 290C remains in place and so the nozzle conduit 100 rotates around the nozzle scraper 290A - 290C. Apertures 300A to 300C within the nozzle scraper 290A - 290C receive any residue deposits which protrude from the inner wall of the nozzle conduit 100 and are dislodged by the cutting edges 310A to 310C.

As can be seen in Figure 6, the arrangement of the scraper aperture 300C and the cutting edge 310C is such that as the nozzle conduit rotates, the debris is urged axially along the nozzle scraper 290C towards the combustion chamber.

Hence, it can be seen that embodiments are provided for cleaning the inlet of a combustion device. This technique fixes the cleaning splines and moves the nozzle around the splines by means of a pneumatic rotary actuator located in the centre of the head. This allows a straight gas path into the system while allowing for the removal of material within the nozzle. This enables a straight through nozzle to be provided which allows an unrestricted inlet path.

Embodiments bury the drive cogs for the rotation within the purged ceramic region of the head assembly. The purge gas provided within the actuation shaft 180 is typically nitrogen which passes from the shaft housing through the shaft and into the gear cavity of the ceramic insulator. This not only protects the gear assembly, but also provides positive pressure to stop the effluent gas stream coming back up the shaft housing.

Embodiments provide for a fixed scraper with a rotating nozzle, a pneumatically actuated cleaning mechanism, plus rotary actuation of the nozzle, together with a rotating scraper on the base of the nozzle driven off a single actuator. This provides for a clear gas path, since the cleaning mechanism can be kept on the opposite side of the nozzle from the gas path, more force can be applied for cleaning and the actuators can be of a significantly more solid construction, as they are no longer required to allow gas to pass.

In embodiments, the rotary actuator has a geared cog attached to its spline. This cog engages a similar geared cog on the nozzle, so that movement of the actuator causes the nozzles to move. The degree of movement depends on the gearing. For example, a 120° movement on the rotary actuator may move the nozzle more than 360°, or at least past one of the cleaning splines, or sufficient to pass a fixed cleaning device in order to remove deposits from the nozzle. As the nozzle is driven past the cleaning device, this action scrapes the surface of the nozzle, ensuring a clear gas path is maintained. In addition, the cleaning mechanism can be directed downwards. In one embodiment, a rotating mechanism on the underside of the ceramic is provided which removes any deposition on the surface of the ceramic (i.e., a head scraper).

By decoupling the cleaning device from the source of movement, more energy and force can be applied to the cleaning action. By changing the way that the cleaning of the inlet occurs, a wider range of cleaning devices can be used which includes: cleaning splines, a semi-circular cleaning cutter, and/or a bladed cleaner. All of these could be fixed, or can be used in concert with a downwards-acting actuator. By increasing the efficiency of the cleaning, the mean time between services can be increased, and the range of effluent gas streams that may be treated can also be increased to include those which produce inconvenient residues.

Introduction of fuel/oxygen injects or lances is made possible by means of a concentric inject or lance. The lance and associated pipework does not restrict the gas flow as they sit in the widest part of the outlet portion 240. The transition within the outlet portion 240 is smooth.

The nozzle scraper 290A - 290C removes powder build-up from the internal diameter of the nozzle conduit 100. The nozzle scraper 290A is a slotted scraper with sharp edges to remove residue build-up. The nozzle scraper 290B is a drilled scraper with increased scraping faces. The nozzle scraper 290C is a helix scraper; rotational force will expand and contract the scraper 290C, resulting in any build-up falling away.

By minimizing deviations in the pipework, the gas flow path is made more streamlined which, in turn, reduces the amount of powder which will build up. Using a larger diameter inlet pipe allows more standard components to be used. Fusing flexible bellows on the inlet assembly 200 eliminates the thermal break created by the use of an O-ring, increasing the conductivity of the bellows components and increasing the overall thermal profile of the inlet, leading to better power handling and effectiveness.

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

Reference signs

Housing 10 Casing 20 External surface 25 Insulator 30

Inlet assembly aperture 40 Actuator aperture 50 Sight glass 70 Feed 75

Nozzle conduit 100

Inlet aperture 110

Outlet aperture 120

Annular flange 130

Actuating mechanism 140

Outlet aperture scraper 150

Gear wheel 160

Actuating gearwheel 170

Actuation shaft 180

Internal conduit configuration 185

Pneumatic motor 190

Inlet assembly 200

Inlet aperture 210

Outlet aperture 220

Annular flange 230

Outlet portion 240; 240A

Lance 250

Lance inlet 260 O ring 280

Nozzle scraper 290A-290C Scraper aperture 300A-300C Cutting edge 310A-310C

Claims

1. A radiant burner head assembly for coupling with a combustion chamber, comprising: a housing; a nozzle conduit located within said housing, said nozzle conduit having an inlet aperture and an outlet aperture for conveying an effluent gas stream from an inlet assembly coupleable with said inlet aperture to said outlet aperture for delivery of said effluent gas stream to said combustion chamber for treatment therewithin; a nozzle conduit scraper housed in a fixed position within said housing, said nozzle conduit scraper being located within said nozzle conduit; and an actuator operable to rotate said nozzle conduit within said housing, around said nozzle conduit scraper, to reduce effluent gas stream deposits within said nozzle conduit.

2. The assembly of claim 1, comprising said inlet assembly fixed to said housing and wherein said nozzle conduit scraper is connected with said inlet assembly which retains said nozzle conduit scraper in said fixed position within said housing.

3. The assembly of claim 1 or 2, comprising a rotatable seal between said inlet assembly and said nozzle conduit.

4. The assembly of any preceding claim, wherein said nozzle conduit scraper is hollow.

5. The assembly of any preceding claim, wherein said nozzle conduit scraper is cylindrical.

6. The assembly of any preceding claim, wherein said nozzle conduit scraper has a cutting edge for dislodging said effluent gas stream deposits as said nozzle conduit rotates.

7. The assembly of claim 6, wherein said nozzle conduit scraper comprises at least one aperture which defines said cutting edge.

8. The assembly of claim 6 or 7, wherein said cutting edge is shaped to direct said effluent gas stream deposits towards said outlet aperture.

9. The assembly of any preceding claim, wherein an external diameter of said nozzle conduit scraper corresponds with an internal diameter of said nozzle conduit.

10. The assembly of any preceding claim, wherein said inlet assembly comprises a lance extending into said nozzle conduit for delivery of a gas stream.

11. The assembly of any preceding claim, wherein said actuator engages with said nozzle conduit within a void of said housing and said actuator comprises a conduit operable to convey a purge gas to said void.

12. The assembly of any preceding claim, wherein said actuator engages with a plurality of said nozzle conduits, each having a corresponding nozzle conduit scraper housed therewithin, said actuator being operable to simultaneously rotate each nozzle conduit around said corresponding nozzle conduit scraper to reduce effluent gas stream deposits concurrently within each nozzle conduit.

13. The assembly of any preceding claim, comprising a scraper located outside said nozzle conduit, proximate said outlet aperture, said actuator being operable to rotate said scraper to reduce effluent gas stream deposits on said outlet aperture.

14. A method, comprising: providing a housing; locating a nozzle conduit within said housing, said nozzle conduit having an inlet aperture and an outlet aperture for conveying an effluent gas stream from an inlet assembly coupleable with said inlet aperture to said outlet aperture for delivery of said effluent gas stream to a combustion chamber for treatment therewithin; housing a nozzle conduit scraper in a fixed position within said housing, said nozzle conduit scraper being located within said nozzle conduit; and rotating said nozzle conduit within said housing, around said nozzle conduit scraper, with an actuator to reduce effluent gas stream deposits within said nozzle conduit.

15. A radiant burner head assembly as hereinbefore described with reference to the accompanying drawings.

16. A method as hereinbefore described with reference to the accompanying drawings.