Field of the Invention

[0001 ] The present invention generally relates to a burner for melting a substance to create a homogenous mixture for X-ray fluorescence spectroscopy.

Background Art

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0003] X-ray fluorescence spectroscopy (XRF) is a typically utilised analytical technique for the determination of bulk elemental composition. In order for a sample matter to be analysed by XRF, one method of sample preparation involves the sample matter being crushed into powdered form in order for the sample matter to be fused (melted) into a flux prior to the formation of a resultant glass bead or fusion bead. The fusion bead, typically in the shape of a disk, produces a substantially homogeneous sample, thereby overcoming known analysis difficulties of particle size variation and minera!ogical effects.

[0004] The fusion process involves the melting of the sample in conjunction with an x-ray flux in a high temperature furnace at a temperature range typically between 1050°C and 12GG°C. Additionally, the melted flux is required to be agitated during the fusion process to ensure homogeneous distribution of the sample matter throughout the flux. As such, manual handling of the fusion process exposes a user to a range of dangerous conditions.

[0005] High temperature gas burners are extensively utilised to melt the sample for XRF analysis. Gas burners typically utilise combustion enrichment through the use of high purity oxygen gas. The oxygen additive is very costly and adds complexity to an industrial sample preparation machine. It is therefore advantageous economically and from an engineering standpoint to remove the need for oxygen enrichment from a system ail together. [0006] The development of a high temperature gas only burner will provide cost savings and mechanical simplicity.

[0007] It is against this background that the present invention has been developed.

[0008] Reference to cited material or information contained in the text should not be understood as a concession that the material or information was part of the common general knowledge or was known in Australia or any other country.

[0009] It is an object of this invention to provide a burner which ameliorates, mitigates or overcomes, at least one disadvantage of the prior art, or which will at least provide the public with a practical choice

[0010] In one embodiment, the present invention seeks to provide a burner for producing a flame including:

a tube;

a fan arranged to provide atmospheric gases including oxygen into the tube; a fuel gas inlet arranged to provide fuel gas into the tube; and

a mixing device upstream of the fan and fuel gas inlet and a burner head upstream of the mixing device;

wherein the profile of the burner head is arranged to direct the mixed atmospheric gases and fuel gas to a common region in an upper cavity in the burner head for combustion

[0011 ] Directing mixed atmospheric gases and fuel gas to a common region within the burner head allows focused heat to be generated from the common region. This allows temperatures to be reached that would typically require a separate purified oxygen source.

[0012] Preferably, the upper cavity of the burner head includes an internal wall arranged to restrict the mixed atmospheric gases and fuel gas from escaping from within the upper cavity

[0013] By restricting the escape of gases, the flame from ignited gases remains localised allowing more head and stopping the flame from spreading. [0014] Preferably, the upper cavity of the burner head includes a base with a spherical cup profile.

[0015] Preferably, a plurality of passageways open into the base of the upper cavity of the burner head, and wherein the plurality of passageways are arranged to direct the mixed atmospheric gas and fuel gas into the upper cavity.

[0016] Preferably, the passageways are aligned along the normal to the base.

[0017] The passageways being perpendicular to the curve of the spherical cup causes the passageways to all direct to the common region in the upper cavity.

[0018] Preferably, the burner head includes a lower cavity arranged to attach to the tube and supply the mixed atmospheric gas and fuel gas to the upper cavity.

[0019] This allows the burner head to connect to the tube of the burner.

[0020] Preferably, the plurality of passageways open into the lower cavity.

[0021 ] This provides a fuel path from the lower cavity to the upper cavity.

[0022] Preferably, the lower cavity includes a lower spherical cup ceiling.

[0023] Preferably, the tube includes a curved tube section, a coupling reducer section and a straight tube section.

[0024] In a further embodiment, the present invention seeks to provide a burner head including:

an upper cavity, the upper cavity defined by an opening;

a side wall; and

a base;

wherein a plurality of apertures in the base are arranged to direct gas to single region in the upper cavity.

[0025] The burner head directing the gas to a single common region allows for focused heat to be generated from the common region. This allows temperatures to be reached that would typically require a separate purified oxygen source. [0026] Preferably, each of the plurality of apertures are attached to a separate passageway, wherein each of the separate passageways are directed towards the single common region in the upper cavity.

[0027] Preferably, the plurality of apertures are arranged in a star profile.

[0028] Preferably, the base is profiled as a spherical cup.

[0029] Preferably, the burner includes a lower cavity arranged to attach to a gas source.

[0030] Preferably, the lower cavity includes an opening, a lower side wall and a ceiling.

[0031 ] Preferably, each of the separate passageways opens into the lower cavity at the ceiling.

[0032] Preferably, the ceiling is a spherical cup.

[0033] In a further embodiment, the present invention seeks to provide a burner for producing a flame having a temperature greater than 500°C, the burner comprising: a passage having a flow means at a first end, the flow means inducing the flow of a first gas through the passage;

an inlet for delivering fuel into the passage;

a nozzle at a second end of the passage, the nozzle having a mixing means at an end of the nozzle distal from the passage, the mixing means being adapted to mix the first gas and the fuel together to form a mixed gas;

a burner head in fluid communication with the mixing means, the burner head being configured to direct the mixed gas to a central region of a combustion chamber whereupon the mixed gas is ignited to produce the flame.

[0034] Preferably the flow means is a fan.

[0035] Preferably the first gas is atmospheric gas. The fuel may be in the form of a gas, and includes gas having a fuel mist suspended therein.

[0036] Preferably the inlet injects the fuel gas into the passage, and may atomise the gas as it passes through the inlet. [0037] The mixing means may be in the form of a swirl device or other mixing device.

[0038] In a further embodiment, the present invention seeks to provide a burner for producing a flame having a temperature greater than 500°C, the burner comprising a passage and a burner head, the passage delivers a mixed gas formed from a fuel gas and atmospheric gas to the burner head, the mixed gas passes through the burner head which delivers the mixed gas to a central region of a combustion chamber whereafter the mixed gas is ignited to produce the flame.

[0039] Preferably the burner further comprises a flow means to induce flow through the passage.

[0040] Preferably the burner further comprises a mixing means to mix the fuel gas and atmospheric gas.

[0041 ] Preferably the burner further comprises a nozzle for accelerating the flow of the mixed gas prior to the burner head.

[0042] Preferably the flame has a temperature greater than 650°C.

Brief Description of the Drawings

[0043] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

Figure 1 is a side view of a burner according to a first embodiment of the present invention;

Figure 2 is an exploded view of the burner of Figure 1 ;

Figure 3 is a rear view of the burner of Figure 1 ;

Figure 4 is a perspective view of a burner bead for use in the burner of Figure 1 ; Figure 5 is a cross sectional view of the burner head of Figure 4;

Figure 8 is a top down view of the burner head of Figure 4;

Figure 7 is a side view of the burner head of Figure 4; and

Figure 8 is a bottom up view of the burner head of Figure 4.

[0044] In the drawings like structures are referred to by like numerals throughout the views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the present invention.

Description of Embodiments

[0045] It is known that melting of sample matter in conjunction with an x-ray flux at a high temperature to create molten matter and pouring the molten matter into moulds is a suitable method for producing fusion beads. This is described in detail in Australian Patent Application No. 2012241172, the contents of which are included in the subject matter of this application by way of reference. Commonly, a burner is used in this process whereby the burner requires a high purity oxygen gas and a fuel gas to reach the required flame temperature.

[0046] Broadly, embodiments of the present invention relate to a burner 10 including a burner head 12 which is profiled to produce a flame of 65Q°C or higher. This is achieved by mixing the atmospheric, oxygen containing gases with a fuel gas and directing the mixed gas through the burner head 12 to a common region according to the geometry of components of the burner head 12.

[0047] Referring to Figures 1 to 8, the invention according to the first embodiment is in the form of a burner 10 with burner head 12. The burner 10 includes a fan 28 at its base that draws atmospheric gas/air including oxygen into the body of the burner to be supplied to the burner head 12. A curved tube section 24 having one end connected to the fan 28, whereby the tube section 28 receives the atmospheric gas blown by the fan 28. Adjacent the end of the curved tube section 24 which is distal the fan 28, the tube section includes a fuel gas inlet 20 arranged to inject fuel gas into the lumen of the curved tube section 24. A coupling reducer section 22 is connected to the end of the curved tube section 24 distal the fan 28. [0048] The coupling reducer section 22 receives the atmospheric gas blown from the fan 28 and the fuel gas injected through the fuel gas inlet 20. The lumen of the coupling reducer section 22 distal the curved tube section 24 has a smaller diameter than the lumen of the coupling reducer section 22 proximal the curved tube section 24. The reduced diameter of the lumen of the coupling reducer section 22 distal the curved tube section 24 increases the velocity of the gas at the reduced diameter section and reduces the gases pressure. This in turn causes an increase in the flame temperature.

[0049] The skilled addressee will recognize that a straight tube section can be used in place of the coupling reducer section 22 and still fail within the scope of the present invention.

[0050] A swirl device 16 is attached to the end of the coupling reducer section 22 distal the curved tube section 24 The swirl device 16 is arranged to redirect gases passing therethrough, causing the gases to mix. In this embodiment the swirl device 16 is a swirl flap made up of arms 17. The skilled addressee will recognize that alternative mixing/swirl devices can be used to mix the atmospheric gas and the fuel gas and that these alternatives fall within the scope of the present invention. The distance between the swirl device 16 and the fuel gas inlet 20 must be sufficient to allow the fuel gas to mix with atmospheric oxygen before combustion, as would be understood by the skilled addressee.

[0051 ] A straight tube section 18 having a bore with a uniform internal diameter, is connected to the coupling reducer section 22 over the swirl device 16 so as to receive the gases that mix as they pass through the swirl device. An O-ring 15 seals the straight tube section 18 to the coupling reducer section 22. A burner head 12 is attached to the end of straight tube section 18 distal the coupling reducer section 22 to form an end of the burner 10. The profile of the burner head 12 is such that the mixed gas passing through the burner head 12 is focused towards a single region at a combustion area to focus and increase the temperature of combustion. The profile of the burner head 12 that enables the focusing of the mixed gases is explored below.

[0052] With specific reference to Figures 4 to 8, the burner head 12 is shown. Burner head 12 includes a base face 42 that is arranged to engage with and attach to the straight tube section 18. Burner 12 also includes external side faces 32 that extend the burner head away from the straight tube section 18. In one embodiment, the external side faces 32 join together to form a hexagonal prism profile. The skilled addressee will recognize that the hexagonal prism profile can be altered and still stay within the scope of the present invention. The hexagonal head provides an easily engageab!e interface for manipulation of the burner head 12 by a tool.

[0053] The burner head 12 includes an upper cavity 35 that defines a combustion space where the mixed fuel gas and atmospheric gases are ignited. The upper cavity 35 is defined by an open face 33, an upper cylindrical side wall 34 and upper spherical cup base 36. The cylindrical side wall acts as a cowl to assist focusing of the mixed fuel gas and atmospheric gases in the upper cavity 35 for combustion. The cylindrical side wall restricts the ability of mixed fuel gas and atmospheric gases from escaping out the open face 33 from the upper cavity 35 prior to combustion.

[0054] Upper spherical cup base 36 provides a concave base, with respect to the upper cavity 35, and includes a plurality of supply gas apertures 38 arranged to deliver mixed fuel gas and atmospheric gas into the upper cavity 35 from the straight tube section 18. Alternatively there is provided a fiat based cavity wherein the exit holes are configured/angled to direct the gas/air flow to a central region.

[0055] A lower cavity 43 extends into the burner head 12 from the base face 42. The lower cavity 43 is defined by base face 42, a lower cylindrical side wail 45 and lower spherical cup ceiling 41. The lower cylindrical side wail 45 and spherical cup ceiling 41 are arranged to attach to the straight tube section 18 and provide mixed fuel gas and atmospheric gas into the upper cavity 35. Spherical cup ceiling 41 includes a plurality of passageways 40. Each of the plurality of passageways 40 open into the lower cavity 43 and connect to a corresponding supply gas apertures 38.

[0056] In one embodiment the spherical cup ceiling 41 has a curvature that matches the curvature of the upper spherical cap base 36. In other embodiments the underside has a different shape to the top section.

[0057] In one embodiment, the straight section 18 is welded to the burner head 12 at one end, while the other end of the straight section 18 is adapted to be screwed into the coupling reducer section 22 to fix the burner head 12 in place. Alternative connection means can be used to connect the burner head 12 to the straight tube section 18. [0058] Each of the plurality of passageways 40 extend into the supply gas apertures 38 with an alignment along the normal to the curvature of the upper spherical cup base 36. This alignment of each of the plurality of passageways directs mixed fuel gas and atmospheric gas from the straight tube section through each of the plurality of passageways towards a common centre within the upper cavity 35. This creates a focus region in the upper cavity 35 to which is directed the mixed gas resulting in an increase in the temperature generated during combustion.

[0059] In one embodiment of the present invention, the supply gas apertures are arranged on the upper spherical cup base 36 in a star pattern.

[0060] A method of using the burner 10 and burner head 12 of the present invention will now be described with reference to the drawings.

[0061 ] A fuel gas supply is connected to the fuel gas inlet 20 and fuel gas is injected into the lumen of the burner 10 at curved tube section 24. The fan 28 blows atmospheric gases including oxygen info the base of the curved tube section 24. The atmospheric gases and the fuel gas intermingle and pass into the coupling reducer section 22.

[0062] The atmospheric gases and fuel gas then pass through the swirl device 16 and become more uniformly mixed. From the swirl device 16, the more uniformly mixed atmospheric gases and fuel gas pass through the straight tube section into lower cavity 43 of the burner head 12. The more uniformly mixed atmospheric gases and fuel gas are forced through passageways 40 and supply gas apertures 38 into upper cavity 35.

[0063] As the passageways 40 are aligned along the normal to the curvature of the upper spherical cup 36 the mixed atmospheric gases and fuel gas are directed to a common region in the upper cavity 35. The upper cylindrical side wail 34 also assist in keeping gases passing into the upper cavity 35 from dispersing prior to ignition. The mixed atmospheric gases and fuel gas are ignited in the upper cavity 35 to form a flame.

[0064] Using the burner 10, the present embodiment enables a flame of 650°C or higher without needing a high purity oxygen gas. [0065] The burner may be a standalone apparatus or may be formed as part of another piece of equipment.

Alterations and Modifications to the Embodiments

[0066] Various additions, modifications and substitutions regarding design and construction can be made without departing from the spirit and scope of the invention.

[0067] Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention. The present invention is not to be limited in scope by any of the specific embodiments described herein. These embodiments are intended for the purpose of exemplification only. Functionally equivalent products, formulations and methods are dearly within the scope of the invention as described herein.

[0068] Reference to positional descriptions, such as lower and upper, are to be taken in context of the embodiments depicted in the figures, and are not to be taken as limiting the invention to the literal interpretation of the term but rather as would be understood by the skilled addressee.

[0069] Throughout this specification, unless the context requires otherwise, the word “comprise” or variations such as“comprises” or“comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.