CN114424051A

CN114424051A - Laser induced spectroscopy system and process

Info

Publication number: CN114424051A
Application number: CN202080063209.6A
Authority: CN
Inventors: R·J·莫纳汉; J·J·诺瓦克斯基; L·E·卡拉汉; G·K·乌班纳克
Original assignee: Shenke Technology Co ltd
Current assignee: Shenke Technology Co ltd
Priority date: 2019-09-05
Filing date: 2020-08-21
Publication date: 2022-04-29
Also published as: EP4025900A4; WO2021045911A1; EP4025900A1; KR20220053654A

Abstract

A dedicated linkage assembly for a laser induced breakdown spectroscopy ("LIBS") system is provided. The linkage assembly may facilitate attachment of the laser housing of the LIBS system to an existing sample supply chamber, such as a volume or weight feeder. Typically, the linkage assembly may include a dedicated purge head and inert gas assembly that facilitate attachment of the laser housing and may enhance the functionality of the LIBS system.

Description

Laser induced spectroscopy system and process

RELATED APPLICATIONS

The present application claims the benefit of priority from U.S. patent application serial No. 16/561,638 entitled LASER-INDUCED SPECTROSCOPY system and PROCESS (LASER-INDUCED SPECTROSCOPY SYSTEM AND processes), filed 2019, 9, 5, incorporated herein by reference in its entirety.

Background

1. Field of the invention

The present invention relates generally to laser induced breakdown spectroscopy ("LIBS") systems. More particularly, the present invention relates generally to linkage assemblies that may be used in LIBS systems.

2. Description of the related Art

Laser induced breakdown spectroscopy ("LIBS") is a technique that uses pulsed laser energy to break down small amounts of material. More specifically, a laser is used to ionize a material and form a local plasma, which is a continuum of light frequencies radiated from the material. These light frequencies are collected and analyzed to determine the chemical composition of the ablated material. With these data, various information specific to the sample material, such as moisture content, ash content, calorific value, and ash melting temperature, can be easily output.

Despite the use and advancement of LIBS technology, it may be difficult to incorporate LIBS systems into existing feed systems. Therefore, there remains a need for new and efficient systems and methods for interfacing LIBS systems with existing systems and structures.

SUMMARY

One or more embodiments of the present invention generally relate to a linkage assembly for a laser induced breakdown spectroscopy system. Typically, the linkage assembly includes a purge head comprising: (a) a base for connecting the purge head to the linkage assembly; (b) a protrusion protruding from the base for extending at least partially into the sample supply chamber, the protrusion comprising a tapered front face and a slot opening positioned between the base and the front face; and (c) a perforation extending through the base and the protrusion, wherein the perforation is configured to allow the laser light to pass through and contact the sample.

One or more embodiments of the present invention generally relate to a system for laser induced breakdown spectroscopy. In general, a laser induced breakdown spectroscopy system includes: (a) a laser housing comprising a laser source and a spectrometer; and (b) a linkage assembly for connecting the laser housing to the sample supply chamber. Furthermore, the link assembly comprises a purge head comprising: (i) a base for connecting the purge head to the linkage assembly; (ii) a protrusion protruding from the base for extending at least partially into the sample supply chamber, the protrusion comprising a tapered front face and a slot opening positioned between the base and the front face; and (iii) a perforation extending through the base and the protrusion, wherein the perforation is configured to allow the laser to pass through and contact the sample.

One or more embodiments of the invention generally relate to a method for operating a laser induced breakdown spectroscopy system. Generally, the method comprises: (a) providing a laser housing including a laser source and a spectrometer, the spectrometer connected to a sample supply chamber via a linkage assembly; and (b) contacting the sample with the laser when at least a portion of the sample contacts the tapered front face of the purge head. Furthermore, the link assembly comprises a purge head comprising: (i) a base for connecting the purge head to the linkage assembly; (ii) a protrusion protruding from the base for extending at least partially into the sample supply chamber, the protrusion comprising a tapered front face and a slot opening positioned between the base and the front face; and (iii) a perforation extending through the base and the protrusion, wherein the perforation is configured to allow the laser to pass through and contact the sample.

One or more embodiments of the present invention generally relate to a linkage assembly for a laser induced breakdown spectroscopy system. Generally, the connecting rod assembly includes an inert gas flange assembly including: (a) an inert gas flange comprising an inert gas inlet configured to transfer an inert gas into the inert gas flange; and (b) a removable lens housing comprising a first lens and a second lens. A removable lens housing is at least partially disposed within the inert gas flange and is in fluid communication with the inert gas inlet. Further, the first lens includes an aperture configured to allow a flow of inert gas to flow from the lens housing to an exterior of the linkage assembly.

One or more embodiments of the present invention generally relate to a system for laser induced breakdown spectroscopy. In general, a laser induced breakdown spectroscopy system includes: (a) a laser housing comprising a laser source and a spectrometer; and (b) a linkage assembly for connecting the laser housing to the sample supply chamber. Generally, the connecting rod assembly includes an inert gas flange assembly including: (i) an inert gas flange comprising an inert gas inlet configured to transfer an inert gas into the inert gas flange; and (ii) a removable lens housing comprising a first lens and a second lens. A removable lens housing is at least partially disposed within the inert gas flange and is in fluid communication with the inert gas inlet. Further, the first lens includes an aperture configured to allow a flow of inert gas to flow from the lens housing to the sample supply chamber.

One or more embodiments of the invention generally relate to a method for operating a laser induced breakdown spectroscopy system. Generally, the method comprises: (a) providing a laser housing including a laser source and a spectrometer, the spectrometer connected to a sample supply chamber via a linkage assembly; and (b) contacting the sample with the laser inside the sample supply chamber. The connecting rod assembly includes an inert gas flange assembly, which includes: (i) an inert gas flange comprising an inert gas inlet configured to transfer an inert gas into the inert gas flange; and (ii) a removable lens housing comprising a first lens and a second lens. Further, a removable lens housing is disposed at least partially within the inert gas flange and in fluid communication with the inert gas inlet, and the first lens includes an aperture configured to allow a flow of inert gas to flow from the lens housing to the sample supply chamber.

Brief Description of Drawings

Embodiments of the invention are described herein with reference to the following drawings, in which:

FIG. 1 depicts an exemplary embodiment in which a LIBS system is incorporated into a coal feed system;

FIG. 2 depicts an enlarged view of the connecting rod assembly from FIG. 1.

FIG. 3 depicts a front perspective view of a purge head of a link assembly according to one embodiment of the present invention;

FIG. 4 depicts a rear perspective view of a purge head of the link assembly according to one embodiment of the present invention;

FIG. 5 depicts a front view of a purge head of a link assembly according to an embodiment of the invention;

FIG. 6 depicts a side view of a purge head of a link assembly according to an embodiment of the invention;

FIG. 7 depicts a bottom plan view of a purge head of the link assembly according to an embodiment of the invention;

FIG. 8 depicts a front perspective view of an inert gas assembly of the connecting rod assembly according to one embodiment of the present invention;

FIG. 9 depicts a front view of an inert gas assembly of the connecting rod assembly in accordance with an embodiment of the present invention;

FIG. 10 depicts a side view of an inert gas assembly of the connecting rod assembly according to one embodiment of the present invention;

FIG. 11 depicts a side view of an inert gas assembly of the connecting rod assembly according to an embodiment of the present invention; and

FIG. 12 depicts a side perspective view of an inert gas assembly of the connecting rod assembly according to one embodiment of the present invention.

Detailed description of the invention

The LIBS system allows real-time analysis of various types of particle-based materials present in existing feed systems. More specifically, the LIBS system may be mounted to a sample supply chamber, such as a sample feeder downspout, such that the LIBS system may immediately analyze the particle-based feed stream in real-time as the feed stream is introduced into the apparatus or reactor. However, when the LIBS system is incorporated into existing feed systems that utilize particle-based feedstreams, there may be performance and durability issues.

The linkage assembly of the present invention is capable of addressing many of the previous deficiencies associated with incorporating LIBS systems into existing feed systems. More specifically, the linkage assembly of the present invention may be used to facilitate attachment of the LIBS system to an existing feeding system and enhance the function and operation of the LIBS system. As described in greater detail below, the connecting rod assembly of the present invention may utilize a dedicated purge head and/or a dedicated inert gas assembly to provide the desired functionality of the connecting rod assembly described herein.

FIG. 1 depicts an exemplary LIBS system 10 that includes a linkage assembly 16 that may be used in conjunction with a coal feed system 18. It should be understood that the LIBS system shown in fig. 1 is only one example of a system in which the present invention may be implemented. Thus, the present invention may be used in a variety of other particle-based feed systems where efficient and effective analysis of a particle-based feed stream during operation is desired. The exemplary LIBS system 10 shown in fig. 1 will now be described in more detail.

As shown in FIG. 1, the major components of the LIBS system 10 include a laser cabinet 12, a linkage assembly 16, a control cabinet 20, and an inert gas source (not shown in FIG. 1). Typically, the laser cabinet 12 may contain a 100MJ laser, focusing optics, return optics, a spectrometer, and mirrors. The laser cabinet 12 and linkage assembly 16 may be mounted directly to a sample supply chamber 14, such as the coal feeder downspout 14 depicted in fig. 1. As shown in fig. 1, a linkage assembly 16 connects the laser cabinet 12 with the sample supply chamber 14. Furthermore, as shown in fig. 1, the coal feeder downspout 14 may flow directly into an existing feed system 18, which feed system 18 may feed a particulate feed stream, such as coal, into the plant or reactor.

The control cabinet 20 includes hardware for controlling the lasers and other components in the laser cabinet 12, and may include, for example, a computer, pulse delay generator, laser controller, cooling system, and data analysis tools. The control cabinet 20 may be located on the floor and communicate with the laser cabinet 12.

Conventional LIBS systems including laser construction and arrangement are described in U.S. patent No. 6,771,368 and U.S. patent No. 8,619,255, which are incorporated herein by reference in their entirety.

Knowing the chemical composition of a particle feed stream, such as coal, in real time can better control the operation of the plant or reactor. The LIBS system 10 in fig. 1 allows for analytical measurements of particle feed streams, such as coal, prior to the feed time, which may facilitate diagnosis and control of coal pile output. More specifically, the LIBS system 10 may allow feeding of particulate feedstock, such as coal, at a constant energy rate by measuring and evaluating various characteristics of the incoming particulate feedstock in real time before it is introduced into the actual feeder. For example, the LIBS system 10 may measure the chemical composition, total ash content, and/or ash species concentration of the particulate feedstock prior to introducing it into the feed system.

The sample supply chamber 14 in fig. 1 is depicted as a weight-based downspout; however, it is contemplated that the LIBS system 10 and linkage assembly 16 of the present invention may be used with a variety of sample supply chambers, including, for example, other types of weight-based feeders and/or volume-based feeders, the function of which is to be used with other types of particle-based samples.

The linkage assembly 16 for connecting the laser cabinet 12 and the sample supply chamber 14 is depicted in greater detail in fig. 2. As shown in FIG. 2, the connecting rod assembly 12 may include a purge head 22, an inert gas assembly 24, and a zero leak valve 26. The zero leak valve 26 may comprise any valve known in the art that may prevent fluid flow between the purge head 22 and the inert gas assembly 24. In certain embodiments, the zero leak valve may comprise a sliding gate valve.

The purge head 22 may be used to connect the linkage assembly 16 and the laser cabinet 12 directly to the sample supply chamber 14. As shown in fig. 2, the base of the purge head 22 may be attached to the sample supply chamber 14, while the projections of the purge head 22 extend into the sample supply chamber 14 to collect the particulate sample therein.

As shown in fig. 2, the purge head 22 is designed such that at least a portion of the purge head 22 may be placed in the moving stream of particulate material within the sample supply chamber 14. This configuration allows the particulate sample material to span across the front face of the purge head 22 and expose the sample material to laser light from the laser cabinet 12.

All of the above embodiments, and in particular the purge head 22 and inert gas flange assembly 24, will be described in more detail below. It should be noted that while some of the following features and characteristics of the purge head 22 and inert gas flange assembly 24 may be listed separately, it is contemplated that each of the following features and/or characteristics of the purge head 22 and inert gas flange assembly 24 are not mutually exclusive and, so long as they do not conflict, may be combined and occur in any combination.

Figures 3-7 provide various depictions of the purge head 22. As shown in fig. 3, 6 and 7, the purge head 22 may include an integral base including a mounting base 28, an extension base 30, a first chamfer 32, a second chamfer 34 and a third chamfer 36. The base is designed to support a projection 38 of the purge head 22, which projection 38 extends from the base into the sample supply chamber. As shown in fig. 2, the base may attach the purge head 22 to the linkage assembly and the sample supply chamber via a mounting base 28. The mounting base 28 may include a plurality of attachment holes 40 into which bolts or other attachment means may be introduced.

The projections 38 of the purge head 22 facilitate the passage of particulate sample material across the laser sight at a predetermined distance within the sample supply chamber. This may therefore produce a uniform flow of particle sample across the laser detection location within the sample supply chamber. The purge head 22 is therefore important because it allows the LIBS system to access the sample material inside the moving sample supply chamber and it provides a consistent position of the sample material within the sample supply chamber relative to the laser focus. In various embodiments, the sweeping head 22 may comprise a ratio of the length of the projections 38 to the base length (including 28, 30, 32, 34, and 36) of at least 1:1, 1.5:1, 1.8:1, or 2:1 and/or less than 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, or 4: 1. It should be noted that all "length" measurements are measured in the direction of the longitudinal axis 50 of the cleaning head 22.

As shown in fig. 3, 5 and 6, the projection 38 may include a tapered front face 42. This tapered front face 42 of the projections 38 may cause particulate sample material in the sample supply chamber to contact the face stock surface of the purge head 22 during LIBS system operation. As shown in fig. 6, the angle (B) of the tapered front face 42 of the cleaning head 22 relative to the longitudinal axis 50 of the purge head is at least 25, 30, 35, 40, 45, 50, 55, 60, 65, or 70 degrees and/or less than 90, 85, or 80 degrees.

In addition, as shown in fig. 3-5 and 7, the projections 38 may include shaped openings 44 that are present on the front face of the purge head 22. As shown in fig. 4 and 7, the shaped opening 44 may extend longitudinally from the tapered front face 42 of the purge head 22 into a slot opening 46 and a laser perforation 48. The shaped opening 44 on the tapered front face 42 may serve as the primary contact area for the laser to contact the particulate sample material as it contacts the tapered front face 42 of the purge head 22. The defined shape of the shaped opening 44 may be specific to prevent particulate sample material from becoming caught and accumulating within the purge head 22. As shown in fig. 5, the diameter of the shaped opening expands from a location extending downward from the longitudinal axis 50 of the sweeping head 22 to an opening at the bottom surface of the tapered front face 42. In various embodiments, the shaped opening 44 may comprise a U-shaped or V-shaped opening. As shown in fig. 5, in one or more embodiments, the shaped opening can include an angle (a) of at least 5, 10, 15, or 20 degrees and/or less than 90, 80, 70, 60, 50, 40, 35, 30, or 25 degrees.

Due to their unique shape, the tapered front face 42 and shaped opening 44 may achieve the desired effect of setting the sample particulate material in the same position relative to the laser focusing optics. In addition, the tapered front face 42 and shaped opening 44 may also facilitate self-cleaning of the laser target area within the sample supply chamber, as the shape of these components may help prevent sample material from accumulating at the laser target area.

As shown in fig. 4, 6 and 7, the tab 38 may include a slot opening 46 on the bottom side of the tab 38. During laser firing and sample material ablation, a slight explosion of the sample may occur and a small piece of sample material may be ejected into the body of the purge head 22. However, due to gravity, such explosive material may be allowed to escape from the purge head 22 through the slot opening 46 in the bottom of the purge head 22. Without the slot opening 46, the exploding sample material would agglomerate inside the purge head 22 and eventually block the laser beam path. Generally, the total volume of the slot openings 46 may be greater than the total volume of the shaped openings 44. In various embodiments, the sweeping head 22 comprises a ratio of the overall length of the sweeping head to the slot opening length of at least 1.5:1, 2:1, 2.5:1, or 3:1 and/or less than 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, or 4: 1.

Further, as shown in fig. 7, the purge head 22 may include perforations 48 that extend through the base of the purge head 22 as well as the projections 38. The perforations 48 may be configured to allow the laser to pass through the purge head 22 and contact the sample in the sample supply chamber. In various embodiments, as shown in fig. 7, the shaped opening 44 has a maximum width at the bottom of the shaped opening 44. In such embodiments, the maximum width of the shaped openings 44 may be greater than the average width of the perforations 48. In one or more embodiments, the purge head 22 may include a ratio of the average width of the perforations 48 to the maximum width of the shaped openings 44 of at least 1.5:1, 2:1, 2.5:1, or 3:1 and/or less than 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, or 4: 1. In one or more embodiments, the projections 38 comprise at least 25, 30, 35, 40, 45, 50, 55, 60, or 65% of the overall length of the sweeping head 22.

In general, the cleaning head can be designed and manufactured from various metal alloys, preferably stainless steel. Further, in various embodiments, the purge head 22 may be coated with a spray-on durability coating to help increase the durability of the purge head 22. Exemplary durable coatings may include ceramic-based coatings.

Turning now to the inert gas assembly 24, various views of the inert gas assembly 24 are shown in FIGS. 8-12. As shown in fig. 8-12, the inert gas assembly 24 may include an inert gas flange 54 and a removable lens housing 56 disposed within an aperture of the inert gas flange 54. In addition, the inert gas flange 54 may include a plurality of connection holes 58 to facilitate the introduction of bolts to enable the inert gas assembly 24 to be attached to the purge head 22 and zero leak valve 26. In addition, the inert gas flange 54 may also include other connection holes 60 to facilitate the introduction of bolts so that the inert gas assembly 24 may be attached to the laser cabinet 12.

As shown in fig. 10-12, the inert gas flange 54 may include an inert gas inlet 66, the inert gas inlet 66 configured to transfer and introduce an inert gas into the inert gas flange 54 and the lens housing 56. The inert gas inlet 66 may be in the form of a tube, bore, or conduit configured to transfer inert gas from an inert gas source. In certain embodiments, the inert gas may include argon.

Due to the configuration depicted in fig. 8-12, the resulting inert gas assembly 24 may form a hermetic assembly that forces an inert gas, such as argon, through the zero-leak valve 26 and the perforations of the purge head 22 and into the sample supply chamber 14. The inert gas may provide a number of benefits to the linkage assembly 16 and the LIBS system 10. For example, the inert gas assembly 24 may provide the following benefits: (i) the inert gas may function as a fire extinguishing agent within the LIBS system 10; (ii) due to the gas-tight construction of the inert gas assembly 24, the flow of inert gas within the linkage assembly 16 may help prevent dust and other contaminants from entering the laser cabinet and damaging the laser optics; and (iii) inert gas can be used as a signal booster for laser data collection.

Generally, in various embodiments, the zero-leak valve 26 is closed while inert gas is pumped into the inert gas flange 54 and the lens housing 56. After filling the inert gas flange 54 and lens housing 56 with inert gas, the zero-leak valve 26 may then be opened to allow inert gas to flow into the purge head 22 and sample supply chamber 14.

As shown in fig. 10 and 11, the lens housing 56 may include a solid lens 62 and a separate lens 64 that includes an aperture 68. In some embodiments, the aperture 68 may be positioned in the center of the lens 64. The holes 68 may have a diameter of at least 1, 2, 3, 4, 5, or 6mm and/or less than 25, 20, 15, 10, 9, 8, or 6 mm. Typically, the aperture 68 needs to be large enough to facilitate the transfer of the inert gas, but small enough to reduce the introduction of the particle sample into the lens housing 56.

Additionally or alternatively, in various embodiments, the lens 64 having the aperture 68 may include at least 1, 2, 3, 4, 5, 6,7, 8 additional apertures 68 surrounding the central aperture in addition to the central aperture 68. In such embodiments, these additional holes may have a smaller diameter than central hole 68, and thus may help mitigate backflow of inert gas into lens housing 56. In other words, these additional holes (not shown) may be used to enhance the thrust vector characteristics of inert gas assembly 24.

Typically, the lens 64 with the aperture 68 is the lens facing the purge head 22 and the sample supply chamber 14, while the solid lens 62 will face the laser cabinet 12.

In various embodiments, the solid lens 62 does not contain any apertures and is a solid lens capable of preventing any fluid flow or solids from exiting the lens housing 56. Accordingly, this may prevent the laser housing 12 from being introduced and contaminated by any particulate sample or other contaminants that may be inadvertently introduced into the linkage assembly 16.

As shown in fig. 8 and 9, the

lenses

62 and 64 may have a circular shape. In addition,

lenses

62 and 64 may be made of any transparent material that is capable of efficiently transmitting laser light. In certain embodiments,

lenses

62 and 64 may be made of glass, polycarbonate, or polyolefin.

As shown in fig. 10-12, the lens housing 56 may be held in place with one or more O-rings 70. Thus, the lens housing 56 may be easily removed from the inert gas flange 54 due to the use of these O-rings. As shown in fig. 8 and 9, an O-ring may protrude from the lens housing 56. The double O-ring arrangement 70 allows for the delivery of inert gas through the inert gas inlet 66 to the center of the lens housing 56.

Generally, the inert gas flange 56 may be designed and manufactured from various metal alloys, preferably stainless steel. Further, in various embodiments, the inert gas flange 56 may be coated with a spray-on durability coating to help improve the durability of the purge head 22. Exemplary durable coatings may include ceramic-based coatings.

The method of using the LIBS system 10 is now described in more detail below. During operation of the LIBS system 10, a particulate sample to be tested, such as coal, may be introduced into the sample supply chamber 14 and will subsequently contact the tapered front face 42 of the purge head 22. The particle sample may then be ablated with a laser while contacting the tapered front face 42 of the purge head 22. Once the sample material is ablated, the resulting plasma plume emits light. This light may be captured by a spectrometer located in the laser cabinet 12. The captured LIBS spectral data may then be sent from the spectrometer to a computer for further analysis. Based on this analysis, the feed rate of the feed system 18 may be adjusted accordingly based on the characteristics and properties of the particulate sample being tested.

Definition of

It is to be understood that the following is not intended to be an exclusive listing of defined terms. Other definitions may be provided in the foregoing description, for example, where a defined term is used concomitantly in the context.

The terms "a", "an" and "the", as used herein, mean one or more.

As used herein, the term "and/or" when used in a list of two or more items means that any one of the listed items can be used alone or any combination of two or more of the listed items can be used. For example, if a composition is described as comprising components A, B and/or C, the composition may comprise a alone; b alone; a separate package C; a and B in combination; a and C in combination; b and C in combination; or a combination of A, B and C.

As used herein, the terms "comprising," "including," and "comprising" are open-ended transition terms used to transition from subject matter recited before the term to one or more elements recited after the term, wherein the one or more elements listed after the transition term are not necessarily the only elements that make up the subject matter.

As used herein, the terms "having," "has," and "having" have the same open-ended meaning as "comprising," "including," and "including" provided above.

As used herein, the terms "comprising," "including," and "including" have the same open-ended meaning as "comprising," "comprises," and "comprising" provided above.

Numerical range

The present description uses numerical ranges to quantify certain parameters relating to the invention. It should be understood that when numerical ranges are provided, such ranges are to be construed as providing literal support for claim limitations that only recite the lower value of the range as well as claim limitations that only recite the upper value of the range. For example, a disclosed numerical range of 10 to 100 provides literal support for a claim reciting "greater than 10" (without an upper limit) and a claim reciting "less than 100" (without a lower limit).

The claims are not to be limited to the disclosed embodiments

The preferred forms of the invention described above are to be used as illustration only, and should not be used in a limiting sense to interpret the scope of the present invention. Those skilled in the art can easily make modifications to the above-described exemplary embodiments without departing from the spirit of the present invention.

The inventors hereby state their intent to rely on the doctrine of equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.

Claims

1. A linkage assembly for a laser induced breakdown spectroscopy system, the linkage assembly comprising a purge head, wherein the purge head comprises:

(a) a base for connecting the purge head to the linkage assembly;

(b) a protrusion protruding from the base for extending at least partially into a sample supply chamber, the protrusion comprising a tapered front face and a slot opening positioned between the base and the tapered front face; and

(c) a perforation extending through the base and the protrusion, wherein the perforation is configured to allow the laser light to pass through and contact the sample.

2. The connecting rod assembly of claim 1, wherein the tapered front face includes a shaped opening extending from the tapered front face to the slot opening.

3. The connecting rod assembly of claim 2, wherein the shaped opening comprises an angle of at least 5 degrees and less than 80 degrees.

4. The link assembly of any one of claims 1-3, wherein the tapered front face has an angle of at least 25 degrees and less than 85 degrees with respect to a longitudinal axis of the purge head.

5. The link assembly of any one of claims 1-4, wherein a length of the protrusion constitutes at least 25% of an overall length of the purge head.

6. The connecting rod assembly of any one of claims 2-5, wherein the shaped opening comprises a maximum width, wherein the maximum width of the shaped opening is greater than an average width of the perforations.

7. The connecting rod assembly of any one of claims 1-6, further comprising a leak-proof valve and an inert gas assembly comprising an inert gas flange and a lens housing.

8. A laser induced breakdown spectroscopy system, the laser induced breakdown spectroscopy system comprising:

(a) a laser housing comprising a laser source and a spectrometer; and

(b) a linkage assembly for connecting the laser housing to a sample supply chamber, wherein the linkage assembly comprises a purge head comprising:

(i) a base for connecting the purge head to the linkage assembly;

(ii) a protrusion protruding from the base for extending at least partially into a sample supply chamber, the protrusion comprising a tapered front face and a slot opening positioned between the base and the front face; and

(iii) a perforation extending through the base and the protrusion, wherein the perforation is configured to allow the laser light to pass through and contact the sample.

9. The laser induced breakdown spectroscopy system of claim 8, wherein the tapered front face comprises a shaped opening extending from the tapered front face to the slot opening.

10. The laser induced breakdown spectroscopy system of claim 9, wherein the shaped opening comprises an angle of at least 5 degrees and less than 80 degrees.

11. The laser induced breakdown spectroscopy system of any one of claims 8 to 10, wherein the tapered front face has an angle of at least 25 degrees and less than 85 degrees with respect to a longitudinal axis of the sweeping head.

12. The laser induced breakdown spectroscopy system of any one of claims 8 to 11, wherein the length of the protrusion constitutes at least 25% of the overall length of the purge head.

13. The laser induced breakdown spectroscopy system of any one of claims 9 to 12, wherein the shaped opening comprises a maximum width, wherein the maximum width of the shaped opening is greater than an average width of the perforations.

14. The laser induced breakdown spectroscopy system of any one of claims 8 to 13, wherein the linkage assembly further comprises a valve and an inert gas assembly, the inert gas assembly comprising an inert gas flange and a lens housing.

15. A method for operating a laser induced breakdown spectroscopy system, the method comprising:

(a) providing a laser housing comprising a laser source and a spectrometer connected to a sample supply chamber via a linkage assembly, wherein the linkage assembly comprises a purge head comprising:

(i) a base for connecting the purge head to the linkage assembly;

(iii) a perforation extending through the base and the protrusion, wherein the perforation is configured to allow the laser light to pass through and contact the sample;

(b) contacting the laser light with the sample when at least a portion of the sample contacts the tapered front face of the purge head.

16. The method of claim 15, wherein the tapered front face comprises a shaped opening extending from the tapered front face to the slot opening.

17. The method of claim 16, wherein the shaped opening comprises an angle of at least 5 degrees and less than 80 degrees.

18. The method of any of claims 15-17, wherein the tapered front face has an angle of at least 25 degrees and less than 85 degrees with respect to a longitudinal axis of the sweeping head.

19. The method of any of claims 15-19, wherein the length of the protrusion constitutes at least 25% of the overall length of the sweeping head.

20. The method of any one of claims 15-19, wherein the linkage assembly further comprises a valve and an inert gas assembly comprising an inert gas flange and a lens housing.

21. A link assembly for a laser induced breakdown spectroscopy system, the link assembly comprising an inert gas flange assembly, wherein the inert gas flange assembly comprises:

(a) an inert gas flange comprising an inert gas inlet configured to transfer an inert gas into the inert gas flange; and

(b) a removable lens housing comprising a first lens and a second lens,

wherein the removable lens housing is at least partially disposed within the inert gas flange and is in fluid communication with the inert gas inlet,

wherein the first lens includes an aperture configured to allow the flow of inert gas to flow from the lens housing to an exterior of the linkage assembly.

22. The link assembly of claim 21, wherein the second lens comprises a solid lens.

23. A link assembly according to any of claims 21 or 22 wherein said aperture is located in the centre of said first lens.

24. The link assembly of any one of claims 21-23, wherein the first lens includes a plurality of additional apertures surrounding the aperture.

25. The connecting rod assembly of any one of claims 21-24, wherein the inert gas assembly comprises one or more O-rings for positioning the lens housing.

26. The connecting rod assembly of any one of claims 21-25, wherein the inert gas comprises argon.

27. The connecting rod assembly of any one of claims 21-26, further comprising a purge head and a leak-proof valve, wherein the inert gas inlet is in fluid communication with the purge head and the leak-proof valve.

28. A laser induced breakdown spectroscopy system, the laser induced breakdown spectroscopy system comprising:

(a) a laser housing comprising a laser source and a spectrometer; and

(b) a linkage assembly for connecting the laser housing to a sample supply chamber, wherein the linkage assembly comprises an inert gas flange assembly, wherein the inert gas flange assembly comprises:

(i) an inert gas flange comprising an inert gas inlet configured to transfer an inert gas into the inert gas flange; and

(ii) a removable lens housing comprising a first lens and a second lens,

wherein the first lens comprises an aperture configured to allow the flow of inert gas to flow from the lens housing to the sample supply chamber.

29. The laser induced breakdown spectroscopy system of claim 28, wherein the second lens comprises a solid lens.

30. The laser induced breakdown spectroscopy system of any one of claims 28 or 29, wherein the aperture is positioned in the center of the first lens.

31. The laser induced breakdown spectroscopy system of any one of claims 28 to 30, wherein the first lens comprises a plurality of additional apertures surrounding the aperture.

32. The laser induced breakdown spectroscopy system of any one of claims 28 to 31, wherein the inert gas assembly comprises one or more O-rings for positioning the lens housing.

33. The laser induced breakdown spectroscopy system of any one of claims 28 to 32, wherein the inert gas comprises argon.

34. The laser induced breakdown spectroscopy system of any one of claims 28 to 33, wherein the linkage assembly further comprises a purge head and a leak-proof valve, wherein the inert gas inlet is in fluid communication with the purge head and the leak-proof valve.

35. A method for operating a laser induced breakdown spectroscopy system, the method comprising:

(a) providing a laser housing comprising a laser source and a spectrometer connected to a sample supply chamber via a linkage assembly, wherein the linkage assembly comprises an inert gas flange assembly, wherein the inert gas flange assembly comprises:

(ii) a removable lens housing comprising a first lens and a second lens,

wherein the first lens comprises an aperture configured to allow the flow of inert gas to flow from the lens housing to the sample supply chamber; and is

(b) Contacting the laser light with the sample within the sample supply chamber.

36. The method of claim 35, wherein the second lens comprises a solid lens.

37. The method of any one of claims 35 or 36, wherein the aperture is positioned in the center of the first lens, wherein the first lens comprises a plurality of additional apertures surrounding the aperture.

38. The method of any one of claims 35-37, wherein the inert gas assembly comprises one or more O-rings for positioning the lens housing.

39. The method of any one of claims 35-38, wherein the inert gas comprises argon.

40. The method of any one of claims 35-39, wherein the connecting rod assembly further comprises a purge head and a leak-tight valve, wherein the inert gas inlet is in fluid communication with the purge head and the leak-tight valve.