Explosion-proof and flameproof enclosure for raman systems

Abstract

The present invention relates to explosion-proof and fire-resistant enclosures for Raman systems. Raman analytical systems are zoned to provide cost-effective fire resistance and explosion-proofing, including relatively small enclosures associated with particular subsystems. One or more of the excitation source, spectrometer, and / or controller are disposed in separate fire-resistant or explosion-proof enclosures. Remote optical measurement probes can also be disposed in separate fire-resistant or explosion-proof enclosures. The gratings and detectors of the spectrometer can be disposed in separate enclosures with a sealed window therebetween to deliver Raman spectral signals from the grating to the detector. Conveniently, the sealed window of the detector enclosure can serve the dual purpose of maintaining fire resistance or explosion-proofing while maintaining cooling within the enclosure. In practical situations, wireless interfaces can be used for communication between the enclosures to reduce or eliminate physical electrical feedthroughs.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to explosion-proof and flameproof enclosures for spectroscopic systems used in hazardous areas. BACKGROUND

[0002] Induced radiation effects such as Raman scattering and fluorescence have become extremely valuable tools associated with non-destructive determination of molecular composition. Raman spectroscopy is an established and practical method of chemical analysis and characterization applicable to many different chemical substances.

[0003] Raman spectroscopy is gaining increasing acceptance in on-line process monitoring, in large part due to the development of instrument and related component technology. For many process applications, Raman spectrometers have proven to have significant advantages over alternative technologies such as gas chromatography, IR spectroscopy, and NIR spectroscopy. As a non-destructive, real-time technique, Raman spectroscopy is compatible with a wide variety of samples including opaque solids, aqueous solutions, emulsions, and gases without the need for sample preparation.

[0004] A Raman analytical system has three main components: an excitation source, a sampling device, and a detector. While these three components have appeared in different forms over the years, modern Raman instruments typically use a laser as the excitation source, a spectrometer (i.e., a spectrograph) as the detector, and a microscope or fiber-optic probe as the sampling device. A complete system typically further includes a computer processor executing analysis software.

[0005] To characterize compositions in remote or harsh environments, optical fibers are advantageously used to deliver excitation energy to the sample under investigation and to carry scattered radiation back to the instrument for spectroscopic analysis. An excitation laser providing the appropriate wavelength of stimulus is coupled to an input fiber, and the collection path typically includes a second fiber carrying the return radiation information to a spectrograph.

[0006] In some cases, the fiber-optic Raman probe can be located at a significant distance from other equipment. This installation is increasingly used in industrial applications for material handling, process monitoring, and process control. As an example, industrial Raman spectroscopy for chemical process monitoring and control can use laser energy from an excitation source installed in a central control room instrument. This instrument couples the laser energy into a fiber-optic cable that is routed to a remote probe. The remote probe can be installed, for example, in a pipe, a process vessel, or other location that can be hundreds of meters away from the laser source.

[0007] Modern Raman instruments can also be configured to monitor multiple sampling points in a process. In a traditional industrial installation, multiple remote probes can be coupled to a central instrument via separate fiber optic cables. This central instrument can house the laser source, spectrometer, detector (e.g., charge-coupled device (CCD)), and control electronics. U.S. Patent No. 7,158,225, incorporated herein by reference, describes a multi-channel fiber-coupled Raman instrument that uses basic building blocks in the form of laser sources, probes / optics, fiber switches, and other features to provide a variety of possible configurations.

[0008] Raman signals are inherently very weak. To reliably acquire Raman signals, a relatively high-power laser is typically used for excitation, with ratings in the one-watt or higher range. Many wavelengths can be effectively used for Raman spectroscopy, ranging from ultraviolet (UV) to near-infrared (near-IR or NIR). In the 1990s, only high-power gas lasers were suitable for Raman spectroscopy. More recently, solid-state lasers (e.g., DPSS, diode-pumped solid-state) have spectral characteristics that are compatible with Raman spectroscopy.

[0009] A common near-infrared wavelength for Raman spectroscopy is 785 nm, which has a concentrated energy distribution when focused. Under certain operating conditions, and over time, this energy distribution can lead to deflagration and combustion of flammable and explosive hazardous substances being monitored. Published U.S. Patent Application Publication No. 20170184503 discloses a safety protection apparatus for Raman spectroscopic detection, which includes a detection chamber and a lid forming an explosion-proof container that defines a space for housing a sample to be detected. A detection instrument, such as a Raman detection probe, can be inserted into the space so that if hazardous conditions such as deflagration and explosion of flammable, explosive substances occur during detection, these hazardous conditions can be confined within the explosion-proof container and effectively prevented from causing harm to operators or damage to the on-site detection operation.

[0010] However, despite the effectiveness of the above-described safety protection apparatus, such apparatus is limited to separately loaded solid or powder samples and is not suitable or suitable for in-line process monitoring and control. Moreover, the apparatus is designed only for the tip of a Raman probe and does not address other aspects of the Raman system further upstream, including the laser excitation source or other subsystems.

[0011] Accordingly, there remains a need for further contributions in this field of technology. SUMMARY

[0012] The present disclosure includes apparatuses and methods for partitioned Raman analysis systems to provide cost-effective flame and explosion resistance. Exemplary embodiments include judicious use of smaller housings associated with particular subsystems, depending on the target application, taking into account the required housing size, need for optical and / or electrical feedthroughs, and type and level of energy content.

[0013] A Raman analysis system according to the present disclosure includes an excitation energy source (e.g., a laser) that emits excitation radiation, optical devices (e.g., lenses, filters, sealed windows, optical fibers, and complementary connectors configured to achieve the functionality described herein) operable to transmit the excitation radiation to a sample under investigation and to transmit light energy collected from the sample to a spectrograph, and a controller that receives electrical signals from the spectrograph to display or store a Raman spectrum of radiation from the sample. According to embodiments of the present disclosure, one or more of the energy source, the spectrograph, and the controller are disposed in a separate flame- or explosion-resistant housing.

[0014] The spectrograph can include a grating operable to separate the light energy collected from the sample into Raman spectral signals, and the spectrograph can include a detector for receiving the Raman spectral signals and converting the spectral signals into electrical signals for transmission to the controller. In certain embodiments, at least a portion of the spectrograph can be disposed in a flame- or explosion-resistant housing separate from other components of the Raman analysis system. For example, the grating and the detector can be disposed in separate housings.

[0015] According to another embodiment, the grating of the spectrograph can be disposed in a first housing that includes a first sealed window, where the detector of the spectrograph is disposed in a second housing that includes a second sealed window. In such a configuration, Raman spectral signals from the grating can be transmitted through the first and second sealed windows to the detector.

[0016] According to at least one embodiment of the present disclosure, the Raman analysis system can further include a remote optical measurement probe. In such embodiments, an excitation optical fiber carries excitation radiation from the laser to the remote probe, and a collection optical fiber carries collected light energy from the remote optical probe to the spectrograph. According to the present disclosure, an optical feedthrough can penetrate a flame- or explosion-resistant housing containing the spectrograph to deliver light energy collected from the sample to the grating while maintaining the flame- or explosion-resistance of the housing. In embodiments, the system can further include an electrical feedthrough to deliver electrical signals from the detector of the spectrograph to the controller while maintaining the flame- or explosion-resistance of the housing.

[0017] In at least one embodiment, a thermoelectric cooler (e.g., a Peltier-type device), other solid-state cooling device, or other suitable cooling device or method can be disposed in the second enclosure for the purpose of cooling the detector to reduce heat-induced noise. Conveniently, a second sealed window can be used to maintain the flameproof or explosion-proof nature of the second enclosure while maintaining the dual purpose of cooling within the second enclosure. A first electrical feedthrough can penetrate the second enclosure to provide electrical signals to control the cooling device, and a second electrical feedthrough can penetrate the second enclosure to deliver electrical signals from the detector to the controller.

[0018] Embodiments of the present disclosure can employ wireless communication to reduce or eliminate the number of electrical feedthroughs. For example, a wireless communication transmitter can be used to deliver wireless signals representing electrical signals from the detector to the controller. In further embodiments, one or more of the energy source, the spectrometer, and the controller can be disposed in separate flameproof or explosion-proof enclosures, with wireless interfaces used for communication between the various enclosures, where physical electrical feedthroughs are actually reduced or eliminated. In embodiments, a remote optical measurement probe can also be disposed in a separate flameproof or explosion-proof enclosure.

[0019] In at least one embodiment of the present disclosure, the system is adapted such that the excitation source is disposed within another flameproof or explosion-proof enclosure that includes a window and optics configured to deliver excitation radiation to a sample under investigation. In certain embodiments, the system further includes a remote optical probe configured to collect optical energy from the sample and disposed within another flameproof or explosion-proof enclosure that includes a window configured to deliver the collected optical energy from the probe to the spectrometer. In at least one embodiment, the excitation source and the controller are disposed within a common flameproof or explosion-proof enclosure. BRIEF DESCRIPTION OF DRAWINGS

[0020] The described embodiments and other features, advantages, and disclosures contained herein, as well as realizations thereof, will become apparent to those of ordinary skill in the art from the descriptions herein, which follow reference to the accompanying drawings, in which:

[0021] Figure 1 A schematic illustration of a Raman spectroscopy system according to the present disclosure is shown;

[0022] Figure 2 A detailed schematic illustration of a spectrometer of a Raman spectroscopy system according to the present disclosure is shown; Figure 1

[0023] Figure 3 A detailed schematic illustration of a spectrometer of a Raman spectroscopy system according to the present disclosure is shown; Figure 1 ​a schematic illustration of a spectrograph of a Raman spectroscopy system, including an optics housing and a detector housing; and

[0024] Figure 4 A detailed schematic illustration of a detector housing according to the present disclosure is shown. DETAILED DESCRIPTION

[0025] As illustrated by the so-called "fire triangle" or "flammable triangle", three elements must be present for an explosion to occur: heat (or some other ignition source), fuel, and oxidizer (usually oxygen). In addition, the fuel and oxygen must be in the correct mixture. Too little fuel (i.e., lean mixture) or too much fuel (i.e., rich mixture) can not ignite. These explosion limits are defined as the "lower explosion limit" (LEL) and the "upper explosion limit" (UEL).

[0026] With respect to equipment design for potentially explosive and / or flammable environments, there are various industry protection standards, including the North American standard ANSI / UL 1203 and the international standard IEC 60079-1. The ANSI standard relates to explosion-proof and dust-ignition-proof electrical equipment for hazardous (classified) locations, and the IEC standard covers protection of equipment by a flame-proof enclosure "d" (often referred to as "Ex-d", for explosion-proof - pressure- tight enclosure). Other industry standards in this field include EN 60079-1 in Europe, Canadian Standards Association (CSA) 60079-1, and C22.2 No. 30 Explosion-Proof Enclosures for Class I Hazardous Locations. The present disclosure can refer to these and other recognized protection standards known to those skilled in the art. The present disclosure can further refer to aspects of systems and structures disclosed herein as explosion-proof and / or flame-proof, meaning that the described structures meet the requirements of one or more known protection standards. For the purposes of the present disclosure, explosion-proof and flame-proof are used interchangeably to indicate that the described structures meet the requirements of one or more known protection standards.

[0027] In contrast to "inherently safe" technology, where a safe failure prevents ignition or explosion from occurring first, explosion-proof technology recognizes that an ignition can occur, and therefore counteracts against explosion. Such equipment is designed to predict that an explosion can occur, but limits the flame explosion to the confines of a defined area. This requires the use of high-strength materials such as steel or aluminum with the ability to contain the explosion within the confines of the enclosure.

[0028] To meet industry protection standards, explosion-proof enclosures must be able to withstand explosions caused by the sparking contacts, high temperatures, and / or electrical faults of the equipment. Such enclosures are designed so that the hot gases produced by an internal explosion are cooled to below the ignition temperature of the surrounding flammable atmosphere as they escape through the joints of the enclosure unit. Explosion-proof enclosures must be tested to ensure that the enclosure will not rupture as a result of an internal explosion. Furthermore, the outer surface of the enclosure cannot become hot enough to ignite the surrounding atmosphere as a result of the thermal energy within the unit. This thermal energy can be the result of normal operation or an electrical fault of the heat-generating equipment within the enclosure, for example.

[0029] The most commonly used material for explosion-proof enclosures is metal, such as cast aluminum and steel, including stainless steel. As a result, these enclosures tend to be bulky and heavy. Due to the weight of such enclosures, there can be complications during installation of the system. Repairs to such enclosures should only be performed by trained personnel using appropriate tools. Because the mechanical integrity of the system determines its safety, the safety can be compromised if not checked at set times. Furthermore, implementation of any changes to a conventional system can be difficult to perform.

[0030] Perhaps equally important, the steel or aluminum materials used to manufacture the enclosures are expensive, and their cost increases in a non-linear fashion. Typically, when the explosion-proof volume is doubled, the cost can be much more than twice as high. One of the reasons is that as the enclosed volume increases, the wall thickness must increase at a higher rate to ensure containment. Essentially, the walls of the enclosure must have the ability to allow cooling of the flame front within the enclosure to prevent ignition of the surrounding material or the surrounding environment. However, this ratio does have limitations, as a wall that is too thick can rupture under pressure and compromise the protection.

[0031] The terms "explosion-proof" and "flame-proof" can have the same meaning, i.e., the applicable equipment is constructed so that internal ignition of a flammable atmosphere is not transmitted outside the enclosure, thereby preventing ignition of the surrounding flammable material. Equipment that operates in these potentially explosive environments and contains or can create an ignition source need to be enclosed so that safe operation can be ensured. In practical applications, this is achieved by a flame-proof enclosure that safely encloses an explosion caused by ignition of an explosive gas mixture admitted to the enclosure so that neither flame nor incandescent particles can escape the enclosure.

[0032] When equipment may contain high-energy electric arcs or sparks during normal operation, fire protection is the preferred method of protection, as explosions are not easily prevented in hazardous air. This consideration can be applied to certain Raman system installations. For example, Raman probes can be used to analyze petroleum products and other flammable materials. Raman subsystems, including equipment operating in potentially explosive atmospheres, and equipment containing or capable of forming ignition sources, should be enclosed to ensure safe operation.

[0033] Figure 1 A schematic diagram of a Raman analysis system 100 suitable for an industrial plant environment is shown. System 100 may include a controller 102. In embodiments, for example, controller 102 may be a computer (e.g., a laptop computer) including a processor and a display 103. Controller 102 may include software executable on controller 102 and is configured to coordinate the operation of excitation source 104, which emits excitation energy (e.g., light) transmitted to probe 106 via optical excitation fiber 112. In at least one embodiment, as a non-limiting example, excitation source 104 may be a narrowband laser, such as a DPSS laser.

[0034] Probe 106 may include optics and optical components adapted to transmit light energy to and from sample 120 in a counter-propagating excitation / collection beam 118. For example, the optics of probe 106 may include a sealed window 122 at the distal end of probe 106 adjacent to sample 120. Sample 120 may include a liquid, slurry, gas, and / or solid, and the optics of probe 106 may be selected using appropriate beam-forming and focusing optics for the specific composition of sample 120. Excitation / collection beam 118 includes excitation energy of a selected wavelength from excitation source 104.

[0035] System 100 may further include a spectrometer 108 (i.e., a spectrometer) in communication with probe 106. Optical signals (e.g., light energy) collected from sample 120 are collected by probe 106 and can be routed to spectrometer 108 via optical collection fiber 114. The collected optical signals include Raman scattering generated when excitation energy in excitation / collection beam 118 strikes sample 120. Spectrometer 108 is adapted to convert the collected optical signals into electrical signals representing Raman spectra for observation and analysis via controller 102.

[0036] The system 100 can include an optical arrangement consisting of lenses, mirrors, other optical devices, filters, sealed windows, one or more probes, optical fibers and complementary connectors, and support elements arranged, adapted, and / or configured to convey excitation energy from the excitation source 104 to the sample under investigation 120 and to convey optical energy collected from the sample 120 to the spectrograph 108. In at least one embodiment, the optical arrangement can include the excitation fiber 112, the collection fiber 114, the probe 104, and suitable complementary connectors and support elements.

[0037] Different types of signals embedded within the collected optical signals can be distributed with respect to Figure 1 The illustrated arrangement. In certain embodiments, the excitation fiber 112 can be a single fiber exhibiting a relatively high energy content (e.g., a relatively high power density). The excitation / collection beam 118 to and from the sample 120 can also have a relatively high energy content as it includes laser excitation energy focused into a beam. The collection fiber 114 can include a bundle of fibers having at least a reduced energy content lower than the excitation fiber 112. The excitation source 104 and the spectrograph 108 can be electrically connected to the controller 102 via paths 110 and 116, respectively, and the paths 110 and 116 can be low energy electrical connections.

[0038] In at least one embodiment of the present disclosure, the optical arrangement can be configured for free space coupling of excitation energy between the source 104 and the probe 106. For example, in certain embodiments, the source 104 and the probe 106 can be disposed within a common housing with a free space coupling therebetween, as further described herein. The benefits or advantages of this embodiment can depend on, for example, the power density of the excitation energy. Additionally or alternatively, in other embodiments, the optical arrangement can be configured for free space coupling of the optical signals collected from the sample 120 and the spectrograph 108.

[0039] In terms of explosion-proof and flame-proof protection, Figure 1 The entire system 100 can be encapsulated in an explosion-proof and / or flame-proof housing, but such a housing is impractical and not cost-effective. Such a housing would be relatively large, and as discussed herein, the cost of the housing increases geometrically with the size of the housing. In a broad and general sense, one aspect of the present disclosure includes the use of relatively small housings associated with particular subsystems of the system 100, depending on the size required, the need for optical and / or electrical feedthroughs, the type and level of energy content, and other system characteristics. The housing configurations according to the present disclosure can further depend on how the system 100 is configured for a particular application.

[0040] Figure 2Further details of the spectrograph 108 are shown, which can include two subsystem modules, including an optics module 204 including optics 203 and a diffraction grating 202, and a detector module 210 including a detector 206, which is typically enclosed by Figure 2 In embodiments, the optics module 204 and the detector module 210 can include additional lenses, mirrors, filters, other optics, and complementary connectors and support members configured to enable the capabilities of the optics module and the detector module described herein.

[0041] In at least one embodiment, the detector 206 can include a CCD detector or other suitable detector known in the art. The system 100 can include one housing adapted to enclose both the optics module 204 and the detector module 210. In such embodiments, at least optical and electrical feedthroughs can provide an interface between the spectrograph 108 and other components of the system 100. For example, such embodiments can include an optical feedthrough 212 at the point where the collection fiber 114 interfaces with the spectrograph 108, as shown in Figure 2 Such embodiments can further include an electrical feedthrough 214 at the point where the connection path 116 interfaces with the spectrograph 108. While the optical feedthrough 212 and the electrical feedthrough 214 can carry relatively safe, lower energy signals (e.g., relatively low power density), the housing containing both the optics module 204 and the detector module 210 would be relatively large and in some cases larger than necessary. Alternatively, the optical feedthrough 212 can include a window and suitable optical components to enable free space coupling between the probe 106 and the spectrograph 108, with the collection fiber 114 omitted in such embodiments.

[0042] In at least one embodiment, the system 100 can include separate housings for the optics module 204 and / or the detector module 210. In at least one such embodiment, the detector module 210 can be located in a separate housing from the rest of the spectrograph 108. As Figure 3As shown, detector module 210 may be contained within detector housing 302, which is configured to meet the requirements of applicable explosion-proof and / or fire-resistant industrial standards—e.g., ANSI / UL 1203 and / or IEC60079-1. Detector housing 302 isolates detector module 210 from other components of spectrograph 108, which may only include low-energy optical signals that do not require explosion-proof or fire-resistant protection. For example, in such an embodiment, optical module 204, including optics 203 and grating 202, may be encapsulated within optical housing 304 to maintain a clean environment; however, since the energy of the optical signals therein is relatively low and since there are no electrical signals, optical housing 304 may not need to be explosion-proof or fire-resistant.

[0043] The optical device housing 304 may include a window 308 to enable the transmission (e.g., via free-space coupling) of optical signals from the optical module 204 within the optical device housing 304 to the detector 206 of the detector module 210 within the detector housing 302 via the window 306. Windows 306 and 308 may be at least substantially transparent to the optical signals—e.g., to the wavelength of the optical signals. Those skilled in the art, benefiting from this disclosure, will know of means for integrating windows such as window 306 into explosion-proof and / or fire-resistant housings such as detector housing 302.

[0044] Another advantage arises when the detector housing 302 requires a window for other purposes. For example... Figure 4 As shown, a detector 400 (e.g., a CCD camera) may be positioned within a Dewar flask 402, which may include a thermoelectric cooler 404 (e.g., a Peltier cooling device) adapted to reduce the temperature of the Dewar flask 402 and / or the detector 400 to reduce background radiation and dark current, which cause noise to the electrical signal generated by the detector 400 from the optical signal. Such a Dewar flask 402 may include a window 408, as described in U.S. Patent No. 10,753,805, the entire contents of which are incorporated herein by reference. In such embodiments, the Dewar flask 402 and window 408 may be configured to meet explosion-proof and / or fire-resistant requirements. While such embodiments require feedthroughs 410 and 412 for the output signal of the detector 400 and for powering the thermoelectric cooler 404, these are relatively low-power signals that cannot be combined in a single feedthrough.

[0045] Accordingly, in accordance with at least one embodiment of the present disclosure, the Dewar 402 enclosing the cooled detector 400 of the Raman analysis system can also be an explosion-proof or fire-proof enclosure having a window 408 that enables spectral input (e.g., optical signals) to the detector 400, the window 408 being a sealed window that meets the constraints and requirements of explosion-proof and / or fire-proof protection standards.

[0046] Depending on the overall configuration of the system 100 and its application, the system 100 can include additional enclosures for other components and subsystems of the system 100. For example, the probe 106 can be contained in an explosion-proof and / or fire-proof enclosure. In such embodiments, with reference to Figure 1 , the window 122 can be a window of the explosion-proof and / or fire-proof enclosure, at least to some extent similar to the windows 306, 308. In further embodiments, the probe 106 can include a second window and suitable optical components (e.g., optics) configured for free-space coupling of the probe 106 and the spectrograph 108, so as to enable the transfer of the optical signals collected from the sample 120 to the spectrograph 108 without the collection fiber 114.

[0047] In additional embodiments, the excitation source 104 and the controller 102 can be contained within a common explosion-proof and / or fire-proof enclosure or within separate explosion-proof and / or fire-proof enclosures, each including feedthroughs and / or windows to enable and facilitate the transmission and transfer of signals and / or optical energy through the system 100 (e.g., via free-space coupling). For example, in embodiments of the system 100 in which the excitation source 104 is disposed within an explosion-proof and / or fire-proof enclosure, such enclosure can include a feedthrough in communication with the controller 102 and a window in optical communication with the probe 106, in some embodiments via the excitation fiber 112. Alternatively, such enclosed housing of the excitation source 104 can include a feedthrough in optical communication with the probe 106 via the excitation fiber 112 and a wireless connection with the controller 102, as further described herein. In additional embodiments, such enclosure can include a window configured for free-space coupling of the excitation energy of the excitation source 104 with the probe 106. Alternatively, in some embodiments, the excitation source 104 and the probe 106 can be disposed within a common explosion-proof and / or fire-proof enclosure.

[0048] In another aspect of the present disclosure, the number of feedthroughs, and in particular electrical feedthroughs, can be reduced, if not eliminated. For example, as Figure 1As shown, spectral information from the spectrometer 108 can be communicated to the controller 102 through a connection path 116. Such a communication path 116 can be relatively low power, and thus instead of a hard-wired electrical connection, can be a wireless communication connection (e.g., Bluetooth, ZigBee, WirelessHART, or other suitable protocol known in the art), eliminating the need for a wiring feedthrough. In another embodiment, the components of the system 100 can have WiFi or internet connectivity including respective hardware, enabling the various subsystems to be included in an Internet of Things (IoT) architecture. For example, the spectrometer 108 can include a wireless transmitter or transceiver configured for wireless communication, and the controller 102 can include a wireless receiver or transceiver compatibly configured for wireless communication with the spectrometer 108. In an embodiment, the excitation source 104 can include a wireless receiver or transceiver compatibly configured for wireless communication with the controller 102.

[0049] The controller 102 can be configured to perform further operations including control structures to provide the functionality described herein. In certain embodiments, the controller 102 forms part of a processing subsystem including one or more computing devices having memory, processing, and / or communication hardware. The controller 102 can be a single device or a distributed device, and the functionality of the controller 102 can be performed by hardware and / or software. The controller 102 can include one or more arithmetic logic units (ALUs), central processing units (CPUs), memories, limiters, regulators, filters, format converters, etc., which are not shown for the sake of clarity. In at least one embodiment, the controller 102 is programmable to perform algorithmic and process data according to operational logic defined by programming instructions such as software or firmware. Alternatively or additionally, the operational logic of the controller 102 can be defined at least in part by hardwired logic or other hardware, for example, using any suitable type of application-specific integrated circuit (ASIC). The controller 102 can be dedicated exclusively to the functionality described herein, or can further be used to regulate, control, and activate one or more other subsystems or aspects of a Raman analysis system.

[0050] While various embodiments of a Raman analysis system, and methods of use and construction thereof, have been described in considerable detail herein, these embodiments are provided by way of non-limiting example of the disclosure described herein. Accordingly, it is to be understood that various alterations and modifications can be made without departing from the scope of the disclosure. It is the scope of the disclosure that is to be limited only by the terms of the appended claims.

[0051] Furthermore, in describing representative embodiments, this disclosure may have presented methods and / or processes as a specific sequence of steps. However, the methods or processes should not be limited to the specific sequence of steps described herein, to the extent that they do not depend on the specific sequence of steps set forth herein. Other sequences of steps are also possible and therefore remain within the scope of this disclosure.

Claims

1. A Raman analysis system (100), comprising: Excitation source (104), said excitation source being adapted to generate excitation radiation; Optical devices (106, 112, 114) are configured to transmit the excitation radiation to the sample under study and to transmit light energy collected from the sample to a spectrometer (108), wherein the collected light energy includes the Raman spectrum of the sample. The spectrometer (108) includes a grating (202) and a detector (206), the grating (202) being operable to separate light energy collected from the sample into a Raman spectral signal, and the detector (206) being configured to receive the Raman spectral signal and convert the Raman spectral signal into an electrical signal representing the Raman spectrum of the sample; A controller (102) communicating with the spectrometer (108), the controller (102) being configured to receive the electrical signal from the detector (206) to display and / or store the Raman spectrum of the sample; and At least one explosion-proof enclosure (402), wherein the at least one explosion-proof enclosure is a Dewar flask (402) made of cast aluminum or steel and configured to contain an internal explosion without breaking, wherein the detector (206) of the spectrometer (108) is disposed in the Dewar flask (402) and separate from other components of the Raman analysis system (100), wherein the Dewar flask (402) includes an explosion-proof sealed window (408) configured to allow the Raman spectral signal to be transmitted to the detector (206), and wherein the Dewar flask (402) includes one or more feedthroughs (410, 412) configured to provide electrical connection while maintaining the explosion-proof integrity of the Dewar flask (402).

2. The Raman analysis system (100) according to claim 1, wherein, The Dewar flask (402) is made of stainless steel.

3. The Raman analysis system (100) according to claim 1 further comprises: An excitation fiber adapted to transmit the excitation radiation from the excitation source (104) to a remote optical probe configured to collect the light energy from the sample; as well as A collecting optical fiber, the collecting optical fiber being adapted to transmit the collected light energy from the probe to the spectrograph (108), The at least one housing (302, 304, 402) includes an optical feedthrough configured to allow light energy collected from the sample to be transmitted to the grating (202), while further enhancing the flame retardancy or explosion-proof properties of the at least one housing (302, 304, 402).

4. The Raman analysis system (100) according to claim 1, wherein, The at least one housing (302, 304, 402) includes an electrical feeder configured to allow electrical signals from the detector (206) to be transmitted to the controller (102) while maintaining the flame retardancy or explosion-proof properties of the at least one housing (302, 304, 402).

5. The Raman analysis system (100) according to claim 1, wherein: The grating (202) of the spectrometer (108) is disposed in the flame-retardant or explosion-proof first housing (302, 304, 402) of the at least one housing (302, 304, 402), and the first housing (302, 304, 402) includes a first sealed window; The detector (206) of the spectrometer (108) is disposed within a flame-retardant or explosion-proof second housing (302, 304, 402) of the at least one housing (302, 304, 402), the second housing (302, 304, 402) including a second sealed window; and The Raman spectral signal from the grating (202) is transmitted to the detector (206) through the first sealed window and the second sealed window.

6. The Raman analysis system (100) according to claim 5, further comprising a thermoelectric cooling device disposed in the second housing (302, 304, 402) and configured to cool the detector (206) and / or the second housing (302, 304, 402) to reduce thermally induced noise in the electrical signal. in, The second sealing window is configured to both achieve flame retardancy or explosion protection of the second housing (302, 304, 402) and maintain cooling within the second housing (302, 304, 402).

7. The Raman analysis system (100) according to claim 6, wherein, The second housing (302, 304, 402) includes: A first electrical feeder, configured to provide an electrical control signal to control the cooling device; and A second electrical feeder is configured to enable the electrical signal to be transmitted from the detector (206) to the controller (102).

8. The Raman analysis system (100) according to claim 6 further includes a wireless communication transmitter or a first transceiver disposed in the second housing (302, 304, 402) and configured to transmit a wireless signal representing the electrical signal from the detector (206) to the controller (102), the controller (102) including a wireless communication receiver or a second transceiver.

9. The Raman analysis system (100) according to claim 1, wherein, The excitation source (104) is disposed within another flame-retardant or explosion-proof enclosure (302, 304, 402), which includes a window and optics configured to transmit the excitation radiation to the sample under study.

10. The Raman analysis system (100) according to claim 1, further comprising a remote optical probe configured to collect light energy from the sample and disposed within another flame-retardant or explosion-proof enclosure (302, 304, 402), the other flame-retardant or explosion-proof enclosure including a window configured to transmit the collected light energy from the probe to the spectrometer (108).

11. The Raman analysis system (100) according to claim 1, wherein, The excitation source (104) and the controller (102) are housed within a common flame-retardant or explosion-proof enclosure (302, 304, 402).

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