Flame base detector with ignition system protection

Abstract

A flame-based detector with an ignition system is protected from corrosion by flowing a protective gas over the ignition system. The protective gas layer protects the ignition system from corrosive components in the exhaust gas.

Description

Technical Field

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[0001] Cross - reference to related applications None applicable

[0002] The present invention generally relates to flame - based detectors and methods of manufacturing and using such detectors.

Background Art

[0003] For the detection of test substances of samples present in a fluid stream, flame - based detectors are used. Such detectors include two types: a flame ionization detector (FID; hydrogen flame ionization detector) and a flame photometric detector (FPD).

[0004] The flame ionization detector operates by burning the test substance to be analyzed to form ions. When used in chromatographic analysis equipment, the sample test substance eluted from the separation column is mixed with a combustible gas such as hydrogen and passed through a burner. Air is also guided (introduced) around the burner, and when the burner is ignited, a stable flame is formed by the combustion of the fuel and air continuously supplied to the burner. An ion collector such as an electrode is arranged downstream of the burner to collect the ions formed in the flame. Also, a measuring instrument is connected to the ion collector to measure the change in the current generated by the ions contacting the ion collector. The generation of these ions is proportional to the concentration of organic species in the sample guided to the FID.

[0005] Flame photometers operate similarly to flame ionization detectors, but rely more on the chemiluminescence reaction of the test substance than on the ionization reaction. Typically, FPDs are used to detect the presence or absence of sulfur or phosphorus in a sample. Similar to FIDs, FPDs mix the sample with flammable fuel and air in a flame. When the test substance, such as sulfur and phosphorus, burns in the flame, it transforms into a luminescent species. Instead of collecting ions, FPDs collect the light emitted when the test substance luminescents in the flame. FPDs contain photomultiplier tubes (PMTs) that collect the light (photons) emitted when the test substance burns in the flame. This emission from excited species can be used to determine the concentration of the test substance and to quantify the concentration of specific excited species. FPDs often incorporate photomultiplier tubes (PMTs), and a wavelength-selective filter positioned between the FPD's flame and the PMT measures the number of photons and, consequently, the intensity of the light emitted from phosphorus and sulfur-containing compounds.

[0006] U.S. Patent No. 4,346,055 discloses a flame ionization detector in which an igniter is mounted above the collector body downstream of the jet. Ignition occurs when the hydrogen-air gas reaches a hot filament at a suitable concentration. However, the device is problematic because the FID exhaust gas may contain corrosive substances such as sulfides from the analytical sample, which can corrode the solder joint between the hot filament and wire of the igniter, causing high circuit resistance or an open circuit. This may also prevent the flame from igniting.

[0007] Burner ignition can be complicated by various device conditions or procedures. Furthermore, operators typically do not have a complete understanding of all conditions present during ignition attempts, which exacerbates troubleshooting difficulties. If the device itself is in a state where it cannot or should not ignite, operators usually need to repeat ignition attempts to succeed, and since they do not understand why ignition fails, the ignition procedure can become significantly longer and more difficult than desired.

[0008] This can become even more problematic when attempting to reignite the detector in the event of flame extinction during continuous chromatograph operation. For example, if the flame goes out during analysis, immediate reignition is necessary to quickly restart the detector's operation; otherwise, a significant portion of the analysis results may be lost or compromised. Therefore, there is a need to improve the reliability and ease of flame ignition in flame-based detectors. There is also a need to reduce maintenance and extend the lifespan of such detectors. [Overview of the project]

[0009] In one aspect of the present invention, a flame-based detector (FID or FPD, etc.) is provided. This flame-based detector comprises a housing, a burner disposed in the upstream region of the housing, a fuel passage for supplying combustible fuel to the burner, an air passage for supplying air to the burner, and an ion collector or photon collector. The flame-based detector also comprises an ignition device in the downstream region of the housing, and a protective gas port located upstream of the ignition device and configured to allow a protective gas to flow onto the ignition device.

[0010] In another embodiment, a detection system is provided, comprising a flame-based detector as described herein, an instrument configured to measure a signal from a collector, and a controller in signal communication with one or more other components of the detection system. These detection systems include an air source and / or a protective gas source fluidly connected to a protective gas port.

[0011] In yet another embodiment, a method for operating a flame-based detector is provided. This method includes igniting a flame in the flame-based detector, supplying a sample to the detector, and flowing a protective gas over the detector's ignition device.

[0012] The above and other features and advantages of the device and method will become apparent from the following detailed description, in conjunction with the attached claims. [Brief explanation of the drawing]

[0013] [Figure 1] This is a cross-sectional view of a typical embodiment of this flame-based detector. [Figure 2] This is a diagram of a typical embodiment of a detection system equipped with a flame-based detector. [Modes for carrying out the invention]

[0014] This instruction will be best understood when read in conjunction with the attached drawings, as detailed below. These features are not necessarily drawn to actual size. For practical purposes, the same reference number represents the same feature.

[0015] This flame-based detector is mounted in a housing and features a protective gas port configured to blow exhaust gases away from the ignition device when ignition is not being performed. The protective gas port forms a protective gas layer that shields the ignition device, reducing contact between solder joints and exhaust gases. This flame-based detector offers several advantages, including suppression of corrosion of the ignition device, a reduction in the risk of open circuits caused by the ignition device, and an improved probability of successful ignition. Furthermore, because corrosion is slower, the effective life of the ignition device is extended, reducing the frequency of maintenance and replacement of the ignition device.

[0016] Figure 1 shows a cross-section of one embodiment of the flame-based detector. More specifically, Figure 1 shows an exemplary flame ionization detector (FID; hydrogen flame ionization detector) 102, but it is understood that a flame photometric detector (FPD) may also have many of the same components. The flame ionization detector comprises a housing 104 having an upstream region 104a and a downstream region 104b. The housing 104 may comprise one or more components, such as two or more liquid-tightly connected tubes. Suitable materials for the housing include metals such as stainless steel and titanium, alloys, ceramics, or combinations thereof.

[0017] The flame-based detector also includes a burner 106 located in the upstream region of the housing. The burner may be made from a single, solid material or from an assembly of burner components. The burner may be manufactured by machining, 3D printing, or casting. The material that can be used to manufacture the burner may be any metal, alloy, or polymer that is wear-resistant and can withstand high temperatures, such as about 200°C to about 1000°C. For example, this material may be a high-performance alloy containing elements such as chromium, manganese, nickel, copper, titanium, molybdenum, silicon, columbium, tantalum, carbon, phosphorus, sulfur, nitrogen, iron, or a combination thereof. For example, the high-performance alloy may be a nitronic alloy, commercially available from HP Alloys, Tipton, Ind.

[0018] This flame-based detector includes a fuel channel 108 for supplying combustible fuel to the burner. In most cases, the sample after it has left the column during analysis also flows through the fuel channel 108, so the fuel channel is not considered to be limited to a fuel-only channel. The fuel can be hydrogen or a mixture of hydrogen and a diluent. The fuel channel 108 can be integrated with the burner 106 as shown in Figure 1, or it may be a separate component. This flame-based detector also includes an air channel 110 for supplying air to the burner. Similarly, the air channel 110 can be integrated with the burner 106, or it may be a separate component. The air and fuel mix in the burner 106 to produce a flame 112.

[0019] This flame-based detector includes a signal collector extending from the upstream to the downstream region within the housing. The signal collector may be an ion collector 114 in an FID or a photon collector in an FPD. The ion collector is typically positioned adjacent to the flame produced by ignition of an air-fuel mixture in a burner. The ion collector may comprise one or more polarization electrodes that collect ions generated as the sample passes through the flame. The collection of ions generates an ionization current. This current is proportional to the rate at which carbon atoms enter the flame and therefore serves as a measure of the hydrocarbon concentration in the sample. The ion collector is electrically coupled to a circuit extending through the housing so that signals can be transmitted. These concentrations and associated information may be stored and analyzed separately, or output to a display device.

[0020] In some embodiments, the FID comprises a pair of positive and negative electrodes used to provide a potential difference in the FID. Typically, the burner acts as the positive electrode, and the collector, located above the flame, is the negative electrode. Thus, ions are attracted to the collector, and when they collide with it, they induce a measurable current. The measurable current roughly corresponds to the proportion of reduced carbon atoms in the flame. The detector's response is determined by the number of carbon atoms (ions) that collide with the detector per unit time. This makes the detector useful because it is more sensitive to mass than to concentration, as the detector's response is not significantly affected by changes in the carrier gas flow rate.

[0021] In some embodiments, the ion collector is made of stainless steel, titanium, tungsten, palladium, platinum, or a combination thereof. The ion collector can have any suitable size or shape, including but not limited to tubes, cylinders, plates, etc.

[0022] This flame-based detector includes an ignition device 116 in the downstream region 104b of the housing. The ignition device 116 can be any of a variety of ignition devices capable of igniting the combustion of the combustible fuel supplied to the burner. In some embodiments, the ignition device includes a filament such as a nickel-chromium (NiCr) wire. The filament is electrically connectable to a power source, which may be the same as or different from the power source for the other components of the detector. The ignition device may reside within the housing or within an ignition device fixture 118 mounted on the housing 104. The ignition device 116 may be connected to the ignition device fixture 118 or the housing 104 by a solder joint 120.

[0023] The ignition device is used for initial ignition and re-ignition of the burner. The ignition device, such as a high-temperature filament, is mounted downstream of the burner in the housing. When the gas to be analyzed and hydrogen appear in the burner, they typically begin to mix with the air introduced into the surroundings. The gas burns when it reaches the high-temperature filament in the downstream region of the housing. The normal gas flow rate is such that the resulting flame front cannot propagate at a speed sufficient to move upstream toward the burner. Therefore, one or more flows of gas (usually air) are reduced. When the air-to-hydrogen ratio becomes sufficiently small, the flame front propagates at a speed large enough to move upstream toward the burner in the slow-moving gas, igniting the burner. At this point, the flow of gas, such as air, increases to a speed desirable for the analysis and operation of the flame-based detector. Once the burner is ignited, the flame generally remains in place. However, if the flame goes out for any reason, the process is repeated.

[0024] Flame photometric detectors are ignited in the same way as flame ionization detectors. However, because FPDs use a flame that contains substantially more hydrogen than air, ignition is usually assisted by increasing the airflow while maintaining a constant hydrogen flow.

[0025] After the burner is ignited, the ignition device is no longer needed for reuse if no re-ignition is required, and generally is not needed even during sample analysis. In some embodiments, the present flame-based detector includes a protective gas port 122 that is upstream of the ignition device 116 and configured to flow a protective gas over the ignition device. When ignition is complete, the protective gas port is opened and the protective gas 124 flows over the ignition device. In some embodiments, the protective gas is flowed over the ignition device each time a sample is supplied to the detector. For example, the protective gas port can be opened and the protective gas can begin to flow over a lead period (at least 1 second, or at least 5 seconds, 10 seconds, 30 seconds, or 60 seconds, etc.) before the sample is supplied to the detector. As an alternative or in addition, the protective gas port can be closed and the flow of the protective gas can be stopped over a lag period (at least 30 seconds, or at least 1 minute, 2 minutes, or 5 minutes, etc.) after the supply of the sample to the detector is stopped.

[0026] In some embodiments, when a sample containing or suspected of containing a corrosive substance is being supplied to the detector, the protective gas port is opened and the protective gas flows over the ignition device. For example, if the sample contains sulfur, chlorine, or other substances that burn to produce acidic, alkaline, or corrosive substances, the exhaust gas 126 will corrode the filament of the ignition device 116 and / or the solder joint 120 connecting the ignition device to the flame detector. The protective gas layer 124 can suppress the diffusion of the corrosive substance to the ignition device 116. On the other hand, the flow of air can blow the exhaust gas 126 away from the ignition device 116 and further suppress the diffusion. In some embodiments, the protective gas port is opened and the protective gas flows over the ignition device only when a sample containing or suspected of containing a corrosive substance is being supplied to the detector.

[0027] As shown in FIG. 1, the protective gas port 122 is disposed within the housing 104 of the detector 102, close enough to form a gaseous protective layer 124 and spaced upstream from the ignition device 116. In some embodiments, the protective gas port 122 has a shape that increases the area of the gaseous protective layer 124, such as an oval shape whose major axis is substantially perpendicular to the flow of the exhaust gas 126. The flame above the burner is maintained by the flow of combustible fuel and air. When the gasified sample is sent to the burner, it can be flame-ionized. After passing through the ion collector, the exhaust gas 126 will flow around the ignition device 116 and reach the exhaust port 128 of the detector 102. The gaseous protective layer blows away the exhaust gas from the ignition device and / or prevents substantially all or most of the exhaust gas from contacting the ignition device. In some embodiments, the pressure of the gaseous protective layer is from about 1 psi to about 10 psi, but can be increased or decreased based on the pressure of the exhaust gas or other considerations. In some embodiments, the flow of the gaseous protective layer is from about 50 ml / min to about 200 ml / min, but can be increased or decreased based on the flow of the exhaust gas or other considerations.

[0028] Any gas, preferably a non-flammable gas, can be used as the protective gas. The protective gas is provided downstream of the collector so as not to interfere with the analysis or detection of the sample. In some embodiments, the protective gas is air. In such embodiments, the protective gas port can be fluidly connected to the same air source as the burner or to a different air source. In some embodiments, the protective gas is carbon dioxide (CO2), nitrogen (N2), argon (Ar), xenon (Xe), nitrous oxide (N2O), helium (He), air, or chlorofluorocarbon (CFC), and the protective gas port can be fluidly connected to a source of such gas.

[0029] The protective gas port can be configured to promote laminar flow of protective gas over the ignition device. The flame base detector may also have other features for forming or assisting the formation of the protective gas layer. In some embodiments, the flame base detector comprises one or more flame-expanding plates adjacent to the protective gas port. The flame-expanding plates can be positioned to direct or shape the flow of protective gas exiting the protective gas port, and / or to contain or redirect the protective gas onto the ignition device.

[0030] In some embodiments, the flame-based detector includes an outlet 128 in the downstream region 104b of the housing 104 for discharging exhaust gas 126 from the housing 104. The outlet 128 may include an opening that allows the exhaust gas to flow out of the housing, or it may include one or more components such as a valve, seal, device, or adapter. In some embodiments, the outlet 128 includes a flame retarder that can be press-fitted into the opening in the downstream region of the housing. A typical flame retarder has sufficient thermal conductivity to remove heat from a flame attempting to move through a narrow passage. The detector may also include an exhaust device that facilitates the connection of piping, such as a conduit, for collecting the exhaust gas.

[0031] Detection system In another embodiment, the Disclosure provides a detection system comprising the flame-based detector and one or more connecting components. For example, the detection system may include a controller operably connected to the flame-based detector and controlling the flow of a sample, combustible fuel, and / or air by the operation of one or more valves between each gas source and the flame-based detector. The detection system may further include valves, flow regulators, conduits, and other components between each gas source and the flame-based detector. As an example, one embodiment of the detection system includes various gas sources, fluid delivery components, power supplies and / or voltage differential sources, vacuum sources, as well as various measuring instruments and sensors. In the use herein, a gas source includes a gas-filled container (such as a canister or tank), which may or may not be pressurized. For example, a tank of pressurized hydrogen gas can be used as a fuel source. The gas source may also include a panel connected to a gas distribution system as commonly found in a laboratory. The sample source is generally a channel from a chromatography column, or includes such a channel.

[0032] Figure 2 shows one embodiment of a detection system 201 comprising a flame-based detector 202 having a housing 204, a burner 206, and an ion collector 214. When the flame 212 is ignited above the burner 206, ions pass through the ion collector 214, which is electrically connected by one or more electrical contacts extending through the housing 204 to a measuring instrument 242 (such as a high-impedance pico-ammeter) capable of measuring the ions collected by the collector 214. An igniter 216 is mounted on the inner wall of the housing 204, but may also be located within the igniter fixture and be electrically connected to a current source 240, which can supply current to the igniter 216 when heating to combustion temperature is desired. The flame-based detector 202 also includes an outlet 228 and a flame retarder 229. The detection system may also include a controller 270 that is in signal communication with one or more other components of the detection system.

[0033] The protective gas port 222 is fluidly connected to the protective gas source 252 by a protective gas valve 257, which can operate to start, stop, increase, or decrease the flow of protective gas. In the embodiment shown in Figure 2, the protective gas port 222 can receive air from an air source 256 and / or protective gas from 252 by the operation of the protective gas valve 257. Alternatively, air from the air source 256 may be used as the protective gas. That is, the detection system does not need to have a separate protective gas source as the same air source 256 that supplies air to the burner 206 also supplies air to the protective gas port 222. Or, if the detection system 201 has a protective gas source 252, the air source 256 for the burner 206 does not need to be fluidly connected to the protective gas port 222. In such embodiments, the protective gas source 252 may be air or another gas. In embodiments where the protective gas is not air, the protective gas source 252 may include carbon dioxide (CO2), nitrogen (N2), argon (Ar), xenon (Xe), nitrous oxide (N2O), helium (He), or chlorofluorocarbon (CFC). In some embodiments, the detection system includes a makeup gas source, and the makeup gas is also used as the protective gas. In such embodiments, the makeup gas source is fluidly connected to the protective gas port.

[0034] The controller 270 can be one or more computing devices (e.g., personal computers) and may comprise one or more types of hardware, firmware, and / or software, as well as one or more memories and databases. The controller 270 is in signal communication with other systems, devices, or components of the detection system 201 (for example, partially represented by dashed lines in Figure 2). More specifically, in Figure 2, the controller 270 is in signal communication with the measuring instrument 242, the protective gas source 252 or protective gas valve 257, and the current source 240. The controller 270 is also in signal communication with the air source 256, the fuel source 254, or valves connected to such sources that control the flow from them. In some embodiments, it is possible to add or remove components with which the controller 270 is in communication.

[0035] This detection system may comprise a combustible fuel source 254, an air source 256, an eluted sample from a chromatography column 280, a measurement system, and various other components. Each gas source may include a measurement system capable of measuring hydrogen 254, air 256, and / or the eluted sample 258 in specific quantities prior to supplying the mixture to the burner 206. The measurement system may also combine the measured hydrogen, air, and / or the eluted sample as a specific mixture prior to delivering the sample to the burner 206. For example, the measurement system may measure hydrogen 254 and combine it with the eluted sample prior to supplying the mixture to the burner 206.

[0036] The controller 270 can be configured to receive data from the measuring instrument 242 and determine the concentrations of ions and test substances in the sample based on this data. The display method for the test substance can be selected by the manufacturer or user of the detection system 201, but it is often displayed as a graph with time on the x-axis and detector response on the y-axis.

[0037] In some embodiments, the flame-based detector or detection system is included in analytical instruments such as chromatographic analyzers. For example, the detection system 201 can be fluidly connected to a gas chromatography column 280. The chromatographic analyzer may further include other chromatographic components such as a sample injector 282 or an oven surrounding the chromatography column.

[0038] How to operate a flame-based detector Another aspect of the present invention provides a method for operating a flame-based detector that protects the ignition device from corrosion and reduces the frequency of detector maintenance. This method may include igniting a flame in the flame-based detector and flowing a protective gas over the detector's ignition device. In some embodiments, this method includes igniting the flame before or during the supply of a sample to the flame-based detector. In some embodiments, this method includes flowing a protective gas over the ignition device each time a sample is supplied to the detector. This method may include flowing the protective gas over a lead period before a sample is supplied to the detector, as described above. As an alternative or addition, this method may include continuing the flow of the protective gas over a lag period after the supply of a sample to the detector has been stopped.

[0039] Definition of Terms It should be understood that the technical terms used herein are for the purpose of describing specific embodiments only and are not intended to be limiting in any way. The definitions of these terms are an addition to the technical and scientific meanings of the definition terms as generally understood and accepted in the art of the subject matter of this teaching.

[0040] The term "connected" means that two components are fluidly connected, physically connected, or both. The term "fluidically connected" means that two components are in fluid communication, and includes not only direct connections between these two components, but also indirect connections where one or more other components are present in the flow path between the two components. For example, a first component and a second component are fluidly connected if, when fluid flows from the first component to the second component or vice versa, the outlet of the first component is physically connected to the inlet of the second component, or a conduit connects the first and second components, or one or more intervening elements such as a valve, pump, or other structure are present between the two components. Components can be physically connected by any preferred method, such as the use of fittings, brazing, and other techniques. Generally, liquid-tight physical connections and / or physical connections that minimize dead volume are desirable for this device.

[0041] Two or more systems, devices, or components are “signal-connected” if they can communicate with each other by signals traveling through some kind of signal path. A signal path can be physical, electrical, magnetic, electromagnetic, electrochemical, optical, wired, or wireless. A signal path can also include additional systems, devices, or components.

[0042] The term "flow path" generally refers to any structure configured to allow fluid flow. A flow path may be a tube or channel formed in a substrate. A flow path may be formed by, or include, one or more tubes or channels that are in fluid communication. While a flow path typically has one inlet and one outlet, in some embodiments it may have multiple inlets and / or outlets. The shape of a flow path may vary widely and include circular, rectangular, square, D-shaped, trapezoidal, or other polygonal cross-sections. A flow path may include various shapes (for example, rectangular in one part and trapezoidal in another). In some embodiments, the cross-sectional area of ​​the flow path is substantially constant.

[0043] The term "port" encompasses any opening or structure that allows fluid to pass through (including inlets, outlets, conduits, openings, or other openings). The term "conduit" generally encompasses any structure, such as tubes, that defines a flow path for fluid to move from one point (e.g., the inlet of a conduit) to another point (e.g., the outlet of a conduit), although conduits can also deliver fluid to intermediate points. Conduits can be flexible, rigid, or both, to some extent or in part. Typically, conduits are relatively long and / or linear, providing a flow path from one component (e.g., a gas source) to another.

[0044] In this disclosure, the terms “substantial” or “substantially” mean within the limits or extent acceptable to a person skilled in the art. The terms “approximately” and “about” mean within the limits or amount acceptable to a person skilled in the art. The term “about” generally represents ±15% of a specified number. For example, “about 10” could mean a range of 8.5 to 11.5. For example, “approximately the same” means that the items being compared are considered to be the same by a person skilled in the art. Where a range of values ​​is described in this disclosure, unless otherwise explicitly specified in the context, it is understood that each midpoint between the upper and lower limits of that range is also specifically disclosed to one-tenth of the lower limit. Any smaller range between any stated value or midpoint within the range and any other stated value or midpoint within the range is also included in this disclosure. These smaller upper and lower limits may be independently included in or excluded from the scope, and each of these smaller limits is also included in the disclosure, in accordance with any specifically excluded limits of the scope described. If the scope described includes one or both limits, the scope excluding one or both of those included limits is also included in the disclosure.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this disclosure pertains. Any methods and materials similar to or equivalent to those described herein may be used in carrying out or testing the teachings herein, but only some exemplary methods and materials are described here. All patents and publications referenced herein are expressly incorporated herein.

[0046] In use herein and in the claims, the terms “a,” “an,” and “the” include both singular and plural referents unless otherwise specified in the context. For example, “a component” includes one component and multiple components. The terms “first” and “second” conduits (or other “first” and “second” elements) are terms used to distinguish different elements, not terms that impose numerical limitations. Furthermore, a device having first and second elements may also include third, fourth, fifth, and so on, unless otherwise specified.

[0047] In consideration of this disclosure, the method can be implemented in accordance with the teachings provided. Furthermore, various components, materials, structures, and parameters are included only as examples and illustrations and are not limiting in any way. In consideration of this disclosure, the teachings can be implemented in other applications, and the components, materials, structures, and equipment for realizing these applications can still be determined within the scope of the claims.

[0048] Exemplary Embodiments Exemplary embodiments provided in accordance with the subject matter of this disclosure include, but are not limited to, the following:

[0049] Embodiment 1. A flame base detector comprising a housing having an upstream region and a downstream region; a burner disposed in the upstream region of the housing; a fuel passage for supplying combustible fuel to the burner; an air passage for supplying air to the burner; a collector which is a collector in the housing and is an ion collector or a photon collector; an ignition device in the downstream region; a protective gas port located upstream of the ignition device and configured to allow protective gas to flow onto the ignition device; and an exhaust port located in the downstream region of the housing for discharging exhaust gas from the housing.

[0050] Embodiment 2. The flame base detector according to Embodiment 1, wherein the protective gas port has an oval shape.

[0051] Embodiment 3. The flame-based detector according to Embodiment 1 or 2, wherein the ignition device is a filament mounted inside or downstream of the collector tube.

[0052] Embodiment 4. The flame base detector according to Embodiment 3, further comprising an ignition device connected to a housing, wherein the filament is located inside the ignition device.

[0053] Embodiment 5. The flame base detector according to Embodiment 4, wherein the filament is soldered to a housing or ignition device.

[0054] Embodiment 6. A flame base detector according to any one of Embodiments 1 to 5, wherein the protective gas port is configured to promote laminar flow of protective gas on the ignition device.

[0055] Embodiment 7. A flame-based detector according to any one of Embodiments 1 to 6, wherein the burner comprises a nozzle for forming a jet containing fuel and air.

[0056] Embodiment 8. A flame base detector according to any one of Embodiments 1 to 7, wherein the nozzle comprises an outer nozzle surface and an inner nozzle bore, the fuel passage is the inner nozzle bore, and the air passage introduces air to the outer nozzle surface.

[0057] Embodiment 9. A flame-based detector according to any one of Embodiments 1 to 8, wherein the collector is an ion collector.

[0058] Embodiment 10. The flame-based detector according to Embodiment 9, wherein the ion collector is a collector tube having one end located in the upstream region for receiving ions from a burner and the other end located in the downstream region for discharging gas.

[0059] Embodiment 11. A flame-based detector according to any one of Embodiments 1 to 8, wherein the collector is a photon collector.

[0060] Embodiment 12. The flame-based detector according to Embodiment 11, comprising a photomultiplier tube (PMT).

[0061] Embodiment 13. A detection system comprising a flame-based detector according to any one of Embodiments 1 to 12, a measuring instrument configured to measure a signal from a collector, and a controller in signal communication with one or more other components of the detection system.

[0062] Embodiment 14. The detection system according to Embodiment 13, further comprising a combustible fuel source fluidly connected to a fuel flow path and an air source fluidly connected to an air flow path.

[0063] Embodiment 15. The detection system according to Embodiment 13, wherein an air source is fluidly connected to a protective gas port.

[0064] Embodiment 16. The detection system according to Embodiment 13 or 14, further comprising a protective gas source fluidly connected to a protective gas port.

[0065] Embodiment 17. The detection system according to any one of embodiments 13 to 16, further comprising a protective gas valve that is in signal communication with a controller and is fluidly connected to an air source and / or protective gas source.

[0066] Embodiment 18. A method for operating a flame-based detector according to any one of Embodiments 1 to 12, comprising: igniting a flame in the flame-based detector; supplying a sample to the detector; and flowing a protective gas over the ignition device of the detector.

[0067] Embodiment 19. The method according to Embodiment 18, wherein a protective gas is flowed over the ignition device each time a sample is supplied to the detector.

[0068] Embodiment 20. The method according to Embodiment 18, wherein a protective gas is flowed if the sample contains sulfur, chlorine, or other substances that burn to produce acidic, alkaline, or corrosive substances.

[0069] Embodiment 21. The method according to Embodiment 18, further comprising flowing a protective gas over a lead period before a sample is supplied to the detector, and / or continuing to flow the protective gas over a lag period after the supply of the sample to the detector is stopped.

[0070] Embodiment 22. The method according to Embodiment 21, wherein the read period is at least 1 second.

[0071] Embodiment 23. The method according to Embodiment 21, wherein the lag period is at least 30 seconds.

[0072] Embodiment 24. The method according to Embodiment 18, wherein protective gas is flowed into the protective gas port at a flow rate of approximately 50 ml / min to approximately 200 ml / min.

[0073] Embodiment 25. The method according to any one of Embodiments 18 to 24, wherein the protective gas is selected from the group consisting of air, carbon dioxide (CO2), nitrogen (N2), argon (Ar), xenon (Xe), nitrous oxide (N2O), helium (He), air, chlorofluorocarbons (CFCs), and mixtures thereof.

[0074] Embodiment 26. The method according to any one of Embodiments 18 to 25, wherein the protective gas port receives air from an air source, protective gas from a protective gas source, and / or makeup gas from a makeup gas source.

[0075] The above description relating to exemplary or preferred embodiments should be considered as examples only and not as limiting the invention as defined by the embodiments. Naturally, many variations and combinations of the above features are available without departing from the invention as shown in the embodiments. Such variations are not considered departures from the scope of the invention and are all included within the scope of the incidental embodiments. All of the contents of all references cited herein are incorporated herein by reference.

Claims

1. A housing having an upstream area and a downstream area, A burner disposed within the upstream region of the housing, A fuel passage for supplying combustible fuel to the burner, An air passage for supplying air to the burner, A collector within the housing, which is an ion collector or a photon collector, The ignition device in the downstream region, A protective gas port located upstream of the ignition device and configured to allow protective gas to flow onto the ignition device, An outlet located in the downstream region of the housing for discharging exhaust gas from the housing, A flame-based detector equipped with the following features.

2. The flame base detector according to claim 1, wherein the protective gas port has an oval shape.

3. The flame base detector according to claim 1, wherein the ignition device is a filament installed inside or downstream of the collector tube.

4. The flame base detector according to claim 3, further comprising an ignition device connected to the housing, wherein the filament is located inside the ignition device.

5. The flame base detector according to claim 4, wherein the filament is soldered to the housing or ignition device.

6. The flame base detector according to claim 1, wherein the protective gas port is configured to promote laminar flow of the protective gas on the ignition device.

7. The flame-based detector according to claim 1, wherein the burner comprises a nozzle for forming a jet containing fuel and air.

8. The flame base detector according to claim 1, wherein the nozzle comprises an outer nozzle surface and an inner nozzle bore, the fuel passage is the inner nozzle bore, and the air passage guides air to the outer nozzle surface.

9. The flame-based detector according to claim 1, wherein the collector is an ion collector.

10. The flame-based detector according to claim 9, wherein the ion collector is a collector tube having one end located in the upstream region for receiving ions from the burner and the other end located in the downstream region for discharging gas.

11. The flame-based detector according to claim 1, wherein the collector is a photon collector.

12. The flame-based detector according to claim 11, comprising a photomultiplier tube (PMT).

13. A detection system comprising: a flame-based detector according to claim 1; a measuring instrument configured to measure a signal from the collector; and a controller in signal communication with one or more other components of the detection system.

14. The detection system according to claim 13, further comprising a combustible fuel source fluidly connected to the fuel passage and an air source fluidly connected to the air passage.

15. The detection system according to claim 14, wherein the air source is fluidly connected to the protective gas port.

16. The detection system according to claim 13, further comprising a protective gas source fluidly connected to the protective gas port.

17. The detection system according to claim 13, further comprising a protective gas valve that communicates with the controller via signals and is fluidly connected to an air source and / or a protective gas source.

18. A method for operating the flame-based detector described in claim 1, The flame is ignited in the flame base detector, The sample is supplied to the detector, The protective gas is flowed over the ignition device of the detector, Methods that include...

19. The method according to claim 18, wherein the protective gas is flowed over the ignition device each time a sample is supplied to the detector.

20. The method according to claim 18, wherein the protective gas is discharged when the sample contains sulfur, chlorine, or other substances that burn to produce acidic, alkaline, or corrosive substances.

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