Flame-based detectors with ignition feed connection

Abstract

Flame-based detectors with an igniter have an ignition booster port to facilitate ignition. The ignition booster port directs a gas near the igniter, thus facilitating combustion.

Description

REFERENCE TO RELATED REGISTRATIONS

[0001] No. AREA OF INVENTION

[0002] The present invention relates generally to flame-based detectors and methods for the manufacture and use of such detectors. BACKGROUND OF THE INVENTION

[0003] Flame-based detectors are used to detect analytes present in a fluid stream within a sample. Two such detectors are the flame ionization detector (FID) and the flame photometer detector (FPD).

[0004] Flame ionization detectors (FIDs) combust the analytes to be analyzed to form ions. When used with a chromatographic analyzer, the sample analytes eluted from a separation column are mixed with a combustible gas such as hydrogen and passed through a burner. Air is supplied at the periphery of the burner, and upon ignition of the burner, a stable flame is produced by the combustion of the fuel and the air that continues to be supplied to the burner. An electrode or other ion collector is positioned downstream of the burner to collect the ions formed in the flame. A measuring device is connected to the ion collector to measure the current changes caused by the ions coming into contact with the ion collector. The generation of these ions is proportional to the concentration of organic species in the sample introduced into the FID.

[0005] Flame photometric detectors (FPDs) function similarly to flame ionization detectors, but rely on chemiluminescent reactions of the analytes rather than ionization reactions. Typically, an FPD is used to detect the presence of sulfur or phosphorus in a sample. Like the flame ionization detector (FID), the FPD mixes a sample with a combustible fuel and air in a flame, and analytes such as sulfur and phosphorus are converted into light-emitting species as they burn in the flame. Instead of collecting ions, the FPD collects the light emitted by the analytes as they luminesce in the flame. A photomultiplier is positioned within the FPD to collect the light (photons) emitted as the analytes burn in the flame. The light emission from the excited chemical species can be used to determine the analyte concentration and quantify the concentration of a specific excited species.FPDs often contain a photomultiplier tube (PMT) to measure the number of photons and thus the intensity of the light emitted by phosphorus- and sulfur-containing compounds, with wavelength-selective filters arranged between the flame of the FPD and the PMT.

[0006] US patent 4,346,055 discloses a flame ionization detector in which the igniter is mounted above a collector body located downstream of the beam. When the hydrogen-air gas reaches the hot filament at a suitable concentration, it is ignited. However, a disadvantage of this device is that the FID exhaust gas can contain corrosive substances such as sulfide from the analyzed sample, and the exhaust gas can corrode the igniter or parts thereof (such as its filament), thus hindering ignition of the burner.

[0007] An example of a current procedure for igniting a flame-based detector involves closing the channel supplying compensating gas to the detector; opening the hydrogen channel; and opening the air channel. Igniting the burner can be made difficult by various conditions of the device or the procedure. Furthermore, the operator is usually unaware of all the conditions present during the ignition attempt, which further increases the difficulty. If the device itself is in a condition unfavorable or unsuitable for ignition, the operator will typically have to make repeated ignition attempts before successful ignition occurs, without knowing why the ignition is unsuccessful. Thus, the ignition process can be considerably longer and more difficult than desirable.

[0008] This can be even more problematic when attempting to reignite a detector after a flame failure that occurs during chromatography operation. For example, flame loss during an analysis requires immediate re-ignition to quickly resume detector operation. Otherwise, the results of a significant portion of the analysis will be compromised or lost. 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 requirements and extend the service life of such detectors. SUMMARY OF THE INVENTION

[0009] As one aspect of the present invention, flame-based detectors are provided. The flame-based detector comprises a housing, a burner arranged in the upstream region of the housing, a fuel flow path for supplying a combustible fuel to the burner, an air flow path for supplying air to the burner, and an ion or photon collector. The flame-based detector further comprises an igniter located in the downstream region of the housing and an ignition feed port near the igniter configured to direct an ignition feed gas to the igniter.

[0010] As a further aspect, detector systems are provided that include a flame-based detector described here, a measuring device configured to measure a signal from the collector, and a control unit that is in signal communication with one or more other components of the detector system.

[0011] As a further aspect, methods for igniting a flame-based detector are provided. The method includes supplying fuel and air to the detector so that the fuel and air flow to the igniter; directing an ignition booster gas to the detector's igniter; and igniting a flame in the flame-based detector.

[0012] These and other features and advantages of the present devices and methods will become apparent from the following detailed description in conjunction with the attached claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a cross-sectional drawing of a representative embodiment of the present flame-based detector. Fig. Figure 2 is a diagram of a representative embodiment of a detector system comprising the present flame-based detector. The Fig. 3A and Fig. Figure 3B shows an embodiment of the present flame-based detector with an ignition feed connection which is in fluid communication with an ignition feed gas line.

[0013] The present instructions are best understood by referring to the following detailed description in conjunction with the accompanying drawings. The features are not necessarily shown to scale. Where practical, the same reference numerals refer to the same features. DETAILED DESCRIPTION

[0014] The flame-based detectors presented here include an ignition booster port mounted on a housing and configured to blow ignition booster gas onto the igniter. The ignition booster port can intermittently blow gas into the igniter, thereby increasing the contact area between the hydrogen-air gas mixture and the hot filament. By increasing the contact area between the hydrogen-air gas mixture and the hot filament, the heat from the igniter can ignite the gas mixture even if the igniter (e.g., a filament) is slightly corroded and / or deformed. These flame-based detectors offer several advantages, such as an improved probability of successful ignition and / or an improved ignition success rate over essentially the entire lifespan of the detector.Furthermore, the service life of the detonator can be extended, as ignition can be achieved reliably and / or quickly despite corrosion or deformation, which can reduce the frequency of maintenance and / or replacement of the detonator.

[0015] Fig. Figure 1 shows a cross-section of an embodiment of the present flame-based detectors. In particular, it shows Fig. 1 An exemplary flame ionization detector (FID) 102, although it should be noted that the flame photometry detector (FPD) can comprise many of the same components. The flame ionization detector comprises a housing 104 with an upstream region 104a and a downstream region 104b. The housing 104 can consist of one or more parts, for example, two or more tubes connected fluid-tight. Suitable materials for the housing include, for example, stainless steel, titanium or other metals, metal alloys, ceramics, or combinations thereof.

[0016] The flame-based detectors presented here also include a burner 106, which is located within the upstream portion of the housing. The burner may be manufactured from a single piece of material or from an array of burner components. The burner may be manufactured by machining, 3D printing, or casting. The material used to manufacture the burner may be any metal, alloy, or polymer that is wear-resistant and can withstand high temperatures, for example, temperatures from approximately 200 °C to approximately 1000 °C. The material may, for example, 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. The high-performance alloy may, for example, be a NITRONIC alloy, which is commercially available from HP Alloys in Tipton, Indiana.

[0017] The present flame-based detectors include a fuel flow path 108 to supply the burner with a combustible fuel. In most cases, the sample also flows through the fuel flow path 108 after exiting the column during analysis, and the fuel flow path is not intended to be limited to a fuel-only flow path. The fuel can be hydrogen or a mixture of hydrogen and a diluent. The fuel flow path 108 can be configured as shown in Fig. As shown in Figure 1, the flame-based detectors can be an integral part of the burner 106 or a separate component. The present flame-based detectors include an air flow path 110 to supply the burner with air. The air flow path 110 can also be an integral part of the burner 106 or a separate component. Air and fuel mix at the burner 106 to generate a flame.

[0018] The flame-based detectors presented here include a signal collector within the housing, extending from the upstream to the downstream region. The signal collector can be an ion collector in a FID or a photon collector in a FPD. Ion collectors are typically positioned adjacent to the flame, which is generated by igniting the air-fuel mixture at the burner. The ion collector may include one or more polarized electrodes that collect the ions produced when the sample passes through the flame. The collection of ions causes an ionization current. This current is proportional to the rate at which carbon atoms enter the flame and is therefore a measure of the hydrocarbon concentration in the sample. The ion collector is electrically coupled to a circuit extending through the housing, enabling signal transmission.Information about these concentrations can be stored for further analysis or displayed on a display device such as a measuring instrument.

[0019] In some embodiments, the FID comprises a pair of positive and negative electrodes used to generate a potential difference within the FID. Typically, the burner acts as the positive electrode, and the negative electrode is the collector positioned above the flame. The ions are thus attracted to the collector and, upon impact, induce a current that can be measured. The measured current corresponds approximately to the fraction of reduced carbon atoms in the flame. The detector's response is determined by the number of carbon atoms (ions) that strike the detector per unit time. This means the detector responds to mass rather than concentration, which is advantageous because the detector's response is not strongly affected by changes in the carrier gas flow rate.

[0020] In some embodiments, the ion collector is made of stainless steel, titanium, tungsten, palladium, platinum, or combinations thereof. The ion collector can be any suitable size or shape, including but not limited to tubes, cylinders, plates, or others.

[0021] Flame-based detectors typically include an igniter used for the initial ignition and reignition of the flame. The present flame-based detectors include an igniter 116 located in the downstream region 104b of the housing. The igniter 116 can be one of a variety of igniters capable of causing the combustion of the combustible fuel supplied to the burner. In some embodiments, the igniter includes a filament, for example, a NiCr wire, which can be heated to a temperature sufficient to ignite the fuel-air mixture. The filament can be electrically connected to a power supply, which may be identical to or different from the power supply for other components of the detector. The igniter may be located within the housing or within an igniter device 118 attached to the housing 104.

[0022] Typically, a filament or other igniter is located in the housing 104 downstream of the burner. As hydrogen enters the burner, it begins to mix with air, which is normally supplied around its circumference. When the gases reach the hot filament in the downstream portion of the housing, they are combusted. Generally, the normal gas flow rate is such that the resulting flame front cannot propagate with sufficient velocity to travel upstream toward the burner. Therefore, the flow of one or more gases is reduced. When the air-to-hydrogen ratio is sufficiently reduced, the flame front propagates at a sufficiently higher velocity to travel upstream in the slower-flowing gases and ignite the burner.At this point, the flow rate of air or other gas is increased to a rate required for analysis and operation of the flame-based detector. Once the burner is ignited, the flame generally remains in position; however, should it go out for any reason, the process is repeated.

[0023] Flame photometric detectors are ignited in a similar way to flame ionization detectors. However, since an FPD uses a flame that is essentially enriched with hydrogen instead of air, ignition in an FPD is typically aided by increasing the airflow while keeping the hydrogen flow constant to prevent an explosion upon flame ignition.

[0024] In current flame-based detectors, when a user wishes to ignite a flame at the burner 106 of the detector 102, hydrogen or another fuel is fed through the fuel flow path into the housing, where it typically reaches a desired level within seconds. Air is then introduced into the housing. After passing through the collector 114, the fuel-air mixture 125 flows to the igniter 116 of the detector 102. When the igniter 116 is sufficiently hot and a sufficient quantity of the fuel-air mixture 125 comes into contact with it, the combustion of the fuel-air mixture 125 creates an ignition path 117, which can then propagate to the burner 106.

[0025] In some embodiments, the present flame-based detectors include an ignition booster port 122. As in Fig. As shown in Figure 1, the ignition booster port 122 is arranged in the housing 104 of the detector 102, positioned at a distance from the igniter 116 to supply a gas that promotes the ignition of a fuel-air mixture by the igniter. When ignition is desired, the combustible fuel is passed through the burner. Air is also passed through, and as the airflow is slowly increased, the concentration of hydrogen and air reaches a range in which the fuel-air mixture can be readily ignited, although less readily if the igniter is corroded or deformed. When the concentration is in this range, the ignition booster gas can blow the fuel-air mixture into the igniter to make as much contact as possible with the hot filament. The ignition booster port 122 opens, and an ignition booster gas 124 flows into the housing 104.In some embodiments, the ignition booster gas 124 is supplied while a fuel / air mixture is being supplied to the detector; for example, the ignition booster port can be opened and the ignition booster gas can begin to flow into the housing. After a desired period of time, the airflow is changed to a specific value set by the user, and the ignition booster port is closed. In some embodiments, the ignition booster gas is supplied to the detector continuously or before the fuel / air mixture. For example, the ignition booster gas 124 can be supplied to the housing 104 before the fuel / air mixture is supplied to the detector and / or before ignition is desired.In such embodiments, the ignition gas 124 can flow at a pressure and / or flow rate desired for ignition, or it can flow at a reduced pressure and / or flow rate, which are then increased when ignition is desired. The reduced pressure and / or flow rate of the ignition gas 124 can be achieved by partially closing the ignition port 122 or a valve fluidically connected to the ignition port 122.

[0026] The ignition booster gas can be fuel and / or air, or it can be another gas that is also burned, or it can be another gas that is not burned but promotes ignition by pushing the fuel and / or air towards the igniter. The ignition booster gas blows the fuel / air mixture towards the igniter and / or increases the amount or percentage of the fuel / air mixture that comes into contact with the igniter.

[0027] The ignition feed port may be of any suitable size or shape. In some embodiments, the ignition feed port is circular or oval, and its diameter or longest dimension is about 0.3 mm to about 1.0 mm. In some embodiments, the pressure of the ignition feed gas is about 5 psi to about 80 psi, although the pressure may be increased or decreased based on the pressure of the fuel / air mixture or other considerations. In some embodiments, the flow rate of the ignition feed gas is at least about 18 ml / min, or at least about 24 ml / min, or at least about 36 ml / min; alternatively, about 180 ml / min or less, or about 135 ml / min or less, or about 90 ml / min or less. It is intended that any of the foregoing minimum and maximum values ​​may be combined to form a range.It is intended that the flow rates can be increased or decreased based on the exhaust gas flow rate or other considerations.

[0028] In some embodiments, the ignition feed port 122 is located directly opposite the igniter 116; or downstream or upstream of the igniter, for example, about 1 mm to about 25 mm upstream or downstream. The ignition feed gas may flow directly toward the igniter or at an angle to the igniter. The igniter and the ignition feed port may be located on opposite sides of the housing (for example, if the housing has a substantially circular interior, the igniter may be positioned at 0° and the ignition feed port may be located at about 180°, or about 90°, or about 135°, or between about 165° and about 195°, or at other angles around the interior of the housing). In some embodiments, the flame-based detector includes one, two, three, four, or more ignition feed ports; if multiple ignition feed ports are present, they may be positioned evenly around the interior of the housing (e.g.,at approximately 90°, approximately 180° and approximately 270°) or they may be positioned unevenly.

[0029] The ignition gas can be any gas, preferably a non-flammable gas. In some embodiments, the ignition gas is air. In such embodiments, the ignition gas port can be fluidically connected to the same or a different air supply as the burner. In some embodiments, the ignition gas is air, carbon dioxide (CO2), nitrogen (N2), argon (Ar), xenon (Xe), nitrous oxide (N2O), helium (He), hydrogen (H), or a chlorofluorocarbon (CFC), and the ignition gas port can be fluidically connected to a source of such gases.

[0030] The ignition feed port can be configured to promote a laminar flow of the ignition feed gas toward the igniter. The flame-based detectors can also include other features for shaping or assisting the shaping of the ignition feed gas flow. In some embodiments, the flame-based detectors include one or more baffles adjacent to the ignition feed gas port. The baffles can be positioned to direct or shape the flow of ignition feed gas exiting the port and / or to confine or redirect the ignition feed gas toward the igniter.

[0031] In some embodiments, the present flame-based detectors include an exhaust port 128 in the downstream region 104b of the housing 104 to allow exhaust gas to escape from the housing 104. The exhaust port 128 may include an opening that allows the exhaust gas to escape from the housing, or it may include one or more components such as valves, seals, connectors, or adapters. In some embodiments, the exhaust port 128 includes a flame guard that can be pressed into an opening in the downstream region of the housing. Typical flame guards have sufficient thermal conductivity to dissipate heat from the flame as it attempts to move through narrow passages. The detectors may also include an exhaust fitting that facilitates the connection of a pipe or other container for collecting the exhaust gas. Detector systems

[0032] As a further aspect, the present disclosure provides detector systems comprising the present flame-based detectors and one or more connected components. For example, a detector system may include a control unit that is functionally connected to a flame-based detector to control the flow of the sample, combustible fuel, and / or air, for example, by actuating one or more valves between the respective gas supplies and the flame-based detector. The detector systems may further include valves, flow regulators, lines, and other components between the respective gas supplies and the flame-based detector. For example, one embodiment of a detector system comprises various gas sources, fluid supply components, a power source and / or a voltage differential source, as well as various measuring instruments and sensors.As used here, gas sources include containers (such as canisters or tanks) filled with the gas, which may or may not be pressurized. For example, a fuel source might be a tank of pressurized hydrogen gas. Gas sources also include consoles connected to a gas distribution system, such as those typically found in laboratories. The sample source is generally a flow path from, or includes, a chromatography column.

[0033] Fig. Figure 2 shows an embodiment of a detector system 201 comprising a flame-based detector 202, which in turn includes a housing 204, a burner 206, and an ion collector 214. A fuel supply line 208 carries combustible fuel from the fuel source 254 to the burner 206, and an air supply line 211 carries air from the air source 256 to the burner 206. A flame 212 is ignited over a burner 206, and ions pass through the ion collector 214, which is electrically connected to a measuring device 242 (e.g., a high-impedance picoammeter). The measuring device 242 can measure the ions collected by the collector 214 via one or more electrical contacts extending through the housing 204. The exhaust gas from the collector can be discharged from the housing 204 through the exhaust port 228 and the optional flame guard 229.

[0034] A detonator 216 is attached to an inner wall of the housing 204 (alternatively, it can be located in a recess / fitting, as in Fig. (1 shown and described). The detonator 216 is electrically connected to a power source 240, so that electric current can be supplied to the detonator 216 when it is to be heated to a combustion temperature. The detector system can also include a control unit 270, which is in signal communication with one or more other components of the detector system.

[0035] The ignition feed port 222 is fluidically connected to an ignition feed gas source 252, whereby an ignition feed gas valve 257 can be actuated to start, stop, increase or decrease the flow of the ignition feed gas. In the Fig. In the embodiment shown in section 2, the ignition feed port 222 can receive air from the air source 256 and / or an ignition feed gas from 252 by actuating the ignition feed gas valve 257.

[0036] It is also provided that air from the air source 256 is used as the ignition gas; that is, the same air source 256 that supplies the burner 206 with air also supplies the ignition gas port 222 with air, so that the detector system does not need to include a separate ignition gas source. Alternatively, the air source 257 for the burner 206 does not need to be fluidically connected to the ignition gas port 222 if the detector system 201 includes an ignition gas source 252. The ignition gas source 252 in such embodiments can be air or another gas. In embodiments where the ignition gas is not air, the ignition gas source 252 can contain carbon dioxide (CO2), nitrogen (N2), argon (Ar), xenon (Xe), nitrous oxide (N2O), helium (He), hydrogen (H), or a chlorofluorocarbon (CFC).In some embodiments, the detector system includes a compensating gas supply, and the compensating gas is also used as the ignition booster gas; in such embodiments, the compensating gas supply is fluidically connected to the ignition booster gas connection.

[0037] The control unit 270 can be one or more computing units, for example, a computer such as a personal computer, and can include one or more types of hardware, firmware, and / or software, as well as one or more storage devices and databases. The control unit 270 is in signal communication with other systems, devices, or components of the detector system 201 (such as partially indicated by dashed lines in Fig. 2 shown). In particular, the control unit 270 is located in Fig. 2 in signal connection with the measuring device 242, the ignition feed source 252 or the ignition feed valve 257 and the power supply 240. The control unit 270 is also in signal connection with the air source 256, the fuel source 254 or with valves connected to these sources and controlling the flow from these sources. In some embodiments, the control unit 270 may be connected to additional or fewer components.

[0038] The detector system can include a source of combustible fuel 254, an air source 256, eluted sample(s) from chromatographic columns, a metering system, and a variety of other components. Each gas source includes a metering system that can dose hydrogen 254, air 256, and / or eluted sample(s) in specific quantities before the mixture is fed to the burner 206. Additionally, the metering system can combine the dosed hydrogen, air, and / or eluted sample(s) into specific mixtures before the samples are fed to the burner 206. For example, the metering system can dose hydrogen 254 and combine it with the eluted sample(s) before the mixture is fed to the burner 206.

[0039] The control unit 270 can be configured to receive data from the measuring device 242 and use this data to determine the concentration of ions and analytes in the sample. The way in which the analyte is displayed can be selected by the manufacturer or user of the detector system 201, often showing a graph with time on the x-axis and the detector response on the y-axis.

[0040] In some embodiments, the flame-based detectors or detector systems are incorporated into an analytical instrument, for example, a chromatographic analyzer. For instance, the detector system 201 may be fluidically connected to a gas chromatography column 280. The chromatographic analyzer may further comprise other chromatographic components, for example, a sample injector 282 or an oven that encloses the chromatography column.

[0041] The Fig. Figure 1 shows an embodiment of the present flame-based detector 302 with an ignition feed connection 322, which is in fluid communication with an ignition feed gas line 321. More precisely, an ignition feed fitting 323 is attached to the housing 304 by means of fastening elements 325, although other clamps or connection means could also be used. The ignition feed fitting 323 has one or more bores that form a flow path and / or accommodate a line. As shown in Fig. As shown in Figure 3B, the ignition feed fitting 321 includes a central bore 327 which accommodates the ignition feed gas line 321. Alternatively, the line 321 could be attached directly to 304 by soldering, welding, etc., thereby rendering the fitting (connecting piece) 323 superfluous.

[0042] Fig.Figure 3B also shows that a sealing material 329 can be positioned at one end of the fitting 323, forming a fluid-tight seal where the bore 327 allows ignition booster gas to flow into the ignition booster port 322. The detector 302 also includes an ignition device 318, which is inserted into the housing 304 and connected to a port or flow line 319. Method for igniting a flame-based detector

[0043] As a further aspect of the present invention, methods for igniting a flame-based detector are provided, which facilitate the ignition of the burner. The methods may include supplying fuel and air to the detector so that the fuel and air flow to the igniter; directing an ignition booster gas toward the igniter of the detector; and igniting a flame in the flame-based detector. In some embodiments, the ignition booster gas of the flame-based detector is directed and stopped for one or more cycles during the ignition period. For example, the cycles include allowing the ignition booster gas to flow for about 0.05 seconds to about 0.1, 0.3, or 0.5 seconds and stopping the ignition booster gas for about 0.5 seconds to about 1, 3, or 5 seconds. The cycles may be stopped when the burner is ignited, at the end of the current cycle, or by interrupting the current cycle.The present methods may also include supplying air to the detector through the air flow path and slowly increasing the airflow to the detector. In some embodiments, the method includes stopping the flow of the ignition feed gas, for example by closing the ignition feed port, after the air supply period, immediately or within seconds after the end of the air supply period. Defined terms

[0044] It is understood that the terminology used here serves only to describe specific embodiments and is not to be understood restrictively. The defined terms apply in addition to their technical and scientific meanings as generally understood and accepted in the technical field of this teaching.

[0045] The term "connected" means that two components are fluidically or physically connected, or both. The term "fluidically connected" means that two components are in fluid communication and includes direct connections between the two components as well as indirect connections where one or more other components are located in the flow path between the two components. For example, a first component and a second component are fluidically connected if an outlet of the first component is physically connected to an inlet of the second component, or if a pipe connects the first and second components, or if one or more intermediary components, such as a valve, pump, or other structure, are located between the two components while fluid flows from the first component to the second component or vice versa.Components can be physically connected in any suitable manner, for example by using clamping sleeves, (hard) soldering, and other methods. In general, for the devices at hand, physical connections that are fluid-tight and / or minimize dead volume are desirable.

[0046] Two or more systems, devices, or components are in "signal communication" when they can communicate with each other via signals transmitted through some kind of signal path. Signal paths can include physical, electrical, magnetic, electromagnetic, electrochemical, optical, wired, or wireless connections. Signal paths can also include additional systems, devices, or components.

[0047] The term "flow path" generally refers to any structure configured to provide fluid flow. The flow path may be a pipe or a channel formed in a substrate. A flow path may be formed by or comprise one or more fluid-connected pipes or channels. A flow path typically has an inlet and an outlet, although in some embodiments a flow path may have multiple inlets and / or outlets. The geometry of a flow path can vary widely and includes circular, rectangular, square, D-shaped, trapezoidal, or other polygonal cross-sections. A flow path may comprise different geometries (e.g., rectangular in one section and trapezoidal in another). In some embodiments, the cross-sectional area of ​​a flow path is essentially constant.

[0048] The term "connection" encompasses any opening or structure that allows the flow of a fluid, including an inlet, outlet, pipe, or other opening or mouth. The term "pipe" generally encompasses any structure, such as a tube, that defines a flow path for a fluid to travel from one point (e.g., a pipe inlet) to another point (e.g., a pipe outlet), although a pipe can also deliver fluids to intermediate points. A pipe can be flexible, rigid, or to some extent or in certain sections both. Typically, a pipe is relatively elongated and / or linear and provides a flow path from one component (e.g., a gas source) to another.

[0049] In some embodiments, the detectors include a flexible sealing material. For example, the ignition-promoting fitting may have a flexible sealing material, such as an elastic, substantially fluid-tight material in the form of an O-ring, at one or more openings. In some embodiments, a fitting or other component of the detector includes one or more recesses for receiving a flexible sealing material. The flexible sealing material may have any suitable shape, such as a toroidal O-ring, a gasket with a rectangular cross-section, a metal gasket, or another flexible material. In some embodiments where the flexible sealing material is in the form of an O-ring, the O-ring should be compressed by 15% to 25% or by 20% to create a fluid-tight seal.Alternatively, a flat or cylindrical gasket could be used as the compliant sealing material instead of an O-ring, with the desired compression percentage varying. In some embodiments, the compliant sealing material can be made from various rubbers, such as fluoropolymers, buna-n, EPDM, or, in extreme cases, metal with a compliant overcoating, depending on the temperatures and gases used in the detectors. The compliant sealing material can also be coated with a chemically inert coating if the material permits.

[0050] In this disclosure, the terms "essential" or "substantial" mean within acceptable limits or to an extent acceptable to a person skilled in the art. The terms "approximately" and "about" mean within a limit or quantity acceptable to a person skilled in the art. The term "about" generally refers to plus or minus 15% of the stated number. For example, "about 10" may denote a range from 8.5 to 11.5. For example, "approximately equal" means to a person skilled in the art that the items being compared are considered to be equal. Where a range of values ​​is given in this disclosure, it should be understood that any intermediate value, accurate to the tenth of a unit of the lower limit, is also expressly disclosed between the upper and lower limits of that range, unless the context clearly requires otherwise.Every smaller range between a specified value or an intermediate value within a specified range and any other specified or intermediate value within that specified range is included in this disclosure. The upper and lower limits of these smaller ranges may be independently included in or excluded from the range, and any range containing one, neither, or both limits within the smaller ranges is also included in this disclosure, subject to any limit expressly excluded within the specified range. If the specified range contains one or both limits, ranges that exclude one or both of these contained limits are also included in this disclosure.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as generally understood by a person skilled in the art in the field to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein may also be used in the practical application or testing of the teachings presented here, some exemplary methods and materials are now described. All patents and publications mentioned herein are expressly incorporated by reference.

[0052] As used in the description and the attached claims, the terms "a", "an", "one", and "the" include both singular and plural references unless the context clearly indicates otherwise. For example, "a component" includes one component and multiple components. The terms "first" and "second" line (or other "first" and "second" elements) are terms used to distinguish different elements and are not terms that impose a numerical limit, and a device comprising a first and a second element may also include a third, a fourth, a fifth, etc., unless otherwise specified.

[0053] In light of this disclosure, it should be noted that the present methods can be implemented in accordance with the present teachings. Furthermore, the various components, materials, structures, and parameters are listed only for illustration and as examples and are not to be understood in a limiting sense. In light of this disclosure, the present teachings can be implemented in other applications and components, materials, structures, and equipment for implementing these applications, while maintaining the scope of the appended claims. EXAMPLE EXECUTION FORMS

[0054] Exemplary embodiments provided in accordance with the subject matter disclosed herein include, but are not limited to, the following: Embodiment 1. Flame-based detector, comprising: a housing with an upstream region and a downstream region; a burner arranged within the upstream region of the housing; a fuel flow path for supplying a combustible fuel to the burner; an air flow path for supplying air to the burner; a collector within the housing, wherein the collector is an ion collector or a photon collector; an igniter in the downstream region; an ignition feed port near the igniter configured to direct an ignition feed gas towards the igniter; and an exhaust port in the downstream region of the housing for venting exhaust gas from the housing. Embodiment 2. Flame-based detector according to embodiment 1, wherein the igniter is a filament located inside or downstream of the collector tube. Embodiment 3. Flame-based detector according to embodiment 2, which further comprises an ignition device connected to the housing, wherein the filament is located inside the ignition device. Embodiment 4. Flame-based detector according to embodiment 1, which further comprises an ignition-promoting fitting connected to the housing. Embodiment 5. Flame-based detector according to one of embodiments 1 to 4, wherein the ignition feed port is configured to blow the shielding gas directly onto the igniter. Embodiment 6. Flame-based detector according to one of embodiments 1 to 5, wherein the igniter and the ignition booster connection are located on opposite surfaces of the housing. Embodiment 7. Flame-based detector according to one of embodiments 1 to 4, wherein the ignition feed connection is located at a distance of approximately 1 mm to approximately 25 mm from the igniter. Embodiment 8. Flame-based detector according to one of embodiments 1 to 4, wherein the ignition feed port is located at an angle and at a distance of about 1 mm to about 25 mm upstream or downstream of the igniter. Embodiment 9. Flame-based detector according to one of embodiments 1 to 8, wherein the ignition booster port is circular or oval. Embodiment 10. Flame-based detector according to one of embodiments 1 to 9, wherein the ignition booster connection has a diameter or longest dimension of about 0.3 mm to about 1.0 mm. Embodiment 11. Flame-based detector according to one of embodiments 1 to 10, comprising a plurality of said ignition-promoting connections arranged uniformly around the interior of the housing. Embodiment 12. Flame-based detector according to one of embodiments 1 to 11, wherein the burner comprises a nozzle for forming a jet of fuel and air. Embodiment 13. Flame-based detector according to one of embodiments 1 to 12, wherein the collector is an ion collector. Embodiment 14. Flame-based detector according to one of embodiments 1 to 12, wherein the collector is a photon collector. Embodiment 15. Flame-based detector according to embodiment 14, wherein the flame-based detector comprises a photomultiplier tube (PMT). Embodiment 16. Detector system comprising a flame-based detector according to one of embodiments 1 to 15, a measuring instrument and a control unit, wherein the measuring instrument is configured to measure a signal from the collector, and wherein the control unit is in signal communication with one or more other components of the detector system. Embodiment 17. Detector system according to embodiment 16, which further comprises a combustible fuel source fluidically connected to the fuel flow path and an air source fluidically connected to the air flow path. Embodiment 18. Detector system according to embodiment 16 or embodiment 17, wherein the air source is fluidically connected to the ignition feed port. Embodiment 19. Detector system according to one of embodiments 16 to 18, which further comprises an ignition supply gas source which is fluidically connected to the ignition supply port. Embodiment 20. Detector system according to one of embodiments 16 to 19, which further comprises an ignition booster gas valve which is in signal communication with the control unit and is fluidically connected to the air source and / or the ignition booster gas source. Embodiment 21. Method for igniting a flame-based detector according to any one of embodiments 1 to 15, wherein the method comprises: supplying fuel and air to the detector so that the fuel and air flow to the igniter; directing an ignition booster gas towards the igniter of the detector; and igniting a flame in the flame-based detector. Embodiment 22. Method according to embodiment 21, wherein the method comprises: intermittently guiding the ignition propellant gas during an ignition period. Embodiment 23. Method according to embodiment 22, wherein the ignition booster gas is guided and stopped for one or more cycles during the ignition period, the cycles comprising guiding the ignition booster gas for about 0.05 seconds to about 0.3 seconds and stopping the ignition booster gas for about 0.5 seconds to about 3 seconds. Embodiment 24. Method according to one of embodiments 21 to 23, wherein the method comprises increasing the airflow to the detector over an air rise period and stopping the flow of the ignition booster gas substantially immediately after the end of the air rise period. Embodiment 25. Method according to one of embodiments 21 to 24, wherein the ignition booster gas flows through the ignition booster port at a flow rate of about 18 ml / min to about 90 ml / min. Embodiment 26. Method according to one of embodiments 21 to 25, wherein the ignition propellant gas is selected from the group consisting of carbon dioxide (CO2), nitrogen (N2), argon (Ar), xenon (Xe), nitrous oxide (N2O), helium (He), hydrogen (H), chlorofluorocarbons (CFCs) and mixtures thereof.

[0055] The foregoing descriptions of exemplary or preferred embodiments are to be understood as illustrations and not as limitations of the present invention as defined by the embodiments. As is readily apparent, numerous variations and combinations of the features set forth above can be used without departing from the present invention as set forth in the embodiments. Such variations are not considered to be a departure from the scope of the invention, and all such variations are to be included within the scope of the following embodiments. All references cited herein are incorporated by reference in their entirety. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 4,346,055

[0006]

Claims

[1] Flame-based detectors include: a housing with an upstream area and a downstream area; a burner that is located within the upstream area of ​​the housing; a fuel flow path for supplying a combustible fuel to the burner; an air flow path for supplying air to the burner; a collector inside the housing, wherein the collector is an ion collector or a photon collector; a detonator in the downstream area; an ignition feed port near the igniter, configured to direct an ignition feed gas onto the igniter; and An exhaust gas opening in the downstream area of ​​the housing for venting exhaust gas from the housing. [2] Flame-based detector according to claim 1, wherein the igniter is a filament located inside or downstream of the collector tube. [3] Flame-based detector according to claim 2, further comprising an ignition device connected to the housing, wherein the filament is located inside the ignition device. [4] Flame-based detector according to claim 1, further comprising an ignition-promoting fitting connected to the housing. [5] Flame-based detector according to claim 1, wherein the ignition feed port is configured to blow the shielding gas directly onto the igniter. [6] Flame-based detector according to claim 1, wherein the igniter and the ignition feed connection are located on opposite surfaces of the housing. [7] Flame-based detector according to claim 1, wherein the ignition feed port is located at a distance of about 1 mm to about 25 mm from the igniter. [8] Flame-based detector according to claim 1, wherein the ignition feed port is located at an angle and at a distance of about 1 mm to about 25 mm upstream or downstream of the igniter. [9] Flame-based detector according to claim 1, wherein the ignition feed port has a diameter or longest dimension of about 0.3 mm to about 1.0 mm. [10] Flame-based detector according to claim 1, comprising a plurality of said ignition-promoting connections arranged uniformly around the interior of the housing. [11] Flame-based detector according to claim 1, wherein the burner comprises a nozzle for forming a jet of fuel and air. [12] Flame-based detector according to claim 1, wherein the collector is an ion collector. [13] Flame-based detector according to claim 1, wherein the collector is a photon collector. [14] Flame-based detector according to claim 13, wherein the flame-based detector comprises a photomultiplier tube (PMT). [15] Detector system comprising a flame-based detector according to claim 1, a measuring instrument and a control unit, wherein the measuring instrument is configured to measure a signal from the collector and wherein the control unit is in signal communication with one or more other components of the detector system. [16] Detector system according to claim 15, further comprising a combustible fuel source fluidically connected to the fuel flow path and an air source fluidically connected to the air flow path. [17] Detector system according to claim 15, wherein the air source is fluidically connected to the ignition feed port. [18] Detector system according to claim 15, further comprising an ignition supply gas source which is fluidically connected to the ignition supply port. [19] Detector system according to claim 15, further comprising an ignition booster gas valve which is in signal communication with the control unit and is fluidically connected to the air source and / or the ignition booster gas source. [20] Method for igniting a flame-based detector according to claim 1, wherein the method comprises: Supplying fuel and air to the detector so that the fuel and air flow to the igniter; Guiding an ignition propellant gas to the detector's igniter; and Igniting a flame in the flame-based detector.

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