Device for the mobile detection of organic compounds

Abstract

Device (1) for the mobile detection of organic compounds comprising at least one first flame ionization detector (3), wherein the first flame ionization detector (3) has at least one combustion chamber (6), electrical connections (14, 15, 16, 17, 18), fluidic connections (7, 9, 19) and fluidic supply lines (8, 10) to the combustion chamber (6), and further comprising a second flame ionization detector (4), wherein the second flame ionization detector (4) has at least one combustion chamber (6), electrical connections (14, 15, 16, 17, 18), fluidic connections (7, 9, 19) and fluidic supply lines (8, 10) to the combustion chamber (6), and further comprising a support (5). characterized by that the first flame ionization detector (3) and the second flame ionization detector (4) are realized in the same support (5), that the two flame ionization detectors share at least one component of a flame ionization detector during operation and that the first flame ionization detector (3) and the second flame ionization detector (4) have a common combustion chamber (6) and / or at least one common electrical connection (14, 15, 16, 17, 18) and / or at least one common fluidic connection (7, 9, 19) and / or at least one common fluidic supply line (8, 10).

Description

[0001] The invention is based on a device for the mobile detection of organic compounds comprising at least a first flame ionization detector, wherein the first flame ionization detector has at least one combustion chamber, electrical connections, fluidic connections and fluidic feed lines to the combustion chamber and further comprising a second flame ionization detector, wherein the second flame ionization detector has at least one combustion chamber, electrical connections, fluidic connections and fluidic feed lines to the combustion chamber and further comprising a carrier.

[0002] Furthermore, the invention relates to a method for producing a device according to the invention.

[0003] The use of flame ionization detectors is well known in the art for the detection of organic compounds, particularly hydrocarbon-containing compounds. The detection principle of a flame ionization detector is based on measuring the electrical conductivity of an oxyhydrogen flame, which increases with the addition of hydrocarbon-containing compounds. Specifically, the sample gas to be analyzed is mixed with a fuel gas, preferably hydrogen, and both the gas mixture and an oxidizing agent, preferably oxygen or air, are fed into a combustion chamber. In the combustion chamber, the sample gas is ionized in an oxyhydrogen flame, and the ion current is measured as a measure of the hydrocarbon concentration in the sample gas.

[0004] The mobile use of flame ionization detectors, for example, for checking the tightness of gas lines, as well as their use as field devices, are particularly important in practice. Therefore, it is known to design flame ionization detectors in miniaturized versions.

[0005] Various microsystems technology processes are suitable for the production of miniaturized flame ionization detectors. In low-temperature cofired ceramics (LTCC), unfired – so-called green – ceramic films are individually structured, stacked, laminated (lamination generally refers to the bonding of layers using an adhesive), and subjected to a sintering profile at a peak temperature between approximately 850 °C and 900 °C. The maximum temperatures encountered during sintering differ from the production of high-temperature cofired ceramics (HTCC), which are sintered at temperatures between 1600 °C and 1800 °C. Thick-film hybrid techniques are also known, in which conductor tracks or resistors are applied to pre-sintered ceramic substrates using a screen-printing process.When the printed substrate is fired, the applied pastes fuse into layers. Subsequently, discrete components are assembled, if necessary.

[0006] In some applications, the distinction between the methane content of a sample gas and the total hydrocarbon content (THC) is relevant. To measure the methane content, a catalyst is placed upstream of the flame ionization detector. This catalyst burns all hydrocarbons except methane, so that the downstream flame ionization detector only measures methane.

[0007] In order to determine both the methane and THC content of a sample gas, it is known to switch the operation of a flame ionization detector between operation with and without a catalyst. However, this has the disadvantage that the methane and THC contents cannot be measured simultaneously, but only sequentially. It is also known to feed the sample gas to two flame ionization detectors, with a catalyst upstream of one flame ionization detector and the other flame ionization detector operating without a catalyst. While this design ensures the possibility of simultaneous determination of the methane and THC contents, it also has the disadvantage that both the energy required to operate the two flame ionization detectors and the cost of the electrical and fluidic connections are very high.

[0008] From the document DE 10 2012 015 204 A1 a method for producing a flame ionization detector and a corresponding miniaturized flame ionization detector are known, wherein the manufacturing method comprises an LTTC method.

[0009] In addition, the document EP 2 837 935 A1 discloses a method for producing a functional unit comprising a gas converter and a flame ionization detector, wherein the functional unit is produced by means of a ceramic multilayer process.

[0010] Flame ionization detectors are also known from the documents DE 26 26 232 A1, CN 205809017 U, EP 3 299 807 A1, DE 2 257 099 A and US 2018 / 0275113 A1.

[0011] Based on the prior art described above, the object of the present invention is to provide a device for the mobile detection of organic compounds that can be operated particularly advantageously. Furthermore, the object of the invention is to provide a method for producing a device according to the invention.

[0012] According to a first teaching of the present invention, the above-mentioned object is achieved by a device as described in the introduction in that the first flame ionization detector and the second flame ionization detector are realized in the same carrier and that the first flame ionization detector and the second flame ionization detector have a common combustion chamber and / or at least one common electrical connection and / or at least one common fluidic connection and / or at least one common fluidic supply line.

[0013] The arrangement of two flame ionization detectors on a common carrier already reduces the heating energy required for the operation of the two flame ionization detectors due to the spatial proximity.

[0014] Furthermore, the device according to the invention is characterized in that the two flame ionization detectors are combined on the same support in such a way that at least one component of a flame ionization detector is shared by both flame ionization detectors. In addition to the spatial proximity of the two flame ionization detectors, the inventive combination of the flame ionization detectors also allows for a reduction in the required heating energy and / or the number of electrical and / or fluidic connections and / or fluidic supply lines.

[0015] In addition to the aforementioned advantages, the device according to the invention has the further advantages of minimizing costs, weight and volume.

[0016] Overall, a device according to the invention can be operated particularly advantageously compared to the operation of two separate flame ionization detectors.

[0017] According to one embodiment, the device according to the invention comprises two miniaturized flame ionization detectors, so that the device according to the invention can also be manufactured by a microsystem technology method.

[0018] According to a further preferred embodiment, the first flame ionization detector and the second flame ionization detector have a common combustion chamber. The fluidic supply lines of the first flame ionization detector are arranged at a distance from the fluidic supply lines of the second flame ionization detector such that a first measuring range of the first flame ionization detector is present, wherein a first oxyhydrogen flame burns in the first measuring range during operation, and a second measuring range of the second flame ionization detector is present, wherein a second oxyhydrogen flame burns in the second measuring range during operation.

[0019] According to an alternative embodiment, the first flame ionization detector has a first combustion chamber and the second flame ionization detector has a second combustion chamber.

[0020] Particularly preferably, the first flame ionization detector and the second flame ionization detector have a common combustion chamber and at least one common electrical connection in the form of common ignition electrodes. Particularly advantageously, according to this embodiment, the flame of two flame ionization detectors can be ignited by a pair of ignition electrodes, thereby further reducing the number of electrical connections required to operate two flame ionization detectors.

[0021] It is particularly advantageous if the common ignition electrodes are arranged substantially centrally in the common combustion chamber in such a way that the first measuring range of the first flame ionization detector and the second measuring range of the second flame ionization detector are each arranged on one side of the ignition electrodes.

[0022] According to an alternative embodiment, the two flame ionization detectors have a common combustion chamber, wherein a first pair of ignition electrodes is arranged in the region of the first measuring range of the first flame ionization detector and wherein a second pair of ignition electrodes is arranged in the region of the second measuring range of the second flame ionization detector.

[0023] According to a further advantageous embodiment, the first flame ionization detector and the second flame ionization detector have a common combustion chamber, wherein a first exhaust gas outlet is arranged in the region of the first measuring range of the first flame ionization detector and wherein a second exhaust gas outlet is arranged in the region of the measuring range of the second flame ionization detector and wherein a third exhaust gas outlet is arranged between the first measuring range and the second measuring range, which prevents mixing of the gases from the first flame ionization detector and the second flame ionization detector.

[0024] According to a further advantageous embodiment, the electrical connections of the first flame ionization detector comprise a measuring electrode and a counter electrode, and the electrical connections of the second flame ionization detector comprise a measuring electrode and a counter electrode, wherein the first flame ionization detector and the second flame ionization detector have a common counter electrode. This embodiment also ensures the advantage of reducing the number of electrical connections required for operating the device according to the invention.

[0025] A further embodiment is characterized in that the first flame ionization detector has a first thermistor and that the second flame ionization detector has a second thermistor, wherein the first thermistor and the second thermistor have a common tap.

[0026] Furthermore, it is further advantageous if, alternatively or in addition to a common combustion chamber and / or common electrical connections, fluidic connections are also common to the first and the second flame ionization detector.

[0027] According to one embodiment, the fluidic connections of the first flame ionization detector and the second flame ionization detector each comprise a fuel gas inlet and a hydrogen and sample gas inlet, wherein the first flame ionization detector and the second flame ionization detector have a common fuel gas inlet and / or a common hydrogen and sample gas inlet.

[0028] Oxygen or air are generally suitable as fuel gases.

[0029] The presence of a hydrogen and sample gas inlet requires that the sample gas is mixed externally with hydrogen. It is also conceivable for the flame ionization detectors to have at least one fuel gas inlet, at least one hydrogen inlet, and at least one sample gas inlet. All designs for the fluidic connections and / or supply lines can also be implemented with separate fuel gas, hydrogen, and sample gas inlets. In this respect, the invention also encompasses the aforementioned embodiments.

[0030] According to a particularly preferred embodiment, the branching into a first fuel gas supply line for operating the first flame ionization detector and a second fuel gas supply line for operating the second flame ionization detector and / or the branching into a first hydrogen and sample gas supply line for operating the first flame ionization detector and a second hydrogen and sample gas supply line for operating the second flame ionization detector is integrated into the carrier. This embodiment not only has the advantage of reducing the number of fluidic connections, but integrating the branching into the carrier also has the advantage of preventing potential leaks by reducing the number of lines that need to be connected for the branching.

[0031] The device according to the invention can, in principle, be used for a variety of purposes. As already explained at the beginning, in some applications it is relevant to analyze a sample gas for both its methane and THC content.

[0032] According to a further embodiment, a gas converter, in particular a catalyst, is arranged in the area of ​​the hydrogen and sample gas supply line of the second flame ionization detector. The integration of the gas converter into the hydrogen and sample gas supply line ensures that the sample gas can be prepared prior to analysis, particularly in cases where the first flame ionization detector and the second flame ionization detector have a common hydrogen and sample gas inlet. For example, a catalyst burns all hydrocarbons except methane, so that only methane can be measured in the downstream combustion chamber during operation.

[0033] The integration of a catalyst into the device according to the invention has the advantage that less heating power is required for the oxidation of the hydrocarbons compared to an externally operated catalyst. This results in further energy savings for the operation of the device.

[0034] In an alternative embodiment, a gas converter, in particular a catalyst, is arranged outside the common carrier and thus externally upstream of the second catalyst. According to this embodiment, the first flame ionization detector and the second flame ionization detector each have their own hydrogen and sample gas inlets.

[0035] Furthermore, the inventive combination or integration of at least two flame ionization detectors is also suitable for the analysis of two different sample gases. In this case, too, the first flame ionization detector and the second flame ionization detector each have their own hydrogen and sample gas inlets. All of the above-described possibilities for using different components together are also conceivable for this configuration.

[0036] According to a further advantageous embodiment, the device according to the invention comprises more than two flame ionization detectors arranged on the same carrier or implemented in the same carrier, wherein at least two flame ionization detectors have a common combustion chamber and / or at least one common electrical connection and / or at least one common fluidic connection and / or at least one common fluidic supply line. According to this embodiment, all combinations of jointly used components are conceivable.

[0037] According to one embodiment, the common carrier is formed as a chip or wafer. Particularly preferably, the carrier is a ceramic monolith.

[0038] According to a further preferred embodiment, all electrical and fluidic connections are arranged on one side of the carrier, so that the device as a whole is designed as an SMD component.

[0039] Furthermore, the object set out at the outset is not achieved according to the invention by a method described at the outset in that the device described above is produced by a microsystem technology method.

[0040] Particularly preferably, the device is manufactured using ceramic multilayer technology, wherein the separate and common components of the flame ionization detectors are already realized during production by appropriate structuring of the ceramic foils to be connected to one another.

[0041] In a particularly advantageous manner, the combination and integration of the flame ionization detectors according to the invention can be realized during production.

[0042] In detail, there are now numerous possibilities for designing and developing the device and method according to the invention. Reference is made to the claims subordinate to the independent claims as well as to the following description of preferred embodiments in conjunction with the drawings. The drawings show: Fig. 1 a combination of two flame ionization detectors known from the state of the art, Fig. 2 a first embodiment of a device according to the invention, Fig. 3 a second embodiment of a device according to the invention, Fig. 4 a third embodiment of a device according to the invention and Fig. 5 shows a further embodiment of a device according to the invention, Fig. 6 shows a further embodiment of a device according to the invention and Fig. 7 an embodiment of a method.

[0043] In the illustrated embodiments, all flame ionization detectors are designed such that the fluidic supply lines are arranged opposite one another on the combustion chamber. This is advantageous, but not a mandatory limitation of the device according to the invention. Other geometric arrangements of the fluidic supply lines are also conceivable and advantageous.

[0044] Furthermore, the following exemplary embodiments always describe a configuration in which the measurement gas is mixed with hydrogen before being introduced into the device according to the invention. This is advantageous, but should not necessarily limit the invention. Configurations with separate inlets for the fuel gas, the hydrogen, and the measurement gas are also conceivable.

[0045] Fig. 1 shows a combination known from the prior art comprising a first flame ionization detector 3 and a second flame ionization detector 4. Each flame ionization detector 3, 4 is arranged on a separate carrier 5.

[0046] In addition, each flame ionization detector 3, 4 has a combustion chamber 6 in which the ionization of the sample gas and thus the detection of the organic compounds takes place. Each flame ionization detector 3, 4 has an oxygen inlet 7, with the introduced oxygen being fed into the combustion chamber 6 via an oxygen supply line 8. Furthermore, each flame ionization detector 3, 4 has a hydrogen and sample gas inlet 9, with the hydrogen being fed into the combustion chamber 6 together with the sample gas via a hydrogen and sample gas supply line 10.

[0047] The second flame ionization detector 4 also has a catalyst 11 in the area of ​​the hydrogen and sample gas supply line 10, in which all hydrocarbon-containing compounds except methane are oxidized. Thus, the first flame ionization detector 3 is designed to measure the total hydrocarbon content (THC), and the second flame ionization detector 4 is designed to measure methane.

[0048] In addition, the first flame ionization detector 3 and the second flame ionization detector 4 have further electrical connections and fluidic connections for operation.

[0049] In detail, each flame ionization detector 3, 4 has two ignition electrodes 14 for igniting the oxyhydrogen flame within the combustion chamber 6. Furthermore, each flame ionization detector 3, 4 has a measuring electrode 15 and a counter electrode 16. To monitor the temperature, each flame ionization detector 3, 4 has a thermistor 17 and thermistor taps 18.

[0050] In addition, two exhaust gas outlets 19 are arranged on each combustion chamber 6.

[0051] Fig. Figure 2 shows a first embodiment of two flame ionization detectors 3, 4 combined on a common carrier. The two flame ionization detectors 3, 4 have a common combustion chamber 6 and two common ignition electrodes 14. The ignition electrodes 14 are arranged essentially centrally in the combustion chamber 6, so that the first measuring area 12 of the first flame ionization detector 3 and the second measuring area 13 of the second flame ionization detector 4 are each arranged on one side of the ignition electrodes 14. In this way, two oxyhydrogen flames can advantageously be ignited with one pair of ignition electrodes 14 during operation.

[0052] In addition, an exhaust gas outlet 19 is arranged on the combustion chamber 6 in the area of ​​the first measuring range 12 of the first flame ionization detector 3 and in the area of ​​the second measuring range 13 of the second flame ionization detector 4. Another exhaust gas outlet 19 is arranged in the central area of ​​the combustion chamber 6. This third exhaust gas outlet 19 ensures that no mixing of the measuring gases to be analyzed occurs from the area of ​​the first flame ionization detector 3 and from the area of ​​the second flame ionization detector 4.

[0053] Furthermore, the illustrated device 1 is characterized by the presence of a common oxygen inlet 7. The branching into two separate oxygen supply lines 8 is advantageously realized through or in the support 5, which is advantageous with regard to the connection of the illustrated device 1. Furthermore, the illustrated combination of two flame ionization detectors 3, 4 has a common hydrogen and measurement gas inlet 9. This also advantageously reduces the number of fluidic connections of the illustrated device 1.

[0054] The first flame ionization detector 3 has a catalyst 11 in the area of ​​the hydrogen and sample gas supply line 10, which oxidizes all hydrocarbons except methane during operation. Thus, the first flame ionization detector 3 is designed to measure methane.

[0055] In the combustion chamber 6, a measuring electrode 15 is arranged in the first measuring range 12 of the first flame ionization detector 3 and in the second measuring range 13 of the second flame ionization detector 4. Furthermore, a common counter electrode 16 is provided, which extends over the first measuring range 12 of the first flame ionization detector 3 and over the second measuring range 13 of the second flame ionization detector 4. Compared to the operation of two separate flame ionization detectors, this eliminates the need for an electrical connection.

[0056] Furthermore, a thermistor 17 for temperature monitoring is arranged on the combustion chamber 6, both in the first measuring range 12 of the first flame ionization detector 3 and in the second measuring range 13 of the second flame ionization detector 4. The first flame ionization detector 3 and the second flame ionization detector 4 share a common thermistor tap 18.

[0057] As a result, the device 1 shown has a minimum number of electrical and fluidic connections due to the maximum combination of the two flame ionization detectors 3, 4 on a common carrier 5, so that the device shown can be operated with particularly little effort.

[0058] Fig. 3 shows a further embodiment of a device 1 according to the invention. In contrast to the device shown in Fig. In the embodiment shown in Figure 2, two separate combustion chambers 6 are present. According to this configuration, a pair of ignition electrodes 14 is arranged in each combustion chamber 6.

[0059] In addition, as described in the Fig. 2, a common oxygen inlet 7, a common hydrogen and sample gas inlet 9, a common counter electrode 16, and common thermistor taps 18 are present. Therefore, this embodiment also has a reduced number of electrical and fluidic connections.

[0060] The Fig. The embodiment of a device 1 according to the invention shown in Figure 4 differs from that shown in Fig. 2 in that two hydrogen and measuring gas inlets 9 are provided. According to one embodiment, a catalyst 11 (not shown here) is connected externally upstream of the first flame ionization detector 3, so that the conditioned measuring gas is already introduced at the hydrogen and measuring gas inlet 9. The remaining components are Fig. 2 described accordingly used together.

[0061] According to another embodiment, the illustrated device 1 can also be used to measure two different sample gases. During operation, a first sample gas is introduced into the first flame ionization detector 3, and a second sample gas is introduced into the second flame ionization detector 4.

[0062] Fig. Figure 5 schematically shows an embodiment in which three flame ionization detectors are implemented on a common carrier 5. The flame ionization detectors have a common oxygen inlet 7 and a common combustion chamber 6. Different measurement gases can be introduced into the hydrogen and measurement gas inlets 9 during operation.

[0063] In contrast, Fig. 6 an embodiment of the device 1 according to the invention with three flame ionization detectors, each flame ionization detector having its own combustion chamber 6.

[0064] In Fig.Figure 7 shows a first embodiment of a method 2. According to the method 2 shown, the device 1 according to the invention is manufactured using ceramic multilayer technology 20. In detail, individual ceramic foils are structured and bonded together in such a way that the combination of the components of the plurality of flame ionization detectors is already realized during the manufacturing process. Reference symbol 1 device 2 procedures 3 Flame ionization detector 4 Flame ionization detector 5 carriers 6 combustion chamber 7 Oxygen inlet 8 Oxygen supply line 9 Hydrogen and sample gas inlet 10 Hydrogen and sample gas supply line 11 Catalyst 12 first measuring range 13 second measuring range 14 ignition electrodes 15 measuring electrode 16 Counter electrode 17 Thermistor 18 Thermistor tap 19 Exhaust outlet 20 ceramic multilayer technology

Claims

[1] Device (1) for the mobile detection of organic compounds comprising at least a first flame ionization detector (3), wherein the first flame ionization detector (3) has at least one combustion chamber (6), electrical connections (14, 15, 16, 17, 18), fluidic connections (7, 9, 19) and fluidic feed lines (8, 10) to the combustion chamber (6) and further comprising a second flame ionization detector (4), wherein the second flame ionization detector (4) has at least one combustion chamber (6), electrical connections (14, 15, 16, 17, 18), fluidic connections (7, 9, 19) and fluidic feed lines (8, 10) to the combustion chamber (6) and further comprising a carrier (5), characterized by , that the first flame ionization detector (3) and the second flame ionization detector (4) are realized in the same carrier (5), that the two flame ionization detectors share at least one component of a flame ionization detector during operation and that the first flame ionization detector (3) and the second flame ionization detector (4) have a common combustion chamber (6) and / or at least one common electrical connection (14, 15, 16, 17, 18) and / or at least one common fluidic connection (7, 9, 19) and / or at least one common fluidic supply line (8, 10). [2] Device (1) according to claim 1, characterized byin that the first flame ionization detector (3) and the second flame ionization detector (4) have a common combustion chamber, wherein the fluidic supply lines (8, 10) of the first flame ionization detector (3) are arranged at a distance from the fluidic supply lines (8, 10) of the second flame ionization detector (4) in such a way that a first measuring range (12) of the first flame ionization detector (3) is present, wherein a first oxyhydrogen flame burns in the first measuring range (12) during operation, and that a second measuring range (13) of the second flame ionization detector (4) is present, wherein a second oxyhydrogen flame burns in the second measuring range (13) during operation. [3] Device (2) according to claim 1 or 2, characterized by that the first flame ionization detector (3) and the second flame ionization detector (4) have a common combustion chamber (6) and common ignition electrodes (14). [4] Device (1) according to claim 3, characterized bythat the common ignition electrodes (14) are arranged centrally in the common combustion chamber (6) in such a way that the first measuring range (12) of the first flame ionization detector (3) and the second measuring range (13) of the second flame ionization detector (4) are each arranged on one side of the ignition electrodes (14). [5] Device (1) according to one of claims 1 to 4, characterized by in that the first flame ionization detector (3) and the second flame ionization detector (4) have a common combustion chamber (6), wherein a first exhaust gas outlet (19) is arranged in the region of the measuring range (12) of the first flame ionization detector (3), and wherein a second exhaust gas outlet (19) is arranged in the region of the second measuring range (13) of the second flame ionization detector (4), and wherein a third exhaust gas outlet (19) is arranged between the first measuring range (12) and the second measuring range (13). [6] Device (1) according to one of claims 1 to 5, characterized by that the electrical connections (14, 15, 16, 17, 18) of the first flame ionization detector (3) comprise a measuring electrode (15) and a counter electrode (16) and that the electrical connections (14, 15, 16, 17, 18) of the second flame ionization detector (4) comprise a measuring electrode (15) and a counter electrode (16), wherein the first flame ionization detector (3) and the second flame ionization detector (4) have a common counter electrode (16). [7] Device (1) according to one of claims 1 to 6, characterized by that the first flame ionization detector (3) has a first thermistor (17) and that the second flame ionization detector (4) has a second thermistor (17), wherein the first thermistor and the second thermistor (17) have a common thermistor tap (18). [8] Device (1) according to one of claims 1 to 7, characterized bythat the fluidic connections (7, 9, 19) of the first flame ionization detector (3) and the second flame ionization detector (4) each have a fuel gas inlet (7) and a hydrogen and measuring gas inlet (9), wherein the first flame ionization detector (3) and the second flame ionization detector (4) have a common fuel gas inlet (7) and / or a common hydrogen and measuring gas inlet (9). [9] Device (1) according to claim 8, characterized bythat a branch into a first fuel gas supply line (8) for the operation of the first flame ionization detector (3) and into a second fuel gas supply line (8) for the operation of the second flame ionization detector (4) and / or a branch into a first hydrogen and measuring gas supply line (10) for the operation of the first flame ionization detector (3) and into a second hydrogen and measuring gas supply line (10) for the operation of the second flame ionization detector (4) is integrated into the carrier (5). [10] Device (1) according to one of claims 1 to 9, characterized by that a gas converter, in particular a catalyst (11), is arranged in the region of the hydrogen and measuring gas supply line (10) of the second flame ionization detector (4). [11] Device (1) according to one of claims 1 to 10, characterized bythat the device (1) has more than two flame ionization detectors (3, 4) which are realized in the same carrier (5), wherein at least two flame ionization detectors (3, 4) have at least one common electrical connection (14, 15, 16, 17, 18) and / or at least one common fluidic connection (7, 9, 19) and / or a common fluidic supply line (8, 10).

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