Low-temperature ignition device and method based on platinum metal catalytic hydrogen combustion

Abstract

The ignition device of the hydrogen flame ionization detector comprises a spring-shaped catalysis unit, ignition gas enters from one end of the catalysis unit and is blown out from the other end of the catalysis unit, and the surface of the catalysis unit is pure platinum or platinum alloy. The low-temperature ignition device and method based on platinum metal catalysis hydrogen combustion have the advantages of being low in cost, low in temperature, safe and efficient, electric spark-free, low-temperature, safe and efficient ignition can be achieved, and the low-temperature ignition device and method are suitable for hydrogen flame ionization detectors and other scenes needing hydrogen ignition; the problems of high cost, low safety, short service life, high energy consumption and the like in a traditional ignition mode are solved, and the method has a wide application prospect.

Description

Technical Field

[0001] This application relates to the field of hydrogen flame ionization detection, and in particular to a cryogenic ignition device and method based on platinum metal catalytic hydrogen combustion. Background Technology

[0002] The flame ionization detector (FID) is one of the most widely used detectors in gas chromatography. It generates a flame by burning a mixture of hydrogen and air, ionizing the sample and detecting its concentration. Traditional FID ignition involves applying a high-current DC voltage to an ignition coil, heating the ignition wire to a red-hot state (a temperature exceeding the ignition point of hydrogen at 482°C), thus igniting the hydrogen-air mixture. However, this ignition method has the following problems.

[0003] 1. Circuit board design: A circuit board for outputting ignition voltage needs to be designed, which has high labor and R&D costs.

[0004] 2. Electric spark ignition: First, a DC voltage is applied to heat the ignition wire to a red-hot state, and then the mixture of hydrogen and air is ignited. This method has high energy consumption and poses a risk of electrical sparks.

[0005] 3. Limited lifespan: Prolonged electric heating and high temperatures can cause the ignition wire to age or be damaged, reducing its lifespan.

[0006] 4. Insufficient safety: In flammable and explosive environments, traditional ignition methods pose a risk of electrical sparks and are difficult to meet the stringent requirements of special equipment such as explosion-proof equipment.

[0007] Therefore, it is necessary to develop a safer cryogenic ignition device to achieve efficient, low-temperature, and safe ignition, avoid the generation of electrical sparks, and extend the device's lifespan. Summary of the Invention

[0008] To address the aforementioned issues, this invention proposes an ignition device and method based on platinum metal catalysis for hydrogen combustion. By utilizing the specific catalytic properties of platinum metal for hydrogen, low-temperature ignition is achieved, thus solving the problems of high design cost, short ignition wire life, low safety, and high energy consumption inherent in traditional hydrogen flame ionization detector ignition methods. This application achieves safe and efficient ignition by optimizing the material, shape, and position of the ignition unit.

[0009] Item 1. An ignition device for a hydrogen flame ionization detector, comprising a spring-shaped catalytic unit, wherein ignition gas enters from one end of the catalytic unit and exits from the other end of the catalytic unit, and the surface of the catalytic unit is pure platinum or a platinum alloy.

[0010] Item 2. The ignition device according to Item 1, wherein the catalytic unit is arranged in a vertical direction, and the ignition gas enters from the lower end of the catalytic unit and exits from the upper end of the catalytic unit.

[0011] Item 3. The ignition device according to Item 1, wherein the platinum alloy is a platinum-iridium alloy, a platinum-palladium alloy, a platinum-ruthenium alloy, or a platinum-tungsten alloy, and the platinum content in the platinum alloy is 90% or more.

[0012] Item 4. The ignition device according to Item 1 further includes a catalytic control unit, a temperature control unit, a burner head, a gas control unit, and an ignition control unit. The ignition control unit is communicatively connected to the catalytic control unit, the gas control unit, and the temperature control unit, respectively. The catalytic control unit is communicatively connected to the catalytic unit. The gas control unit is connected to the temperature control unit through a pipe. The burner head is connected to the temperature control unit. The catalytic unit is located directly above the burner head.

[0013] Item 5. The ignition device according to Item 1, wherein the diameter of the catalytic unit is 0.2 to 1 mm.

[0014] Item 6. A method for ignition using any one of items 1 to 5, comprising the following steps: Adjust the catalytic converter to be directly above the burner head; Preheated gas is introduced into the catalytic unit to activate it; The ignition gas is delivered to the catalytic unit for ignition; After successful ignition, hydrogen and air are continuously supplied to maintain flame combustion.

[0015] Item 7. The ignition method according to Item 6, wherein the preheating gas is an inert gas and / or an ignition gas.

[0016] Item 8. The ignition method according to Item 6, wherein the temperature of the preheated gas is 20°C to 100°C.

[0017] Item 9. The ignition method according to Item 6, wherein the ignition gas comprises hydrogen and air, and the volume ratio of hydrogen to air is 1:5 to 1:15.

[0018] Item 10. The ignition method according to Item 6, wherein the distance between the catalytic unit and the combustion head is 5 to 25 mm, preferably 5 to 15 mm.

[0019] The ignition device provided in this application features low temperature, safety, and hydrogen specificity, making it suitable for scenarios where hydrogen and air are mixed and then ignited in a hydrogen flame ionization detector. It is especially suitable for electrical equipment with high safety requirements, such as explosion-proof gas chromatographs.

[0020] The ignition device and ignition method described in this application have the following advantages.

[0021] 1. Low-temperature ignition: Utilizing the catalytic properties of platinum metal, the ignition temperature is significantly lower than that of traditional methods, reducing energy consumption and equipment wear.

[0022] 2. High safety: No voltage ignition is required, avoiding the generation of electrical sparks, making it particularly suitable for flammable and explosive environments.

[0023] 3. Extended lifespan: Low-temperature ignition reduces the aging and damage of platinum wires, extending the service life of the device.

[0024] 4. Hydrogen specificity: Platinum wire exhibits high selectivity for hydrogen catalytic combustion, ensuring the efficiency and safety of the ignition process.

[0025] 5. Low cost: The simple mechanical structure design enables low-temperature ignition without the need for complex ignition circuits. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the ignition device described in this application.

[0027] Figure 2 This is a flowchart of the ignition method described in this application. Detailed Implementation

[0028] Specific embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While specific embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0029] This invention provides an ignition device based on platinum metal catalytic hydrogen combustion, comprising a catalytic unit, a catalytic control unit, a temperature control unit, a burner head, a gas control unit, and an ignition control unit. Specifically, the ignition control unit is communicatively connected to the catalytic control unit, the gas control unit, and the temperature control unit, and the catalytic control unit is also communicatively connected to the catalytic unit. The gas control unit is connected to the temperature control unit via a pipeline. The temperature control unit includes a temperature control module and a heating chamber. Hydrogen and air in the gas control unit are respectively connected to the temperature control module via pipelines. The carrier gas (usually an inert gas) in the gas control unit is connected to the heating chamber via a pipeline. The heating chamber is connected to the temperature control module via a pipeline. The burner head is connected to the temperature control module, and the catalytic unit is located directly above the burner head.

[0030] The ignition control unit includes computer control software, which is used to start and stop the ignition process, monitor the ignition status, and control the flame status by controlling the gas flow to ensure safety and stability.

[0031] The function of the catalytic control unit is to adjust the spatial position of the catalytic unit in the ignition device to ensure that the platinum catalyst is located directly above the burner head and maintains a preset distance from the burner head.

[0032] The temperature control unit preheats the gas and monitors and controls the temperature of hydrogen, air, carrier gas, and the device in real time to ensure that the ignition process is within a safe temperature range and monitors the flame status in real time. It includes a temperature control module and a heating chamber, wherein the temperature control module can heat hydrogen and air, and the heating chamber can heat the carrier gas.

[0033] The gas control unit includes a hydrogen inlet, an air inlet, a carrier gas inlet, and a gas mixing chamber. The hydrogen inlet delivers hydrogen to the temperature control module, the air inlet delivers air to the temperature control module, the carrier gas inlet delivers carrier gas to the heating chamber, and the gas mixing chamber mixes hydrogen and air according to a preset ratio and delivers the mixture to the temperature control module for heating. The function of the gas control unit is to control the gas flow rate into the burner head, and after exiting the burner head, the gas enters the catalytic unit.

[0034] The burner head is a gas outlet that can output gas with a stable flow, and it can spray the gas heated by the heating box and / or temperature control module to the catalytic unit.

[0035] The catalytic unit catalyzes and activates the combustion reaction of hydrogen and air to achieve ignition at low temperatures. It includes a platinum catalyst, which is a spring-shaped metal wire with a surface of pure platinum or a platinum alloy, and a diameter of 0.2–1 mm. The catalytic unit is located above the burner head. Ignition gas escapes from the burner head, enters from one end of the catalytic unit, and exits from the other end.

[0036] When ignition is performed using a hydrogen flame ionization detector including the ignition device described in this application, the catalytic control unit adjusts the catalytic unit to a preset distance directly above the burner head. Then, the gas control unit delivers gas to the temperature control unit, which preheats the gas. The preheated gas flows out through the burner head, enters from one end of the catalytic unit, and exits from the other end. The preheated gas activates the catalytic unit. Then, the gas control unit delivers ignition gas to the catalytic unit for ignition. After successful ignition, hydrogen and air are continuously supplied to maintain flame combustion.

[0037] In this application, the catalytic unit is designed as a spiral spring structure, which gives the catalytic unit a large specific surface area, enabling it to catalyze the combustion reaction of hydrogen and air at room temperature. The larger the specific surface area, the faster the catalytically activated hydrogen combustion and the shorter the ignition time.

[0038] In some embodiments, the catalytic unit is a pure platinum wire or a platinum alloy wire, for example, a platinum-iridium alloy, a platinum-palladium alloy, a platinum-ruthenium alloy, or a platinum-tungsten alloy.

[0039] In some implementations, the platinum alloy contains 90% or more platinum.

[0040] In some embodiments, the catalytic unit is a metal wire plated with platinum or a platinum alloy on another substrate, such as a nickel-chromium alloy, pure nickel, pure copper, pure iron, or their alloys.

[0041] In some implementations, the catalytic unit is vertically positioned directly above the burner head, with ignition gas entering from the lower end of the catalytic unit and exiting from the upper end.

[0042] In some implementations, the distance between the catalytic unit and the burner head is set to 5–25 mm, for example, it can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, or 25 mm.

[0043] In some implementations, the distance between the catalytic unit and the burner head is set to 5–15 mm.

[0044] In some implementations, the distance between the catalytic unit and the combustion head is set to 10 mm.

[0045] In some embodiments, when the preheating gas activates the catalytic unit, the preheating gas may be an inert gas and / or an ignition gas.

[0046] In some implementations, the ignition gas includes hydrogen and air.

[0047] In some implementations, the inert gas is nitrogen.

[0048] In some implementations, the gas control unit sends ignition gas to the temperature control module for preheating, and the preheated gas is sprayed out through the burner head to the catalytic unit to activate the catalytic unit.

[0049] In some implementations, the gas control unit sends nitrogen to the heating chamber for preheating, and the preheated gas is sprayed through the burner head to the catalytic unit to activate the catalytic unit.

[0050] In some implementations, the gas control unit simultaneously delivers ignition gas and nitrogen to the temperature control unit for preheating, and the preheated gas is injected through the burner head to the catalytic unit to activate the catalytic unit.

[0051] In some embodiments, the temperature of the preheating gas is 20°C to 100°C, for example, it can be 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C.

[0052] In some embodiments, the volume ratio of hydrogen to air in the ignition gas is 1:5 to 1:15, for example, it can be 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, or 1:15.

[0053] In some embodiments, the volume ratio of hydrogen to air in the ignition gas is 1:5 to 1:10.

[0054] In this application, the communication connection between the units can be a wired connection, a wireless connection, or a dedicated communication protocol. This application does not limit the communication method, as long as it can realize communication between the units.

[0055] This application provides a low-temperature ignition device and method based on platinum metal catalytic hydrogen combustion, which features low cost, low temperature, safety, and high efficiency. It can achieve sparkless, low-temperature, safe, and efficient ignition, and is suitable for scenarios requiring hydrogen ignition, such as hydrogen flame ionization detectors. It solves the problems of high cost, low safety, short lifespan, and high energy consumption in traditional ignition methods, and has broad application prospects.

[0056] Example Example 1 use Figure 1 The ignition device shown has a catalytic unit made of pure platinum wire, which is 12 cm long, 0.2 mm in diameter, and has a spring-like spiral shape, and is arranged vertically.

[0057] During ignition, the catalytic unit is positioned 10 mm directly above the burner head. The gas activating the catalytic unit is the ignition gas, a mixture of hydrogen and air with a volume ratio of 1:10. The ignition temperature is between 20°C and 100°C. The mixed gas enters from the bottom of the catalytic unit and exits from the top. The temperature value fed back by the temperature sensor above the catalytic unit is recorded, along with the ignition time (in seconds).

[0058] Example 2: Effect of Platinum Content in Catalytic Unit on Ignition Performance use Figure 1 The device described in this example is used for ignition, but it differs from Example 1 in that the catalytic unit uses a platinum-iridium alloy wire with a platinum content of 95% and a platinum-iridium alloy wire with a platinum content of 90%, respectively. The temperature value fed back by the temperature sensor above the catalytic unit is recorded, and the time required for ignition (in seconds) is recorded. The experimental data are detailed in Table 1.

[0059] Table 1

[0060] As shown in Table 1, the lower the temperature, the longer the ignition time required; the higher the temperature, the shorter the ignition time required. The higher the platinum content, the shorter the ignition time; the lower the platinum content, the longer the ignition time. At 20℃, the ignition time is 15 seconds, which allows for ignition at room temperature.

[0061] Example 3: Effect of Substrate on Ignition Performance use Figure 1 The device described in this example is used for ignition. The difference from Example 1 is that the catalytic unit is made of nickel-chromium Cr20Ni80 platinum-plated metal wire and pure nickel platinum-plated metal wire, respectively. The temperature value fed back by the temperature sensor above the catalytic unit is recorded, along with the ignition time (in seconds). Detailed experimental data are shown in Table 2.

[0062] Table 2

[0063] As shown in Table 2, the ignition times of the two platinum-plated materials and the pure platinum wire at different temperatures are basically the same. The combustion of hydrogen and oxygen in the air catalyzed by platinum metal mainly occurs on the catalyst surface; therefore, the time required for the platinum-plated materials to catalyze hydrogen combustion is not significantly different from that of the pure platinum wire.

[0064] Example 4: Effect of Catalytic Unit Shape on Ignition Performance use Figure 1 The device described in this embodiment is used for ignition, but it differs from Embodiment 1 in that it uses catalytic units of different shapes. The temperature value fed back by the temperature sensor above the catalytic unit is recorded, and the time required for ignition (in seconds) is recorded. The experimental data are detailed in Table 3.

[0065] The shape of the catalytic unit is as follows.

[0066] The catalytic unit is paperclip shaped; specifically, platinum wires of the same length are bent into a two-dimensional paperclip shape.

[0067] The catalytic unit is shaped like a mosquito coil. Specifically, platinum wires of the same length are coiled into a two-dimensional planar mosquito coil spiral shape, which can increase the specific surface area for contact with hydrogen compared to a paperclip shape.

[0068] The catalytic unit is spring-shaped; specifically, platinum wires of the same length are made into a three-dimensional spring spiral and set horizontally.

[0069] Table 3

[0070] As shown in Table 3, the paperclip-shaped catalytic unit exhibits some catalytic activity. However, due to its large volume, it cannot contact a large amount of hydrogen, resulting in a longer ignition time, and at low temperatures, it fails to ignite even after more than 60 seconds. Both the mosquito coil-shaped and spring-shaped catalytic units can ignite hydrogen within 30 seconds, with the mosquito coil-shaped unit taking slightly longer. The ignition time of the horizontally fixed spring-shaped catalytic unit is not significantly different from that of the mosquito coil-shaped unit, likely because it is limited to the gas outlet area, resulting in a similar effective contact area with hydrogen. The vertically fixed spring-shaped catalytic unit requires the shortest ignition time. This is because the catalyst shape and fixing method both increase gas permeability and the specific surface area in contact with hydrogen, leading to good catalytic effect and short ignition time.

[0071] Example 5: Effect of the volume ratio of hydrogen to air in the ignition gas on ignition performance use Figure 1 The device described in this example is used for ignition, but it differs from Example 1 in that the volume ratio of hydrogen to air in the ignition gas (hydrogen-air ratio) is different, and the ignition temperature is 20°C. The temperature value fed back by the temperature sensor above the catalytic unit is recorded, and the time required for ignition (in seconds) is recorded. The experimental data are detailed in Table 4.

[0072] Table 4

[0073] As shown in Table 4, the lower the hydrogen ratio, the longer the ignition time. The higher the hydrogen ratio, the shorter the required ignition time. Increasing the hydrogen ratio increases the contact area between hydrogen and the catalytic unit per unit time, thus shortening the ignition time.

[0074] Example 6: Effect of the distance between the catalytic unit and the burner head on ignition performance use Figure 1 The device described in this example is used for ignition, but it differs from Example 1 in that the distance between the catalytic unit and the burner head is different. The temperature value fed back by the temperature sensor above the catalytic unit is recorded, and the time required for ignition (in seconds) is recorded. The experimental data are detailed in Table 5.

[0075] Table 5

[0076] The data in Table 5 show that the closer the catalytic unit is to the nozzle, the shorter the required ignition time; conversely, the farther the distance, the longer the required ignition time. This is because, limited by the internal spatial structure of the ignition device, the farther the distance, the smaller the hydrogen molecular weight. As the gas is ejected upwards, the more severe the dispersion, resulting in a very small amount of hydrogen activated by the catalyst, thus requiring a longer catalytic combustion time. When the distance is sufficiently far, the activated hydrogen molecular weight is too small to burn in air, thus failing to ignite the hydrogen. Too close a distance would directly scorch the catalytic unit, and the catalytic unit would also affect the flame shape. Considering both ignition time and other factors, this application uses a uniform distance of 10 mm.

[0077] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An ignition device for a hydrogen flame ionization detector, wherein, It includes a spring-shaped catalytic unit, with ignition gas entering from one end of the catalytic unit and exiting from the other end. The surface of the catalytic unit is pure platinum or a platinum alloy.

2. The ignition device according to claim 1, wherein, The catalytic unit is arranged vertically, and the ignition gas enters from the lower end of the catalytic unit and exits from the upper end of the catalytic unit.

3. The ignition device according to claim 1, wherein, The platinum alloy is a platinum-iridium alloy, a platinum-palladium alloy, a platinum-ruthenium alloy, or a platinum-tungsten alloy, and the platinum content in the platinum alloy is 90% or more.

4. The ignition device according to claim 1, wherein, It also includes a catalytic control unit, a temperature control unit, a burner head, a gas control unit, and an ignition control unit. The ignition control unit is communicatively connected to the catalytic control unit, the gas control unit, and the temperature control unit, respectively. The catalytic control unit is communicatively connected to the catalytic unit. The gas control unit is connected to the temperature control unit through a pipeline. The burner head is connected to the temperature control unit. The catalytic unit is located directly above the burner head.

5. The ignition device according to claim 1, wherein, The diameter of the catalytic unit is 0.2 to 1 mm.

6. A method for ignition using the ignition device according to any one of claims 1 to 5, wherein, Includes the following steps: Adjust the catalytic converter to be directly above the burner head; Preheated gas is introduced into the catalytic unit to activate it; The ignition gas is delivered to the catalytic unit for ignition; After successful ignition, hydrogen and air are continuously supplied to maintain flame combustion.

7. The ignition method according to claim 6, wherein, The preheating gas is an inert gas and / or an ignition gas.

8. The ignition method according to claim 6, wherein, The temperature of the preheated gas is 20℃~100℃.

9. The ignition method according to claim 6, wherein, The ignition gas includes hydrogen and air, with a hydrogen to air volume ratio of 1:5 to 1:

15.

10. The ignition method according to claim 6, wherein, The distance between the catalytic unit and the combustion head is 5–25 mm, preferably 5–15 mm.

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