Ignition wire and its detector

Abstract

This patent relates to the field of hydrogen ionization detection technology. This patent provides an ignition wire, which includes: an ignition wire body, which is symmetrically shaped and is used for gas ignition and flame state signal collection; a contact end, which is used for external connection of voltage and external test circuit. Due to its own inertness, the ignition wire provided by this patent is not easily aged when used as an ignition wire; as a collector, it is spiral and coaxial with the nozzle, collecting signals in multiple stages to improve the collection efficiency; it serves as both an ignition wire and a collector, and at the same time as a flame state judging device, saving space and materials of the hydrogen ionization detector, reducing the volume and weight of the detector, and lowering the design and installation difficulty of the detector.

Description

Technical Field

[0001] This patent relates to the technical field of hydrogen ionization detection. Background Art

[0002] In the structure of the hydrogen ionization detector of a gas chromatograph, the ignition wire of the ignition device mostly uses alloy wire or precious metal wire; the collector mostly uses a circular or cylindrical stainless steel material (prone to rust); the flame state judgment method mostly uses methods such as the baseline jump of the instrument or the temperature above the flame of the hydrogen ionization detector to judge, and the ignition device, the collector, and the flame judgment device are independent of each other, occupying more space and hardware materials.

[0003] After the combustible gas (hydrogen) and the combustion-supporting gas (air / purified air) enter the hydrogen ionization detector, under the action of the igniter, a local high temperature is generated to ignite the flame.

[0004] When an organic substance flows out of the chromatographic column and enters the hydrogen ionization detector, electrochemical ionization occurs in the flame, generating positive and negative ions and electrons. Ions will be generated at the flame. Under the action of the polarization voltage, the positive ions move towards the collector (negative electrode), and the negative ions and electrons move towards the polarization electrode (positive electrode), forming a microcurrent. When flowing through the input resistor, a voltage drop is generated across its two ends. It is amplified by a microcurrent amplifier and a signal is recorded on a recorder.

[0005] In the structure of the hydrogen ionization detector of a gas chromatograph: the ignition wire of the ignition device mostly uses alloy wire or precious metal wire. During long-term use, due to the long-term burning of the flame of the hydrogen ionization detector, the ignition wire ages relatively fast and has a short service life. The collector mostly uses a circular or cylindrical stainless steel material. During long-term use, the carbon from the combustion of organic substances in the sample is deposited on the collector, causing carbon deposition on the collector and reducing the collection efficiency of the collector. The ignition device, the collector, and the flame state judgment device are independent of each other, occupying more space and hardware materials. Summary of the Invention

[0006] The purpose of this patent is to provide an ignition wire, including: an ignition wire body, which is symmetric, such as spiral, and is used for gas ignition and flame state signal collection; a contact end, which is used for external connection of voltage and external test circuit.

[0007] The second object of this patent is to provide a detector, comprising: positive or negative wire, polarized electrode wire, nozzle, auxiliary gas inlet, combustion gas inlet, sample inlet, ignition wire, circuit processing unit, polarized electrode, housing; the ignition wire is connected to the circuit processing unit through two positive or negative electrode wires, and whether the ignition wire is lit is controlled by the circuit processing unit; the nozzle communicates with the sample inlet, and the outer layer is surrounded by the polarized electrode, and the polarized electrode is connected to the circuit processing unit through the polarized electrode wire; the auxiliary gas inlet and the burner inlet are two holes on the housing, and an external gas source is connected through pipelines; the sample inlet is another hole on the housing, and a sample or a sample / carrier gas mixture is introduced through a pipeline; the ignition wire is fixed on the housing and is controlled by the circuit control unit.

[0008] The third object of this patent is to provide a method for controlling and collecting signals of a detector, which comprises the following steps: igniting the ignition wire, and the ignition of the ignition wire includes controlling DRV1 to be at a high level, DRV2 to be at a high level, and the ignition wire is connected to the circuit processing unit; controlling DRV3 to be at a high level, and the ignition wire body is lit; the ignition wire is connected to the temperature measurement circuit, and the ignition wire is connected to the temperature measurement circuit includes controlling DRV1 to be at a high level, DRV2 to be at a low level, the ignition wire is connected to the temperature measurement circuit, detecting the flame temperature, and the circuit processing unit judges the flame temperature and then judges whether the ignition is successful; the temperature measurement circuit confirms that the ignition is successful, and the ignition wire is connected to the signal collection circuit. The ignition wire is connected to the signal collection circuit includes: controlling DRV1 to be at a low level, and the ignition wire is connected to the signal collection circuit to collect the current signal of the sample flowing out of the nozzle and burning.

[0009] Further, before the ignition wire is ignited, it also includes that the auxiliary gas is introduced into the detector through the auxiliary gas inlet, the combustion gas is introduced into the detector through the combustion gas inlet, and the sample gas is introduced into the detector through the sample inlet.

[0010] Further, the detection of the flame temperature is that the ADUC845 chip generates a constant current source, generates a voltage on the ignition wire, and calculates the flame temperature value by collecting the voltage on the platinum wire coil.

[0011] Further, if the ignition is unsuccessful, it also includes repeating the ignition operation and the temperature measurement operation.

[0012] Due to its own inertia, the ignition wire provided by this patent is not easy to age as an ignition wire; as a collecting electrode, it is spiral and coaxial with the nozzle, collecting signals in multiple stages, improving the collection efficiency; it serves as both an ignition wire and a collecting electrode, and at the same time as a flame state judging device, saving space and materials of the hydrogen ionization detector, reducing the volume and weight of the detector, and reducing the design and installation difficulty of the detector. Description of the Drawings

[0013] Figure 1 It is a diagram of the ignition wire.

[0014] Among them, 1 is the ignition wire body and 2 is the contact end.

[0015] Figure 2 is a hydrogen ionization detector.

[0016] Among them, 1 and 2 are the positive or negative wires of the ignition wire, 3 is the polarization electrode wire, 4 is the nozzle, 5 is the auxiliary gas inlet, 6 is the combustion gas inlet, 7 is the sample inlet, 8 is the ignition wire, 9 is the circuit processing unit, 10 is the polarization electrode, and 11 is the housing.

[0017] Figure 3 is the control circuit diagram of the circuit processing unit. Specific implementation mode

[0018] Embodiment

[0019] An ignition wire for a hydrogen ionization detector of a gas chromatograph, comprising:

[0020] The ignition wire body 1, which is coaxial with the combustion flame; made of an inert material such as a noble metal wire with conductivity and not easy to age; serves both as an ignition head, realized by applying an external voltage through the contact end; and as a collecting electrode, realized by being coaxial with the flame to receive the flame signal in a three-dimensional multi-layer around the flame, and the signal collection is realized through the change of the conductive resistance signal. The ignition wire body can be in a spiral shape or other shapes to achieve coaxiality with the gas flow direction and the flame, that is, the direction of flame combustion is from a to b; at the same time, it realizes multi-stage signal collection to improve the collection efficiency; serves both as an ignition wire, a collecting electrode, and a flame state judging device, and judges the flame state of the detector by obtaining the resistance change of the noble metal wire; saves the space and materials of the hydrogen ionization detector, reduces the volume and weight of the detector, and reduces the design and installation difficulty of the detector.

[0021] The contact end 2 is used for connecting an external voltage. By applying an external voltage, the temperature of the ignition wire body is increased to ignite the flame, that is, the ignition head function is realized; at the same time, an external test circuit is connected to collect the change of the resistance signal to realize the collection of the flame signal. The resistance of the ignition wire body is positively correlated with the temperature change. The flame temperature of the hydrogen ionization detector is reflected by measuring the resistance between the contact ends, and then the flame state of the hydrogen ionization detector is judged. When it is determined that the flame is burning normally, the detection starts. When the organic matter flows out of the chromatographic column and enters the hydrogen ionization detector, electrochemical ionization occurs in the flame, generating positive and negative ions and electrons. Under the action of the polarization voltage, the positive ions move towards the collecting electrode, and the negative ions and electrons move towards the polarization electrode, forming a microcurrent. The microcurrent between the contact ends is amplified by a microcurrent amplifier and then a signal is recorded on the recorder to form a chromatogram, completing the signal collection.

[0022] A hydrogen ionization detector for a gas chromatograph, comprising: positive or negative wire 1, positive or negative wire 2, polarization wire 3, nozzle 4, auxiliary gas inlet 5, combustion gas inlet 6, sample inlet 7, ignition wire 8, circuit processing unit 9, polarization electrode 10, housing 11;

[0023] The ignition wire is connected to the circuit processing unit through two positive or negative electrode wires, and whether the ignition wire is lit is controlled by the circuit processing unit; the nozzle communicates with the sample inlet, and the outer layer is surrounded by a polarization electrode, and the polarization electrode is connected to the circuit processing unit through a polarization wire; the auxiliary gas inlet and the burner inlet are two holes on the housing, and an external gas source is connected through pipelines; the sample inlet is another hole on the housing, and a sample or a sample / carrier gas mixture is introduced through a pipeline; the ignition wire is fixed on the housing and is controlled by the circuit control unit.

[0024] A method for controlling an ignition wire and collecting signals for a hydrogen ionization detector of a gas chromatograph, comprising the following steps:

[0025] 1. The auxiliary gas is introduced into the detector through the auxiliary gas inlet and the combustion gas is introduced into the detector through the combustion gas inlet, and the sample gas is introduced into the detector through the sample inlet;

[0026] 2. The ignition wire is connected to the circuit processing unit through the positive or negative wire:

[0027] Control DRV1 to be at a high level and DRV2 to be at a high level, and the ignition wire is connected to the circuit processing unit.

[0028] Control DRV3 to be at a high level, and the ignition wire body is lit.

[0029] 3. After the ignition operation is completed, the ignition wire is connected to the temperature measurement circuit (TemperatureMeasurement) on the circuit processing unit for flame temperature detection. According to the positive temperature characteristic of the platinum wire and its linear relationship with temperature, the circuit processing unit judges the flame temperature, and then determines the flame state (i.e., whether the ignition is successful) according to the flame temperature; after the ignition wire body is lit, control DRV1 to be at a high level and DRV2 to be at a low level, and the ignition wire is connected to the temperature measurement circuit to detect the flame temperature.

[0030] The detection of the flame temperature is to generate a constant current source by the ADUC845 chip to generate a voltage on the ignition wire; due to the positive temperature characteristic of the ignition wire (for example, the resistance of the platinum wire is positively correlated with temperature) and its linear relationship with temperature, the ADUC845 calculates the flame temperature value by collecting the voltage on the platinum wire coil.

[0031] 4. When the ignition is not successful, re-execute the ignition operation in step 2 and the temperature measurement operation in step 3.

[0032] 5. After the temperature measurement circuit confirms successful ignition, the ignition wire is connected to the signal collection circuit (Signal) on the circuit processing unit and used as the collection electrode of the detector. After the sample enters the detector through the sample inlet and flows out from the nozzle, electrochemical ionization occurs in the flame. Under the action of the electric field formed by the polarization voltage on the polarization electrode, electrons form a microcurrent. After being amplified by the microcurrent amplifier, a chromatographic signal is formed on the display; that is, control DRV1 to be at a low level, connect the ignition wire to the signal collection circuit and use it as the collection electrode.

[0033] Due to its own inertia, the ignition wire provided by this patent is not easy to age when used as an ignition wire; as a collection electrode, it is spiral and coaxial with the nozzle, collecting signals in multiple stages to improve the collection efficiency; it serves as both an ignition wire and a collection electrode, and at the same time as a flame state judgment device, saving space and materials of the hydrogen ionization detector, reducing the volume and weight of the detector, and lowering the design and installation difficulty of the detector.

Claims

1. A method for controlling a detector and collecting signals, characterized in that the detector includes: a positive or negative wire, a polarized electrode wire, a nozzle, an auxiliary gas inlet, a combustion gas inlet, a sample inlet, an ignition wire, a circuit processing unit, a polarized electrode, and a housing; the ignition wire includes an ignition wire body and a contact end; the ignition wire body is symmetric and is used for igniting gas and collecting flame state signals; the symmetric shape is a spiral shape; the contact end is used for externally connecting a voltage and an external test circuit; the ignition wire is connected to the circuit processing unit through two positive or negative electrode wires, and whether the ignition wire is lit is controlled by the circuit processing unit; the nozzle communicates with the sample inlet, and the outer layer is surrounded by a polarized electrode, and the polarized electrode is connected to the circuit processing unit through a polarized electrode wire; the auxiliary gas inlet and the combustion gas inlet are two holes on the housing, and an external gas source is connected through pipelines; the sample inlet is another hole on the housing, and a sample or a sample / carrier gas mixture is introduced through a pipeline; the ignition wire is fixed on the housing and is controlled by the circuit control unit; the method for controlling and collecting signals includes the following steps: Igniting the ignition wire, which includes controlling DRV1 to be at a high level, DRV2 to be at a high level, and connecting the ignition wire to the circuit processing unit; controlling DRV3 to be at a high level, and the ignition wire body is lit; Connecting the ignition wire to the temperature measurement circuit, which includes controlling DRV1 to be at a high level, DRV2 to be at a low level, connecting the ignition wire to the temperature measurement circuit, detecting the flame temperature, and judging whether the ignition is successful by the circuit processing unit based on the flame temperature; After the temperature measurement circuit confirms successful ignition, connecting the ignition wire to the signal collection circuit, which includes: controlling DRV1 to be at a low level, and connecting the ignition wire to the signal collection circuit to collect the current signal of the sample flowing out of the nozzle and burning; 2. The method according to claim 1, characterized in that Before igniting the ignition wire, it also includes introducing auxiliary gas into the detector through the auxiliary gas inlet, introducing combustion gas into the detector through the combustion gas inlet, and introducing sample gas into the detector through the sample inlet.

3. The method according to claim 1, wherein The detection of the flame temperature is to generate a constant current source by the ADUC845 chip, generate a voltage on the ignition wire, and calculate the flame temperature value by collecting the voltage on the platinum wire coil.

4. The method according to claim 1, characterized in that If the ignition is unsuccessful, it also includes repeatedly performing the ignition operation and the temperature measurement operation.

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