TWI796829B - Gas detection system and detection method using the same - Google Patents

Abstract

A gas detection system and a detection method using the same are provided, the gas detection system including: a gas inlet, configured for an analyte to be inputted therein; a heating unit, connected with the gas inlet, configured to heat the analyte and make at least one target gas in the analyte to form at least one detection target; and a detection module, including a detection unit connected with the heating unit and a processing unit communicated with the detection unit, the detection unit configured to detect a content of the at least one detection target and producing at least one detection signal, the processing unit receiving the at least one detection signal and producing a detection result data according to the at least one detection signal; wherein the at least one target gas includes organochloride, and the at least one detection target includes hydrogen chloride.

Description

Gas detection system and detection method thereof

The invention relates to a detection system, in particular to a gas detection system and a detection method thereof.

Organochlorine compounds are often used as industrial solvents or paint removers, etc. Among them, dichloromethane has a low boiling point and is easy to volatilize into the air. If the exhaust gas is discharged inadvertently and causes leakage, it may cause harm to the human body. Even though dichloromethane does not accumulate in the human body, inhaling a large amount of dichloromethane can cause dizziness, nausea, numbness or tingling in the extremities; inhaling a small amount of dichloromethane can cause decreased concentration and increase the risk of operation , so it is necessary to monitor the ambient concentration of dichloromethane.

However, conventional detection methods for organochlorine compounds, such as but not limited to, using gas chromatography-mass spectrometry for analysis, can effectively achieve qualitative and quantitative purposes, but the operation is time-consuming and costly, and it is impossible to take samples and detect them in the environment immediately. The environmental concentration of organic chlorine compounds; if it is detected by means of extraction or photoionization, it is easily affected by other volatile gases, resulting in low accuracy, and it is not conducive to the detection of low concentrations. There are shortcomings that need to be improved urgently.

Therefore, it is necessary to provide a novel and progressive gas detection system and its detection method to solve the above problems.

The main purpose of the present invention is to provide a gas detection system and its detection method, which can be used for rapid sampling and detection of organic chlorine compounds in the environment, with good detection efficiency and high accuracy.

In order to achieve the above object, the present invention provides a gas detection system, comprising: an air inlet pipeline for inputting a gas to be tested; a heating unit connected to the air inlet pipeline for heating the gas to be tested and making the gas to be tested At least one target gas in the gas forms at least one detection target; and a detection module includes a detection unit connected to the heating unit and a processing unit connected to the detection unit, the detection unit is used to detect the at least one detection target and generate at least one detection signal, the processing unit can receive the at least one detection signal and obtain a detection result data accordingly; wherein, the at least one target gas includes organic chlorine compounds, and the at least one detection target includes hydrogen chloride.

In order to achieve the above object, the present invention further provides a detection method of the aforementioned gas detection system, comprising the following steps: sampling: inputting the gas to be tested to the heating unit; decomposing: heating the gas to be tested and making the at least one The target gas forms the at least one detection target; detection: input the at least one detection target to the detection unit and obtain the at least one detection signal through the detection unit; and obtain the result: the processing unit obtains the detection according to the at least one detection signal Results data.

The following examples illustrate possible implementations of the present invention, but are not intended to limit the scope of protection of the present invention.

Please refer to FIGS. 1 to 3 , which show a preferred embodiment of the present invention. The gas detection system of the present invention includes an air intake pipeline 10 , a heating unit 20 and a detection module 30 .

The gas inlet pipeline 10 is used to input a gas to be tested; the heating unit 20 is connected to the gas inlet pipeline 10, and the heating unit 20 is used to heat the gas to be tested and make at least one target gas in the gas to be tested form at least one Detection target; the detection module 30 includes a detection unit 31 connected to the heating unit 20 and a processing unit 32 connected to the detection unit 31, the detection unit 31 is used to detect the content of the at least one detection target and generate at least one The detection signal, the processing unit 32 can receive the at least one detection signal and obtain a detection result data accordingly; wherein the at least one target gas includes organic chlorine compounds, and the at least one detection target includes hydrogen chloride. With hydrogen chloride, which is relatively easy to detect, the purpose of rapid sampling and detection of the concentration of organic chlorine compounds in the environment can be achieved.

The heating temperature of the heating unit 20 is not lower than 700° C., so that the at least one target gas is fully pyrolyzed to release the at least one detection target, and the detection sensitivity is increased. Since other interfering gases do not form the same detection target, even if the concentration of the at least one target gas is within a low concentration range of 0 ppb to 20 ppb, it can be effectively detected without being easily affected by these interfering gases. Preferably, the intake pipeline 10 is additionally provided with a sampling pump 11, and the sampling pump 11 controls the intake flow rate of the intake pipeline 10 to be not less than 1.0L/min, so as to ensure that the intake air volume is sufficient for further pyrolysis. sample detection.

Further, the detection unit 31 includes a detection cavity 311 for inputting the at least one detection target, a detection light source 312, and a light detector 313 arranged on two sides of the detection cavity 311 opposite to the detection light source 312, the The light of the detection light source 312 can pass through the at least one detection target and form a light to be detected projected to the light detector 313, and the light detector 313 receives the light to be detected and generates the at least one detection signal. The detection module 30 further includes a flow regulating valve 33 connected between the heating unit 20 and the detection unit 31 , and the processing unit 32 can control the flow regulating valve 33 to control the flow rate and flow rate of sample injection. The detection module 30 further includes an operation display interface 34 for external operation, the operation display interface 34 communicates with the processing unit 32 and can display the detection result data. The detection result data can be, for example but not limited to, the value related to the content of the at least one target gas, the value related to the content of the at least one detection target, text prompts and warning lights generated after the processing unit 32 interprets, etc. , easy to operate and view the test results. In this embodiment, the detection module 30 is an off-axis integrated cavity spectral laser analyzer, which can obtain the content of the at least one detection target immediately and quickly, and has good detection efficiency. Of course, the detection module 30 can also use other analyzers as required.

The gas detection system further includes a dilution calibrator 40 that can be connected to the intake pipeline 10, and the dilute calibrator 40 is used to input a standard gas containing a known concentration of the target gas and a diluent gas, the dilute calibrator 40 mixing the standard gas and the dilution gas into at least one calibration gas and outputting it to the detection unit 31, the detection unit 31 detects the at least one calibration gas and generates at least one calibration signal, the processing unit 32 receives the at least one calibration signal and Based on this, the at least one detection signal is corrected to increase the accuracy of the detection result. Preferably, the intake pipeline 10 is further provided with a branch pipeline 12 between the sampling pump 11 and the dilution calibrator, and the branch pipeline 12 is provided with a bypass valve for discharging the excess of the at least one Calibration gas; the dilution calibrator 40 can control the output flow of the at least one calibration gas to be greater than the sampling flow of the sampling pump 11, so as to ensure that the gas to be tested entering the heating unit 20 is all the at least one calibration gas, thereby reducing the external Gas interference, increase the accuracy of detection.

With reference to FIG. 3 , the present invention further provides a detection method of the aforementioned gas detection system, which includes the following steps: Sampling S1: inputting the gas to be tested to the heating unit 20; decomposition S2: heating the gas to be tested and using The at least one target gas forms the at least one detection target; detection S3: input the at least one detection target to the detection unit 31 and obtain the at least one detection signal through the detection unit 31; and obtain the result S4: the processing unit 32 according to The at least one detection signal obtains the detection result data. With the above method, the content of the at least one target gas can be calculated by detecting the content of the at least one detection target, so that the at least one target gas that is difficult to measure can be sampled and detected quickly and accurately.

The detection method further includes the following steps: input a plurality of known gases with different contents of the at least one target gas to obtain a plurality of reaction results, and define a plurality of content indicators according to the plurality of reaction results; and the processing unit 32 is further based on the detection The corresponding result of the signal and the multiple content index obtains the test result data, so that the multiple content index can be established to obtain the test result data accurately and quickly.

It should be noted that the aforementioned organochlorine compounds may include, for example, chlorine-containing organic compounds such as dichloromethane and dichloroethylene, or any other gas that can generate hydrogen chloride after thermal decomposition. The following is a further test with the plurality of known gases to verify the feasibility of the present invention for gas detection of organic chlorine compounds. With reference to Fig. 4, the X-axis represents the dichloromethane concentration that the dilution calibrator enters into the intake pipeline 10, and the Y-axis represents the hydrogen chloride concentration measured by the gas detection system; the sampling pump 11 controls the intake pipeline 10 The inflow rate is 1.5 L/min, and the heating temperature is 850°C. It can be clearly seen from FIG. 4 that within the concentration range of methylene chloride from 30ppb (the minimum concentration that the dilution calibrator can output) to 1000ppb, the concentration of methylene chloride input into the intake pipeline 10 is different from that measured by the gas detection system. The obtained hydrogen chloride concentration shows a good linear response trend, and the R ² value is greater than 0.999, which is feasible for measurement. In view of the fact that the concentration of dichloromethane in the general clean room or working space is mostly between 0ppb and 20ppb, the gas detection system is also discussed separately when the concentration of dichloromethane changes in low steps (1ppb, 3ppb and 5ppb respectively). As can be seen from Figures 5 to 7, the gas detection system and its detection method can still maintain a good linear response trend for dichloromethane with low concentration and low-level concentration changes, and the sensitivity and accuracy are good, which can realize Real-time sampling and detection of dichloromethane gas.

10: Intake pipeline 11: Sampling pump 12: branch pipeline 20: Heating unit 30: Detection module 31: Detection unit 311: detection cavity 312: Detect light source 313: Light detector 32: Processing unit 33: Flow regulating valve 34: Operation display interface 40: Dilution Corrector S1~S4: steps

Fig. 1 is a schematic diagram of the structural configuration of a preferred embodiment of the present invention. Fig. 2 is a structural block diagram of a preferred embodiment of the present invention. Fig. 3 is a flow block diagram of a preferred embodiment of the present invention. Fig. 4 is a trend graph of a preferred embodiment of the present invention in the range of methylene chloride concentration from 30 ppb to 1000 ppb. Fig. 5 is a trend diagram of a preferred embodiment of the present invention when the concentration of dichloromethane varies in steps of 1 ppb. Fig. 6 is a trend diagram of a preferred embodiment of the present invention when the concentration of dichloromethane varies in steps of 3 ppb. Fig. 7 is a trend diagram of a preferred embodiment of the present invention when the concentration of dichloromethane varies in steps of 5 ppb.

10: Intake pipeline

11: Sampling pump

12: branch pipeline

20: Heating unit

30: Detection module

311: detection cavity

312: Detect light source

313: Light detector

33: Flow regulating valve

40: Dilution Corrector

Claims (9)

A gas detection system, comprising: an air inlet pipeline for inputting a gas to be tested; a heating unit connected to the air inlet pipeline for heating the gas to be tested and forming at least one target gas in the gas to be tested At least one detection target; and a detection module, including a detection unit connected to the heating unit and a processing unit connected to the detection unit, the detection unit is used to detect the content of the at least one detection target and generate at least one detection signal , the processing unit can receive the at least one detection signal and obtain a detection result data accordingly; wherein, the at least one target gas includes organic chlorine compounds, and the at least one detection target includes hydrogen chloride; wherein, the gas detection system further includes a A dilution calibrator connected to the intake pipeline, the dilution calibrator is used to input a standard gas containing a known concentration of the target gas and a diluent gas, and the dilute calibrator mixes the standard gas and the diluent gas into at least one The calibration gas is output to the detection unit. The detection unit detects the at least one calibration gas and generates at least one calibration signal. The processing unit receives the at least one calibration signal and calibrates the at least one detection signal accordingly. The gas detection system as claimed in claim 1, wherein the heating temperature of one of the heating units is not lower than 700°C. The gas detection system as described in claim 1, wherein the air intake line is further provided with a sampling pump, and the sampling pump controls the flow rate of the air intake line to not be less than 1.0 L/min. The gas detection system according to claim 1, wherein the detection module further includes a flow regulating valve connected between the heating unit and the detection unit, and the processing unit can control the flow regulating valve. The gas detection system as described in claim 1, wherein the intake pipeline is further provided with a sampling pump and a branch pipeline between the sampling pump and the dilution calibrator, and the branch pipeline is used to discharge excess of the at least A calibration gas. The gas detection system as claimed in claim 1, wherein the detection module is an off-axis integrated cavity spectral laser analyzer. The gas detection system as described in claim 5, wherein the heating temperature of one of the heating units is not lower than 700°C; the air inlet pipeline is further provided with a sampling pump, and the sampling pump controls the inflow of the air inlet pipeline to be not less than 1.0L/min; the detection module also includes a flow regulating valve connected between the heating unit and the detection unit, the processing unit can control the flow regulating valve; the detection module also includes an externally operated An operation display interface, the operation display interface communicates with the processing unit and can display the detection result data; the detection unit includes a detection chamber for inputting the at least one detection target, a detection light source, and a detection light source opposite to the detection light source. The light detectors on both sides of the detection cavity, the light of the detection light source can pass through the at least one detection target and form a light to be detected projected to the light detector, and the light detector receives the light to be detected and generates the light to be detected At least one detection signal; the detection module is an off-axis integrated cavity spectral laser analyzer; and the concentration of the at least one target gas is between 0ppb and 20ppb. A detection method using the gas detection system described in any one of claims 1 to 7, comprising the following steps: sampling: inputting the gas to be tested to the heating unit; decomposition: heating the gas to be tested and making the at least one target The gas forms the at least one detection target; detection: input the at least one detection target to the detection unit and obtain the at least one detection signal through the detection unit; and obtain the result: the processing unit obtains the detection result according to the at least one detection signal material. The detection method as described in Claim 8, further comprising the following steps: inputting a plurality of known gases with different contents of the at least one target gas to obtain a plurality of reaction results, and defining a plurality of content indicators according to the plurality of reaction results; and The processing unit also obtains the detection result data according to the corresponding results of the detection signal and the plurality of content indicators.

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