A H2S gas detection device based on pulsed ultraviolet fluorescence method

Abstract

The present invention discloses an H2S gas detection device based on the pulsed ultraviolet fluorescence method, which includes an intake gas path, a detection gas path, a bypass gas path, and an exhaust gas path. An SO2 detection mechanism is provided in the detection gas path. The detection gas path and the bypass gas path are arranged in parallel, and a second solenoid valve and a third solenoid valve are respectively connected to the detection gas path and the bypass gas path. The second solenoid valve and the third solenoid valve are respectively two-in-one-out solenoid valves. Among them, the intake gas path includes a sample gas path, an H2S gas path, and an SO2 gas path. The H2S gas path is connected to the sample gas path through a fourth solenoid valve, and the SO2 gas path is directly connected to the sample gas path. The inlet ends of the second solenoid valve and the third solenoid valve are respectively connected to the H2S gas path and the SO2 gas path. The present invention can achieve continuous monitoring without shutdown, reduce the loss of hydrogen sulfide gas in the gas path, and improve the measurement accuracy, precision, and stability of the instrument.

Description

Technical Field

[0001] The invention relates to an atmospheric environment detection technology, and in particular to an H2S gas detection device based on a pulsed ultraviolet fluorescence method. Background Art

[0002] The function of the ultraviolet fluorescence hydrogen sulfide analyzer is to continuously monitor hydrogen sulfide and sulfur dioxide gases in the ambient air online, and to achieve real-time monitoring of the two gases through the cooperation of sub-modules such as the sulfur dioxide scrubber and the hydrogen sulfide converter.

[0003] In the prior art, an intermittent gas transmission line is usually used when the sample gas is injected, resulting in the gas in the hydrogen sulfide gas line being in a static state when the sulfur dioxide gas in the sample gas is detected. The sulfur dioxide scrubber not only adsorbs sulfur dioxide, but also adsorbs hydrogen sulfide gas to a certain extent. Long-term adsorption will reduce the concentration of hydrogen sulfide in the sample gas. When the gas line is switched, the hydrogen sulfide gas is detected, and the actual detection value will be lower than the actual concentration value of the hydrogen sulfide gas in the ambient atmosphere, affecting the accuracy of the measurement result. Summary of the invention

[0004] In order to solve the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide an H2S gas detection device based on pulsed ultraviolet fluorescence method, which can realize continuous monitoring without stopping, reduce the loss of hydrogen sulfide gas in the gas path, and improve the measurement accuracy, precision and stability of the instrument.

[0005] The technical solution adopted by the present invention to solve the technical problem is: an H2S gas detection device based on pulsed ultraviolet fluorescence method, comprising an intake gas path, a detection gas path, a bypass gas path and an exhaust gas path, wherein a SO2 detection mechanism is provided in the detection gas path, the detection gas path and the bypass gas path are arranged in parallel, and the detection gas path and the bypass gas path are respectively connected to a second solenoid valve and a third solenoid valve, wherein the second solenoid valve and the third solenoid valve are two-input and one-output solenoid valves;

[0006] Wherein, the air inlet gas path includes a sample gas path, an H2S gas path and an SO2 gas path, the H2S gas path and the sample gas path are connected via a fourth solenoid valve, and the SO2 gas path and the sample gas path are directly connected;

[0007] The inlet ends of the second solenoid valve and the third solenoid valve are connected to the H2S gas circuit and the SO2 gas circuit respectively.

[0008] Optionally, two SO2 scrubbers are provided in the H2S gas circuit, the two SO2 scrubbers are arranged in parallel, and the output ends of the two SO2 scrubbers are commonly connected to the H2S converter.

[0009] Optionally, the exhaust gas circuit is connected to the detection gas circuit and the bypass gas circuit respectively, and an air resistance is provided in the exhaust gas circuit.

[0010] Optionally, a first three-way connection and a second three-way connection are provided in the sample gas circuit;

[0011] One of the first three-way passages is connected to the vacuum pump through an air pipe, and the other two passages are connected to the sample gas circuits respectively; one of the second three-way passages is connected to the air resistor through an air pipe, and the other two passages are connected to the sample gas circuits respectively;

[0012] The first three-way connection is located in the front-stage gas path of the second three-way connection.

[0013] Optionally, the sample gas circuit is provided with a hydrocarbon removal pipe between the first tee and the second tee.

[0014] Optionally, the SO2 detection mechanism includes an air chamber and an optical path system, and a light beam emitted by the optical path system is directed toward the air chamber to detect SO2.

[0015] Optionally, the optical path system includes a light source, a collimating lens, a reflective filter assembly, a beam splitter, a photodiode, a first focusing lens, an aperture, a second focusing lens, a bandpass filter, a photomultiplier tube, and an extinct device;

[0016] The light beam emitted by the light source is collimated by a collimating lens, reflected by a reflective filter assembly, and directed to a spectroscope. After the light beam is split by the spectroscope, one light beam is directed to a photodiode, and the other light beam is directed to a first focusing lens, and then to an air chamber after passing through a first condensing lens and an aperture. The SO2 gas in the air chamber absorbs the light beam and excites fluorescence. The fluorescent light is converged by a second focusing lens, and then passes through a bandpass filter and is received by a photomultiplier tube.

[0017] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0018] 1. The present invention adopts two SO2 scrubbers, which can complete the maintenance of the instrument without power outage, has the advantages of continuously recording air quality data, eliminating the influence of power outage on instrument performance, and reducing maintenance costs;

[0019] 2. The present invention adopts a double solenoid valve connection, which can allow the sample gas in the H2S gas circuit to continue to be transported while detecting the sample gas in the SO2 gas circuit, thereby avoiding intermittent gas transmission stoppage of the hydrogen sulfide gas circuit sample gas, reducing the adsorption amount of H2S gas in the sample gas by the SO2 scrubber, and further improving the accuracy of H2S gas detection in the sample gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the optical path system of the SO2 detection mechanism of the present invention. DETAILED DESCRIPTION

[0022] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] like Figure 1 As shown, the present invention discloses an H2S gas detection device based on pulsed ultraviolet fluorescence method, which includes an intake gas path 1, a detection gas path 2, a bypass gas path 3 and an exhaust gas path 4, the exhaust gas path 4 is respectively connected to the detection gas path 2 and the bypass gas path 3, and an air block 8 is provided in the exhaust gas path 4, a SO2 detection mechanism is provided in the detection gas path 2, the detection gas path 2 and the bypass gas path 3 are arranged in parallel, and the detection gas path 2 and the bypass gas path 3 are respectively connected to a second solenoid valve 5 and a third solenoid valve 6, the second solenoid valve 5 and the third solenoid valve 6 are two-input and one-output solenoid valves respectively.

[0025] In the present invention, the air intake path 1 includes a sample gas path 101, an H2S gas path 102, and an SO2 gas path 103. The H2S gas path 102 is connected to the sample gas path 101 via a fourth solenoid valve 104, which is normally open, and the SO2 gas path 103 is directly connected to the sample gas path 101. In addition, in the detection gas path 2 and the bypass gas path 3, the inlet ends of the second solenoid valve 5 and the third solenoid valve 6 are connected to the H2S gas path 102 and the SO2 gas path 103, respectively.

[0026] In the present invention, two SO2 scrubbers 105 are provided in the H2S gas circuit 102. The two SO2 scrubbers 105 are arranged in parallel, and the output ends of the two SO2 scrubbers 105 are commonly connected to the H2S converter 106. The H2S converter 106 can convert the H2S gas into SO2.

[0027] In addition, the sample gas circuit 101 is provided with a first tee 107 and a second tee 108, wherein the first tee 107 is located in the front-stage gas circuit of the second tee 108. One of the passages of the first tee 107 is connected to the vacuum pump 7 through an air pipe, and the other two passages are respectively connected to the sample gas circuit 101; one of the passages of the second tee 108 is connected to the air block 8 through an air pipe, and the other two passages are respectively connected to the sample gas circuit 101. The vacuum pump 7, the first tee 107, the second tee 108, the air block 8 and the corresponding air pipes together constitute the exhaust gas circuit 4.

[0028] In the present invention, the sample gas circuit 101 is provided with a hydrocarbon removal pipe 109 between the first tee 107 and the second tee 108 for removing hydrocarbon gases in the sample gas.

[0029] When detecting the sample gas, the sample gas first enters the H2S gas path 102 and the SO2 gas path 103 respectively through the sample gas path 101 under the action of the first solenoid valve 110. When the detection gas path 2 detects the sample gas in the SO2 gas path 103, the air inlet end of the second solenoid valve 5 is connected with the SO2 gas path 103, and the air inlet end of the third solenoid valve 6 is connected with the H2S gas path 102. At this time, the gas chamber detects the S concentration in the SO2 gas path 103, and the sample gas in the H2S gas path 102 can directly and continuously pass through the bypass gas path 3. In this process, the sample gas in the H2S gas path 102 can continuously pass through the SO2 scrubber. 105, thereby preventing the SO2 scrubber 105 from absorbing H2S gas, and then the sample gas through the bypass gas line 3 and the detection gas line 2 is discharged through the exhaust gas line 4; when the detection gas line 2 detects the sample gas in the H2S gas line 102, the air inlet end of the second solenoid valve 5 is connected to the H2S gas line 102, and the air inlet end of the third solenoid valve 6 is connected to the SO2 gas line 103. The sample gas first passes through the SO2 scrubber 105 to filter out the SO2 gas, and then the H2S gas in the sample gas is converted into SO2 gas through the H2S converter 106, and then enters the detection gas line 2 to detect the S concentration in the H2S gas line 102. Finally, the sum of the S concentrations in the H2S gas line 102 and the SO2 gas line 103 is the S concentration in the sample gas.

[0030] When exhausting the exhaust gas circuit 4 of the present invention, the first solenoid valve 110 is closed, and the sample gas passes through the air block 8, and then passes through the second tee 108, the hydrocarbon removal pipe 109, and the first tee 107 in sequence, and the hydrocarbon substances in the first tee 107, the second tee 108 and the hydrocarbon removal pipe 109 are purged and removed, and then discharged through the vacuum pump 7.

[0031] In the present invention, the SO2 detection mechanism includes an air chamber 201 and an optical path system. The light beam emitted by the optical path system is directed toward the air chamber 201 to detect SO2.

[0032] Specifically, the optical path system includes a light source 202 , a collimating lens 203 , a reflective filter assembly 204 , a beam splitter 205 , a photodiode 206 , a first focusing lens 207 , an aperture 208 , a second focusing lens 209 , a bandpass filter 210 , a photomultiplier tube 211 , and an extinct filter 212 .

[0033] like Figure 2 As shown, the light beam emitted by the light source 202 is collimated by the collimating lens 203, reflected by the reflective filter assembly 204, and directed to the spectroscope 205. After the light beam is split by the spectroscope 205, one light beam is directed to the photodiode 206, and the other light beam is directed to the first focusing lens 207, and then directed to the gas chamber 201 after passing through the first condensing lens 207 and the aperture 208. The SO2 gas in the gas chamber 201 absorbs the light beam and excites fluorescence. The fluorescent light is converged by the second focusing lens 209, and then passes through the bandpass filter 210 and is received by the photomultiplier tube 211, while the light not absorbed by the SO2 gas is removed by the de-luminator 212.

[0034] In the present invention, the light source 202 uses a xenon lamp. Since the light intensity of the xenon lamp decreases with the extension of the use time, the reference light intensity of the optical path is measured by the photodiode 206 to achieve compensation for the light signal intensity and achieve the purpose of accurately measuring the gas concentration. The present invention places the photodiode 206 at the front end of the detection gas chamber 201, which can reduce the interference of factors such as fluorescent light, gas flow, and gas distribution uniformity in the gas chamber 201 on the reference light intensity, and improve the measurement stability.

[0035] In addition, the aperture 208 can be an adjustable circular aperture, which can assist in calibrating the optical path during assembly and maintenance of the optical path system. In addition, the aperture size of the adjustable circular aperture can be adjusted to reduce the probability of stray light in the optical path entering the air chamber 201, obtain the optimal aperture, and improve the detection sensitivity. When calibrating the optical path system or assembling the optical path, first adjust the aperture of the aperture 208 to the minimum, and after the instrument runs stably, adjust the xenon lamp and the reflective filter assembly 204 to allow the photodiode 206 to obtain the maximum light intensity. At this time, the optical path is in the optimal state. Then, manually adjust the aperture size of the aperture 208, calculate the signal-to-noise ratio of the instrument, and determine the aperture when the instrument obtains the minimum signal-to-noise ratio. This aperture is the optimal aperture of the optical path.

[0036] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

[0037] Except for the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features will not be described here in detail.

Claims

1. A H2S gas detection device based on pulsed ultraviolet fluorescence method, characterized in that: It includes an intake air path, a detection air path, a bypass air path and an exhaust air path, wherein the detection air path is provided with a SO2 detection mechanism, the detection air path and the bypass air path are arranged in parallel, and the detection air path and the bypass air path are respectively connected with a second solenoid valve and a third solenoid valve, wherein the second solenoid valve and the third solenoid valve are two-input and one-output solenoid valves; Wherein, the air inlet gas path includes a sample gas path, an H2S gas path and an SO2 gas path, the H2S gas path and the sample gas path are connected via a fourth solenoid valve, and the SO2 gas path and the sample gas path are directly connected; The inlet ends of the second solenoid valve and the third solenoid valve are connected to the H2S gas circuit and the SO2 gas circuit respectively.

2. The H2S gas detection device based on pulsed ultraviolet fluorescence method according to claim 1 is characterized in that: In the H2S gas circuit, two SO2 scrubbers are provided, the two SO2 scrubbers are arranged in parallel, and the output ends of the two SO2 scrubbers are commonly connected to the H2S conversion furnace.

3. The H2S gas detection device based on pulsed ultraviolet fluorescence method according to claim 2 is characterized in that: The exhaust gas path is connected to the detection gas path and the bypass gas path respectively, and an air resistance is arranged in the exhaust gas path.

4. The H2S gas detection device based on pulsed ultraviolet fluorescence method according to claim 3 is characterized in that: In the sample gas path, a first three-way connection and a second three-way connection are provided; One of the first three-way passages is connected to the vacuum pump through an air pipe, and the other two passages are connected to the sample gas circuits respectively; one of the second three-way passages is connected to the air resistor through an air pipe, and the other two passages are connected to the sample gas circuits respectively; The first three-way connection is located in the front-stage gas path of the second three-way connection.

5. The H2S gas detection device based on pulsed ultraviolet fluorescence method according to claim 4 is characterized in that: The sample gas circuit is provided with a hydrocarbon removal pipe between the first three-way connection and the second three-way connection.

6. The H2S gas detection device based on pulsed ultraviolet fluorescence method according to claim 5 is characterized in that: The SO2 detection mechanism includes an air chamber and an optical path system. The optical path system emits a light beam toward the air chamber to detect SO2.

7. The H2S gas detection device based on pulsed ultraviolet fluorescence method according to claim 6 is characterized in that: The optical path system includes a light source, a collimating lens, a reflective filter assembly, a beam splitter, a photodiode, a first focusing lens, an aperture, a second focusing lens, a bandpass filter, a photomultiplier tube, and an extinction device; The light beam emitted by the light source is collimated by a collimating lens, reflected by a reflective filter assembly, and directed to a spectroscope. After the light beam is split by the spectroscope, one light beam is directed to a photodiode, and the other light beam is directed to a first focusing lens, and then to an air chamber after passing through a first condensing lens and an aperture. The SO2 gas in the air chamber absorbs the light beam and excites fluorescence. The fluorescent light is converged by a second focusing lens, and then passes through a bandpass filter and is received by a photomultiplier tube.

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