An on-line sampling device

Abstract

The application discloses an online sampling device and belongs to the technical field of gas detection. The device comprises a sealed shell with an inner cavity, a protective gas conveying structure and an exhaust pipe which are connected to the inner cavity, and a flow regulating valve arranged on the exhaust pipe; a pretreatment system arranged in the sealed shell and comprising a buffer structure, a pressure reducer, a first three-way valve, a filter and a water removal structure which are connected in sequence, the first three-way valve being provided with an A1 port, an A2 port and an A3 port, the A1 port being connected to the pressure reducer, and the A2 port being connected to the filter; a sampling system comprising a six-way valve and a carrier gas conveying structure, the six-way valve being arranged in the sealed shell, two ports of the six-way valve being connected with a constant flow ring, and the water removal structure being connected to one port of the six-way valve; the carrier gas conveying structure being connected to another port of the six-way valve; and a pipeline purging system comprising a purging structure which can be connected to the buffer structure or the A3 port. The device is suitable for the pretreatment and collection of various sampling gases and can improve the accuracy of detection results.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas detection, in particular to an online sampling device. BACKGROUND

[0002] Online detection of the gas generated in the reaction process can not only obtain the composition and content variation trend of the generated product, realize reaction mechanism analysis and reaction parameter optimization, but also detect harmful substances generated in the reaction and control the emission of pollutants.

[0003] However, the current gas phase detection instrument has specific requirements for the properties of the sample when performing online detection, such as the pressure of the sampling gas being normal pressure or slightly higher than normal pressure, not containing water and dust, etc. However, different reaction processes differ greatly, and the generated gas phase product components are complex. When the pressure of the sampling gas is large, it is easy to cause damage to the gas phase detection instrument; when the sampling gas contains easily oxidizable components, during the valve switching process, external air may enter the pipeline, causing the easily oxidizable components to oxidize, affecting the accuracy of the detection result.

[0004] Therefore, there is an urgent need for an online sampling device that can realize online pretreatment and collection of the gas mixture flowing out of various reaction devices, so as to meet the sampling requirements of the gas detection device, and transport the sample to the gas detection device to realize online detection, thereby improving the accuracy of the detection result. SUMMARY

[0005] The purpose of the present application is to provide an online sampling device to realize online pretreatment and collection of the gas mixture flowing out of various reaction devices, so as to meet the sampling requirements of the gas detection device, and transport the sample to the gas detection device to realize online detection, thereby improving the accuracy of the detection result.

[0006] As conceived above, the technical solution adopted by the present application is:

[0007] An online sampling device, comprising:

[0008] A closed housing having an inner cavity, the closed housing being provided with a protective gas delivery structure and an exhaust pipe both communicating with the inner cavity, the exhaust pipe being provided with a flow regulating valve;

[0009] A pretreatment system arranged in the closed housing, the pretreatment system comprising a buffer structure, a pressure reducer, a first three-way valve, a filter and a water removal structure connected in sequence, the first three-way valve having an A1 port, an A2 port and an A3 port, the A1 port being connected to the pressure reducer, and the A2 port being connected to the filter;

[0010] The sampling system comprises a six-way valve and a carrier gas conveying structure, the six-way valve is located in the closed shell, a dosing ring is connected between two ports of the six-way valve, the water removal structure is communicated with one port of the six-way valve, and the sample gas can enter the dosing ring through the buffer structure, the pressure reducer, the first three-way valve, the filter and the water removal structure in sequence or through the first three-way valve, the filter and the water removal structure in sequence, the carrier gas conveying structure is communicated with another port of the six-way valve, and the gas sample in the dosing ring can be conveyed to a gas detection mechanism through the carrier gas.

[0011] The pipeline purging system comprises a purging structure, the purging structure can be connected to the buffer structure or the A3 port, and the purging structure is used for purging and cleaning the pipeline.

[0012] Further, the pretreatment system further comprises a first pressure detector and a second pressure detector, the first pressure detector is arranged on the buffer structure, and the second pressure detector is arranged on a connecting pipeline between the pressure reducer and the A1 port.

[0013] Further, the pretreatment system further comprises a second three-way valve located in the closed shell, the second three-way valve has a B1 port, a B2 port and a B3 port, the B1 port can be connected to the purging structure or a reaction device, the B2 port is connected to the buffer structure, and the B3 port is connected to the A3 port of the first three-way valve.

[0014] Further, the pretreatment system further comprises a third three-way valve located in the closed shell, the third three-way valve has a C1 port, a C2 port and a C3 port, the C1 port is communicated with the purging structure, the C2 port is communicated with the B1 port of the second three-way valve, and the C3 port is used for connecting a reaction device.

[0015] Further, the online sampling device further comprises a third pressure detector arranged on the closed shell, and the third pressure detector is used for detecting the pressure of the inner cavity.

[0016] Further, the online sampling device further comprises a temperature detector and a heating structure, the temperature detector is used for detecting the temperature of the inner cavity, and the heating structure is arranged inside or outside the closed shell and is used for heating the inner cavity.

[0017] Further, an insulation layer is arranged outside the closed shell.

[0018] Further, the exhaust pipe comprises a first exhaust pipe and a second exhaust pipe communicated with each other, the flow regulating valve is arranged on the first exhaust pipe, and the safety valve is arranged on the second exhaust pipe.

[0019] Further, the online sampling device further comprises a fourth three-way valve for connecting with the reaction device, the fourth three-way valve has a D1 port, a D2 port and a D3 port, the D1 port is communicated with the buffer structure or the first three-way valve, the D2 port is used for connecting the reaction device, and the D3 port is communicated with a second exhaust pipeline.

[0020] Further, the online sampling device further comprises a fifth three-way valve, the fifth three-way valve has an E1 port, an E2 port and an E3 port, the E1 port is communicated with one of the ports of the six-way valve, the E2 port can be communicated with the gas detection mechanism, and the E3 port is communicated with a first exhaust pipeline.

[0021] The online sampling device provided by the application has the following beneficial effects:

[0022] The online sampling device provided by the application has the following beneficial effects: BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural schematic diagram of the online sampling device provided by the application;

[0024] Figure 2 is a working state schematic diagram of the online sampling device provided by the application Figure 1 .

[0025] Figure 3 is a working state schematic diagram of the online sampling device provided by the application Figure 2 .

[0026] In the drawings:

[0027] 101, closed housing; 102, second three-way valve; 103, buffer structure; 104, pressure reducer; 105, first pressure detector; 106, second pressure detector; 107, first three-way valve; 108, filter; 109, water removal structure; 110, six-way valve; 111, third pressure detector; 112, temperature detector; 113, protective gas delivery structure; 114, flow regulating valve; 115, safety valve; 116, carrier gas delivery structure; 117, third three-way valve; 118, delivery line; 119, purge structure;

[0028] 201, reaction device; 202, fourth three-way valve; 203, second evacuation line;

[0029] 301, gas detection mechanism; 302, fifth three-way valve; 303, first evacuation line. DETAILED DESCRIPTION

[0030] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the present application will be further described below in conjunction with the accompanying drawings and through specific embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all.

[0031] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0033] In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like, orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in description, and have no special meaning.

[0034] As shown in Figures 1 to 3 The present embodiment provides an online sampling device, which comprises a sealed shell 101, a pretreatment system, a sampling system and a pipeline purge system. The sealed shell 101 has an inner cavity, and the sealed shell 101 is provided with a protective gas delivery structure 113 and an exhaust pipe communicating with the inner cavity thereof. The exhaust pipe is provided with a flow regulating valve 114. The protective gas can be delivered into the sealed shell 101 through the protective gas delivery structure 113, and the discharge amount of the protective gas can be controlled by adjusting the flow regulating valve 114, so that the pressure in the inner cavity is maintained within a preset pressure range. Further, the exhaust pipe comprises a first exhaust pipe and a second exhaust pipe in communication. The first exhaust pipe is provided with the flow regulating valve 114, and the second exhaust pipe is provided with a safety valve 115. By providing the safety valve 115, the safety performance of the online sampling device can be improved, and the pressure in the sealed shell 101 can be prevented from exceeding the safety range.

[0035] The pretreatment system is arranged in the sealed shell 101, and the pretreatment system comprises a buffer structure 103, a pressure reducer 104, a first three-way valve 107, a filter 108 and a water removal structure 109 connected in sequence. The first three-way valve 107 has an A1 port, an A2 port and an A3 port. The A1 port is connected to the pressure reducer 104, and the A2 port is connected to the filter 108. The sampling system comprises a six-way valve 110 and a carrier gas delivery structure 116. The six-way valve 110 is located in the sealed shell 101, and a dosing ring is connected between two ports of the six-way valve 110. The water removal structure 109 communicates with one port of the six-way valve 110. When the pressure of the sampling gas is greater than or equal to the set pressure, the sampling gas can enter the dosing ring in sequence through the buffer structure 103, the pressure reducer 104, the first three-way valve 107, the filter 108 and the water removal structure 109. When the pressure of the sampling gas is less than the set pressure, the sampling gas enters the dosing ring in sequence through the first three-way valve 107, the filter 108 and the water removal structure 109. The carrier gas delivery structure 116 communicates with another port of the six-way valve 110, and the gas sample in the dosing ring can be delivered to a gas detection mechanism 301 through the carrier gas delivery structure 116.

[0036] The pipeline purging system includes a purging structure 119, which can be connected to a buffer structure 103 or port A3. The purging structure 119 is used for purging and cleaning the pipeline. Specifically, the purging structure 119 is a gas storage tank containing purging gas. The purging gas in the storage tank can be compressed by a compressor and then passed through the buffer structure 103, pressure reducer 104, first three-way valve 107, filter 108, water removal structure 109, six-way valve 110, and metering loop to purge residual sample gas, facilitating the pretreatment and collection of the sample gas in the next run and improving detection accuracy. Of course, the purging gas can also bypass the buffer structure 103 and pressure reducer 104 and enter directly through port A3 of the first three-way valve 107.

[0037] Furthermore, in this embodiment, the buffer structure 103 is preferably a buffer tank to buffer the sample gas. The pressure reducer 104 is preferably a damping pressure reducer to further reduce the pressure of the sample gas after passing through the buffer tank, thereby reducing the pressure of the sample gas so that the sample gas is lower than the set pressure to meet the sample introduction requirements of the gas detection device. The water removal structure 109 is a gas-liquid separation device, such as a tubular condenser (the specific structure is not shown in this invention). The filter 108 is preferably a metal filter, and considering that the temperature of the sample gas may be high, the filter 108 needs to have a temperature resistance ≥200℃.

[0038] Furthermore, the pretreatment system also includes a first pressure detector 105 and a second pressure detector 106. The first pressure detector 105 is disposed in the buffer structure 103, and the second pressure detector 106 is disposed in the connecting pipeline between the pressure reducer 104 and the A1 port. It is understood that the sampling and injection device has a controller, and both the first pressure detector 105 and the second pressure detector 106 are connected to the controller. The first pressure detector 105 is used to detect the pressure of the injection gas in the buffer tank, and the second pressure detector 106 is used to detect the pressure of the injection gas after passing through the damping pressure reducer. By detecting the pressure of the injection gas through the first pressure detector 105 and the second pressure detector 106, the pressure of the injection gas after passing through the buffer tank and the pressure reducing damper is reduced to a pressure that the subsequent gas detection mechanism 301 can adapt to. The first pressure detector 105 and the second pressure detector 106 are both preferably gas pressure sensors.

[0039] Furthermore, the pretreatment system also includes a second three-way valve 102 located within the sealed housing 101. The second three-way valve 102 has ports B1, B2, and B3. Port B1 can be connected to the purge structure 119 or the reaction device 201. Port B2 is connected to the buffer structure 103 via a pipeline, and port B3 is connected to port A3 of the first three-way valve 107 via a pipeline. It is understood that by setting the second three-way valve 102, the sample gas can be selectively allowed to pass through the buffer tank and pressure-reducing damper. Specifically, when the pressure of the sample gas is greater than or equal to the set pressure, ports B1 and B2 of the second three-way valve 102 are connected, while ports B1 and B3 are not connected. In this case, the sample gas is depressurized by the buffer tank and pressure-reducing damper before entering the filter 108. When the pressure of the sample gas is less than the set pressure, ports B1 and B3 of the second three-way valve 102 are connected, while ports B1 and B2 are not connected. At this time, the sample gas directly enters the filter 108 through the first three-way valve 107.

[0040] Furthermore, the pretreatment system also includes a third three-way valve 117 located within the sealed housing 101. The third three-way valve 117 has ports C1, C2, and C3. Port C1 is connected to the purge structure 119, port C2 is connected to port B1 of the second three-way valve 102, and port C3 is used to connect to the reaction device 201. It is understood that when pretreatment and sampling of the introduced gas are required, ports C3 and C2 are connected, while ports C1 and C2 are not connected. When purging of residual gas samples in the sampling system and pretreatment system is required, ports C1 and C2 are connected, while ports C1 and C3 are not connected.

[0041] like Figure 1 As shown, the online sample introduction device also includes a third pressure detector 111, which is disposed on the sealed housing 101 and used to detect the pressure inside the cavity. It is understood that the third pressure detector 111 is connected to the controller, and by detecting the pressure inside the sealed housing 101 through the third pressure detector 111, the pressure inside the sealed housing 101 is maintained within a preset pressure range in conjunction with the protective gas delivery structure 113 and the flow regulating valve 114. In this embodiment, the protective gas is preferably an inert gas.

[0042] Further, the online sampling device further comprises a temperature detector 112 and a heating structure (not shown in the figure). The heating structure is arranged inside or outside the sealed shell 101 to heat the protective gas in the sealed shell 101 so that the temperature of the sealed shell 101 is increased. In the embodiment, the heating structure is arranged inside the sealed shell 101, which can be an electric heater or a heat exchanger using high-temperature liquid to release heat. The temperature detector 112 is arranged to detect the temperature in the inner cavity of the sealed shell 101, and the temperature detector 112 is connected to the controller. Of course, the heating structure can also be a structure arranged around the sealed shell 101 using electric heating or liquid heat exchange, and the sealed shell 101 is used to heat the gas in the inner cavity.

[0043] It can be understood that when the sampling gas contains high-boiling components, the protective gas in the sealed shell 101 can be heated by the heating structure, so that the temperature in the sealed shell 101 is increased, thereby avoiding the high-boiling components in the sampling gas from condensing in the pretreatment system and the sampling system, which affects the subsequent detection results. Further, in order to avoid the loss of temperature in the sealed shell 101, a heat preservation layer (not shown in the figure) is arranged outside the sealed shell 101. By the heat preservation layer, the loss of temperature in the sealed shell 101 can be reduced.

[0044] As shown in Figure 1 The online sampling device further comprises a fourth three-way valve 202, which has a D1 port, a D2 port and a D3 port. The D1 port is connected to the C3 port of the third three-way valve 117 through the conveying pipeline 118, the D2 port is connected to the reaction device 201, and the D3 port is connected to the second exhaust pipeline 203. It can be understood that when sampling is needed, the D2 port is connected to the reaction device 201, and the D2 port is connected to the D1 port, and the D2 port and the D3 port are not connected. When sampling is not needed, the D2 port and the D3 port are connected, and the gas generated by the reaction device 201 is exhausted through the second exhaust pipeline 203.

[0045] The reaction device 201 described above can be a small reaction device in a laboratory or a large reaction device in a factory, such as a thermogravimetric analyzer, a fluidized bed, a fixed bed reactor, a catalyst evaluation device, etc.

[0046] As shown in Figure 1As shown, the online sample acquisition device also includes a fifth three-way valve 302, which has ports E1, E2, and E3. Port E1 is connected to one of the ports of the six-way valve 110, port E2 is connected to the gas detection mechanism 301, and port E3 is connected to the first venting line 303. When the gas sample in the quantitative loop is detected, ports E1 and E2 are connected, while ports E1 and E3 are not connected. At this time, the carrier gas delivered by the carrier gas delivery structure 116 to the six-way valve 110 can carry the gas sample in the quantitative loop to the gas detection mechanism 301, thereby detecting the gas sample. When the quantitative loop is purged by the purging structure 119, ports E1 and E3 are connected, while ports E1 and E2 are not connected.

[0047] The aforementioned gas detection mechanism 301 includes any one or more of the following: gas chromatograph, mass spectrometer, infrared analyzer, flue gas analyzer, and electrochemical detector. Of course, it may also include other devices capable of detecting gases, which will not be listed in this embodiment.

[0048] The following is a detailed description of the operation process of this online sample introduction device.

[0049] Taking the example where the pressure of the sample gas is greater than or equal to the set pressure. For ease of description, the six ports of the six-way valve 110 are defined as the first port, the second port, the third port, the fourth port, the fifth port, and the sixth port, respectively. The first port and the fourth port are connected by a metering loop, the second port is connected to the carrier gas delivery structure 116, the third port is connected to the E1 port of the fifth three-way valve 302, the fifth port is connected to the third venting pipeline, and the sixth port is connected to the water removal structure 109.

[0050] 1. Gas sample collection

[0051] like Figure 2 As shown, port D2 of the fourth three-way valve 202 is connected to the reaction device 201, and ports D2 and D1 are connected. Ports C2 and C3 of the third three-way valve 117 are connected. Ports B1 and B2 of the second three-way valve 102 are connected. Ports A1 and A2 of the first three-way valve 107 are connected. Ports 6 and 1 of the six-way valve 110 are connected, and ports 4 and 5 are connected. At this time, the gas generated in the reaction device 201 can sequentially pass through the fourth three-way valve 202, the third three-way valve 117, the second three-way valve 102, the buffer tank, the damping pressure reducer, the first three-way valve 107, the filter 108, and the water removal structure 109 into the six-way valve 110, realizing the collection of gas samples through the quantitative loop. Further, the carrier gas delivery structure 116 is connected to the second port of the six-way valve 110, and ports 2 and 3 are connected. At this time, the carrier gas delivery structure 116 provides carrier gas for the gas detection mechanism 301.

[0052] In the above process, protective gas is supplied to the sealed housing 101 through the protective gas delivery structure 113. The pressure inside the sealed housing 101 is controlled in real time by the flow regulating valve 114 and the third pressure detector 111, so that the pressure inside the sealed housing 101 is maintained within the preset pressure range. This setting can prevent small molecules in the sample gas from slightly leaking at the connection between the pipeline and the valve body, and can also prevent easily oxidizable components in the sample gas from being oxidized by the trace amounts of air entering the pipeline during valve switching, thereby improving the accuracy of the detection results.

[0053] If the sampled gas contains high-boiling-point components, the temperature inside the sealed housing 101 can be controlled in real time through the heating structure and temperature detector 112, so that the temperature inside the sealed housing 101 is maintained within the preset temperature range, thus preventing the high-boiling-point components from condensing in the pipeline.

[0054] 2. Gas sample transport

[0055] like Figure 3 As shown, the six-way valve 110 is adjusted so that its first and second ports are connected, its third and fourth ports are connected, and its sixth and fifth ports are connected. At this time, the carrier gas delivered by the carrier gas delivery structure 116 passes through the second port, the first port, the metering loop, the fourth and third ports, and the fifth three-way valve 302 before entering the gas detection mechanism 301, enabling the gas sample in the metering loop to be delivered to the gas detection mechanism 301 for detection. Furthermore, during this process, the D2 and D3 ports of the fourth three-way valve 202 can be connected, allowing the gas generated in the reaction device 201 to be vented through the second vent pipe 203. Alternatively, the D2 and D1 ports of the fourth three-way valve 202 can be kept connected, and the gas is discharged through the third exhaust pipe connected to the fifth port of the six-way valve 110.

[0056] Furthermore, when purging is required, ports D2 and D3 of the fourth three-way valve 202 are connected, and port C1 of the third three-way valve 117 and port B1 of the second three-way valve 102 are connected. For thorough purging, ports B1 and B2 of the second three-way valve 102 are first connected to purge the buffer tank, pressure reducing damper, first three-way valve 107, filter 108, and water removal structure 109. Then, ports B1 and B3 of the second three-way valve 102 are connected to purge the pipeline between the second three-way valve 102 and the first three-way valve 107. Similarly, when purging the six-way valve 110, ports one and six, and ports four and five, are connected to purge the metering loop.

[0057] To sum up, the online sampling device provided in the embodiment can realize pressure reduction of the sampling gas with relatively large pressure through the buffer structure 103 and the pressure reducer 104, and can filter and remove water from the sampling gas. On the other hand, the protective gas conveying structure 113 can convey protective gas into the closed shell 101, so that the closed shell 101 is filled with protective gas and has a certain pressure, thereby effectively avoiding the trace leakage of small molecular components in the sampling gas, and avoiding the trace air from entering the pipeline when the valve body is switched, so that the easily oxidized components in the sampling gas are oxidized. The online sampling device can be suitable for the pretreatment and collection of various sampling gases, and can improve the accuracy of the detection result.

[0058] The above embodiments only illustrate the basic principles and characteristics of the present application, and the present application is not limited to the above embodiments. Without departing from the spirit and scope of the present application, various changes and modifications can be made to the present application, and these changes and modifications all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. An online sample introduction device, characterized in that, include: The sealed housing (101) has an inner cavity. The sealed housing (101) is provided with a protective gas delivery structure (113) and an exhaust pipe that are both connected to the inner cavity. The exhaust pipe is provided with a flow regulating valve (114). A pretreatment system is disposed within the sealed housing (101). The pretreatment system includes a buffer structure (103), a pressure reducer (104), a first three-way valve (107), a filter (108), and a water removal structure (109) connected in sequence. The first three-way valve (107) has an A1 port, an A2 port, and an A3 port. The A1 port is connected to the pressure reducer (104), and the A2 port is connected to the filter (108). The sampling system includes a six-way valve (110) and a carrier gas delivery structure (116). The six-way valve (110) is located inside the sealed housing (101). A metering loop is connected between two ports of the six-way valve (110). The dewatering structure (109) is connected to one port of the six-way valve (110). The sample gas can enter the metering loop sequentially through the buffer structure (103), the pressure reducer (104), the first three-way valve (107), the filter (108), and the dewatering structure (109), or sequentially through the first three-way valve (107), the filter (108), and the dewatering structure (109). The carrier gas delivery structure (116) is connected to the other port of the six-way valve (110) and can deliver the gas sample in the metering loop to the gas detection mechanism (301) via the carrier gas. The pipeline purging system includes a purging structure (119), which can be connected to the buffer structure (103) or the A3 port, and the purging structure (119) is used for purging and cleaning the pipeline. The pretreatment system also includes a second three-way valve (102) located within the sealed housing (101). The second three-way valve (102) has a B1 port, a B2 port, and a B3 port. The B1 port can be connected to the purge structure (119) or the reaction device (201). The B2 port is connected to the buffer structure (103). The B3 port is connected to the A3 port of the first three-way valve (107). The online sample introduction device also includes a third pressure detector (111) disposed on the sealed housing (101), the third pressure detector (111) being used to detect the pressure of the inner cavity; The exhaust pipe includes a first exhaust pipe and a second exhaust pipe that are connected to each other. The first exhaust pipe is equipped with the flow regulating valve (114), and the second exhaust pipe is equipped with a safety valve (115).

2. The online sample introduction device according to claim 1, characterized in that, The pretreatment system further includes a first pressure detector (105) and a second pressure detector (106). The first pressure detector (105) is disposed on the buffer structure (103), and the second pressure detector (106) is disposed on the connecting pipeline between the pressure reducer (104) and the A1 port.

3. The online sample introduction device according to claim 1, characterized in that, The pretreatment system also includes a third three-way valve (117) located in the sealed housing (101), the third three-way valve (117) having a C1 port, a C2 port and a C3 port, the C1 port being connected to the purge structure (119), the C2 port being connected to the B1 port of the second three-way valve (102), and the C3 port being used to connect to the reaction device (201).

4. The online sample introduction device according to claim 1, characterized in that, The online sample introduction device also includes a temperature detector (112) and a heating structure. The temperature detector (112) is used to detect the temperature of the inner cavity, and the heating structure is disposed inside or outside the sealed housing (101) and is used to heat the inner cavity.

5. The online sample introduction device according to claim 4, characterized in that, The sealed shell (101) is provided with an insulation layer on the outside.

6. The online sample introduction device according to any one of claims 1-5, characterized in that, The online injection device also includes a fourth three-way valve (202) for connection to the reaction device (201). The fourth three-way valve (202) has a D1 port, a D2 port and a D3 port. The D1 port is connected to the buffer structure (103) or the first three-way valve (107). The D2 port is used to connect to the reaction device (201). The D3 port is connected to a second venting pipeline (203).

7. The online sample introduction device according to any one of claims 1-6, characterized in that, The online sample introduction device also includes a fifth three-way valve (302), which has an E1 port, an E2 port and an E3 port. The E1 port is connected to one of the ports of the six-way valve (110), the E2 port is connected to the gas detection mechanism (301), and the E3 port is connected to the first venting pipeline (303).

Images