Gas online detection device for single-point and multi-point measurement system

Abstract

The utility model discloses an on-line gas detection device for a single-point and multi-point measurement system. The single-point measurement system comprises a controller, a sample injection valve, a blowback electromagnetic valve and a sampling pump, the controller controls the opening and closing of the sampling valve, the reverse blowing electromagnetic valve and the sampling pump, the sampling valve and the sampling pump are opened, the sampling probe collects a gas sample, the gas sample passes through the sampling valve and then enters the mist filter, and the gas sample after liquid particles are filtered out is pumped and conveyed into the dehumidifier through the sampling pump; the dehumidifier removes moisture in a gas sample and then sends the gas sample into the analyzer, when a preset condition is met, the controller outputs a closing signal to the sample injection valve and outputs an opening signal to the blowback electromagnetic valve, the sample injection valve is closed, a flow path is isolated, the blowback electromagnetic valve blows nitrogen to the sampling probe through a pipeline, blowback self-cleaning is carried out, and the sample injection valve is closed. Automatic sampling analysis and timed back flushing self-cleaning are realized; the multiple points further comprise an emptying pump and an emptying valve which are used for emptying replacement, and multi-flow-path wait-free circulation measurement and automatic back flushing self-cleaning of all the flow paths are achieved.

Description

Technical Field

[0001] This utility model relates to the field of gas detection, specifically to an online gas detection device for single-point and multi-point measurement systems. Background Technology

[0002] Traditional gas analysis methods, such as chemical analysis and gas chromatography, often employ manual sampling. The characteristic of manual sampling is that it involves manually collecting gas samples at a specific point in time for analysis. Its disadvantages are obvious: manual sampling of the gas is required, and analysis must be performed in a laboratory, where the operator's skill significantly impacts the accuracy of the analysis; it can only analyze single components one by one, lacking multi-input and signal processing capabilities; the analysis is time-consuming and labor-intensive, with slow response times, low efficiency, and difficulty in providing real-time information on operating conditions.

[0003] Therefore, there is an urgent need for an online gas detection device for single-point and multi-point measurement systems, capable of continuous analysis of multiple components such as hydrogen, oxygen, and dew point, saving labor and time, and greatly improving production efficiency and accuracy. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides an online gas detection device for single-point and multi-point measurement systems. This device can analyze various gases during the production process at one or more sampling points, and it can also be continuous and automatic, greatly improving production efficiency and accuracy while saving labor costs.

[0005] The technical solution adopted in this utility model is:

[0006] This invention provides an online gas detection device for a single-point measurement system, comprising a controller, a sampling valve QV, a backflush solenoid valve YV2, and a sampling pump AP1; the sampling valve QV is used to connect to the sampling probe SP and the mist filter F1.

[0007] The backflush solenoid valve YV2 is used to connect to the sampling probe SP and the nitrogen inlet; the sampling pump AP1 is used to connect to the dehumidifier DM; the dehumidifier DM is connected to the mist filter F1; and the dehumidifier DM is connected to the analyzer.

[0008] The controller controls the opening and closing of the injection valve QV, backflush solenoid valve YV2, and sampling pump AP1. When the injection valve QV and sampling pump AP1 are open, the sampling probe SP collects a gas sample. The gas sample then enters the mist filter F1 after passing through the injection valve QV. After filtering out liquid particles, the gas sample is drawn by the sampling pump AP1 and transported to the dehumidifier DM. The dehumidifier DM removes moisture from the gas sample before sending it to the analyzer. When the preset conditions are met, the controller outputs a shut-off signal to the injection valve QV and an open signal to the backflush solenoid valve YV2. The injection valve QV closes, the flow path is isolated, and the backflush solenoid valve YV2 opens, blowing nitrogen gas through the pipeline to the sampling probe SP for backflush self-cleaning.

[0009] Furthermore, it also includes two flow meters FM, namely FM1 and FM2. FM1 is connected to the sampling pump AP1 and the dehumidifier DM. FM1 is a fast venting flow meter used to improve the response speed of the analyzer. FM2 is connected to the dehumidifier DM and the analyzer. FM2 is a sample flow meter used to regulate the flow rate of the gas sample entering the analyzer.

[0010] Furthermore, it also includes an electric contact pressure gauge PI, a peristaltic pump RP, an explosion-proof pneumatic control box, a filter pressure reducing valve PR, a fine filter F2, a triple unit PR3, a needle valve NV, and two three-way ball valves BV3.

[0011] The electric contact pressure gauge PI is set between the injection valve QV and the mist filter F1 to monitor the blockage of the pipeline between the sampling probe and the injection valve QV, so as to enable timely self-cleaning through backflushing.

[0012] The peristaltic pump RP is connected to the mist filter F1 and the drain port to promptly remove the mist-like impurities separated by the mist filter F1, ensuring the normal operation of the subsequent system.

[0013] The explosion-proof pneumatic control box is connected to the injection valve QV and the triplet PR3. The triplet PR3 is connected to the compressed air inlet to form a controllable explosion-proof pneumatic valve.

[0014] The filter pressure reducing valve PR is located between the backflush solenoid valve YV2 and the nitrogen inlet to form a controllable backflush function valve.

[0015] An adjustable flow needle valve NV is connected in parallel to both ends of the sampling pump AP1 to balance and regulate the output flow of the sampling pump.

[0016] The fine filter F2 is placed between the dehumidifier DM and the flow meter FM2 to perform a final high-precision filtration on the sample gas after it has been dried by the dehumidifier DM, so as to ensure the cleanliness of the sample entering the analytical instrument.

[0017] Two three-way ball valves BV3 are connected. One of the three-way ball valves is located between the fine filter F2 and the dehumidifier DM. The other three-way ball valve is used to connect the zero gas and the range gas, and is used to calibrate and compare the zero point value and the range value of the analytical instrument.

[0018] Furthermore, the alarm contact switch of the electric contact pressure gauge PI is connected to the controller, the alarm contact switch of the dehumidifier DM is connected to the controller, and the controller is connected to the alarm device. When the pressure value of the electric contact pressure gauge PI and / or the temperature value of the dehumidifier DM exceeds the set threshold, an alarm contact switch signal is output to the controller. The controller then outputs an alarm signal to the alarm device, which triggers an alarm. Afterward, the controller will process the relevant signals and output a fault status alarm.

[0019] This utility model also provides an online gas detection device for a multi-point measurement system, including a controller, a sampling pump AP1, a venting pump AP2, multiple injection valves MV1 and venting valves MV2, and a backflush solenoid valve YV2. The injection valves MV1 and venting valves MV2 are connected to multiple sampling probes SP, with each sampling probe SP corresponding to one injection valve MV1 and one venting valve MV2. The injection valves MV1 are connected to the sampling pump AP1, and the venting valves MV2 are connected to the venting pump AP2. The backflush solenoid valves YV2 are connected to the sampling probes SP and the nitrogen inlet. The sampling pump AP1 is connected to the dehumidifier DM, and the dehumidifier DM and the mist... Filter F1 is connected, dehumidifier DM is connected to the analyzer, vent pump AP2 is used to connect to the analyzer and another mist filter F1, each sampling probe SP corresponds to one flow path, the controller is used to control the on / off state and working time of the sampling valve, vent valve and backflush solenoid valve of each flow path, when a certain flow path is working normally, the controller outputs an opening signal to the backflush solenoid valve and vent valve of other flow paths to perform backflush self-cleaning and vent replacement, and multiple flow paths can achieve sequential cyclic measurement without waiting time through the controller;

[0020] The controller controls the opening and closing of the sampling pump AP1, the venting pump AP2, multiple injection valves MV1 and venting valve MV2, and the backflush solenoid valve YV2. The injection valve MV1 of a certain flow path is open, while the injection valves MV1 of other flow paths are closed. After the sampling probe SP collects the gas sample, the gas sample enters the mist filter F1 after passing through the injection valve MV1 of this flow path. After filtering out liquid particles, the gas sample is drawn by the sampling pump AP1 and transported to the dehumidifier DM. The dehumidifier DM removes the moisture from the gas sample before sending it to the analyzer. At the same time, during the normal operation of this flow path, the controller outputs an opening signal to the venting valve MV2 and the backflush solenoid valve YV2 of other flow paths to perform backflush self-cleaning and venting replacement.

[0021] Furthermore, each flow path corresponding to each sampling probe SP includes an analysis flow path and a vent flow path. Each analysis flow path includes an injection valve MV1, a sampling pump AP1, and a mist filter F1, which are used to deliver the gas to be tested to the analyzer for analysis and detection. Each vent flow path includes a vent valve MV2, a vent pump AP2, and a mist filter F1, which are used for venting and replacement.

[0022] Furthermore, it also includes three flow meters, namely FM1, FM2 and FM3. FM1 is connected to the sampling pump AP1 and the dehumidifier DM. FM1 is a venting flow meter used to improve the gas analysis response speed. FM2 is connected to the dehumidifier DM and the analyzer. FM2 is a sample gas flow meter used to adjust the flow rate of the gas sample entering the analyzer. FM3 is connected to the venting pump AP2 and the analyzer. FM3 is a venting flow meter used to adjust the flow rate when the flow path is directly vented.

[0023] Furthermore, it also includes an electric contact pressure gauge PI, a fine filter F2, two three-way ball valves BV3 and a needle valve NV, as well as three peristaltic pumps RP;

[0024] The electric contact pressure gauge PI is set between the mist filter F1 and the dehumidifier DM in the analytical flow path to monitor the blockage of the pipeline between the sampling probe and the injection valve MV, so as to enable timely self-cleaning through backflushing.

[0025] Three peristaltic pumps RP are connected to the mist filter F1 in the analysis flow path, the dehumidifier DM, and the mist filter F1 in the venting flow path, respectively, and are used to discharge the condensate at the bottom of the mist filter and the dehumidifier without affecting the airtightness.

[0026] Both sampling pump AP1 and venting pump AP2 are connected in parallel to an adjustable flow needle valve NV, which is used to balance and regulate the output flow of sampling pump AP1 and venting pump AP2.

[0027] The fine filter F2 is placed between the dehumidifier DM and the flow meter FM3 to perform a final high-precision filtration on the sample gas after it has been cooled and dried by the dehumidifier DM, so as to ensure the cleanliness of the sample entering the analytical instrument.

[0028] Two three-way ball valves BV3 are connected. One of the three-way ball valves is located between the fine filter F2 and the dehumidifier DM. The other three-way ball valve is used to connect the zero gas and the range gas, and is used to calibrate and compare the zero point value and the range value of the analytical instrument.

[0029] Furthermore, multiple injection valves MV1 and vent valves MV2 are all electric ball valves.

[0030] Furthermore, the controller is connected to the electrical contact pressure gauge PI, three flow meters, and the dehumidifier DM. When the negative pressure gauge pointer reaches the alarm set value, it outputs a negative pressure alarm signal to the controller. The controller then controls the injection valve MV and the backflush solenoid valve YV to perform a backflush self-cleaning process. If the negative pressure is still not eliminated, the controller outputs a fault alarm. During normal operation, if the float of the flow meter drops to a certain set alarm position, or if the temperature of the dehumidifier DM's cold drying constant temperature dehumidification is abnormal and exceeds the alarm value, the controller will output a corresponding alarm signal. The controller will then output a fault alarm to remind the user to conduct timely on-site troubleshooting and maintenance.

[0031] The beneficial effects of this utility model are:

[0032] 1. A gas online detection device for a single-point measurement system uses a controller to enable the sampling valve, backflush valve and sampling pump to work together to achieve "automatic sampling and analysis" and "timed backflush self-cleaning", thereby greatly ensuring the stable operation of the analysis system while significantly reducing maintenance.

[0033] 2. An online gas detection device for multi-point measurement systems, which uses a controller to control the injection valve, backflush valve, sampling pump,

[0034] The vent valve and vent pump work together to allow for cyclic sampling and analysis at multiple sampling points while the flow path of the next sampling point to be analyzed has already begun to vent. This enables seamless connection between multiple sampling point cyclic sampling and analysis, unaffected by residual gas during flow path switching. Each time the current sampling point flow path analysis ends and the analysis continues to the next flow path, the flow path that has finished analysis will immediately undergo automatic backflushing and cleaning of the sampling probe and sampling pipeline. This ensures that the backflushing process of each sampling point analysis flow path will not occupy or affect the analysis work of other flow paths. It can realize multi-flow path cyclic measurement without waiting and automatic backflushing and self-cleaning of each flow path, thus realizing a maintenance-free automatic multi-path cyclic detection system.

[0035] 3. The gas online detection device of this utility model for single-point and multi-point measurement systems can continuously, automatically, quickly and accurately perform single-point or multi-point cyclic analysis and measurement of various gases (such as hydrogen, oxygen, dew point, CO, CO2, etc.) in the production process of silicon steel continuous annealing unit. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of an online gas detection device for a single-point measurement system according to Embodiment 1 of this utility model.

[0037] Figure 2 This is a schematic diagram of the structure of an online gas detection device for a multi-point measurement system, according to Embodiment 2 of this utility model. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solution of this utility model will be clearly and completely described below in conjunction with the accompanying drawings and a preferred embodiment. Example 1

[0039] refer to Figure 1 This embodiment 1 provides a gas online detection device for a single-point measurement system. The device includes a controller (not shown in the figure), a sampling valve QV, an electric contact pressure gauge PI, a backflush solenoid valve YV2, a mist filter F1, a sampling pump AP1, a dehumidifier DM, flow meters FM1 and FM2, a peristaltic pump RP, an explosion-proof pneumatic control box, a filter pressure reducing valve PR, a fine filter F2, a triplet PR3, a needle valve NV, an automatic drain DR, and two three-way ball valves BV3. The controller in this embodiment is a PLC controller.

[0040] The injection valve QV is connected to the sampling probe SP and the mist filter F1. The backflush solenoid valve YV2 is connected to the sampling probe SP and the nitrogen inlet. The sampling pump AP1 is connected to the dehumidifier DM. The dehumidifier DM is connected to the mist filter F1. The dehumidifier DM is connected to the analyzer.

[0041] After the sampling probe SP collects a gas sample, the gas sample enters the mist filter F1 through the injection valve QV. After filtering out liquid particles, the gas sample is drawn by the sampling pump AP1 and transported to the dehumidifier DM. The dehumidifier DM removes moisture from the gas sample before sending it to the analyzer. When the preset conditions are met (the preset conditions refer to the measurement time set by the controller), the controller outputs a shut-off signal to the injection valve QV and an open signal to the backflush solenoid valve YV2. The injection valve QV closes, the flow path is isolated, and the backflush solenoid valve YV2 opens, blowing nitrogen gas through the pipeline to the sampling probe SP for backflush self-cleaning.

[0042] To achieve multi-stage filtration from coarse to fine, automatic backflushing and self-cleaning, automatic dehumidification and drainage, self-balancing and adjustable sampling suction force, on-site calibration, and pressure function, this utility model also includes two flow meters FM, namely FM1 and FM2. Flow meter FM1 is connected to the sampling pump AP1 and the dehumidifier DM, and flow meter FM2 is connected to the dehumidifier DM and the analyzer. They are used for rapid venting in the sampling flow path to improve the system's analytical response speed and to regulate the flow rate of the gas sample entering the analyzer. An electric contact pressure gauge PI is installed between the injection valve QV and the mist filter F1 for monitoring. The system monitors the blockage status of the pipeline between the sampling probe and the injection valve MV to ensure timely self-cleaning via backflushing. The peristaltic pump RP connects to the mist filter F1 and the drain port to discharge condensate from the lower end of the mist filter without affecting airtightness. The explosion-proof pneumatic control box connects to the injection valve QV and the triplet PR3. The triplet PR3 connects to the compressed air inlet to form a controllable explosion-proof pneumatic valve to meet the system's explosion-proof and controlled application requirements. The triplet PR3 consists of a filter, a pressure reducing valve, and a lubricator. The triplet PR3 purifies the compressed air and lubricates the pneumatic actuator. A pressure reducing valve PR is positioned between the backflush solenoid valve YV2 and the nitrogen inlet, forming a controllable backflush function valve to meet the system's backflush self-cleaning application requirements. An adjustable flow needle valve NV is connected in parallel to both ends of the sampling pump AP1, used to balance and regulate the sampling pump's output flow rate. A fine filter F2 is positioned between the dehumidifier DM and the flow meter FM2, used for a final high-precision filtration of the sample gas after it has been cooled and dried by the dehumidifier DM, ensuring the cleanliness of the sample entering the analytical instrument. Two three-way ball valves BV3 are connected, one of which is positioned between the fine filter and the flow meter. Between filter F2 and dehumidifier DM, the flow path for gas sample and calibration gas is switched. Another three-way ball valve is used to connect zero gas and standard gas, which is used to facilitate users to verify and compare the zero point and range values ​​of the analytical instrument on site, and to facilitate maintenance. Among them, zero gas is a pure gas without the gas component to be tested, range gas is a gas containing the gas component to be tested at a known concentration, gas sample refers to the gas to be tested, and calibration gas refers to the standard gas for calibrating the instrument, which is a standard gas of known concentration. Automatic drain valve DR is connected to the drain port to discharge condensate at the bottom of the dehumidifier without affecting the airtightness.

[0043] To implement the dehumidification temperature alarm function, the alarm contact switch of the electric contact pressure gauge PI is connected to the controller, the alarm contact switch of the dehumidifier DM is connected to the controller, and the controller is connected to the alarm device. Thresholds are set within the controller. The alarm setting value for the pressure value of the electric contact pressure gauge PI is -0.1 bar; the alarm setting value for the temperature of the dehumidifier DM is 8℃. The alarm device is used to monitor for leaks of flammable and toxic gases inside the cabinet. When the pressure value of the electric contact pressure gauge PI and / or the temperature value of the dehumidifier DM exceed the set threshold, an alarm contact switch signal is output to the controller. The controller then outputs an alarm signal to the alarm device, which then triggers an alarm.

[0044] For the gas online detection device of this utility model used in a single-point measurement system, a 600W*800D*1900H cabinet is generally used.

[0045] The single-point system's injection valve, backflush valve, and sampling pump operate automatically in coordination under PLC control, enabling automatic sampling and analysis as well as timed backflush self-cleaning. This greatly ensures the stable operation of the analysis system while significantly reducing maintenance. Individual components can be manually controlled on-site.

[0046] During sampling and analysis, the PLC controller of the single-point system continuously receives the on / off status signals of various valves, the analog output signals of the analysis results from the measuring points, and abnormal signals from the pressure gauge PI, flow meter, and dehumidifier. Based on the current operating status, the controller promptly outputs open or close signals to each valve. Upon receiving abnormal signals, it outputs alarm information, including negative pressure alarms before the pump, over-temperature alarms for the dehumidifier, and low flow alarms for the analyzer. When the negative pressure gauge pointer reaches the alarm set value, it indicates excessive negative pressure before the pump and pipeline blockage. The controller outputs a negative pressure alarm signal, which then controls the injection valve MV and backflush solenoid valve YV to perform a backflush self-cleaning process. If the negative pressure is not eliminated, the controller outputs a fault alarm. During normal operation, if the flow meter float drops to a set alarm position, or if the temperature of the dehumidifier DM's cold-drying constant-temperature dehumidification process becomes abnormal and exceeds the alarm value, a corresponding alarm signal will be output to the controller, which will then output a fault alarm to remind users to promptly conduct on-site troubleshooting and maintenance. Example 2

[0047] This embodiment provides a gas online detection device for a multi-point measurement system, referencing... Figure 2 The device includes a controller (not shown in the figure), sampling pump AP1, venting pump AP2, filter pressure reducing valve PR, fine filter F2, electrical contact pressure gauge PI, dehumidifier DM, automatic drainer DR, two mist filters F1, needle valve NV and three-way ball valve BV3, three flow meters and peristaltic pump RP, multiple injection valves MV1 and venting valve MV2 and backflush solenoid valve YV2. The controller is a PLC controller.

[0048] Multiple injection valves MV1 and vent valves MV2 are used to connect to multiple sampling probes SP. Each sampling probe SP corresponds to one injection valve MV1 and one vent valve MV2. Multiple injection valves MV1 are connected to sampling pump AP1, and multiple vent valves MV2 are connected to vent pump AP2. Multiple backflush solenoid valves YV2 are used to connect to the sampling probe SP and the nitrogen inlet. Sampling pump AP1 is used to connect to dehumidifier DM. Dehumidifier DM is connected to mist filter F1. Dehumidifier DM is connected to analyzer. Vent pump AP2 is used to connect to analyzer and another mist filter F1. Each sampling probe SP corresponds to one flow path. The controller is used to control the on / off status and working time of the injection valve, vent valve and backflush solenoid valve of each flow path. When a certain flow path is working normally, the controller outputs an open signal to the backflush solenoid valve and vent valve of other flow paths to perform backflush self-cleaning and vent replacement. Multiple flow paths are cyclically measured sequentially without waiting time through the controller.

[0049] When the injection valve MV1 of a certain flow path is opened and the injection valve MV1 of other flow paths is closed, the sampling probe SP collects a gas sample. The gas sample then enters the mist filter F1 after passing through the injection valve MV1 of this flow path. After filtering out liquid particles, the gas sample is drawn by the sampling pump AP1 and transported to the dehumidifier DM. The dehumidifier DM removes moisture from the gas sample before sending it to the analyzer. At the same time, during normal operation of this flow path, the controller outputs an opening signal to the vent valve MV2 and the backflush solenoid valve YV2 of other flow paths to perform backflush self-cleaning and venting replacement. Venting replacement specifically involves the vent valve and vent pump working together to directly replace and vent residual gas by extracting the gas sample, preparing for subsequent sampling and analysis operations.

[0050] Each sampling probe SP includes an analysis flow path and a vent flow path for each flow path. Each analysis flow path includes an injection valve MV1, a sampling pump AP1, and a mist filter F1, which are used to deliver the gas to be tested to the analyzer for analysis and detection. Each vent flow path includes a vent valve MV2, a vent pump AP2, and a mist filter F1, which are used for venting and replacement.

[0051] The detection device in this embodiment also includes three flow meters, namely FM1, FM2, and FM3. FM1 is connected to the sampling pump AP1 and the dehumidifier DM to improve the gas analysis response speed. FM2 is connected to the dehumidifier DM and the analyzer to regulate the flow rate of the gas sample entering the analyzer. FM3 is connected to the vent pump AP2 and the analyzer to regulate the flow rate when the flow path is directly vented, preparing for subsequent sampling and analysis operations. The filter pressure reducing valve PR is located between the backflush solenoid valve YV2 and the nitrogen inlet to form a controllable backflush function valve to meet the application requirements of system backflush self-cleaning. The electrical contact pressure gauge PI is located between the mist filter F1 and the dehumidifier DM in the analysis flow path to monitor the blockage status of the pipeline from the sampling probe to the injection valve QV, so as to promptly perform backflush self-cleaning. The three peristaltic pumps RP are respectively connected to the mist filter F1, the dehumidifier DM, and the vent pump AP2 in the analysis flow path. The mist filter F1 in the airflow path is connected to discharge condensate from both the mist filter and the lower end of the dehumidifier without affecting airtightness. An adjustable flow needle valve NV is connected in parallel to both ends of the sampling pump AP1 and the venting pump AP2 to balance and regulate their output flow rates. The fine filter F2 is located between the dehumidifier DM and the flow meter FM3 to perform a final high-precision filtration of the sample gas after it has been cooled and dried by the dehumidifier DM, ensuring the cleanliness of the sample entering the analytical instrument. Two three-way ball valves BV3 are connected; one is located between the fine filter F2 and the dehumidifier DM, and the other connects to the zero gas and standard gas, used to calibrate and compare the zero point and range values ​​of the analytical instrument. The automatic drainer DR is connected to the drain port; when the liquid level in the automatic drainer DR reaches a certain point, the liquid is automatically discharged from the device through the drain port.

[0052] Specifically, multiple injection valves MV1 and vent valves MV2 all use electric ball valves. Electric ball valves have a large flow diameter, good airtightness, and no flow direction requirements, and can easily realize open and close position feedback.

[0053] Specifically, the controller is connected to the electrical contact pressure gauge PI, three flow meters, and the dehumidifier DM. When the negative pressure gauge pointer reaches the alarm set value, it indicates that the negative pressure before the pump is too high and there is a blockage in the pipeline. The controller outputs a negative pressure alarm signal to the controller, which then controls the injection valve MV and the backflush solenoid valve YV to perform a backflush self-cleaning process. If the negative pressure is not eliminated, the controller will output a fault alarm. During normal operation, if the float of the flow meter drops to a certain set alarm position, or if the temperature of the dehumidifier DM's cold drying constant temperature dehumidification is abnormal and exceeds the alarm value, the controller will output a corresponding alarm signal, which will then output a fault alarm to remind the user to conduct timely on-site troubleshooting and maintenance.

[0054] Referring to the table below, this embodiment uses a three-path cyclic measurement workflow as an example:

[0055]

[0056] Each flow path operates in a fixed cycle (default 5 minutes). Within the 5-minute working cycle of this flow path, the backflushing and self-cleaning of the previous flow path is carried out simultaneously for the first two minutes, and the venting and replacement of the next flow path is carried out simultaneously for the next 3 minutes. The purpose of venting and replacement is to extract the residual gas in the sampling pipeline in advance to prepare for seamless connection of flow path switching.

[0057] This invention equips each flow path with an injection valve MV1 and a vent valve MV2, thus ensuring that each flow path includes an analytical flow path and a vent flow path. In addition, each flow path has a backflush solenoid valve YV2. Under the control of the PLC controller, multiple valves enable cyclic measurement of multiple flow paths without waiting and automatic backflush and self-cleaning of each flow path, greatly improving measurement efficiency. Example 3

[0058] Based on the above embodiments 1 and 2, and considering the operating characteristics of process gas in the steel industry, the pretreatment process of the two devices is mainly divided into filtration, dehumidification, sampling, and flow regulation. The filtration adopts a three-stage filtration method. The first stage is the sampling probe SP filtration, with a filtration accuracy of 5-10 μm; the second stage is the mist filter F1 filtration, with an accuracy of 2-5 μm; and the third stage is the fine filter F2 filtration, with an accuracy of 0.1-1 μm. The dehumidification process is generally carried out after entering the sampling pump AP1 and before entering the analyzer, so that the dew point of the sample before entering the analyzer is reduced to 3-5°C. If the flue gas sample has a high moisture content, dehumidification can be performed once before entering the sampling pump AP1.

[0059] Preferably, the sampling pump AP1 is a diaphragm sampling pump with a pumping capacity of up to 7 L / min, an output pressure of up to 1.2 Bar, and a vacuum degree of up to 433 mmHg.

[0060] Preferably, the flow meter is a glass tube rotor flow meter with a built-in needle valve to adjust the flow rate. Its main functional parameters are:

[0061] The flow rate range of the sample analyzer is 0.1–1 L / min.

[0062] The flow rate range of the venting flow meter is 0.6 to 6 L / min.

[0063] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications are also within the protection scope of the present utility model.

Claims

1. A gas online detection device for a single-point measurement system, characterized in that, It includes a controller, injection valve QV, backflush solenoid valve YV2, and sampling pump AP1; injection valve QV is used to connect to sampling probe SP and mist filter F1. The backflush solenoid valve YV2 is used to connect to the sampling probe SP and the nitrogen inlet; the sampling pump AP1 is used to connect to the dehumidifier DM; the dehumidifier DM is connected to the mist filter F1; and the dehumidifier DM is connected to the analyzer. The controller controls the opening and closing of the injection valve QV, backflush solenoid valve YV2, and sampling pump AP1. When the injection valve QV and sampling pump AP1 are open, the sampling probe SP collects a gas sample. The gas sample then enters the mist filter F1 after passing through the injection valve QV. After filtering out liquid particles, the gas sample is drawn by the sampling pump AP1 and transported to the dehumidifier DM. The dehumidifier DM removes moisture from the gas sample before sending it to the analyzer. When the preset conditions are met, the controller outputs a shut-off signal to the injection valve QV and an open signal to the backflush solenoid valve YV2. The injection valve QV closes, the flow path is isolated, and the backflush solenoid valve YV2 opens, blowing nitrogen gas through the pipeline to the sampling probe SP for backflush self-cleaning.

2. The gas online detection device for a single-point measurement system according to claim 1, characterized in that, It also includes two flow meters FM, namely FM1 and FM2. FM1 is connected to the sampling pump AP1 and the dehumidifier DM. FM1 is a fast venting flow meter used to improve the response speed of the analyzer. FM2 is connected to the dehumidifier DM and the analyzer. FM2 is a sample flow meter used to regulate the flow rate of the gas sample entering the analyzer.

3. The gas online detection device for a single-point measurement system according to claim 1, characterized in that, It also includes an electric contact pressure gauge PI, a peristaltic pump RP, an explosion-proof pneumatic control box, a filter pressure reducing valve PR, a fine filter F2, a triple unit PR3, a needle valve NV, and two three-way ball valves BV3. The electric contact pressure gauge PI is set between the injection valve QV and the mist filter F1 to monitor the blockage of the pipeline between the sampling probe and the injection valve QV, so as to enable timely self-cleaning through backflushing. The peristaltic pump RP is connected to the mist filter F1 and the drain port to promptly remove the mist-like impurities separated by the mist filter F1, ensuring the normal operation of the subsequent system. The explosion-proof pneumatic control box is connected to the injection valve QV and the triplet PR3. The triplet PR3 is connected to the compressed air inlet to form a controllable explosion-proof pneumatic valve. The filter pressure reducing valve PR is located between the backflush solenoid valve YV2 and the nitrogen inlet to form a controllable backflush function valve. An adjustable flow needle valve NV is connected in parallel to both ends of the sampling pump AP1 to balance and regulate the output flow of the sampling pump. The fine filter F2 is placed between the dehumidifier DM and the flow meter FM2 to perform a final high-precision filtration on the sample gas after it has been dried by the dehumidifier DM, so as to ensure the cleanliness of the sample entering the analytical instrument. Two three-way ball valves BV3 are connected. One of the three-way ball valves is located between the fine filter F2 and the dehumidifier DM. The other three-way ball valve is used to connect the zero gas and the range gas, and is used to calibrate and compare the zero point value and the range value of the analytical instrument.

4. The gas online detection device for a single-point measurement system according to claim 3, characterized in that, The alarm contact switch of the electric contact pressure gauge PI is connected to the controller, the alarm contact switch of the dehumidifier DM is connected to the controller, and the controller is connected to the alarm device. When the pressure value of the electric contact pressure gauge PI and / or the temperature value of the dehumidifier DM exceed the set threshold, the alarm contact switch signal is output to the controller. The controller outputs an alarm signal to the alarm device, and the alarm device sounds an alarm. Afterwards, the controller will judge and process the relevant signals and output a fault status alarm.

5. A gas online detection device for a multi-point measurement system, characterized in that, The system includes a controller, sampling pump AP1, vent pump AP2, multiple injection valves MV1 and vent valves MV2, and backflush solenoid valve YV2. The injection valves MV1 and vent valves MV2 are used to connect to multiple sampling probes SP. Each sampling probe SP corresponds to one injection valve MV1 and one vent valve MV2. The injection valves MV1 are connected to sampling pump AP1, and the vent valves MV2 are connected to vent pump AP2. The backflush solenoid valve YV2 is used to connect to the sampling probe SP and the nitrogen inlet. Sampling pump AP1 is used to connect to dehumidifier DM. Dehumidifier DM and mist... Filter F1 is connected, dehumidifier DM is connected to the analyzer, vent pump AP2 is used to connect to the analyzer and another mist filter F1, each sampling probe SP corresponds to one flow path, the controller is used to control the on / off state and working time of the sampling valve, vent valve and backflush solenoid valve of each flow path, when a certain flow path is working normally, the controller outputs an opening signal to the backflush solenoid valve and vent valve of other flow paths to perform backflush self-cleaning and vent replacement, and multiple flow paths can achieve sequential cyclic measurement without waiting time through the controller; The controller controls the opening and closing of the sampling pump AP1, the venting pump AP2, multiple injection valves MV1 and venting valve MV2, and the backflush solenoid valve YV2. The injection valve MV1 of a certain flow path is open, while the injection valves MV1 of other flow paths are closed. After the sampling probe SP collects the gas sample, the gas sample enters the mist filter F1 after passing through the injection valve MV1 of this flow path. After filtering out liquid particles, the gas sample is drawn by the sampling pump AP1 and transported to the dehumidifier DM. The dehumidifier DM removes the moisture from the gas sample before sending it to the analyzer. At the same time, during the normal operation of this flow path, the controller outputs an opening signal to the venting valve MV2 and the backflush solenoid valve YV2 of other flow paths to perform backflush self-cleaning and venting replacement.

6. The gas online detection device for a multi-point measurement system according to claim 5, characterized in that, Each sampling probe SP includes an analysis flow path and a vent flow path for each flow path. Each analysis flow path includes an injection valve MV1, a sampling pump AP1, and a mist filter F1, which are used to deliver the gas to be tested to the analyzer for analysis and detection. Each vent flow path includes a vent valve MV2, a vent pump AP2, and a mist filter F1, which are used for venting and replacement.

7. The gas online detection device for a multi-point measurement system according to claim 6, characterized in that, It also includes three flow meters, namely FM1, FM2 and FM3. FM1 is connected to the sampling pump AP1 and the dehumidifier DM. FM1 is a venting flow meter used to improve the gas analysis response speed. FM2 is connected to the dehumidifier DM and the analyzer. FM2 is a sample gas flow meter used to adjust the flow rate of the gas sample entering the analyzer. FM3 is connected to the venting pump AP2 and the analyzer. FM3 is a venting flow meter used to adjust the flow rate when the flow path is directly vented.

8. The gas online detection device for a multi-point measurement system according to claim 7, characterized in that, It also includes an electric contact pressure gauge PI, a fine filter F2, two three-way ball valves BV3 and a needle valve NV, as well as three peristaltic pumps RP; The electric contact pressure gauge PI is set between the mist filter F1 and the dehumidifier DM in the analytical flow path to monitor the blockage of the pipeline between the sampling probe and the injection valve MV, so as to enable timely self-cleaning through backflushing. Three peristaltic pumps RP are connected to the mist filter F1 in the analysis flow path, the dehumidifier DM, and the mist filter F1 in the venting flow path, respectively, and are used to discharge the condensate at the bottom of the mist filter and the dehumidifier without affecting the airtightness. Both sampling pump AP1 and venting pump AP2 are connected in parallel to an adjustable flow needle valve NV, which is used to balance and regulate the output flow of sampling pump AP1 and venting pump AP2. The fine filter F2 is placed between the dehumidifier DM and the flow meter FM3 to perform a final high-precision filtration on the sample gas after it has been cooled and dried by the dehumidifier DM, so as to ensure the cleanliness of the sample entering the analytical instrument. Two three-way ball valves BV3 are connected. One of the three-way ball valves is located between the fine filter F2 and the dehumidifier DM. The other three-way ball valve is used to connect the zero gas and the range gas, and is used to calibrate and compare the zero point value and the range value of the analytical instrument.

9. A gas online detection device for a multi-point measurement system according to claim 5, characterized in that, Multiple injection valves MV1 and vent valve MV2 are all electric ball valves.

10. A gas online detection device for a multi-point measurement system according to claim 5, characterized in that, The controller is connected to the electrical contact pressure gauge PI, three flow meters, and the dehumidifier DM. When the negative pressure gauge pointer reaches the alarm set value, it outputs a negative pressure alarm signal to the controller. The controller then controls the injection valve MV and the backflush solenoid valve YV to perform a backflush self-cleaning process. If the negative pressure is still not eliminated, the controller outputs a fault alarm. During normal operation, if the float of the flow meter drops to a certain set alarm position, or if the temperature of the dehumidifier DM's cold drying constant temperature dehumidification is abnormal and exceeds the alarm value, the controller will output a corresponding alarm signal. The controller will then output a fault alarm to remind the user to conduct timely on-site troubleshooting and maintenance.

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