Sampling system and sampling method for HCl

Abstract

The invention relates to a sampling system and method for HCl, the sampling system comprises a sampling gun, a cyclone separator, an absorption module and an air exhaust module which are sequentially arranged in a communicating mode in the flue gas flowing direction, and the sampling gun is used for collecting flue gas in a flue; the cyclone separator is used for separating fly ash in the flue gas and collecting the fly ash in an ash hopper at the bottom, and discharging the separated flue gas at the same time; the absorption module is used for absorbing and storing HCl in the separated flue gas after receiving the separated flue gas; and the air exhaust module is used for receiving the deacidified flue gas flowing through the absorption module and providing flowing power for the flue gas in the sampling system. The cyclone separator can timely remove fly ash in the flue gas after receiving the flue gas sampled by the sampling gun so as to eliminate interference of solid impurities, so that the fly ash is prevented from adsorbing HCl or influencing subsequent sampling, a clean sample is provided for subsequent analysis of HCl, and the accuracy of a detection result is improved.

Description

Technical Field

[0001] This disclosure relates to a method for detecting components in coal-fired flue gas, specifically, to a sampling system and method for HCl. Background Technology

[0002] In industrial flue gas environmental monitoring, the detection of hydrogen chloride (HCl) concentration in fly ash-containing flue gas is crucial, as the data is directly used to assess the degree of pollution and optimize treatment processes. As an acidic gaseous pollutant, excessive emissions of HCl can corrode equipment, pollute the atmosphere, and may also harm human health; therefore, it is necessary to accurately obtain its true concentration.

[0003] Currently, most flue gas sampling methods using fly ash containment employ fiber cartridge filtration, where fine fibers block fly ash, preparing the flue gas for HCl sampling. However, during sampling, fly ash accumulates inside the cartridge, forming a filter layer. The metal oxides and unburned carbon within this layer physically and chemically adsorb HCl, altering its morphology and distribution. This results in the sample failing to reflect the original state of the flue gas, ultimately distorting HCl detection results and increasing errors, thus impacting subsequent treatment assessments and process adjustments. Summary of the Invention

[0004] The purpose of this disclosure is to provide a sampling system and method for HCl, so as to at least partially solve the technical problems existing in the related art.

[0005] To achieve the above objectives, this disclosure provides a sampling system for HCl, comprising a sampling gun, a cyclone separator, an absorption module, and an extraction module arranged sequentially along the flue gas flow direction, wherein... The sampling gun is used to collect flue gas inside the flue. The cyclone separator is used to separate fly ash from the flue gas and collect it in the ash hopper at the bottom, while simultaneously discharging the separated flue gas. The absorption module is used to absorb and store HCl in the separated flue gas after receiving it; and The extraction module is used to receive the flue gas after it has passed through the absorption module for acid removal and to provide the flow power for the flue gas in the sampling system.

[0006] Optionally, it also includes a heating chamber, in which the cyclone separator is housed to maintain the separated flue gas at a preset temperature.

[0007] Optionally, the absorption module includes a first absorption bottle disposed downstream of the cyclone separator, the first absorption bottle containing a sodium hydroxide solution.

[0008] Optionally, there may be multiple first absorption bottles, which are connected in series along the flue gas flow direction.

[0009] Optionally, the vacuum module includes a vacuum pump, and the absorption module further includes a second absorption bottle connected between the vacuum pump and the first absorption bottle, the second absorption bottle containing a desiccant.

[0010] Optionally, the first absorption bottle and the second absorption bottle are connected by a connector made of high borosilicate glass.

[0011] Optionally, the absorption module further includes an ice bath for holding the first absorption bottle and the second absorption bottle.

[0012] Optionally, the pumping module includes a flow meter disposed downstream of the vacuum pump.

[0013] Optionally, it also includes a fluid velocity meter inserted into the flue near the sampling gun.

[0014] A second aspect of this disclosure is to provide a sampling method that uses the sampling system provided in this disclosure.

[0015] Through the above technical solution, the cyclone separator in the sampling system provided in this disclosure can remove fly ash from the flue gas in a timely manner after receiving the flue gas sampled by the sampling gun to eliminate interference from solid impurities, avoid fly ash adsorbing HCl or affecting subsequent sampling, provide a clean sample for subsequent HCl analysis, and improve the accuracy of the detection results. At the same time, the absorption module can fix and store the HCl in the flue gas to prevent HCl loss during the sampling process. The gas extraction module provides power to the entire system throughout the process, ensuring that the flue gas flows stably through the sampling gun, cyclone separator, absorption module and other links, ensuring sufficient sampling volume and sufficient absorption reaction.

[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the sampling system provided in an exemplary embodiment of this disclosure; Figure 2 This is a flowchart of a sampling method provided by an exemplary embodiment of this disclosure.

[0018] Explanation of reference numerals in the attached figures 1-Sampling gun; 2-Cyclone separator; 21-Ash hopper; 22-Outlet; 3-Absorption module; 31-First absorption bottle; 32-Second absorption bottle; 4-Gas extraction module; 41-Vacuum pump; 42-Flow meter; 43-Vacuum gauge; 5-Heating box; 6-Ice bath box; 7-Flue; 8-Connector; 9-Fluid velocity meter. Detailed Implementation

[0019] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0020] In this disclosure, unless otherwise stated, directional terms such as "upstream" and "downstream" are defined according to the direction of flue gas flow; directional terms such as "top" and "bottom" are defined based on the usage habits of the sampling system provided in this disclosure. Specifically, please refer to [reference needed]. Figure 1 The drawing orientation is shown. "Inner" and "outer" refer to the outline of the corresponding component itself. Terms such as "first" and "second" used in this disclosure are for distinguishing one element from another and do not have sequential or importance. Furthermore, in the following description, when referring to the accompanying drawings, the same reference numerals in different drawings denote the same or similar elements.

[0021] Reference Figure 1This disclosure provides a sampling system for HCl, which may include a sampling gun 1, a cyclone separator 2, an absorption module 3, and an extraction module 4 arranged sequentially along the flue gas flow direction. The sampling gun 1 is used to collect flue gas within a flue 7. During sampling, the sampling gun 1 extends along a preset path into the sampling position of the flue 7 to extract the flue gas. The cyclone separator 2 is used to separate fly ash from the flue gas and collect it in an ash hopper 21 at the bottom, and can also discharge the separated flue gas. The cyclone separator 2 in the embodiments provided in this disclosure utilizes centrifugal force to achieve gas-solid separation of flue gas. When the flue gas containing fly ash, delivered by the sampling gun 1, enters the cyclone separator 2, the flue gas rotates at high speed along the inner wall of the cyclone separator 2. At this time, the fly ash particles in the flue gas, because their density is much greater than that of the gas, are thrown towards the wall under the action of centrifugal force, and then fall down the wall into the ash hopper 21 at the bottom. The less dense gas, i.e., the separated flue gas, converges towards the central area of ​​the cyclone separator 2 during the rotation process, and is finally discharged to the outside from the outlet 22 located at the top of the cyclone separator 2, thereby completing the effective separation of fly ash and flue gas. The absorption module 3 can be used to receive the separated flue gas, absorb and store HCl in the separated flue gas. By sampling HCl in the separated flue gas, the sampling can directly target the pure gaseous components, greatly reducing the interference of impurities, thereby ensuring that the final detection data can truly reflect the actual parameters of HCl in the original flue gas. The extraction module 4 can receive the flue gas absorbed by the absorption module 3 and discharge it downstream. Furthermore, the extraction module 4 can provide flow power for the flue gas in the sampling system. In the embodiments provided in this disclosure, from the moment the flue gas enters the sampling gun 1, through the cyclone separator 2, the absorption module 3, the extraction module 4, and finally the discharge system, the entire process requires continuous power. The extraction module 4 can provide negative pressure power for the entire flow of the flue gas, thereby effectively avoiding problems such as stagnation and uneven flow rate of the flue gas in the pipeline or components, ensuring that the flue gas flows stably along the preset path, and guaranteeing sufficient separation in the cyclone separator 2 and full absorption of HCl in the absorption module 3, ensuring the continuity and efficiency of the sampling process.

[0022] Through the above technical solution, the cyclone separator 2 in the sampling system provided in this disclosure can remove fly ash from the flue gas in a timely manner after receiving the flue gas sampled by the sampling gun 1 to eliminate solid impurities and prevent fly ash from adsorbing HCl or affecting subsequent sampling, thus providing a clean sample for subsequent HCl analysis and improving the accuracy of the detection results. At the same time, the absorption module 3 can fix and store the HCl in the flue gas to prevent HCl loss during the sampling process. The exhaust module 4 provides power to the entire system throughout the process, ensuring that the flue gas flows stably through the sampling gun, cyclone separator, absorption module and other links, ensuring sufficient sampling and sufficient absorption reaction.

[0023] Accordingly, this disclosure also provides a method for sampling HCl, referring to... Figure 2 and combined Figure 1 The method includes: Step S1, the sampling gun 1 is inserted into the flue gas 7 to be sampled, collects the target flue gas, and delivers it to the cyclone separator 2; Step S2, the cyclone separator 2 receives the flue gas, separates the fly ash in the flue gas through centrifugal force, and temporarily stores the fly ash, while simultaneously discharging the separated flue gas after fly ash removal to the absorption module 3; Step S3, the absorption module 3 receives the separated flue gas from the cyclone separator, reacts with HCl through an internal absorbent to complete the absorption and storage of hydrogen chloride in the flue gas, and then discharges the deacidified flue gas after HCl removal; Step S4, the extraction module 4 discharges the deacidified flue gas downstream of the sampling system, thus completing one HCl sampling and flue gas treatment process. It should be noted that throughout the entire sampling process, the extraction module 4 continuously provides stable power for the flue gas flow of the entire sampling system, from the moment the flue gas enters the sampling gun 1, to its subsequent flow through various components and finally its discharge from the sampling system, thereby ensuring that the flue gas can flow smoothly and stably along the set path.

[0024] Reference Figure 1 The sampling system may also include a heating chamber 5, in which the cyclone separator 2 can be housed to maintain the separated flue gas at a preset temperature. In the embodiments provided in this disclosure, the preset temperature can be 110~130℃, preferably 120℃. When the flue gas entering the sampling system from the sampling gun 1 is wet flue gas containing a lot of water vapor, or when the ambient humidity of the cyclone separator 2 is high, causing a small amount of ambient water vapor to seep into the cyclone separator 2 and mix with the separated flue gas that is about to be transported to the absorption module 3, the flue gas temperature can be effectively maintained within the preset range by using the heating chamber 5 to keep the separated flue gas warm. This prevents the water vapor and the acidic HCl in the flue gas from condensing before reaching the absorption module 3, ensuring the accuracy of subsequent HCl sampling and analysis.

[0025] Reference Figure 1 The absorption module 3 may include a first absorption bottle 31 located downstream of the cyclone separator 2, which may contain a sodium hydroxide solution. The first absorption bottle 31 greatly facilitates the addition, replacement, and subsequent sampling and analysis of the sodium hydroxide solution, improving the convenience and reliability of the sampling process. In the embodiments provided in this disclosure, after receiving clean flue gas (i.e., the separated flue gas), the sodium hydroxide solution in the first absorption bottle 31 can react rapidly and completely with HCl, efficiently capturing HCl in the flue gas and preventing it from being lost with the flue gas, ensuring sufficient HCl sampling. Furthermore, when it is necessary to detect the concentration of hydrogen chloride in the flue gas, stable salts such as sodium chloride generated by the reaction of sodium hydroxide and hydrogen chloride remain in the solution. Subsequent chemical analysis can accurately calculate the salt content, thereby inferring the HCl concentration in the original flue gas and ensuring accurate detection data.

[0026] Reference Figure 1 The number of first absorption bottles 31 is multiple, and the multiple first absorption bottles 31 are connected in series along the flue gas flow direction. In the embodiment provided in this disclosure, the number of first absorption bottles 31 can be two, and the two first absorption bottles 31 are connected in series downstream of the cyclone separator 2, thereby realizing multi-stage absorption of HCl, effectively improving the HCl capture rate, avoiding sample loss caused by incomplete absorption of a single bottle, and ensuring the accuracy of subsequent HCl parameter detection.

[0027] Reference Figure 1 The extraction module 4 may include a vacuum pump 41 to provide stable negative pressure for the sampling system, thereby ensuring that the flue gas flows smoothly and continuously through components such as the sampling gun 1, cyclone separator 2, and first absorption bottle 31, preventing flue gas stagnation from affecting sampling efficiency. The absorption module 3 may also include a second absorption bottle 32 connected between the vacuum pump 41 and the first absorption bottle 31. The second absorption bottle 32 may contain a desiccant to remove moisture from the flue gas and prevent moisture from flowing downstream and damaging the vacuum pump 41. In the embodiments provided in this disclosure, the desiccant may be color-changing silica gel, which can efficiently adsorb residual moisture in the sampling system, preventing moisture from entering the vacuum pump 41 with the flue gas; and can also visually indicate the moisture saturation state through color changes, facilitating timely replacement and ensuring the stable operation of the sampling system.

[0028] In the embodiments provided in this disclosure, the first absorption bottle 31 and the second absorption bottle 32 can be connected by a connector 8 made of borosilicate glass. On the one hand, this gives the connector 8 strong chemical stability, enabling it to withstand the corrosion of HCl in the flue gas and preventing the connector 8 from being corroded and producing impurities or leaks; on the other hand, the high borosilicate glass has good high-temperature resistance and can be adapted to the system's insulation requirements of 110~130℃, so that the connector 8 will not deform or crack due to temperature changes, thereby ensuring the stable operation of the sampling system.

[0029] Reference Figure 1 The absorption module 3 also includes an ice bath 6 for holding the first absorption bottle 31 and the second absorption bottle 32, so as to provide a low temperature environment for the first absorption bottle 31 and the second absorption bottle 32, thereby reducing the loss of volatile substances and ensuring the stability of the sampling process.

[0030] Reference Figure 1 The extraction module 4 may also include a flow meter 42 located downstream of the vacuum pump 41. On one hand, the flow rate data can be used to determine whether the negative pressure provided by the vacuum pump 41 is stable, ensuring sufficient HCl absorption and controllable sampling volume. On the other hand, accurate flow rate recording provides crucial data support for subsequent calculations of sampling volume and flue gas flow rate, while also facilitating timely detection of problems such as pipe blockage and leakage that cause abnormal flow rates. Figure 1As shown, a vacuum gauge 43 can also be installed upstream of the vacuum pump 41 to monitor the negative pressure at the inlet of the vacuum pump 41 in real time, thereby determining whether the flue gas flow is stable.

[0031] Reference Figure 1 The sampling system may also include a fluid velocity meter 9 inserted near the sampling gun 1 in the flue 7. The fluid velocity meter 9 can be a Pitot tube to accurately obtain the actual flow velocity of the original flue gas in the flue 7. Thus, the flue gas collected by the sampling gun 1 can be judged based on the measured flow velocity to determine whether the flue gas is representative, so as to avoid sample deviation caused by only collecting flue gas with abnormal flow velocity.

[0032] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0033] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0034] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A sampling system for HCl, characterized in that, It includes a sampling gun, a cyclone separator, an absorption module, and an extraction module, which are sequentially connected along the flue gas flow direction. The sampling gun is used to collect flue gas inside the flue. The cyclone separator is used to separate fly ash from the flue gas and collect it in the ash hopper at the bottom, while simultaneously discharging the separated flue gas. The absorption module is used to absorb and store HCl in the separated flue gas after receiving it; and The extraction module is used to receive the flue gas after it has passed through the absorption module for acid removal and to provide the flow power for the flue gas in the sampling system.

2. The sampling system according to claim 1, characterized in that, It also includes a heating chamber, in which the cyclone separator is housed to maintain the separated flue gas at a preset temperature.

3. The sampling system according to claim 1, characterized in that, The absorption module includes a first absorption bottle located downstream of the cyclone separator, and the first absorption bottle contains a sodium hydroxide solution.

4. The sampling system according to claim 3, characterized in that, There are multiple first absorption bottles, which are connected in series along the flue gas flow direction.

5. The sampling system according to claim 3, characterized in that, The vacuum pump module includes a vacuum pump, and the absorption module further includes a second absorption bottle connected between the vacuum pump and the first absorption bottle, the second absorption bottle containing a desiccant.

6. The sampling system according to claim 5, characterized in that, The first absorption bottle and the second absorption bottle are connected by a connector made of high borosilicate glass.

7. The sampling system according to claim 5, characterized in that, The absorption module also includes an ice bath for holding the first absorption bottle and the second absorption bottle.

8. The sampling system according to claim 5, characterized in that, The pumping module includes a flow meter located downstream of the vacuum pump.

9. The sampling system according to claim 1, characterized in that, It also includes a fluid velocity meter inserted into the flue near the sampling gun.

10. A sampling method, characterized in that, The sampling method uses the sampling system according to any one of claims 1-9 of this disclosure.

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