A gas phase divalent mercury catalytic reducing agent efficiency detection system and detection method

Abstract

The present invention provides a gas phase divalent mercury catalytic reducing agent efficiency detection system, which includes a divalent mercury generator, a divalent mercury pyrolyzer, a catalytic reduction reactor and a mercury measuring instrument; the inlet end of the divalent mercury generator is connected to a gas source; the inlet end of the divalent mercury pyrolyzer and the inlet end of the catalytic reduction reactor are respectively connected to the outlet end of the divalent mercury generator through an intake pipeline, and an intake control valve is provided on each intake pipeline; the outlet end of the divalent mercury pyrolyzer and the outlet end of the catalytic reduction reactor are respectively connected to the mercury measuring instrument through an exhaust pipeline, and an exhaust control valve is provided on each exhaust pipeline. The above detection system has high stability and accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of gas phase divalent mercury catalytic reducing agent performance detection, in particular to a gas phase divalent mercury catalytic reducing agent efficiency detection system and detection method. Background Art

[0002] Mercury and its compounds are a class of toxic and hazardous substances. Even a trace amount of mercury can cause great harm to human health and the natural environment such as ecological water, soil and atmosphere, and it is difficult to completely eliminate. Mercury has the characteristics of inter-regional migration, enrichment in organisms, toxicity transmission in the food chain, and strong latency, which has attracted widespread attention from the world. In addition to natural causes such as volcanic eruptions, rock weathering, and forest fires, human activities such as mineral fuel combustion, metal smelting, cement production, and chlor-alkali industry have gradually become important sources of mercury pollution in the atmosphere. Although the mercury content in coal is relatively low, given the growing global energy demand, coal resources occupy an important position in the world energy system. Therefore, the combustion and utilization of coal has become one of the main sources of anthropogenic mercury emissions to the atmosphere.

[0003] At present, many countries around the world have formulated laws, regulations and industry standards specifically for limiting mercury emissions from coal-fired power plants. Whether it is establishing a mercury emission inventory or evaluating the efficiency of various mercury removal technologies, accurate measurement of mercury forms is undoubtedly an important prerequisite and foundation.

[0004] Mercury exists in three forms in the combustion products: gaseous elemental mercury Hg 0 (g), gaseous oxidized mercury Hg 2+ (g) and particulate mercury Hg adsorbed on solid products P . Since the current online analysis and detection technologies for mercury concentration are all based on the method of detecting elemental mercury, the measurement of oxidized mercury must first be converted into elemental mercury. The wet chemical conversion method uses a liquid conversion unit to convert divalent mercury into elemental mercury, but the reaction reagent needs to be replaced regularly, the detection accuracy is easily affected by human interference, and the operation is complicated. The high-temperature thermal conversion method is to decompose and reduce divalent mercury into elemental mercury under high temperature (above 800°C) in the flue gas. This method has high requirements for instruments and equipment and requires additional heat. During the temperature reduction process, the elemental mercury that has been decomposed and reduced may be oxidized again, thereby reducing the conversion efficiency and measurement accuracy. The solid catalytic reduction method uses a solid catalytic reducing agent to catalytically reduce divalent mercury into elemental mercury in the temperature range of 200°C to 400°C. This method is simple to operate, does not require external energy, and has high conversion efficiency. It has become an advanced catalytic reducing agent for oxidized mercury in the continuous detection device for flue gas mercury forms. Therefore, it is very necessary to design a solid catalytic reducing agent to detect the conversion efficiency performance of oxidized mercury for the development of efficient catalytic reducing agents.

[0005] At present, there are still many problems in some gas-phase divalent mercury conversion efficiency detection methods. For example, in the selection of mercury source, the divalent mercury reagent (such as mercuric chloride reagent) heating dilution method is used, but it is difficult to ensure the provision of a constant flow and constant concentration of divalent mercury. Its uncertainty and discontinuity cannot accurately evaluate the conversion efficiency of the catalytic reducer. The reaction conditions of the wet chemical calibration method are very complex, there are uncertainties in the conversion process and chemical reaction, and the conversion efficiency is low. Summary of the invention

[0006] The first object of the present invention is to provide a gas phase divalent mercury catalytic reducing agent efficiency detection system, which can solve the problems of low stability and poor accuracy in the existing divalent mercury catalytic reducing agent efficiency detection process;

[0007] The second object of the present invention is to provide a method for detecting the efficiency of a gas-phase divalent mercury catalytic reducing agent, which uses the gas-phase divalent mercury catalytic reducing agent efficiency detection system as described above to detect the efficiency of the divalent mercury catalytic reducing agent.

[0008] The present invention provides a gas phase divalent mercury catalytic reducing agent efficiency detection system, which comprises a divalent mercury generator, a divalent mercury pyrolyzer, a catalytic reduction reactor and a mercury measuring instrument;

[0009] The inlet end of the divalent mercury generator is connected to a gas source;

[0010] The inlet end of the divalent mercury pyrolyzer and the inlet end of the catalytic reduction reactor are respectively connected to the outlet end of the divalent mercury generator through an air intake pipeline, and an air intake control valve is provided on each air intake pipeline;

[0011] The outlet end of the divalent mercury pyrolyzer and the outlet end of the catalytic reduction reactor are respectively connected to the mercury measuring instrument through an exhaust pipeline, and each exhaust pipeline is provided with an exhaust control valve.

[0012] Preferably, a mass flow meter is provided at the inlet end of the divalent mercury generator.

[0013] Preferably, the outlet end of the divalent mercury generator is provided with a first three-way valve;

[0014] The first valve port of the first three-way valve is connected to the outlet end of the divalent mercury generator;

[0015] The second valve port of the first three-way valve is connected to the inlet end of the divalent mercury pyrolyzer through the first air intake pipeline, and the first air intake pipeline is provided with a first air intake control valve;

[0016] The third valve port of the first three-way valve is connected to the inlet end of the catalytic reduction reactor through a second intake pipeline, and a second intake control valve is arranged on the second intake pipeline.

[0017] Preferably, the divalent mercury generator comprises a divalent mercury permeation tube, a thermal conductive medium quartz glass ball, a first electric heating element and a first temperature controller;

[0018] The first electric heating element is electrically connected to the first temperature controller, and the first electric heating element has a heating cavity;

[0019] The heat-conducting medium quartz glass balls and the divalent mercury permeation tube are arranged in the heating chamber, and the heat-conducting medium quartz glass balls are distributed around the divalent mercury permeation tube;

[0020] The inlet end of the divalent mercury permeation tube is the inlet end of the divalent mercury generator.

[0021] Preferably, the divalent mercury pyrolyzer comprises a pyrolysis reaction tube, a first quartz wool, a first constant temperature medium quartz glass ball, an acid scavenger, a first thermocouple, a second electric heating element, a second temperature controller and a first heat-insulating shell;

[0022] The second temperature controller is electrically connected to a second electric heating element, the second heating element is disposed in the first heat-insulating housing, and the pyrolysis reaction tube is plugged into the second electric heating element;

[0023] Along the flow direction of the airflow, the pyrolysis reaction tube is provided with a first constant temperature medium quartz glass ball and an acid scavenger in sequence;

[0024] A first quartz wool is arranged between the first constant temperature medium quartz glass ball and the acid scavenger, and outside the constant temperature medium quartz ball and the acid scavenger;

[0025] The first thermocouple is electrically connected to the second temperature controller, and the first thermocouple is inserted into the first quartz wool outside the acid scavenger;

[0026] The inlet end of the pyrolysis reaction tube is the inlet end of the divalent mercury pyrolyzer, and the outlet end of the pyrolysis reaction tube is the outlet end of the divalent mercury pyrolyzer.

[0027] Preferably, the catalytic reducing agent reactor comprises: a catalytic reduction reaction tube, a second quartz wool, a second constant temperature medium quartz glass ball, a second thermocouple, a third electric heating element, a third temperature controller and a second heat preservation shell;

[0028] The third electric heating element is electrically connected to the third temperature controller, the third electric heating element is arranged in the second heat-insulating shell, and the catalytic reduction reaction tube is plugged into the third electric heating element;

[0029] The second constant temperature medium quartz glass ball is arranged in the catalytic reduction reaction tube, and second quartz wool is arranged at both ends of the second constant temperature medium quartz glass ball;

[0030] The second thermocouple is plugged into the second quartz wool near the outlet end of the catalytic reduction reaction tube;

[0031] The inlet end of the catalytic reduction reaction tube is the inlet end of the catalytic reducing agent reactor, and the outlet end of the catalytic reduction reaction tube is the outlet end of the catalytic reducing agent reactor.

[0032] Preferably, the outlet ends of the divalent mercury pyrolyzer and the catalytic reduction reactor are provided with a second three-way valve;

[0033] The first valve port of the second three-way valve is connected to the outlet end of the divalent mercury pyrolyzer through a first exhaust pipeline, and a first exhaust control valve is arranged on the first exhaust pipeline;

[0034] The second valve port of the second three-way valve is connected to the outlet end of the catalytic reduction reactor through a second exhaust pipeline, and a second exhaust control valve is arranged on the second exhaust pipeline;

[0035] The third valve port of the second three-way valve is communicated with a mercury measuring instrument.

[0036] Preferably, a gas cooler is provided on the connecting pipeline between the third valve port of the second three-way valve and the mercury measuring instrument.

[0037] Preferably, the outlet end of the mercury measuring instrument is connected to an activated carbon purifier.

[0038] A method for detecting the efficiency of a gas-phase divalent mercury catalytic reducing agent, which uses the gas-phase divalent mercury catalytic reducing agent efficiency detection system as described above to detect the efficiency of a gas-phase divalent mercury catalytic reducing agent, and comprises the following steps:

[0039] A divalent mercury generator is used to generate a divalent mercury standard gas flow with a constant concentration and a continuous and stable flow rate;

[0040] Pass the divalent mercury standard gas into the divalent mercury pyrolyzer, and observe the mercury value measured by the mercury meter after the temperature of the divalent mercury pyrolyzer reaches the set temperature. When the mercury value is completely stable, the system is considered stable, and the calibrated initial mercury concentration is recorded;

[0041] Stop supplying divalent mercury standard gas to the divalent mercury pyrolyzer, and pass the divalent mercury standard gas into the catalytic reducer reactor, observe the mercury concentration after conversion, and record the mercury value after the mercury value stabilizes. Compare the mercury value in this step with the initial mercury concentration to obtain the catalytic reducer conversion efficiency.

[0042] Beneficial effects:

[0043] The divalent mercury standard gas is generated by the divalent mercury generator, and the divalent mercury standard gas is controlled by the air intake control valve and the exhaust control valve to enter the divalent mercury pyrolyzer and the catalytic reduction reactor respectively. Mercury of all valence states is completely cracked at high temperature in the divalent mercury pyrolyzer, and the divalent mercury is reduced in the catalytic reduction reactor. Finally, the catalytic reaction efficiency of the catalyst is obtained by detecting the mercury concentration of the gas discharged from the divalent mercury pyrolyzer and the catalytic reduction reactor. The above detection system has high stability and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 This is a schematic diagram of the structure of a gas-phase divalent mercury catalytic reducing agent efficiency detection system provided in a specific embodiment of the present invention.

[0046] Description of reference numerals:

[0047] 1: mass flow meter; 2: divalent mercury generator; 3: divalent mercury pyrolyzer; 4: catalytic reduction reactor; 5: gas cooler; 6: mercury measuring instrument; 7: activated carbon purifier; 8: first intake control valve; 9: second intake control valve; 10: first exhaust control valve; 11: second exhaust control valve; 12: first three-way valve, 13: second three-way valve;

[0048] 21: divalent mercury permeation tube; 22: thermal conductive medium quartz glass ball; 23: first heating element; 24: first temperature controller;

[0049] 31: pyrolysis reaction tube; 32: first quartz wool; 33: first constant temperature medium quartz glass ball; 34: acid scavenger; 35: first thermocouple; 36: second electric heating element; 37: second temperature controller; 38: first heat preservation shell;

[0050] 41: catalytic reduction reaction tube; 42: second quartz wool; 43: second constant temperature medium quartz glass ball; 44: second thermocouple; 45: third electric heating element; 46: third temperature controller; 47: second heat-insulating shell. DETAILED DESCRIPTION

[0051] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0053] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] like Figure 1 As shown, in this embodiment, a gas-phase divalent mercury catalytic reducing agent efficiency detection system is provided, which includes a divalent mercury generator 2, a divalent mercury pyrolyzer 3, a catalytic reduction reactor 4 and a mercury measuring instrument 6.

[0055] The inlet end of the divalent mercury generator 2 is connected to the gas source, and the inlet end of the divalent mercury pyrolyzer 3 and the inlet end of the catalytic reduction reactor 4 are respectively connected to the outlet end of the divalent mercury generator 2 through an intake pipeline, and an intake control valve is provided on each intake pipeline.

[0056] The outlet end of the divalent mercury pyrolyzer 2 and the outlet end of the catalytic reduction reactor 4 are respectively connected to the mercury measuring instrument 6 through an exhaust pipeline, and each exhaust pipeline is provided with an exhaust control valve.

[0057] In this embodiment, a divalent mercury standard gas is generated by a divalent mercury generator 2, and the divalent mercury standard gas is controlled by an air intake control valve and an exhaust control valve to enter the divalent mercury pyrolyzer 2 and the catalytic reduction reactor 4 respectively, and mercury of all valence states is completely cracked at high temperature in the divalent mercury pyrolyzer 2, and the divalent mercury is reduced in the catalytic reduction reactor 4, and finally the catalytic reaction efficiency of the catalyst is obtained by detecting the mercury concentration of the gas discharged from the divalent mercury pyrolyzer 2 and the catalytic reduction reactor 4. The above detection system has high stability and accuracy.

[0058] The inlet end of the divalent mercury generator 2 is provided with a mass flow meter 1. By providing the mass flow meter 1, the amount of the mercury-containing carrier gas entering the divalent mercury generator 2 can be controlled.

[0059] Specifically, a first three-way valve 12 is provided at the outlet end of the divalent mercury generator 2 , and a first valve port of the first three-way valve 12 is communicated with the outlet end of the divalent mercury generator 2 .

[0060] The second valve port of the first three-way valve 12 is connected to the inlet end of the divalent mercury pyrolyzer 3 through the first intake pipeline, and the first intake pipeline is provided with a first intake control valve 8 .

[0061] The third valve port of the first three-way valve 12 is connected to the inlet end of the catalytic reduction reactor 4 through the second intake pipeline, and the second intake control valve 9 is arranged on the second intake pipeline.

[0062] Mercury generator 2

[0063] The divalent mercury generator 2 includes a divalent mercury permeation tube 21 , a quartz glass ball 22 as a heat-conducting medium, a first electric heating element 23 and a first temperature controller 24 .

[0064] The first electric heating element 23 is electrically connected to the first temperature controller 24 , and the first electric heating element 23 has a heating cavity.

[0065] The heat-conducting medium quartz glass balls 22 and the divalent mercury permeation tube 21 are arranged in the heating chamber, and the heat-conducting medium quartz glass balls 22 are distributed around the divalent mercury permeation tube 21 .

[0066] The inlet end of the divalent mercury permeation tube 21 is the inlet end of the divalent mercury generator 21 .

[0067] The divalent mercury permeation tube 21 is used as a divalent mercury source, which can provide continuous and stable divalent mercury to meet the requirement of long-term evaluation of the conversion effect of the catalytic reducing agent.

[0068] The temperature of the heating layer is precisely controlled by the first temperature controller 24 , and the quartz glass balls filled between the divalent mercury permeation tube 21 and the first heating element 23 can heat the mercury permeation tube evenly, thereby ensuring stable release of divalent mercury and reducing experimental errors.

[0069] Mercury divalent pyrolyzer 3

[0070] The divalent mercury pyrolyzer 3 comprises a pyrolysis reaction tube 31 , a first quartz wool 32 , a first constant temperature medium quartz glass ball 33 , an acid scavenger 34 , a first thermocouple 35 , a second electric heating element 36 , a second temperature controller 37 and a first heat-insulating shell 38 .

[0071] The second temperature controller 37 is electrically connected to the second electric heating element 36 . The second heating element 36 is disposed in the first heat-insulating shell 38 . The pyrolysis reaction tube 31 is plugged into the second electric heating element 36 .

[0072] Along the flow direction of the airflow, the first constant temperature medium quartz glass ball 33 and the acid scavenger 34 are sequentially arranged in the pyrolysis reaction tube 31 .

[0073] The first quartz wool 32 is arranged between the first constant temperature medium quartz glass ball 33 and the acid scavenger 34 and outside the first constant temperature medium quartz ball 33 and the acid scavenger 34 .

[0074] The first thermocouple 35 is electrically connected to the second temperature controller 37 , and the first thermocouple 35 is inserted into the first quartz wool outside the acid scavenger 34 .

[0075] The inlet end of the pyrolysis reaction tube 31 is the inlet end of the divalent mercury pyrolyzer 3 , and the outlet end of the pyrolysis reaction tube 31 is the outlet end of the divalent mercury pyrolyzer 3 .

[0076] The quartz glass balls filled in the high-temperature cracking section can better ensure the complete cracking of divalent mercury, and the filled acid scavenger can absorb the acid gas produced by cracking to prevent the secondary recombination of acid gas and elemental mercury, which will affect the calibration results.

[0077] Catalytic reducer reactor 4

[0078] The catalytic reducing agent reactor 4 comprises: a catalytic reducing reaction tube 41 , a second quartz wool 42 , a second constant temperature medium quartz glass ball 43 , a second thermocouple 44 , a third electric heating element 45 , a third temperature controller 46 and a second heat preservation shell 47 .

[0079] The third electric heating element 45 is electrically connected to the third temperature controller 46 . The third electric heating element 45 is disposed in the second heat-insulating shell 47 . The catalytic reduction reaction tube 41 is plugged into the third electric heating element 45 .

[0080] The second constant temperature medium quartz glass ball 43 is disposed in the catalytic reduction reaction tube 41 , and second quartz wool 42 is disposed at both ends of the second constant temperature medium quartz glass ball 43 .

[0081] The second thermocouple 44 is plugged into the second quartz wool 42 near the outlet end of the catalytic reduction reaction tube 41 .

[0082] The inlet end of the catalytic reduction reaction tube 41 is the inlet end of the catalytic reducing agent reactor 4 , and the outlet end of the catalytic reduction reaction tube 41 is the outlet end of the catalytic reducing agent reactor 4 .

[0083] Inserted temperature measuring thermocouples are installed in the quartz wool of the pyrolysis section and the catalytic reduction reaction section to monitor the reaction temperature in real time, thereby ensuring that divalent mercury can be completely decomposed, and the reaction process of the catalytic reducing agent can be monitored to obtain reasonable results.

[0084] A second three-way valve 13 is provided at the outlet ends of the divalent mercury pyrolyzer 3 and the catalytic reduction reactor 4 .

[0085] The first valve port of the second three-way valve 13 is connected to the outlet end of the divalent mercury pyrolyzer 3 through the first exhaust pipeline, and the first exhaust control valve 10 is arranged on the first exhaust pipeline.

[0086] The second valve port of the second three-way valve 13 is connected to the outlet end of the catalytic reduction reactor 4 through a second exhaust pipeline, and a second exhaust control valve 11 is arranged on the second exhaust pipeline.

[0087] The third valve port of the second three-way valve 13 is communicated with the mercury measuring instrument 6 .

[0088] A gas cooler 5 is provided on the connecting pipeline between the third valve port of the second three-way valve 13 and the mercury measuring instrument 6. The gas cooler 5 can ensure that the mercury analyzer operates within a reasonable temperature range.

[0089] The outlet end of the mercury measuring instrument 6 is connected to an activated carbon purifier 7. The activated carbon purifier 7 recovers the tail gas.

[0090] The gas pipes used in this embodiment are all made of stainless steel pipes with polytetrafluoroethylene coating inside, the connectors and valves are made of polytetrafluoroethylene parts, and the divalent mercury pyrolysis reaction tube and catalytic reduction reaction tube are made of quartz glass material, which can eliminate the adsorption effect of mercury by the system itself to the greatest extent.

[0091] In this embodiment, a method for detecting the efficiency of a gas-phase divalent mercury catalytic reducing agent is also provided, which uses the gas-phase divalent mercury catalytic reducing agent efficiency detection system as described above to detect the efficiency of a gas-phase divalent mercury catalytic reducing agent, and comprises the following steps:

[0092] The divalent mercury generator 2 generates a divalent mercury standard gas flow with a constant concentration and a continuous and stable flow rate.

[0093] The divalent mercury standard gas is introduced into the divalent mercury pyrolyzer 3. After the temperature of the divalent mercury pyrolyzer 3 reaches the set temperature, the mercury value measured by the mercury meter is observed. After the mercury value is completely stable, the system is considered to be stable, and the calibrated initial mercury concentration is recorded.

[0094] Stop supplying the divalent mercury standard gas to the divalent mercury pyrolyzer 3, and pass the divalent mercury standard gas into the catalytic reducer reactor 4, observe the mercury concentration after conversion, and record the mercury value after the mercury value stabilizes. Compare the mercury value in this step with the initial mercury concentration to obtain the catalytic reducer conversion efficiency.

[0095] In order to further illustrate the above method, this embodiment also provides a specific implementation of the above method.

[0096] When in use, the first heating element 23 is adjusted to a temperature of T°C by the first temperature controller 24, the carrier gas is controlled by the mass flow meter 1 and passed into the divalent mercury generator 2, and the quartz glass ball 22 as a heat-conducting medium filled in the divalent mercury generator 2 maintains a uniform temperature in the mercury generator, thereby uniformly heating the divalent mercury permeation tube 21, ensuring that the divalent mercury is continuously and stably generated and input into the system.

[0097] Open the pyrolysis section valve (first air inlet control valve 8), set the temperature of the second electric heating element 36 through the second temperature controller 37 to 800°C (at 800°C, all valence mercury will be pyrolyzed at high temperature), and observe the mercury value measured by the mercury measuring instrument 6 when the furnace temperature reaches the set temperature. When the mercury value is completely stable, the system is considered stable. The mercury value at this time is the concentration of divalent mercury released by the divalent mercury permeation tube at temperature T°C. The initial mercury concentration is calibrated accordingly, and the recorded value is A;

[0098] After the catalytic reduction reaction section 4 is filled and installed, the pyrolysis section valve is closed, and the catalytic reduction reaction section valve (the second air intake control valve 9) is opened to allow the gas containing the calibrated concentration of divalent mercury to pass into the catalytic reduction agent reaction section 4, and observe the mercury concentration after conversion. After the mercury value is stable, record the mercury value B at this time. The mercury value B is compared with the mercury value A to obtain the catalytic reduction agent conversion efficiency.

[0099] It should be noted that after the gas comes out of the divalent mercury pyrolysis section or the catalytic reduction reaction section, it is cooled to below 100° C. in the gas cooling section 5 , enters the mercury detection instrument 6 , and finally is discharged after absorbing mercury in the activated carbon absorption section 7 .

[0100] After each measurement using the detection system provided in this embodiment, the pyrolysis reaction tube 31, the first constant temperature medium quartz glass ball 33 and the acid scavenger 34 filled in the pyrolysis reaction tube 31 need to be replaced, and the adsorbent in the activated carbon purifier 7 needs to be regularly updated.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gas phase divalent mercury catalytic reducing agent efficiency detection system, characterized in that: Including divalent mercury generator, divalent mercury pyrolyzer, catalytic reduction reactor and mercury measuring instrument; The inlet end of the divalent mercury generator is connected to a gas source; The inlet end of the divalent mercury pyrolyzer and the inlet end of the catalytic reduction reactor are respectively connected to the outlet end of the divalent mercury generator through an air intake pipeline, and an air intake control valve is provided on each air intake pipeline; The outlet end of the divalent mercury pyrolyzer and the outlet end of the catalytic reduction reactor are respectively connected to the mercury measuring instrument through an exhaust pipeline, and each exhaust pipeline is provided with an exhaust control valve; The outlet end of the divalent mercury generator is provided with a first three-way valve; The first valve port of the first three-way valve is connected to the outlet end of the divalent mercury generator; The second valve port of the first three-way valve is connected to the inlet end of the divalent mercury pyrolyzer through the first air intake pipeline, and the first air intake pipeline is provided with a first air intake control valve; The third valve port of the first three-way valve is connected to the inlet end of the catalytic reduction reactor through a second air intake pipeline, and a second air intake control valve is provided on the second air intake pipeline; The divalent mercury pyrolyzer comprises a pyrolysis reaction tube, a first quartz wool, a first constant temperature medium quartz glass ball, an acid scavenger, a first thermocouple, a second electric heating element, a second temperature controller and a first heat-insulating shell; The second temperature controller is electrically connected to a second electric heating element, the second electric heating element is arranged in the first heat-insulating shell, and the pyrolysis reaction tube is plugged into the second electric heating element; Along the flow direction of the airflow, the pyrolysis reaction tube is provided with a first constant temperature medium quartz glass ball and an acid scavenger in sequence; A first quartz wool is arranged between the first constant temperature medium quartz glass ball and the acid scavenger, and outside the constant temperature medium quartz ball and the acid scavenger; The first thermocouple is electrically connected to the second temperature controller, and the first thermocouple is inserted into the first quartz wool outside the acid scavenger; The inlet end of the pyrolysis reaction tube is the inlet end of the divalent mercury pyrolyzer, and the outlet end of the pyrolysis reaction tube is the outlet end of the divalent mercury pyrolyzer; The catalytic reducing agent reactor comprises: a catalytic reduction reaction tube, a second quartz wool, a second constant temperature medium quartz glass ball, a second thermocouple, a third electric heating element, a third temperature controller and a second heat preservation shell; The third electric heating element is electrically connected to the third temperature controller, the third electric heating element is arranged in the second heat-insulating shell, and the catalytic reduction reaction tube is plugged into the third electric heating element; The second constant temperature medium quartz glass ball is arranged in the catalytic reduction reaction tube, and second quartz wool is arranged at both ends of the second constant temperature medium quartz glass ball; The second thermocouple is plugged into the second quartz wool near the outlet end of the catalytic reduction reaction tube; The inlet end of the catalytic reduction reaction tube is the inlet end of the catalytic reducing agent reactor, and the outlet end of the catalytic reduction reaction tube is the outlet end of the catalytic reducing agent reactor.

2. The gas phase divalent mercury catalytic reducing agent efficiency detection system according to claim 1, characterized in that: A mass flow meter is provided at the inlet end of the divalent mercury generator.

3. The gas phase divalent mercury catalytic reducing agent efficiency detection system according to claim 1, characterized in that: The divalent mercury generator comprises a divalent mercury permeation tube, a heat-conducting medium quartz glass ball, a first electric heating element and a first temperature controller; The first electric heating element is electrically connected to the first temperature controller, and the first electric heating element has a heating cavity; The heat-conducting medium quartz glass balls and the divalent mercury permeation tube are arranged in the heating chamber, and the heat-conducting medium quartz glass balls are distributed around the divalent mercury permeation tube; The inlet end of the divalent mercury permeation tube is the inlet end of the divalent mercury generator.

4. The gas phase divalent mercury catalytic reducing agent efficiency detection system according to claim 1, characterized in that: The outlet ends of the divalent mercury pyrolyzer and the catalytic reduction reactor are provided with a second three-way valve; The first valve port of the second three-way valve is connected to the outlet end of the divalent mercury pyrolyzer through a first exhaust pipeline, and a first exhaust control valve is arranged on the first exhaust pipeline; The second valve port of the second three-way valve is connected to the outlet end of the catalytic reduction reactor through a second exhaust pipeline, and a second exhaust control valve is arranged on the second exhaust pipeline; The third valve port of the second three-way valve is communicated with a mercury measuring instrument.

5. The gas phase divalent mercury catalytic reducing agent efficiency detection system according to claim 4, characterized in that: A gas cooler is arranged on the connecting pipeline between the third valve port of the second three-way valve and the mercury measuring instrument.

6. The gas phase divalent mercury catalytic reducing agent efficiency detection system according to claim 4, characterized in that: The outlet end of the mercury measuring instrument is connected to an activated carbon purifier.

7. A method for detecting the efficiency of a gas-phase divalent mercury catalytic reducing agent, characterized in that: The gas phase divalent mercury catalytic reducing agent efficiency detection system as claimed in any one of claims 1 to 6 is used to detect the gas phase divalent mercury catalytic reducing agent efficiency, which comprises the following steps: A divalent mercury generator is used to generate a divalent mercury standard gas flow with a constant concentration and a continuous and stable flow rate; Pass the divalent mercury standard gas into the divalent mercury pyrolyzer, and observe the mercury value measured by the mercury meter after the temperature of the divalent mercury pyrolyzer reaches the set temperature. When the mercury value is completely stable, the system is considered stable, and the calibrated initial mercury concentration is recorded; Stop supplying divalent mercury standard gas to the divalent mercury pyrolyzer, and pass the divalent mercury standard gas into the catalytic reducer reactor, observe the mercury concentration after conversion, and record the mercury value after the mercury value stabilizes. Compare the mercury value in this step with the initial mercury concentration to obtain the catalytic reducer conversion efficiency.

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