Elemental mercury generating device

Abstract

The invention relates to an elemental mercury generating device which comprises a carrier gas unit, an elemental mercury generating unit and a gas mixing unit, the elemental mercury generating unit is used for providing a mercury source, and the elemental mercury generating unit comprises an inlet and an outlet; the carrier gas unit is respectively connected with the inlet and the outlet and is used for providing stable carrier gas and adjusting the concentration of elemental mercury generated by the elemental mercury generation unit; and the gas mixing unit is connected with the outlet and is used for adjusting gas uniformity and removing gaseous active mercury. The device can accurately control the concentration of elemental mercury, can provide elemental mercury with stable concentration for a long time, and is suitable for laboratory gas reaction simulation and standard gas instrument calibration. In practice, the concentration of elemental mercury can be adjusted by changing the flow rate of diluent gas, the flow rate of the constant temperature device and the permeation rate of the permeation membrane of the mercury permeation tube so as to meet different experiment and calibration requirements.

Description

Technical Field

[0001] The invention relates to the technical field of environmental science analysis and environmental monitoring devices, in particular to an element mercury generating device. Background Art

[0002] Mercury is the only heavy metal that exists in liquid form at room temperature and pressure. It is highly toxic, bioaccumulative, and can be transported over long distances. 0 ) is the main form of mercury in the atmospheric environment (>95%), and its chemical activity is low, tending to be transported globally. GEM can be oxidized in the atmosphere to generate reactive mercury (RM). RM generally includes gaseous reactive mercury (RGM, Hg 2+ ) and particulate mercury (PBM, Hg p ), which has relatively strong chemical activity and tends to settle at the pollution source and its downwind area. Once it settles in the surface environment, it can be converted into more toxic methylmercury by anaerobic microorganisms, thereby posing a threat to the surface ecosystem and human health. In addition, RM can also be reduced to GEM by photochemical methods. It can be seen that providing a stable concentration of elemental mercury generation device for instrument calibration and experimental simulation is the basis of mercury chemical mechanism and global migration trend, which is of great significance for conducting research on chemical mechanisms related to atmospheric elemental mercury.

[0003] Mercury has a high saturated vapor pressure and strong volatility, so the production requirements for elemental mercury are relatively high. Common methods of generating elemental mercury include mercury reduction method and mercury permeation tube method. Mercury reduction method refers to the use of a reducing agent to reduce the divalent mercury (Hg 2+ ) is reduced to gaseous elemental mercury, which is then carried into the analyzer for calibration using a carrier gas. This method involves a variety of chemical substances, and the concentration of elemental mercury produced is affected by the reactants (Hg 2+ ) concentration is significantly affected and produces large fluctuations, making it difficult to achieve constant concentration and long time series preparation of elemental mercury.

[0004] The permeation tube method is a dynamic elemental mercury gas distribution method that can produce a large volume of continuous elemental mercury gas. However, the elemental mercury generated by the existing elemental mercury generation device based on simple heating of the permeation tube is affected by factors such as gas path disturbance and heating temperature fluctuation, and it is difficult to achieve a constant concentration of elemental mercury. At the same time, elemental mercury may be oxidized into gaseous active mercury in the gas pipeline, and the concentration level of elemental mercury generated is difficult to control.

[0005] Therefore, there is an urgent need for an elemental mercury generating device. Summary of the invention

[0006] The present invention provides an element mercury generating device to solve the problems that the element mercury generating device in the conventional technology cannot continuously provide element mercury with a stable flow rate and concentration for a long time, and has low efficiency and complicated operation.

[0007] The present invention provides an elemental mercury generating unit for providing a mercury source, wherein the elemental mercury generating unit comprises an inlet and an outlet; The carrier gas unit is connected to the inlet and the outlet respectively, and is used to provide a stable carrier gas and adjust the concentration of elemental mercury generated by the elemental mercury generating unit; The gas mixing unit is connected to the outlet, and is used to adjust gas uniformity and remove gaseous active mercury.

[0008] The elemental mercury generating device, preferably, the elemental mercury generating unit includes a mercury permeation tube, a reaction vessel, a plurality of glass balls, a partition and a constant temperature device, the reaction vessel is arranged in the constant temperature device, the reaction vessel is provided with the inlet and the outlet, the reaction vessel is provided with the glass balls, the partition and the mercury permeation tube, the glass balls are arranged close to the inlet side of the reaction vessel, the mercury permeation tube is arranged close to the outlet side of the reaction vessel, and the mercury permeation tube is placed on the partition, the inlet and the outlet are respectively connected to the carrier gas unit, and the outlet is also connected to the gas mixing unit.

[0009] The elemental mercury generating device, preferably, the mercury permeation tube comprises a sealing cover, a tube body and a semi-permeable membrane, the sealing cover is arranged at the bottom end of the tube body, the sealing cover is placed on the partition, the semi-permeable membrane is arranged at the upper end of the tube body, and the tube body is filled with liquid mercury.

[0010] In the elemental mercury generating device, preferably, the reaction vessel is a U-shaped tube, the tube mouth of the U-shaped tube is provided with a cover, and the tube wall of the U-shaped tube is provided with the inlet and the outlet.

[0011] In the elemental mercury generating device, preferably, the thermostat is a container for placing liquid, and the temperature control range of the thermostat is 0-100°C with an accuracy of ±0.1°C.

[0012] In the elemental mercury generating device, preferably, the gas mixing unit comprises a gas static mixer, a filter membrane device and a gas pipeline, and the outlet is connected to the gas static mixer and the filter membrane device in sequence through the gas pipeline.

[0013] The elemental mercury generating device, preferably, the gas static mixer comprises a body, a flange interface, an air inlet cover, an air outlet cover, an air inlet interface, an air outlet interface, an air inlet, an air outlet and a corrugated sheet, the air inlet interface and the air inlet cover, the air outlet interface and the air outlet cover are respectively connected through the flange interface, the corrugated sheet is provided in the body to realize zigzag flow of the fluid in the body, the air inlet interface and the air outlet interface are provided at both ends of the body, the air inlet interface is provided with the air inlet cover, the air outlet interface is provided with the air outlet cover, the air inlet cover is provided with the air inlet, the air inlet is connected to the outlet through the air pipeline, the air inlet and outlet covers are provided with the air outlet, and the air outlet is connected to the filter membrane clamp through the air pipeline.

[0014] The elemental mercury generating device, preferably, the filter membrane device comprises a filter membrane clip and a cation exchange membrane, the filter membrane clip is connected to the gas pipeline, and the cation exchange membrane is installed in the filter membrane clip.

[0015] The elemental mercury generating device, preferably, the carrier gas unit includes a mass flowmeter for generating carrier gas, a mass flowmeter for diluting gas, a first pipeline and a second pipeline, the mass flowmeter for generating elemental mercury is arranged on the first pipeline, the first pipeline is connected to the inlet, the mass flowmeter for diluting gas is arranged on the second pipeline, both ends of the second pipeline are respectively connected to the first pipeline and the gas pipeline, and the first pipeline and the second pipeline are Teflon hard tubes.

[0016] In the elemental mercury generating device, preferably, the mass flow meter for generating the carrier gas should have a range of 0-3 L / min, and the mass flow meter for the dilution gas should have a range of 0-10 L / min.

[0017] The beneficial effects are: The gas mixing unit comprises a gas static mixer, a filter membrane clamp and a gas pipeline.

[0018] The interior of the gas static mixer is assembled by corrugated sheets, which can make the fluid flow in a "zigzag" shape in three-dimensional space, achieving the effect of gas mixing.

[0019] There is a cation exchange membrane used to remove gaseous active mercury that may be produced in the pipeline, which needs to be replaced regularly.

[0020] The present invention can realize accurate control of elemental mercury concentration, provide elemental mercury of stable concentration for a long time, and is suitable for laboratory gas reaction simulation and standard gas instrument calibration. In practice, the elemental mercury concentration can be adjusted by changing the dilution gas flow rate, the constant temperature device flow rate and the permeability of the mercury permeation tube permeation membrane to meet different experimental and calibration requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of the elemental mercury generating device provided by the present invention; Figure 2 It is a schematic diagram of the structure of the gas static mixer provided by the present invention; Figure 3 is a cross-sectional view of a gas static mixer; Figure 4 is a side view of a gas static mixer; Figure 5 It is a time series diagram of elemental mercury concentration generated by the elemental mercury generating device provided by the present invention.

[0022] In the figure: 1. Mass flow meter for generating carrier gas; 2. Mass flow meter for dilution gas; 3. Cover; 4. Glass ball; 5. Reaction dish; 6. Container; 7. Partition; 8-1, sealing cover; 8-2, tube body; 8-3, semi-permeable membrane; 9. Gas static mixer; 10. Filter membrane clamp; 11. Corrugated sheet; 12. Flange interface; 13-1, air inlet; 14-1, air inlet interface; 14-2, air outlet interface; 15-1, air inlet cover; 15-2, air outlet cover 16. Gas pipeline; 17. Inlet; 18. Outlet; 19-1, first pipeline; 19-2, second pipeline. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the term "upper" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the use of terms such as "first" and "second" to define components is only for the convenience of distinguishing the above components. If not otherwise stated, the above terms have no special meaning and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" 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 an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The present invention provides an elemental mercury generating device, including a carrier gas unit, an elemental mercury generating unit and a gas mixing unit. The elemental mercury generating unit is used to provide a mercury source, and the elemental mercury generating unit includes an inlet and an outlet; the carrier gas unit is respectively connected to the inlet and the outlet, and is used to provide a stable carrier gas and adjust the concentration of elemental mercury generated by the elemental mercury generating unit; the gas mixing unit is connected to the outlet, and the gas mixing unit is used to adjust the gas uniformity and remove gaseous active mercury. The present invention can achieve accurate control of the elemental mercury concentration, provide a stable concentration of elemental mercury for a long time, and is suitable for laboratory gas reaction simulation and standard gas instrument calibration. In practice, the elemental mercury concentration can be adjusted by changing the dilution gas flow rate, the constant temperature device flow rate and the permeability of the mercury permeation tube permeation membrane to meet different experimental and calibration requirements.

[0027] The entire technical process is described in detail below using an elemental mercury generating device as an example.

[0028] Reference Figure 1 As shown, an element mercury generating device includes a carrier gas unit, an element mercury generating unit and a gas mixing unit. The carrier gas unit is connected to the inlet 17 and the outlet 18 of the elemental mercury generating unit respectively, and is used to provide a stable carrier gas and adjust the concentration of elemental mercury generated by the elemental mercury generating unit; The elemental mercury generating unit is used to provide a mercury source; The gas mixing unit is connected to the outlet 18 and is used to adjust gas uniformity and remove gaseous active mercury.

[0029] Continue to refer to Figure 1 As shown, the carrier gas unit includes a mass flowmeter 1 for generating carrier gas, a mass flowmeter 2 for diluting gas, a first pipeline 19-1 and a second pipeline 19-2. The mass flowmeter 1 for generating elemental mercury is arranged on the first pipeline 19-1, and the first pipeline 19-1 is connected to the inlet 17. The mass flowmeter 2 for diluting gas is arranged on the second pipeline 19-2, and both ends of the second pipeline 19-2 are respectively connected to the first pipeline 19-1 and the gas pipeline 16.

[0030] Nitrogen is generally used as the carrier gas, and other inert gases can also be used instead. The nitrogen cylinder needs to be decompressed using a pressure reducing valve to make the gas pressure about 0.5MPa.

[0031] Among them, the range of the mass flow meter 1 used to generate the carrier gas should be 0-3L / min, and the range of the mass flow meter 2 used to dilute the gas should be 0-10L / min.

[0032] The first pipeline 19-1 and the second pipeline 19-2 are made of Teflon hard tubes and connected by metal adapters of corresponding sizes that meet national standards. The connection between the Teflon hard tube and the reaction vessel 5 is connected by a rubber hose of appropriate size. It is worth noting that since the pressure resistance of the rubber hose is not strong, the rubber hose and the pressure reducing valve should be checked frequently, and if damaged, they should be replaced immediately.

[0033] Among them, Teflon rigid tubes have low adsorption capacity for zero-valent mercury, which can minimize the impact of pipeline adsorption on the generated mercury vapor concentration and contribute to the stability of the gas concentration.

[0034] It should be noted that, since the permeability coefficient of the mercury permeation tube is highly correlated with temperature, if the gas flow rate is too high, it may cause temperature fluctuations in the reaction vessel 5, so it is necessary to control the gas flow rate flowing through the reaction vessel 5 within an appropriate range. In addition, the mass flow meter 1 for generating the carrier gas and the mass flow meter 2 for the dilution gas can be connected to a computer to improve the portability of the system control.

[0035] Continue to refer to Figure 1 As shown, the elemental mercury generating unit includes a mercury permeation tube, a reaction dish 5, a plurality of glass balls 4, a partition 7 and a constant temperature device, wherein the constant temperature device is provided with a reaction dish 5, the reaction dish 5 is provided with an inlet 17 and an outlet 18, the reaction dish 5 is provided with a plurality of glass balls 4, a partition 7 and a mercury permeation tube, the glass balls 4 are arranged close to the inlet 17 side of the reaction dish 5, the mercury permeation tube is arranged close to the outlet 18 side of the reaction dish 5, and the mercury permeation tube is placed on the partition 7, the inlet 17 and the outlet 18 are respectively connected to the carrier gas unit, and the outlet 18 is also connected to the gas mixing unit.

[0036] The glass balls 4 are uniform in size, smooth in surface, and 5-6 mm in diameter, and are placed in front of the partition 7 and on the side of the inlet 17 of the reaction vessel 5. The glass balls 4 form a complex gas passage, which plays a role in heating the carrier gas.

[0037] Continue to refer to Figure 1 As shown, the mercury permeation tube includes a sealing cover 8-1, a tube body 8-2 and a semi-permeable membrane 8-3. The sealing cover 8-1 is arranged at the bottom end of the tube body 8-2. The tube body 8-2 is made of PTFE. The sealing cover 8-1 is placed on the partition 7. The semi-permeable membrane 8-3 is arranged at the upper end of the tube body 8-2. The tube body 8-2 is filled with liquid mercury to form a semi-enclosed structure with an outer wall made of PTFE and filled with liquid mercury.

[0038] Among them, the semi-permeable membrane 8-3 is provided with small holes, the internal pressure of the mercury permeation tube is stable, and the vaporization speed of mercury remains unchanged at a specific temperature.

[0039] Continue to refer to Figure 1 As shown, the reaction vessel 5 is a U-shaped tube, the tube mouth of the U-shaped tube is provided with an internal thread, the cover 3 is screwed to the tube mouth through the internal thread, and the tube wall of the U-shaped tube is provided with an inlet 17 and an outlet 18.

[0040] The cover 3 is made of Teflon.

[0041] Continue to refer to Figure 1 As shown, the thermostat is a container 6 for placing liquid. Since the mercury permeation tube has a high requirement for temperature accuracy, the thermostat is generally a water bath thermostat. The temperature control range is 0-100°C with an accuracy of ±0.1°C.

[0042] Among them, the mercury permeation tube uses the principle that the permeation rate of the permeation tube equipped with a mercury permeation source remains unchanged at constant temperature and pressure. The inert carrier gas is used to flow through the tube body 8-2 to obtain standard gas of different concentrations. The mercury permeation tube has certain requirements on temperature, pressure and device stability. The permeation range is generally 10~1000ng / min, which is related to the tube length, tube diameter and permeation membrane, and can be customized according to actual conditions.

[0043] The relationship between permeability and temperature is: (1) Where: is the permeability at temperature t0, ng / min; is the permeability at temperature t1, ng / min; is the temperature coefficient.

[0044] Among them, the calculation formula for the theoretical concentration of elemental mercury in the mercury permeation tube is: (2) Where: is the theoretical concentration of elemental mercury, ng / cm3; Q1, Q2 are the flow rates of carrier gas and dilution gas, cm3 / min; q is the permeability, ng / min.

[0045] However, the permeability of the mercury permeation tube is greatly affected by temperature and pressure. Therefore, when changing the carrier gas flow rate or just starting the ventilation period, you need to wait for 10-20 minutes to allow the system to fully stabilize. In addition, when the mercury permeation tube is not in use, it should be sealed and placed in a fume hood.

[0046] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the gas mixing unit includes a gas static mixer 9, a filter membrane device and a gas pipeline 16, and the outlet 18 is connected to the gas static mixer 9 and the filter membrane device in sequence through the gas pipeline.

[0047] The gas static mixer 9 includes a body, a flange interface 12, an air inlet cover 15-1, an air outlet cover 15-2, an air inlet interface 14-1, an air outlet interface 14-2, an air inlet 13-1, an air outlet 13-2 and a corrugated sheet 11, wherein the air inlet interface 14-1 is connected to the air inlet cover 15-1, and the air outlet interface 14-2 is connected to the air outlet cover 15-2 via the flange interface 12, i.e., the air inlet cover 15-1 is arranged outside the air inlet interface 14-1, and the air outlet cover 15-2 is arranged outside the air outlet interface 14-2. A corrugated sheet 11 is provided in the body to realize a zigzag flow of the fluid in the body, and an air inlet interface 14-1 and an air outlet interface 14-2 are provided at both ends of the body, an air inlet cover 15-1 is provided on the air inlet interface 14-1, and an air outlet cover 15-2 is provided on the air outlet interface 14-2, an air inlet 13-1 is provided on the air inlet cover 15-1, and the air inlet 13-1 is connected to the outlet 18 through an air pipeline 16, and the air inlet and outlet cover 15-2 is provided with an air outlet 13-2, and the air outlet 13-2 is connected to the filter membrane clamp 10 through an air pipeline 16.

[0048] The air inlet interface 14 - 1 and the air outlet interface 14 - 2 are made of Teflon material respectively, and the diameter and length of the air inlet interface 14 - 1 and the air outlet interface 14 - 2 can be selected according to the elemental mercury concentration and the dilution gas flow rate.

[0049] The membrane filter device includes a membrane filter holder 10 and a cation exchange membrane. The membrane filter holder 10 is connected to the gas pipeline 16. The membrane filter holder 10 is equipped with a cation exchange membrane. The cation exchange membrane is used to remove gaseous active mercury that may be generated in the pipeline and needs to be replaced regularly.

[0050] Since zero-valent mercury has a strong adsorption capacity on materials such as metal and silica gel, in order to ensure the stability of elemental mercury concentration, the use of metal and silica gel materials should be avoided or reduced as much as possible in the gas path after passing through the mercury permeation tube. PTFE materials and quartz glass can be used as substitutes.

[0051] Example 1 This embodiment adopts Figure 1 The elemental mercury generation system shown in the figure was tested at 0℃ and 30℃ for elemental mercury generation, and the LUMEX RA915-M was used to continuously measure the elemental mercury concentration generated. The LUMEX RA915-M mercury analyzer uses high-frequency plug background correction technology (ZAAS-HFM) to perform mercury analysis based on the principle of atomic vapor absorption of the 254nm resonance emission line. Figure 5 The elemental mercury concentrations generated by this elemental mercury generating device at 0°C and 30°C are presented in Table 1.

[0052] Table 1 Elemental mercury concentration at different temperatures (ng / m 3 )

[0053] *Indicates data not reported In the table, the mercury concentration at 30°C is 2186.14±62.8(2 )ng / m 3 , the maximum value is 2229.49ng / m 3 , the minimum value is 2135.49ng / m 3 ; Mercury concentration at 0°C was 239.32±23.24(2 )ng / m 3 , the maximum value is 265.91ng / m 3 , the minimum value is 212.63ng / m 3 The above test results show that the elemental mercury generation system of this embodiment can accurately and stably generate elemental mercury concentration.

[0054] 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 make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An elemental mercury generating device, characterized in that: It includes a carrier gas unit, an elemental mercury generating unit and a gas mixing unit. The elemental mercury generating unit is used to provide a mercury source, and the elemental mercury generating unit includes an inlet and an outlet; The carrier gas unit is connected to the inlet and the outlet respectively, and is used to provide a stable carrier gas and adjust the concentration of elemental mercury generated by the elemental mercury generating unit; The gas mixing unit is connected to the outlet, and is used to adjust gas uniformity and remove gaseous active mercury.

2. The elemental mercury generating device according to claim 1, characterized in that: The elemental mercury generating unit comprises a mercury permeation tube, a reaction vessel, a plurality of glass balls, a partition and a constant temperature device, wherein the reaction vessel is arranged in the constant temperature device, the reaction vessel is provided with the inlet and the outlet, the reaction vessel is provided with the glass balls, the partition and the mercury permeation tube, the glass balls are arranged close to the inlet side of the reaction vessel, the mercury permeation tube is arranged close to the outlet side of the reaction vessel, and the mercury permeation tube is placed on the partition, the inlet and the outlet are respectively connected to the carrier gas unit, and the outlet is also connected to the gas mixing unit.

3. The elemental mercury generating device according to claim 2, characterized in that: The mercury permeation tube comprises a sealing cover, a tube body and a semi-permeable membrane. The sealing cover is arranged at the bottom end of the tube body, the sealing cover is placed on the partition, the semi-permeable membrane is arranged at the upper end of the tube body, and liquid mercury is contained in the tube body.

4. The elemental mercury generating device according to claim 3, characterized in that: The reaction vessel is a U-shaped tube, the tube mouth of the U-shaped tube is provided with a cover, and the tube wall of the U-shaped tube is provided with the inlet and the outlet.

5. The elemental mercury generating device according to claim 4, characterized in that: The temperature control range of the thermostat is 0-100°C, with an accuracy of ±0.1°C.

6. The elemental mercury generating device according to claim 5, characterized in that: The gas mixing unit comprises a gas static mixer, a filter membrane device and a gas pipeline, and the outlet is connected to the gas static mixer and the filter membrane device in sequence through the gas pipeline.

7. The elemental mercury generating device according to claim 6, characterized in that: The gas static mixer includes a body, a flange interface, an air inlet cover, an air outlet cover, an air inlet interface, an air outlet interface, an air inlet, an air outlet and a corrugated sheet. The air inlet interface and the air inlet cover, the air outlet interface and the air outlet cover are respectively connected through the flange interface. The corrugated sheet is provided in the body to realize a zigzag flow of the fluid in the body. The air inlet interface and the air outlet interface are provided at both ends of the body. The air inlet interface is provided with the air inlet cover, the air outlet interface is provided with the air outlet cover, the air inlet cover is provided with the air inlet, the air inlet is connected to the outlet through the air pipeline, the air inlet and outlet covers are provided with the air outlet, and the air outlet is connected to the filter membrane clamp through the air pipeline.

8. The elemental mercury generating device according to claim 7, characterized in that: The filter membrane device comprises a filter membrane clip and a cation exchange membrane. The filter membrane clip is connected to the gas pipeline, and the cation exchange membrane is installed in the filter membrane clip.

9. The elemental mercury generating device according to claim 8, characterized in that: The carrier gas unit includes a mass flow meter for generating carrier gas, a mass flow meter for diluting gas, a first pipeline and a second pipeline. The mass flow meter for generating elemental mercury is arranged on the first pipeline, and the first pipeline is connected to the inlet. The mass flow meter for diluting gas is arranged on the second pipeline, and both ends of the second pipeline are respectively connected to the first pipeline and the gas pipeline. The first pipeline and the second pipeline are Teflon hard tubes.

10. The elemental mercury generating device according to claim 9, characterized in that: The range of the mass flow meter used to generate the carrier gas should be 0-3L / min, and the range of the mass flow meter used to generate the dilution gas should be 0-10L / min.

Images