Standard gaseous mercury generating device

Abstract

The utility model discloses a standard gaseous mercury generating device which comprises a diluent gas generating part, a carrier gas passage and a dilution passage which are simultaneously communicated with the diluent gas generating part, a buffer tank of which two gas inlets are simultaneously communicated with the carrier gas passage and the dilution passage, and a three-way valve of which a gas inlet is connected with a gas outlet of the buffer tank, the tail gas treatment part is communicated with a first gas outlet of the three-way valve, and the gaseous mercury detection equipment connector is communicated with a second gas outlet of the three-way valve. The utility model provides a standard gaseous mercury generation device which is simple in structure, can effectively avoid the influence of dead volume in a pipeline, can accurately regulate and control the flow of a gas path, ensures that mercury vapor and diluent gas are accurately and dynamically injected, ensures the reliability of a product, can stably and continuously generate mercury vapor with specific concentration in the working process, and improves the production efficiency. A reliable and stable gaseous mercury standard substance generating device is provided for a gaseous mercury detection device.

Description

Technical Field

[0001] This application relates to the field of gaseous mercury detection, and more specifically to a gaseous mercury standard generating device. Background Technology

[0002] Mercury is the only liquid metal in nature and the only heavy metal that exists primarily in the atmosphere in gaseous form. It is an environmental pollutant with strong physiological toxicity. The chemical behavior of mercury in the atmosphere plays a crucial role in controlling its global biogeochemical cycle. When mercury enters the atmosphere, it can migrate long distances within a hemisphere and be deposited in terrestrial and aquatic environments, entering food webs or being released back into the atmosphere. Therefore, mercury has been listed as a priority pollutant by my country and organizations such as the United Nations Environment Programme, the World Health Organization, the European Union, and the US Environmental Protection Agency. In particular, my country is one of the regions with the highest atmospheric mercury emissions globally. Anthropogenic mercury emissions from Asia, primarily my country, account for approximately 50% of global atmospheric mercury emissions. my country faces enormous pressure in mercury pollution control and in fulfilling international conventions. Atmospheric mercury mainly exists in two forms: gaseous mercury and particulate mercury. Gaseous mercury (HgO) is the main form of mercury in the atmosphere, with a concentration of pg / m³. 3 -ng / m 3 Atmospheric mercury accounts for over 90% of the total mercury content in ambient air. Therefore, accurate measurement of gaseous mercury is a prerequisite for understanding the environmental behavior of atmospheric mercury and an important condition for controlling mercury pollution in the air.

[0003] Gaseous mercury pollution in my country mainly involves the coal, natural gas, and petroleum chemical industries, and is also closely related to environmental protection. Since the implementation of the Minamata Convention on Mercury, my country has attached great importance to mercury pollution control and emission reduction. The quality of gaseous mercury monitoring data in the environment is directly related to the evaluation of my country's compliance with the Convention. Therefore, establishing a gaseous mercury standard and traceability system to improve relevant detection technologies and enhance data quality is of great significance for my country's compliance efforts to gain international recognition. Furthermore, traceability of gaseous mercury values ​​requires corresponding standard substances as "chemical weights," but mercury reacts with the inner walls of metal packaging storage containers, making long-term storage impossible, which has always been a challenge in the development of standard substances. Currently, based on the mature dynamic diffusion method, this technology is applied to mercury substances with low vapor pressure to prepare corresponding gaseous standard substances. Combined with precise control of gas flow rate and stable control of the dynamic equilibrium of the mercury gas-liquid phase, a specially designed gaseous mercury standard device has been developed to prepare gaseous mercury standard substances, ensuring accurate and reliable values. Utility Model Content

[0004] To address the shortcomings of existing technologies, this application provides a gaseous mercury standard generator with a simple structure. It can effectively avoid the influence of dead volume in the pipeline, accurately control the gas flow rate, and ensure the accurate dynamic injection of mercury vapor and dilution gas, thus guaranteeing the reliability of the product. During operation, it can stably and continuously generate mercury vapor of a specific concentration, providing a reliable and stable gaseous mercury standard material generator for gaseous mercury detection equipment.

[0005] A gaseous mercury standard generating device comprises a dilution gas generating unit, a carrier gas passage and a dilution passage connected to the dilution gas generating unit, a buffer tank with two inlets connected to both the carrier gas passage and the dilution passage, a three-way valve with the inlets connected to the outlet of the buffer tank, a tail gas treatment unit connected to the first outlet of the three-way valve, and a gaseous mercury detection device connection port connected to the second outlet of the three-way valve.

[0006] Furthermore, the dilution gas generating unit consists of a dilution gas source and a flow controller connected to the dilution gas source via a pipeline.

[0007] Preferably, the diluent gas generated by the diluent gas source is nitrogen or air, and the nitrogen or air is pumped into the pipeline by the diluent gas source.

[0008] Furthermore, the carrier gas passage consists of a second flow controller connected to the first flow controller via a pipeline, a pressure regulating valve connected to the second flow controller, and a gaseous mercury generator connected to the pressure regulating valve via a pipeline; the gaseous mercury generator is connected to an inlet of the buffer tank via a pipeline.

[0009] Preferably, the gaseous mercury generator consists of a sealed thermostatic chamber and a diffuser tube vertically installed inside the thermostatic chamber; the inlet of the thermostatic chamber is connected to a pressure regulating valve through a pipeline, and the outlet is connected to an inlet of a buffer tank through a pipeline.

[0010] Preferably, the diffuser tube is closed at the bottom and open at the top, and contains liquid mercury; the air inlet and outlet of the constant temperature chamber are arranged opposite each other.

[0011] Furthermore, the dilution path is a No. 1 rotor flowmeter connected to the air inlet and the connecting pipeline of the No. 1 flow controller and the No. 2 flow controller via a pipeline. The No. 1 rotor flowmeter is also connected to another air inlet of the buffer tank via a pipeline.

[0012] In addition, the exhaust gas treatment unit consists of an exhaust gas treatment device whose inlet is connected to the first outlet of the three-way valve, a second rotor flow meter whose inlet is connected to the outlet of the exhaust gas treatment device, and a vacuum pump whose extraction port is connected to the outlet of the second rotor flow meter.

[0013] Compared with the prior art, the embodiments of this application have the following beneficial effects:

[0014] This invention has a simple structure, effectively avoids the influence of dead volume in the pipeline, can accurately control the gas flow rate, ensures accurate dynamic injection of mercury vapor and dilution gas, and guarantees the reliability of the product. During operation, it can stably and continuously generate a specific concentration of mercury vapor, providing a reliable and stable gaseous mercury standard material generation device for gaseous mercury detection equipment.

[0015] Some of the additional features of this application will be described in the following description. These additional features will become apparent to those skilled in the art upon examination of the following description and the accompanying drawings, or upon understanding the production or operation of the embodiments. The features disclosed in this application can be implemented and achieved through the practice or use of various methods, means, and combinations thereof with respect to the specific embodiments described below. Attached Figure Description

[0016] The accompanying drawings, which are provided to further illustrate this application and constitute a part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute a limitation thereof. In the drawings, the same reference numerals denote the same components.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Explanation of reference numerals in the attached diagram: 1. Dilution gas source; 2. Flow controller No. 1; 3. Flow controller No. 2; 4. Pressure regulating valve; 5. Gaseous mercury generator; 51. Constant temperature chamber; 52. Diffuser tube; 6. Rotor flow meter No. 1; 7. Buffer tank; 8. Three-way valve; 9. Tail gas treatment device; 10. Rotor flow meter No. 2; 11. Vacuum pump; 12. Connection port for gaseous mercury detection equipment. Detailed Implementation

[0019] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0020] It should be noted that if the terms "first," "second," etc., are used in the specification, claims, and accompanying drawings of this application, they are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] In this application, when terms such as "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" are used, they indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly for better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0022] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0023] Furthermore, in this application, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] Example 1

[0026] like Figure 1As shown, a gaseous mercury standard generating device comprises a dilution gas generating unit, a carrier gas passage and a dilution passage connected to the dilution gas generating unit, a buffer tank 7 with two inlets connected to both the carrier gas passage and the dilution passage, a three-way valve 8 with the inlet connected to the outlet of the buffer tank 7, a tail gas treatment unit connected to the first outlet of the three-way valve 8, and a gaseous mercury detection device connection port 12 connected to the second outlet of the three-way valve 8.

[0027] The dilution gas generating unit consists of a dilution gas source 1 and a flow controller 2 connected to the dilution gas source 1 via a pipeline.

[0028] The dilution gas generated by the dilution gas source 1 is nitrogen or air, and the nitrogen or air is pumped into the pipeline by the dilution gas source 1.

[0029] The carrier gas passage consists of a second flow controller 3 connected to the first flow controller 2 via a pipeline, a pressure regulating valve 4 connected to the second flow controller 3, and a gaseous mercury generator 5 connected to the pressure regulating valve 4 via a pipeline; the gaseous mercury generator 5 is connected to an air inlet of the buffer tank 7 via a pipeline.

[0030] The gaseous mercury generator 5 consists of a sealed constant temperature chamber 51 and a diffuser tube 52 vertically installed inside the constant temperature chamber 51; the air inlet of the constant temperature chamber 51 is connected to the pressure regulating valve 4 through a pipeline, and the air outlet is connected to one air inlet of the buffer tank 7 through a pipeline.

[0031] The diffuser tube 52 is closed at the bottom and open at the top, and contains liquid mercury; the air inlet and outlet of the constant temperature chamber 51 are arranged opposite each other.

[0032] The thermostat chamber maintains its internal environment at a specific temperature, while the pressure regulator keeps the internal pressure constant. Under constant pressure and temperature, the liquid mercury in the diffuser tube can continuously generate gaseous mercury at a fixed diffusion rate. This gaseous mercury, carried by the diluent gas, eventually enters the buffer tank.

[0033] The dilution path is a first rotor flow meter 6 connected to the air inlet and the connecting pipe of the first flow controller 2 and the second flow controller 3 through the pipe. The first rotor flow meter 6 is also connected to another air inlet of the buffer tank through the pipe.

[0034] The exhaust gas treatment unit consists of an exhaust gas treatment device 9 whose inlet is connected to the first outlet of the three-way valve 8, a second rotor flowmeter 10 whose inlet is connected to the outlet of the exhaust gas treatment device 9, and a vacuum pump 11 whose extraction port is connected to the outlet of the second rotor flowmeter 10.

[0035] The exhaust gas treatment device mainly uses potassium permanganate solution to absorb gaseous mercury. Alternatively, depending on the actual needs, other methods and equipment such as manganese dioxide absorption or potassium permanganate absorption can be used as exhaust gas treatment devices. Those skilled in the art can complete the setup and use of this exhaust gas treatment device without creative labor, so it will not be elaborated here.

[0036] The actual working process and principle of the device are as follows:

[0037] (1) Select a high-purity nitrogen cylinder or air pump as the source of dilution gas, open the cylinder or start the air pump so that the dilution gas enters the pipeline.

[0038] (2) Adjust the No. 1 flow controller to complete the adjustment of the total flow rate of the dilution gas;

[0039] (3) Adjust the flow controller No. 2 to regulate the flow rate of dilution gas in the carrier gas passage;

[0040] (4) One dilution gas enters the buffer tank through the No. 1 rotor flow meter, and the other dilution gas enters the gaseous mercury generator through the No. 2 flow controller and pressure reducing valve, and carries the gaseous mercury in the gaseous mercury generator into the buffer tank through the dilution gas.

[0041] (5) The dilution gas carrying gaseous mercury is mixed with the dilution gas entering the buffer tank through the same dilution path in the buffer tank. Since the flow rate of the dilution gas through the carrier gas path and the dilution path is constant, and the diffusion rate of gaseous mercury from the gaseous mercury generation source is constant, the ratio of dilution gas to gaseous mercury entering the buffer tank is constant, that is, the value of gaseous mercury in the mixed gas in the buffer tank is constant.

[0042] (6) Start the vacuum pump to continuously draw the mixed gas in the buffer tank through the first outlet of the three-way valve, so that the mixed gas can be treated by the tail gas treatment device and then discharged at the vacuum pump.

[0043] The speed at which the vacuum pump extracts the mixed gas is determined by the reading of the No. 2 rotor flow meter. The extraction speed of the vacuum pump is adjusted according to the tail gas treatment device's ability to process gaseous mercury in the mixed gas. It is essential that the tail gas treatment device can completely remove the gaseous mercury from the mixed gas.

[0044] (7) After the operation is stable, switch the three-way valve to the second outlet and use the method described in GBZ / T300.18-2917 "Determination of Toxic Substances in Workplace Air - Part 18: Mercury and Its Compounds" to measure the value of gaseous mercury in the mixed gas at the connection port of the gaseous mercury detection device, record the standard measurement value, and switch the three-way valve back to the first outlet after the measurement is completed.

[0045] (8) Connect the gaseous mercury detection device that needs to be calibrated or tested to the gaseous mercury detection device connection port, switch the three-way valve to the second outlet, read and record the detection value on the gaseous mercury detection device, and then switch the three-way valve back to the first outlet.

[0046] (9) Compare the standard measured value with the test measured value. If the two measured values ​​are the same, the gaseous mercury detection equipment meets the standard. Otherwise, the gaseous mercury detection equipment needs to be adjusted and returned to step (8) for recalibration or testing.

[0047] The above method can be used to obtain a mixed gas with a standard value for gaseous mercury generated by the device, and this mixed gas can be used to calibrate or test gaseous mercury detection equipment that needs to be calibrated or tested.

[0048] It should be noted that all features disclosed in this specification, or all steps in all methods or processes disclosed, may be combined in any way, except for mutually exclusive features and / or steps.

[0049] Furthermore, the specific embodiments described above are exemplary. Those skilled in the art can devise various solutions inspired by the disclosure of this utility model, and these solutions all fall within the scope of this utility model and its protection. Those skilled in the art should understand that this utility model specification and its drawings are illustrative and not intended to limit the scope of the claims. The scope of protection of this utility model is defined by the claims and their equivalents.

Claims

1. A gaseous mercury standard generating device, characterized in that, It comprises a dilution gas generating unit, a carrier gas passage and a dilution passage connected to the dilution gas generating unit, a buffer tank (7) with two inlets connected to the carrier gas passage and the dilution passage, a three-way valve (8) with the inlet connected to the outlet of the buffer tank (7), a tail gas treatment unit connected to the first outlet of the three-way valve (8), and a gaseous mercury detection device connection port (12) connected to the second outlet of the three-way valve (8).

2. The gaseous mercury standard generating device according to claim 1, characterized in that, The dilution gas generating unit consists of a dilution gas source (1) and a flow controller (2) connected to the dilution gas source (1) via a pipeline.

3. The gaseous mercury standard generating device according to claim 2, characterized in that, The dilution gas generated by the dilution gas source (1) is nitrogen or air, and the nitrogen or air is pumped into the pipeline by the dilution gas source (1).

4. The gaseous mercury standard generating device according to claim 3, characterized in that, The carrier gas passage consists of a second flow controller (3) connected to the first flow controller (2) via a pipeline, a pressure regulating valve (4) connected to the second flow controller (3), and a gaseous mercury generator (5) connected to the pressure regulating valve (4) via a pipeline; the gaseous mercury generator (5) is connected to an air inlet of the buffer tank (7) via a pipeline.

5. The gaseous mercury standard generating device according to claim 4, characterized in that, The gaseous mercury generator (5) consists of a sealed thermostatic chamber (51) and a diffuser (52) vertically installed inside the thermostatic chamber (51); the air inlet of the thermostatic chamber (51) is connected to the pressure stabilizing valve (4) through a pipeline, and the air outlet is connected to one air inlet of the buffer tank (7) through a pipeline.

6. The gaseous mercury standard generating device according to claim 5, characterized in that, The diffuser tube (52) is closed at the bottom and open at the top, and contains liquid mercury; the air inlet and outlet of the constant temperature chamber (51) are arranged opposite to each other.

7. The gaseous mercury standard generating device according to claim 6, characterized in that, The dilution path is a first rotor flow meter (6) that is connected to the air inlet and the first flow controller (2) and the second flow controller (3) through a pipeline. The first rotor flow meter (6) is also connected to another air inlet of the buffer tank through a pipeline.

8. The gaseous mercury standard generating device according to claim 7, characterized in that, The exhaust gas treatment unit consists of an exhaust gas treatment device (9) whose inlet is connected to the first outlet of the three-way valve (8), a second rotor flow meter (10) whose inlet is connected to the outlet of the exhaust gas treatment device (9), and a vacuum pump (11) whose extraction port is connected to the outlet of the second rotor flow meter (10).

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