Standard gas generating device

Abstract

The utility model provides a kind of standard gas generating device, comprising: liquid storage tank, liquid feeding pump, first critical flow control element and gasification mechanism, the liquid storage tank is suitable for accommodating standard solution, the liquid feeding pump is formed fluid communication with liquid storage tank, the first critical flow control element is arranged downstream of the liquid feeding pump, for stabilizing the flow of the standard solution that flows from the liquid feeding pump, the gasification mechanism is arranged downstream of the first critical flow control element, for the standard solution that flows from the first critical flow control element is gasified into standard gas.The utility model standard gas generator can conveniently obtain different component, different concentration standard gas, better satisfy actual need, first critical flow control element can also be used to improve the stability of flow, reduce control cost.

Description

Technical Field

[0001] This utility model belongs to the field of detection equipment technology, and in particular relates to a standard gas generating device. Background Technology

[0002] The development of gas-sensitive materials typically requires evaluating their technical properties, such as sensitivity, response time, and selectivity to specific gases. This evaluation necessitates the use of standard gases with known composition and concentration. A standard gas generator is a device used to produce stable, accurate standard gases with known composition and concentration. It can precisely control parameters such as the mixing ratio, flow rate, and pressure of the gas feedstock to generate gas mixtures that conform to international or industry standards (e.g., zero gas, span gas, specific concentration gas, etc.). These standard gases can then be used for the development of gas-sensitive materials and the calibration of gas sensors.

[0003] Currently, standard gas generating devices mainly include components such as a gas source system, a mixing and dilution system, a pressure control system, a temperature control system, an output interface, and an intelligent control unit. However, the gas source system generally uses steel cylinders to store standard gases, resulting in a limited variety of gases that can be provided. Only gases with relatively stable chemical properties can be prepared into standard gases, while many chemically active and volatile organic compounds cannot be prepared into standard gases in steel cylinders, making it difficult to meet the actual needs of the research and development of new gas-sensitive materials. In addition, different types and concentrations of standard gases are required in the performance evaluation of gas-sensitive materials, but the types and concentrations of standard gases stored in steel cylinders are fixed, which requires the use of multiple standard gases, increasing storage and usage costs. Furthermore, the mixing and dilution system usually uses a mass flow controller (MFC) to detect and control the gas flow. However, existing mass flow controllers have many disadvantages: (1) The measurement medium is dependent. It is only suitable for the detection of specific gases or liquids (such as N2, O2, Ar, etc.). If the gas type is changed (especially gases with different thermal conductivity or specific heat capacity), it needs to be recalibrated, otherwise the measurement error will be large; (2) The measurement range is limited. The low range (such as 0-10 sccm) cannot work under high flow conditions, while the high range (such as 0-100 slm) has a significantly reduced accuracy under low flow conditions (such as below 1% of the range); (3) The response speed is slow. Traditional solenoid valves or piezoelectric valves require a certain response time (e.g., 0.5s-2s), which cannot meet the testing needs of rapid dynamic flow. (4) It is sensitive to pressure and temperature. Mass flow meters usually need to work under the calibrated pressure. If the back pressure or inlet pressure fluctuates, it may cause test deviation. In addition, changes in ambient temperature may also cause test deviation of mass flow meters.

[0004] Therefore, a new technical solution is needed in this field to solve the above problems. Utility Model Content

[0005] In view of this, the present invention aims to provide a standard gas generating device to solve the technical problems of high cost and poor testing accuracy of existing standard gas generating devices.

[0006] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0007] A standard gas generating device includes a solution vaporization component and a gas dilution component, and the two are connected together;

[0008] The solution vaporization assembly includes a liquid storage assembly. The outlet end of the liquid storage assembly is connected to the inlet end of a first valve guide downstream of it. The outlet end of the first valve guide is connected to the inlet end of a liquid addition pump downstream of it. The outlet end of the liquid addition pump is connected to the inlet end of a second valve guide downstream of it. The outlet end of the second valve guide is connected to the inlet end of a first flow control assembly downstream of it. The outlet end of the first flow control assembly is connected to the inlet end of a third valve guide downstream of it. The outlet end of the third valve guide is connected to the inlet end of a vaporization mechanism downstream of it. The outlet end of the vaporization mechanism is connected to an outlet pipe.

[0009] The gas dilution assembly includes a gas storage assembly. The outlet end of the gas storage assembly is connected to the inlet end of a downstream pressure reducing valve. The outlet end of the pressure reducing valve is connected to the inlet end of a downstream fourth valve guide. The outlet end of the fourth valve guide is connected to the inlet end of a downstream second flow control assembly. The outlet end of the second flow control assembly is connected to the inlet end of a downstream fifth valve guide. The outlet end of the fifth valve guide is connected to the inlet end of a downstream temperature and humidity regulating mechanism. The outlet end of the temperature and humidity regulating mechanism is connected to a downstream connecting gas pipe. The connecting gas pipe is connected to an outlet pipe.

[0010] The liquid storage assembly includes a plurality of liquid storage tanks, which are connected in parallel, and the liquid storage tanks are used to contain standard solutions.

[0011] The gas storage assembly includes a first gas storage tank and a second gas storage tank, which are arranged in parallel upstream of the second flow control assembly.

[0012] Furthermore, the first flow control assembly includes a plurality of first critical flow control elements, which are connected in parallel. The first critical flow control elements include a critical flow venturi nozzle, a critical flow nozzle, a critical flow orifice, or a Laval nozzle.

[0013] Furthermore, the second flow control assembly includes a plurality of second critical flow control elements, which are connected in parallel. The second critical flow control elements include a critical flow venturi nozzle, a critical flow nozzle, a critical flow orifice, or a Laval nozzle.

[0014] Furthermore, a liquid concentration sensor is installed inside the storage tank.

[0015] Furthermore, the temperature and humidity regulating mechanism includes a regulating box, a heating component, and an air guide pipe. The heating component and the air guide pipe are installed inside the regulating box. The air guide pipe is connected to a connecting air pipe. The regulating box contains humidifying liquid. The air guide pipe is a reverse osmosis pipe, and a temperature and humidity sensor is installed inside the air guide pipe.

[0016] Furthermore, the first gas storage tank is used to contain dilution gas, which is compressed air, nitrogen, methane, or hydrogen hexafluoride.

[0017] Furthermore, the second gas storage tank is used to contain standard gas.

[0018] Furthermore, a first buffer bladder is connected between the liquid pump and the second valve guide, the first buffer bladder forming a first fluid space, and the first fluid space is in fluid communication with the liquid pump and the first critical flow control element respectively.

[0019] Furthermore, a second buffer bladder is connected between the pressure reducing valve and the fourth valve guide, the second buffer bladder forming a second fluid space, and the second fluid space is in fluid communication with the pressure reducing valve and the second critical flow control element.

[0020] Furthermore, a pressure sensor is connected between the pressure reducing valve and the fourth valve guide.

[0021] Compared with the prior art, the standard gas generating device of this utility model has the following advantages:

[0022] (1) By selecting a suitable standard solution, the standard gas generator of this invention can easily obtain standard gases of different compositions and concentrations, thereby better meeting practical needs. Using a vaporization mechanism to directly vaporize the standard solution in the storage tank into standard gas avoids evaporation, dilution, and contamination of the standard gas during storage, reducing storage costs. Compared to traditional mass flow meters, the first critical flow control element has many advantages, including high flow stability, fast response speed, simple structure, high reliability, and wide applicability. Specifically, when the standard solution flows through the first critical flow control element, the downstream pressure will drop below the critical pressure ratio (approximately 0.528 for air), and the flow velocity will reach the speed of sound. At this point, changes in downstream pressure will not affect the flow rate, thus significantly improving the stability of the standard solution flow rate and reducing control costs.

[0023] (2) The parallel structure of the liquid storage tank can enrich the composition and concentration of the standard solution, thereby obtaining a variety of standard gases; multiple parallel first critical flow control elements can not only expand the flow range, improve system redundancy and reliability, but also optimize dynamic response, achieve precision control, and extend the life of the elements. The first critical flow control elements include critical flow Venturi nozzles, critical flow nozzles, critical flow orifices or Laval nozzles, which can enrich the types of first critical flow control elements; the setting of the first gas storage tank and the second critical flow control element can use dilution gas to conveniently further dilute the standard gas, so as to better adjust the concentration of the standard gas. In addition, the second critical flow control element has many advantages such as high flow stability, fast response speed, simple structure, good reliability, and wide applicability; multiple parallel second critical flow control elements can not only expand the flow range, improve system redundancy and reliability, but also optimize dynamic response, achieve precision control, and extend the life of the elements. The second critical flow control elements include critical flow Venturi nozzles, critical flow nozzles, critical flow orifices or Laval nozzles, which can enrich the types of second critical flow control elements.

[0024] (3) The liquid concentration sensor can conveniently and accurately measure the concentration of the corresponding standard solution in the storage tank, so as to provide data support for adjusting the concentration of the standard gas; the temperature and humidity adjustment mechanism can conveniently adjust the temperature and humidity of the dilution gas, and thus adjust the temperature and humidity of the entire standard gas; the pressure reducing valve can significantly reduce the pressure in the pipeline, making it easy to control the flow rate of the dilution gas; the pressure sensor can conveniently and accurately measure the pressure of the dilution gas flowing out of the pressure reducing valve.

[0025] (4) The first buffer tank can stabilize the flow rate of the standard solution flowing out from the liquid pump, so that the pressure upstream of the first critical flow control element can also be kept stable; the second buffer tank can stabilize the flow rate of the dilution gas flowing out from the pressure reducing valve, so that the pressure upstream of the second critical flow control element can also be kept stable; the second gas storage tank can conveniently store standard gas, enrich the source of standard gas, so as to better meet the actual needs of users; the dilution gas is compressed air, nitrogen, methane or hydrogen hexafluoride, which can enrich the types of dilution gas to meet the differentiated needs of users. Attached Figure Description

[0026] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0027] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0028] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present utility model;

[0029] Figure 3 This is a schematic diagram of the structure of Embodiment 3 of this utility model.

[0030] Explanation of reference numerals in the attached figures:

[0031] 10. Liquid storage tank; 20. Liquid concentration sensor; 30. First valve guide; 40. Liquid pump; 50. First buffer bladder; 60. Second valve guide; 70. First critical flow control element; 80. Third valve guide; 90. Vaporization mechanism; 100. Gas outlet pipe; 110. First gas storage tank; 120. Pressure reducing valve; 130. Pressure sensor; 140. Second buffer bladder; 150. Fourth valve guide; 160. Second critical flow control element; 170. Fifth valve guide; 180. Temperature and humidity control mechanism; 181. Control box; 182. Heating component; 183. Gas guide pipe; 190. Connecting gas pipe; 200. Second gas storage tank. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0033] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0034] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] like Figures 1 to 3 As shown, a standard gas generating device includes a storage tank 10, a liquid dispensing pump 40, a first critical flow control element 70, and a vaporization mechanism 90. The storage tank 10 is adapted to contain a standard solution. The liquid dispensing pump 40 is in fluid communication with the storage tank 10. The first critical flow control element 70 is arranged downstream of the liquid dispensing pump 40 to stabilize the flow rate of the standard solution flowing out of the liquid dispensing pump 40. The vaporization mechanism 90 is arranged downstream of the first critical flow control element 70 to vaporize the standard solution flowing out of the first critical flow control element 70 into a standard gas.

[0037] The specific implementation method is as follows:

[0038] In a preferred embodiment of this utility model, the outlet end of the liquid storage component is connected to the inlet end of the first valve guide 30 downstream of it, the outlet end of the first valve guide 30 is connected to the inlet end of the liquid adding pump 40 downstream of it, and the outlet end of the liquid adding pump 40 is connected to the inlet end of the second valve guide 60 downstream of it. The liquid storage component includes a plurality of liquid storage tanks 10, which form a parallel structure. The liquid storage tanks 10 contain standard solutions, and a liquid concentration sensor 20 is installed inside the liquid storage tanks 10. In this embodiment, the composition and concentration of the standard solution can be adjusted according to actual needs. Each storage tank 10 is connected to the addition pump 40 via a first valve 30 located downstream of it. The first valve 30 enables any one or more of the three parallel storage tanks 10 to be connected to the addition pump 40, simplifying the number of control valves and optimizing the pipeline layout. Each storage tank 10 can contain standard solutions with different compositions and concentrations, enriching the composition and concentration range of the standard solutions. Alternatively, the number of storage tanks 10 can also be set to other suitable numbers. The liquid concentration sensor 20 is used to measure the concentration of the standard solution in each storage tank 10. The type of liquid concentration sensor 20 is not limited, such as an optical concentration sensor, an electrical concentration sensor, or a density concentration sensor. The type of addition pump 40 is not limited, such as a peristaltic pump, a gear pump, or a plunger pump. The number of addition pumps 40 can also be set to multiple according to actual needs.

[0039] In a preferred embodiment of this invention, a first buffer bladder 50 is connected between the liquid dispensing pump 40 and the second valve guide 60. The first buffer bladder 50 forms a first fluid space, which is in fluid communication with both the liquid dispensing pump 40 and the first critical flow control element 70. In this embodiment, when the pressure of the liquid dispensing pump 40 increases, excess standard solution can temporarily enter the first fluid space of the first buffer bladder 50. Correspondingly, when the pressure of the liquid dispensing pump 40 decreases, the standard solution in the first buffer bladder 50 can flow to the first critical flow control element 70 in a timely manner, thereby ensuring that the pressure upstream of the first critical flow control element 70 is always maintained at a relatively stable level.

[0040] In a preferred embodiment of the present invention, the outlet end of the second valve guide 60 is connected to the inlet end of the first flow control component downstream of it, and the outlet end of the first flow control component is connected to the inlet end of the third valve guide 80 downstream of it. The first flow control component includes a plurality of first critical flow control elements 70, and the plurality of first critical flow control elements 70 form a parallel structure. The first critical flow control element 70 includes a critical flow venturi nozzle, a critical flow nozzle, a critical flow orifice, or a Laval nozzle. In this embodiment, the first critical flow control element 70 is arranged downstream of the dosing pump 40 to stabilize the flow rate of the standard solution flowing out of the dosing pump 40. Compared with traditional mass flow meters, the first critical flow control element 70 has many advantages such as high flow stability, fast response speed, simple structure, high reliability, and wide applicability. Therefore, when the standard solution flows through the first critical flow control element 70, the downstream pressure will drop below the critical pressure ratio (approximately 0.528 for air), and the flow velocity will reach the speed of sound. At this time, changes in downstream pressure will not affect the flow rate, thereby significantly improving the stability of the standard solution flow rate and reducing control costs. This utility model includes three first critical flow control elements 70 connected in parallel, each... Each of the first critical flow control elements 70 is selected to be connected to the liquid addition pump 40 via a second valve guide 60 located upstream of it, and to the vaporization mechanism 90 via a third valve guide 80 located downstream of it. The arrangement of the second and third valve guides 60 facilitates control of the standard solution flow within any one or more of the three parallel first critical flow control elements 70, further simplifying the number of control valves and optimizing the piping layout. Alternatively, the number of first critical flow control elements 70 can be set to other suitable numbers, and the type of the first critical flow control elements 70 is not limited, such as critical flow venturi nozzles, critical flow nozzles, critical flow orifices, or Laval nozzles. The critical flow venturi nozzle (i.e., Critical...) is an example of such a nozzle. A flow venturi nozzle consists of a contraction section, a throat, and a divergence section, similar to a traditional venturi tube, but the throat design ensures critical flow conditions. A critical flow nozzle consists of a contraction section and a straight throat, without a divergence section, and the throat cross-sectional area is constant. A critical flow orifice is an orifice arranged on a thin plate with sharp orifice edges, without a contraction or divergence section. A Laval nozzle consists of a contraction section, a throat, and a divergence section, but its divergence section is longer and is designed specifically for supersonic flow.

[0041] In a preferred embodiment of this invention, the outlet end of the third valve guide 80 is connected to the inlet end of the downstream vaporization mechanism 90, and the outlet end of the vaporization mechanism 90 is connected to the outlet pipe 100. In this embodiment, the vaporization mechanism 90 vaporizes the standard solution flowing out from the first critical flow control element 70 into standard gas. The specific structure of the vaporization mechanism 90 is not limited. For example, the vaporization mechanism 90 includes a vaporization box, a spiral tube arranged in the vaporization box, a heater for heating the spiral tube, etc. The spiral tube can be made of stainless steel or other suitable materials to give it good heat resistance, corrosion resistance, and low adsorption. The type of heater is not limited, as long as it can effectively vaporize the standard solution in the spiral tube into standard gas. The vaporization mechanism 90 outputs the standard gas through a suitable outlet pipe 100, and then uses these standard gases for instrument calibration, quality control, and experimental analysis. This invention directly vaporizes the standard solution in the storage tank 10 into standard gas through the vaporization mechanism 90, avoiding the volatilization, dilution, and contamination of the standard gas during storage, significantly reducing storage costs and achieving ready-to-use.

[0042] In a preferred embodiment of this utility model, the gas dilution assembly includes a gas storage assembly. The outlet end of the gas storage assembly is connected to the inlet end of a downstream pressure reducing valve 120. The outlet end of the pressure reducing valve 120 is connected to the inlet end of a downstream fourth valve guide 150. The outlet end of the fourth valve guide 150 is connected to the inlet end of a downstream second flow control assembly. The outlet end of the second flow control assembly is connected to the inlet end of a downstream fifth valve guide 170. The outlet end of the fifth valve guide 170 is connected to the inlet end of a downstream temperature and humidity regulating mechanism 180. The outlet end of the temperature and humidity regulating mechanism 180 is connected to the downstream... A gas pipe 190 is connected to an outlet pipe 100. The second flow control assembly includes a plurality of second critical flow control elements 160, which are arranged in parallel. The second critical flow control elements 160 include critical flow venturi nozzles, critical flow nozzles, critical flow orifices, or Laval nozzles. The gas storage assembly includes a first gas storage tank 110 and a second gas storage tank 200, which are arranged in parallel upstream of the second flow control assembly. The first gas storage tank 110 contains dilution gas, which is compressed air, nitrogen, methane, or hydrogen hexafluoride. In this embodiment, the dilution gas can be, but is not limited to, compressed air, nitrogen, methane, or hydrogen hexafluoride, thereby enriching the types of dilution gases and meeting the differentiated needs of users. The second critical flow control element 160 is arranged downstream of the first gas storage tank 110 to stabilize the flow rate of the dilution gas flowing out of the first gas storage tank 110. The second critical flow control element 160 is connected to the outlet pipe 100 of the vaporization mechanism 90 through the connecting pipe 190, so as to use the dilution gas to dilute the standard gas discharged from the vaporization mechanism 90, thereby better regulating the concentration of the standard gas. Three second critical flow control elements 160 are connected in parallel, and each second critical flow control element 160 is connected to the first gas storage tank 110 through the fourth valve 150 located upstream of it, and to the connecting pipe 190 through the fifth valve 170 located downstream of it. The connection of the fourth valve guide 150 and the fifth valve guide 170 facilitates the control of the dilution gas flow within any one or more of the three parallel second critical flow control elements 160, further simplifying the number of control valves and optimizing the pipeline layout. Alternatively, the second critical flow control elements 160 can be configured in other suitable numbers, and the type of the second critical flow control elements 160 is not limited, such as a critical flow venturi nozzle, critical flow nozzle, critical flow orifice, or Laval nozzle. A pressure reducing valve 120 is also provided between the first gas storage tank 110 and the second critical flow control element 160. The setting of the pressure reducing valve 120 significantly reduces the pressure in the pipeline, facilitating the control of the dilution gas flow rate. The type of pressure reducing valve 120 is not limited, such as a spring diaphragm pressure reducing valve 120, a piston pressure reducing valve 120, or a bellows pressure reducing valve 120, etc.

[0043] In a preferred embodiment of this invention, a pressure sensor 130 is connected between the pressure reducing valve 120 and the fourth valve guide 150. In this embodiment, the pressure sensor 130 conveniently and accurately measures the pressure of the dilution gas flowing out of the pressure reducing valve 120. The type of pressure sensor 130 is not limited, such as a piezoresistive pressure sensor 130, a capacitive pressure sensor 130, or a piezoelectric pressure sensor 130.

[0044] In a preferred embodiment of this invention, a second buffer bladder 140 is connected between the pressure reducing valve 120 and the fourth valve guide 150. The second buffer bladder 140 forms a second fluid space, which is in fluid communication with both the pressure reducing valve 120 and the second critical flow control element 160. In this embodiment, when the flow rate of the diluent gas is too high, excess diluent gas can temporarily enter the second fluid space of the second buffer bladder 140. Conversely, when the flow rate of the diluent gas is too low, the diluent gas in the second buffer bladder 140 can flow to the second critical flow control element 160 in a timely manner, ensuring that the pressure upstream of the second critical flow control element 160 remains at a relatively stable level.

[0045] In a preferred embodiment of this utility model, the temperature and humidity regulating mechanism 180 includes a regulating box 181, a heating component 182, and an air guide pipe 183. The heating component 182 and the air guide pipe 183 are installed inside the regulating box 181. The air guide pipe 183 is connected to a connecting air pipe 190. The regulating box 181 contains a humidifying liquid. The air guide pipe 183 is a reverse osmosis pipe, and a temperature and humidity sensor is installed inside the air guide pipe 183. In this embodiment, the regulating chamber 181 has a generally sealed cavity. The heating element 182 is arranged inside the regulating chamber 181, and the gas guide pipe 183 is arranged inside the regulating chamber 181 and connected to the connecting gas pipe 190 to allow the dilution gas to flow through it. By controlling the opening and closing or output power of the heating element 182, the temperature of the dilution gas can be easily adjusted, thereby controlling the temperature of the entire standard gas. The type of heating element 182 is not limited, such as an electric heater, a heat pump heater, etc. Humidifying liquid is provided in the regulating chamber 181, and the gas guide pipe 183 is a reverse osmosis pipe, so that the humidifying liquid can permeate into the gas guide pipe 183 to humidify the dilution gas. The humidifying liquid can be tap water, distilled water, or other suitable liquids. The reverse osmosis pipe can uniformly and accurately adjust the humidification amount and avoid drastic fluctuations in the humidity of the dilution gas caused by excessively rapid humidification. A suitable temperature and humidity sensor is also provided in the gas guide pipe 183 to monitor the temperature and humidity of the dilution gas in real time.

[0046] In a preferred embodiment of this invention, the second gas storage tank 200 is connected to the connecting gas pipe 190, and the second gas storage tank 200 contains a standard gas. In this embodiment, the standard gas in the second gas storage tank 200 can be a standard gas prepared by this invention, or it can be obtained by other means (e.g., purchased from the market). The second gas storage tank 200 is arranged in parallel with the first gas storage tank 110 upstream of the second critical flow control element 160. For example, the second gas storage tank 200 is arranged between the pressure reducing valve 120 and the pressure sensor 130 via a pipeline (see...). Figure 3 Alternatively, the second gas storage tank 200 can be connected to the fourth valve 150 via a pipeline, so that the standard gas in the second gas storage tank 200 can be fully mixed with the dilution gas in the first gas storage tank 110 by passing through the second critical flow control element 160. Alternatively, the second gas storage tank 200 can also be directly connected to the connecting gas pipe 190, as long as the dilution gas in the first gas storage tank 110 can be used to successfully dilute the standard gas in the second gas storage tank 200.

[0047] Example 1:

[0048] Figure 1 This is a structural schematic diagram of the first embodiment of this utility model. (See diagram below.) Figure 1 As shown, this utility model includes components such as a liquid storage tank 10, a liquid addition pump 40, a first critical flow control element 70, and a vaporization mechanism 90. The liquid storage tank 10, the liquid addition pump 40, the first critical flow control element 70, and the vaporization mechanism 90 are connected sequentially via suitable pipelines.

[0049] like Figure 1 As shown, the storage tank 10 is used to contain standard solutions. The composition and concentration of the standard solutions can be adjusted according to actual needs. This invention includes three parallel storage tanks 10. Each storage tank 10 is selectively connected to a dispensing pump 40 via a first valve 30 located downstream of it, and each storage tank 10 is suitable for containing standard solutions of different compositions and / or different concentrations. The first valve 30 allows for easy connection of any one or more of the three parallel storage tanks 10 to the dispensing pump 40, simplifying the number of control valves and optimizing the pipeline layout. Containing standard solutions of different compositions and / or different concentrations in each storage tank 10 enriches the range of compositions and concentrations of standard solutions. Alternatively, the number of storage tanks 10 can be more or less than three, such as one, two, four, etc. Each storage tank 10 is equipped with a liquid concentration sensor 20 for measuring the concentration of the corresponding standard solution in each storage tank 10. The type of liquid concentration sensor 20 is not limited; for example, it can be an optical concentration sensor, an electrical concentration sensor, or a density concentration sensor.

[0050] likeFigure 1 As shown, the inlet of the liquid adding pump 40 is connected to the first valve guide 30, while the outlet of the liquid adding pump 40 is connected to the first critical flow control element 70. The type of liquid adding pump 40 is not limited; for example, it can be a peristaltic pump, gear pump, plunger pump, etc. Furthermore, the number of liquid adding pumps 40 can be set to multiple according to actual needs, such as two or three.

[0051] like Figure 1 As shown, this invention also includes a first buffer bladder 50. The first buffer bladder 50 is arranged between the dispensing pump 40 and the first critical flow control element 70, and forms a variable first fluid space within the first buffer bladder 50. The first fluid space is in fluid communication with both the dispensing pump 40 and the first critical flow control element 70. Therefore, when the pressure of the dispensing pump 40 increases, excess standard solution can temporarily enter the first fluid space of the first buffer bladder 50; correspondingly, when the pressure of the dispensing pump 40 decreases, the standard solution in the first buffer bladder 50 can flow to the first critical flow control element 70 in a timely manner. In this way, the pressure upstream of the first critical flow control element 70 can always be maintained at a relatively stable level.

[0052] like Figure 1As shown, the first critical flow control element 70 is arranged downstream of the liquid addition pump 40 to stabilize the flow rate of the standard solution flowing out of the liquid addition pump 40. Compared with traditional mass flow meters, the first critical flow control element 70 has many advantages such as high flow stability, fast response speed, simple structure, high reliability, and wide applicability. Therefore, when the standard solution flows through the first critical flow control element 70, the downstream pressure will drop below the critical pressure ratio (approximately 0.528 for air), and the flow velocity will reach the speed of sound. At this time, changes in downstream pressure will not affect the flow rate, thereby significantly improving the stability of the standard solution flow rate and reducing control costs. This utility model includes three first critical flow control elements 70 connected in parallel. Each first critical flow control element 70 is selectively connected to the liquid addition pump 40 via a second valve guide 60 located upstream of it, and is selectively connected to the vaporization mechanism 90 via a third valve guide 80 located downstream of it. The second valve guide 60 and the third valve guide 80 allow for convenient control of the standard solution flow within any one or more of the three parallel first critical flow control elements 70, further simplifying the number of control valves and optimizing the piping layout. Alternatively, the number of first critical flow control elements 70 can be set to other suitable numbers, such as one, two, or four. The type of first critical flow control element 70 is not limited; for example, it can be a critical flow venturi nozzle, a critical flow nozzle, a critical flow orifice, or a Laval nozzle. Among them, the Critical Flow Venturi Nozzle consists of a contraction section, a throat, and a diverging section, similar to a traditional Venturi tube, but the throat design ensures critical flow conditions; the Critical Flow Nozzle consists of a contraction section and a straight throat, without a diverging section, and the throat cross-sectional area is constant; the Critical Flow Orifice is an orifice arranged on a thin plate, with sharp orifice edges, without a contraction or diverging section; the Laval Nozzle consists of a contraction section, a throat, and a diverging section, but its diverging section is longer and is designed specifically for supersonic flow.

[0053] like Figure 1As shown, the vaporization mechanism 90 is arranged downstream of the first critical flow control element 70. Specifically, the vaporization mechanism 90 is arranged downstream of the third valve guide 80. The vaporization mechanism 90 can vaporize the standard solution flowing out of the first critical flow control element 70 into a standard gas. The specific structure of the vaporization mechanism 90 is not limited; for example, the vaporization mechanism 90 includes a vaporization box, a spiral tube arranged in the vaporization box, and a heater for heating the spiral tube. The spiral tube can be made of stainless steel or other suitable materials, giving it good heat resistance, corrosion resistance, and low adsorption. The type of heater is not limited, as long as it can effectively vaporize the standard solution in the spiral tube into a standard gas. The vaporization mechanism 90 outputs the standard gas through a suitable outlet pipe 100, and then uses these standard gases for instrument calibration, quality control, and experimental analysis. This utility model directly vaporizes the standard solution in the storage tank 10 into a standard gas through the vaporization mechanism 90, which can avoid the standard gas from evaporation, dilution, and contamination during storage, significantly reducing storage costs and achieving ready-to-use.

[0054] Example 2:

[0055] Figure 1 This is a structural schematic diagram of the second embodiment of this utility model. (See diagram below.) Figure 1 As shown, this utility model also includes a first gas storage tank 110 and a second critical flow control element 160. The first gas storage tank 110 is used to contain dilution gas. The dilution gas can be, but is not limited to, compressed air, nitrogen, methane, or hydrogen hexafluoride, thereby enriching the types of dilution gases and meeting the differentiated needs of users. The second critical flow control element 160 is arranged downstream of the first gas storage tank 110 to stabilize the flow rate of the dilution gas flowing out of the first gas storage tank 110. Furthermore, the second critical flow control element 160 is configured to be connected to the outlet pipe 100 of the vaporization mechanism 90 via a connecting pipe 190, so as to dilute the standard gas discharged from the vaporization mechanism 90 with the dilution gas, thereby better regulating the concentration of the standard gas.

[0056] like Figure 2As shown, this utility model includes three parallel second critical flow control elements 160. Each second critical flow control element 160 is connected to a first gas storage tank 110 via a fourth valve guide 150 located upstream of it, and to a connecting gas pipe 190 via a fifth valve guide 170 located downstream of it. The arrangement of the fourth valve guide 150 and the fifth valve guide 170 allows for convenient control of the flow of dilution gas within any one or more of the three parallel second critical flow control elements 160, further simplifying the number of control valves and optimizing the pipeline layout. Alternatively, the number of second critical flow control elements 160 can be set to other suitable numbers, such as one, two, or four. The type of second critical flow control element 160 is not limited; for example, it can be a critical flow venturi nozzle, a critical flow nozzle, a critical flow orifice, or a Laval nozzle.

[0057] like Figure 2 As shown, a pressure reducing valve 120 is also provided between the first gas storage tank 110 and the second critical flow control element 160. The pressure reducing valve 120 can significantly reduce the pressure in the pipeline, making it easier to control the flow rate of the dilution gas. The type of pressure reducing valve 120 is not limited, such as a spring diaphragm type pressure reducing valve 120, a piston type pressure reducing valve 120, a bellows type pressure reducing valve 120, etc.

[0058] like Figure 2 As shown, a pressure sensor 130 is also provided between the pressure reducing valve 120 and the second critical flow control element 160. The pressure sensor 130 allows for convenient and accurate measurement of the pressure of the dilution gas flowing out of the pressure reducing valve 120. The type of pressure sensor 130 is not limited, such as a piezoresistive pressure sensor 130, a capacitive pressure sensor 130, a piezoelectric pressure sensor 130, etc.

[0059] like Figure 2 As shown, this invention also includes a second buffer bladder 140, which is arranged between the pressure reducing valve 120 and the second critical flow control element 160. A variable second fluid space is formed within the second buffer bladder 140, and this second fluid space is in fluid communication with both the pressure reducing valve 120 and the second critical flow control element 160. Therefore, when the flow rate of the diluent gas is too high, excess diluent gas can temporarily enter the second fluid space of the second buffer bladder 140; correspondingly, when the flow rate of the diluent gas is too low, the diluent gas within the second buffer bladder 140 can flow to the second critical flow control element 160 as needed. This ensures that the pressure upstream of the second critical flow control element 160 remains at a relatively stable level.

[0060] like Figure 2As shown, a temperature and humidity regulating mechanism 180 is also provided on the connecting gas pipe 190. This temperature and humidity regulating mechanism 180 includes components such as a regulating box 181, a heating element 182, and a gas guide pipe 183. The regulating box 181 has a generally sealed cavity; the heating element 182 is arranged inside the regulating box 181; the gas guide pipe 183 is arranged inside the regulating box 181 and communicates with the connecting gas pipe 190 to allow the diluent gas to flow through it. Thus, by controlling the opening and closing or the output power of the heating element 182, the temperature of the diluent gas can be easily adjusted, thereby controlling the temperature of the entire standard gas. The type of heating element 182 is not limited, such as an electric heater, a heat pump heater, etc. A humidifying liquid is provided in the regulating box 181, and the gas guide pipe 183 is a reverse osmosis pipe, allowing the humidifying liquid to permeate into the gas guide pipe 183 to humidify the diluent gas. The humidifying liquid can be tap water, distilled water, or other suitable liquids. The reverse osmosis tube is designed to uniformly and precisely adjust the humidification rate, preventing drastic fluctuations in the humidity of the dilution gas caused by excessively rapid humidification. A suitable temperature and humidity sensor is also installed inside the gas delivery tube 183 to monitor the temperature and humidity of the dilution gas in real time.

[0061] Example 3:

[0062] Figure 2 This is a schematic diagram of the structure of the third embodiment of the present invention. The present invention also includes a second gas storage tank 200. The second gas storage tank 200 is used to contain a standard gas. It should be noted that the "standard gas" in the second gas storage tank 200 can be a standard gas prepared by the present invention, or it can be obtained by other means (e.g., purchased from the market). The second gas storage tank 200 is arranged in parallel with the first gas storage tank 110 upstream of the second critical flow control element 160. For example, the second gas storage tank 200 is arranged via a pipeline between the pressure reducing valve 120 and the pressure sensor 130 (see...). Figure 2 Figure 3 Figure 3 Alternatively, the second gas storage tank 200 can be connected to the fourth valve 150 via a pipeline. In this way, the standard gas in the second gas storage tank 200 can be thoroughly mixed with the dilution gas in the first gas storage tank 110 by passing through the second critical flow control element 160. Alternatively, the second gas storage tank 200 can also be directly connected to the connecting gas pipe 190, as long as the dilution gas in the first gas storage tank 110 can be used to smoothly dilute the standard gas in the second gas storage tank 200.

[0063] The beneficial effects of this utility model are as follows:

[0064] (1) By selecting a suitable standard solution, the standard gas generator of this invention can easily obtain standard gases of different compositions and concentrations, thereby better meeting practical needs. Using a vaporization mechanism to directly vaporize the standard solution in the storage tank into standard gas avoids evaporation, dilution, and contamination of the standard gas during storage, reducing storage costs. Compared to traditional mass flow meters, the first critical flow control element has many advantages, including high flow stability, fast response speed, simple structure, high reliability, and wide applicability. Specifically, when the standard solution flows through the first critical flow control element, the downstream pressure will drop below the critical pressure ratio (approximately 0.528 for air), and the flow velocity will reach the speed of sound. At this point, changes in downstream pressure will not affect the flow rate, thus significantly improving the stability of the standard solution flow rate and reducing control costs.

[0065] (2) The parallel structure of the liquid storage tank can enrich the composition and concentration of the standard solution, thereby obtaining a variety of standard gases; multiple parallel first critical flow control elements can not only expand the flow range, improve system redundancy and reliability, but also optimize dynamic response, achieve precision control, and extend the life of the elements. The first critical flow control elements include critical flow Venturi nozzles, critical flow nozzles, critical flow orifices or Laval nozzles, which can enrich the types of first critical flow control elements; the setting of the first gas storage tank and the second critical flow control element can use dilution gas to conveniently further dilute the standard gas, so as to better adjust the concentration of the standard gas. In addition, the second critical flow control element has many advantages such as high flow stability, fast response speed, simple structure, good reliability, and wide applicability; multiple parallel second critical flow control elements can not only expand the flow range, improve system redundancy and reliability, but also optimize dynamic response, achieve precision control, and extend the life of the elements. The second critical flow control elements include critical flow Venturi nozzles, critical flow nozzles, critical flow orifices or Laval nozzles, which can enrich the types of second critical flow control elements.

[0066] (3) The liquid concentration sensor can conveniently and accurately measure the concentration of the corresponding standard solution in the storage tank, so as to provide data support for adjusting the concentration of the standard gas; the temperature and humidity adjustment mechanism can conveniently adjust the temperature and humidity of the dilution gas, and thus adjust the temperature and humidity of the entire standard gas; the pressure reducing valve can significantly reduce the pressure in the pipeline, making it easy to control the flow rate of the dilution gas; the pressure sensor can conveniently and accurately measure the pressure of the dilution gas flowing out of the pressure reducing valve.

[0067] (4) The first buffer tank can stabilize the flow rate of the standard solution flowing out from the liquid pump, so that the pressure upstream of the first critical flow control element can also be kept stable; the second buffer tank can stabilize the flow rate of the dilution gas flowing out from the pressure reducing valve, so that the pressure upstream of the second critical flow control element can also be kept stable; the second gas storage tank can conveniently store standard gas, enrich the source of standard gas, so as to better meet the actual needs of users; the dilution gas is compressed air, nitrogen, methane or hydrogen hexafluoride, which can enrich the types of dilution gas to meet the differentiated needs of users.

[0068] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A standard gas generating device, characterized in that: It includes a solution vaporization component and a gas dilution component, and the two are connected; The solution vaporization assembly includes a liquid storage assembly. The outlet end of the liquid storage assembly is connected to the inlet end of a first valve guide (30) downstream of it. The outlet end of the first valve guide (30) is connected to the inlet end of a liquid addition pump (40) downstream of it. The outlet end of the liquid addition pump (40) is connected to the inlet end of a second valve guide (60) downstream of it. The outlet end of the second valve guide (60) is connected to the inlet end of a first flow control assembly downstream of it. The outlet end of the first flow control assembly is connected to the inlet end of a third valve guide (80) downstream of it. The outlet end of the third valve guide (80) is connected to the inlet end of a vaporization mechanism (90) downstream of it. The outlet end of the vaporization mechanism (90) is connected to an outlet pipe (100). The gas dilution assembly includes a gas storage assembly. The outlet end of the gas storage assembly is connected to the inlet end of a downstream pressure reducing valve (120). The outlet end of the pressure reducing valve (120) is connected to the inlet end of a downstream fourth valve guide (150). The outlet end of the fourth valve guide (150) is connected to the inlet end of a downstream second flow control assembly. The outlet end of the second flow control assembly is connected to the inlet end of a downstream fifth valve guide (170). The outlet end of the fifth valve guide (170) is connected to the inlet end of a downstream temperature and humidity regulating mechanism (180). The outlet end of the temperature and humidity regulating mechanism (180) is connected to a downstream connecting gas pipe (190). The connecting gas pipe (190) is connected to an outlet pipe (100). The liquid storage assembly includes a plurality of liquid storage tanks (10), which are connected in parallel. The liquid storage tanks (10) are used to contain standard solutions. The gas storage assembly includes a first gas storage tank (110) and a second gas storage tank (200), which are arranged in parallel upstream of the second flow control assembly.

2. The standard gas generating device according to claim 1, characterized in that: The first flow control assembly includes a plurality of first critical flow control elements (70), which are connected in parallel. The first critical flow control elements (70) include a critical flow venturi nozzle, a critical flow nozzle, a critical flow orifice, or a Laval nozzle.

3. The standard gas generating device according to claim 1, characterized in that: The second flow control assembly includes a plurality of second critical flow control elements (160), which are arranged in parallel. The second critical flow control elements (160) include critical flow venturi nozzles, critical flow nozzles, critical flow orifices, or Laval nozzles.

4. A standard gas generating device according to claim 1, characterized in that: A liquid concentration sensor (20) is installed inside the storage tank (10).

5. A standard gas generating device according to claim 1, characterized in that: The temperature and humidity control mechanism (180) includes a control box (181), a heating element (182), and an air guide pipe (183). The heating element (182) and the air guide pipe (183) are installed inside the control box (181). The air guide pipe (183) is connected to a connecting air pipe (190). The control box (181) contains humidifying liquid. The air guide pipe (183) is a reverse osmosis pipe, and a temperature and humidity sensor is installed inside the air guide pipe (183).

6. A standard gas generating device according to claim 1, characterized in that: The first gas storage tank (110) is used to contain dilution gas, which is compressed air, nitrogen, methane or hydrogen hexafluoride.

7. A standard gas generating device according to claim 1, characterized in that: The second gas storage tank (200) is used to contain standard gas.

8. A standard gas generating device according to claim 1, characterized in that: A first buffer bladder (50) is connected between the liquid pump (40) and the second valve guide (60). The first buffer bladder (50) forms a first fluid space, which is in fluid communication with the liquid pump (40) and the first critical flow control element (70).

9. A standard gas generating device according to claim 1, characterized in that: A second buffer bladder (140) is connected between the pressure reducing valve (120) and the fourth valve guide (150). The second buffer bladder (140) forms a second fluid space, which is in fluid communication with the pressure reducing valve (120) and the second critical flow control element (160).

10. A standard gas generating device according to claim 1, characterized in that: A pressure sensor (130) is connected between the pressure reducing valve (120) and the fourth valve guide (150).

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