A constant release source

Abstract

The utility model discloses a constant release source, including release source body, flow controller, air inlet pipe and air outlet pipe and gas source, form source chamber in release source body inside, be equipped with with source chamber intercommunication air inlet, air outlet and sample injection port on release source body, one end of air inlet pipe is with source chamber intercommunication through air inlet, the other end of air inlet pipe is connected with gas source, air outlet pipe is connected with air outlet, and flow controller is located on air inlet pipe for adjusting the gas flow of entering source chamber. The utility model not only has improved the accuracy of detection result, but also has enhanced the adaptability and practicality of equipment under different geographical and environmental conditions.

Description

Technical Field

[0001] This utility model relates to the field of environmental monitoring technology, and in particular to a constant release source. Background Technology

[0002] When testing the release source of VOCs / gas release chambers, special attention must be paid to the environmental conditions at the equipment installation site. Since atmospheric pressure varies from place to place, this difference can significantly affect the performance of ordinary release sources. Specifically, the release rate of ordinary release sources will exhibit significant inconsistencies under different atmospheric pressure conditions, leading to large deviations in actual test results and affecting the accuracy and reliability of the data. To address this issue, this invention proposes an innovative release source design scheme. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies that do not consider atmospheric pressure in the release source, and to provide a solution that not only improves the accuracy of detection results but also enhances the adaptability and practicality of the equipment under different geographical and environmental conditions. To achieve the above objectives, this invention provides a constant release source, including a release source body, a flow controller, an inlet pipe, an outlet pipe, and a gas source. A source cavity is formed inside the release source body. The release source body is provided with an inlet, an outlet, and a sample injection port that communicate with the source cavity. One end of the inlet pipe is connected to the source cavity through the inlet, and the other end of the inlet pipe is connected to the gas source. The outlet pipe is connected to the outlet. The flow controller is located on the inlet pipe and is used to compensate for the flow rate of the gas entering the source cavity. The inlet pipe is provided with an outlet end, which passes through the inlet and is placed at the lower end of the source cavity. This arrangement allows the gas entering the source cavity to flow from bottom to top, mix thoroughly with the sample, and be uniformly output from the outlet pipe in the form of saturated vapor, ensuring a stable release rate. The smooth inner wall of the source cavity reduces gas retention and improves response consistency.

[0004] Furthermore, the release source is provided with a heat insulation layer and an internal anti-adsorption coating. The heat insulation layer is used to maintain the temperature stability inside the source cavity and reduce the interference of the external environment on the release rate, while the internal anti-adsorption coating effectively prevents the target substance from being adsorbed or reacted inside the cavity, ensuring a constant and pure release concentration.

[0005] Furthermore, the internal anti-adsorption coating is a Teflon coating.

[0006] Furthermore, the release source is a component made of Teflon material. The Teflon coating has excellent chemical inertness and surface non-stickiness, which can effectively prevent the adsorption or catalytic decomposition of organic matter and trace gases on the cavity wall, and is especially suitable for the stable release of highly active compounds in VOC detection.

[0007] Furthermore, a temperature control device is included, located inside or outside the source cavity. This device comprises a temperature sensor and a heating element. The temperature sensor monitors the temperature of the source cavity or liquid sample in real time and feeds the data back to the control system. The heating element automatically adjusts its heating power according to a set value, achieving precise temperature stability. Combined with an insulation layer and an internal anti-adsorption coating, this ensures a highly consistent release rate at different temperatures, effectively eliminating the influence of temperature on the detection results.

[0008] Furthermore, the heating element is spirally disposed inside or outside the source cavity. This structure increases the contact area between the heating element and the gas, making the temperature distribution within the source cavity more uniform and further improving temperature control accuracy.

[0009] Furthermore, the source cavity includes a first section, a second section, and a third section, wherein the inner diameter of the first section is larger than the inner diameter of the second section, which in turn is larger than the inner diameter of the third section. This stepped structural design enables gradual compression and mixing of the gas as it passes through, enhancing airflow stability, reducing turbulence and dead zones, thereby improving the uniformity of the release concentration and the response speed.

[0010] Furthermore, the first section has a funnel structure, and a funnel transition section is provided between the second and third sections. The funnel structure of the first section facilitates the injection of liquid standard samples, allowing the liquid to flow smoothly along the inner wall into the depths of the cavity and reducing residue; the funnel transition section allows the gas to transition smoothly between the second and third sections, further reducing airflow turbulence. The sample injection port is equipped with a self-sealing diaphragm to ensure immediate closure after injection and prevent leakage.

[0011] Furthermore, the source body is a component made of polytetrafluoroethylene (PTFE), glass, steel, or aluminum. All of these materials possess good chemical stability and mechanical strength. PTFE and glass are particularly suitable for high-purity gas release scenarios due to their strong surface inertness, resistance to adsorption, and corrosion resistance, effectively preventing the loss or contamination of trace substances during transmission and ensuring the accuracy and repeatability of detection results.

[0012] Furthermore, it also includes a source cavity cover, which is sealed to the release source body. The sealing connection uses an O-ring with a precision-machined end face to ensure that the system is leak-free during long-term operation.

[0013] Furthermore, it also includes an absorption device connected to the air outlet.

[0014] Furthermore, the absorption device is a TENAX tube, an activated carbon adsorption tank, or other absorption / adsorption container with the same function.

[0015] This invention also provides a method for calibrating the release rate of a release source: A constant release source is provided as described above. A liquid standard sample is injected into the source cavity. Then, the gas source and the release source containing the liquid standard sample are placed on a precision balance, and the initial weight is recorded. The gas source is turned on, and the gas flow rate entering the source cavity is adjusted according to the local temperature / atmospheric pressure value by a flow controller. Clean gas enters the source cavity through the inlet pipe, mixes with the liquid standard sample in the source cavity, and is discharged from the outlet. After a period of release, the remaining weight of the gas source and the release source containing the liquid standard sample after release is recorded again. Finally, the initial weight is subtracted from the sum of the remaining weight and the weight lost by the gas source to obtain the release amount of the release source during this period.

[0016] Furthermore, an absorption device and a constant release source as described above are provided. The absorption device is installed on the gas outlet. Before installation, the absorption device is weighed, and then the liquid standard sample is injected into the source cavity. The gas supply is turned on, and the gas flow rate entering the source cavity is adjusted by the flow controller according to the local temperature / atmospheric pressure value. The clean gas enters the source cavity through the inlet pipe, mixes with the liquid standard sample in the source cavity, and is discharged from the gas outlet into the absorption device. After a period of release, the absorption device is removed and weighed a second time. The weight difference of the absorption device before and after is the release amount of the release source during this period.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] This invention designs a device for injecting liquid standard samples through an injection port. The device can effectively connect to an external pure gas source using an inlet pipe, and the flow rate of the input gas can be precisely adjusted by a flow controller. After entering the device, the pure gas passes through the liquid standard sample, making full contact with it and carrying out the saturated gas components of the standard sample. Subsequently, these saturated gases are output through a specially designed outlet. This process not only ensures the consistency, stability, and repeatability of the concentration in the output gas environment, but also takes into account the possible impact of atmospheric pressure differences in different regions, thereby achieving the requirement of consistent release under various environmental conditions. This design can meet the high standard requirements for release sources in experimental or industrial applications, and performs particularly well in scenarios where precise control of gas concentration and release is required. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the principle structure of a constant release source provided by this utility model;

[0021] Figure 2 This is a schematic diagram of the structure of a constant release source provided by this utility model;

[0022] Figure 3 yes Figure 2 A perspective diagram.

[0023] The diagram includes:

[0024] 1. Release source; 11. Source cavity; 111. First section; 112. Second section; 113. Third section; 114. Funnel transition section; 12. Air inlet; 13. Air outlet; 14. Sample injection port; 15. Insulation layer; 16. Internal anti-adsorption coating; 2. Flow controller; 3. Air inlet pipe; 31. Air inlet end; 32. Air outlet end; 4. Air outlet pipe; 5. Air source; 6. Temperature control device; 61. Temperature sensor; 62. Heating element. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiment is one embodiment of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Please refer to Figures 1 to 3 This invention provides a constant release source.

[0027] Example 1

[0028] like Figure 1 As shown, the constant release source body includes a release source body 1, a flow controller 2, an air inlet pipe 3, an air outlet pipe 4, and an air source 5, forming a source cavity 11 inside the release source body 1;

[0029] like Figure 2 and Figure 3As shown, in this preferred embodiment, the source cavity 11 includes a first segment 111, a second segment 112, and a third segment 113. The inner diameter of the first segment 111 is larger than the inner diameter of the second segment 112, which is larger than the inner diameter of the third segment 113. The first segment 111 has a funnel structure, and a funnel transition segment 114 is provided between the second segment 112 and the third segment 113. In this embodiment, a source cavity 11 cover for sealing the source cavity 11 is also provided. The material of the source cavity 11 cover is the same as that of the release source body 1. The source cavity 11 cover and the release source body 1 are sealed together. Specifically, the source cavity 11 cover and the release source body 1 can be connected by threads and fitted with a sealing ring to achieve a tight seal, ensuring good airtightness inside the source cavity 11. In addition, in some embodiments, the source cavity 11 cover and the release source body 1 can also be fixed and sealed by welding or riveting, further improving structural stability and sealing reliability.

[0030] In this embodiment, the first section 111 has a funnel structure, which facilitates the injection of liquid standard samples and allows the liquid to flow smoothly along the inner wall into the depth of the cavity, reducing residue. The funnel transition section allows the gas to transition smoothly between the second section 112 and the third section 113, further reducing airflow disturbance. In this way, whether it is the injection of liquid standard samples or gas flow, turbulence and resistance can be effectively reduced, and the stability and uniformity of release can be improved.

[0031] The release source 1 is provided with an air inlet 12, an air outlet 13, and a sample injection port 14 that communicate with the source cavity 11. In this embodiment, a cover is provided for the source cavity 11. Therefore, for the sake of structural rationality, the air inlet 12, air outlet 13, and sample injection port 14 are all provided on the cover of the source cavity 11. The air inlet pipe 3 is provided with an air inlet end 31 and an air outlet end 32. In this embodiment, the air outlet end 32 of the air inlet pipe 3 passes through the air inlet 12 and communicates with the source cavity 11, and is located at the bottom of the third section 113 of the source cavity 11. The air inlet end 31 of the air inlet pipe 3 is connected to an external gas source 5. The gas source 5 is a bottled dry gas source 5, such as compressed air or nitrogen, to ensure the purity of the gas source 5 and improve the accuracy and stability of the detection.

[0032] The flow controller 2 is mounted on the inlet pipe 3 and positioned between the gas source 5 and the inlet 12. The flow controller 2 is a gas flow controller capable of temperature / atmospheric pressure compensation, automatically adjusting the gas flow rate entering the source chamber 11 based on temperature / atmospheric pressure values. Alternatively, the flow controller 2 can be manually adjusted based on ambient atmospheric pressure and the temperature of the source or liquid sample for flow compensation. Specifically, an atmospheric pressure sensor is designed to automatically detect atmospheric pressure and provide real-time feedback to the flow controller 2, enabling the flow controller 2 to automatically acquire atmospheric pressure values ​​for control. Alternatively, an additional operating controller can be used to manually input atmospheric pressure values, which are then transmitted to the flow controller 2. Whether automatically acquired or manually input, the flow controller 2 can precisely control the release amount of the source, ensuring that the release amount is not affected by local atmospheric pressure.

[0033] like Figure 1 As shown, the release source 1 is provided with a heat insulation layer 15 and an internal anti-adsorption coating 16, wherein the internal anti-adsorption coating 16 is a Teflon coating. The internal anti-adsorption coating 16 is coated on the inner wall surface of the source cavity 11, effectively preventing the concentration of the standard sample from decreasing due to adsorption during transmission, ensuring the constant and accurate release amount. In some preferred embodiments, the release source 1 is a component made entirely of Teflon material. In this case, an additional Teflon internal anti-adsorption coating 16 can be provided as needed. Of course, in other embodiments, other materials can be used for the internal anti-adsorption coating 16 to achieve better protection, such as explosion-proof and sealing.

[0034] In some embodiments, to further monitor the temperature changes inside the source cavity 11, a temperature control device 6 can be installed inside the source cavity 11. Alternatively, in some embodiments, the temperature control device can be installed on the outside of the source cavity 11. For example, a temperature control layer can be formed between the inner wall of the release source body 1 and the source cavity 11, and the temperature control device 6 can be installed thereon. Or, the temperature control device 6 can be directly installed on the outer surface of the release source body 1 to achieve temperature control of the source cavity 11. The temperature control device 6 in this embodiment includes a temperature sensor 61 and a heating element 62. For example, the heating element 62 can be a heating wire, a ceramic heating element, or other heating elements. To achieve overall temperature uniformity inside the source cavity 11, the heating element 62 is spirally arranged inside the source cavity 11. Of course, the surface of the components placed inside the source cavity 11 is coated with Teflon to reduce the impact on the internal environment.

[0035] The working principle of this utility model is as follows: the standard liquid to be tested is injected through the injection port and flows smoothly into the depth of the source cavity 11 through the first section 111 of the funnel structure, reducing residue; the gas source 5 enters the source cavity 11 through the air inlet pipe 3, and the clean gas and the liquid standard are mixed and then stably output from the air outlet 13 in the form of saturated steam. The flow controller 2 adjusts the gas flow rate in real time according to the ambient temperature and pressure to ensure a constant release concentration. The temperature control device 6 works in conjunction with the heating wire and the sensor to maintain a constant temperature and uniform temperature in the cavity. The Teflon internal anti-adsorption coating 16 effectively prevents the standard from adsorbing on the cavity wall, ensuring output accuracy.

[0036] The entire system operates in a sealed and reliable environment, suitable for continuous or intermittent release of high-precision gas standard substances. In addition, the source chamber 11 cover and the chamber body are fastened with a corrosion-resistant sealing ring to ensure no leakage during long-term operation. When the outlet 13 is connected to the output pipeline, it is also treated with anti-adsorption to further ensure the consistency of standard sample transmission.

[0037] This invention also provides a method for calibrating the release rate of a release source:

[0038] A constant release source is used, and a liquid standard sample is injected into the source cavity 11. Then, the gas source 5 and the release source body 1 containing the liquid standard sample are placed on a precision balance, and their weight is recorded as the initial weight. The liquid standard sample is left to stand at the bottom of the source cavity 11. Then, the gas source 5 is turned on to supply gas, and the gas flow rate entering the source cavity 11 is adjusted by the flow controller 2 according to the local temperature / atmospheric pressure value. The clean gas enters the bottom of the source cavity 11 through the air inlet pipe 3, mixes with the liquid standard sample in the source cavity 11, and is discharged from the air outlet 13 in the form of saturated steam. After a period of release, the remaining weight of the gas source (5) and the release source body (1) containing the liquid standard sample after release is calculated. Finally, the initial weight is subtracted from the sum of the remaining weight and the weight lost by the gas source, which is the release amount of the release source during this period. Preferably, the weight lost by the gas source is obtained by subtracting the initial weight of the gas source from the weight after release.

[0039] Example 2

[0040] The difference between this embodiment and Embodiment 1 is that an absorption device is also provided. The absorption device is connected to the gas outlet 13. This absorption device can be a TENAX tube, an activated carbon adsorption tank, or other absorption / adsorption tanks with the same function. In this embodiment, the Tenax tube is a sampling tube filled with a porous polymer adsorbent, mainly used to capture and enrich volatile organic compounds (such as benzene, TVOC, etc.) in the air. Currently, the mainstream type is the Tenax-TA tube, which is suitable for high-boiling-point VOCs (such as alcohols, aldehydes, chlorobenzene), has a high breakthrough volume, and meets national standards such as GB50325. The new generation product, the Tenax-GR tube, contains 23% to 30% graphitized carbon black, which enhances the capture ability of low-boiling-point trace organic compounds and has better chromatographic peak symmetry. It can be selected according to actual needs. During operation, the absorption device is first installed on the outlet 13. Before installation, the absorption device is weighed. Then, the liquid standard sample is injected into the source chamber 11. The gas supply is then turned on, and the flow rate entering the source chamber 11 is adjusted by the flow controller 2 according to the local temperature / atmospheric pressure. The clean gas enters the bottom of the source chamber 11 through the inlet pipe 3, mixes with the liquid standard sample in the source chamber 11, and is discharged from the outlet 13 into the absorption device as saturated steam. After a period of release, the absorption device is removed and weighed again. The weight difference of the absorption device before and after the weighing represents the amount of gas released during this period. Everything else is the same as in Example 1, achieving the same technical effect.

[0041] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A constant release source, characterized in that, The system includes a release source (1), a flow controller (2), an inlet pipe (3), an outlet pipe (4), and a gas source (5). A source cavity (11) is formed inside the release source (1). The release source (1) is provided with an inlet (12), an outlet (13), and a sample injection port (14) that are connected to the source cavity (11). One end of the inlet pipe (3) is connected to the source cavity (11) through the inlet (12), and the other end of the inlet pipe (3) is connected to the gas source (5). The outlet pipe (4) is connected to the outlet (13). The flow controller (2) is located on the inlet pipe (3) and is used to compensate the flow rate of the gas entering the source cavity (11). The inlet pipe (3) is provided with an outlet end (32). After the outlet end (32) passes through the inlet (12), it is placed at the lower end inside the source cavity (11).

2. A constant release source according to claim 1, characterized in that: The release source (1) is provided with a heat insulation layer (15) and an internal anti-adsorption coating (16), wherein the internal anti-adsorption coating (16) is a Teflon coating.

3. A constant release source according to claim 1, characterized in that: The release source is a component made of Teflon material.

4. A constant release source according to claim 1, characterized in that: It also includes a temperature control device (6), which is located inside or outside the source cavity (11). The temperature control device (6) includes a temperature sensor (61) and a heating element (62).

5. A constant release source according to claim 4, characterized in that: The heating element (62) is spirally disposed inside or outside the source cavity (11).

6. A constant release source according to claim 1, characterized in that: The source cavity (11) includes a first segment (111), a second segment (112) and a third segment (113), wherein the inner diameter of the first segment (111) is greater than the inner diameter of the second segment (112) and the inner diameter of the third segment (113).

7. A constant release source according to claim 6, characterized in that: The first segment (111) has a funnel structure, and a funnel transition section is provided between the second segment (112) and the third segment (113).

8. A constant release source according to claim 1, characterized in that: It also includes a source cavity (11) cover, which is sealed to the release source body (1).

9. A constant release source according to claim 1, characterized in that: It also includes an absorption device, which is connected to the air outlet (13).

10. A constant release source according to claim 9, characterized in that: The absorption device is a TENAX tube or an activated carbon adsorption tank.

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