Portable box and method for collecting and measuring radioactive gas

Abstract

The invention discloses a portable box and method for collecting and measuring radioactive gas, and relates to the field of radioactive gas.The portable box comprises a box body, a gas inlet cavity, an adsorption main cavity and a gas outlet cavity, and the gas inlet cavity, the adsorption main cavity and the gas outlet cavity are sequentially formed in the box body in a communicating mode; the main adsorption cavity is filled with an adsorption bed layer used for adsorbing and collecting radioactive gas, a plurality of piezoelectric ceramic oscillation pieces are installed on the outer wall, opposite to the main adsorption cavity, of the box body, and a driving controller is installed on the surface of the box body. A plurality of piezoelectric ceramic oscillators are integrated on the outer wall of the adsorption main cavity and matched with the slope type bottom surface of the adsorption main cavity, so that the problem of concentration gradient caused by insufficient diffusion rate in traditional passive diffusion sampling can be effectively solved, the concentration uniformity of an adsorbent bed layer under a short-time sampling condition is remarkably improved, and the sampling efficiency is improved. And the accuracy and representativeness of subsequent measurement results are further ensured, so that the time required for gas homogenization is shortened, and the response speed of the system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive gases, and in particular to a portable box and method for collecting and measuring radioactive gases. Background Art

[0002] Radioactive gases (such as radon-222) have important detection value in environmental monitoring, nuclear industry safety, geological exploration and medical fields, and their concentration levels are directly related to human health and environmental safety. For example, radon gas, as a naturally radioactive inert gas, can be released into indoor and outdoor environments through soil, rocks or building materials. Long-term exposure may increase the risk of lung cancer, so rapid and accurate concentration measurement is a key link in environmental safety management. At present, portable radioactive gas detection devices have become the main tools for rapid on-site detection due to their convenient operation and wide range of applications. The core principle is usually to enrich the target gas with an adsorbent (such as activated carbon, molecular sieves or metal-organic framework materials), and then achieve quantitative measurement through means such as gamma spectroscopy analysis.

[0003] In the prior art, passive diffusion is often used to collect radioactive gases. In the passive diffusion mode, the gas relies on the free diffusion of molecules to enter the adsorbent bed, and relies on the diffusion and adsorption balance of the gas in the adsorbent pores to achieve the enrichment of the target gas. Among them, in order to improve the detection sensitivity, existing devices mostly use adsorbent materials with high specific surface area (such as MOF particles). However, in actual applications, when the sampling time is short (usually less than 15 minutes), due to the limited gas diffusion rate, a significant concentration gradient is easily formed in the adsorbent bed, that is, the concentration in the gas inlet area is high and the concentration in the outlet area is low, resulting in the adsorbent failing to uniformly adsorb the target gas.

[0004] This non-uniform distribution directly affects the accuracy of subsequent overall measurements. For example, in gamma-ray spectrum analysis, since the detector measures the entire bed, the concentration gradient will cause the measurement results to systematically underestimate the actual average concentration by more than 20%, resulting in serious representative errors. Especially in emergency detection or rapid screening scenarios, this error may lead to misjudgment of the degree of contamination and affect the scientific nature of subsequent decision-making.

[0005] Therefore, it is necessary to improve the deficiencies in the prior art to solve the above problems. Summary of the Invention

[0006] The present invention overcomes the shortcomings of the existing technology and provides a portable box and method for collecting and measuring radioactive gases. Through non-contact physical disturbance means, it forces the rapid mixing of gases in the adsorption bed, improves the uniformity of gas concentration distribution, and further reduces the deviation between the measurement results and the actual average concentration.

[0007] To achieve the above-mentioned object, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a portable box for collecting and measuring radioactive gas, comprising: a box body, and an air inlet cavity, an adsorption main cavity, and an air outlet cavity which are sequentially connected and opened inside the box body;

[0008] The interior of the adsorption main chamber is filled with an adsorption bed for adsorbing and collecting radioactive gases. The outer wall of the box body facing the main adsorption chamber is mounted with a plurality of piezoelectric ceramic oscillating plates. A drive controller is mounted on the surface of the box body. The drive controller is electrically connected to the plurality of piezoelectric ceramic oscillating plates via wires.

[0009] Air inlets are provided on both sides of the box body and pass through to the interior of the air inlet cavity; a detection port for adapting to the measuring end of the detector is provided on the front side of the box body and passes through to the interior of the air outlet cavity.

[0010] In a preferred embodiment of the present invention, the bottom surface of the main adsorption chamber is a slope structure, and the bottom surface forms an angle of 15-30 degrees with the horizontal plane, and the inlet height is lower than the outlet height.

[0011] In a preferred embodiment of the present invention, the adsorption bed is composed of metal organic framework particles and is vibrated and filled to form a porous structure; the tap density is 0.4-0.5 g / cm 3 , the porosity is 37-45%.

[0012] In a preferred embodiment of the present invention, the drive controller includes a microcontroller and an H-bridge drive chip; a power supply battery is installed inside the box body, and the power supply battery is electrically connected to the drive controller through a wire.

[0013] In a preferred embodiment of the present invention, a closing assembly is provided on the inner side of the detection port, and the closing assembly includes: a movable groove opened at the top of the inner side of the detection port, a baffle slidably connected to the inner side of the movable groove, and a sliding groove opened on the front side of the box body; the sliding groove passes through the inner side of the movable groove, and the baffle is fixed with a shift bar on the side facing the sliding groove.

[0014] In a preferred embodiment of the present invention, the diameter of the baffle is the same as the diameter of the detection port, and a sealing ring is provided at the connection.

[0015] In a preferred embodiment of the present invention, a filter is installed on the inner side of the air inlet, and the filtering accuracy of the filter is 200-400 μm.

[0016] In a second aspect, the present invention provides a method for using a portable box for collecting and measuring radioactive gases, comprising the following steps:

[0017] S1. Place the box in the test environment for passive diffusion, so that the radioactive gas enters the adsorption main chamber through the air inlet and the air inlet cavity in sequence, and is captured by the adsorption bed;

[0018] S2. During sampling or before measurement, start the drive controller to drive the piezoelectric ceramic oscillator in an intermittent oscillation mode to generate normal mechanical vibration toward the adsorption main cavity;

[0019] S3. Connect the measuring end of the detector to the detection port to perform overall radioactivity measurement.

[0020] In a preferred embodiment of the present invention, in step S2, a single oscillation period of the intermittent oscillation mode is 2-4 seconds for operation and 8-10 seconds for stop; and the oscillation period is 5-10 times.

[0021] In a preferred embodiment of the present invention, in step S2, the driving signal of the piezoelectric ceramic oscillating piece is a square wave pulse with a frequency of 38-40 kHz.

[0022] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0023] (1) The present invention provides a portable box and method for collecting and measuring radioactive gases. By integrating a number of piezoelectric ceramic oscillating plates on the outer wall of the adsorption main chamber and cooperating with the sloped bottom surface of the adsorption main chamber, the concentration gradient problem caused by insufficient diffusion rate in traditional passive diffusion sampling can be effectively solved. Compared with the improved method in the prior art that simply relies on extending the sampling time or increasing the flow rate, the gas can be evenly distributed without changing the sampling conditions, thereby significantly improving the concentration uniformity of the adsorbent bed under short-time sampling conditions, further ensuring the accuracy and representativeness of subsequent measurement results, thereby shortening the time required for gas homogenization and improving the system response speed.

[0024] (2) The piezoelectric ceramic oscillator in the present invention is installed on the outer wall of the box body located in the adsorption main cavity, and adopts a non-contact driving method, which avoids direct contact between mechanical parts and adsorbent, and prevents the adsorbent particles from being broken or the bed disturbed which may be caused by the traditional stirring homogenization structure. Compared with the material loss and decreased adsorption efficiency easily caused by mechanical stirring in the prior art, the non-contact vibration can not only maintain the integrity of the adsorbent, but also ensure the structural stability in long-term use, further extending the maintenance cycle and service life.

[0025] (3) The present invention adopts an intermittent oscillation mode by driving the controller, which can significantly reduce the system energy consumption while ensuring the homogenization effect, avoiding the rapid depletion of the battery caused by continuous high-frequency vibration. The intermittent mode can reduce invalid energy consumption in a single sampling, and can achieve thousands of oscillation cycles in conjunction with a lithium polymer battery, further improving the portability and field endurance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0027] Figure 1 is a three-dimensional structural diagram of a preferred embodiment of the present invention;

[0028] Figure 2 This is a half-section structural diagram of the preferred embodiment of the present invention;

[0029] Figure 3 This is a structural diagram of the connection between the air inlet and the air inlet cavity in a preferred embodiment of the present invention;

[0030] In the figure: 1. Box body; 11. Air inlet chamber; 12. Adsorption main chamber; 13. Air outlet chamber; 2. Adsorption bed; 3. Piezoelectric ceramic oscillator; 4. Drive controller; 5. Air inlet; 6. Detection port; 7. Power supply battery; 8. Moving slot; 81. Baffle; 82. Slide slot; 83. Dial; 9. Filter. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0033] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0035] Example 1:

[0036] like Figure 1 、 Figure 2 and Figure 3 As shown, a portable box for collecting and measuring radioactive gas comprises: a box body 1, and an air inlet chamber 11, an adsorption main chamber 12 and an air outlet chamber 13 which are sequentially connected and opened inside the box body 1; the interior of the adsorption main chamber 12 is filled with an adsorption bed 2 for adsorbing and collecting radioactive gas, a plurality of piezoelectric ceramic oscillation plates 3 are installed on the outer wall of the box body 1 opposite to the adsorption main chamber 12, a drive controller 4 is installed on the surface of the box body 1, and the drive controller 4 is electrically connected to the plurality of piezoelectric ceramic oscillation plates 3 through wires; air inlets 5 are provided on both sides of the box body 1 and pass through to the interior of the air inlet chamber 11; a detection port 6 for adapting to the measuring end of the detector is provided on the front of the box body 1 and passes through to the interior of the air outlet chamber 13.

[0037] It should be noted that the bottom surface of the adsorption main chamber 12 is a slope structure, and the bottom surface forms an angle of 15-30° with the horizontal plane, preferably 15°. The inlet height is lower than the outlet height. The sloped adsorption main chamber 12 forms a gravity-assisted flow field through the bottom height difference. Combined with the constant width design, it can reduce the dead volume of gas flow and improve the contact efficiency between gas and adsorbent; the detector adapted to the detection port 6 is preferably suitable for the GFG model CC28 nuclide gas measurement detector; the model of the piezoelectric ceramic oscillator 3 is preferably DEVEY; the box body 1 is preferably 6061-T6 aluminum alloy or PEEK engineering plastic. The former uses high strength and lightweight characteristics to adapt to portable scenarios, and the latter relies on radiation resistance and chemical inertness to meet the needs of complex environments.

[0038] Specifically, when passively diffusing and collecting radioactive gas, the radioactive gas enters the air inlet chamber 11 through the air inlet 5, initially reduces its flow rate, and then flows into the adsorption main chamber 12. The sloped adsorption main chamber 12 uses gravity and spatial gradients to promote the migration of gas to the outlet. The mechanical and chemical properties of the box body 1 material ensure the structural stability and service life of the equipment during field operations. At the same time, the drive controller 4 controls the vibration generated by the plurality of piezoelectric ceramic oscillating pieces 3 to be transmitted to the adsorption main chamber 12 through the chamber wall, thereby destroying the laminar boundary layer of the gas in the adsorption bed 2, making the gas distribution more uniform, and thereby reducing the concentration gradient during short-term sampling.

[0039] When measuring the collected radioactive gas, the measuring end of the detector adapted to the detection port 6 is placed inside the detection port 6, and a number of piezoelectric ceramic oscillating plates 3 are controlled by the driving controller 4 to generate high-frequency mechanical vibrations that are transmitted to the adsorption bed 2 through the cavity wall, triggering micro-acoustic flow effects and local turbulence in the pores, which can destroy the laminar diffusion boundary layer of gas molecules. At the same time, the sloped bottom surface causes the vibration energy to be transmitted in a directional manner toward the outlet, synergistically promoting the migration of gas to the low concentration area, accelerating the concentration balance in the bed, and effectively solving the concentration gradient problem caused by insufficient diffusion rate in traditional passive diffusion sampling during measurement. Compared with the improved method in the existing technology that simply relies on extending the sampling time or increasing the flow rate, uniform gas distribution can be achieved without changing the sampling conditions, thereby significantly improving the concentration uniformity of the adsorbent bed under short-time sampling conditions, further ensuring the accuracy and representativeness of subsequent measurement results, thereby shortening the time required for gas homogenization and improving the system response speed.

[0040] In this embodiment, the adsorption bed 2 is composed of metal organic framework particles and is vibrated and filled to form a porous structure; the tap density is 0.4-0.5 g / cm3, and the porosity is 37-45%.

[0041] It should be noted that the metal organic framework particle MOF material is preferably ZIF-8, and the filling adopts the layered vibration filling method, that is, 10 Hz low-frequency vibration is used, and filling is divided into 3 layers. After each layer is filled, it is left to stand for 2 minutes to eliminate particle agglomeration, and the preferred tap density is controlled to be 0.45 g / cm3 and the porosity is 40%.

[0042] Specifically, the adsorption bed 2 uses ZIF-8 as the core adsorption material, and radioactive gases (such as Rn-222) are captured by the adsorption bed 2. The porous structure provides a high specific surface area and quickly adsorbs gas molecules. When the ultrasonic vibration is activated, the micro-acoustic flow effect induces local turbulence in the pores, destroying the diffusion restriction, thereby improving the adsorption capacity and adsorption uniformity.

[0043] In this embodiment, the drive controller 4 includes a microcontroller and an H-bridge drive chip; a power supply battery 7 is installed inside the box body 1, and the power supply battery 7 is electrically connected to the drive controller 4 through a wire.

[0044] It should be noted that the microcontroller is preferably STM32L071 (low-power MCU), and the H-bridge driver chip adopts DRV2603 to achieve efficient electrical signal conversion; the power supply battery 7 is preferably a 3.7V lithium polymer type, and the driving voltage is ensured to be stable through the voltage stabilizing circuit; the control circuit of the drive controller 4 can be implemented by simple programming by technicians in this field, which is common knowledge in this field, so this application document no longer explains the control method and circuit connection in detail, and no specific details are given here.

[0045] Specifically, during sampling or before measurement, the user starts the drive controller 4, and the microcontroller generates a square wave signal, which is amplified by the H-bridge driver chip to drive the piezoelectric ceramic oscillator 3, generating normal mechanical vibration, which is transmitted to the adsorption bed 2 through the cavity wall to induce the micro-acoustic flow effect, destroying the laminar diffusion boundary layer of gas molecules, and coordinating the directional energy transfer of the slope cavity to achieve rapid homogenization of gas concentration.

[0046] In this embodiment, a closing assembly is provided on the inner side of the detection port 6, and the closing assembly includes: a movable groove 8 opened at the top of the inner side of the detection port 6, a blocking piece 81 slidably connected to the inner side of the movable groove 8, and a sliding groove 82 opened on the front side of the box body 1; the sliding groove 82 passes through the inner side of the movable groove 8, and a shift bar 83 is fixed on the side of the blocking piece 81 facing the sliding groove 82.

[0047] It should be noted that the diameter of the baffle 81 is the same as the diameter of the detection port 6, and a sealing ring is provided at the connection, which is preferably a Φ20mm×2mm fluororubber O-ring; wherein, when the baffle 81 is in the non-measuring state, the user moves the dial 83 to make the baffle 81 close the detection port 6.

[0048] Specifically, in the non-measurement state, the baffle 81 is closed and compresses the sealing ring to isolate external pollution; during measurement, the user slides the dial bar 83 to make the dial bar 83 slide in the slide groove 82, driving the baffle 81 to rise into the movable groove 8, exposing the detection port 6 for the detector to be inserted, quickly docking, and improving operability.

[0049] In this embodiment, a filter screen 9 is installed inside the air inlet 5 , and the filtering accuracy of the filter screen 9 is 200-400 μm.

[0050] Specifically, when the gas enters, the filter 9 physically intercepts impurities such as dust, protecting the adsorption bed 2 from pollution, thereby reducing particle clogging of the adsorption bed 2 and increasing its service life.

[0051] Example 2:

[0052] A method for using a portable box for collecting and measuring radioactive gases comprises the following steps:

[0053] S1. Place the box body 1 in the test environment for passive diffusion, so that the radioactive gas enters the adsorption main chamber 12 through the air inlet 5 and the air inlet chamber 11 in sequence, and is captured by the adsorption bed 2;

[0054] S2. During sampling or before measurement, the drive controller 4 is started to drive the piezoelectric ceramic oscillating piece 3 in an intermittent oscillation mode to generate normal mechanical vibration toward the adsorption main cavity 12;

[0055] S3. Connect the measuring end of the detector to the detection port 6 to perform overall radioactivity measurement.

[0056] In this embodiment, in step S2, the single oscillation period of the intermittent oscillation mode is 2-4s on and 8-10s off; the oscillation period is 5-10 times; the driving signal of the piezoelectric ceramic oscillating piece 3 is a square wave pulse with a frequency of 38-40kHz.

[0057] Specifically, after the user places the box at the test point, passive diffusion allows the gas to enter the adsorption chamber; oscillation is started to destroy the concentration gradient, and finally the detector is docked to measure the overall radioactivity. The operation is simple. In 5 minutes of sampling, the uniformity within 30 seconds of oscillation is >95%, and the measurement result deviation is <5%. It also has low energy consumption and is suitable for portable and rapid deployment.

[0058] Among them, by adopting the intermittent oscillation mode, the system energy consumption can be significantly reduced while ensuring the equalization effect, avoiding the rapid depletion of the battery caused by continuous high-frequency vibration. The intermittent mode can reduce invalid energy consumption in a single sampling, and can achieve thousands of oscillation cycles in conjunction with the lithium polymer battery, further improving the portability and field endurance of the equipment.

[0059] The above description is based on the ideal embodiment of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered as illustrative and non-restrictive in all respects. The scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0060] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A portable box for collecting and measuring radioactive gases, characterized in that include: A box body, and an air inlet cavity, an adsorption main cavity and an air outlet cavity which are sequentially connected and opened inside the box body; The interior of the adsorption main chamber is filled with an adsorption bed for adsorbing and collecting radioactive gases. The outer wall of the box body facing the main adsorption chamber is mounted with a plurality of piezoelectric ceramic oscillating plates. A drive controller is mounted on the surface of the box body. The drive controller is electrically connected to the plurality of piezoelectric ceramic oscillating plates via wires. Air inlets are provided on both sides of the box body and pass through to the interior of the air inlet cavity; a detection port for adapting to the measuring end of the detector is provided on the front side of the box body and passes through to the interior of the air outlet cavity.

2. A portable box for collecting and measuring radioactive gases according to claim 1, characterized in that: The bottom surface of the main adsorption chamber is a slope structure, and the bottom surface forms an angle of 15-30 degrees with the horizontal plane, and the inlet height is lower than the outlet height.

3. A portable box for collecting and measuring radioactive gases according to claim 1, characterized in that: The adsorption bed is composed of metal organic framework particles and is vibrated to form a porous structure; the tap density is 0.4-0.5g / cm 3 , the porosity is 37-45%.

4. A portable box for collecting and measuring radioactive gases according to claim 1, characterized in that: The drive controller includes a microcontroller and an H-bridge drive chip; a power supply battery is installed inside the box body, and the power supply battery is electrically connected to the drive controller through a wire.

5. The portable box for collecting and measuring radioactive gas according to claim 1, characterized in that: A closing assembly is provided on the inner side of the detection port, and the closing assembly includes: a movable groove opened at the top of the inner side of the detection port, a blocking piece slidably connected to the inner side of the movable groove, and a sliding groove opened on the front side of the box body; the sliding groove passes through the inner side of the movable groove, and the blocking piece is fixed with a shift bar on the side facing the sliding groove.

6. A portable box for collecting and measuring radioactive gases according to claim 5, characterized in that: The diameter of the baffle is the same as that of the detection port, and a sealing ring is provided at the connection.

7. The portable box for collecting and measuring radioactive gas according to claim 1, characterized in that: A filter screen is installed on the inner side of the air inlet, and the filtering accuracy of the filter screen is 200-400 μm.

8. A method for using a portable box for collecting and measuring radioactive gas according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Place the box in the test environment for passive diffusion, so that the radioactive gas enters the adsorption main chamber through the air inlet and the air inlet cavity in sequence, and is captured by the adsorption bed; S2. During sampling or before measurement, start the drive controller to drive the piezoelectric ceramic oscillator in an intermittent oscillation mode to generate normal mechanical vibration toward the adsorption main cavity; S3. Connect the measuring end of the detector to the detection port to perform overall radioactivity measurement.

9. The method for using the portable box for collecting and measuring radioactive gas according to claim 8, characterized in that: In the step S2, a single oscillation period of the intermittent oscillation mode is 2-4 seconds for operation and 8-10 seconds for rest; and the oscillation period is 5-10 times.

10. The method for using the portable box for collecting and measuring radioactive gas according to claim 8, characterized in that: In step S2, the driving signal of the piezoelectric ceramic oscillating piece is a square wave pulse with a frequency of 38-40 kHz.

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