A card-type radioactive aerosol monitor

Abstract

This invention relates to the field of nuclear radiation monitoring and protection, and provides a plug-in type radioactive aerosol monitor, including a plug-in type aerosol detection device, a signal processing and expansion unit, an electronic control unit, a terminal display and communication expansion unit, a differential pressure sensor, and a sampling system. The plug-in type aerosol detection device has a differential pressure sensor connected in parallel at both ends. The signal processing and expansion unit processes the aerosol detector signal and flow signal to identify radioactive aerosol nuclides and calculate the activity concentration of characteristic nuclides in each corresponding energy range. The electronic control unit acquires the differential pressure and flow information, executes the control function of the pump in the sampling system, and prompts the user on the status of the filter paper. This invention is convenient to operate, efficient, and easy to maintain; it has a fast measurement response, strong nuclide identification capability, and a natural radon and thorium progeny compensation function; after detecting anomalies, it can retain representative samples in real time, and the sampling analysis results are highly comparable to real-time monitoring values.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation monitoring and protection, specifically to a plug-in type radioactive aerosol monitor. Background Technology

[0002] Various artificial radioactive materials may be present in the operation of nuclear-related sites and in the gaseous exhaust streams of nuclear processes. When these materials enter the atmosphere, they form artificial radioactive aerosols with specific aerodynamic characteristics. The deposition of these aerosols on the skin of workers can cause external radiation exposure, while inhalation can cause internal radiation hazards. Leaks or releases into the atmosphere can cause radiation damage to the public who come into contact with them. Therefore, it is necessary to monitor the activity concentration of artificial radioactive materials in the gaseous exhaust streams of nuclear-related sites and processes to ensure that air quality in areas where personnel are active meets standards and to protect the safety of workers and the public.

[0003] Currently widely used radioactive aerosol monitors generally use filter paper strips for online monitoring or sampling over a period of time before repositioning the sample for measurement. Sampling analysis uses a single filter paper strip for fixed-volume or fixed-time sampling, followed by laboratory physicochemical analysis. These devices generally suffer from problems such as long response times, inability to quickly obtain representative samples after anomalies are detected, and inability to compare the analysis results of periodic routine sampling with real-time monitoring values. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art by providing a card-type radioactive aerosol monitor that can simultaneously monitor and sample radioactive aerosols. The sampling analysis results have good comparability with the monitoring results. Furthermore, the card-type design is easy to operate and has a low failure rate.

[0005] The objective of this invention is achieved through the following technical measures.

[0006] A card-type radioactive aerosol monitor includes a card-type aerosol detection device, a signal processing and expansion unit, an electronic control unit, a terminal display and communication expansion unit, a differential pressure sensor, and a sampling system. The card-type aerosol detection device has a differential pressure sensor connected in parallel across its two ends, which monitors the pressure difference across the aerosol filter paper in real time. The sampling system uses a mass flow meter to measure the sampling flow rate in real time. The signal processing and expansion unit processes the aerosol detector signal and the flow rate signal to identify radioactive aerosol nuclides and calculate the activity concentration of characteristic nuclides in each corresponding energy range. The electronic control unit… The unit acquires differential pressure and flow rate information, executes the control function of the vacuum pump in the sampling system, and prompts the user about the usage status of the filter paper; the plug-in aerosol detection device includes an aerosol detector and an aerosol sampling device. The aerosol detector includes a PIPS (passivated ion implantation planar silicon detector) or a CdZnTe (zinc chromium telluride detector), a charge-sensitive preamplifier circuit, an electrical connector, and a multi-arm collimation device. The PIPS or CdZnTe is arranged differentially, and can be implemented by encapsulating two chips inside a single detector, or by combining two independent detectors; The area and shape of the sensitive zone can be combined and expanded according to requirements. The multi-arm collimation device is close to the front of the aerosol detector, and the arm length and number of arms can be adjusted according to different application requirements. The aerosol sampling device includes an air inlet, a housing, filter paper, a filter paper holder, a lifting arm, a return spring, an air outlet pipe, and a paper replacement base. The housing and the paper replacement base are sealed together. An airtight coaxial connector is installed on the upper end cover of the housing, and the lower opening is an air flow channel. The air inlet is welded to the outside of the housing and communicates with the sampling chamber inside the housing. The aerosol detector uses a multi-arm collimation device, PIPS, or CdZnT. e. The charge-sensitive preamplifier circuit boards are sequentially packaged together and arranged inside the housing. The lifting arm is connected to the paper changing base via a bearing. The connection between the lifting arm and the bearing is an eccentric cam structure. The lower part of the air outlet pipe is fitted with a spring fixing seat, and a return spring is fitted over the spring fixing seat. The spring fixing seat is connected to the bottom end of the paper changing base, so that the return spring maintains a certain amount of compression. A single filter paper is placed on the filter paper holder. When the lifting arm is pressed, the cam acts on the air outlet pipe, and the air outlet pipe compresses the return spring, so that the filter paper holder between the upper end of the air outlet pipe and the lower end of the housing is separated, making it easy to remove and insert the filter paper holder.

[0007] In the above technical solution, the filter paper holder is made of stainless steel and has a honeycomb structure in the central area, which supports the filter paper and does not block the airflow. The filter paper holder is nested in the silicone seal. When the reset spring is reset, it pushes out the air outlet pipe, and the air outlet pipe presses the silicone seal to the bottom of the sampling chamber inside the shell to achieve air path sealing.

[0008] The "insertion-type" method specifically involves inserting a single filter paper for aerosol sampling once, and replacing it with a new filter paper after one measurement cycle. A single filter paper is placed on the filter paper holder, and the lifting arm is operated to achieve the sealing and separation of the filter paper holder and the aerosol detector. The reset spring, in its natural state, provides feedback to the lifting arm, locking the filter paper holder and the aerosol detector, thus sealing the gas path and ensuring the filter paper is ready. The paper replacement base secures the entire aerosol sampling device to the support or target location.

[0009] In the above technical solution, the aerosol detector in the plug-in aerosol detection device has an acid-resistant configuration, which is suitable for long-term use in environments with certain concentrations of acidic gases such as HF acid and NOx.

[0010] In the above technical solution, the aerosol detector in the plug-in aerosol detection device has energy spectrum measurement and natural radon and thorium progeny compensation functions, and can identify artificial alpha radioactive nuclides such as U-235, U-238, Pu-239, Am-241, or Po-210.

[0011] In the above technical solution, the signal processing and expansion unit has the ability to acquire multi-channel signals at high speed and real time with full waveform, and to perform parallel data processing and transformation; it can calculate the activity concentration of radionuclides aerosols corresponding to each energy range in real time based on the energy spectrum analysis technology; it provides expandable data storage and query functions; the extended peripherals have scanning, recognition and input functions; and it supports the standard MODBUS protocol and TCP / IP protocol.

[0012] In the above technical solution, the electronic control unit is connected to the terminal display and communication expansion unit, the air pump, the mass flow meter and the differential pressure sensor. The electronic control unit collects the operating status parameters of the system, receives human-machine interaction instructions from the terminal display and communication expansion unit and issues corresponding execution commands, controls the start and stop of the air pump and its automatic operation, and receives feedback signals; according to the set value, it issues commands to control the mass flow meter and the regulating valve to automatically adjust the valve opening and stabilize the flow at the set value.

[0013] In the above technical solution, the sampling system includes a regulating valve, a mass flow meter, a gas sampling port, a vacuum release valve, and a vacuum pump. When the stability of the operating flow rate is required to be high, the regulating valve and the mass flow meter can be configured as an integrated electric flow controller with feedback function, which is controlled by the electronic control unit. The vacuum pump provides sampling power for the monitoring instrument. A pressure relief protection valve is set at the inlet end of the vacuum pump. The pressure relief protection valve is a one-way opening pressure adjustable type.

[0014] In the above technical solution, the terminal display and communication extension unit interface displays parameters, status indicators, and alarm information for 16 channels, including activity concentration, flow rate, differential pressure, and pump status, providing a user-friendly human-machine interface. The communication extension function enables remote interaction and backup of all measurement information from the monitor, performs parameter reading and configuration of the signal processing and extension unit and the electronic control unit, facilitates wireless communication extension, and enables subsystem networking.

[0015] In the above technical solution, the plug-in type radioactive aerosol monitor is integrated into an open rack, or into a cabinet, or a box, or a modular unit. It can be installed in a floor-standing, wall-mounted, vehicle-mounted, airborne, or shipborne manner, and is widely used in monitoring fields such as laboratories, hot chamber repair workshops, fuel element production and reprocessing, caverns, nuclear emergency response, aerial surveying, and aircraft.

[0016] In the above technical solution, the plug-in type radioactive aerosol monitor is configured in two types: airtight conventional type and tight type. The conventional type meets the requirement of no more than 10. -3 Pa·m 3 The leakage rate is / s, and the leak-proof system meets the requirement of not exceeding 10. -8 Pa·m 3 / s leakage rate, covering different application needs.

[0017] In the above technical solution, the filter paper used in the insert-type radioactive aerosol monitor is marked with a barcode or QR code as a unique identification code. During use, the data can be entered by the external scanning module of the signal processing and expansion unit, and the measurement data will be automatically saved to the corresponding directory of the filter paper for easy retrieval. The filter paper supports both continuous online monitoring and sampling monitoring functions, and is also convenient for laboratory physicochemical analysis and archiving.

[0018] Compared with the prior art, the plug-in type radioactive aerosol monitor of the present invention has the following advantages:

[0019] First, a card-insertion aerosol detection device was creatively designed. Under the action of a lifting arm and a return spring, aerosol sampling and measurement are performed using a single insertion of a single filter paper. The device offers fast measurement response, simple operation, and high reliability. The measured object is also the sampling object, resulting in high sampling real-time performance and representativeness, and good comparability between sampling analysis results and monitoring results.

[0020] Second, the airtightness of the monitoring instrument's sampling system meets the general and extreme requirements of online monitoring equipment, with a leakage rate not exceeding 10%. -8 Pa·m 3 / s, meeting relevant requirements such as monitoring of highly toxic radioactive aerosols of Po-210 in lead-based reactors.

[0021] Third, the system features a modular design, high integration, small size, rich expansion functions, and novel combination methods. It can meet the diverse application needs of various nuclear-related locations and is widely used in laboratories, hot chamber repair workshops, fuel element production and reprocessing, underground storage, nuclear emergency response, aerial surveying, and other related monitoring fields. It has a promising market prospect and high promotion value.

[0022] In summary, this invention features a simple structure, convenient operation, high efficiency, and easy maintenance; modular design, high integration, strong scalability, and wide applicability; fast measurement response, strong nuclide identification capability, and compensation function for natural radon and thorium daughter bodies; and the ability to retain representative samples in real time after anomalies are detected, with good comparability between sampling analysis results and real-time monitoring values. Attached Figure Description

[0023] Figure 1 This is a schematic diagram illustrating the principle of the plug-in type radioactive aerosol monitor according to an embodiment of the present invention.

[0024] Figure 2 This is a cross-sectional view of the insert-type aerosol detection device in an embodiment of the present invention.

[0025] The components include: 1. Insert-type aerosol detection device; 2. Signal processing and expansion unit; 3. Terminal display and communication expansion unit; 4. Electrical control unit; 5. Mass flow meter; 6. Differential pressure sensor; 7. Regulating valve; 8. Pressure relief protection valve; 9. Air pump; 10. Coaxial connector; 11. Air inlet; 12. Housing; 13. Concave sampling chamber; 14. Lifting arm; 15. Filter paper holder; 16. Air outlet fitting; 17. Reset spring; 18. Air outlet; 19. Paper replacement base. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0027] like Figure 1 As shown, this embodiment of the invention provides a card-type radioactive aerosol monitor, including a card-type aerosol detection device 1, a signal processing and expansion unit 2, an electronic control unit 4, a terminal display and communication expansion unit 3, a differential pressure sensor 6, and a sampling system.

[0028] In this embodiment, the air pump 9 provides sampling power for the monitoring instrument. The sampling inlet and outlet are shown in the direction of the arrows. The inlet and outlet can provide interfaces with external air pipelines or be directly connected to the ambient atmosphere of the target area. The pressure relief valve 8 at the inlet end of the air pump 9 is a one-way opening pressure adjustable type to prevent impact on the pump under unexpected operating conditions and protect the air pump.

[0029] When the sampling gas passes through the insert-type aerosol detector 1, it enters the concave sampling chamber 13 through the inlet 11, passes through the filter paper on the filter paper holder 15, and then flows out from the outlet 18. Simultaneously with aerosol sampling, the aerosol detector directly opposite the filter paper continuously measures it. The aerosol detector and the signal processing and expansion unit are connected via two pairs of coaxial connectors 10 for power supply and signal transmission.

[0030] The differential pressure sensor 6, connected in parallel across the two ends of the plug-in aerosol detector, monitors the pressure difference across the aerosol filter paper in real time, while the mass flow meter 5 measures the system sampling flow rate in real time. The signal processing and expansion unit 2 performs comprehensive processing on the aerosol detector signal and flow signal, identifies artificial and natural radon and thorium progeny radioactive aerosol nuclides such as U-235, U-238, Pu-239, Am-241, and Po-210, and calculates the activity concentration of characteristic nuclides in each corresponding energy range. The electronic control unit 4 acquires the pressure difference and flow information, executes the control function of the air pump, prompts the user on the status of the filter paper, and issues commands to control the flow meter and regulating valve to automatically adjust the valve opening according to the set value, stabilizing the flow rate at the set value.

[0031] The terminal display and communication expansion unit 3 connects the electronic control unit and the signal processing and expansion unit, completing integrated display, human-machine interaction, and communication expansion functions. The terminal interface displays monitoring parameters such as activity concentration, flow rate, and differential pressure, as well as operating status indicators and alarm information; it provides a user-friendly human-machine interface, enabling functions such as pump start / stop control, real-time energy spectrum acquisition and analysis, calibration, and historical record query. The communication expansion function enables remote interaction and redundant backup of key measurement information from the monitor, remote parameter reading and configuration of the signal processing and expansion unit and electronic control unit, wireless communication expansion, and subsystem networking.

[0032] The conventional airtight plug-in type radioactive aerosol monitor sampling system uses a stainless steel tube, compression fitting, metal hose, and sealing ring structure. Equipped with a single diaphragm pump, the overall leakage rate can be kept to no more than 10%. -3 Pa·m 3 / s; The sampling system of the tight-fitting plug-in type radioactive aerosol monitor uses welded stainless steel pipes, and irregularly shaped pipe fittings are made by physical bending or mold casting. Combined with a high-performance dual-diaphragm vacuum pump, the overall system leakage rate is no greater than 10%. -8 Pa·m 3 / s.

[0033] like Figure 2 As shown, the insert-type aerosol detection device includes an air inlet 11, a housing 12, an aerosol detector, filter paper, a filter paper holder 15, a lifting arm 14, a reset spring 17, an air outlet pipe 18, a paper replacement base 19, etc.

[0034] A sealing ring is provided between the housing 12 and the paper-changing base 19, and they are connected by a screw to achieve fastening and sealing. The housing 12 is cylindrical with openings at both ends and has a concave internal structure. An airtight coaxial connector 10 is installed on the upper end cover, and the lower opening is an air flow channel. The air inlet 11 is welded to the outside of the housing and communicates with the concave sampling chamber 13 inside the housing to form an air flow channel.

[0035] The aerosol detector is located outside the concave sampling chamber 13, and its lower end is sealed to the housing 12 by a sealing ring and a sealing sheet. The multi-arm collimator, PIPS or CdZnTe detector, and preamplifier circuit board in the aerosol detector are packaged together in sequence. The circuit board is connected to the coaxial connector 10 at the top of the end cover through wiring to provide power and transmit signals.

[0036] The paper changing base 19 is fixed to the corresponding main structure by screws on the back. The lifting arm 14 is connected to the paper changing base 19 via a KR12 bearing, and the connection between the lifting arm 14 and the bearing is an eccentric cam structure. When the lifting arm 14 is pressed, the cam acts on the air outlet pipe 18, which compresses the return spring 17, causing the filter paper holder 15 between the upper end of the air outlet pipe 18 and the lower end of the housing 12 to separate, facilitating the removal and insertion of the holder. The air outlet pipe 18 is a one-piece machined stainless steel part, and the contact surface with the filter paper holder 15 is polished to a surface roughness of no more than 0.8μm and is designed with a limit auxiliary guide, allowing the filter paper holder 15 to be blindly inserted.

[0037] The filter paper holder 15 is made of stainless steel and has a honeycomb structure in the central area. It supports the filter paper and does not block the airflow. The filter paper holder 15 is nested in the silicone seal. When the reset spring 17 is reset, it pushes out the air outlet pipe 18. The air outlet pipe 18 presses the silicone seal to the bottom of the concave sampling chamber 13 to achieve air path sealing.

[0038] The lower part of the air outlet pipe 18 is fitted with a spring fixing seat, and the spring fixing seat is fitted with a return spring 17. The spring fixing seat is connected to the bottom end of the paper changing base 19 through a screw, so that the return spring 17 maintains a certain amount of compression. The spring fixing seat slides tightly with the outlet pipe, which plays the role of limiting and preventing the return spring 17 from moving laterally.

[0039] The "insertion-type" method specifically involves inserting a single filter paper for aerosol sampling once, and replacing it with a new filter paper after one measurement cycle. A single filter paper is placed on the filter paper holder, and the lifting arm is operated to achieve the sealing and separation of the filter paper holder and the aerosol detector. The reset spring, in its natural state, provides feedback to the lifting arm, locking the filter paper holder and the aerosol detector, thus sealing the gas path and ensuring the filter paper is ready. The paper replacement base secures the entire aerosol sampling device to the support or target location.

[0040] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A card-type radioactive aerosol monitor, characterized in that: The system includes a card-type aerosol detector, a signal processing and expansion unit, an electronic control unit, a terminal display and communication expansion unit, a differential pressure sensor, and a sampling system. The card-type aerosol detector has a differential pressure sensor connected in parallel at both ends, which monitors the pressure difference across the aerosol filter paper in real time. The mass flow meter in the sampling system measures the sampling flow rate in real time. The signal processing and expansion unit processes the aerosol detector signal and flow rate signal, identifies the radioactive aerosol nuclides, and calculates the activity concentration of characteristic nuclides in each corresponding energy range. The electronic control unit acquires the pressure difference and flow rate information, executes the control function of the vacuum pump in the sampling system, and prompts the user about the filter paper's usage status. The card-type aerosol detector includes an aerosol detector and an aerosol sampling device. The aerosol detector includes a PIPS or CdZnTe, a charge-sensitive preamplifier circuit, an electrical connector, and a multi-arm collimation device. The PIPS or CdZnTe is arranged differentially, and the area and shape of the sensitive region can be combined and expanded according to requirements. The multi-arm collimation device is close to the aerosol detector. The aerosol sampling device, with its arm length and number adjusted according to different application requirements, includes an air inlet, housing, filter paper, filter paper holder, lifting arm, reset spring, air outlet pipe, and paper replacement base. The housing and paper replacement base are sealed together. An airtight coaxial connector is installed on the upper end cover of the housing, and the lower opening serves as an airflow channel. The air inlet is welded to the outside of the housing and communicates with the sampling chamber inside. The multi-arm collimation device, PIPS or CdZnTe, and charge-sensitive preamplifier circuit board in the aerosol detector are arranged in the following order: The components are packaged together and arranged inside the housing. The lifting arm is connected to the paper changing base via a bearing. The connection between the lifting arm and the bearing is an eccentric cam structure. The lower part of the air outlet pipe is fitted with a spring fixing seat, and the spring fixing seat is fitted with a return spring. The spring fixing seat is connected to the bottom end of the paper changing base, so that the return spring maintains a certain amount of compression. A single sheet of filter paper is placed on the filter paper holder. When the lifting arm is pressed, the cam acts on the air outlet pipe, and the air outlet pipe compresses the return spring, so that the filter paper holder between the upper end of the air outlet pipe and the lower end of the housing is separated, making it easy to remove and insert the filter paper holder.

2. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The filter paper holder is made of stainless steel with a honeycomb structure in the center, which supports the filter paper without obstructing airflow. The filter paper holder is nested in the silicone seal. When the reset spring is reset, it pushes out the air outlet pipe, which presses the silicone seal to the bottom of the sampling chamber inside the housing, thus achieving a gas path seal.

3. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The aerosol detector in the plug-in aerosol detection device has an acid-resistant configuration, making it suitable for long-term use in acidic gas environments.

4. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The aerosol detector in the plug-in aerosol detection device has energy spectrum measurement and natural radon and thorium progeny compensation functions, and can identify artificial alpha radioactive U-235, U-238, Pu-239, Am-241, or Po-210 nuclides.

5. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The signal processing and expansion unit features high-speed real-time full-waveform acquisition of multi-channel signals, parallel data processing and transformation; an algorithm based on energy spectrum analysis technology calculates the activity concentration of radionuclides aerosols in real time for each energy range; provides scalable data storage and query functions; and supports standard MODBUS and TCP / IP protocols.

6. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The electronic control unit is connected to the terminal display and communication expansion unit, the air pump, the mass flow meter, and the differential pressure sensor. The electronic control unit collects the operating status parameters of the system, receives human-machine interaction commands from the terminal display and communication expansion unit and issues corresponding execution commands, controls the start and stop of the air pump and its automatic operation, and receives feedback signals. According to the set value, it issues commands to control the mass flow meter and the regulating valve to automatically adjust the valve opening and stabilize the flow rate at the set value.

7. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The sampling system includes a regulating valve, a mass flow meter, a gas sampling port, a vacuum release valve, and a vacuum pump. The regulating valve and the mass flow meter are configured as an integrated electric flow controller with feedback function, controlled by an electronic control unit. The vacuum pump provides sampling power to the monitoring instrument. A pressure relief protection valve is installed at the inlet end of the vacuum pump. The pressure relief protection valve is a one-way opening pressure adjustable type.

8. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The terminal display and communication extension unit interface displays parameters, status indicators, and alarm information for 16 channels, including activity concentration, flow rate, differential pressure, and pump status. The communication extension function enables remote interaction and backup of all measurement information of the monitor, performs parameter reading and configuration of the signal processing and extension unit and the electronic control unit, wireless communication extension, and subsystem networking.

9. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The plug-in type radioactive aerosol monitor can be integrated into an open rack, a cabinet, a box, or a modular unit, and can be installed in a floor-standing, wall-mounted, vehicle-mounted, airborne, or shipborne manner.

10. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The plug-in type radioactive aerosol monitor is available in two types: airtight (standard) and tight (high-tight). The standard type meets the requirement of a total density of no more than 10. -3 Pa·m 3 The leakage rate is / s, and the leak-proof system meets the requirement of not exceeding 10. -8 Pa·m 3 / s leakage rate, covering different application needs.

11. The card-type radioactive aerosol monitor according to claim 1, characterized in that: The filter paper used in the plug-in type radioactive aerosol monitor is marked with a barcode or QR code as a unique identification code. During use, it can be entered by the external scanning module of the signal processing and expansion unit. The measurement data will be automatically saved to the directory corresponding to the filter paper. The filter paper supports both continuous online monitoring and sampling monitoring functions.

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