Passive explosive detection apparatus

Abstract

This invention provides a passive explosive detector, comprising a body, a heating head assembly, a detection assembly, a ventilation duct, and a swirl component. The heating head assembly is disposed at one end of the body and has a heating chamber formed within it. The detection assembly is disposed within the body. The ventilation duct has an inlet air duct and an outlet air duct. The inlet air duct connects the heating chamber to the outside, and the outlet air duct connects the heating chamber and the detection assembly. The swirl component is located in the inlet air duct, or between the inlet air duct and the heating chamber. The passive explosive detector of this invention has the advantage of accurate detection results.

Description

Technical Field

[0001] This invention relates to the field of explosives detectors, and more particularly to a passive explosives detector. Background Technology

[0002] Explosive detectors are commonly used equipment in the security inspection field, and are considered one of the three major security inspection products along with X-ray security scanners and walk-in security gates. These detectors primarily rely on ion mobility spectrometry (IMS) technology to achieve efficient detection and identification of explosive gas molecules. IMS is an effective method for rapidly analyzing trace amounts of chemical substances, particularly suitable for detecting explosives, drugs, and other hazardous materials. This technology measures the migration behavior of ions in a sample within an electric field, and uses the differences in migration rates of different ions under a specific electric field to achieve qualitative and quantitative analysis of the substance. Passive explosive detectors utilize this principle, integrating multiple functional modules such as detection and analysis, identification and alarm, and human-computer interaction, aiming to provide an efficient and accurate security inspection method.

[0003] However, in practical applications, the detector is susceptible to various problems during operation. On the one hand, the distribution of explosive gas molecules is uneven, and on the other hand, the detector is easily affected by vibration, which affects the accuracy and reliability of the detection results. Summary of the Invention

[0004] This invention provides a passive explosive detector to solve the problems of uneven distribution of explosive gas during operation and easy interference from vibration factors that affect the detection results in existing passive explosive detectors.

[0005] This invention provides a passive explosives detector, comprising: Organism; A heating head assembly is disposed at one end of the machine body, and a heating cavity is formed within the heating head assembly; The detection components are housed within the machine body; The ventilation duct has an internal air inlet duct and an air outlet duct. The air inlet duct connects the heating chamber to the outside, and the air outlet duct connects the heating chamber to the detection component. The swirl component is located in the air inlet duct, or between the air inlet duct and the heating chamber.

[0006] In some embodiments, the air inlet duct surrounds the outer periphery of the air outlet duct, a blower is provided at the end of the air inlet duct away from the heating chamber, and an exhaust fan is provided at the end of the detection component away from the air outlet duct.

[0007] In some embodiments, the swirl component includes: An air guide component has a vent and an air guide cavity, the vent being connected to the air inlet duct and the air guide cavity being connected to the heating cavity; Multiple blades are spaced apart on the outer periphery of the vent to guide the airflow at the vent to the periphery of the vent and into the air guide cavity.

[0008] In some embodiments, the inner wall surface of the air guide includes: A tapered surface, the inner diameter of which gradually increases along the direction from the ventilation duct to the heating head assembly; An annular surface, wherein the annular surface is connected to the end of the conical surface that is away from the ventilation duct; The blades are used to guide the airflow at the vent to the conical surface.

[0009] In some embodiments, the air guide is provided with an annular groove corresponding to the ventilation opening, the blade is installed in the annular groove, an annular baffle is provided on the side of the blade away from the ventilation pipe, and the air outlet duct passes through the ventilation opening and the annular baffle.

[0010] In some embodiments, the outlet of the detection component is connected to the inlet of the exhaust fan via a connecting pipe, which is a flexible pipe.

[0011] In some embodiments, at least a portion of the inner diameter of the connecting pipe gradually increases along the direction from the detection component to the exhaust fan.

[0012] In some embodiments, the passive explosive detector includes: Multiple support components are snapped into the ventilation pipe; The shock absorber is provided in a one-to-one correspondence with the plurality of the support members, and the shock absorber is located between the support member and the ventilation pipe.

[0013] In some embodiments, a plurality of the supports are arranged at intervals, and a groove is provided on one of the outer peripheral surface of the ventilation duct and the surface of the support, and a protrusion is provided on one of the outer peripheral surface of the ventilation duct and the surface of the support, the protrusion extending into the groove.

[0014] In some embodiments, the passive explosive detector includes: A flow guide is provided inside the air guide cavity. The flow guide has a flow guide port and a flow guide cavity. The flow guide port is connected to the inlet of the air outlet duct, and the flow guide cavity is connected to the heating cavity.

[0015] First, the passive explosive detector of this invention, by setting a swirling component, forces the external airflow to form a swirling flow before entering the heating chamber, thereby significantly enhancing the disturbance effect of the airflow in the heating chamber. This allows the analyte to be heated and volatilized in the heating chamber to be more evenly distributed in the airflow, avoiding sampling deviations caused by uneven local concentrations.

[0016] Secondly, the passive explosive detector of this invention introduces a swirling flow into the heating chamber, which can improve the mixing efficiency between the molecules of the substance to be detected and the airflow under the premise of the same sample volatilization concentration. This increases the number of molecules of the substance to be detected entering the detection component per unit time, thereby improving the detection sensitivity and the accuracy of the results, and ensuring that the passive explosive detector can maintain high-precision detection capabilities.

[0017] Furthermore, since swirling can smooth the airflow path and reduce the occurrence of turbulence, making the airflow more orderly and stable, this also helps to reduce unnecessary vibration, thereby reducing the impact of vibration on the detection components and improving the accuracy of the detection results. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention 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 invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a half-section structural diagram of the passive explosive detector provided by the present invention.

[0020] Figure 2 This is a schematic diagram of the passive explosives detector provided by the present invention.

[0021] Figure 3 This is a schematic diagram of the installation of the support components and connecting pipes of the passive explosive detector provided by the present invention.

[0022] Figure 4 This is a schematic diagram of the swirling component of the passive explosives detector provided by the present invention.

[0023] Figure 5 This is a half-sectional structural diagram of the swirl component of the passive explosive detector provided by the present invention.

[0024] Figure 6 This is a schematic diagram of the blades and annular baffle of the passive explosive detector provided by the present invention.

[0025] Figure 7 This is a schematic diagram of the air guide component of the passive explosive detector provided by the present invention.

[0026] Figure 8 This is a schematic diagram of the swirling component and the flow guide of the passive explosive detector provided by the present invention.

[0027] Figure 9 This is a gas flow path diagram of the passive explosive detector provided by the present invention.

[0028] Figure label: 100. Passive explosive detector; 1. Main body; 2. Heating head assembly; 21. Heating chamber; 3. Detection assembly; 4. Ventilation duct; 41. Air inlet duct; 42. Air outlet duct; 5. Swirl component; 51. Air guide component; 511. Ventilation opening; 512. Air guide cavity; 513. Annular groove; 514. Conical surface; 515. Annular surface; 52. Blade; 53. Annular baffle; 6. Blower; 7. Exhaust fan; 8. Connecting pipe; 9. Support component; 10. Flow guide component; 11. Flow guide port; 12. Flow guide cavity; 13. Return air component; 130. First air inlet; 131. Return air outlet; 132. Return air chamber; 133. Return air switch; 14. Second air inlet. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] like Figures 1 to 9 As shown, the passive explosive detector 100 of this embodiment of the invention includes a body 1, a heating head assembly 2, a detection assembly 3, a ventilation pipe 4, and a swirl component 5.

[0031] The heating head assembly 2 is located at one end of the body 1, and a heating cavity 21 is formed inside the heating head assembly 2.

[0032] The detection component 3 is located inside the body 1.

[0033] The ventilation duct 4 forms an air inlet duct 41 and an air outlet duct 42 inside. The air inlet duct 41 connects the heating chamber 21 to the outside, and the air outlet duct 42 connects the heating chamber 21 to the detection component 3.

[0034] The swirl component 5 is located in the air inlet duct 41, or between the air inlet duct 41 and the heating chamber 21.

[0035] For ease of description, the left and right directions are taken as the extension directions of the machine body 1, where the left and right directions are as follows: Figure 1 As shown.

[0036] The heating head assembly 2 is located at the left end of the body 1. It has a heating chamber 21 inside for containing and heating the sample. The heating head assembly 2 includes an end cap and a heating element. The end cap is opened to put the sample into the heating chamber 21, and the heating element is used to ignite the sample.

[0037] External airflow enters the heating chamber 21 through the air inlet duct 41 in the ventilation pipe 4, and mixes thoroughly with the test substance after combustion in the heating chamber 21 to form a high-temperature airflow carrying the test substance molecules. Subsequently, the high-temperature airflow is delivered to the detection component 3 through the air outlet duct 42. The detection component 3 analyzes and identifies the composition of the test substance molecules carried in the airflow to achieve the detection of sample components.

[0038] The detection principle of detection component 3 is based on ion mobility spectrometry (IMS). This technology is a highly sensitive detection method that utilizes the differences in ion mobility of different substances in an electric field for component analysis. Its working process mainly includes: after the gas to be tested enters detection component 3, its molecules are ionized into charged particles under the action of an ionization source; under the action of a uniform electric field, these ions move towards the electrode at a velocity related to their mass and shape; since different substances have different ion mobilities, they arrive at the detector at different times, forming characteristic migration spectra. By comparing with a database of known substances' migration times, rapid identification and judgment of target molecules such as explosives in the sample can be achieved. Ion mobility spectrometry has advantages such as fast response speed, high sensitivity, and no need for a complex vacuum system, making it particularly suitable for on-site detection of trace explosives.

[0039] In this process, the swirling component 5 is disposed inside the air inlet duct 41 or at the connection between the air inlet duct 41 and the heating chamber 21, so that the airflow entering from the air inlet duct 41 is guided into a swirling flow state when passing through the swirling component 5.

[0040] First, the passive explosive detector 100 provided in this embodiment of the invention, by setting up a swirling component 5, forces the external airflow to form a rotating flow state before entering the heating chamber 21, i.e., a so-called "swirling flow." This swirling flow not only changes the originally relatively straight trajectory of the airflow but also significantly enhances the disturbance effect of the airflow inside the heating chamber 21. Because the swirling flow has a strong lateral diffusion capability, it can effectively disrupt the boundary layer that may form near the wall of the heating chamber 21, thereby promoting a faster and more uniform distribution of molecules released by the analyte after heating throughout the airflow. This avoids sampling deviation problems caused by uneven local concentrations, providing a more stable and reliable gas sample basis for subsequent detection processes.

[0041] Secondly, in this embodiment of the invention, the introduction of swirling flow into the heating chamber 21 not only enhances the fluidity of the airflow itself, but more importantly, significantly improves the mixing efficiency between the analyte molecules and the airflow under the premise of the same sample evaporation concentration. Specifically, the strong disturbance effect brought about by the swirling flow greatly increases the heat and mass transfer rate in the airflow, thereby accelerating the evaporation rate of the target substance in the sample and enhancing its diffusion ability in the airflow. This efficient mixing process directly leads to a significant increase in the number of analyte molecules entering the detection component 3 per unit time, which macroscopically manifests as an enhanced detection signal intensity and a shortened response time. This not only helps to improve the detection sensitivity, but also further ensures the accuracy and repeatability of the detection results, enabling the passive explosive detector 100 to maintain high detection accuracy and stability even under complex environmental conditions.

[0042] Furthermore, from an airflow dynamics perspective, swirling flow exhibits a more orderly and stable flow path compared to ordinary turbulent airflow. This stable airflow state reduces potential instability phenomena such as localized vortices and backflows during airflow operation within the equipment, thereby effectively reducing mechanical vibrations caused by airflow turbulence within the system. Especially for high-precision analysis modules like detection component 3, even minute mechanical vibrations can interfere with the detection signal, affecting the final judgment result. Therefore, by incorporating the swirling flow component 5, not only is the airflow state optimized, but it also objectively achieves vibration reduction and noise reduction, further minimizing the impact of vibration on detection component 3.

[0043] Therefore, the passive explosive detector 100 of this invention has significant advantages such as accurate detection results, high sensitivity, and fast response speed, and has good application prospects and promotion value.

[0044] In some embodiments, such as Figure 1 As shown, the air inlet duct 41 surrounds the outer periphery of the air outlet duct 42. A blower 6 is provided at the end of the air inlet duct 41 away from the heating chamber 21, and an exhaust fan 7 is provided at the end of the detection component 3 away from the air outlet duct 42.

[0045] The ventilation duct 4 includes an inner duct and an outer duct. The inner duct is inserted into the outer duct. The inner circumferential wall of the inner duct defines an air outlet duct 42. The outer circumferential wall of the inner duct and the inner circumferential wall of the outer duct define an air inlet duct 41. The air inlet duct 41 surrounds the outer circumference of the air outlet duct 42, forming a nested duct design. This design not only optimizes the internal space layout of the equipment, but also improves the compactness and efficiency of the airflow path.

[0046] For ease of description, Figure 1 The vertical direction is marked in the middle. Both the supply fan 6 and the exhaust fan 7 are located below the ventilation duct 4.

[0047] A blower 6 is provided at the end of the air inlet duct 41 away from the heating chamber 21, that is, a blower 6 is provided at the right end of the air inlet duct 41. The blower 6 is used to forcefully push outside air into the heating chamber 21. The detection component 3 is located at the right end of the air outlet duct 42. The end of the detection component 3 away from the air outlet duct 42 is equipped with an exhaust fan 7. That is, the right end of the detection component 3 is equipped with an exhaust fan 7. The exhaust fan 7 can ensure that the high temperature airflow containing the molecules of the substance to be tested coming out of the heating chamber 21 can be effectively extracted and transported to the detection component 3 through the air outlet duct 42.

[0048] The passive explosive detector 100 of this invention incorporates a coordinated driving mechanism of a blower 6 and an exhaust fan 7 in its overall structural design, significantly enhancing the flow performance and velocity of the airflow throughout the detection process. This design allows fresh external air to be introduced into the device at higher pressure and a more stable flow rate, thoroughly mixing with the analyte volatilized from the heating chamber 21. This enhanced gas flow not only improves the diffusion efficiency of sample molecules in the airflow but also ensures that the mixed gas is delivered to the detection component 3 in a shorter time and in a more uniform state, providing a high-quality gaseous sample for subsequent component analysis. Compared to traditional structures that rely on natural convection or a single airflow drive, this solution effectively overcomes problems such as gas transport lag and uneven mixing through a dual-fan active control strategy, further improving detection response speed and data accuracy.

[0049] Furthermore, in this embodiment of the invention, by setting up a blower 6 and an exhaust fan 7, and combining this with the optimization effect of the swirling component 5 on the airflow pattern, the three form a synergistic effect: the blower 6 provides a stable and continuous intake airflow, the exhaust fan 7 maintains a negative pressure environment at the outlet, and the swirling component 5 guides the airflow direction, causing the air entering the heating chamber 21 to form a rotating flow state. This rotating airflow has a stronger disturbance capability, which helps to improve the uniformity of the distribution of the molecules of the analyte in the airflow, while also effectively reducing turbulence caused by sudden changes in airflow and directional disorder. Thus, not only is the overall efficiency of gas transmission improved, but the mechanical vibration problem caused by airflow instability is also significantly reduced.

[0050] The stable airflow environment formed by the combined action of the blower 6, exhaust fan 7, and swirl component 5 significantly reduces internal vibrations in the passive explosive detector 100 during operation, thereby minimizing potential interference from these vibrations to the detection component 3. Especially when the detection component 3 employs high-sensitivity ion mobility spectrometry, even minute mechanical vibrations can cause signal drift or misjudgment. Therefore, by optimizing the airflow path and suppressing vibration, this invention effectively ensures the detection component 3 operates in a stable environment, further improving the accuracy and repeatability of the detection results. In some embodiments, such as Figures 4 to 8 As shown, the swirl component 5 includes an air guide 51 and multiple blades 52. The air guide 51 forms an air vent 511 and an air guide cavity 512. The air vent 511 is connected to the air inlet duct 41, and the air guide cavity 512 is connected to the heating cavity 21. The multiple blades 52 are spaced apart on the outer periphery of the air vent 511 to guide the airflow at the air vent 511 to the periphery of the air vent 511 and into the air guide cavity 512.

[0051] Multiple blades 52 are arranged sequentially at intervals around the outer periphery of the vent 511, and the blades 52 are inclined to facilitate the generation of swirling air. The number of blades 52 can be set according to actual needs and is not limited here.

[0052] After the external airflow enters the air inlet duct 41, it enters the air guide cavity 512 through the vent 511, and then flows to the heating cavity 21. The function of the blades 52 is to guide the external airflow entering through the vent 511 to the surrounding area, so that it enters the air guide cavity 512 in a rotating manner, thereby forming a swirling flow.

[0053] The passive explosive detector 100 of this invention features multiple inclined blades 52 at the ventilation opening 511. These blades 52 are arranged according to a certain angle and distribution pattern, effectively guiding the incoming airflow. Through this structural design, the external airflow is forced to change its flow direction before entering the heating chamber 21, forming a stable airflow state with rotational characteristics, i.e., a swirling flow. This swirling flow structure significantly enhances the turbulence capability of the airflow within the heating chamber 21, resulting in stronger lateral diffusion and mixing efficiency as the airflow moves within the heating chamber 21. After being heated and volatilized, the analyte can be more quickly and uniformly integrated into the swirling flow, thereby improving the uniformity of sample molecule distribution throughout the airflow and ultimately enhancing the accuracy of the detection results from the detection component 3.

[0054] In some embodiments, the inner wall surface of the air guide 51 includes a conical surface 514 and an annular surface 515. The inner diameter of the conical surface 514 gradually increases along the direction from the ventilation pipe 4 to the heating head assembly 2. The annular surface 515 is connected to the end of the conical surface 514 away from the ventilation pipe 4. The blade 52 is used to guide the airflow at the vent 511 to the conical surface 514.

[0055] An annular surface 515 is located on the left side of the conical surface 514, and the annular surface 515 is connected to the left end of the conical surface 514. The inner diameter of the conical surface 514 gradually increases from right to left. Multiple blades 52 are used to uniformly guide the external airflow entering from the vent 511 to the surface of the conical surface 514, so that the external airflow is distributed in a diffused manner along the inclined structure of the conical surface 514 and gradually transforms into a swirling flow state. The annular surface 515 further guides the swirling flow into the heating chamber 21.

[0056] The passive explosive detector 100 of this invention effectively guides the flow path of external airflow by providing a conical surface 514 and an annular surface 515 on the air guide 51. The inner diameter of the conical surface 514 gradually increases along the direction from the ventilation pipe 4 to the heating head assembly 2, allowing the incoming swirling airflow to gradually diffuse during flow, reducing airflow disturbance caused by abrupt changes in cross-section. The annular surface 515 is located on one side of the conical surface 514, serving to transition and stabilize the airflow, allowing the swirling airflow to enter the heating chamber 21 more smoothly. In some embodiments, such as... Figure 6 As shown, the air guide 51 has an annular groove 513 corresponding to the ventilation opening 511, the blade 52 is installed in the annular groove 513, and an annular baffle 53 is provided on the side of the blade 52 away from the ventilation pipe 4. The air outlet duct 42 passes through the ventilation opening 511 and the annular baffle 53.

[0057] An annular groove 513 is provided on the outer periphery of the vent 511. The right end of each blade 52 is fixedly installed in the annular groove 513, and the left side of each blade 52 is fixedly connected to an annular baffle 53. In this embodiment of the invention, by providing an annular groove 513 on the air guide 51 and fixing the blade 52 in the annular groove 513, and providing an annular baffle 53 on the side of the blade 52 away from the ventilation pipe 4, a stable installation of the blade 52 is achieved. This structural design not only enhances the connection strength between the blade 52 and the air guide 51, but also effectively prevents adverse phenomena such as blade displacement, loosening, or even falling off under the impact of high-speed airflow, ensuring the overall stability and reliability of the swirl component 5.

[0058] The exhaust duct 42 passes between the vent 511 and the annular baffle 53, making the air inlet duct 41 and the exhaust duct 42 independent of each other in terms of spatial layout and preventing interference, thus further optimizing the structure of the internal air path system of the equipment. This design not only improves the compactness of the overall structure, but also helps to reduce the size of the equipment, improve space utilization, and facilitate subsequent assembly and maintenance.

[0059] Optionally, multiple blades 52 are integrally formed with an annular baffle 53.

[0060] In some embodiments, the outlet of the detection component 3 is connected to the inlet of the exhaust fan 7 via a connecting pipe 8, which is a flexible pipe.

[0061] The connecting pipe 8 is made of flexible pipe to prevent the vibration generated by the exhaust fan 7 from being directly transmitted to the detection component 3, thus preventing such vibration from interfering with the precision measurement of the detection component 3 and affecting the accuracy of the detection results.

[0062] Furthermore, the flexible tube's bendable nature allows for flexible adjustment of the relative positions between the detection component 3 and the exhaust fan 7 according to actual installation requirements. This facilitates layout optimization and maintenance of the passive explosive detector 100. Whether adapting to tight space constraints or simplifying maintenance and component replacement, the flexible tube provides significant convenience, making the passive explosive detector 100 not only more stable but also easier to install and debug. In addition, the flexible tube can compensate for assembly errors between the detection component 3 and the exhaust fan 7, thereby simplifying the assembly process of the passive explosive detector 100.

[0063] Optionally, the connecting tube 8 is a silicone tube or a polyurethane hose.

[0064] In some embodiments, at least a portion of the inner diameter of the connecting pipe 8 gradually increases along the direction from the detection component 3 to the exhaust fan 7.

[0065] The entire connecting pipe 8 is a tapered pipe, meaning that the inner diameter of the connecting pipe 8 gradually decreases from top to bottom. Alternatively, the upper end of the connecting pipe 8 is a tapered pipe with the inner diameter gradually decreasing from top to bottom, and the lower end of the connecting pipe 8 is an annular pipe.

[0066] The passive explosive detector 100 of this invention features a tapered connecting pipe 8, meaning its inner diameter gradually decreases from the detection component 3 to the exhaust fan 7, or at least exhibits this tapering characteristic in a certain section. This design ensures a smooth transition of airflow during outward flow, avoiding the abrupt cross-sectional changes that may occur in traditional straight pipe designs. The airflow can flow orderly under the gradually changing pipe diameter, reducing turbulence and drag loss. This not only improves the overall airflow transmission efficiency but also ensures the stability and consistency of the airflow during transport.

[0067] Furthermore, the tapered tube design helps reduce vibrations generated during the outflow process. Improved airflow stability and uniformity reduce mechanical vibrations caused by turbulent airflow, thus preventing these vibrations from affecting the detection component 3. This is particularly important for high-sensitivity ion mobility spectrometry detection techniques, where even minor vibrations can lead to signal drift or misinterpretation; therefore, reducing unnecessary vibrations is crucial for improving the accuracy and repeatability of detection results.

[0068] In some embodiments, such as Figure 3 As shown, the passive explosive detector 100 includes multiple support members 9 and shock absorbers, with the support members 9 being snapped into the ventilation pipe 4. The shock absorbers are arranged in a one-to-one correspondence with the multiple support members 9, and are located between the support members 9 and the ventilation pipe 4.

[0069] Multiple support members 9 are arranged sequentially at intervals along the left and right direction. The support members 9 are located below the ventilation pipe 4, and the shock absorbers are located between the support members 9 and the ventilation pipe 4.

[0070] By installing a shock absorber between the support 9 and the ventilation pipe 4, mechanical vibrations generated from the external environment or during equipment operation can be effectively isolated, preventing these vibrations from being directly transmitted to the interior of the ventilation pipe 4. This allows the airflow inside the ventilation pipe 4 to flow in a more stable and smooth environment, avoiding airflow disturbances or pressure fluctuations caused by vibrations. This ensures the continuity and uniformity of the gas transmission process, thereby guaranteeing the accuracy of the test results.

[0071] For example, both the support member 9 and the shock absorber are provided with 3 to 6. Optionally, the shock absorber is a flexible pad, such as a silicone pad or a rubber pad.

[0072] In some embodiments, a plurality of support members 9 are arranged at intervals, and a groove is provided on one of the outer peripheral surface of the ventilation pipe 4 and the surface of the support member 9, and a protrusion is provided on one of the outer peripheral surface of the ventilation pipe 4 and the surface of the support member 9, with the protrusion extending into the groove.

[0073] The outer peripheral surface of the ventilation duct 4 and the surface of the support member 9 are provided with grooves, while the other is provided with corresponding protrusions. These protrusions extend into the corresponding grooves, and the shock absorbers are set in the grooves.

[0074] The passive explosive detector 100 of this invention uses protrusions and grooves to achieve a stable connection between the ventilation pipe 4 and the support member 9. Furthermore, a shock absorber is further provided inside the groove, so that the shock absorber can be tightly embedded in the groove and form effective contact with the ventilation pipe 4 or the support member 9, thereby reducing the impact of external vibration on the ventilation pipe 4.

[0075] In other embodiments, such as Figure 9 As shown, the passive explosive detector 100 includes a return air component 13, which is located inside the heating chamber 21. The outer periphery of the return air component 13 is provided with a plurality of first air inlets 130, which are used to connect the air inlet duct 41 and the heating chamber 21.

[0076] The return air component 13 has a return air inlet 131 and a return air cavity 132, and the heating cavity 21, the return air inlet 131, the return air cavity 132 and the air outlet duct 42 are in sequential fluid communication.

[0077] The return air component 13 is located on the left side of the guide component 10. Its outer edge has a first air inlet 130 that is connected to the guide cavity 512. When a swirling flow is generated in the guide cavity 512, it enters the heating cavity 21 through the first air inlet 130, forming a stable rotating flow state inside the heating cavity 21. This allows the incoming external airflow to fully mix with the heated and volatilized molecules to be detected, improving the uniformity of the distribution of the molecules to be detected in the airflow. Subsequently, the mixed airflow passes through the return air inlet 131 and the return air cavity 132 in sequence, and is then transported to the detection component 3 for component analysis through the air outlet duct 42.

[0078] Optionally, a plurality of first air inlets 130 are arranged circumferentially around the return air element 13.

[0079] Optionally, the cross-section of the first air inlet 130 is elongated and arc-shaped, so that the swirling flow can maintain its rotational characteristics without being disrupted when passing through the first air inlet 130.

[0080] In other embodiments, the return air member 13 forms an air guide sidewall that gradually tilts toward the central axis of the return air member 13 from the first air inlet 130 toward the return air outlet 131.

[0081] In other words, the air guide sidewall is conical, meaning the inner diameter of the air guide sidewall gradually increases from left to right.

[0082] Since the swirling air needs to be turned back in the heating chamber 21 before entering the return air inlet 131, the airflow velocity at the return air inlet 131 is relatively high. The inner diameter of the guide sidewall gradually increases from left to right, so that after the high-temperature airflow enters the return air chamber 132, the airflow is diffused by the action of the conical guide sidewall to disperse the energy of the high-speed airflow and guide the airflow to be more evenly distributed throughout the return air chamber 132.

[0083] In some embodiments, the passive explosive detector includes a flow guide 10, which is disposed in the air guide cavity 512. The flow guide 10 has a flow guide port 11 and a flow guide cavity 12. The flow guide port 11 is connected to the inlet of the air outlet duct 42, and the flow guide cavity 12 is connected to the heating cavity 21.

[0084] The return air component 13, the flow guide component 10, and the air guide component 51 are arranged sequentially from left to right, and the inlets of the heating chamber 21, the flow guide chamber 12, the flow guide port 11, and the air outlet duct 42 are fluidly connected in sequence. The high-temperature airflow carrying the molecules of the substance to be detected flows from the heating chamber 21 through the return air port 131 into the return air chamber 132, then into the flow guide chamber 12, and then through the flow guide port 11 into the air outlet duct 42, and finally flows towards the detection component 3.

[0085] A second air inlet 14 is provided on the outer periphery of the air guide 10. The second air inlet 14 corresponds to and is connected to the first air inlet 130. The airflow in the air guide cavity 512 passes through the second air inlet 14 and the first air inlet 130 in sequence before entering the heating cavity 21.

[0086] In other embodiments, the inner diameter of the flow channel 12 gradually decreases from left to right.

[0087] Therefore, when the high-temperature airflow enters the return air chamber 132, it first encounters a gradually expanding space, allowing the airflow to gradually diffuse within this area. Through this diffusion process, the airflow dissipates the kinetic energy generated by its reversal within the heating chamber 21, reducing turbulence and local pressure fluctuations, thus achieving a smoother transition. Subsequently, as the airflow continues to advance, the inner diameter of the guide chamber 12 gradually decreases, guiding the airflow to gradually converge. This tapering design helps to refocus the diffused and stabilized airflow, forming a more orderly and compact flow state, facilitating its smooth flow to the outlet air duct 42, and ultimately into the detection component 3 for analysis.

[0088] In other embodiments, such as Figure 9 As shown, a return air switch 133 is provided at the return air vent 131. The return air switch 133 is electrically connected to the controller of the passive explosive detector 100. When the preset conditions are met, the controller controls the return air switch 133 to open.

[0089] For example, the controller controls the return air switch 133 according to the time. In the initial stage of the passive explosive detector 100, the return air switch 133 remains closed, allowing the sample in the heating chamber 21 sufficient time to be fully heated, thus avoiding premature introduction of airflow that may interfere with the sample heating process.

[0090] When the preset time threshold is reached, the controller will automatically open the return air switch 133 and simultaneously start the blower 6 and the exhaust fan 7. At this time, fresh outside air is forcefully pushed into the heating chamber 21 through the blower 6, fully mixed with the volatilized molecules of the test substance, and then enters the detection component 3.

[0091] The passive explosive detector 100 of this invention effectively improves detection accuracy through two aspects of design. On the one hand, by setting the swirling component 5, the airflow entering the heating chamber 21 forms a stable rotating flow state under the action of the blades 52 and the air guide 51, thereby significantly enhancing the disturbance effect of the airflow in the heating chamber 21. This allows the molecules of the substance to be detected to be more evenly distributed in the airflow after being heated and volatilized, thereby increasing the number and distribution uniformity of the substance molecules delivered to the detection component 3 per unit time, and improving the detection sensitivity and the accuracy of the results.

[0092] On the other hand, in terms of vibration reduction and noise reduction, firstly, since the swirling flow can smooth the airflow path and reduce the occurrence of turbulence, making the airflow more orderly and stable, this also helps to reduce unnecessary vibration. Secondly, the passive explosive detector 100 of this embodiment of the invention provides spaced support for the ventilation pipe 4 by setting multiple support members 9 and configuring shock absorbers between the support members 9 and the ventilation pipe 4, effectively isolating and absorbing vibrations from the outside or generated during equipment operation. At the same time, the connecting pipe 8 is made of flexible materials, such as silicone tubes or polyurethane hoses, further blocking the transmission path of vibration from the exhaust fan 7 to the detection component 3, avoiding airflow disturbance or signal fluctuation caused by vibration, and ensuring that the detection component 3 works in a stable environment. Thus, while improving gas flowability, it also greatly improves the operational stability of the entire system and the repeatability and reliability of the detection results, achieving a comprehensive performance improvement from airflow optimization to structural vibration reduction.

[0093] The passive explosive detector 100 of this invention is a portable trace explosive detection device based on a combination of thermal desorption and ion mobility spectrometry. It features a compact structure, fast response speed, high sensitivity, and ease of operation. The complete working process and its resulting technical effects will be described in detail below.

[0094] The entire testing instrument 100 is mainly composed of the main body 1, heating head assembly 2, testing assembly 3, ventilation pipe 4, swirl component 5, blower 6, exhaust fan 7, connecting pipe 8, support component 9, and shock absorber component. The heating head assembly 2 is located at one end of the body 1, and has a heating chamber 21 inside for accommodating and heating the sample. The ventilation duct 4 runs through the body 1, forming an air inlet duct 41 and an air outlet duct 42, which are responsible for introducing external air and discharging the gas after detection, respectively. The detection assembly 3 is located at the other end of the body 1 and is used to identify and analyze the target molecules carried in the airflow. The swirling component 5 is located in the air inlet duct 41 or in the connection area between it and the heating chamber 21, and is used to optimize the airflow pattern. The blower 6 and the exhaust fan 7 are located at the ends of the air inlet duct 41 and the air outlet duct 42, respectively, and work together to drive the airflow circulation. The connecting pipe 8 uses a flexible material (such as silicone or polyurethane hose) to connect the detection assembly 3 and the exhaust fan 7 to reduce vibration and noise. Multiple support components 9 are arranged at intervals below the ventilation duct 4 and are protected against vibration by shock absorbers.

[0095] When the device is started, the sample to be tested is first placed into the heating chamber 21 by opening the heating head assembly 2. Subsequently, the controller keeps the return air switch 133 closed to ensure that the sample is not disturbed by airflow in the initial stage and is fully heated and volatilized. After a preset time, the controller automatically opens the return air switch 133 and simultaneously starts the blower 6 and the exhaust fan 7. At this time, external air enters the air inlet duct 41 under the action of the blower 6 and forms a stable rotating airflow under the guidance of the blades 52 in the swirl component 5. After being further stabilized by the conical surface 514 and the annular surface 515 of the air guide 51, this swirling airflow enters the heating chamber 21 and is fully mixed with the heated and volatilized molecules of the sample to be tested, forming a high-temperature carrying airflow.

[0096] The mixed airflow sequentially passes through the return air inlet 131, the return air cavity 132, and the guide cavity 12, and is finally delivered to the detection component 3 through the outlet air duct 42. The detection component 3 uses ion mobility spectrometry to ionize, separate, and detect molecules in the gas to be tested. Different types of explosive molecules exhibit different migration times due to their unique ion mobility, thus enabling qualitative and quantitative analysis. To improve detection accuracy, the connecting pipe 8 adopts a flexible conical design, which not only improves airflow transmission efficiency but also effectively reduces turbulence caused by vibration and abrupt changes in cross-section, avoiding affecting the stability of the detection signal.

[0097] Furthermore, in terms of mechanical structure, multiple support members 9 are evenly distributed below the ventilation duct 4 along the left-right direction. Each support member 9 is equipped with a shock absorber (such as a silicone pad or rubber pad) between itself and the ventilation duct 4, forming a multi-point vibration reduction system. This design effectively isolates external environmental vibrations and mechanical vibrations generated during equipment operation, preventing vibrations from being transmitted into the ventilation duct 4, ensuring the smoothness of airflow, and thus further improving the accuracy and repeatability of the test results.

[0098] In summary, the passive explosive detector 100 of this invention achieves efficient control of the airflow path through the synergistic effect of the swirling component 5, the blower 6, and the exhaust fan 7, significantly enhancing the mixing efficiency between sample molecules and the airflow, and improving detection sensitivity and response speed. Simultaneously, through structural optimization methods such as flexible connections and vibration-damping supports, vibration interference during instrument operation is effectively reduced, providing a more stable working environment for the detection component 3. Overall, this detector possesses advantages such as high detection accuracy, stable operation, and strong anti-interference capabilities, making it suitable for various rapid explosive detection scenarios such as airport security checks, border inspections, and security at key locations, and has broad prospects for widespread application.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A passive explosive detection apparatus, characterized by, include: Body (1); A heating head assembly (2) is disposed at one end of the body (1), and a heating cavity (21) is formed inside the heating head assembly (2). The detection component (3) is located inside the body (1); The ventilation duct (4) has an air inlet duct (41) and an air outlet duct (42) inside. The air inlet duct (41) connects the heating chamber (21) to the outside, and the air outlet duct (42) connects the heating chamber (21) to the detection component (3). The swirl component (5) is located in the air inlet duct (41), or between the air inlet duct (41) and the heating chamber (21); The air inlet duct (41) surrounds the outer periphery of the air outlet duct (42). A blower (6) is provided at one end of the air inlet duct (41) away from the heating chamber (21), and an exhaust fan (7) is provided at one end of the detection component (3) away from the air outlet duct (42). The swirl component (5) includes: An air guide (51) is provided, which has a vent (511) and an air guide cavity (512). The vent (511) is connected to the air inlet duct (41), and the air guide cavity (512) is connected to the heating cavity (21). Multiple blades (52) are spaced apart on the outer periphery of the vent (511) to guide the airflow at the vent (511) to the periphery of the vent (511) and into the air guide cavity (512). The inner wall surface of the air guide (51) includes: A conical surface (514), the inner diameter of which gradually increases along the direction from the ventilation pipe (4) to the heating head assembly (2); An annular surface (515) is connected to the end of the conical surface (514) that is away from the ventilation pipe (4). The blade (52) is used to direct the airflow at the vent (511) to the conical surface (514). The air guide (51) is provided with an annular groove (513) corresponding to the ventilation opening (511), the blade (52) is installed in the annular groove (513), and an annular baffle (53) is provided on the side of the blade (52) away from the ventilation pipe (4). The air outlet duct (42) passes through the ventilation opening (511) and the annular baffle (53). Return air component (13) is provided in the heating chamber (21) and forms a return air inlet (131) and a return air cavity (132). The outer periphery of the return air component (13) is provided with a plurality of first air inlets (130), which are used to connect the air inlet duct (41) and the heating chamber (21). The return air component (13) forms an air guide sidewall, which gradually tilts toward the central axis of the return air component (13) from the first air inlet (130) toward the return air outlet (131). A flow guide (10) is provided in the air guide cavity (512). The flow guide (10) has a flow guide port (11) and a flow guide cavity (12). The flow guide port (11) is connected to the inlet of the air outlet duct (42), and the flow guide cavity (12) is connected to the heating cavity (21). As the airflow moves forward, the inner diameter of the flow guide cavity (12) gradually decreases.

2. The passive explosive detection apparatus of claim 1, wherein, The outlet of the detection component (3) is connected to the inlet of the exhaust fan (7) via a connecting pipe (8), which is a flexible pipe.

3. The passive explosives detector of claim 2, wherein, At least part of the inner diameter of the connecting pipe (8) gradually increases in the direction from the detection component (3) to the exhaust fan (7).

4. The passive explosive detector according to any one of claims 1-3, characterized in that, The passive explosive detector includes: Multiple support members (9) are snapped into the ventilation pipe (4); The shock absorber is provided in a one-to-one correspondence with the plurality of the support members (9), and the shock absorber is provided between the support member (9) and the ventilation pipe (4).

5. The passive explosive detector according to claim 4, characterized in that, Multiple support members (9) are arranged at intervals. A groove is provided on one of the outer peripheral surface of the ventilation pipe (4) and the surface of the support member (9). A protrusion is provided on one of the outer peripheral surface of the ventilation pipe (4) and the surface of the support member (9). The protrusion extends into the groove.

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