JP2005337764A - Conveyance device and dangerous substance detection device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an explosive detection device using a neutron method capable of avoiding a problem of reflection line protection by streaming or the like, and having the large number of detections (throughput) per unit time and a light device weight. <P>SOLUTION: Concerning a conveyance device and the explosive detection device using it, a device is provided, having the conveyance device equipped with a moving part and a fixed part, and forming a space constituted of the moving part and the fixed part as one or a plurality of closed spaces and open spaces by allowing a part or the whole of the moving part to be brought close to or separated from the fixed part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transport apparatus and a dangerous substance detection apparatus using the same, and relates to an apparatus for detecting whether or not explosives or forbidden drugs are mixed in a luggage, for example, in a luggage inspection at an airport.

  Conventional techniques for detecting explosives and forbidden drugs include the X-ray CT method for identifying explosives and forbidden drugs by measuring the density and shape of the inside of the test object, and explosives and forbidden drugs from the test object. There are known chemical detection methods for identifying explosives and forbidden drugs by detecting vapor, or neutron methods for identifying explosives and forbidden drugs by measuring the distribution of elemental components of a test object. Here, explosives and forbidden drugs can be distinguished from other substances in the element content of their constituent elements (for example, carbon, oxygen, nitrogen, etc.), so the neutron method can measure the content of such elements Is an effective means for detecting explosives and forbidden drugs.

  The X-ray CT method has the advantage that explosives can be classified in relatively detail from the shape and density distribution, but detection of explosives and forbidden drugs molded in combination with camouflage substances such as plastic explosives is not possible. Have difficulty. Chemical detection methods also need to detect explosives and forbidden drug vapors. Therefore, it is difficult to detect an explosive that is housed in a sealed container so as not to release steam to the outside. The neutron method is an effective means as described above. However, explosives and forbidden drug detectors using the neutron method are difficult to use due to radiation protection problems due to neutron streaming and the like. In addition, in order to prevent the above-mentioned streaming and the like so as to eliminate radiation protection problems, it is necessary to make the moving part curved or maze-like, and the entire apparatus including the transport apparatus becomes large, and the apparatus weight also increases. There was a problem of increasing. As a method of avoiding radiation protection problems due to streaming etc., as a method of transporting the transported goods by opening and closing the door at the moving part and opening the door to move the moving part during the time when the neutron beam is generated Japanese Laid-Open Patent Publication No. 1-92648 is known.

JP-A-1-92648

  In the above prior art (Japanese Patent Laid-Open No. 1-92648), the door itself, which also serves as a shield, is heavy, so it takes time to open and close the door, and only when the door is opened and the generation of neutrons is stopped However, there has been a problem that it takes a lot of time for transportation and the throughput of the dangerous goods inspection is lowered.

  An object of the present invention is to avoid a problem of radiation protection due to streaming or the like, and to have a high number of detections (throughput) per unit time and a light weight of the apparatus, and a transport apparatus using the neutron method and a danger using the same. It is to provide an object detection device.

  In order to achieve the above object, the present invention comprises a rotating bed that rotates together with a rotating shaft, and a partition that partitions the rotating bed into a plurality of parts, and a moving part on which a conveyed product is placed on the partitioned rotating bed, And a fixed part that is installed adjacent to the moving part and forms a closed space in close contact with one of the parts partitioned by the partitioning part of the moving part. A means for detecting an object is provided.

  According to the present invention, it is possible to supply an explosives detection device using a neutron method that has a high number of detections (throughput) per unit time and a low device weight, while avoiding radiation protection problems due to streaming or the like.

  In order to describe an embodiment of the present invention, a schematic structure of an explosives detection device to which the present invention is applied will be described with reference to FIG. The basic structure shown in FIG. 1 can be used for detecting forbidden drugs in addition to explosives.

  As shown in FIG. 1, the explosives detection device 1 includes a transported object (inspection object) 3 carried by a carry-in device 2a comprising a conveyor, an unloading device 2b for unloading the transported object 3, an inspection space 5, tritium and A fast neutron (hereinafter simply referred to as neutron) and α-ray detector 7a using a hydrogen fusion reaction, a γ-ray detector 12a for detecting γ-rays generated by a nuclear reaction between a neutron and a substance, and a carrier 3 Inspection object monitoring device 13 for monitoring that it is installed in inspection space 5, open space 4, open or closed space detection device 14 for detecting that inspection space 5 is open or closed space, open space 4, an open / closed space detector 14 for detecting that the inspection space 5 is open or closed, and a neutron detector 15a for measuring a neutron flux outside the inspection space 5. The signal from the inspection object monitoring device 13 is connected to the neutron generation control device 6 b and functions to generate neutrons only when the transported object (inspection object) 3 exists in the inspection space 5. The open and closed space detection device 14 is a device that detects whether the examination space 5 is a closed space or an open space, and a signal from the open and closed space detection device 14 is connected to the neutron generation control device 6b. The neutron is generated only when the inspection space 5 forms a closed space. The open and closed space detection device 14 is a device that detects whether the examination space 5 is a closed space or an open space, and a signal from the open and closed space detection device 14 is connected to the neutron generation control device 6b. When the neutron detector 15a detects a neutron flux of a certain size or more, it functions to stop neutron generation. The signal from the α-ray detector 7a is sent to the coincidence signal processing device 16 through the α-ray detection circuit 7b. Neutrons and α rays generated by the fusion reaction of tritium and deuterium are generated in a direction of approximately 180 °. Also, since the neutron energy is 14 MeV and the α-ray energy is 3.5 MeV, the neutron and α-ray velocities are constant, and the γ-ray speed is compared with the neutron and α-ray velocities. Therefore, if the positions of the neutron generation point 9 and the α-ray detector 7a installed two-dimensionally are fixed, the α-ray detection time and the γ-ray detection time can be fixed. By measuring the energy of γ-rays, the type and position of the element can be fixed. In the coincidence signal processing device 16, the signals from the α-ray detection circuit 7b and the γ-ray detection circuit 12b are α-ray and γ-ray signals caused by the same α-ray and neutron generated by the same fusion reaction. In the data collection / analysis device 17, a three-dimensional distribution of elements is derived based on the values of the alpha ray detection time, the gamma ray detection time, and the gamma ray energy, and is compared with the elemental composition data of the explosive. Thus, the position and amount of explosives are identified. Further, the identification result is displayed by the output device 18.

  FIG. 2 shows another example of the configuration of the explosive detection device in the present embodiment. The difference from FIG. 1 is that the fusion reaction of deuterium and deuterium was used for the neutron generation reaction in the neutron generator 6a. A neutron having an energy of 2.5 MeV is generated by a fusion reaction between deuterium and deuterium. The generated neutrons are converted into thermal neutrons with low energy by the neutron moderator 19 and irradiated on the thermal neutron inspection object 3. Γ-rays emitted when thermal neutrons are trapped in the substance are measured by the γ-ray detector 12a. Since the energy of the emitted γ-ray has a specific value depending on the element, the element can be identified by measuring the energy of the γ-ray. In this apparatus, since it is difficult to measure the three-dimensional distribution of elements, the amount of the element in the whole or a part of the inspection object 3 is measured. Therefore, the explosives detection accuracy is lower than the method using fast neutrons, but the generated neutrons are low energy neutrons. Compared to this, there is an advantage that the thickness can be reduced and the weight of the entire apparatus is reduced.

  An example of the conveyance part of the explosives detection apparatus in embodiment of this invention is shown to FIG. 3a and 3b. The transfer portion includes a carry-in device 2a composed of a conveyor and the like, a carry-out device 2b, a transfer device rotating door 20 composed of a plurality of doors, a transfer device rotating shaft 21, a transfer device fixing wall 22, a transfer device rotating floor 23a, and a transfer device. It has a rotating ceiling 23b. The inspection object 3 is carried from the carry-in device 2a into the open space 4 constituted by the plurality of transfer device rotary doors 20, the transfer device rotary floor 23a, and the transfer device rotary ceiling 23b. The inspection object 3 carried into the open space 4 is installed in an open space composed of a transport device rotating door 20 that rotates around the transport device rotating shaft 21, a transport device rotating floor 23a, and a transport device rotating ceiling 23b. As the rotation proceeds, the inspection space 5 forms a closed space by closely contacting the transfer device rotating door 20, the transfer device rotating floor 23a, the transfer device rotating ceiling 23b, and the transfer device fixing door 22. The transfer device rotary door 20, the transfer device rotary floor 23a, the transfer device rotary ceiling 23b, and the transfer device fixed wall 22 have performance as shielding walls for neutrons and γ rays. It is a shielded space for lines. As the neutron shielding wall, water, polyethylene, polyethylene containing boron, concrete, lithium hydride, lithium fluoride and the like are preferable. As the γ-ray shielding material, iron, stainless steel, lead, titanium and the like are preferable. Thus, neutrons are generated from the neutron generator 6a when the transfer device rotary door 20, the transfer device rotary floor 23a, the transfer device rotary ceiling 23b, and the transfer device fixed wall 22 form a shielding space.

  The γ-ray generated by the nuclear reaction between the constituent element of the inspection object 3 and the neutron is detected by the γ-ray detector 12a installed in the shielding space. The detection that the transfer device rotating door 20, the transfer device rotating floor 23a, the transfer device rotating ceiling 23b, and the transfer device fixed wall 22 form a shielded space is detected by the open and closed space detection device 14 installed outside the closed space. Only when a closed space is formed, neutrons are generated. In addition, a neutron detector 15a is also installed outside the closed space, and functions to stop neutron generation when a neutron flux of a certain size or more is detected. As the rotation progresses, the transfer device rotating door 20, the transfer device rotating floor 23a, the transfer device rotating ceiling 23b, and the transfer device rotating wall 22 are separated, so that the space in which the inspection object 3 is installed forms an open space. When the space is formed, the inspection object 3 is carried out. As described above, the space formed by the transfer device rotating door 20, the transfer device rotating floor 23a, the transfer device rotating ceiling 23b, and the transfer device fixed wall 22 is continuously opened and closed, and neutrons are formed when forming the closed space. The number of detections per unit time (throughput) is reduced by carrying in and out the inspection object 3 when forming an open space, avoiding radiation protection problems in streaming and the like. It is possible to provide an explosive detection device using a neutron method that is high and light in weight.

  FIG. 4 shows another example of the transport portion of the explosives detection device in the embodiment of the present invention. By making the carry-in direction and the carry-out direction straight, it becomes easy to combine with other explosives detection devices.

  FIG. 5 shows another example of the transport portion of the explosives detection device in the embodiment of the present invention. By increasing the number of conveyance device revolving doors 20, the number of detections (throughput) per unit time can be improved when the conveyance device revolving door 20 is rotated at a constant rotation speed.

  FIG. 6 shows the result of calculating the effective radiation dose distribution. When polyethylene and stainless steel containing boron are used as the material for the equipment, the effective dose on the equipment surface is 0.6 μSv / h or less with the same weight (less than 10 t) and size as large X-ray CT equipment. Confirmed that there was no problem.

  7a to 7c show an example of the open and closed space detecting device 14 in the embodiment of the present invention. With the rotation of the conveyance device rotation door 20 that rotates about the conveyance device rotation shaft 21, the conveyance device rotation door 20 and the open / closed space detector 14a come into contact with each other. The open / closed space detecting device 14 determines that the space is closed based on a signal that the contact has been made. Thereafter, along with the further rotation of the transport device rotating door 20 that rotates about the transport device rotating shaft 21, the open / closed space detector 14a is pushed by the transport device rotating door 20, and the open / closed space detector support shaft. It rotates around 14c. The open / closed space detector 14a is pressed against the transfer device rotating door 22 by a spring or the like. With the further rotation of the transfer device rotating door 20 that rotates about the transfer device rotating shaft 21, the transfer device rotating door 20 and the open / closed space detecting device 14a are separated from each other. Judge that.

  8a to 8h show an example of a method for conveying a conveyed product in the embodiment of the present invention. The inspection object 3 is installed by extruding the inspection object 3 from the carry-in device 2a including a conveyor. The inspection object installation table 24 is installed on the inspection object installation table fixing table 27 on the inspection object installation table 24 from the inspection object loading table 26. The inspection object carry-in table 26 has a rotatable structure, and the inspection object installation base in which the inspection object 3 is installed at an angle at which neutrons can be efficiently irradiated according to the shape of the inspection object 3. The angle with respect to 24 inspection object installation stand fixing bases 27 can be set. The inspection object 3 that has been inspected is pulled out together with the inspection object installation table 24 by pulling a hook attached to the inspection object installation table 24, and installed on the inspection object carry-out table 25. The inspection object 3 on the inspection object installation stand 24 on the inspection object carry-out stand 25 is unloaded by being pushed out to a carry-out device 2b composed of a conveyor or the like. After the inspection object 3 is pushed out, the inspection object installation table 24 in a state where nothing is installed on the upper part is installed on the front surface of the carry-in device 2a by the inspection object installation table moving device 28. Move to the loading table 26 and fix. By repeating the above procedure continuously, the inspection object 3 is continuously carried in and out.

The flow chart of the system of the explosive detection device of the present invention. The flowchart of the system of the other explosives detection apparatus of this invention. Schematic of the explosives detection apparatus using the conveying apparatus of this invention. Schematic of the explosives detection apparatus using the conveying apparatus of this invention. Sectional drawing of the conveyance partial structure of the explosives detection apparatus using the conveyance apparatus of this invention. The front view of the conveyance partial structure of the explosives detection apparatus using the conveyance apparatus of this invention. Sectional drawing of the conveyance partial structure of the explosives detection apparatus using the conveyance apparatus of this invention. The closed space detection figure of the explosives detection apparatus using the conveying apparatus of this invention. The sequence of conveyance of the explosives detection apparatus using the conveyance apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Explosives detection apparatus, 2a ... Carry-in apparatus, 2b ... Carry-out apparatus, 3 ... Inspection object, 4 ... Open space, 5 ... Inspection space, 6a ... Neutron generator, 6b ... Neutron generation control apparatus, 7a ... Alpha ray Detector, 7b ... α ray detection circuit, 8 ... α ray, 9 ... neutron generation point, 10a ... fast neutron, 10b ... thermal neutron, 11 ... γ ray, 12a ... γ ray detector, 12b ... γ ray detection circuit, 13 ... Inspection object monitoring device, 14 ... Open and closed space detection device.

Claims (8)

  A rotating bed that rotates together with the rotating shaft, and a partition part that divides the rotating bed into a plurality of parts, a moving part on which the conveyed product is placed on the partitioned rotating bed, and a moving part that is installed adjacent to the moving part and moves A conveyance part comprising: a fixed part that is in close contact with one of the parts partitioned by the partition part to form a closed space; and means for detecting a dangerous substance of a conveyed product in the closed space. apparatus.   2. The conveying apparatus according to claim 1, wherein the rotary floor has a circular shape, and the partition portion includes a rotary door extending radially from a rotary shaft at the center of the circular rotary floor.   3. The transport apparatus according to claim 1, wherein the means for detecting a dangerous substance in the transported object is a neutron generator.   A neutron generator for generating neutrons, and a charged particle generated by the neutron generator, which is installed in a portion where the closed space of the transfer device is located, and the transfer device according to any one of claims 1 to 3 is detected. A charged particle detector, a γ detector generated from a transported object when irradiated with neutrons generated by the neutron generator, and a constituent element in the transported object created based on the acquired charged particle and γ-ray signals A dangerous substance detection apparatus comprising: means for outputting information about distribution.   The hazardous material detection apparatus according to claim 4, wherein the neutron generator reacts neutrons using a fusion reaction.   The dangerous substance detection apparatus according to claim 1 or 4, wherein an angle of a conveyance installation table provided on the rotating floor is adjusted according to a shape of the conveyance object.   5. The neutron shielding material such as water, polyethylene, boron-containing polyethylene, concrete, lithium hydride and lithium fluoride is used for at least a part of the moving part and the fixed part. Dangerous goods detection device. The dangerous substance detection device according to claim 4, wherein a γ-ray shielding material is used for at least a part of the moving part and the fixed part.

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