JP2019097498A - Electric field forming device, cold storage vessel, and construction method of electric field forming device - Google Patents

Abstract

To provide an electric field forming device having light weight, easy to be handled, and capable of changing shape or size of an area of formed electric field freely.SOLUTION: An electric field forming device 20 has a mesh-shaped electrode 21 and a dielectric sheet 40 having alarger surface area than the electrode 21. The electrode 21 forms an electric field by supplying AC voltage (sine wave) at high voltage from an electric power supply 30. The dielectric sheet 40 is a sheet consisting of an insulation to which carbon nanotube is milled, and arranged with overlapping the electrode 21. The dielectric sheet 40 is dielectric separated by the electric field formed by the electrode 21. An electric charge induced by the dielectric separation is generated on a surface of the dielectric sheet 40. By the electric charge generated on the surface of the dielectric sheet 40, the electric field is formed. Foods are mounted in the formed electric field. Freshness of the foods is maintained by an added electric field (electrical field).SELECTED DRAWING: Figure 4

Description

  TECHNICAL FIELD The present invention relates to an electric field forming apparatus, a cold storage, and a method of installing an electric field forming apparatus used for a cold storage for storing food and the like.

  There is known a technique for applying an electric field (electric field) to a food to be cold-held to maintain the freshness of the food for a long time (see Patent Document 1). When the food is placed in an electric field, the food supercooling phenomenon occurs, or the respiration of the food (vegetables) is suppressed, or the generation or decomposition of ethylene gas that causes the food to rot is promoted, and the food freshness is maintained for a long time Be done.

  Patent Document 1 describes an electric field forming panel for forming an electric field. The electric field forming panel includes an electrode, an insulating material stacked on the electrode, and a protective sheet covering the electrode and the insulating material. The electrodes are stainless steel nets.

JP, 2013-96675, A

  The electric field forming panel described in Patent Document 1 forms an electric field by means of electrodes. Therefore, the electrodes used for containers etc. are large and heavy. Currently, in order to install heavy electrodes in containers, fasteners are provided on the walls of the containers, and dedicated installation equipment is provided on the containers.

  In addition, it is difficult to fold or round the electrode which is a stainless steel net. Thus, large and heavy electrodes are not easy to handle.

  Further, in the electric field forming panel described in Patent Document 1, it is difficult to freely change the shape and size of the electric field region to be formed according to the application and the situation of the site because the electric field is formed by the electrodes. is there.

  Further, in the electric field forming panel described in Patent Document 1, since the electric field is formed by the electrode, the electrode must be enlarged in order to enlarge the area of the electric field to be formed. That is, the electric field forming panel is enlarged. In addition, when the electrode is large, a power supply with a large output is required.

  In addition, the warehouse for storing food must always be kept clean, and it is required that the cleaning work be easy. However, since the electric field forming panel described in Patent Document 1 is large and heavy, there is a problem that the cleaning operation becomes difficult when the electric field forming panel is installed in a warehouse.

  In addition, in order to prevent leakage from the electric field forming panel, it is necessary to waterproof the electric field forming panel and to insulate between the electric field forming panel and the wall of the warehouse. In the case of the electric field forming panel constituted only by the electrodes as in the electric field forming panel described, if the electrode is enlarged with the expansion of the electric field to be formed, the cost for waterproofing and insulation increases. There is a problem of

  The present invention has been made in view of the above circumstances, and provides a means that is lightweight and easy to handle, and can freely change the shape and size of the region of the electric field to be formed. It is in.

  (1) An electric field forming apparatus according to the present invention comprises an electrode, and a dielectric sheet having a larger surface area than the electrode and capable of dielectric separation.

  The electrodes are energized to form an electric field. The dielectric sheet is dielectrically separated by the electric field formed by the electrodes. The dielectrically separated dielectric sheet forms an electric field according to the shape and surface area of the surface.

  The dielectric sheet is lighter and easier to handle than the electrodes. In addition, since an electric field is formed in accordance with the shape and surface area of the surface of the dielectric sheet, the shape and size of the region of the electric field to be formed can be freely changed.

  (2) The electric field formation device concerning the present invention may be provided with a plurality of the above-mentioned dielectric sheets.

  By using a plurality of dielectric sheets, the shape and size of the region of the electric field to be formed can be freely selected.

(3) The dielectric sheet may have a sheet-like insulating member and a conductor included in the insulating member.

  The conductor is, for example, a metal atom, a metal particle, a metal powder, a carbon nanotube or the like. The conductor contained inside the sheet-like insulating member increases the charge amount of charge appearing on the surface of the dielectric sheet. As a result, the strength of the electric field (electric field strength) can be increased.

  (4) The insulating member may be a cloth made of an insulating fiber, and the conductor may be a metal attached to the fiber.

  (5) The dielectric sheet may further include a lamination member laminated on the sheet-like insulation member. The laminated member is a sheet-like insulator containing a conductive metal.

  The laminated member containing a conductive metal further increases the charge amount of the charge appearing on the surface of the dielectric sheet. As a result, the strength of the electric field (electric field strength) can be further enhanced.

  (6) The electrode may have a conductive member having conductivity and a waterproof sheet covering the conductor.

  The waterproof sheet can prevent an accident such as a short circuit.

  (7) The dielectric sheet may be overlapped with the electrode in the thickness direction.

  By arranging the dielectric sheet so as to overlap with the electrodes in the thickness direction, the charge appearing on the surface of the dielectric sheet can be further increased. As a result, the strength of the electric field (electric field strength) can be further increased.

  (8) The electric field forming apparatus according to the present invention may further include an auxiliary dielectric member disposed in the electric field formed by the dielectric sheet and capable of dielectric separation.

  The auxiliary dielectric member is dielectrically separated by an electric field formed by the dielectric sheet to newly form an electric field. That is, the auxiliary dielectric member suppresses the attenuation of the strength of the electric field formed by the dielectric sheet. As a result, an electric field (electric field) necessary for maintaining the freshness can be applied not only to food located near the dielectric sheet but also to food located far from the dielectric sheet.

  (9) Preferably, the auxiliary dielectric member is at least one of a seal, a sheet, a shrink and a net.

  The auxiliary dielectric member, which is a seal, is used, for example, as a seal member for sealing a cardboard box for packing food. The auxiliary dielectric member, which is a sheet, is placed on a cardboard box for packing food. An auxiliary dielectric member, which is a shrink, covers the carton for packing the food. The auxiliary dielectric member, which is a net, encloses the food. That is, foods such as mango and melon are put into the net. The auxiliary dielectric member enhances the electric field strength in the vicinity of the food. As a result, a stronger electric field can be applied to the food packaged in the cardboard box.

  (10) The electric field forming apparatus according to the present invention may further include a power supply that supplies an alternating voltage to the electrode.

  (11) A storage cooler according to the present invention includes a mounting member made of an insulator installed on the inner surface of the box, an electrode mounted on the mounting member, and a power supply device for supplying an AC voltage to the electrode. And a dielectric sheet disposed in the box and dielectrically separated by an alternating voltage supplied to the electrodes.

  The cold storage case is, for example, a cold storage container, a cold storage car, a refrigerator or the like. The mounting member made of an insulator installed on the inner surface of the box provides insulation between the electrode and the wall, ceiling or floor of the cooler.

  (12) The method of installing an electric field forming apparatus according to the present invention comprises: a first step of installing a mounting member made of an insulator in a box body; a second step of mounting an electrode and a dielectric sheet on the mounting member; And a third step of connecting a power supply that outputs an alternating voltage.

  The present invention can also be understood as a method of installing an electric field forming apparatus.

  According to the present invention, it is possible to provide an electric field forming apparatus which is lightweight and easy to handle, and which can freely change the shape and size of the area of the electric field to be formed.

FIG. 1 is a perspective view of a cold storage container 10 according to the first embodiment. FIG. 2 is a cross-sectional view of the cold storage container 10. FIG. 3 is a functional block diagram of the power supply device 30. As shown in FIG. FIG. 4 is a plan view of the electrode 21 and the dielectric sheet 40. FIG. 5 is an enlarged sectional view of the electrode 21. As shown in FIG. FIG. 6 is an explanatory view for explaining a method of installing the electric field forming device 20. As shown in FIG. FIG. 7 is a diagram showing experimental results. FIG. 8 is a perspective view of the refrigerator 60. As shown in FIG. FIG. 9 is a diagram showing experimental results. FIG. 10 is a diagram according to the first modification, wherein (A) is a perspective view of a box 45 whose lid is stopped using the auxiliary dielectric sheet 44, and (B) is a box covered with the auxiliary dielectric sheet 44. 45 is a perspective view of FIG. FIG. 11 is a diagram showing experimental results of the first modification. FIG. 12 is a diagram showing experimental results of the first modification. FIG. 13 is an enlarged cross-sectional view of a dielectric sheet 50 according to the second modification. FIG. 14 is a view showing a state in which the electrode 21 and the dielectric sheet 40 are disposed apart from each other.

  Hereinafter, embodiments of the present invention will be described. The embodiments described below are merely examples of the present invention, and it goes without saying that the embodiments of the present invention can be appropriately modified without departing from the scope of the present invention.

  In the present embodiment, a cold storage container 10 shown in FIG. 1 will be described. The cold storage container 10 includes a box 11 shown in FIG. 1, a cooling device (not shown), an electric field forming device 20 shown in FIG. 2, and a power supply device 30 shown in FIG.

  The box body 11 has a floor, a ceiling, and square walls. An insulating sheet 13 made of an insulator is attached to the inner wall surface 12 of the box 11. The insulating sheet 13 insulates between an electrode 21 described later and the box 11. The insulating sheet 13 is a polyurethane sheet made of, for example, polyurethane. In addition, if it has insulation, materials other than polyurethane may be used. For example, the insulating sheet 13 is fixed to the inner wall surface 12 of the box 11 by an adhesive, or fixed to the inner wall surface 12 of the box 11 using a fastener such as a screw or a bolt, or It is hooked to a fastener provided on the inner wall surface 12 or suspended from the ceiling of the solid 11 using a string or the like. In addition, the insulating sheet 13 is attached to the inner wall surface 12 of the box 11 using various methods. The insulating sheet 13 is an example of the mounting member of the present invention.

  The insulating sheet 13 is provided on a pair of opposing inner wall surfaces 12 of the box body 11. The insulating sheet 13 is, for example, about half the length between the floor and the ceiling of the box 11, and is disposed at an intermediate position between the floor and the ceiling of the box 11. Insulating sheet 13 may be provided on the entire surface of the inner wall surface of box 11.

  The cooling device is installed inside the box 11 or on the outer wall of the box 11. Inside the box body 11, a duct to which the air cooled by the cooling device is sent, and an outlet are provided. The cooling device maintains the temperature inside the box 11 at a set temperature. For example, an existing cooling device is used.

[Power supply unit 30]

  The power supply device 30 shown in FIG. 3 is a power supply that supplies a high voltage AC voltage (sine wave) to the electrodes 21 described later. The power supply device 30 outputs, for example, a high voltage AC voltage of 1000 V to 2000 V. In the following description, electrical connection using a circuit board pattern, a lead wire and a cable will be described simply as “connect”.

  The power supply device 30 has an input terminal 31 connected to a commercial AC power supply such as 100 V or 200 V, a rectifier circuit 32 connected to the input terminal 31, a smoothing circuit 33 connected to the rectifier circuit 32, a smoothing circuit 33 It has a booster circuit 34 connected, a conversion circuit 35 connected to the booster circuit 34, an output terminal 36 connected to the conversion circuit 35, and a control circuit 37 for controlling the operation of the booster circuit 34 and the conversion circuit. . Each circuit is realized by, for example, a pattern circuit board, an IC mounted on the pattern circuit board, a resistor, a capacitor, a diode, or the like.

  The rectifier circuit 32 is, for example, a diode bridge that performs full-wave rectification. The rectifier circuit 32 rectifies the commercial AC voltage input to the input terminal 31 and outputs it as a pulsating current. The smoothing circuit 33 is, for example, a smoothing capacitor. The smoothing circuit smoothes the pulsating current output from the rectifying circuit 32 and outputs it as a DC voltage. The booster circuit 34 is, for example, a DC / DC converter such as a boost chopper. The booster circuit 34 boosts and outputs the input DC voltage. The conversion circuit 35 is a circuit that converts the input DC voltage into an AC voltage (sine wave) and outputs it. For the conversion circuit 35, various circuits such as an inverter circuit can be used. The drive of the booster circuit 34 and the converter circuit 35 is controlled by controlling the drive of the control circuit 37, the booster circuit 34, and the switching element of the converter circuit 35.

[Electric field forming device 20]

  As shown in FIGS. 2 and 4, the electric field forming apparatus 20 includes an electrode 21 and one or more dielectric sheets 40.

  The electrode 21 is attached to the insulating sheet 13 in contact with the insulating sheet 13 provided in the box 11. The electrodes 21 can be attached to the insulating sheet 13 using various attachment methods. For example, the electrode 21 is hung from the ceiling of the box 11 or hooked to a fastener attached to the wall of the box 11, or attached to the insulating sheet 13 using a fastener such as a screw or a bolt Or attached to the insulating sheet 13 using an adhesive, a tape, a hook-and-loop fastener or the like. In addition, it is preferable to use the attachment method of the tape which can attach or detach the electrode 21, a surface fastener, etc. FIG.

  FIG. 6A shows an example in which the electric field forming device 20 is installed on a pair of opposing inner wall surfaces 12 of the box body 11. However, as shown in FIG. 6B, the installation stand 14 may be provided in the box 11, and the electric field forming device 20 may be installed on the installation stand 14 via the insulating sheet 13. An alternating voltage (sine wave) of a high voltage is supplied to the electrode 21 of the electric field forming device 20 through the feeding cable 15 connected to the output terminal 36 of the power supply device 30.

  As shown in FIG. 5, the electrode 21 includes a conductive member 22, waterproof sheets 23 and 24, and a terminal 25.

  As shown in FIG. 4, the outer shape of the conductive member 22 is rectangular. The conductive member 22 is made of a conductive metal formed in a mesh shape. For example, the conductive member 22 is formed by combining copper, aluminum or iron wires in a mesh shape. Alternatively, the conductive member 22 is formed by plating a conductive metal with a more conductive metal such as silver. The conductive member 22 is set to 5 mesh to 30 mesh (the number of meshes per inch). The number of meshes per unit length is adjusted depending on the application and the like.

  The terminal 25 is provided in contact with the conductive member 22. The terminal 25 forms, for example, a connector connected to a connector of a cable extending from the output terminal 36 of the power supply 30. A high voltage AC voltage is supplied to the conductive member 22 through the terminal 25.

  The waterproof sheets 23 and 24 shown in FIG. 5 are made of a waterproof sheet. The waterproof sheets 23, 24 may be composite sheets such as tarpaulins. The insulation performance is not important for the waterproof sheets 23 and 24. Since the insulation performance is not required, thin and light sheets can be used as the waterproof sheets 23 and 24.

  As shown in FIG. 4, the dielectric sheet 40 is a sheet having a larger surface area than the electrodes 21. The dielectric sheet 40 is disposed so that the upper end portion thereof overlaps the electrode 21 (specifically, the protective sheets 23 and 24) in the thickness direction. The dielectric sheet 40 is attached to the electrode 21 and the insulating sheet 13 using, for example, a tape or a seal.

  For the dielectric sheet 40, a sheet capable of dielectric separation is used. Although it is possible to use a sheet made of a normal insulator, it is preferable to select a sheet that is easy to perform dielectric separation. For example, a sheet made of a synthetic resin such as polyvinyl chloride containing carbon nanotubes, or a sheet made of a synthetic resin into which conductive metal atoms such as copper and silver, metal particles, metal powder and the like are mixed can be used as the dielectric sheet 40. It is preferably used. In addition, the content rate of a carbon nanotube and a metal is restrict | limited to the extent to which the dielectric sheet 40 does not have electroconductivity.

  Further, as the dielectric sheet 40, a cloth-like sheet made of an insulating fiber such as a synthetic resin into which conductive metal atoms, metal particles, metal powder and the like are kneaded may be used.

  Further, the thickness of the dielectric sheet 40 is made thin so that the charge amount of the charge appearing on the surface of the dielectric sheet is large. The dielectric sheet 40 is about 50 μm to 1 mm. Preferably, the dielectric sheet 40 is 100 μm to 300 μm in consideration of strength and ease of dielectric separation.

  For the dielectric sheet 40, for example, metal particles of the order of μm are used. A small amount of metal particles will not respond to the metal detector, but if the blending ratio is large, it may respond to the metal detector. It was confirmed that the dielectric sheet 40 does not respond to the metal detector when metal particles of the order of nm are used for the dielectric sheet 40. As the dielectric sheet 40 in which metal particles of nm order are used, for example, Nanofasu manufactured by Toyo Can Co., Ltd. can be used.

[Operation of Electric Field Forming Device 20]

  The electrode 21 supplied with the high voltage AC voltage from the power supply device 30 forms an electric field (electric field). The electric field formed by the electrodes 21 causes dielectric separation in the dielectric sheet 40. The dielectric separation generates charges on the surface of the dielectric sheet 40. The charge generated on the surface of the dielectric sheet 40 forms an electric field. The electric field formed is applied to the food.

  Further, as shown in FIG. 6B, when the electric field forming device 20 has a plurality of dielectric sheets 40, the left dielectric sheet in the dielectric sheet 40 (FIG. 6B) is disposed so as to overlap the electrodes 21. The electric field formed by 40) dielectrically isolates the other dielectric sheet 40 (the dielectric sheet 40 in the middle of FIG. 6B) disposed close to the dielectric sheet 40, and the other dielectric sheet 40 Form The electric field formed by the other dielectric sheet 40 dielectrically separates the still another dielectric sheet 40 (the right dielectric sheet 40 in FIG. 6B), and the still another dielectric sheet 40 forms an electric field.

  Note that one dielectric sheet 40 and the other dielectric sheet 40 are arranged so as to overlap each other in the thickness direction. In addition, the other dielectric sheets 40 and the further dielectric sheets 40 are arranged to overlap each other in the thickness direction. However, one dielectric sheet 40 and the other dielectric sheet 40 may be spaced apart from each other, and the other dielectric sheet 40 and the further dielectric sheet 40 may be spaced apart from each other. May be

[Construction method]
With reference to FIG. 6, the construction method of the electric field formation apparatus 20 is demonstrated. The construction method of the electric field forming apparatus 20 includes a first step, a second step, and a third step.

  The first step is a step of attaching the insulating sheet 13 in the cold storage container 10. As shown in FIG. 6 (A), the worker attaches the insulating sheet 13 to the inner wall surface 12 of the box 11 of the cold storage container 10, or as shown in FIG. 6 (B), the worker The installation stand 14 is installed in the box 11, and the insulating sheet 13 is attached to the installation stand 14.

  The second step is a step of attaching the electrode 21 and one or more dielectric sheets 40 to the insulating sheet 13. A worker attaches the electrode 21 and the dielectric sheet 40 to the insulating sheet 13 using a tape, an adhesive, a fastener, or a support.

  The third step is a step of connecting the power supply device 30 and the electrode 21 using the feeding cable 15. The worker connects the other end of the feeding cable 15 whose one end is connected to the output terminal 36 of the power supply device 30 to the terminal 25 of the electrode 21, and connects the power supply device 30 and the electrode 21.

[Example]

  The electric field intensity was measured according to the distance from the electrode 21 (dielectric sheet 40) of the electric field forming device 20. The measurement results are shown in FIG. 7 (A). When the 50 cm (long) x 50 cm (horizontal) x 25 cm (height) cardboard box 16 is placed in the electric field formed by the electric field forming apparatus 20, the voltage on the surface of the cardboard box 16 (close to the electrode 21) The surface voltage of the upper side of the side was measured. The measurement results are shown in FIG. 7 (B).

  As shown in FIG. 7A, even when the electric field is formed using the dielectric sheet 40, it is confirmed that the electric field (electric field) of the strength necessary to maintain the freshness of the food is formed. Further, as shown in FIG. 7B, the electric field formed by using the dielectric sheet 40 generates a charge by dielectric separation on the surface of the cardboard box 16 placed in the electric field. confirmed.

  A test of maintaining freshness was carried out using the electric field forming device 20 in the refrigerator 60 shown in FIG. Specifically, the insulating sheet 13 was attached to the inner wall surface of the inside 61 of the refrigerator 60, the electric field forming device 20 was installed on the insulating sheet 13, and the food was placed in the inside 61. The experimental results are shown in FIG.

  FIG. 9A shows an experimental result in the conventional refrigerator (without the electric field forming device 20). FIG. 9 (B) is an experimental result in a 3D air refrigerator. A 3D air refrigerator is a refrigerator that rapidly cools food by cold air. FIG. 9C shows an experimental result in the refrigerator 60 in which the electric field forming device 20 is provided. As shown in FIG. 9C, in the refrigerator 60 provided with the electric field forming device 20, it was confirmed that the freshness of the food is well maintained.

  Data of 22nd to 24th in FIG. 9 are data obtained by transferring food to a commercially available ordinary refrigerator after storage for each of 1 to 21 days in each refrigerator, and observing transition of freshness. As the 22nd-24th data in FIG. 9C show, the food stored in the refrigerator 60 provided with the electric field forming device 20 maintains good freshness even after being transferred to a normal refrigerator It was confirmed that it was.

[Effect of the embodiment]

  In the present embodiment, the dielectric sheet 40 is dielectrically separated by an electric field (electric field) formed by the electrodes 21, and the dielectric sheet 40 which is dielectrically separated generates an electric field (electric field strength) applied to food. Therefore, the electric field forming device 20 can be made thin, light and free as compared with the conventional electric field forming device in which the electric field applied to the food is formed only by the electrodes. Since the electric field forming device 20 can be made thin and free, the electric field forming device 20 can be installed even in a limited space such as a refrigerator where the installation space is between the outer wall and the inner wall. Moreover, even if it installs in the inner wall surface of a refrigerator or a container, it does not affect the space which accommodates foodstuffs. Further, since the electric field forming device 20 can be lightened, the electric field forming device 20 can be attached to the inner wall surface of a refrigerator or a container using a simple attachment method such as a tape. In addition, since the electric field forming device 20 can be made light and thin, there is little possibility of affecting the cleaning operation in a warehouse or the like. That is, the electric field forming apparatus 20 of the present invention can facilitate the cleaning operation when used in a warehouse or the like, as compared with the conventional electric field forming apparatus which forms an electric field only by the electrodes.

  In addition, although the conventional electrode formed of a stainless steel net or the like is difficult to fold or roll, the dielectric sheet 40 can be folded or rolled. Therefore, the electric field forming apparatus 20 is easy to handle and can be easily installed in a container, a refrigerator, etc., removed from the container, and the like.

  Also, since the dielectric sheet 40 is dielectrically separated by the electric field formed by the electrodes 21 and the other dielectric sheet 40 is dielectrically separated by the electric field formed by the dielectric sheet 40, the dielectric sheet 40 is added. The shape and size of the region of the electric field to be formed can be freely changed. Therefore, the electric field forming device 20 can be used regardless of the size of the container, from small containers to large containers.

  Further, in the present embodiment, since the area of the electric field to be formed can be expanded by increasing the dielectric sheet 40, it is not necessary to add the insulating sheet 13 with the expansion of the area of the electric field to be formed. Therefore, the increase in cost can be suppressed as compared with the conventional electric field forming apparatus 20 in which an electric field is formed only by the electrodes and the electrodes and insulators must be added as the area of the formed electric field is expanded.

  Further, in the present embodiment, a sheet made of a synthetic resin such as polyvinyl chloride containing carbon nanotubes, a sheet made of a synthetic resin containing conductive metal atoms such as copper and silver, metal particles, metal powder, etc. Since a sheet that is easy to separate is used for the dielectric sheet 40, it is possible to suppress a decrease in the strength of the electric field (electric field strength) formed by the electric field forming device 20 as compared to the case where a simple insulating sheet is used. As a result, the effect of maintaining the freshness of food can be enhanced.

  Further, in the present embodiment, since the electrodes 21 are covered with the waterproof sheets 23 and 24, a short circuit due to condensation or the like is prevented.

  Further, in the present embodiment, since the dielectric sheet 40 induces charges on the surface by dielectric separation, even if the operator mistakenly touches the surface of the dielectric sheet 40, the current is enough to affect the human body. It does not flow to the human body. That is, there is no occurrence of an electric shock accident affecting the human body. As a result, it is possible to make the worker work safely.

  Further, in the present embodiment, since the electrode 21 and the dielectric sheet 40 are attached to the insulating sheet 13, there is no need to cover the electrode 21 and the dielectric sheet 40 with the insulating layer. Therefore, the electric field forming device 20 can be made lighter and thinner than the conventional electric field forming device provided with the insulating layer on the electrode.

  Further, in the present embodiment, since the end of the dielectric sheet 40 is overlapped with the electrode 21 in the thickness direction, the dielectric sheet 40 is more than the case where the dielectric sheet 40 and the electrode 21 are separated as shown in FIG. It becomes easy to separate dielectrically. Therefore, the strength of the electric field (electric field strength) formed by the dielectric sheet 40 can be increased.

  Further, in the present embodiment, one dielectric sheet 40 (the dielectric sheet 40 on the left in FIG. 6B) and the other dielectric sheet 40 (the dielectric sheet 40 in the middle of FIG. 6B) are in the thickness direction Because they are arranged so as to overlap with each other, the strength of the electric field formed by the other dielectric sheets 40 can be made stronger than when they are not arranged so as to overlap. Further, the other dielectric sheet 40 (the dielectric sheet 40 in the middle in FIG. 6B) and the further dielectric sheet 40 (the right dielectric sheet 40 in FIG. 6B) are arranged to overlap each other in the thickness direction Because of this, the strength of the electric field formed by the other dielectric sheets 40 can be further enhanced than in the case where they are not overlapped. As a result, the strength of the electric field formed by the electric field forming device 20 can be further enhanced.

  Further, in the present embodiment, by using a sheet containing metal particles of nm order for the dielectric sheet 40, the dielectric sheet 40 can be made not to respond to the metal detector. Since it does not respond to the metal detector, even if the dielectric sheet 40 is broken, the broken dielectric sheet 40 is prevented from reacting to the metal detector and affecting the import and export operations.

[Modification 1]

  In this modification, an example in which the electric field forming device 20 further includes an auxiliary dielectric sheet 44 (FIG. 10) will be described.

  As shown in FIG. 10A, the auxiliary dielectric sheet 44 is a seal for stopping a box 45 such as a cardboard box containing food, or a shrink member for shrinking the box 45. Alternatively, the auxiliary dielectric sheet 44 is a sheet which is put on the box 45 as shown in FIG. 10 (B).

  The auxiliary dielectric sheet 44 is a sheet of synthetic resin or the like containing conductive metal. For example, the auxiliary dielectric sheet 44 shown in FIG. 8B is a sheet in which metal atoms such as copper, metal particles and metal powder (hereinafter, metal particles and the like) are kneaded in PE (polyethylene) film. Alternatively, the auxiliary dielectric sheet 44 shown in FIG. 8A is an adhesive sheet in which metal particles and the like are kneaded into the base material.

  The content rate of metal particles and the like possessed by the auxiliary dielectric sheet 44 is limited to the extent not having conductivity. That is, the auxiliary dielectric sheet 44 does not cause an electric shock.

Example 1

  As shown in FIG. 11A, a box 45 having a length of 25 cm is disposed with a distance of 10 cm from the electrode 21 (dielectric sheet 40), and the electric field strength (field strength) of the back side of the box 45 Was measured. The upper surface of the box 45 is covered with an auxiliary dielectric sheet 44 made of a PE film into which copper particles of 5 μm or less are kneaded. The ratio of copper to PE film is about 8% by weight.

  Further, as shown in FIG. 11 (B), a box 45 of 25 cm in length is disposed at a distance of 10 cm from the electrode 21 (dielectric sheet 40), and a distance of 40 cm from the electrode 21 is disposed. Another box 45 of 25 cm was placed, and another box 45 of 25 cm in length was placed at a distance of 70 cm from the electrode 21, and the top surfaces of the three boxes 45 were covered with the auxiliary dielectric sheet 44 respectively. The auxiliary dielectric sheet 44 is made of a PE film into which 5 μm copper particles are kneaded.

  Further, as shown in FIG. 12A, one box 45 of 25 cm in length is disposed with a distance of 10 cm from the electrode 21 (dielectric sheet 40), and a distance of 40 cm from the electrode 21 (dielectric sheet 40). , And another box 45 of 25 cm in length was placed, and the two boxes 45 were surrounded by the auxiliary dielectric sheet 44. The auxiliary dielectric sheet 44 is made of a PE film into which 5 μm copper particles are kneaded. Note that “enclose” means covering the box 45 with the auxiliary dielectric sheet 44 so that the auxiliary dielectric sheet 44 does not contact the box 45.

  Further, as shown in FIG. 12B, a box 45 of 25 cm in length is disposed with a distance of 10 cm from the electrode 21 (dielectric sheet 40), and a distance of 40 cm from the electrode 21 (dielectric sheet 40). The other box 45 of 25 cm in length was placed, and the auxiliary dielectric sheet 44 was put on the two boxes 45 so as to cover the two boxes 45. The auxiliary dielectric sheet 44 is made of a PE film into which 5 μm copper particles are kneaded.

  As shown in FIG. 11 and FIG. 12, it was confirmed that the electric field strength necessary for maintaining the freshness of the food and the surface voltage of the auxiliary dielectric sheet 44 necessary for maintaining the freshness of the food can be obtained. The test conditions were a room temperature of 23 ° C. and a humidity of 35%, and were generally in a dry state. In a refrigerator or the like, humidity higher than 35% is assumed. As the humidity rises, it is expected that the amount of charge induced on the surface of the dielectric sheet 40 will increase. That is, in a refrigerator or the like, it can be expected that the electric field strength can be added to the food better than the test result.

  In addition, when the sheet | seat containing the metal particle of a nm order is used as the auxiliary | assistant dielectric sheet 44, it was confirmed like the dielectric sheet 40 that it does not respond | correspond to a metal detector.

[Effect of Modification 1]

  The metal-containing auxiliary dielectric sheet 44 is dielectrically separated by the electric field formed by the dielectric sheet 40. The dielectrically separated auxiliary dielectric sheet 44 enhances the strength of the electric field applied to the box 45. As a result, the effect of maintaining the freshness of the food is further enhanced.

  Further, in the present embodiment, by using a sheet including metal particles of nm order as the auxiliary dielectric sheet 44, the auxiliary dielectric sheet 44 can be made not to respond to the metal detector. Since it does not respond to the metal detector, even if the auxiliary dielectric sheet 44 is broken, the broken auxiliary dielectric sheet 44 is prevented from reacting to the metal detector and affecting the import and export operations.

  In addition, since the auxiliary dielectric sheet 44 does not have conductivity, even if a worker touches the auxiliary dielectric sheet 44, there is no risk of electric shock.

  Also, the auxiliary dielectric sheet 44 can be recovered after use and reused.

  Further, when the auxiliary dielectric sheet 44 is the adhesive sheet or shrink shown in FIG. 8A, the auxiliary dielectric sheet 44 can be disposed as a part of the conventional work, so that the freshness of the food can be increased without increasing the time and effort of the work. The effect of maintaining can be enhanced.

  In this modification, an example in which the auxiliary dielectric sheet 44 is disposed outside the cardboard box 45 has been described. However, the auxiliary dielectric sheet 44 may be disposed inside the box 45 so as to wrap the food.

[Modification 2]

  In the first modification described above, the auxiliary dielectric sheet 44 which is a tape, a sheet, and a shrink has been described. However, the auxiliary dielectric sheet may be net-like. Specifically, the auxiliary dielectric sheet is manufactured by being knitted in a net shape by fibers such as conductive metal atoms, synthetic particles into which metal particles, and metal powder are kneaded. For example, foods such as mango and melon are packaged in a net-like auxiliary dielectric sheet and placed in a box 45. Alternatively, a net-like auxiliary dielectric sheet is put on the box 45 itself containing the food.

  The net-like auxiliary dielectric sheet enhances the strength of the electric field applied to the food as in the first modification. As a result, the effect of maintaining the freshness of the food is further enhanced.

  In addition, by using a net including metal particles of nm order as the auxiliary dielectric sheet, the auxiliary dielectric sheet can be made not to respond to the metal detector. Since it does not react to the metal detector, even if the auxiliary dielectric sheet is broken, the broken auxiliary dielectric sheet is prevented from reacting to the metal detector and affecting the import and export operations.

  Further, as in the first modification, the net-like auxiliary dielectric sheet is less likely to cause an electric shock to the operator, and can be recovered after being used for reuse.

  In addition, the net-like auxiliary dielectric sheet can secure water molecules (water) in the gaps between the fibers. The auxiliary dielectric sheet, which secures water molecules in the gap between the fibers, is more susceptible to dielectric separation. Therefore, the strength of the electric field applied to the food is further enhanced, and as a result, the effect of maintaining the freshness of the food is further enhanced.

[Modification 3]

  In this modification, the dielectric sheet 50 shown in FIG. 13 will be described. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted.

  The dielectric sheet 50 has a dielectric sheet 40 and a laminated member 26 laminated on the dielectric sheet 40. The laminating member 26 is a sheet containing a conductive metal. For example, the laminating member 26 is a synthetic resin sheet having an insulating property.

[Effect of Modification 3]

  In the present modification, the strength of the electric field formed by the electrode sheet 50 can be further enhanced by the laminated member 26. As a result, the effect of maintaining the freshness of food can be further enhanced.

[Other modifications]

  In the first embodiment described above, an example in which the pair of electrode sheets 20 is provided in the box 11 has been described. However, only one electrode sheet 20 may be provided, or two or more pairs may be provided. For example, the electrode sheet 20 may be provided on two pairs of mutually opposed inner wall surfaces of the box 11, and the electrode sheet 20 may be provided on the floor or ceiling of the box 11.

  Moreover, in the above-mentioned 1st Embodiment, the power supply device 30 which converts a commercial alternating voltage into the alternating voltage of a high voltage and outputs it was demonstrated. However, the power supply device 30 may convert the DC voltage output from the battery into a high voltage AC voltage.

10 ... cold storage container 13 ... insulating sheet 20 ... electric field forming device 21 ... electrode 22 ... conductive member 23 ... waterproof sheet 24 ... waterproof sheet 25 ... terminal 26 · · · · Stacking member 30 · · · power supply device 44 · · · auxiliary dielectric sheet 60 · · · refrigerator

Claims (12)

An electrode,
An electric field forming apparatus comprising: a dielectric sheet having a larger surface area than the electrodes and capable of dielectric separation.   The electric field forming apparatus according to claim 1, comprising a plurality of the dielectric sheets. The dielectric sheet is
Sheet-like insulation member,
The electric field forming apparatus according to claim 1, further comprising a conductor included inside the insulating member. The insulating member is a cloth made of insulating fibers,
The electric field forming apparatus according to claim 3, wherein the conductor is a metal attached to the fiber. The dielectric sheet is
It further has a lamination member laminated on the sheet-like insulation member,
The electric field forming device according to claim 3 or 4, wherein the laminated member is a sheet-like insulator containing a conductive metal.   The electric field forming device according to any one of claims 1 to 5, wherein the electrode includes a conductive member having conductivity and a waterproof sheet covering the conductor.   The electric field forming apparatus according to claim 6, wherein the dielectric sheet is overlapped with the electrode in a thickness direction.   The electric field forming apparatus according to any one of claims 1 to 7, further comprising an auxiliary dielectric member disposed in the electric field formed by the dielectric sheet and capable of dielectric separation.   The electric field forming apparatus according to claim 8, wherein the auxiliary dielectric member is at least one of a seal, a sheet, a shrink and a net.   The electric field forming apparatus according to any one of claims 1 to 9, further comprising a power supply device for supplying an alternating voltage to the electrode. With a box,
A mounting member made of an insulator installed on the inner surface of the box;
An electrode attached to the attachment member;
A power supply for supplying an alternating voltage to the electrode;
And a dielectric sheet disposed in the box and dielectrically separated by an alternating voltage supplied to the electrodes. A first step of installing a mounting member made of an insulator in the box body;
A second step of attaching an electrode and a dielectric sheet to the attachment member;
And a third step of connecting the electrode and a power supply device for outputting an alternating voltage.