JP2021088369A - Storage - Google Patents

Abstract

To provide a storage allowing formation of an electric field in a storage space, while suppressing lowering of a loading capacity.SOLUTION: A container 1 has a container body 2 having a storage space 20 storing objects and electrodes 5 forming an electric field in the storage space 20. The electrodes 5 are buried in the container body 2. The electrodes 5 have tabular shapes. The container body 2 has a floor part 24, a ceiling part 25 arranged facing the floor part 24, and side wall parts 26 connecting the floor part 24 to the ceiling part 25. The electrodes 5 are buried in the ceiling part 24. The ceiling part 25 has a heat insulation material 23 and outer walls 22 provided outside the heat insulation material 23. The electrodes 5 are buried in the heat insulation material 23.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vault.

As described in Patent Document 1, by forming an electric field in the accommodation space in the container and storing the fresh food in this electric field forming atmosphere, the freshness of the fresh food is lengthened as compared with the case where the electric field is not formed. It is known that it can be kept. The container of Patent Document 1 has a configuration in which plate-shaped electrodes for forming an electric field in the container are provided on the floor surface, side surface, or ceiling surface in the container.

Japanese Unexamined Patent Publication No. 2012-250773

However, in Patent Document 1, since the electrodes are provided so as to project from the inner wall of the container into the accommodation space, the volume of the accommodation space is reduced, and the load capacity is reduced accordingly.

An object of the present invention is to provide a storage capable of forming an electric field in a storage space while suppressing a decrease in load capacity.

Such an object is achieved by the following invention.

(1) A storage body having a storage space for accommodating an object, and
It has an electrode that forms an electric field in the accommodation space, and has
The storage is characterized in that the electrodes are embedded in the storage body.

(2) The storage according to (1) above, wherein the electrode is in the shape of a sheet or a plate.

(3) The storage main body has a floor portion, a ceiling portion arranged to face the floor portion, and a side wall portion connecting the floor portion and the ceiling portion.
The storage according to the above (1) or (2), wherein the electrode is embedded in the ceiling portion.

(4) The ceiling portion has an insulating heat insulating material and an outer wall provided outside the heat insulating material.
The storage according to (3) above, wherein the electrode is embedded in the heat insulating material.

(5) The storage according to (4) above, wherein the separation distance between the electrode and the outer wall is larger than the separation distance between the electrode and the storage space.

(6) The ceiling portion has an inner wall provided inside the heat insulating material.
The storage according to (4) or (5) above, wherein the inner wall has an insulating property.

(7) From (1) above, the floor portion and the side wall portion have an inner wall, an outer wall provided outside the inner wall, and a heat insulating material provided between the inner wall and the outer wall (1). The vault according to any of 6).

According to the present invention as described above, since the electrodes are embedded in the main body of the storage, it is possible to provide a storage capable of forming an electric field in the storage space while suppressing a decrease in the load capacity.

It is a perspective view which shows the whole of the container which concerns on 1st Embodiment. It is sectional drawing which shows the inside of the container body. It is sectional drawing which shows the ceiling part of the container body. It is sectional drawing which shows the deformation example of an electrode. It is sectional drawing which shows the deformation example of an electrode. It is sectional drawing which shows the inside of the container body which concerns on 2nd Embodiment. It is a figure which shows the voltage applied to the electrode of the container which concerns on 3rd Embodiment. It is a figure which shows the voltage applied to the electrode of the container which concerns on 3rd Embodiment. It is a figure which shows the voltage applied to the electrode of the container which concerns on 3rd Embodiment. It is a figure which shows the voltage applied to the electrode of the container which concerns on 3rd Embodiment. It is sectional drawing which shows the inside of the container body which concerns on 4th Embodiment. It is sectional drawing which shows the inside of the container body which concerns on 5th Embodiment. It is a figure which shows the voltage applied to an electrode.

<First Embodiment>
The container 1 (storage) shown in FIG. 1 is a mobile container mounted on a truck, a ship, an airplane, or the like. In particular, the container 1 of the present embodiment is a reefer container having a cooling function, a container main body 2 (storage main body) having a storage space 20 for accommodating an object, and a cooling device 3 for cooling the inside of the accommodation space 20. And an electric field forming device 4 that forms an electric field in the accommodation space 20. The container 1 has, for example, a configuration conforming to an international standard (ISO standard), and is a “20-foot container” having a total length of 20 feet or a “40-foot container” having a total length of 40 feet. As described above, the container 1 having excellent convenience and versatility, and further having sufficient reliability, has a configuration conforming to the international standard.

However, the container 1 does not necessarily have to comply with an international standard (ISO standard), and the shape of the container 1 is not particularly limited. Further, the container 1 may not be a mobile container but a fixed container used by being fixed to a store, a warehouse, or the like. Further, for example, it may be installed on a loading platform such as a truck. Further, the storage is not limited to the container 1, and can be applied to, for example, a cooling warehouse, a refrigerator, and the like.

The objects are not particularly limited, and for example, seafood such as fish, shrimp, crab, squid, octopus, and shellfish, processed foods thereof, fruits such as strawberries, apples, bananas, tangerines, grapes, and pears, and fruits. These processed foods, vegetables such as cabbage, lettuce, cucumber, tomato, these processed foods, fresh foods such as meat such as beef, pork, chicken, horse meat, various dairy products such as milk, cheese, yogurt, various organs, In particular, organs for transplantation and the like can be mentioned. Among these, the object is particularly preferably fresh food. It is preferable that these objects are stored in a refrigerator, that is, in a non-freezing (non-freezing) state.

The container body 2 has a substantially rectangular parallelepiped shape extending in the depth direction in FIG. 2, and a storage space 20 for accommodating an object is provided inside the container body 2. Further, as shown in FIG. 2, the container main body 2 has an inner wall 21, an outer wall 22, and an insulating heat insulating material 23 provided between the inner wall 21 and the outer wall 22. As a result, the accommodation space 20 is sufficiently insulated so that it is not easily affected by the outside air temperature. Therefore, the cooling device 3 can efficiently cool the inside of the accommodation space 20. Further, when the container 1 is used, the container body 2 (inner wall 21 and outer wall 22) is connected to the ground. A member (not shown) may be interposed between the inner wall 21 and the heat insulating material 23, between the outer wall 21 and the heat insulating material 23, inside the inner wall 21 or outside the outer wall 21.

Here, the constituent materials of the inner wall 21 and the outer wall 22 are not particularly limited, but various metals such as stainless steel, iron, and aluminum can be used, respectively. As a result, a robust and sturdy container body 2 can be obtained. The heat insulating material 23 is not particularly limited as long as it has insulating properties, and for example, glass wool, cellulose fibers, foams (polyurethane foam, polyethylene foam, polypropylene foam, etc.) and the like can be used. As a result, excellent heat insulating properties can be exhibited.

Further, the container body 2 is erected from the floor portion 24 located on the lower side in the vertical direction, the ceiling portion 25 located on the upper side of the floor portion 24 and facing the floor portion 24, and the floor portion 24, and is erected from the floor portion 24. It has a side wall portion 26 connecting the ceiling portion 25 and the ceiling portion 25, and the accommodation space 20 is formed by being surrounded by the side wall portion 26. The floor portion 24, the ceiling portion 25, and the side wall portion 26 are connected and fixed to each other via, for example, a frame 27. However, these connection and fixing methods are not particularly limited, and may be fixed by welding the outer walls to each other or the inner walls to each other, for example.

Here, as shown in FIG. 2, the floor portion 24 and the side wall portion 26 each have an inner wall 21, an outer wall 22, and a heat insulating material 23 provided between the inner wall 21 and the outer wall 22, respectively. On the other hand, the ceiling portion 25 has an outer wall 22 and a heat insulating material 23 provided inside the outer wall 22. That is, the ceiling portion 25 has a configuration in which the inner wall 21 is omitted from the floor portion 24 and the side wall portion 26, and the heat insulating material 23 faces the accommodation space 20. In other words, the container body 2 is located outside the inner wall 21 and has a "U" -shaped inner wall 21 that opens upward in the vertical direction in a cross-sectional view (cross-sectional view orthogonal to the longitudinal direction). It is composed of a "R" -shaped outer wall 22 provided by surrounding the wall and a "R" -shaped heat insulating material 23 provided between the inner wall 21 and the outer wall 22, and the heat insulating material 23 of the ceiling portion 25. Is exposed in the accommodation space 20. As described above, by not providing the inner wall 21 on the ceiling portion 25, the formation of an electric field in the accommodation space 20 is less likely to be hindered, as will be described later.

Further, a pair of double doors 28, 29 are provided at the front end of the container body 2 on the front side in FIG. 1. Through the doors 28 and 29, the object can be carried into the accommodation space 20 or the object can be taken out from the accommodation space 20. However, the arrangement and configuration of the doors 28 and 29 are not particularly limited. On the other hand, a cooling device 3 is provided at the inner end of FIG. 1 of the container body 2. In the container 1 of the present embodiment, the wall located at the inner end of FIG. 1 of the container body 2 is composed of the panel of the cooling device 3, but the present invention is not limited to this, and the side wall of the container body 2 is not limited to this. It may be composed of a part 26.

As shown in FIG. 2, the cooling device 3 is provided at the end of the accommodation space 20 on the back side when viewed from the doors 28 and 29, and has a suction unit 31 for sucking air in the accommodation space 20 and a suction unit 31 for sucking air. A cooling device 32 that cools the air sucked from the unit 31, a blowout unit 33 that blows out the air cooled by the cooling device 32, that is, cold air into the accommodation space 20, and a temperature sensor 34 that detects the temperature in the accommodation space 20. Have.

The blowing portion 33 is provided near the floor portion 24 of the accommodation space 20, and blows cold air toward the floor portion 24. The cold air blown out from the blowout portion 33 flows along the plurality of grooves 241 formed in the floor portion 24 along the longitudinal direction of the container body 2, hits the doors 28 and 29, or rises in front of the doors 28 and 29, and is accommodated. It reaches the ceiling 25 of the space 20. On the other hand, the suction unit 31 is provided in the vicinity of the ceiling portion 25, and sucks the cold air that has risen from the floor portion 24 to the ceiling portion 25 or its vicinity. Further, the temperature and air volume of the cold air are controlled so that the temperature in the accommodation space 20 detected by the temperature sensor 34 becomes the target temperature.

According to such a configuration, cold air can be efficiently circulated over the entire area of the accommodation space 20, and the temperature in the accommodation space 20 can be maintained at the target temperature. Therefore, the object accommodated in the accommodation space 20 can be appropriately cooled evenly. The settable temperature in the accommodation space 20 is not particularly limited, but is preferably about −30 ° C. to + 30 ° C., for example. However, the configuration and arrangement of the cooling device 3 is not particularly limited as long as the inside of the accommodation space 20 can be cooled.

The electric field forming device 4 has a function of forming an electric field in the accommodation space 20 and causing the formed electric field to act on an object accommodated in the accommodation space 20. As shown in FIG. 2, such an electric field forming device 4 applies a driving voltage (alternate voltage Vac) for forming an electric field to the electrode 5 embedded in the ceiling portion 25 of the container body 2 and the electrode 5. It has a voltage applying device 7.

The electrode 5 has a plate shape, particularly a flat plate shape, and is widely provided over almost the entire area of the ceiling portion 25. As a result, the electric field can be evenly distributed over a wider range of the accommodation space 20. Further, the electrode 5 is embedded in the heat insulating material 23 of the ceiling portion 25. That is, the electrode 5 is arranged inside the heat insulating material 23. By embedding the electrode 5 in the heat insulating material 23 of the ceiling portion 25 in this way, the electrode 5 does not protrude into the accommodation space 20, so that the volume (loading capacity) of the accommodation space 20 caused by the electrode 5 The decrease can be prevented. Therefore, it becomes a container 1 that can accommodate a larger number of objects. Further, since the electrode 5 is insulated by the heat insulating material 23 and the electrode 5 is not exposed to the accommodation space 20, for example, contact between the electrode 5 and the object can be prevented.

In particular, by making the electrode 5 plate-shaped, the thickness T of the electrode 5 is suppressed, and the electrode 5 can be easily embedded in the ceiling portion 25. Further, the thickening of the heat insulating material 23 of the ceiling portion 25 is suppressed, and the decrease in the capacity (loading capacity) of the accommodation space 20 can be effectively suppressed. The thickness T of the electrode 5 is not particularly limited, but is preferably 2 mm or less, and more preferably 1 mm or less, for example. As a result, the electrode 5 becomes sufficiently thin, and the above-mentioned effect becomes more remarkable. The constituent material of such an electrode 5 is not particularly limited as long as it has conductivity, and for example, various metal materials such as aluminum and copper can be used.

However, the shape of the electrode 5 is not particularly limited. For example, the electrode 5 may be in the form of a sheet (film) thinner than the above-mentioned plate. As a result, the thickness T of the electrode 5 is further suppressed, and the above-mentioned effect becomes more remarkable. In this case, for example, aluminum foil, copper foil, or the like can be used as the electrode 5. There is no clear distinction between "plate-like" and "sheet-like (film-like)", but for example, "plate-like" is one that is hard to some extent and does not substantially deform due to its own weight (excluding slight bending). A "shape", which is flexible and deformed by its own weight, can be distinguished as a "sheet shape (film shape)".

Further, as shown in FIG. 3, the separation distance D1 between the electrode 5 and the outer wall 22 of the ceiling portion 25 is larger than the separation distance D2 between the electrode 5 and the accommodation space 20 (inner surface 251 of the ceiling portion 25). That is, D1> D2. As a result, the separation distance D1 can be made as large as possible while embedding the electrode 5 in the heat insulating material 23. Therefore, the capacitance C formed between the electrode 5 and the outer wall 22 of the ceiling portion 25 can be reduced accordingly. As a result, it becomes difficult to form an electric field distributed between the electrode 5 and the outer wall 22 of the ceiling portion 25, and it becomes easy to form an electric field distributed in the accommodation space 20. Therefore, the electric field can be efficiently and effectively applied to the object accommodated in the accommodation space 20. Although not particularly limited, it is preferable to obtain the separation distances D1 and D2 as average separation distances, respectively.

The relationship between the separation distances D1 and D2 is preferably D1 / D2 ≧ 2, more preferably D1 / D2 ≧ 4, and even more preferably D1 / D2 ≧ 10. As a result, the separation distance D1 becomes larger, and the above-mentioned effect becomes more remarkable. That is, it becomes more difficult to form an electric field distributed between the electrode 5 and the outer wall 22 of the ceiling portion 25, and it becomes easier to form an electric field distributed in the accommodation space 20. Therefore, the electric field can be applied more efficiently and effectively to the object accommodated in the accommodation space 20. However, the relationship between the separation distances D1 and D2 is not limited to this, and D1 ≦ D2 may be satisfied.

The configuration of the electrode 5 is not particularly limited. For example, as shown in FIG. 4, the electrode 5 may have a corrugated plate shape. By forming irregularities on the surface of the electrode 5 in this way, the surface area of the electrode 5 becomes larger than that of, for example, the flat electrode 5. Therefore, an electric field distributed in the accommodation space 20 is likely to be formed. Further, for example, as shown in FIG. 5, a plurality of through holes 51 may be provided in the electrode 5. The through holes 51 may be regularly provided over the entire area of the electrode 5, or may be irregularly provided. The shape of the through hole 51 is not particularly limited, and may be, for example, a slit shape extending in the width direction or the length direction of the container 1.

The number of electrodes 5 installed is not particularly limited, and may be two or more, for example, as described in the embodiments described later. In other words, the electrode 5 of this embodiment may be divided into a plurality of electrodes. The location of the electrode 5 is not particularly limited, and may be, for example, a floor portion 24 or a side wall portion 26. When the electrode 5 is embedded in the floor portion 24, the electrode 5 may be embedded in the heat insulating material 23 of the floor portion 24 to remove the inner wall 21 from the floor portion 24, and the electrode 5 may be embedded in the side wall portion 26. The electrode 5 may be embedded in the heat insulating material 23 of the side wall portion 26, and the inner wall 21 may be removed from the side wall portion 26.

However, it is preferable that the electrode 5 is embedded in the ceiling portion 25 as in the present embodiment. The first reason for this is that the decrease in strength can be suppressed. It is necessary to remove the inner wall 21 from the place where the electrode 5 is embedded, and depending on the configuration of the container 1, this may lead to a decrease in the strength of the container body 2. When the inner wall 21 is removed from the ceiling portion 25, it is considered that the strength of the container body 2 is less likely to decrease as compared with the case where the inner wall 21 is removed from the floor portion 24 and the side wall portion 26. Further, the second reason is that damage to the container 1 can be suppressed. The ceiling portion 25 is overwhelmingly less frequently in contact with the object, the container pallet on which the object is loaded, the forklift for transporting the container pallet into the accommodation space 20, and the like, as compared with the floor portion 24 and the side wall portion 26. Since the inner wall 21 is removed at the place where the electrode 5 is embedded, the heat insulating material 23 is exposed in the accommodation space 20, so that the heat insulating material 23 and the electrode 5 may be damaged by the above-mentioned contact. Therefore, by embedding the electrode 5 in the ceiling portion 25 having a low contact frequency, damage to the container 1 can be suppressed more effectively.

The voltage applying device 7 includes, for example, a high-voltage transformer, and as shown in FIG. 3, applies an alternating voltage Vac, which is a driving voltage for forming an electric field, to the electrode 5. When the voltage applying device 7 applies the alternating voltage Vac to the electrode 5, an electric field is formed in the accommodation space 20 based on the potential difference between the electrode 5 and the container body 2 connected to the ground. By applying this electric field to the object accommodated in the accommodation space 20, the freshness of the object can be maintained. Therefore, the object can be stored for a longer period of time as compared with the case where an electric field is not formed. In particular, in the present embodiment, since the electrodes 5 are widely provided over almost the entire area of the ceiling portion 25, an electric field can be effectively formed over the entire area of the accommodation space 20.

The amplitude of the alternating voltage Vac is not particularly limited, but is preferably about 0.1 kV to 20 kV, for example. By applying an alternating voltage Vac having such an amplitude to the electrode 5, an electric field having sufficient strength can be formed in the accommodation space 20, and the above-mentioned effect can be more reliably exhibited. The frequency of the alternating voltage Vac is not particularly limited, but is preferably about 5 Hz to 50 kHz, for example. The waveform of the alternating voltage Vac may be any waveform such as a sine wave, a square wave, or a sawtooth wave.

<Second Embodiment>
Next, with respect to the container 1 of the second embodiment, a part different from the above-described first embodiment will be mainly described.

As shown in FIG. 6, in the container 1 of the present embodiment, the ceiling portion 25 is also provided between the inner wall 21, the outer wall 22, and the inner wall 21 and the outer wall 22 in the same manner as the floor portion 24 and the side wall portion 26. It also has a heat insulating material 23. By providing the inner wall 21 also in the ceiling portion 25 in this way, the strength of the container 1 can be increased as compared with the configuration in which the inner wall 21 does not exist as in the first embodiment, for example. Further, it is possible to prevent the heat insulating material 23 from being exposed in the accommodation space 20, and it is also possible to protect the heat insulating material 23 and the electrodes 5.

The inner wall 21 of the ceiling portion 25 has an insulating property. As a result, the inner wall 21 of the ceiling portion 25 functions like a shield layer, and it is possible to prevent the inner wall 21 of the ceiling portion 25 from hindering the formation of an electric field in the accommodation space 20. The constituent material of the inner wall 21 of the ceiling portion 25 is not particularly limited as long as it has an insulating property, and for example, various resin materials, various glass materials, various ceramics, and the like can be used. Among these, it is preferable to use various ceramics from the viewpoint of mechanical strength.

Even with such a second embodiment, the same effect as that of the first embodiment described above can be exhibited.

<Third Embodiment>
Next, with respect to the container 1 of the third embodiment, a part different from the above-described first embodiment will be mainly described.

In the third embodiment, the voltage application device 7 changes the state of the electric field formed in the accommodation space 20 with time. By changing the state of the electric field in the storage space 20 over time, for example, the growth (division) of microorganisms contained in the food can be increased as compared with the case where the state of the electric field in the storage space 20 is kept constant. It can be suppressed. Therefore, the freshness of the object accommodated in the accommodation space 20 can be maintained for a longer period of time.

The growth of microorganisms is suppressed by changing the state of the electric field in the accommodation space 20 over time because the microorganisms have the property of starting division after becoming accustomed to the environment to some extent. By changing the state of the electric field over time, the microorganisms can switch to a different environment before they become accustomed to the current environment, which can prevent the microorganisms from becoming accustomed to the environment, resulting in the growth of the microorganisms. It can be suppressed. Examples of microorganisms contained in the object include salmonella, enterohemorrhagic Escherichia coli (O157, O111, etc.), Vibrio parahaemolyticus, Clostridium perfringens, Staphylococcus aureus, Clostridium botulinum, Bacillus cereus, and norovirus, which are considered to be the causes of food poisoning. And so on.

Here, "changing the state of the electric field with time" means, for example, changing at least one of the amplitude and frequency of the alternating voltage Vac applied to the electrode 5 with time. The method of changing the state of the electric field over time is not particularly limited, and examples thereof include several methods shown below.

As a first method, as shown in FIG. 7, a method of intermittently applying an alternating voltage Vac having a reference of 0 V and a constant amplitude and frequency to the electrode 5 can be mentioned. In FIG. 7, the voltage applying device 7 alternately repeats the first state in which the alternating voltage Vac is applied to the electrodes 5 and the second state in which the alternating voltage Vac is not applied to each electrode 5. That is, the first state in which the electric field is formed in the accommodation space 20 and the second state in which the electric field is not formed are alternately repeated. In this way, by alternately repeating the first state and the second state, the state of the electric field can be changed over time with relatively simple control.

As a second method, as shown in FIG. 8, a method of changing the amplitude of the alternating voltage Vac applied to the electrode 5 over time can be mentioned. Note that changing the amplitude of the alternating voltage Vac over time means that the amplitude of the alternating voltage Vac may be changed periodically or irregularly. In FIG. 8, the voltage applying device 7 sets the first state in which the alternating voltage Vac having the reference of 0V and the amplitude of E1 is applied to the electrode 5, and the alternating voltage Vac of the reference of 0V and the amplitude of E2 (≠ E1). The second state applied to the electrode 5 is alternately repeated. By alternately repeating the first state and the second state, the state of the electric field can be changed over time with relatively simple control.

The amplitude E1 is preferably twice or more, more preferably three times or more, and even more preferably four times or more the amplitude E2. As a result, the state of the electric field in the accommodation space 20 can be sufficiently different between the first state and the second state, and the acclimatization of microorganisms to the environment can be effectively suppressed.

As a third method, as shown in FIG. 9, a method of changing the frequency of the alternating voltage Vac applied to the electrode 5 over time can be mentioned. Note that changing the frequency of the alternating voltage Vac over time means that the frequency of the alternating voltage Vac may be changed periodically or irregularly. In FIG. 9, the voltage applying device 7 has a first state in which an alternating voltage Vac having a frequency of f1 is applied to the electrode 5 and a second state in which an alternating voltage Vac having a frequency f2 (≠ f1) is applied to the electrode 5. Repeat alternately. By alternately repeating the first state and the second state, the state of the electric field can be changed over time with relatively simple control.

The frequency f1 is preferably 10 times or more, more preferably 50 times or more, and further preferably 100 times or more the frequency f2. As a result, the state of the electric field in the accommodation space 20 can be sufficiently different between the first state and the second state, and it is possible to effectively suppress the microorganisms from becoming accustomed to the environment.

As a fourth method, as shown in FIG. 10, a bias voltage Vb, which is a constant voltage, is intermittently applied to the electrode 5 while applying an alternating voltage Vac whose reference is 0 V and whose amplitude and frequency are constant. There is a way to do it. In FIG. 10, the voltage applying device 7 alternately repeats the first state in which the superimposed voltage Vd of the alternating voltage Vac and the bias voltage Vb is applied to the electrode 5 and the second state in which the alternating voltage Vac is applied to the electrode 5. .. By alternately switching between the first state and the second state, the state of the electric field can be changed over time with relatively simple control. In particular, in this method, since the alternating voltage Vac can be kept constant, the control becomes simpler than the second and third methods of changing the amplitude and frequency of the alternating voltage Vac.

The bias voltage Vb is smaller than the amplitude (maximum value) of the alternating voltage Vac. As a result, the superimposed voltage Vd can be used as an AC voltage. Therefore, in the first state, an electric field can be more reliably formed in the accommodation space 20. The bias voltage Vb is preferably 0.1 to 0.6 times, more preferably 0.2 times to 0.5 times, and 0.3 times to 0 times the amplitude of the alternating voltage Vac. It is more preferable to be 4.4 times. This makes it possible to balance the time when the superimposed voltage Vd is on the positive side and the time when it is on the negative side, that is, it is possible to prevent one from becoming excessively longer than the other, and it is more efficient in the first state. An electric field can be formed in the accommodation space 20. In addition, the state of the electric field in the accommodation space 20 can be sufficiently different between the first state and the second state, and it is possible to effectively suppress the microorganisms from becoming accustomed to the environment.

The first to fourth methods have been described above as methods for changing the state of the electric field over time. In any of the first to fourth methods, the state of the electric field is set to 1 depending on the temperature in the accommodation space 20 and the type of the object (the type of microorganism contained in the food) contained in the accommodation space 20. It is preferable to change the temperature at intervals of 1 minute or more and 60 minutes or less, preferably at intervals of 2 minutes or more and 40 minutes or less, and preferably at intervals of 3 minutes or more and 30 minutes or less. In other words, the time of the first state and the second state is preferably 1 minute or more and 60 minutes or less, more preferably 2 minutes or more and 40 minutes or less, and 3 minutes or more and 30 minutes or less, respectively. Is even more preferable. This makes the time of the first state and the time of the second state sufficiently short, respectively, and more reliably allows the microorganism to switch to another environment before it becomes accustomed to the current environment. In addition, it is possible to prevent the time of the first state and the time of the second state from becoming excessively short, respectively, and effectively prevent the microorganisms from returning to the original environment before starting to respond to the new environment. be able to. That is, the state of the electric field can be changed at intervals slightly shorter than the division rate of the microorganism. Thereby, the division of microorganisms can be suppressed more effectively. The time in the first state and the time in the second state may be the same or different.

Here, the microorganism has (1) a division rate of about 10 to 40 minutes in a temperature range of about 10 ° C. to 40 ° C., (2) the lower the temperature, the lower the division rate, (3). It is known that (4) almost all microorganisms cannot grow at 0 ° C or lower, except for some microorganisms. Therefore, as described above, by changing the state of the electric field within 60 minutes, preferably within 40 minutes, more preferably within 30 minutes, the time until the microorganisms become accustomed to the environment (for example, about 10 minutes) can be increased. In addition, the state of the electric field can be changed at intervals sufficiently shorter than the division rate of microorganisms. Therefore, the growth of microorganisms can be suppressed more reliably.

Further, in any of the first to fourth methods, the electric field may be changed periodically or irregularly. In other words, the time of the first state and the time of the second state may be substantially the same each time, or the time of the first state and the time of the second state may change irregularly each time. By changing the electric field periodically, the drive control of the voltage applying device 7 becomes simpler than in the case where the electric field is changed irregularly. On the other hand, by changing the electric field irregularly, there is a possibility that the growth of microorganisms can be suppressed more effectively than in the case where the electric field is changed periodically. It is speculated that if the electric field is changed periodically, the microorganisms may become accustomed to the periodic environmental change itself. In this way, even if the microorganisms may become accustomed to the periodic environmental changes themselves, if the electric field is changed irregularly, the growth of the microorganisms can be suppressed more effectively.

As a method of changing the state of the electric field with time, the above-mentioned first to fourth methods may be appropriately combined. Further, in each of the first to fourth methods described above, the first state and the second state are alternately repeated, but the present invention is not limited to this, and for example, the first state and the second state and the electric field state are used. May have at least one different state (third state, fourth state, fifth state, etc.), and these plurality of states may be repeated in order or randomly.

<Fourth Embodiment>
Next, with respect to the container 1 of the fourth embodiment, a part different from the above-described first embodiment will be mainly described.

As shown in FIG. 11, in the container 1 of the present embodiment, the three electrodes 5 are embedded in the heat insulating material 23 of the ceiling portion 25. Hereinafter, for convenience of explanation, these three electrodes 5 are also referred to as electrodes 5A, 5B, and 5C.

The three electrodes 5A, 5B, and 5C are arranged side by side in the width direction of the container 1 and separated from each other. Further, the electrodes 5A, 5B, and 5C each have a longitudinal shape extending in the longitudinal direction of the container 1. The electrodes 5A, 5B, and 5C are independently connected to the voltage applying device 7. As a result, three electric field forming systems can be provided, and even if one electric field forming system fails, an electric field can be formed by the other two electric field forming systems. As a result, the risk of not being able to form an electric field due to a failure is reduced, and high reliability can be exhibited.

The voltage application device 7 can also apply different voltages to the electrodes 5A, 5B, and 5C. By applying different voltages to the electrodes 5A, 5B, and 5C, the electric field can be changed periodically or irregularly as in the second embodiment described above.

The voltage applied to the electrodes 5A, 5B and 5C is not particularly limited. For example, the first alternating voltage Vac1 which is the voltage applied to the electrode 5A, the second alternating voltage Vac2 which is the voltage applied to the electrode 5B, and the third alternating voltage Vac3 which is the voltage applied to the electrode 5C mutually have frequencies. It may be different. Further, for example, the frequency and amplitude may be different between the first alternating voltage Vac1, the second alternating voltage Vac2, and the third alternating voltage Vac3. Further, for example, the same waveforms may be used for the first alternating voltage Vac1, the second alternating voltage Vac2, and the third alternating voltage Vac3, and their phases may be shifted from each other.

In this embodiment, the electrodes 5A, 5B, and 5C are provided as a plurality of electrodes to which different voltages are applied, but at least two electrodes 5 are provided, and the same or different voltages are applied to these electrodes. If so, it is not limited to this. For example, any one of the electrodes 5A, 5B, and 5C may be omitted, or conversely, at least one electrode to which a voltage can be applied independently may be added.

Further, in the present embodiment, the electrodes 5A, 5B, and 5C are arranged side by side in the width direction of the container 1, but the arrangement thereof is not particularly limited. For example, the electrodes 5A, 5B, and 5C may be arranged side by side in the longitudinal direction of the container 1. Further, the electrodes 5A and 5B may be arranged side by side in the width direction of the container 1, and the electrodes 5A and 5B and the electrodes 5C may be arranged side by side in the longitudinal direction of the container 1.

<Fifth Embodiment>
Next, with respect to the container 1 of the fifth embodiment, a part different from the above-described first embodiment will be mainly described.

As shown in FIG. 12, in the container 1 of the present embodiment, the two electrodes 5 are embedded in the heat insulating material 23 of the ceiling portion 25. Hereinafter, for convenience of explanation, these two electrodes 5 are also referred to as electrodes 5A and 5B. Then, the voltage applying device 7 applies the first alternating voltage Vac1 to the electrode 5A, and applies the second alternating voltage Vac2 having the opposite phase to the first alternating voltage Vac1 to the electrode 5B. As shown in FIG. 13, the first alternating voltage Vac1 and the second alternating voltage Vac2 have the same waveform, and have the same frequency and amplitude.

Since the container body 2 is connected to the ground, the potential difference ΔV1 between the electrode 5A and the electrode 5B becomes equal to that of the electrode 5A by shifting the first alternating voltage Vac1 and the second alternating voltage Vac2 by 180 °. It is larger than the potential difference ΔV2 with the container body 2 and the potential difference ΔV3 between the electrode 5B and the container body 2. That is, the relationship is ΔV1> ΔV2 and ΔV1> ΔV3. Therefore, an electric field is more likely to be formed between the electrode 5A and the electrode 5B than between the electrode 5A and the container body 2 or between the electrode 5B and the container body 2.

Therefore, the electric field can be formed over a wider area of the accommodation chamber 20, and the electric field can be efficiently applied to the object placed at any position in the accommodation chamber 20. The "opposite phase" refers to the case where the phase difference between the first alternating voltage Vac1 and the second alternating voltage Vac2 coincides with 180 °, and a slight error (for example, ± 10%) that may occur in technology. It is a meaning including the case of having.

The storage of the present invention has been described above based on the illustrated embodiment, but the present invention is not limited thereto. For example, the configuration of each part can be replaced with an arbitrary configuration that exhibits the same function, or an arbitrary configuration can be added. In addition, each of the above-described embodiments can be combined as appropriate.

1 Container 2 Container body 20 Storage space 21 Inner wall 22 Outer wall 23 Insulation material 24 Floor part 241 Groove 25 Ceiling part 251 Inner surface 26 Side wall part 27 Frame 28 Door 29 Door 3 Cooling device 31 Suction part 32 Cooling device 33 Blow-out part 34 Temperature sensor 4 Electrode forming device 5 Electrode 5A Electrode 5B Electrode 5C Electrode 7 Voltage applying device 51 Through hole C Capacity D1 Separation distance D2 Separation distance

Claims (7)

The main body of the vault, which has a storage space for accommodating objects,
It has an electrode that forms an electric field in the accommodation space, and has
The storage is characterized in that the electrodes are embedded in the storage body. The storage according to claim 1, wherein the electrodes are in the shape of a sheet or a plate. The storage main body has a floor portion, a ceiling portion arranged to face the floor portion, and a side wall portion connecting the floor portion and the ceiling portion.
The storage according to claim 1 or 2, wherein the electrode is embedded in the ceiling portion. The ceiling portion has an insulating heat insulating material and an outer wall provided outside the heat insulating material.
The storage according to claim 3, wherein the electrodes are embedded in the heat insulating material. The storage according to claim 4, wherein the distance between the electrode and the outer wall is larger than the distance between the electrode and the storage space. The ceiling portion has an inner wall provided inside the heat insulating material.
The storage according to claim 4 or 5, wherein the inner wall has an insulating property. Any one of claims 1 to 6, wherein the floor portion and the side wall portion have an inner wall, an outer wall provided outside the inner wall, and a heat insulating material provided between the inner wall and the outer wall. The vault described in the section.

Images