CN113438899A

CN113438899A - Storage cabinet and storage method

Info

Publication number: CN113438899A
Application number: CN202080013732.8A
Authority: CN
Inventors: 大野正树; 大平刚
Original assignee: Mars Inc
Current assignee: Mars Inc
Priority date: 2019-05-14
Filing date: 2020-03-13
Publication date: 2021-09-24
Also published as: JP2020186845A; WO2020230437A1

Abstract

A storage cabinet is capable of keeping freshness of an object for a long period of time by changing the state of an electrostatic field with time. The storage cabinet (1) is provided with an electrostatic field forming device (15) which forms an electrostatic field in a storage chamber (10) capable of storing food. The electrostatic field forming device (15) changes the state of the electrostatic field with time. The electrostatic field forming means (15) may change the electrostatic field periodically or irregularly. The storage cabinet (1) has a storage rack (13) as an electrode disposed in the storage chamber (10), and the electrostatic field forming device (15) applies an alternating voltage to the storage rack (13).

Description

Storage cabinet and storage method

Technical Field

The invention relates to a storage cabinet and a preservation method.

Background

For example, as described in patent document 1, it is known that the freshness of fresh food can be maintained for a longer period of time than in the case where an electrostatic field is not formed by forming an electrostatic field in a refrigerator and storing the fresh food in the atmosphere.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2007-78271

Disclosure of Invention

Technical problem to be solved by the invention

However, in patent document 1, the state of the formed electrostatic field is uncertain. It is also difficult to maintain the freshness of fresh food for a long period of time, assuming that the state of the electrostatic field is constant, that is, assuming that the alternating voltage applied to the electrodes for forming the electrostatic field is constant.

The invention aims to provide a storage cabinet and a storage method capable of keeping freshness of objects for a long time.

Means for solving the problems

The purpose is realized by the following technical scheme.

(1) A storage cabinet is characterized in that,

has an electrostatic field forming device for forming an electrostatic field in a storage chamber capable of storing an object,

the electrostatic field forming means changes the state of the electrostatic field with time.

(2) The storage cabinet according to (1) above, wherein the electrostatic field forming means periodically changes the electrostatic field.

(3) The storage cabinet according to item (1) above, wherein the electrostatic field forming device changes the electrostatic field irregularly.

(4) The storage cabinet according to any one of the above (1) to (3), comprising an electrode disposed in the storage chamber,

the electrostatic field forming means applies an alternating voltage to the electrodes.

(5) The storage cabinet according to item (4) above, wherein the electrode functions as a storage shelf on which the object is placed.

(6) The storage cabinet according to (4) or (5), wherein the electrostatic field forming device changes the amplitude of the alternating voltage with time.

(7) In the storage container according to (4) or (5), the electrostatic field forming device alternately repeats a state in which the alternating voltage is applied and a state in which the alternating voltage is not applied.

(8) In the storage container according to (4) or (5), the electrostatic field forming device may apply a bias voltage having a constant voltage value to the electrode simultaneously with the application of the alternating voltage, and may change the magnitude of the bias voltage with time.

(9) The storage cabinet according to (8) above, wherein the electrostatic field forming device maintains the alternating voltage constant.

(10) In the storage container according to (4) or (5), the electrostatic field forming device maintains the alternating voltage constant.

(11) The storage cabinet according to any one of the above (1) to (10), wherein the electrostatic field forming device changes the state of the electrostatic field with time at intervals of 60 minutes or less.

(12) The storage cabinet according to any one of the above (1) to (11), comprising a cooling device for cooling the storage chamber.

(13) A storage method, characterized in that an object is placed in an electrostatic field, and the state of the electrostatic field is changed with time.

Drawings

Fig. 1 is a perspective view showing a storage cabinet according to a preferred embodiment of the present invention.

Fig. 2 is a front view showing the storage chamber of the storage cabinet of fig. 1.

Fig. 3 is a graph showing a method of forming an electrostatic field formed in the housing chamber.

Fig. 4 is a graph showing a method of forming an electrostatic field formed in the housing chamber.

Fig. 5 is a graph showing a method of forming an electrostatic field formed in the housing chamber.

Fig. 6 is a graph showing a method of forming an electrostatic field formed in the housing chamber.

Detailed Description

Hereinafter, the storage cabinet and the storage method according to the present invention will be described in detail based on the embodiments shown in the drawings.

The storage cabinet 1 shown in fig. 1 is used as a refrigerator for refrigerated preservation of food. However, the storage cabinet 1 is not limited thereto, and may also be used as a room temperature cabinet, a heating cabinet, a freezer cabinet, or the like, for example. The food to be stored in the storage cabinet 1 by refrigeration is not particularly limited, and examples thereof include marine products such as fish, shrimp, crab, squid, octopus, and shellfish, and processed foods thereof; fruits such as strawberry, apple, banana, orange, grape, pear, etc. and processed food thereof; cabbage, lettuce, cucumber, tomato and other vegetables and their processed food; fresh food of meat such as beef, pork, chicken, horse meat, etc.; milk, cheese, yogurt, and other various dairy products; cereals such as wheat flour, rice flour, buckwheat flour, etc., and flour made from these cereals. The object stored in the storage cabinet 1 is not limited to food, and may be, for example, a product other than food such as a flower, a medicine, and an organ.

The storage cabinet 1 may be a fixed type storage cabinet disposed in a store, a warehouse, or the like, a storage cabinet provided in a cargo box of a truck, or a container type storage cabinet mounted on a truck, a ship, an airplane, or the like.

The storage cabinet 1 has a main body 11, and the main body 11 is provided with a storage chamber 10 for storing food therein. As shown in fig. 2, the main body 11 includes, for example: an outer wall 111, an inner wall 112, and an insulating material 113 disposed between the outer wall 111 and the inner wall 112. In addition, an opening connected to the housing chamber 10 is formed in the front surface of the main body 11. In addition, the storage cabinet 1 has a pair of doors 12 closing the opening of the main body 11. A pair of doors 12 is openably and closably connected to the main body 11. Food can be taken out of and put into the storage chamber 10 by opening the door 12, and the food in the storage chamber 10 can be cooled by closing the door 12 to enclose the cool air in the storage chamber 10. These main body 11 and door 12 are grounded, respectively.

The structure of the main body 11 and the door 12 is not particularly limited as long as the functions can be exerted. For example, in the present embodiment, the main body 11 has one accommodation chamber 10, but the present invention is not limited thereto, and the main body 11 may have a plurality of accommodation chambers 10. In the present embodiment, the opening is formed in the front surface of the body 11, but the present invention is not limited thereto, and for example, an opening may be formed in the upper surface or the side surface of the body 11. In the present embodiment, a pair of doors 12 is provided, but the number of doors 12 is not limited to this, and for example, one door or three or more doors may be provided.

As shown in fig. 2, the storage cabinet 1 includes a storage rack 13 disposed in the storage chamber 10. The storage rack 13 includes a plurality of support columns 131 and a plurality of storage rack plates 132 supported by the plurality of support columns 131 and arranged in parallel in the vertical direction. The storage rack 13 is provided in the storage chamber 10 in an insulated state with respect to the main body 11. In particular, in the present embodiment, the storage rack 13 is fixed to the ceiling portion of the main body 11 via the insulator 14, and is suspended from the main body 11. By suspending the storage rack 13 from the ceiling portion in this way, for example, the storage rack 13 can be made larger than in the case where the storage rack 13 is placed on the bottom plate portion of the main body 11, and the dead space in the storage chamber 10 can be reduced. Therefore, if the storage chambers 10 have the same size, more food can be stored, and if the storage amount is the same, the storage chambers 10 can be reduced in size. As will be described later, the storage rack 13 has conductivity and also functions as an electrode to which a voltage for forming an electrostatic field in the storage chamber 10 is applied.

The storage cabinet 1 further includes a machine room 19 provided above the main body 11. A cooling device 16 for cooling the housing chamber 10 is provided in the machine chamber 19; and an electrostatic field forming device 15 for forming an electrostatic field in the storage chamber 10. A touch panel type display screen 191 (an input unit and a display unit) is provided on the front surface of the machine room 19. In particular, in the present embodiment, settings related to driving of the electrostatic field forming device 15 can be made via the display screen 191. The arrangement of the machine chamber 19 is not particularly limited, and may be provided below the main body 11 or may be provided behind the main body 11. The cooling device 16 and the electrostatic field forming device 15 may be provided at different positions from the machine room 19.

The cooling device 16 includes a compressor 161, a condenser 162, and the like, and cools the storage chamber 10 by supplying cool air into the storage cabinet 1. The temperature in the storage chamber 10 is not particularly limited, but is preferably about-7 ℃ to 15 ℃.

The electrostatic field forming device 15 has a high voltage transformer, and applies an alternating voltage Vac to the storage rack 13. An alternating voltage Vac is applied to the storage rack 13 by the electrostatic field forming device 15, thereby forming an electrostatic field in the storage chamber 10. By forming an electrostatic field in the storage chamber 10, it is possible to promote the ripening of the food stored in the storage chamber 10 while maintaining the freshness thereof. Therefore, the food can be preserved for a longer period of time than in the case where the electrostatic field is not formed, and the degree of deliciousness of the food can be increased.

The amplitude of the alternating voltage Vac is not particularly limited, but is preferably, for example, about 0.1kV to 20 kV. By applying the alternating voltage Vac having such an amplitude to the storage rack 13, an electrostatic field having a sufficient intensity can be formed in the storage chamber 10, and the above-described effects can be exerted more reliably. The frequency of the alternating voltage Vac is not particularly limited, but is preferably, for example, about 5Hz to 50 kHz.

Next, the electrostatic field formed in the housing chamber 10 by the electrostatic field forming device 15 will be described in more detail. The electrostatic field forming device 15 changes the state of the electrostatic field in the storage chamber 10 with time. By changing the state of the electrostatic field in the storage chamber 10 with time, for example, the growth (division) of microorganisms contained in the food can be suppressed as compared with a case where the state of the electrostatic field in the storage chamber 10 is kept constant. Therefore, the freshness of the food stored in the storage chamber 10 can be maintained for a longer period of time. Here, the reason why the growth of microorganisms is suppressed by changing the state of the electrostatic field in the housing chamber 10 with time is that microorganisms have a property of starting to divide after adapting to the environment to some extent. By changing the state of the electrostatic field over time, it is possible to switch to a different environment before the microorganisms adapt to the previous environment. Therefore, adaptation of the microorganism to the environment can be suppressed, and as a result, proliferation of the microorganism can be suppressed. Examples of the microorganisms contained in foods include salmonella, enterohemorrhagic escherichia coli (O157, O111, and the like), vibrio parahaemolyticus, clostridium welchii, staphylococcus aureus, clostridium botulinum, bacillus cereus, and norwalk virus, which cause food poisoning.

Here, "changing the state of the electrostatic field with time" means, for example, changing at least one of the amplitude and the frequency of the alternating voltage Aac applied to the storage rack 13 with time. The method of changing the state of the electrostatic field with time is not particularly limited, but examples thereof include the following methods.

As the method 1, as shown in fig. 3, a method in which an alternating voltage Vac whose reference is 0V and whose amplitude and frequency are constant is intermittently applied to the storage rack 13 can be cited. In fig. 3, the electrostatic field forming device 15 alternately repeats a 1 st state in which the alternating voltage Vac is applied to the storage rack 13 and a 2 nd state in which the alternating voltage Vac is not applied to the storage rack 13. Thereby, the 1 st state in which the electrostatic field is formed and the 2 nd state in which the electrostatic field is not formed are alternately repeated. By alternately repeating the 1 st state and the 2 nd state in this way, the state of the electrostatic field can be changed over time by relatively simple control.

The amplitude of the alternating voltage Vac is not particularly limited, but is preferably 0.1kV to 20kV, for example. This makes it possible to sufficiently differentiate the states of the electrostatic fields in the housing chamber 10 in the 1 st state and the 2 nd state, and to effectively suppress adaptation of the microorganisms to the environment. The reference of the alternating voltage Vac may not be 0V. The term "constant amplitude and frequency" means that the amplitude and frequency are completely constant, and includes some (for example, about ± 10%) fluctuation due to technical reasons.

As the method 2, as shown in fig. 4, a method of changing the amplitude of the alternating voltage Vac applied to the storage rack 13 with time can be cited. The term "changing the amplitude of the alternating voltage Vac with time" means that the amplitude of the alternating voltage Vac may be changed periodically or irregularly (randomly). In fig. 4, the electrostatic field forming device 15 alternately repeats a 1 st state in which an alternating voltage Vac having an amplitude of E1 is applied to the stocker 13 with reference to 0V, and a 2 nd state in which an alternating voltage Vac having an amplitude of E2(≠ E1) is applied to the stocker 13 with reference to 0V. By alternately repeating the 1 st state and the 2 nd state, the state of the electrostatic field can be changed over time by relatively simple control.

The amplitudes E1 and E2 are not particularly limited as long as they are different from each other, but are preferably 0.1kV to 20kV, for example. The amplitude E1 is preferably 2 times or more, more preferably 3 times or more, and still more preferably 4 times or more the amplitude E2. This makes it possible to sufficiently differentiate the states of the electrostatic fields in the housing chamber 10 in the 1 st state and the 2 nd state. Therefore, the adaptation of the microorganism to the environment can be effectively suppressed. The reference of the alternating voltage Vac may not be 0V.

As the 3 rd method, as shown in fig. 5, a method of changing the frequency of the alternating voltage Vac applied to the storage rack 13 with time can be cited. Note that changing the frequency of the alternating voltage Vac with time means that the frequency of the alternating voltage Vac may be changed periodically or may be changed irregularly (randomly). In fig. 5, the electrostatic field forming device 15 alternately repeats a 1 st state in which an alternating voltage Vac having a frequency of f1 is applied to the stocker 13 and a 2 nd state in which an alternating voltage Vac having a frequency of f2(≠ f1) is applied to the stocker 13. By alternately repeating the 1 st state and the 2 nd state, the state of the electrostatic field can be changed with time by relatively simple control.

The frequencies f1 and f2 are not particularly limited, but are preferably 5Hz to 50kHz, for example. The frequency f1 is preferably 10 times or more, more preferably 50 times or more, and still more preferably 100 times or more the frequency f 2. This makes it possible to sufficiently differentiate the states of the electrostatic fields in the housing chamber 10 in the 1 st state and the 2 nd state. Therefore, the adaptation of the microorganism to the environment can be effectively suppressed. The reference of the alternating voltage Vac may be other than 0V.

As the 4 th method, as shown in fig. 6, a method can be cited in which an alternating voltage Vac having a constant amplitude and frequency with a reference of 0V is applied to the storage rack 13, and a bias voltage Vb that is a constant voltage is intermittently applied thereto. In fig. 6, the electrostatic field forming device 15 alternately repeats a 1 st state in which a superimposed voltage Vd of an alternating voltage Vac and a bias Vb is applied to the storage rack 13 and a 2 nd state in which the alternating voltage Vac is applied to the storage rack 13. By alternately switching the 1 st state and the 2 nd state, the state of the electrostatic field can be changed over time by relatively simple control. In particular, in this method, since the alternating voltage Vac can be kept constant, the control can be made simpler than in the

methods

2 and 3 in which the amplitude and frequency of the alternating voltage Vac are changed.

The bias voltage Vb has a smaller amplitude (maximum value) than the alternating voltage Vac. This allows the superimposed voltage Vd to be an ac voltage. Therefore, in the state 1, the electrostatic field can be more reliably formed in the housing chamber 10. The bias voltage Vb is preferably 0.1 to 0.6 times, more preferably 0.2 to 0.5 times, and still more preferably 0.3 to 0.4 times the amplitude of the alternating voltage Vac. This makes it possible to balance the time during which the superimposed voltage Vd is on the positive side with the time during which the superimposed voltage Vd is on the negative side. Therefore, one can be prevented from being excessively longer than the other, and in the 1 st state, an electrostatic field can be more effectively formed in the housing chamber 10. In addition, the states of the electrostatic fields in the housing chamber 10 in the 1 st state and the 2 nd state can be sufficiently different. Therefore, the adaptation of the microorganism to the environment can be effectively suppressed.

As described above, the 1 st to 4 th methods have been described as methods for changing the state of the electrostatic field with time. In any of the methods 1 to 4, although the temperature in the storage chamber 10 and the type of food (the type of microorganism included in the food) stored in the storage chamber 10 vary, the state of the electrostatic field is preferably changed at intervals of 1 minute or more and 60 minutes or less, more preferably at intervals of 2 minutes or more and 40 minutes or less, and still more preferably at intervals of 3 minutes or more and 30 minutes or less. In other words, the time for the 1 st state and the time for the 2 nd state are preferably 1 minute or more and 60 minutes or less, more preferably 2 minutes or more and 40 minutes or less, and still more preferably 3 minutes or more and 30 minutes or less, respectively. This makes it possible to sufficiently shorten the time of the 1 st state and the time of the 2 nd state, respectively, and to more reliably switch to another environment before the microorganisms adapt to the current environment. In addition, the time of the 1 st state and the time of the 2 nd state can be prevented from becoming excessively short, and the microorganisms can be effectively prevented from returning to the original environment before the start of the new environment. That is, the state of the electrostatic field may be changed at intervals of time slightly shorter than the division speed of the microorganisms. This can more effectively inhibit the division of the microorganism. The time of the 1 st state and the time of the 2 nd state may be the same or different.

Here, it is known that the microorganism (1) has a division rate of about 10 minutes to 40 minutes in a temperature range of about 10 ℃ to 40 ℃; (2) the lower the temperature, the lower the cleavage rate; (3) hardly proliferated at 10 ℃ or lower except a part of microorganisms; (4) almost all microorganisms cannot proliferate at 0 ℃ or lower. Therefore, as described above, by changing the state of the electrostatic field at intervals of 60 minutes or less, preferably at intervals of 40 minutes or less, more preferably at intervals of 30 minutes or less, the state of the electrostatic field can be changed at intervals sufficiently shorter than the speed of the microorganisms splitting, taking into consideration the time until the microorganisms adapt to the environment (for example, about 10 minutes). Therefore, the growth of microorganisms can be more reliably suppressed.

In any of the methods 1 to 4, the electrostatic field forming device 15 may change the electrostatic field periodically or may change the electrostatic field irregularly (randomly). In other words, the time of the 1 st state and the time of the 2 nd state may be substantially the same for each time, or the time of the 1 st state and the time of the 2 nd state may be irregularly changed for each time. By periodically changing the electrostatic field, control of the drive of the electrostatic field forming device 15 becomes simpler than in the case where the electrostatic field is irregularly changed. On the other hand, by irregularly changing the electrostatic field, the growth of microorganisms may be more effectively suppressed than in the case where the electrostatic field is periodically changed. It is presumed that, when the electrostatic field is periodically changed, the microorganisms may adapt to the periodic environmental change itself. In this way, even if the microorganisms are adapted to the periodic environmental change itself, the growth of the microorganisms can be more effectively suppressed by irregularly changing the electrostatic field.

Further, as a method of changing the state of the electrostatic field with time, the above-described methods 1 to 4 can be appropriately combined. For example, the method 1 and the method 2 may be combined, and the electrostatic field forming device 15 may repeat the 1 st state in which the alternating voltage Vac having an amplitude of E1 is applied to the storage rack 13, the 2 nd state in which the alternating voltage Vac having an amplitude of E2(≠ E1) is applied to the storage rack 13, and the 3 rd state in which the alternating voltage Vac is not applied to the storage rack 13 in this order. For example, the method 1 and the method 3 may be combined, and the electrostatic field forming device 15 may repeat the 1 st state in which the alternating voltage Vac having the period f1 is applied to the stocker 13, the 2 nd state in which the alternating voltage Vac having the period f2(≠ f1) is applied to the stocker 13, and the 3 rd state in which the alternating voltage Vac is not applied to the stocker 13 in this order. For example, in combination with the method 2 and the method 3, the electrostatic field forming device 15 may alternately repeat the 1 st state in which the alternating voltage Vac having the amplitude E1 and the period f1 is applied to the bank 13 and the 2 nd state in which the alternating voltage Vac having the amplitude E2(≠ E1) and the period f2(≠ f1) is applied to the bank 13 in this order. In addition, the electrostatic field forming device 15 may repeat the 1 st state in which the alternating voltage Vac having the amplitude of E1 is applied to the storage rack 13, the 2 nd state in which the superimposed voltage Vd obtained by superimposing the alternating voltage Vac and the bias voltage Vb is applied to the storage rack 13, and the 3 rd state in which the alternating voltage Vac is not applied to the storage rack 13 in this order, in combination with the 1 st method and the 4 th method.

In the above-described 1 st to 4 th methods, the 1 st state and the 2 nd state are alternately repeated, but the present invention is not limited to this, and for example, at least one state (the 3 rd state, the 4 th state, and the 5 th state …) in which the state of the electrostatic field is different from the 1 st state and the 2 nd state may be provided, and these plural states may be sequentially repeated.

In the method 2 described above, since the 1 st state of the amplitude E1 and the 2 nd state of the amplitude E2 are alternately repeated, the amplitude of the alternating voltage Vac can be said to be periodically changed. In the method 2, since the amplitude of the alternating voltage Vac may change with time, the amplitude of the alternating voltage Vac may be changed irregularly at arbitrary time intervals without alternately repeating specific electrostatic fields called the 1 st state and the 2 nd state, for example. The "arbitrary time" may be constant or may vary regularly or irregularly. By irregularly changing the amplitude of the alternating voltage Vac in this manner, as described above, even when the microorganisms are subjected to the periodic environmental change itself, the growth of the microorganisms can be more effectively suppressed.

Similarly, in the above-described method 3, since the 1 st state at the frequency f1 and the 2 nd state at the frequency f2 are alternately repeated, it can be said that the frequency of the alternating voltage Vac periodically changes. In the method 3, since the frequency of the alternating voltage Vac may be changed with time, the frequency of the alternating voltage Vac may be changed irregularly at arbitrary time intervals without sequentially repeating predetermined specific electrostatic fields called the 1 st state and the 2 nd state, for example. The "arbitrary time" may be constant or may vary regularly or irregularly. By irregularly changing the frequency of the alternating voltage Vac in this manner, as described above, even when the microorganisms are subjected to the periodic environmental change itself, the growth of the microorganisms can be more effectively suppressed.

The electrostatic field forming device 15 is provided with a safety device, not shown, for preventing a user from getting an electric shock, a fire, or the like. The safety device may be configured such that, for example, a sensor for detecting the opening/closing of the door 12 provided in the main body 11 is provided, and the voltage application to the storage rack 13 is stopped after the door 12 is opened. Further, the safety device may be configured to stop the application of the voltage to the storage rack 13 when the abnormal voltage is detected.

The storage cabinet and the storage method according to the present invention have been described based on the illustrated embodiments, but the present invention is not limited thereto. For example, the structure of each part may be replaced with any structure that performs the same function, and any structure may be added.

In the above embodiment, the alternating voltage Vac is used as the voltage applied to the storage rack 13 by the electrostatic field forming device 15, but the voltage applied to the storage rack 13 is not limited thereto as long as the electrostatic field can be formed in the storage chamber 10, and for example, a dc voltage may be used. When a dc voltage is used, the voltage may be a voltage having a substantially constant voltage value, a voltage having a periodically changing voltage value, or a voltage having an irregularly changing voltage value.

Industrial applicability

As described above, the storage cabinet 1 of the present invention includes the electrostatic field forming device 15, and the electrostatic field forming device 15 forms an electrostatic field in the storage chamber 10 capable of storing the object. Further, the electrostatic field forming device 15 changes the state of the electrostatic field with time. With such a storage cabinet 1, for example, the growth (division) of microorganisms contained in food can be suppressed as compared with a case where the state of the electrostatic field in the storage chamber 10 is kept constant. Therefore, the freshness of the food stored in the storage chamber 10 can be preserved for a longer period of time. Therefore, it has excellent industrial applicability.

Description of the reference numerals

1 storage cabinet

10 receiving chamber

11 main body

12 door

13 storage rack

14 insulating body

15 electrostatic field forming device

16 Cooling device

19 mechanical chamber

111 outer wall

112 inner wall

113 heat insulating material

131 support

132 storage shelf board

161 compressor

162 condenser

191 display screen

Ac alternating voltage

E1 amplitude

E2 amplitude

Vac alternating voltage

Vb bias voltage

Vd superimposed voltage

frequency f1

frequency f2

Claims

1. A storage cabinet is characterized in that,

2. A storage cabinet according to claim 1, wherein the electrostatic field forming means periodically varies the electrostatic field.

3. The storage cabinet according to claim 1, wherein the electrostatic field forming means varies the electrostatic field irregularly.

4. A storage cabinet according to any one of claims 1 to 3, wherein there are electrodes arranged within the receiving chamber,

5. The storage cabinet according to claim 4, wherein the electrode functions as a storage rack on which the object is placed.

6. A storage cabinet according to claim 4 or 5, wherein the electrostatic field forming means varies the amplitude of the alternating voltage over time.

7. A storage cabinet according to claim 4 or 5, wherein said electrostatic field forming means alternately repeats a state in which said alternating voltage is applied and a state in which said alternating voltage is not applied.

8. A storage cabinet according to claim 4 or 5, wherein the electrostatic field forming means is capable of applying a bias voltage of a constant voltage value to the electrodes while applying the alternating voltage thereto, such that the magnitude of the bias voltage varies with time.

9. A storage cabinet according to claim 8, wherein the electrostatic field forming device maintains the alternating voltage constant.

10. A storage cabinet according to claim 4 or 5, wherein the electrostatic field forming means varies the frequency of the alternating voltage over time.

11. A storage cabinet according to any one of claims 1 to 10, wherein the electrostatic field forming means changes the state of the electrostatic field with the passage of time at intervals of 60 minutes or less.

12. A storage cabinet according to any one of claims 1 to 11, wherein there is cooling means for cooling the interior of the receiving compartment.

13. A storage method characterized in that an object is placed in an electrostatic field,

the state of the electrostatic field is caused to change over time.