Freezer, refrigerator, and defroster

Abstract

A freezer (10) freezes an object (90) while applying electron energy thereto, the freezer including: a freezer body (11), an electron energy device (12), an air filter device (13), a photocatalyst, and an irradiation device (14). The freezer body (11) stores and cools the object (90) inside a dark chamber (11A). The electron energy device (12) applies electron energy to the object (90) stored in the dark chamber (11A). The air filter device (13) generates an air flow (91A) which circulates in the dark chamber (11A) and, at the same time, filters the air flow (91A) by means of a filter element (13A). The photocatalyst is carried on the filter element (13A) and exhibits a bactericidal action when in an excited state. The irradiation device (14) irradiates, in the dark chamber (11A), the filter element (13A) with light (14A) in a wavelength region that causes both a bactericidal action and an action of bringing the photocatalyst into an excited state.

Description

Freezers, coolers, and thawers

[0001] The present disclosure relates to freezers, coolers, and thawers.

[0002] Conventionally, various freezing / thawing techniques and cold storage techniques have been developed to maintain the freshness of food ingredients, foods, and other objects for extended periods of time. Among these techniques, there is a technique that freezes, thaws, or cools an object while applying energy such as an electric field or a magnetic field (hereinafter referred to as "electronic energy") to the object, thereby suppressing cell destruction in the object and preventing a decrease in the object's freshness. For example, International Publication No. 01 / 024647 discloses a technique for freezing an object while applying an electric field and a magnetic field to the object.

[0003] The mechanism by which electron energy suppresses deterioration of freshness has not been fully elucidated. For example, some literature states that "electric fields in electron energy are useful," while other literature states that "magnetic fields in electron energy are useful." In this disclosure, both "electric fields for suppressing deterioration of freshness of objects" and "magnetic fields for suppressing deterioration of freshness of objects" are considered to be included in "electronic energy."

[0004] The technology described in WO 01 / 024647 aims to improve the quality of an object by preventing an increase in the number of viable bacteria in the object through the effect of inhibiting microbial growth, but this technology cannot actively reduce the number of viable bacteria, and therefore further improvement is needed.

[0005] The present disclosure makes it possible to actively reduce the number of viable bacteria when freezing, thawing, or keeping cold an object while applying electronic energy to the object.

[0006] In one aspect of the present disclosure, a freezer that freezes an object by applying electronic energy to the object and cooling the object comprises a freezer main body, an electronic energy device, an air filter device, a photocatalyst, and an irradiation device. The freezer main body stores and cools the object inside a darkroom, which is a place not exposed to light. The electronic energy device applies the electronic energy to the object stored in the darkroom. The air filter device is installed inside the darkroom and generates an airflow that circulates within the darkroom while filtering the airflow with a filter element, thereby sterilizing microorganisms from the airflow. The photocatalyst is supported on the filter element and exhibits a bactericidal effect when in an excited state. The irradiation device irradiates the filter element with deep ultraviolet light, which is light in a wavelength range that combines bactericidal effect and the ability to excite the photocatalyst, in the darkroom when the photocatalyst is in its ground state. The electronic energy device includes an electrode disposed in the darkroom and on which the object is set, and a power supply that outputs AC power to the electrode to provide the electronic energy to the object set on the electrode. The frequency of the power output by the power supply is set to be lower than the lowest frequency of the electromagnetic waves that can cause resonance with the electrode.

[0007] In another aspect of the present disclosure, a refrigerator that cools an object by applying electronic energy to it comprises a refrigerator main body, an electronic energy device, an air filter device, a photocatalyst, and an irradiation device. The refrigerator main body stores the object in a darkroom, which is a place not exposed to light, and keeps the object cool. The electronic energy device applies the electronic energy to the object stored in the darkroom. The air filter device is installed in the darkroom and generates an airflow that circulates within the darkroom while filtering the airflow with a filter element, thereby sterilizing microorganisms from the airflow. The photocatalyst is supported on the filter element and exhibits a bactericidal effect when in an excited state. The irradiation device irradiates the filter element with deep ultraviolet light, which is light in a wavelength range that combines bactericidal action and the ability to excite the photocatalyst, in the darkroom when the photocatalyst is in its ground state. The electronic energy device includes an electrode disposed in the darkroom and on which the object is set, and a power supply that outputs AC power to the electrode to provide the electronic energy to the object set on the electrode. The frequency of the power output by the power supply is set to be lower than the lowest frequency of the electromagnetic waves that can cause resonance with the electrode.

[0008] In another aspect of the present disclosure, a thawing cabinet for thawing a frozen object by applying electronic energy includes a thawing cabinet main body, an electronic energy device, an air filter device, a photocatalyst, and an irradiation device. The thawing cabinet main body stores the object inside a darkroom, which is a place not exposed to light, and thaws the object. The electronic energy device applies the electronic energy to the object stored in the darkroom. The air filter device is installed inside the darkroom and generates an airflow that circulates within the darkroom while filtering the airflow with a filter element, thereby removing microorganisms from the airflow. The photocatalyst is supported on the filter element and exhibits a bactericidal effect when in an excited state. The irradiation device irradiates the filter element with deep ultraviolet light, which is light in a wavelength range that combines bactericidal effect and the effect of exciting the photocatalyst, in the darkroom when the photocatalyst is in its ground state. The electronic energy device includes an electrode disposed in the darkroom and on which the object is set, and a power supply that outputs AC power to the electrode to provide the electronic energy to the object set on the electrode. The frequency of the power output by the power supply is set to be lower than the lowest frequency of the electromagnetic waves that can cause resonance with the electrode.

[0009] 1 is a schematic diagram of a freezer 10 according to a first embodiment; FIG. 2 is a perspective view of an air filter device 13 according to the first embodiment, with a part of a filter element 13A shown broken away; FIG. 3 is a schematic diagram of a refrigerator 20 according to a second embodiment; FIG. 4 is a schematic diagram of a thawing chamber 30 according to a third embodiment; and FIG. 5 is a perspective view of an air filter device 13 according to the third embodiment.

[0010] A freezer 10 according to a first embodiment of the present disclosure will be described with reference to Figures 1 and 2. This freezer 10 freezes an object 90 (a block of meat placed on a metal container 90A in Figure 1) by applying electronic energy to the object 90 and cooling it.

[0011] As shown in FIG. 1 , the freezer 10 includes a freezer main body 11 having a rectangular parallelepiped internal space 11A (hereinafter referred to as the "darkroom"). The freezer main body 11 cools objects 90 stored in the darkroom 11A. The freezer main body 11 includes a hinged door 11C that can be opened and closed on the front side of the freezer 10. A cooling device 11B is installed within the darkroom 11A. The cooling device 11B blows low-temperature air 91 along the ceiling of the darkroom 11A, thereby lowering the temperature within the darkroom 11A and cooling the objects 90. The cooling device 11B is installed so as to cover the entire left wall of the darkroom 11A.

[0012] The freezer 10 is equipped with an electronic energy device 12 that provides electronic energy to objects 90 stored in a darkroom 11A. This electronic energy device 12 includes a plurality of electrodes 12A arranged in the darkroom 11A and a power supply device 12B arranged on top of the freezer main body 11. An object 90 placed on a tank 90A can be placed on each electrode 12A. The power supply device 12B provides electronic energy to the objects 90 by outputting AC power to the electrodes 12A.

[0013] Each electrode 12A is a metal shelf net on which the container 90A can be placed, and has, for example, a square shape with a side length of approximately 40 cm. The electrodes 12A can be attached to four shelf posts 12C extending vertically within the darkroom 11A.

[0014] Each shelf column 12C has a plurality of hooks arranged vertically and capable of engaging the electrodes 12A. Therefore, by changing the hooks with which the electrodes 12A engage, the vertical position of the electrodes 12A can be changed. Furthermore, the shelf columns 12C are made of metal and are electrically connected to the electrodes 12A that are engaged therewith. Therefore, when the power supply unit 12B applies power to the shelf columns 12C, the power is transmitted to the electrodes 12A via the shelf columns 12C.

[0015] Furthermore, power supply device 12B outputs AC power to electrode 12A by using commercial power sources commonly used in Japan without frequency conversion. Therefore, the frequency of the power output by power supply device 12B is equal to the frequency of the commercial power source (i.e., 50 Hz or 60 Hz). This frequency is lower than the lowest frequency of the electromagnetic waves at which each electrode 12A can resonate.

[0016] Furthermore, power supply unit 12B supplies power to various components in freezer 10 that require power, such as electrodes 12A, cooling unit 11B, and air filter unit 13 (described below). Control box 10A is installed alongside power supply unit 12B above darkroom 11A and controls the power supply from power supply unit 12B. Control box 10A and power supply unit 12B are covered by an openable cover 10B on the front side of freezer 10.

[0017] The freezer 10 includes an air filter device 13 in the darkroom 11A. The air filter device 13 generates an air current 91A that circulates within the darkroom 11A. The air filter device 13 is installed along the upper right corner of the darkroom 11A, on the opposite side from the cooling device 11B.

[0018] As shown in FIG. 2 , the air filter device 13 includes a cylindrical crossflow fan 13B that is elongated in the direction of the rotation axis. The crossflow fan 13B includes an intake area 13C and an exhaust area 13D that extend in the direction of the rotation axis. The crossflow fan 13B draws in air 91 through the intake area 13C and exhausts it through the exhaust area 13D, thereby generating an airflow 91A that circulates within the darkroom 11A. This reduces stagnation of the air 91 within the darkroom 11A. The crossflow fan 13B is connected to a motor 13E. When power is supplied to the motor 13E from the power supply device 12B (see FIG. 1 ), the driving force of the motor 13E rotates the crossflow fan 13B, drawing in and exhausting the air 91.

[0019] The air filter device 13 has an outlet 13F that extends in the rotational axis direction along the discharge area 13D of the crossflow fan 13B. Because this outlet 13F opens facing downward, air 91 discharged from the discharge area 13D of the crossflow fan 13B passes through the outlet 13F and flows downward from the air filter device 13. Because the outlet 13F has approximately the same length as the crossflow fan 13B, the airflow 91A discharged from the outlet 13F is approximately band-shaped.

[0020] The air filter device 13 includes a filter element 13A that covers the entire suction area 13C of the crossflow fan 13B. The filter element 13A filters the air 91 passing through the air filter device 13 to remove microorganisms (not shown). In other words, the air filter device 13 generates an airflow 91A and passes the airflow 91A through the filter element 13A, thereby removing microorganisms from the airflow 91A.

[0021] The suction area 13C of the cross-flow fan 13B extends from the upper side to the left side of the cross-flow fan 13B, so the filter element 13A is curved and disposed so as to cover the upper surface and the left surface of the cross-flow fan 13B.

[0022] The filter element 13A carries a photocatalyst (not shown). This photocatalyst becomes excited when irradiated with light of a relatively short wavelength (e.g., deep ultraviolet light). Furthermore, when the photocatalyst is placed in a location where it is not exposed to light or where it is exposed only to light of a relatively long wavelength (e.g., infrared light), it loses its excited state and returns to its ground state. Furthermore, the photocatalyst exhibits a bactericidal effect in the excited state but does not exhibit a bactericidal effect in the ground state.

[0023] The photocatalyst is, for example, an ultrafine powder of anatase-type titanium dioxide supporting fine metallic silver. Commercially available photocatalysts such as "Hikari Gintec (registered trademark)" can also be used.

[0024] The air filter device 13 includes an irradiation device 14 that is disposed above the filter element 13A and that irradiates deep ultraviolet light 14A downward. The deep ultraviolet light 14A is light in a wavelength range that has both a bactericidal effect and an effect of exciting a photocatalyst. The irradiation device 14 includes a plurality of LED units that are arranged along the rotation axis direction of the crossflow fan 13B, and each LED unit has four deep ultraviolet LEDs that are oriented downward.

[0025] The irradiation device 14 irradiates the filter element 13A with deep ultraviolet rays 14A in the darkroom 11A. At this time, the deep ultraviolet rays 14A are irradiated from the side of the filter element 13A where the air 91 flows in. When the deep ultraviolet rays 14A are irradiated onto the filter element 13A, the photocatalyst in the ground state becomes excited.

[0026] The main advantages of the freezer 10 of this embodiment are described below. The freezer 10 generates a circulating airflow 91A within the darkroom 11A, where the object 90 to be frozen is stored. The air 91 contained in the airflow 91A is filtered by the filter element 13A, thereby removing microorganisms within the darkroom 11A. The freezer 10 also sterilizes microorganisms captured by the filter element 13A using the bactericidal action of the photocatalyst and the bactericidal action of the deep ultraviolet light 14A, thereby preventing live microorganisms from returning to the darkroom 11A. Here, the photocatalyst transitions from an excited state to a ground state within the darkroom 11A, where it is not irradiated with deep ultraviolet light 14A, and no longer exhibits bactericidal activity. The irradiation device 14 irradiates the filter element 13A, on which the photocatalyst is supported, with deep ultraviolet light 14A within the darkroom 11A, thereby returning the photocatalyst to an excited state with bactericidal activity. Therefore, the photocatalyst maintains its bactericidal activity while the irradiation device 14 is irradiating it with deep ultraviolet light 14A. Therefore, according to the freezer 10, the number of viable bacteria in the darkroom 11A can be effectively reduced when freezing the object 90 while applying electronic energy to the object 90. Note that while the irradiation device 14 is irradiating the deep ultraviolet light, no light other than the light irradiated by the irradiation device 14 is incident on the filter element 13A.

[0027] Furthermore, the photocatalyst in the freezer 10 is anatase-type titanium dioxide carrying metallic silver, which can inhibit the growth of microorganisms captured by the filter element 13A.

[0028] Furthermore, the air filter device 13 generates a band-shaped airflow 91A, reducing stagnation of the air 91 in the darkroom 11A. This improves the efficiency with which the air filter device 13 sterilizes microorganisms in the darkroom 11A. Furthermore, the irradiation device 14 irradiates the filter element 13A with deep ultraviolet light 14A from the side into which the air 91 flows. Microorganisms filtered out by the filter element 13A are likely to be attached to the side into which the air flows, and therefore can be effectively sterilized. Therefore, the number of live bacteria in the darkroom 11A can be efficiently reduced.

[0029] Furthermore, the frequency of the power output from the power supply unit 12B to the electrode 12A is lower than the lowest frequency of the electromagnetic waves at which each electrode 12A can resonate. This prevents the electrode 12A from functioning as an antenna radiating electromagnetic waves due to the AC power output from the power supply unit 12B. This prevents the power output to impart electronic energy to the target object 90 from being lost in the form of electromagnetic waves radiated from the electrode 12A.

[0030] Next, the refrigerator 20 according to the second embodiment will be described mainly with reference to Fig. 3. The refrigerator 20 according to the second embodiment has a configuration in which some changes have been made to the freezer 10 according to the first embodiment. Therefore, the changes will be mainly described.

[0031] The refrigerator 20 cools the object 90 (a block of meat placed on a metal container 90A in FIG. 3 ) while applying electronic energy to the object 90, thereby maintaining the object 90 at a low temperature that does not freeze the object 90. While electronic energy is being applied to the object 90, such as a block of meat, its freezing temperature decreases. Therefore, the refrigerator 20 may maintain the object 90 at a temperature below the freezing point.

[0032] The refrigerator 20 includes a refrigerator body 21 that stores and keeps cool objects 90 inside a darkroom 11A. This refrigerator body 21 includes a cooling device 21B that cools objects 90 to a temperature at which they will not freeze, instead of the cooling device 11B (see FIG. 1) of the first embodiment. The configuration of the refrigerator body 21 other than the cooling device 21B is the same as that of the freezer body 11, so detailed description thereof will be omitted.

[0033] The refrigerator 20 is equipped with an electronic energy device 12 that applies electronic energy to the object 90 stored in the darkroom 11A. The configuration of this electronic energy device 12 is similar to that of the electronic energy device 12 of the first embodiment, and therefore a detailed description thereof will be omitted.

[0034] The refrigerator 20 is equipped with an air filter device 13 provided in the darkroom 11A. The air filter device 13 generates an air current 91A that circulates within the darkroom 11A and filters the air 91 contained in the air current 91A with a filter element 13A, thereby removing microorganisms from the air current 91A. The configuration of the air filter device 13 is similar to that of the air filter device 13 of the first embodiment (see FIG. 2), and therefore a detailed description thereof will be omitted.

[0035] The refrigerator 20 circulates air 91 within the dark chamber 11A, where the object 90 to be kept cold is stored, and filters the air 91 with a filter element 13A to remove microorganisms within the dark chamber 11A. The refrigerator 20 also sterilizes the microorganisms filtered by the filter element 13A using the bactericidal action of the photocatalyst and the bactericidal action of deep ultraviolet light 14A, thereby preventing live microorganisms from returning to the dark chamber 11A. If the photocatalyst is not exposed to deep ultraviolet light 14A within the dark chamber 11A, it transitions from its excited state to its ground state and no longer exhibits bactericidal activity. Therefore, the irradiation device 14 irradiates the filter element 13A, on which the photocatalyst is supported, with deep ultraviolet light 14A within the dark chamber 11A, thereby returning the photocatalyst to its bactericidal excited state. Therefore, the photocatalyst maintains its bactericidal activity as long as the irradiation device 14 irradiates deep ultraviolet light 14A. Therefore, according to the refrigerator 20, when the object 90 is kept cold while electron energy is applied to the object 90, the number of live bacteria in the darkroom 11A can be actively reduced.

[0036] Moreover, the cooler 20 has the same configuration as the freezer 10 according to the first embodiment, except for the cooling device 21B. Therefore, the cooler 20 also has advantages resulting from the same configuration as the freezer 10.

[0037] Next, a defrosting box 30 according to a third embodiment will be described mainly with reference to Figures 4 and 5. The defrosting box 30 according to the third embodiment is the freezer 10 according to the first embodiment with some modifications. Therefore, the modifications will be mainly described.

[0038] The thawing chamber 30 thaws a frozen object 90 (a block of meat placed on a metal container 90A in FIG. 4) by applying electronic energy thereto.

[0039] As shown in Fig. 4, the defrosting chamber 30 is equipped with air filter devices 13 and 33, which are respectively disposed in the upper right and upper left corners of the darkroom 11A. Here, the air filter device 13 (see Fig. 5) has the same configuration as the air filter device 13 according to the first embodiment. Furthermore, the air filter devices 13 and 33 in the defrosting chamber 30 have exactly the same configuration, except that they are reversed left and right depending on their installation positions. Therefore, detailed descriptions of the air filter devices 13 and 33 will be omitted.

[0040] The thawing cabinet 30 includes a thawing cabinet main body 31 that stores and thaws an object 90 inside the darkroom 11A. The thawing cabinet main body 31 includes a heater 31B that raises the temperature inside the darkroom 11A in order to thaw the object 90, instead of the cooling device 11B according to the first embodiment.

[0041] In this embodiment, a heater 31B is attached to each air filter device 13, 33. As shown in Fig. 5, the heater 31B is disposed downstream of the air outlet 13F of the air filter device 13 in the flow direction of the airflow 91A. The heater 31B is a cord heater disposed in parallel to the air outlet 13F, but various heaters, such as a rod-shaped cartridge heater, can also be used.

[0042] The thawing cabinet 30 is equipped with an electronic energy device 12 that applies electronic energy to the object 90 stored in the darkroom 11A. This electronic energy device 12 has the same configuration as the electronic energy device 12 according to the first embodiment, and therefore a detailed description thereof will be omitted.

[0043] The thawing chamber 30 described above circulates air 91 within the dark chamber 11A containing the object 90 to be thawed and filters the air 91 with a filter element 13A to remove microorganisms within the dark chamber 11A. The thawing chamber 30 also sterilizes the microorganisms filtered by the filter element 13A using the bactericidal action of the photocatalyst and the bactericidal action of deep ultraviolet light 14A, thereby preventing live microorganisms from returning to the dark chamber 11A. If the photocatalyst is not exposed to deep ultraviolet light 14A within the dark chamber 11A, its excited state transitions to its ground state and it no longer exhibits bactericidal activity. Therefore, the irradiation device 14 irradiates the filter element 13A carrying the photocatalyst with deep ultraviolet light 14A within the dark chamber 11A, thereby returning the photocatalyst to its bactericidal excited state. Therefore, the photocatalyst maintains its bactericidal activity as long as the irradiation device 14 irradiates the filter element 13A with deep ultraviolet light 14A. Therefore, according to the thawing cabinet 30, when the object 90 is thawed while applying electronic energy to the object 90, the number of live bacteria in the darkroom 11A can be actively reduced.

[0044] Although the present invention has been described based on the above-described embodiments, various improvements and modifications can be made without departing from the spirit and purpose of the present invention. For example, the present invention is not limited to the specific structure described above, and modifications can be made as follows. Furthermore, the features of each embodiment can be separated from each other or combined in any manner.

[0045] Although each embodiment has only one of the functions of freezing, refrigeration, or thawing, the device according to the present disclosure may have at least two of the functions of freezing, refrigeration, and thawing.

[0046] The electrodes of the electronic energy device are not limited to the form of a rack on which a container containing an object is placed and electronic energy is applied to the object through the container. For example, the electrodes may be in the form of a shelf on which an object can be placed directly, or in the form of a container into which an object can be placed directly. The electrodes may also be arranged, for example, along the wall of a darkroom. In this case, a support structure for the object may be provided adjacent to the electrode in the darkroom, and the object may be supported by the support structure, thereby setting the object on the electrode.

[0047] According to a first aspect of the present disclosure, a freezer freezes an object by applying electronic energy to the object and cooling it. The freezer includes a freezer main body that stores and cools the object inside a darkroom. The freezer also includes an electronic energy device that applies electronic energy to the object stored in the darkroom. The freezer also includes an air filter device that is installed inside the darkroom and generates an airflow that circulates within the darkroom and filters the airflow with a filter element, thereby sterilizing microorganisms from the airflow. The freezer also includes a photocatalyst supported on the filter element and that exhibits a bactericidal effect when in an excited state. The freezer also includes an irradiation device that irradiates the filter element with light in a wavelength range that combines bactericidal effect and the effect of exciting the photocatalyst inside the darkroom.

[0048] In a first aspect, the freezer circulates air in a dark chamber containing the object to be frozen and filters the airflow with a filter element to eliminate microorganisms in the dark chamber. The freezer also sterilizes microorganisms filtered by the filter element using the bactericidal action of the photocatalyst and the bactericidal action of light, thereby preventing the microorganisms from returning to the dark chamber as viable bacteria. Here, the photocatalyst loses its excited state (returns to its ground state) in the dark chamber, thereby losing its bactericidal action. In contrast, the irradiator irradiates the filter element carrying the photocatalyst with light in the dark chamber, thereby returning the photocatalyst to its excited state with bactericidal action. Therefore, the photocatalyst maintains its bactericidal action as long as the irradiator irradiates light. Therefore, the freezer described above can achieve a sterilization function that actively reduces the number of viable bacteria in the dark chamber when freezing the object by applying electronic energy to the object.

[0049] In a second embodiment, the photocatalyst is an ultrafine powder of anatase-type titanium dioxide carrying fine metallic silver, and the light is deep ultraviolet light.

[0050] Photocatalysts composed of ultrafine anatase titanium dioxide powder supported with fine metallic silver are known to exhibit strong antibacterial effects due to the synergistic effect of titanium dioxide and metallic silver and the large specific surface area. Deep ultraviolet light, a type of light also used for sterilization purposes, can excite anatase titanium dioxide. Therefore, according to the second aspect, the antibacterial effect of the photocatalyst can be utilized to suitably realize the freezer of the present disclosure.

[0051] In a third aspect, the air filter device includes a crossflow fan that is elongated in the direction of the rotation axis and has an air intake region and an air discharge region that are each set as regions that expand in the circumferential direction. The filter element covers the intake region from the upstream side of the intake. The irradiation device irradiates the filter element with light from the upstream side.

[0052] According to the third aspect, the air filter device reduces stagnation of air in the darkroom by making the air intake and exhaust into band-like flows, thereby improving the efficiency of the air filter device in sterilizing microorganisms in the darkroom. Furthermore, the irradiation device irradiates light from the upstream side of the intake, where microorganisms filtered by the filter element are likely to be attached, thereby enabling more effective sterilization. Therefore, according to the above embodiment, the efficiency of sterilization, which reduces the number of live bacteria in the darkroom, can be improved.

[0053] In a fourth aspect, the electronic energy device includes an electrode and a power supply. The electrode is placed in a darkroom and an object is set thereon. The power supply outputs AC power to the electrode, thereby providing electronic energy to the object set on the electrode. The frequency of the power output by the power supply is set to be lower than the lowest frequency of the electromagnetic waves at which the electrode can resonate.

[0054] According to the fourth aspect, it is possible to prevent the electrodes from functioning as antennas that radiate electromagnetic waves due to the AC power output from the power supply device. Therefore, according to the above embodiment, it is possible to provide a freezer that prevents the power output for providing electronic energy to an object from being lost in the form of electromagnetic waves radiated from the electrodes.

[0055] In a fifth aspect of the present disclosure, a refrigerator keeps an object cool while applying electronic energy to it. The refrigerator includes a refrigerator body that stores and cools an object inside a dark chamber. The refrigerator also includes an electronic energy device that applies electronic energy to the object stored in the dark chamber. The refrigerator also includes an air filter device that is installed inside the dark chamber and generates an airflow that circulates within the dark chamber and filters the airflow with a filter element, thereby sterilizing microorganisms from the airflow. The refrigerator also includes a photocatalyst that is supported on the filter element and exhibits a bactericidal effect when in an excited state. The refrigerator also includes an irradiation device that irradiates the filter element with light in a wavelength range that combines bactericidal effect and the effect of exciting the photocatalyst inside the dark chamber.

[0056] According to a fifth aspect, a refrigerator circulates air in a dark chamber containing an object to be kept cold and filters the airflow with a filter element to sterilize microorganisms in the dark chamber. The refrigerator also sterilizes microorganisms filtered by the filter element using the bactericidal action of a photocatalyst and the bactericidal action of light, thereby preventing the microorganisms from returning to the dark chamber as viable bacteria. Here, the photocatalyst loses its excited state (returns to its ground state) in the dark chamber, thereby losing its bactericidal action. In contrast, an irradiation device irradiates the filter element carrying the photocatalyst with light in the dark chamber, thereby returning the photocatalyst to its excited state with bactericidal action. Therefore, the photocatalyst maintains its bactericidal action as long as the irradiation device irradiates the light. Therefore, the above-described refrigerator can achieve a sterilization function that actively reduces the number of viable bacteria in the dark chamber when providing electronic energy to the object while keeping the object cool.

[0057] In a sixth aspect of the present disclosure, a thawing cabinet thaws a frozen object by applying electronic energy to it. The thawing cabinet includes a thawing cabinet main body that stores and thaws the object inside a darkroom. The thawing cabinet also includes an electronic energy device that applies electronic energy to the object stored in the darkroom. The thawing cabinet also includes an air filter device that is installed inside the darkroom and generates an airflow that circulates within the darkroom and filters the airflow with a filter element, thereby sterilizing microorganisms from the airflow. The thawing cabinet also includes a photocatalyst that is supported on the filter element and exhibits a bactericidal effect when in an excited state. The thawing cabinet also includes an irradiation device that irradiates the filter element with light in a wavelength range that combines bactericidal effect and the effect of exciting the photocatalyst inside the darkroom.

[0058] A thawing cabinet according to a sixth aspect circulates air in a dark chamber containing an object to be thawed and filters the airflow with a filter element to sterilize microorganisms in the dark chamber. The thawing cabinet also sterilizes microorganisms filtered by the filter element using the bactericidal action of the photocatalyst and the bactericidal action of light, thereby preventing the microorganisms from returning to the dark chamber as viable bacteria. The photocatalyst loses its excited state (returns to its ground state) in the dark chamber, thereby losing its bactericidal effect. In contrast, the irradiation device irradiates the filter element carrying the photocatalyst with light in the dark chamber, thereby returning the photocatalyst to its excited state with bactericidal activity. Therefore, the photocatalyst maintains its bactericidal action as long as the irradiation device irradiates the object with light. Therefore, the above-described thawing cabinet can achieve a sterilization function that actively reduces the number of viable bacteria in the dark chamber when thawing the object while applying electronic energy to the object.

Claims

1. A freezer for freezing an object by cooling it while providing electronic energy to the object, comprising: a freezer main body for storing and cooling the object inside a darkroom, which is a place not exposed to light; an electronic energy device for providing the electronic energy to the object stored in the darkroom; an air filter device provided in the darkroom for generating an airflow circulating within the darkroom and filtering the airflow with a filter element, thereby sterilizing microorganisms from the airflow; a photocatalyst supported on the filter element and exhibiting a bactericidal effect when in an excited state; and an irradiation device for irradiating the filter element with deep ultraviolet light, which is light in a wavelength range that combines a bactericidal effect and an effect of exciting the photocatalyst, while in the darkroom where the photocatalyst is in the ground state; the electronic energy device comprises: an electrode provided in the darkroom on which the object is set; and a power supply device for outputting AC power to the electrode to provide the electronic energy to the object set on the electrode, A freezer, wherein a frequency of the power output by the power supply device is set to a frequency lower than a minimum frequency of electromagnetic waves at which the electrodes can resonate.

2. A freezer as claimed in claim 1, comprising a cooling device installed in a state covering the wall surface of the darkroom and blowing out low temperature air along the ceiling of the darkroom, wherein the air filter device comprises: a cross flow fan formed long in the direction of the rotation axis and having air intake and exhaust areas each set as a band-shaped area extending circumferentially; and an outlet arranged so as to extend long along the exhaust area, for blowing out downward the air exhausted by the cross flow fan into the exhaust area; and further wherein the air filter device is arranged along a corner of the ceiling of the darkroom opposite the cooling device, so that the intake area is an area extending from above towards the cooling device.

3. A freezer according to claim 1 or 2, wherein the photocatalyst is an ultrafine powder of anatase type titanium dioxide carrying fine metallic silver.

4. A freezer as claimed in claim 1 or 2, wherein the air filter device is provided with a cross-flow fan formed long in the direction of the rotation axis and having air intake and exhaust areas each set as a band-like area extending in the circumferential direction, the filter element covers the intake area from the upstream side of the intake, and the irradiation device irradiates the light onto the filter element from the upstream side.

5. A refrigerator for keeping an object cool while providing it with electronic energy, comprising: a refrigerator body for storing the object inside a darkroom, which is a place not exposed to light, and keeping the object cool; an electronic energy device for providing the electronic energy to the object stored in the darkroom; an air filter device provided in the darkroom for generating an airflow circulating within the darkroom and filtering the airflow with a filter element, thereby sterilizing microorganisms from the airflow; a photocatalyst supported on the filter element and exhibiting a bactericidal effect when in an excited state; and an irradiation device for irradiating the filter element with deep ultraviolet light, which is light in a wavelength range that combines a bactericidal effect and an effect of exciting the photocatalyst, while the photocatalyst is in the ground state, in the darkroom, the electronic energy device comprising: an electrode provided in the darkroom on which the object is set; and a power supply device for outputting AC power to the electrode to provide the electronic energy to the object set on the electrode, A frequency of the power output by the power supply device is set to a frequency lower than a minimum frequency of electromagnetic waves at which the electrodes can resonate.

6. A cooler as claimed in claim 5, comprising a cooling device installed in a state covering a wall surface of the darkroom and blowing out low temperature air along the ceiling of the darkroom, the air filter device comprising: a cross flow fan formed long in the direction of the rotation axis and having air intake and exhaust areas each set as a band-shaped area expanding in the circumferential direction; and an outlet arranged so as to extend long along the exhaust area, for blowing out downward the air exhausted by the cross flow fan into the exhaust area; and further, the air filter device is arranged along a corner of the ceiling of the darkroom opposite the cooling device, so that the intake area is an area expanding from above towards the cooling device.

7. A thawing cabinet for thawing a frozen object by applying electronic energy thereto, comprising: a thawing cabinet main body for storing the object inside a darkroom, which is a place not exposed to light, and thawing the object; an electronic energy device for applying the electronic energy to the object stored in the darkroom; an air filter device provided in the darkroom for generating an airflow circulating within the darkroom and filtering the airflow with a filter element, thereby sterilizing microorganisms from the airflow; a photocatalyst supported on the filter element and exhibiting a bactericidal effect when in an excited state; and an irradiation device for irradiating the filter element with deep ultraviolet light, which is light in a wavelength range that combines a bactericidal effect and an effect of exciting the photocatalyst, while the photocatalyst is in the ground state, in the darkroom, the electronic energy device comprising: an electrode provided in the darkroom on which the object is set; and a power supply device for outputting AC power to the electrode to apply the electronic energy to the object set on the electrode, A defrosting chamber, wherein a frequency of the power output by the power supply device is set to a frequency lower than a minimum frequency of electromagnetic waves at which the electrodes can resonate.

8. A thawing cabinet as described in claim 7, further comprising a heater for raising the air temperature within the darkroom to thaw the object, wherein the air filter device comprises: a cross-flow fan formed long in the direction of the rotation axis, with the air intake area and exhaust area each set as a band-shaped area extending circumferentially; and an outlet arranged so as to extend long along the exhaust area, for blowing out the air exhausted by the cross-flow fan to the exhaust area, wherein the heater is attached to a position downstream of the exhaust area of ​​the air, extending long along the outlet.

9. A thawing chamber as described in claim 8, wherein the darkroom has a hinged door that can be opened and closed on the front side, and the air filter device comprises: a first air filter device arranged along the right-hand corner of the ceiling of the darkroom so as to make the suction area an area that expands from above to the left side, and a second air filter device having exactly the same configuration as the first air filter device except that it is reversed left to right from the first air filter device and arranged along the left-hand corner of the ceiling of the darkroom, and wherein the heaters are attached one by one corresponding to the first air filter device and the second air filter device.

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