Refrigerating showcase provided with sterilization countermeasures

Abstract

[Problem] To provide a refrigerating showcase in which the occurrence and growth of bacteria, molds and viruses are prevented; and to also provide a sterilization method for preventing the occurrence and growth of bacteria, molds and viruses in a refrigerating showcase. [Solution] A refrigerating showcase 10 comprises a space 20 which accommodates an article to be refrigerated (hereinafter, simply referred to as an "accommodation space"), and a circulation path 30 through which air from the accommodation space 20 is circulated in the accommodation space 20. The circulation path 30 includes an ultraviolet ray UV-C light source 47 that irradiates the air in the circulation path 30 with ultraviolet ray UV-C.

Description

Refrigerated showcases with disinfection measures

[0001] The present invention relates to a refrigerated showcase that has been provided with a sterilization measure, and a sterilization method for a refrigerated showcase.

[0002] In order to prevent the adhesion and proliferation of bacteria and mold in refrigerated showcases, it has been proposed to generate plasma in the circulating cold air to generate ozone and active oxygen, and to irradiate this ozone and active oxygen with electrons generated by corona discharge (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2001-221565

[0004] The proposed refrigerated showcase has been shown to be able to effectively suppress the growth of bacteria and mold floating or adhering to the product display room by using high concentrations of negative ions and oxygen radicals. However, the ozone and active oxygen generated by plasma generation are undesirable because they are gases that have an odor and are harmful to the human body. Corona discharge is also dangerous to the human body.

[0005] An object of the present invention is to provide a refrigerated showcase that has been subjected to a novel sterilization measure that does not use plasma or corona discharge. Another object of the present invention is to provide a novel sterilization method for a refrigerated showcase.

[0006] In order to achieve the above object, the refrigerated showcase having the sterilization measures of the present invention is characterized by comprising: a space for storing refrigerated items (hereinafter simply referred to as "storage space"), a circulation path for circulating air from the storage space back into the storage space, and an ultraviolet UV-C light source for irradiating the air in the circulation path with ultraviolet UV-C. Also, the sterilization method for a refrigerated showcase of the present invention is characterized by irradiating the air in the circulation path with ultraviolet UV-C in a refrigerated showcase having a storage space for storing refrigerated items and a circulation path for circulating air from the storage space back into the storage space.

[0007] According to the present invention, a refrigerated showcase and a sterilization method therefor can be provided which do not use plasma or corona discharge and therefore do not generate odors or gases that are harmful to the human body.

[0008] 5 is a diagram showing the wavelength range of ultraviolet light UV-C. FIG. 6 is a diagram showing the relationship between the relative ratio of absorption coefficients in DNA / RNA of bacteria, fungi, etc. and ultraviolet light wavelength. Photographs showing the mold growth state of commercially available bread depending on whether or not ultraviolet light UV-C is irradiated and for how long the irradiation time is. A sketch of a refrigerated showcase of embodiment 1 of the present invention. A front view of a refrigerated showcase of embodiment 1 of the present invention. A side cross-sectional view of a refrigerated showcase of embodiment 1 of the present invention (cross-sectional view A-A in FIG. 5). A side cross-sectional view of a refrigerated showcase of embodiment 2 of the present invention (cross-sectional view substantially the same as FIG. 6).

[0009] The refrigerated showcase with the sterilization countermeasure of the present invention and the sterilization method for the refrigerated showcase will be described in detail below with reference to the drawings. However, the present invention is not limited to the following description. In the following Figures 1 to 7, identical parts may be designated by the same reference numerals, and their description may be omitted. Furthermore, for the sake of convenience, the structure of each part may be appropriately simplified in the drawings, and the dimensional ratios of each part may be shown schematically and different from the actual ones. In this specification, unless otherwise specified, terms such as "top, upper part, upper," "bottom, lower, lower," "middle," "up and down," "horizontal," "front," and "rear" used to refer to the position, arrangement, and direction of the refrigerated showcase in its usage mode. Furthermore, "-" indicating a numerical range includes the lower and upper limits. In this specification, the term "just before" used to describe a positional relationship means "20 cm or less," preferably "1-10 cm," and more preferably "1-5 cm."

[0010] <Regarding targets for sterilization in refrigerated showcases> The present invention is intended to sterilize refrigerated showcases, but the bacteria whose occurrence and proliferation should be prevented are bacteria in a broad sense, and also include mold and viruses (hereinafter, bacteria, mold, and viruses may be simply referred to as "bacteria, etc.").

[0011] <Regarding the Shape and Structure of the Refrigerated Showcase> There are various types of refrigerated showcases, but any structure or shape is included in the present invention as long as it does not deviate from the technical concept of the present invention. That is, it may be an open type, a closed type, a reach-in type with an opening and closing door, or the like. In addition, shapes and structures such as an open type multi-tier type, a flat type, a closed type box type, a tabletop type, a three-sided glass type, and a four-sided glass type may be adopted.

[0012] <Cooling methods in refrigerated showcases> The cooling method in refrigerated showcases is usually one that forces the circulation of air or cold air (hereinafter, "air or cold air" will be referred to as "air"), which is desirable from the viewpoint of efficient cooling, but natural convection of air is also acceptable. In forced air circulation types, heat is exchanged using a cooling device placed on the top, bottom, or back side, and the cooled air is then forcibly circulated using a blower fan or suction fan, thereby cooling the inside of the showcase.

[0013] <Regarding Sterilization Means for Refrigerated Showcases> The present inventors searched for various sterilization means for refrigerated showcases in order to implement sterilization measures for refrigerated showcases. Such sterilization means included photocatalysts in the circulation path, spraying of hypochlorous acid, circulation, generation of ozone or ions in the air circulation path, and ultraviolet UV-C, and extensively examined the advantages and disadvantages of these sterilization means. The results of this examination are shown in Table 1. In Table 1, ◎, ◯, △, and × indicate the degree of merit, demerit, and advantage or disadvantage, respectively, with ◎ indicating the best and × indicating the worst.

[0014]

[0015] Photocatalysts in circulating air have the advantage of effectively oxidizing and decomposing airborne bacteria, viruses, mold, and chemicals that cause unpleasant odors without producing any distinctive odors or gases that are harmful to the human body. However, they are not effective at oxidizing and decomposing bacteria and chemicals that adhere to objects such as the interior surfaces of showcases. Another drawback is that organic matter decomposition residues adhere to the photocatalyst-supporting substrate, requiring periodic cleaning (e.g., approximately once every six months) to achieve the desired oxidative decomposition function.

[0016] The spraying and circulation of hypochlorous acid has the advantage of effectively oxidizing and decomposing airborne bacteria, viruses, mold, and chemical substances that cause unpleasant odors, as well as being able to oxidize and decompose to some extent bacteria and the chemical substances attached to objects such as the inside of a showcase. However, it has the disadvantage of emitting chlorine compound gases that have a distinctive odor and are harmful to the human body, which requires the replenishment of hypochlorous acid.

[0017] Ozone has the advantage of effectively oxidizing and decomposing airborne bacteria, viruses, mold, and chemical substances that cause unpleasant odors, as well as being able to oxidize and decompose to some extent bacteria and chemical substances attached to objects such as the interior surfaces of showcases. Ozone is also advantageous in that it is generated using discharge or UV lamps, eliminating the need for chemicals such as hypochlorous acid. However, it has the disadvantage of generating ozone gas, which has a distinctive odor and is harmful to the human body.

[0018] Since ions are mainly generated by discharge, there are advantages in that chemicals such as hypochlorous acid are not required and no odors or gases that are harmful to the human body are generated. However, there is a disadvantage in that the oxidative decomposition performance against bacteria, viruses, mold, and chemical substances that are floating in the air and that cause unpleasant odors, as well as the oxidative decomposition performance against bacteria and chemical substances attached to objects such as the inside of a showcase, is lower than other methods.

[0019] Although UV-C ultraviolet light cannot be expected to have deodorizing properties, it does inhibit the growth of bacteria, viruses, and mold floating in the air, as well as bacteria attached to objects such as the inside of a display case, by destroying their nucleic acids (RNA and DNA). Therefore, it has the advantage of having stronger sterilization capabilities than photocatalysts, hypochlorous acid, ozone, and ion-based oxidative decomposition. It also has the advantage of not producing distinctive odors or gases that are harmful to the human body. Furthermore, UV-C ultraviolet light is effective in inhibiting the growth of pathogenic microorganisms that are resistant to chemicals and chlorine.

[0020] <About the disinfecting function of ultraviolet UV-C> Figure 1 shows the wavelength range of light. UV-C ultraviolet light is in the short wavelength range (10-280 nm) of ultraviolet light (wavelength 10-380 nm). Light sources for UV-C ultraviolet light include LEDs, cold cathode lamps, and hot cathode lamps. Light sources in the UV-B (wavelength 280-320 nm), UV-A (wavelength 320-400 nm), and visible light range (wavelength 380-420 nm) do not have the same disinfecting ability as UV-C ultraviolet light, but they still have some disinfecting effect, so they can be used in combination with UV-C ultraviolet light.

[0021] Figure 2 shows the ultraviolet absorption characteristics (ultraviolet wavelength dependence on the relative ratio of absorption coefficients) of the DNA and RNA of bacteria, fungi, etc. As is clear from Figure 2, the ultraviolet absorption characteristics of the DNA and RNA of bacteria, fungi, etc. are high in the range of approximately 250-280 nm, indicating a high effect of preventing the occurrence and proliferation of bacteria, fungi, etc., and of disinfecting them.

[0022] Table 2 shows the inactivation effect of ultraviolet light (ultraviolet light using a germicidal lamp with a wavelength of 254 nm) on bacteria, mold, etc., as a function of the cumulative dose of ultraviolet light (mJ / cm ２ ) [=UV irradiance (mW / cm ２ ) × irradiation time (seconds) for comparison.

[0023]

[0024] As is clear from Table 2, molds such as Aspergillus niger (black mold), Aspergillus oryzae, and Penicillium glabra have higher resistance to inactivation by ultraviolet light than other bacteria and viruses, but it can also be seen that they can be inactivated by increasing the amount of ultraviolet light irradiation (cumulative irradiation amount).

[0025] Figure 3 shows photographs taken by our company showing the mold growth on commercially available dry bread with and without UV-C irradiation and the change in the time elapsed after irradiation. Specifically, the light from a cold cathode UV lamp (UV-CCL) was irradiated at a distance of 5 cm from the bread (1.74 mW / cm ２ ) for 240 seconds (i.e., irradiated with an amount sufficient to inactivate 99.9% of Aspergillus oryzae) and no irradiation at all were sealed in transparent plastic bags, and the state of mold growth was photographed over time.

[0026] As is clear from Figure 3, mold growth was observed in the non-UV-irradiated bread after 73 hours, and the mold-growing area expanded with the passage of time at 168, 185, and 200 hours. In contrast, mold growth was not observed in the non-UV-irradiated bread before 185 hours, and only slight mold growth was observed after 185 and 200 hours.

[0027] As shown in Figures 2, 3, Tables 1 and 2, ultraviolet light UV-C is effective in sterilizing bacteria, mold, etc., and it is believed that when ultraviolet light UV-C is irradiated onto the circulating air in a refrigerated showcase, bacteria, mold, and other microorganisms in the circulating air are sterilized.

[0028] In order to achieve the above-mentioned object of the present invention, and taking into account the results of the above-mentioned studies, the refrigerated showcase of the present invention is equipped with a circulation path that circulates air from the space that stores refrigerated items (i.e., the storage space) into the storage space, and an ultraviolet UV-C light source that irradiates the air in the circulation path with ultraviolet UV-C, thereby preventing the occurrence and proliferation of bacteria, mold, etc.

[0029] [Embodiment 1] Fig. 4 is a schematic diagram of a refrigerated open showcase 10 according to Embodiment 1 of the present invention, Fig. 5 is a front view of the refrigerated open showcase 10 according to the first embodiment, and Fig. 6 is a cross-sectional view taken along line A-A of the front view. The refrigerated open showcase 10 includes a base 11, an upper panel 12, a lower panel 13, an upper front panel 14, a lower front panel 15, a left panel 16, a right panel 17, and a rear panel 18 (here, the upper panel 12, the lower panel 13, the upper front panel 14, the lower front panel 15, the left panel 16, the right panel 17, and the rear panel 18 are collectively referred to as "panels"). The upper front panel 14 and the lower front panel 15 are provided on the front side of the refrigerated open showcase 10, and a front opening 25 is formed between the upper front panel 14 and the lower front panel 15. The upper, lower, left and right sides, and rear side, excluding the front side, are separated from the outside air by the top panel 12, bottom panel 13, left panel 16, right panel 17, and rear panel 18, respectively. The refrigerated open showcase can be provided with one, multiple, or multiple types of storage devices for refrigerated items, such as shelves 22 for storing the refrigerated items, in a storage space 20 for storing food and other refrigerated items. Refrigerated items include, but are not limited to, vegetables, fruits, beverages, frozen desserts, meat, eggs, etc. Other refrigerated items include, but are not limited to, ice packs, medicines, etc.

[0030] The refrigerated open showcase 10 of the first embodiment may include a blower fan 45 and / or a suction fan (not shown; the same applies below) for moving the air inside. The air movement path within the refrigerated open showcase 10 of the first embodiment is set so as to cool the refrigerated items present in the storage space 20. In the first embodiment shown in Figures 4-6, air flows downward through an outlet 35 on the top panel 12 side to cool the refrigerated items. After cooling the refrigerated items, the warmed air in the storage space 20 flows into a circulation path 30 through an inlet 36 on the bottom panel 13 side by the suction action of the blower fan 45 (described below). The circulation path 30 may include a lower circulation path 32 including the inlet 36, an upper circulation path 31 including the outlet 35, and an intermediate circulation path 33 between the lower circulation path 32 and the upper circulation path 31. The air that flows into the lower circulation path 32 is cooled by a cooling device (not shown) and a blower fan 45 provided in the circulation path 30, and moves toward the outlet 35 of the top plate 12 via the intermediate circulation path 33 and the upper circulation path 31. The outlet 35 preferably includes a straightener to straighten the air flowing out therefrom. Examples of the straightener include a honeycomb-shaped, lattice-shaped, or other structure in which elements of the same shape are connected together. A portion of the air in the circulation path 30 can also be configured to flow out from the intermediate circulation path 33 into the storage space 20. The circulation path 30 extending from the inlet 36 to the outlet 35 can be formed by the space between at least three panels, i.e., the upper panel 12, the lower panel 13, the upper front panel 14, the lower front panel 15, the left panel 16, the right panel 17, and the back panel 18, and partition panels (e.g., upper partition panel 41, lower partition panel 42, and middle partition panel 43). The circulation path 30 can also be formed as a separate member (e.g., a cylindrical body, a tubular body, a flexible pipe, etc.) from the panels 12, 13, 14, 15, 16, and 17 and the partition panels 41, 42, and 43. The cross-sectional shape of the circulation path 30 is not limited, and examples thereof include a circular, elliptical, triangular, rectangular, and trapezoidal shape.

[0031] The circulation path 30 is further equipped with an ultraviolet UV-C light source 47. The position of the ultraviolet UV-C light source 47 in the circulation path 30 is not particularly limited, but it can be installed, for example, upstream of the blower fan 45 immediately after the entrance 36 (i.e., before the intake port of the blower fan 45) or upstream immediately before the exit 35. The circulation path 30 can also include a photocatalyst (not shown) that is irradiated with ultraviolet UV-C from the ultraviolet UV-C light source 47 to enhance the sterilization effect of the refrigerated showcase 10. The photocatalyst material is generally titanium oxide or tungsten oxide fine particles, which are supported on the surface of a porous metal mesh, ceramic foam, or glass fiber and used as a filter. When multiple ultraviolet UV-C light sources 47 are installed in the circulation path 30, the photocatalyst can be installed corresponding to only some of the ultraviolet UV-C light sources 47.

[0032] The storage device for the refrigerated goods provided in the storage space 20 of the refrigerated open showcase 10 may be fixed or detachable. Examples of the storage device for the refrigerated goods include one or more shelves 22, a hanging device for the refrigerated goods, etc. The shelf 22 may be provided horizontally or may be inclined toward the front or the like, and the angle of inclination may be adjustable. The spacing between the multiple shelves 22 may be changeable.

[0033] The left panel 16 and the right panel 17 are formed to separate only the left and right sides of the circulation path 30 from the outside air, but in order to enhance the refrigeration effect on the refrigerated items in the storage space 20, the entire left and right sides of the storage space 20 can also be formed to separate them in the same way as the circulation path 30.

[0034] 7 is a side cross-sectional view of a refrigerated open showcase 10 showing another embodiment 2 of the present invention. In embodiment 1, the ultraviolet UV-C light source 47 is provided upstream of the blower fan 45 immediately after the entrance 36, but in embodiment 2, the ultraviolet UV-C light source 47 is provided upstream just before the exit 35. The only difference between embodiments 1 and 2 is the installation position of the ultraviolet UV-C light source 47, and there are no other differences.

[0035] In the first and second embodiments, an open case has been described as an example, but the present invention is not limited to this and may be a closed case. Closed cases may be box-shaped, tabletop-shaped, with three glass sides, four glass sides, five glass sides, reach-in cases with opening and closing doors, and the like, and it should be understood that the present invention includes cases of these shapes as long as they do not deviate from the technical concept of the present invention.

[0036] In the first and second embodiments, the air in the circulation path 30 flows downward from the outlet 35, and the air that flows into the storage space 20 descends while forming an air curtain at the front open portion 25 of the storage space 20, and flows into the inlet 36 below the circulation path 30. This flow of air from above to below in the storage space 20 can be achieved by forced circulation using the blower fan 45 and / or the suction fan. Furthermore, even if the blower fan 45 or the suction fan is not used, natural convection can be achieved by providing a cooling device (not shown) above the circulation path 30.

[0037] Furthermore, when the blower fan 45 and / or the suction fan are used, the air flow in the storage space 20 is not limited to a downward flow. For example, the outlet 35 may be provided on one of the left panel 16 side and the right panel 17 side, and the inlet 36 may be provided on the other side, so that the air flow in the storage space 20 can be formed horizontally, diagonally, or the like.

[0038] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0039] This application claims priority based on Japanese Patent Application No. 2023-125523, filed August 1, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0040] According to the present invention, it is possible to provide a refrigerated showcase 10 in which the occurrence and proliferation of bacteria, mold, etc. on the inner surface of the refrigerated showcase 10 and in food stored in the refrigerated showcase 10 is reduced without using plasma or corona discharge, without using various chemicals for maintenance, and without generating odors or gases that are harmful to the human body. The sterilization method of the present invention makes it possible to reduce the occurrence and proliferation of bacteria, mold, etc. on the inner surface of the refrigerated showcase 10 and in food stored in the storage space 20 of the refrigerated showcase 10 without temporarily removing fixtures in the storage space 20, such as shelves 22, for cleaning, without using chemicals for maintenance, and without generating odors or gases that are harmful to the human body.

[0041] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes.

[0042] (Appendix 1) A refrigerated showcase comprising: a space for storing items to be refrigerated (hereinafter simply referred to as "storage space"); a circulation path for circulating air from the storage space back to the storage space; and an ultraviolet UV-C light source for irradiating the air in the circulation path with ultraviolet UV-C. (Appendix 2) The refrigerated showcase according to Appendix 1, wherein the refrigerated showcase has a plurality of shelves. (Appendix 3) The refrigerated showcase according to Appendix 1 or 2, wherein the circulation path has an inlet and an outlet and includes air straightening means near the outlet. (Appendix 4) The refrigerated showcase according to Appendix 3, wherein the straightening means has a structure in which elements of the same shape are connected together. (Appendix 5) The refrigerated showcase according to Appendix 4, wherein the structure in which elements of the same shape are connected together is a honeycomb shape or a lattice shape. (Appendix 6) The refrigerated showcase according to any one of Appendices 1 to 5, wherein the refrigerated showcase is an open showcase. (Appendix 7) The refrigerated showcase according to appendix 6, wherein the air from the outlet forms an air curtain on the front surface of the storage space. (Appendix 8) The refrigerated showcase according to any one of appendices 1 to 5, wherein the refrigerated showcase is a closed showcase. (Appendix 9) The refrigerated showcase according to any one of appendices 1 to 8, wherein the circulation path is provided with a photocatalyst that is irradiated with ultraviolet UV-C from the ultraviolet UV-C light source. (Appendix 10) The refrigerated showcase according to any one of appendices 3 to 5, wherein the circulation path is provided with a blower fan and / or a suction fan that sends air from the inlet to the outlet. (Appendix 11) The refrigerated showcase according to any one of appendices 3 to 5, wherein the ultraviolet UV-C light source is provided immediately upstream of the rectification means. (Appendix 12) The refrigerated showcase according to appendix 10, wherein the ultraviolet UV-C light source is provided immediately upstream of the blower fan. (Supplementary Note 13) A sterilization method for a refrigerated showcase comprising a space for storing refrigerated items (hereinafter simply referred to as "storage space") and a circulation path for circulating air from the storage space to the storage space, the sterilization method for a refrigerated showcase comprising irradiating the air in the circulation path with ultraviolet light UV-C. (Supplementary Note 14) The sterilization method for a refrigerated showcase according to Supplementary Note 13, wherein the circulation path causes natural convection or forced circulation of the air in the storage space.(Appendix 15) The sterilization method for a refrigerated showcase according to Appendices 13 or 14, wherein the circulation path has an inlet for letting in air from the storage space and an outlet for letting the air in the circulation path flow out to the storage space, and the ultraviolet light UV-C is irradiated onto air immediately downstream of the inlet and / or immediately upstream of the outlet. (Appendix 16) The sterilization method for a refrigerated showcase according to any one of Appendices 13 to 15, wherein the refrigerated showcase is an open showcase, and an air curtain is formed in front of the open showcase by the air flowing out from the outlet. (Appendix 17) The sterilization method for a refrigerated showcase according to any one of Appendices 13 to 16, wherein a photocatalyst is provided in the circulation path, and the photocatalyst is irradiated with the ultraviolet light UV-C.

[0043] 10 Refrigerated showcase 11 Base 12 Top panel 13 Bottom panel 14 Upper front panel 15 Lower front panel 16 Left panel 17 Right panel 18 Back panel 20 Storage space for refrigerated items (storage space) 22 Shelf 25 Front open section 30 Circulation path 31 Upper circulation path 32 Lower circulation path 33 Intermediate circulation path 35 Exit from circulation path (to storage space) 36 Entrance to circulation path (from storage space) 41 Upper partition plate forming upper circulation path 31 between itself and the top panel 12 42 Lower partition plate forming lower circulation path 32 between itself and the bottom panel 13 43 Intermediate partition plate forming intermediate circulation path 33 between itself and the back panel 18 45 Blower fan 47 Ultraviolet UV-C light source

Claims

1. A refrigerated showcase comprising: a space for storing refrigerated goods (hereinafter simply referred to as the "storage space"); a circulation path for circulating air from said storage space back to said storage space; and an ultraviolet UV-C light source for irradiating the air in said circulation path with ultraviolet UV-C.

2. The refrigerated showcase according to claim 1, wherein said refrigerated showcase has a plurality of shelves.

3. The refrigerated showcase according to claim 1, wherein said circulation path has an inlet and an outlet, and includes air straightening means near said outlet.

4. The refrigerated showcase according to claim 3, wherein said flow straightening means is a structure in which elements of the same shape are connected together.

5. The refrigerated showcase according to claim 4, wherein the structure in which the same shapes are connected together is a honeycomb shape or a lattice shape.

6. The refrigerated showcase of claim 1, wherein the refrigerated showcase is an open showcase.

7. The refrigerated showcase according to claim 1, wherein the circulation path is provided with a photocatalyst that is irradiated with ultraviolet light UV-C from the ultraviolet light source UV-C.

8. The refrigerated showcase according to claim 3, wherein the circulation path is provided with a blower fan and / or a suction fan for blowing air from the inlet to the outlet.

9. The refrigerated showcase according to claim 3, wherein the ultraviolet UV-C light source is provided immediately before the upstream side of the rectifying means.

10. The refrigerated showcase according to claim 8, wherein the ultraviolet UV-C light source is provided immediately upstream of the blower fan.

11. A sterilization method for a refrigerated showcase having a space for storing refrigerated items (hereinafter simply referred to as the "storage space") and a circulation path for circulating air from the storage space to the storage space, comprising irradiating the air in the circulation path with ultraviolet light UV-C.

12. The sterilization method for a refrigerated showcase according to claim 11, wherein the circulation path causes natural convection or forced circulation of air in the storage space.

13. A sterilization method for a refrigerated showcase as described in claim 11 or 12, wherein the circulation path has an inlet for introducing air from the storage space and an outlet for discharging the air in the circulation path into the storage space, and the ultraviolet UV-C is irradiated onto the air immediately downstream of the inlet and / or immediately upstream of the outlet.

14. A sterilization method for a refrigerated showcase according to claim 11, wherein the refrigerated showcase is an open showcase, and an air curtain is formed in front of the open showcase by air flowing out from the outlet.

15. The sterilization method for a refrigerated showcase according to claim 11, further comprising providing a photocatalyst in the circulation path, and irradiating the photocatalyst with the ultraviolet light UV-C.

Images