JP3838726B2 - Photocatalytic freshness maintenance device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a device for maintaining the freshness of plants such as vegetables, fruits, and florets, and more particularly to a freshness maintaining device for maintaining the freshness of plants using a photocatalyst.
[0002]
[Prior art]
For example, when storing, displaying, or transporting plants such as vegetables, fruits, and flowers, maintaining the freshness becomes an important issue. From such plants, it is known that ethylene gas, which is a plant growth hormone, is generated, and such gas reduces the freshness of the plant.
[0003]
In view of this, for example, as shown in Japanese Patent Publication No. 4-30820, a method of decomposing ethylene gas using a photocatalyst and maintaining the freshness of a plant has been proposed. According to this method, ethylene gas generated from a plant is expected to be decomposed by the intervention of a photocatalyst and maintain the freshness of the plant.
[0004]
Further, as shown in Japanese Patent Laid-Open No. 6-327965, air containing a gas that impedes freshness maintenance is forced to flow between the ultraviolet irradiation lamp and the photocatalyst, and the freshness maintenance inhibiting gas contained in this air is removed. A device has also been developed.
[0005]
[Problems to be solved by the invention]
However, the conventional photocatalytic freshness maintaining device disclosed in such a publication is not equipped with means for preventing a decrease in the amount of light of the ultraviolet irradiation lamp due to air blowing, which is detrimental to a decrease in the catalytic action and thus to a freshness maintenance. It has been found by the present inventors that a decrease in the removal efficiency of the gas becomes a problem. That is, when the ultraviolet irradiation lamp, particularly the socket part, which is the heat generating part of the lamp, is cooled by the blowing of the forced air blowing means, the amount of ultraviolet light from the lamp is reduced, so that the function of the photocatalyst is lowered, resulting in freshness. A reduction in the efficiency of removing gases that are harmful to retention occurs.
[0006]
The photocatalytic freshness maintaining device is often placed in a low-temperature atmosphere such as a refrigerator in order to maintain the freshness of the plant, so that the lamp is likely to be cooled.
[0007]
As a result of earnestly examining means for further improving the removal efficiency of the gas that hinders the maintenance of plant freshness in the photocatalytic freshness holding device, the present inventors have prevented cooling of the socket portion that supplies power to the ultraviolet irradiation lamp. As a result, it has been found that the removal efficiency of the freshness maintenance inhibiting gas can be further improved, and the present invention has been completed.
[0008]
This invention is made | formed in view of such an actual condition, and it aims at providing the photocatalyst type freshness holding | maintenance apparatus which can further improve the removal efficiency of freshness maintenance inhibitory gas.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a photocatalytic freshness maintaining device according to the present invention includes an ultraviolet irradiation lamp, a photocatalyst irradiated with light from the ultraviolet irradiation lamp, and a gap between the ultraviolet irradiation lamp and the photocatalyst. Through which the air taken from the outside of the apparatus flows and forced air blowing means for blowing out the air that has passed through the gap to the outside of the apparatus, and the forced air blowing means supplies the power to the ultraviolet irradiation lamp by the forced air blowing means. A heat generating part protection means for preventing the air from being excessively cooled by the blown air is attached.
[0010]
The heat generating part protecting means is preferably a waterproof socket. If it is a waterproof socket, cold air does not enter the socket, cooling at the socket portion can be prevented as much as possible, and a decrease in the amount of light of the ultraviolet irradiation lamp can be prevented as much as possible. Moreover, it is economical because a commercially available waterproof socket can be used as a socket with a heating part protection means for an ultraviolet irradiation lamp.
[0011]
In the present invention, the ultraviolet lamp is not particularly limited, but a straight tube shape is preferable. This is because it is easy to obtain and easy to maintain. The ultraviolet rays emitted from the lamp are particularly preferably those having a wavelength of 400 nm to 200 nm from the viewpoint of improving the freshness keeping efficiency. Note that the light emitted from the lamp may include visible light and infrared light other than ultraviolet light.
[0012]
In the present invention, the forced air blowing means is not particularly limited, and a centrifugal fan, an axial fan, a sirocco fan, or the like is used.
[0013]
In the present invention, the lamp lighting control means and the air blowing control means are linked, and after the ultraviolet irradiation lamp is turned on, the air blowing by the forced air blowing means is started after a predetermined time delay. preferable. The predetermined time is preferably 10 to 60 seconds, more preferably 20 to 40 seconds. If such a configuration is adopted, even if the apparatus is placed in a low-temperature atmosphere, the ultraviolet irradiation lamp is sufficiently warmed and air blowing starts in a state where the original ultraviolet intensity of the lamp is obtained. Accordingly, the lamp does not emit light at a low temperature, and the photocatalyst is irradiated with sufficiently strong ultraviolet rays. As a result, the removal efficiency of the freshness-preventing inhibitory gas contained in the air flowing in contact with the photocatalyst is further improved. Can be improved.
[0014]
In the freshness maintaining device according to the present invention, an air inlet and an air outlet are formed, and the air sucked from the air inlet by the forced air blowing means flows through a gap between the ultraviolet irradiation lamp and the photocatalyst, The air that has circulated through the gap is blown out of the apparatus through the exhaust port. The amount of air taken in from the intake port and discharged from the exhaust port is appropriately determined according to the number of lamps arranged in the apparatus. The amount of air blown by the forced blower may be variable.
[0015]
In the present invention, as the photocatalyst, a semiconductor having a band gap of 0.5 to 5 eV, preferably a semiconductor having 1 to 3 eV is preferably used. When this semiconductor is irradiated with light having energy greater than the forbidden band width, electron excitation occurs from the valence band to the conduction band, holes are generated in the valence band, and electrons are generated in the conduction band. Holes and electrons appear on the semiconductor surface by diffusion or the like, and promote the reaction as a photocatalyst in the gas layer or liquid layer. Specific examples of the semiconductor include metal oxides such as tin dioxide, zinc oxide, tungsten trioxide, cerium oxide, titanium dioxide, barium titanate, and ferric oxide; zinc sulfide, cadmium sulfide, lead sulfide, zinc selenide. Metal chalcogenides such as cadmium selenide; group IV elements such as silicon and germanium; compounds of group III and group V elements such as gallium phosphide, gallium arsenide and indium phosphide; polyacetylene, polypyrrole, polythiophene, polyaniline, An organic semiconductor such as polyvinyl carbazole is exemplified. In the present invention, metal oxides such as zinc oxide, tungsten trioxide, titanium dioxide, and cerium oxide are particularly preferably used. In the present invention, such a semiconductor is preferably formed into a photocatalyst molded body by the following method, for example, but it is also possible to use the semiconductor powder as it is without necessarily forming the molded body.
[0016]
As a first method, a semiconductor powder such as titanium oxide powder is formed into a tablet shape using a compression molding machine or the like and used as a photocatalyst molded body as it is. Alternatively, the compression-molded photocatalyst layer is attached to a plate with an adhesive or the like and used as a photocatalyst molded body. As the plate-like material, metal, resin, ceramic, or the like is used.
[0017]
As a second method, a semiconductor powder such as titanium oxide powder is adhered to a nonwoven fabric as a carrier using charging or a binder to obtain a photocatalyst molded body.
[0018]
As a third method, for example, as disclosed in JP-A-6-327965, semiconductor powder such as titanium oxide powder is dispersed in clay or gypsum, and then water for curing is added to form a slurry, which is used as a mold. The catalyst molded product is used as it is as a photocatalyst molded product. Or it is good also as a photocatalyst molded object by sticking the catalyst layer which consists of the catalyst molded product obtained in that way on a plate-shaped object. The catalyst molded product may contain particles, fibers, and the like as a reinforcing agent. Further, when molding the catalyst molding, the semiconductor powder may be dispersed in water in advance, and clay or gypsum may be added later.
[0019]
As a fourth method, a semiconductor powder such as titanium oxide powder and latex are mixed and then applied to a support, and then dried at room temperature or high temperature to obtain a catalyst molded product, which is used as a photocatalyst molded product as it is. Use. Alternatively, this catalyst product is supported on a substrate or the like.
[0020]
As a fifth method, for example, as shown in Japanese Patent Application Laid-Open No. 4-215841, a metal alkoxide such as titanium tetraisopropoxide is applied to a carrier such as metal, resin, ceramic, or paper and dried. The obtained catalyst molding is used as a photocatalyst molding.
[0021]
[Action]
In the photocatalytic freshness maintaining apparatus according to the present invention, a heating part protection means (waterproof socket) for preventing excessive cooling by the air blown by the forced air blowing means is attached to the portion that supplies power to the ultraviolet irradiation lamp. It is. For this reason, the cool air by the forced air blowing means does not enter the socket which is the heat generating part, the cooling at the socket part can be prevented as much as possible, and the decrease in the light amount of the ultraviolet irradiation lamp can be prevented as much as possible. If the decrease in the amount of light in the ultraviolet irradiation lamp can be prevented, the photocatalyst is irradiated with sufficiently strong ultraviolet rays, the photocatalyst function is fully exerted, and the freshness maintenance inhibitor gas contained in the air flowing in contact with the photocatalyst The removal efficiency can be further improved.
[0022]
The photocatalytic freshness maintaining apparatus according to the present invention is simply placed in a warehouse, refrigerator, showcase, or other substantially sealed space (although not necessarily sealed), and is stored or mounted around it. It becomes possible to maintain the freshness of the placed plant over a long period of time.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on embodiments shown in the drawings.
[0024]
1 is an exploded perspective view of a photocatalytic freshness maintaining apparatus according to an embodiment of the present invention, FIG. 2 is a front view of a rear panel to which the ultraviolet irradiation lamp shown in FIG. 1 is attached, and FIG. 3 is a photocatalyst holder shown in FIG. 4 is a cross-sectional view of the main part of the holder unit constituting the photocatalyst holder, FIG. 5 is a cross-sectional view of the main part showing a structure for mounting the photocatalyst molded body to the holder unit, and FIG. 6 is a front view of the holder unit. Is a perspective view of an instrument for attaching the lower part of the photocatalyst holder to the back panel, FIG. 8 is a circuit diagram showing an example of a control circuit of a photocatalytic freshness maintaining device according to another embodiment of the present invention, and FIG. FIG. 10 is a perspective view of a main part of a freshness holding device according to still another embodiment, and FIG. 10 is an exploded perspective view of the freshness holding device according to still another embodiment of the present invention.
[0025]
First embodiment
As shown in FIGS. 1 and 2, the photocatalytic freshness maintaining device 2 according to the present embodiment includes a back panel 6 in which a plurality of ultraviolet irradiation lamps 4 are arranged substantially in parallel along the vertical direction. The back panel 6 is detachably mounted on the inner back surface of the casing 8 of the apparatus.
[0026]
As shown in FIG. 1, an intake panel 11 having an intake port 10 is mounted on the front side of the lower end of the casing 8, and an exhaust panel 13 having an exhaust port 12 formed on the front side of the upper end. Is attached. A blower fan 14 as a forced blower is mounted on the upper portion of the casing 8 located on the back side of the exhaust panel 13, and the air taken from the intake port 10 flows along the axial direction of the lamp 4, and the exhaust port 12 is exhausted.
[0027]
As shown in FIG. 1, the photocatalyst holder 16 is detachable from the back panel 6 in order to secure a flow path along the axial direction of each lamp 4 and to arrange the photocatalyst molded body on three sides of each lamp 4. Fixed to. A front panel 18 is mounted on the front surface of the casing 8 to which the photocatalyst holder 16 is attached.
[0028]
In the present embodiment, as shown in FIG. 2, a total of eight straight tube-shaped ultraviolet irradiation lamps 4 are mounted on the back panel 6 substantially in parallel along the vertical direction. The ultraviolet rays emitted from each lamp 4 are preferably those having a wavelength of 400 nm to 200 nm from the viewpoint of improving the freshness keeping efficiency. The light emitted from the lamp 4 may include visible light and infrared light other than ultraviolet light. The length and wattage of these lamps 4 are selected from commercially available standard products.
[0029]
Both ends of each lamp 4 are held by sockets 20 fixed to the back panel 6, and power is supplied to the lamps 4 from here. Each lamp 4 can be easily removed and replaced from the socket 20. In the present embodiment, these sockets 20 are all constituted by commercially available waterproof sockets (heat generating part protection means).
[0030]
As shown in FIG. 2, a driving device such as a glow socket 22 and a ballast 24 is attached to each lamp 4 on the portion of the rear panel 6 located on the upper part of the upper socket 20. Control is possible for each book or for each book.
[0031]
A stopper plate 26 to which the upper ends of the two photocatalyst holders 16 shown in FIG. 1 are attached is mounted on the portion of the back panel 6 located between the upper socket 20 and the driving device. A bolt through a bolt hole 28 formed in the upper corner of the photocatalyst holder shown in FIG. 3 is attached to the stopper plate 26, and the upper part of the photocatalyst holder 16 can be detachably attached to the stopper plate 26. ing.
[0032]
On the surface of the rear panel located below the lower end socket 20 of the lamp 4 shown in FIG. 2, ball catch stoppers 30 are fixed for every four lamps. As shown in FIG. 7, the ball catch stopper 30 has a fitting recess 31, and the projection 33 of the projection fitting 32 is detachably fitted in a one-touch manner. The balls 34 are elastically held on both sides of the recess 31, and the protrusions 33 enter the recess 31, so that the balls 34 fit into the ball receiving grooves 36 formed on both sides of the protrusion 33. It is supposed to be. The convex metal fitting 32 is fixed to the back surface of the lower end of the photocatalyst holder 16 shown in FIG. 3 at a position corresponding to the ball catch stopper 30 shown in FIG. That is, the lower end portion of the photocatalyst holder 16 is detachably fixed to the rear panel 6 shown in FIGS. 1 and 2 by the convex fitting 32 and the ball catch stopper 30 shown in FIG.
[0033]
As shown in FIGS. 3 to 6, the photocatalyst holder 16 of this embodiment is configured by combining four holder units 40 by welding or the like. In addition, the code | symbol 42 in FIG. 3 shows the handle for attaching and removing operation of the photocatalyst holder 16 with respect to the back panel 6. FIG.
[0034]
As shown in FIG. 4, each unit 40 has a three-way wall having a U-shaped cross section so as to surround three sides of the lamp 4 other than the back panel 6, and a claw portion 44 is provided at each corner of the three-way wall. And 46 are formed. The claw portions 44 positioned at both end corners can be integrally formed when the holder unit 40 is bent and formed with a steel plate, and the claw portions 46 at the intermediate corner portions are formed by welding a plate material or the like. When the entire unit 40 or the photocatalyst holder 16 is molded by synthetic resin extrusion or the like, the claw portions 44 and 46 can be molded integrally with the unit 40 or the photocatalyst holder 16.
[0035]
By forming the claw portions 44 and 46, the catalyst molded bodies 48 are slidably mounted inside the three-way walls of the units 40, respectively. In the present embodiment, the catalyst molded body 48 has a cross-sectional shape that is close to a trapezoidal shape, and the tapered surfaces of both end portions thereof are engaged with the claw portions 44 and 46. In addition, an elastic sheet-like cushioning member 54 is mounted inside the claw portions 44 and 46 so that the claw portions 44 and 46 do not directly contact the catalyst molded body 48. Damage to the catalyst molded body 48 is prevented.
[0036]
As shown in FIG. 5, the catalyst molded body 48 includes an unglazed substrate 50 as a photocatalyst support and a photocatalyst layer 52 supported on the surface recess thereof. In this embodiment, the photocatalyst layer 52 is obtained by agglomerating a semiconductor powder having a band gap of 0.5 to 5 eV, preferably 1 to 3 eV, and a water curable compound with water. It is. The water-curable compound is an inorganic compound having a property of reacting with water to form a hydrate and agglomerating, and is generally used as an inorganic adhesive in the field of civil engineering construction. Specifically, calcium sulfate, calcium silicate, calcium aluminate, calcium ferrate, celite, sealant, gehlenite, anorthite, dolomite and the like are exemplified. Examples of the water curable compound include calcined gypsum, Portland cement, dolomite plaster, lime volcanic ash cement, alumina cement, magnesia cement and the like obtained from the above compound as a raw material. In this embodiment, calcium sulfate and calcined gypsum obtained using this as a main raw material are particularly suitable. The water curable compound is usually used as a powder. By using powder, the semiconductor powder can be uniformly dispersed.
[0037]
The method of kneading the semiconductor powder and the water-curable compound powder with water is not particularly limited, and after mixing and stirring these powders to obtain a mixture, water may be added and kneaded. After adding water to the powder and kneading, a water-curable compound may be added and kneaded.
[0038]
The weight ratio of the semiconductor to the water curable compound is 10: 1 to 1:10, preferably 6: 1 to 1: 6. The amount of water is usually 25 to 200 parts by weight with respect to 100 parts by weight of the total amount of the semiconductor and the water curable compound.
[0039]
After the semiconductor and the water-curable compound are kneaded with water, the kneaded product may be directly poured into the concave portion of the substrate 50 shown in FIG. 5 and condensed, or condensed in another mold and condensed into a predetermined shape. Then, it may be attached to the concave portion of the substrate 50 shown in FIG.
[0040]
Although the thickness of this photocatalyst layer 52 is not specifically limited, 30 mm or less is preferable and 1-10 mm is especially preferable. When the thickness is too thick, the function as a photocatalyst tends to decrease.
[0041]
The surface of the photocatalyst layer 52 may be provided with unevenness to increase the contact area with air. With this configuration, the area of the portion that functions as a catalyst increases, and the flow of air passing therethrough is disturbed, so that the efficiency of removing gases that are harmful to maintaining freshness is improved.
[0042]
The distance L (see FIG. 4) between the catalyst layer 52 and the lamp 4 is preferably 1 to 500 mm, and more preferably 5 to 100 mm. If it is less than 1 mm, the circulation of air passing through the gap tends to be difficult, and if the gap is too large, the removal efficiency of gas that is harmful to maintaining freshness tends to be lowered.
[0043]
In this embodiment, as shown in FIGS. 2 and 4, an elastic sealing member 60 is provided on the surface of the back panel 6 located on both sides of the lamp 4 at the portion where the photocatalyst holder 16 and the back panel 6 are in contact. Is attached. Due to the contact between the seal member 60 and the photocatalyst holder 16, an air flow path along the axial direction of each lamp 4 is formed between the photocatalyst holder 16 and the back panel 6. Air taken from the intake port 10 shown in FIG. 1 flows through the air flow passages along the lamps 4 and is finally exhausted from the exhaust port 12.
[0044]
In this embodiment, as shown in FIGS. 1, 3, and 6, a peep hole 62 is formed in each unit 40 constituting the photocatalyst holder 16. This viewing hole 62 is also formed at the same position in the photocatalyst molded body 48 shown in FIG. Further, a viewing window glass 64 is formed at a position corresponding to the viewing hole 62 on the front panel 18 of the casing 8 shown in FIG. Therefore, it is possible to observe the lighting of each lamp 4 from the outside of the apparatus.
[0045]
By driving the fan 14 shown in FIG. 1, the air taken in from the air inlet 10 flows upward through the flow passages formed in the gaps between the lamps 4 and the photocatalyst molded body 48 shown in FIG. The gas is discharged from the exhaust port 12 shown in FIG. While flowing through the gap between each lamp 4 and the photocatalyst molded body 48, the air comes into contact with the surface of the photocatalyst layer 52 shown in FIG. The contained harmful gas (for example, ethylene) for maintaining the freshness is decomposed and removed. Then, clean air from which harmful substances have been removed is discharged from the exhaust port.
[0046]
Therefore, the photocatalytic freshness maintaining apparatus 2 according to the present embodiment includes a warehouse, a refrigerator, a showcase, and other substantially sealed spaces (for example, which are not necessarily sealed) in which plants such as vegetables, fruits, and flowers are stored. It is possible to keep the freshness of the plants stored or placed in the surrounding area for a long time simply by placing them in the inside.
[0047]
Moreover, in this embodiment, as shown in FIG. 1, the photocatalyst holder 16 can be easily removed from the back panel 6 to which the ultraviolet irradiation lamp 4 is attached. By removing the photocatalyst holder 16, the ultraviolet irradiation lamp 4 can be easily attached and replaced. Further, by removing the photocatalyst holder 16, the photocatalyst molded body 48 can be easily removed and replaced from the photocatalyst holder 16.
[0048]
Moreover, in the present embodiment, as shown in FIG. 4, the photocatalyst holder 16 is molded so as to surround the respective ultraviolet irradiation lamps 4 other than the back panel 6, and the photocatalyst molded body 48 is attached to the portion. Therefore, the light from the lamp 4 is directly irradiated to the photocatalyst layer 52 of the photocatalyst molded body 48, and the function as a photocatalyst is sufficiently exhibited. Further, since air is forced to flow through these gaps along the axial direction, the contact area between the air and the catalyst layer 52 is increased, and a gas such as ethylene that is harmful to maintaining freshness is efficiently removed. It becomes possible to disassemble.
[0049]
In particular, in the present embodiment, as shown in FIG. 2, since the sockets 20 attached to both ends of all the ultraviolet irradiation lamps 4 are waterproof sockets, the cool air from the fan 14 is generated in the socket 20 that is a heat generating part. Without entering, the cooling at the socket 20 portion can be prevented as much as possible, and a decrease in the amount of light of the ultraviolet irradiation lamp 4 can be prevented as much as possible. If the decrease in the amount of light in the ultraviolet irradiation lamp 4 can be prevented, the photocatalyst layer 52 is irradiated with sufficiently strong ultraviolet rays, the function of the photocatalyst layer 52 is fully exerted, and the air flowing in contact with the photocatalyst layer 52 is circulated. The removal efficiency of the contained freshness retention inhibitory gas can be further improved.
[0050]
Second embodiment
In the present embodiment, a photocatalytic freshness maintaining apparatus was assembled in the same manner as in the first embodiment except that the ultraviolet irradiation lamp 4 and the fan 14 were driven using the control circuit shown in FIG.
[0051]
As shown in FIG. 8, in this embodiment, it is assumed that there are a plurality of photocatalytic freshness holding devices 2 shown in FIG. 1, and each freshness holding device 2 is driven by two fans 14 and eight lamps 4. An individual control circuit 70 for controlling is mounted, and a main control unit 72 is connected to each individual control circuit 70.
[0052]
The main control unit 72 has an outlet 74 connected to a power source of 100 V and 60 Hz, for example. The outlet 74 is connected to the lamp 4 connected to the individual control circuit 70 of each device 2 via a lamp switch 76 (lamp lighting control means) for turning on / off the power supply to the lamp 4. By turning on / off the lamp switch 76, the lighting of the lamp 4 is controlled.
[0053]
The lamp switch 76 is turned on when the main switch 77 is turned on and the switch drive circuit 79 is operated. The switch drive circuit 79 simultaneously drives the relay switch 78 to start the timer 80. The timer 80 measures a predetermined time and turns on the relay switch 82 after the predetermined time. When the switch 82 is turned on, the switch drive circuit 84 is driven, and the fan switch 86 (forced air blowing means) is turned on by the drive circuit 84. For this reason, the fan switch 86 is turned on with a predetermined time delay after the lamp switch 76 is turned on.
[0054]
The predetermined time set in the timer 80 is preferably 10 to 60 seconds, more preferably 20 to 40 seconds.
[0055]
The main control unit 72 includes a warning lamp 86 indicating that it is connected to a power supply, a warning lamp 88 that is turned on when the main switch 77 is turned on, and a warning lamp 90 that is turned on when the ultraviolet irradiation lamp 4 is turned on. And a warning lamp 92 that is turned on when the fan 14 is driven.
[0056]
In the photocatalytic freshness maintaining apparatus 2 according to the present embodiment, when the main switch 77 of the main control unit 72 shown in FIG. 8 is turned on, first, a current flows through the switch drive circuit 79, and this is driven to drive the lamp switch 76. Is turned on, power is supplied to the ultraviolet irradiation lamps 4 attached to the respective freshness maintaining devices 2, and the lamps 4 are turned on. The timer 80 shown in FIG. 8 measures the time since the main switch 77 is turned on, and turns on the relay switch 82 after a predetermined time has elapsed. As a result, the switch drive circuit 84 turns on the fan switch 86 with a predetermined time delay after the lamp switch 76 is turned on, and drives the two fans 14 of each freshness maintaining device.
[0057]
In the freshness holding device 2 according to the present embodiment, the same operational effects as the freshness holding device according to the first embodiment are exhibited, and the following operational effects are superimposed.
[0058]
In other words, in the present embodiment, the blowing is started in a state where the ultraviolet irradiation lamp 4 is sufficiently warmed and the original ultraviolet intensity of the lamp 4 is obtained. Therefore, the lamp 4 does not emit light at a low temperature, and the photocatalyst molded body 48 (see FIGS. 4 and 5) held by the photocatalyst holder 16 is irradiated with sufficiently strong ultraviolet rays. As a result, the photocatalyst molded body The removal efficiency of the freshness-keeping inhibiting gas contained in the air that circulates in contact with 48 can be further improved.
[0059]
Third embodiment
In this embodiment, as shown in FIG. 9, the photocatalyst holder 16a is maintained in the same manner as the first embodiment except that the configuration of the photocatalyst holder 16a is different from that of the first embodiment shown in FIGS. The device was assembled. That is, a waterproof socket is used as the socket 20.
[0060]
As shown in FIG. 9, in this embodiment, the photocatalyst layer 52a is supported on the entire back surface of the photocatalyst holder 16a, and the photocatalyst layer 52a is opposed to the ultraviolet irradiation lamp 4. Further, a peep hole 62a is formed in the photocatalyst holder 16a in the same manner as in the first embodiment.
[0061]
The photocatalytic freshness maintaining apparatus according to this embodiment is different from the freshness maintaining apparatus according to the first embodiment except that the area of the catalyst layer 52a irradiated with ultraviolet rays by a single lamp 4 is small. The same effect as the freshness keeping device according to the embodiment can be expected.
[0062]
Fourth embodiment
In this embodiment, as shown in FIG. 10, the photocatalytic holder 16b is maintained in the same manner as in the first embodiment except that the configuration of the photocatalyst holder 16b is different from that of the first embodiment shown in FIGS. The device was assembled. That is, a waterproof socket is used as the socket 20.
[0063]
As shown in FIG. 10, in this embodiment, each holder 16b includes a cylindrical holder unit 17 and a single ultraviolet ray so that a single ultraviolet irradiation lamp 4 is arranged for each photocatalyst holder 16b. And a detachable mounting panel 19 on which the lamp 4 is held.
[0064]
A cylindrical catalyst layer 52 b is supported on the inner surface of the holder unit 17. The center axis of the lamp 4 is arranged along the center axis of the cylindrical catalyst layer 52b, and a predetermined gap serving as an air flow path is formed between the lamp 4 and the catalyst layer 52b. A panel 19 is detachably attached to the unit 17. Regarding the peep hole, a peep hole 62b may be formed on the unit 17 side, or a peep hole 62c may be formed on the panel 19 side.
[0065]
The photocatalytic freshness holding device according to the present embodiment is different from the freshness holding device according to the first embodiment, except that it is necessary to attach a holder 16b for each single ultraviolet irradiation lamp 4. The same effect as the freshness keeping device according to the embodiment can be expected.
[0066]
The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.
[0067]
For example, the manufacturing method of the photocatalyst layers 52, 52a, and 52b is not particularly limited to the above-described embodiment.
[0068]
【Example】
Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.
[0069]
Example 1
The photocatalytic freshness maintaining apparatus shown in FIGS. As the ultraviolet irradiation lamp 4, eight chemical lamps manufactured by Toshiba Lighting & Technology Corp. having a dominant wavelength of 352 nm, a length of 630 mm, and a wattage of 30 W were used.
[0070]
As the socket 20, a waterproof socket of product number DSF-WT-21N manufactured by Toshiba Lighting & Technology Corp. was used.
[0071]
The photocatalyst layer 52 shown in FIG. 5 was manufactured as follows. While mixing 10 parts by weight of titanium dioxide (anatase type), 10 parts by weight of calcined gypsum (made by Yoshino Gypsum, Class B) and 6 parts by weight of glass fiber, while gradually adding 20 parts by weight of water, A kneaded product was obtained by kneading using a mixer such as a ball mill. Next, the kneaded product is poured into the concave portion of the unglazed substrate 50 (see FIG. 5), left to dry in an atmosphere of 20 ° C. for 12 hours, and then left in an oven at 120 ° C. for 5 hours. A photocatalytic layer 52 was obtained.
[0072]
The minimum gap L between the ultraviolet irradiation lamp 4 and the photocatalyst molded body 48 shown in FIG. 4 was 11.5 mm.
[0073]
The fan 14 shown in FIG. 1 is driven simultaneously with the lighting of the ultraviolet irradiation lamp 4, and air containing 5 ppm of ethylene and having a temperature of 5 ° C. is supplied from the air inlet 10 of the apparatus 2 to a flow rate of 300 m.^Three/ Sent in time. The ethylene concentration at the exhaust port 12 was 1.3 ppm.
[0074]
Reference example 1
A freshness maintaining apparatus was assembled in the same manner as in Example 1 except that a normal socket of product number DSF-3202UW manufactured by Toshiba Lighting & Technology was used as the socket shown in FIG.
[0075]
The ethylene concentration at the exhaust port 12 was 4 ppm.
[0076]
【The invention's effect】
As described above, according to the present invention, the cool air generated by the forced air blowing means does not enter the socket as the heat generating part, and cooling at the socket part can be prevented as much as possible, and the light amount of the ultraviolet irradiation lamp can be reduced. Reduction can be prevented as much as possible. If the decrease in the amount of light in the ultraviolet irradiation lamp can be prevented, the photocatalyst is irradiated with sufficiently strong ultraviolet rays, the photocatalyst function is fully exerted, and the freshness maintenance inhibitor gas contained in the air flowing in contact with the photocatalyst The removal efficiency can be further improved.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a photocatalytic freshness holding device according to an embodiment of the present invention.
FIG. 2 is a front view of a rear panel to which the ultraviolet irradiation lamp shown in FIG. 1 is attached.
FIG. 3 is a front view of the photocatalyst holder shown in FIG. 1;
FIG. 4 is a cross-sectional view of a main part of a holder unit constituting a photocatalyst holder.
FIG. 5 is a cross-sectional view of a principal part showing a structure for attaching a photocatalyst molded body to a holder unit.
FIG. 6 is a front view of the holder unit.
FIG. 7 is a perspective view of an instrument for attaching the lower part of the photocatalyst holder to the back panel.
FIG. 8 is a circuit diagram showing an example of a control circuit of a photocatalytic freshness maintaining device according to another embodiment of the present invention.
FIG. 9 is a perspective view of a main part of a freshness keeping device according to still another embodiment of the present invention.
FIG. 10 is an exploded perspective view of a freshness holding device according to still another embodiment of the present invention.
[Explanation of symbols]
2 ... Photocatalytic freshness maintaining device
4 ... UV irradiation lamp
6 ... Back panel
8 ... Casing
10 ... Inlet
12 ... Exhaust vent
14 ... Fan
16, 16a, 16b ... Photocatalyst holder
18 ... Front panel
20 ... Socket (Waterproof socket; Heating part protection means)
40 ... Holder unit
44, 46 ... Nail
48 ... Photocatalyst block
50 ... Board
52 ... Photocatalyst layer
54 ... Buffer member
60 ... Sealing material
70 ... Individual control circuit
72 ... Main control unit
76 ... Fan switch
77 ... Main switch
80 ... Timer
86 ... Fan switch

Claims (2)

An ultraviolet irradiation lamp,
A photocatalyst irradiated with light from the ultraviolet irradiation lamp;
Forced air blowing means for flowing air taken from the outside of the apparatus through the gap between the ultraviolet irradiation lamp and the photocatalyst, and blowing out the air that has circulated through the gap to the outside of the apparatus ,
When the switch is turned on and the switch driving circuit is operated, the lamp lighting control means is turned on to turn on the ultraviolet irradiation lamp, and the timer is started simultaneously with the operation of the switch driving circuit for 10 to 60 seconds. A control unit having a circuit for measuring a predetermined time set between them and turning on the forced air blowing means after the predetermined time ,
The part for supplying electric power to the ultraviolet irradiation lamp is equipped with a heat generating part protection means for preventing excessive cooling with the air blown by the forced air blowing means,
The forced air means, by the operation of the control unit, after the lighting of the ultraviolet irradiation lamp, is turned on with a delay predetermined time, photocatalytic freshness retaining device for starting the blower.   The photocatalytic freshness holding device according to claim 1, wherein the heat generating part protecting means is a waterproof socket.

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