Air purification device and air purification method

Abstract

To provide an air purification device capable of more surely decomposing organic materials contained in air, and capable of rendering the air into an appropriate temperature.SOLUTION: In an air purification device 1 equipped with a thin plate arrangement section 20 where multiple thin plates 21 are arranged with gaps, the thin plate arrangement section 20 has a configuration that includes coating layers carried on both surfaces of each thin plate 21 and a pipe 27 that penetrates through the multiple thin plates 21. The coating layer is composed of a layer of metal substituted hydroxyapatite in which a part of the calcium of calcium hydroxyapatite is replaced by a metal selected from titanium, zirconium, iron, and tungsten. The multiple thin plates 21 function both as a carrier for the coating layer and as fins of a heat exchanger formed by circulating fluid through the pipe 27.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an air purification device and an air purification method using the air purification device. [Background technology]

[0002] In recent years, with the spread of infections caused by the new coronavirus, efforts are being made to prevent infection by wearing masks and installing partitions such as acrylic panels. It is believed that masks and partitions can greatly reduce the possibility of exposure to viruses contained in relatively large droplets expelled by coughing and sneezing. However, it is said that fine droplets expelled with breathing and talking become aerosols and remain suspended in the air for a long time and spread. Frequent ventilation is also recommended, but it is difficult to completely replace the air in a room.

[0003] Therefore, the inventor came to the conclusion that the current measures are insufficient to prevent infection, and that an air purifying device is needed that takes in indoor air, breaks down organic matter such as viruses contained in the air, and exhausts clean air. With such an air purifying device, it is possible to reduce damage caused not only by the new coronavirus, but also by other viruses such as influenza viruses and avian influenza viruses, and bacteria. In particular, with regard to the avian influenza virus, in recent years, there has been a continuous increase in the number of birds kept in chicken coops that have been infected and culled, and the rise in egg prices due to the decline in egg production has become a problem, so measures are urgently needed.

[0004] Various proposals have been made for devices that purify air. Among these is a type of device that aims to decompose organic matter in the air by carrying a photocatalyst on a filter through which air passes and irradiating it with ultraviolet light (see, for example, Patent Document 1).

[0005] However, since air passes through the filter carrying the photocatalyst in an instant, it is actually very difficult to decompose the organic matter contained in the circulating air by the action of the photocatalyst. Therefore, there is a demand for an air purifier that can more reliably decompose the organic matter contained in the air.

[0006] Furthermore, the present inventor believes that it is important that the environment in which humans and animals live and work is not only clean, but also that it is at an appropriate temperature. For example, if the temperature rises in a factory where many workers work, the physical burden on the workers increases and production efficiency decreases. It is also known that the production of eggs drops sharply when the environmental temperature of a chicken coop for laying eggs is high at 27°C or higher, and it is considered desirable to keep the temperature at 25°C or lower in order to maintain a stable production volume. Therefore, the present applicant came up with the idea of ​​manufacturing a device that can decompose and purify organic matter in the air, as well as maintain the air at an appropriate temperature. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2016-128154 A Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the above-mentioned circumstances, an object of the present invention is to provide an air purifying device that can more reliably decompose organic matter contained in the air and maintain the air at an appropriate temperature, and an air purifying method that uses the air purifying device. [Means for solving the problem]

[0009] In order to solve the above problems, the air purifying device according to the present invention comprises: "A thin plate juxtaposition section in which a plurality of thin plates are arranged side by side with gaps therebetween, The thin plate juxtaposition portion has coating layers supported on the front and back surfaces of the thin plates and a pipe penetrating the plurality of thin plates, the coating layer is a layer of metal-substituted hydroxyapatite in which part of the calcium of calcium hydroxyapatite is substituted with a metal selected from titanium, zirconium, iron, and tungsten; The thin plates have both the function of supporting the coating layer and the function of acting as fins of a heat exchanger formed by circulating a fluid through the pipe.

[0010] Photocatalysts such as titanium oxide and tungsten oxide do not have the ability to adsorb organic matter, so even if a photocatalyst is supported on a filter through which air passes, it is actually very difficult for the photocatalyst to decompose the organic matter contained in the air that momentarily passes through the filter.

[0011] In contrast, in the present configuration, the thin plate has a coating layer on the front and back sides, which is a layer of metal-substituted hydroxyapatite in which part of the calcium in calcium hydroxyapatite has been substituted with a metal selected from titanium, zirconium, iron, and tungsten. The calcium hydroxyapatite portion in the metal-substituted hydroxyapatite has excellent ability to adsorb organic matter. On the other hand, the portion in the metal-substituted hydroxyapatite in which calcium has been substituted with a metal selected from titanium, zirconium, iron, and tungsten (hereinafter referred to as the "metal-substituted portion") has a photocatalytic effect.

[0012] Therefore, with the air purifier of this configuration, first the organic matter is adsorbed from the air passing by in an instant, rendering it immobile, and then the organic matter is decomposed by the photocatalytic action of the metal replacement part, thus performing a "two-stage air purification." In other words, with the air purifier of this configuration, a "time lag" is provided between the adsorption and decomposition of the organic matter. The photocatalytic action of the metal replacement part can be exerted by the light (natural light or light from lighting) in the environment in which the air purifier is installed.

[0013] In addition, if the metal-substituted hydroxyapatite is supported on the filter, the air passes through the air holes that penetrate the filter in the thickness direction, so even if the metal-substituted hydroxyapatite is supported around the air holes, the distance that the air flows through is short and the adsorption of organic matter may be insufficient. In contrast, in this configuration, the air flows through the gaps between the thin plates, and the air flows along the front and back surfaces of the thin plates. This makes the contact between the air and the coating layer planar, and the contact distance between the air and the coating layer can be increased, so that the organic matter in the air is effectively adsorbed.

[0014] Furthermore, in the thin plate juxtaposition section of this configuration, in addition to separating (adsorbing / capturing) and decomposing organic matter such as viruses from the air, the air is also heated to an appropriate temperature. For this process, a fluid is circulated through the pipes, and heat is exchanged between the fluid and the air. For example, in a high-temperature environment such as summer, cold water such as groundwater is supplied to the pipes. On the other hand, in a low-temperature environment such as winter, hot water such as industrial wastewater is supplied to the pipes. Because the pipes penetrate multiple thin plates, the fluid exchanges heat with the air flowing through the gaps between the thin plates as it flows through the pipes, and the air is heated to an appropriate temperature.

[0015] In the process of such heat exchange, the thin plates penetrating the pipe not only carry the coating layer but also act as fins of the heat exchanger, absorbing heat from the air flowing through the gaps between the thin plates through the thin plates acting as fins, and releasing heat from the fluid flowing inside the pipe through the thin plates acting as fins, thereby enabling efficient heat exchange between the fluid and the air.

[0016] In addition to the above configuration, the air purifying device according to the present invention further comprises: The thin plate may have at least a plurality of protrusions and / or recesses, and also have a plurality of open small holes.

[0017] If the air flow were laminar, a boundary layer where no air flow exists would be created between the thin plate having the coating layer and the layer of air, which could result in insufficient contact between the air and the coating layer. In contrast, the thin plate of the present configuration has at least one of a convex portion and a concave portion, which creates turbulence in the air that flows through it. As a result, the air changes direction in various ways as it flows, making it easier for it to come into contact with the coating layer.

[0018] In addition, in this configuration, the thin plates have a number of small holes, so that the air that becomes turbulent in the gap between one thin plate and the adjacent thin plate can flow into the adjacent gap through the small holes. In this way, the air does not only flow through the gap between the two thin plates, but also flows through the small holes to the adjacent gap and the adjacent gap, so the air flow becomes more turbulent and the contact between the air and the coating layer becomes better.

[0019] In addition to the above configuration, the air purifying device according to the present invention further comprises: "The hole through which the pipe passes in the thin plate has a peripheral wall portion at the opening edge that rises above the plane of the thin plate, The peripheral wall portion may define the distance between adjacent thin plates.

[0020] The peripheral wall portion acts as a spacer that determines the distance between the thin plates when arranging the thin plates side by side, so that the work of arranging the thin plates side by side at a constant interval can be easily performed. In addition, the distance between the thin plates can be easily adjusted by changing the height of the peripheral wall portion.

[0021] Next, the air purification method according to the present invention comprises the steps of: "An air purification method using the air purification device described above, Air is passed through the gap between the thin plates, and organic matter contained in the air is adsorbed by the calcium hydroxyapatite portion of the metal-substituted hydroxyapatite constituting the coating layer, and the adsorbed organic matter is decomposed by the photocatalytic action of the portion of the metal-substituted hydroxyapatite where calcium is substituted with the metal. Heat is exchanged between the air flowing through the gap between the thin plates and the fluid flowing through the pipes.

[0022] This is an air purification method using the air purification device with the above-mentioned configuration. As mentioned above, this is a "two-stage air purification" method in which organic matter is first adsorbed from the air passing by in an instant and made immobile, and then the organic matter is decomposed by photocatalysis, and there is a "time lag" between the adsorption and decomposition of the organic matter.

[0023] In addition, in the air purification method of this configuration, a fluid is passed through a pipe that penetrates the multiple thin plates that make up the thin plate juxtaposition section, and heat is exchanged between the fluid and the air. Therefore, the multiple thin plates, in addition to carrying the coating layer, also function as fins of a heat exchanger. Therefore, heat can be efficiently exchanged between the fluid and the air by absorbing heat from the air passing through the gaps between the thin plates through the thin plates as fins, and releasing heat from the fluid passing through the pipe through the thin plates as fins. Effect of the Invention

[0024] As described above, according to the present invention, it is possible to provide an air purifying device that can more reliably remove organic matter contained in the air and maintain the air at an appropriate temperature, and an air purifying method that uses the air purifying device. [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic configuration diagram of an air purification device according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a schematic diagram of an air purification device according to a second embodiment of the present invention. [Diagram 3] FIG. 10(a) is a perspective view of a main portion of an air purifying device according to a third embodiment of the present invention, and FIG. 10(b) is a plan view of a main portion of the air purifying device according to the third embodiment. [Figure 4] FIG. 11 is an exploded perspective view of a main portion of an air purifying device according to a fourth embodiment of the present invention. [Diagram 5] FIG. 2 is a partial perspective view of a thin plate that constitutes the air purification device of the present embodiment. [Figure 6] 6(a) is a partial cross-sectional view of the thin plate in FIG. 5, and (b) is an explanatory diagram of a state in which a pipe passes through a plurality of thin plates arranged side by side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an air purifying device according to a specific embodiment of the present invention and an air purifying method using the air purifying device will be described with reference to the drawings. First, an air purifying device 1 according to a first embodiment will be described mainly with reference to FIG.

[0027] The air purifying device 1 comprises, in this order, a blower 10, a pre-filter section 40, a thin plate juxtaposition section 20, and an ultraviolet ray irradiation section 30, which are housed in a substantially rectangular parallelepiped casing 60. The casing 60 is provided with an air intake port and an exhaust port (both not shown) so as to communicate with the space outside the air purifying device 1.

[0028] The air blower 10 is a type that compresses and blows air by rotating a fan, and passes the air taken in from an air intake through a pre-filter section 40, a thin plate juxtaposition section 20, and an ultraviolet ray irradiation section 30 in that order. In the air blower 10, the amount of air blown can be adjusted by controlling a motor (not shown) that drives the fan to rotate.

[0029] The pre-filter section 40 has a filter F disposed in the space between the blower 10 and the thin plate juxtaposition section 20. The filter F can be made of a nonwoven fabric or a mesh. The filter F can be supported by the casing 60 so as to be replaceable.

[0030] The thin plate juxtaposition section 20 is constituted by 200 to 400 thin plates 21 arranged in parallel with gaps between them. Each thin plate 21 is a rectangular plate material and has a thin thickness of 0.15 mm to 0.3 mm. The gaps between the thin plates 21 are uniform and are 2.0 mm to 4.0 mm. The thin plates may be made of aluminum, which has high thermal conductivity and is lightweight. Alternatively, they may be made of copper, which has high thermal conductivity and is inexpensive, or stainless steel, which has relatively high thermal conductivity and is resistant to corrosion.

[0031] As shown in Fig. 5, each thin plate 21 has a large number of minute protrusions 22. Specifically, one protrusion 22 is formed by making two parallel cuts and pressing thin plate 21, causing the portion between the two cuts to protrude.

[0032] Each thin plate 21 has a plurality of through holes 24. As shown in FIG. 5 and FIG. 6(a), each hole 24 has a peripheral wall 24a rising along the opening edge. The height of the peripheral wall 24a rising from the plane of the thin plate 21 can be 2.0 mm to 4.0 mm. As shown in FIG. 6(b), such peripheral wall 24a acts as a spacer that defines the distance between the thin plates 21 when multiple thin plates 21 are arranged side by side. Therefore, the work of arranging multiple thin plates 21 at a constant interval can be easily performed. Also, the distance between the thin plates 21 can be easily adjusted by the height of the peripheral wall 24a. The peripheral wall 24a can be formed by performing burring when forming the hole 24.

[0033] A coating layer (not shown) is formed on the front and back surfaces of each thin plate 21, including the surfaces of the protrusions 22 and the peripheral wall portion 24a. The coating layer is a layer of metal-substituted hydroxyapatite. Metal-substituted hydroxyapatite is calcium hydroxyapatite (Ca10(PO4)6(OH)2) in which part of the calcium is substituted with a metal selected from titanium, zirconium, iron, and tungsten.

[0034] Coating of the metal-substituted hydroxyapatite on the thin plate 21 can be performed by first coating the front and back surfaces of the thin plate 21 with an adhesive, and then spraying and attaching the metal-substituted hydroxyapatite powder onto the adhesive, or by spraying and applying a slurry in which the metal-substituted hydroxyapatite powder is mixed into an adhesive coating agent onto the thin plate 21, or by immersing the thin plate 21 in the slurry. Among these, the method of attaching the metal-substituted hydroxyapatite powder onto the adhesive that has been coated on the front and back surfaces of the thin plate 21 in advance is preferable because the exposed surface area of ​​the metal-substituted hydroxyapatite particles is large, and therefore the adsorption and photocatalytic effects can be effectively exerted. Note that the metal-substituted hydroxyapatite coated on the front and back surfaces of the thin plate 21 may have different types of metals substituted for calcium in calcium hydroxyapatite on the front and back surfaces.

[0035] In metal-substituted hydroxyapatite, the calcium hydroxyapatite portion has excellent ability to adsorb organic matter. On the other hand, the metal-substituted portion (where calcium is substituted with a metal such as titanium) in metal-substituted hydroxyapatite has a photocatalytic effect. That is, when the metal-substituted portion absorbs light energy equivalent to the band gap between the valence band and the conduction band, electrons in the valence band are excited to the conduction band, and these electrons reduce other substances. In the valence band, electrons are lost to generate holes, and the holes oxidize other substances by stealing electrons from them. This type of oxidation-reduction action breaks down organic matter such as viruses, bacteria, and substances that cause odors.

[0036] Metal-substituted hydroxyapatite can be obtained by mixing an aqueous solution of the starting material for calcium hydroxyapatite (e.g., an aqueous solution of calcium nitrate or phosphoric acid) with an aqueous solution containing the metal ion to be substituted for calcium (e.g., an aqueous solution of titanium sulfate when the metal is titanium) in a prescribed ratio, adjusting the liquid property (pH) to cause precipitation, and filtering out the precipitate.

[0037] After arranging a number of thin plates 21 covered with the coating layer in this way side by side with the peripheral wall portion 24a as a spacer, a pipe 27 is inserted into the hole portion 24 provided at the corresponding position of each thin plate 21. After penetrating all the thin plates 21 in the orthogonal direction, the pipe 27 is folded back in a U-shape and penetrates all the thin plates 21 again in the opposite direction. By repeating this process multiple times, one pipe 27 can be arranged in a serpentine manner for each thin plate juxtaposition portion 20. One end of the pipe 27 is a supply port 27a for supplying a fluid, and the other end is a discharge port 27b for discharging the fluid that has flowed through the pipe 27. The supply port 27a and the discharge port 27b may open in opposite directions as shown in the figure, or may open in the same direction. The pipe 27 may be made of copper, which has high thermal conductivity.

[0038] Although not shown in the figures, some of the holes 24 formed in each thin plate 21 can be used to support the multiple thin plates 21. Specifically, a shaft (not shown) having male threads at least on both ends is inserted into the hole 24 so that the shaft penetrates all of the thin plates 21. Then, both ends of the shaft are fastened with nuts to the outermost thin plate 21 or to a supporting side plate disposed further outward. In this way, the multiple thin plates arranged side by side at regular intervals can be fixed by the shaft and nuts.

[0039] The ultraviolet irradiator 30 is a space provided on the opposite side of the thin plate juxtaposition section 20 from the pre-filter section 40, and a plurality of ultraviolet irradiators 35 are attached to the inner surface of the casing 60. The ultraviolet irradiators 35 may be ultraviolet discharge tubes or light-emitting diodes (LEDs) that emit light with wavelengths in the ultraviolet range. The ultraviolet irradiators 35 irradiate ultraviolet light onto the air passing through the ultraviolet irradiator 30.

[0040] In addition to the above configuration, the air purifying device 1 is equipped with a control device (not shown). The control device is a computer equipped with a storage device consisting of a main storage device and an auxiliary storage device, and a central processing unit, and the storage device stores a program that causes the computer to function as air processing means. The air processing means mainly performs a process of adjusting the air flow speed by controlling the motor of the blower 10, and a process of adjusting the flow speed and temperature of the fluid supplied to the pipe 27. The control device may also perform a process of recording the detection results by the carbon dioxide concentration sensor together with the operating conditions of the air purifying device 1.

[0041] In the air purifier 1 configured as described above, when the blower 10 is operated, the air taken in from the air intake first passes through the pre-filter section 40. As a result, foreign matter such as dust and dirt that is larger than the organic matter to be treated in the thin plate juxtaposition section 20 is removed by the filter F from the air before it flows into the thin plate juxtaposition section 20. Note that in the case of an air purifier used in an environment with little foreign matter such as dust and dirt, the pre-filter section 40 can be omitted.

[0042] Air that has passed through the pre-filter section 40 flows into the thin plate juxtaposition section 20. At that time, the air flows into the gaps between the thin plates 21. Because the front and back surfaces of the thin plates 21 are covered with a coating layer of metal-substituted hydroxyapatite, the excellent adsorption action of the calcium hydroxyapatite portion adsorbs organic matter contained in the air. In other words, organic matter is captured from the air passing by in an instant, and the organic matter becomes immobile.

[0043] The distance between the thin plates 21 is very short at 2.0 mm to 4.0 mm, and the gap between the thin plates 21 that serves as the air flow path is extremely narrow, so that the air easily comes into contact with the coating layer, and organic matter in the air is effectively captured.

[0044] If the metal-substituted hydroxyapatite is supported on the filter, the air passes through the air holes penetrating the filter in the thickness direction. Therefore, even if the metal-substituted hydroxyapatite is supported around the air holes, the distance over which the circulating air comes into contact with the metal-substituted hydroxyapatite is short, and there is a risk that organic matter will not be captured sufficiently. In contrast, in this embodiment, the air is circulated through the narrow gap between the thin plates 21, and the air flows along the front and back surfaces of the thin plates 21, so that the contact between the air and the coating layer is planar. This allows the contact distance of the circulating air with the coating layer to be long, and organic matter in the air is effectively captured.

[0045] Furthermore, if the air flow were laminar, a boundary layer where no air flow exists would be formed between the thin plate 21 having the coating layer and the air layer, which could result in insufficient contact between the air and the coating layer. In contrast, the thin plate 21 of this embodiment has many minute protrusions 22, and a coating layer is also formed on the surfaces of the protrusions 22. Therefore, the air that becomes turbulent due to the presence of the protrusions 22 is likely to come into contact with the coating layer as it flows while changing direction in various ways.

[0046] In addition, in this embodiment, each thin plate 21 has many small holes 22a. Therefore, air that becomes turbulent in the gap between one thin plate 21 and the adjacent thin plate 21 flows into the adjacent gap through the small holes 22a. In this way, the air not only flows through the gap between the two thin plates 21, but also flows through the small holes 22a to the adjacent gap and the adjacent gap, so the air flow becomes more turbulent and the contact between the air and the coating layer becomes better.

[0047] In this way, the organic matter that is captured by the calcium hydroxyapatite in the coating layer from the air passing by in an instant and becomes immobile is decomposed by the photocatalytic action of the metal replacement part in the coating layer. That is, in the air purifier 1, the organic matter is not decomposed at the stage where the air flows, but rather, the organic matter is first captured and made immobile, and then decomposed, thereby performing a "two-stage air purification". In other words, in the air purifier 1 of this embodiment, a "time lag" is provided between the adsorption and decomposition of the organic matter. The photocatalytic action of the metal replacement part can be exerted by the light (natural light or light from lighting) in the environment in which the air purifier 1 is installed.

[0048] In addition, in the thin plate juxtaposition section 20, in addition to the process of separating (adsorbing and capturing) and decomposing organic matter such as viruses from the air, the process of adjusting the air temperature is performed. For the latter process, a fluid is circulated through the pipe 27, and heat is exchanged between the fluid and the air. For example, in a high-temperature environment such as summer, cold water such as groundwater is supplied to the pipe 27 from the supply port 27a. On the other hand, in a low-temperature environment such as winter, hot water such as industrial wastewater is supplied to the pipe 27 from the supply port 27a. Since the pipe 27 penetrates a large number of thin plates 21, the fluid supplied to the pipe 27 exchanges heat with the air flowing through the gaps between the thin plates 21 while flowing through the pipe 27, and flows out of the thin plate juxtaposition section 20 after the temperature becomes appropriate. The fluid after heat exchange with the air is discharged from the discharge port 27b.

[0049] In the process of such heat exchange, the multiple thin plates 21 penetrating the pipes 27 act as fins of the heat exchanger in addition to carrying the coating layer. Therefore, heat can be efficiently exchanged between the fluid and the air by absorbing heat from the air flowing through the gaps between the thin plates 21 via the thin plates 21 as fins, and releasing heat from the fluid flowing inside the pipes 27 via the thin plates 21 as fins.

[0050] The air that has been separated from organic matter such as viruses in the thin plate juxtaposition section 20 and has been brought to an appropriate temperature through heat exchange flows into the ultraviolet irradiating section 30. The air passing through the ultraviolet irradiating section 30 is irradiated with ultraviolet rays from an ultraviolet irradiator 35. As a result, even if there are traces of viruses or bacteria remaining in the treated air in the thin plate juxtaposition section 20, they are inactivated by the ultraviolet rays. The air that has been made more purified by passing through the ultraviolet irradiating section 30 is discharged from the air purifier 1 through the exhaust port.

[0051] The inner surface of the casing 60 on which the ultraviolet irradiator 35 is attached may be a mirror surface or a mirror-polished surface. The ultraviolet light irradiated from the ultraviolet irradiator 35 is reflected by the mirror surface or the mirror-polished surface, thereby reducing the attenuation of the ultraviolet light after irradiation from the ultraviolet irradiator 35, and thus the inactivation effect of the ultraviolet light can be further enhanced.

[0052] Next, an air purifying device 2 of a second embodiment will be described mainly with reference to Fig. 2. The air purifying device 2 differs from the air purifying device 1 of the first embodiment in the air blowing mechanism in the blower 10 and the arrangement of each component. The same components as those in the air purifying device 1 are given the same reference numerals and detailed description will be omitted.

[0053] The air purifier 2 comprises, in this order, a blower 10, a thin plate juxtaposition section 20, a pre-filter section 40, and an ultraviolet ray irradiation section 30. The blower 10 is a type that draws in air by rotating a fan, and passes the air taken in from an air intake through the ultraviolet ray irradiation section 30, the pre-filter section 40, and the thin plate juxtaposition section 20, in that order.

[0054] In the air purifier 2, an ultraviolet ray irradiation section 30 is disposed upstream of the thin plate juxtaposition section 20 in the air flow direction. Therefore, by irradiating ultraviolet rays in the ultraviolet ray irradiation section 30, air in which viruses and bacteria have been inactivated to a certain extent is introduced into the thin plate juxtaposition section 20. This makes it possible to reduce the processing load in the thin plate juxtaposition section 20, which captures organic matter and then decomposes it by photocatalysis.

[0055] Like the air purifier 1, the air purifier 2 configured in this manner removes organic matter from the air flowing through the thin plate juxtaposition section 20 by the adsorption action of the calcium hydroxyapatite in the coating layer, and by exchanging heat between the air flowing through the thin plate juxtaposition section 20 and the fluid flowing through the pipe 27, clean air at an appropriate temperature is discharged, and the organic matter adsorbed to the coating layer is then decomposed by the photocatalytic action of the metal replacement section.

[0056] Next, an air purifier of a third embodiment will be described with reference to Fig. 3. The difference from the air purifier 1 of the first embodiment and the air purifier 2 of the second embodiment is mainly the positional relationship between the thin plate juxtaposition section 20 and the ultraviolet ray irradiation section 30. Therefore, Fig. 3 shows only the thin plate juxtaposition section 20 and the ultraviolet ray irradiation section 30 as the main parts. The same reference numerals are used for the same configurations as the air purifiers 1 and 2, and detailed description will be omitted.

[0057] With respect to the configuration other than the thin plate juxtaposition section 20 and the ultraviolet irradiation section 30, the blower 10 may be of a pressure blowing type as in the air purifier 1, and the pre-filter section 40 may be arranged on the same side as the blower 10 with respect to the thin plate juxtaposition section 20, or the blower 10 may be of a suction type as in the air purifier 2, and the pre-filter section 40 may be arranged on the opposite side of the blower 10 with respect to the thin plate juxtaposition section 20.

[0058] In the air purifier 1, the ultraviolet irradiating section 30 is disposed downstream of the thin plate juxtaposition section 20 in the air flow, while in the air purifier 2, the ultraviolet irradiating section 30 is disposed upstream of the thin plate juxtaposition section 20. In contrast, in the third embodiment, the ultraviolet irradiating section 30 is disposed so as to surround the thin plate juxtaposition section 20. Specifically, the ultraviolet irradiating section 30 includes a square cylindrical casing 63 that is open in the direction in which air flows, and the thin plate juxtaposition section 20 is housed inside the casing 63.

[0059] 3(b), a plurality of ultraviolet irradiators 35 are attached to the inner surfaces of a pair of side surfaces 63b that are orthogonal to the plane of the thin plate 21 among the four surfaces constituting the casing 63. Here, the ultraviolet irradiators 35, which are ultraviolet discharge tubes, are shown attached to the side surfaces 63b via the attachment parts 31, but the ultraviolet irradiators 35 may be LEDs that emit ultraviolet light. Note that the ultraviolet irradiators 35 are not shown in FIG. 3(a).

[0060] According to this configuration, ultraviolet light is irradiated from the ultraviolet irradiator 35 toward the coating layer covering the thin plate 21 in the thin plate juxtaposition section 20. Therefore, the photocatalytic action of decomposing the organic matter adsorbed on the coating layer by the metal replacement section can be made to proceed extremely efficiently compared to the case where the action is caused by natural light or lighting in the environment where the air purifier is placed. Note that the irradiation of ultraviolet light by the ultraviolet irradiator 35 does not necessarily need to be performed constantly, and can be made to be intermittent irradiation.

[0061] The inner surface of the side surface 63b on which the ultraviolet irradiator 35 is attached can be a mirror surface or a mirror-polished surface, similar to the surface on which the ultraviolet irradiator 35 is attached in the air purifiers 1 and 2. By reflecting the ultraviolet light irradiated from the ultraviolet irradiator 35, attenuation of the ultraviolet light after irradiation from the ultraviolet irradiator 35 is reduced, and sufficient light energy can be imparted to the coating layer. Therefore, the metal-substituted portion of the metal-substituted hydroxyapatite can fully exert its photocatalytic effect.

[0062] In the air purifier of this third embodiment, like the air purifiers 1 and 2, organic matter is removed from the air flowing through the thin plate juxtaposition section 20 by the adsorption action of the calcium hydroxyapatite in the coating layer, and heat is exchanged between the air flowing through the thin plate juxtaposition section 20 and the fluid flowing through the pipe 27, thereby discharging clean air at an appropriate temperature, and the organic matter adsorbed to the coating layer is then decomposed by the photocatalytic action of the metal replacement section.

[0063] Next, an air purifier according to a fourth embodiment will be described with reference to Fig. 4. The fourth embodiment differs from the third embodiment in the relationship between the thin plate juxtaposition section 20 and the ultraviolet ray irradiation section 30, but is similar to the third embodiment in the differences and similarities between the air purifiers 1 and 2. Therefore, Fig. 4 illustrates only the thin plate juxtaposition section 20 and the ultraviolet ray irradiation section 30 as the main parts. The same reference numerals are used for the same configurations as the above embodiments, and detailed description will be omitted.

[0064] While in the third embodiment the thin plate juxtaposition section 20 is surrounded by the ultraviolet ray irradiation section 30, in the fourth embodiment the thin plate juxtaposition section 20 and the ultraviolet ray irradiation section 30 are integrated. Specifically, in the fourth embodiment, an ultraviolet ray discharge tube serving as an ultraviolet ray irradiator 35 penetrates the many thin plates 21 arranged in parallel. A plurality of ultraviolet ray irradiators 35 are provided at positions that do not interfere with the pipe 27 that also penetrates the thin plates 21. Note that the inner surface of the casing (not shown) in the portion housing the thin plate juxtaposition section 20 with the ultraviolet ray irradiation section 30 integrated therewith can be a mirror surface or a mirror-polished surface.

[0065] In the fourth embodiment having such a configuration, similarly to the third embodiment, ultraviolet light is irradiated toward the coating layer covering the thin plate 21. This allows the photocatalytic action of decomposing the organic matter adsorbed on the coating layer by the metal replacement part to proceed efficiently. In addition, in the fourth embodiment, the distance between the ultraviolet light irradiator 35 and the coating layer is shorter than in the third embodiment, so that the efficiency of decomposing the organic matter is high and the organic matter can be decomposed in a short time.

[0066] In addition, when the inner surface of the casing is a mirror surface or a mirror-polished surface, in the third embodiment, the mirror surface or mirror-polished surface (the inner surface of the side surface 63b) is on the back side with respect to the irradiation direction of the ultraviolet rays, whereas in the fourth embodiment, the mirror surface or mirror-polished surface is the surface that is directly irradiated with the ultraviolet rays. Therefore, the intensity of the ultraviolet rays reflected by this surface is high, and the effect of suppressing attenuation of the ultraviolet rays after irradiation is higher.

[0067] Furthermore, in the fourth embodiment, the thin plate juxtaposition section 20 and the ultraviolet ray irradiation section 30 are integrated, so that the entire device can be made compact.

[0068] In the air purifying device of the fourth embodiment, like the air purifying devices of the above embodiments, organic matter is removed from the air flowing through the thin plate juxtaposition section 20 by the adsorption action of the calcium hydroxyapatite in the coating layer, and heat is exchanged between the air flowing through the thin plate juxtaposition section 20 and the fluid flowing through the pipe 27, thereby discharging clean air at an appropriate temperature, and the organic matter adsorbed to the coating layer is then decomposed by the photocatalytic action of the metal replacement section.

[0069] The present invention has been described above with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and various improvements and design changes are possible without departing from the spirit of the present invention, as described below.

[0070] For example, an air purifying device having a configuration combining the third and fourth embodiments can be used. That is, a pipe 27 penetrates a number of thin plates 21 arranged in parallel in the thin plate juxtaposition section 20, an ultraviolet irradiator 35 which is an ultraviolet discharge tube penetrates the number of thin plates 21, and the thin plate juxtaposition section 20 is further surrounded by an ultraviolet irradiating section 30. In this configuration, the amount of ultraviolet light that can be irradiated to the coating layer is increased. Therefore, even if a large amount of organic matter is contained in the air, the organic matter can be efficiently decomposed.

[0071] Furthermore, the air purifying device of the above embodiment can be used alone or multiple units can be installed side by side in large facilities such as hospitals, schools, nursing homes, factories, chicken coops for raising many birds, etc. In this case, the control device can be shared by multiple air purifying devices.

[0072] Furthermore, in the above embodiment, a case where one pipe 27 is provided per one thin plate juxtaposed section 20 has been exemplified, but the present invention is not limited to this, and multiple pipes 27 can be provided per one thin plate juxtaposed section 20. This makes it possible to reduce the temperature difference in the temperature distribution of the air after heat exchange with the fluid flowing through the pipe 27, even if the area of ​​each thin plate 27 is large.

[0073] In the above, cold water or hot water is exemplified as the fluid circulating through pipe 27, but a refrigerant such as chlorofluorocarbon (alternative freon) may be used, and heat may be exchanged with the air through repeated compression and expansion to heat or cool the air. [Explanation of symbols]

[0074] 1,2 Air purifier 10 Blower 20 Thin plate parallel installation section 21 thin plate 22 Convex 22a Small hole 24 Hole 24a Peripheral wall part 27 Pipe 35 Ultraviolet irradiator

Claims

1. A thin plate juxtaposition portion is provided in which a plurality of thin plates are arranged in parallel with gaps therebetween, The thin plate juxtaposition portion has coating layers supported on the front and back surfaces of the thin plates and a pipe penetrating the plurality of thin plates, the coating layer is a layer of metal-substituted hydroxyapatite in which part of the calcium of calcium hydroxyapatite is substituted with a metal selected from titanium, zirconium, iron, and tungsten; The thin plates have both a function of supporting the coating layer and a function as fins of a heat exchanger formed by circulating a fluid through the pipe. An air purifying device characterized by:

2. The thin plate has a plurality of projections and / or recesses, and also has a plurality of open small holes.

2. The air purifying device according to claim 1.

3. the hole portion through which the pipe passes in the thin plate has a peripheral wall portion at an opening edge rising from a plane of the thin plate, The peripheral wall defines the distance between adjacent thin plates.

3. The air purifying device according to claim 1 or 2.

4. An air purification method using the air purification device according to claim 1, Air is passed through the gap between the thin plates, and organic matter contained in the air is adsorbed by the calcium hydroxyapatite portion of the metal-substituted hydroxyapatite constituting the coating layer, and the adsorbed organic matter is decomposed by the photocatalytic action of the portion of the metal-substituted hydroxyapatite where calcium is substituted with the metal. Heat is exchanged between the air flowing through the gap between the thin plates and the fluid flowing through the pipe. An air purification method comprising:

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