Air treatment device

Abstract

To provide an air treatment device that can treat air more quickly and effectively.SOLUTION: According to an embodiment, an air treatment device has a cylindrical housing, a fan, and a photocatalytic filter. The housing is equipped with a suction port and an exhaust port. The fan creates a flow of air directing from the suction port to the exhaust port. The photocatalytic filter is provided inside the housing, and a ceramic base material made of cordierite carries a photocatalytic material of an anatase structure to be 100 wt.%. Then, the photocatalytic filter is arranged on the air flow.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to an air treatment device. [Background technology]

[0002] In general, an air treatment device takes in ambient air into a housing, irradiates the surface of a photocatalytic filter with ultraviolet light from a light source located inside the housing, sterilizes the air passing over the surface of the photocatalytic filter and the air around the photocatalytic filter, and then discharges the air outside the housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-235153 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide an air treatment device that can treat air more quickly and effectively. [Means for solving the problem]

[0005] According to an embodiment, the air treatment device includes a cylindrical housing; a fan; and a photocatalytic filter. The housing has an air intake port and an exhaust port. The fan generates an air flow from the air intake port to the exhaust port. The photocatalytic filter is provided within the housing, and is made of a ceramic substrate made of cordierite, on which an anatase-structured photocatalytic material is supported at 100% by weight. The photocatalytic filter is then positioned in the air flow. [Effects of the Invention]

[0006] According to the present invention, an air treatment device can be provided that can treat air more quickly and effectively. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic perspective view showing an air treatment device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the air treatment device shown in FIG. 1, viewed in the +Y-axis direction from a certain ZX plane indicated by the dashed dotted line with reference symbol II. [Figure 3] FIG. 3 is a front view of the air treatment device shown in FIG. [Figure 4] FIG. 4 is a diagram showing a photocatalytic filter unit of the air treatment device shown in FIG. [Figure 5] FIG. 5 is a schematic perspective view showing a photocatalytic filter of the photocatalytic filter unit shown in FIG. [Figure 6] FIG. 6 is a graph showing the content of titanium oxide carried on the base material and the base material of the photocatalytic filter of the comparative example and the photocatalytic filter of this embodiment. [Figure 7] FIG. 7 is a graph showing the ammonia remaining rate versus test time when an air treatment device having the photocatalytic filter of the comparative example shown in FIG. 6 and an air treatment device having the photocatalytic filter of this embodiment are operated. [Figure 8] FIG. 8 is a graph showing the base material, base material weight, titanium oxide loading amount, and titanium oxide weight ratio of the photocatalytic filter of the comparative sample, the photocatalytic filter of Example Sample 1 of this embodiment, and the photocatalytic filter of Example Sample 2 of this embodiment. [Figure 9] FIG. 9 is a graph showing the titanium oxide weight percentage and the time required to deodorize 50% of ammonia when an air treatment device having the photocatalytic filter of the comparison sample shown in FIG. 8, the photocatalytic filter of Example Sample 1 of this embodiment, and the photocatalytic filter of Example Sample 2 of this embodiment are operated. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the air treatment device 100 according to this embodiment, air circulating or remaining in the sterilization and deodorization area 112 (sterilization treatment unit) can be sterilized, disinfected, or sterilized by passing air through the sterilization and deodorization area (sterilization treatment unit) 112 or irradiating the air with ultraviolet light while passing the air through the area. Sterilizing, disinfecting, or sterilizing air refers to inactivating or adsorbing bacteria, viruses, odorous substances, and the like present in the air. Furthermore, although the following embodiments will be described using sterilization as an example, the term "sterilization" can be replaced with "sterilization" or "sterilization."

[0009] The air treatment device (100) of this embodiment includes a cylindrical housing (102), a fan (118), and a photocatalytic filter (110a) disposed within the housing (102). The housing (102) includes an air intake (104) and an exhaust (120). The fan (118) generates an air flow from the air intake (104) to the exhaust (120). The photocatalytic filter (110a) is made of a cordierite ceramic substrate with an anatase structure photocatalytic material supported thereon (100% by weight), and is disposed in the air flow. The use of such a photocatalytic filter (110a) can reduce the amount of residual ammonia, for example, more quickly, thereby enabling more effective treatment of the air. Therefore, the use of such an air treatment device (10) can enable more effective treatment of the air more quickly.

[0010] The air treatment device (100) according to the embodiment includes an ultraviolet module (134) that is disposed opposite the photocatalytic filter (110a) and irradiates the photocatalytic material with light. Therefore, when the photocatalytic material on the surface of the photocatalytic filter (110a) is irradiated with UV-A from the ultraviolet module (134), it decomposes bacteria, viruses, and odorous substances contained in the air passing through the photocatalytic filter (110a) and the air around the photocatalytic filter (110a) into water and carbon dioxide, and suppresses the activity of viruses and bacteria. Therefore, when UV-A is irradiated onto the surface of the photocatalytic filter (110a), it exerts a sterilizing and deodorizing effect on the air passing through the photocatalytic filter (110a). Therefore, by using such an air treatment device (10), air can be treated more quickly and effectively.

[0011] The photocatalytic material of the photocatalytic filter (110a) of the air treatment device (100) according to the embodiment is a ceramic substrate that supports titanium oxide as a photocatalytic material with an anatase structure in an amount of 10% to 20% by weight. When a photocatalytic filter (110a) carrying 10% to 20% by weight of titanium oxide as a photocatalytic material with an anatase structure is used on such a cordierite ceramic substrate, the amount of residual ammonia, for example, can be reduced in a significantly shorter time than when, for example, steatite is used as the ceramic substrate. Furthermore, the use of titanium oxide with an anatase structure allows the amount of residual ammonia, for example, to be reduced more quickly than when titanium oxide with a rutile structure is used. Therefore, by using such an air treatment device (10), air can be treated more quickly and effectively.

[0012] The photocatalytic material of the photocatalytic filter (110a) of the air treatment device (100) according to this embodiment does not include a photocatalytic material with a rutile structure. Therefore, the amount of residual ammonia, for example, can be reduced more quickly than when the air treatment device (10) contains both the anatase structure and the rutile structure. Therefore, by using such an air treatment device (10), air can be treated more quickly and effectively.

[0013] Hereinafter, embodiments will be described with reference to the drawings.

[0014] 1 is a schematic perspective view showing an air circulation type air treatment device 100 according to an embodiment. The air treatment device 100 according to the embodiment can be installed in various places, such as homes, offices, medical facilities, nursing homes, restaurants, accommodation facilities, and toilet booths. As shown in FIG. 1, an XYZ Cartesian coordinate system is set for the air treatment device 100.

[0015] Fig. 2 is a schematic cross-sectional view of the position indicated by symbol II in Fig. 1. Fig. 3 is a front view of the air treatment device 100 shown in Fig. 2. Fig. 4 is a schematic view of the photocatalytic filter unit 110 of the air treatment device 100. Fig. 5 is a schematic perspective view of the photocatalytic filter 110a of the photocatalytic filter unit 110 of the air treatment device 100.

[0016] As shown in Figures 1 to 3, the air treatment device 100 has a housing 102, an air intake 104, a first light-shielding grill 106, a pre-filter 108, a photocatalytic filter unit (photocatalytic filter assembly) 110, a sterilization and deodorization area 112, a light source unit 114, a second light-shielding grill 116, a fan 118, an exhaust vent 120, and a controller 122.

[0017] The housing 102 is formed in a cylindrical shape. In this embodiment, it is formed in a substantially rectangular parallelepiped shape. In this embodiment, the lower end of the housing 102 is opened as an intake port 104, and the upper end is opened as an exhaust port 120. The outer dimensions of the housing 102 are, for example, 310 mm wide along the X-axis direction, 130 mm deep along the Y-axis direction, and 800 mm high along the Z-axis direction.

[0018] A first light-shielding grill 106 is provided above (downstream of) the air intake 104 at the bottom end of the housing 102. The first light-shielding grill 106 is formed so as to cover the entire XY plane inside the housing 102. In this embodiment, the first light-shielding grill 106 allows air to flow upward through the air intake 104 and the first light-shielding grill 106, but suppresses or prevents light from a light source (ultraviolet module) 134 (described later) of the light source unit 114 from leaking downward. The first light-shielding grill 106 is made up of a number of plates bent into a substantially L-shape or a substantially "L" shape, and arranged in the width direction of the housing 102.

[0019] A pre-filter 108 is provided above the first light-shielding grille 106 (downstream of the air flow). The pre-filter 108 is formed in a mesh shape so as to cover the entire XY plane inside the housing 102. As an example, the pre-filter 108 can be formed from a metal material, have a substantially rectangular shape with a width of 300 mm and a depth of 120 mm, a wire diameter of Φ0.16 mm, and 50 mesh.

[0020] The prefilter 108 is detachable from the housing 102 when the front panel 102a is removed from the housing 102. The prefilter 108 can be removed from the front surface of the housing 102 by moving it in the -Y-axis direction, for example, and can be attached to the front surface of the housing 102 by moving it in the +Y-axis direction. The prefilter 108 may be configured so that it can be removed from the side surface of the housing 102 by moving it in the +X-axis direction, for example, and can be attached to the side surface of the housing 102 by moving it in the -X-axis direction. The ±X-axis directions may be reversed.

[0021] A photocatalytic filter unit 110 is provided above the pre-filter 108 (downstream in the air flow). The photocatalytic filter unit 110 is formed in a substantially rectangular shape with a width of 300 mm and a depth of 120 mm.

[0022] The photocatalytic filter unit 110 is detachable from the housing 102 when the front panel 102a is removed from the housing 102. Like the pre-filter 108, the photocatalytic filter unit 110 can be removed from the front surface of the housing 102 by moving it in the -Y-axis direction, for example, and can be attached to the front surface of the housing 102 by moving it in the +Y-axis direction. The photocatalytic filter unit 110 may be configured so that it can be removed from the side surface of the housing 102 by moving it in the +X-axis direction, for example, and can be attached to the side surface of the housing 102 by moving it in the -X-axis direction. The ±X-axis directions may be reversed.

[0023] As shown in FIG. 4, the photocatalytic filter unit 110 has, for example, three photocatalytic filters 110a and a frame body 110b that supports the photocatalytic filters 110a.

[0024] The photocatalytic filter 110a shown in Fig. 5 comprises a base material (photocatalyst carrier) having a plurality (countless) of holes connecting (communicating) the front surface (upper surface) and the back surface (lower surface), and a photocatalytic material carried on the surface of the base material, and is formed, for example, in a rectangular plate shape. The front surface (photocatalytic material), which is the largest area of ​​the plate-shaped photocatalytic filter 110a, faces the light source 134. Note that the front surface (photocatalytic material) and back surface (photocatalytic material) of the photocatalytic filter 110a can also be used in reverse.

[0025] The base material of the photocatalytic filter 110a is formed with an appropriate large surface area and porosity from an inorganic material (ceramic) called cordierite, which is a compound of magnesium oxide, aluminum oxide, and silicon dioxide. Therefore, the base material of the photocatalytic filter 110a is formed as an appropriate porous body.

[0026] The photocatalytic material is formed of a metal oxide such as titanium oxide, etc. In this embodiment, the photocatalytic material is titanium oxide fine particles having an anatase structure.

[0027] When manufacturing the photocatalytic filter 110a, titanium oxide particles having an anatase structure are contained in an aqueous slurry. Then, a ceramic porous body serving as a base material is immersed in the aqueous slurry to allow the titanium oxide particles to adhere to the ceramic porous body, and the ceramic porous body is dried. After that, the porous base material is fired for 6 hours at 100°C and 6 hours at 200°C, for a total of 12 hours, to support the porous photocatalyst.

[0028] The thickness and loading of the photocatalytic material can be adjusted by repeatedly immersing the base material in an aqueous slurry containing titanium oxide microparticles and drying it. On the other hand, if the thickness of the photocatalytic material is increased, ultraviolet rays (UV-A) may not reach the inner part of the photocatalytic material (the surface side of the base material), and this part of the photocatalytic material may not be irradiated with ultraviolet rays. Therefore, the thickness of the photocatalytic material should be formed to an appropriate thickness that can exert effects such as deodorization.

[0029] In this way, the photocatalytic filter 110a is, for example, porous and formed to have air permeability in the vertical direction in this embodiment, but it is preferable to form it to appropriately block ultraviolet rays (UV-A and UV-C) in the vertical direction. The photocatalytic filter unit 110 is formed to block light such as UV-A and UV-C, and to allow air that has passed through the pre-filter 108 to flow upward through the photocatalytic filter unit 110. The photocatalytic filter 110a is formed to an appropriate thickness and porosity in relation to, for example, the distance from the light source 134 and the amount of light from the light source 134. In this embodiment, three ceramic plates with dimensions of 100 mm, height of 8 mm, and hole diameter of 3 mm are arranged side by side in the longitudinal direction (X-axis direction).

[0030] In this embodiment, the photocatalytic filter 110a carries, for example, 8 g of photocatalytic material (titanium oxide) on 58 g of a ceramic (cordierite) plate measuring 100 mm x 100 mm x 8 mm as the base material. Therefore, the weight ratio of titanium oxide as the photocatalytic material is, for example, approximately 12%. The weight of the photocatalytic material carried is preferably, for example, 6.4 g or more (weight ratio: 10% or more) to 14.5 g or less (weight ratio: 20% or less) relative to the 58 g base material. In practice, it is preferable that the weight ratio of the photocatalytic material carried by the photocatalytic filter 110a be within a narrower range of 10% or more and 20% or less relative to the base material.

[0031] The weight of the base material and photocatalytic material of the photocatalytic filter 110a varies depending on, for example, the size and shape of the sterilization / deodorization area 112, but it is preferable that the weight ratio of the photocatalytic material carried by the photocatalytic filter 110a be within the range of 10% or more and 20% or less of the base material.

[0032] A sterilization / deodorization area (air treatment section) 112 is provided above the photocatalytic filter unit 110 (downstream of the air flow). In this embodiment, the sterilization / deodorization area 112 is formed as a substantially rectangular parallelepiped space. It is preferable that the inner walls of the sterilization / deodorization area 112 are formed so as not to absorb light from the light source 134 of the light source section 114, but to appropriately reflect the light.

[0033] A light source unit 114 is provided above the sterilization / deodorization area 112 (downstream of the air flow). The light source unit (LED light source unit) 114 is provided near the upper end of the sterilization / deodorization area 112. The light source unit 114 has light source boards 132 and light sources 134 arranged, for example, in two rows. The light source boards 132 are spaced apart in the Y-axis direction (short direction) and extend in the X-axis direction (longitudinal direction). The light source boards 132 are electrically connected to the controller 122. The light source boards 132 may be arranged in a single row, or three or more rows.

[0034] In this embodiment, a plurality of light sources 134, each emitting light downward, are provided on the light source substrate 132 of the light source unit 114. The light sources 134 irradiate the air in the sterilization and deodorization area 112 with UV-A and UV-C as ultraviolet rays. The light sources 134 include a light source that emits UV-A and a light source that emits UV-C. The UV-A light source and the UV-C light source are each formed of, for example, an LED.

[0035] UV-A is a first ultraviolet ray having a peak wavelength of, for example, 320 nm or more and 400 nm or less, and is used to illuminate the surface of the photocatalytic filter unit 110. UV-C is a second ultraviolet ray having a peak wavelength of, for example, 200 nm or more and 320 nm or less, and is used to sterilize the air passing through the space of the sterilization and deodorization area 112 by irradiating it evenly.

[0036] A second light-shielding grill 116 is provided above the light source unit 114 (downstream of the air flow). The second light-shielding grill 116 is formed so as to cover the entire XY plane inside the housing 102. In this embodiment, the second light-shielding grill 116 allows air to flow upward through the air intake 104, the first light-shielding grill 106, the pre-filter 108, the photocatalytic filter unit 110, the sterilization and deodorization area 112, and the light source unit 114, but suppresses or prevents light from the light source 134 from leaking upward. The second light-shielding grill 116 is made up of a number of plates bent in a substantially L-shape or a substantially "L" shape, and arranged in the width direction of the housing 102.

[0037] A pair of fans 118 are arranged in the X-axis direction (longitudinal direction) above the second light-shielding grille 116 (downstream of the air flow). The fans 118 are disposed inside the housing 102, above the intermediate portion between the upper and lower portions of the housing 102. In this embodiment, an example using two fans 118 will be described. The number of fans may be one, or three or more.

[0038] The pair of fans 118 may be, for example, axial fans with blades and frame portions made of resin, measuring 120 mm and having a height of 38 mm.

[0039] The pair of fans 118 are electrically connected to the controller 122. In this embodiment, the pair of fans 118 rotate under the control of the controller 122, and create an air flow within the housing 102 that flows from the lower side of the pair of fans 118 to the upper side. That is, in this embodiment, the pair of fans 118 draw air through the intake port 104 on the lower side of the housing 102 and exhaust the air through the exhaust port 120 on the upper side. The pair of fans 118 have, for example, the same structure and rotate in the same direction. An imaginary extension line of the central axis C of the pair of fans 118 is disposed so as to pass through the intake port 104 and the exhaust port 120.

[0040] An exhaust port 120 and a controller 122 are provided above the pair of fans 118 (downstream of the air flow). In this embodiment, the controller 122 and the exhaust port 120 are arranged in the short direction (Y-axis direction) at the upper end of the air processing device 100. The controller 122 is disposed in the -Y-axis direction relative to the exhaust port 120.

[0041] The exhaust port 120 is formed, for example, in a grid shape, so as to prevent the user's fingers and the like from reaching the fan 118 .

[0042] Next, the operation of the air treatment device 100 according to this embodiment will be described with reference to FIGS.

[0043] 6 shows the titanium oxide content of a photocatalytic filter of a comparative example and the photocatalytic filter 110a of this embodiment, both of which use cordierite as a base material. The size of the photocatalytic filter of the comparative example is the same as that of the photocatalytic filter 110a of this embodiment.

[0044] The photocatalytic filter of the comparative example contains, by weight, 91% base material, 1% titanium oxide with a rutile structure, and 8% titanium oxide with an anatase structure.

[0045] The photocatalytic filter 110a of this embodiment contains, by weight, 87% base material, 0% rutile titanium oxide, and 13% anatase titanium oxide. The photocatalytic material of the photocatalytic filter 110a of this embodiment does not contain rutile titanium oxide.

[0046] Here, an air treatment device was prepared in which three photocatalytic filters of the comparative example described above were arranged side by side in the frame 110b of the photocatalytic filter unit 110, and an air treatment device in which three photocatalytic filters 110a of this embodiment were arranged side by side in the frame 110b of the photocatalytic filter unit 110. The air treatment device in which the photocatalytic filter of the comparative example is arranged is referred to as the air treatment device of the comparative example, and the air treatment device in which the photocatalytic filter 110a of this embodiment is arranged is referred to as the air treatment device 100 of this embodiment. The only difference between the air treatment device of the comparative example and the air treatment device 100 of this embodiment is the composition of the photocatalytic filter.

[0047] Then, a test was conducted to measure the residual rate of ammonia for the air treatment device of the comparative example and the air treatment device 100 of this embodiment, in accordance with the test for measuring deodorizing performance specified in Appendix B of the Japan Electrical Manufacturers' Association standard JEM 1467 for household air purifiers.

[0048] Therefore, the test devices are the air treatment device of the comparative example and the air treatment device 100 of this embodiment. The test gas is ammonia (NH3). The initial concentration of the test gas is 10 ppm. The internal volume of the space in which the test device is placed is 1 m 3 The ammonia measurement device used was the Photoacoustic Gas Monitor INNOVA1412i manufactured by LumaSense Technologies.

[0049] The air treatment device of the comparative example and the air treatment device 100 of this embodiment were operated in two modes (first mode and second mode) and tested.

[0050] First, the air treatment device of the comparative example and the air treatment device 100 of this embodiment were operated in the first mode.

[0051] In the first mode, the fan 118 rotates, drawing air through the intake port 104 and discharging it through the exhaust port 120. In this first mode, no light is emitted from the light source 134 of the light source unit 114. In other words, the light source 134 is in the OFF state. In addition, no light, including natural light, enters the interior of the air treatment device 100 (inside the sterilization and deodorization area 112).

[0052] As the fan 118 rotates, air is drawn into the sterilization / deodorization area 112 through the air intake 104, the first light-shielding grille 106, the pre-filter 108, and the photocatalytic filter unit 110. The air that has entered the sterilization / deodorization area 112 is exhausted from the air exhaust 120 via the fan 118 as the fan 118 rotates. At this time, the air that has entered the housing 102 from the air intake 104 travels in a substantially straight line through the housing 102, passing through the first light-shielding grille 106, the pre-filter 108, the photocatalytic filter unit 110, the sterilization / deodorization area 112, and the second light-shielding grille 116, before being exhausted from the air exhaust 120. As a result, there are no points within the air treatment device 100 where the air flow bends significantly, which makes it possible to suppress pressure loss in the air flowing within the air treatment device 100.

[0053] In this state, FIG. 7 shows a graph in which the horizontal axis represents test time and the vertical axis represents ammonia residual rate when air treatment is performed using the air treatment device of the comparative example and the air treatment device 100 of this embodiment.

[0054] When the air treatment device 100 of this embodiment was operated in the first mode (dashed line in FIG. 7), the ammonia residual rate decreased significantly faster than when the air treatment device of the comparative example was used (solid line in FIG. 7). When the air treatment device 100 of this embodiment was used, it took about 25 to 30 minutes for the ammonia residual rate to decrease from 100% to approximately 0%. In contrast, when the photocatalytic filter of the comparative example was used, it took about 120 minutes or more, and it is estimated that it would take more than 240 minutes, for the ammonia residual rate to decrease from 100% to approximately 0%.

[0055] In this way, by using the air treatment device 100 of this embodiment and flowing air containing ammonia through the photocatalytic filter 110a of this embodiment, the air treatment device 100 of this embodiment can obtain an appropriate ammonia decomposition effect without irradiating the photocatalytic filter 110a with light (UV-A), as will be described later. Therefore, according to the air treatment device 100 of this embodiment, by using the photocatalytic filter 110a of this embodiment, in which the photocatalytic material with an anatase structure is supported on the ceramic substrate of cordierite to make it 100% by weight, air can be treated more quickly and effectively.

[0056] In the second mode, the fan 118 was driven to cause air to flow from the intake port 104 to the exhaust port 120. In this second mode, the LEDs were driven to irradiate UV-A and UV-C from the light source unit 114 to the photocatalytic filter of the comparative example and the photocatalytic filter 110a of this embodiment.

[0057] As the fan 118 rotates, air is drawn into the sterilization / deodorization area 112 through the air intake 104, the first light-shielding grille 106, the pre-filter 108, and the photocatalytic filter unit 110. The air that has entered the sterilization / deodorization area 112 is exhausted from the air exhaust 120 via the fan 118 as the fan 118 rotates. At this time, the air that has entered the housing 102 from the air intake 104 travels in a substantially straight line through the housing 102, passing through the first light-shielding grille 106, the pre-filter 108, the photocatalytic filter unit 110, the sterilization / deodorization area 112, and the second light-shielding grille 116, before being exhausted from the air exhaust 120. As a result, there are no points within the air treatment device 100 where the air flow bends significantly, which makes it possible to suppress pressure loss in the air flowing within the air treatment device 100.

[0058] In this way, the air treatment device 100 takes in the air surrounding the air treatment device 100 through the air intake 104 on the outside of the air treatment device 100. UV-A is irradiated from the light source 134 through the sterilization / deodorization area 112 toward the photocatalytic material on the surface of the photocatalytic filter unit 110. When UV-A is irradiated, the photocatalytic material on the surface (top) of the photocatalytic filter unit 110 generates active oxygen and OH radicals. The generated active oxygen and OH radicals decompose bacteria, viruses, and odorous substances contained in the air passing through the photocatalytic filter unit 110 and the air surrounding the photocatalytic filter unit 110 into water and carbon dioxide, and suppress the activity of viruses and bacteria. Therefore, when UV-A is irradiated onto the photocatalytic material on the surface of the photocatalytic filter unit 110, the air passing through the photocatalytic filter unit 110 is sterilized and deodorized. Therefore, the air passing through the photocatalytic filter unit 110 enters the sterilization and deodorization area 112 while being sterilized and deodorized.

[0059] UV-C is irradiated from light source 134 into sterilization and deodorization area 112. The UV-C is irradiated over a wide area within sterilization and deodorization area 112 using reflected light within sterilization and deodorization area 112. As a result, UV-C is evenly irradiated onto the air within sterilization and deodorization area 112. At this time, the irradiation of UV-C suppresses the activity of viruses and bacteria (germs) contained in the air within sterilization and deodorization area 112 after sterilization and deodorization using a photocatalyst, thereby exerting a sterilization effect.

[0060] By making the sterilization / deodorization area 112 a large space and continuously irradiating the large space with UV-C, it is possible to sterilize the air passing through the sterilization / deodorization area 112 the entire time it remains in the sterilization / deodorization area 112. Therefore, UV-C effectively exerts a sterilizing effect, and the sterilized air can be discharged from the exhaust port 120.

[0061] While the light source 134 of this embodiment continues to emit light, the air treatment device 100 continues to exert a sterilization and deodorization effect by decomposing substances in the photocatalytic filter unit 110 using UV-A light emitted by the light source 134, and a sterilization effect using UV-C. Therefore, the air treatment device 100 can sterilize the air more effectively due to the double effect of sterilizing the air passing through the photocatalytic filter unit 110 and sterilizing the air within the space of the sterilization and deodorization area 112.

[0062] When UV-A from the light source 134 illuminates the photocatalytic material on the surface of the photocatalytic filter unit 110, it is possible that not all of the UV-A is absorbed by the photocatalytic material on the surface of the photocatalytic filter unit 110; instead, some of the UV-A passes through, and the remaining portion is reflected by the photocatalytic material on the surface of the photocatalytic filter unit 110. Some of the UV-A reflected by the photocatalytic material on the surface of the photocatalytic filter unit 110 may travel toward the light source 114 through the space within the sterilization and deodorization area 112. The intensity of the light is inversely proportional to the square of the distance from the light source. In this embodiment, the housing 102 is elongated in the Z-axis direction. Therefore, the UV-A reflected by the photocatalytic material on the surface of the photocatalytic filter unit 110 attenuates as it approaches the light source 114.

[0063] In this embodiment, if UV-A and UV-C rays reach the upper side of the sterilization and deodorization area 112, the second light-shielding grill 116 is present above the sterilization and deodorization area 112 and the light source unit 114. Therefore, the UV-A and UV-C rays are reflected by the second light-shielding grill 116, preventing the UV-A and UV-C rays from reaching the upper side from the second light-shielding grill 116.

[0064] Furthermore, at least a portion of the UV-A and UV-C rays irradiated onto the surface of the photocatalytic filter unit 110 may reach the pre-filter 108 below the photocatalytic filter unit 110, and further the first shading grill 106. At this time, the UV-A and UV-C rays are reflected by the first shading grill 106. This prevents the UV-A and UV-C rays from reaching the lower side from the first shading grill 106.

[0065] In this way, by rotating the fan 118 and illuminating the light source 134, the air treatment device 100 takes in air through the air intake 104, passes it through the housing 102, and continuously sterilizes and deodorizes the air that has passed through the air intake 104, while continuing to exhaust it through the exhaust 120.

[0066] When the air treatment device 100 of this embodiment was operated in the second mode (the two-dot chain line in FIG. 7), the ammonia residual rate decreased significantly faster than when the comparative air treatment device was used (the single-dot chain line in FIG. 7). When the air treatment device 100 of this embodiment was used, it took approximately 15 to 20 minutes for the ammonia residual rate to decrease from 100% (10 ppm) to approximately 0%. In contrast, when the comparative air treatment device was used, it took approximately 100 to 110 minutes for the ammonia residual rate to decrease from 100% to approximately 0%. Therefore, with the air treatment device 100 of this embodiment, air can be treated more quickly and effectively by using the photocatalytic filter 110a of this embodiment, in which the anatase-structured photocatalytic material is supported on a cordierite ceramic substrate to form 100% by weight.

[0067] Furthermore, when using the air treatment device 100 of this embodiment, the ammonia residual rate can be reduced more quickly than the air treatment device of the comparative example, whether in the first mode or the second mode, i.e., whether or not UV-A or UV-C is irradiated.

[0068] Therefore, according to the air treatment device 100 of this embodiment, by using the photocatalytic filter 110a of this embodiment, in which the photocatalytic material of an anatase structure is supported on the ceramic substrate of cordierite to be 100% by weight, the air can be treated more quickly and effectively.

[0069] Next, FIG. 8 shows the base material, base material weight, titanium oxide loading amount, and titanium oxide weight ratio of a photocatalytic filter of a comparative sample (different from the photocatalytic filter of the comparative example in FIG. 6 and the photocatalytic filter 110a of this embodiment), the photocatalytic filter 110a of Example Sample 1 of this embodiment, and the photocatalytic filter 110a of Example Sample 2 of this embodiment. The photocatalytic filter 110a of Example Sample 1 and the photocatalytic filter 110a of Example Sample 2 of this embodiment are products similar to the photocatalytic filter 110a of this embodiment in FIG. 6. In other words, the difference between Example Samples 1 and 2 is due to variations during the manufacturing of the photocatalytic filter 110a. As mentioned above, such variations in the photocatalytic filter 110a are acceptable in terms of the titanium oxide weight ratio of 10% or more and 20% or less.

[0070] The photocatalytic filters of these comparative samples, the photocatalytic filter 110a of Example Sample 1 of this embodiment, and the photocatalytic filter 110a of Example Sample 2 of this embodiment were produced using the same method as described above. That is, a ceramic porous body serving as a base material was immersed in an aqueous slurry containing titanium oxide fine particles having an anatase structure to adhere the titanium oxide fine particles to the ceramic porous body, and then dried. The porous base material was then fired for 6 hours at 100°C and 6 hours at 200°C, for a total of 12 hours, to support the porous photocatalytic material.

[0071] Steatite is used as the ceramic porous body (base material) of the photocatalytic filter of the comparative sample. Furthermore, cordierite is used as the ceramic porous body (base material) of the photocatalytic filter 110a of Example Sample 1 of this embodiment and the photocatalytic filter 110a of Example Sample 2 of this embodiment. It was found that using cordierite as the base material allows a larger amount of titanium oxide to be supported relative to the weight of the base material than using steatite. Even when the same cordierite is used as the base material, the weight percentage of titanium oxide was 14% for Example Sample 1 and 18% for Example Sample 2, resulting in some variation. Taking variation into account, it can be said that the weight percentage of titanium oxide in cordierite base material can be manufactured to be, for example, approximately 10% to 20%.

[0072] An air treatment device equipped with the photocatalytic filter of the comparative sample will be referred to as the air treatment device of the comparative sample, an air treatment device equipped with the photocatalytic filter 110a of practical sample 1 of this embodiment will be referred to as the air treatment device 100 of practical sample 1 of this embodiment, and an air treatment device equipped with the photocatalytic filter 110a of practical sample 2 of this embodiment will be referred to as the air treatment device 100 of practical sample 2 of this embodiment. The only difference between the air treatment device of the comparative sample, the air treatment device 100 of practical sample 1 of this embodiment, and the air treatment device 100 of practical sample 2 of this embodiment is the composition of the photocatalytic filter.

[0073] A test to measure the residual rate of ammonia was conducted on the air treatment device of the comparison sample, the air treatment device 100 of Example Sample 1 of this embodiment, and the air treatment device 100 of Example Sample 2 of this embodiment, in accordance with the test for measuring deodorizing performance specified in Appendix B of the Japan Electrical Manufacturers' Association Standard JEM 1467 for household air purifiers, as described above.

[0074] In this state, Figure 9 shows a graph in which the horizontal axis represents the titanium oxide weight percentage (%) and the vertical axis represents the ammonia 50% deodorization time (minutes) when air treatment was performed using the air treatment device 100 of the comparative sample, the air treatment device 100 of practical sample 1 of this embodiment, and the air treatment device 100 of practical sample 2 of this embodiment in the second mode described above.

[0075] In the air treatment device of the comparison sample, it took 56 minutes for 50% of ammonia to be deodorized, while in the air treatment device 100 of practical sample 1 of this embodiment and the air treatment device 100 of practical sample 2 of this embodiment, it took 4 minutes each.

[0076] Therefore, by using cordierite, which is more porous than steatite, as the base material, the photocatalytic filter 110a can support an appropriate amount of titanium oxide, and the residual ammonia rate can be reduced to half of the initial rate more quickly.

[0077] Therefore, according to the air treatment device 100 of this embodiment, by using the photocatalytic filter 110a of this embodiment, in which the photocatalytic material of an anatase structure is supported on the ceramic substrate of cordierite to be 100% by weight, the air can be treated more quickly and effectively.

[0078] The dirt on the photocatalytic filter 110a of the photocatalytic filter unit 110 is mainly the accumulation of decomposition products and impurities generated by reaction with the catalyst, and foreign matter (contamination) contained in the air that flows in. Since it is expected to be difficult to take the amount of foreign matter into account, the performance of the photocatalytic filter 110a can be maintained by efficiently timing the removal of minute foreign matter that flows into the air treatment device 100 from the photocatalytic filter unit 110. For example, the performance of the photocatalytic filter 110a can be maintained by washing the photocatalytic filter 110a with water.

[0079] In this embodiment, the housing 102 has been described as being approximately rectangular parallelepiped in shape. The housing 102 may be cylindrical, elliptical cylindrical, or any other suitable polygonal pipe shape such as triangular, pentagonal, or hexagonal. In this case, the shapes of the pre-filter 108 and the photocatalytic filter unit 110 are changed to fit the shape of the inside of the housing 102. Therefore, for example, the shape of the photocatalytic filter 110a of the photocatalytic filter unit 110 is not limited to a rectangular shape and may be changed as appropriate.

[0080] In the air processing device 100 according to this embodiment, an example has been described in which the air intake 104 is disposed on the lower side and the air exhaust 120 is disposed on the upper side. The air intake 104 may take in air from the side of the lower part of the housing 102, rather than from the lower side of the housing 102. The air exhaust 120 may discharge air to the side of the upper part of the housing 102, rather than from the upper side of the housing 102.

[0081] Furthermore, the air treatment device 100 according to this embodiment may take in air through an intake port indicated by reference numeral 120 on the upper side of the housing 102, or may take in air from the side surface of the upper part of the housing 102. The air treatment device 100 according to this embodiment may exhaust air through an exhaust port indicated by reference numeral 104 on the lower side of the housing 102, or may exhaust air to the side surface of the lower part of the housing 102. That is, the direction of the airflow by the fan 118 may be reversed, with the first ventilation section (first port) 120 on the upper side serving as the intake port to take in air into the housing 102, and the second ventilation section (second port) 104 on the lower side serving as the exhaust port to exhaust air from inside the housing 102. In this case, the prefilter 108 may be disposed, for example, between the intake port indicated by reference numeral 120 and the light source unit 114, and sterilized and deodorized air is discharged from the exhaust port indicated by reference numeral 104.

[0082] The air treatment device 100 according to this embodiment may be placed on the floor or supported on a wall. When the air treatment device 100 is supported on a wall, the base (legs) 126 may not be necessary.

[0083] According to at least one embodiment of the air treatment device 100 described above, air can be treated more quickly and effectively.

[0084] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0085] 100...air treatment device, 102...casing, 102a...front panel, 104...air intake, 106...light-shielding grill, 108...pre-filter, 110...photocatalytic filter unit, 110a...photocatalytic filter, 110b...frame, 112...sterilization and deodorization area, 114...light source unit, 116...light-shielding grill, 118...fan, 120...exhaust port, 122...controller, 126...base 132...Light source board, 134...Light source.

Claims

1. a cylindrical housing having an intake port and an exhaust port; a fan that generates a flow of air from the intake port toward the exhaust port; a photocatalytic filter provided in the housing, in which a photocatalytic material with an anatase structure is supported on a ceramic substrate made of cordierite to a weight percentage of 100%, and which is placed in the air flow; An air treatment device comprising:

2. an ultraviolet module disposed opposite the photocatalytic filter and irradiating the photocatalytic material with light; The air treatment device of claim 1 , comprising:

3. The photocatalytic material supports the titanium oxide having an anatase structure in an amount of 10% or more and 20% or less by weight relative to the ceramic substrate.

3. An air treatment device according to claim 1 or claim 2.

4. The photocatalytic material does not include a photocatalytic material having a rutile structure.

3. An air treatment device according to claim 1 or claim 2.

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