Air purifier

Abstract

To provide an air purifier that can improve sterilization efficiency. [Solution] The air purifier 100 is a device that sterilizes air by irradiating it with ultraviolet light. The air purifier 100 comprises a box 2, an air passage 3, a blower 4, an ultraviolet irradiation unit 5, a high thermal conductor 6, and a cooling unit 7. The air passage 3 is formed inside the box 2. The blower 4 blows air through the air passage 3. The ultraviolet irradiation unit 5 irradiates the air flowing through the air passage 3 with ultraviolet light. The high thermal conductor 6 conducts heat from the ultraviolet irradiation unit 5. The cooling unit 7 is exposed to the air flowing through the air passage 3 and releases heat from the high thermal conductor 6. The ultraviolet irradiation unit 5 and the cooling unit 7 are connected via the high thermal conductor 6 and are installed in parallel on substantially the same plane.

Description

Technical Field

[0001] The present invention relates to an air purifying device.

Background Art

[0002] Patent Document 1 discloses an air purifying device 100 that sterilizes air by irradiating it with ultraviolet rays (ultraviolet light). The air purifying device 100 described in Patent Document 1 includes an ultraviolet irradiation unit (light source 21), a high thermal conductor (heat pipe 23), and a cooling unit (heat sink 24).

[0003] The ultraviolet irradiation unit (light source 21) irradiates the air in the ventilation path (flow path) with ultraviolet rays (ultraviolet light). The high thermal conductor (heat pipe 23) conducts the heat from the ultraviolet irradiation unit (light source 21). The cooling unit (heat sink 24) releases the heat from the high thermal conductor (heat pipe 23) by being exposed to the air in the ventilation path (flow path).

[0004] The bottom portion 31 where the ultraviolet irradiation unit (light source 21) is installed and the side portion 32 where the cooling unit (heat sink 24) is installed form an L-shaped support member 30.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, in the air purifying device described in Patent Document 1, inside the ventilation path (flow path), the ultraviolet irradiation unit (light source 21) is installed at the bottom portion 31 corresponding to the horizontal side of the L shape, and the cooling unit (heat sink 24) is installed at the side portion 32 corresponding to the vertical side of the L shape.

[0007] In this configuration, ultraviolet light from the ultraviolet irradiation unit (light source 21) is blocked by the cooling unit (heat sink 24) in the region where the irradiation intensity is high. Consequently, the air purifier 100 described in Patent Document 1 suffered from a decrease in sterilization efficiency.

[0008] This invention has been made in view of the above-mentioned problems, and aims to provide an air purifier that can improve sterilization efficiency. [Means for solving the problem]

[0009] The first aspect of the present invention is an air purifier that sterilizes air by irradiating it with ultraviolet light. The air purifier comprises a box, an air passage, a blower, an ultraviolet irradiation unit, a high thermal conductor, and a cooling unit. The air passage is formed inside the box. The blower blows air through the air passage. The ultraviolet irradiation unit irradiates the air flowing through the air passage with ultraviolet light. The high thermal conductor conducts heat from the ultraviolet irradiation unit. The cooling unit is exposed to the air flowing through the air passage and releases heat from the high thermal conductor. The ultraviolet irradiation unit and the cooling unit are connected via the high thermal conductor and are installed in parallel on substantially the same plane. [Effects of the Invention]

[0010] According to the air purifying device of the present invention, sterilization efficiency can be improved. [Brief explanation of the drawing]

[0011] [Figure 1] This is an overall perspective view showing the entire air purifier according to the embodiment, cut out in a longitudinal section. [Figure 2] This is a longitudinal cross-sectional view showing the enclosure of an air purifier in which the ultraviolet irradiation unit is located downstream of the airflow path. [Figure 3] This is a longitudinal cross-sectional view showing the enclosure of an air purifier in which the ultraviolet irradiation unit is located upstream of the airflow path. [Figure 4] This is a side view showing the irradiation cooler. [Figure 5]It is a graph showing the relationship between the irradiation angle of ultraviolet rays and the relative irradiation intensity in a UV-LED. [Figure 6] It is a perspective view showing an irradiation cooling body. [Figure 7] It is a side view showing the irradiation cooling body of the air purifying device according to Modification 1. [Figure 8] It is a longitudinal sectional view showing the housing of the air purifying device according to Modification 2. [Figure 9] It is a longitudinal sectional view showing the housing of the air purifying device according to Modification 3. [Figure 10] It is a cross-sectional view showing the housing of the air purifying device according to Modification 4. [Figure 11A] It is a side view of an irradiation cooling body having a high thermal conductor of Other Example 1. [Figure 11B] It is a side view of an irradiation cooling body having a high thermal conductor of Other Example 2. [Figure 11C] It is a side view of an irradiation cooling body having a high thermal conductor of Other Example 3.

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and the description thereof will not be repeated.

[0013] Also, in the descriptions given below, even when terms such as "upper" and "lower" that mean specific positions and directions are used, these terms are used for convenience in order to facilitate understanding of the content of the embodiments and have nothing to do with the directions in actual implementation. [Embodiment]

[0014] Referring to FIG. 1, the air purifying device 100 according to the embodiment will be described. FIG. 1 is an overall perspective view showing the entire air purifying device 100 according to the embodiment with a longitudinal section cut away.

[0015] As shown in FIG. 1, the air purifying apparatus 100 is a device that sterilizes air by irradiating it with ultraviolet light. The air purifying apparatus 100 includes a housing 2, a ventilation passage 3, a blower 4, an ultraviolet irradiation unit 5, a high thermal conductor 6, and a cooling unit 7.

[0016] The ventilation passage 3 is formed inside the housing 2. The blower 4 causes air to flow through the ventilation passage 3. The ultraviolet irradiation unit 5 irradiates the air flowing through the ventilation passage 3 with ultraviolet light. The high thermal conductor 6 conducts heat from the ultraviolet irradiation unit 5. The thermal conductivity of the high thermal conductor 6 is 230 [m / W·K] or more (equivalent thermal conductivity of aluminum).

[0017] The cooling unit 7 releases heat from the high thermal conductor 6 by being exposed to the air flowing through the ventilation passage 3. The ultraviolet irradiation unit 5 and the cooling unit 7 are connected via the high thermal conductor 6. The ultraviolet irradiation unit 5 and the cooling unit 7 are installed in parallel on substantially the same plane (for example, the same plane). In particular, when the length of the side surface of the housing 2 in the height direction is longer than the width of the bottom surface of the housing 2 or the width of the top surface of the housing 2, it is more preferable that the ultraviolet irradiation unit 5 and the cooling unit 7 are installed in parallel on the side surface of the housing 2, but they may be installed in parallel on the top surface or the bottom surface of the housing 2.

[0018] By installing the ultraviolet irradiation unit 5 and the cooling unit 7 in parallel on substantially the same plane, the ultraviolet light from the ultraviolet irradiation unit 5 is less likely to be blocked by the cooling unit 7. Therefore, the air purifying apparatus 100 can improve the sterilization efficiency by sufficiently sterilizing the air in the ventilation passage 3 with ultraviolet light.

[0019] The air purifier 100 further comprises a housing 1. The housing 1 houses a box 2 inside. The housing 1 has an air intake 10 and an air outlet 18. The air intake 10 takes in air from outside the housing 1. The air intake 10 is provided with a filter (not shown) to remove dust from the air it takes in. The air intake 10 is formed, for example, at the bottom of the side plate 11 of the housing 1. The air outlet 18 blows out sterilized air from inside the housing 1. The air outlet 18 or its surroundings is provided with an ultraviolet absorber (not shown) to prevent ultraviolet rays from leaking outside the housing 1. The air outlet 18 is formed, for example, at the top plate 19 of the housing 1.

[0020] The box body 2 has an air intake port 20 and an air outlet port 28. The air intake port 20 draws in air taken in from the air intake port 10 of the housing 1. The air intake port 20 is formed, for example, at the bottom of the side plate 21 of the box body 2. The air outlet port 28 sends the sterilized air to the air outlet port 18 of the housing 1. The air outlet port 28 is formed, for example, at the top plate 29 of the box body 2.

[0021] The ventilation passage 3 is the space through which air drawn in from the air intake 20 flows to the air outlet 28. Therefore, the ventilation passage 3 is in communication with the air intake 20 and the air outlet 28. The ventilation passage 3 is, for example, a rectangular parallelepiped space with the air's upstream and downstream directions as its longitudinal direction. Of course, the ventilation passage 3 may be a space of other shapes.

[0022] The blower 4 moves air through the air passage 3, drawing air into the air intake 20 and expelling it from the air outlet 28. The blower 4 can be any device that moves air through the air passage 3, such as a fan 41 or a blower. The blower 4 may be located inside the air passage 3, as shown in Figure 1, or it may be located outside the air passage 3. If the blower 4 is located outside the air passage 3, it is preferable that it is located near the air intake 10 and the air outlet 28. For example, if the blower 4 is a blower, the blower is located near the air outlet 28 (inside or outside the air passage 3). The blower 4 moves air through the air passage 3 by drawing in air.

[0023] The direction in which the blower 4 directs the airflow is aligned with the same plane in which the ultraviolet irradiation unit 5 and the cooling unit 7 are installed. For example, the direction in which the blower 4 directs the airflow, and the direction aligned with the same plane in which the ultraviolet irradiation unit 5 and the cooling unit 7 are installed, is vertical. The output (airflow rate) of the blower 4 can be changed according to the room temperature. When the room temperature is high, the ultraviolet irradiation unit 5 is more likely to reach the maximum allowable temperature, so the output of the blower 4 is set high. On the other hand, when the room temperature is low, the ultraviolet irradiation unit 5 is less likely to reach the maximum allowable temperature, so the output of the blower 4 may be set low.

[0024] If the blower 4 has a fan 41, for example, it also has a mesh guard 40 above the fan 41. The mesh guard 40 prevents the user from being caught in the fan 41, thus ensuring safety. The blower 4 also has a shield (not shown) to prevent the fan 41 from being exposed to ultraviolet rays. The fan, protected by the shield, is not exposed to ultraviolet rays, thus preventing material degradation and allowing for long-term use.

[0025] The ultraviolet irradiation unit 5 inactivates pathogens and viruses contained in the air by irradiating it with ultraviolet light. The optical axis of the ultraviolet light irradiated by the ultraviolet irradiation unit 5 is perpendicular to the airflow in the ventilation passage 3. For example, if the airflow in the ventilation passage 3 is vertical, the optical axis of the ultraviolet light irradiated by the ultraviolet irradiation unit 5 extends horizontally. The maximum irradiation intensity and wavelength of the ultraviolet light irradiated by the ultraviolet irradiation unit 5 are selected to be suitable for the installation environment of the air purifier 100. The ultraviolet irradiation unit 5 is connected directly or indirectly to the high thermal conductor 6. The ultraviolet irradiation unit 5 generates heat when irradiated with ultraviolet light, but this heat is dissipated to the high thermal conductor 6.

[0026] The high thermal conductor 6 may be a metal component or a heat pipe, as long as it has a thermal conductivity of 230 [m / w·K] or higher (equivalent to the thermal conductivity of aluminum). From the viewpoint of processability and versatility, aluminum (Al) or copper (Cu) components are preferred for the metal component that becomes the high thermal conductor 6.

[0027] The cooling section 7 is a heat sink having a number of elongated bodies 70 (for example, pins 71 or fins, as described later). Each elongated body 70 extends in a direction perpendicular to the airflow in the ventilation passage 3. For example, if the airflow in the ventilation passage 3 is vertical, each elongated body 70 extends horizontally. Therefore, since the airflow and the longitudinal direction of the number of elongated bodies 70 are perpendicular, the cooling section 7 efficiently dissipates heat from the high thermal conductor 6. In other words, the cooling section 7 is efficiently cooled. Note that the elongated bodies 70 shown in Figure 1 are pins 71 as an example, but they may also be fins or other elongated shapes that increase the specific surface area.

[0028] The high thermal conductor 6 is installed on the outside of the enclosure 2. The ultraviolet irradiation unit 5 and the cooling unit 7 are installed inside the enclosure 2. By installing the high thermal conductor 6 on the outside of the enclosure 2, the airflow in the ventilation passage 3 is not obstructed by the high thermal conductor 6. Therefore, the air purifier 100 can sufficiently cool the cooling unit 7 with the air in the ventilation passage 3, thereby improving the sterilization efficiency. The high thermal conductor 6 may be connected to the ultraviolet irradiation unit 5 and / or the cooling unit 7 via an intermediate material (not shown). The intermediate material is a liquid or film with high thermal conductivity. An example of a liquid with high thermal conductivity is thermally conductive grease. The intermediate material increases the contact area between the high thermal conductor 6 and the ultraviolet irradiation unit 5 and / or the cooling unit 7, so heat is transferred efficiently.

[0029] The side plate 21 of the enclosure 2 has an irradiation hole 25 and a cooling hole 27. The irradiation hole 25 guides the ultraviolet irradiation unit 5 from the high thermal conductor 6 installed outside the enclosure 2 to the inside of the enclosure 2 (ventilation passage 3). The cooling hole 27 guides the cooling unit 7 from the high thermal conductor 6 installed outside the enclosure 2 to the inside of the enclosure 2 (ventilation passage 3). Due to the irradiation hole 25 and the cooling hole 27, even if the high thermal conductor 6 is installed outside the enclosure 2, the ultraviolet irradiation unit 5 and the cooling unit 7 connected to the high thermal conductor 6 reach the ventilation passage 3 inside the enclosure 2.

[0030] The ultraviolet irradiation unit 5 reaches the ventilation passage 3, thereby sufficiently irradiating the air flowing through the ventilation passage 3 with ultraviolet light. The cooling unit 7 reaches the ventilation passage 3, and is sufficiently cooled by the air flowing through the ventilation passage 3. Although not shown in the figure, the high thermal conductor 6 is joined to the side plate 21 of the box body 2 from the outside by contact with bolts or the like. Because the high thermal conductor 6 is joined to the side plate 21 of the box body 2 by contact, even if the high thermal conductor 6 is heavy, the box body 2 is less likely to lose its balance and is more likely to stand upright stably.

[0031] In the example shown in Figure 1, the intermediate position h in the airflow path 3 in the upstream and downstream directions coincides with the intermediate position in the ultraviolet irradiation section 5 in the upstream and downstream directions. Cases where these intermediate positions do not coincide will be explained below with reference to Figures 2 and 3.

[0032] Figure 2 is a longitudinal cross-sectional view showing the casing 2 of the air purifier 100, in which the ultraviolet irradiation unit 5 is located downstream of the air in the ventilation passage 3. Figure 3 is a longitudinal cross-sectional view showing the casing 2 of the air purifier 100, in which the ultraviolet irradiation unit 5 is located upstream of the air in the ventilation passage 3.

[0033] As shown in Figure 2, the ventilation passage 3 has an intermediate ventilation position h, which is an intermediate position h in the upstream and downstream directions of the air. The example shown in Figure 2 is when the intermediate position in the upstream and downstream directions of the ultraviolet irradiation unit 5 is located downstream of the ventilation passage intermediate position h. In this case, the cooling unit 7 is installed so as not to be located upstream of the ultraviolet irradiation unit 5 (for example, only downstream of the ultraviolet irradiation unit 5).

[0034] In the example shown in Figure 2, the ultraviolet irradiation unit 5 is located downstream of the air passage 3. Therefore, the volume of the air passage 3 is large upstream of the ultraviolet irradiation unit 5, and small downstream of the ultraviolet irradiation unit 5. On the upstream side of the air passage 3 from the ultraviolet irradiation unit 5 (the side with the larger volume), the ultraviolet rays are not blocked by the cooling unit 7, and thus sterilization is sufficiently achieved. Therefore, the air purifier 100 can improve sterilization efficiency by sufficiently sterilizing the side with the larger volume in the air passage 3.

[0035] Next, as shown in Figure 3, the ventilation passage 3 has an intermediate ventilation passage position h, which is an intermediate position h in the upstream and downstream directions of the air. The example shown in Figure 3 is when the intermediate position in the upstream and downstream directions of the ultraviolet irradiation unit 5 is located upstream of the ventilation passage intermediate position h. In this case, the cooling unit 7 is installed so as not to be located downstream of the ultraviolet irradiation unit 5 (for example, only upstream of the ultraviolet irradiation unit 5).

[0036] In the example shown in Figure 3, the ultraviolet irradiation unit 5 is located upstream of the air passage 3. Therefore, the volume of the air passage 3 is large downstream of the ultraviolet irradiation unit 5, and small upstream of the ultraviolet irradiation unit 5. On the downstream side of the air passage 3 from the ultraviolet irradiation unit 5 (the side with the larger volume), the ultraviolet rays are not blocked by the cooling unit 7, and thus sterilization is sufficiently achieved. Therefore, the air purifier 100 can improve sterilization efficiency by sufficiently sterilizing the side with the larger volume in the air passage 3.

[0037] Here, the intermediate position h in the ventilation passage is the intermediate position h between the upstream and downstream ends of the air in the ventilation passage 3. As shown in Figure 3, the upstream end of the air in the ventilation passage 3 is, for example, the upper surface of the mesh guard 40 on the blower 4. The downstream end of the air in the ventilation passage 3 is, for example, the lower surface of the top plate 29 on the box body 2.

[0038] Next, referring to Figure 4, we will explain the ultraviolet irradiation unit 5, the high thermal conductor 6, and the cooling unit 7. Hereinafter, the ultraviolet irradiation unit 5, the high thermal conductor 6, and the cooling unit 7 may be collectively referred to as the irradiation cooler 5-7. Figure 4 is a side view showing the irradiation cooler 5-7.

[0039] As shown in Figure 4, the elongated body 70 of the cooling section 7 is a pin 71. That is, the cooling section 7 is a pin structure having a large number (at least a few) of pins 71. The cooling section 7 may also be a fin structure having a large number (at least a few) of fins.

[0040] As shown in Figure 4, the ultraviolet irradiation unit 5 has an ultraviolet light source 50. The ultraviolet light source 50 emits ultraviolet light. Here, let X [m] be the distance between the ultraviolet light source 50 and the pin 71. Let θ [rad] be the predetermined irradiation angle of the ultraviolet light from the optical axis. Let H [m] be the amount of protrusion of the pin 71 from the high thermal conductor 6. The predetermined irradiation angle θ [rad] is the angle at which the irradiation intensity is half of the maximum irradiation intensity of ultraviolet light from the ultraviolet light source 50 (i.e., the half-power angle). In this case, the following equation (1) is satisfied. X≧H / tan(π / 2-θ)···(1)

[0041] If equation (1) is satisfied, then only ultraviolet rays in the region irradiated at an angle from the optical axis greater than or equal to a predetermined irradiation angle will be blocked by the cooling unit 7, and ultraviolet rays in other regions will not be blocked by the cooling unit 7.

[0042] If the predetermined irradiation angle is the half-power angle, the portion of the irradiated ultraviolet light that is greater than or equal to the predetermined irradiation angle does not contribute much to sterilization. Therefore, only the portion of the ultraviolet light that does not contribute much to sterilization (weak ultraviolet light) is blocked by the cooling unit 7, while the rest is not blocked. Consequently, the air purifier 100 can improve its sterilization efficiency.

[0043] The ultraviolet light source 50 is, for example, an LED (Light Emitting Diode) that emits ultraviolet light. UV-LEDs, which emit ultraviolet light, have a long lifespan but generate a large amount of heat. In particular, if the number of UV-LEDs is increased to improve sterilization efficiency, the amount of heat generated will increase even more. However, the large amount of heat from the UV-LEDs is sufficiently dissipated from the cooling unit 7 via the high thermal conductor 6.

[0044] Here, at the ultraviolet light source 50, the position closest to the pin 71 is denoted as a1, and the intermediate position in the upstream / downstream direction of the air is denoted as a2. On the other hand, at the numerous pins 71, the position closest to the ultraviolet light source 50 is denoted as b1, and the intermediate position in the upstream / downstream direction of the air is denoted as b2. In this case, the distance X [m] between the ultraviolet light source 50 and the pin 71 is the distance between any position a1 to a2 and any position b1 to b2.

[0045] When X[m] is the distance between a1 and b1, the above equation (1) is satisfied, and the ultraviolet light source 50 and the cooling unit 7 are relatively far apart. Therefore, although the high thermal conductor 6 becomes large, the area of ​​ultraviolet light from the ultraviolet light source 50 that is blocked by the cooling unit 7 becomes extremely small.

[0046] On the other hand, when X[m] is the distance between a2 and b2, the ultraviolet light source 50 and the cooling unit 7 are relatively close to each other in the case that equation (1) above is satisfied. Therefore, although the area of ​​ultraviolet light from the ultraviolet light source 50 that is blocked by the cooling unit 7 is not extremely small, the high thermal conductor 6 does not become very large.

[0047] The arbitrary positions a1-a2 and b1-b2, which serve as the reference for X[m], can be freely set. The closer the arbitrarily set positions are to a1 and b1, the further the ultraviolet light source 50 and the cooling unit 7 will be. On the other hand, the closer the arbitrarily set positions are to a2 and b2, the closer the ultraviolet light source 50 and the cooling unit 7 will be.

[0048] The most preferable case is when X[m] is the distance between a1 and b1. This is because, in this case, the area of ​​ultraviolet light from the ultraviolet light source 50 that is blocked by the cooling unit 7 becomes extremely small. However, in this case, the high thermal conductor 6 becomes large (and therefore heavy), so there is concern about the weight balance of the box body 2 on which the high thermal conductor 6 is installed. Nevertheless, if the high thermal conductor 6 is in contact with and joined to the side plate 21 of the box body 2, the box body 2 is more likely to stand stably without losing its balance.

[0049] As a specific example, let H = 0.04 [m] (= 40 mm) and θ = 60·π / 180 [rad] (= 60°). In this case, according to equation (1) above, X ≥ 0.07 [m] (= 70 mm).

[0050] Therefore, in this specific example, if X is 0.07 [m] (= 70 mm) or greater, the air will be sufficiently sterilized without being blocked by the cooling unit 7, except for weak ultraviolet light.

[0051] Next, we will explain the half-power angle in detail with reference to Figure 5. Figure 5 is a graph showing the relationship between the irradiation angle and relative irradiation intensity of ultraviolet light in a UV-LED. In the semicircular graph in Figure 5, the circumference represents the irradiation angle relative to the optical axis, and the radius represents the relative irradiation intensity.

[0052] As shown in Figure 5, the graph illustrating the relationship between the irradiation angle relative to the optical axis and the relative irradiation intensity assumes a room temperature of 25°C (=298.13[K]) and a pulse forward current of 350mA (=0.35[A]). Under these conditions, when the irradiation angle relative to the optical axis is 27° (=27·π / 180[rad]), the relative irradiation intensity (actual irradiation intensity relative to maximum irradiation intensity) is 1.0. On the other hand, when the irradiation angle relative to the optical axis is 0° (=0[rad]), i.e., at the optical axis, the relative irradiation intensity (actual irradiation intensity relative to maximum irradiation intensity) is approximately 0.87. Furthermore, when the irradiation angle relative to the optical axis is 60° (=60·π / 180[rad]), the relative irradiation intensity (actual irradiation intensity relative to maximum irradiation intensity) is approximately 0.5, or about half. Therefore, the half-power angle is θ = 60·π / 180[rad] when the irradiation angle relative to the optical axis is 60°.

[0053] The predetermined irradiation angle is not limited to the half-power angle, but is the angle at which the irradiation intensity is obtained by dividing the maximum irradiation intensity by the square of Napier's number (e) (θ = 1 / e 2 ) is also acceptable.

[0054] The predetermined irradiation angle is "θ = 1 / e 2 If this is the case, then of the irradiated ultraviolet light, the region above a predetermined irradiation angle contributes almost nothing to sterilization. For this reason, only the region of ultraviolet light that contributes almost nothing to sterilization (extremely weak ultraviolet light) is blocked by the cooling unit 7, and the rest is not blocked. Therefore, the air purifier 100 can further improve its sterilization efficiency.

[0055] The predetermined irradiation angle θ may be an angle within the range of -θ that corresponds to 68.3% of the total irradiation energy of ultraviolet light. In this case, the predetermined irradiation angle is the angle that corresponds to the standard deviation of the irradiation intensity.

[0056] At this predetermined irradiation angle, the portion of the irradiated ultraviolet light that exceeds this angle does not contribute much to sterilization. Therefore, only the portion of the ultraviolet light that does not contribute much to sterilization (weak ultraviolet light) is blocked by the cooling unit 7, while the rest is not blocked. Consequently, the air purifier 100 can improve its sterilization efficiency.

[0057] The predetermined irradiation angle θ may be an angle within the range of -θ that corresponds to 95.4% of the total irradiation energy of ultraviolet light. In this case, the predetermined irradiation angle is an angle equal to twice the standard deviation of the irradiation intensity.

[0058] At this predetermined irradiation angle, the portion of the irradiated ultraviolet light that exceeds this angle contributes almost nothing to sterilization. Therefore, only the portion of the ultraviolet light that contributes almost nothing to sterilization (extremely weak ultraviolet light) is blocked by the cooling unit 7, while the rest is not blocked. Consequently, the air purifier 100 can further improve its sterilization efficiency.

[0059] To increase the cooling efficiency of the cooling unit 7, one could increase H to increase the specific surface area of ​​each pin 71, or decrease X to increase the heat transport capacity of the high thermal conductor 6. Increasing H or decreasing X makes it more difficult to satisfy equation (1) mentioned above, in other words, ultraviolet rays that contribute to sterilization are more easily blocked by the cooling unit 7. Therefore, parameters other than H and X that can increase the cooling efficiency will be examined below with reference to Figure 6.

[0060] The details of the irradiation coolers 5-7 will be described below with reference to Figure 6. Figure 6 is a perspective view showing the irradiation coolers 5-7.

[0061] As shown in Figure 6, the high thermal conductor 6 is plate-shaped. The plate-shaped high thermal conductor 6 has length, width, and thickness. The ultraviolet irradiation unit 5 and the cooling unit 7 are installed in parallel along the length direction on one surface of the high thermal conductor 6 along the length direction and width direction.

[0062] Hereinafter, the thickness, heat transport capacity, and thermal conductivity of the high thermal conductor 6 will be D[m], Q[W], and λ[W / m·K], respectively. The distance between the intermediate position a2 in the length direction of the ultraviolet irradiation section 5 and the intermediate position b2 in the length direction of the cooling section 7 will be Δx[m]. The dimension of the ultraviolet irradiation section 5 in the width direction will be W[m]. The temperature difference between the maximum allowable temperature of the ultraviolet irradiation section 5 and room temperature will be ΔT[K]. Furthermore, as an assumption, it will be assumed that the thermal energy transmitted through the high thermal conductor 6 is transported one-dimensionally within a member with a constant cross-sectional area from the ultraviolet irradiation section 5 to the cooling section 7, and that heat dissipation occurs only in the cooling section 7 and not from the ultraviolet irradiation section 5 to the cooling section 7. In this case, the following equation (2) is satisfied. D≧-(Q∆x) / (λ∙W∆T) (2)

[0063] By satisfying equation (2), the cooling unit 7 is sufficiently cooled so that the ultraviolet irradiation unit 5 remains below the maximum allowable temperature. Therefore, the ultraviolet irradiation unit 5 does not exceed the maximum allowable temperature, and its ultraviolet irradiation function does not deteriorate. Consequently, the air purifier 100 can improve its sterilization efficiency.

[0064] As a specific example, let's assume ΔT = 35 [K]. If ΔT = 35 [K], then for example, the maximum allowable temperature of the ultraviolet irradiation section 5 (more specifically, the ultraviolet light source 50) is 333.13 [K] (= 60°C), and the room temperature is 298.13 [K] (= 25°C). Also, let's assume Q = 130 [W], λ = 230 [W / m·K], Δx = 0.17 [m], and W = 0.1 [m]. In this case, from equation (2) above, D ≥ 0.027 [m] (= 27 mm).

[0065] Therefore, in this specific example, if D is 0.027 [m] (=27 mm) or greater, the cooling unit 7 is sufficiently cooled so that the ultraviolet irradiation unit 5 is below the maximum allowable temperature. [Example 1]

[0066] Hereinafter, with reference to Figure 7, a modified example 1 of the above-described embodiment will be explained. Figure 7 is a side view showing the irradiation coolers 5 to 7 of the air purifier 100 according to modified example 1.

[0067] In the examples shown in Figures 1 to 6, the cooling unit 7 of the irradiation cooler 5 to 7 is installed only above or below the ultraviolet irradiation unit 5 (i.e., only one of them). In contrast, in the example shown in Figure 7, the cooling unit 7 of the irradiation cooler 5 to 7 is installed both above and below the ultraviolet irradiation unit 5 (i.e., both).

[0068] The cooling unit 7 shown in Figure 7 is installed with one unit below the ultraviolet irradiation unit 5 and two units above the ultraviolet irradiation unit 5. Of the cooling unit 7, for example, the uppermost unit and the lowermost unit have a pin structure in which the elongated body 70 is a pin 71. Of the cooling unit 7, for example, the middle unit has a fin structure in which the elongated body 70 is a fin 72. Of course, the cooling unit 7 is not limited to the example shown in Figure 7, and the number of units and the pin structure or fin structure are selected to suit the installation environment of the air purifier 100. Note that the width direction (depth direction of the paper in Figure 7) is not shown in Figure 7, but both the ultraviolet irradiation unit 5 and the cooling unit 7 may be installed with multiple units (for example, 4 units) in the width direction.

[0069] Each unit of the ultraviolet irradiation section 5 has an irradiation base 85. The irradiation base 85 connects the ultraviolet light source 50 and the high thermal conductor 6. Each unit of the cooling section 7 has a cooling base 87. The cooling base 87 connects a plurality of pins 71 or fins 72 to the high thermal conductor 6. The cooling section 7 may also have a Peltier element 87p and a power supply mechanism 84 that supplies DC power to the Peltier element 87p. The Peltier element 87p absorbs heat on one side and dissipates heat on the other side when DC power is supplied from the power supply mechanism 84. The Peltier element 87p may constitute the cooling base 87. [Differentiation 2]

[0070] Hereinafter, a modified example 2 of the above-described embodiment will be explained with reference to Figure 8. Figure 8 is a longitudinal cross-sectional view showing the casing 2 of the air purifier 100 according to modified example 2.

[0071] As shown in Figure 8, the air purifier 100 has multiple blowers 4. Of the multiple blowers 4, the blower 47 closest to the cooling unit 7 has the highest output.

[0072] Because the blower 47 closest to the cooling unit 7 has the highest output, the cooling unit 7 is sufficiently cooled. Therefore, the air purifier 100 can improve its sterilization efficiency.

[0073] The box body 2 may have an air guide 22 between adjacent blowers 4. The air guide 22 guides the air supplied from each adjacent blower 4. [Difference 3]

[0074] Hereinafter, a third modification of the above-described embodiment will be explained with reference to Figure 9. Figure 9 is a longitudinal cross-sectional view showing the casing 2 of the air purifier 100 according to the third modification.

[0075] As shown in Figure 9, the blower 4 is installed in contact with the side plate 21 of the box body 2. The side plate 21 in contact with the blower 4 is the side plate 21 in which the irradiation hole 25, cooling hole 27, and air intake port 20 are formed. In other words, the blower 4 and the irradiation cooling bodies 5-7 are installed on the side plate 21 in which the air intake port 20 is formed. This installation simplifies the structure of the air purification device 100, thereby improving manufacturability.

[0076] The pins 71 of the cooling unit 7 are shorter the closer they are to the ultraviolet irradiation unit 5 and longer the further they are from the ultraviolet irradiation unit 5. For example, each pin 71 of the cooling unit 7 is designed to have a length such that its tip aligns with a predetermined irradiation angle θ. It is preferable that the pins 71 of the cooling unit 7 are installed so that they gradually become longer as they move away from the ultraviolet irradiation unit 5. Figure 9 shows the case where the cooling unit 7 is located downstream of the ultraviolet irradiation unit 5, but similarly, when the cooling unit 7 is located upstream of the ultraviolet irradiation unit 5, it is preferable that the pins 71 of the cooling unit 7 are installed so that they gradually become longer as they move away from the ultraviolet irradiation unit 5. For example, as shown in Figure 9, three adjacent rows of pins 71 in a vertical cross-section are the same length as a single pin group, and the pin groups are installed so that they become longer as they move away from the ultraviolet irradiation unit 5. A single pin group may consist of two adjacent rows of pins 71 in a vertical cross-section, or it may consist of four or more rows of pins 71.

[0077] This design makes the cooling unit 7 less susceptible to ultraviolet light, and ensures that each pin 71 is sufficiently long. Therefore, the air purifier 100 can sufficiently cool the cooling unit 7, thereby improving sterilization efficiency.

[0078] The elongated body 70 of the cooling unit 7 has an ultraviolet reflecting material 75 that covers the pins 71. The ultraviolet reflecting material 75 reflects ultraviolet light from the ultraviolet irradiation unit 5. The ultraviolet light reaching the cooling unit 7 does not contribute much (or hardly contributes at all) to sterilization, but by being reflected, it contributes to sterilization to a small extent compared to when it is blocked. Therefore, the air purifier 100 can improve its sterilization efficiency. [Differentiation Example 4]

[0079] Hereinafter, with reference to Figure 10, Modification 4 of the above-described embodiment will be explained. Figure 10 is a cross-sectional view showing the box body 2 of the air purifier 100 according to Modification 4. In Figure 10, since it is a cross-section (a surface cut at a certain height), the direction towards the back of the paper is the upstream side (the side closer to the bottom), and the direction towards the front of the paper is the downstream side (the side closer to the top).

[0080] In the embodiments and modifications 1 to 3, the ultraviolet irradiation unit 5 and the cooling unit 7 were described as being installed in the upstream / downstream direction (vertical direction). In contrast, in modification 4, as shown in Figure 10, the ultraviolet irradiation unit 5 and the cooling unit 7 are installed in a direction perpendicular to the upstream / downstream direction (horizontal direction), that is, at the same height.

[0081] In the irradiation coolers 5 to 7, the ultraviolet irradiation unit 5 is located on the side closer to the center of the box 2, and the cooling unit 7 is located on the side further from the center of the box 2 (the wall side). The ultraviolet irradiation unit 5 consists of two units, and it is preferable that these two units are symmetrical with respect to the center of the box 2. Similarly, the cooling unit 7 also consists of two units, and it is preferable that these two units are also symmetrical with respect to the center of the box 2.

[0082] In the example shown in Figure 10, the central part of the box 2, which is the main part of the ventilation passage 3, is not blocked by the cooling unit 7, and is therefore thoroughly sterilized. Thus, the air purifier 100 can improve its sterilization efficiency.

[0083] Because the ultraviolet irradiation unit 5 and the cooling unit 7 are installed perpendicular to the upstream and downstream directions, ultraviolet rays are not blocked by the cooling unit 7 on the upstream and downstream sides from the ultraviolet irradiation unit 5. Therefore, when the air passage 3 is longer in the upstream and downstream direction (and shorter in the direction perpendicular to the upstream and downstream direction), the upstream and downstream direction, which has a larger volume, is sufficiently sterilized. Thus, the air purifier 100 can improve its sterilization efficiency.

[0084] Embodiments and modifications thereof of the present invention have been described above with reference to the drawings. However, the embodiments and modifications thereof are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. Of the configurations described in the embodiments and modifications thereof, all configurations other than those described as the first aspect of the present invention in "Means for Solving the Problem" are arbitrary and can be deleted and modified as appropriate.

[0085] (1) In the embodiments and their modifications, the ultraviolet irradiation unit 5 and the cooling unit 7 are described as being installed in parallel on the same plane, but they are not limited to being on the same plane, and may be substantially on the same plane. Another example of substantially being on the same plane is shown in Figure 11A, where the high thermal conductor 6 consists of multiple sheets (for example, two sheets, a first high thermal conductor 61 and a second high thermal conductor 62), and each sheet (for example, the first high thermal conductor 61 and the second high thermal conductor 62) overlaps. In the overlapping portion, a liquid with high thermal conductivity (for example, thermal conductivity grease) or film may be sandwiched between them to allow sufficient heat transfer between the first high thermal conductor 61 and the second high thermal conductor 62. Another example of substantially being on the same plane is shown in Figure 11B, where the high thermal conductor 6 has irregularities (a protrusion 63 in the illustrated example) in the portion where the cooling unit 7 is installed. A liquid with high thermal conductivity (e.g., thermally conductive grease) or a film may be placed between the uneven surface and the cooling section 7 to ensure sufficient heat transfer. Furthermore, another example 3 of substantially coplanar surfaces is shown in Figure 11C, where a curved surface 64 is formed in the high thermal conductor 6 where the cooling section 7 is installed. A liquid with high thermal conductivity (e.g., thermally conductive grease) or a film may be placed between the curved surface 64 and the cooling section 7 to ensure sufficient heat transfer.

[0086] (2) In the embodiments and their modifications, it was explained that the airflow in the ventilation passage 3 (vertical direction) and the optical axis of the ultraviolet light irradiated by the ultraviolet irradiation unit 5 (horizontal direction) are orthogonal. These directions are not limited to orthogonal, and may be in the range of -80° to +80°, for example.

[0087] (3) In the embodiments and their modifications, it was explained that the airflow in the ventilation passage 3 (vertical direction) and the longitudinal direction of the elongated body 70 (horizontal direction) are perpendicular. These directions are not limited to perpendicular, and may be in the range of -80° to +80°, for example.

[0088] (4) In the embodiments and their modifications, the elongated body 70 of the cooling unit 7 has been described mainly as a pin 71, but it may also be a fin 72. If the elongated body 70 is a fin 72, then "pin 71" in the embodiments and modifications shall be read as "fin 72".

[0089] (5) In the embodiments and their modified examples, the high thermal conductor 6 and the cooling section 7 are shown as separate components, but the high thermal conductor 6 and the cooling section 7 may be made from the same component. Specifically, the high thermal conductor 6 is formed in the shape of the cooling section 7 (for example, a fin structure or a pin structure) at the location where the cooling section 7 is installed.

[0090] (6) In the embodiments and their modifications, the high thermal conductor 6 has been described as being flat, as shown in Figure 6, but it may also be curved. If the side plate 21 of the box body 2 is flat, the high thermal conductor 6 along the side plate 21 is preferably flat, but if the side plate 21 of the box body 2 is curved, the high thermal conductor 6 along the side plate 21 is preferably curved. An example of a curved side plate 21 of the box body 2 is when the box body 2 is cylindrical (the side surface is a circumferential surface, and the top and bottom surfaces are flat). [Industrial applicability]

[0091] This invention provides an air purifying device and has industrial applicability. [Explanation of Symbols]

[0092] h Ventilation path middle position 1 Housing 2 box body 3 Ventilation duct 4. Blower 5. UV irradiation area 6. High thermal conductors 7 Cooling section 20 Air intake ports 21 Side panels of the box 28 Air outlet 29 Box top 41 Fans 50 UV light source 70 Long Body 71 pins 72 fins 100 Air Purifiers

Claims

1. This is an air purifier that sterilizes the air by irradiating it with ultraviolet light. The box and, A ventilation passage formed inside the aforementioned box, A blower that flows the air through the aforementioned ventilation passage, An ultraviolet irradiation unit that irradiates the air flowing through the ventilation passage with ultraviolet light, A high thermal conductor that conducts heat from the ultraviolet irradiation area, A cooling section that is exposed to the air flowing through the aforementioned ventilation passage and releases heat from the high thermal conductor, Equipped with, An air purifier in which the ultraviolet irradiation unit and the cooling unit are connected via the high thermal conductor and installed in parallel on substantially the same plane.

2. The high thermal conductor is installed outside the box, The air purifier according to claim 1, wherein the ultraviolet irradiation unit and the cooling unit are installed inside the box.

3. The aforementioned ventilation passage has an intermediate position in the ventilation passage, which is an intermediate position in the upstream and downstream direction of the air. The air purifying device according to claim 1 or 2, wherein if the intermediate position of the ultraviolet irradiation unit in the upstream-downstream direction is located upstream of the airflow intermediate position of the air passage, the cooling unit is installed so as not to be located downstream of the airflow downstream of the ultraviolet irradiation unit.

4. The aforementioned ventilation passage has an intermediate position in the ventilation passage, which is an intermediate position in the upstream and downstream direction of the air. The air purifying device according to claim 1 or 2, wherein if the intermediate position of the ultraviolet irradiation unit in the upstream-downstream direction is located downstream of the airflow intermediate position of the air passage, the cooling unit is installed so as not to be located upstream of the airflow relative to the ultraviolet irradiation unit.

5. The cooling section has a fin structure or pin structure having a plurality of fins or pins. The ultraviolet irradiation unit has an ultraviolet light source that emits the ultraviolet light, When the distance between the ultraviolet light source and the fin or pin is X [m], the predetermined irradiation angle of the ultraviolet light from the optical axis is θ [rad], and the amount of protrusion of the fin or pin from the high thermal conductor is H [m], The predetermined irradiation angle θ [rad] is the angle at which the irradiation intensity is half of the maximum irradiation intensity of the ultraviolet light from the ultraviolet light source. An air purifier according to claim 1 or claim 2, satisfying X ≥ H / tan(π / 2 - θ).

6. The aforementioned high thermal conductor is in the form of a plate having length, width, and thickness. The ultraviolet irradiation unit and the cooling unit are installed in parallel in the direction of the length on one surface of the high thermal conductor along the direction of the length and the direction of the width, When the thickness, heat transport capacity, and thermal conductivity of the high thermal conductor are D [m], Q [W], and λ [W / m·K], respectively, the distance between the midpoint of the ultraviolet irradiation section in the length direction and the midpoint of the cooling section in the length direction is Δx [m], the dimension of the ultraviolet irradiation section in the width direction is W [m], and the temperature difference between the maximum allowable temperature of the ultraviolet irradiation section and room temperature is ΔT [K], An air purifier according to claim 1 or claim 2, satisfying D ≥ -(Q・Δx) / (λ・W・ΔT).

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