Fluid sterilization apparatus and fluid sterilization method

Abstract

We provide a power-saving fluid sterilization device. [Solution] The fluid sterilization device comprises: a sterilization space forming unit 2 which forms a film-like sterilization space 8 in which a fluid is flowed and ultraviolet light is irradiated, and which is set to a thickness that allows ultraviolet light to pass through the fluid; a light source unit 1 which has a plurality of ultraviolet light-emitting elements 10 and irradiates the sterilization space 8 with ultraviolet light emitted by the elements 10, and the light-emitting surface 9 is a plane facing the surface of the sterilization space 8; and a light intensity control unit 100 which controls the light intensity distribution of the light-emitting surface 9 of the light source unit 1 based on the fluid velocity distribution of the fluid in the sterilization space 8.

Description

Technical Field

[0001] The present invention relates to a fluid sterilization apparatus and a fluid sterilization method.

Background Art

[0002] There is known a sterilization apparatus that sterilizes and inactivates bacteria and viruses in a liquid by irradiating ultraviolet light. A mercury lamp is widely used as a light source.

[0003] Patent Document 1 describes a fluid sterilization apparatus having a liquid film forming portion having two plate materials. The two plate materials are arranged to face each other such that their main surfaces are parallel, and the distance between the two plate materials is set to be sufficiently narrow. By flowing a liquid between the two plate materials, a thin liquid film can be formed. Then, the liquid is sterilized by irradiating ultraviolet light perpendicular to the main surface of the liquid film. It is described that an ultraviolet lamp is used as the light source. Thus, by making the liquid into a thin film shape, even a liquid with low transmittance can be efficiently sterilized.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the sterilization apparatus of Patent Document 1, since an ultraviolet lamp is used, it takes time to light up and it is difficult to control the light quantity. Further, a mercury lamp cannot change the wavelength of ultraviolet light. Therefore, when the transmittance of the fluid fluctuates or the flow rate changes, the light quantity may become excessive, and there is a problem in terms of power saving.

[0006] The present invention has been made in view of such a background, and aims to provide a power - saving fluid sterilization apparatus. [Means for solving the problem]

[0007] One aspect of the present invention is, A space through which a fluid is flowed and ultraviolet light is irradiated, comprising a sterilization space forming section that forms a film-like sterilization space set to a thickness that allows ultraviolet light to pass through the fluid, A light source unit having multiple ultraviolet light-emitting elements, which irradiates the sterilization space with ultraviolet light emitted by the light-emitting elements, and whose light-emitting surface is a plane facing the surface of the sterilization space, The fluid sterilization apparatus includes a light intensity control unit that controls the light intensity distribution of the light-emitting surface of the light source unit based on the flow rate distribution, flow velocity distribution, or turbidity distribution of the fluid in the sterilization space.

[0008] Other aspects of the present invention include: A space through which a fluid is flowed and ultraviolet light is irradiated, comprising a sterilization space forming section that forms a film-like sterilization space set to a thickness that allows ultraviolet light to pass through the fluid, The device comprises a light source unit having multiple ultraviolet light-emitting elements, which irradiates the sterilization space with ultraviolet light emitted by the light-emitting elements, and the light-emitting surface is a planar surface facing the surface of the sterilization space, The sterilization space formation section is located in a fluid sterilization device and has partitions that divide the sterilization space into multiple flow channels.

[0009] Other aspects of the present invention include: A fluid conduction step is performed in which the fluid is flowed through a membrane-like sterilization space, which is set to a thickness that allows ultraviolet light to penetrate the fluid, in a space in which ultraviolet light is irradiated with ultraviolet light, The process includes a UV light irradiation step in which a light source unit having multiple UV-emitting light-emitting elements, the light-emitting surface of which is a planar shape facing the surface of the sterilization space, is used to irradiate the sterilization space with UV light emitted by the light-emitting elements, The aforementioned ultraviolet light irradiation step involves controlling the light intensity distribution of the light-emitting surface of the light source based on the flow rate distribution, flow velocity distribution, or turbidity distribution of the fluid in the sterilization space, as a fluid sterilization method.

[0010] Other aspects of the present invention include: A fluid conduction step is performed in which the fluid is flowed through a membrane-like sterilization space, which is set to a thickness that allows ultraviolet light to penetrate the fluid, in a space in which ultraviolet light is irradiated with ultraviolet light, The process includes a UV light irradiation step in which a light source unit having multiple UV-emitting light-emitting elements, the light-emitting surface of which is a planar shape facing the surface of the sterilization space, is used to irradiate the sterilization space with UV light emitted by the light-emitting elements, The fluid conduction step is a fluid sterilization method in which the sterilization space is divided into multiple flow paths. [Effects of the Invention]

[0011] In the above embodiment, the light intensity distribution of the light-emitting surface of the light source is controlled based on the flow rate distribution, flow velocity distribution, or turbidity distribution of the fluid in the sterilization space. Therefore, it is possible to achieve uniform and efficient sterilization and inactivation of the fluid while appropriately controlling the light intensity to save power.

[0012] As described above, according to the above embodiment, a power-saving fluid sterilization device can be realized. [Brief explanation of the drawing]

[0013] [Figure 1] A plan view showing the configuration of the fluid sterilization device in Embodiment 1. [Figure 2] A cross-sectional view showing the configuration of a fluid sterilization device in Embodiment 1, wherein the cross-sectional view is perpendicular to the main surface of the sterilization space forming section. [Figure 3] A cross-sectional view showing the configuration of the light source unit, with the cross-section perpendicular to the main surface of the diffuser plate. [Figure 4] A block diagram showing the control relationships between the flow meter, light intensity control unit, and flow velocity control unit. [Figure 5] A plan view showing the configuration of the fluid sterilization device in Embodiment 2. [Figure 6] A block diagram showing the control relationships between the flow meter and the light intensity control unit. [Figure 7] A plan view showing the configuration of the fluid sterilization device in Embodiment 3. [Figure 8]Block diagram showing the control relationships among a flow meter, a transmittance measurement device, a light intensity control unit, and a flow rate and flow velocity control unit.

Embodiments for Carrying out the Invention

[0014] A fluid sterilization device includes a sterilization space forming unit that forms a membranous sterilization space in a space where fluid flows and is irradiated with ultraviolet light, and the thickness of the ultraviolet light penetrating the fluid is set; a light source unit having a plurality of ultraviolet light emitting elements that irradiate the sterilization space with ultraviolet light emitted by the light emitting elements, and the light emitting surface is planar and faces the surface of the sterilization space; and a light intensity control unit that controls the light intensity distribution of the light emitting surface of the light source unit based on the flow rate distribution, flow velocity distribution, or turbidity distribution of the fluid in the sterilization space.

[0015] In the above fluid sterilization device, the sterilization space forming unit may have a partition wall that divides the sterilization space into a plurality of flow paths. This can stabilize and facilitate the control of the flow rate and flow velocity distributions in the sterilization space.

[0016] In the above fluid sterilization device, the light intensity control unit may control the light intensity for each region corresponding to each of the flow paths on the light emitting surface. This can efficiently and uniformly sterilize and inactivate the fluid, and also achieve power saving.

[0017] In the above fluid sterilization device, it may have a flow rate and flow velocity control unit that controls the flow rate or flow velocity of each of the flow paths. This can further achieve power saving.

[0018] In the above fluid sterilization device, each flow path is provided with a flow rate and flow velocity variable unit that narrows the flow path to make the flow rate or flow velocity of the fluid variable, and the flow rate and flow velocity control unit may control the flow rate or flow velocity of the fluid by the flow rate and flow velocity variable unit. The flow rate and flow velocity of each flow path can be easily controlled.

[0019] In the above-described fluid sterilization apparatus, a flow meter may be provided to measure the flow rate of the fluid flowing into or out of the sterilization space, and the flow rate and velocity control unit may control the flow rate and velocity of each flow path based on the flow rate of the fluid measured by the flow meter. Even if the flow rate into the sterilization space changes, sterilization and inactivation can be performed efficiently, and power consumption can be reduced.

[0020] The above-described fluid sterilization apparatus may include a flow meter for measuring the flow velocity of the fluid flowing into or out of the sterilization space, and the flow rate and flow velocity control unit may control the flow rate and flow velocity of each flow path based on the flow rate of the fluid measured by the flow meter. Even if the flow velocity of the fluid flowing into the sterilization space changes, sterilization and inactivation can be performed efficiently, and power consumption can be reduced.

[0021] In the above-described fluid sterilization apparatus, a permeability measuring device may be provided to measure the permeability of the fluid, and the flow rate and flow velocity control unit may control the flow rate and flow velocity of each flow path based on the permeability of the fluid measured by the permeability measuring device. Even if the permeability of the fluid changes, sterilization and inactivation can be performed efficiently, and power consumption can be reduced.

[0022] In the above-described fluid sterilization apparatus, the flow rate and velocity control unit may select whether to open or close each of the flow paths based on the flow rate or velocity of the fluid flowing into or out of the sterilization space, and the light intensity control unit may control the light intensity distribution of the light-emitting surface to turn off the light-emitting element in the region corresponding to the closed flow path. This makes it possible to sterilize and inactivate the fluid efficiently and uniformly while saving power.

[0023] In the above-described fluid sterilization apparatus, the flow rate control unit may control the fluid flowing through each of the flow paths to ensure uniform flow velocity.

[0024] In the above-described fluid sterilization apparatus, the light source unit may further include a diffuser plate that diffuses the ultraviolet light emitted by each of the light-emitting elements in a planar manner. This allows for more uniform sterilization and inactivation of the fluid.

[0025] The fluid sterilization device comprises a sterilization space forming unit which is a space through which a fluid flows and is irradiated with ultraviolet light, and which forms a film-like sterilization space set to a thickness that allows ultraviolet light to pass through the fluid; and a light source unit which has a plurality of ultraviolet light-emitting elements and irradiates the sterilization space with ultraviolet light emitted by the elements, and the light-emitting surface is a plane facing the surface of the sterilization space, and the sterilization space forming unit has partitions that divide the sterilization space into a plurality of flow paths.

[0026] The above-described fluid sterilization apparatus may include a light intensity control unit that controls the light intensity of the entire light-emitting surface.

[0027] A fluid sterilization method includes a fluid flow step in which the fluid to be sterilized is flowed into a membrane-like sterilization space, which is a space in which ultraviolet light is irradiated onto the fluid, and the thickness of the membrane is set to allow ultraviolet light to pass through the fluid. The system includes a UV light irradiation step in which a light source unit having multiple UV-emitting light-emitting elements, the light-emitting surface of which is a surface facing the surface of the sterilization space, is used to irradiate the sterilization space with UV light emitted by the light-emitting elements, and in the UV light irradiation step, the light intensity distribution of the light-emitting surface of the light source unit is controlled based on the flow rate distribution, flow velocity distribution, or turbidity distribution of the fluid in the sterilization space.

[0028] In the above-described fluid sterilization method, in the fluid conduction step, the sterilization space may be divided into a plurality of flow paths, and the flow rate or flow velocity of each flow path may be controlled based on the flow rate or flow velocity of the fluid flowing into or out of the sterilization space, and in the ultraviolet light irradiation step, the light intensity distribution of the light-emitting surface of the light source unit may be controlled according to the flow rate or flow velocity of each flow path.

[0029] A fluid sterilization method includes a fluid flow step in which the fluid to be sterilized is flowed into a membrane-like sterilization space, which is a space in which ultraviolet light is irradiated onto the fluid, and the thickness of the membrane is set to allow ultraviolet light to pass through the fluid. The process includes an ultraviolet light irradiation step in which a light source unit having multiple ultraviolet light-emitting elements, the light-emitting surface of which is a planar shape facing the surface of the sterilization space, is used to irradiate the sterilization space with ultraviolet light emitted by the light-emitting elements, and in the fluid conduction step, the sterilization space is divided into multiple flow channels.

[0030] (Embodiment 1) Figure 1 is a plan view showing the configuration of the fluid sterilization device in Embodiment 1. Figure 2 is a cross-sectional view showing the configuration of the fluid sterilization device in Embodiment 1, and is a cross-sectional view perpendicular to the main surface of the sterilization space forming section (cross-sectional view at line II-II in Figure 1). As shown in Figures 1 and 2, the fluid sterilization device in Embodiment 1 includes a light source unit 1, a sterilization space forming section 2, a partition wall 3, a flow rate / velocity variable section 4, an inlet 5, an outlet 6, a light intensity control unit 100, a flow rate / velocity control unit 101, and a flow meter 102.

[0031] The fluid sterilization device in Embodiment 1 is a device that sterilizes and inactivates a fluid by flowing it in a thin, flat plate form and irradiating it with ultraviolet light. By making the fluid thin, efficient sterilization and inactivation can be achieved even when the fluid's transmittance is low. The fluid to be sterilized can be a gas or a liquid, and as long as it has fluidity, it may be a mixture of gas and liquid, a mixture of gas and powdered solid, etc. In the case of a liquid, examples include water, oil, alcohol, and solvents using these as solvents.

[0032] As shown in Figure 3, the light source unit 1 has a plurality of light-emitting elements 10 and a diffuser plate 11. The light source unit 1 achieves planar light emission by diffusing the ultraviolet light emitted by the plurality of light-emitting elements 10 with the diffuser plate 11.

[0033] The light-emitting element 10 is a device made of a group III nitride semiconductor that emits ultraviolet light. Its emission wavelength is, for example, 200 to 300 nm, and is particularly preferably 250 to 280 nm. Multiple light-emitting elements 10 are arranged in a planar manner as shown in Figure 3. The light-emitting elements 10 may be mounted on a submount to constitute a light-emitting device. Alternatively, the light-emitting device may be mounted on a drive circuit board. Alternatively, the light-emitting elements 10 may be directly mounted on the drive circuit board.

[0034] The number and arrangement of the light-emitting elements 10 are arbitrary, as long as they are set so that ultraviolet light is emitted in a planar direction due to scattering of ultraviolet light by the diffuser plate 11. For example, multiple light-emitting elements 10 can be arranged in a triangular lattice or square lattice pattern when viewed from the horizontal. However, light-emitting elements 10 may not be placed in areas that overlap with the partition wall 3, which will be described later, when viewed from above.

[0035] The light-emitting elements 10 may be arranged so that ultraviolet light emitted from multiple light-emitting elements 10 is irradiated to each channel 7. In this case, the multiple light-emitting elements may have different emission wavelengths. For example, they may include light-emitting elements with wavelengths of 270 nm and 280 nm, or they may include light-emitting elements with wavelengths of 265 nm and 280 nm. By using multiple light-emitting elements with different emission wavelengths in this way, various types of bacteria and viruses can be efficiently killed or inactivated.

[0036] The diffuser plate 13 has a flat plate shape. The diffuser plate 13 is made of a material that transmits ultraviolet light. For a diffuser plate that diffuses ultraviolet light, it is important to select a material with a low ultraviolet absorption rate as the constituent material. For example, the light absorption rate of the diffuser plate 13 should be 5% or less. The diffuser plate 13 can be made of materials such as quartz, sapphire, ultraviolet-transmitting glass, acrylic, fluororesins such as PTFE and PFA, etc.

[0037] Generally, a diffuser plate 13 is a component that diffuses light by creating minute irregularities or small curves at the interface formed by materials with different refractive indices, thereby obstructing the straight-line propagation of light. This makes it possible to create a uniform light source, where even point light sources placed at intervals on a plane become a surface light source across the entire plane. Specifically, one method is to arrange irregularities with random or directional shapes in a random or regular pattern on the surface of a transparent plate. In the case of materials such as resin, this can be achieved by dispersing spherical particles called diffusers within the transparent plate, or by incorporating air like bubbles. The diffusers are not limited to spherical shapes; they may also have elliptical or nearly spherical shapes.

[0038] As shown in Figure 3, the diffuser plate 11 is positioned so that one surface faces the sterilization space formation section 2. Multiple light-emitting elements 10 are arranged on the other surface of the diffuser plate 11, and ultraviolet light is emitted from this other surface. The ultraviolet light emitted by the multiple light-emitting elements 10 is diffused in a planar manner by the diffuser plate 11. In this way, the combination of the light-emitting elements 10 and the diffuser plate 11 realizes a planar light source with a planar light-emitting surface 9. In the light source section 1, the light-emitting surface 9 is the side of the diffuser plate 11 opposite to the side where the light-emitting elements 10 are located.

[0039] In Embodiment 1, as shown in Figure 3, there is a gap between the light-emitting element 10 and the diffuser plate 11, but the light-emitting element 10 and the diffuser plate 11 may be in contact. When there is a gap between the light-emitting element 10 and the diffuser plate 11, air exists between the light-emitting element 10 and the diffuser plate 11.

[0040] Although the diffuser plate 11 is not required, providing it allows for the diffusion of ultraviolet light, thereby uniformly sterilizing and inactivating the fluid.

[0041] The sterilization space forming section 2 is a component that forms a sterilization space and has a sterilization space 8 inside. The sterilization space 8 is a space through which a fluid flows and which is irradiated with ultraviolet light emitted by the light source section 1. The sterilization space forming section 2 has a flat plate shape and is rectangular in plan view. The sterilization space 8 has a flat plate shape and is rectangular in plan view. The thickness of the film should be thin enough to allow sufficient transmission of ultraviolet light.

[0042] As shown in Figure 1, the sterilization space forming section 2 has an inlet 5 in the center of one of its four sides. Also, as shown in Figure 1, the sterilization space forming section 2 has an outlet 6 in the center of the side opposite to the side where the inlet 5 is located. The inlet 5 is an opening for introducing fluid into the sterilization space 8 inside the sterilization space forming section 2. The outlet 6 is an opening for discharging fluid from the sterilization space 8 inside the sterilization space forming section 2. The cross-sections of the inlet 5 and outlet 6 perpendicular to the axial direction are rectangular. The direction of fluid inflow into and out of the sterilization space 8 is parallel to the main surface of the sterilization space 8.

[0043] Note that the positions of the inlet 5 and outlet 6 are not limited to Embodiment 1. For example, the inlet 5 and outlet 6 may be provided at both ends of the main surface of the sterilization space forming section 2. In this case, the direction of fluid inflow and outflow into the sterilization space 8 will be perpendicular to the main surface of the sterilization space 8. Also, in Embodiment 1, there is one inlet 5 and one outlet 6, but multiple inlets 5 and outlets 6 may be provided.

[0044] The sterilization space forming section 2 is made of a transparent material that transmits ultraviolet light emitted from the light source section 1. The light source section 1 is also provided above one of the two main surfaces of the sterilization space forming section 2. The light source section 1 is positioned so that its light-emitting surface 9 faces the sterilization space forming section 2, and so that the light-emitting surface 9 of the light source section 1 and the main surface of the sterilization space forming section 2 are parallel. This allows the ultraviolet light emitted from the light source section 1 to pass through the sterilization space forming section 2 and irradiate the sterilization space 8 inside the sterilization space forming section 2. Note that the sterilization space forming section 2 does not need to be made entirely of transparent material; areas other than those that transmit ultraviolet light do not need to be made of transparent material.

[0045] The sterilization space forming unit 2 may be configured as follows, for example. The sterilization space forming unit 2 may be configured by arranging two flat plates opposite each other with a gap in between, and sealing the ends of the flat plates. In this case, by making at least one of the two flat plates a transparent material that can transmit ultraviolet light emitted from the light source unit 1, the fluid can be irradiated with ultraviolet light. The material of the transparent material may be, for example, quartz, sapphire, ultraviolet-transmitting glass, acrylic, or fluororesins such as PTFE or PFA. One of the two flat plates may be a transparent material and the other a reflective material. The reflective material may be made of a sintered body of a metal such as Al, Mg, Rh, or Ru, or a fluororesin such as PTFE. Also, if both of the two flat plates are transparent materials, two light source units 1 may be provided and configured to irradiate the sterilization space forming unit 2 with ultraviolet light from both sides.

[0046] The sterilization space forming section 2 has partition walls 3. The partition walls 3 are arranged in a striped pattern, dividing the sterilization space into multiple striped flow channels 7. The direction of the stripes is parallel to the direction from the inlet 5 side to the outlet 6 side. The stripes also extend from the vicinity of the inlet 5 to the vicinity of the outlet 6. Furthermore, the partition walls 3 are in contact with both main surfaces of the sterilization space 8. These partition walls 3 form multiple independent flow channels 7. Due to the partition walls 3, the fluid flowing into the sterilization space 8 from the inlet 5 is divided into multiple flow channels 7, which merge near the outlet 6 before being discharged from the outlet 6.

[0047] The material of partition wall 3 can be any material that is resistant to ultraviolet light. It may be a transparent material such as quartz or fluororesin, or it may be a reflective material.

[0048] In Embodiment 1, multiple stripe-shaped flow channels 7 are formed extending from the inlet 5 side to the outlet 6 side. However, the shape of the partition wall 3 and the flow channels 7 can be arbitrary as long as multiple independent flow channels 7 are formed. For example, they may be stripe-shaped, extending in a direction that forms an angle with respect to the direction from the inlet 5 side to the outlet 6 side.

[0049] The flow rate and velocity variable unit 4 is installed in each flow path 7 and is a device that varies the flow rate of each flow path 7. For example, the flow rate can be adjusted by installing a sluice gate in the flow path 7 and adjusting the width of the flow path 7. The flow rate and velocity variable unit 4 can also completely block the fluid so that no fluid flows into the flow path 7. The flow rate and velocity in the flow rate and velocity variable unit 4 are controlled by the flow rate and velocity control unit 101. Alternatively, the flow rate and velocity variable unit 4 may control whether the flow path 7 is completely open or completely closed. In addition to controlling the flow rate, the flow velocity may also be controlled. It is preferable to install the flow rate and velocity variable unit 4 near the inlet of each flow path 7.

[0050] The variable flow rate / velocity section 4 may be a device that controls the flow rate by providing a sliding plate and narrowing the flow path 7 by sliding the plate. Alternatively, the variable flow rate / velocity section 4 may be a device that controls the flow path by providing a door with one end fixed and rotating around the fixed end, and narrowing the flow path 7 by rotating the door.

[0051] The light intensity control unit 100 is a device that controls the light intensity of the light source unit 1 and controls the light intensity distribution of the light-emitting surface of the light source unit 1. The light intensity distribution can be controlled by turning each light-emitting element 10 on or off and by the current value.

[0052] The flow rate / velocity control unit 101 is a device that controls the flow rate or velocity in each flow rate / velocity variable unit 4 using a flow meter 102.

[0053] The flowmeter 102 is positioned near the inlet 5 and measures the flow velocity of the fluid flowing into the sterilization space 8. It may also be positioned near the outlet 6 instead of the inlet 5 to measure the flow velocity of the fluid flowing out of the sterilization space 8. Alternatively, a flow meter may be provided instead of the flowmeter 102 to measure the flow rate of the fluid flowing into the sterilization space 8.

[0054] As shown in the block diagram in Figure 4, the flow rate and velocity control unit 101 controls the flow rate and velocity based on the fluid velocity measured by the flow meter 102. The light intensity control unit 100 controls the light intensity distribution of the light-emitting surface of the light source unit 1 based on the fluid velocity measured by the flow meter 102 and the fluid velocity and velocity control amount of each channel 7 controlled by the flow rate and velocity control unit 101. The light intensity control unit 100 may also control the light intensity for each region corresponding to each channel 7.

[0055] Next, the operation of the fluid sterilization device in Embodiment 1 will be described.

[0056] The fluid that flows into the sterilization space 8 from the inlet 5 is separated into multiple channels 7 by the partition wall 3, flows through each channel 7, then merges back into one and is discharged from the outlet 6. Because the sterilization space 8 is a thin, flat plate, the fluid also flows in a flat shape.

[0057] Ultraviolet light emitted from the light source 1 is irradiated onto the fluid flowing through the sterilization space 8. Since the sterilization space 8 is a sufficiently thin, flat plate, ultraviolet light can be transmitted through the fluid even if the fluid's transmittance is low. Therefore, fluids with low transmittance can be efficiently and evenly sterilized and inactivated.

[0058] Furthermore, the light-emitting surface 9 of the light source unit 1 has a planar shape, so ultraviolet light is irradiated onto almost the entire surface of the fluid flowing in a flat manner. As a result, a wide area of ​​the fluid can be irradiated, and the fluid can be sterilized and inactivated efficiently and evenly.

[0059] Furthermore, in the fluid sterilization device of Embodiment 1, the flow velocity and flow rate of the fluid near the inlet 5 or outlet 6 are measured by the flow meter 102. Based on the measured flow velocity and flow rate, the flow velocity control unit 101 controls each flow velocity variable unit to control the flow rate and flow velocity of each flow path 7.

[0060] For example, the flow path 7 to be used is selected according to the fluid velocity and flow rate at the inlet 5 and outlet 6. The flow rate / velocity variable unit 4 is opened for the flow path 7 that is used, and the flow rate / velocity variable unit 4 is closed for the flow path 7 that is not used. Specifically, the number of flow paths 7 used is increased as the flow rate increases. This ensures that the fluid velocity flowing through each flow path 7 remains as constant as possible, and that the sterilization efficiency does not fluctuate even if the fluid flow rate changes over time. In Embodiment 1, the flow rate / velocity variable unit 4 is completely opened and closed, but the flow rate may be controlled in stages or continuously.

[0061] In the fluid sterilization device of Embodiment 1, the light intensity distribution of the light-emitting surface 9 of the light source unit 1 is controlled based on the flow rate and flow velocity measured by the flow meter 102, and the amount of flow rate and flow velocity controlled by the flow rate and flow velocity control unit 101 for each flow path 7.

[0062] For example, in the light-emitting surface 9 of the light source unit 1, the corresponding light-emitting element 10 is turned off in the area that overlaps with the flow channel 7 that is not used in a plan view, and the light intensity distribution of the light-emitting surface 9 is controlled so that the light intensity is 0 or sufficiently low. Since the light source unit 1 uses the light-emitting element 10 as a source of ultraviolet light, it is easy to turn the light-emitting element 10 on and off and control the light intensity, and the light intensity distribution of the light-emitting surface 9 can be easily controlled. In this way, by controlling the light intensity distribution of the light-emitting surface 9 according to the flow rate and flow velocity of the flow channel 7, power saving of the fluid sterilization device can be achieved.

[0063] As described above, the fluid sterilization device in Embodiment 1 can stably sterilize and inactivate even when the flow rate changes, and it is possible to realize a fluid sterilization device that is energy-efficient. Furthermore, the fluid sterilization device in Embodiment 1 is suitable when the fluid permeability is low.

[0064] In Embodiment 1, both the flow rate and flow velocity of each channel 7 and the light intensity distribution of the light-emitting surface 9 are controlled. However, it is also possible to control only the flow rate and flow velocity of each channel 7, without controlling the light intensity distribution of the light-emitting surface 9, and instead control the entire surface of the light-emitting surface 9 as a whole.

[0065] (Embodiment 2) Figure 5 is a plan view showing the configuration of the fluid sterilization device in Embodiment 2. As shown in Figure 5, the fluid sterilization device in Embodiment 2 is configured by omitting the partition wall 3, the flow rate and velocity variable unit 4, and the flow rate and velocity control unit 101 from the fluid sterilization device in Embodiment 1, and replacing the light intensity control unit 100 with a light intensity control unit 200. The other configurations are the same as in Embodiment 1. Since the partition wall 3 is not provided in the sterilization space forming unit 2, the sterilization space 28 is a thin, flat plate, and the flow path is not divided.

[0066] As shown in the block diagram of Figure 5, the light intensity control unit 200 controls the light intensity distribution of the light-emitting surface 9 of the light source unit 1 based on the fluid flow rate and flow velocity measured by the flow meter 102. If the fluid flow rate and flow velocity near the inlet 5 and outlet 6 are known, the fluid velocity distribution in the flat plate-shaped sterilization space 28 can also be determined. For example, the fluid velocity distribution can be determined by simulation. Of course, it can also be measured in person. Therefore, by controlling the light intensity distribution of the light-emitting surface 9 according to the fluid velocity distribution, the fluid can be sterilized and inactivated efficiently and uniformly, and power saving can also be achieved. Specifically, it is conceivable to set the light intensity higher in areas with high fluid velocity and lower in areas with low fluid velocity.

[0067] (Embodiment 3) Figure 7 is a plan view showing the configuration of the fluid sterilization apparatus in Embodiment 3. The fluid sterilization apparatus in Embodiment 3 is the same as the fluid sterilization apparatus in Embodiment 1, but with the addition of a transmittance measuring device 303, a light intensity control unit 300 instead of the light intensity control unit 100, and a flow rate velocity control unit 301 instead of the flow rate velocity control unit 101. The other configurations are the same as in Embodiment 1.

[0068] The transmittance measuring device 303 is a device for measuring the transmittance of a fluid. The position of the transmittance measuring device 303 can be any position as long as transmittance can be measured. In Embodiment 3, the transmittance of the fluid is measured near the inlet 5.

[0069] As shown in the block diagram of Figure 8, the flow velocity control unit 301 controls the flow velocity and flow rate of each channel 7 based on the fluid velocity and flow rate measured by the flow meter 102, and the transmittance measured by the transmittance measuring device 303. The light intensity control unit 300 controls the light intensity distribution of the light-emitting surface 9 based on the fluid velocity and flow rate measured by the flow meter 102, the transmittance measured by the transmittance measuring device 303, and the flow velocity and flow rate of each channel 7.

[0070] For example, if the fluid's transmittance is low, the overall light intensity of the light-emitting surface 9 is increased, and if the transmittance is high, the overall light intensity of the light-emitting surface 9 is decreased. In this way, power saving can be achieved by changing the light intensity according to the fluid's transmittance.

[0071] Furthermore, the number of channels 7 used may be dynamically increased or decreased depending on the fluid's permeability. When the fluid's permeability is low, the number of channels 7 used can be increased, and the light-emitting elements 10 on the unused channels 7 can be turned on to increase the irradiation area, thereby enabling more efficient sterilization and inactivation. When the permeability is high, the number of channels 7 used can be decreased, and the light-emitting elements 10 on the unused channels 7 can be turned off to reduce the irradiation area, thereby saving power. In this way, even if the fluid's permeability fluctuates, power can be saved without reducing sterilization efficiency by dynamically selecting which channels 7 to use.

[0072] (Modified form of the embodiment) In this embodiment, the fluid velocity in the sterilization space may have an in-plane distribution depending on the position and number of inlets 5 and outlets 6. In such cases, the flow rate control unit may be used to adjust the flow velocity in each channel 7 to be uniform. This allows for more uniform sterilization and inactivation of the fluid.

[0073] In this embodiment, the sterilization space is a thin, flat plate, but it is not limited to a flat plate as long as it is a thin film that allows fluid to pass through. It may also be a thin film such as a cylindrical or spherical shell. Furthermore, the light-emitting surface 9 of the light source unit 1 may also be a surface that is opposite to the film.

[0074] In this embodiment, the light source unit 1 has one flat diffuser plate 11, but multiple diffusers may be provided, divided for each flow path 7.

[0075] In this embodiment, the light intensity distribution of the light-emitting surface of the light source is controlled based on the fluid velocity distribution of the sterilization space, but it is not limited to this. The light intensity distribution of the light-emitting surface of the light source can be controlled based on one or more of the flow rate distribution, fluid velocity distribution, or turbidity distribution of the fluid in the sterilization space. This makes it possible to reduce the power consumption of the fluid sterilization device. [Explanation of Symbols]

[0076] 1: Light source part 2: Sterilization space forming part 3: Bulkhead 4: Variable flow rate and flow velocity section 5:Inlet 6: Outlet 7: Flow channel 8: Sterilization space 9: Light-emitting surface 10: Light-emitting element 11: Diffuser 100: Light intensity control unit 101: Flow Rate and Velocity Control Unit 102: Current meter

Claims

1. A space through which a fluid is flowed and ultraviolet light is irradiated, comprising a sterilization space forming section that forms a film-like sterilization space set to a thickness that allows ultraviolet light to pass through the fluid, A light source unit having multiple ultraviolet light-emitting elements, which irradiates the sterilization space with ultraviolet light emitted by the light-emitting elements, and whose light-emitting surface is a plane facing the surface of the sterilization space, A fluid sterilization device comprising: a light intensity control unit that controls the light intensity distribution of the light-emitting surface of the light source unit based on the flow rate distribution, flow velocity distribution, or turbidity distribution of the fluid in the sterilization space.

2. The fluid sterilization apparatus according to claim 1, wherein the sterilization space forming section has partitions that divide the sterilization space into a plurality of flow paths.

3. The fluid sterilization apparatus according to claim 2, wherein the light intensity control unit controls the light intensity for each region of the light-emitting surface corresponding to each of the flow channels.

4. The fluid sterilization apparatus according to claim 2, further comprising a flow rate and flow velocity control unit that controls the flow rate or flow velocity of each of the aforementioned flow channels.

5. Each of the aforementioned flow paths is provided with a flow rate / flow velocity variable unit that narrows the flow path to vary the flow rate or flow velocity of the fluid, The fluid sterilization apparatus according to claim 4, wherein the flow rate and flow velocity control unit controls the flow rate or flow velocity of the fluid using the flow rate and flow velocity variable unit.

6. The system includes a flow meter for measuring the flow rate of the fluid flowing into or out of the sterilization space, The fluid sterilization apparatus according to claim 4, wherein the flow rate and flow velocity control unit controls the flow rate and flow velocity of each of the flow paths based on the flow rate of the fluid measured by the flow meter.

7. The system includes a flowmeter for measuring the flow velocity of the fluid flowing into or out of the sterilization space. The fluid sterilization apparatus according to claim 4, wherein the flow rate and flow velocity control unit controls the flow rate and flow velocity of each of the flow channels based on the flow rate of the fluid measured by the flow meter.

8. The system includes a transmittance measuring device for measuring the transmittance of the aforementioned fluid, The fluid sterilization apparatus according to claim 4, wherein the flow rate and flow velocity control unit controls the flow rate and flow velocity of each of the flow channels based on the permeability of the fluid measured by the permeability measuring device.

9. The flow rate and velocity control unit selects whether to open or close each of the flow paths based on the flow rate or velocity of the fluid flowing into or out of the sterilization space. The fluid sterilization apparatus according to claim 4, wherein the light intensity control unit controls the light intensity distribution of the light-emitting surface to turn off the light-emitting element in the region corresponding to the closed flow path.

10. The fluid sterilization apparatus according to claim 4, wherein the flow rate and velocity control unit controls the fluid flowing through each of the flow paths to be uniform in velocity.

11. The fluid sterilization apparatus according to any one of claims 1 to 10, wherein the light source unit further comprises a diffusion plate that diffuses ultraviolet light emitted by each of the light-emitting elements in a planar manner.

12. A space through which a fluid is flowed and ultraviolet light is irradiated, comprising a sterilization space forming section that forms a film-like sterilization space set to a thickness that allows ultraviolet light to pass through the fluid, The device comprises a light source unit having multiple ultraviolet light-emitting elements, which irradiates the sterilization space with ultraviolet light emitted by the light-emitting elements, and the light-emitting surface is a planar surface facing the surface of the sterilization space, The sterilization space forming section is a fluid sterilization device having partitions that divide the sterilization space into multiple flow channels.

13. The fluid sterilization apparatus according to claim 12, further comprising a light intensity control unit that controls the light intensity of the entire light-emitting surface.

14. A fluid conduction step is performed in which the fluid is flowed through a membrane-like sterilization space, which is set to a thickness that allows ultraviolet light to penetrate the fluid, in a space in which ultraviolet light is irradiated with ultraviolet light, The process includes a UV light irradiation step in which a light source unit having multiple UV-emitting light-emitting elements, the light-emitting surface of which is a planar shape facing the surface of the sterilization space, is used to irradiate the sterilization space with UV light emitted by the light-emitting elements, A fluid sterilization method comprising controlling the light intensity distribution of the light-emitting surface of the light source unit based on the flow rate distribution, flow velocity distribution, or turbidity distribution of the fluid in the sterilization space during the ultraviolet light irradiation step.

15. In the fluid conduction step, the sterilization space is divided into a plurality of flow paths, and the flow rate or flow velocity of each flow path is controlled based on the flow rate or flow velocity of the fluid flowing into or out of the sterilization space. The fluid sterilization method according to claim 14, wherein in the ultraviolet light irradiation step, the light intensity distribution of the light-emitting surface of the light source is controlled according to the flow rate or flow velocity of each of the flow channels.

16. A fluid conduction step is performed in which the fluid is flowed through a membrane-like sterilization space, which is set to a thickness that allows ultraviolet light to penetrate the fluid, in a space in which ultraviolet light is irradiated with ultraviolet light, The process includes a UV light irradiation step in which a light source unit having multiple UV-emitting light-emitting elements, the light-emitting surface of which is a planar shape facing the surface of the sterilization space, is used to irradiate the sterilization space with UV light emitted by the light-emitting elements, A fluid sterilization method comprising the fluid conduction step of dividing the sterilization space into multiple flow paths.

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