JP7591602B2 - Ultraviolet sterilization device - Google Patents

Description

This invention relates to an ultraviolet sterilization device that uses an LED light source to sterilize various liquids such as river water, industrial water, well water, drinking water, pure water, industrial wastewater, domestic wastewater, syrup, etc., by irradiating them with ultraviolet light.

Devices that sterilize a liquid to be treated by irradiating it with ultraviolet light have been widely known for some time, and in particular, ultraviolet sterilization devices are already in widespread use in which a quartz tube containing an ultraviolet lamp is placed inside a reactor, and while the liquid to be treated is circulated through the reactor, the ultraviolet light emitted by the ultraviolet lamp is irradiated onto the liquid to be treated, thereby sterilizing the liquid. However, devices using ultraviolet lamps like this tend to lose their ultraviolet light irradiation level over time due to deterioration, and so when a decrease in the amount of ultraviolet light irradiation is observed, the ultraviolet lamp needs to be replaced.

In order to overcome these drawbacks, an ultraviolet sterilization device has been developed that uses an ultraviolet LED light source instead of a conventional ultraviolet lamp, which can maintain a good amount of ultraviolet irradiation for a relatively long period of time compared to the ultraviolet lamps described above, as shown in Patent Document 1.

JP 2016-123930 A

However, in industrial and other flow-type ultraviolet sterilizers, low- or high-pressure ultraviolet lamps are still commonly used as light sources. The main reason for this is that ultraviolet lamps can treat large volumes of liquid to be treated, and are capable of inactivating general bacteria, which are more resistant to ultraviolet light than E. coli, by 3 logs or more. In contrast, ultraviolet sterilizers using UV LED light sources that are already known have inferior UV irradiation efficiency compared to those using the above-mentioned ultraviolet lamps, and can only target E. coli and other bacteria that are less resistant to ultraviolet light, making it difficult to target general bacteria that are relatively more resistant to ultraviolet light than E. coli. However, although it is possible to inactivate general bacteria by increasing the irradiation dose by slowing the flow rate, this is not practical because the flow rate is too low.

Furthermore, when a reactor with a circular cross section was used in a conventional ultraviolet LED sterilization device, when sterilizing the liquid to be treated flowing through the reactor, the ultraviolet light sometimes did not reach the central axis of the reactor, or the strength of the light was too weak, making it difficult to treat a large flow rate of the liquid to be treated. Therefore, in order to solve this problem, as shown in Patent Document 1, it was necessary to place many ultraviolet LED light sources inside the device, which was costly and could cause problems due to heat generation.

The present application aims to solve the above-mentioned problems by providing an ultraviolet sterilization device equipped with an ultraviolet LED light source that can inactivate general bacteria that are more resistant to ultraviolet light than E. coli and the like, and can efficiently treat large amounts of the liquid to be treated.

In order to solve the above-mentioned problems, the first invention of the present application is an ultraviolet sterilization device comprising a cylindrical reactor having one end as an inlet for water to be treated and the other end as an outlet for the water to be treated, an ultraviolet LED light source capable of irradiating ultraviolet light toward the water to be treated flowing through the reactor, and a casing that houses the ultraviolet LED light source and the reactor, wherein the reactor has one side recessed to form a recess so that the cross-sectional shape of the longitudinal center of the reactor is flattened, and a plurality of ultraviolet LED light sources are arranged opposite the recess in the longitudinal direction of the reactor at intervals such that ultraviolet light from the ultraviolet LED light source is irradiated from the ultraviolet LED light source toward the water to be treated flowing within the longitudinal center of the reactor, so that irradiation of ultraviolet light from the ultraviolet LED light source is uninterrupted within the range of the recess .
It is something.

The second invention of the present application is an ultraviolet sterilization device comprising a cylindrical reactor having one end as an inlet for water to be treated and the other end as an outlet for the water to be treated, an ultraviolet LED light source capable of irradiating ultraviolet light toward the water to be treated flowing through the reactor, and a casing for housing the ultraviolet LED light source and the reactor, wherein the reactor has a cross-sectional shape in the longitudinal center of the reactor flattened by forming recesses on both sides, and a plurality of ultraviolet LED light sources are arranged along the longitudinal direction of the reactor at opposing positions of the pair of recesses, with an interval such that ultraviolet light from the ultraviolet LED light source is irradiated from the ultraviolet LED light source toward the water to be treated flowing within the longitudinal center of the reactor, so that irradiation of ultraviolet light from the ultraviolet LED light source is uninterrupted within the range of the recess.

The ultraviolet LED light source of the present invention can be a deep ultraviolet LED light source. The peak wavelength of the deep ultraviolet LED light source is preferably in the range of 260 nm to 285 nm, and more preferably in the range of 260 nm to 265 nm. The ultraviolet LED light source of the present invention is preferably used after devising the structure of the device, such as processing the shape so that the irradiation direction spreads in a cone shape so that the irradiation to the reactor is not interrupted, installing a heat sink to prevent heat generation, etc., and considering the balance of the arrangement.

In the first aspect of the present invention, a reflector may be provided at a position facing the center of the reactor in the longitudinal direction . By providing a reflector in this manner, the light emitted from the UV LED light source arranged on one side hits the reflector and is reflected, and is then irradiated again toward the reactor, so that it is possible to further increase the irradiation intensity of the UV light.

In the second invention, the ultraviolet LED light source is disposed on one side of the center of the length of the reactor and on the other side opposite to the one side. By disposing the ultraviolet LED light source on both sides of the center of the reactor as described above, it is possible to irradiate the liquid to be treated flowing through the reactor with ultraviolet light from both sides of the reactor, so that the liquid to be treated flowing through the reactor can be reliably irradiated with ultraviolet light.

In the first invention of the present application , the reactor is formed such that one side in the longitudinal direction is recessed to form a recess, thereby making the cross-sectional shape of the longitudinal center of the reactor flat, and the ultraviolet LED light source is arranged at a position opposite the recess.In the second invention of the present application, the reactor is formed such that both sides in the longitudinal direction are recessed to form a recess, thereby making the cross-sectional shape of the longitudinal center of the reactor flat, and the ultraviolet LED light source is arranged at a position opposite the pair of recesses.

By arranging the UV LED light source in the recessed position of the reactor as described above, efficient arrangement can be achieved without creating wasted space between the reactor and the UV LED light source inside the casing, improving layout flexibility and enabling the device to be made more compact.

As described above, the first and second inventions of the present application use an ultraviolet LED light source as the light source, and therefore have the advantage that, compared to conventional ultraviolet lamp devices, instant lighting can be achieved and an energy-saving device can be obtained. Also, as described above, the cross-sectional shape of the center of the reactor is flattened, so that the liquid layer of the liquid to be treated flowing through the reactor can be made thin.

Therefore, by irradiating this thin liquid layer with ultraviolet light, it is possible to reliably irradiate the entire treated liquid flowing through the reactor with ultraviolet light, and sterilization can be performed efficiently. In addition, by irradiating such a thin liquid layer with ultraviolet light, the intensity of the ultraviolet light that reaches the liquid layer is high. Therefore, it is possible to increase the sterilization effect with the minimum number of ultraviolet LED light sources necessary, making it possible to inactivate not only E. coli and the like, but also general bacteria that are relatively resistant to ultraviolet light.

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention . FIG. 2 is a cross-sectional view showing the reactor of Example 1. FIG. 3 is an end view of line A-A in FIG. 2 . Cross-sectional view of line B-B in Figure 1. Cross-sectional view of line C-C in Figure 1. FIG. 2 is a conceptual diagram showing the positional relationship between the light beam from the ultraviolet LED light source and the reactor in Example 1. FIG. 4 is a cross-sectional view showing a second embodiment of the second invention of the present application . FIG. 4 is a cross-sectional view showing a reactor of Example 2. Cross-sectional view taken along line D-D in Figure 6.

Regarding the first embodiment of the present invention , as shown in Fig. 1, (1) is a reactor housed in a long rectangular parallelepiped casing (2). The reactor (1) is a quartz tube with a circular cross section, and a long recess (3) is provided in one side of the center of the quartz tube, excluding both ends, as shown in Fig. 2, so that the cross section of the recess (3) is flattened as shown in Fig. 3. The opening at one end of the reactor (1) serves as an inlet (15) for introducing the liquid to be treated from the outside into the reactor (1), and the opening at the other end serves as an outlet (16) for discharging the liquid to be treated that has flowed in from the inlet (15) to the outside. The reactor (1) in this embodiment is formed of a quartz tube as described above, but in other different embodiments, it is not limited to this, and may be formed of an ultraviolet-transmitting glass tube, a fluororesin tube, or the like.

As shown in Fig. 1, the side walls (4) at both ends of the length of the casing (2) each have a side wall opening (5), and the reactor (1) is arranged horizontally inside the casing (2), with both ends of the reactor (1) penetrating the pair of side wall openings (5) so that they protrude outward. The reactor (1) is assembled to the casing (2) so that the recess (3) is located at the top in Fig. 1 within the casing (2) and the upper surface (6) of the recess (3) of the reactor (1) is arranged horizontally.

In addition, opening protrusions (7) are arranged on both side walls (4) of the casing (2) so as to protrude from both ends of the reactor (1). As shown in FIG. 1, ultraviolet LED modules (8) are arranged at regular intervals at positions facing the recesses (3) provided in the reactor (1). This ultraviolet LED module (8) is composed of eight ultraviolet LED elements that serve as ultraviolet LED light sources (11) attached to the surface of a substrate (10) as shown in FIG. 4.

As shown in Figure 1, the ultraviolet LED module (8) is slightly shorter than the length of the recess (3) so that it can be positioned within the recess (3). The ultraviolet LED module (8) is assembled into the casing (2) with the ultraviolet LED light source (11) side of the ultraviolet LED module (8) positioned opposite the recess (3) of the reactor (1) at a fixed distance as shown in Figures 1 and 5.

As shown in Figures 1 and 5, the reactor (1) is provided with a reflector (12) that is long in the longitudinal direction of the reactor (1) on the other side opposite to the side on which the recess (3) is provided. In other words, the reflector (12) is formed to have a length that is slightly longer than the length of the UV LED module (8). As shown in Figures 1 and 5, the reflector (12) is curved to cover the outer periphery of the recess (3) of the reactor (1), and both long sides of the reflector (12) are connected and fixed to both sides (13) of the UV LED module (8).

By assembling the reflector (12) as described above, the reflector (12) is positioned opposite the ultraviolet LED light source (11) via the reactor (1), as shown in FIG. 1. By providing the reflector (12) in this manner, the ultraviolet light (14) emitted from the ultraviolet LED light source (11) of the ultraviolet LED module (8) strikes the reflector (12) and is reflected, and the ultraviolet light (14) is irradiated again toward the reactor (1), making it possible to more efficiently promote the inactivation of bacteria and the like in the liquid to be treated.

The method of sterilizing the liquid to be treated using the ultraviolet sterilization device configured as described above is described below. First, the ultraviolet LED light source (11) attached to the ultraviolet LED module (8) is turned on, and ultraviolet light (14) is irradiated from the ultraviolet LED light source (11) to the recess (3) of the reactor (1). In this state, the liquid to be treated is continuously circulated from the inlet (15) of the reactor (1) to the outlet through the opening protrusion (7) of the casing (2). As a result, when the liquid to be treated passes through the recess (3) of the reactor (1), ultraviolet light (14) is irradiated from the ultraviolet LED light source (11) fixedly arranged on the ultraviolet LED module (8), and bacteria in the liquid to be treated are continuously sterilized.

Here, eight ultraviolet LED light sources (11) are fixed to the ultraviolet LED module (8) as described above. The ultraviolet light (14) emitted from these eight light sources is directed toward the reactor (1) as shown in FIG. 6. At this time, since each light source individually emits ultraviolet light (14), if the spacing between the ultraviolet LED light sources (11) is too wide, there is a risk that there will be areas in the reactor (1) that are not irradiated with the ultraviolet light (14).

If there are any areas in the reactor (1) where the ultraviolet light (14) is not irradiated, the liquid to be treated may not be sterilized sufficiently, and the sterilization effect may be reduced. Therefore, as shown in FIG. 6, the number and spacing of the ultraviolet LED light sources (11) and the distance from the ultraviolet LED light source (11) to the reactor (1) are adjusted in advance so that the irradiation from the ultraviolet LED light source (11) is reliably and uninterrupted at all positions in the reactor (1).

In addition, as described above, in this embodiment, the ultraviolet LED light source (11) is disposed opposite the recess (3) of the reactor (1) that has a flat cross-sectional shape, so that the liquid layer of the liquid to be treated flowing through the reactor (1) is thin. Therefore, by irradiating this thin liquid layer with ultraviolet light (14), it is possible to reliably and evenly irradiate the entire liquid to be treated flowing through the recess (3) of the reactor (1) with ultraviolet light (14), and the sterilization operation can be performed efficiently.

In addition, by irradiating such a thin liquid layer with ultraviolet light (14), the liquid layer is irradiated with relatively strong ultraviolet light (14), so the sterilization effect can be enhanced using the minimum number of ultraviolet LED light sources (11). This makes it possible to inactivate not only E. coli and the like, but also general bacteria that are highly resistant to ultraviolet light, and it is not necessary to use a large number of ultraviolet LED light sources (11), making it possible to keep the cost of the device itself low.

In the first embodiment, the recess (3) is provided on one side of the reactor (1), but in the second embodiment, the recesses (33) are formed and arranged on both sides of the reactor (31) so as to face each other. The second embodiment, which is the second invention of the present application , will be described below. As shown in FIG. 7, the reactor (31) is housed in a long rectangular parallelepiped casing (32) as in the first embodiment. The reactor (31) has a pair of recesses (33) long in the length direction of the quartz tube, as shown in FIG. 8, provided at opposing positions on both sides of the center of the quartz tube, excluding both ends, so that the cross section of the recesses (33) is flattened. One end opening of the reactor (31) serves as an inlet (45) for introducing the liquid to be treated from the outside into the reactor (31), and the other end opening serves as an outlet (46) for discharging the liquid to be treated that has flowed in from the inlet (45) to the outside. Incidentally, the reactor (31) in this embodiment is formed of a quartz tube as described above, but in other embodiments, it is not limited to this, and may be formed of an ultraviolet ray transmitting glass tube, a fluororesin tube, or the like.

As shown in FIG. 7, the side walls (34) at both ends of the length of the casing (32) each have a side wall opening (35), and the reactor (31) is disposed horizontally within the casing (32), with both ends of the reactor (31) penetrating the pair of side wall openings (35) so that they protrude outward. The reactor (31) is attached to the casing (32) so that the recess (33) is positioned horizontally in the vertical direction in FIG. 7.

In addition, opening protrusions (37) that are continuous with both ends of the reactor (31) are arranged on both side walls (34) of the casing (32). As shown in FIG. 7, ultraviolet LED modules (38) are arranged at regular intervals at positions facing the recesses (33) provided in the reactor (31). This ultraviolet LED module (38) is the same as that in the first embodiment, and eight ultraviolet LED elements that serve as ultraviolet LED light sources (41) are fixedly arranged on the surface of the substrate (40).

As shown in Figure 7, the length of the ultraviolet LED module (38) is slightly shorter than the length of the recess (33) so that the ultraviolet LED module (38) can be positioned within the recess (33). As shown in Figure 9, the ultraviolet LED module (38) is assembled into the casing (32) with the ultraviolet LED light source (41) side of the ultraviolet LED module (38) positioned opposite the recess (33) of the reactor (31) at a fixed distance.

As described above, by forming recesses (33) on both sides of the reactor (31) and assembling ultraviolet LED modules (38) at positions corresponding to the recesses (33) and arranging the ultraviolet LED light sources (41) facing each other on both sides of the center of the reactor (31), it is possible to irradiate the liquid to be treated flowing through the reactor (31) with light from both sides of the reactor (31). Therefore, the liquid to be treated flowing through the recess of the reactor can be irradiated with ultraviolet light from both sides of the reactor, making it possible to reliably inactivate bacteria in the liquid to be treated. The sterilization method for the liquid to be treated using the ultraviolet sterilization device configured as described above is the same as in Example 1 above.

1, 31 Reactor 2, 32 Casing 3, 33 Recess 11, 41 UV LED light source 12 Reflector 14 UV light 15, 45 Inlet 16, 46 Outlet

Claims (2)

This ultraviolet sterilization device comprises a cylindrical reactor having one end as an inlet for water to be treated and the other end as an outlet for the water to be treated, an ultraviolet LED light source capable of irradiating ultraviolet light toward the water to be treated flowing through the reactor, and a casing to house the ultraviolet LED light source and the reactor, wherein the reactor has one side recessed to form a recess so that the cross-sectional shape of the longitudinal center of the reactor is flattened, and a plurality of ultraviolet LED light sources are arranged opposite the recess in the longitudinal direction of the reactor at intervals such that ultraviolet light from the ultraviolet LED light source is irradiated from the ultraviolet LED light source to the water to be treated flowing within the longitudinal center of the reactor, and at intervals such that irradiation of ultraviolet light from the ultraviolet LED light source is uninterrupted within the range of the recess so that ultraviolet light is irradiated to all positions within the recess of the reactor . This ultraviolet sterilization device comprises a cylindrical reactor having one end as an inlet for water to be treated and the other end as an outlet for the water to be treated, an ultraviolet LED light source capable of irradiating ultraviolet light toward the water to be treated flowing through the reactor, and a casing to house the ultraviolet LED light source and the reactor, wherein the reactor has a cross-sectional shape in the center of the longitudinal direction of the reactor flattened by forming recesses on both sides, and a plurality of ultraviolet LED light sources are arranged in the longitudinal direction of the reactor at opposing positions of the pair of recesses, with an interval such that irradiation of ultraviolet light from the ultraviolet LED light source is uninterrupted within the range of the recess so that ultraviolet light from the ultraviolet LED light source is irradiated from the ultraviolet LED light source to all positions within the recess of the reactor toward the water to be treated flowing within the center of the longitudinal direction of the reactor .