JP2024058667A - Optical Monitors and Sensors - Google Patents

Abstract

[Problem] To suppress deterioration of the performance of an optical monitor caused by condensation. [Solution] An optical monitor according to an embodiment includes a housing, a sensor, and a dew point lowering unit. The housing has a space inside and is provided with a window that allows light passing through an object to be monitored to pass into the space. The sensor detects the light that has passed through the window. The dew point lowering unit is provided in the housing, and cools the space to lower the dew point of the gas in the space below the temperature of the object to be monitored. [Selected Figure] Figure 5

Description

Embodiments of the present invention relate to optical monitors and optical sensors.

Conventionally, ultraviolet irradiation devices are known that perform sterilization, disinfection, decolorization, and other processes by irradiating treated water with ultraviolet light. An optical monitor may be provided in the ultraviolet irradiation device to monitor fluctuations in the water quality of the treated water. The optical monitor includes, for example, a housing that defines a sealable space inside, a window provided in the housing that allows light from the monitored object (treated water) to pass into the sealable space, and a sensor provided in the housing that detects the light that has passed through the window.

JP 2006-153739 A JP 2001-66244 A Japanese Patent Application Laid-Open No. 9-281100

In optical monitors like those described above, condensation can occur due to the temperature difference between the object being monitored and the space inside the housing. For example, in optical monitors used in ultraviolet irradiation equipment, the treated water being monitored is at a lower temperature than the outside air, so condensation is likely to occur on the window. When condensation occurs on the window, the sensor is unable to detect light correctly, reducing the performance of the optical monitor.

Therefore, one of the objectives of the embodiment is to provide an optical monitor and an optical sensor that can suppress the degradation of the performance of the optical monitor caused by condensation.

The optical monitor of the embodiment includes a housing, a sensor, and a dew point lowering unit. The housing has a space inside and is provided with a window that allows light passing through the monitored object to pass into the space. The sensor detects the light that has passed through the window. The dew point lowering unit is provided in the housing, and cools the space to lower the dew point of the gas in the space below the temperature of the monitored object.

FIG. 1 is a schematic diagram showing an outline of a treatment procedure for water to be treated by a water treatment system using an ultraviolet irradiation device according to a first embodiment. FIG. 2 is a schematic perspective view showing the appearance of the ultraviolet irradiation device according to the first embodiment. FIG. 3 is a schematic first cross-sectional view of the ultraviolet irradiating device according to the first embodiment. FIG. 4 is a second schematic cross-sectional view of the ultraviolet irradiating device according to the first embodiment. FIG. 5 is a schematic cross-sectional view of the optical monitor according to the first embodiment. FIG. 6 is a schematic cross-sectional view of an optical monitor according to the second embodiment. FIG. 7 is a schematic cross-sectional view of an optical monitor according to the third embodiment.

Below, several embodiments and modifications of the present disclosure will be described with reference to the drawings. The configurations of the embodiments and modifications described below, as well as the actions and effects brought about by said configurations, are merely examples and are not limited to the contents described below.

<Embodiment>
FIG. 1 is a schematic diagram showing an outline of a treatment procedure for water to be treated by a water treatment system using an ultraviolet irradiation device 100 (see FIG. 2 etc.) according to the first embodiment.

As shown in FIG. 1, in the water treatment system according to the first embodiment, first, in the water intake process S1, raw water is taken from a river, underground water, lake, groundwater, or the like. Then, in the coagulation and sedimentation process S2, the raw water taken in S1 is introduced into a coagulation and sedimentation tank, and a coagulant is added to the introduced raw water. Then, in the activated carbon filtration process S3, the supernatant water of the raw water that has been through the coagulation and sedimentation process S2 is extracted and sent to an activated carbon filtration tank, where foreign matter is filtered out of the supernatant water.

Then, in the UV disinfection step S4, the water that has gone through the activated carbon filtration step S3 (hereinafter referred to as treated water W) is sent to the ultraviolet irradiation device 100, where it is sterilized, disinfected, and decolorized using ultraviolet light (UV: Ultra Violet). Then, in the chlorine injection step S5, the treated water W that has gone through the UV disinfection step S4 is sent to a chlorine injection tank, where chlorine is injected into the treated water W. Then, in the water distribution step S6, the treated water W that has gone through the chlorine injection step S5 is distributed to ordinary homes and businesses.

The structure of the ultraviolet irradiation device 100 used in the UV disinfection process of S4 will be described in more detail below with reference to Figures 2 to 4.

Figure 2 is a schematic perspective view showing the appearance of the ultraviolet irradiation device 100 according to the first embodiment.

As shown in FIG. 2, the ultraviolet irradiation device 100 includes a treatment tank (reaction tank, reactor) 10 for temporarily storing the treatment water W (see also FIG. 3 and FIG. 4) to be treated. The treatment tank 10 includes a water inlet 21 that receives the treatment water W from the direction of arrow A201, and a discharge outlet 22 that discharges the treatment water W in the direction of arrow A202. The treatment tank 10 also has a cylindrical shape. In the following description, the direction along the flow of the treatment water W is the X direction, the direction in which the cylindrical treatment tank 10 extends is the Y direction, and the direction perpendicular to the X direction and Y direction is the Z direction.

Cover members 20 and 30, which have functions such as light blocking, electric shock prevention, electromagnetic shielding, and condensation suppression, are attached to both ends of the treatment tank 10 in the Y direction (see also FIG. 3 below). In addition, the treatment tank 10 is provided with an optical monitor 50 that monitors fluctuations in the water quality of the treated water in the treatment tank 10 (see also FIG. 4 below).

Fig. 3 is a schematic first cross-sectional view of the ultraviolet irradiation device 100 according to the first embodiment. More specifically, Fig. 3 is a diagram showing a state in which the ultraviolet irradiation device 100 shown in Fig. 2 is cut along the YZ plane.
Fig. 4 is a schematic second cross-sectional view of the ultraviolet irradiation device 100 according to the first embodiment. More specifically, Fig. 4 is a diagram showing a state in which the ultraviolet irradiation device 100 shown in Fig. 2 is cut along the XZ plane.

3 and 4, the ultraviolet irradiation device 100 includes multiple (four in the illustrated example) ultraviolet irradiation members 60 that irradiate ultraviolet rays to the treatment water W introduced into the treatment tank 10. Each ultraviolet irradiation member 60 includes an ultraviolet lamp 61 that irradiates ultraviolet rays and a tubular protective tube 62 that covers the ultraviolet lamp 61.

As shown in FIG. 3, the protective tube 62 extends along the Y direction. One end of the protective tube 62 (the end on the left side of the paper in FIG. 3) protrudes outside the lid 40 that is provided between the treatment tank 10 and the cover member 20 to cover the treatment tank 10, and the other end of the protective tube 62 (the end on the right side of the paper in FIG. 3) protrudes outside the treatment tank 10. The protective tube 62 is made of a transparent dielectric material that transmits ultraviolet light.

As shown in FIG. 3, the ultraviolet lamp 61 also extends in the Y direction inside the protective tube 62. Both ends of the ultraviolet lamp 61 in the Y direction are connected to an electronic ballast 80 provided outside the treatment tank 10 via wiring 70. The electronic ballast 80 is a device that supplies power to the ultraviolet lamp 61 and maintains the stability of the discharge.

As shown in FIG. 4, the ultraviolet irradiation members 60 are arranged to be spaced apart from each other. For example, the ultraviolet irradiation members 60 are arranged to form vertices of a rectangle when viewed in the Y direction.

As shown in FIG. 4, a plurality of optical monitors 50 (four in the illustrated example) are provided in one-to-one correspondence with the ultraviolet ray irradiation members 60. In other words, the optical monitors 50 are provided so as not to be affected by ultraviolet rays from ultraviolet ray irradiation members 60 other than the corresponding ultraviolet ray irradiation member 60.

More specifically, the optical monitor 50 at the top left of FIG. 4 is provided in a position and orientation that allows it to monitor only the ultraviolet light from the ultraviolet light irradiation member 60 at the top right of FIG. 4. The optical monitor 50 at the top right of FIG. 4 is provided in a position and orientation that allows it to monitor only the ultraviolet light from the ultraviolet light irradiation member 60 at the top left of FIG. 4. The optical monitor 50 at the bottom left of FIG. 4 is provided in a position and orientation that allows it to monitor only the ultraviolet light from the ultraviolet light irradiation member 60 at the bottom right of FIG. 4. The optical monitor 50 at the bottom right of FIG. 4 is provided in a position and orientation that allows it to monitor only the ultraviolet light from the ultraviolet light irradiation member 60 at the bottom left of FIG. 4.

The optical monitor 50 also includes a housing 51, a cap 52, and a dew point lowering structure 53. The housing 51 includes an insertion portion 51a that is inserted into the inside of the treatment tank 10, and an exposed portion 51b that is exposed to the outside of the treatment tank 10. A more specific structure of each part of the optical monitor 50 is as shown in the following Figure 5.

Figure 5 is a schematic cross-sectional view of the optical monitor 50 according to the first embodiment.

As shown in FIG. 5, a sealable space S is provided inside the housing 51. The housing 51 is provided with a window 501 that allows ultraviolet light (see dashed arrow) from the ultraviolet light irradiation member 60 to pass into the space S, and a sensor 502 that detects the ultraviolet light that has passed through the window 501.

The window 501 is made of a transparent material such as quartz glass or PFA (perfluoroalkoxy fluororesin), etc. The window 501 is provided at the end of the insertion portion 51a of the housing 51 on the ultraviolet ray irradiation member 60 side, that is, at the end of the insertion portion 51a.

The sensor 502 is formed of, for example, an O/E (Optical/Electronic) converter. The sensor 502 is provided at the end of the exposed portion 51b of the housing 51 opposite the ultraviolet irradiation member 60. The sensor 502 has a flange 502a, and the flange 502a is sandwiched between the end of the exposed portion 51b of the housing 51 opposite the ultraviolet irradiation member 60 and the cap 52, thereby fixing the sensor 502. The outer peripheral surface of the end of the exposed portion 51b of the housing 51 opposite the ultraviolet irradiation member 60 and the inner peripheral surface of the cap 52 in contact with the outer peripheral surface are fixed by screw portions 511 and 521 that screw into each other.

However, in the optical monitor 50 described above, the treated water being monitored has a lower temperature than the outside air, so condensation is likely to occur on the window 501. When condensation occurs on the window 501, the sensor 502 is unable to properly detect ultraviolet rays, and the performance of the optical monitor 50 is reduced.

Therefore, in the first embodiment, a dew point lowering structure 53 that lowers the dew point of the air in the space S below the temperature of the treatment water W is provided in the exposed portion 51b of the housing 51. As a result, in the first embodiment, condensation on the window 501 is suppressed, and as a result, deterioration in the performance of the optical monitor 50 is suppressed.

In the first embodiment, the dew point lowering structure 53 is configured as a cooling block that cools the space S to lower the dew point of the air in the space S to a temperature lower than the temperature of the treatment water W. More specifically, the dew point lowering structure 53 is configured as a liquid cooling block that cools the space S by transferring heat in the space S to a liquid outside the housing 51.

More specifically, the dew point lowering structure 53 includes a heat sink 531, a flow path configuration portion 532, and a heat absorption element 533.

The heat sink 531 is configured as a metal plate. The heat sink 531 is arranged to protrude into the inside of the space S.

The flow path configuration section 532 configures a flow path for the cooling liquid. The flow path is connected to an inlet pipe 534, which is a pipe that receives the cooling liquid along the arrow A501, and an outlet pipe 535, which is a pipe that discharges the cooling liquid along the arrow A502.

The heat absorbing element 533 is sandwiched between the heat sink 531 and the flow path configuration portion 532. The heat absorbing element 533 is, for example, a Peltier element.

With this configuration, the heat in the space S is absorbed by the cooling liquid flowing through the flow path in the flow path configuration part 532 via the heat sink 531 and the heat absorption element 533. As a result, the dew point of the air in the space S is kept below the temperature of the treated water W.

As described above, the ultraviolet irradiation device 100 according to the first embodiment includes a treatment tank 10, an ultraviolet irradiation member 60, and an optical monitor 50. The treatment water W is introduced into the treatment tank 10. The ultraviolet irradiation member 60 is provided inside the treatment tank 10 and irradiates the treatment water W introduced into the treatment tank 10 with ultraviolet light. The optical monitor 50 monitors fluctuations in the water quality of the treatment water W introduced into the treatment tank 10.

Here, in the first embodiment, the optical monitor 50 includes a housing 51, a window 501, a sensor 502, and a dew point lowering structure 53. The housing 51 has an insertion portion 51a that is inserted into the inside of the treatment tank 10, and an exposed portion 51b that is exposed to the outside of the treatment tank 10. A sealable space S is provided inside the housing 51. The window 501 is provided in the insertion portion 51a so as to pass ultraviolet rays from the ultraviolet irradiation member 60 into the sealable space S. The sensor 502 is provided in the exposed portion 52b so as to detect the ultraviolet rays that have passed through the window 501. The dew point lowering structure 53 is provided in the exposed portion 51b so as to lower the dew point of the air in the sealable space S to a temperature below that of the treatment water W.

According to the above configuration, the dew point lowering structure 53 can lower the dew point of the air in the space S to below the temperature of the treatment water W. This prevents condensation from forming on the window 501 and prevents the sensor 502 from being unable to properly detect ultraviolet rays, thereby preventing a decrease in the performance of the optical monitor 50.

In the first embodiment, the dew point lowering structure 53 is configured as a cooling block that cools the sealable space S to lower the dew point of the air in the sealable space S below the temperature of the water to be treated W, more specifically, as a liquid-cooled block that cools the space S by transferring heat in the space S to a liquid (cooling liquid) outside the housing 51. With this configuration, it is easy to lower the dew point of the air in the space S below the temperature of the water to be treated W.

Second Embodiment
In the above-described first embodiment, a configuration is exemplified in which the space S is cooled by a dew point lowering structure 53 configured as a liquid cooling block in order to suppress condensation on the window 501. However, the method for cooling the space S is not limited to liquid cooling. For example, as a second embodiment, a configuration is conceivable in which the space S is cooled by a dew point lowering structure 253 configured as an air cooling block, as shown in the following Fig. 6.

Figure 6 is a schematic cross-sectional view of an optical monitor 250 according to the second embodiment. In the following, the description of the configuration common to the second and first embodiments will be omitted as appropriate.

As shown in FIG. 6, the dew point lowering structure 253 according to the second embodiment is common to the first embodiment in that it is configured as a cooling block that cools the space S. However, the dew point lowering structure 253 according to the second embodiment is not configured as a liquid-cooled block as in the first embodiment, but as an air-cooled block that cools the space S by transferring heat in the space S to the air outside the housing 51.

More specifically, the dew point lowering structure 253 includes a fan 601 that creates an air flow and a heat sink 610 that is exposed to the outside of the housing 51.

The heat sink 610 has a metal plate 611 and fins 612 that are integrally provided on the surface of the plate 611. The heat sink 610 is disposed on the opposite side of the heat sink 531 with respect to the heat absorption element 533. In other words, the heat absorption element 533 is sandwiched between the heat sink 531 and the plate 611.

With the above configuration, the heat in the space S moves to the heat sink 531, the heat absorption element 533, and the heat sink 610, and the heat in the heat sink 610 is discharged outside the housing 51 along the air flow created by the fan 601.

As described above, in the second embodiment, the dew point lowering structure 253 is configured as a liquid-cooled block that cools the sealable space S by transferring heat within the space S to the air outside the housing 51. With this configuration, it is possible to easily lower the dew point of the air within the space S to below the temperature of the treated water W, as in the first embodiment described above.

Third Embodiment
In the above-described first and second embodiments, a configuration is exemplified in which the space S is cooled to lower the dew point of the air in the space S to a temperature lower than or equal to the temperature of the treatment water W. However, it is possible to lower the dew point of the air in the space S by a method other than cooling the space S. For example, as a third embodiment, a configuration shown in the following Fig. 7 can be considered in which the dew point in the space S is lowered by continuously flowing dry air into the space S.

Figure 7 is a schematic cross-sectional view of an optical monitor 350 according to the third embodiment. In the following, the description of the configuration common to the third embodiment and the first embodiment (or the second embodiment) will be omitted as appropriate.

As shown in FIG. 7, in the third embodiment, an intake port 801 and an exhaust port 802 provided in a housing 351 having an insertion portion 351a and an exposed portion 351b correspond to a dew point lowering structure 800.

The air intake 801 takes in dry air into the space S from the direction of the arrow A801. For example, dehumidified compressed air is used as the dry air. The air exhaust 802 exhausts air from the space S in the direction of the arrow A802. This ensures that the space S is always filled with dry air, so that the dew point of the air in the space S is kept below the temperature of the treated water W.

As described above, in the third embodiment, the dew point lowering structure 800 includes an intake port 801 that receives dry air into the sealable space S, and an exhaust port 802 that exhausts air from the sealable space S. With this configuration, it is possible to easily lower the dew point of the air in the space S to below the temperature of the treatment water W, as in the first and second embodiments described above.

<Modification>
The configurations of the first to third embodiments described above can be combined in any manner. That is, the technology disclosed herein includes any of the following: a combination of liquid cooling and air cooling, a combination of liquid cooling and dry air, a combination of air cooling and dry air, and a combination of liquid cooling, air cooling and dry air.

In addition, the heat sink 352 and heat absorption element 533 in the first and second embodiments described above are not essential components. In other words, if liquid cooling or air cooling is used, it is possible to lower the dew point of the air in the space S within the housing 51 even if the heat sink 352 and heat absorption element 533 are not provided.

As another dew point lowering structure different from the first to third embodiments described above, a structure in which a sealable space provided within the housing is evacuated to maintain the space essentially at a vacuum is also conceivable. This structure can also lower the dew point of the air within the sealable space.

In addition, the technology of the present disclosure can be used not only in an optical monitor that monitors the amount of ultraviolet light from an ultraviolet light irradiation member, but also in a general optical monitor that monitors a monitoring target using images, etc. In other words, the technology of the present disclosure also assumes the following configuration.
"A housing having a sealable space inside,
a window provided in the housing to allow light from a monitored object to pass into the sealable space;
a sensor provided in the housing to detect the light passing through the window;
a dew point lowering structure provided in the housing to lower a dew point of air in the sealable space to a temperature lower than a temperature of the object to be monitored;
"An optical monitor with

(Additional Note)
(1)
a treatment tank into which treated water is introduced;
an ultraviolet ray irradiation member provided inside the treatment tank and configured to irradiate the treatment water introduced into the treatment tank with ultraviolet rays;
an optical monitor for monitoring fluctuations in the water quality of the treated water introduced into the treatment tank;
Equipped with
The optical monitor includes:
a housing having an insertion portion inserted into the inside of the treatment tank and an exposure portion exposed to the outside of the treatment tank, the housing having a sealable space therein;
a window provided in the insertion portion so as to pass the ultraviolet light from the ultraviolet light irradiation member into the sealable space;
a sensor provided on the exposed portion to detect the ultraviolet light passing through the window;
a dew point lowering structure provided in the exposed portion so as to lower the dew point of the air in the sealable space to a temperature lower than the temperature of the water to be treated;
An ultraviolet irradiation device comprising:
(2)
The dew point lowering structure includes a cooling block that cools the sealable space to lower the dew point of the air in the sealable space to a temperature lower than the temperature of the treatment water.
An ultraviolet irradiation device as described in (1).
(3)
the cooling block includes a liquid cooling block that cools the sealable space by transferring heat in the sealable space to a liquid outside the housing;
An ultraviolet irradiation device as described in (2).
(4)
The cooling block includes an air-cooling block that cools the sealable space by transferring heat in the sealable space to air outside the housing.
An ultraviolet irradiation device as described in (2).
(5)
The cooling block includes a heat sink having a plate and fins provided on a surface of the plate.
An ultraviolet irradiation device as described in (2).
(6)
The cooling block includes a heat absorbing element that absorbs heat in the sealable space and releases the heat to the outside of the housing.
An ultraviolet irradiation device as described in (2).
(7)
The dew point lowering structure includes an intake port for receiving dry air into the sealable space, and an exhaust port for discharging air from the sealable space.
An ultraviolet irradiation device as described in (1).
(8)
a treatment tank into which treated water is introduced;
a plurality of ultraviolet lamps disposed inside the treatment tank and configured to irradiate ultraviolet light onto the treatment water introduced into the treatment tank;
a plurality of optical monitors, each of which is partially installed within the treatment tank, for detecting ultraviolet light emitted by one of the plurality of ultraviolet lamps;
Equipped with
Each of the plurality of optical monitors comprises:
a window provided on a side facing the one ultraviolet lamp, for passing ultraviolet light from the one ultraviolet lamp into an internal space;
a sensor for detecting the ultraviolet light passing through the window;
a dew point lowering structure for lowering the dew point of the air in the internal space to a temperature lower than the temperature of the water to be treated;
including,
Ultraviolet irradiation device.

Although the above describes the embodiments and modifications of the present invention, the above-mentioned embodiments and modifications are presented as examples and are not intended to limit the scope of the invention. The above-mentioned novel embodiments and modifications can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. The above-mentioned embodiments and modifications are included within the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

10 Processing tank 50, 250, 350 Optical monitor 51 Housing 51a Insertion part 52b Exposed part 53 Dew point lowering structure (cooling block, liquid cooling block)
253 Dew point lowering structure (cooling block, air-cooling block)
533 Heat absorbing element 60 Ultraviolet ray irradiating member 501 Window 502 Sensor 610 Heat sink 611 Plate 612 Fin 800 Dew point lowering structure 801 Intake port 802 Exhaust port S Space

Claims (6)

A housing having an internal space and a window through which light passing through a monitoring target passes into the space;
a sensor for detecting light transmitted through the window;
a dew point lowering unit provided in the housing and configured to cool the space to lower a dew point of gas in the space to a temperature equal to or lower than the temperature of the object to be monitored;
An optical monitor with The optical monitor of claim 1, wherein the dew point lowering unit cools the gas in the space by transferring heat in the space to a liquid outside the housing. The optical monitor of claim 1, wherein the dew point lowering unit cools the gas in the space by transferring heat in the space to the gas outside the housing. The optical monitor of claim 1, wherein the dew point lowering section includes a heat sink having a plate and fins provided on a surface of the plate. The optical monitor of claim 1, wherein the dew point lowering section includes a heat absorbing element that absorbs heat in the space and releases it outside the housing. A housing having an internal space and a window through which light passing through a monitoring target passes into the space;
a sensor for detecting light transmitted through the window;
a dew point lowering unit provided in the housing, the dew point lowering unit having an intake port for receiving dry gas into the space and an exhaust port for discharging gas from the space, in order to lower the dew point of the gas in the space to a temperature below the temperature of the monitored object;
An optical sensor comprising:

Images