JP7411770B2 - water treatment equipment - Google Patents

Description

The present invention relates to a water treatment device for reusing water to be treated, such as pure water used in semiconductor manufacturing processes or liquid crystal manufacturing processes, or nutrient solutions used for agricultural cultivation. .

For example, in the manufacturing process of semiconductor elements and liquid crystal glass, large amounts of pure water are used to clean semiconductor wafer substrates, liquid crystal glass substrates, glass substrates, etc.In the agricultural field, on the other hand, crops are grown using hydroponic cultivation. This requires a large amount of nutrient solution. Regarding the use of these large amounts of water, it is desired to collect and reuse the purified water and nutrient solution after use from the viewpoint of reducing the burden on the environment and effectively utilizing water resources.

When treating pure water, nutrient solution, etc. so that it can be reused, a water treatment device is generally installed in a part of the flow path that circulates the water to be treated. Ultraviolet lamps (ultraviolet light sources) are often installed for purification. When performing sterilization and purification using an ultraviolet lamp, an ultraviolet sensor for measuring ultraviolet rays may be provided in order to measure the ultraviolet irradiance necessary for sterilizing and purifying the water to be treated.

For example, in the ultraviolet irradiation device of Patent Document 1, an ultraviolet monitoring window is provided in a reaction tank through which water to be treated flows, and an ultraviolet monitor, which is an ultraviolet sensor, is installed in this ultraviolet monitoring window. The ultraviolet irradiance transmitted through the water to be treated is measured by an ultraviolet monitor, and the ultraviolet transmittance of the water to be treated is calculated from this ultraviolet illuminance and the ultraviolet illuminance irradiated from the irradiation part, and the irradiation is performed based on this ultraviolet transmittance. Deterioration of parts can be detected.

On the other hand, in the ultraviolet water treatment system of Patent Document 2, the ultraviolet water treatment device is provided with an ultraviolet illuminance meter for measuring ultraviolet rays, and the illuminance is measured by this illuminance meter. In this system, the measured illuminance is compared with a preset setting value, and depending on the condition, it is possible to predict a decrease in the illuminance of the ultraviolet lamp or a lamp burnout.

A water treatment device using an ultraviolet lamp described above has been disclosed in which an ozone supply device is added in order to further enhance the sterilization and purification ability (see, for example, Patent Document 3). In this water treatment equipment, an ozone supply device is placed on the primary side of the ultraviolet irradiation device, and the water to be treated that has been supplied with ozone passes through an ultraviolet lamp in a reaction vessel, where it is sterilized and purified by the ultraviolet light from the ultraviolet lamp. . In addition, a photocatalyst is provided in the reaction vessel, and this photocatalyst also sterilizes the water to be treated and decomposes organic matter.

In order to sterilize and purify a large amount of water to be treated and make it reusable using these water treatment devices, a large number of water treatment devices are required, and the number of ultraviolet lamps used will also increase accordingly. . In this case, in order to maintain a constant sterilization and purification function using ultraviolet rays, it is necessary that each ultraviolet lamp during operation is reliably lit and the ultraviolet irradiance reaches a predetermined level or higher. Therefore, in recent years, there has been a demand for water treatment equipment that can intensively monitor the on/off status of ultraviolet lamps and the decrease in ultraviolet illuminance.

Patent No. 5649703 JP2009-82774A Patent No. 4229363

In order to check the on/off state of the UV lamps, for example, it is possible to detect the on/off control signal for each UV lamp, but in this case, even though the control signal is in the on state, Depending on the lifespan of the ultraviolet lamp, it may actually be turned off and cannot be detected accurately.
On the other hand, it is possible to visually check the on/off status of ultraviolet lamps on-site, but in semiconductor manufacturing facilities and agricultural sites, water flow channels can reach several tens of meters, so this is not possible. It takes time and effort to visually check the lighting status of each of the many ultraviolet lamps installed along the road.

On the other hand, Patent Document 1 and Patent Document 2 attempt to centrally monitor the status of the UV lamps all at once, but in these cases the UV lamps and the UV sensors are in close proximity, so Components including the ultraviolet sensor are likely to deteriorate due to ultraviolet rays. Therefore, it is necessary to take measures such as thickening the coating of the signal transmission wiring of the ultraviolet sensor. Furthermore, in order to prevent the attenuation of ultraviolet light, it is necessary to narrow the distance between the ultraviolet lamp and the flow path, but this makes it difficult to arrange the ultraviolet sensor within the flow path.
For these reasons, it is difficult to use many UV irradiation devices of this type to construct long water treatment channels in the semiconductor manufacturing and agricultural fields, and it is difficult to accurately measure the on/off status of UV lamps and the status of UV irradiance. becomes difficult to do.

Furthermore, when an ozone supply device is provided in the ultraviolet irradiation device as in Patent Document 3, in order to effectively sterilize and purify the water to be treated to which ozone has been supplied using an ultraviolet lamp, it is necessary to use ultraviolet rays with a wavelength of around 254 nm. It is necessary to irradiate it to generate a radical reaction. In this case, since the illuminance of ultraviolet light with a wavelength of around 254 nm tends to be extremely attenuated as the distance from the light source of the ultraviolet lamp increases, the distance between the ultraviolet lamp and the flow path must be further narrowed. It becomes more difficult to place a UV sensor inside.

For the above reasons, it may become impossible to accurately measure the decrease in the amount of ultraviolet irradiation due to deterioration of the ultraviolet lamp, etc., and as a result, there is a possibility that the water to be treated cannot be sufficiently irradiated with ultraviolet rays.
Therefore, when this ultraviolet irradiation device is used, for example, in the semiconductor manufacturing process, the combined sterilization and purification using the ozone supply device and photocatalyst cannot be performed effectively due to the insufficient amount of ultraviolet rays, and particularly high quality is required. It may have an adverse effect on semiconductor products.
On the other hand, when used for agricultural cultivation, the nutrient solution contains impurities, which causes the problem that the glass through which ultraviolet rays can be easily smeared due to the adhesion of these impurities. In this case, the amount of ultraviolet irradiation decreases more drastically, and the sterilization and purification effect of ultraviolet rays becomes insufficient.

If the UV sensor is installed inside the reaction tank, it will be difficult to remove it in the event of a breakdown, etc., and especially if the water treatment equipment is downsized, it will become even more difficult to install and remove, making maintenance difficult. have.

The present invention was developed to solve the above-mentioned problems, and its purpose is to centralize the deterioration state of ultraviolet lamps even when they are used in large numbers in long channels due to large amounts of water treatment. The purpose of the present invention is to provide a water treatment device capable of efficiently treating water with a high sterilization and purification function while minimizing the harmful effects of ultraviolet rays on components.

In order to achieve the above object, the invention according to claim 1 provides an ultraviolet lamp that irradiates ultraviolet rays containing germicidal radiation to water to be treated, a reaction tank having a built-in ultraviolet lamp and through which water to be treated flows, and a reaction tank. On the outside, there is a transmitting part that can transmit ultraviolet rays in a wavelength range longer than the germicidal radiation that has passed through the water to be treated, and an ultraviolet sensor that measures the ultraviolet irradiance of the UV radiation in a wavelength range longer than the germicidal radiation that has passed through the transparent part. control system that detects the deterioration state of the UV lamp by determining that the UV lamp has reached the end of its lifespan when the UV illuminance in the wavelength range longer than the germicidal line falls below a predetermined value based on the UV illuminance measurement value of the UV sensor. It is a water treatment equipment equipped with a section.

The invention according to claim 2 is a water treatment device in which the ultraviolet light that reaches the ultraviolet sensor has a wavelength of 300 to 400 nm.
The invention according to claim 3 is a water treatment apparatus having an ozone supply section that supplies ozone to water to be treated.

According to the invention according to claim 1, on the outside of the reaction tank, there is a transmitting part that can transmit ultraviolet rays in a wavelength range longer than the germicidal radiation among the UV light that has passed through the water to be treated, and a transmitting part that is longer than the germicidal radiation that has passed through the transmitting part. An ultraviolet sensor is installed to measure the ultraviolet irradiance of the ultraviolet rays in the wavelength band , and based on the measured value of the ultraviolet rays of the ultraviolet rays in the wavelength band, the life of the ultraviolet lamp is determined when the ultraviolet irradiance in the wavelength band longer than the germicidal line decreases to a predetermined value or less. In addition, since a control unit for detecting the deterioration state of the ultraviolet lamp is provided, the state of the ultraviolet lamp can be checked without providing an ultraviolet sensor inside the reaction tank. For this reason, it is possible to create a configuration that prevents ultraviolet rays with wavelengths that have an adverse effect on components from leaking to the outside, and by measuring ultraviolet rays with less harmful wavelengths outside the reaction tank, it can prevent damage to components such as ultraviolet sensors. , it is possible to secure the ultraviolet light intensity necessary for sterilization and purification. Even when UV lamps are used in large numbers in long channels, such as in semiconductor manufacturing processes that require large amounts of water treatment, it is possible to intensively monitor the deterioration status of ultraviolet lamps, which increases accordingly . If a problem occurs with the ultraviolet sensor, the ultraviolet sensor can be removed from the outside of the reaction tank for easy maintenance.

According to the invention according to claim 2, the adverse effect of visible light on the ultraviolet sensor can be suppressed.
According to the invention according to claim 3, most of the bacteria in the water to be treated are sterilized due to the sterilizing effect of ozone supplied by the ozone supply unit, and most of the organic matter including the dead bodies of sterilized bacteria can be decomposed. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows one embodiment of the water treatment apparatus of this invention. FIG. 2 is a block diagram of the water treatment device of FIG. 1. FIG. FIG. 2 is a schematic vertical cross-sectional view showing the reaction tank in FIG. 1. FIG. (a) is a partially enlarged schematic sectional view of a reaction tank. (b) is a graph showing the relationship between the distance of ultraviolet rays and the illuminance. It is a graph showing a lifespan curve of an ultraviolet lamp depending on the water to be treated. It is a graph showing the illuminance attenuation characteristics of pure water. It is a graph showing the illuminance attenuation characteristic of a nutrient solution.

EMBODIMENT OF THE INVENTION Below, the deterioration detection apparatus of the water treatment apparatus and the ultraviolet lamp for water treatment apparatuses in this invention is demonstrated in detail based on drawing. FIG. 1 shows a schematic diagram of an embodiment of a water treatment device, and FIG. 2 shows a block diagram of the water treatment device.

In the figure, a water treatment device (hereinafter referred to as the device main body 1) is incorporated as a part of a circulation channel that supplies pure water or nutrient solution to, for example, semiconductor manufacturing equipment or agricultural equipment. It is installed to sterilize and purify water or nutrient solution as water to be treated, and then return it to the flow path.

The device main body 1 includes a reaction tank 2, an ultraviolet sensor 3, an ozone supply section 4 that supplies ozone, a storage/control device 5, and a photocatalyst 7. Among these, the ultraviolet sensor 3 and the storage/control device 5 perform water treatment. A deterioration detection device for an ultraviolet lamp for equipment (hereinafter referred to as the detection device main body 6) is constructed.

In this apparatus main body 1, a reaction tank 2 has a built-in ultraviolet lamp 10 serving as an ultraviolet irradiation unit that irradiates the water to be treated with ultraviolet rays, and a photocatalyst 7 is provided inside the reaction tank 2. An inlet side connection port 11 is provided on the primary side of the reaction tank 2, and an outlet side connection port 12 is provided on the secondary side, and an ozone supply section 4 is connected to the inlet side connection port 11. The inflow channel 15 is connected to the side, and the outflow channel 16 is connected to the outlet side connection port 12 of the reaction tank 2, so that it is disposed in a part of the circulation channel. With this configuration, the device main body 1 has an ozone supply function by the ozone supply unit 4, an ultraviolet irradiation function by the ultraviolet lamp 10, and a photocatalytic function by the photocatalyst 7, and has a trinity function that organically combines these functions. The water to be treated is effectively sterilized and purified.

In FIG. 3, an ultraviolet lamp 10 is placed in the center of a reaction tank 2, an inner glass tube 20 for protection is provided on the outer circumference of the ultraviolet lamp 10, and an outer glass tube 21 is provided on the outer circumference of the inner glass tube 20. is placed. A substantially cylindrical flow path 22 for water to be treated is formed between the inner glass tube 20 and the outer glass tube 21, and a flow path 22 is formed in the length direction along the inner and outer circumferential sides of the flow path 22. A photocatalyst 7 is arranged. In this way, by arranging the ultraviolet lamp 10 in the center of the reaction tank 2, the entire reaction tank 2 can be made compact, and ultraviolet rays can be irradiated radially from the ultraviolet lamp 10 toward the water to be treated. This effectively sterilizes and purifies the water to be treated.

Here, ultraviolet rays are invisible electromagnetic waves that are shorter than the wavelength of visible light and longer than the wavelength of X-rays, and generally represent light with a wavelength of about 100 to 400 nm. Among these, ultraviolet rays with a wavelength of 250 to 270 nm are said to have particularly strong bactericidal properties, and ultraviolet rays with a wavelength of around 254 nm have even higher bactericidal properties and are called germicidal radiation (sterilizing radiation).

The ultraviolet lamp 10 in this embodiment is one that emits mainly ultraviolet light with a wavelength around 254 nm. As a result, when the ozone-containing water to be treated is irradiated with ultraviolet rays with a wavelength of approximately 254 nm by the ozone supply section 4 described later, ozone is decomposed into active oxygen and oxygen due to accelerated oxidation, and the active oxygen Various reactive oxygen species are created. The hydroxyl radicals generated at this time have stronger oxidizing power than ozone, and can more effectively kill microorganisms that are resistant to ozone.

Furthermore, the ultraviolet lamp 10 also contains light other than ultraviolet light with a wavelength of about 254 nm, specifically, ultraviolet light with a wavelength of about 400 nm or more. Among these, it is difficult for the ultraviolet sensor 3 to detect ultraviolet light with a wavelength around 254 nm, but the ultraviolet sensor 3 can detect light with a wavelength around around 400 nm and more.
The approximately 400 nm vicinity herein means 350 nm±50 nm. However, although this value varies depending on the spectral distribution of the ultraviolet lamp 10, ultraviolet rays with a wavelength longer than at least 254 nm are preferable.

The ultraviolet lamp 10 may be a fluorescent lamp that emits light with a wavelength of approximately 400 nm, or a lamp in which a plurality of LEDs are arranged. Further, the ultraviolet lamp 10 may have various shapes such as a linear shape, a cylindrical shape, a spiral shape, and a wave shape depending on the shape and internal structure of the reaction tank 2.

In FIGS. 4(a) and 4(b), the inner glass tube 20 is made of, for example, quartz glass for reasons such as ultraviolet transmittance, heat resistance, and strength, and is at least a distance L from the ultraviolet lamp 10 of 4 to 5 mm. They are formed with inner diameters that are separated by a certain degree. When the inner glass tube 20 is made of quartz glass, it becomes possible to transmit ultraviolet light having wavelengths from about 254 nm to about 400 nm. The reason why the inner glass tube 20 is formed with the above-mentioned dimensions is that if the distance from the ultraviolet lamp 10 is less than 4 mm, the elongated end may be distorted due to processing precision or the like. This is because the distortion between them will increase, and there is a possibility that they will come into contact with the ultraviolet lamp 10 and cannot be properly assembled. On the other hand, if the distance is greater than 5 mm, the water to be treated cannot be sufficiently irradiated with ultraviolet rays having a wavelength of approximately 254 nm, the attenuation rate of which increases as the distance increases.

The outer glass tube (transmission part) 21 on the outer surface side of the reaction tank 2 is made of glass that has the property of being able to transmit ultraviolet rays having a wavelength longer than about 254 nm. For this reason, the outer glass tube 21 is made of, for example, borosilicate glass, and this borosilicate glass only transmits ultraviolet light with a wavelength around 400 nm, and transmits germicidal radiation with a wavelength around 254 nm. I can't.

Since the inner glass tube 20 and the outer glass tube 21 are each made of the above materials, when the ultraviolet rays are irradiated from the ultraviolet lamp 10, as shown in FIG. 4(b), light with a wavelength of about 254 nm is internalized. When this light passes through the glass tube 20 and reaches the water to be treated, the illumination intensity decreases significantly and becomes zero at a position where the length X is about several mm from the outer peripheral surface of the inner glass tube 20. In this case, since the photocatalyst 7 on the inner peripheral side is within this length X, ultraviolet rays with a wavelength of approximately 254 nm act on the photocatalyst. On the other hand, light having a wavelength of around 370 to 400 nm, which is a long wavelength component in the ultraviolet band, passes through the inner glass tube 20, the flow path 22, and the outer glass tube 21 while the illuminance gradually decreases.

As shown in FIG. 4(a), the ultraviolet sensor 3 is placed close to the outside of the outer glass tube (transmission part) 21, and the ultraviolet sensor 3 detects when the water to be treated passes through the reaction tank 2. The illuminance of the ultraviolet rays from the ultraviolet lamp 10 that passes through the inner glass tube 20, flow path 22, and outer glass tube (transmission section) 21 can be measured. The ultraviolet sensor 3 is a sensor capable of detecting ultraviolet illuminance with a wavelength longer than about 254 nm, and in FIG. The illuminance of the ultraviolet rays is measured, and the deterioration of the ultraviolet lamp 10 can be diagnosed based on the magnitude of the illuminance via the storage/control device 5, which will be described later.

A filter 25 is provided on the light receiving side of the ultraviolet sensor 3 to cut off visible light having a wavelength longer than approximately 400 nm. This filter 25 cuts visible light to suppress its adverse effect on the ultraviolet sensor 3, and is provided so that the ultraviolet sensor 3 can measure only the illuminance of wavelengths around approximately 400 nm. The filter 25 does not need to have the property of cutting ultraviolet rays of less than about 400 nm. This is because, as described above, ultraviolet rays with a wavelength of less than approximately 400 nm attenuate to 0% illuminance before reaching the ultraviolet sensor 3.

The photocatalyst 7 is provided in a structure that is difficult to peel off by oxidizing the surface of a metal titanium base material to generate titanium oxide, such as a net, a titanium wire, an aggregate of fibrous titanium materials, or a porous titanium material. It is provided by coating the surface side of a material such as titanium or titanium alloy with titanium dioxide. When the metal titanium base material is formed into a thin shape, the reaction area becomes larger and the reactivity with ozone becomes better. The metal titanium base material may be a material other than titanium or titanium alloy, for example, glass or silica gel may be used as a material and titanium oxide may be formed on the surface of this material, but in consideration of durability. , those formed on a titanium base material are desirable. The photocatalyst 7 is easily activated by ultraviolet light having a wavelength of about 250 to 350 nm.

In the apparatus main body of FIG. 1, the ozone supply section 4 is connected to the primary side of the reaction tank 2 as described above, and is provided so as to be able to supply ozone to the water to be treated flowing toward the reaction tank 2 side. The ozone supply section 4 includes an ozonizer 30, an ejector 31, an ozone supply pipe 32, and a check valve 33.

The ozonizer 30 has a structure having a discharge gap between an earth electrode 41 and a dielectric 42 to which a high voltage electrode is attached, and applies a high voltage between the earth electrode 41 and the dielectric 42 to cause a discharge. Ozone is generated using the air flowing through the discharge gap as a raw material. Air is continuously supplied to the discharge gap of the ozonizer 30 by a pump (not shown), and the generated ozone (and dissolved oxygen) is provided so as to be supplied to the ejector 31 via an ozone supply pipe 32 connected to the ozonizer 30. It will be done.

The ejector 31 is made of a resin such as fluororesin, or ceramic or metal, and is provided in the inflow channel 15 to inject ozone generated by the ozonizer 30 into the water to be treated flowing through the inflow channel 15. It is possible to mix. A check valve 33 for backflow prevention is provided between the ejector 31 and the ozonizer 30, and the ozone and dissolved oxygen that have passed through the check valve 33 pass through a passage (not shown) inside the ejector 31, thereby increasing the flow rate. The ozone water dissolves into the water to be treated in the form of bubbles while being accelerated, producing a mixed liquid (ozone water) in the form of fine bubbles, which can be supplied to the reaction tank 2 side.

In FIG. 2, the storage/control device 5 is electrically connected to the reaction tank 2, the ultraviolet sensor 3, and the ozone supply section 4, and selects a specific wavelength from the ultraviolet illuminance at a wavelength near approximately 400 nm measured by the ultraviolet sensor 3. It has the function of converting into ultraviolet irradiance. The device main body 1 has a function of detecting whether the ultraviolet lamp 10 is turned off or deteriorated from the ultraviolet illuminance of this specific wavelength.

In this case, in the graph of FIG. 5 showing the change in illuminance of the ultraviolet lamp 10 at wavelengths around 400 nm over time, the storage/control device 5 can detect that the ultraviolet lamp 10 is in the off state when the ultraviolet illuminance is zero. It has a function of detecting that it is at the end of its life when the ultraviolet illuminance falls below a preset processing value.

In this embodiment, the ultraviolet irradiance at a specific wavelength is the above-mentioned ultraviolet irradiance at a wavelength of about 254 nm that causes a radical reaction in the water to be treated, and the above-mentioned ultraviolet irradiance at a wavelength of about 400 nm, which has a low sterilization and purification effect on the water to be treated. By measuring the ultraviolet irradiance of 254 nm, it is possible to recognize the ultraviolet irradiance with a wavelength of about 254 nm, which has the best sterilization and purification properties.

The storage/control device 5 includes a storage section 50 for storing various data, and a control section 51 capable of detecting the operating state of the device main body 1.
The storage unit 50 stores illuminance attenuation characteristic data 55, measurement results of ultraviolet illuminance by the ultraviolet sensor 3, and the like. The illuminance attenuation characteristic data 55 is stored in the storage unit 50 for each type of water to be treated for conversion from the ultraviolet illuminance of the ultraviolet lamp 10 measured by the ultraviolet sensor 3 to the ultraviolet illuminance of a specific wavelength.

The illuminance attenuation characteristic data 55 in this example is a graph corresponding to two types of water to be treated: pure water used in semiconductor manufacturing applications shown in FIG. 6, and (culture) solution used in agricultural applications shown in FIG. Equipped with In each graph, the solid curve shows the characteristics of ultraviolet light (light with a wavelength of 100 to 400 nm) emitted when the ultraviolet lamp 10 is irradiated, and the units are shown on the two vertical axes in the graph. The broken line curve shows the characteristics of visible light (light with a wavelength of approximately 400 to approximately 780 nm) emitted when irradiated with an ultraviolet lamp 10 in order to compare with the characteristics of ultraviolet light, and the vertical axis on the left side of the graph The unit is shown in .

Based on these illuminance attenuation characteristic data 55, the ultraviolet illuminance at a wavelength around approximately 400 nm measured by the ultraviolet sensor 3 (400 nm illuminance: unit mW/cm ² ) is changed from the ultraviolet illuminance at a wavelength around approximately 254 nm (254 nm illuminance). : unit: mW/cm ² ), the storage/control device 5 performs the conversion as follows.
It should be noted that the ultraviolet lamp 10 is generally considered to have reached the end of its lifespan when the ultraviolet illuminance at a wavelength around 254 nm becomes 70% or less of the illuminance when new. However, this lifespan is just a general story, and this lifespan varies depending on the manufacturer of the ultraviolet lamp.

In the case of pure water in Figure 6, the graph shows that, for example, when the 400 nm illuminance is the initial value B of 0.02 mW/cm ² , the 254 nm illuminance is approximately 8 mW/cm 2 , and when the 400 nm illuminance is 0.018 mW/cm ² , the 254 nm illuminance is approximately 8 mW/cm ² . When the illuminance is approximately 5.75 mW/cm ² and the 400 nm illuminance is 0.017 mW/cm ² , the 254 nm illuminance is converted to approximately 4.5 mW/cm ² .

On the other hand, in the case of visible light in the graph, for example, when the illuminance of this visible light (visible light illuminance: unit LX) is the initial value B of 280LX, the 254 nm illuminance is approximately 8 mW/ ^cm2 , and this visible light illuminance is , there is almost no change even when the 254 nm illuminance is reduced to approximately 4.5 W/cm ² . That is, even if visible light illuminance were measured, it would not change until the measured value became smaller than about 4.5 W/cm ² , so it would not be possible to confirm a decrease in 254 nm illuminance until that stage.

The same is true for the nutrient solution in FIG. 7, and from the graph, for example, when the 400 nm illuminance is the initial value B of 0.01 mW/cm ² , the 254 nm illuminance is approximately 8 mW/cm ² , and the 400 nm illuminance is approximately 0.0095 mW/cm 2 ² , the 254 nm illuminance is converted to approximately 5.6 mW/cm ² .

In the case of visible light in FIG. 7, for example, when the visible light illuminance is 270LX, which is the initial value B, the 254 nm illuminance is approximately 8 mW/ ^cm2 , and this visible light illuminance has decreased to approximately 5.6 W/ ^cm2 . Sometimes it tends to go up. As a result, even if visible light illuminance is measured, a decrease in 254 nm illuminance cannot be confirmed.
As described above, by measuring 400 nm illuminance and converting the measurement result to 254 nm illuminance, it is possible to precisely measure the decrease in illuminance of the ultraviolet lamp 10.

In FIGS. 6 and 7, the dashed-dotted line represents the lifespan standard of 254 nm illuminance. As for the lifespan of the ultraviolet lamp 10, it is recommended to replace it when the illuminance decreases from the initial value B to, for example, 70%. This is the case when it becomes 5.6mW/ ^cm2 . More preferably, the life span is determined when the 254 nm illuminance decreases from the initial value B illuminance to 90% illuminance.
Note that in the case of pure water in FIG. 6, the illuminance of visible light does not change even when the illuminance decreases to 55%, so it is difficult to judge the lifespan of the ultraviolet lamp 10 by measurement with a visible light sensor.
In other words, 70% of the initial value of the UV illuminance at 254 nm is 90% of the initial value of the UV illuminance near 400 nm, so by measuring the UV illuminance around 400 nm with this UV sensor 3, the life of the UV lamp 3 can be determined. can be diagnosed.

On the other hand, the control unit 51 in the storage/control device 5 converts the ultraviolet illuminance measured by the ultraviolet sensor 3 into the ultraviolet illuminance of a specific wavelength, that is, the ultraviolet illuminance of a wavelength of approximately 254 nm, via the illuminance attenuation characteristic data 55. However, it has a function of detecting whether the ultraviolet lamp 10 is turned off or deteriorated from this converted value.

Based on the results of the UV illuminance at a wavelength of about 254 nm, the control unit 51 determines when the UV lamp 10 needs to be replaced, when the reaction tank 2 needs to be cleaned, and whether the UV lamp 10 is turned off due to wear or failure. It has a function of emitting a predetermined signal to notify the user, and by checking this signal, it is possible to take a predetermined action depending on the status of the ultraviolet lamp 10.

In this embodiment, the ultraviolet irradiance at a specific wavelength, which is calculated from the ultraviolet irradiance when the water to be treated passes through the reaction tank 2, is the ultraviolet irradiance at a wavelength of approximately 254 nm. The ultraviolet irradiance can also be set to different wavelengths depending on the type of fluid to be treated.

Although the ultraviolet sensor 3 measures the ultraviolet irradiance at a wavelength around 400 nm from the ultraviolet lamp 10, it is also possible to measure the ultraviolet irradiance at a different wavelength, and depending on the type of the ultraviolet lamp 10, etc. When the wavelengths are different, an appropriate ultraviolet sensor 3 can be used depending on the ultraviolet lamp 10.
A lamp such as a low-pressure or high-pressure mercury lamp may be used instead of the ultraviolet lamp 10 as long as it can emit ultraviolet rays.

Moreover, the water to be treated may be other than pure water or a nutrient solution, and for example, a culture solution for aquaculture may be used as the water to be treated. In this case, by storing the illuminance attenuation characteristic data 55 corresponding to the water to be treated in the storage unit 50, it becomes possible to detect whether the ultraviolet lamp 10 is turned off or deteriorated depending on the water to be treated.

Next, an example of the operation of the water treatment apparatus described above and a control example for detecting whether the ultraviolet lamp is turned off or deteriorated during this operation will be described.
In FIG. 1, when water to be treated is sent to the apparatus main body 1 side by a pump (not shown), this water to be treated flows into the ozone supply section 4 through the inflow channel 15.

At this time, the ozone (and dissolved oxygen) generated by the ozonizer 30 is mixed with the water to be treated via the ejector 31 provided in the inflow channel 15, and the ozone in the form of microbubbles is mixed into the water to be treated in the form of bubbles. A dissolved mixed liquid (ozone water) is generated. In this case, if the concentration of ozone supplied is low, bacteria cannot be sterilized and organic matter cannot be decomposed, and if the ozone is high concentration, there is a risk of shortening the lifespan of equipment and parts on the downstream side. Therefore, the total amount of water to be treated, the amount of water to be treated, and the lower and upper limits of ozone concentration for effective ozone treatment are comprehensively determined. The amount of ozone supplied in step 4 is adjusted to 0.05 to 2.0 (g/H).

Most of the bacteria in the water to be treated are sterilized by the sterilizing effect of the supplied ozone, and most of the organic matter including the dead bodies of the sterilized bacteria is decomposed.

Next, when the water to be treated containing ozone flows into the reaction tank 2 from the inlet side connection port 11, it passes through the ultraviolet lamp 10 and the photocatalyst 7 in the flow path 22, and the water to be treated containing ozone is exposed to the ultraviolet lamp. By being irradiated with ultraviolet rays, a radical called .OH (hydroxy radical or OH radical) (a chemical species with unpaired electrons and highly activated) is generated.

Since this OH is highly activated, it can almost sterilize bacteria that remain in the water to be treated without being sterilized when ozone treatment is performed in the ozone supply unit 4, and it can also sterilize bacteria that remain in the water to be treated without being decomposed. Most of the remaining organic matter can be decomposed.

As described above, in the reaction tank 2, the combination of the generation of OH radicals by the ultraviolet lamp 10 and the photocatalyst 7 and the low concentration of ozone, that is, the organic bond, ensures that residual bacteria and organic matter are removed. Purify bacteria.
The water to be treated that has been sterilized and purified in the reaction tank 2 is returned to the circulation channel from the outlet side connection port 12 via the outflow channel 16.

When checking the irradiation state of the ultraviolet lamp 10 while the apparatus body 1 described above is in operation, the ultraviolet light intensity of the ultraviolet lamp 10 at a wavelength of 400 nm is measured with the ultraviolet sensor 3 while the water to be treated is flowing in the reaction tank 2. By converting this measurement result into ultraviolet illuminance with a wavelength around 254 nm via the illuminance attenuation characteristic data 55 of the storage/control device 5, it is possible to detect whether the ultraviolet lamp 10 is turned off or deteriorated from this ultraviolet illuminance. It has become.

Specifically, for example, the state of the ultraviolet lamp 10 is checked by the following procedure. Here, FIG. 5 shows a lifespan curve of the ultraviolet lamp 10 depending on the water to be treated, and represents a curve that serves as a reference for the attenuation of the illuminance of light with a wavelength near 400 nm over time. Data on the life curve of the ultraviolet lamp, which serves as this reference, is also stored in the storage unit 50.

When the operation of the water treatment equipment is started, the storage/control device determines whether the total operating time (hereinafter referred to as total time) has reached the predetermined time A in the graph of FIG. It is judged as 5. This "predetermined time A" is set based on the time from when the new ultraviolet lamp 10 is turned on for the first time until the illuminance becomes stable. The reason for allowing the predetermined time A to elapse is that, as shown by the two-dot chain line in the figure, the illuminance is difficult to stabilize when a new ultraviolet lamp 10 is initially turned on, and as time passes, the illuminance gradually increases and becomes stable. It's for a reason. The predetermined time A is preferably about 900 seconds, for example, and is set as appropriate depending on the type of ultraviolet lamp 10 and individual differences.

When the total time reaches a predetermined time A (for example, 900 seconds), at that stage, the ultraviolet light intensity near 400 nm (400 nm illuminance) transmitted through the outer glass tube 21 is measured by the ultraviolet sensor 3 under the control of the control unit 51, The measurement result is stored in the storage unit 50 as an initial value B of ultraviolet illuminance (hereinafter referred to as initial value B).

From this stage, the water to be treated can be practically sterilized and purified by the main body 1 of the apparatus, so the water to be treated is supplied to the ozone supply section 4, the ultraviolet lamp 10 of the reaction tank 2, the photocatalyst 7 to perform sterilization and purification.

In this water treatment process, the control unit 51 compares the slope of the actually measured 400 nm illuminance at time ΔT, which is a certain period of time in FIG. 5, with the slope of the life curve of reference data. In this case, the slope in the decreasing direction is assumed to be a positive value.

At this time, when the slope of the 400 nm illuminance at time ΔT is larger than the slope of the life curve, the controller 51 subsequently determines whether the illuminance of the ultraviolet lamp 10 is less than 90% of the initial value B.

When the ultraviolet illuminance of the ultraviolet lamp 10 falls below a predetermined value, for example, when it is less than 90% of the initial value B, it is determined that the ultraviolet illuminance is insufficient, and the control unit 51 determines that the ultraviolet lamp 10 is at the end of its life. Detect that. Thereafter, a notification that the ultraviolet lamp 10 needs to be replaced is issued by a lamp (not shown) or a warning sound, and by this notification, the lifespan of the ultraviolet lamp 10 is promptly confirmed from the storage/control device 5 external to the main body of the apparatus. be able to. If the ultraviolet lamp 10 is replaced based on this result, the processing capacity of the apparatus main body 1 can be maintained and stable operation can be continued.

On the other hand, when the illuminance of the ultraviolet lamp 10 is 90% or more of the initial value B, the control unit 51 determines that the lamp has not reached the end of its life, and continues the illuminance detection process.

As shown by the two-dot chain line in FIG. 5, when the slope of the 400 nm illuminance at time ΔT becomes larger than the slope of the life curve, at least (a) the water to be treated inside the reaction tank 2 passes through. This is thought to be due to precipitates or the like adhering to the area where the UV rays are exposed, or (b) the ultraviolet lamp 10 deteriorating earlier than expected for some reason. In this case, a lamp or a warning sound is used to notify that the reaction tank 2 needs to be cleaned.

After cleaning the reaction tank 2, a reset button (not shown) is pressed, and the control unit 51 determines whether or not this reset button has been pressed. If the reset button is not pressed, a notification is issued that the reaction tank 2 needs to be cleaned again. In this way, the reset button is provided to confirm whether or not the reaction tank has been cleaned.

After the reset button is pressed, the control unit 51 determines whether the actually measured value of the 400 nm illuminance is larger than the value D of the ultraviolet illuminance for the elapsed time T of the life curve up to that point. As a result of this determination, when the value of the measured 400 nm illuminance is equal to or higher than the ultraviolet illuminance D of the life curve, the determination of the ultraviolet illuminance is continued. On the other hand, if the value of the 400 nm illuminance is less than the ultraviolet illuminance D, it is assumed that the ultraviolet lamp 10 is deteriorating faster than expected due to the above-mentioned (b) reason, and the abnormality of the ultraviolet lamp 10 is notified to the outside. do.

During the operation of the apparatus main body 1 described above, interrupt control is performed by the control section 51. In this interrupt control, it is determined whether or not the ultraviolet illuminance is zero, and when it is zero, it is detected that the ultraviolet lamp 10 is in the off state, and an alarm is issued by a lamp or a warning sound. On the other hand, if these values are greater than zero, the detection process continues.

On the other hand, the determination as to whether the ultraviolet illuminance of the ultraviolet lamp 10 is zero may be performed by other than interrupt control. In this case, after the procedure of comparing the slope of the 400 nm illuminance at the time ΔT described above with the reference life curve, it is determined whether the ultraviolet illuminance is zero. When this is zero, it is detected that the ultraviolet lamp 10 is in the off state, and a procedure is carried out to issue an alarm with a lamp or an alarm sound.Subsequently, the ultraviolet illuminance of the ultraviolet lamp 10 is set to a predetermined value in the same manner as in the above-mentioned procedure. The procedure for determining whether the level has decreased below or below should be carried out.

Further, the step of comparing the slope of the 400 nm illuminance at a certain time ΔT and the slope of the life curve may be omitted; in this case, the ultraviolet illuminance of the ultraviolet lamp 10 reaches less than 90% of the initial value B. The end of the life of the ultraviolet lamp 10 can be detected based only on this. Therefore, the control procedure can be simplified.

Next, the operation of the above-described embodiments of the water treatment equipment and the deterioration detection device for an ultraviolet lamp for water treatment equipment of the present invention will be explained.
The device main body 1 includes a reaction tank 2 containing an ultraviolet lamp 10, a photocatalyst 7, and an ozone supply section 4. An ultraviolet sensor 3 is disposed outside the reaction tank 2, and the ultraviolet rays measured by the ultraviolet sensor 3 are The storage/control device 5 detects the illuminance of a specific wavelength of the ultraviolet lamp 10 based on the illuminance conversion result, so even if a large amount of water treatment is required and the number of device bodies 1 increases, the ultraviolet sensor Based on the measurement results in step 3, the on/off states and deterioration states of all the ultraviolet lamps 10 can be centrally monitored via the storage/control device 5.

In this case, the ultraviolet sensor 3 is placed close to the outside of the outer glass tube 21, and the ultraviolet sensor 3 detects the ultraviolet illuminance at a wavelength of approximately 400 nm. It can be made of borosilicate glass or the like that blocks ultraviolet rays. As a result, in the flow path 22 inside the outer glass tube 21, while providing an excellent sterilization and purification function to the water to be treated through a radical reaction caused by ultraviolet rays with a wavelength of approximately 254 nm, the ultraviolet rays with a wavelength of approximately 254 nm have a negative effect on components. This prevents ultraviolet rays from leaking to the outside from the outer glass tube 21, prevents the harmful effects of the ultraviolet rays on the ultraviolet sensor 3 and other parts, and prevents deterioration.

In addition, the ultraviolet light intensity with a wavelength of about 400 nm transmitted through the borosilicate glass 21 is measured by the ultraviolet sensor 3, and from the measurement result of the ultraviolet light intensity, the ultraviolet light intensity with a wavelength of about 254 nm is transmitted through the illuminance attenuation characteristic data 55 in the storage unit 50. Since the illuminance can be confirmed in terms of illuminance, it is possible to accurately grasp the ultraviolet illuminance of approximately 254 nm, which is most effective for sterilization and purification of water to be treated. Therefore, even when the device main body 1 is used in a semiconductor manufacturing process that requires a high water treatment system, it is possible to maintain the ultraviolet illuminance of each device main body 1 at a high level and manufacture high-quality products.

The storage/control device 5 stores illuminance attenuation characteristic data 55 for each type of water to be treated, such as pure water used in semiconductor manufacturing applications and nutrient solution used in agricultural applications. When treating water, even the slightest attenuation of ultraviolet light can be measured to check the state of deterioration in detail.

In addition, the detection device main body 6 for detecting deterioration of the ultraviolet lamp 10 can easily attach the ultraviolet sensor 3 and the storage/control device 5 to the water treatment equipment to accurately detect the extinguished state or deterioration state of the ultraviolet lamp 10, and react. There is no adverse effect on the water treatment performance of the tank 2 or the ozone supply section 4.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and the present invention is not limited to the scope of the invention described in the claims of the present invention. It is possible to make various changes.

1 Apparatus main body 2 Reaction tank 3 Ultraviolet sensor 4 Ozone supply section 5 Memory/control device 6 Detection device main body 7 Photocatalyst 10 Ultraviolet lamp 21 Outer glass tube (transmission section)
50 Storage unit 51 Control unit
55 Illuminance attenuation characteristic data

Claims (3)

An ultraviolet lamp that irradiates ultraviolet rays containing germicidal radiation to the water to be treated; a reaction tank that contains the ultraviolet lamp and through which the water to be treated flows ; A transmitting part that can transmit ultraviolet rays in a wavelength band longer than the germicidal radiation, and an ultraviolet sensor that measures the ultraviolet irradiance of the ultraviolet rays in a wavelength band longer than the germicidal radiation transmitted through the transmitting part ,
A control unit that detects a deterioration state of the ultraviolet lamp by determining that the ultraviolet lamp has reached the end of its life when the ultraviolet illuminance in a wavelength range longer than the germicidal line falls below a predetermined value based on the ultraviolet illuminance measurement value of the ultraviolet sensor. A water treatment device characterized by comprising: The water treatment device according to claim 1, wherein the ultraviolet light that reaches the ultraviolet sensor has a wavelength of 300 to 400 nm. The water treatment device according to claim 1 or 2, further comprising an ozone supply section that supplies ozone to the water to be treated.

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