JP6666136B2 - UV irradiation device - Google Patents

Description

Embodiment relates to ultraviolet irradiation device.

  Fluids such as liquids, such as water, and gases, such as air, can be contaminated by microorganisms. These microorganisms can adversely affect consumer health. Therefore, microorganisms present in the fluid need to be inactivated before the fluid is used for consumption.

  As a method for inactivating harmful microorganisms in a fluid, there is a method using ultraviolet light having a wavelength of 200 nm to 300 nm. It is known that ultraviolet light having a wavelength in the range of 200 nm to 300 nm is absorbed by, for example, DNA, RNA and proteins, inactivates harmful microorganisms that damage genes, and suppresses proliferation. Many devices and systems have been proposed and put to practical use, utilizing the inactivating effect of ultraviolet rays on microorganisms and utilizing the inactivating effect of harmful microorganisms in a fluid.

  On the other hand, a conventional mercury lamp, a recently developed ultraviolet LED (Light Emitting Diode: light emitting diode) without using mercury, and the like are used as an ultraviolet irradiation member for irradiating ultraviolet rays. An ultraviolet irradiation device in which one or a plurality of ultraviolet irradiation members are provided in a flow path of a fluid to be processed is disclosed.

JP 2014-22445 A JP 2012-115715 A JP 2012-205615 A JP 2006-346676 A

  However, in the above-described ultraviolet irradiation device, the ultraviolet irradiation member generates heat by the supplied electric power or the like, but the change in the performance of the ultraviolet irradiation device based on the temperature change of the ultraviolet irradiation member has not yet been sufficiently considered.

In order to solve the above-described problems and achieve the object, a control device according to an embodiment includes an ultraviolet irradiation plate, a fluid inlet into which a fluid to be treated flows, and a fluid to be treated that flows from the fluid inlet and is connected to the fluid inlet. Has a space through which the ultraviolet light irradiation direction is directed to the fluid to be treated, and holds a UV irradiation plate; a fluid outlet connected to the chamber at a position different from the fluid inlet, and a fluid outlet for discharging the fluid to be treated; A plurality of DC power supplies for supplying DC power to the ultraviolet irradiation member, and a control device are provided. The ultraviolet irradiation plate has a plurality of ultraviolet irradiation units and includes a base holding the plurality of ultraviolet irradiation units. The ultraviolet irradiation unit is a holding member, an ultraviolet irradiation member that is held by the holding member and irradiates the processing target fluid with ultraviolet light, a temperature detection unit that is provided on the holding member and detects temperature information regarding the temperature of the ultraviolet irradiation member, Is provided. The control device sets the voltage of the DC power to supply the DC power to the ultraviolet irradiation member whose temperature information is detected based on the temperature information from the temperature detection unit, and corresponds to the temperature of the ultraviolet irradiation member converted from the temperature information. If the converted temperature is higher than the preset upper limit temperature, the voltage of the DC power is reduced, and based on a preset relationship between the converted temperature and the flow rate of the fluid to be processed, the ultraviolet irradiation member corresponding to the converted temperature Calculate the flow velocity of the fluid to be processed flowing through the ultraviolet irradiation section assigned to.

FIG. 1 is a diagram illustrating an ultraviolet irradiation device according to the first embodiment. FIG. 2 is a sectional view taken along the line II-II in FIG. FIG. 3 is an enlarged view of the ultraviolet irradiation plate. FIG. 4 is an enlarged view of the ultraviolet irradiation unit. FIG. 5 is a graph showing the relationship between the temperature of the ultraviolet irradiation unit and the flow velocity of the fluid to be processed. FIG. 6 is a graph showing the relationship between the intensity of the ultraviolet light emitted from the ultraviolet irradiation member and the voltage supplied to the ultraviolet irradiation member. FIG. 7 is a graph showing the relationship between the amount of ultraviolet irradiation and the inactivation rate of harmful microorganisms. FIG. 8 is a sectional arrow view showing a temperature distribution and an ultraviolet irradiation dose distribution in each region in the chamber. FIG. 9 is a graph showing the relationship between the flow rate for each voltage supplied to the ultraviolet irradiation member and the temperature of the ultraviolet irradiation section measured by the temperature sensor. FIG. 10 is a block diagram illustrating a control system of the ultraviolet irradiation device. FIG. 11 is a flowchart illustrating a voltage control process performed by the control device.

  The following exemplary embodiments and modifications include similar components. Therefore, in the following, the same reference numerals are given to the same components, and the overlapping description is partially omitted. A part included in the embodiment or the modification can be configured to be replaced with a corresponding part of another embodiment or the modification. In addition, the configuration, position, and the like of a part included in the embodiment and the modified example are the same as those of the other embodiment and the modified example unless otherwise specified.

  An object of the ultraviolet processing apparatus according to the following embodiments is to cope with heat generation of an ultraviolet irradiation member configured by an ultraviolet LED or the like.

<Embodiment>
FIG. 1 is a diagram illustrating an ultraviolet irradiation device 10 according to the first embodiment. FIG. 2 is a sectional view taken along the line II-II in FIG. FIG. 3 is an enlarged view of the ultraviolet irradiation plate 18. In the following description, the term “upstream side” refers to the upstream side in the direction in which the fluid to be treated flows, which is indicated by a white arrow in FIG. The downstream side is the downstream side in the direction in which the fluid to be processed flows.

  As shown in FIG. 1, the ultraviolet irradiation device 10 includes a fluid inlet 12, a chamber 14, a fluid outlet 16, and an ultraviolet irradiation plate 18.

  The fluid inlet 12 is arranged on the upstream side of the ultraviolet irradiation device 10. The fluid inlet 12 has, for example, a hollow cylindrical shape. The fluid to be processed flows into the fluid inlet 12.

  The chamber 14 is, for example, formed in a hollow cylindrical shape having an ultraviolet irradiation chamber 20 through which the fluid to be processed flowing from the fluid inlet 12 flows. As shown in FIG. 2, the ultraviolet irradiation chamber 20 is, for example, rectangular in plan view. An inlet 22 is open at an upstream end of the chamber 14. The fluid inlet 12 is connected to the inlet 22 of the chamber 14. An outlet 24 is open at the downstream end of the chamber 14. The outlet 24 is provided at a position facing the inlet 22.

  The fluid outlet 16 is arranged downstream of the ultraviolet irradiation device 10. The fluid outlet 16 is formed, for example, in a hollow cylindrical shape. The fluid outlet 16 is connected to the chamber 14 at a position different from the fluid inlet 12. Specifically, the fluid outlet 16 is connected to an outlet 24 of the chamber 14. Therefore, the fluid outlet 16 is provided at a position facing the fluid inlet 12. The fluid outlet 16 discharges the fluid to be treated, which has been treated by the ultraviolet rays in the chamber 14.

  The ultraviolet irradiation plate 18 irradiates ultraviolet rays to perform disinfection, sterilization, and the like on the fluid to be processed. The ultraviolet irradiation plate 18 is held in the chamber 14 so that the irradiation direction of the ultraviolet light is directed to the fluid to be processed. The ultraviolet irradiation plate 18 is provided so as to cover one surface of the ultraviolet irradiation chamber 20 and close one surface of the chamber 14. In other words, the ultraviolet irradiation chamber 20 is surrounded by the chamber 14 and the ultraviolet irradiation plate 18.

  The ultraviolet irradiation plate 18 has a base 26 and one or more ultraviolet irradiation units 27.

  The base 26 is, for example, a plate-shaped member. The base 26 is fixed inside the chamber 14. The base 26 holds one or more ultraviolet irradiation units 27.

  In the present embodiment, the number of the ultraviolet irradiation units 27 is 24. The ultraviolet irradiation unit 27 is provided on the surface of the base 26 facing the inside of the chamber 14. The ultraviolet irradiation units 27 are arranged in a matrix on the surface of the base 26. For example, 24 ultraviolet irradiation units 27 are arranged in a matrix of 3 × 8 at the same interval. The ultraviolet irradiation unit 27 is provided on the base 26 with an irradiation surface, which is a surface on which ultraviolet light is irradiated, facing the inside of the chamber 14. Each ultraviolet irradiation unit 27 has an ultraviolet irradiation unit 28 and a temperature sensor 30.

  FIG. 4 is an enlarged view of the ultraviolet irradiation unit 27. As shown in FIG. 4, the ultraviolet irradiation section 28 includes a stem 32, an ultraviolet irradiation member 34, a case 36, an ultraviolet transmission member 38, and a pair of conductive wires 40.

  The stem 32 is an example of a holding member. The stem 32 is, for example, a plate-shaped member. The stem 32 is fixed to one surface of the base 26 facing the inside of the chamber 14.

  The ultraviolet irradiation member 34 is, for example, an LED (Light Emitting Diode) that irradiates ultraviolet light. The ultraviolet irradiation member 34 is held on one surface of the stem 32 facing the inside of the chamber 14. The ultraviolet irradiation member 34 is fixed with the irradiation direction of the ultraviolet light directed toward the inside of the chamber 14. The ultraviolet irradiation member 34 irradiates the processing target fluid with ultraviolet light. It is preferable that the ultraviolet irradiation member 34 emits ultraviolet light having a wavelength of 200 nm to 300 nm, which has a disinfecting effect on harmful microorganisms.

  The case 36 is, for example, a cylindrical member. The case 36 is provided on the stem 32 so as to cover the side surface of the ultraviolet irradiation member 34.

  The ultraviolet transmitting member 38 is, for example, a plate-shaped member. The ultraviolet transmitting member 38 is provided on the irradiation side of the case 36. The stem 32, the case 36 and the ultraviolet transmitting member 38 form a watertight space. Thus, the stem 32, the case 36, and the ultraviolet transmitting member 38 protect the ultraviolet irradiating member 34 from the fluid to be processed. The ultraviolet ray transmitting member 38 includes a material that transmits ultraviolet rays. The ultraviolet transmitting member 38 is preferably made of, for example, quartz glass or the like that almost transmits ultraviolet light having a wavelength of 200 nm to 300 nm. Thereby, the ultraviolet rays irradiated by the ultraviolet irradiation member 34 can be used efficiently.

  The pair of conducting wires 40 are electrically connected to the ultraviolet irradiation member 34. The pair of conducting wires 40 supply DC power to the ultraviolet irradiation member 34.

  The temperature sensor 30 is an example of a temperature detection unit, and is provided on the stem 32. The temperature sensor 30 is provided, for example, on the back surface of the stem 32 opposite to the surface on which the ultraviolet irradiation member 34 is fixed. The temperature sensor 30 detects and outputs temperature information on the temperature of the ultraviolet irradiation member 34. For example, the temperature sensor 30 detects and outputs an electric signal corresponding to the temperature of the ultraviolet irradiation member 34.

  Next, the operation of the above-described ultraviolet irradiation device 10 will be described.

  The fluid to be treated containing harmful microorganisms flows into the chamber 14 from the fluid inlet 12. The fluid to be processed receives ultraviolet light having a wavelength of 200 nm to 300 nm irradiated from the ultraviolet irradiation member 34 of the ultraviolet irradiation section 28. As a result, the microorganisms contained in the fluid to be treated are inactivated by receiving ultraviolet light, thereby suppressing the harmfulness and the proliferative power of damaging the gene when absorbed by DNA, RNA and protein. The target fluid that has received the ultraviolet rays is discharged from the fluid outlet 16.

  Here, the flow of the fluid to be processed in the chamber 14 will be described with reference to FIG. In FIG. 2, the flow vector of the fluid to be processed in the chamber 14 is indicated by thin black arrows. The length of the arrow indicates the flow rate of the target fluid. At the connection point between the fluid inlet 12 and the chamber 14, the width of the flow path through which the fluid to be processed flows is increased. On the other hand, at the connection point between the chamber 14 and the fluid outlet 16, the width of the flow path through which the fluid to be processed flows is reduced. As a result, the flow rate of the fluid to be processed is reduced at the corner of the chamber 14 near the connection point where the width of the flow path is changed, and in some cases, a vortex is generated to form a stagnation area. On the other hand, the distribution of the flow velocity of the fluid to be processed is high in the central portion of the chamber 14 and slow in the vicinity of the side wall of the chamber 14.

  When DC power is supplied through the conductive wire 40, the ultraviolet irradiation member 34 emits ultraviolet light and generates heat, so that the temperature of the ultraviolet irradiation section 28 rises. Here, when the temperature is higher than the temperature of the fluid to be processed flowing in the vicinity of the ultraviolet irradiation unit 28, heat is transmitted from the ultraviolet irradiation unit 28 to the fluid to be processed.

  Here, the relationship between the temperature of the ultraviolet irradiation unit 28 and the flow rate of the fluid to be processed will be described. FIG. 5 is a graph showing the relationship between the temperature of the ultraviolet irradiation unit 28 and the flow rate of the fluid to be processed. The heat transfer coefficient between the ultraviolet irradiation unit 28 and the processing target fluid changes according to the flow rate of the processing target fluid. Thus, when the voltage supplied to the ultraviolet irradiation member 34 is constant, the relationship between the temperature of the ultraviolet irradiation unit 28 measured by the temperature sensor 30 and the flow rate of the fluid to be processed is as shown in FIG. Specifically, when the flow rate of the processing target fluid is low, the temperature of the ultraviolet irradiation unit 28 increases, and as the flow rate of the processing target fluid increases, the temperature of the ultraviolet irradiation unit 28 decreases.

  Next, the relationship between the intensity of the ultraviolet light emitted from the ultraviolet irradiation member 34 and the voltage supplied to the ultraviolet irradiation member 34 will be described. FIG. 6 is a graph showing a relationship between the intensity of the ultraviolet light emitted from the ultraviolet irradiation member 34 and the voltage supplied to the ultraviolet irradiation member 34. As shown in FIG. 6, the intensity of the ultraviolet light emitted from the ultraviolet irradiation member 34 increases in proportion to the voltage supplied to the ultraviolet irradiation member 34 when the flow rate of the fluid to be processed is constant.

Next, the relationship between the amount of ultraviolet irradiation D and the inactivation rate S of harmful microorganisms will be described. FIG. 7 is a graph showing the relationship between the ultraviolet irradiation dose D and the inactivation rate S of harmful microorganisms. The amount of ultraviolet irradiation D is determined by the intensity of ultraviolet light I and the exposure time T, which is the time during which the fluid to be treated is exposed to ultraviolet light. Here, as in the following equation, in a deleterious microbial count N ₀ contained in the fluid to be treated before the ultraviolet irradiation in the fluid inlet 12, conventional value obtained by dividing the harmful microorganisms number N after UV irradiation in the fluid outlet 16 The product of the logarithm and “−1” is defined as the inactivation rate S. In this case, the relationship between the amount of ultraviolet irradiation D and the inactivation rate S of harmful microorganisms is shown in FIG. Specifically, when the UV irradiation amount D is small, the inactivation effect is small, and the inactivation effect increases as the UV irradiation amount D increases.
S = −Log (N / N ₀ )

  Next, a description will be given of the temperature distribution and the ultraviolet irradiation amount distribution of each region in the chamber 14 when the voltage supplied to all the ultraviolet irradiation members 34 is kept constant at the same value. FIG. 8 is a cross-sectional view showing a temperature distribution and an ultraviolet irradiation amount distribution in each region in the chamber 14. From the above relationship, when there is a flow velocity distribution in the ultraviolet irradiation device 10 and the voltage supplied to all the ultraviolet irradiation members 34 is kept constant at the same value, the temperature distribution in each region as shown in FIG. UV irradiation dose distribution is obtained.

  The length of the oblique hatching area in FIG. 8 indicates the height of the temperature of the ultraviolet irradiation member 34. Therefore, the region near the side wall of the chamber 14 where the length of the oblique hatching region is long indicates that the temperature of the ultraviolet irradiation member 34 is high. This is because the flow rate of the fluid to be processed is low near the side wall of the chamber 14 and the cooling effect of the fluid to be processed on the ultraviolet irradiation member 34 is small.

  The length of the dot hatched area in FIG. 8 indicates the magnitude of the ultraviolet irradiation dose D. Therefore, the region near the side wall of the chamber 14 where the length of the dot hatched region is long indicates that the ultraviolet irradiation amount D is large. This is because the flow rate of the fluid to be processed is low near the side wall of the chamber 14 and the passage time required to pass through the region is long.

  As can be seen from FIG. 8, depending on the region in the chamber 14 through which the fluid to be processed passes, some of the harmful microorganisms in the fluid to be processed may emit an excessive amount D of ultraviolet light with respect to the target inactivation rate S. Or the remaining part of the harmful microorganisms may receive only an insufficient amount of ultraviolet irradiation D for the target inactivation rate S. Therefore, when the voltage supplied to all the ultraviolet irradiation members 34 is kept constant at the same value, the microorganisms may not be inactivated or not depending on the region in the chamber 14 through which the fluid to be processed passes.

  Next, control based on the relationship between the flow rate for each voltage supplied to the ultraviolet irradiation member 34 and the temperature of the ultraviolet irradiation unit 28 measured by the temperature sensor 30 in the ultraviolet irradiation apparatus 10 of the present embodiment will be described. FIG. 9 is a graph showing the relationship between the flow rate for each voltage supplied to the ultraviolet irradiation member 34 and the temperature of the ultraviolet irradiation section 28 measured by the temperature sensor 30. In the ultraviolet irradiation device 10 of the present embodiment, as shown in FIG. 9, the relationship between the flow rate of each voltage supplied to the ultraviolet irradiation member 34 and the temperature of the ultraviolet irradiation unit 28 measured by the temperature sensor 30 is checked. Based on the relationship between the voltage and the ultraviolet intensity shown in FIG. 6, the ultraviolet irradiation member 34 is adjusted so that the same amount of ultraviolet radiation is applied to any region in the chamber 14 in accordance with the flow velocity distribution of the fluid to be processed in the chamber 14. Control the voltage supplied to the

  FIG. 10 is a diagram illustrating a control system of the ultraviolet irradiation device 10. The ultraviolet irradiation device 10 includes a DC power supply unit 48 and a control device 50.

  The DC power supply unit 48 has a plurality of DC power supplies 52. Each DC power supply 52 is electrically connected to one of the ultraviolet irradiation members 34. In other words, the DC power supply 52 is connected to the ultraviolet irradiation member 34 in a one-to-one relationship. The plurality of DC power supplies 52 supply DC power to the plurality of ultraviolet irradiation members 34. Each DC power supply 52 individually supplies DC power of a different voltage to the ultraviolet irradiation member 34 based on an operation signal from the control device 50.

  The control device 50 includes, for example, an arithmetic processing device including a processor such as a CPU (Central Processing Unit), and a storage device including a RAM (Random Access Memory), a ROM (Read Only Memory), and an HDD (Hard Disk Drive). It is a computer having hardware. The control device 50 controls the ultraviolet irradiation device 10.

  The control device 50 is connected to the temperature sensor 30 of the ultraviolet irradiation unit 27 and the DC power supply 52 of the DC power supply unit 48. The control device 50 sets the voltage of the DC power supply 52 that supplies DC power to the ultraviolet irradiation member 34 from which the electric signal has been detected, based on the electric signal from the temperature sensor 30 and the like. Specifically, control device 50 uses the electric signal obtained from temperature sensor 30 to convert the electric signal into a temperature by a preset conversion formula. Control device 50 sets the voltage supplied by DC power supply 52 for the converted temperature. The control device 50 outputs an operation signal for instructing the set voltage to the DC power supply 52 that supplies power to the ultraviolet irradiation member 34 provided with the temperature sensor 30. Thus, the control device 50 controls the voltage supplied to each of the ultraviolet irradiation members 34 by individually raising and lowering the voltage in accordance with a change in the temperature of the ultraviolet irradiation member 34.

  FIG. 11 is a flowchart illustrating a voltage control process performed by control device 50. The control device 50 executes the voltage control process shown in FIG. 11 by causing the arithmetic processing device to read the program stored in the storage unit.

The control device 50 controls the target inactivation rate S of the harmful microorganisms to be set in advance, and the distance L in the flow direction in which the fluid to be treated in the ultraviolet irradiation section assigned to each of the ultraviolet irradiation members 34 is set in advance. _{1 to n} , the preset upper limit temperature TH _LIM of the ultraviolet irradiation member 34 is stored in the storage device (S100). Here, the upper limit temperature TH _LIM indicates an upper limit temperature at which the ultraviolet irradiation member 34 is not damaged.

Next, based on the relationship between the ultraviolet ray irradiation amount D and the harmful microorganism inactivation rate S shown in FIG. 7, the control device 50 is set as the ultraviolet irradiation amount necessary to obtain the target inactivation rate S. The target UV irradiation amount _DT is calculated (S110).

Next, the control device 50 converts the electric signals acquired from the respective temperature sensors 30 into the converted temperatures T _1... Corresponding to the temperatures of the ultraviolet irradiation members 34 based on the relationship between the predetermined electric signal and the converted temperature _{. n} is converted (S120). The control device 50 compares the converted temperatures T _{1... N} with a preset upper limit temperature TH _LIM (S130).

When the converted temperature T _{1... N} of the ultraviolet irradiation member 34 is higher than the upper limit temperature TH _LIM (S130: NO), the control device 50 _{reduces the} DC power voltage V _1. An operation signal for lowering is output to DC power supply 52 (S140), and step S120 and subsequent steps are repeated.

On the other hand, if the converted temperature T _{1... N} of the ultraviolet irradiation member 34 is _lower than the upper limit temperature TH _LIM of the ultraviolet irradiation member 34 (S130: YES), the control device 50 reads the voltage output from each DC power supply 52 (S130: YES). S150).

The control device 50 converts the voltages V _{1... N} supplied to the ultraviolet irradiation members 34 shown in FIG. 9, the conversion temperatures T _1. The flow velocity u _{1... N} of the fluid to be processed flowing in the ultraviolet irradiation section assigned to each ultraviolet irradiation member 34 corresponding to the temperature T ₁ .

The controller 50 is assigned to each of the ultraviolet irradiation members 34 based on the flow velocities u _{1... N of the} fluid to be processed in the irradiation section of each ultraviolet irradiation member 34 and the distances L _1. The passage time Δt _{1... N} required for the target fluid to pass through the irradiated section is calculated. The control device 50 calculates the ultraviolet intensity I _{1... N} of the ultraviolet light of each ultraviolet irradiation member 34 from the voltages V ₁ . Specifically, the control device 50 determines the ultraviolet intensity I _{1... N} based on the relationship between the voltage V _{1... N} supplied to the ultraviolet irradiation member 34 shown in FIG. calculate.

The controller 50 determines the amount of ultraviolet irradiation D _{1... N} received by the fluid to be processed while passing through the irradiation section assigned to each ultraviolet irradiation member 34 from the calculated transit time Δt _{1... N} and the ultraviolet intensity I _1. Is calculated (S180). More specifically, the control unit 50, the transit time Delta] t 1 _{... n} required for the fluid to be treated passes over the ultraviolet intensity I _{1 ... n,} to calculate the amount of UV irradiation D _{1 ... n.}

The control device 50 integrates the ultraviolet irradiation amounts D _{1... N} of the plurality (for example, all) of the ultraviolet irradiation members 34, divides the integrated values by the number M of the integrated ultraviolet irradiation members 34, and averages the average ultraviolet irradiation amount D. _m is calculated (S190).

The control device 50 compares the average ultraviolet irradiation amount _Dm with the target ultraviolet irradiation amount _DT (S200).

When the average ultraviolet irradiation amount _Dm is smaller than the target ultraviolet irradiation amount _DT (S200: YES), the control device 50 outputs an operation signal to uniformly increase the voltages V1 to _n to all the DC power supplies 52. , _N of the DC power supplied to the plurality of ultraviolet irradiation members 34 are uniformly increased (S210). Thereafter, control device 50 repeats the processing of step S120 and subsequent steps.

On the other hand, when the average ultraviolet irradiation amount D _m is equal to or greater than the target ultraviolet irradiation amount D _T (S200: NO), the control device 50 determines the average ultraviolet irradiation amount D _m and the ultraviolet irradiation of the irradiation section allocated to each ultraviolet irradiation member 34. The amounts D _{1... N} are compared (S220).

Controller 50, when the average amount of UV irradiation _{D m} and one of the ultraviolet irradiation amount _{D 1 ... n} are different (S220: NO), the different amount of UV irradiation _{D 1 ... n} and the average amount of UV irradiation and _{D m} The magnitude relation is compared (S230).

When the ultraviolet irradiation amount D _{1... N} in any irradiation section is lower than the average ultraviolet irradiation amount D _m (S230: YES), the control device 50 outputs an operation signal for increasing the voltage V _1. The voltage V _{1... N} of DC power supplied to the power supply 52 and supplied to the ultraviolet irradiation member 34 that irradiates the irradiation section with ultraviolet light is increased (S210). Thereafter, control device 50 repeats the processing of step S120 and subsequent steps.

If the ultraviolet irradiation amount D _{1... N} in the irradiation section is higher than the average ultraviolet irradiation amount D _m (S230: NO), the control device 50 sends an operation signal to lower the voltage V _1. , And the voltage V _{1... N} of the DC power supplied to the ultraviolet irradiation member 34 that irradiates the irradiation section with ultraviolet light is reduced (S140). Thereafter, control device 50 repeats the processing of step S120 and subsequent steps.

When all of the ultraviolet irradiation amounts D _{1... N} of the plurality of ultraviolet irradiation members 34 are _equal to the average ultraviolet irradiation amount D _m (S220: YES), the control device 50 determines that the average ultraviolet irradiation amount D _m and the target ultraviolet irradiation amount D _T. Are compared (S240).

When the average ultraviolet irradiation amount _Dm is not equal to the target ultraviolet irradiation amount _DT (S240: NO), the control device 50 outputs an operation signal to lower the voltages V1 to _n to all the DC power supplies 52, The voltage V _{1... N} of the DC power supplied to the ultraviolet irradiation member 34 is uniformly reduced (S140). If the average ultraviolet irradiation amount D _m in step S240 is not equal to the target ultraviolet irradiation amount D _T , it means that the average ultraviolet irradiation amount D _m is larger than the target ultraviolet irradiation amount D _T from the relationship with step S200. is there. Thereafter, control device 50 repeats the processing of step S120 and subsequent steps.

Controller 50, when the average amount of UV irradiation _{D m} is equal to the target amount of UV irradiation _{D T} (S240: YES), step S120 to repeat the subsequent processing.

  As described above, the ultraviolet irradiation device 10 according to the embodiment includes the temperature sensor 30 that detects an electric signal related to the temperature of the ultraviolet irradiation member 34, and thus can cope with heat generated by the ultraviolet irradiation member 34.

For example, when the conversion temperature T _{1... N} becomes higher than the upper limit temperature TH _LIM set for suppressing the damage of the ultraviolet irradiation member 34, the control device 50 decreases the voltage V _1. . Thereby, the ultraviolet irradiation device 10 can suppress the damage of the ultraviolet irradiation member 34 and extend the life.

The control device 50 can estimate the flow velocities u _{1... N} of the fluid to be processed in the irradiation section of each ultraviolet irradiation member 34 from the converted temperatures T ₁ . Accordingly, the ultraviolet irradiation device 10 can make the ultraviolet irradiation doses D _{1... N} irradiated to the fluid to be processed substantially uniform in the chamber 14. In particular, in the ultraviolet irradiation device 10, since the temperature sensor 30 is provided corresponding to each of the ultraviolet irradiation members 34, even if the shapes of the fluid inlet 12, the chamber 14, and the fluid outlet 16 are different, each of the ultraviolet sensors is different. The ultraviolet irradiation amounts D _{1... N} can be controlled in accordance with the flow rates u _{1... N} of the fluid to be processed flowing through the irradiation section of the irradiation member 34.

Furthermore, the control device 50, the ultraviolet irradiation dose D ₁ of the fluid to be treated is subjected at the irradiation interval of each ultraviolet irradiation member 34 from the flow rate _... can calculate _n, further, the average UV dose D from the ultraviolet irradiation dose D _{1 ... n m} can be calculated.

The control device 50 responds to the average ultraviolet irradiation amount D _m , the target ultraviolet irradiation amount D _T set based on the target inactivation rate S, and the ultraviolet irradiation amounts D _1. , _N of the DC power supplied to the ultraviolet irradiation member 34 can be controlled individually or uniformly.

Thereby, the ultraviolet irradiation device 10 can prevent excessive power consumption by individually controlling the voltages V _{1... N} of the ultraviolet irradiation members 34 while making the ultraviolet irradiation amounts D _1. At the same time, the inactivation rate of harmful microorganisms can be improved.

Since the ultraviolet irradiation device 10 controls the voltages V _{1... N} based on the flow rates u _{1... N} of the processing fluid, the voltages V _{1. n} can be controlled. Thereby, the ultraviolet irradiation device 10 can individually monitor the state including the temperature of the ultraviolet irradiation member 34 while improving the uniformity of the temperature of the ultraviolet irradiation member 34.

  The shape, number, connection relationship, and the like of the configuration of each embodiment described above may be appropriately changed.

  For example, the shapes of the fluid inlet 12, the chamber 14, and the fluid outlet 16 may be appropriately changed. In the above embodiment, the chamber 14 has a rectangular shape, but the chamber 14 may have a cylindrical shape.

  In the above-described embodiment, an example in which the ultraviolet irradiation plate 18 is provided on one surface of the chamber 14 has been described, but a plurality of ultraviolet irradiation plates 18 may be provided on a plurality of surfaces of the chamber 14. For example, two ultraviolet irradiation plates 18 may be provided in the chamber 14 so as to face each other with the irradiation space where the fluid to be processed flows interposed therebetween. Further, the ultraviolet irradiation plate 18 may be provided in the chamber 14 so that three or more ultraviolet irradiation plates 18 surround the irradiation space.

  Although several embodiments of the present invention have been described, these embodiments are provided by way of example and are not intended to limit the scope of the invention. These new embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

  DESCRIPTION OF SYMBOLS 10 ... UV irradiation apparatus, 12 ... Fluid inlet, 14 ... Chamber, 16 ... Fluid outlet, 18 ... UV irradiation plate, 20 ... UV irradiation chamber, 26 ... Base, 27 ... UV irradiation unit, 28 ... UV irradiation part, 30 ... Temperature sensor, 32: stem, 34: ultraviolet irradiation member, 36: case, 38: ultraviolet transmission member, 40: conducting wire, 48: DC power supply unit, 50: control device, 52: DC power supply.

Claims (6)

An ultraviolet irradiation plate ,
A fluid inlet into which the fluid to be treated flows,
A chamber that is connected to the fluid inlet, has a space in which the fluid to be processed flowing from the fluid inlet flows, and holds the ultraviolet irradiation plate in an irradiation direction of ultraviolet light to the fluid to be processed;
A fluid outlet connected to the chamber at a position different from the fluid inlet, and discharging the fluid to be treated;
A plurality of DC power supplies for supplying DC power to the plurality of ultraviolet irradiation members,
And a control device ,
The ultraviolet irradiation plate,
Has multiple UV irradiation units,
A base holding the plurality of ultraviolet irradiation units,
The ultraviolet irradiation unit,
A holding member;
An ultraviolet irradiation member that is held by the holding member and irradiates the processing target fluid with the ultraviolet light,
A temperature detection unit provided on the holding member, for detecting temperature information on the temperature of the ultraviolet irradiation member,
The control device includes:
Based on the temperature information from the temperature detection unit, set the voltage of the DC power to supply the DC power to the ultraviolet irradiation member where the temperature information is detected,
If the converted temperature corresponding to the temperature of the ultraviolet irradiation member converted from the temperature information is higher than a preset upper limit temperature, the voltage of the DC power is reduced,
Based on a preset relationship between the flow rate of the fluid to be treated and the reduced temperature, calculating the flow rate of the fluid to be treated flowing through the irradiation region of the ultraviolet assigned to the ultraviolet radiation member corresponding to the reduced temperature Do
UV irradiation device.   The control device includes:
  The calculated flow velocity and the passage time through which the treatment fluid passes through the irradiation section from the distance of the irradiation section in the direction in which the treatment fluid flows,
  Calculating the ultraviolet intensity of the ultraviolet light of the ultraviolet light irradiation member from the voltage supplied to the ultraviolet light irradiation member,
  From the transit time and the ultraviolet intensity, calculate the amount of ultraviolet radiation received by the fluid to be processed while passing through the irradiation section.
  The ultraviolet irradiation device according to claim 1.   The control device includes:
  Integrating the ultraviolet irradiation amount of the plurality of ultraviolet irradiation members, calculating the average ultraviolet irradiation amount divided by the number of ultraviolet irradiation members and averaging,
  When the average ultraviolet irradiation amount is less than a target ultraviolet irradiation amount determined from a preset target inactivation rate, the voltage of the DC power supplied to the plurality of ultraviolet irradiation members is uniformly increased.
  The ultraviolet irradiation device according to claim 2.   The control device includes:
  Integrating the ultraviolet irradiation amount of the plurality of ultraviolet irradiation members, calculating the average ultraviolet irradiation amount divided by the number of ultraviolet irradiation members and averaging,
  The voltage of the DC power supplied to the ultraviolet irradiation member in the irradiation section in which the ultraviolet irradiation amount is lower than the average ultraviolet irradiation amount is increased.
  The ultraviolet irradiation device according to claim 2.   The control device includes:
  Integrating the ultraviolet irradiation amount of the plurality of ultraviolet irradiation members, calculating the average ultraviolet irradiation amount divided by the number of ultraviolet irradiation members and averaging,
  The voltage of the DC power to be supplied to the ultraviolet irradiation member in the irradiation section in which the ultraviolet irradiation amount is higher than the average ultraviolet irradiation amount is reduced.
  The ultraviolet irradiation device according to claim 2.   The control device includes:
  Integrating the ultraviolet irradiation amount of the plurality of ultraviolet irradiation members, calculating the average ultraviolet irradiation amount divided by the number of ultraviolet irradiation members and averaging,
  All the ultraviolet irradiation amounts of the plurality of ultraviolet irradiation members are equal to the average ultraviolet irradiation amount, and the average ultraviolet irradiation amount is greater than the target ultraviolet irradiation amount determined from a preset target inactivation rate. If larger, the voltage of the DC power of the plurality of ultraviolet irradiation members is uniformly reduced.
  The ultraviolet irradiation device according to claim 2.

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