JP6054167B2 - UV irradiation equipment - Google Patents

Description

  The present invention relates to an ultraviolet irradiation device used as, for example, a water sterilization purification device in a water purifier.

  Many ultraviolet irradiation apparatuses using ultraviolet rays are already known as a method for sterilizing and purifying water.

  A conventional ultraviolet irradiation device includes a casing (also called a reactor), one ultraviolet lamp provided in the center of the casing, a lighting switch for lighting the ultraviolet lamp, a lighting display lamp displayed by the lighting switch, And a temperature sensor provided inside the casing to turn off the ultraviolet lamp (see Patent Document 1).

  In general, an ultraviolet lamp has a slow rise due to its characteristics. Accordingly, the running state of the treated water is started after a predetermined time after the ultraviolet lamp is turned on. On the other hand, since the heat generation amount of the ultraviolet lamp is large, the temperature of the treated water rises in the on state of the ultraviolet lamp in the treated water stopped state. Therefore, the ultraviolet lamp is turned off when the temperature of the treated water exceeds a predetermined value. This control will be described with reference to FIG.

  At time t1 in FIG. 7, when the lighting switch is turned on, the lighting display lamp is blinked and the ultraviolet lamp is turned on. In this case, the blinking state of the lighting display lamp is maintained in accordance with the rising time of the ultraviolet lamp, for example, a predetermined time of 2 minutes. During this time, since the treated water is in a stopped state, the temperature of the treated water rises due to the output of the ultraviolet lamp. It is assumed that the operator does not turn on the faucet of the ultraviolet irradiation device (for example, water purifier) when the lighting display lamp is blinking.

  Next, when the above-described predetermined time has elapsed, the lighting display lamp is turned on at time t2, and the operator who has seen this turns on the faucet of the water purifier at time t3. As a result, the treated water of the water purifier becomes a running water state, and the water temperature of the treated water decreases. Thereafter, the water temperature becomes stable.

  Next, at time t4, when the operator turns off the faucet of the water purifier, the treated water of the water purifier is stopped, and the temperature of the treated water rises due to the heat generated by the ultraviolet lamp.

  Finally, at time t5, when the temperature sensor detects a predetermined temperature of the treated water temperature, for example, 60 ° C., the lighting display lamp is turned off and the ultraviolet lamp is also turned off.

  Thus, according to the conventional control method shown in FIG. 7, the ultraviolet lamp is turned on simultaneously with the turning on of the lighting switch, and the ultraviolet lamp is turned off simultaneously with the predetermined temperature detection of the temperature sensor.

JP 10-2111488 A

  However, in the above-described conventional ultraviolet irradiation device, the ultraviolet lamp is turned on for a predetermined time earlier than the start of the flowing state of the treated water, and the ultraviolet lamp is turned on after the end of the flowing state until the predetermined temperature is detected by the temperature sensor. Connected. Accordingly, since the ultraviolet lamp needs to be turned on for a very long time compared to the time when the treated water is flowing, there is a problem that power consumption is large.

  In the above-described conventional ultraviolet irradiation device, instead of detecting the predetermined temperature of the temperature sensor, it has also been proposed to turn off the ultraviolet lamp when the temperature sensor temperature changes to a predetermined value ( Reference: Paragraphs 0015 and 0016 of Patent Document 1. In this case, the off-state of the ultraviolet lamp becomes a little faster, but the on-state of the ultraviolet lamp lasts for a long time, so that the power consumption is still large.

In order to solve the above-described problems, an ultraviolet irradiation device according to the present invention has a casing for inflow and outflow of treated water, an ultraviolet light source disposed inside the casing, and an illuminance of the treated water in the casing. The illuminance sensor for detection and the illuminance sensor output at a predetermined time smaller than the illuminance sensor output fluctuation period are calculated according to the illuminance fluctuation amount of the treated water, and the ultraviolet ray is determined according to the calculated illuminance fluctuation amount. A control unit for controlling the light source, and when the variation amount of the illuminance of the treated water is equal to or greater than a predetermined value, the control unit drives the ultraviolet light source on, and when the variation amount of the illuminance of the treated water is less than the predetermined value The control unit intermittently drives the ultraviolet light source .

  That is, the inventors of the present application focused on the fact that the amount of fluctuation in the illuminance of the treated water clearly represents the running water state and the stopped water state of the treated water. It was found that when the variation in the illuminance of the treated water is large, the treated water is in a flowing water state, while when the variation in the illuminance of the treated water is small, the treated water is in a stopped state. Therefore, the ultraviolet lamp can be driven according to the running water flow state and the water stop state. For example, the ultraviolet lamp is turned on when the treated water is flowing, and the ultraviolet lamp is driven intermittently when the treated water is stopped.

  According to the present invention, since the ultraviolet lamp is driven according to the running water state and the stopped water state of the treated water, the power consumption can be reduced. Further, by intermittently driving the ultraviolet lamp when the treated water is in a stopped state, the rising of the ultraviolet lamp can be accelerated when the treated water changes from the stopped state to the flowing water state. Furthermore, the lighting switch and the lighting display lamp in the conventional ultraviolet irradiation device can be dispensed with.

It is a perspective view which shows embodiment of the ultraviolet irradiation device concerning this invention. It is a top view of the ultraviolet irradiation device of FIG. It is a side view of the ultraviolet irradiation device of FIG. It is a cross-sectional view of the ultraviolet irradiation device of FIG. It is a flowchart for demonstrating operation | movement of the control part of FIG. FIG. 6 is a timing chart for supplementarily explaining the flowchart of FIG. 5. It is a timing diagram for demonstrating the control method of the conventional ultraviolet irradiation device.

  FIG. 1 is a perspective view showing an embodiment of an ultraviolet irradiation apparatus according to the present invention, and FIGS. 2, 3, and 4 are a top view, a side view, and a cross-sectional view of FIG.

  1 to 4, reference numeral 1 denotes a hollow cylindrical casing having an inflow hole 1a and an outflow hole 1b of treated water. The casing 1 is preferably made of aluminum or an aluminum alloy as an ultraviolet reflecting material. When a material that does not have an ultraviolet reflection function is used, the ultraviolet reflection material may be applied only to the inner wall side.

  Referring to FIG. 4, a rod-shaped ultraviolet lamp 2 is disposed in the center of the casing 1. The ultraviolet lamp 2 is connected to a wiring 2a for external connection. The ultraviolet lamp 2 is accommodated in an ultraviolet lamp protective tube 3 made of an ultraviolet ray passing material such as quartz so that treated water does not enter. Two or more ultraviolet lamps may be provided side by side.

  As the ultraviolet lamp 2, there are a hot cathode tube and a cold cathode tube, but a cold cathode tube is preferable from the viewpoint of life and miniaturization. In the case of a hot cathode tube, a current is passed through a negative electrode (filament coil) and rapidly heated to emit thermoelectrons and then cooled. The life is further deteriorated due to the deterioration of the coil. On the other hand, the cold cathode tube does not require the residual heat of the negative electrode when it is turned on / off.

  An illuminance sensor 4 that detects the illuminance of the treated water is provided inside the casing 1. The illuminance sensor 4 includes a photodiode or the like that converts ultraviolet light into current. In this case, a wavelength conversion element that converts ultraviolet light into visible light, a photodiode that converts visible light into current, or the like may be included. Furthermore, an amplifier may be incorporated.

  The treated water flows in from the inflow hole 1 a of the casing 1, passes through the vicinity of the illuminance sensor 4, and flows out from the outflow hole 1 b of the casing 1.

  Returning to FIG. 1, the output S1 of the illuminance sensor 4 is sent to the control unit 5. As a result, the control unit 5 calculates the amount of variation in the illuminance of the treated water based on the output S1 of the illuminance sensor 4, and The ultraviolet lamp 2 is controlled via the inverter circuit 6 according to the fluctuation amount. A drive circuit other than the inverter circuit may be used.

  The control unit 5 is constituted by a microcomputer, for example, and includes a CPU, a ROM, a RAM, an A / D converter, a D / A converter, an input / output interface, and the like.

  Next, the control operation of the control unit 5 of FIG. 1 will be described with reference to the flowchart of FIG. 5 and the timing chart of FIG. The routine of the flowchart of FIG. 5 is executed every predetermined time, for example, 30 ms. This predetermined time is assumed to be shorter than the fluctuation cycle of the output S1 of the illuminance sensor 4. Moreover, as shown to (A) of FIG. 6, the output S1 of the illumination intensity sensor 4 will be in a change state and a non-change state according to the running water flow state and the water stop state.

  First, at step 501, the control unit 5 takes in the output S1 of the illuminance sensor 4, that is, the illuminance of the treated water by A / D conversion.

Next, in step 502, the control unit 5 calculates the variation amount D of the illuminance of the treated water. For example,
D ← ｜ S1-S1 ₀ ｜
+ | S1 ₀ -S1 ₁ |
However, S1 ₀ is the previous value of S1
S1 ₁ is calculated as the previous value of S1. Note that the fluctuation amount D may be another calculation method. As a result, the fluctuation amount of the illuminance of the treated water changes as shown in FIG.

  Next, in step 503, the control unit 5 determines whether or not the fluctuation amount D is equal to or greater than a predetermined value α. As a result, if D ≧ α, that is, if the treated water is flowing, the process proceeds to step 504, and the drive signal S2 is set to “1” (ON state). On the other hand, if D <α, that is, if the treated water is in a stopped state, the process proceeds to step 505, and the drive signal S2 is inverted.

  At step 506, the routine of FIG.

When the routine of FIG. 5 is executed every 30 ms, a drive signal S2 shown in FIG. 6C is obtained. As shown in the enlarged view of (C) of FIG. 6 (C ′) of FIG. 6, when the treated water is in a flowing state, the drive signal S2 is “1” (on state), and the ultraviolet lamp 2 is in the on state. was sustained, while if the treated water is a water stop state, the driving signal S2 becomes 50% intermittent state duty ratio, the ultraviolet lamp 2 is intermittently driven.

  At this time, the temperature of the treated water changes as shown in FIG. For example, if the treated water is in a flowing water state, the temperature of the treated water is stabilized at about 28 ° C., whereas if the treated water is in a stopped state, the temperature of the treated water changes in the range of 25 to 30 ° C.

  As can be seen from FIG. 6, since the ultraviolet lamp 2 is in an intermittent state when the treated water is in a stopped state, when the operator turns on the faucet at time t1 ′, the treated water enters the flowing water state and the ultraviolet light is turned on. Ramp 2 rises immediately. On the other hand, when the operator turns off the faucet at time t2 ', the treated water enters the water stop state and the ultraviolet lamp 2 enters the intermittent state almost immediately. Therefore, although a little power consumption is required for the intermittent state of the ultraviolet lamp 2, the ON state of the ultraviolet lamp 2 substantially matches the flowing state of the treated water, and as a result, the power consumption can be reduced. In particular, when the running water state is frequently generated, power consumption can be greatly reduced.

  The present invention can be applied to any modifications within the obvious scope of the above-described embodiment.

  In addition to the water purifier described above, the present invention can be used for water sterilization and purification devices in water coolers, water servers, humidifiers, dishwashers, washing machines, dental chairs, and the like.

1: Casing
1a: Inflow hole 1b: Outflow hole
2: UV lamp
2a: Wiring
3: UV lamp protection tube
4: Illuminance sensor 5: Control unit 6: Inverter circuit

Claims (2)

A casing for inflow and outflow of treated water;
An ultraviolet light source disposed inside the casing;
An illuminance sensor for detecting the illuminance of the treated water in the casing;
A fluctuation amount of the illuminance of the treated water is calculated based on the output of the illuminance sensor every predetermined time smaller than a fluctuation cycle of the output of the illuminance sensor, and the ultraviolet light source is controlled according to the calculated fluctuation amount of the illuminance. and a control unit for,
When the fluctuation amount of the illuminance of the treated water is equal to or greater than a predetermined value, the control unit drives the ultraviolet light source on, and when the fluctuation amount of the illuminance of the treated water is less than the predetermined value, the control unit UV irradiation device that intermittently drives . The ultraviolet irradiation device according to claim 1, wherein the ultraviolet light source includes a cold cathode tube.

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