JPS61198545A - Light irradiator - Google Patents

Abstract

PURPOSE:To provide a light irradiator by which the emission of light from a non-electrode light emission tube can be monitored with a stable sensitivity, by detecting the change in the temperature of an irradiated object which is caused by the absorption of microwaves leaking from the tube. CONSTITUTION:When a non-electrode light emission tube 33 almost completely absorbs microwaves emitted from an electroconductive antenna 34 and properly emits ultraviolet light, the temperature of irradiated sewage 36 in a disposal tank 35 does not change. When the absorption of the microwaves decreases due to the abnormality of the light emission tube 33, the microwaves leak out of the tube and are all absorbed by the sewage 36 so that its temperature rises. If the change in the temperature is out of a prescribed range, a calculator 12 finds out the leak of a large quantity of microwaves, and sends out the result of calculation to a display unit 13 so that the unit shows 'Light emission tube abnormal' or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a light irradiation device that irradiates light onto an object using an electrodeless arc tube that is excited by microwaves and emits light.

[Technical background of the invention]

In recent years, electrodeless arc tubes excited by microwaves have attracted attention due to their highly efficient light emission, and devices using them as light sources have been developed and are beginning to spread widely in industry.

For example, light irradiation devices that use electrodeless arc tubes that emit ultraviolet light to sterilize bacteria contained in or attached to water, liquid foods, sewage, etc. are in widespread use.

Here, when accurately grasping the temporal deterioration state 1 light emitting state etc. of the electrodeless arc tube arranged in these light irradiation devices,
As shown in FIG. 4, optical measuring means 21 such as an ultraviolet intensity meter
A processing space 3 in which the object to be processed 36 is irradiated with ultraviolet light and processed.
5, and the electrodeless arc tube 33 emits light according to the measured value of the ultraviolet intensity meter 21.
Since UV light intensity meter 21 optically measures incident ultraviolet light, if a substance such as water scale adheres or accumulates on the surface of ultraviolet intensity meter 21, the measurement sensitivity is significantly reduced. Therefore, even when the electrodeless arc tube 33 is emitting light normally, the amount of light detected by the two-light emission monitoring means is reduced, so the light emission monitoring means erroneously detects that the two light-emissions are abnormal. Measures such as stopping the operation of the light irradiation device were taken, resulting in a decline in processing performance.

In addition, to avoid this, it may be possible to install the ultraviolet intensity meter 21 inside the electrodeless arc tube 33 so that it does not come into contact with the object to be treated 36, but with this structure,
The ultraviolet intensity meter 21 is interposed in the microwave propagation space, which obstructs the microwave propagation, resulting in a reduction in the amount of light emitted from the electrodeless arc tube 33.

Furthermore, this is not a problem specific to luminescence monitoring devices for electrodeless arc tubes that emit ultraviolet light; for example, for luminescence monitoring means for electrodeless arc tubes that emit colored light, optical measurement methods such as illumination meters, etc. Since the means were provided, problems similar to those described above arose.

[Purpose of the invention]

The purpose of the present invention is to solve the above problem, eliminate optical measuring means, and improve luminous efficiency by detecting the temperature change of the irradiated object caused by absorbing microwaves leaked from the electrodeless arc tube. To provide a light irradiation device capable of monitoring the light emission state of an electrodeless arc tube with stable sensitivity without prompting a decrease in sensitivity.

[Summary of the invention]

The present invention includes a microwave source supplying microwaves;
An electrodeless arc tube that absorbs this microwave and emits light,
In a light irradiation device that has an irradiation space in which the light emitted from the arc tube irradiates the irradiated object, the irradiated object is generated by absorbing microwaves that leak from the arc tube and reach the irradiation space. The present invention provides a light irradiation device that does not reduce the amount of light irradiated into the irradiation space because it includes a light emission monitoring means that monitors the light emission state of the two arc tubes by detecting temperature changes.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a water irradiation device for sewage treatment according to the present invention. As shown in the figure, a magnetron 32 that emits microwaves is attached to one end of a rectangular waveguide 31, and a conductive antenna 34 that absorbs microwaves is provided at the other end. Further, an electrodeless light emitting tube 33 arranged so as to surround the conductive antenna 34 receives the supplied microwave and emits ultraviolet light. It is housed inside a processing tank 35 which is a space.

In this way, a luminescent substance (not shown) sealed in the electrodeless arc tube 33 is excited by the microwaves supplied from the microwave supply source 30, and the electrodeless arc tube 33 emits ultraviolet light to the sewage water 36 that is the object to be irradiated. The treatment tank 35 is irradiated.

In addition, the light emission monitoring means 10 includes a first temperature detection element 11a that detects the water temperature of the sewage water 36 before being irradiated with ultraviolet light, that is, the temperature of the sewage water 36 supplied to the treatment tank 35, and a first temperature detection element 11a that detects the water temperature of the sewage water 36 that is supplied to the treatment tank 35, and a first temperature detection element 11a that detects the water temperature of the sewage water 36 supplied to the treatment tank 35, that is, the temperature of the sewage water 36 that is detected after irradiation with ultraviolet light, that is, the temperature of the sewage water 36 that is discharged from the treatment end. a second temperature sensing element 11b that detects the water temperature of the sewage 36, and each of these temperature sensing elements 11a.
, a temperature change detection section comprising a calculation unit 12 which inputs and calculates temperature signals output from the temperature change detection section; and a display that displays the light emission state of the non-electrode arc tube 33 in accordance with the output signal of the temperature change detection section. It is composed of a container 13.

The first temperature sensing element 11a consists of a thermocouple, and is installed at any location on the pipe leading to the treatment tank 35, which is the irradiation space, and measures the normal water temperature Ta of the sewage 36 before being irradiated with ultraviolet light as described above. do. The second temperature detection element 11b is also composed of a thermocouple, so that it can measure the treated water temperature Tb of the sewage 36 after being irradiated with ultraviolet light.

It is disposed near the processing tank 35 of a pipe connected to the processing tank 35. In addition, the computing unit 12 is connected to each temperature sensing element 11a.
, llb, and calculates the temperature change ΔT between the normal water temperature -Ta and the treated water temperature Tb, and changes the output signal according to the calculation result. The display 13 to which the output signal of the arithmetic unit 12 is input is provided externally to display the light emitting state of the electrodeless arc tube 33, as described above.

Next, the operation of the light emission monitoring means 10 configured as described above will be described.

When the electrodeless arc tube 33 almost completely absorbs the microwave radiated from the conductive antenna 34 and emits normal ultraviolet light, there is no change in the water temperature of the sewage 36 in the treatment tank 35. Therefore, the temperature difference 'r between the normal water temperature Ta and the treated water temperature Tb mentioned above becomes almost zero, and the calculation result of this calculator 12 is transmitted to the display 13.
3 indicates that the light emitting state is normal.

If an abnormality occurs in the electrodeless arc tube 33, such as when the emitted substance sealed in the electrodeless arc tube 33 decreases due to deterioration or damage over time, the microelectrode arc tube 33 Wave absorption is reduced.

Therefore, the microwave leaks out of the electrodeless arc tube 33. This leaked microwave is completely absorbed by the sewage water 36 that is the object to be irradiated within the treatment tank 35 . In other words, sewage 3
6 is subjected to microwave dielectric heating in the treatment tank 35, so the treatment water temperature Tb increases.

Here, if the temperature change ΔT is outside the predetermined range, the computing unit 12 detects that a large amount of microwave has leaked,
As mentioned earlier, the calculator 12 displays the result of this calculation on the display 1.
Output to 3. In response to this, the display 13 displays 2, for example, an error in the arc tube. The predetermined range of the temperature change ΔT, which is the detection standard for the display contents, depends on the volume of the treatment tank 35, the flow rate of the sewage 36 being supplied, the intensity of the microwave radiated from the conductive antenna 34, etc. of the light irradiation device. In this embodiment, the temperature of the incoming sewage is about 10°C, the volume of the treatment tank 35 is 301, and the flow rate of the sewage 36 to be supplied is 10 l/min, although it is determined as appropriate depending on the structure etc.
, ? The microwave intensity is a light irradiation device with a processing capacity of 1 kW, and it is set so that when 70% or more of the microwaves emitted to the electrodeless arc tube 33 leaks, an error message is displayed on the arc tube. Therefore, the range of T corresponding to this temperature change is predetermined as ±2°C, and if it is within this range, it is considered normal, and if it is out of this range, it is considered abnormal.

Further, as shown in FIG. 2, sewage 36 is caused to flow into the electrodeless arc tube 33 located within the microwave propagation space 37,
A case will be described assuming a light irradiation device that irradiates ultraviolet light. Regarding the light emission monitoring means arranged in this device, a first temperature sensing element 11a is installed in the pipe leading to the processing tank 35.
The structure is such that the second temperature sensing element 11b is disposed near the processing tank 35 on the pipe passing through the processing tank 35. Further, in this case, consideration is given to the increase in the temperature Tb of the treated water that is directly caused by the microwave dielectric heating of the sewage water 360 that occurs in the gap 39 between the wall surface 38 surrounding the 2-inch four-wave propagation space and the end of the electrodeless arc tube 33.

It is preferable that the arithmetic operation of the arithmetic unit 12 be carried out.

In the above embodiment, since the first temperature sensing element 11a and the second temperature sensing element 11b may be disposed in a pipe communicating with the processing tank 35, the irradiation space 35 of the existing device
It can be easily installed and light emission monitoring can be performed.

Further, in the above-described embodiment, the first temperature sensing element 11a is provided in the pipe leading to the processing tank 35, but it may be arranged in the processing tank 35 near the pipe.

The temperature sensing element can be arranged without being limited to the above-described embodiment, such as by arranging the second temperature sensing element 11b near the pipe of the processing tank 35.

As another example, as shown in FIG.
The computer 121 may be placed in the computer and connected to the arithmetic unit 121. Here, the computing unit 121 differentiates the temperature signal output by the temperature detection element 11 by a predetermined time, calculates the temporal change in water temperature of the sewage water 36, and calculates the leakage of microwaves from the electrodeless arc tube 33. It is something that senses things. In other words, if the electrodeless arc tube 33 almost completely absorbs the microwave radiated from the conductive antenna 34 and emits normal ultraviolet light, the temporal water temperature change calculated by the calculator 121 However, if an abnormality occurs in the electrodeless light emitting tube 33 and the absorption of microwaves decreases, the temporal water temperature change will become large, and the computing unit 12+ will detect that a large amount of microwaves leak from the electrodeless light emitting tube g33. This calculation result is sent to the display 13.

According to this embodiment, since it is sufficient to dispose one temperature detection element for detecting the temperature of the sewage water 36 in the treatment tank 35, the number of components constituting one light emission monitoring means can be reduced.

In the above embodiments, a light irradiation device using an electrodeless arc tube that emits ultraviolet light as a light source has been described.
Except for light emission in the infrared region, which causes a significant temperature rise of the irradiated object, for example, visible light is irradiated onto the irradiated object, a fluid;
A light irradiation device used to optically inspect impurities contained in an object to be irradiated also has the above-mentioned configuration.

The light emitting state of the electrodeless arc tube can be monitored.

In addition, in all of the above embodiments, a thermal lightning pair is used as the temperature sensing element, but the present invention is not limited to this, and it is also possible to use a temperature sensing element such as a platinum resistance thermometer, a transistor temperature sensor, etc. . In addition, in order to clearly show the light emitting state of the electrodeless arc tube to the outside world, the light emitting state is displayed using two indicators, but this can also be done by using a recognition means such as a buzzer. The light emitting state can also be clearly indicated by means for stopping the supply of a certain fluid or means for stopping the supply of microwaves.

In addition, in one or more embodiments, light is irradiated onto sewage, but the object to be irradiated is not limited to this.
Any fluid that absorbs microwaves, such as tap water, ultrapure water, fluid foods, fluid chemicals, etc., can have the same structure as the above-mentioned embodiments and still achieve the effects of the present invention.

In addition, in the above implementation full, a magnetron, a rectangular waveguide,
Microwaves are supplied and propagated by antennas,
The configuration is not limited to this one, and microwaves that cause the electrodeless arc tube to emit light may be supplied in any configuration.

〔Effect of the invention〕

According to the present invention, no optical measuring means is used.

Since it is equipped with a means to detect the temperature change of the irradiated object caused by absorbing the microwave leaked from the arc tube, it does not increase the luminous efficiency.

The light emitting state of an electrodeless arc tube can be monitored with stable sensitivity.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of one embodiment of the light irradiation device according to the present invention, Figs. 2 and 3 are schematic diagrams of other embodiments, and Fig. 4 is a schematic diagram of a conventional example (1). ...... Luminescence monitoring means. 11, lla, llb...Temperature sensing element. 12.12'...... Arithmetic unit. 13... Display unit. 30...Microwave source. 33... Electrodeless arc tube. 35...... Processing tank (irradiation space). 36...Irradiated object Figure 3 Figure 4

Claims (1)

[Claims] A light having a microwave supply source that supplies microwaves, an electrodeless arc tube that absorbs the microwave and emits light, and an irradiation space that irradiates an object with the light emitted from the arc tube. In the irradiation device, leakage from the arc tube;
A light irradiation device characterized by comprising a light emission monitoring means for monitoring the light emission state of the light emitting tube by detecting a temperature change of the irradiated object caused by absorbing the microwaves that have reached the irradiation space. .