JPS59186684A - Process for maintaining high output of low pressure ultraviolet ray lamp used in ultraviolet ray treatment of service water and waste water and low pressure ultraviolet ray lamp therefor - Google Patents

Abstract

PURPOSE:To maintain the dose of short wavelength ultraviolet rays at high output level by controlling voltage and intensity of current to be supplied to a low pressure ultraviolet ray lamp basing on the detected temp. of the water to be treated at the lower temp. side than the peak value of the dose of a short wavelength ultraviolet ray lamp of low pressure. CONSTITUTION:A temp. detector 5 is provided to the inside of a treating tank 1 and connected to a temp. detecting unit 6 provided to the outside of the tank 1. The temp. in the treating tank 1 detected by the temp. detector 5 is used as the control signal for the temp. detecting unit 6 which is added to a dimmer device 7 provided to a low pressure mercury lamp 2. The voltage or intensity of current to be supplied to the low pressure mercury lamp 2 is controlled in the dimmer device 7 by the above described signal and is supplied to a lighting device 8 of the low pressure mercury lamp 2. The waste to be treated is fed at ca. 10-40 deg.C water temp. to the treating tank 1 in the above described water treating apparatus. On one hand, the operation of the low pressure mercury lamp 2 is preferred to be set to result 20-30 deg.C temp. as optimum temp.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for maintaining a high output of short-wavelength ultraviolet rays emitted from a low-pressure mercury lamp in an ultraviolet irradiation treatment method for industrial wastewater using a low-pressure ultraviolet mercury lamp, and a low-pressure ultraviolet ray used in the method. It concerns mercury lamps.

Ultraviolet irradiation treatment methods for industrial wastewater using ultraviolet mercury lamps have conventionally included sterilization, deodorization, decolorization, and carbon dioxide treatment of industrial wastewater.
For OD treatment, etc., there are known methods in which ultraviolet rays are irradiated singly into the water to be treated from a low-pressure mercury lamp, or methods in which ultraviolet rays are irradiated with ozone while blowing ozone into the water to be treated.

In the ultraviolet irradiation treatment method for wastewater for these purposes, short wavelength ones (mainly consisting of germicidal radiation) are more effective than long wavelength ones, so mercury lamps with wavelengths of 365? H7L
Rather than the high-pressure or ultra-high pressure mercury lamps that emit long-wavelength ultraviolet rays as mentioned above, UV rays with wavelengths of 254 nm and 313 nm are used.
Low-pressure mercury lamps are used, which mainly emit ultraviolet rays with short wavelengths such as m.

However, when the ambient temperature of low-pressure mercury lamps increases, the internal pressure of the mercury lamp also increases.
A large amount of ultraviolet rays with long wavelengths such as 15 nm and 565 nm are generated.

Furthermore, if the ambient temperature of the mercury lamp is too low, the necessary excitation cannot be obtained inside the mercury lamp, and a sufficient output of ultraviolet rays cannot be obtained.

Therefore, as shown in Figure 1a, a bell-shaped curve can be drawn between the ambient temperature of a mercury lamp and the amount of short-wavelength ultraviolet rays centered on the optimal ambient temperature at which the amount of short-wavelength ultraviolet rays reaches its peak value. .

In many commercially available low-pressure mercury lamps, the optimum ambient temperature is set to about 0°C.

Furthermore, commercially available low-pressure mercury lamps generally have a protective tube made of quartz or the like covering their outer periphery.

This is to ensure insulation when the mercury lamp is inserted into the water to be treated, and at the same time to prevent mercury from entering the water to be treated due to breakage of the mercury lamp.

However, on the other hand, since the outer circumference of the mercury lamp is protected by a quartz tube, there is a considerable difference between the water temperature of the water to be treated and the ambient temperature of the mercury lamp inside the quartz tube, and even when the water temperature is low, the ambient temperature may already have reached the optimum ambient temperature.

Also, if a protective tube such as a quartz tube is installed around the mercury lamp,
The protection tube itself absorbs the ultraviolet rays, resulting in a decrease in the efficiency of ultraviolet irradiation. That is, when a high-quality quartz tube is used as a protective tube, it usually absorbs about 20% of ultraviolet rays, especially ultraviolet rays in a short wavelength range such as 254 nm, and the amount of ultraviolet rays irradiated to the water to be treated is reduced.

Furthermore, the oxygen in the air between the mercury lamp and the protection tube is converted into ozone by ultraviolet rays, but since ozone absorbs ultraviolet rays in the short wavelength range well, the amount of ultraviolet rays irradiated to the water to be treated is reduced. It will decrease.

The intensity of ultraviolet light from a mercury lamp, which is a single light source, attenuates in inverse proportion to the square of the distance. Since the diameter of the treatment tank cannot be made too large, there is a large degree of freedom in the diameter of the protection tube. In other words, when the diameter of the protection tube is small, the ventilation effect decreases, and when it is large, the effective volume of the treatment tank decreases, reducing the sterilization capacity1. Using a mercury lamp
The aim is to maintain a high output of short-wavelength ultraviolet rays emitted from a low-pressure mercury lamp in the ultraviolet irradiation treatment method for industrial wastewater. When inserted into the water to be treated, and at a temperature lower than the peak value of the short-wavelength ultraviolet rays of the low-pressure mercury lamp, the voltage or current amount supplied to the low-pressure mercury lamp is adjusted according to the water temperature of the water to be treated, which is detected by a detector. It controls and adjusts the amount of short wavelength ultraviolet rays to maintain the amount of short wavelength ultraviolet rays at a high output.

In other words, by directly inserting a low-pressure mercury lamp into the water to be treated without providing a protective tube around its outer circumference, the ambient temperature around the low-pressure mercury lamp will not become abnormally high even though the water temperature is low; Since the mercury lamp is not saturated at temperatures lower than the peak value of the short-wavelength ultraviolet rays of the low-pressure mercury lamp, the temperature of the water detected by the detector varies depending on the temperature of the water to be treated.
By controlling the voltage or current supplied to the low-pressure mercury lamp (F), it is possible to increase the amount of short-wavelength ultraviolet rays to compensate for the weight loss in the low-temperature range, so it is possible to maintain the amount of short-wavelength ultraviolet rays at a high output. (Figure 1b).

The present invention will be explained below based on the illustrated embodiment. Figure 2 shows an embodiment in which the present invention is applied to an ultraviolet irradiation treatment method using ozone, and / indicates a treatment tank. The water to be treated is fed into the tank through an inlet/a provided at the lower end and discharged to the outside through an outlet/b provided at the upper end.

A low-pressure mercury lamp is inserted into the treatment tank without an external protection tube, and an ozone supply pipe 3 is connected below the low-pressure mercury lamp.

A diffuser plate is provided.

Ozone is supplied from an externally installed ozone generator or the like from the ozone supply pipe 3, and this ozone becomes bubbles from the diffuser plate and is sent into the processing tank, while the low pressure The mercury lamp emits ultraviolet rays in the short wavelength range. A portion of the irradiated ultraviolet rays is sent into the treatment tank and activates ozone bubbles to sterilize, deodorize, bleach or color the water to be treated. Purification treatment such as removal of COD is effectively carried out.

There is no temperature sensor S installed in the processing tank constructed as described above, and this temperature sensor S is connected to a temperature detection unit B provided outside. The temperature inside the processing tank/was used as a control signal by temperature detection unit A, and this control signal was sent to the low-pressure mercury lamp through a narrow gap.
1. In addition to the vM light device 7, the dimmer device 7 is configured to control the voltage or current supplied to the low-pressure mercury lamp unit by the above control signal and apply it to the lighting device g of the low-pressure mercury lamp unit.

In the treatment equipment configured as above, the water to be treated is 1
The water is sent into the treatment tank at a temperature of about 0 to 40°C.

On the other hand, the optimal temperature of the low-pressure mercury lamp inserted into the treatment tank is set as close to the upper limit of the temperature change range of the water to be treated as possible, for example, close to 40° C. in the above water temperature range. However, in general, the optimum temperature for low-pressure mercury lamp operation is 2.
Since it is preferable to set the temperature in the range of 0 to 30°C, in this case, the temperature of the water to be treated is adjusted to keep the upper limit to 20 to 0°C.

In addition, in this invention, the low-pressure mercury lamp is inserted into the water to be treated without providing an external protective tube such as a quartz tube, so there is almost no difference between the water temperature and the ambient temperature of the low-pressure mercury lamp. When there is no difference in temperature and the water temperature reaches the optimum operating temperature of the low-pressure mercury lamp, the amount of short-wavelength ultraviolet rays (mainly the germicidal dose) reaches its peak value.
is generated and irradiated into the water to be treated.

On the other hand, if the water temperature is lower than the optimum operating temperature of the low-pressure mercury lamp, this water temperature is detected by the temperature detector S, and from this,
The control signal controls the dimmer 7 to increase the voltage or current supplied to the low-pressure mercury lamp λ and applies it to the lighting device g.

In addition, in this invention, the optimum temperature of the low-pressure mercury lamp is set as close as possible to the upper limit of the water temperature change range of the water to be treated. Therefore, on the lower side of the optimum temperature, the mercury lamp is in an unsaturated state, and the mercury lamp is supplied to the mercury lamp. When the voltage or current amount is increased,
The amount of short-wavelength ultraviolet rays irradiated from the low-pressure mercury lamp can be increased in proportion to this.

Therefore, as mentioned above, when the temperature is lower than the optimum temperature of the low-pressure mercury lamp, if the voltage or current amount is increased and applied to the lighting device g to compensate for the reduction in the amount of short-wavelength ultraviolet rays, the short-wavelength It is possible to irradiate an amount of short wavelength ultraviolet rays comparable to the peak value of the amount of wavelength ultraviolet rays.

Therefore, in the present invention, the amount of short-wavelength ultraviolet rays can be maintained at a high output over the entire temperature change range of the water to be treated, and effective purification treatment can be performed.

In addition, in this invention, since the mercury lamp unit is directly inserted into the water to be treated without providing a protective tube around the outer circumference of the mercury lamp unit, the surface of the mercury lamp unit is constantly cooled by the water to be treated. operation can be stabilized.

Furthermore, unlike conventional mercury lamps, the ultraviolet rays emitted from the mercury lamp are not absorbed by the protective tube such as a quartz tube, and the ozone generated between the mercury lamp and the protective tube absorbs ultraviolet rays in the short wavelength range. There are many things.

Therefore, in the mercury lamp of the present invention, high-output ultraviolet rays could be continuously irradiated for a long period of time. In contrast, a mercury lamp is surrounded by a quartz tube with one end open (a mercury lamp is surrounded by an open-jacket illiterate quartz tube).
The round-sealed jacket type) was unable to irradiate high-power ultraviolet rays for a long time (see Figure 5).

In this invention, the mercury lamp is directly inserted into the water to be treated without providing a protective tube around its outer periphery, and FIG. 4 shows the mercury lamp used for this purpose.

According to FIG. 4, both ends of the U-shaped mercury-filled tube 9 in which mercury and inert dregs such as Alcon are sealed form base tube portions α and α with relatively small diameters, and base tube portions 9a, Electrodes 99b, 9b are provided at the tips of 9α, and lead wires are drawn out from the electrode portions qb, qb to be connected to an external light control device 7.

Reference numerals 10 and 10 are joint tubes having approximately the same diameter as the mercury-filled tube 9, and the joint tubes 10 and 10 have an electrode section at the tip as described above. b.

The base tube portions 9a, 9a of the mercury-filled tube 9 provided with the mercury-filled tube 9b are inserted, and the base tube portion α is further inserted into the joint tube 10.10.

9a and the electrode parts qb, qb are filled with a sealing material such as a non-hardening synthetic resin, such as a silicone-based synthetic resin.
to connect the joint tube 10.10 and the mercury-filled tube 9.

Further, a disk-shaped plate 7 is provided at the upper end of the joint pipes 10, 10.
．． 2, and the lower blade of the mercury-sealed tube 9 is provided with a support member consisting of a dish member /3 having a downward protrusion /3a at the center of its bottom and a support plate //I for fixing the opening /a.

The dish member /3 is placed on the support plate lll by inserting the downward protrusion /(la into the opening /lla, and a cushion backing /S is interposed on the dish member /3, and the lower end of the mercury-sealed tube is make the person accept the part.

On the other hand, a plurality of holding rods /A, . Spacer/7 in between
intervene.

In addition, threaded grooves are provided at both ends of the holding rod/B, and the plate plate/Ω and the holding member/3 to the support plate/guidance are protruded from the joint pipe 10, which is connected with a sealing material//. 10 and the mercury-sealed tube 7 are sandwiched between the supporting cylinders consisting of a grate plate/1g and a plate member/3 to support plate/g.
・Attach the holding rod /A,... to the plate plate 7.2 and the dish member /3.
or fixed to a support plate.

In addition, the extension %f10. In order to maintain airtightness inside the lo, in this embodiment, an upper cover is provided at the upper end of the plate 7.2.
A is provided, and a lower cover/qb is further provided at the lower end of the plate via a ground backing 20. Also,!
/ is a guide rod for assembling the device.

As described above, the low-pressure mercury lamp is inserted directly into the treatment tank without providing a storage tube around its outer periphery, but according to this embodiment, the low-pressure mercury lamp is The pipe has a U-shape, and there is a holding bar/4. ... is provided, and at the same time, both ends of the mercury-filled tube are inserted into the joint tube 10.10, and the two tubes are connected by filling the insertion portion with a sealing material of non-hardening synthetic resin. Therefore, it has high mechanical strength and is difficult to receive external shock, and the external shock is absorbed by the sealing material.

Therefore, according to this embodiment, the low pressure mercury lamp is
Even if the t's is inserted into the treatment tank, there is no risk of the mercury lamp being damaged inside the treatment tank, and ultraviolet irradiation treatment of the water to be treated can be carried out extremely safely. Since it is coated with an insulating sealant made of silicone-based synthetic resin, there is no risk of electrical leakage even if it is inserted into the water to be treated, making it ideal for use in the present invention.

[Brief explanation of the drawing]

Figure 1 compares the relationship between changes in ambient temperature and short-wavelength ultraviolet light intensity reduction rate in low-pressure mercury lamps according to the conventional method and the present invention. Relationship curve between and the amount of short-wavelength ultraviolet rays, Figure 1 (/,)
is a relationship curve between the ambient temperature of the low-pressure mercury lamp of the present invention and the short-wavelength ultraviolet rays, FIG. 2 is a schematic diagram showing an embodiment of the present invention, and FIG. Figure 4 shows the mercury lamp used in the present invention, and Figure 4(a) is a 1m side view;
FIG. 4(b) is a longitudinal cross-sectional view of the same as above. In the figure, / is a treatment tank, S is a low-pressure mercury lamp, and the left is a temperature detector.
B is a temperature detection unit, 7 is a light control device, g is a lighting device,
9 is a mercury-filled tube, 10, 10 are joint tubes, // is a sealing material, /A, . . . are holding rods.

Claims (2)

[Claims] (1) In the ultraviolet irradiation treatment method for industrial wastewater using a low-pressure mercury lamp, the low-pressure mercury lamp is directly inserted into the water to be treated without providing a protective tube around its outer periphery, and the peak value of the amount of short-wavelength ultraviolet rays of the low-pressure mercury lamp is On the lower temperature side, the amount of short-wavelength ultraviolet rays is adjusted by controlling the voltage or amount of current supplied to the low-pressure mercury lamp according to the temperature of the water to be treated detected by a detector. A method for maintaining high output of ultraviolet low-pressure mercury lamps during ultraviolet irradiation treatment. (2) A relatively small-diameter base tube portion is formed at both ends of the U-shaped mercury-filled tube, an electrode portion connected to a lead wire is provided in the base tube portion, and the base tube portion is further inserted into the joint tube. , the insertion part is filled with a non-hardening synthetic resin, and a plurality of holding rods are provided on the outer periphery of the mercury-filled tube, and a high output is maintained in the ultraviolet irradiation treatment of wastewater. Ultraviolet low pressure mercury lamp.