JPH10214592A - Bactericidal lamp and bactericidal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong the life of a bactericidal lamp and enhance efficiency. SOLUTION: Since a discharge tube 1 is made of quartz, mercury vapor staying inside of the tube 1 cannot be combined with a material of the discharge tube 1 even after a lapse of time, thereby preventing any absorption of an ultraviolet ray by the tube material even after a lapse of time so as not to reduce a radiant level. Since an electrode coil 3 is a cold cathode of a cylindrical structure having a groove in a discharge space, it operates in a hollow cathode mode, thus suppressing sputtering of the electrode. Furthermore, since a distance between the periphery of the electrode coil 3 and the wall of the discharge tube 1 is smaller than the inner diameter of the groove, no cathode glow can be intruded between the periphery of the electrode coil 3 and the tube wall, in which sputtering can be suppressed and the tube wall cannot be blackened even after a lapse of time. Consequently, the lifetime of a lamp can be remarkably prolonged. Noble mixture gas including Ne is enclosed in the discharge tube 1, so that a positive column is widened inside the tube during electric discharge. Moreover, the positive column is longer than the diameter of the discharge tube, thereby enhancing radiant efficiency of an ultraviolet ray.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a germicidal lamp for irradiating ultraviolet rays used for sterilizing hot water and the like, and a germicidal apparatus using the germicidal lamp.

[0002]

2. Description of the Related Art Conventionally, in this kind of germicidal lamp, the discharge tube is composed of soft glass with reduced sodium and lead contents, so that mercury in the discharge tube causes alkali and alkaline earth components in the soft glass to be reduced. And gradually combine over time. Thereby, the mercury combined with the alkali component and the alkaline earth component absorbs ultraviolet light having a spectrum of 253 nm effective for sterilization emitted from the mercury, and the sterilizing effect is reduced. The amount of mercury combined with the alkali component and alkaline earth component increases with time, and accordingly, the ultraviolet rays having a 253 nm spectrum absorbed by the mercury increase. For this reason, the amount of ultraviolet light having a spectrum of 253 nm radiated from the germicidal lamp to the outside in a relatively short time (3000 hours) is reduced, and there is a problem that the life of the germicidal lamp is short.

In particular, a germicidal lamp used in a germicidal apparatus for sterilizing hot water for 24 hours in a bath or the like requires a lamp life of about three years (30000 hours or more) in order to reduce the number of replacements of the germicidal lamp and facilitate maintenance. However, the conventional germicidal lamp described above has a problem that it does not satisfy the specifications at all.

[0004]

In the above-mentioned conventional germicidal lamp, mercury in the discharge tube is combined with alkali and alkaline earth components in the soft glass used as the tube material, so that the 253 nm effective germicidal radiation of mercury is effective. Since the ultraviolet rays of the spectrum are absorbed by the tube wall, the level of ultraviolet rays radiated to the outside decreases with time, and the sterilizing effect is reduced, so that the life is short. For this reason, there has been a problem that the specification of the sterilizer which requires a lamp life of about three years is not satisfied at all.
Ultraviolet lamps using a quartz discharge tube that does not contain alkali or alkaline earth components have also been put into practical use, but those that have been put to practical use have a large tube size and are inconvenient to use. In comparison with this, there are problems such as a large tube diameter and low ultraviolet radiation efficiency.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a germicidal lamp having a long life and high efficiency, and a germicidal apparatus using the germicidal lamp, which can be easily maintained.

[0006]

According to a first aspect of the present invention, there is provided a discharge tube formed of a material which transmits ultraviolet light and having a discharge medium sealed therein, and a discharge tube provided at both ends of the discharge tube and having a discharge space side. The cold cathode has a cylindrical portion having a concave portion, and the distance between the outer peripheral portion of the cylindrical portion and the inner wall surface of the discharge tube is smaller than the inner diameter of the concave portion of the cylindrical portion.

With such a configuration, the pair of electrodes form a cold cathode by forming a cylindrical structure having a depression on the discharge space side. Therefore, when a high frequency voltage of about 800 V is applied to the electrode tube, both electrodes are turned off. Since hollow-mode discharge occurs in the tube, sputtering of an electrode material such as tungsten or molybdenum is suppressed. Further, by making the distance between the outer peripheral portion of the electrode and the inner wall of the discharge tube smaller than the inner diameter of the recess of the same electrode, the cathode glow is prevented from entering between the outer peripheral portion of the electrode and the inner wall of the discharge tube. Has been confirmed by experiments. Therefore, sputtering of the electrode material on the outer peripheral portion of the electrode is suppressed. When the sputtering is suppressed in this manner, the inner wall of the discharge tube does not blacken even with the lapse of time, and for this reason, the level of ultraviolet radiation to the outside of the tube does not decrease with time. The electrode is formed easily and lightly by winding a wire around an electrode axis, for example. Furthermore, if the discharge tube is formed of quartz or alumina silicate that does not contain alkali or alkaline earth components, mercury in the tube does not adhere to the tube wall even after a lapse of time. For this reason, the ultraviolet ray of 253 nm is not absorbed by the tube wall, and the level of ultraviolet radiation to the outside of the tube does not decrease over time due to the above reason. At least in the depressions of the electrodes or between the layers of the double coil forming the electrodes, at least one of oxides of the first, second, third, fourth, fifth and sixth groups of the periodic table. If one type is applied or impregnated, the work function of the electrode is reduced, so that photoelectrons are easily emitted and the lighting performance of the discharge tube is improved. In addition, when the oxide is impregnated between the layers of the double coil, oxide consumption due to sputtering is greatly reduced. The discharge tube has a diameter of 8 mm.
If the length is made longer than that of the tube diameter, the discharge path becomes longer, and ultraviolet rays are efficiently radiated out of the tube.

The electrode according to the second aspect of the present invention is formed by winding a conductive wire around a plurality of layers around the outer periphery of an electrode shaft.

With this configuration, for example, even if the inner diameter of the depression of the electrode or the inner diameter of the discharge tube is determined for various reasons, the number of layers of the conductive wire wound around the electrode shaft can be adjusted. Accordingly, the condition that the distance between the outer peripheral portion of the electrode having the cylindrical structure and the inner wall of the discharge tube is smaller than the inner diameter of the depression of the electrode can be satisfied, and the sputtering of the electrode material can be suppressed. For this reason, the size of the inner diameter of the discharge tube and the inner diameter of the depression of the electrode can be set quite freely, and the design of the germicidal lamp becomes free accordingly.

According to a third aspect of the present invention, a thin film of an oxide of an element of Group 3 of the periodic table is formed on at least the inner wall of the discharge tube.

With such a configuration, examples of the oxides of the elements of Group 3 of the periodic table include alumina, gallium oxide, yttrium oxide, lanthanum oxide, and cerium oxide. The third electrode formed on the inner wall of the discharge tube
A thin film of an oxide of the group element prevents mercury from adhering to the tube wall. Therefore, even if the discharge tube is formed of soft glass, the thin film prevents mercury from being combined with the alkali component or alkaline earth component of the tube material, so that the discharge tube is formed of quartz or alumina silicate. In addition, mercury does not adhere to the tube wall. For this reason, the ultraviolet ray of 253 nm is not absorbed by the tube wall, and the level of ultraviolet radiation to the outside of the tube does not decrease over time due to the above reason. If the thin film is formed on the inner wall of a discharge tube made of quartz or alumina silicate, the adhesion of mercury to the tube wall is more completely prevented.

According to a fourth aspect of the present invention, the filling in the discharge tube includes a mixed gas of Ne and another rare gas.

[0013] With such a configuration, in addition to mercury, a gas in which Ne is mixed with at least one element of, for example, argon, krypton, and xenon is sealed in the discharge tube. More specifically, for example, 10 mg of mercury
e A gas mixture of 97% -Ar3% of 10,000 Pascal is sealed in the discharge tube. Thereby, at the time of discharge, the diffusivity of electron mercury is improved by Ne, and the positive column spreads widely on the cross section of the tube, so that ultraviolet rays having a mercury resonance line of 253 nm are efficiently emitted.

According to a fifth aspect of the present invention, assuming that the inner diameter of the hollow of the cylindrical electrode is Dcm, the depth of the hollow is dcm, and the pressure of the filled gas is p Pascal, pD ≧ 2500 and d ≧ 0.5D
To satisfy.

With such a configuration, if the conditions of pD ≧ 2500 and d ≧ 0.5D are satisfied, the discharge tube is stable in the hollow mode by experiments, even if the size of the discharge tube and the size of the electrode are changed. And the sputtering is suppressed. Therefore, the size and the shape of the discharge tube can be easily reduced as long as the conditions of pD ≧ 2500 and d ≧ 0.5D are satisfied.

According to a sixth aspect of the present invention, the discharge tube is bent into a U-shape.

With such a configuration, even if the discharge path in the discharge tube is lengthened, the length of the germicidal lamp is short, so that the germicidal lamp can be downsized as a whole. Further, lead wires from the electrodes provided at both ends of the discharge tube are arranged close to each other in the same direction, so that the lead wires do not have to be routed.

According to a seventh aspect of the present invention, there is provided a container in which water flows in and out, and a container arranged in close proximity to the container.
The germicidal lamp according to any one of the above, and a power supply device that supplies power to the germicidal lamp.

With such a configuration, when a high frequency voltage of, for example, about 800 V (or a low frequency of about the commercial frequency) is supplied to the germicidal lamp from the power supply device, the germicidal lamp is turned on, and ultraviolet rays of 253 nm are arranged in close proximity. Irradiates a container formed of an ultraviolet transmitting member. Accordingly, the warm water flowing into the container is sterilized by the ultraviolet light from the sterilizing lamp, and then flows out.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the first embodiment of the germicidal lamp of the present invention.
FIG. 3 is a side view showing the configuration of the embodiment. However, the illustrated germicidal lamp omits the central part of the discharge tube, and mainly shows the electrode housing at the tube end. 1 is a discharge tube portion made of quartz (or made of alumina silicate), 2 is an exhaust tube tip portion cut by discharging air or the like from the discharge tube portion 1, 3 is an electrode coil made of dangsten which operates in a follow mode, and 4 is A dungsten electrode shaft 5 around which the electrode coil 3 is wound, a molybdenum foil 5 connected to the electrode shaft 4 for adjusting the coefficient of thermal expansion of the electrode portion,
Reference numeral 6 denotes outer wells which are conductive wires connected to the molybdenum foil 5 and taken out from the enclosing portion 7, and 7 denotes quartz (or alumina silicate) integrally formed at the end of the quartz discharge tube portion 1. Is a mercury sealed in the discharge tube portion 1.

FIG. 2 is a sectional view showing a detailed example of the electrode section shown in FIG. An electrode coil 3 is formed by winding a conductive wire around the electrode shaft 4 in two layers. The tip of the electrode shaft 4 is disposed so as to be retracted by d from the tip of the electrode coil 3, and the inner diameter of the electrode coil 3 is D. The distance between the outer diameter of the electrode coil 3 and the inner wall of the discharge tube 1 is l,
The inner diameter of the discharge tube part 1 is L. Incidentally, the inner diameter of the coil,
The outer diameter is the distance between the tangents of the circular section of the coil as shown in the figure.

Next, the configuration of the present embodiment will be described in more detail. An electrode coil 3 made of a tungsten wire is wound around an electrode axis 4 having a diameter D (cm). The electrode coil 3 is formed by double winding (double layer winding). The electrode axis 4 at the center of the electrode coil 3 has a depth d (c
m), forming a so-called hollow cathode electrode. The distance between the electrode coil 3 and the tube wall of the discharge tube portion 1 is 1 apart. The other end of the electrode shaft 4 protrudes from the discharge tube portion 1 to the sealing portion 7 and is connected to a molybdenum foil 5. The molybdenum foil 5 is further connected to an outer well 6 outside the sealing portion 7. The sealing portion 7 seals the electrode portion and the conductive portion to this electrode portion to the discharge tube portion 1 while maintaining a vacuum. Further, an exhaust pipe tip portion 2 evacuated from the discharge tube and cut off remains in a portion of the discharge tube portion 1 away from the electrode coil 3.

Here, an example of actual dimensions of a portion where the electrode coil 3 shown in FIG. 2 is mounted is described as follows.
The inner diameter L of the discharge tube part 1 is 0.4 cm, and the inner diameter D of the depression of the electrode coil 3 is O.D. 12 cm, the depth d of the depression of the electrode coil 3 is 0.2 cm, and the distance 1 between the outer peripheral portion of the electrode coil 3 and the inner wall of the discharge tube portion 1 is 0.05 cm. At this time, the outer diameter of the discharge tube portion 1 is 0.6 cm, and the total length of the tube is 35 cm. 10 mg of mercury and Ne9
About 10,000 Pa (10,000 Pascal, about 80 Torr) is filled with a mixed gas of 7% -Ar 3%.

With such a configuration, an external power supply (not shown) passes between the two electrode coils 3 through the outer wells 6.
When a high-frequency voltage of about 00 V is applied, discharge starts in the tube of the discharge tube unit 1, a discharge current of about 16 mA flows, and Hg atoms in the tube are excited to emit 253 nm ultraviolet rays, which are resonance lines. Thereby, the function as a germicidal lamp is exhibited.

As described above, the electrode structure of the present embodiment is formed of a cold cathode having a cylindrical structure, and has a depth d on the discharge space side of the coil electrode 3.
, The electrodes operate in a so-called hollow mode. That is, glow, which is light emission on the front surface of the cathode, is formed in the depression. As a result, in a general cold cathode, secondary electrons are emitted by the impact of mercury ions and discharge continues, so that the electrode material is scattered by the ions, for example, tungsten of the electrode material is sputtered, and the tube wall is blackened early. At the same time, it is possible to prevent the electrodes from being thin and the electrodes being worn out early and having a short life.

That is, in the electrode of this embodiment, since the cathode glow is formed inside the depression, 27k electrons for maintaining the discharge are emitted by the photoelectron effect of the cathode glow light emission. Therefore, the sputtering of the electrode material by the mercury ions does not occur so much, and even if it does occur, the electrode material is scattered on the inner surface on the opposite side of the dent because it is inside the dent, and leaks little to the outside of the dent.

For this reason, the blackening of the inner wall surface of the discharge tube portion 1 due to the sputtering is prevented, so that the radiation level of 253 nm ultraviolet rays to the outside of the tube due to the blackening does not decrease, and the electrode life is reduced. Is significantly longer. Furthermore, since the distance l between the outer peripheral surface of the electrode coil 3 and the inner wall surface of the discharge tube is smaller than the maximum diameter D of the cylindrical depression,
The cathode glow is rarely formed between the outer peripheral portion of the coil electrode 3 and the tube wall. Therefore, the sputtering of the coil electrode material does not occur on the outer peripheral surface of the electrode coil 3 and the black portion of the tube wall in this portion is not generated. Can be prevented. Therefore, the life of the discharge tube portion 1 is extended for the same reason as described above.

In this embodiment, the first, second, third, fourth, and fourth groups of the periodic table are arranged at least in the depressions of the electrode coil 3 or between the layers of the double coil of the electrode coil 3. 5
At least one of oxides of Group 6 and Group 6 elements is applied or impregnated. As a result, the work function of the electrode coil 3 is reduced, so that photoelectrons are easily emitted. In addition, when oxide is impregnated between the layers of the double coil, oxide consumption due to sputtering is greatly reduced.

Furthermore, a thin film of an oxide of an element of Group 3 of the periodic table, for example, alumina, gallium oxide, scandium oxide, yttrium oxide, lanthanum oxide, cerium oxide, etc., is formed on the inner wall of the discharge tube portion 1 of this embodiment. Is formed. This thin film prevents mercury or mercury oxide from adhering to the tube wall.

Incidentally, a mixed gas of a rare gas containing Ne (neon) is sealed as a sealing gas for the discharge tube portion 1 of the present embodiment. If a mixture of at least one of neon, argon, krypton, and xenon is used as the sealing gas, a so-called penning effect occurs, the discharge starting voltage and the like are reduced, and the lighting performance of the discharge tube 1 is improved. , It is easy to maintain the lighting state. Further, when discharging, Ne
The diffusivity of charged particles such as electron mercury is improved, the positive column widely spreads in the cross section of the discharge tube, and the mercury resonance line 253n
m is emitted efficiently and the potential gradient of the positive column is increased, so that the efficiency is further improved. If only a heavy gas such as argon is sealed, the positive column shrinks, and a stable discharge cannot be maintained.

As a result of an experiment with the above-described configuration in which the size of the discharge tube portion 1 and the size of the electrode were variously changed, the inner diameter of the hollow of the cylindrical electrode was D (cm) and the depth was d (cm). ,
When the filling gas pressure is p (Pa) and the distance 1 between the outer peripheral portion of the electrode coil 3 and the tube wall of the discharge tube portion 1 is: pD ≧ 2500 (cm · Pa) d ≧ 0.5D (cm) l <D It was found from the experiment that if the condition of (1) is satisfied, the lighting operation is stably performed in the hollow cathode mode, so that spattling hardly occurs. When the pressure is low or the electrode depression is small, the above condition is not satisfied and the hollow mode lighting is not performed, so that the cathode glow is formed on the outer surface of the coil electrode 3 and spattering occurs. I found out the result of the experiment.

According to the present embodiment, since quartz or alumina silicate is used as the material of the discharge tube portion 1, the mercury sealed in the discharge tube portion 1 is bonded to the tube material of the discharge tube portion 1. Can be prevented from adhering to the pipe wall.
As a result, even if time passes, 253n generated in the pipe
The ultraviolet rays of the m spectrum are not absorbed by the tube material of the discharge tube portion 1, and the level of the ultraviolet rays radiated out of the tube does not decrease with time, so that the life of the discharge tube can be extended. Further, by forming a thin film of an oxide of an element of Group 3 of the periodic table on the inner wall of the discharge tube section 1, it is possible to reduce the adhesion of mercury or mercury oxide to the inner wall of the tube, and the mercury is discharged. The connection to the tube material of the tube portion 1 is completely cut off, so that the life of the discharge tube can be prolonged.

Further, a cold cathode having a cylindrical structure is formed by the electrode coil 3 and the electrode shaft 4, and a hollow is provided on the discharge space side of the electrode, so that the electrode is operated in a hollow mode and the outer peripheral portion of the electrode coil 3 is By making the distance l to the inner wall of the discharge tube portion 1 smaller than the inner diameter D of the electrode coil 3, the sputtering of the electrode coil 3 can be substantially eliminated, and the inner wall of the discharge tube portion 1 can be prevented from being blackened. Life can be extended. Oxides of the first, second, third, fourth, fifth and sixth groups of the periodic table in at least the depressions of the electrode coil 3 or between the layers of the double coil of the electrode coil 3 Since at least one of them is coated or impregnated, oxide consumption due to sputtering can be prevented, the life of the electrodes can be extended, and the life of the discharge tube can be prolonged.

Furthermore, since the rare gas containing Ne is sealed in the discharge tube portion 1 together with the mercury, the positive column is expanded at the time of discharge, and the ultraviolet radiation efficiency of the 253 nm spectrum can be improved, and the discharge can be improved. Since the starting voltage can be reduced, the starting is facilitated, and the hollow mode discharge can be performed efficiently and stably. Further, in this example, the discharge tube has a tube diameter of 8 mm or less and has a tube length longer than the tube diameter, so that the ultraviolet radiation efficiency can be improved. Due to the above effects, the life of the discharge tube can be made three years or longer, and the ultraviolet radiation efficiency can be improved.

Since the material of the discharge tube portion 1 is quartz or alumina silicate, ozone is generated by the emission of vacuum ultraviolet light that converts oxygen in the air into ozone. If not used, not only will there be an adverse effect on the living body, but also only the problem of corrosion of metal parts near the germicidal lamp will remain. Therefore, by containing titanium oxide on the inner surface, outer surface, or inside the material of the discharge tube portion 1 to block vacuum ultraviolet rays and eliminate ozone generation, there is no adverse effect on living bodies and no corrosion of metal parts. A life-long germicidal lamp can be obtained.

Further, when a thin film of an oxide of an element of Group 3 of the periodic table is formed on the inner surface of the discharge tube 1, even if soft glass is used as the material of the discharge tube 1, mercury is generated in the soft glass. 253n effective for sterilization emitted by mercury because the thin film prevents the alkali and alkaline earth components from binding to
The absorption of ultraviolet light in the m spectrum is eliminated, and the life of the discharge tube can be greatly extended even when the soft glass is used.

FIG. 3 is a side view showing the structure of a second embodiment of the germicidal lamp according to the present invention. 1 is a discharge tube portion made of quartz (or alumina silicate), 2 is an exhaust tube tip portion,
Reference numeral 3 denotes a molybdenum electrode coil that operates in a follow mode, 4 denotes a molybdenum electrode shaft around which the electrode coil 3 is wound, 5 denotes a molybdenum foil that is connected to the electrode shaft 4 and adjusts a coefficient of thermal expansion of an electrode portion, 6 Is an outer wells which is a conductive wire connected to the molybdenum foil 5 and taken out from the enclosing portion 7, and 7 is a quartz (or alumina silicate) integrally formed at an end of the quartz discharge tube portion 1. This is the enclosed part. Further, the discharge tube portion 1 is bent in a U-shape, and a pair of outer wells 6 are pulled out in the same direction and arranged close to each other. The material of the electrode coil 3 and the electrode shaft 4 may be tungsten.

Next, the configuration of the present embodiment will be described in more detail. Inner diameter L = 0.35c of discharge tube part 1 made of quartz
m, inner diameter D of the depression of the electrode coil 3 = 0.1 cm, depth d of the depression of the coil electrode 3 = 0.1 cm, distance l = 0.05 cm between the outer peripheral portion of the molybdenum electrode coil 3 and the tube wall, discharge The outer diameter of the tube 1 is 0.7 cm, and the total length of the discharge tube 1 is 2 cm.
0 cm is bent into a U-shape. About 5300 Pa (40 Torr) of a mixed gas of 10 mg of mercury and 50% of Ne and 50% of Ar is sealed in the discharge tube section 1. When a high-frequency voltage of about 800 V is applied between the two electrodes in such a configuration, the discharge tube unit 1 starts discharging, and a voltage of about 20 V is applied.
mA current flows. This excites the Hg atoms in the tube and emits 253 nm ultraviolet rays, which are resonance lines.
Thereby, the function as a germicidal lamp is exhibited. Alumina is applied to the inner surface of the tube. Thereby, about 1 W of 253 nm ultraviolet light is emitted outside the tube.

The inner diameter of the hollow of the cylindrical electrode is represented by D (c
m), its depth is d (cm), and the charged gas pressure is p (P
a), assuming that the distance 1 between the outer peripheral portion of the electrode coil 3 and the tube wall of the discharge tube portion 1 is: pD ≧ 2500 (cm · Pa) d ≧ 0.5D (cm) If l <D is satisfied For the same reason as in the embodiment of FIG. 1, the above-mentioned U-shaped germicidal lamp can also take various dimensions.

The first, second, third, fourth, fifth, fifth, and fifth groups of the periodic table are arranged at least in the depressions of the electrode coil 3 or between the layers of the double coil of the electrode coil 3. At least one oxide of Group 6 is applied or impregnated. Further, a thin film of an oxide of an element of Group 3 of the periodic table, for example, alumina, gallium oxide, scandium oxide, yttrium oxide, lanthanum oxide, or cerium oxide is formed on the inner surface of the discharge tube portion 1 of this embodiment. I have. For this reason, the present embodiment has the same effect as the first embodiment shown in FIG. In addition, in this example, by forming the discharge tube portion 1 in a U-shape, the entire discharge tube can be shortened to 12 cm as compared with a straight tube having the same discharge path length, and can be made compact. It is easy to store in a sterilizer or the like. In addition, when the overall size is determined, since the discharge path length is longer than that of a straight tube, a germicidal lamp with high ultraviolet radiation efficiency can be obtained.

FIG. 4 is a schematic view showing the configuration of an embodiment of the sterilizing apparatus of the present invention. Reference numeral 42 denotes a sterilizing tank through which warm water to be sterilized flows, and has a shape in which a cylindrical sterilizing lamp housing is formed in the middle. Inner wall 42 of this sterilization tank 42
a is formed of a material through which ultraviolet rays of 253 nm are transmitted. Further, a U-shaped germicidal lamp 41 similar to that shown in FIG. 3 is inserted into the germicidal lamp housing portion of the germicidal tank 42, and the germicidal lamp 41 is connected to a power supply device 45. A water pipe 43 is connected to the upper part of the sterilization tank 42,
A drain pipe 44 is connected to a central portion of the lower end of the sterilizing tank 42.

Next, the operation of this embodiment will be described. The hot water 1 to be treated is supplied from the water pipe 43 to the sterilizing tank 42.
00 flows in. When a high frequency voltage of about 800 V is supplied to the germicidal lamp 41 from the power supply 45, the germicidal lamp 4
1 lights up, and irradiates ultraviolet rays of 253 nm to the warm water in the sterilization tank 42 through the inner wall of the sterilization tank 42. This allows
The hot water in the sterilizing tank 42 is sterilized by ultraviolet rays, and the sterilized hot water is discharged from the drainage pipe 44 to an external bathtub (not shown) or the like.

According to the present embodiment, since the lamp shown in FIG. 3 is used as the germicidal lamp 41 and has a long life and lasts about three years, the lamp replacement and maintenance of the germicidal apparatus can be extremely facilitated. . In addition, since the germicidal lamp 41 has good ultraviolet radiation efficiency, it has an effect of saving power and has an effect of reducing the electricity rate of the apparatus. Further, since the shape of the sterilizing lamp 41 is U-shaped and compact, the longitudinal direction of the sterilizing tank 42 can be shortened accordingly, and the sterilizing apparatus can be downsized. Further, since both the lead wires from both electrodes of the sterilizing lamp 41 are taken out from the upper part, it is not necessary to route one lead wire as in the case of using a straight tube, and the wiring is simplified. The assemblability of the device can be improved.

It should be noted that even if the straight tube shown in FIG. 1 is used as the sterilizing lamp 41, the effect of reducing the size of the sterilizing device is not so large, but the other effects are almost the same as above. The water to be treated may be water instead of warm water.

[0045]

According to the first aspect of the present invention, as described above, the sputtering of the electrode material is suppressed, the blackening of the tube wall of the discharge tube is eliminated, and the tube is formed using quartz or alumina silicate as the electrode material. Because we eliminated the adhesion of mercury to the walls,
The life of the germicidal lamp can be significantly extended.

According to the second aspect of the present invention, the distance between the outer peripheral portion of the electrode and the inner wall of the discharge tube can be freely adjusted by winding the wire around the electrode axis in a plurality of layers. The degree of freedom in designing a germicidal lamp with a long life without blackening of the tube wall can be improved.

According to the third aspect of the invention, by forming a thin film of an element of Group 3 of the periodic table on at least the inner wall of the discharge tube, regardless of the material of the discharge tube, mercury adheres to the inner wall surface. This can prolong the life of the germicidal lamp.

According to the invention of claim 4, Ne is contained in the discharge tube.
By encapsulating a mixed gas of and a rare gas, the positive column at the time of discharge can be expanded, and the radiation efficiency of ultraviolet rays can be improved.

According to the fifth aspect of the present invention, it is possible to satisfy the conditions for avoiding a low filling gas pressure or a small inner diameter of the depression of the electrode so that the life is longer and the shape is longer than the tube diameter. An efficient small germicidal lamp can be easily designed.

According to the sixth aspect of the present invention, a small and efficient germicidal lamp can be easily manufactured by bending the discharge tube into a U-shape.

According to the seventh aspect of the present invention, the use of a long-life germicidal lamp eliminates the need for frequent lamp replacement, thereby improving the maintainability of the apparatus.

[Brief description of the drawings]

FIG. 1 is a side view showing the configuration of a first embodiment of a germicidal lamp according to the present invention.

FIG. 2 is a cross-sectional view showing a detailed configuration example near the electrode unit shown in FIG.

FIG. 3 is a side view showing a configuration of a second embodiment of the germicidal lamp of the present invention.

FIG. 4 is a schematic view showing a configuration of an embodiment of a sterilization apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge tube part 2 Exhaust tube tip part 3 Electrode coil 4 Electrode shaft 5 Molybdenum foil 6 Outer wells 7 Enclosure part 8 Mercury 41 Sterilization lamp 42 Sterilization tank 43 Water pipe 44 Drain pipe 45 Power supply device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nobuyoshi Hatae 4-3-1 Higashi-Shinagawa, Shinagawa-ku, Tokyo Inside Toshiba Lighting & Technology Corporation (72) Inventor Shigehisa Kawatsuru 4-3-1 Higashi-Shinagawa, Shinagawa-ku, Tokyo Toshiba Lighting & Technology Corporation

Claims (7)

[Claims] 1. A discharge tube formed of a material that transmits ultraviolet light and enclosing a discharge medium therein; and a tube portion provided inside both ends of the discharge tube and having a recess on the discharge space side, and a tube portion. Distance between the outer periphery of the
A germicidal lamp, comprising: a cold cathode having a diameter smaller than the inner diameter of the hollow of the cylindrical portion. 2. The germicidal lamp according to claim 1, wherein the electrode is formed by winding a conductive wire around a plurality of layers on an outer peripheral portion of an electrode shaft. 3. The germicidal lamp according to claim 1, wherein a thin film of an oxide of an element of Group 3 of the periodic table is formed on at least the inner wall of the discharge tube. 4. The discharge tube according to claim 1, further comprising a gas mixture of Ne and another rare gas.
A germicidal lamp according to any one of claims 1 to 3. 5. An inner diameter of a hollow of the cylindrical electrode is Dc.
The germicidal lamp according to any one of claims 1 to 4, wherein pD ≧ 2500 and d ≧ 0.5D are satisfied, where m is the depth of the recess, dcm is the filling gas pressure, and p is Pascal. 6. The germicidal lamp according to claim 1, wherein the discharge tube is bent into a U-shape. 7. A germicidal lamp according to claim 1, which is disposed in close proximity to said container, and a power supply device for supplying power to said germicidal lamp. A disinfection device comprising: