JPH1125847A - Multiple tube type discharge lamp, its lighting device and photochemical reaction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damages due to thermal impacts and to reduce variation of light-emitting characteristics by providing base end parts at an upper and lower end parts in an outer enclosure tube respectively and a support member with a holding band, which has a support to support an end part of a light- emitting tube and is wound around a periphery of a small diameter part. SOLUTION: A slender tube 14 of a light-emitting tube 1 is welded in recessed parts 46, 46 of a pair of clamping members 45, 45, and the end parts of the clamping parts 45, 45 are also fixed at end rim parts 43, 43 of cover bodies 42, 42 by welding or screwing. A supporting member of the light-emitting tube 1 is structured by a flange part 41, an end rim part 43, a cover 44, a clamping member 45 and a recessed part 46. Holding bonds 7, 7 are wound around a small diameter part 12 of an end part made by making slender an outer diameter of a valve 11 of the light-emitting tube 1 from an intermediate part via cushion material such as heat resistant alumina wool 75, 75 cut in strip, and end rim parts 71, 71 of the bands 7, 7 are fixed. Thereby, even if the light- emitting tube 1 is extends by thermal expansion, loosened parts will not cause cracks in the valve 11 of the light-emitting tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-tube high-pressure metal vapor discharge lamp having a long arc tube and a photochemical reaction apparatus using the discharge lamp, which is mainly used for industrial purposes such as photochemical reactions. .

[0002]

2. Description of the Related Art The arc tube of a high-pressure metal vapor discharge lamp is made of alumina (Al ₂ O 3) having excellent heat resistance, pressure resistance and corrosion resistance.
A light-transmitting material made of ceramics such as O ₃ ) is used as a bulb, and electrodes are sealed at both ends. The arc tube is filled with mercury, a luminous metal, or the like, which evaporates during lighting and has a predetermined lamp voltage, and an inert gas such as argon or xenon for facilitating starting.

In addition, this type of discharge lamp requires an envelope to keep the arc tube warm, to prevent oxidation of metallic materials, and to block harmful ultraviolet rays. The interior of the envelope is vacuum or an inert gas containing nitrogen. The atmosphere is maintained, and the arc tube has a multi-tube structure of at least a double tube or more, in which the arc tube is supported in an outer tube via a support member.

[0004] One type of such a multi-tube high-pressure metal vapor discharge lamp is a discharge lamp that emits visible light, ultraviolet light, or the like having a specific wavelength used as a light source for a photochemical reaction device or the like. This is because light of a specific wavelength promotes a specific photochemical reaction.In a photochemical reaction apparatus, a high-pressure metal vapor discharge lamp as the light source is provided in a reaction tank main body containing a reaction solution. The immersion is performed so that the reaction liquid is chemically reacted by light emitted from the discharge lamp.

The discharge lamp for this kind of application has a hermetically sealed multi-layer structure in which an arc tube is housed in a long cylindrical outer tube made of quartz glass or hard glass. And the reaction solution is prevented from entering the outer tube. The main body of the reaction tank is deepened to increase the reaction efficiency, and accordingly, a discharge lamp having a large emission length is required. Therefore, the length of the surrounding tube is several tens cm.
And several meters, and the power is increased to tens to several tens of kilowatts.

The high-pressure metal vapor discharge lamp having such a multiplex structure has a power supply terminal provided at the sealing portion at the end of the long cylindrical envelope and a support member serving as a power supply line in the envelope. It is placed and makes electrical connection with the support of the arc tube. The support member has a supporting portion at the end of the arc tube, a holding band made of a metal plate wound around the outer periphery of the bulb end, and a leaf spring elastically contacting the inner surface of the envelope. The arc tube is supported at an axial position of the envelope.

In this high-pressure metal vapor discharge lamp, a voltage is applied to electrodes provided at both ends of the arc tube to generate arc discharge between the electrodes, and the heat of the arc discharge raises the temperature of the arc tube. . Due to the rise in the temperature of the arc tube, a luminous metal such as mercury and a halide therein evaporates, and the metal atom emits light in a spectrum peculiar to the element. The lamp characteristics change due to the evaporation of the luminescent metal. However, when the temperature of the coldest part stops rising and there is no change in the temperature, the vapor pressure becomes constant and the characteristics become stable.

[0008]

DISCLOSURE OF THE INVENTION The above-mentioned discharge lamp having an envelope whose length is several tens of cm to several meters has a long arc tube, a large weight, and a support in consideration of earthquake resistance and durability. It costs. However, the cylindrical arc tube bulb made of ceramics is clamped and held by the holding band, but the surface is smooth, and the metal plate holding band wound on this surface will add more weight than expected or vibrate. The holding may shift when receiving an impact. In addition, a ceramic valve wound by a holding band made of a metal plate has a problem that the contact portion is easily damaged by thermal shock or mechanical damage, and the valve end portion is easily damaged.

In the structure in which the holding band made of a metal plate is fixed by tightening, the band length is set according to the valve having the minimum outside diameter, so that a gap is formed at the joint. There is a phenomenon that a temperature difference occurs between the portion where the band at the end of the valve is in contact with the gap and the gap due to a difference in heat conduction, that is, a temperature difference occurs around the circumference of the end of the valve, making it impossible to maintain uniform heat. This temperature difference affects the lamp voltage, causing variations in the lamp output and reducing the reaction efficiency.

A problem to be solved by the present invention is that in a high pressure discharge lamp using a particularly long arc tube for photochemical reactions, a band for supporting the arc tube provided on the outer periphery near the end of the arc tube bulb is used. That is, there is a risk that the valve may be damaged or temperature uniformity may be impaired.

An object of the present invention is to provide a multi-tube discharge lamp and a photochemical reaction apparatus which prevent breakage of the arc tube bulb due to thermal shock and reduce variation in light emission characteristics.

[0012]

According to a first aspect of the present invention, there is provided a multi-tube discharge lamp having a cylindrical ceramic bulb having a smaller outer diameter in the vicinity of upper and lower ends with respect to an outer diameter of an intermediate portion. A long arc tube in which electrodes are sealed at upper and lower ends of the bulb, a power supply member connected to the upper and lower electrodes of the arc tube, a power supply portion for accommodating the arc tube and the power supply member, and a power supply portion at one end. And a support band provided with a base end at the upper and lower ends of the outer tube to support the end of the arc tube, and a holding band wound around the outer periphery of a small diameter portion at the end of the arc tube bulb. And a support member having the following.

Since the outer diameter of the arc tube bulb is reduced in the vicinity of the end, there is a step at the boundary with the outer diameter of the bulb in the middle.
Even if the winding is loosened due to thermal expansion, the holding band does not move out of the small diameter portion.

The base end of the support member referred to in the present invention refers to a base member of a tube member such as a stem sealed at the tube end. The power supply member is a general term for a power supply body, a power supply line, a lead wire, and the like provided in the outer tube for supplying power to the electrodes.

According to a second aspect of the present invention, there is provided a multi-tube discharge lamp having a cylindrical ceramic bulb whose outer diameter near the upper and lower ends is made smaller than the outer diameter of the middle part, and upper and lower ends of the bulb. A long arc tube in which the electrodes are respectively sealed, a power supply member connected to the upper and lower electrodes of the arc tube, and an envelope tube that accommodates the arc tube and the power supply member and has a power supply portion at one end. A base portion is provided at each of the upper and lower ends of the outer tube, and a supporting portion for supporting the end portion of the arc tube and a small-diameter portion outer periphery of the arc tube bulb end portion are wound around a heat-resistant cushioning material. And a support member having a band.

In addition to the same effect as described in the first aspect, the small-diameter portion near the end of the arc tube made of ceramic and the holding band made of metal are both hard and slippery, but between them. Heat-resistant, flexible and resilient cushioning material, such as alumina wool, is interposed, so winding is easy and reliable, and the cushioning material absorbs stress, moving the cushioning material and the retaining band. Never do.

Further, by winding alumina wool or the like over the entire circumference of the small diameter portion, there is little occurrence of a temperature difference on the peripheral surface of the end portion of the valve, and there is no gap at the joint of the band of the valve. However, the buffer material such as alumina wool interposed therebetween complements this and can reduce the variation in lamp voltage.

The multi-tube discharge lamp according to a third aspect of the present invention is characterized in that the heat-resistant cushioning material is wider than the holding band, and the portion protruding from the band is thick.

In addition to the same operations as those described in the first and second aspects, when a thick buffer material such as alumina wool is projected from the end of the holding band from the wound portion, the projecting portion is formed. Can stop the movement of the holding band.

A multi-tube discharge lamp according to a fourth aspect of the present invention is characterized in that the heat-resistant buffer material is selected from alumina wool, zirconia wool and silica wool. In addition to the same operation as described in claim 3,
Since it is a fibrous cushioning material made of alumina, zirconia, silica, or the like, it has high heat resistance, flexibility, and elasticity, and can reliably and firmly hold the holding band by increasing the winding force of the holding band.

A multi-tube discharge lamp according to a fifth aspect of the present invention is characterized in that the total length of the arc tube in which the electrodes are sealed is 25 cm or more.

In a discharge lamp having a large arc tube, particularly a long arc tube, which has a large difference in expansion and contraction due to a thermal effect at the time of flickering in vertical lighting, the same effect as described in the first to fourth aspects is exerted.

The multi-tube discharge lamp according to claim 6 of the present invention is characterized in that the outer tube containing the arc tube and the power supply member is further disposed in one or more outer tubes. I do.

The outer tube is not limited to a single tube, but may be a double tube, a triple tube, or the like having the same functions as those described in the first to fifth aspects.

According to a seventh aspect of the present invention, there is provided a discharge lamp lighting device according to any one of the first to sixth aspects, wherein the lighting circuit is connected to an output side of the lighting circuit. And a discharge lamp.

The lighting can be easily performed at a low voltage by using a normal lighting circuit device. The photochemical reaction device according to claim 8 of the present invention is a light source comprising the multi-tube discharge lamp according to any one of claims 1 to 6, and the discharge lamp lighting device according to claim 7. And a reaction tank main body accommodating the light source.
9. The photochemical reaction device according to claim 1 to claim 7.
Since the light source and the discharge lamp lighting device having the functions described in (1) and (2) are provided, a predetermined chemical reaction can be obtained with few accidents caused by the discharge lamp.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 5 show a multi-tube high-pressure metal vapor discharge lamp L for high-output visible light emission used in vertical lighting as a light source for photochemical reactions according to the present invention, and FIG. FIG. 2 is an enlarged side view near the upper end of the arc tube in FIG. 1, FIG. 3 is an enlarged front view near the lower end of the arc tube in FIG. 1, FIG. 4 is a top view of FIG.
FIG. 5 is a cross-sectional view of a portion taken along line AA of FIG. (In FIG. 1, a part of the arc tube and a part of the support member are shown by solid lines.) In the figure, 1 is the arc tube, and 2 is a cylinder made of quartz glass or hard glass having sealing portions at both ends. An arc tube 1 supports the arc tube 1 via support members 4A and 4B inside. Reference numeral 3 denotes a second envelope, which has a long cylindrical shape made of hard glass and has a substantially hemispherically closed lower end and an upper end sealed therein. Is housed and supported. Nitrogen and an inert gas are sealed inside.

The second outer tube 3 also serves as a pair of power supply pins 32a and 32b serving as power supply portions outside the sealing portion 31, and as a pair of support members connected to the power supply pins 32a and 32b inside. Feeders 51a, 51b, and the feeders 51a,
Insulators 52a, 52b attached to the tip of 51b
And guide rods 53a, 53b made of metal wires attached to the insulators 52a, 52b.

The support members 5A and 5B include holders 54a and 54b formed by bending a metal plate fitted to both ends of the first envelope 2 into a ring shape, and the holders 54a and 54b. , 54b provided with elasticity by bending a metal plate provided on the side surface of each of the spring bodies 55b, 55b (FIG. 1).
The spring body of the middle and upper end holder 54a is not shown. ) And a U-shaped spring body 55c formed of a metal plate provided on a holder 54b on the lower end side in a cross shape. And the support members 5A, 5B
The first outer pipe 2 is connected to the second outer pipe by the spring bodies 55b, 55b provided on the side surfaces and the lower U-shaped spring body 55c contacting the inner wall of the outer pipe 3. 3 are supported on substantially concentric axes. Further, two hollow sliding tubes 56 are provided in the holder 5A on the upper end side of the first envelope 2.
a and 56b are fixed, and the sliding tubes 56a and 56b are fixed.
The guide rods 53a and 53b described above are inserted in b.

In the figure, 6A is a power supply line connected to the upper end side of the first envelope 2 and 6B is a power supply line connected to the lower end side. One end of each of the power supply lines 51a and 51b is connected to the insulator. It is fixed by a nut 57 between 52a and 52b. The power supply line 6B connected to the lower end is covered with an insulating tube 61 made of quartz glass for the most part.
The power supply pins 32a and 32b, the power supply 51a,
A power supply member is constituted by 51b and the power supply lines 6A and 6B.

As shown in FIG. 1, the first surrounding tube 2 has stems 21a and 21b forming base ends sealed at both ends, and bands 22a and 22b are attached to the stems 21a and 21b.
The support members 4A and 4B supporting the arc tube 1 are attached to the tips of the support rods 23a and 23b made of metal wires fixed by the above, and the power supply members connected to the power supply lines 6A and 6B from the stems 21a and 21b. Are extended and are connected to the support members 4A and 4B.

In FIG. 1, 25, 25,...
Are fixed to a plurality of positions of the support rods 23a and 23b at predetermined intervals by a leaf spring member formed of a metal plate so as to elastically contact the inner wall of the support rod 23a. Also, 26, 26,...
is a ring-shaped getter material made of barium (Ba) or the like, and the getter materials 26, 26,... are evaporated by high-frequency heating and deposited on the inner wall surface of the first envelope 2 to form a getter film. It is formed so as to adsorb the impurity gas in the outer tube 2.

As shown in FIG. 2 and FIG. 3, the luminous bulb 1 is provided with an end cap 13 made of niobium and having both ends of a light-transmitting ceramic bulb 11 made of alumina (Al ₂ O ₃ ) or the like. Are hermetically sealed and joined via a heat-resistant adhesive 17. The outer diameter of the valve 11 is such that a small-diameter portion 12 is formed in the vicinity of both ends with respect to the intermediate portion, for example, the outer surface side is reduced in diameter by grinding. Reference numeral 14 denotes a thin tube which also serves as an exhaust pipe hermetically bonded to the end cap 13 and has an electrode 15 in which a tungsten wire is tightly wound three times in a tight manner.
The electrode shafts 16a and 16b of a and 15b are fixed.
Further, a predetermined amount of sodium and mercury and xenon gas for starting assistance are sealed in the arc tube 1.

The arc tube 1 is supported by support members 4A and 4B which are cut from a metal plate. The support members 4A, 4B are formed by welding a pair of semicircular cover members 42, 42 having a flange portion 41 around the periphery thereof at edge portions 43, 43, and a cylindrical cover 44 formed in the center, and a concave portion 4 in the center.
A pair of U-shaped clamping members 45, 45 having 6, 46
And the flange 41 is cut or raised or a separate L
Locking pieces 47, 47 formed by attaching a letter shape
(One is not visible on the back side.) And the holding bands 7, 7 attached to the locking pieces 47, 47.

Then, while the thin tube 14 of the arc tube 1 is in the concave portions 46, 46 of the pair of holding members 45, 45, the welding 4
The ends of the holding members 45, 45 are also fixed to the edge portions 43, 43 of the cover members 42, 42 by welding or screws.
3, the cover 44 (the cover body 42), the holding member 45, and the concave portion 46 constitute support portions of the support members 4A and 4B of the arc tube 1.

The bulb 11 of the arc tube 1 has an outer diameter smaller than that of the middle part. The small-diameter part 12 at the end is provided with a buffer material such as heat-resistant alumina wool 75, 75 cut into a belt shape. The bands 7, 7 are wound, and the end portions 71, 71 of the bands 7, 7 are fixed by being fixed with at least one screw 72. And at this time, valve 1
The alumina wool 75 wound around the small-diameter portion 12 is slightly wider than the width of the holding band 7 and slightly protrudes toward the end cap 14, and the protruding portion 76 is thicker than the portion tightened by the band 7. is there.

Also, two hollow sliding tubes 4 are provided on the flange portion 41 of the cover body 42 of the upper support member 4A.
9 and 49 are fixed, and the guide rods 23 supported by the upper stem 21a are provided in the slide tubes 49 and 49.
a, 23a are inserted, and the lower support member 4B is fixed to the distal ends of support rods 23b, 23b supported by the lower stem 21b.
Is pivotally supported substantially at the center in the first envelope 2. Although not shown, the support members 4A and 4B, such as around the cover body 42, are provided with spring bodies that come into contact with the inner wall of the surrounding tube 2.

A locking piece 81 having a square tubular portion is attached to the flange portion 41 of the cover body 42 of the upper support member 4A, and a rectangular plate made of ceramic is mounted in the tubular portion. The base end of the electrical insulator 82 is inserted and fixed. The band 7 or the flange portion 41 of the lower support member 4B is provided with a guide 86 formed of an electrical insulator such as a ceramic having a through hole 85 and a cutout in the flange portion 41.

A through hole 83 formed near the tip of the electric insulator 82 near the upper electrode 15a has a high melting point metal such as a molybdenum wire, a tungsten wire, a rhenium wire, a tantalum wire, a tungsten / rhenium wire or the like. A distal end portion 88 of a flexible proximity conductor 87 made of an alloy wire or the like is attached. The proximity conductor 87 extends near the outer surface of the arc tube bulb 11 obliquely with respect to the axis of the arc tube 1, and is electrically connected to the holding member 45 of the lower support member 4B by welding or screwing. ing. At this time, the proximity conductor 87 extending below the through hole 85 of the guide 86 may have some slack.

In the drawing, reference numeral 73 denotes a holding member 4 which has been superposed.
5 and 45 are screws for fixing and connecting the power supply line 24. Although the cylindrical cover 44 is provided on the upper side in the above description, a similar cover may be provided on the lower side, and the cover 44 can keep the end of the arc tube 1 tube warm.

The discharge lamp L having such a structure is shown in FIG.
Are incorporated in a photochemical reaction device C, a part of which is used. In FIG. 6, C1 is a photochemical reaction tank main body, and a discharge lamp L
Is immersed in the reaction solution C2 of the reaction tank main body C1 in a state where the sealing portion 31 side of the second outer tube 3 is turned up, that is, in a vertical state. In the figure, C3 is a lid, and C4 is a packing.

Next, the operation of the photochemical reaction device will be described.

The discharge lamp L is lit, for example, as shown in FIG. 7 by connecting a lighting device E to an output side E1 of a lighting circuit having a step-up transformer and a ballast. That is,
When a voltage is applied to the power supply pins 32a and 32b via the lighting device E, the power supply pin 32a, the power supply body 51a, the power supply line 6A, and the lead wire 24a of the second envelope 2 are applied to the upper electrode 15a.
-Clamping member 45 of support member 4A-Narrow tube 1 of arc tube 1
4-electrode shaft 16a-electrode 15a, and the lower electrode 1
5b includes a power supply pin 32b, a power supply body 51b, a power supply line 6B,
To the lead wire 24b of the second outer tube 2, the holding member 45 of the support member 4B, the thin tube 14 of the arc tube 1, the electrode shaft 16b, the electrode 15b and the holding member 45 of the support member 4B, the proximity conductor 87, and the tip end portion 88. Is energized.

This energization causes a discharge to occur between the upper electrode 15a, which has the closest conductor interval, and the tip 88 of the proximity conductor 87, and to the lower electrode 15b having the same potential as the proximity conductor 87. The light emission of the predetermined wavelength is performed between the electrode 15a and the electrode 15b in the arc tube 1, and the reaction liquid C1 is irradiated with light to cause a photochemical reaction. Can be.

In such a discharge lamp L, the discharge tube 1 is heated to a high temperature by the discharge heat during lighting, and members in the tube including the inner first outer tube 2 and the outer second outer tube 3, ie, members inside the tube. The support members 4A, 4B, 5A and 5B including the arc tube 1 and the proximity conductor 87 also become high in temperature and thermally expand.

In response to this thermal expansion and contraction at the time of turning off the light, the arc tube 1 is formed by the hollow sliding tubes 49, 49 provided on the flange portion 41 of the support member 4A by the stem 21a of the first envelope tube 2.
This expansion and contraction can be absorbed by sliding on the surfaces of the guide rods 23a, 23a supported by the support. The first outer tube 2 is formed by hollow sliding tubes 56a, 56b provided on holders 54a of the support members 4A, 4B, and guide rods 53a, 53b.
This expansion and contraction can be absorbed by sliding on the surface of the. Further, the support members 5A and 5B are provided with a spring body 55b,
Since only 55b and 55c are in elastic contact with the inner wall of the tube, the expansion and contraction in the tube axis direction and the radial direction can be easily moved by sliding.

Even if the arc tube 1 expands due to thermal expansion, the flexible tube, which is inclined and stretched between the upper electric insulator 82 and the guide 86 composed of the lower electric insulator, is used. Since the slack that occurs in the proximity conductor 87 occurs downward in a substantially straight line when viewed from above and below between the stretches due to gravity,
The loosened portion does not come into contact with the outer surface of the bulb 11 of the arc tube 1, and the bulb 11 does not crack due to thermal shock. Also, since no excessive weight load is applied to the proximity conductor 87, no break occurs.

Even if thermal stress is applied to the support members 4A and 4B holding the bulb 11 of the arc tube 1 where the temperature rises most, the small diameter portion 12 has heat resistant, flexible and elastic alumina wool. At the boundary between the small diameter portion 12 and the normal outer diameter portion, there is a stepped portion 18, and the alumina wool 75 does not deviate from the small diameter portion 12. Therefore, the alumina wool 75 and the holding band 7 wound around the alumina wool 75 do not move.

When the thicker alumina wool 75 is projected from the edge of the holding band 7 from the winding portion, the protrusion 76 can restrict the movement of the holding band 7. It is not preferable that the light emission characteristic is on the side of the discharge path in the center of the bulb 11 opposite to the end cap 14 because the light emission characteristics may be reduced.

The holding band 7 has edge portions 71, 71.
May be fixed with a plurality of screws 72, but it is preferable that only one screw has no effect when other screws are tightened, and the cushioning material 75 can be wound with substantially uniform stress. .

Further, since the alumina wool 75 is wound around the small diameter portion 12, a temperature difference is hardly generated on the peripheral surface of the end portion of the valve 11. Even if there is a gap, the interposed alumina wool 75 complements the gap and can reduce the variation in lamp voltage.

Therefore, not only when the lamp is turned on but also when a vibration or impact is applied to the discharge lamp L or the like, the alumina wool 75 can be used.
In addition, the holding band 7 can reliably support the arc tube 1 without moving from the small-diameter portion 12, and can uniformly maintain the temperature of the ends to reduce variations in lamp voltage and improve the efficiency of the reactor. it can.

The present invention is not limited to the embodiment. For example, in the above-described embodiment, the buffer material such as alumina wool is interposed between the small diameter portion at the arc tube bulb end and the holding band. Since the step portion is formed at the boundary of, stable holding is possible without moving the holding band.

In the above embodiment, a high-pressure sodium lamp has been described as a discharge lamp. However, a mercury lamp filled with mercury or a metal halide lamp filled with mercury and a halide may be used. Not limited to this, a discharge lamp for ultraviolet radiation or for visible light and ultraviolet radiation may be used.

The material of the bulb forming the arc tube is not limited to alumina, but may be a translucent ceramic of another material. The material of the bulb forming the envelope is not limited to that of the embodiment but may be other materials. The material may be used.

Further, the structure and material of the support member for supporting the arc tube and the like are not limited to those of the embodiment, and the material of the metal member may be niobium, stainless steel, nickel or the like as appropriate in consideration of heat resistance, corrosion resistance and the like. You can choose.

[0057]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example in which the present invention is applied to a 50 KW high-pressure sodium lamp will be described. The external structure is a discharge lamp L having substantially the same configuration as that of the embodiment shown in FIGS. 1 to 5. The arc tube 1 has a length of about 1750 mm (light emission length of about 1620 mm) and an alumina tube (coefficient of thermal expansion of about 8.0). × 10 ^-6 cm / cm / ° C)
The outer diameter of the middle part is about 52.1 mm, the inner diameter is about 48.0 m
m, a valve 11 having a small diameter portion 12 having an outer diameter of about 52.1 mm in a portion obtained by grinding the outer surface from the end to about 25 mm is used, and sodium, mercury and xenon gas are sealed inside. The inner first outer tube 2 has a length of about 2 mm.
It is made of quartz glass having a size of 30 cm and an outer diameter of about 8 cm, and the inside is evacuated. Further, the outer second outer tube 3 is made of hard glass having a length of about 290 cm and an outer diameter of about 13 cm,
Nitrogen is sealed inside.

The lamp L was turned on for a total of about 15,000 hours in a normal use state (blinking vertically), and no abnormality occurred in the holding band 7 of the arc tube 1 and normal lighting could be performed. .

[0059]

According to the first to sixth aspects of the present invention, the stepped portion is formed at the boundary between the small-diameter portion and the middle portion at the arc tube bulb end portion. The held holding band does not move, and the arc tube can be stably held in the envelope.

According to the second to sixth aspects of the present invention, a buffer material such as alumina wool having heat resistance, flexibility and elasticity is provided between the small diameter portion at the end of the arc tube bulb and the holding bulb. With the interposition, it is possible to more stably hold the arc tube in the outer tube, prevent damage to the arc tube bulb, and use a cushioning material wound around the bulb to keep the end of the tube uniform in temperature and keep the lamp warm. This has the effect of preventing variations in voltage and the like.

According to the seventh aspect of the invention, the lamp voltage can be stabilized and the lighting characteristics can be improved. Further, according to the invention of claim 8, since the light source and the discharge lamp lighting device having the effects described in the above claims 1 to 7 are provided, there are few accidents caused by the discharge lamp and the cost is low. A photochemical reaction device that can obtain a predetermined chemical reaction can be provided.

[Brief description of the drawings]

FIG. 1 is a partially cutaway schematic front view showing a multiple tube discharge lamp according to an embodiment of the present invention.

2 is a partially cutaway enlarged front view showing the vicinity of the upper end of the arc tube in FIG. 1;

FIG. 3 is a partially cut-away enlarged front view showing the vicinity of a lower end portion of the arc tube in FIG. 1;

FIG. 4 is a top view of FIG. 2;

FIG. 5 is a cross-sectional view of a portion crossed along the line AA in FIG. 1;

FIG. 6 is a sectional front view showing a part of the photochemical reaction device of the present invention.

FIG. 7 is a schematic circuit diagram showing a lighting circuit device for a multi-tube discharge lamp according to the present invention.

[Explanation of symbols]

L: Multi-tube discharge lamp 1: Arc tube 2: First envelope 3: Second envelope 11: Arc tube bulb (ceramic bulb) 12: Small diameter portion 15a, 15b: Electrodes 21a, 21b: Base Ends (stems) 24a, 24b: power supply member (lead wire) 4A, 4B, 5A, 5B: support member 6A, 6B, 32a, 32b: power supply portion (power supply line, power supply pin) 7: holding band 75: heat resistance C: Photochemical reaction device C1: Reaction tank body E: Lighting circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Hiroki Sasaki, Inventor 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Lighting & Technology Corporation (72) Inventor Akihiro Yonezawa 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Lighting & Technology Corporation

Claims (8)

[Claims] 1. A long arc tube having a cylindrical ceramic bulb whose outer diameter in the vicinity of the upper and lower ends is smaller than the outer diameter of the intermediate part, and electrodes respectively sealed at the upper and lower ends of the bulb; A power supply member connected to the upper and lower electrodes of the arc tube; an outer tube containing the arc tube and the power supply member and having a power supply portion provided at one end; and a base end portion at the upper and lower ends of the outer tube. And a support member having a holding band wound around an outer periphery of a small-diameter portion at an end of the arc tube bulb. 2. A long arc tube having a cylindrical ceramic bulb whose outer diameter in the vicinity of the upper and lower ends is smaller than the outer diameter of the middle part, and electrodes respectively sealed at the upper and lower ends of the bulb; A power supply member connected to the upper and lower electrodes of the arc tube; an outer tube containing the arc tube and the power supply member and having a power supply portion provided at one end; and a base end portion at the upper and lower ends of the outer tube. And a support member having a holding band wound around the outer periphery of the small diameter portion of the arc tube bulb via a heat-resistant cushioning material. Multi-tube discharge lamp. 3. The multi-tube discharge lamp according to claim 2, wherein the heat-resistant buffer material is wider than the holding band, and a portion protruding from the band is thick. 4. The heat-resistant cushioning material is alumina wool,
4. The multi-tube discharge lamp according to claim 2, wherein the discharge lamp is selected from zirconia wool and silica wool. 5. The total length of an arc tube in which electrodes are sealed is 25 cm.
The multi-tube discharge lamp according to any one of claims 1 to 4, wherein: 6. The method according to claim 1, wherein the envelope accommodating the arc tube and the power supply member is further disposed in one or more envelopes. A multi-tube discharge lamp as described. 7. A discharge lamp comprising: a lighting circuit; and a multi-tube discharge lamp according to any one of claims 1 to 6 connected to an output side of the lighting circuit. Lighting device. 8. A light source comprising the multi-tube discharge lamp according to any one of claims 1 to 6; a discharge lamp lighting device according to claim 7; and a reaction vessel containing the light source. A photochemical reaction device comprising: a main body;