JPS62281249A - high output germicidal lamp - Google Patents

Abstract

PURPOSE:To make the effective radiation of bactericidal rays attainable, by using amalgam of a mercury-vapor supply source, while situating this amalgam in the more tube end side than an electrode, and attaching it to an internal lead-in wire. CONSTITUTION:Amalgam 17 is used as a mercury-vapor supply source 15, and since this amalgam 17 is attached to internal lead-in wires 5-7, the amalgam 17 is heated to an optimum temperature during lighting, whereby the inside of a light emitting tube 1 is maintained in such a state of low pressure mercury vapor that is favorable of emitting far ultraviolet rays of 254nm. This mercury vapor supply source 15 is made up of housing the amalgam 17 in a metallic capsule 16. And, the amalgam 17 consists of at least one type of metal and mercury selected from Bi, In, Pb, Sn, Zn, Ag and Cd. With this constitution, bactericidal rays are efficiently radiable without using a complex water cooling device in despite of superoutput.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Object of the Invention] (Field of Industrial Application) The present invention relates to a high-output germicidal lamp used for purifying various gases and liquids and for various other sterilizations. .

(Prior art) A germicidal lamp is constructed by having a pair of electrodes installed at both ends of the bulb, and a rare gas and mercury sealed inside the bulb, and its lighting principle is exactly the same as that of a known fluorescent lamp. This lamp differs from a fluorescent lamp in that it does not use a phosphor coating, and the glass tube that makes up the bulb is made of glass or quartz glass, which has excellent transmittance to far ultraviolet rays. Lamps emit far ultraviolet light from mercury vapor, so they are used to sterilize water at water and sewage treatment plants, as well as in a wide range of fields such as sterilizing various gases and producing, processing, and treating products. .

However, conventional sterilizing lamps had a relatively low output, with an input per ml distance a between poles of 1 W (watt) or less, and a total input per lamp of about ioow at most.

Low-output sterilizing lamps naturally have low sterilizing ability, so if they are to be used in large-scale equipment such as water purification facilities, they must be used in large numbers and require a large number of attached parts.

For these reasons, there has recently been a demand for the development of high-output germicidal lamps.

As a high-output germicidal lamp, one described in Japanese Patent Application Laid-Open No. 56-160755 is known.

In this publication, an arc tube made of ozone-free quartz glass is used, and a cathode and an anode are installed in the arc tube at 1 tlA.
A total of two sets of electrodes are installed, one at each end, and a rare gas and mercury are sealed inside the arc tube to create an arc length of 3.
At 00tm, lamp current is 4 amperes, power consumption is 200W.
lamps are listed.

However, recently there has been a demand for a lamp with a much higher output than the germicidal lamp described in the above publication, and the development of a high-output germicidal lamp that can be lit with an arc length of 1000M or more and a lamp current of 3 to 15 amperes is in progress. I'm forced to.

(Problem to be Solved by the Invention) In such a high-output germicidal lamp, in order to efficiently obtain far ultraviolet rays of 254 rv, that is, germicidal radiation, emitted by the light emission of mercury, it is necessary to improve the vapor pressure of mercury. niυ
The question is whether to do so immediately.

In other words, when the arc length is 1000 m or more, the lamp current is 3~
For a high-power germicidal lamp that can be operated at 15 amperes, the input density during operation (input per unit length = 'iV/a
tt) is about 1 compared to a conventional 100W class germicidal lamp.
This means that the wall temperature of the arc tube reaches around 150 degrees Celsius when the lamp is lit under natural cooling (air cooling). If mercury is introduced in this form, the optimum vapor pressure cannot be obtained.

For this reason, a method has been considered to house the bulb in a container and forcefully cool it by flowing water into the container to maintain the temperature of the wall of the arc tube at a temperature that provides the optimum mercury vapor pressure. However, in this case, the water flow rate and temperature must be strictly controlled, and the container's water-tight structure and the insulation structure of the current-carrying parts are complicated and large, making it impractical. .

In the present invention,? ! 254n to properly maintain the vapor pressure of mercury without using complicated water cooling means.
The purpose of the present invention is to provide a high-output germicidal lamp that can efficiently produce far ultraviolet rays, that is, germicidal radiation.

[Structure of the Invention] (Means for Solving the Problems) The present invention uses amalgam as a mercury vapor source,
This amalgam is characterized in that it is located closer to the tube end than the electrodes disposed at both ends of the arc tube and is attached to an internal lead-in wire connected to these electrodes.

(Function) According to this configuration, amalgam is used as the mercury vapor supply source, and this amalgam is attached to the internal lead-in wire, so that the amalgam is heated to an optimal temperature during lighting, and the inside of the arc tube is heated to 254 nm. Maintains low-pressure mercury vapor conditions that are favorable for emitting deep ultraviolet rays.

(Embodiment of the Invention) The present invention will be described below based on an embodiment shown in the drawings.

In the figure, 1 is an arc tube made of ozone-free quartz.
It is formed with an inner diameter of 20 rm and a tube length of 130 C)s. At both ends of the arc tube 1 are stems 2 made of hard glass, etc.
2, and electrodes are supported by these stems 2,2. Note that the thermal expansion coefficient between the ozone-free quartz of the arc tube 1 and the hard glass of the stem 2.2 is preferably between these coefficients.

m1ft is provided with a cathode 3 and an anode 4 as one set at each end of the arc tube 1, and a total of two sets are provided at both ends.

The cathode 3 is made of a coiled filament, and both ends are connected to internal lead-in wires 5 and 6, respectively. The filament cathode 3 is made of, for example, a triple coil so as to withstand a large current, and coated with an oxide of at least one of barium, calcium, and strontium as an electron emitting material (not shown).

The anode 4 is made of a coil or a solid object, is arranged to protrude toward the discharge space side than the filament cathode 3, and is connected to another internal lead-in wire 7.

The distance between the pair of anodes 4.4 facing each other, that is, the distance between the electrodes is set to 1000ffi#+4+.

Each of the internal lead-in wires 5.6 and 7 hermetically passes through the stem 2 and is guided to the outside.

and each pair of filament cathodes 3 facing each other
The internal lead-in wire 5.6 is connected to the secondary winding 9.9 of the transformer 8 outside the lamp, and the other internal lead-in wire 5.6 is connected to the anode 4 of the pair facing the lamp. The lead-in wire 7 is connected to another secondary winding 11 of the transformer 8 via a ballast 10 outside the lamp.

Further, the internal lead-in lines 6 and 7 are connected to each other outside the lamp, so that a lamp current is also applied to the cathode 3.

The primary winding 12 of the transformer support 8 is connected to a commercial power source, for example AC FE1.
Connected to 00V or 200V power supply.

Inside the arc tube 1, argon gas is sealed at 1 Torr as a rare gas for starting, and mercury vapor is supplied H1.
It accommodates 5.

As shown in FIG. 2, the mercury vapor supply source 15 is constructed by housing an amalgam 17 in a metal capsule 16.

The metal capsule 16 is made of Fe, Co, Ni, and Nb.

It is made of one or more metals selected from Ta5Cr and Ti, or an alloy containing these metals, and also amalgam 1
7 is B1, ln, pb, Sn, Zn.

It consists of at least one metal selected from Ag and Cd and mercury.

In this example, B1-In/lA is used as the amalgam 17.
3-H0 (Hg 4%) was used at 240ゝ♂',
The metal capsule 16 is made of nickel (N1) with an inner diameter of 3M.
I use a vibrator with both ends closed.

The metal capsule 16 has a small hole 18 of a size that prevents the amalgam 17 from flowing out even if it is in a molten state.
It is also provided with a container 19 for fixation.

Such a metal capsule 16 is housed in the arc tube 1 with the fixing leg 19 connected to either the internal lead-in wire 5.6 or 7, and in this case, the amalgam housed in the metal capsule 16 is Specifically, the internal temperature at the end of the arc tube 1 is set to 100 to 130°C so that 11 is located closer to the end of the arc tube 1 than the cathode 3 and 1ifi 4.
It is installed in a position that is in a certain area.

When examining the distribution of the temperature inside the arc tube 1, it has been confirmed through experiments that the lamp of this example has a temperature distribution as shown in FIG. 3 while the lamp is lit. Since there is a region where the temperature is about 100 to 130° C., the amalgam 17 can be positioned in this region.

Note that 20 is a molybdenum foil plated with indium, and the indium on the surface forms a partial alloy with mercury during lighting, and plays the role of limiting mercury vapor pressure.

Further, 21 is a getter for adsorbing hydrogen, which is often used in discharge lamps.

In the lamp with the above configuration, the primary winding 12 of the transformer 8 is connected to a commercial power source, for example, an AC 100 V or 200 V power source, and a potential difference is generated between both ends of the secondary winding 11 of the transformer 8. Apply it between the electrodes to light the lamp. When the lamp is lit with a lamp current of 7 A, a lamp power of 500 W can be obtained in a natural cooling state.

The discharge form is as follows. That is, in the first AC half cycle, current flows from one set of anodes 4 to the other set of cathodes 3, and in the next AC half cycle, current flows from the other set of anodes 4 to one set of cathodes 3, This is repeated alternately to sustain the discharge.

The characteristics of the germicidal lamp having such a configuration will be explained.

The germicidal lamp according to the present invention has a lamp current of 3.
~15A, approximately 1 compared to conventional low-output germicidal lamps
0 times, the electrode must function to emit a large amount of thermionic electrons with a low vapor pressure, and also to accept a large amount of electrons that fly in at extremely high speed due to the low vapor pressure. be.

For this reason, the filament cathode 3 is coated with an electron radioactive material and is constantly heated by an external power source, and the anode 4 is placed protruding from the filament cathode 3 toward the discharge space, each of which generates a large amount of heat. This is done so that the role of emitting electrons and the role of accepting large amounts of electrons flying in at high speed are divided. Therefore, each of the filament cathodes 3 and anodes 4 can be designed independently to satisfy their respective functions, and a 7R pole with a long life can be constructed.

The filament cathode 3 and the anode 4, which are configured independently as described above, each have a total of three independent filament cathodes 3 and anodes 4.
Since the filament current and the lamp current are connected to the internal lead-in wires 5, 6, and 7 of the book, the load is reduced even when a large current is passed through, and the mechanical support of the electrodes can be ensured.

By the way, the lamp with the above configuration has a power input density of 5 W.
/ crtr, the tube wall temperature is unusually high for a low-pressure mercury lamp, as shown in FIG.

Under these conditions, if mercury is encapsulated in a single form as in the past, the vapor pressure of mercury would be 2 x 10
'ITorr, which deviates from the region of low-pressure mercury discharge.

Therefore, the present invention uses amalgam as a means for controlling mercury vapor pressure. Amalgam suppresses mercury vapor pressure depending on the temperature at which it is placed, and can control the water fM vapor pressure to be lower than that of mercury alone.
Moreover, the vapor pressure that can be controlled varies depending on the composition even at the same temperature. Therefore, it has the characteristic that the mercury vapor pressure can be controlled more easily than mercury alone.

Additionally, as mentioned above, the mercury vapor pressure of amalgam differs depending on the temperature at which it is placed, so in order to maintain a constant vapor pressure reproducibly, it is necessary to install the amalgam in a location where it will reach a predetermined temperature during lighting. There is. Furthermore, the interior of the arc tube 1 is affected by radiant heat from the discharge, convection heat from the sealed gas, and radiant heat from the high-temperature electrodes, and the amalgam needs to be shielded from these heats.

Therefore, a structure is adopted in which the amalgam 17 is housed in a metal capsule 16 and the metal capsule 16 is attached to the internal lead-in wire 7 via the legs 19.

With this structure, the amalgam 17 can be installed at a position where it reaches a predetermined temperature during lighting, that is, within an area of about 100 to 130"C, and even if the lamp is tilted, it will not move to another temperature range. It is also not affected by radiant heat from discharge, convection heat from the sealed gas, and radiant heat from high-temperature electrodes.

Such amalgam 17 evaporates when the temperature reaches about 100 to 130°C and is released into the arc tube 1 through the small hole 18, reducing the mercury vapor pressure inside the tube to the germicidal line, that is, 254 nl.
It is possible to maintain low-pressure mercury conditions that are convenient for efficiently emitting deep ultraviolet rays.

Note that the present invention is not limited to the above embodiments.

That is, the metal capsule 16o and the amalgam 17 can have various compositions, and are not limited to being attached to the internal lead-in wire 7 connected to the anode 4, but can also be attached to other internal lead-in wires 5 or 6. Furthermore, the number of lamps used is not limited to one at each end, but a plurality of lamps or one round of the entire lamp may be used.

Furthermore, the electrodes are not limited to having a cathode and an anode set at each end.

The present invention is effective when applied to a high-output germicidal lamp that is lit with an arc length of 1000 m or more and a lamp current of 3 to 15 amperes.

[Effects of the Invention] As explained above, according to the present invention, amalgam is used as a mercury vapor supply source, and this amalgam is located closer to the tube end than the electrodes disposed at both ends of the arc tube, and is connected to these electrodes. Since it is attached to the connected internal lead-in wire, the amalgam is heated to the optimal temperature during lighting and the inside of the arc tube is heated to 254.
Maintain low pressure mercury vapor conditions convenient for emitting nrA deep ultraviolet light. Therefore, despite the high output, germicidal radiation can be emitted efficiently without using complicated water cooling means.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a block diagram of a high-output sterilizing lamp, Fig. 2 is a block diagram of a metal capsule and amalgam, and Fig. 3 is a characteristic diagram showing the temperature distribution within the arc tube. . 1... Arc tube, 3... Filament cathode, 4...
Anode, 5.6.7... Internal introduction line, 15... Mercury vapor source, 16... Metal capsule, 17... Amalgam, 18... Small hole. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 214 Figure 3

Claims (3)

[Claims] (1) Electrodes connected to internal lead-in wires are attached to both ends of an arc tube made of a transparent material with excellent far-ultraviolet transmittance, and a rare gas and a mercury vapor supply source are sealed inside the arc tube.
Arc length 1000mm or more and lamp current 3-15
A high-output germicidal lamp that is lit at amperes, characterized in that an amalgam is used as the mercury vapor supply source, and the amalgam is located closer to the tube end than the electrode and attached to the internal lead-in wire. High output germicidal lamp. (2) The above amalgam contains Bi, In, Pb, Sn, Z
2. The high-output germicidal lamp according to claim 1, which is an alloy of mercury and at least one metal selected from n, Ag, and Cd. (3) The above amalgam includes Fe, Co, Ni, Nb, T
The amalgam is housed in a container made of one or more metals selected from a, Cr, and Ti, or an alloy containing these metals, and this container is equipped with small holes large enough to prevent the amalgam from flowing out, and the container is made of a metal with a diameter larger than that of the cathode and anode. 3. A high-output germicidal lamp according to claim 1 or 2, characterized in that the lamp is located on the tube end side and attached to the internal lead-in wire.