JPH06103964A - Mercury carrier and mercury vapor filled discharge lamp employing aforesaid mercury carrier - Google Patents

Abstract

PURPOSE:To provide a mercury carrier which can control impurity gas emitted out of pellets, and can keep the amount of mercury impregnation highly accurate, as well as to provide a mercury vapor filled discharge lamp employing the aforesaid carrier. CONSTITUTION:A mercury carrier and a mercury vapor filled discharge lamp using this mercury carrier are provided wherein each inorganic porous pellet 81 having continuous holes 82 is impregnated with liquid mercury, and in the pellet 81 the average opening diameter (do) of the continuous holes is made smaller than an average hole diameter (d1). In the inorganic porous pellets, since the average opening diameter (do) of the continuous holes is made smaller than the average cavity hole (d1), a specific surface becomes small, and impurity is thereby emitted less. In addition, since each opening section is slenderer than the inside of each hole, mercury impregnated inside is prevented from unguardedly flowing out and evaporating, so that the amount of contained liquid mercury can be kept highly accurate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mercury carrier used when mercury is enclosed in a lamp and a mercury vapor discharge lamp using the same.

[0002]

2. Description of the Related Art Mercury vapor discharge lamps typified by fluorescent lamps have mercury enclosed in the arc tube. Conventionally, when mercury is enclosed in the arc tube, liquid mercury is weighed using a Mercury dozer. Then, this weighed liquid mercury was introduced into the arc tube through the exhaust tube. However, since liquid mercury has a large surface tension, it is difficult to accurately weigh a small amount of mercury, and there is a problem in that the amount of enclosed mercury varies widely. On the other hand, in the mercury vapor discharge lamp, the minimum filling amount of the enclosed mercury amount is determined from the characteristics of the lamp.If it is less than this limit, the lamp output will be significantly reduced and the life will be shortened. become. For this reason, conventionally, the average filling amount has been increased so that the minimum required amount of mercury can be secured even if the variation becomes the lower limit in consideration of the variation of the weighed mercury. However, when excess mercury is filled in the lamp, many mercury particles adhere to the inner surface of the bulb,
In the case of a fluorescent lamp or the like, there is a problem that the appearance is significantly deteriorated because it can be seen from the outside during lighting, and more mercury is wasted through the waste lamp.

For this reason, there has been conventionally known a technique of encapsulating mercury in the form of amalgam or an intermetallic compound in a lamp. Since mercury amalgam and intermetallic compounds are solid at room temperature, they are easy to handle and can be accurately weighed, so that there is an advantage that variations in the filling amount in the lamp can be reduced. However, since amalgam has a low mercury vapor pressure, it is effective for fluorescent lamps with a high tube wall load and lamps used under high ambient conditions, but the starting characteristics of lamps used under normal conditions are It is not good, especially in a low temperature environment, it is difficult to start, and the light output during lighting is low, and there is a concern that it may go out.

Therefore, recently, a technique has been proposed in which the inorganic porous pellets are impregnated with liquid mercury to form a mercury carrier, and the impregnated liquid mercury is brought into the lamp by accommodating such mercury carrier in the lamp. There is.

Inorganic porous pellets are wholly continuous 1
It consists of individual lumps, and micropores of microscopic size are continuously formed in the lumps to form continuous pores, or a large number of fine particles are locally fused. It is known that voids formed between particles are continuous with each other to form continuous pores throughout.

Such inorganic porous pellets are heated in a vacuum to remove air and water remaining in the continuous pores, and are poured into liquid mercury to pressurize the pores. Liquid mercury can be infiltrated into the glass to form a mercury carrier impregnated with mercury.

In such a mercury carrier, since the liquid mercury in the continuous pores communicates with the outside world through the openings, the mercury vapor pressure in the surrounding environment becomes equal to that of the liquid mercury in the pores, and the atmospheric pressure becomes And is in equilibrium. For this reason, if such a mercury carrier is enclosed in a lamp, the amount of filled mercury can be accurately controlled, it is easy to handle, and the vapor pressure of mercury becomes the same as that of liquid mercury. Even in the atmosphere, there is an advantage that the mercury vapor pressure in the lamp can be maintained in a relatively optimum state.

[0008]

However, this type of inorganic porous pellet may release an impure gas from the pellet itself. In the case of conventional, inorganic porous pellets, the average size of the opening of each successive holes (hereinafter, referred to as the average opening diameter d _o) and, pores inside of the average size (hereinafter, the average pore diameter d _i and referred) and the size is substantially equal, a relatively large Therefore specific surface (surface area per unit weight or unit volume). Therefore, a large amount of impure gas is emitted from the pellets enclosed in the bulb, and there is a problem that the starting voltage of the lamp increases.

Further, when the size of the opening of each successive holes (average opening diameter d _o) is relatively large, the liquid mercury in the continuous pores are communicated outside the communication through the opening, impregnation Liquid mercury is easily dropped or scattered undesirably.

That is, the mercury carrier obtained by impregnating liquid mercury into the inorganic porous pellets as described above is stored in a capsule and carried, or is managed in this storage state. When subjected to vibration or the like, a part of the liquid mercury in the pellet may flow out through the opening, and the impregnated amount of the liquid mercury may change before being enclosed in the lamp. Also, when this mercury carrier is introduced into the lamp, it is inserted through the exhaust pipe, but since the ambient environment is evacuated in the dozer before the introduction of the lamp and after the introduction in the lamp due to the exhaust process, Liquid mercury evaporates through the openings,
This evaporated mercury is carried away outside the lamp along with the exhaust gas, and the amount of mercury sealed in the lamp may vary.

The present invention has been made on the basis of such a situation, and suppresses the release of excess impurities from the inorganic porous pellets to prevent the starting voltage from rising, and the impregnated liquid mercury is undesired. It is an object of the present invention to provide a mercury carrier capable of maintaining the impregnated amount with high accuracy without dropping off or evaporating to the inside and a mercury vapor discharge lamp using the same.

[0012]

The mercury carrier of the present invention is an inorganic porous pellet having continuous pores impregnated with liquid mercury, and the inorganic porous pellet has an average opening diameter of continuous pores. The feature is that d _o is made smaller than the average hole diameter d _i , that is, the size of the opening portion of the continuous hole is made smaller than the inner size.

Further, in the mercury vapor discharge lamp of the present invention, a mercury carrier obtained by impregnating liquid porous mercury into an inorganic porous pellet in which the average opening diameter d _o of continuous pores is smaller than the average pore diameter d _i is used. Is characterized by.

[0014]

According to the mercury carrier of the present invention, since the size of the open pores of the inorganic porous pellet is smaller than the size of the inside, the specific surface area is small and the emission of impurities is small. Become. In addition, since the size of the opening is smaller than the inside of the hole, the mercury impregnated into the inside undesirably flows out or evaporates even if the mercury carrier is vibrated or the outside pressure becomes low. Therefore, the amount of liquid mercury impregnated in the inorganic porous pellets can be maintained with high accuracy.

Therefore, according to the mercury vapor discharge lamp of the present invention, a large amount of impure gas is not released into the bulb, the rise of the starting voltage is prevented, and the variation of the enclosed mercury amount can be reduced. .

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings.

FIG. 3 shows a ring-shaped fluorescent lamp, and the inner surface of the bulb 1 made of a ring-shaped glass tube is shown in FIG.
As shown in FIG. 3, a phosphor coating 2 is formed, and the open end of the bulb 1 is closed by the flare stem 3. An exhaust thin tube 4 is connected to the flare stem 3,
The thin exhaust tube 4 communicates with a discharge space inside the bulb 1 through a communication hole 5. Lead wires 6 and 6 are sealed to the stem 3, and a filament electrode 7 is provided on the inner ends of the lead wires 6 and 6. A rare gas for starting such as argon is sealed in the valve 1.

A mercury carrier 8 is housed in the exhaust thin tube 4. The mercury carrier 8 is an inorganic porous pellet 8
1 is impregnated with liquid mercury (not shown),
As the inorganic porous pellet 81, a ceramic such as α-alumina or γ-alumina is used, which is a ceramic having less hydroxyl groups (OH groups) than silica, and a large number of continuous pores 82 ... It has a structure with.

In the mercury carrier 8 of the present invention, the inorganic porous pellet 81 has a small spherical shape, as schematically shown in FIG. Although not shown, the inorganic porous pellets 81 are actually continuous pores 82 like ant nests throughout the whole.
, And liquid mercury is entirely impregnated in the holes 82.

[0020] In this case, each successive holes 82 ..., the average cross-sectional area (average pore diameter d of the average of the size of the opening 82a which opens to the outer surface of the pellet 81 (average opening diameter d _o) an internal void 82b It is smaller than _i ). That is, in each of the continuous holes 82, the entrance 82a is narrow, but the inside 82b
Is getting wider. The ratio of the average opening diameter d _o and the average pore diameter d _i is (average opening diameter d _o / average pore diameter d _i ) ≦ 1/2, and actually (d _o / d _i ) ≦ 1 / It is often 3. A method of manufacturing such a mercury carrier 8 will be described.

A fine powder of α-alumina or γ-alumina is mixed with an appropriate amount of organic powder, carbon powder and the like and mixed, and this is molded into small spheres. The organic powder is scattered by firing this, or the residual carbon is removed by further firing in water vapor or wet hydrogen.

In this product, the raw material fine alumina powders are in close contact with each other, and these adjacent particles are fused to each other at their contact points to form a continuous lump, and the interparticles are initially formed. Existing voids and voids generated by removing the organic powder and the carbon powder form mesh-like voids that are continuous with each other, forming continuous voids such as so-called ant nests. .

Then, the average opening diameter d _o is calculated as the average pore diameter d _i.
To make it smaller than the size of alumina fine powder,
This can be achieved by selecting the mixing amount and size of the organic powder or carbon powder to be mixed with this.

The above-mentioned ceramic porous pellet 81
Is heated in vacuum to remove residual water and eliminate air in the pores. Then, the porous pellet 81 is cooled in a vacuum, immersed in a pool of liquid mercury and pressurized. Then, liquid mercury intrudes into the continuous pores 82 ... Of the porous pellet 81 by an external pressure.

The mercury content of the mercury carrier 8 thus obtained is determined by the degree of vacuum when the porous pellet 81 is evacuated and the pressure when the liquid mercury is immersed, in addition to the porosity.

Mercury carrier 8 produced in this way
Is housed in the exhaust thin tube 4 as shown in FIG.
The inside of the valve 1 is evacuated through and the inert gas is sealed therein, and then the exhaust thin tube 4 is sealed off. Then, when the mercury carrier 8 is heated from the outside of the exhaust thin tube 4 by a burner flame or high frequency heating, the mercury impregnated in the mercury carrier 8 is evaporated, and the evaporated mercury is condensed in another low temperature part.

When the ring-shaped fluorescent lamp having such a structure is turned on, the mercury condensed by the heat radiation from the filament electrode 7 and the mercury impregnated in the mercury carrier 8 are heated and evaporated, and a discharge current is generated. As the mercury vapor pressure rises, the light output increases. When mercury is evaporated from the mercury carrier 8 and becomes excessive, the excessive mercury is condensed in the coldest portion, and the inside of the discharge space is maintained at a predetermined mercury vapor pressure.

In such a structure, the mercury carrier 8 is a solid inorganic porous pellet 81 and liquid mercury 8
Since it is configured to be impregnated with 2, it is easy to handle, and the content of mercury can be controlled relatively easily.
Variations in the amount of mercury enclosed are reduced. For this reason, even if the average enclosed amount is reduced, the required enclosed amount can be secured, and mercury can be significantly saved.

Further, since the mercury in the mercury carrier 8 is ordinary liquid mercury, the mercury vapor pressure is equal to that of pure water silver, and therefore, the startability of the lamp and the low temperature lighting characteristics are good.

In the mercury carrier 8 of the above-described embodiment, the inorganic porous pellet 81 has the average opening diameter d _o of the continuous pores 82 ... Which is smaller than the average pore diameter d _i. The surface area (surface area per unit weight or unit volume) becomes small. Therefore, the inorganic porous pellet 81
Impure gas is less likely to be released from the.

Therefore, when this mercury carrier 8 is used for a lamp of a lamp, the emission of the impure gas is small, so that the rise of the starting voltage can be suppressed, the blackening of the bulb can be prevented, and the lamp can be prevented. Longer life.

When the inorganic porous pellet 81 is formed of α-alumina, since the content of hydroxyl (OH) groups is small, the amount of water taken in is small and so-called impurities are small. It contributes to prevent increase of starting voltage and blackening of the valve.

In the inorganic porous pellet 81 of the mercury carrier 8, the average pore diameter d _o of the continuous pores 82 ... Is made smaller than the average pore diameter d _i , that is, the inlet / outlet is deeper than the inner space. Since it is narrow, it is difficult for the liquid mercury impregnated in the internal void 82b to escape. Therefore, even if the completed mercury carrier 8 is transported or managed, even if it is subjected to vibration or shock, the mercury inside will not accidentally jump out or drop out.

When the mercury carrier 8 is used for the lamp 1, a vacuum is drawn in the dozer before charging and after the charging by the evacuation process of the lamp 1. However, since the inlet / outlet 82a is thin, mercury is evaporated by evaporation. Will not be taken out of the lamp with exhaust air. For this reason, it is possible to significantly reduce the variation in the amount of mercury sealed in the lamp 1.

[0035] The ratio between the average opening diameter d _o average pore diameter d _i is valid (average opening diameter d _o / average pore diameter d _i) of ≦ 1/2 range, d _o / d _i When it exceeds 1/2, there is no great difference from the conventional one. (Experimental Example) The results of experiments on the present invention will be described below.

The inventors of the present invention manufactured the inorganic porous pellet 81 from a porous ceramic made of α-alumina,
The pellet 81 has an average particle diameter d after firing of 2.4 mm and an average opening diameter d _o / average pore diameter d _i of 1/3, and the pellet 81 is impregnated with liquid mercury. ) And a mercury carrier (B) having a conventional structure in which a pellet 81 having an average opening diameter d _o / average pore diameter d _i of 1 is impregnated with liquid mercury, to manufacture a ring-shaped fluorescent lamp of 30 W each. did.

With respect to each of these mercury carriers (A) and (B), the amount of mercury immediately after pellet production and after the lamp was enclosed was measured by chemical analysis.
Is the street.

[0038]

[Table 1]

As is clear from the measured values in Table 1, the mercury carrier (A) of the present invention and the conventional mercury carrier (B).
Immediately after the carrier is manufactured, it is recognized that the mercury carrier of the present invention has a slightly large internal void, so that the mercury content also slightly increases.

After the bulb is sealed, the loss in the case of the mercury carrier (A) of the present invention is about 17.5%, but the loss in the case of the conventional mercury carrier (B) is about 29.
It is 3%, which is a little less than double the loss.

This is because the mercury carrier (A) of the present invention has a narrow entrance / exit, so that the liquid mercury impregnated in the mercury carrier is restricted from evaporating and scattering due to heat in the exhaust process or exhaust. This is because it is difficult. Therefore, when the mercury carrier (A) of the present invention is used, the amount of enclosed mercury is stable.

The results of measuring the starting voltage of each lamp are shown in Table 2 below. In addition, in Table 2, as a precaution, the measurement was performed also in the case of the lamp (C) in which 8 mg of liquid mercury was enclosed on average without using the pellet.

[0043]

[Table 2]

From the results shown in Table 2 above, it was confirmed that the lamp using the mercury carrier (A) of the present invention suppressed the increase in the starting voltage, and the amount of the impure gas discharged into these bulbs was small. This is because.

The present invention is not limited to the above embodiment, and the mercury carrier 8 is not limited to being housed in the exhaust thin tube 4 of the lamp 1, but is attached to the stem 3 or the lead wire. The structure may be fixed to 6 or the like,
Therefore, the shape of the mercury carrier 8 is not limited to a spherical shape, and various forms such as a circular or square rod, a disc, and an annular plate can be implemented.

Further, the mercury carrier of the present invention is not limited to being enclosed in a fluorescent lamp, but can be applied to a lamp such as a high pressure mercury lamp, that is, a lamp containing mercury.

[0047]

As described above, according to the mercury carrier of the present invention, the inorganic porous pellet has the average open diameter d _o of continuous pores smaller than the average pore diameter d _i .
The specific surface area is small and the emission of impurities is small. Also, since the size of the opening is made smaller than the inside of the pores, the mercury impregnated inside does not inadvertently flow out or evaporate, and a large amount of mercury remains in the continuous pores. It is prevented from further escaping, so that even if it is subjected to vibration or the outside is in a low pressure state, the rate of escape is reduced. Therefore, the amount of liquid mercury impregnated in the inorganic porous pellets can be maintained with high accuracy.

Further, according to the mercury vapor discharge lamp of the present invention, since the above-mentioned mercury carrier is used, a large amount of impure gas is not released into the bulb, the rise of the starting voltage is prevented, and the bulb is blackened. Prevents and prolongs run life. Moreover, the variation in the amount of enclosed mercury is reduced, which has the advantage of stabilizing the lamp characteristics.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a sectional structure of a mercury carrier according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an end portion of the annular fluorescent lamp of the same embodiment.

FIG. 3 is a side view of the annular fluorescent lamp of the same embodiment.

[Explanation of symbols]

1 ... Bulb, 2 ... Fluorescent substance coating, 3 ... Stem, 4 ... Exhaust tube, 6 ... Lead wire, 7 ... Filament electrode, 8 ... Mercury carrier, 81 ... Inorganic porous pellet, 82 ... Continuous pores, 82a ... Openings, 82b ... Internal voids.

Claims (6)

[Claims] 1. A mercury carrier in which an inorganic porous pellet having continuous pores is impregnated with liquid mercury, wherein the inorganic porous pellet has an average opening diameter d _o of continuous pores.
Is smaller than the average pore diameter d _i . 2. A mercury carrier obtained by impregnating liquid porous mercury with an inorganic porous pellet having continuous pores, wherein the opening size of continuous pores in the inorganic porous pellet is smaller than the size of internal pores. A mercury carrier characterized by. 3. The mercury carrier according to claim 1, wherein the inorganic porous pellet has an average opening diameter d _o / average pore diameter d _i of 1/2 or less. 4. The mercury carrier according to claim 1 or 2, wherein the inorganic porous pellets are formed of α-alumina. 5. A mercury vapor discharge lamp in which a mercury carrier is sealed in a bulb and the mercury carrier is impregnated with liquid mercury in an inorganic porous pellet having continuous pores, wherein the inorganic porous pellet is continuous void. Average opening diameter d _o
Is smaller than the average hole diameter d _i . 6. The mercury vapor discharge lamp according to claim 5, wherein the inorganic porous pellet has a value of average opening diameter d _o / average pore diameter d _i of 1/2 or less.