DE2422411A1 - HIGH PRESSURE MERCURY VAPOR DISCHARGE LAMP - Google Patents

Description

PHILIPS PATENTVERWALTUNG GFiBH, 2000 Hamburg 1, Steindamm 9k

High pressure mercury vapor discharge lamp

The invention relates to a high pressure mercury vapor discharge lamp with a discharge vessel, on or in the means to maintain a discharge, e.g. electrodes or high-frequency generators are arranged. The discharge vessel contains mercury, at least one noble gas as ignition gas, at least one of the halogens iodine, bromine and chlorine, at least one of the metals sodium, lithium, potassium, cesium, calcium, strontium, barium, and possibly cadmium, gallium, in-

PHD 74-085 -Z-

Sc S09850 / 0426

dium, thallium, tin, scandium, yttrium and rare earths, these metals being wholly or partly in the form of their halides.

Such lamps are primarily used for general lighting used for purposes such as street lighting. In addition to mercury and a noble gas, they preferably contain iodine as halogen and sodium in addition to indium and thallium as Metals. These metals are stimulated to emit light, while mercury is used as a collision gas to increase the pressure, but is practically uninvolved in excitation and ionization processes (Philips Technische Rundschau 2 £ (1968) 345-354).

German patent specification 1 184 008 discloses high-pressure mercury vapor discharge lamps known, which consist of a discharge vessel made of quartz glass or hard glass, the one at a Operating pressure of 4 to 30 atmospheres, completely evaporating amount of mercury and the addition of one or more halogen compounds one or more metals of I. or / and II. or / and III. Group (s) of the periodic table for color enhancement contains. As examples of these halogen compounds, in addition to sodium, potassium and lithium iodide, only Thallium iodide and cadmium iodide are listed.

The high pressure mercury vapor discharge lamp according to the German patent specification 1 464 181 consists of a closed, translucent lamp bulb, the two solid metal electrodes, one completely evaporating during operation and at the same time Amount of mercury giving a vapor pressure between 1 and 15 atmospheres and at least one iodide of the metals sodium. Contains thallium and indium, the amounts of iodides being such that a partial pressure is created for each iodide during operation sets between 1 and 200 Torr. These lamps can Uoa. also the iodides of the metals lithium, cesium, calcium, Contains cadmium and barium. Because the vapor pressures of the alkali metal and alkaline earth metal halides are relatively low

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the practical problem is to get enough halide in the gas phase. According to German patent specification 1,464,181, an excess of the semi-volatile halides is introduced into the flask and the vapor pressure is set with the aid of the temperature of the inside wall of the flask. In order to obtain the partial pressures specified above, the temperature of the specified halides must ^{assume values of up to 1200 0} C, which means that the limits of the thermal load capacity of the wall material, Z..B. of quartz and hard glass, can be reached or exceeded. Wall temperatures above 800 to 900 ^° C. have a negative effect on the service life of the lamps. In a lamp, for example, argon, mercury, Thallojodid, sodium iodide and iodine containing ", which in itself marginally acceptable inner wall temperature results of about 900 ⁰ C to a partial pressure of the sodium iodide of about 10 Torr. This pressure is too low to achieve an optimum Maintain luminous efficacy.

The invention is based on the object of a high-pressure mercury vapor Discharge lamp of the type mentioned to achieve an increase in the light yield without this the heat load on the vessel wall must be increased. In other words: the problem should be solved from the low volatility especially of the alkali metal and alkaline earth metal halides and that consists in that not enough halide is in the vapor state under normal conditions.

This object is achieved in that the The discharge vessel of the lamp also has at least one volatile halide, preferably a halide of the element Contains aluminum, which is able to with the low volatility alkali metal and alkaline earth metal halides to form gaseous compound. This results in an increase in the effective partial pressure at a given wall temperature of the non-volatile compounds achieved.

Halides, which are particularly prone to this compound formation

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Form stable dimers in the gas phase. The appearance of dimers can be found with low-volatile as well as easily volatile halides. There are several halides in the gas phase If there are stable dimers present, heterodimers or complexes occur in addition to the actual dimers. United if such highly volatile and semi-volatile halides are now obtained, a significant increase is achieved the effective vapor pressure of the non-volatile component.

It is known per se that two halides can combine to form volatile complexes. In this way you can Reversible conversion of low-volatility halides in considerable concentration into the gas phase (Z. anorg. gen. Chem. 395 (1973) 77-81). The invention is based on the knowledge that this effect can be used for systems that for the generation of light in metal halide discharge lamps from Are interested.

It has been found experimentally that, in particular, the vapor pressure of sodium, calcium, strontium and barium halides in "connection with aluminum halides so increased It is possible that this results in a significant increase in the light output.

It has also been found that this effect also occurs if the lamps also contain other additional halides, such as thallium and indium iodide. In these lamps The increase in the sodium partial pressure as a result of the more intense sodium radiation can lead to a shift in the color temperature to lead. However, this can be compensated for by adding the amounts of the remaining mostly volatile halides chooses accordingly.

It was found that even then there was an increase in the luminous efficiency is achieved if further volatile halides are added in addition to the aluminum halides, which are also used for

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Complex formation-capable, ..- z'iB. Halides of trivalent iron, ■ tin ^r (H) - ^: halides _r , indium: (III) halides. - ■ "■

The amounts of 'volatile. Halides are based primarily on those of the semi-volatile halides entered; the 'amount' of readily volatile halides is preferably in the range 0.1-3 per mole of the semi-volatile halide; the "best results are achieved with approximately equimolar amounts ^r -""- ~ - ■ ' ^l '"'■

When selecting the halogens, the following should be considered: In the experiments that led to the invention ⁷ , a series of Ghloridi systems have proven to be the most effective. that · when-using -of ^! Tungsten electrades ^; due to the relatively aggressive gas atmosphere to one. Attack on the electrode material can come, which is primarily to Wandabschwärzungen and consequently ^J einerAbnahme- ^DER: may cause light output ·. For this grimde- ^; alternatively, other halogen combinations were investigated which had almost the same increase in the light yield with "but behaved more inertly towards the electrode material. It was found that the halogen combinations listed below in one Gradation are suitable ', which corresponds to the order in which they are listed:

'^; ' ⁷ ■■ - ■■ 1.' Iodide-chloride systems '■'" Z. bromide-bromide systems

3. Iodide-bromide systems

The attack on the tungsten electrodes can be suppressed if a ratio of chloride to iodide or bromide to iodide of 1: 1 is established in the gas phase. This can be achieved both by adding appropriate amounts of AlJ ₇ and by adding other volatile iodides, for example TlJ and SnJ ^. /

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The invention is explained in more detail below with reference to the drawing and several examples. Show it. _ ⁼ :

1 shows an embodiment of the high-pressure mercury vapor according to the invention discharge lamp j

2 shows an embodiment of a discharge vessel for a; Lamp according to Fig. 1 and · -> ■ '■■ -.-; -. ·

3 shows another embodiment of the discharge vessel.

In FIg. 1 Is 1 the quartz glass discharge vessel, a lamp according to the invention, which consumes approximately ¥ 400 during operation. At both ends of the discharge vessel 1 there is a pinch seal 2 and 3, respectively, into which the power supply elements 4 and 5 are melted. These Stromzuführurigselemente are in. Discharge vessel connected to tungsten electrodes 6 and 7, between which the discharge occurs during operation. The discharge vessel -1. Is arranged in an evacuated or inert gas-filled outer bulb 8, for example made of hard glass, -the at one end a pinch ^ -. Schung 9 has through which power supply wires 10 and 11 are guided in a vacuum-tight manner. The power supply wires 10 'and 11 are connected to the power supply elements' 4 and 5 and at the same time serve as supporting poles for the discharge vessel. Also, the power lead wires, 1Q. ^: and H. connected to contacts of a lamp cap 12 .: The discharge vessel according to FIG. 2 is equipped with pointed electrodes 6 and 7, while in the discharge vessel according to FIG. 3 the electrodes 6 and 7 are coiled. In addition, the interior of the discharge vessel according to FIG. 2 is oval and that of the vessel according to FIG. 3 is cylinder-shaped. The other reference symbols in FIGS. 2 and 3 have the same meaning as those in FIG. 1.

In the following examples, discharge vessels with the following dimensions were used:

509850/0426 ~ ^? ~

Electrode gap:
• ν 40 mm mm Inner diameter : 15th , 5 cm Volume: Fig. 2: 11 , 5 cm Fig. 3: 7th , 3

When discharge vessel according to Fig. 2, it was necessary to provide (not shown) with a heat reflector the lower electrode chamber in order to bring it to temperatures corresponding to a wall temperature of 700 to 800 ⁰ C.

example 1

A discharge vessel according to FIG

15 mg NaI

9.6 mg ₅

30 mg Hg ■

and further filled with argon to a pressure of 25 torr.

A light yield m of 92 lm / W and a color temperature FT of the emitted radiation of 2600 K were measured on a lamp with this discharge vessel. The values of light yield and color temperature of a completely analog lamp, the discharge vessel of which did not contain any AlCl ^, are used for comparison. The luminous efficacy of this lamp was 59.5 lm / W and the color temperature 3100 K. A lamp whose discharge vessel contained only 9.6 mg AlCl and 30 mg Hg serves as a further comparison lamp. This lamp had a luminous efficacy of only 37 lm / W and a color temperature of 5900 K.

Examples 2 to 5

In order to increase the dependence of the light output on the amount of AlCl ^ determine, further firing tests with different fillings were carried out analogously to Example 1, the results of which listed in Table I together with those of Example 1

are.

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Examples 6 and 7

Examples 1 and 2 were repeated with the proviso that the amount of mercury was increased. The results are also listed in Table I.

Examples 8-10

Examples 1 to 5 were repeated with the proviso that NaBr-AlBr, systems were investigated. Fill quantities and measurement results can be found in Table II.

Examples 11-17

To determine the light output depending on different types Halogen components of the aluminum halide, Example 3 was repeated with different fillings. Fillings and measurement results are shown in Table III.

Examples 18-21

The dependence of the light output on the discharge vessel type was determined in experiments, their conditions and results are summarized in Table IV.

Examples 22-25

Example 1 was repeated with the proviso that in addition to AlCl, SnI ₂ , InCl or FeCl were also introduced into the discharge vessel. Fillings and measurement results are listed in Table V.

Examples 26 to 51

Sodium iodide, Thallium iodide and Indian iodide in the following composition (Mixture A)

30 mg NaI

3.2 mg TlJ

0.4 mg InJ

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and 32 mg of mercury were introduced. These discharge vessels were used for comparison with other discharge vessels, the also different amounts of AlCl ^ (Examples 26 to 29) or AlBr, (Examples 30 and 31). In some cases were also the amounts of sodium iodide, thallium iodide and indium iodide varies. The results are shown in Table VI.

Examples 32 to 34 ■

Lamps were examined whose discharge vessels contained alkaline earth metal halides and aluminum chloride. Analog lamps without aluminum chloride are used as comparison lamps. The results are shown in Table VII; they show that the luminous efficacies of the alkaline earth metal halide lamps with aluminum chloride are 25 to 75 % higher.

Examples 35 to 37

Lamps were investigated whose discharge vessels in addition to the alkaline earth metal halides also contain other halides such as sodium iodide, Contained thallium iodide and indium iodide. The results are listed in Table VII.

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TABEL Example no.

1 3

4 5

6 7

Comparison compare cti

contents

15 mg NaJ _ / _V m ₆ ** _& ^,

9.6 mg AlCl ₃ 30 mg Hg 37

15 mg NaI 6.25 mg AlCl ₃ 30 mg Hg 82.3 15 mg NaI 9.6

^ (lm / W) FT (K) mg Hg 59.5 3100

■ zn w, «. ti ™ -ζ · 7 sun

5 g, 15 mg NaI 15 mg NaI 15 mg NaI 5900 2900

2600

^ u mg ng yi, y 2800 mg AlCl ₃ 30 mg Hg 88.5 3100. ₃ 30 mg Hg 80.5 3200

mg AlCl ₃ 30 mg Hg 92
mg AlCl ₃

mg Hg 91.5

mg AlClJ

15 mg NaI 6.25 mg AlCl ₃ 50 mg Hg 99.5 15 mg NaI 9.6 mg AlCl ₃ 50 mg Hg 96.7

2250 2700

II-

Example No. Content · /.

Comparison 10.3 rag ITaBr 10.3 mg NaBr

10

.10.3 mg NaBr, 10.3 x mg NaBr

30 mg Hg 12.5 mg AlBr-19.25 mg'AlBr ₃ 26. mg AlBr,

(Ww) ττ (κ)

mg Hg ' 53 9 4150 30th mg Ed 68 30th mg Ed .73, 5 3000 30th 73 3100

■! OAB ¹ BIlB

cn '· \ ο CD OO cn O O -P- σ>

Example no.

. ¹² ·

'

14 15

16 17

Inb

15 mg NaI 13 mg

15 mg NaI 26 mg

15 mg NaI 40.7 mg AlI ₅

15 mg NaI. ' 6.25 mg AlCl ₅

15 mg NaI, "

AlBr

10.3 mg. NaBr 26 mg AlBr ₅ 10.3 mg NaBr. 13 mg AlBr ₅ 30 mg Hg ■; . · ■■ '· ..'. 30 mg Hg "', ·. · ■■". ','
'30. mg Hg ·, ·

20.35 mg AlJ ₅ "x 30 mg Hg
20.35 mg AlJ, - 30 mg Hg

. 30 mg Hg;

20.35 mg AlJ, /

30 mg Hg '75.1

(lm / W) 5 " 3 • ,1 EI (K) .- 91 3 8th '2800. 78 4th '3OOO' 61, 3100 • "\ · · 78 2900 '69, '3150 73 . 3100> 75 3000

TABLE IV

cn ο co οο cn ο

Example no. Content

18 15 mg NaI

19 15 mg NaI

13 mg AlCl 13 mg AlCl

Vessel type <7jKlm / W) FT (K) 30 mg Hg Fig. 2 91.5 2800 30 mg Hg Fig. 3 99.5 2800

20 10.3 mg NaBr 26 mg AlBr ₃ 30 mg Hg Fig. 2 73

21 10.3 mg NaBr 26 mg AlBr ₃ 30 mg Hg Fig. 3 86.8

3100 3200

. . . ■ ■ EABEIlE T; "·; '"> ·. ■; . ■ ': / ·. ;

Example no. · '■ Contents',,., · ''. ','; ... '. ·. . . ,, '"' ^ (lrn / W) / PI (K)

Equally 15 mg NaI 8; mg SnI ₂ , '· ■' ■ ·, 30 mg Hg '50 2850 '. '■. 15 mg NaI 8 mg SnI ₉ '9.6 mg AlCl,''30 mg Hg 81.5. 3200 ''

15 mg. NaJ 6.65 ng AlCl- 11 mg InCl,, 30 mg Hg 74.1 3900,

CTl '. " , * 23 O · CO ■ co cn ■ 24 O O . 25th ro CD

15 mg NaI 6.5 mg AlCl ₅ '7.9 mg PeCl ₅ 30 rag Hg · 65.9 3400 ^; . 15 mg NaI 10 mg AlOl ₅ 4 mg PeCl ₅ 30 mg Hg. '· 74' 2900 ■

TABLE VI

CjD ÖD CXI O

E.g. No. Contents vessel type (lm / W) FT (K)

VgX. Mischimg A. 32 mg Hg Fig. 2 72 3900

26 Mixture A 13 mg AlCl ₃ 32 mg Hg Fig. 2 92.5 2750

Compare mixture A 32 mg Hg

27

28

Mixture A 13 mg AlCl ₃ 32 mg Hg Fig. 3

Mixture A + 6.4 mg TlJ + 0.8 mg JnJ + 13 mg AlCl ₃ + 32 mg Hg

Compare 15 mg NaI 38 mg TlI 30 mg Hg

29 15 mg NaI 38 mg TlI 30 mg Hg

6.3 mg AlCl ₃

Compare mixture A 32 mg Hg

30 30.9 mg NaBr 4 mg TlBr 48 mg Hg

0.6 mg JnJ 40 mg AlBr ₃

31 Mixture A 26.7 mg AlBr, 32 mg Hg

Fig. 3 80 5 3800 Fig. 3 104, 2800 Fig. 3 104 5 2850 Fig. 2 82, 3100 Fig, 2 96 2850 Fig. 2 72 3900 Fig. 2 93 3200

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5098 50/0426

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Claims (5)

Patent claims: 1.) High pressure mercury vapor discharge lamp with a Discharge vessel, on or in which means for maintaining the discharge are arranged, and the mercury, at least a noble gas as ignition gas, at least one of the halogens iodine, bromine and chlorine, at least one of the metals sodium, lithium, Potassium, cesium, calcium, strontium, barium, and possibly cadmium, gallium, indium, thallium, tin, scandium, Contains yttrium and rare earths, these metals being wholly or partly in the form of their halides, thereby characterized in that the discharge vessel (1) also'at least contains a volatile halide which is capable of interacting with the volatile alkali metal and alkaline earth metal halides to form a gaseous compound. 2. High pressure mercury vapor discharge lamp after Claim 1, characterized in that the discharge vessel (1) is a halide of the element as a volatile halide Contains aluminum. 3. High pressure mercury vapor discharge lamp according to claim 2, characterized in that the discharge vessel (1) In addition, as volatile halides, the halides of trivalent iron, divalent tin and / or des contains trivalent indium. 4. High pressure mercury vapor discharge lamp according to claim 1, 2 or 3, characterized in that the discharge vessel (1) the volatile halides in an amount ranging from 0.1 to 3 moles per mole of the volatile halides contains. 5 0 9850/0426