DE1539501A1 - Low pressure mercury vapor discharge lamp - Google Patents

Description

PM. 1021

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DipK-Ing. HORST AUER

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Applicant: NVPH.U, ^J S'GLQE.LAMPENFABRIEKEII

Act ·, PHN-1021
Registration dated «" jß, Sept »1966

"Low pressure mercury vapor discharge

lamp."

o The invention relates to low-pressure mercury

^ ⁰ silver vapor discharge lamps, especially fluorescent lamps

lamps.

Low pressure mercury vapor discharge lamp -

5 pens are known to have the highest beneficial effect at the implementation of the supplied electrical energy in

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Ultravialettstrahlung when the mercury vapor pressure .Among the operating conditions 4 to 1E / .mu.m, which corresponds to the Dam.fdurck which is liquid box situated at a temperature of 35 ° C to 45 ^P mercury at equilibrium. Low-pressure mercury vapor discharge lamps are therefore always designed in such a way that this condition is met at normal operating temperature.

If the electrical energy supplied is increased in such a lamp, the light output increases up to a certain limit. However, the efficiency will decrease as a result of the increase in the electrical energy supplied, more heat is developed, which increases the operating temperature and demnacl. the mercury vapor pressure also rises. The conversion of electrical energy into ultraviolet radiation is adversely affected by this, resulting in the above-mentioned efficiency balance. *

Even if these normal low-pressure mercury vapor discharge lamps burn in a room in which the prevailing temperature is higher than the normal room temperature of around 25 ^° C, e.g. in a closed fitting of small dimensions, the mercury vapor pressure will exceed the optimum value, which significantly reduces the efficiency.

In order to keep the mercury vapor pressure at the optimum value fcu in the above-mentioned cases, can take any measure. to be hit. Man. can z, 13. cool one skin of the pipe wall "in such a way that the calibration

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it concentrating mercury has a temperature of 35 ° to 45 ⁰ C.

Another known means of achieving the required mercury vapor pressure in the discharge lamp consists in the use of a mercury amalgam, which is located in the lamp at a point which is a temperature under the operating conditions of the student. temperature assumes at which the prevailing mercury vapor pressure over the amalgam receives the above-mentioned value ve η 4 to 10 / um. If this temperature is higher than the temperature of 35 ° to 45 ⁰ C that applies to φ normal lamps at maximum efficiency, it is possible to put a heavier load on the mood or burn at a higher temperature! to leave and thus to achieve a higher light output.

The 8 mercury amalgam is usually found on the inner wall of the discharge lamp in the smock part between the electrodes. With elongated lamps, mercury amalgam is sometimes found in two or more places in this central part housed. In the manufacture of such lamps

first of all, at one point on the wall, a lot of a ^ Metal that can form an amalgam with mercury, e.g. Indium, attached. The lamps are then switched on with

Fluorescent powder covered, the covered lamps sintered "O

° and the electrodes mounted. The lamps are then co

£ ° ventilates and filled with an ignition gas, e.g. argon. Even

A quantity of mercury is introduced into the lamp. That

* - Weight of this amount of mercury must be in a certain

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"** · Relate to the weight of the attached metal. In the case of indium, this ratio is about 1 part by weight of mercury

PHN.1021

silver to three parts by weight of indium.

The mode of operation of an amalgam lamp can be summarized as follows:

After switching on the lamp, the ' Electrodes are heated, which causes them to emit electrons .. As a result a discharge arises in the discharge space and rises the temperature in this room increases so that mercury secretes from the amalgam and gets into the discharge chamber * This continues until an "equilibrium state is reached. The operating temperature of the lamp must then be so high be that the required mercury vapor pressure of 4 to 10 / µm prevails over the amalgam.

It is obvious that required to reach the right Queekeilberdamptdrucks time depends after switching 'of the bulb among other von.der still present in> _(^ ntladungsraum mercury vapor quantity. If the lamp for a longer time have been extinguished, so the mercury is almost completely in Amalgam and reaching the correct mercury vapor pressure will take longer than if the lamp was only off for a short time.

This relatively long start-up time a major disadvantage of such amalgam lamps. ίο The invention aims to remedy this disadvantage,

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oppose co.

"" "* A low pressure mercury vapor discharge

£ j lamp according to the invention has a discharge space in which ^ there are thermally emitting electrodes, and it has the characteristic that there are in the discharge space

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part of the lamp, e.g. the wall, its temperature is not directly influenced by the temperature of the electrodes when the lamp is in operation, a small amount of metal is located, which can form an amalgam with mercury, and that it is close to at least one of the electrodes on a part whose temperature is after the lamp is switched on The temperature of this electrode is directly affected, a small amount of metal resides with mercury Can form amalgam.

By attaching a small amount of metal, which can form an amalgam with mercury on the part that is close to at least one of the electrodes and its temperature depends on the temperature.-dieeer Electrode is directly influenced, makes itself very quickly after switching on the lamp releases a quantity of mercury, whereby the start-up time is shortened considerably. The electrodes reach quickly after switching on a high temperature and then heat mainly through Radiation, the amalgam in their direct vicinity.

The amalgam that is on part of the lam-

pe is located whose temperature is not directly related to the temperature the electrodes are affected, e.g. on a part the wall between the electrodes, is practically excluded lent heated over the discharge. This achieves this Amalgam the required temperature much later.

The amalgam that is on the part near at least one of the electrodes cannot one have the function of regulating the vapor pressure, since in the Bej

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the lamp reaches such a high temperature, that a short time after switching on the lamp, the mercury has completely evaporated from it (the desired Mercury vapor pressure will range from 4 to 10 Aim due to the amalgam, which is located at a different point on the lamp).

Apparently, this is a disadvantage for the quick ignition of the lamp, as it is on the rapid development of mercury from the amalgam is based on this part. But this is not the pail, as follows from the following.

■ After the lamp has been switched off, there is mercury vapor in the discharge space. Do you want the lamp re-ignite after not too long, so is located There is still a sufficient quantity of mercury vapor in the discharge space for rapid ignition. If the lamp has been out for a long time, it is probably Too little mercury in the discharge space for a quick one Ignition, but then there is amalgam in sufficient quantity on the one close to one of the electrodes Part formed. In a non-burning lamp, the mercury is distributed over both places which amalgam can form.

The portion close to at least one of the electrodes is preferably electrical from the electrodes. This has the advantage that it is not hit by the discharge and therefore

cannot vaporize and / or atomize so easily.

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PHN.1021 V- -7- '-

This part can be formed by a metal ring, for example surrounding the electrode and not by one support wire connected to the electrodes which is e.g. fastened in a pinch.

As the metal for the amalgams come (besides mercury) the elements cadmium, indium, thorium, gallium and zinc in question, the miι these different elements amalgams formed are at different temperatures, the, required mercury vapor pressure * It is therefore possible according to the operating select one of these elements . Naturally, the point of use of the lamps must also be taken into account, especially in the case of closed fittings of small dimensions.

Ee is beneficial to at least one Instead of using indium as an amalgam-forming metal, ittdium amalgam yields at a temperature of 90 ° to 95 ° C between the above-mentioned desired vapor pressure 4 and 10 yum. A high load on the lamp is therefore permissible. Also the ambient temperature, e.g. in closed Fittings, may be higher than when using amalgams, which have the correct vapor pressure at lower Deliver temperature.

Another advantage of using indium is that it is easy to attach. The melting point of indium (156 ° C) is so high that the point at which the indium is located during the manufacture of the lamp does not necessarily have to be specially cooled. As is well known, the Manufacture the whole lamp to a higher temperature

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heated, and since it is necessary to first apply the amalgam forming metal to the wall, it is important * that the metal, during this heat treatment, does not Spread over the Böhrenwand.

The higher the operating temperature of the lamp and accordingly the amalgam is chosen for the required mercury vapor pressure of 4 to 10 / µm, the more The mercury vapor pressure is lower at room temperature be in the discharge space. Pur such lamps is the application of the invention is of particularly great importance,

. In a special embodiment one Low-pressure mercury vapor discharge lamp according to the invention If there is a metal with mercury on the part near at least one of the electrodes Amalgam forms which at the same temperature gives a lower vapor pressure than the amalgam which is attached another place in the lamp, e.g. on the wall, when cooling down after switching off the lamp then the mercury vapor flow becomes that the metal on this part will be stronger than in the Trap that the same Asialgam forming metal is used in all parts of the lamp. For example, you can use a Combination of cadmium amalgam on the wall and indium amalgam use on the above mentioned part *

The invention is based on the drawing for example explained in more detail * The figure shows a low-pressure mercury single-point discharge lamp with a / wall 1,

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the inside of which is covered with a luminous layer 2. At the ends of the discharge space there are, of the pinches 3 and 4 supported, the thermally emitting'Elektroden 5 and 6. With 7 and 8 are two denotes annular parts which the electrodes 5 or 6 surrounded. These rings are connected by retaining wires 9 and 10, isolated from the electrodes 5 and 6, in the Pinches 3 and 4 attached. On the rings 7 and 8 there is an amount of indium or an amount of amalgam, which is denoted by 11 and 12, respectively. At 13 is a lot denoted by indium metal or amalgam, äiö on the wall of the discharge lamp.

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Claims (5)

PAIENTANSxRUECHE t Ί 539501 (1 J low-pressure mercury vapor discharge lamp with a discharge space in which there are thermally emitting electrodes, characterized in that there is a part of the lamp in the discharge space, e.g.% of the wall, the temperature of which is not directly influenced by the temperature of the electrodes when the lamp is in operation , a small amount of metal is located that can form an amalgam with mercury, and that near at least one of the electrodes on a second part, the temperature of which is directly influenced by the temperature of these electrodes after the lamp is switched on, there is a small amount of metal, which can form an amalgam with mercury " 2. Low-pressure silver vapor discharge lamp according to claim 1, characterized in that the second part is electrically isolated from the electrodes. 3. Low pressure mercury vapor discharge lamp according to claim 1 or 2, characterized in that the second part consists of a metal ring "surrounding the electrodes. 4. Low-pressure mercury vapor discharge lamp according to claim 1, ² or 3 »characterized in that the metal which can form an amalgam with mercury consists of indium at at least one point. 5. Low pressure queek silver vapor discharge lamp according to claim 1, 2, 3 or 4 * net ι that the amalgam that is on the second part? · is found or can be formed there, with the same Τ · ΐι-. üeratur has a lower vapor pressure than the Aa * lg * jn, ' 909881/0434 / " BAD ORlOiNAt 15T395Q1 that is in a different place in the lamp. 909881/04 24 BATH ORIGINAL Blank page