DE1089479B - Electric noble gas high pressure discharge lamp - Google Patents

Description

GERMAN

The main patent 1 065 530 describes an electric noble gas high-pressure discharge lamp for continuous operation, in which the electrode spacing is at least twice the clear diameter of the discharge tube and which has a discharge vessel made of quartz glass or a transparent material that can withstand thermal loads similar to quartz glass, has been proposed. In this lamp, a filling pressure of the gas between 5 and 350 Torr, reduced to a lamp without dead space, is used to achieve wall stabilization of the high pressure discharge. The lamp is operated with a low gradient and low current density without any artificial cooling in such a way that the average power concentration in the discharge is between 5 and 200 W / cm ³ . The inert gas filling can contain additives, including metal vapors.

Although it is known to use metal vapors in noble gas high-pressure discharge lamps, e.g. B. mercury, but it is usually the long-known spherical high-pressure discharge lamps, in which the distance between the electrodes is only a fraction of the bulb diameter. These lamps contain an inert gas filling under high pressure of several atmospheres and do not burn in a wall-stabilized manner. In addition, noble gas high-pressure discharge lamps with the addition of mercury are known, in which the electrode spacing is a few centimeters with an inner diameter of the lamp bulb of a few millimeters. But even with these lamps, the noble gas is already under a pressure of several atmospheres at room temperature. In addition to the lamps mentioned, elongated high pressure gas discharge lamps have been built for exposing photosensitive papers which contain mercury and a noble gas, including xenon, as ignition gas. These lamps have relatively low power consumption of about 3 kW and less and are operated with only low currents, so that the average current densities are below 1 A / cm ² . In accordance with their intended use, the lamps are designed in such a way that a radiation yield of long-wave UV is achieved with a high degree of constancy.

The lamps according to the invention contain mercury in the discharge vessel as an additive to the inert gas filling in a small amount of 0.01 to 0.7 mg / cm ³ , the current density of the discharge being more than 2 A / cm ² .

In contrast to the previously known mercury long-arc lamps with xenon as ignition gas, which are intended for a maximum power consumption of up to 3 kW and are operated with low currents, the lamp type according to the invention is for current-electric
Noble gas high pressure discharge lamp

Addendum to patent 1,065,530

Applicant:

Patent trust company

for electric light bulbs m.b.H.,

Munich 2, Windenmacherstr. 6th

Dipl.-Ing. Horst Grabner, Berlin-Zehlendorf,
has been named as the inventor

strong lamps with higher power consumption.

The upper limit of the amount of mercury to be added of 0.7 mg / cm ³ is due to the embodiments of lamps down to power consumption of 3 kW, since with decreasing power consumption and smaller tube diameter, a larger amount of mercury is required to to achieve optimal light output.

As already described in detail in the main patent, the special feature of the invention the lamp type on which the main patent is based, that despite the relatively low noble gas filling pressure of less than 350 Torr, the lamps show a pronounced high pressure character. Compared to the previously known Lamps with, among other things, high pressures, low currents, small discharge cross-sections, high power concentrations are almost the same with the lamps according to the main patent Luminous efficacies achieved with low power concentration, low pressure and wall stabilization, when working with higher currents and large arc diameters.

If the mercury is added to the noble gas filling of the lamps according to the main patent, then the mercury remains Preserve the high pressure character of the lamps, d. i.e., the temperature of about 7000 ° K, as it is for the lamps is indicated after the main patent, does not change. The gradient is created by the addition of mercury elevated; the light output is not only retained, but also increases. In doing so, the lamps according to the invention as surprising and

009 608/160

It was newly pointed out that the course of the increase in light output is completely different from that of the previously known Mercury long-arc lamps with xenon as ignition gas. In the case of the last-mentioned lamps with increasing pressure, d. H. so with increasing amount of mercury per cubic centimeter, the light output continuously to. In contrast, with the lamps according to the invention there is initially a fast one Increase in the luminous efficacy takes place, but even with a small addition of mercury, so with relatively low operating pressure, in an area of almost constant, maximum yield.

In the figure, the dependence of the light yield and the gradient on the amount of mercury added is shown for an embodiment of the lamp according to the invention. The lamp has a tube diameter of 30 mm; As a noble gas, it contains a xenon filling with a filling pressure of 100 Torr, which corresponds to a reduced filling pressure of about 70 Torr. With a constant arc power of 170 W / cm, a lamp length of 120 cm results in a power consumption of approximately 20 kW. The current density is about 6 A / cm ² . The curves show that the gradient increases with increasing mercury content. In the area of the increasing voltage gradient, the luminous intensity or the luminous flux also increase rapidly at the same time. Already at a filling quantity of 0.2 mg Hg / cm ³ , which corresponds approximately to a mercury operating pressure of only 200 Torr, the light yield almost reaches its maximum value. If the addition of mercury is increased further, the light yield practically no longer increases.

According to the invention there is accordingly a xenon-mercury discharge low pressure and high gas temperature with a luminous efficacy as with a high pressure mercury vapor discharge lamp. the Lamps can be manufactured for any high output. While with lamps with a pure noble gas filling at high power consumption, e.g. 65 kW, a luminous flux of over 2,000,000 lumens can be achieved With lamps according to the invention with the addition of mercury for the inert gas filling, far higher luminous fluxes can be achieved with the same power consumption.

Claims (1)

Claim: Electric noble gas high-pressure discharge lamp for continuous operation, in which the electrode spacing is at least twice the clear diameter of the discharge tube and the discharge vessel is made of quartz glass or a transparent material that can withstand thermal loads in a similar way to quartz glass and which has one on one wall to stabilize the high pressure discharge Lamp without dead space has a reduced filling pressure of the gas between 5 and 350 Torr and is operated without any artificial cooling with a low gradient and low current density such that the average power concentration in the discharge is between 5 and 200 W / cm ³ , according to patent 1065 530 , characterized in that as an additive to the noble gas filling · mercury is contained in a small amount of 0.01 to 0.7 mg / cm ³ in the discharge vessel, the current density of the discharge being more than 2 A / cm ² . Considered publications:
Lichttechnik, Vol. 10, 1958, pp. 108/109 and 364 to 369. 1 sheet of drawings © 009 608/160 9.60