Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/24—Means for obtaining or maintaining the desired pressure within the vessel
  • H01J61/28—Means for producing, introducing, or replenishing gas or vapour during operation of the lamp
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/52—Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space
  • H01J61/523—Heating or cooling particular parts of the lamp
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/70—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr
  • H01J61/72—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr having a main light-emitting filling of easily vaporisable metal vapour, e.g. mercury

Definitions

• the invention relates to a method for operating an amalgam lamp with a nominal power P n0 minai. comprising a discharge space containing a filling gas, in which between electrodes applied to a maximum of UVC emission lamp voltage U opt j mU m is applied or a maximum of UVC emission designed lamp current l op timum, the discharge space for an amalgam depot accessible is, which is heated by means of a heating element by a heating current l He iz is passed through the heating element.
• amalgam lamps mercury is introduced into the discharge space in the form of a solid amalgam alloy.
• the binding of the mercury in the amalgam counteracts a release into the discharge space. This allows higher operating currents (and higher temperatures), so that compared to conventional mercury low pressure lamps three to six times higher performance and power densities can be achieved.
• the amalgam lamp consists of a quartz glass tube, which is closed on both sides with bruises through which a current feedthrough is laid in each case into the discharge space to form a helical electrode.
• One of the bruises is to be provided with a cavity open to the discharge space, into which the amalgam is introduced.
• the solid amalgam is thus disposed outside the discharge. It is heated separately.
• a heater is provided in the vicinity of the amalgam deposits, which has its own circuit and a temperature control.
• the helical electrode simultaneously constitutes the heating means for heating the amalgam.
• Amalgam lamps are usually power-controlled, sometimes operated under current control, the nominal power or the nominal current being designed for the optimum mercury concentration in the discharge space and correspondingly maximum UVC intensity.
• the temperature of the helical electrode is kept constant, so that the amalgam deposit remains at approximately constant temperature and so is given an optimum mercury vapor pressure for operation, but only as long as the external conditions do not change
• the outside temperature or by heating the lamp - for example by a housing in a small space - it is easy to increase the temperature in the amalgam reservoir, so that the amalgam lamp is no longer operated in its optimum operating, resulting in reduced power and light output.
• amalgam lamps are operated by means of a power-controlled ballast in the operating mode "constant power.”
• constant power the maximum UVC power for commercial amalgam lamps at a mercury vapor pressure is around 0.8 Pa.
• FIG 3 the UVC emission is plotted in relative units against the mercury vapor pressure in [Pa].
• this system can not be kept stable at the optimum operating point, such as at a mercury vapor pressure of 0.8 Pa.
• the invention is therefore based on the object of specifying a mode of operation for an amalgam lamp which ensures stable operation in the region of the optimum performance.
• this object is on the one hand according to the invention achieved in that a desired value of the lamp current l so n is set on the basis of the features of the aforementioned method, which is lower than optimum, and that the heating current l He i Z wherein Falling below a lower limit value 11 is switched on or increased for the lamp current and switched off or reduced when exceeding an upper limit value 12 for the lamp current.
• the invention makes use of the property of the amalgam lamp, according to which the lamp current increases in the region of the optimum of the mercury vapor pressure in the discharge space - with power control of the amalgam lamp - with the mercury partial pressure.
• the current / voltage operating point of the lamp is not - as usual - aligned to the optimum of UVC emission and thus to the optimal mercury vapor pressure, but in the area below the optimal mercury vapor pressure, ie laid in the direction of a lower lamp current.
• an additional actuator namely by applying a heating current or by increasing an already applied heating current. This makes it possible to stabilize the control system and prevent a rocking.
• the amalgam deposit is heated or heated higher, so that the mercury vapor pressure increases. in the Ideally, the operating point shifts to the optimum of mercury vapor pressure and UVC emission.
• This mode of operation makes it possible to stabilize the working point "A" of the amalgam lamp in the vicinity of the optimum, whereby the laying of the working point "A” with respect to the optimum can be so slight that the UVC emission is not appreciably reduced.
• n and l as is optimum in the range of 0.1 to 10% of l op timum.
• a slight shift of the operating point is sufficient, since it is only important to be able to use the heating of the amalgam reservoir as a further actuator for the control can.
• a difference of more than 10% requires frequent or continuous heating of the amalgam reservoir without any noteworthy contribution to the stability of the control system. With a difference of less than 0.1%, there is little improvement in the control stability.
• limit values 11 and 12 are provided for switching on or off or for increasing or decreasing the heating current.
• the lower limit may be lower than 11 l be n, and the upper limit 12 may be between l and n are as l op timum.
• the upper limit 12 may be between l and n are as l op timum.
• the heating current is switched on or falls below the setpoint value l so n and off or reduced again when exceeding 1 so n.
• the operation of the invention has proven particularly useful when loptimum at a mercury vapor pressure in the range of 0.2 to 2 Pa, preferably by 0.8 Pa results.
• the shift of the operating point of the lamp current to lower values is illustrated schematically in FIG.
• the above-mentioned technical problem is solved in an equivalent manner also by a mode of operation in which a set value of the lamp voltage U so n is set, which is higher than U ⁇ «TMTM, and that the heating current l He iz when exceeding a Upper limit value U1 is switched on or increased for the lamp voltage and switched off or reduced when falling below a lower limit value U2 for the lamp voltage.
• the invention makes use of the property of the amalgam lamp, according to which the lamp voltage decreases with the mercury partial pressure in the region of the optimum of the mercury vapor pressure in the discharge space.
• the current / voltage operating point of the lamp is not - as usual - aligned to the optimum of UVC emission and thus to the optimal mercury vapor pressure, but in the range below the optimal mercury vapor pressure, ie laid in the direction of a higher lamp voltage. Although this results in a lower mercury vapor pressure, but with the possibility to increase it again by means of an additional actuator, namely by applying a heating current or by increasing an already applied heating current. This makes it possible to stabilize the control system and prevent a rocking.
• the amalgam deposit is heated or heated higher, so that the mercury vapor pressure increases. Ideally, the operating point shifts to the optimum of mercury vapor pressure and UVC emission.
• This mode of operation makes it possible to stabilize the working point "A" of the amalgam lamp in the vicinity of the optimum, whereby the laying of the working point "A” with respect to the optimum can be so slight that the UVC emission is not appreciably reduced.
• an operation is preferred in which the difference between U so n and U optimum lies in the range of 0.1 to 10% of Ultimum.
• a slight shift of the operating point is sufficient, since it is only important to be able to use the heating of Amalggamdepots as another actuator for the scheme can.
• a difference of more than 10 volts requires frequent or continuous heating of the amalgam reservoir without any additional significant contribution to the stability of the control system. With a difference of less than 1 volt, there is little improvement in control stability.
• threshold values U1 and U2 are provided for switching on or off or for increasing or decreasing the heating current.
• the upper limit value U1 may be higher than U so n, and the lower limit value U2 may be between U so n and U 0 pti mU m.
• the lower limit value U2 may be between U so n and U 0 pti mU m.
• the heating current is switched on when falling below the target value U so n or increased and switched off or reduced when exceeding U so n again.
• the heating current ⁇ ⁇ ⁇ ⁇ preferably set as a function of the height of a desired lamp current I so n, wherein the heating current between 20% to 70%, preferably less than 50% of the desired lamp current l is so n.
• a low heating current of less than 20% of the target lamp current I so requires a long heating period before the mercury vapor pressure rises appreciably and therefore leads to slow regulation.
• a high heating current of more than 70% of the target lamp current I so n easily leads to overheating and overshoot of the control.
• the heating current is therefore set as low as possible and as high as necessary, more preferably less than 50% of the nominal lamp current.
• the heating element for heating the amalgam depot may have a separate heating device.
• one of the electrodes is helical and serves as a heating element for the amalgam depot.
• the mode of operation according to the invention for an amalgam lamp requires a dependence of the lamp voltage on the mercury vapor pressure. This dependence is particularly pronounced in amalgam lamps with a neon- or helium-containing filling gas. Therefore, the mode of operation according to the invention makes advantageous advantageous in particular in an amalgam lamp, in which the discharge space contains a neon or helium-containing filling gas.
• FIG. 2 is a circuit diagram illustrating a part of the power supply of the amalgam lamp
• Figure 3 is a diagram of the dependence of the UVC emission from the mercury vapor pressure
• Figure 1 shows schematically one of the two ends of an amalgam lamp 20, which is characterized by a nominal power of 800 W (at a nominal lamp current of 8 A), a radiator length of 150 cm and thus by a power density of slightly less than 5 W / cm. It consists of a quartz glass tube 1, the striglos at its ends with bruises 2 is sen, are embedded in the molybdenum foils 3 and the ends of metallic terminals 4 to a helical electrode 5.
• the electrode 5 has for this purpose legs 15, which are connected to the molybdenum foil 3.
• an arc 13 is generated during operation, the foot 14 of which terminates on the surface of the electrode 5.
• the upper edge of the electrode, on which the base 14 of the arc 13 attacks, is marked with a dashed line 12.
• the pinch 2 at the illustrated end is provided with a cavity 9 which serves as a receptacle for an amalgam reservoir 6.
• the cavity 9 has an opening 7 to the discharge space 8.
• the opening width of the opening 7 is significantly narrower than the maximum clear width of the cavity 9 and also narrower than the maximum diameter of the amalgam reservoir 6, so that the amalgam is trapped in the cavity 9 and can not enter the discharge space 8 in solid form.
• the maximum opening width of the opening 7 is 2 mm.
• the amalgam reservoir 6 is fixed in the vicinity of the electrode 5.
• the electrode 5 is heated by the arc 13 to a temperature that depends on the current performance of the amalgam lamp 20, and the effect on the Amalgamvorrat 6 depending on the distance.
• the distance is measured between the top edge 12 of the electrode coil and the top edge 16 of the amalgam reservoir; he is in the embodiment about 4.5 cm.
• the helical electrodes 5a, 5b lie opposite one another within the discharge space 8 of the amalgam lamp 20 (shown in broken lines).
• An amalgam reservoir is provided only in the cavity 9 adjacent to the helical electrode 5a.
• the power supply of the amalgam lamp 20 comprises two independent circuits A and B.
• Circuit “A” serves to heat the electrode 5a and thus to additionally heat the amalgam supply
• the second circuit “B” is used to apply the lamp current of nominal 7 A.
• the circuits "A” and “B” are part of a ballast and a controller 21.
• the discharge space 8 of the amalgam lamp 21 contains, in addition to mercury, a noble gas, namely neon.
• the amalgam lamp 21 shows a maximum UVC emission in the case of a mercury vapor pressure by 0.8 Pa, as the diagram of Figure 3 shows schematically; in which the UVC emission in relative units against the mercury vapor pressure in [Pa] is plotted.
• the lamp voltage is dependent on such amalgam lamps. and the lamp current in the case of power control from the mercury vapor pressure, as shown schematically in the diagram of Figure 4.
• the lamp voltage U On the left ordinate is the lamp voltage U and on the right ordinate the lamp current I is plotted in relative units against the mercury partial pressure p Hg in [Pa].
• the optimum operating voltage U and best possible arrangement of the optimum operating current I op timum give a mercury vapor pressure of 0.8 Pa.
• the amalgam lamp 21 with a nominal power of 800 W is operated by means of a power-controlled ballast in the operating mode "constant power".
• the temperature of the electrode 5a, and thus the temperature of the amalgam supply 6 are reduced, so that the mercury concentration in the discharge space 8 decreases, and thereby the efficiency of the UVC radiation is slightly reduced.
• the heating current "l He iz" is switched on as soon as the setpoint for the operating current has fallen below 7.0 A, and it is turned off when the operating current has reached 7 A.
• the heating current is 30% of the target lamp current lson, ie about 2 , 0 A.
• the operating voltage is switched to the operating voltage instead of the operating current.
• the amalgam lamp 21 with a nominal power of 800 W. operated by means of a power-controlled ballast in the operating mode "constant power".
• the heating current "I H eiz" is switched on as soon as the desired value for the operating voltage has exceeded 115 V, and is turned off when the operating voltage is 115 V reached again.
• the heating current is 30% of the target lamp current I so n, So about 2.0 A.

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• 2010
  • 2010-04-06 DE DE201010014040 patent/DE102010014040B4/de active Active
• 2011
  • 2011-03-14 WO PCT/EP2011/001262 patent/WO2011124310A1/de active Application Filing
  • 2011-03-14 US US13/635,156 patent/US9048083B2/en active Active
  • 2011-03-14 EP EP11711030A patent/EP2556530A1/de not_active Withdrawn
  • 2011-03-14 CN CN201180016685.3A patent/CN102812535B/zh active Active

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