Combination of DBD and electrode gas discharge lamps for fluid treatment system
Publication Date: 2007-Feb-28
The IP.com Prior Art Database
Multilamp fluid treatment system comprising combinations of electrodeless gas discharge lamp(s) and standard filament driven gas discharge lamps.
The invention relates to a treatment system or a treatment reactor comprising at least
one electrodeless gas discharge lamp combined with at least one filament driven gas
discharge lamp, installed into a housing for containing a medium like a fluid and/or a gas and/or a solid material which is to be treated by means of the radiation generated by the electrodeless lamp and/or the filament driven lamp.
As an alternative to conventional mercury based discharge lamps, electrodeless mercury
free lamps based on excimer generation of noble gas or noble gas-halogene mixtures are of increasing importance especially as a source for generating high intensive and high power UV light within a narrow spectrum and with a high efficiency. Capacitive coupling by using the walls of the lamp as dielectric barrier is the dominating driving mode for these types of lamps, called dielectric barrier discharge lamps. Typically, these 15
lamps have a cylindrical, a dome shaped or a coaxial design and they are cooled by means of an internal and/or an external flow of water. The basic principle of these lamps is the generation of excimer radiation by means of a dielectric barrier discharge. Usually, at least one of the two electrodes of such a lamp is located outside the discharge volume at or around the lamp envelope so that the energy supply is
accomplished by capacitive coupling through the walls of the lamp envelope into the discharge volume to initiate there the gas discharge.
If electrically conductive fluids are treated by means of the radiation generated by such
a lamp, the energy supply of the lamp can be fed via the treated fluid (see US 6633109
and US 5843784) so that the electrode which is in electrical contact with the fluid does not need to be positioned directly at the lamp envelope. Especially the metallic housing of a related fluid treatment system or reactor containing the dielectric barrier discharge lamp and the fluid can be used as one of the electrodes. This has the advantage that the losses of the generated radiation caused by absorption and/or shadowing at an electrode 30
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which surrounds the lamp envelope are eliminated.
These well known dielectric barrier discharge lamps are used for example in flat lamps
for liquid crystal display (LCD) backlighting, as cylindrical lamps for photocopiers, and
as co-axial lamps for surface and water treatment purposes. The primary emission
wavelength of dielectric barrier discharge lamps is determined by the type and pressure of the gas filling. By means of luminescent layers, in this case phosphor layers, which are deposited onto the inner surfaces of the lamp envelope, in this case made of two quartz...