US 5,753,106 A · Method of, and apparatus for, and irradiation unit for oxidative photopurification

Abstract

An annular throughflow photoreactor for oxidative photopurification includes an elongate radiation source surrounded by a transparent wall in the form of a spacer tube at a radial spacing of more than 3 cm, preferably in the range of more than 3 cm to 13 cm. The irradiance, i.e. the radiant flux per irradiated area is thereby reduced in comparison to a classic annular photoreactor. At unchanged irradiation power, this results in considerably increased quantum yields or extent of photoconversion in cases in which such conversion is dependent upon the square root of the irradiance, and thus enables enormous savings in radiation energy. Under such conditions, the photoconversion may be additionally increased by using low absorber concentrations and infeeding further absorber on the inside of the outer wall of the photoreactor as well as by working in the presence of gaseous oxygen at an oxygen pressure up to 3 bar and, preferentially, at pH 3. The throughflow photoreactor may comprise an annular single chamber or dual chamber photoreactor or a tank reactor having an annular array of irradiation units including the spacer tubes. A plural number of such photoreactors may be series connected.

Claims40

Dependent claims

An apparatus for oxidative photopurification of an optically transparent medium contaminated by at least one oxidizable carbon compound, said apparatus comprising:

an elongate radiation source defining a lengthwise axis and emitting radiation including UV radiation in the wavelength range below 280 nm during operation;
said elongate radiation source comprises at least one medium pressure mercury lamp;
an annular reaction chamber coaxially surrounding said at least one medium pressure mercury lamp for receiving an optically transparent medium contaminated by at least one oxidizable carbon compound and containing a dissolved radical forming absorber which forms two free radicals upon photolysis by said UV radiation in the wavelength range below 280 nm emitted by said at least one medium pressure mercury lamp, each one of said two free radicals being capable of initiating a sequence of oxidizing radical reactions by reacting with said at least one oxidizable carbon compound;
a transparent wall, which is made of quartz glass and transparent for said UV radiation in the wavelength range below 280 nm emitted by said at least one medium pressure mercury lamp, for passing said UV radiation into said medium present in said reaction chamber;
and
said transparent wall made of quartz glass surrounding said at least one medium pressure mercury lamp at a radial spacing of more than 3 cm from said lengthwise axis of said at least one medium pressure mercury lamp.

3 more elements

Dependencies are inferred from the claim text.

Method of, and apparatus for, and irradiation unit for oxidative photopurification

Life of this patent

Method of, and apparatus for, and irradiation unit for oxidative photopurification

Life of this patent

Abstract

Claims40