Products

Application Examples: Customised Lab Scale and Pilot Scale Loop Photoreactor System

In synthesis, photochemistry is the method of choice. UV light can vastly speed up many chemical syntheses – or make them possible in the first place. Unlike with thermal excitation, light-induced reactions frequently take place at room temperature and are therefore less destructive. Sensitive molecules remain intact and there are fewer by- products.

Our product and competence in the domain of preparative photochemistry and photochemical environmental techniques.

We sell UV-radiation sources and standard photochemical reactors for immediate use to perform a great variety of preparative tasks at laboratory and pilot levels. UV-radiation sources and corresponding reactors may be adapted and optimized for specific procedures. ATEX/ IECEx certification of radiation for electrical powers of 2.5 to 40 kW are available on request.

In many countries there are already regulations governing the testing for photochemically induced degradation of pharmaceuticals and cosmetics. Akown delivers appropriate photoreactors. For units of production, we sell entire systems of irradiation, where parts may be taken from standard programs comprising a variety of dimensions and types of radiation sources. We neither construct nor sell photochemical reactors for production units as this task remaining entirely within the domain of competence and responsibility of the user. However, in cooperation with our partner uv-technik Speziallampen GmbH, we offer consulting services based on scientific and technical expertise.

Furthermore, we offer the possibility to analyse the reactor geometry of planned or existing production scale photoreactors utilizing professional flow-simulation along with physical radiation data to optimise photo-chemical processes.

UV medium-pressure lamps are produced as linear lamps asstandard. They consist of a sealed discharge tube made of quartz glass. The dischargevessel is filled with noble gases with a low pressure in the range of severalmillibar. Moreover, UV medium pressure lamps contain a small amount of mercuryand dopants, such as iron, gallium or other elements. During operation, aplasma is generated in the lamps which emits radiation. As a rule, the plasmais excited by establishing a current flow between the electrodes, which arefused or crimped at both ends of the lamp. Electrode free medium pressure lampscan be stimulated to light by means of microwaves. By varying the length, thediameter (Graphic 1) and the filling, UV medium-pressure lamps can beinfluenced in their performance and adapted to different operating conditions.UV medium-pressure lamps must always be operated on a suitable ballast.

Graphic I: Typical specific performance of UV medium pressure lamps in W/cm light emitting length as a function of Ø

UV medium pressure lamps emit radiation from the UV range to the infrared (Graphic 2).

Graphic 2: Section from the electromagnetic spectrum with its typical classification

A considerable part of the radiation power of a medium pressure lamp is in the infrared range (Graphic 3).
The lamps therefore require cooling.

Graphic 3: Distribution of the power of a typical UV medium pressure lamp, Hg type across the spectrum

Automated control system for UV immersion lamp consists of Power Control Panel and Operator Panel which can be engineered depending on the degree of automation required and scope for the integration of instruments.

Electronic power supply enables stepless and accurate regulation of power to the UV lamp. Furthermore, it provides features for e.g., measurement and control of process parameters, Data logging and transfer, safety interlocks and user-friendly interface.