Measurement Technology Sinks Costs for Filter Systems

Together with project partners, the LZH is developing an inexpensive measurement system, which monitors the efficiency of filter systems for gaseous emissions resulting from the laser processing of polymers. This technology allows improved exploitation of the filter, and not only reduces operation costs, but also saves natural resources.

During laser processing of plastics and wood materials, complex particulate and gaseous emissions are generated. Due to workplace and process-safety reasons, these emissions must be captured and filtered. Air-cleaning is typically carried out using a combination of a particulate filter system and a gas adsorption system.

The gaseous hydrocarbons are usually removed using an active charcoal adsorption filter system. Since the active charcoal must be replaced regularly, from an operational cost standpoint, its absorbing capacity should be exploited optimally.

By placing online sensor technology at the filter exit, the adsorption potential of the active charcoal can best be monitored. When the gas filtration level is lower than a pre-set threshold level, an optical and/or acoustical signal is given. Since the hydrocarbon concentration must be measured with adequate accuracy in the ppm-range, the exhaust gasses are enriched before they are measured. Thus, the detection threshold of the online monitoring system can be lowerd by a factor of 10 – 100.

The LZH is currently working on an enrichment unit based on the adsorption/desorption process. The enriched gasses are detected by a metal oxide sensor array (Fanalmatic GmbH), based on the principle of an "electric nose".

The set-up and operation of the pilot unit should be completed by the end of 2003, in cooperation with the Herding GmbH. The system will be optimised and checked with special emphasis being placed on long-term stability. Special attention will also be paid on creating an inexpensive end product for the user.

The Arbeitsgemeinschaft industrieller Forschungsvereinigungen „Otto von Guericke“ e.V. (AiF) supports the project through the program ProInno.

Set-up of the filter system for laser exhaust gasses with a particulate filter and active-charcoal adsorption, including the online monitoring unit.

Business Development & Communications Department
Michael Botts
Public Relations
Tel.: +49 511 2788-151
Fax: +49 511 2788-100
The Laser Zentrum Hannover e.V. (LZH) carries out research and development in the field of laser technology and is supported by the Ministry of Economic Affairs, Labour and Transport of the State of Lower Saxony (Niedersächsisches Ministerium für Wirtschaft, Arbeit und Verkehr).