13. November 2019
The filtration and treatment of hot gas flows plays a key role in tackling the increasing demands for environmental protection and cost-effectiveness. Operating temperatures of over 260 °C dispense with reheating of the exhaust gas and protect downstream units like heat exchangers, catalysts, or gas scrubbers from deposits. However, higher operating temperatures place greater strain on the filter media used. Components made from PTFE can be used up to a maximum of 260 °C and can be set alight by smoldering particles. Although ceramic filters withstand higher temperatures, they have a limited length and robustness. The new four-ply, inherently stable filter media laminate made of stainless steel from GKD combines three different filter media – including metal nonwoven – to form a high-performance filter media laminate for hot gas filtration. It impresses with a retention rate previously only seen at the same level of efficiency in PTFE filter media. Unlike PTFE, however, the metal filter laminate is temperature resistant up to 600 °C and can therefore also be used where polymer filter media no longer work. What’s more, the good weldability that the material provides ensures secure sealing between the raw gas side and clean gas side. As Trimetric filter elements are self-supporting, they do not require a filter basket. Unlike with ceramic cartridges, they can be cleaned outside of the filter housing using a high-pressure cleaner, enabling them to be reused multiple times. Thanks to their mechanical robustness, the inherently stable Trimetric filter elements even withstand vibration stress from pulsed pressure increases during cleaning, so there is no risk of breakage as there is with ceramic filters. Compared with cartridges made of pure metal nonwoven or powder, Trimetric filter media laminates also impress with optimum regenerability and a long service life. Generally speaking, there is no limit to the cartridge length and any external diameter from 60 to 600 millimeters is possible. The shape, too, has virtually no restrictions: A cylindrical form is usual, but in principle any other geometry is also possible. Trimetric filter media laminates can be used in all designs of standard dust filters and can be used in existing cartridge filter systems without alteration. With only a slight modification of the fastening elements in the filter housing, even existing bag filter systems or systems based on filter leaves can be converted. As such, the new Trimetric filter media make a long-term contribution to increasing process efficiency, cost-effectiveness, and reducing CO2 emissions in hot gas filtration.