Metal filters are critical to process and environmental quality. Unfortunately in doing their job, filters capture particulates and eventually clog and foul. Fouling can disrupt process fluid flow and can cause process shutdowns, here's how to reduce fouling and improve filter performance. Oh and maybe save a lot of money!
In this blog post you will learn:
How silicon coatings change the surface properties of metal filters.
Coatings like Dursan and Notak™ are bonded to the surface of metal filters by a patented chemical vapor deposition process. The coating gas penetrates the filter and creates a micro thin barrier coating throughout the filter area. Even sintered metal frits can be treated. The barrier coating bonds and penetrates into the surface creating a corrosion resistant, fouling resistant surface with high lubricity. The sputter depth profile below highlights the silicon steel diffusion zone and bond to the stainless steel filter surface. See how Dursan can solve your material problem.
After processing, the filter will take on the surface properties of the coating, enhancing the corrosion resistance, fouling resistance, lubricity, surface energy/ hydrophobicity of the filter. Read more about how our coatings prevent fouling.
Wear and Friction Data
Pin-on-disc comparison of Dursan (carboxysilane) to an oxidized stainless steel surface shows a 50% reduction in wear rate and a 35% reduction in coefficient of friction, improving the efficiency and wear resistance of the filter. Read the complete study.
Carbon Coking Fouling Resistance
Coking and fouling studies show SilcoTek® coatings and coatings combined with a surfactant reduce fouling by 50% or more. Reducing the particulate binding effect and making the filter easier to clean.
ASTM G31 immersion testing compared a Dursan coated surface with silicon and uncoated stainless steel. The Dursan coated surface improved corrosion resistance by an order of magnitude, improving metal filter durability. Get our latest on corrosion prevention, get our corrosion presentation.
A key to particulate binding and fouling is surface energy management. A low surface energy surface will reduce the particulate bond energy and make filter cleaning easier. Surfaces like Notak™ (F-Dursan in the graph) offer the lowest surface energy and highest contact angle of any silicon surface tested. The Notak surface reduces surface energy by 80% compared to stainless steel.
What's it all mean? How Does a Low Friction Low Surface Energy Surface Prevent Membrane Fouling?
So what will a low surface energy high lubricity filter surface contribute to fouling prevention and improved filter performance? Let's compare the differential pressure of an uncoated filter (graph below, top 2 lines) with a Dursan coated filter under simulated process conditions. The coated filter (lower line) had nearly twice the life and half the differential pressure of the uncoated filter.* That means that Dursan or other SilcoTek coatings can help extend the life of your metal filter while reducing energy loss and system back pressure.
Interested in fouling resistance? Read our webinar presentation and learn about how our coatings reduce fouling in many applications.
Fouling reduction can benefit many applications including:
- Heat exchanger fouling
- Refinery fouling and coking
- Mold release
- Automotive fouling & fuel injector fouling
*Data courtesy of Porvair Filtration.