Presentations from China, Australia, South-Africa, Europe and North-America showed that the topics are of worldwide interest.
In times of global business and worldwide activities, the conference organized by Evonik Fibres is a successful platform for companies already engaged in business around the globe or for those planning to do so in the future.
P84 Fiber Blends : Confirmation of Superior Filtration Performance on a VDI 3926 test rig
First trials with P84 / PTFE blends were soon followed by blending the whole range of materials used for needle felts in order to improve their filtration performance. Because of its unique multi-lobal cross section the yellow polyimide fiber manufactured by Evonik Fibres/Austria is well known to offer superior filtration efficiency compared to conventional fibers with round cross sections.
In terms of thermal stability P84 has a position close to PTFE, which has been used as a scrim material in high temperature filtration since P84 was launched on the market. More stringent environmental regulations and need for better performance and process stability led to blending of P84 with PTFE as well as low cost fibers. The advantage of P84 blends very soon proved to pay off the sometimes higher price in various applications.
All P84 blended products proved their advantage during comparative testing under standardized conditions, confirming the actual results in various field applications.
The P84 blend exhibits 40 times lower clean gas dust concentrations after ageing. Residual pressure drop was slightly lower and the cleaning cycle time twice as long as with the PTFE felt.
- Waste incinerators
- Cement: bypass, kiln/mill dedusting
- Bio mass combustion (Temperature peaks up to 260°C)
Procon/P84 blends have become a standard solution when PPS felts are suitable because of their oxidative and thermal stability, but due to difficult dusts filter media with higher filtration efficiency are needed. Blending PPS with P84 reduces dust incorporation and improves filtration efficiency, pressure drop and cycle time. These products combine the superior resistance of Procon against acid dew point crossings with the excellent filtration performance of P84 at a comparably low price.
- Coal Fired Boiler, especially after coal dust fired boiler without absorbent dosing and after absorption systems with high dust load (high absorbent recirculation)
- Cement kiln/mill dedusting
- Police filter after waste incinerators (Peak temperatures below 190-200°C, continuous operating temperature typically <150°C, depending on operating conditions and bag life expectation)
Poly Acrylic Homopolymer/P84 blends The P84 blend exhibits lower differential pressure and cycle time at a comparable clean gas dust concentration compared to the 100% PAN needle felt.
The results of the tests according to VDI 3629 confirm the superior filtration performance of P84 blends with PAN (poly acrylic homo-polymer), Procon (PPS) and PTFE. Wherever a 100% P84 felt is not suitable from either the technical or the economical point of view these blends open a wide range of applications to be upgraded with the well known advantages of P84.
- Coal mills
- Cement grinding mills
- Coal Fired Boiler (Peak temperatures below 125-140°C).