Electrostatic ReCyclone® MH system for recovery of nanoparticles of metal oxides (ZnO) placed downstream of a 260m3/h reactor.
Electrostatic ReCyclone® EH system to increase silicon nanoparticle collection (30-60 nm) after a supersonic expansion of a SiH4 plasma jet at a maximum continuum flow rate of 62 m3/h at 100ºC.
Recent adoption of electrostatic recirculation in the same cyclone system has successfully proven to further reduce particle emissions, even in the [1;5]µm particle size range, assuring future regulation compliance, particularly where legal limits are very tight, with the objective of bag filter redundancy.
A DC high voltage is applied in the concentrator, allowing the recirculation of very fin nanometric particles, more resistant to centrifugal forces, to the cyclone collector.
After having been separated in the recirculator and concentrated in the recirculation flow, electrically charged fine particles are attracted by the cyclone walls, while agglomerating with larger particles entering the system, both promoting their easier capture.
Since particles are not captured on the walls of the recirculator, contrary to ESPs, ReCyclone® systems avoid the problem of dust colmatation and condensation.
Additionally, ReCyclone® EH systems are also immune to either low or high dust electrical resistivity and the HV required power is only 10 to 15 % of that used in ESPs. Electrostatic recirculation for fine particle capture was the winner of the Portuguese Environmental Press Award in 2008 and nominee for the European Environmental Press Award 2008.