Innovnano (PR - nanoparticles)

Electrostatic ReCyclone® MH system for recovery of nanoparticles of metal oxides (ZnO) placed downstream of a 260m3/h reactor. 

The system is composed by 1 hurricane and 1 electrostatic recirculator
MVD: 1.3 µm
Efficiency: 90-96%
Confidencial 06 (PR - Nanoparticles) - Physical Sciences

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.

  • The system is composed by 2 Hurricane machined cyclones and 4 machined type Electrostatic ReCirculators, both with ø 80 mm
  • Expected and measured efficiency: > 90%
Physical Sciences
ReCyclone EH
Optimized cyclones with electrostatic recirculation

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.


1. Air with fly ash from the boiler or from the pre-separator
2. Hurricane Cyclones. (Batteries of 2, 4, 6 or 8 units )
3. Rotary discharge valve
4. Collected particles
5. Cleaned Air
6. Electrostatic recirculators.
7. Recirculation fan
8. DC High Voltage

Note: supporting structure, insulation and ductwork are not represented
An increasingly high number of industries, from the fine chemicals to the cosmetics industry, are investing on the design and production of nanoparticles, such as metal oxides, in specific reactors. There is a need to recover these very fine powders from the exhaust streams often at high temperature, pressure and moisture.

The very fine particle size precludes the use of mechanical collectors by themselves. The main problem of using barrier filters is product hold-up and breakage of the nanoparticles.

Client's needs include a system to effectively recover the maximum amount of nanoparticles that can operate in continuous and is easy to clean.
Nanoparticles | General Arrangement

Nanoparticles can be produced by an array of fully scaled patent protected technologies. The traditional and most common manufacturing methods are plasma based used to produce simple and complex, multi-component mixed metal oxides.

Dried nanoparticles are usually collected with barrier filters or our Electrostatic Recyclone that separate and collect the dried powder produced in the plasma reactor.