Plateau 2011 (EC - Fertilizers)

Mechanical ReCyclone® MH system convertible to an electrostatic ReCyclone EH®.

This equipment is composed by 18 hurricane cyclones and 18 mechanical recirculators working at a flowrate of 50 400m3/h at 40ºC. System designed for product recovery and emission control of animal fertilizer dust.

Expected emissions: < 50mg/Nm3
Measured emissions: < 40mg/Nm3

Plateau ASP
Numerically optimized cyclones, considering particle agglomeration

Hurricane geometries maximize powder collection for each different application, while minimizing reentrainment and keeping pressure drop at reasonable levels.

These high efficiency cyclones are the output of nonconvex nonlinear problems formulated and solved after years of work in partnership with the Faculty of Engineering of Porto.

A single Hurricane is more efficient than any other known cyclone available in the market for the same pressure drop, usually resulting in less than half of the emissions of other high efficiency cyclones available.

1. Air and Dust from Dryer or Boiler
2. Hurricane Cyclone
3. Valve
4. Collected Particles
5. Clean Air
ReCyclone MH
Optimized cyclones with mechanical recirculation

In order to obtain very high efficiencies and compliance with emission limits, an improve recirculation system has been designed to take advantage of the Hurricane cyclones. A mechanical ReCyclone®

(ReCyclone® MH) is made up of a Hurricane with a particle separator (straight-through cyclone), placed downstream of the cyclone - called the "recirculator".

The main purpose of the recirculator is to reintroduce the fine non captured particles into the cyclone after those have been driven to the outer walls of the recirculator by centrifugal forces. While this tangential gas stream is enriched in particles, the axial gas stream exhaust to the stack is clean of particles. Recirculation is achieved through an additional fan. 

Since the recirculation system only serves the purpose of dust separation (and not collection), the particles are exclusively collected in the cyclone and the need of rapping mechanisms is thus avoided. 

Efficiency increases due to recirculation and agglomeration of very small particles with larger ones coming directly from the process. A ReCyclone® MH decreases emissions of Hurricane cyclones alone by 40 to 60%. As with cyclone systems, ReCyclone® MH systems are very robust, do not have temperature limitations and do not have moving parts to be frequently changed. Finally, recirculation control provides the benefit of handling variable process flow rates.


The next figure exemplifies a ReCyclone® MH in stainless steel AISI 304L for particle recovery in drying process. Recirculators can be disposed vertically, as shown, or horizontally.


1. Air and dust from boiler or dryer
2. Hurricane cyclone ( Batteries of 2, 4, 6 or 8 units )
3. Discharge valve
4. Collected Particles
5. Clean air
6. Recirculator
7. Fan

Note: supporting structure, insulation and ductwork are not represented

The recovery of fertilizers typically after drying tunnels or drum dryers is associated with a high load of particulates and very humid gas streams.

The recovery of these products is commonly performed by dryer cyclones as they allow for a direct powder capture and avoid filter clogging due to condensation. Arrangements with cyclones and/or with bag filters are usual in the industry.

Client's needs include a low maintenance high efficiency cyclone system that is efficient enough to comply with regulatory PM limits avoiding the use of a bag filter as the primary or final stage deduster.

Fertilizers | General Arrangement

The recovery of fertilizers after a dryer is commonly performed by dryer cyclones to capture most of the powder and an end stage dedusting system (either Bag Filter, a Hurricane or Mechanical ReCyclone) before the stack.