Improving API yield with new revolutionary particle agglomeration-enhancing cyclone geometries

Improving API yield with new revolutionary particle agglomeration-enhancing cyclone geometries

03/21/2017, 4:15 PM - 5:00 PM

Meeting Room 4


Reverse flow cyclones are gas-solid separation devices with low investment and operation costs but with difficulty capturing fine and low-density API particles, leading to below optimal product recovery (PR) yields. This presentation addresses the design of numerically optimized reverse-flow gas cyclones (Hurricane) and the understanding of agglomeration in cyclones to significantly increase API´s yield. This understanding lead to more accurate models of collection efficiency estimation, capable of explaining why sub-micrometer particles are often captured with much higher efficiency than predicted by standard models. This knowledge has been incorporated into ACS proprietary numerical simulation tool-the PACyc (Particle Agglomeration in CYClones, CEJ 162 (2010) 861–876). ACS has demonstrated significant increases in PR when compared with other high efficiency cyclones in processes such as recovery after drying processes, after micronization and milling and product waste compliance.


  • Júlio Paiva


    Head of Research and Development

    Advanced Cyclone Systems


Type of Session

  1. Type of Session

Learning Objectives

  1. Learning Objectives 1. The simulation of reverse-flow cyclones has been the subject of several different approaches, but none of the proposed theories is capable of consistently giving good predictions when applied to predicting experimental grade-collections obtained with different geometries, operating conditions and particle-size distributions. Of all these, the Mothes and Loffler (1988) model gives predictions which are better correlated with available data, using a finite dispersion model as proposed by Salcedo and Fonseca, 1996. These difficulties have led cyclone designers to base their geometries on empirical testing, such that a widely accepted basic rule to succeed in cyclone design is to use only geometries that have been experimentally tested (Heumann, 1991). ACS has a different approach due the existence of a proprietary model: PACyc model. 2. PACyc model was built combining a therotical model of particle agglomeration within a defined flow-fieds (Sommerfeld 2002 and Sommerfeld and Ho 2003) with Mothes and Loffler model 1998 (which defines the flow field in each cyclone area and correspondante efficiency after establishing each mass balance). Analysing the joint effect of discrete models with Lagragian and Eulerian approach in highly turbulent vorticial flows, the model builds a particle history along the clustering/agglomerating effect, and allows in the aftermath, to reconstruct each particle effiency after interparticle interation. 3. The effect of agglomeration arises as a consequence of each small particle being collected as a part of a much larger cluster. The smaller particle, using a classic approach, would have a very small collection efficiency, but after being a part of a much larger (less denser) cluster, its overall efficiency is much larger than expected. The model, due to its capability of having each particle history, is able to backtrace each cluster and define each Initial particle, leading to a update forecasted efficiency, much larger than any classical model.


  1. Track
    Enhancing Processing & Production Utilizing Innovation

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