SCI和EI收录∣中国化工学会会刊

›› 2009, Vol. 17 ›› Issue (2): 330-339.

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Kinetics of Reaction-Crystallization of Struvite in the Continuous Draft Tube Magma Type Crystallizers——Influence of Different Internal Hydrodynamics

Joanna Koralewska1, Krzysztof Piotrowski2, Boguslawa Wierzbowska1, Andrzej Matynia1   

  1. 1. Department of Chemistry, Wroclaw University of Technology, 50-370 Wroclaw, Poland;
    2. Department of Chemical and Process Engineering, Silesian University of Technology, 44-101, Gliwice, Poland
  • 收稿日期:2008-01-07 修回日期:2008-12-15 出版日期:2009-04-28 发布日期:2009-04-28
  • 通讯作者: Krzysztof Piotrowski,E-mail:krzysztof.piotrowski@polsl.pl

Kinetics of Reaction-Crystallization of Struvite in the Continuous Draft Tube Magma Type Crystallizers——Influence of Different Internal Hydrodynamics

Joanna Koralewska1, Krzysztof Piotrowski2, Boguslawa Wierzbowska1, Andrzej Matynia1   

  1. 1. Department of Chemistry, Wroclaw University of Technology, 50-370 Wroclaw, Poland;
    2. Department of Chemical and Process Engineering, Silesian University of Technology, 44-101, Gliwice, Poland
  • Received:2008-01-07 Revised:2008-12-15 Online:2009-04-28 Published:2009-04-28

摘要: A laboratory-scale reaction-crystallization process of struvite synthesis from diluted water solution of Mg2+,NH4+ and PO43- ions was studied.The research covered the tests of two original constructions of continuous jet-pump Draft Tube Magma(DTM)-type crystallizers with internal circulation of suspension(upward/downward).Interactions between constructional,hydrodynamic and kinetic factors were established and discussed.Nucleation and linear growth rates of struvite crystals were calculated on the basis of population density distribution.Kinetic model of idealized Mixed Suspension Mixed Product Removal(MSMPR) crystallizer considering the size-dependent growth mechanism was applied(Rojkowski hyperbolic equation).For comparison purposes the kinetic data corresponded to a simpler,continuous draft tube-type crystallizer equipped with propeller agitator were analyzed.It was concluded that crystal product of larger size was withdrawn from the jet-pump DTM crystallizer of the descending flow of suspension in a mixing chamber.

关键词: reaction-crystallization, struvite, phosphorus recycling, nucleation, crystals growth, DTM MSMPR crystallizers, size-dependent growth kinetics, liquid jet pump, propeller agitator

Abstract: A laboratory-scale reaction-crystallization process of struvite synthesis from diluted water solution of Mg2+,NH4+ and PO43- ions was studied.The research covered the tests of two original constructions of continuous jet-pump Draft Tube Magma(DTM)-type crystallizers with internal circulation of suspension(upward/downward).Interactions between constructional,hydrodynamic and kinetic factors were established and discussed.Nucleation and linear growth rates of struvite crystals were calculated on the basis of population density distribution.Kinetic model of idealized Mixed Suspension Mixed Product Removal(MSMPR) crystallizer considering the size-dependent growth mechanism was applied(Rojkowski hyperbolic equation).For comparison purposes the kinetic data corresponded to a simpler,continuous draft tube-type crystallizer equipped with propeller agitator were analyzed.It was concluded that crystal product of larger size was withdrawn from the jet-pump DTM crystallizer of the descending flow of suspension in a mixing chamber.

Key words: reaction-crystallization, struvite, phosphorus recycling, nucleation, crystals growth, DTM MSMPR crystallizers, size-dependent growth kinetics, liquid jet pump, propeller agitator