Process analysis and control of atomization and mixing zones in spray flames

喷雾火焰中纳米颗粒的合成是由复杂的化学和物理过程（多物理场和化学反应：前体和气体供应、雾化、喷雾形成、液滴蒸发、反应化学、颗粒合成和配制）的相互作用引起的。这些现象发生的时间和长度都大不相同。为了优化现有技术并开发新的方法，以便在技术层面上进行有效的实施和过程控制，需要从根本上理解各个过程及其相互作用。拟议项目旨在对主要工艺步骤（前体化学、雾化、反应、混合和夹带）进行详细的工艺分析和控制，以揭示进一步工艺优化的潜力。该项目的一个主要假设是，混合和反应区可以通过有针对性地调节气体流量以及通过添加和再循环淬灭气体来控制和优化。液滴-液滴和液滴-气体相互作用的详细研究可以揭示群燃烧现象和蒸发动力学的空间和临时解决的测量。前体浓度对温度的影响，以及对液滴蒸发和颗粒成核提供了深入了解液滴和颗粒的历史。雾化、液滴蒸发和反应的密切联系和控制是充分发挥火焰喷雾热解潜力和设计合适的工艺路线以定制化合成功能材料的关键步骤。

The synthesis of nanoparticles in spray flames results from the interplay of complex chemical and physical processes (multiphysics and chemical reaction: precursor and gas supply, atomization, spray formation, droplet evaporation, reaction chemistry, particle synthesis and formulation). These phenomena occur on substantially varying time and length scales. In order to optimize the existing technology and to develop new approaches for an efficient implementation and process control at the technical level, the individual processes and their interplay needs to be understood from a fundamental point of view. The proposed project aims at a detailed process analysis and control of the primary process steps (precursor chemistry, atomization, reaction, mixing, and entrainment) in order to reveal potentials for further process optimization. A main hypothesis of this project is that the mixing and reaction zones can be controlled and optimize by the targeted adjustment of gas flows, and by adding and recirculating quenching gases. Detailed studies of droplet-droplet and droplet-gas interactions can reveal group combustion phenomena and evaporation kinetics from spatially and temporary resolved measurements. The influence of precursor concentrations on temperature, as well as on droplet evaporation and particle nucleation provide deep insights into the droplet and particle histories. The close connections and control of atomization, droplet evaporation and reaction is a key step to tap the full potential of flame spray pyrolysis and to design proper process routes for the tailored synthesis of functional materials.