Realization and analysis of jet-based direct mixing gas phase aggregation for the formation of hetero-aggregates with new properties

提出的研究工作的总体目标是促进基于在气相形成的异聚集体的新颗粒产品的开发。为了实现这一目标，首先需要建立气相工艺，以控制形成足够数量和质量的异质聚集体。由于这些过程显然仍然缺乏，因此提出，实现和模拟了基于射流的过程，作为SPP 2289的第一个资助期的一部分，该资助期由Technische Universität Berlin的Kruggel-Emden和Bergische Universität Wuppertal的Schmidt小组申请。基于喷气机的流程包括三个步骤。在第一步中，如果需要，在可能的分解发生后，将不同的初级颗粒作为载气流的一部分分离出来。在第二步中，带有不同主粒子的射流相互作用，允许不同主粒子接触，从而形成异质聚集体。在第三步中，形成的异质聚集体需要以受控的方式从射流相互作用区移除。请注意，热稳定不被认为是第一个资助期的一部分。目前，在优化异质聚集体的产量和质量方面，概述的工艺以及三个子工艺的工艺参数是未知的。因此，应该研究后一个整体过程，包括三个子过程，这需要一个过程分析，可以基于离线取样形成的聚集体分析来执行，但是，也应该探索通过激光衍射和流动分析来获得空间分辨的过程的方法，以了解相关的子过程。此外，形成的异聚集体的结构应该通过离线成像技术（SEM， EDX）来评估，以将结构与单一聚集体的性质联系起来。此外，由于时间和长度尺度较小，因此具有挑战性，因此将气相过程作为DEM/CFD的一部分重新创建。在适当的模型校准和模型验证（通过详细的实验调查基准来实现）之后，其目的是了解作为资助期一部分的实验无法获得的过程细节。因此，该模型旨在为未来进行从头开始的工艺设计提供所有必要的成分，这对于未来开发基于异聚集体的新型颗粒产品的总体目标至关重要。异质聚集体的整体行为和基本特性，以及这些特性的优化，不属于这里申请的第一个资助期的一部分，但属于第二个资助期的一部分，因此，来自资助期的第一个和第二个的联合任务将允许实现上述拟议项目的总体目标。

Overall aim of the proposed research work is to contribute to the development of new particulate products based on hetero-aggregates being formed in the gas phase. To reach this goal it is first required to establish gas phase-based processes which allow the controlled formation of hetero-aggregates in sufficient quantity and quality. As these processes are clearly still lacking, a jet-based process is proposed, realized and simulated as part of the first funding period of SPP 2289 applied for here by the groups of Kruggel-Emden at Technische Universität Berlin and Schmidt at Bergische Universität Wuppertal. The jet-based process consists of three steps. In a first step the different primary particles are isolated as part of a carrier gas stream after a possible disaggregation has taken place if required. In a second step the jets with the different primary particles interact with each other allowing for the contact of the different primary particles enabling the formation of hetero-aggregates. In a third step the formed hetero-aggregates need to be removed from the jet interaction zone in a controlled way. Note that thermal stabilization is not considered as part of the first funding period here. Currently the process parameters of the outlined process as well as the three subprocesses are unknown with respect to optimizing throughput and quality of the formed hetero-aggregates. The latter overall process including the three subprocesses should be therefore investigated which requires a process analysis which can be performed based on an analysis of the aggregates formed done off-line by sampling, however methods to get spatially resolved insights into the process by laser diffraction and flow analysis should be also explored to understand about the relevant subprocesses. Additionally, the structure of the formed hetero-aggregates should be evaluated by off-line performed imaging techniques (SEM, EDX) to link structure with single aggregate properties. Furthermore, as the time- and length-scales are small and therefore challenging, the gas phase-based process is recreated as part of a DEM/CFD. After an appropriate model calibration and model validation which is achieved by in detail benchmarking with the experimental investigations, it is thereby aimed for to learn about process details which are not accessible experimentally as part of funding period one. Thereby, the modelling aims for providing all necessary ingredients to perform ab-initio process design in the future which is essential to contribute to the overall aim of developing new particulate products based on hetero-aggregates in the future. The bulk behavior and underlying properties of the hetero-aggregates as well as the optimization of such properties are not part of the first funding period being applied for here, but part of the second whereby the combined tasks from funding period one and two will allow to reach the aforementioned overall aim of the proposed project.