Ultrasonic microreactors are increasingly applied to particle synthesis, crystallization processes, or organic synthesis involving solids because of the clogging prevention offered by ultrasound irradiation. However, the further application of this technology is limited by the scalability of ultrasonic flow reactors. In this work, we combined experiments and numerical simulations for the design of a scaled-up flow reactor. The reactor consists of a perfluoroalkoxy alkane (PFA) tubing immersed in a box to transmit the ultrasound and provide temperature control, to which six Langevin multifrequency transducers are attached. The acoustic pressure distribution was investigated to characterize the effect of ultrasound frequency and the transducer configurations on particle size distribution for the model reaction of barium sulfate synthesis. Operating the scaled-up reactor with six transducers at a frequency of 40 kHz resulted in an acoustic wave distribution with maximum acoustic pressures in the vicinity of the tubular reactor, thus leading to a small particle size distribution and consequently clogging prevention. The productivity of the scaled-up reactor was 14g/h barium sulfate at a remarkably low applied ultrasound power of 0.48W/mL, highlighting the efficient design and the further scale-up potential.

中文翻译：

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放大超声流反应器的设计与表征

由于防止了超声辐射的堵塞，超声微反应器越来越多地应用于颗粒合成，结晶过程或涉及固体的有机合成。但是，该技术的进一步应用受到超声流反应器的可扩展性的限制。在这项工作中，我们将实验和数值模拟相结合，以设计大型流动反应器。该反应堆由浸入盒子中的全氟烷氧基烷烃（PFA）管组成，以传输超声波并提供温度控制，六个Langevin多频换能器连接到该管上。研究了声压分布，以表征超声频率和换能器配置对硫酸钡合成模型反应的粒径分布的影响。用六个换能器以40 kHz的频率运行按比例放大的反应堆会在声波分布附近产生最大声压，从而使管状反应堆附近的声压分布变小，从而防止颗粒堵塞。放大后的反应器的生产率为14g / h硫酸钡，施加的超声波功率极低，仅为0.48W / mL，这突出了高效的设计和进一步放大的潜力。