کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2487555 1114422 2007 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Single-Droplet Evaporation Kinetics and Particle Formation in an Acoustic Levitator. Part 1: Evaporation of Water Microdroplets Assessed Using Boundary-Layer and Acoustic Levitation Theories
موضوعات مرتبط
علوم پزشکی و سلامت داروسازی، سم شناسی و علوم دارویی اکتشاف دارویی
پیش نمایش صفحه اول مقاله
Single-Droplet Evaporation Kinetics and Particle Formation in an Acoustic Levitator. Part 1: Evaporation of Water Microdroplets Assessed Using Boundary-Layer and Acoustic Levitation Theories
چکیده انگلیسی
The suitability of a single droplet drying acoustic levitator as a model for the spray drying of aqueous, pharmaceutically‐relevant solutes used to produce protein‐loaded particles has been examined. The acoustic levitator was initially evaluated by measuring the drying rates of droplets of pure water in dependence of drying‐air temperature and flow rate. The measured drying rates were higher than those predicted by boundary layer theory because of the effects of primary acoustic streaming. Sherwood numbers of 2.6, 3.6, and 4.4 at drying‐air temperatures of 25°C, 40°C, and 60°C were determined, respectively. Acoustic levitation theory could predict the measured drying rates and Sherwood numbers only when a forced‐convection drying‐air stream was used to neuralize the retarding effect of secondary acoustic streaming on evaporation rate. At still higher drying‐air flow rates, the Ranz‐Marshall correlation accurately predicts Sherwood number, provided a stable droplet position in the standing acoustic wave is maintained. The measured Sherwood numbers and droplet Reynolds numbers show that experiments performed in the levitator in still air are taking place effectively under conditions of substantial forced convection. The similitude of these values to those occurring in spray dryers is fortuitous for the suitability of the acoustic levitator as a droplet evaporation model for spray drying. © 2007 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 2274-2283, 2007
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Pharmaceutical Sciences - Volume 96, Issue 9, September 2007, Pages 2274-2283
نویسندگان
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