氮气辅助微粒形成技术制备脂肪酸微粒

N_2-assisted Particle Formation to Micronize Fatty Acids

建立气体饱和溶液微粒形成技术的实验装置，研究在N2辅助下利用该装置获取脂肪酸（月桂酸和肉豆蔻酸）微粒，探讨预膨胀压力、预膨胀温度和喷嘴直径对脂肪酸微粒的粒径以及粒径分布的影响．结果表明，用N2取代CO2可以获取平均直径约10～50μm．形貌基本上为球形的脂肪酸微粒．对两种脂肪酸微粒化的研究表明，在实验考察的压力范围内，微粒的平均粒径随着预膨胀压力的增大而明显减小．其粒径分布随压力的升高而变窄．对月桂酸微粒化的研究表明．随预膨胀温度的升高，微粒平均直径略微增大，粒径分布相差不多．对肉豆蔻酸微粒化的研究表明．微粒的平均粒径随着喷嘴直径减小而减小，其粒径分布随喷嘴直径减小而变窄．

An apparatus for particle formation from gas-saturated process was established; the micronization of two fatty acids （lauric acid and myristic acid） was implemented by using this apparatus and using N2 instead of CO2 in order to obtain lipid particles from pure atomization mechanism. The effects of the pre-expansion pressure, pre-expansion temperature and nozzle size on the produced fatty acid particles were investigated. Results showed that the N2-assisted particle formation process could produce spherical particles with mean sizes of 10-50μm. Increasing the pre-expansion pressure from 4 MPa to 12 MPa could narrow the size distributions of the produced particles and evidently decrease the mean sizes from 40μm to 18μm for lauric acid and from 25μm to 9μm for myristic acid at fixed pre-expansion temperature （323 K for lauric acid and 333 K for myristic acid） and with fixed nozzle size （120 μm for lauric acid and 100μm for myristic acid）. Increasing the pre-expansion temperature from 323 K to 343 K could increase slightly lauric acid particle sizes and shows little effect on the particle size distribution at 333 K using the 100 μm nozzle. Decreasing the nozzle size from 120μm to 60μm could narrow the size distributions of the produced myristic particles and decrease the mean sizes from 10μm to 7μm at pre-expansion temperature 333 K and pre-expansion pressure 12 MPa.