声学微球的静电破碎冷冻干燥制备法  

Preparation of acoustic microspheres by electrostatic breakupand freeze-drying

作　　者：王晓英[1] 裴婧贤 王东保 王军锋[1] WANG Xiaoying;PEI Jingxian;WANG Dongbao;WANG Junfeng(School of Energy and Power Engineering,Jiangsu University,Zhenjiang,Jiangsu 212013,China)

机构地区：[1]江苏大学能源与动力工程学院,江苏镇江212013

出　　处：《排灌机械工程学报》2023年第7期731-739,共9页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(11502097);江苏省自然科学基金资助项目(BK20150511,BK20171301)。

摘　　要：针对静电破碎结合冷冻干燥技术制备声学微球的过程,采用高速数码摄像技术进行浆液破碎过程可视化研究,应用图像分析技术研究不同工况参数对微球粒径、球形度的影响,并基于Back Propagation(BP)神经网络建立理论模型分析各工况参数的重要程度.结果表明:随着电压增大,浆液破碎出现滴状模式、微滴模式和振荡微滴模式.滴状模式下,形成毫米级的微球;微滴和振荡微滴模式下,微球粒径与滴状模式相差一个数量级,为毛细管内径的1/4~1/3.滴状模式下,增大流量,微球粒径差异不大;在微滴模式和振荡微滴模式下,微球粒径随流量增加而逐渐增大.喷嘴直径增大,各破碎模式下制备的微球粒径均有不同程度的增加.由于蒸发作用,微球粒径略小于液滴直径,且施加低电压(0,2 kV)时,流量的增加对微球粒径的影响呈无规律状.接收距离是影响微球球形度的决定性因素,增大接收距离,微球球形度分布范围增大,球形度下降.由BP神经网络分析发现电压、喷嘴直径和流量对微球粒径的影响占比分别为87%,10%和3%,电压是微球粒径的决定性因素.For the preparation of acoustic microspheres by electrostatic breakup combined with freeze-drying technology,a high-speed digital camera technique was used to visualize the slurry breakup process.The image analysis technique was applied to study the influence of different working parameters on the particle size and sphericity of the microspheres.A theoretical model based on a Back Propagation(BP)neural network was established to analyze the importance of each working parameter.The results show that as the voltage increases,the slurry appears in dripping mode,micro-dripping mode,and oscillating micro-dripping mode.In the dripping mode,microspheres of millimeter size are formed.In the micro-dripping and oscillating micro-dripping modes,the microsphere particle size differs from the dripping mode by an order of magnitude,being 1/4-1/3 of the inner diameter of the capillary tube.In the dripping mode,there is little difference in the size of the microspheres when the flow rate is increased,and in the micro-dripping and oscillating micro-dripping modes,the size of the microspheres gradually increases with increasing flow rate.The particle size of the microspheres prepared in each breakup mode has varying degrees of increase as the nozzle diameter increases.Due to evaporation,the particle size of the microspheres is slightly smaller than the droplet diameter,and when low voltages(0 and 2 kV)are applied,the increase in flow rate has an irregular effect on the particle size of the microspheres.The receiving distance is the decisive factor affecting the sphericity of the microspheres.Increasing the receiving distance leads to a wider distribution of roundness and a decrease in the sphericity of the microspheres.The BP neural network analysis shows that the effect of voltage,nozzle diameter,and flow rate on the particle size of the microspheres accounts for 87%,10%and 3%,respectively.Voltage is the determining factor for particle size of microspheres.

关 键 词：静电破碎 制粒 声学微球 粒径 球形度 BP神经网络 

分 类 号：TQ014[化学工程]