• 作者： Lu, Shih-Yuan
• 中文摘要： 本文針對含有氣相反應及布朗碰撞凝結成長的粉體製作程序,其粒子成長特性---理論分析。此粒子成長分析涵蓋整個粒子大小光譜,從分子域直到連續域。經由改寫適用於計算過渡域粒子碰撞係數的Fuchs-Phillips方程式,吾人找出兩個新的無因次群,一是單體Knudsen數,一是度量分子域中之碰撞特性時間與連續域中之擴散特性間相對重要性的無因次比率。此兩無因次群加上先前Landgrebe and Pratsinis(1989)所提出的兩個無因次群,決定涵蓋整個粒子大小光譜之粒子成長特性。吾人以離散-區間模式來處理通用動態方程式以求解粒子成長特性動態,並據以探討這四個無因次群對粒子幾何平均大小及粒子分布之幾何標準偏差之動態的影響。
• 英文摘要： A theoretical investigation of powder production processes involving gas-phase reactions and Brownian coagulation growth is conducted over the entire particle size spectrum, ranging from the free- molecule to continuum regime. In addition to the two dimensionless groups,.theta., a dimensionless chemical reaction time, and X, a dimensionless process residence time, proposed by Landgrebe and Pratsinis (1989) for aerosol coagulation in the free- molecule regime, two new dimensionless groups are identified based on a rewriting of Fuchs-Phillips formula for coagulation coefficients in the transition regime. One dimensionless group, Kn/sub 1/, that we term the monomer Knudsen number, is the ratio of the mean free path of the background gas to the radius of a monomer product particle. The second dimensionless group, E, measures the relative magnitude of two characteristic times, one associated with the collision process in the free-molecule regime and the other with the diffusion process in the continuum regime. A discrete-sectional representation (Wu and Flagan, 1988) of the general dynamic equation is adopted for solution of the particle size evolution. A numerical verification of the theoretical limiting behavior of particle growth in the free-molecule and continuum regimes is successfully carried out through a proper choice of Kn/sub 1/ and E. The behavior of important product particle characteristics such as the geometric mean diameter and geometric standard deviation is studied against process variations manifested through the four dimensionless groups.
• 中文關鍵字： 粒子成長; 布朗凝結; 過渡域; 離散-區間模式; 噴霧式反應器
• 英文關鍵字： Particle Growth; Brownian Coagulation; Transition Regime; Discrete-Sectional Model; Aerosol Reactor