Evaluation of Heterogeneous Nucleation Phenomena on a Cold Substrate of a Binary Vapor Mixture

二元蒸气混合物冷基底上异质成核现象的评价

• 批准号: 09650832
• 负责人: SHINAGAWA Hideo
• 金额: $ 2.11万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650832/
• 关键词: Heterogeneous nucleation; Binary vapor mixture; Reduced pressure; Condctance; Separation; Low temperature

The experiments for the heterogeneous phase transition from mixed benzene and cyclohexane vapor to crystal or liquid droplet were conducted by slowly cooling a copper substrate. In order to evaluate the change in vapor pressure from a feeder to a cold trap, the conductances for rarefied gas flow through five kinds of cylinders with a inner diameter of 3 mm and 5-100 mm length ware measured. The heterogeneous nucleation characteristics of the mixed vapor ware examined on the basis of the equilibrium thermodynamics and classical nucleation theory. On the basis of both experimental results and the classical nucleation theory a dynamic model was used to simulate the heterogeneous vapor-to-crystal or liquid droplet phase transition in a closed chamber at low substrate temperature. The following results ware obtained.1 .According to eutectic and azeotropic nature of the binary mixture in the vapor-solid system and in the vapor-liquid system, respectively, pure solids formed in the region of higher composition of each component and liquid mixture formed in the region of intermeadiate composition.2. The conductance in the case of the ratio of pressures in gas containers in the upstream side and downstream side P_1/P_2=2-1O was significantly less at the same average pressure P_<av> = (P_1 + P_2) 12 than that in the case of the pressure ratio of near unity.3. The formation of liquid mixture occurred under the thermodynamical equilibrium condition.

采用缓慢冷却铜衬底的方法，对苯和环己烷混合蒸气向晶体或液滴的非均相转变进行了实验。为了评估从进料器到冷凝器的蒸汽压力变化，测量了5种内径为3 mm、长度为5-100 mm的圆柱体中稀薄气体流动的电导。在平衡热力学和经典成核理论的基础上考察了混合蒸汽的非均相成核特性。在实验结果和经典成核理论的基础上，采用动力学模型模拟了低衬底温度下非均相气液滴在密闭腔内的相变过程。根据二元混合物在气固体系和气液体系中的共晶性和共沸性，分别在各组分组成较高的区域形成纯固体，在中间化合物组成区域形成液体混合物。在相同平均压力P_1；av&gt；=(P_1+P_2)12的情况下，气瓶上下游侧压力比P_1/P_2=2-1O时的电导明显小于压力比接近单位时的电导。液体混合物的形成是在热力学平衡条件下进行的。

项目成果

Hideo Shinagawa: "Molecular Flow Analysis in Orifice-Containing Tube Using Maxwellian Distribution Function" J.Chem.Eng.Japan. 30-5. 946-948 (1997)

Hideo Shinakawa：“使用麦克斯韦分布函数进行含孔管的分子流分析”J.Chem.Eng.Japan。

Hideo Shinagawa: "A Free Molecular Flow Characteristic Through a Condult with on Oribice-Restrictod Exit" J.Vac.Soc.Japan. 41・6. 581-583 (1998)

Hideo Shinakawa：“通过 Oribice-Restrictod 出口的自由分子流特性”J.Vac.Soc.Japan 41・6 (1998)。

Hideo Shinagawa: "Mole culas Flow Analysig in Orifice-Containing Tube Using Marwellian Distrilrstion Function" J.Chem.Eng.Japan. 30・5. 946-948 (1997)

Hideo Shinakawa：“使用马威尔分布函数进行含孔管中的分子流动分析”J.Chem.Eng.Japan 30・5（1997）。

Hideo Shinagawa: "Molecular Flow analysis in Orifice-Containing Tube Using Maxwellian Distribution Function" J.Chem.Eng.Japan. 30・5. 946-948 (1997)

品川秀夫：“使用麦克斯韦分布函数进行含孔管的分子流分析”J.Chem.Eng.Japan 30・5（1997）。

Hideo Shinagawa: "A Free Molecular Flow Characteristic through a Conduit with an Orifice-Restricted Exit" J.Vac.Soc.Japan. 41・6. 581-583 (1998)

Hideo Shinakawa：“通过带有孔口限制出口的导管的自由分子流特性”J.Vac.Soc.Japan 41・6 (1998)。