1998 Fiscal Year Final Research Report Summary
Evaluation of Heterogeneous Nucleation Phenomena on a Cold Substrate of a Binary Vapor Mixture
| Project/Area Number |
09650832
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
化学工学一般
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
SHINAGAWA Hideo Hiroshima University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (10034365)
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| Co-Investigator(Kenkyū-buntansha) |
OKUYAMA Kikuo Hiroshima University, Faculty of Engineering, Professor, 工学部, 教授 (00101197)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Heterogeneous nucleation / Binary vapor mixture / Reduced pressure / Condctance / Separation / Low temperature |
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| Research Abstract |
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.
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Research Products
(4 results)
