Articles & Issues
- Conflict of Interest
- In relation to this article, we declare that there is no conflict of interest.
- This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright © KIChE. All rights reserved.
All issues
정체류에서 피막전극에 대한 산소의 전달현상
The Oxygen Transport to the Membrane Covered-Electrode in Stagnation Flow
HWAHAK KONGHAK, April 1979, 17(2), 117-124(8), NONE
Download PDF
Abstract
막을 씌운 전극을 사용하여 산소농도를 측정함에 있어서 외부에 stagnation flow를 형성시켰을 때 전류반응을 고찰하였다. stagnation flow에서 산소의 전달현상을 해석하기 위해 몇가지 가정하에 수학적 모델을 세우고 이 결과를 심험치와 비교하였다. 폴리에칠렌 막과 백금전극을 사용한 수용액에의 실험에서는 계산된 유체역학적 boundary layer의 두께가 전극의 반경보다 작거나 거의 같을 때는 유속의 변화에 대한 실험결과는 이론치와 잘 일치한다. 그러나 이보다 커지게 되면 이론치와 실험결과는 많은 차이가 있었으며 이는 일차원적 모델에서 무시되었던 반경방향의 확산이 점차적으로 중요해지기 때문으로 추측된다. 막의 두께가 두꺼워 짐에 따라 수용액에서 유체역학적 상황의 변화에 따른 전류응답이 점차적으로 덜 민감해 지는 것을 알 수 있었다.
The current response of a membrane covered-electrode with respect to the fluid motion in stagnation flow was investigated in this study. The mathematical model was set up to analyze oxygen transport in this flow regime. The current predicted by the model was compared with the results of the experiments performed using polyethylene film and platinum cathode. One dimensional model was in good agreement with the experimental results when the thickness of hydrodynamic boundary layer was smaller than or comparable to the radius of the electrode, but it did not agree well when the thickness exceeded the radius of the electrode. This may be due to the reason that the radial diffusion term neglected in one dimensional model becomes important as well as the axial diffusion term. It appeared that the current response became less sensitive to the hydrodynamics of the outside of membrane as the thickness of membrane increased.