文档介绍：Chapter 6 Transport Phenomena In Biochemical Reactors
Mass Transfer Criteria for Simple plex Systems
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参考阅读:
《生化反应动力学与反应器》
戚以政汪淑雄编著
第6章生化反应器的传递过程
第5章生化反应器的设计与分析
第7章生化反应器的流动模型与放大
Chapter 5 Basic Concepts of Transport Phenomena In Bio-engineering and Chemical Engineering
Transport phenomena and reaction are the basic phenomena in the nature, Chemical Engin. and Bio-engin.
If there is velocity gradient, temperature gradient, or concentration gradient, there must be momentum transfer, heat transfer, and mass transfer.
For momentum transfer, there is Newton’s Law of Viscosity as follows:
-----shear stress, -------viscosity of the fluid.
Momentum flux = - viscosity velocity gradient
Fluids that behave in this fashion are termed Newtonian fluids, Fluids that do not obey this law are referred to as non-Newtonian fluids. The subject of non-Newtonian flow is a subdivision of Rheology.
For the heat transfer, there is Fourier’s Law of Heat Conduction as follows:
q/A -----The local heat flow per unit area; heat flux
k ----- thermal conductivity.
Heat flux = thermal conductivity temperature gradient
jA------the molar diffusion flux of A in a binary system;
DAB ----- mass diffusivity; ------- mass density;
Molar diffusion flux = mass diffusivity density gradient
Assumption of Constant C and DAB in a binary system with chemical reaction, the molar diffusion differential equation:
RA ------ the molar rate of production A
For the mass transfer, there is Fick’s First Law:
If the above situation without reaction in a stable system:
This is Fick’s second Law.
Importance of Study on Transport phenomena
There are microbes, substrate and metabolism products effect on the viscosity of the bio-reaction systems, and then effect on the momentum transfer, heat transfer, and mass transfer. Further the transport factors effect on the bio-reactions, design of reactors and general output of the whole bio-process.
Viscosity
Fluid ics/power required
Heat tran