Condensation of Organic Binary Mixtures Flowing Horizontally in Horizontal Tube Bundle

Both heat and mass transfer in the gas phase and heat transfer in the liquid phase are examined experimentally for film condensation of organic binary mixtures such as ethanol-water and methanol-water. Experimental results on average heat flux, gas-liquid interface temperature and liquid-phase Nusselt number are compared with the analytical solutions based on a stagnant film theory and heat transfer relationships for film condensation from a pure vapor. Experimental results on heat transfer agree well with the analytical solutions, except that the liquid-phase Nusselt number in experimental results in the condition of low mass fraction of water is considerably higher than that in analytical solutions. This high value of the liquid-phase Nusselt number is considered to be caused by dropwise condensation in liquid phase. However, its effect on the tube bundle is not so remarkable compared with that in gravity-controlled condensation on a vertical surface, This is considered to be caused by the condensate inundation effect.