Heat Transfer During Boiling of Mixtures in Forced Flow

Abstract

As in the case of pure substances, during the boiling of mixtures in forced flow in tubes or channels, there is a decrease in saturation temperature because of the pressure drop along the path of flow. In addition, because the more volatile component is converted into vapor first, the liquid becomes richer in the less volatile boiling component. In many industrial processes where the tube diameter is not very small, and, thus, the pressure drop not very large, the rise in boiling temperature, because of the increase in the less volatile component in the liquid, compensates the decrease in boiling temperature as a consequence of the pressure drop. It is thus possible that the saturation temperature even rises downstream. In a two-fluid heat exchanger, the driving temperature gradient decreases. In general, the heat transfer coefficient also decreases.