Abstract:

The mechanism of direct-contact evaporation in a “wet-type dry still” was investigated, where the hold-up of the material directly heated by the immiscible heat carrier was very low.The process of direct-contact evaporation of a single bubble in continuous phase was simulated for the case of bottom feeding.The effects of initial diameter of the bubble on the depth of continuous phase, the time of complete evaporation of the bubble, the instantaneous temperature difference of heat transfer, and the instantaneous coefficient of heat transfer were investigated by simulation.Simultaneously the definition of limited depth of continuous phase was presented, and its expression was deduced.The status of a heated bubble, which was in a deeper position than the limited depth was analyzed.