【摘要】 针对湿含量高达0.604 kg(H2O)/kg(Air)的磷酸二铵尾气脱湿过程,提出雾状与膜状冷凝并存的机制。传热传质数值模拟结果表明,雾状冷凝仅发生在靠近冷壁面的气膜层内,气相主体的湿份通过扩散到达气膜内而冷凝。雾状冷凝权重α=0.2时气膜层内蒸汽分子扩散时间尺度与冷凝时间尺度相当,表明湿份的扩散速率是相变脱湿的控制步骤。更多还原

【Abstract】 A mechanism of simultaneous fogging and film condensation was proposed to the dehumidification of exhaust gas from diammonium phosphate process, in which the humidity is as high as 0.604 kg（H₂O）/kg（Air）. It was shown, through the numerical simulations of heat and mass transfer, that the mist condensation only occurs in the gas film region near the cold wall. Vapors in bulk flow of gas phase are transfered to the film by diffusion. Time scales for vapor diffusion to the film are at the same level with that for vapor condensation in the film, for the typical proportion of mist condensation α=0.2.The results indicated that the rate of vapor diffusion is the control factor for the dehumidification of tail gas by condensation.更多还原