Abstract: Continuous multistage counter-current fractional crystallization process was investigated for the separation of naphthalene and thionaphthene mixture in a column with a length of H=1350 mm and a inner diameter of Φ=50 mm. Impact factors for the separation efficiency of the crystallization column were systemically studied，including speed of stirring，height of crystal bed，fraction of naphthalene in the feed，and flux ratio. The mechanism for purification improvement was discussed，which was found as the counter-current washing. Better purification was obtained when the mass fraction of naphthalene in the feed was increased from 96.628% to 99.99% at 400mm crystal bed height with 10 r/min stirring speed and 2.29 reflux ratio. Finally，the number of theoretical plates about the crystallizer column was calculated，and the results were highly consistent with the experimental results.

摘要： 以萘-硫茚的混合物为实验物系，在高H=1350 mm，内径Φ=50 mm的结晶塔内开展了连续多级逆流分步结晶实验，考察了进料浓度、回流比、晶体床层高度、搅拌作用等操作参数对结晶塔提纯效果的影响，并对结晶塔内提纯强化机理进行探讨。结果表明：结晶塔内结晶强化机理主要为逆流洗涤作用。结晶塔在进料浓度为96.628%、回流比为2.29、晶体床层高度为400 mm、搅拌速率为10 r/min时，提纯效果最好，产品的纯度可达至99.99%。最后给出了结晶塔理论板数的计算方法，计算结果与实验情况相符良好。