Abstract: Traditional baffle plate freezing dehydrator used in Tetrafluoroethylene (TFE) production industry has some defects，such as uneven distribution of cold of TFE cracking gas in large diameter tubes，low efficiency of ice crystals resident time in the dehydrator with the cracked gas into the next processes，and larege flow resistance due to baffle plate. This study designed a new freezing dehydrator in order to avoid the above defeats. Compared with traditional freezing dehydrator，this design adopted variable cross-section enhanced heat transfer tube instead of smooth tube. The tube-side fluid was able to produce strong turbulence and destroy the boundary layer effectively because of spiral flow in twist segment，which could improve the heat transfer efficiency. Water in TFE cracking gas would be quickly frozen and thrown to tube wall turning into ice by centrifugal force. Shell-side using twist tube self-supporting structure could help decrease the shell-side pressure-drop and saves materials. Based on monitoring data in one case，freeze dehydration effect was 30% higher than the original heat exchanger.

Key words: freezing dehydrator, twist oval tube, heat transfer enhancement, industrial application

摘要： 应用于四氟乙烯（TFE）生产工艺的传统单弓形折流板式冷冻脱水器存在换热管径大、裂解气冷量分布不均、脱除的冰晶不能有效在脱水器中停留而随裂解气进入下级以及因折流板原因导致的壳程流动阻力大等缺点。为此本文设计了一种新型冷冻脱水器，与传统冷冻脱水器相比，采用变截面扭曲强化传热管代替光滑圆管，使冷冻脱水器管程流体沿扭曲螺旋线流动，低雷诺数下形成非对称扰流，有效破坏边界层，提高了传热效率；管内TFE裂解气中的水分更快冷冻并在气流离心力作用下迅速甩向管壁，凝结成冰，提高脱水效果；并且壳程改为变空间纵向流动，流动阻力低，节省材料。结合案例监测数据，与传统单弓形折流板式冷冻脱水器进行数据对比，冷冻脱水效果较原换热器提高30%。

关键词: 冷冻脱水, 变截面扭曲管, 强化传热, 工业应用