关键词: 冷冻脱水, 变截面扭曲管, 强化传热, 工业应用

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