(120g) Study on Mass-Transfer Performance of a New Novel Higee — Rotating Jet Bed

Li Yuming, Wang ying, Ji Jianbing, Wang Guangquan,

(College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014, China)

The Rotating Jet Bed(RJB) has been developed by Zhejiang University of Technology, as a more novel type of gas-liquid mass-transfer equipment than Rotating Zigzag Bed(RZB). The rotor of RJB is composed of perforated concentric baffles fixed to a rotating disc. The top of the baffles is in the grooves of the stationary disc, preventing short cut of the gas. Experiments of total reflux distillation with three types of Higee were carried out with ethanol-water systems at atmospheric pressure. The three types of Higee are RJB with rotor of mesh baffles, RJB with rotor of shutter baffles and RZB. The results showed that the number of theoretical plates per meter of RJB, lower than that of RZB, increased with the increase of rotational speed, and increased firstly and then decreased with the increase of gas superficial kinetic energy F-factor. The maximum number of theoretical plates per meter is 40.7 for RJB with rotor of mesh baffles and 40.0 for RJB with rotor of shutter baffles. The specific pressure drop of RJB was far less than that of RZB. When the gas kinetic energy F-factor was 1.1 m.s^-1(kg.m^-3)^0.5, the ratios of the specific pressure drop of RJB with rotor of mesh baffles and shutter baffles to that of RZB were 10.0% and 13.6%, respectively. The gas-phase film volumetric mass-transfer coefficients of RJB with rotor of mess baffles and shutter baffles were correlated with the Reynolds number, Grashof number and Schmidt number. The calculated value agreed well with the experimental value, and the average deviation was less than 15%.

Keywords: distillation, rotating jet bed, mass-transfer, specific pressure drop