滴流床中固相润湿分数的实验研究

A STUDY OF THE EXTERNAL WETTING EFFICIENCY IN A TRICKLE-BED REACTOR

用表面镇镇的填料颗粒催化过氧化氢分解的化学反应法，测定了内径75mm的滴流床中固体填料的外润湿分数实验结果表明，润湿分数随表现气速和液速的增加而增加，降低液体的表面张力、增大粘度也有利于提高润湿分数.当表现液速达到5kg／（m2·s）时，固体填料基本上完全润湿，这与文献报道和作者数值模拟结论一致．

In this work, the chemical reaction method is adapted for experimental measurement of external wetting efficiency f in a trickle bed packed with small size pellets. The chendcal system used is reduction of hydrogen peroxide on the surface of Ni-coated catalysts.The trickle bed is made of glass tubes (75 mm internal diameter) with 0.75 m packing height.φ1.5 mm glass beads and 1.14 mm (equivalent diameter) three-lobed alumina extrudates and two liquld phases (Water, and aqueous solution with 90 wt% ethanol) are used in experiments.It is observed that f increa-ses with the increase of liquid fiow rate. The increase of gaseous flow rate also improvs the wetting efficiency, particularly in the low range of gas flow rate. For the air-ethanol solution system the wetting efficiency is higher than that for the air-water system due to lower surface tension and higher liquid viscosity of the former system. The data suggest that wetting of solid particles approaches complete when the liquid mass flow rate is above 5 kg/m2s, and that Ni-catalyzed decomposition of hydrogen peroxide is a suitable chemical system for experimental dete mination of f. The results obtained may be represented by the following correlation:with an average relative error of 14%.