CAJ | 학술논문

为了获得流态化干燥状态下的粉体干燥曲线,设计了一种小型流化床干燥装置用于粉体材料的干燥特性测定.应用该装置,实验研究了悬浮法PVC粉体的干燥特性.测定的PVC粉体在该流化床中流化参数为操作气速介于0.41～0.55 m/s之间,即流化数ua/umf为1.24～1.67.实验测定了PVC粉体干燥动力学曲线,回归得到描述PVC干燥特性曲线的解析函数为f=-0.622 6+1.254 6exp(2.561 5Φ-0.707 2)/1 + exp(2.561 5Φ-0.707 2).确定了实验条件下PVC干燥的临界湿含量xc及传质系数K分别为0.02 kg/kg和6.0×10-4kg/(m2·s).由于实验方法比较接近工业流态化干燥过程,获得的结果对于工程应用较为可靠,该方法可用于如PVC一样的粉体材料的干燥特性测定.
위료획득류태화간조상태하적분체간조곡선,설계료일충소형류화상간조장치용우분체재료적간조특성측정.응용해장치,실험연구료현부법PVC분체적간조특성.측정적PVC분체재해류화상중류화삼수위조작기속개우0.41～0.55 m/s지간,즉류화수ua/umf위1.24～1.67.실험측정료PVC분체간조동역학곡선,회귀득도묘술PVC간조특성곡선적해석함수위f=-0.622 6+1.254 6exp(2.561 5Φ-0.707 2)/1 + exp(2.561 5Φ-0.707 2).학정료실험조건하PVC간조적림계습함량xc급전질계수K분별위0.02 kg/kg화6.0×10-4kg/(m2·s).유우실험방법비교접근공업류태화간조과정,획득적결과대우공정응용교위가고,해방법가용우여PVC일양적분체재료적간조특성측정.
For obtaining the drying curve of powder under fluidized drying, a normal fluidized-bed dryer is designed to study the drying kinetics of PVC (polyvinyl chloride) powder in the experiment. A new measure system is derived for drying dynamics testing. In the small fluidized-bed dryer, fluidization parameter of PVC powder is tested, and the operating air velocity can be chosen in the range of 0. 41 to 0. 55 m/s. Accordingly,the fluidized number ua/umf is from 1.24 to 1.67. A promising drying model is used to describe the drying process, and then the characteristic drying curve of PVC powder derived from a suspension method can be expressed as f =-0.622 6+1.254 6exp(2.561 5Φ-0.707 2)/1 + exp(2.5615Φ-0.7072). Based on the experiments, the critical moisture respectively. The experimental results in the small fluidized-bed dryer are similar to those of the real fluidized drying process, so the descried method can also be used in determining drying kinetics of powder materials such as PVC powder.