提出一种基于LED光源反射的液固搅拌槽中固体颗粒悬浮特性测定的光纤法.在直径0.38m、底部为椭圆形的搅拌槽中,用该法对水-二氧化硅两相体系固体颗粒悬浮特性进行了测定.结果表明,测量临界离底悬浮转速Njs的测量点应选择在搅拌槽下部区域,径向位置对Njs影响不大;在整个固含率范围内,光纤测量法与取样法测量结果较接近,平均相对误差为4.0%,目测法测定结果比取样法与光纤测量法稍高,光纤法比取样法更快速、简便,具有适用于不透明容器的优势,能快速测定最小均匀悬浮转速Nus,Nus随固含率增大而增大.
An optic method based on LED reflection was proposed for determination of the characteristics of particle suspension in a liquid-solid stirred tank. The characteristics of particle suspension in water-silica two-phase system in an oval-bottomed stirred tank of 380 mm in diameter were measured using this method. The results show that appropriate location of measuring point for critical impeller speed Njs should be in the lower part of the tank and the radial position has little effect on Njs. Njs obtained by the optic method was close to that obtained by the withdrawal sampling method in the whole range of solid loading and the average relative error between them was only 4.0%. Njs obtained by the visual observation was bigger than those from other two methods. The optic method can be operated faster and more easily than the withdrawal sampling method and applied in opaque vessels compared with the visual observation. Nus quickly determined by the optic method is bigger with higher solid loading.