气液固三相并流系统流型的混沌识别

运用确定性混沌分析技术,研究了气液固三相并流系统散式鼓泡流、聚式鼓泡流、柱塞流、泡沫流及环状流压力波动信号的混沌动力学行为。结果表明,吸引子可以用来表征气液固三相并流系统的动力学行为, 混沌特征参数相关维D2和K熵可以用来定量识别以上五种流型。以混沌定量识别为基础,给出了三相并流系统的流型图。

稀释率对新型固液气分流式瘤胃模拟系统发酵效果的影响

本试验旨在研究稀释率对新型固液气分流式瘤胃模拟系统发酵效果的影响。采用单因子完全随机试验设计,共设4个处理,各处理稀释率分别为6%/h、8%/h、10%/h、12%/h,每个处理3个重复,每个重复1个发酵罐。试验期10 d。结果表明:随着稀释率的提高,发酵液pH极显著提高(P<0.01),而氨态氮(NH3-N)浓度则极显著降低(P<0.01)。稀释率由6%/h上升到10%/h,总挥发性脂肪酸(TVFA)及戊酸浓度极显著下降(P<0.01)。稀释率从6%/h提高到8%/h时,原虫数量极显著提高了6.91%(P<0.01),但当稀释率从8%/h提高到12%/h时,原虫数量却极显著下降了5.18%(P<0.01)。随着稀释率从6%/h增加到10%/h,木聚糖酶活性(P<0.01)及微生物蛋白质(MCP)产量(P<0.05)显著或极显著降低,粗蛋白质体外消失率极显著升高(P<0.01)。稀释率为10%/h和12%/h的2个处理,中性洗涤纤维体外消失率显著高于另外2个处理(P<0.05)。结果提示,稀释率能够影响新型固液气分流式瘤胃模拟系统的发酵情况,稀释率为8%/h时,原虫数量以及纤维素类酶活性、各瘤胃发酵参数更加有利于发酵,因此可推荐作为本系统最优运行条件。

细粉颗粒为固相的气液固三相磁稳定床操作特性

The characteristics of magnetically stabilized bed(MSB)were studied in a three-phase system with nitrogen,water and iron powder(and/or Ni-RE-P amorphous alloy catalyst)as gas,liquid and solid phase respectively.The operating state was observed,and the effect of magnetic field and superficial velocity of gas on minimum fluidization velocity were examined.Finally,the MSB using mixture of iron powder and Ni-RE-P amorphous alloy catalyst as solid phase was studied.

气-液-固反应合成超细碳酸钙的研究

对气-液-固三相系统制备碳酸钙进行了探讨,优化了碳化反应参数,研究了石灰石的预处 理技术,在降低氢氧化钙质量分数、提高二氧化碳体积分数和搅拌速度的条件下获得最小粒度的碳酸 钙,并合成了立方形、球形、针形三种形状的碳酸钙。

多相反应器中压力波动信号的非线性分析

通过重构相空间、Poincare截面、分维和Kolmogorov熵等混沌分析方法对气液固三相并流流动系统的压力波动信号进行了定性研究,研究表明:此类系统存在有非线性混沌现象;并用确定性混沌分析方法对其压力波动信号作了进一步探讨。此类系统普遍存在2～3个分维,其中低频大尺度波动对应的分维反映全局动力学行为,其余两个反映局部性质。

Micromixing characteristics in a gas-liquid-solid stirred tank with settling particles

The parallel-competing iodide-iodate reaction scheme was used to study the micromixing performance in a multi-phase stirred tank of 0.3 m diameter.The impeller combination consisted of a half elliptical blade disk turbine below two down-pimping wide-blade hydrofoils,identified as HEDT + 2WH_D.Nitrogen and glass beads of100 μm diameter and density 2500 kg-m^(-3) were used as the dispersed phases.The micromixing could be improved by sparging gas because of its additional potential energy.Also,micromixing could be improved by the solid particles with high kinetic energy near the impeller tip.In a gas-solid-liquid system,the gas-liquid film vibration with damping,due to the frequent collisions between the bubbles and particles,led to the decrease of the turbulence level in the liquid and caused eventually the deterioration of the micromixing.A Damping Film Dissipation model is formulated to shed light on the above micromixing performances.At last,the micromixing time t_m according to the incorporation model varied from 1.9 ms to 6.7 ms in our experiments.