混合均勻度量化之實驗探討及其模式之建構－以固體顆粒混合為例

Quantitatively Characterizing the Degree of Mixing in Solid Mixtures

李文貴(Wun-Gue Lee) ； 王淑美(Shu-Mei Wang)

《致遠管理學院學報》 1期 (2006/08) Pp. 329-342

https://doi.org/10.6595/BDCM.2006.1.18

摘要

材料混合(mixing)或混煉(blending)的均勻度攸關成品的品質、安全及製造成本，以往混合研究大都偏向液體與液體之間或液體與固體之間所作之混合，然而對於不同固體顆粒或粉末之間的混合卻較少探討。尤其在最近奈米材料(nano-material)被熱烈研究之下，對於固體間之混合加工實有被發展之必要。
本研究係以取樣方式進行固體顆拉混合均勻度之量化實驗，並利用統計變方(Statistical variance)有關的Intensity (I)及Scale (S)之觀念，建構其混合均勻度量化模式，並且分析其混合機構，以提供粉末材料混合加工之參考。
我們的研究結果顯示，使用I及S之觀念不但可表示固體顆粒間之混合程度，其混合均勻度(M)可以M=0-I*S之關係式表示，而且能說明其混合機構，亦即混合的好壞取決於I及S之大小，其中I之值與分佈性的混合(distributive mixing or extensive mixing)程度有關，分佈性愈佳表示其值愈低；而S之值則與分散性的混合(dispersive mixing or intensive mixing)程度有關，分散性愈佳表示其值愈低。若分佈性與分散性的混合皆佳（表示I與S之值皆低），則可獲得較高的混合均勻度（表示M值大）。另外實驗發現固體混合均勻度受到固體顆粒之相對粒徑及含量比例之影響至鉅，如果使用粒徑較小的顆粒，由於粒子間的移動性(mobility)較好，有助於顆粒的分佈(distribution)，因而具有較低的I值；若使用可獲致充填密度較大之兩種以上不同粒徑之顆粒混合，表示這些顆粒較易分散(dispersion)，亦即具有較低的S值。

關鍵字

混合 ； 混煉 ； 分散 ； 分佈 ； 約勻度 ； 統計變方

並列摘要

Mixing or blending process is significant in chemical, metallic, ceramic, semiconductor, food, and pharmaceutical industries. An efficient mixing can achieve superior quality of end products and beneficial effects on the decreasing cost of labor, energy and capital. Though considerable and fruitful study has been made of mixing of liquids with liquids or solids with liquids, little work has been done on the mixing of granular solids or powders. However, this problem is of importance in the blending of nano-partical materials.
The object of this study is to quantitatively characterize goodness or poorness of solids mixing based on the statistical variance, and to analyze the mixing mechanism.
Our experimental results indicated that mixedness (M) can be quantitatively characterized by the model of M=1-I*S and explained the mixing mechanism in the solids mixing based on the concepts of intensity(I)and scale(S).The mixedness was given a large dependence of the particle sizes and contents of solids used. If the size of particle used was smaller, it had larger mobility and gave smaller intensity (I) during mixing; however, if the packing fraction of the used particles with different size was larger, these particles were easier to be dispersed and given smaller scale(S).

並列關鍵字

mixing ； blending ； intensity ； scale ； degree of mixing ； mixedness ； statistical variance

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