A THEORETICAL CORRECTION OF THE OUCHIYAMA AND TANAKA FORMULA FOR PREDICTING AVERAGE POROSITY OF PACKED-BEDS CONSISTING OF NONUNIFORM SPHERES

To predict the overall average porosity of a packing of unequal sphere s, Ouchiyama and Tanaka (Ind. Eng. Chem. Fundam. 1981, 20, 66.) establ ished a simple packing model and derived an analytical formula. In thi s model two uniformity assumptions were introduced, which lead to syst ematic errors in the model, making the prediction of the average poros ity higher or the prediction of the packing density lower than experim ental data. This paper proposes a theoretical correction for this mode l. For binary packings of spheres, the correction parameter is fixed, The prediction by our correction is in excellent agreement with experi mental data for a large range of <(epsilon)over bar>(0), the porosity of a packing of equal spheres, and k, the ratio of the smaller to the larger diameter of spheres.