TABLE OF CONTENTS This problem was partially discussed in chapter III. Here, we shall examine this problem in greater detail because it is the essential condition for the separation process in a rarefied gas.
At first sight, it may appear that all the main problems, associated with the settling of the particles in a still medium (simplified case) have been examined and solved since this problem has been studied by experts for more than 100 years. In fact, the problem is very complicated and has not as yet been completely solved. There is only a single solution of the Stokes equation for the case Re ?1. As regards the remaining part of the range of the values of Re, it is necessary to use empirical and semi-empirical relationships. Recently, a large number of experimental material has been obtained for the settling of single particles in different liquids. For gas media, the number of these data is considerably smaller, and for a rarefied gas ( ? P = 380 10 mm Hg) there are almost no experimental data. However, this area is of considerable interest for the fractionation of fine-dispersion materials. It is therefore important to examine the dynamics of single particles in a rarefied gas. In addition to this, in the literature, especially applied literature, there have been many cases of insufficiently efficient theoretical analysis and even a large number of erroneous equations and conclusions. All these factors...
