Measurement void fraction profiles packed

Three different packings were investigated. Details are given in Table I. Figures 1 to 3 show typical examples of the measured void fraction profiles. 

THE MEASUREMENT OF VOID FRACTION PROFILES IN PACKED BEDS... 

Lerou and Froment [l] demonstrated that the structure of the packed bed can be defined by its radial void fraction profile. In order to have adequate and reliable data on void fraction profiles an experimental measuring system was constructed, which is presented here together with suggestions for subsequent analysis. 

Figure 1. Measured radial void fraction profile of a bed packed with small spheres.

The efficiency at which the column or plate count is packed initially in chromatography is important because (1) it determines the shape of the individual band profiles, and (2) it can effect the void fraction and thus the operating pressure. For chromatographic processes where the plate count is important (see Section 7.8.1 on flow rate), developing methods to measure the plate count of the column after it is packed or of a prepacked column is important. There are several methods for measuring the plate count of a packed column, as given below. 

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