Homogeneity particle packing

A homogeneous particle packing can be obtained when the suspension flow units do not change on a time scale of that of the coating process. In industrial practice it is often also desirable that the suspension properties are stable on a longer time scale (shelf life) for economic reasons. This means that sedimentation and ageing cannot be permitted amd must accordingly be prevented. 

Figure 12.13. PVC paste polymer with homogeneous particle size-less efficient packing...

The adsorbent bed is homogeneous and packed with spherical particles of constant diameter... 

The number of transfer units for each mechanism can be estimated from known parameters and mass transfer correlations (4). For example, for a column with particles 0.01 cm in diameter, a superficial velocity of 0.01 cm/sec, and a solute bulk diffusivity of 7 x 10-7 cm2/sec, the estimated number of transfer units in a packed bed of length L for the four mechanisms, axial dispersion, external fluid film mass transfer, pore diffusion, and solid homogeneous particle diffusion,are... 

FIGURE 4.5 (a) PVC paste polymer particles with homogeneous particle size—less efficient packing, (b) PVC paste... 

Diffuse reflectance technique is used for powders and solid samples having rough surface such as paper, cloth. In diffuse reflectance technique, particles size, homogeneity, and packing density of powdered samples play important role on the quality of spectrum. A sample with smaller particle size having narrow size distribution is preferred. Thus, in order to obtain a qualified spectrum, the sample should be ground into smaller size. 

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