Mechanical separation equipment classification

The nature and sizing of equipment depends on the economic values and proportions of the phases as well as certain physical properties that influence relative movements of liquids and particles. Pressure often is the main operating variable so its effect on physical properties should be known. Table 11.1 is a broad classification of mechanical processes of solid-liquid separation. Clarification is the removal of small contents of worthless solids from a valuable liquid. Filtration is applied to the recovery of valuable solids from slurries. Expression is the removal of relatively small contents of liquids from compressible sludges by mechanical means. 

If the dry milling equipment does not include internal classification, or if a separate classifier is not part of the equipment train, feed particle size may affect milled particle size. Additionally, as one main mechanism for particle breakage in these mills is interparticle collisions, the density of solids in the mill or the solids feed rate can be an important parameter to control to obtain reproducible milling results. 

Extraction equipment can be classified by function as providing discrete stages or continuous differential contact. Separation may be by gravity alone or by centrifugal force. Additional energy may be applied to control drop size, either by mechanical agitation or pulsation. This classification is shown in Table 1, along with major examples of available equipment. 

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