The sizing of continuous decanter can be done from experimental data obtained in laboratory
tests to know the characteristics of the suspension, as there are factors that influence
sedimentation, such as the concentration of solids and the area available for operation.
Discontinuous sedimentation information serves as a basis for the design of continuous
decanters, allowing the construction of sedimentation curves, and later the application of
mathematical models for the calculation of design variables. The objective of this work was to
size the area of a continuous decanter applying the mathematical models of Kynch (1952),
Talmagde and Fitch (1955) and Biscaia Junior (1982). In order to determine the best operating
conditions to obtain the calcium carbonate suspensions to be analyzed, was used the Central
Rotatable Composite Design (CRCD), and the results obtained were evaluated applying the
Response Surface Methodology (RSM), in order to observe the effect of the concentration of
the suspension and the diameter in the calculation of the area. Based on the conditions
established in the present study, it was concluded that the sedimentation curves constructed had
excellent correlation coefficients, with values between 0.9437 and 0.999, attesting that the
experimental data provide reliability for the design of a continuous decanter. Applying the
mathematical models of Kynch (1952) and Biscaia Junior (1982) found variations of very
similar areas, between 9 to 60 m2 and 11 to 72 m2, respectively. The Talmagde and Fitch method
resulted in values ranging from 5 to 18 m2 and presented the most adequate modeling,
indicating that approximately 90% variations are explained by the adjusted model (A =
12,450 + 4,105x1/2 + 4,215 x2 − 5,001x2/2). In general, when the interaction effect is not
significant, as in the case of the three methods analyzed, it is possible to affirm that they are
independent factors, where each main effect can be interpreted in isolation.
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