Thai tapioca starch factories have been facing a problem of starch loss in the extraction stage at approximately 30% of the total loss. In an extractor, tapioca starch granules are extracted from pulp through the
mechanisms of centrifugation and filtration. Centrifugal force is the main driving force for filtration. To
improve the starch recovery from pulps, this research investigated the starch–pulp separation mechanism and factors affecting the starch separation efficiency. Experiments were conducted with a pilotscale conical-screen centrifuge at various rotational speeds (900–1500 rpm or 205.50–570.85 RCF) and
liquid-to-solid (L/S) ratios (4.6–11.7). The deposited cake properties, specific cake resistance, and starch
separation efficiency were determined along 6 sections of the filtering screen. Increasing rotational speed
and basket radius resulted in an increase in starch separation efficiency due to an increase in centrifugal
force generating a high pressure drop across the filtering screen. Centrifugal force affected the deposited
cake properties that are specific cake resistance, cake solidosity, cake permeability and cake thickness.