Practical aspects of batch sedimentation control based on fractional density changes

In this paper, a method of monitoring a batch sedimentation process and of controlling the removal of clarified liquid from the batch settler is presented. The proposed method is based only on pressure measurement, and thus an optic sensor is not required. it is shown, that it is possible to monitor the progress of batch sedimentation by measuring hydrostatic pressure at a certain distance from the bottom of the settler. This approach ensures a relatively low-cost control and monitoring of this process. A mathematical model of the phenomenon being used is presented and validated using an experimental batch sedimentation pilot plant. Guidelines for the location of pressure sensor are presented based on simulation investigations. Experimental results also show that it is possible to distinguish between temporary surface disturbances and failure of the sedimentation process. (C) 2009 Elsevier B.V. All rights reserved.