A regulator for continuous sedimentation in ideal clarifier–thickener units

Summary, in English

The purpose of this paper is to present a regulator for control of the continuous-sedimentation process in a clarifier–thickener unit when this is modelled in one space dimension and when the settling properties of the solids obey Kynch’s assumption. The model is a scalar hyperbolic conservation law with space-discontinuous flux function and point source. The most desired type of solution contains a large discontinuity. A common objective is to control the movement of this discontinuity subject to the requirement that the effluent of the process have zero concentration of particles. In addition, there may be a requirement that the underflow concentration of the thickened suspension lie above a predefined value. Based on previous results on the nonlinear behaviour of the process, a nonlinear regulator is presented. It controls the location of the large discontinuity indirectly by controlling the total mass. The process is stabilized significantly and large input oscillations can be handled.

• Author: Stefan Diehl
• Department/s: Mathematics (Faculty of Engineering); Partial differential equations; Numerical Analysis
• Publishing year: 2008
• Language: English
• Pages: 265-291
• Publication/Series: Journal of Engineering Mathematics
• Volume: 60
• Issue: 3-4
• Links: http://dx.doi.org/10.1007/s10665-007-9149-3
• Document type: Journal article
• Publisher: Springer
• Topic: Control Engineering; Mathematics; Water Treatment; Water Engineering; Chemical Engineering
• Keywords: Control; Clarifier–thickener; Continuous sedimentation; Nonlinear regulator; Dynamic behaviour
• Status: Published
• Research group: Partial differential equations; Numerical Analysis
• ISBN/ISSN/Other: ISSN: 0022-0833