Abstract:
The dense medium cyclone (DMC) process used
in coal beneficiation plants is studied from a control system
perspective. Employing the dynamic model of the DMC process
derived from mass flow balance, a model based control strategy
is proposed. The controller adjusts the density of medium
used to enhance separation in the DMC process according to
measurements on percentages of different components in raw
coal. The first objective of the control is to maintain the carbon
content in the clean coal to a set level. The second purpose is
to minimize energy consumption of the DMC process in view
of the fast increasing electricity price. The controller solves
an optimization problem formulated to determine the density
of medium whenever new measurements are available. Both
coal quality and DMC operational constraints are account for.
Simulations, based on measured plant data, are carried out to
verify the feasibility and effectiveness of the control strategy
designed. The results show that the designed controller is able to
fulfil its purpose satisfactorily when the characteristics of the raw
coal varies and when measurement uncertainties are in presence.
