  We introduce two models of industrial drying - a simplified one-equation
model, and a detailed three-equation model. The purpose of the simplified model
is rigorous validation of numerical methods for PDE-constrained optimal
control. The purpose of the detailed model is to be able to predict and control
the behaviour of an industrial disk drier. For both models, we introduce a
fully validated numerical method to compute the optimal source term to maintain
the outlet temperature as close as possible to the set-point temperature. By
performing simulations using realistic parameters for industrial driers, we
illustrate potential applications of the method.
