ABSTRACT
Drying is a complicated process involving simultan-
eous heat, mass, and momentum transfer phenomena,
and effective models are necessary for process design,
optimization, energy integration, and control. The
development of mathematical models to describe dry-
ing processes has been a topic of many research stud-
ies for several decades. Undoubtedly, the observed
progress has limited empiricism to a large extent.
However, the design of dryers is still a mixture of
science and practical experience. Thus the prediction
of Luikov that by 1985 ‘‘would obviate the need for
empiricism in selecting optimum drying conditions,’’
represented an optimistic perspective, which, how-
ever, shows that the efforts must be increased [1].
Presently, more and more sophisticated drying
models are becoming available, but a major question
that still remains is the measurement or determi-
nation of the parameters used in the models. The
measurement or estimation of the necessary param-
eters should be feasible and practical for general
applicability of a drying model.
