ABSTRACT
In the case of drying, it is worth noting that in
many technologically feasible cases the initial mois-
ture content of a product can be reduced by using
other methods that are more energy efficient. For
example, water removal from solids by mechanical
devices such as presses or centrifuges and, in the
evaporator results in energy consumption being ap-
preciably lower overall. During the past decades, the
rise of energy prices was accompanied by increasingly
stringent legislation on pollution, working conditions,
and safety. To meet these requirements as well as to
optimize energy consumption, new ideas in drying
methods and dryer design are required. Considering
the problems encountered in drying (Table 46.1), it is
obvious that this is not an easy task and, because
energy aspects in drying is a broad subject, this chap-
ter is limited to the following points:
. General considerations
. Methods of heat recovery
. Nonconventional energy sources (e.g., micro-
waves, radiofrequency [RF], and induction) . New drying techniques . Control and monitoring of the drying process . Environmental problems.
