Fluidized Particle Concepts and Coefficients
    Like all engineering activities, Fluidized Bed Drying takes its
ideas and operating principles from the principles of  Chemistry,
Physics and the other nature and life sciences.  Also like other
engineering activities, the important principles are usually, when
possible, generalized to simple coefficients.  this is done to
facilitate the selection and use of a mathematical model.

    Fluidized Bed Drying is no exception to the usual engineering
practice of defining the important engineering science principles
involved in terms of coefficients (numbers).  There are many
scientific concepts used to understand fluidized bed drying but
the three important coefficients we will deal with are the;

    a)    Heat Transfer Coefficient.
    b)    Mass Transfer Coefficient.
    c)     Minimum Superficial Velocity for Fluidization.

    All three of these numbers represent their specific engineering
science image in the same way.  If the Heat Transfer Coefficient
becomes larger it means that more heat can be transferred from
the fluidizing air stream to the particles being dried.  If the Mass
Transfer Coefficient becomes larger it means that there is more transfer
of the solvent mass (liquid) from the particles to the fluidizing air passing
by these particles.  If the Minimum superficial velocity becomes larger it
means that more gas pressure is needed to raise the particles into
suspension above the distribution plate.