The optimal design of a convective drier is hereby considered by means
of using a well-known spreadsheet: Microsoft Excel 5.0(TM). The degre
e of freedom analysis enabled a non linear equations system to be set
up, in such a way that it was possible for different design variables
to be considered. The equations system was keyed in to provide a possi
ble solution via the iterative procedure built in the spreadsheet. Oth
er complementary variables were computed to provide a unit cost for th
e operation, thus occasioning the opportunity of considering an econom
ic objective function. Constraint and design variables were identified
in the program. By giving initial values to the design variables, and
by using the optimization capabilities included in Microsoft Excel 5.
0(TM), an optimal set of values for the design variables was determine
d. Finally, the influence of constraint and design variables was analy
zed, where both the input air temperature and the relative humidity of
exhaust air were binding factors.