The simplified model proposed by Jaros and Pabis [8] consists of
two equations: equation of the first drying period taking into account
drying shrinkage (model 18a in Table 1) and semi-theoretical
equation of the second drying period (model 18b in Table 1),
where Mc is the critical moisture content, dry basis; N is the constant
of the model; tc is the time of drying while moisture content
M = Mc, s. The critical moisture content Mc is determined assuming
the continuity of the drying process. The assumption required that
when M is equal to Mc, the drying rate in the first and second period
be equal, that is when (dM/dt)I = (dM/dt)II [8].