A granular insoluble solid material wet with water is being dried in the constant$-$rate period in a square pan. The sides and bottom are insulated. Air flows parallel to the top drying surface at a constant velocity. Pan dimensions $29$ cm$,$ depth of material $30$ mm$,$ air velocity $3\mathrm{.}5$ m$/$s$,$ dry bulb temperature $55$ C$,$ wet bulb temperature $35,$ weight of solid material $12\mathrm{.}7$ kg$,$ initial moisture content $0,3$ kg H$2$O$/$ kg dry solid, final moisture content $0,22$ kg H$2$O$/$ kg dry solid. After the drying process this product is to be frozen in an air blast freezer. The heat transfer coefficient is $22$ W$/$m$2$K$.$ Density of unfrozen solid is $1122$ kg$/$m$3$ and thermal conductivity values of frozen solid is $1\mathrm{.}122$ W$/$mK$.$ Until solid material reaches freezing temperature the freezer must be worked for $5$ min for $1\backslash$deg C decreasing. Air blast freezer temperature $-34,8$ C and freezing temperature $-3,3$C of solid material Predict the drying rate and the time in hours needed for the total process.