A batch of wet solid was on a tray dryer using constant drying conditions and a thickness of material on the tray of 25.4mm. Only the top surface was exposed. The drying rate during the constant-rate period was Nc=2.05kgH2O/h.m2. The ratio Ss/A used was 24.4 kg dry solid/ m2 exposed surface. The initial free moisture was X1=0.55 and the critical moisture content Xc=0.22kg free moisture /kg dry solid. Calculate the time to dry a batch of this material from X1=0.45 to X2=0.30 using the same drying conditions but a thickness of 50.8mm, with drying from the top and bottom surfaces