A batch of wet solid was dried on a tray dryer using constant drying conditions and a thickness of material on the tray of 25.4 mm. Only the top surface was exposed. The drying rate during the constant-rate period was R= 2.05 kg H₂O/h.m² (0.42 Ibm H₂O/h.ft?). The ratio Ls/A used was 24.4 kg dry solid/m² exposed surface (5.0 lbm dry solid/ft²). The initial free moisture was x=0.55 and the critical moisture content xe 0.22 kg free moisture/kg dry solid. Calculate the time to dry a batch of this material from a) x=0.50 to x2 = 0.25 b) X=0.45 to x2 = 0.30 using the same drying conditions but a thickness of 12.7 mm, with drying from the top and bottom surfaces. (Hint: First calculate Ls/A for these new cases.) (5 marks)