Falling-Rate Period in Drying. Gilliland and Sherwood [20] obtained data of the drying of waterwet 7

Falling-Rate Period in Drying. Gilliland and Sherwood [20] obtained data of the drying of waterwet 7 x 7 x 2:54-cm slabs of 193.9 g (bone-dry) brick clay mix for direct-heat convective air drying from the two faces in both the constant- and falling-rate periods. For Xo = 0.273, X = 0.03, the rate of drying in the constant-rate period to Xc = 0.165 was 0.157 g/ h-cm 2 . The air velocity past the two faces was 15.2 m/s, with Td = 25°C and Tw = 17°C. During the falling-rate period, experimental average slab moisture contents were as follows: At the end of the constant-drying-rate period, the

Falling-Rate Period in Drying. Gilliland and Sherwood [20] obtained data of the drying of waterwet 7 x 7 x 2:54-cm slabs of 193.9 g (bone-dry) brick clay mix for direct-heat convective air drying from the two faces in both the constant- and falling-rate periods. For Xo = 0.273, X = 0.03, the rate of drying in the constant-rate period to Xc = 0.165 was 0.157 g/ h-cm 2 . The air velocity past the two faces was 15.2 m/s, with Td = 25°C and Tw = 17°C. During the falling-rate period, experimental average slab moisture contents were as follows: At the end of the constant-drying-rate period, the moisture profile is assumed parabolic. Other experiments give DAB = 0:72 x 10 -4 cm 2 =s. Use (18-62) to predict values of Xavg during the falling-rate period and compare predicted values to experimental values.