In a textile mill, wet cloth passes through a hot air drier. The cloth enters with 90% moisture regain and leaves at 6% moisture regain at a speed of 1.15 m/s. The width of the cloth is 120 cm and its density on bone dry basis is 0.095 kg/m. The temperature of the cloth leaving the drier is 368 K (95 C). The ambient air enters the drier at 303 K (30 C) DB and 298K (25C) WB while the hot air leaves the drier at 393K (120 C) DB and 328 K(55 C) WB. Calculate : (i) the bone dry production of the drier (ii) evaporation taking place in the drier and (iii) air circulation rate. (12) (Oct '98)