What is meant by through circulation drying? A woolen cloth is dried in a hot air dryer from initial moisture content of $100\%$ to final content of $10\%.$ If the critical moisture content is $55\%$ and the equilibrium moisture content is $6\%($at dryer condition$),$ calculate the saving in drying time if the material is dried to $16\%$ instead of $10\%.$ All other drying conditions remain the same. All the moisture contents are on the dry basis.