Quarterly Newsletter April 1993

Abstract

Fluid Bed dryer monitoring and control. In the dryer, the first parameter that is measured is the input temperature.When the dhool enters, the dryer, there is around 2.5 times as much water as dry matter in it.When this highly mobile portion of the dhool moisture has been lost, (at about 40% moisture content wet basis) the rate of drying will start to fall. Once all the free moisture in the tea has been evaporated, we still have some further moisture to evaporate. This is the amount of water that the dry tea is capable of picking up from the atmosphere in storage, in a hygroscopic manner.