MICROWAVE DRYING OF COAL

摘要

A method for drying coal using microwave energy to achieve a controlledaggregate moisture content target rangewithout starting combustion or degrading the coking qualities of the coal.Coal feed stock is first separated into fine grade coal andone or more larger grades. The fine grade coal is loaded onto a conveyor as abed of fixed depth. The fine grade coal is conveyedcontinuously through a microwave-energized heating chamber for drying. Thefine grade coal is dried sufficiently so that when it iscombined with the larger grade coals, the moisture content of the aggregate iswithin a target moisture content range. By volumetricallyand uniformly heating the coal, the microwave heating chamber boils away thewater without heating the coal itself aboveabout 90°C. In this way, the coal does not combust or oxidize, and itscoking qualities are retained.