Method to comminute and dry damp fuel, especially brown coal; involves drying coal in fluidised bed dryer between two comminuting units and using exhaust vapour from dryer to remove dust

摘要

The method involves comminuting the coal in a first comminution unit (1), drying it in an indirectly heated fluidised bed dryer (3) and comminuting it in a second comminution unit (9). Exhaust vapour is removed from the fluidised bed dryer and supplied to a dust collector (5) and to the fluidised bed dryer through an exhaust vapour circuit (6a,7) as fluidisation steam. The exhaust vapour is used to separate the dried, comminuted coal. The whole comminuted material (ZG) from the second comminution unit is supplied with exhaust vapour from the fluidised bed dry between the fluidised bed dryer and the dust collector. The exhaust vapour is used to sort the comminuted goods in the exhaust vapour stream. The fine fraction (F) is supplied to the dust collector in the exhaust vapour and the coarse fraction (G) is fed back to the second comminution unit. The comminuted material is supplied to the second comminution unit independently of the exhaust vapour circuit to the supply point in the exhaust vapour. An Independent claim is included for a device for implementing the method.