| 摘要 |
The method according to the invention for mill drying coal comprises the following steps: a) pre-drying of the coal to a predefinable first moisture level in a pre-dryer (2) and b) milling the coal to a predefinable particle size distribution in a mill, and is characterised in that a water-vapour-containing exhaust air (6) of the pre-drying process is fed to the mill for further drying of the coal to a predefinable second moisture level. The method for mill drying according to the invention has the advantage that, in the case of already existing pre-dryers (2) and mills such as bowl mills (5), the throughput of the entire system of pre-dryers (2) and bowl mills (5) can be significantly increased, since the transit and thus the dwell time through the pre-dryer (2) can be shortened, irrespective of whether the dryer is a tubular dryer or a fluidised bed dryer, if the predefinable first moisture level can be higher on exiting the pre-dryer (2) than if only milling takes place in the existing bowl mill (5) and all the drying takes place in the pre-dryer (2). The capacity of the entire system and thus the throughput and the output of brown coal dust can thus be increased. In addition, the use of the waste heat of the pre-dryer (2) by using the exhaust air (6) or vapour means that a more energy-efficient procedure can be achieved, which means a reduction in the energy input needed. |
