| 摘要 |
Method for producing pulverized coal, the method comprising the steps of heating a drying gas, preferably an inert gas, in a hot gas generator (26) to a predefined temperature; feeding the heated drying gas into a pulverizer (20); introducing raw coal into the pulverizer (20), the pulverizer (20) grinding the raw coal into pulverized coal; collecting a mixture of drying gas and pulverized coal from the pulverizer (20) and feeding the mixture to a filter (34), the filter (34) separating the dried pulverized coal from the drying gas; collecting the dried pulverized coalfor further use and feeding the drying gas from the filter (34) to a recirculation line (38) for returning at least part of the drying gas to the hot gas generator (26); and determining an oxygen level in the drying gas, preferably in the recirculation line (38), and comparing the determined oxygen level to a predetermined oxygen level threshold. According to a preferred embodiment of the invention, if the determined oxygen level is higher than a predetermined oxygen threshold, water is injected into the heated drying gas before it is fed into the pulverizer (20), the volume of water injected being calculated so as to reduce the oxygen level below the predetermined oxygen level threshold. |
