METHOD FOR PRODUCING PULVERIZED COAL

摘要

A method for producing pulverized coal comprising the steps of providing a drying gas heated to a predefined temperature in a hot gas generator (26); 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 coal for further use and feeding the drying gas from the filter (34) to an exhaust line (38); and collecting the drying gas exiting said filter (34) and feeding part of said collected drying gas to a recirculation line (42) for feeding recirculation drying gas to said hot gas generator (26). According to an important aspect of the present invention, the step of providing the drying gas comprises feeding a variable flow rate of hot stove waste gas to the hot gas generator (26) through a hot stove waste gas line (46) so as to maximize the amount of hot stove waste gas used as drying gas. A pressure of the drying gas at a pulverizer gas inlet (24) is controlled by regulating a flow rate of the hot stove waste gas through the hot stove waste gas line (46).