Patent ID: 7850104

Claim:
A coal mill controller comprising: a primary airflow control module; a coal feed control module; differential pressure sensors to sense pressure differences between each of a plurality of sets of two locations within a fuel path of a coal mill, each differential pressure sensed with respect to a powder stage of coal within the fuel path of the coal mill; a mill control module including an instruction set, operable on a processing device interconnected with the primary airflow and coal feed control modules and the differential pressure sensors, to cause the coal mill controller to: receive, from the primary airflow rate control module, a primary airflow rate of a primary airflow into the coal mill; receive, from a coal feed control module, a coal feed rate of coal being fed into the coal mill; receive, from the differential pressure sensors, differential pressures each sensed with respect to a powder stage within the fuel path of the coal mill; determine a recirculated load of coal within the coal mill and a pulverized fuel flow of coal from the coal mill as a function of the differential pressure measurements, the primary airflow rate, and the coal feed rate; estimate a mass of coal powder in each powder stage within the fuel path of the coal mill; and store the determined recirculated load of coal, the estimated masses of coal powder in each powder stage, and the pulverized fuel flow of coal with the received primary airflow rate and coal feed rate.