Abstract: A slide arrangement for blocking or closing off a channel disposed between a coal pulverizer and coal dust burners, and conveying a gas having a high proportion of coal dust. The slide arrangement includes a housing disposed in the channel wall and a shroud or steel structure laterally connected to the housing. A passage for a slide plate is provided in a wall of the housing facing the shroud or steel structure. The passage can be closed off by a closure member except for a narrow gap. The closure member has a circumferential seal that rests against the rearward side of the housing wall. The closure member also has a wear plate that when the closure member is closed is flush with the inner side of the housing wall and forms a smooth passageway.

Abstract: A system for pulverizing coal to be burned in a furnace (20), where nearly all of the coarse ash particles are removed from the coal prior to its introduction to the furnace. The system includes a pulverizing mill (10) having a first classifier (12) in its outlet for separating some of the large, heavy particles and returning them to the pulverizer. A second classifier (16) is connected to the first classifier, and includes a curved duct (16) wherein the solid particles being carried in an airstream are thrown outwardly against an outer wall. A skimmer blade (78) extending through the outer wall skims off a percentage of the large, heavy particles, the percentage depending on how much coarse ash the coal stream contains. The rest of the coal particles are conveyed to a furnace and burned therein. The separated large, heavy particles are passed through an ionizer (30) and then through an electrostatic separator (34), where the inorganic particles are separated from the coal particles.