Abstract: An improved coal mill exhauster fan having an elongated, conical hub welded to the blades and engaging the rear shroud plate to eliminate air gaps along the rear of the fan assembly and to assist in axial to radial directional changes of the coal flow; two-piece blade assemblies having a sub-blade welded directly to the hub and shroud plates, and a protective liner removably secured to the sub-blades only, for example by bolts; a plurality of swept-back stiffener ribs welded to the rear undersides of the sub-blades, hub and shroud to increase rigidity, and with angled deflector faces to reduce erosion; and an improved hub cap or spinner seal which extends further toward the housing inlet than traditional Cooley caps and which forms a smooth, non-turbulent extension of the hub relative to the incoming coal flow.

Abstract: An improved coal pulverizer classifying system in which the feedpipe and classifier cone are provided with extensions to protect coal flow into the pulverizer from the annular fine-lifting airflow from the pulverizer throat. The feedpipe and cone extensions replace traditional intermittent discharge structure, improving flow through the classifier system and reducing the disruptive effects of the discharge on the annular flow from the pulverizer throat. An adjustable classifier venturi is also provided to adjust the exit angle and exit velocity of the fines leaving the classifier cone by the combustion delivery chute.