Coal mill exhauster fan
First Claim
1. An improved coal mill exhauster fan of the type comprising a fan assembly rotating in a housing having an axial coal inlet and a radial coal outlet, the fan assembly comprising a hub attached to rotate with a motorized drive shaft, a plurality of blades attached to the hub, and shroud plates secured to front and rear edges of the blades such that the blades and shroud plates form a structural unit, the improvement comprising an elongated conical hub having a conical sidewall extending to the rear edges of the blades, the rear edges of the blades being radially oriented in alignment with the radial coal outlet, and the blades being welded directly to the conical sidewall of the hub along inside edges of the blades extending from the rear edges of the blades toward the axial coal inlet at an angle parallel to the conical sidewall of the hub.
3 Assignments
0 Petitions
Accused Products
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.
-
Citations
18 Claims
- 1. An improved coal mill exhauster fan of the type comprising a fan assembly rotating in a housing having an axial coal inlet and a radial coal outlet, the fan assembly comprising a hub attached to rotate with a motorized drive shaft, a plurality of blades attached to the hub, and shroud plates secured to front and rear edges of the blades such that the blades and shroud plates form a structural unit, the improvement comprising an elongated conical hub having a conical sidewall extending to the rear edges of the blades, the rear edges of the blades being radially oriented in alignment with the radial coal outlet, and the blades being welded directly to the conical sidewall of the hub along inside edges of the blades extending from the rear edges of the blades toward the axial coal inlet at an angle parallel to the conical sidewall of the hub.
Specification