Exhauster fan bearing assembly and cooling system for pulverizer

Abstract

An exhauster fan bearing assembly for a pulverized solid fuel firing system includes a pedestal housing having an opening at a top portion, the pedestal housing defining an interior space with access thereto through the opening; a bearing housing disposed at the top portion of the pedestal housing, the bearing housing having first and second openings disposed at opposite ends of the bearing housing; first and second bearing assemblies disposed at the first and second openings, respectively; a shaft extending through the bearing housing via the first and second openings, the shaft rotatable about a shaft rotational axis via the first and second bearing assemblies; and a sump housing operably coupled to a bottom of the bearing housing. The sump housing extends through the opening and into the interior space of the pedestal housing. The sump housing defines a reservoir for a lubricant in fluid communication with the first and second bearing assemblies.

1 . An exhauster fan bearing assembly for a pulverized solid fuel firing system, comprising:
 a pedestal housing having an opening at a top portion, the pedestal housing defining an interior space with access thereto through the opening;   a bearing housing disposed at the top portion of the pedestal housing, the bearing housing having first and second openings disposed at opposite ends of the bearing housing;   first and second bearing assemblies disposed at the first and second openings, respectively;   a shaft extending through the bearing housing via the first and second openings, the shaft rotatable about a shaft rotational axis via the first and second bearing assemblies; and   a sump housing operably coupled to a bottom of the bearing housing, the sump housing extending through the opening and into the interior space of the pedestal housing, the sump housing defining a reservoir for a lubricant in fluid communication with the first and second bearing assemblies.   
   
   
       2 . The exhauster fan bearing assembly of  claim 1 , wherein the first and second bearing assemblies each include a fan shaft bearing and a bearing cap. 
   
   
       3 . The exhauster fan bearing assembly of  claim 2 , wherein each fan shaft bearing includes a plurality of rollers, and a level of the lubricant in the sump housing extends substantially to a centerline of a lowest roller of the rollers in each fan shaft bearing. 
   
   
       4 . The exhauster fan bearing assembly of  claim 2 , wherein each bearing cap includes a labyrinth-type housing end cap configured to prevent leakage of the lubricant from the first and second openings of the bearing housing. 
   
   
       5 . The exhauster fan bearing assembly of  claim 1 , wherein the sump housing is retrofitable to an existing bearing housing to increase lubricant capacity and increase a convective surface area for cooling the lubricant. 
   
   
       6 . The exhauster fan bearing assembly of  claim 1 , further comprising an external cooling system having a cooling medium in thermal communication with the lubricant to remove heat from the lubricant. 
   
   
       7 . The exhauster fan bearing assembly of  claim 6 , wherein the external cooling system includes one tube or an array of tubes within the sump housing. 
   
   
       8 . The exhauster fan bearing assembly of  claim 7 , wherein the cooling medium includes an on-site water source. 
   
   
       9 . The exhauster fan bearing assembly of  claim 1 , wherein the sump housing includes a mounting flange extending substantially perpendicular from a wall defining the reservoir, the flange including a plurality of mounting apertures to receive mechanical fasteners to fasten the sump housing to the bearing housing using mechanical fasteners. 
   
   
       10 . The exhauster fan bearing assembly of  claim 9 , wherein the mechanical fasteners include threaded fasteners. 
   
   
       11 . An exhauster for a pulverized solid fuel firing system, comprising:
 a housing;   an exhauster fan for exhausting coal through an exhauster fan housing, the exhauster fan being mountable within the housing on a shaft rotatable about a shaft rotational axis and the housing having an inlet generally aligned with the shaft rotational axis such that coal entering the housing through the inlet contacts the rotating exhauster fan and is redirected thereby along a radial outlet path, the exhauster fan including a plurality of blades; and   an exhauster fan bearing assembly, comprising:
 a pedestal housing having an opening at a top portion, the pedestal housing defining an interior space with access thereto through the opening; 
 a bearing housing disposed at the top portion of the pedestal housing, the bearing housing having first and second openings disposed at opposite ends of the bearing housing; 
 first and second bearing assemblies disposed at the first and second openings, respectively, the shaft extending through the bearing housing via the first and second openings, the shaft rotatable about the shaft rotational axis via the first and second bearing assemblies; and 
 a sump housing operably coupled to a bottom of the bearing housing, the sump housing extending through the opening and into the interior space of the pedestal housing, the sump housing defining a reservoir for a lubricant in fluid communication with the first and second bearing assemblies. 
   
   
   
       12 . The exhauster of  claim 11 , wherein the first and second bearing assemblies each include a fan shaft bearing and a bearing cap. 
   
   
       13 . The exhauster of  claim 12 , wherein each fan shaft bearing includes a plurality of rollers, and a level of the lubricant in the sump housing extends substantially to a centerline of a lowest roller of the rollers in each fan shaft bearing. 
   
   
       14 . The exhauster of  claim 12 , wherein each bearing cap includes a labyrinth-type housing end cap configured to prevent leakage of the lubricant from the first and second openings of the bearing housing. 
   
   
       15 . The exhauster  claim 11 , wherein the sump housing is retrofitable to an existing bearing housing to increase lubricant capacity and increase a convective surface area for cooling the lubricant. 
   
   
       16 . The exhauster of  claim 11 , further comprising an external cooling system having a cooling medium in thermal communication with the lubricant to remove heat from the lubricant. 
   
   
       17 . The exhauster of  claim 16 , wherein the external cooling system includes one tube or an array of tubes within the sump housing. 
   
   
       18 . The exhauster of  claim 17 , wherein the cooling medium includes an on-site water source. 
   
   
       19 . The exhauster of  claim 11 , wherein the sump housing includes a mounting flange extending substantially perpendicular from a wall defining the reservoir, the flange including a plurality of mounting apertures to receive mechanical fasteners to fasten the sump housing to the bearing housing using mechanical fasteners. 
   
   
       20 . The exhauster of  claim 19 , wherein the mechanical fasteners include threaded fasteners.