Method of reducing coal ropes in a burner nozzle for pulverized coal

Abstract

A coal nozzle for a burner on a pulverized coal fired furnace which includes an elongated tubular nozzle having an inlet for receiving a flowing stream of coal/air mixture and an outlet for discharging the flowing stream into a combustion zone of a furnace for combustion, and an inlet elbow connected to the inlet of the tubular nozzle. The interior outer surfaces of the elbow include a staircase surface configuration for engaging the incoming flowing stream whereby coal ropes in the stream are broken up for thereby improving flow distribution of the stream.

1 . A method for reducing the occurrence of coal roping in pulverized coal fired boilers having a burner nozzle conveying a flowing stream of coal/air mixture, comprising:
 providing an elbow at an inlet for said nozzle with interior outer surfaces thereof including a staircase surface configuration; and   conveying a stream of pulverized coal/air mixture through said elbow to said burner nozzle and thereby breaking up coal ropes that occur in said stream.   
     
     
         2 . The method of  claim 1 , including the step of setting faces of said staircase surface configuration at even intervals. 
     
     
         3 . The method of  claim 1 , providing a plurality of annularly arranged and axially aligned fins in the nozzle downstream of said elbow and thereby enhancing the distribution of the stream flowing from said elbow. 
     
     
         4 . The method of  claim 3 , including deflecting and redirecting the stream of pulverized coal/air mixture exiting said elbow inwardly into said nozzle prior to engaging said fins.