| 摘要 |
PURPOSE: To improve igniting property in a low load operation by a method wherein a pulverized coal supplying pipe, supplying the pulverized coal mixed with primary air into the inside of a burner outer-cylinder, is connected tangentially to the rear end of the burner outer-cylinder while a flow passage sectional area variable device is provided in the pulverized coal supplying pipe. CONSTITUTION: A pulverized coal supplying pipe 12 is connected to the rear end unit of a burner outer cylinder 8 tangentially to guide pulverized coal 10, supplied together with primary air 11, into the burner outer cylinder 8. A flow passage sectional area variable device 18, changing the flow passage sectional area of the pulverized coal supplying pipe 12 and provided with an actuator 20 consisting of a movable plate 19, an air cylinder and the like, is provided near the inside connecting wall 12B of the pulverized coal supplying pipe 12. When the load of the burner is low and the flow rate of the primary air 11 is small, the sectional area of the flow passage of the pulverized coal supplying pipe 12 is reduced by the flow passage sectional area variable device 18 where by the pulverized coal 10 and the primary air 11, entering the burner outer cylinder 8, are swirled and the density of the pulverized coal 10 is increased locally to improve the igniting property. |
