Pulverized-coal burner

Abstract

Abstract PURPOSE: To reduce the amount of NOx ideally even in pulverized-coal combustion using pulverized coal as a fuel by arranging adjacently a means for feeding a fuel with insufficient air and a means for feeding a fuel with excessive air. CONSTITUTION: Pulverized coal injected from an insufficient-air flame nozzle 11 is ignited to form a diffusing flame with insufficient air immediately when it receives the radiant heat in a furnace, so that NOx level is low. On the other hand, pulverized coal injected from an excessive-air nozzle 15 is not ignited immediately because it is surrounded by a large amount of primary air and recirculating gas. The latter pulverized coal emits its volatile components during when it is heated by the radiant heat it receives in the furnace, and the volatile components mix with the primary air and recirculating gas to form a pre-mixture, which burns. In this case, since the flame of the pre-mixture is lean, the NOx level is restricted to be low. In addition, since the solid component left after the emission of the volatile components is burnt in a low oxygen concentration, substantially no NOx is generated from this combustion. Accordingly, since NOx generated from the excessive-air flame is limited to a low level, NOx generated from the burner as a whole is also limited to a low level, and hence NOx level is reduced. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Yasuo Takahashi

Bibliographic Details