| 摘要 |
PURPOSE:To enable to make stable burning and reduce NOx by blowing two- step burning air into a furnace in such a manner that a ratio of air to pulverized coal is controlled optionally by extracting pulverized coal containing an air from the place where pulverized coal is low concentrated and the air is utilized as two-step burning air. CONSTITUTION:A by-pass tube 6 equipped with a damper 5 is connected to an underside of a bent part at the downstream of an air conveyer tube 4 for pulverized coal and the by-pass tube 6 is connected to a furnace 2 at the upper part of a burner 3. Low concentrated pulverized coal containing an air is extracted from the place where pulverized coal is low concentrated in the air conveyer tube 4 for pulverized coal through the by-pass tube 6 equipped with the damper 5 and, by opening and closing control of the damper 5, a ratio of air to pulverized coal supplied from the air conveyer tube 4 to the burner 3 is optionally controlled to the most suitable value. Low concentrated pulverized coal containing an air extracted from the by-pass tube 6 is blown into the furnace as secondary burning air. As thick air-fuel mixture is burnt efficiently by a pulverized coal burner and thin air-fuel mixture is utilized as secondary burning air, stable burning and reduction of NOx are obtained.
|
