| 摘要 |
<p>A fluidized bed combustion furnace having a constricted portion (12) at that part of the furnace which is immediatly above a fluidized bed (18), in which constricted portion the flow rate of a combustion gas exceeds the terminal speed of the particles having an average diameter of a fluidizing medium; a plurality of steps secondary air supply ports (22) provided in the wall of the constricted portion; a freeboard portion (13) formed on the constricted portion and having a cross section that causes the flow rate of a combustion gas to fall short of the terminal speed of the particles having an average diameter of the fluidizing medium; at least two combustion gas inlets (16a, 17a) of a combustion gas passages (16, 17), which are formed at that part of the ceiling zone of the freeboard portion which is outside a plane of projection of the constricted portion; and a confluence chamber (25) provided at the outlet portions of the combustion gas passages, in which confluence chamber the combustion gas currents from the combustion gas passages collide with one another and join one another.</p> |
