| 摘要 |
PURPOSE:To uniformize particle concn. in a range over the whole length of a riser piping by providing a particle circulator to the riser piping of a fluidized powder bed and forming an expanded pipe part to the pipe shell of the riser piping. CONSTITUTION:A particle circulator 30 consisting of a cyclone 11, a hopper 12 and a descending pipe 16 integrated in the lower part of a riser piping 10 is provided to the riser piping 10. This riper piping 10 has an expanded pipe part 20 wherefrom the cross-sectional area thereof is changed. The reductive gas blown into the riser piping 10 is raised through the riser piping 10 whose cross-sectional area is gradually made large. As a result, gas volume is increased by pressure drop but the linear velocity is made constant or slightly lowered by increase of the cross-sectional area and the reductive gas is introduced into the cyclone 11. When the gas flow velocity in the riser piping 10 is lowered, particle concn. is made large and therefore the particle concn. can be secured in the upper part where the particle concn. is liable to be dilute. |
