3204 



UPDRAFT 



V ASH ^t \0 



Chapter 26 



DOWNDRAFT 



[^REDUCTION I 



DISENGAGEMENT 

 SECTION 



CYCLONE 



FLUIDIZED 

 BED 



TAR SCRUBBER 

 GAS— > 



r 



,-.'* '-"■>•' ////////, 



I 



I 



|ASH 

 FLUIDIZED BED 



^ 



-BIOMASS FEED 



AIR FEED, 

 PREHEAT 



ASH 



COMBUSTION 

 FLAME 

 SECONDARY 



^^I^AiR NOZZLE SUSPENDED 



FUEL 



BIOMASS-AIR 



Figure 26-26. — Four types of wood gasifiers. (Top left) Updraft. (Top right) Downdraft. 

 (Center) Fluidized bed. (Bottom) Suspended fuel. (Drawings after Reed 1980.) 



