Fluidized bed combustion system utilizing improved connection between the reactor and separator

A fluidized bed combustion system comprising:

• (a) a reactor having a furnace section;
• (b) means for introducing fuel particles into said furnace section;
• (c) means for combusting said fuel particles to form gaseous and solid products of combustion;
• (d) means for fluidizing said furnace section with a fluidizing gas so that said fluidizing gas combines with said gaseous products of combustion to form flue gases which entrain portions of said fuel particles and said solid products of combustion;
• (e) a separator for receiving and separating said flue gases and said entrained material;
• (f) a duct connecting said reactor to said separator for passing said flue gases and said entrained material from said furnace section to said separator, at least a portion of said duct extending within said furnace section;
• and
• (g) wherein said reactor has a side wall and a roof formed by cooling tubes, said duct portion having an inner and an outer side wall and a top and a bottom wall, said bottom wall being formed by bending a portion of said cooling tubes of said reactor side wall from the plane of said reactor side wall and into said furnace section, and said inner side wall of said duct portion being formed by bending a portion of said cooling tubes which form said bottom wall of said first duct portion upwardly to said roof of said reactor.

A duct for connecting a reactor having a furnace section to a separator, at least a portion of walls forming said reactor and said separator being formed by a plurality of cooling tubes, said duct comprising:

• (a) a first duct portion formed at least in part by a portion of said cooling tubes forming said reactor, said first duct portion having an inlet end and an outlet end and at least a portion of said first duct portion extending within said furnace section;
• (b) a second duct portion formed at least in part by a portion of said cooling tubes forming said separator, said second duct portion having an inlet end and an outlet end;
• and
• (c) means connecting said inlet end of said second duct portion to said outlet end of said first duct portion to place said furnace section in fluid flow communication with said separator.