Circulating fluidized bed reactor

Circulating fluidized bed reactor comprising:

• a reactor chamber;
• at least one duct connected with the reactor chamber for drawing off a flue gas having entrained solid particles from the reactor chamber;
• at least one cyclone separator that is connected with the duct for separating solid particles from the flue gas;
• at least one recirculation device for recirculating at least a portion of the separated solid particles from the cyclone separator into the reactor chamber, the at least one recirculation device comprising
• a siphon-trap gas seal including a riser having a circumference, an upper end, and first and second outlet openings disposed on the circumference of the riser proximate to the upper end at a height on the gas seal riser and pointing substantially in the direction of the reactor chamber, each of the openings being disposed at substantially the same height, the first and second outlet openings defining an angle of 60 to 180° to each other,
• a device for fluidizing the portion of the separated solid particles, and
• a device for connecting each opening of the gas seal riser with the reactor chamber.