PURPOSE: To provide a multi-stage fluidized bed type combustion means capable of accomplishing both desulfurization and denitration in the furnace by forming, in multiple stages, the fluidized beds using line stone as a part of the bed material (fluid medium).
CONSTITUTION: The main air fan 20 is operated to supply combustion air uniformly from an air diffuser plate 10 to form a primary fluidized bed. The intra-bed temperature is elevated to or above the ignition point of lime by an ignition burner 23' and lime is supplied onto the air diffuser plate from a fuel supply pipe 16 to perform fluidized combustion. Then the exhaust gas which has been cleared of NOx by the primary fluidized bed enters the secondary fluidized bed by passing through the holes in a partitioning means 12. Combustion air is supplied into the section 13 where said secondary fluidized bed is formed from the main air fan 20 through an electrically operated valve 18 and a header. Unburned gas in the exhaust gas is burned in the section 13, and it is perfectly burned till it reaches the furnace outlet through a free board 14. SO2 and SO3 produced and staying in the secondary fluidized bed are reacted with lime stone S forming a part of the bed material M and converted into CaSO3 and CaSO4, and they are accumulated as bed material M along with unreacted CaO.
AOKI KIYOSHI
ASAI MINORU
| JPS5239834A | 1977-03-28 | |||
| JPS5390672A | 1978-08-09 |
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