| 摘要 |
PURPOSE:To reduce heat loss in the heat retrieving unit of the combustion gas, minimize power loss in a system and prevent a blockade due to scattered particles from the fluidized bed by a method wherein a part of a heat transfer tube extended to the upper space of the fluidized bed is formed with recesses and protrusions on the outer surface as the heat retrieving unit of the combustion exhaust gas, which is provided above the fluidized bed. CONSTITUTION:The combustion exhaust gas generated in the fluidized bed flows out of the bed, passes through the heat retrieving unit 5 provided in the upper space of the fluidized bed 2 and is discharged out of an exhaust port 6 to the outside of the furnace. On the other hand, the vertical transfer tube 3 consists of a single tube. Heat transfer medium 8, flowed into the furnace from an intake port 7, is heated by the combustion exhaust gas 4 in and out of the fluidized bed when it passes through the heat transfer tube 3 and is discharged out of an outlet port 9 to the outside of the furnace. The recesses and protrusions are formed on the outer surface of the heat transfer tubes 3 and fins are provided on above tubes at positions the upper space of the fluidized bed 2. Sleeves 11 are arranged around the fins 10 and the flow path of the combustion exhaust gas is narrowed whereby the heat transfer characteristics may be improved due to the increase of flow speed of gas. |
