Abstract: A fluidizing gas nozzle head suitable to be connected to a fluidizing gas feeding device of a fluidized bed reactor. The fluidizing gas nozzle head includes an inlet channel having a longitudinal axis, an inlet end, and a second end, the inlet end of the inlet channel being adapted to connect the inlet channel in vertical gas flow connection with the fluidizing gas feeding device, four outlet channels, each of the four outlet channels extending from a first end to an outlet end, and a gas distribution space having a bottom face and a ceiling opposite to the bottom face. The second end of the inlet channel and the first ends of the four outlet channels are connected to direct gas flow connection with the gas distribution space. Each of the first ends of the four outlet channels has a central point, which central points define a rectangle with two long sides and two short sides having an aspect ratio of at least 2:1.

Abstract: A fluidizing gas nozzle head suitable to be connected to a fluidizing gas feeding device of a fluidized bed reactor. The fluidizing gas nozzle head includes an inlet channel having a longitudinal axis, an inlet end, and a second end, the inlet end of the inlet channel being adapted to connect the inlet channel in vertical gas flow connection with the fluidizing gas feeding device, four outlet channels, each of the four outlet channels extending from a first end to an outlet end, and a gas distribution space having a bottom face and a ceiling opposite to the bottom face. The second end of the inlet channel and the first ends of the four outlet channels are connected to direct gas flow connection with the gas distribution space. Each of the first ends of the four outlet channels has a central point, which central points define a rectangle with two long sides and two short sides having an aspect ratio of at least 2:1.

Abstract: A method of feeding at least one of light, fine and moist fuel into a furnace of a circulating fluidized bed boiler. Fuel is fed into the furnace through a fuel feed and the fuel is combusted in a turbulent, circulating fluidized bed. A fuel feed area is isolated from the turbulent circulating bed by arranging the fuel feed along at least one channel arranged in a wall of the furnace. Solids of the circulating bed material are introduced onto a first grid section at the bottom of the fuel feed area. The fuel and the solids are mixed and fluidized above the grid section to form a fuel-solids mixture that flows laterally onto a second grid section and a third grid section where the mixture is fluidized. The fluidized bed material is circulated both inside and outside of the furnace. The bed material is separated from the flue gases and returned to the furnace.

Abstract: A method of feeding at least one of light, fine, volatile and moist fuel into a furnace of a circulating fluidized bed boiler. Fuel is introduced into the furnace and is combusted in the presence of a fluidized bed material to form flue gases. The fluidized bed material is circulated both inside the furnace in an internal circulation in which bed material returns along walls of the furnace down to the bottom of the furnace, and outside the furnace in an external circulation that includes at least a solids separator arranged in flow communication with the furnace. Bed material is separated from the flue gases in the separator. The flue gases are removed from the separator for further treatment. The separated bed material is returned to the furnace.