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 circulating fluidized bed boiler includes a furnace for combusting solid carbonaceous fuel in a fast fluidized bed. A solids separator is adjacent to a sidewall of the furnace and separates solids entrained with exhaust gas discharged via an outlet channel. A gas seal conveys at least a portion of the separated solids to a first fluidized bed heat exchange chamber that is arranged downstream of the gas seal and has internal heat exchange surfaces. A first lift channel has a lower end connected to a bottom portion of the first fluidized bed heat exchange chamber and an upper end connected to an upper end of a first return channel for discharging solids from the first fluidized bed heat exchange chamber and taking the cooled solids to a lower portion of the furnace. A second fluidized bed heat exchange chamber is arranged adjacent to a lower sidewall of the furnace.

Abstract: A circulating fluidized bed boiler includes a rectangular furnace having multiple particle separators connected to an upper portion of each of a front wall and a back wall of the furnace. Each particle separator includes a gas outlet, and a flue gas duct system connected to the gas outlets for conducting cleaned flue gas to a back pass. The particle separators are arranged in pairs. Each pair includes a front separator arranged adjacent to the front wall and a back separator arranged adjacent to the back wall. The flue gas duct system includes cross over ducts, each duct connecting the gas outlet of a front separator of a pair of particle separators, across and over the furnace, to the gas outlet of the back separator of the same pair of particle separators, and to the back pass, which back pass is arranged on the back wall side of the furnace.

Abstract: A heat exchanger and a circulating fluidized bed boiler with a heat exchanger including a first fluidized bed heat exchange chamber and a second fluidized bed heat exchange chamber, arranged in connection with a furnace of the circulating fluidized bed boiler, a first inlet channel for introducing hot solids from a particle separator of the external circulation of the circulating fluidized bed boiler into the first heat exchange chamber, a second inlet channel for introducing solids to the second heat exchange chamber, a first discharge for removing a first portion of the cooled solids from the first heat exchange chamber to the second inlet channel and a second discharge for removing cooled solids from the second heat exchange chamber to the furnace, the heat exchange chamber including an inlet for introducing hot solids directly from the internal circulation of the furnace to the second heat exchange chamber.

Abstract: A circulating fluidized bed boiler including a furnace for combusting solid carbonaceous fuel in a fast fluidized bed, the furnace having walls made of water/steam tube panels and used for evaporating water fed therein. A solids separator arranged adjacent to a sidewall of the furnace separates solids entrained with exhaust gas discharged via an outlet channel from an upper portion of the furnace. A gas seal conveys at least a portion of the separated solids to a first fluidized bed heat exchange changer arranged downstream of the gas seal and has internal heat exchange surfaces. A first lift channel has a lower end connected to a bottom portion of the first fluidized bed heat exchanger chamber and an upper end connected to an upper end of a first return channel for discharging solids from the first fluidized bed heat exchange chamber and for taking the cooled solids to a lower portion of 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.

Abstract: A circulating fluidized bed boiler includes a rectangular furnace which is horizontally enclosed by a front wall, a back wall and two sidewalls, and multiple particle separators connected to the upper portion of each of the front wall and the back wall. Each particle separator includes a gas outlet, and flue gas duct system connected to the gas outlets for conducting cleaned flue gas to a back pass. The particle separators are arranged in pairs of particle separators. Each pair of particle separators includes a front separator arranged adjacent to the front wall and a back separator arranged adjacent to the back wall. The flue gas duct system includes cross over ducts, each cross over duct connecting the gas outlet of a front separator of a pair of particle separators, across and over the furnace, to the gas outlet of the back separator of the same pair of particle separators, and to the back pass, which back pass is arranged on the back wall side of the furnace.

Abstract: A circulating fluidized bed boiler includes a furnace for combusting carbonaceous fuel, at least one outlet channel connected to the upper portion of the furnace for removing flue gas and solid particles generated in the combustion of the fuel, each outlet channel provided with a particle separator attached with a flue gas channel for transferring cleaned flue gas and a return duct for transferring separated solid particles to the lower portion of the furnace. The return duct is provided with a gas seal, a heat exchange chamber, a lift channel and an overflow conduit, in which solid particles exiting the gas seal are guided to the upper portion of the heat exchange chamber and from the lower portion of the heat exchange chamber through the lift channel to the furnace, or directly from the upper portion of the heat exchange chamber through the overflow conduit to the furnace.

Abstract: A heat exchanger and a circulating fluidized bed boiler with a heat exchanger including a first fluidized bed heat exchange chamber and a second fluidized bed heat exchange chamber, arranged in connection with a furnace of the circulating fluidized bed boiler, a first inlet channel for introducing hot solids from a particle separator of the external circulation of the circulating fluidized bed boiler into the first heat exchange chamber, a second inlet channel for introducing solids to the second heat exchange chamber, a first discharge for removing a first portion of the cooled solids from the first heat exchange chamber to the second inlet channel and a second discharge for removing cooled solids from the second heat exchange chamber to the furnace, the heat exchange chamber including an inlet for introducing hot solids directly from the internal circulation of the furnace to the second heat exchange chamber.

Abstract: A fluidized bed reactor, comprising a furnace, a heat exchange chamber, a substantially vertical discharge channel connected to the lower part of the heat exchange chamber for removing particulate material from the heat exchange chamber to the furnace, and a substantially vertical auxiliary channel for transferring particulate material from the heat exchange chamber to the furnace and from the furnace to the heat exchange chamber, the lower part of said auxiliary channel being provided with nozzles for fluidizing gas and with a flow conduit for connecting said auxiliary channel to the furnace and a flow conduit in the upper part for connecting said auxiliary channel to said heat exchange chamber. The furnace, heat exchange chamber, discharge channel and auxiliary channel preferably form an integrated structure having the discharge channel and the auxiliary channel adjacently arranged between the furnace and the heat exchange chamber.

Abstract: A circulating fluidized bed reactor includes a furnace, defined by a substantially vertical and planar first wall, and a particle separator having a return duct adjacent to the first wall. In the lower part of the return duct is arranged a gas seal adjacent to a planar tube wall, which wall is the planar wall or a wall defining a space in gas flow connection with the furnace. The width of the horizontal cross section of the lower part of the return duct, measured in the direction of the first wall, is larger than its depth, measured perpendicular to the width. The gas seal includes a seal structure that includes water tubes bent from the tube wall.