Fluidized bed heat exchanger with a chamber (24), comprising at least one solid particles inlet port (22) at least one solid particles outlet port (30), arranged at a distance to the at least one inlet port (22), means (46) for introducing a fluidizing gas from a bottom area (24b) of said chamber (24) into said chamber (24), wall-like heat transfer means (28) in its lower part, extending in a main flow direction of the solid particles on their way from the inlet port (22) to the outlet port (30), substantially parallel to each other, with a space (C) between adjacent heat transfer means (28), at least one baffle (50,52) in its upper part, extending substantially perpendicular to the heat transfer means (28), downwardly from a chamber ceiling (24c), with its lower end at a distance to the heat transfer means (28) and comprising extensions (E), protruding into the space (C) between adjacent heat transfer means (28), and couplings (B) to mechanically connect the said heat transfer means (28) to said extensions (E).

Fluidized bed heat exchanger with a chamber (24), comprising at least one solid particles inlet port (22) at least one solid particles outlet port (30), arranged at a distance to the at least one inlet port (22), means (46) for introducing a fluidizing gas from a bottom area (24b) of said chamber (24) into said chamber (24), wall-like heat transfer means (28) in its lower part, extending in a main flow direction of the solid particles on their way from the inlet port (22) to the outlet port (30), substantially parallel to each other, with a space (C) between adjacent heat transfer means (28), at least one baffle (50,52) in its upper part, extending substantially perpendicular to the heat transfer means (28), downwardly from a chamber ceiling (24c), with its lower end at a distance to the heat transfer means (28) and comprising extensions (E), protruding into the space (C) between adjacent heat transfer means (28), and couplings (B) to mechanically connect the said heat transfer means (28) to said extensions (E).

Provided are: a useful bed medium for a fluidized bed with good fluidity, the bed medium being usable in a fluidized bed furnace using biomass material and coal material as fuel; and a useful bed medium for a fluidized bed with good durability, the bed medium not easily forming an agglomerate of its particles, and being resistant to collapsing. The bed medium for a fluidized bed in a fluidized bed furnace for combusting or gasifying the fuel is formed of artificially-produced spherical refractory particles containing not less than 40% by weight of Al2O3 and not more than 60% by weight of SiO2 and having an apparent porosity of not more than 5%, and a ratio by weight of agglomerated particles in the bed medium is not more than 20% after three heat treatment tests on the bed medium at 900° C. for 2 hours under coexistence with the fuel.

Provided are: a useful bed medium for a fluidized bed with good fluidity, the bed medium being usable in a fluidized bed furnace using biomass material and coal material as fuel; and a useful bed medium for a fluidized bed with good durability, the bed medium not easily forming an agglomerate of its particles, and being resistant to collapsing. The bed medium for a fluidized bed in a fluidized bed furnace for combusting or gasifying the fuel is formed of artificially-produced spherical refractory particles containing not less than 40% by weight of Al2O3 and not more than 60% by weight of SiO2 and having an apparent porosity of not more than 5%, and a ratio by weight of agglomerated particles in the bed medium is not more than 20% after three heat treatment tests on the bed medium at 900° C. for 2 hours under coexistence with the fuel.

The present invention provides a circulating fluidized bed boiler, comprising: furnace side walls; a ceiling; an air distribution plate provided at a bottom of a furnace; and at least one air distribution cone provided on the air distribution plate, wherein each air distribution cone extends upwards from the air distribution plate into an interior of the furnace and has a shape gradually tapered in an extending direction, cone side walls which form the air distribution cone are provided with secondary air ports, the cone side walls are separated from the furnace side walls, and a furnace combustion space is formed and surrounded by the ceiling, the furnace side walls, the air distribution plate, and the cone side walls. The present invention further relates to an air distributor for a circulating fluidized bed boiler, the air distributor being provided on an air distribution plate of the boiler, wherein the air distributor is in a form of an air distribution cone, which extends upwards from the air distribution plate into an interior of a furnace to form a shape gradually tapered in an extending direction, and secondary air ports are formed in air distribution cone side walls forming the air distribution cone. The present invention also relates to an air distributor assembly for a circulating fluidized bed boiler.

The present invention provides a circulating fluidized bed boiler, comprising: furnace side walls; a ceiling; an air distribution plate provided at a bottom of a furnace; and at least one air distribution cone provided on the air distribution plate, wherein each air distribution cone extends upwards from the air distribution plate into an interior of the furnace and has a shape gradually tapered in an extending direction, cone side walls which form the air distribution cone are provided with secondary air ports, the cone side walls are separated from the furnace side walls, and a furnace combustion space is formed and surrounded by the ceiling, the furnace side walls, the air distribution plate, and the cone side walls. The present invention further relates to an air distributor for a circulating fluidized bed boiler, the air distributor being provided on an air distribution plate of the boiler, wherein the air distributor is in a form of an air distribution cone, which extends upwards from the air distribution plate into an interior of a furnace to form a shape gradually tapered in an extending direction, and secondary air ports are formed in air distribution cone side walls forming the air distribution cone. The present invention also relates to an air distributor assembly for a circulating fluidized bed boiler.

Disclosed are an apparatus and a method for measuring the height of a solid bed in a high-temperature and high-pressure fluidized bed system, and a fluidized bed system having the solid bed height measuring apparatus. The solid bed height measuring apparatus includes a lower pressure probe mounted at an upper side as high as a first height from a gas distributor of a fluidized bed reactor to measure pressure of the mounted location, and a middle pressure probe mounted at an upper side as high as a second height from the lower probe to measure pressure of the mounted location. An upper pressure probe is mounted at the top of the fluidized bed reactor to measure the inside pressure of the fluidized bed reactor. First and second differential pressure gauges are used for measuring differential pressures.

Disclosed are an apparatus and a method for measuring the height of a solid bed in a high-temperature and high-pressure fluidized bed system, and a fluidized bed system having the solid bed height measuring apparatus. The solid bed height measuring apparatus includes a lower pressure probe mounted at an upper side as high as a first height from a gas distributor of a fluidized bed reactor to measure pressure of the mounted location, and a middle pressure probe mounted at an upper side as high as a second height from the lower probe to measure pressure of the mounted location. An upper pressure probe is mounted at the top of the fluidized bed reactor to measure the inside pressure of the fluidized bed reactor. First and second differential pressure gauges are used for measuring differential pressures.

The invention relates to a method for starting up a fluidized bed boiler, such as a circulating fluidized bed (CFB) or a bubbling fluidized bed (BFB) boiler, for operation with a predetermined concentration of ilmenite particles in the bed material. The invention also relates to a method for pre-oxidizing ilmenite, to pre-oxidized ilmenite and to the use of pre-oxidized ilmenite in a fluidized bed boiler.

The invention relates to a method for starting up a fluidized bed boiler, such as a circulating fluidized bed (CFB) or a bubbling fluidized bed (BFB) boiler, for operation with a predetermined concentration of ilmenite particles in the bed material. The invention also relates to a method for pre-oxidizing ilmenite, to pre-oxidized ilmenite and to the use of pre-oxidized ilmenite in a fluidized bed boiler.