The present invention relates to a fluidized bed gas distribution nozzle with the following features in its functional position: a gas inlet pipe (10), having: an inner surface (10i), an outer surface (10o), a lower end section (10l) adapted to receive gas from an associated gas source, an upper end section (10u), a plurality of openings (12) formed in the upper end section (10u), each opening (12) extending form the inner surface (10i) of the gas inlet pipe (10) to the outer surface (10o) of the gas inlet pipe (10), a gas distribution cap (20) connected or connectable to the gas inlet pipe (10), having: an upper top (20u), a lower bottom (20l) arranged at a vertical distance below said upper top (20u) and surrounding the gas inlet pipe (10), a peripheral wall (20w) having an inner surface (20i) and an outer surface (20o) and extending between said upper top (20u) and said lower bottom (20l), outlets (22) within the peripheral wall (20w) extending from the inner surface (20i) of the peripheral wall (20w) to the outer surface (20o) of the peripheral wall (20w).

Provided are a pulverized coal boiler with a bottom combustor, and a control method for the pulverized coal boiler, wherein the pulverized coal boiler includes a furnace, at least one bottom combustor and a secondary air distributing device. Each combustor is provided with a combustor spout, and the secondary air distributing device surrounds the combustor and is arranged at the bottom of the furnace. The secondary air distributing device includes an internal secondary air distributing device and an external secondary air distributing device, wherein the internal secondary air distributing device includes an internal secondary air gathering box and an internal secondary air pipe, and the external secondary air distributing device includes an external secondary air gathering box and an external secondary air pipe.

A combustor air bar grid for use within a fluidized bed reactor includes at least two main air collector bars in fluid communication with a source of fluidizing gas, a plurality of primary air bars that are transversal to the main air collector bars and arranged on the at least two main air collector bars such that the main air collector bars support them, and in fluid communication to at least two of the main air collector bars. The main air collector bars and the primary air bars define ash removal openings in the air bar grid and a plurality of fluidized nozzles are arranged to each of the primary air bars for fluidizing the bed reactor. A fluidized bed reactor includes such a combustor air bar grid.

A device with annular spouted fluidized bed can be used for carrying out the majority of the technical processes carried out in fluidized bed devices. The reaction chamber of the device has, throughout at least a part of its height, a downwardly tapering funnel shape with step-structured inner surface. The shape of the reaction chamber, together with the tangential admission thereto of fluidized and other gases, makes it possible to create, in the reaction chamber, an adjustable toroidal fluidized bed, in which the rotation rate of the particles of the material undergoing treatment can be adjusted in both horizontal and vertical planes, and also makes it possible to control the dwell time of particles of different sizes in the reaction zone, the intensity with which materials are treated, and other process parameters.

A device with annular spouted fluidized bed can be used for carrying out the majority of the technical processes carried out in fluidized bed devices. The reaction chamber of the device has, throughout at least a part of its height, a downwardly tapering funnel shape with step-structured inner surface. The shape of the reaction chamber, together with the tangential admission thereto of fluidized and other gases, makes it possible to create, in the reaction chamber, an adjustable toroidal fluidized bed, in which the rotation rate of the particles of the material undergoing treatment can be adjusted in both horizontal and vertical planes, and also makes it possible to control the dwell time of particles of different sizes in the reaction zone, the intensity with which materials are treated, and other process parameters.

A combustor air bar grid for use within a fluidized bed reactor includes at least two main air collector bars in fluid communication with a source of fluidizing gas, a plurality of primary air bars that are transversal to the main air collector bars and arranged on the at least two main air collector bars such that the main air collector bars support them, and in fluid communication to at least two of the main air collector bars. The main air collector bars and the primary air bars define ash removal openings in the air bar grid and a plurality of fluidized nozzles are arranged to each of the primary air bars for fluidizing the bed reactor. A fluidized bed reactor includes such a combustor air bar grid.

An air nozzle arrangement for a fluidized bed boiler, comprising an air feed pipe and an air nozzle which limit an air feed duct configured to supply air to the furnace of the fluidized bed boiler. The air nozzle arrangement comprises a surface configured to guide coarse material along said surface. At least part of said surface is thermally insulated from the air nozzle and/or the air feed pipe. Furthermore, at least part of said surface is configured to protect at least part of said air nozzle and/or air feed pipe. Thus, the temperature of said surface is configured to be high when the fluidized bed boiler is in operation, whereby the solidification of molten material of the fluidized bed in the air nozzle arrangement is reduced.