A circulating fluidized bed boiler, comprising a furnace, a loopseal, and a loopseal heat exchanger arranged in the loopseal. The loopseal heat exchanger comprises at least an inlet chamber, a bypass chamber, and a first heat exchange chamber, heat exchanger pipes arranged in the first heat exchange chamber, and a primary particle outlet for letting out bed material from the first heat exchange chamber. The primary particle outlet has at least a first part and a second part separated from each other by a barrier element in such a way that the first part of the primary particle outlet has a first height and a first width, wherein a ratio of the first height to the first width is less than 0.5 or more than 2. Use of the circulating fluidized bed boiler such that fluidizing gas and bed material are let out from the first heat exchange chamber via the primary particle outlet.

A heat exchanger (10) suitable for recovering heat from bed material of a fluidized bed boiler (1). The heat exchanger (10) comprises first and second heat exchanger tubes (810, 820) and first and second feeding chambers (310, 320) configured to supply bed material to the first and second heat exchanger tubes (810, 820), respectively. The first heat exchanger tubes (810) are arranged on a first side of a plane (P) that intersects the first feeding chamber (310) and the second heat exchanger tubes (820) are arranged on a second side of the plane (P). The first feeding chamber (310) is configured to supply bed material to the second feeding chamber (320).

Material handling systems for fluids are disclosed herein. The fluid may be a liquid, solution, slurry, or emulsion. The systems receive as inputs the fluid, steam, and water. These feed into a surge tank where additives can be introduced. The steam and water are used to control some physical properties and enable the distribution of the fluid as desired. In particular embodiments, the system is useful for handling materials to be sent to a dual-phase fuel feeder for combustion in a fluidized-bed boiler, the energy being used to generate electricity or in various production processes.

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.

A circulating fluidized bed boiler, comprising a furnace, a loopseal, and a loopseal heat exchanger arranged in the loopseal. The loopseal heat exchanger comprises at least an inlet chamber, a bypass chamber, and a first heat exchange chamber, heat exchanger pipes arranged in the first heat exchange chamber, and a primary particle outlet for letting out bed material from the first heat exchange chamber. The primary particle outlet has at least a first part and a second part separated from each other by a barrier element in such a way that the first part of the primary particle outlet has a first height and a first width, wherein a ratio of the first height to the first width is less than 0.5 or more than 2. Use of the circulating fluidized bed boiler such that fluidizing gas and bed material are let out from the first heat exchange chamber via the primary particle outlet.

An arrangement for controlling a flow of solid particles includes a vertical inlet pipe for directing solid particles downwards and having a bottom at a level L0, a first outlet chute and a second outlet chute in particle flow connection with the vertical inlet pipe and a fluidizing device for directing controlled first and second sub flows to the first and second outlet chutes. The arrangement includes a branch in particle flow connection with an opening on a side wall of the vertical inlet pipe for directing the first sub flow of solid particles to the first outlet chute and a horizontally extending intermediate pipe for directing the second sub flow of solid particles to the second outlet chute. The intermediate pipe includes at least one nozzle feeding fluidizing gas to the intermediate pipe and has a first end in particle flow connection with the bottom of the inlet pipe.

Disclosed herein are a fluid sand falling type circulating fluidized bed boiler with a plurality of risers for preventing erosion and corrosion of water tubes and increasing combustion efficiency, and a method of operating the same. The fluid sand falling type circulating fluidized bed boiler with a plurality of risers includes a boiler section into which fuel and oxidizer are injected, a riser section connected to the boiler section so that the fuel and fluid sand supplied from the boiler section are introduced from the bottom of the riser section and flow up, and a relay section provided on the boiler section to supply the fluid sand having passed through the riser section to the boiler section, wherein the fuel is injected from the top of the boiler section and burned while flowing down therein.

A heat exchanger having a first heat transfer tube with a first primary straight part and a first secondary straight part is provided. The heat exchanger includes a first primary bond part and a first secondary bond part. The first primary bond part is welded to the first secondary bond part to form a first primary bond that bonds the first primary straight part and the first secondary straight part of the first heat transfer tube. The first primary bond limits a first primary aperture and a first secondary aperture formed by the holes of the bond parts, wherein the straight parts of the first heat transfer tube extend through the first primary bond via the apertures.

The solution comprises a method of and a system for maintaining steam temperature and therefore electricity production efficiency with decreased loads of a steam turbine power plant comprising a fluidized bed boiler (12) and a fluidized bed superheater (2) adapted to superheat steam supplied to a steam turbine (3). According to the solution, the steam temperature may be maintained by providing, outside a furnace (10), additional heating to the fluidized bed material in its outer circulation, thereby increasing the amount of thermal energy available in the fluidized bed material to be transferred in the fluidized bed superheater (2) to the steam supplied to the steam turbine (3). Such additional heating may be performed by selectably supplying combustible gas with nozzles (111) into and/or burned with a burner in or in the vicinity of the fluidized bed material outside the furnace (10). As an additional aspect of the disclosed solution, the combustible gas may be produced with a gasifier (4).

A heat exchanger (10) suitable for recovering heat from bed material of a fluidized bed boiler (1). The heat exchanger (10) comprises first and second heat exchanger tubes (810, 820) and first and second feeding chambers (310, 320) configured to supply bed material to the first and second heat exchanger tubes (810, 820), respectively. The first heat exchanger tubes (810) are arranged on a first side of a plane (P) that intersects the first feeding chamber (310) and the second heat exchanger tubes (820) are arranged on a second side of the plane (P). The first feeding chamber (310) is configured to supply bed material to the second feeding chamber (320).