Abstract: A boiler includes a flue gas duct and heat exchanger pipes in the flue gas duct. The boiler includes a planar silencer plate, which silencer plate includes sound absorbing material, and said first silencer plate being placed downstream of one of said heat exchanger pipes in the flow direction of flue gases in said flue gas duct. Furthermore, a silencer for a flue gas duct with a rectangular cross-section in a boiler, the silencer including at least a first and a second planar silencer plate substantially parallel to the flow direction of flue gases, the silencer plates including sound absorbing material. The first silencer plate is placed at an angle to the second silencer plate, wherein the width of the resonating area of the flue gas duct becomes narrower in two directions transverse to the flow direction of the flue gases.

Abstract: Disclosed herein is an apparatus and a method for producing a pyrolysis liquid, wherein the pyrolysis liquid is formed by means of pyrolysis from a raw material by forming, and a pyrolysis reactor, a gaseous pyrolysis product by pyrolysis and condensing it in a condenser into a pyrolysis liquid, and feeding circulation gas into the pyrolysis reactor. The circulation gas is conducted by a liquid ring compressor into the pyrolysis reactor and purified before being conducted into the pyrolysis reactor, and the pyrolysis liquid is used as the liquid layer in the liquid ring compressor.

Abstract: The invention relates to a method for producing a pyrolysis liquid, wherein the pyrolysis liquid is formed by means of pyrolysis from a raw material by forming, in a pyrolysis reactor, a gaseous pyrolysis product by pyrolysis and condensing it in a condenser into a pyrolysis liquid, and feeding circulation gas into the pyrolysis reactor. According to the invention, the circulation gas is conducted by means of a liquid ring compressor into the pyrolysis reactor and purified before being conducted into the pyrolysis reactor, and the pyrolysis liquid is used as the liquid layer in the liquid ring compressor. Further, the invention relates to a corresponding apparatus.

Abstract: The invention relates to a method and apparatus for processing the black liquor of a pulp mill to recover the chemicals and energy therein. In the invention, the black liquor is pyrolyzed in a pyrolysis reactor (6), formed gaseous components are lead for utilization, sand is returned to a fluidized-bed boiler, and solid matter is mixed with water, whereby a soda-water solution is returned to the pulping process and solid carbon to the fluidized-bed boiler (1).

Abstract: A pyrolysis apparatus comprises a substantially closed pyrolyzer (4), a supply inlet for supplying pyrolyzable fuel to the pyrolyzer (4), an outlet for taking hot bed material in particle form out of the pyrolyzer, one or more exit outlets (6) for taking condensible gaseous substances separated from the fuel to be pyrolyzed out of the pyrolyzer, a condenser (8) for condensing the condensible gaseous substances into pyrolysis oil, and a line (7) for transferring the condensible gaseous substances from the exit outlet of the pyrolyzer (4) to the condenser (8). The means for maintaining pyrolysis conditions in the pyrolyzer (4) comprise an inlet for taking hot bed material in particle form into the pyrolyzer and means (5) for supplying fluidizing gas to the pyrolyzer. The pyrolyzer (4) is a chamber bounded directly by a furnace (1) of a bubbling fluidized bed boiler, through which chamber fluidized bed material is arranged to be circulated between the inlet and the outlet.

Abstract: A boiler and a method in a boiler producing thermal energy, the method including: combustion or fuel and combustion air in the furnace of the boiler, delimited by walls; receiving of thermal energy by a steam superheater placed on the wall of the furnace and including at least one heat exchange surface, and supplying of gas or a gas mixture to the front of said heat exchange surface to form a barrier layer for protecting the heat exchange surface from flue gases developed in connection with the combustion. At least one supply device is provided in the superheater or in the direct vicinity of the superheater, to supply gas or a gas mixture to the front of said heat exchange surface to form a barrier layer to protect the heat exchange surface from the flue gases in the boiler.

Abstract: A flue gas air preheater and a method for the installation of air pipes for a flue gas air preheater. The method includes cutting an air pipe connected to the preheater and detaching the portion of the air pipe that is to be removed from the preheater for replacement; fitting a separate new air pipe in place of the air pipe portion to be removed; and connecting the new air pipe to the remaining portion of the air pipe in a sealed manner. The fixing may be performed utilizing a fastening sleeve fixed to the end of the new air pipe and inserting it in the remaining portion of the air pipe. The fixing may be performed by a mechanical sealing solution without welding. The air pipe component for the flue gas air preheater includes an air pipe, and a fastening sleeve.

Abstract: A method of scrubbing flue gases of two or more diesel engines and a scrubber for scrubbing flue gases of two or more diesel engines. The scrubber (1) comprises scrubbing means (3) for scrubbing the flue gases, and conduits (4) for conveying the flue gases to said scrubbing means (3) to be scrubbed in the same scrubbing process. The different flue gas flows are arranged to be conveyed in separate conduits (4) all the way to the scrubbing means (3).

Abstract: A pyrolysis apparatus comprises a furnace (1) operating by fluidized bed combustion, a pyrolyzer (4) and flow paths, which connect the furnace (1) and the pyrolyzer (4) for arranging the circulation (C) of carrier material of the fluidized bed combustion between the furnace and the pyrolyzer .The apparatus also comprises a supply inlet (14) for supplying fuel to be pyrolyzed to the pyrolyzer (4), fluidizing gas supply means (5) arranged in the pyrolyzer for fluidizing the mixture of carrier material and fuel, and an outlet (6) for taking condensible gaseous substances separated from the fuel to be pyrolyzed out of the pyrolyzer (4), and a condenser for condensing the condensible gaseous substances.

Abstract: In a method for processing ash, fly ash is separated from a product gas flow obtained from gasification of fuel, which fly ash is burned in fluidized bed combustion to reduce the carbon content of the ash. After this, the flue gases from the combustion are processed. In a first step, the ash is burned in fluidized bed combustion (fluidized bed reactor 1) at a temperature of not higher than 800° C. to reduce the carbon content, and in a second step, the flue gases a burned in an independent combustion process (combustion chamber 7), the combustion conditions reaching the temperature of at least 850° C.

Abstract: A boiler grate including air channels for supplying primary air to a furnace of a boiler. At least one channel, which is open on top, is arranged to collect ash and material from the furnace. At least one removal element is arranged in the channel and to mechanically move ash and material along the channel. A boiler includes a grate, a furnace which is limited by the walls of the furnace and the grate, and an ash chute, which is arranged to remove ash and material from the furnace. The ash removal elements is arranged to move ash and material towards the air chute.

Abstract: A method and an arrangement for optimising combustion conditions in a fluidised-bed boiler, in which combustion gas is fed at two or more height levels, the first of which is a primary level (P) which is located at the height of a furnace bottom and the second is a secondary level (S) which is located above fuel feed height (F), above which secondary level (S) there can be still other combustion gas feed levels (T, . . . ). At least one combustion gas feed level (P, S, T, . . . ) is fed at different points of the furnace (11) in its horizontal direction with combustion gases having different oxygen contents such that zones of different oxygen content can be formed in the horizontal direction of the furnace (11).

Abstract: A flue gas air preheating apparatus for combustion air in a boiler of a power plant. An air pipe is placed in a flue gas duct. An air guide sleeve is provided at an initial end of the air pipe at least partly inside the air pipe. The air guide sleeve is made of a poorly heat conductive material and is designed to diminish turbulence in air flow and has an inflow end and a second end placed inside the air pipe. The shaping of the second end is designed to diminish turbulence in the air flow. The air guide sleeve includes splits or notches that become wider towards the second end. A method and a corrosion shield.

Abstract: A fluidized bed boiler comprises a furnace whose lower part is equipped with a grate comprising means for supplying fluidizing air into the furnace. The furnace also comprises at least one heat transfer surface extending across the furnace and comprising elongated heat transfer tubes on top of each other. The heat transfer surface is supported on the grate from underneath, substantially over its whole length, in the section extending across the furnace.

Abstract: A preheating device for combustion air in a boiler. First heat exchanger structures fitted in a flue gas duct heat primary air. A first air supply area in the wall of the flue gas duct supplies air to be heated to the first heat exchanger structures. Second heat exchanger structures fitted in a flue gas duct heat secondary air. A second air supply area in the wall of the flue gas duct supplies air to be heated to the second heat exchanger structures. The first air supply area is opposite the second air supply area. Also a power plant.

Abstract: The invention relates to the improvement of the fuel-properties of biomass in an integrated manner to facilitate storage, shipping and applicability thereof. In the process, biomass (6) is thermally treated within a combustion process to cause partial torrefaction of the organic matter present in biomass, thus yielding components inert to biological decomposition processes. Constituents (10) separated in gaseous form are utilized as fuel, while the thermally treated biomass (8) remaining in the solid form is utilized in a separate process.

Abstract: A method for reducing nitrogen oxide emissions in oxyfuel combustion, which method comprises supplying in a furnace (11) of a circulating fluidised bed boiler (10) at least one primary gas flow (15) and at least one secondary gas flow (16), which both have been produced by mixing oxygen and circulated flue gas together. The oxygen content of the primary gas (15) is adjusted such that a reducing zone (I) is formed at the bottom of the furnace, in which zone nitrogen oxides are reduced to nitrogen. The oxygen content of the secondary gas is adjusted such that above the reducing zone (I) is formed an oxidising zone (II), in which zone combustion is completed.

Abstract: The invention relates to a method for preventing chlorine deposition on the heat-transferring surfaces of a boiler, particularly on the superheater, in which boiler a fuel with a chlorine content, such as a biomass or waste fuel, is burned. And to which steam boiler is fed, preferably in the superheater area, a compound with a sulphate content, which forms a particular reagent to fix alkali compounds. The said compound is ferric(III)sulphate, Fe2(SO4)3 and/or aluminium(III)sulphate, Al2(SO4)3.

Abstract: A boiler (1) comprising at least: a furnace (2), in whose lower part the combustion used as the primary source of thermal energy of the boiler is configured to take place; devices (6) for supplying fuel into the furnace; devices (3, 7, 8, 26) for supplying combustion air into the furnace; one or more flue gas ducts (11); at least one chamber (17) accommodating at least one steam superheater (15) for recovering thermal energy. Said chamber is configured to allow a direct line of sight (16) between said superheater and said primary source, to enable the reception of thermal energy by means of thermal radiation. Said chamber is further configured to prevent the entry of said flue gases (19) to said superheater either totally or almost totally, to avoid the reception of thermal energy by convection.

Abstract: A method and an equipment for reducing sulphur dioxide emissions of a marine engine, wherein flue gases are scrubbed with a scrubbing solution in a scrubber. Fresh water with added sulphur removal reagent is used as the scrubbing solution.