Abstract: A heat exchanger pipe in a flow duct for gases. The pipe first section has a second section with an inner pipe for transferring heat transfer medium; an outer pipe that radially encloses a part of the inner pipe; and a medium layer between the outer pipe and the part of the inner pipe. The second section of the heat exchanger pipe bends less than 90 degrees. Furthermore, the first section is insulated in its entirety, or non-insulated in the vicinity of other heat recovery surfaces only. In the device the temperature of the heat transfer medium flowing in the inner pipe is at least 500° C., the temperature of the outer surface of the outer pipe is higher than 600° C., or an auxiliary agent is fed to the thermal device.

Abstract: 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.

Abstract: A heat exchanger pipe in a flow duct for gases. The pipe first section has a second section with an inner pipe for transferring heat transfer medium; an outer pipe that radially encloses a part of the inner pipe; and a medium layer between the outer pipe and the part of the inner pipe. The second section of the heat exchanger pipe bends less than 90 degrees. Furthermore, the first section is insulated in its entirety, or non-insulated in the vicinity of other heat recovery surfaces only. In the device the temperature of the heat transfer medium flowing in the inner pipe is at least 500° C., the temperature of the outer surface of the outer pipe is higher than 600° C., or an auxiliary agent is fed to the thermal device.

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: 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.

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: 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 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 supply and a method for preventing corrosion on heat exchange surfaces of a boiler. Additional material is fed to flue gases of a boiler by at least one supply for additional material. The supply includes a cooled case beam that is hollow inside and several nozzles for feeding the additional material.

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: Method in a variable-crown roll in which hydraulic loading elements or a series of hydraulic loading elements are used. Such series of elements acts along a plane of a nip that can be formed between the variable-crown roll and a counter-roll thereof, with such elements or series being situated between a central axle of the roll and a cylindrical mantle which is rotatable about the central axle through radial bearings. The central axle is supported by axle journals thereof on deflection bearings. In the method, the central axle is pivoted about the deflection bearings thereof over an angle which is within a range of about 30.degree. to 180.degree.. By the effect of such pivoting, the variable-crown roll and the mantle thereof are shifted away from the nip, so that the nip is opened. This shifting is produced by the axis of pivoting of the deflection bearings being situated by a certain eccentricity distance further away from a nip line of the closed nip, than the axis of rotation of the roll mantle.