Abstract: The invention relates to an arrangement in a recovery boiler into which spent liquor to be incinerated and combustion air are supplied, the arrangement comprising superheaters (4a-4d) in the upper part of the recovery boiler for recovering heat, at least one boiler bank (11) located in a flue gas duct part (10a) known as the second pass, immediately after the recovery boiler, and at least one economizer (12a-12b) in a duct part after the second pass in the recovery boiler flue gas duct (10). The invention comprises an economizer (21) located parallel with the boiler bank (11) in the second pass.

Abstract: The invention relates to an arrangement in a recovery boiler into which spent liquor to be incinerated and combustion air are supplied, the arrangement comprising superheaters (4a-4d) in the upper part of the recovery boiler for recovering heat, at least one boiler bank (11) located in a flue gas duct part (10a) known as the second pass, immediately after the recovery boiler, and at least one economizer (12a-12b) in a duct part after the second pass in the recovery boiler flue gas duct (10). The invention comprises an economizer (21) located parallel with the boiler bank (11) in the second pass.

Abstract: In a soda recovery boiler, flue gases are led through a so-called economizer (3) to recover heat from flue gases. The flue gases are cooled in the last stage (3b) of the economizer (3) with a circulation water cooler (4) for flue gases, separate from the supply water system of the boiler. The circulation water cooler (4) for flue gases is used for preheating combustion air.

Abstract: In a soda recovery boiler, flue gases are led through a so-called economizer (3) to recover heat from flue gases. The flue gases are cooled in the last stage (3b) of the economizer (3) with a circulation water cooler (4) for flue gases, separate from the supply water system of the boiler. The circulation water cooler (4) for flue gases is used for preheating combustion air.

Abstract: Arrangement in a soda recovery boiler, comprising normal melt chutes (6) for removing molten salt from the recovery boiler (1). The recovery boiler (1) comprises an outlet (8), mounted in the wall of the recovery boiler such that it is situated lower down than the normal melt chutes (6), in which case the molten salt can be removed from the bottom of the recovery boiler substantially through the outlet (8), when the recovery boiler (1) is emptied for maintenance or the like.

Abstract: A method for upgrading a boiler is provided. When operating at a first capacity, the boiler is used such that an open space is kept in radiation communication with a firebox. The open space is also kept as empty. A first set of water circulation tubes are connected to the boiler cylinder in connection with the ascending tubes. When the boiler is operated at a second capacity, which is higher than the first capacity, at least one additional part is arranged in the open space to expand the basic super heater arrangement. Additionally, or alternatively at the second capacity, a second set of water circulation tubes may be connected to the boiler cylinder in connection with the ascending tubes. The second set of water circulation tube has a capacity exceeding that of the first set of water circulation tubes.