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: A recovery boiler plant, which comprises a recovery boiler, wherein in the first part (1a) flue gases travel in a first direction (F1). The furnace also comprises a second part (1b), where the flue gases proceed in a second direction (F2), which second direction differs from the first direction (F1). In addition, the invention relates to a method in a recovery boiler.

Abstract: The invention relates to an arrangement in a recovery boiler, into which spent liquor to be combusted and combustion air are fed, the arrangement comprising superheaters in the upper part of the recovery boiler for recovering heat. Instead of screen tubes the invention is provided with a superheater formed of horizontal elements.

Abstract: A method for reducing nitrogen oxides of a recovery boiler, and a recovery boiler, where the furnace of the recovery boiler is supplied with primary air from primary air nozzles, black liquor from liquor nozzles, secondary air from secondary air nozzles above the primary air nozzles but still below the liquor nozzles, tertiary air from tertiary air nozzles above the liquor nozzles, and quaternary air from quaternary air nozzles above the tertiary air nozzles. Black liquor is supplied to the furnace from first liquor nozzles and second liquor nozzles, which liquor nozzles are arranged substantially on the same level with respect to the height of the furnace, and the droplet size of liquor fed from the second liquor nozzles is substantially smaller than the droplet size of liquor fed from the first liquor nozzles.

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 combusted and combustion air are fed, the arrangement comprising superheaters in the upper part of the recovery boiler for recovering heat. Instead of screen tubes the invention is provided with a superheater formed of horizontal elements.

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.