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: 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 and a system for feeding combustion air of a soda recovery boiler to a furnace. The air is fed to the boiler furnace as primary air jets and auxiliary airjets, which are substantially shorter than the primary air jets. At least one primary airjet is placed between two opposite auxiliary air jets.

Abstract: A method and a system for feeding combustion air of a soda recovery boiler to a furnace (7), in which the air is fed to the boiler furnace (7) as primary air jets (5) and auxiliary air jets (6), which are substantially shorter than the primary air jets. According to the invention, at least one primary air jet (5) is placed between two opposite auxiliary air jets (6).

Abstract: The object of the present invention is a method in cooling medium circulation, whereby the recovery boiler comprises a furnace limited by wall tubes provided with cooling medium circulation and substantially horizontal floor tubes; a supply system for combustion air; and a supply system for black liquor, whereby a so-called smelt layer is formed in a combustion process on the floor composed of the floor tubes. At least in some of the floor tubes, at least on a section of their length, is arranged a longitudinal flow--particularly a spiral flow--for mixing the liquid and steam phases of the cooling medium.