Abstract: A falling film evaporator, includes an outer shell formed by a cylindrical shell and convex ends, at least one tube bundle formed of vertical tubes arranged inside the outer shell, whereby a heat-releasing, condensable vapor can be fed into the vertical tubes from below upwards, and a heat-receiving, vaporizable liquid can be fed to the upper end of the tube bundle to flow downwards along the outer surface of the vertical tubes as a thin liquid layer, whereby an element for discharging non-condensable gases contained in the heat-releasing vapor has been arranged in the tube bundle. The evaporator includes two or more tube bundles each being provided with a tube plate of its own, whereby the vertical tubes of each tube bundle are at their lower ends attached to the tube plate of the corresponding tube bundle and at their upper ends to collecting manifolds of the corresponding tube bundle.

Abstract: The subject of the disclosure is a vertical shell and tube straight tube countercurrent condenser, wherein the condensing steam flows on the shell side of the condenser, and the cooling water on the tube side.

Abstract: A shell and tube heat exchanger include heat surface tubes (6) surrounded by a shell (1), the tubes communicating with an inlet end chamber (11) through a tube sheet (5) at one end and with an outlet end chamber (12) through a tube sheet at the other end, and in the shell side of the tube heat exchanger there is at least one baffle plate made of flat strips for supporting the heat surface tubes and guiding the shell-side flow. The flat strips forming the baffle plate are straight and thinner than the distance between the tubes to be supported, and the required support is achieved by placing each flat strip of the baffle plate in an inclined position with respect to the heat surface tubes so that one of the crosswise edges of the flat strip is supporting one and the other is supporting the other of adjacent tubes.

Abstract: A shell and tube heat exchanger include heat surface tubes (6) surrounded by a shell (1), the tubes communicating with an inlet end chamber (11) through a tube sheet (5) at one end and with an outlet end chamber (12) through a tube sheet at the other end, and in the shell side of the tube heat exchanger there is at least one baffle plate made of flat strips for supporting the heat surface tubes and guiding the shell-side flow. The flat strips forming the baffle plate are straight and thinner than the distance between the tubes to be supported, and the required support is achieved by placing each flat strip of the baffle plate in an inclined position with respect to the heat surface tubes so that one of the crosswise edges of the flat strip is supporting one and the other is supporting the other of adjacent tubes.

Abstract: A falling film evaporator, includes an outer shell formed by a cylindrical shell and convex ends, at least one tube bundle formed of vertical tubes arranged inside the outer shell, whereby a heat-releasing, condensable vapour can be fed into the vertical tubes from below upwards, and a heat-receiving, vaporizable liquid can be fed to the upper end of the tube bundle to flow downwards along the outer surface of the vertical tubes as a thin liquid layer, whereby an element for discharging non-condensable gases contained in the heat-releasing vapour has been arranged in the tube bundle. The evaporator includes two or more tube bundles each being provided with a tube plate of its own, whereby the vertical tubes of each tube bundle are at their lower ends attached to the tube plate of the corresponding tube bundle and at their upper ends to collecting manifolds of the corresponding tube bundle.

Abstract: The present invention refers to a method to recover chemicals in mechanical pulping by evaporating mechanical pulping or recycled fibre plant effluent and burning the received concentrate under oxidative atmosphere to yield sodium carbonate. According to the invention said sodium carbonate is dissolved into water together with CaO in order to convert said sodium carbonate into sodium hydroxide at least partly.

Abstract: The invention relates to a method for combusting an organic waste concentrate, which contains alkali metal compounds, under oxidative conditions for recovering the alkali metal compounds as alkali metal carbonates. According to the invention, the combustion is carried out at a temperature of at least about 850° C. The formed flue gases are cooled below a sticking temperature range of the alkali carbonates by mixing, and simultaneously water (8) is poured on the walls (9) of a cooling zone (2) at least at the sticking temperature range.

Abstract: The invention relates to a method for combusting an organic waste concentrate, which contains alkali metal compounds, under oxidative conditions for recovering the alkali metal compounds as alkali metal carbonates. According to the invention, the combustion is carried out at a temperature of at least about 850° C. The formed flue gases are cooled below a sticking temperature range of the alkali carbonates by mixing, and simultaneously water (8) is poured on the walls (9) of a cooling zone (2) at least at the sticking temperature range.

Abstract: A liquid evaporation method and apparatus wherein the contamination of the heat transfer surfaces is avoided by using a special circulating fluid. The liquid to be evaporated is heated in direct contact with the circulating fluid and conveyed to a vapor separation tank. In the evaporator according to the invention, heat transfer surface contamination may be limited by mixing the liquid to be evaporated with the circulating fluid only after the heat exchanger so that the heat surface contaminating liquid to be evaporated does not make direct contact with the heat surface.