A boiler includes an upper steam drum, an optional intermediate drum, and a lower drum. Each drum is divided by an internal divider into a clean section and a concentrated section. Downcomers connect the upper steam drum to the lower drum, and tubes are connected to convey a heated steam-water mixture from the lower drum into the upper steam drum (through the optional intermediate drum, if provided). An optional superheater has an input terminal connected to receive steam from the clean section of the upper steam drum. An attemperator may be provided to attemperate superheated steam output from an output terminal of the superheater, and the attemperation fluid may optionally be provided from the concentrated side of the upper steam drum.

A boiler includes an upper steam drum, an optional intermediate drum, and a lower drum. Each drum is divided by an internal divider into a clean section and a concentrated section. Downcomers connect the upper steam drum to the lower drum, and tubes are connected to convey a heated steam-water mixture from the lower drum into the upper steam drum (through the optional intermediate drum, if provided). An optional superheater has an input terminal connected to receive steam from the clean section of the upper steam drum. An attemperator may be provided to attemperate superheated steam output from an output terminal of the superheater, and the attemperation fluid may optionally be provided from the concentrated side of the upper steam drum.

An arrangement in a recovery boiler having a furnace for combusting waste liquor and a flue gas duct including vertical flue gas channels, at least some of which are provided with heat recovery units for recovering heat from flue gases. The first flue gas channel downstream of the furnace is provided with a reheater and one of the following heat recovery units: an economizer or a boiler bank. The reheater and the second heat recovery unit are located one after the other in the horizontal incoming direction of the flue gas, so that in a flue gas channel the flue gas flows in a vertical direction from above downwards and heats the reheater and the second heat recovery unit simultaneously. The heat recovery elements of the reheater and the second heat recovery unit may be positioned side by side in a direction that is crosswise with respect to the horizontal incoming direction of the flue gas.

An arrangement in a recovery boiler having a furnace for combusting waste liquor and a flue gas duct including vertical flue gas channels, at least some of which are provided with heat recovery units for recovering heat from flue gases. The first flue gas channel downstream of the furnace is provided with a reheater and one of the following heat recovery units: an economizer or a boiler bank. The reheater and the second heat recovery unit are located one after the other in the horizontal incoming direction of the flue gas, so that in a flue gas channel the flue gas flows in a vertical direction from above downwards and heats the reheater and the second heat recovery unit simultaneously. The heat recovery elements of the reheater and the second heat recovery unit may be positioned side by side in a direction that is crosswise with respect to the horizontal incoming direction of the flue gas.

The invention relates to energy, in particular for the system of separation and superheating of steam for nuclear power plant turbines. The invention is aimed at solving the problem of reducing the mass and dimension parameters while maintaining the efficiency of heat exchange.

The task in the claimed invention is solved by the fact that both tube banks of the first and second superheating stages are rotated vertically at the same height in such a way that they form between them and the inside of the housing two segmental inlet headers, a wedged outlet header with an angle of turn from 10 to 90, and the steam outlet nozzle is located in a vertical case opposite the wedged outlet header. The actual reduction in mass and dimension parameters is 18-25%, which allows using this solution in compact systems for steam separation and superheating.

A method generates superheated steam using heat generated in a boiler of an incineration plant. The pre-superheated steam is fed to a final superheater that includes a plurality of final superheater pipes through which the pre-superheated steam is guided and is finally superheated in the process. The final superheater pipes (are arranged at least partially in at least one cavity (formed in an interior of a wall element of the boiler and/or of a bulkhead arranged in the boiler. The cavity is closed off on a boiler side at least partially by a refractory material layer and is flowed over by flue gas released during combustion. A secondary medium flows through the cavity and is heated via heat transfer from the flue gas via the refractory material layer. The heated secondary medium is fed via a secondary medium feed line to a secondary heat exchanger.

A method generates superheated steam using heat generated in a boiler of an incineration plant. The pre-superheated steam is fed to a final superheater that includes a plurality of final superheater pipes through which the pre-superheated steam is guided and is finally superheated in the process. The final superheater pipes (are arranged at least partially in at least one cavity (formed in an interior of a wall element of the boiler and/or of a bulkhead arranged in the boiler. The cavity is closed off on a boiler side at least partially by a refractory material layer and is flowed over by flue gas released during combustion. A secondary medium flows through the cavity and is heated via heat transfer from the flue gas via the refractory material layer. The heated secondary medium is fed via a secondary medium feed line to a secondary heat exchanger.

A chemical recovery boiler (100), including a furnace (1), comprising a front wall (2), a back wall (3), and the back wall (3) comprising a nose arch (4). The boiler further comprises at least one superheater (5) arranged in upper part of the furnace (1), and a screen pipe system (6), comprising an obliquely arranged screen pipe section (7) positioned before/under the at least one superheater (5) in the furnace (1). The obliquely arranged screen pipe section (7) comprises screen pipes (8) ascending (i) either from the front wall (2) to the back wall (3), and arranged to turn back in a turn (13) from the back wall (3) and extend obliquely upwards from the back wall (3), or (ii) from the back wall (3) to the front wall (2), and arranged to turn back in a turn (13) from the front wall (2) and extend obliquely upwards from the front wall (2). The screen pipe system (6) further comprises a vertically arranged screen pipe section (9) extending from the obliquely arranged screen pipe section (7). The screen pipes (8) of the vertically arranged screen pipe section (9) are arranged to extend parallel with the at least one superheater (5) in upper part of the furnace (1).

A chemical recovery boiler (100), including a furnace (1), comprising a front wall (2), a back wall (3), and the back wall (3) comprising a nose arch (4). The boiler further comprises at least one superheater (5) arranged in upper part of the furnace (1), and a screen pipe system (6), comprising an obliquely arranged screen pipe section (7) positioned before/under the at least one superheater (5) in the furnace (1). The obliquely arranged screen pipe section (7) comprises screen pipes (8) ascending (i) either from the front wall (2) to the back wall (3), and arranged to turn back in a turn (13) from the back wall (3) and extend obliquely upwards from the back wall (3), or (ii) from the back wall (3) to the front wall (2), and arranged to turn back in a turn (13) from the front wall (2) and extend obliquely upwards from the front wall (2). The screen pipe system (6) further comprises a vertically arranged screen pipe section (9) extending from the obliquely arranged screen pipe section (7). The screen pipes (8) of the vertically arranged screen pipe section (9) are arranged to extend parallel with the at least one superheater (5) in upper part of the furnace (1).

Transition castings are disclosed which comprise a steam tube, a water tube, and a pass-through tube, which are joined together by membranes. The ends of the tubes on one vertical end are aligned in a plane, while the ends of the tubes on the other vertical end are aligned in alternating planes, or put another way are angled instead of being in a straight line. The transition castings are used in a transition section of a boiler in which the furnace is divided into a lower furnace and an upper furnace. The lower furnace uses water-cooled membrane walls, while the upper furnace uses steam-cooled membrane walls that act as superheating surfaces. The transition section joins the lower furnace and the upper furnace together.