SE532301C2 - A steam boiler fitted with a cooled device - Google Patents

Description

It is easy to see that in a steam boiler not only the outlet pipe of a cyclone can be subjected to stresses due to heat but the high temperature can be a problem for the material in walls and other components in the entire steam boiler. The object of the present invention is to offer an improved steam boiler where different exposed parts of the steam boiler can become more durable by cooling in an efficient manner.

DESCRIPTION OF THE INVENTION The invention relates to a meadow boiler with a boiler water circulation system which preferably has natural circulation. The circulation system comprises water pipes arranged to be able to circulate boiler water through the pipes in a circuit where water flows from the steam mandrel in the outer downpipe to the fireplace and convection parts and where water and steam go from the fireplace and convection parts up to a steam where steam is separated from the steam. comprises a device intended to cool a selected and exposed part of the boiler.

The cooled device comprises an outer tube and an inner tube placed in the outer tube. The outer pipe has an upper end with an open connection to one of the water pipes for boiler water and a closed lower end. The inner pipe has an upper open end connected to a water pipe for boiler water and a lower open end at the closed lower end of the outer pipe. In some embodiments, the upper open end of the inner tube is located at the upper end of the outer tube and they are connected to the same water line or fl desert for boiler water. The cooled device extends at least partially in the vertical direction downwards from the point where the outer pipe is connected to a water pipe. The vapor barrier may comprise an element which, when using the boiler, is exposed to hot gases.

Said elements which, when using the steam boiler, are exposed to hot gases may consist of a wall in the steam boiler, a holder for heat exchangers in the path of the flue gas or that the cooled device may be arranged in or essentially constitute said wall or holder.

Said element which, when using the boiler, is exposed to hot gases may also consist of, for example, a thermocouple or a continuous pipe which extends through the pipe for boiler water, through the inner tube of the cooled device and at its outermost end connects to the outer of the cooled device. pipe. The boiler may comprise a cyclone for separating particles from hot flue gases, the cyclone having an outlet pipe for the hot gases. The cooled device can then be arranged to create a cooled outlet pipe. The cyclone outlet pipe may be constructed of or comprise a plurality of cooled devices each cooling device comprising an outer tube and an inner tube located in the outer tube and which outer tube at an upper end has a open connection to one of the pipes for boiler water and a closed lower end and the inner tube has an upper end at the upper end of the outer tube and a lower open end at the closed lower end of the outer tube and in that the cooled device extends at least partially in vertical direction downwards from the point where the outer pipe is connected to said water pipe.

In some embodiments, at least some of the pair water conduits may extend within the walls of the cyclone and extend vertically from a lower portion of the cyclone to a higher portion of the cyclone. Some of the boiler water pipes extending inside the walls of the cyclone may then be connected to cooled devices provided with an outer and an inner tube.

According to one embodiment, the steam boiler may have walls forming a flue gas duct in which one or more elements are suspended in the flue gas duct by means of a holder which holder comprises a cooled device in accordance with the invention, i.e. a cooled device with an outer tube and an inner pipe located in the outer pipe and which outer pipe at an upper end has an open connection to one of the water pipes for boiler water and a closed lower end, the inner pipe having an upper open end at the upper end of the outer pipe and a lower open end at the closed lower end of the outer tube and wherein the cooled device extends at least partially in the vertical direction downwards from the point where the outer tube is connected to the water pipe.

According to another embodiment, a flue gas duct formed by the walls of the boiler may comprise a separating partition wall which separates two parts of the flue gas duct from each other. The partition wall can then be at least partially built up of cooled devices according to the invention, i.e. cooled devices which comprise an outer tube and an inner tube placed in the outer tube and which outer tube at an upper end has an open connection to one of the water pipes for boiler water. and a closed lower end wherein the inner tube has an upper open end at the upper end of the outer tube and a lower open end at the closed lower end of the outer tube and wherein the cooled device extends at least partially in the vertical direction downward from the point where it the outer pipe is connected to the water pipe.

According to a further embodiment, the cooled device is used as a dust separating beam in a flue gas duct formed by the walls of the steam boiler. A plurality of cooled devices can then be placed next to each other in the flue gas duct. When the cooled device is used as a dust separating beam, the cooled device can be provided with outer rails which extend along the cooled devices. The upper end of the inner tube may be funnel-shaped.

The inner tube may at its upper end have an orifice which is inclined with respect to the longitudinal axis of the inner tube.

The connection to the boiler water line may be in an area where the lower side of the boiler line has been widened to meet the outer pipe.

At the upper end of the outer tube a lid may be arranged to cover a part of the gap area between the outer and the inner tube.

The inner tube may at its upper end be inclined towards the wall of the outer tube.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 schematically shows a section of a steam boiler.

Figure 2 shows in perspective and in a cross section a cyclone for a steam boiler.

Figure 3 shows a cooled device according to the present invention.

Figure 4 shows, in perspective, the construction of an outlet in a cyclone provided with cooled devices.

Figure 5 is a side view of the upper part of the cyclone outlet shown in Figure 4.

Figure 6 is a top view of a portion of the cyclone outlet shown in Figure 4.

Figure 7 shows a general cut of a detail in the lower part in Fig. 4.

Figure 8 shows, in cross section, part of a cyclone with a cooled outlet pipe.

Figure 9 is a schematic side view of a sand trap between a cyclone and a fireplace in a steam boiler.

Figure 10 is an enlargement of a portion of Figure 9 showing a further embodiment of the cooled device.

Figure 11 shows a cross-section of an embodiment of the cooled device used in the invention.

Figure 12 is a schematic side view of another embodiment.

Figures 13a and 13b show a further embodiment seen in side view and in a top view. 15 14 25 30 53É í-šü fi Figure 14 is a schematic side view of an embodiment in which one or more cooled devices are used as holders for one or more elements suspended in a flue gas duct.

Figure 15 shows schliematically how one or more cooled devices are used as a wall supporting elements.

Figure 16 shows diagrammatically how a partition wall can be arranged in a flue gas duct. Figure 17 shows in section a side view of an embodiment of the invention.

Figure 18 shows a variant of the embodiment shown in Figure 17.

Figures 19 ~ 30 show side views in section of different embodiments of the cooled device itself.

Figures 31a »34b show cross-sections of further embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figure 1, a steam boiler 1 is shown which includes a fireplace 6 where combustion takes place. The steam boiler 1 can, for example, be a so-called CFB boiler (Circulated Fluidizing Bed Boiler) where combustion air is supplied to the bottom. The boiler 1 has a circulation system 2 for boiler water. The circulation system 2 comprises water pipes 3, 4 which are arranged to be able to circulate boiler water through the pipes 3, 4 in a circuit where water and steam run from the fireplace 6 and up to a steam unit 5 where steam is separated from the circuit and water flows Figure 1 indicates reference numerals 3 water pipes where water and steam rise in the direction of the steam bath 5 while reference numeral 4 denotes water pipes where water flows down from the steam bath 5 in the direction of the area of the fireplace 6. The downward water pipes 4 may suitably be arranged separately from the fireplace 6, for example on the outside of the boiler 1 so that water flowing from the steam is not supplied with heat on the way down. Once down in the area of the fireplace 6, the water can then be used to absorb heat energy and transfer the heat energy on to the steam room. The circulation of boiler water in the pipes is driven by the strong heat generated in the fireplace 6. Steam-mixed water with low density rises upwards in the pipes while water with higher density from the steam 5 flows downwards.

Figure 1 and Figure 2 also show that the boiler 1 comprises a cyclone 7 which is used to separate ash and sand from the hot flue gases formed in the fireplace 6. In cyclone 7 the hot flue gases can exit through the outlet pipe 11 while sand and ash fall downwards towards the lower part 9 of the cyclone 7. Combustible material which has not been completely burnt is also separated and can return to the fireplace via the lower part 9 of the cyclone 7. The hot flue gases in the cyclone 7 constitute a great strain on in particular the outlet pipe 11. Such outlet pipes 11 are normally made of refractory sheet metal. However, the outlet pipe is susceptible to gas corrosion, especially in waste-fired boilers. It is also difficult to cope with expansion near the suspension. The result is a limited shelf life, in some cases only 2-3 years. In addition to large costs for each change, the downtime itself also entails costs in non-production. Figure 1 and Figure 2 also show how water pipes 3 for boiler water go inside the walls 8 of the eyklone 7 and from there on to the steam dome 5. Other parts of the steam boiler 1 are also exposed to stresses from the hot gases.

A cooled device 12 will now be explained with reference to Figure 3. The cooled device 12 is shown in Figure 3 as connected to a line 3 for flowing boiler water. The cooled device 12 comprises an outer tube 13 and an inner tube 14 placed in the outer tube 13. The outer tube 13 has an upper end 15, an open connection to the water line 3 for boiler water and a closed lower end 16. The inner tube 14 has an upper open end 17 which is also connected to a water pipe 3 and a lower open end 18 at the closed lower end 16 of the outer tube. In the embodiment according to Figure 3, the lower end 18 of the inner tube 14 is located at the closed lower end 18 of the outer tube 13. end 16 and both the outer pipe 13 and the inner pipe 14 are connected to the same water line 3 for boiler water. However, embodiments are conceivable in which the outer pipe 13 and the inner pipe 14 are connected to different pipes 3 for boiler water.

The cooled device 12 extends at least partially in the vertical direction downwards from the point where the outer pipe 13 is connected to a water pipe 3. Figure 1 shows how the water pipe 3 for boiler water runs horizontally. It is suitable that the cooled device 12 is connected to a place where the water line 3 is horizontal, but it should be understood that the water line 3 could be inclined upwards in the direction of flow. The operation of the cooled device 12 is as follows. As the cooled device 12 extends downwardly into an area of hot flue gases, water contained in the gap between the outer tube 13 and the inner tube 14 will have a vapor-water mixture of lower density than the water contained therein. the inner tube 14. The steam-water mixture therefore rises upwards in the gap between the outer tube 13 and the inner tube 14. The water which is inside the inner tube 14 has a higher density and will instead sink downwards. A portion of the boiler water passing in the line 3 will then be sucked down into the inner pipe 14 and then return upwards and then take up the veins gi from the area around the cooled device 12. It will be appreciated that the boiler water in the water line 3 flows from left to right in the figure shown by the arrows.

Normal water velocity in water line 3 is in the range 0.3 to 1.5 rn / s. The water velocity established in descending pipe 14 is 0.5 to 2.5 m / s and in the outer gap between pipes 13 and 14 is 0.2 to 1.0 rn / s. lO 20 25 30 35 532 311V! According to the present invention, a cooled device 12 operating according to the principle shown in Figure 3 is used to cool a selected and exposed part of the boiler 1.

Referring to Figures 1-2 and 4-8, the boiler may include a cyclone 7 for separating solids from flue gases such as ash, sand or fuel that has not been burned in the fireplace. Water pipes 3 pass the cyclone on their way up to the steam dam 5. Figure 2 shows how water pipes 3 for boiler water extend in a vertical direction from a lower part 9 of the cyclone 7 to a higher located part 10 of the cyclone 7. According to one embodiment, the outlet pipe of the cyclone 7 ll comprise at least one cooled device 12. As explained earlier in connection with Figure 3, the cooled device 12 comprises an outer tube 13 and an inner tube 14 placed in the outer tube 13. The outer tube 13 has in an upper end 15 an open connection to a water pipe 3. The cooled device 12 can then use water passing in the water pipe 3 to cool the outlet pipe 11. In an embodiment which is best seen in Figures 4-7, the outlet pipe 11 is built up of a plurality of the cooled devices 12 which were and one comprises an outer tube 13 and an inner tube 14 located in the outer tube 13.

The water pipe 3 used is suitably one of the water pipes 3 which go inside the walls 8 of the cyclone 7. In practice a number of such water pipes 3 pass through the cyclone 7 and meet higher up in the system. Figures 4 and 5 show how some water pipes 3a are allowed to continue directly upwards when they reach the area of the outlet pipe 11 while other water pipes 3b go to the cooled devices 12 which have an outer pipe 13 and an inner pipe 14 shown in Figs. In Figures 4 and 5, the inflow 3in to the conduits 3a, 3b is established towards the pipe ends lying in a horizontal plane, directed towards the center of the cyclone, and the outlet 3out is established at the pipe ends which are directed vertically in the figure. It is proposed that every other water line 3b may be allowed to reach the cooled devices 12. The cooled devices 12 can then be arranged side by side so that they together form an outlet pipe 11 for hot flue gases as shown in Figure 4.

The function of this embodiment is best seen in Figure S. As shown in Figure 8, boiler water rises upwards in water pipes 3 which run inside the walls of the cyclone 7. When the water reaches the area of the outlet pipe 11, some of the boiler water will go down into the cooled devices 12 forming the outlet pipe 11. This boiler water will move downwards into the inner pipe 14 of the cooled devices 12 while the steam-water mixture due to its lower density will to move upwards in the outer gap between tube 13 and tube 14. Figure 8 also indicates how the cooled devices 12 at their lower end are connected to each other by an annular tube 33.

The cooled device 12 can thus in itself form durable parts of the steam boiler 1 which are exposed to heat. Alternatively, one can also use the cooled device 1 to cool an element such as 15 L? in? P0 when using the boiler 1 is exposed to hot flue gases (directly or indirectly). Such an embodiment will now be explained with reference to Figure 9 and Figure 10. Figure 9 shows a sand trap located in the lower part of the cyclone 7. The sand trap comprises a wall 19 which during operation of the steam arm 1 is subjected to large stresses due to strong heat. As shown in Figure 10, a cooled device 12 according to the present invention is placed inside the wall 19 in the portion XIII marked in Figure 9. It should be noted that the cooled device 12 in the wall 19 of the sand lock is constructed in the same way as the cooled device 12 in Figure 3 and works in the same way.

The cooled device 12 is connected to a line 3 for boiler water which rises inside the walls 8 of the cyclone 7 and part of this boiler water is thus used to cool a wall 19 in the sand trap of the cyclone 7. It can be noted that the water line 3 after the cooled device 12 continues vertically upwards while the line towards the cooled device runs horizontally.

Another embodiment is shown in Figure 11. In the embodiment shown in Figure 11, a through pipe 21 has been passed through the outer wall of the water line 3 and through the inner pipe 14 of the cooled device 12. At its lower end, the through pipe 21 connects to the cooled the outer pipe 13 of the device 12. The through pipe 21 constitutes an element which can be used to introduce additives into the boiler or to suck out flue gases for sampling. Without the cooled device 12, the hot flue gases would act unhindered on this element. The cooled device 12 can now cool the continuous pipe and help to increase its service life.

Another embodiment will now be explained with reference to Figure 12 and Figure 27. In embodiments with an inner through-pipe 21, a thermocouple 20 can be inserted through the through-pipe 21. The thermocouple is then kept cooled by means of the cooled device 12.

Another embodiment will now be explained with reference to Figures 13a and 13b. Figure 13a shows how a number of dust separation beams are designed by hanging a plurality of cooled devices 12 as cooled separation beams in a flue gas duct. The cooled devices 12 may conveniently be suspended in the flue gas duct 23 so as to form a sparse row in the manner shown in Figure 13b. It is to be understood that the cooled devices 12 in Figure 13a are constructed according to the same principle as shown in Figure 3 with an outer tube 13 and an inner tube 14. It is also to be understood that a boiler water line 3 where water fl desolation is established is connected to the the cooled devices of Figure 13a. As shown in Figure 13b, the cooled devices used as partition beams may be provided with outer rails 28 extending along the cooling devices 12. The outer rails 28 help to capture particles, for example ash particles which then fall downwards. A further embodiment is shown in Figure 14. Figure 14 shows how an element 24 in a flue gas duct 23 can be suspended in the flue gas duct 23 in a cooled device 12 which then acts as a holder for this element. The element 24 may be, for example, a tube structure as part of a superheater or economizer. The holder for the tube construction 24 is then cooled and can better withstand heat loads.

Another embodiment is shown in Figure 15. A separately fired superheater 35 is supported here by a wall formed by cooled devices 12, each of which comprises an outer and an inner tube according to the principle stated in Figure 3. It should of course be understood that the cooled devices 12 are also here connected to a water line 3 for boiler water where a water de fate is established. Figure 16 shows an embodiment in which a plurality of cooled devices 12 are allowed to form a partition wall in a flue gas duct, which partition wall separates a part of the flue gas duct 23 from another.

The partition wall here has an increased service life due to its ability to withstand heat. It should of course be understood that also these cooled devices 12 have an outer and an inner tube according to the principle shown in Figure 3 and that they are connected to a pipe 3 for boiler water.

Figure 17 shows schematically how a number of cooled devices 1.2 can be connected to a water pipe 3, for example to form a row of partition beams according to Figures 13a and 13b or a partition wall according to Figure 16.

Figure 18 shows a variant of the arrangement shown in Figure 17. Figure 17 shows how the inner pipe 14 in which water flows down is connected to a different water pipe 3 than the outer pipe 13 in which a water-vapor mixture of lower density moves upwards. Boiler water flows here in a first water pipe 3 and goes down via the inner pipe 14 and up into the gap between pipe 13 and pipe 14 in one or more of the cooled devices 12 into another water pipe 3.

Some further embodiments will now be explained with reference to Figures 19 - 21. In conventional Fields boilers, the cooling pipes are designed to facilitate boiler water to be sucked into the inner pipe 14. Thus, the inner pipe 14 at its upper end 17 can be formed as a funnel 29. to reduce the pressure drop in this part and to some extent direct the rising steam-water mixture away from the inlet of the inner pipe. This embodiment can also be applied when the cooled devices 12 are connected to a water pipe with boiler water where a water fate is established.

In the embodiments according to Figure 20, the effect of the water solder in the pipe 3 is utilized. Here, the inner pipe 14 at its upper end has been given a mouth which is oblique in relation to the longitudinal axis of the pipe. This is so that water flowing from left to right in Figure 20 makes it easier to flow into the inner tube 14 and establishes a static pressure against the inlet of the inner tube. 10 15 20 25 30 E32 3Û'l In the embodiments according to Figure 21, the embodiments are adapted to an established water fl fate in the pipe 3 which to some extent may contain steam. Here, the connection of the cooled device 12 to the water pipe 3 has been placed in an area 31 of the water pipe 3 where the lower side of the water pipe 3 has been widened to meet the outer pipe 13. This lowered position is advantageous if the water pipe 3 contains a lot of steam.

Another aspect will now be explained with reference to Figures 22 ~ 25 where the effect of the water flow in the pipe 3 is utilized. In a cooling device 12 which is connected to a water line 3, it is desirable to form steam in the boiler water which has already passed through the cooled the outer tube 13 of the device 12 is not again sucked into the inner tube 14.

Figure 22 shows how a lid 32 has been arranged at the upper end 15 of the outer tube to cover a part of the gap area between the outer tube 13 and the inner tube 14. When the flow in the water line 3 goes from left to right in Figure 22 it is understood that the lid 32 prevents steam in the outer pipe 13 from entering the water line 3 in this area. The steam instead goes out to the right in the fi gure, ie the steam continues in the water pipe. Instead, boiler water coming from the left in the figure under suction pressure over the inlet is sucked down into the inner pipe 14. The lid also provides a non-vector effect on the steam-water mixture flowing out of the outer tube as the flow rate increases in this area.

Figure 23 shows a similar embodiment, but the lid 32 is here extended. The idea here is that the water flow past with some enhanced ejector effect should entrain the steam and water mixture leaving the cooled device 12.

In the embodiment according to Figure 24, it is shown how the inner tube 14 at its upper end is inclined in the direction of the wall of the outer tube 13. Here, too, the ninth achieves a reduction in the risk of steam being sucked into the inner tube 14.

The embodiment according to Figure 25 shows how to combine the embodiment according to Figure 24 with the embodiment according to Figure 21.

Figure 26 shows an embodiment which is in principle the same as the embodiment according to Figure 21.

In addition, a continuous through-pipe 21 has been added here, which can be used to suck samples out of the steam boiler or to add an additive.

Figure 27 shows an embodiment which is similar to that of Figure 26 but in which the continuous pipe 21 has also been used to insert a tin element 20.

Figure 28 shows an embodiment similar to that of Figure 27, but here a drainage pipe 36 has also been added which can be used to drain the cooled device 12. Figure 20 shows an embodiment in which the inner pipe 14 is placed at the inner wall of the outer tube 13. Also in this way one can reduce the risk of steam being sucked down into the inner tube 14.

Optionally, the inner tube 14 may have a trailing edge 37 at the side of the inner tube 14 which is downstream in the flow direction of the water line 3. The rear edge 37 projecting on the downstream side also helps to reduce the risk of steam being sucked into the inner tube 14.

According to the embodiment shown in Figure 30, the inner tube 14 in its upper part has been divided straight off. The reference numeral 38 denotes holders for the inner tube 14.

Figures 31a and 3b show an embodiment in which the cooled devices 12 are arranged connected to a common upper box 39 which is at an angle in relation to the water line 3 for boiler water. The cooled devices 12 together form a wall which can be, for example, a partition. The cooled devices 12 may be connected to each other by connecting pieces 40 which may be constituted by, for example, welded plates or flat iron.

Figures 32a and 32b show an embodiment similar to that of Figure 31a but where the lower ends of the cooled devices 12 are further connected by a common lower box 34 which at the same time forms a common lower closed end for the outer pipes 13.

Figures 33a and 33b show an embodiment which is in principle the same as that in Figure 32a, but also shows a drainage pipe 36 which is lowered through an inner pipe 14 in a cooling device 12.

Figures 34a and 34b show an embodiment which differs from the embodiment according to Figure 33a in that the drainage pipe 36 does not run through an inner pipe 14 but that one of the outer pipes in a row of the cooled devices contains only one drainage pipe. The flow of water down into the cooled devices 12 here takes place in the inner tubes 14 of the other cooled devices.

It is to be understood that the embodiments shown in the figures can be used in steam boilers of different types and in principle everywhere where one has a heated space or a part which is exposed to heating and where at the same time one has a fl fate of water in a pipe passing by it area or the part that needs to be cooled.

The invention achieves a simple way of cooling parts which are exposed to strong heat. When the invention is applied to the outlet pipe in a cyclone, the advantage is achieved that one can utilize the existing fl fate of boiler water and one does not need a special pipe which is led into the cyclone from the outside with the additional complications that this entails. In addition, you can manage without a separate pump for the fate of cooling water.

Claims (1)

1. 5 20 25 30 53.2 'Ešü fi PATENTKRAV. A steam generator (1) with a fireplace (6) and a boiler water circulation system, which circulation system (2) comprises water pipes (3, 4) arranged to be able to circulate boiler water and steam through the pipes (3, 4) in the operation of the boiler (1). a circuit and which steam arm (1) comprises a cooled device (12) arranged to cool a selected and exposed part of the steam boiler (1), characterized in that the cooled device comprises an outer tube (13) and an inner tube (14) located in the outer pipe (13) and which outer pipe (13) in an upper end (15) has an open connection to a water pipe (3) for boiler water and a closed lower end (16) and the inner pipe (14) has an upper open end (17) connected to this water line (3) for boiler water and a lower open end (18) at the closed lower end (16) of the outer tube (13) and the cooled device (12) extends at least partially in vertical downward direction from the point where the outer tube (13) is connected to it water supply (3). . A steam boiler (1) according to claim 1, characterized in that the cooled device (12) is arranged to cool an element (19, 20, 21) which, when using the steam boiler (1), is exposed to hot gases. . A steam boiler (1) according to claim 2, characterized in that said elements (19, 20, 21) which when exposed to the steam boiler (1) are exposed to hot gases consist of a wall (19) in the boiler (1) and of that the cooled device (12) is arranged inside said wall (19). . A steam boiler (1) according to claim 2, characterized in that said element which, when using the steam boiler (1), is exposed to hot gases consists of a tin element (20). . A steam boiler (1) according to claim 2, characterized in that said element which, when using the steam boiler (1) is exposed to hot gases, consists of a continuous pipe (21) extending through the pipe (3) for boiler water, through the cooled device (12) inner tube (14) and at its outermost end connects to the outer tube (13) of the cooled device (12). A steam boiler (1) according to claim 1, characterized in that the steam boiler (1) comprises a cyclone (7) for separating ash from hot flue gases which cyclone (7) has an outlet pipe (11) for the hot gases and in that it the cooled device (12) is arranged to cool the outlet pipe (11). 20 25 30 10. 11. 12. 13. 14. 15. 16. 532 BEN! A steam boiler (1) according to claim 6, characterized in that the outlet pipe (1 1) is built up of a plurality of cooled devices (12), which cooled devices (12) each comprise an outer pipe (13) and an inner pipe (14 ). A meadow boiler (1) according to any one of claims 6 or 7, characterized in that at least some of the pipes (3) for boiler water go inside the walls (8) of the eyklon (7) and extend in the vertical direction from a lower part (9) of cycloiiii (7) to a higher part (10) of the cyclone (7) and of some of the boilers (3) for boiler water extending into the walls (8) of the cyclone (7) being connected to the cooled devices ( 12) with an outer tube (13) and an inner tube (14). A steam boiler (1) according to claim 1, characterized in that the steam boiler (1) has walls forming a flue gas duct (23) and in that the cooled device (12) constitutes a holder for an element (24) which is suspended in the flue gas duct (23). A steam boiler (1) according to claim 1, characterized in that the steam boiler has walls forming a flue gas duct and in that the cooled device (12) together with a number of identical of the cooled devices (12) form a partition wall separating two parts of the flue gas duct (23) apart. A meadow boiler (1) according to claim 1, characterized in that the meadow boiler (1) has walls (22) which form a flue gas duct (23) and in that the cooled device (12) is placed in a flue gas duct as a separating beam and is provided with outer rails (28). A steam boiler (1) according to claim 1, characterized in that the upper end (17) of the inner tube (14) is funnel-shaped. A steam boiler (1) according to claim 1, characterized in that the inner tube (14) at its upper end (15) has an orifice which is inclined relative to the longitudinal axis of the inner tube (14). A steam pair (1) according to claim 1, characterized in that the connection to the boiler water line (3) is located in an area (31) where the lower side of the boiler line (3) has been widened to meet the outer pipe (13). A steam boiler (1) according to claim 1, characterized in that, at the upper end (15) of the outer tube (13), a lid (32) is arranged to cover a part of the gap area between the outer (13) and the inner tube. (14). A steam boiler (1) according to claim 1, characterized in that the inner tube (14) at its upper end is inclined towards the wall of the outer tube (13).