Flue boiler
By installing a protective plate on the front side of the evaporator header pipe of the flue gas boiler, the problem of liquid leakage caused by wear of the header pipe was solved, the service life was extended and the heat exchange efficiency was improved.
Patent Information
- Application Number
- CN202520501494.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2035-03-21
AI Technical Summary
The header pipes of the evaporator in a flue boiler are often damaged, leading to leaks.
A protective plate is installed in front of the header pipe of the evaporator. The protective plate covers part or all of the projection of the header pipe. The protective plate is made of wear-resistant and high-temperature resistant material to protect the header pipe from being worn by dust in the flue gas.
It extends the service life of the header piping, reduces the risk of leakage, and improves the reliability and heat exchange efficiency of the flue boiler.
Smart Images
Figure CN223882299U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of boilers, and particularly relates to a flue boiler. BACKGROUND
[0002] The sintering operation area of the ironmaking operation department of Beijing Shougang Stock Company Limited has two 360m2 sintering machines (2# sintering machine and 3# sintering machine). In the 18#-22# air box of the 3# sintering machine, a flue boiler with a rated evaporation capacity of 20T / H (QC106.6(84.4) / 495(438.5)-20-2.35 / 320) is built.
[0003] The flue boiler is a boiler in which high-temperature flue gas exchanges heat with water in a pipe bundle to generate steam. The steam-water mixture rises along the pipe bundle into the upper and lower steam drums. After the steam is separated, the water re-enters the lower steam drum along the non-heated downcomer to form a natural circulation. The generated steam is used for power generation by a steam turbine unit.
[0004] During the use of the flue boiler, the applicant found that the header pipe of the evaporator of the flue boiler is often damaged, resulting in liquid leakage. CONTENT OF THE UTILITY MODEL
[0005] The present application aims to at least solve the technical problem that the header pipe of the evaporator of the flue boiler is often damaged. To this end, the present application provides a flue boiler.
[0006] The flue boiler provided by the embodiments of the present application comprises:
[0007] A furnace shell having a mounting cavity and an air inlet and an air outlet in communication with the mounting cavity;
[0008] An evaporator installed in the mounting cavity, wherein the heat exchange pipe of the evaporator is oppositely arranged with the air inlet;
[0009] A protective plate installed on the evaporator and / or the furnace shell, wherein the protective plate is arranged on the front side of the header pipe of the evaporator in the direction from the evaporator to the air inlet, and at least part of the projection of the header pipe is located on the protective plate.
[0010] In some embodiments, the projection of the header pipe is entirely located on the protective plate in the direction from the evaporator to the air inlet.
[0011] In some embodiments, the heat exchange pipe comprises a finned tube and an elbow pipe, the elbow pipe is arranged between the finned tube and the header pipe, and is in communication with the finned tube and the header pipe; at least part of the projection of the elbow pipe is located on the protective plate in the direction from the evaporator to the air inlet.
[0012] In some embodiments, the projection of the elbow pipe is located on the shield plate in the direction from the evaporator to the air inlet.
[0013] In some embodiments, the evaporator has a plurality of header pipes arranged at intervals in the direction from the evaporator to the air inlet; the smoke boiler is provided with a plurality of shield plates, and each of the plurality of shield plates is arranged at the front side of each of the header pipes.
[0014] In some embodiments, the lower end of the shield plate is inclined towards the header pipe.
[0015] In some embodiments, the smoke boiler further comprises a deflector, which is installed on the evaporator and / or the furnace shell, and the deflector is located below the side of the evaporator close to the air inlet.
[0016] In some embodiments, the two ends of the deflector extend beyond the header pipe in the length direction of the header pipe.
[0017] In some embodiments, the smoke boiler further comprises an ash bucket, which is arranged below the evaporator, and the deflector and / or the shield plate are located above the ash bucket.
[0018] In some embodiments, the smoke boiler further comprises a flap valve arranged at the ash outlet of the ash bucket.
[0019] The utility model has at least the following beneficial effects:
[0020] In the direction from the evaporator to the air inlet, the shield plate is arranged at the front side of the header pipe of the evaporator, and at least part of the projection of the header pipe is located on the shield plate. In this way, when the flue gas enters from the air inlet, it passes through the gap between the heat exchange pipes and exchanges heat with the heat exchange pipes. When the gap between the heat exchange pipes is blocked by the ash layer or the like, and the flue gas flows along the dust on the surface of the heat exchange pipes to the two ends of the heat exchange pipes, due to the presence of the shield plate, the flue gas is at least partially blown on the shield plate, and at least part of the header pipe is shielded by the shield plate. The shield plate provides protection for at least part of the header pipe, and the shield plate replaces the header pipe to be worn by the dust in the flue gas, thereby protecting the header pipe, prolonging the service life of the header pipe, and reducing the risk of liquid leakage. BRIEF DESCRIPTION OF DRAWINGS
[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.
[0022] Figure 1 A structural schematic diagram of a flue boiler in one or more embodiments of the present application is shown.
[0023] Figure 2 A structural schematic diagram of a flue boiler in one or more embodiments of the present application is shown. Figure 1 An enlarged view of A in the above figure.
[0024] Figure 3 A structural schematic diagram of a flue boiler in one or more embodiments of the present application is shown.
[0025] Figure 4 A structural schematic diagram of a flue boiler in one or more embodiments of the present application is shown. Figure 1 A structural schematic diagram of B in the above figure.
[0026] Figure 5 A structural schematic diagram of a flue boiler in one or more embodiments of the present application is shown.
[0027] The drawings show: 100 - flue boiler, 110 - furnace shell, 110a - mounting cavity, 110b - air inlet, 110c - air outlet, 120 - evaporator, 121 - heat exchange pipeline, 1211 - finned tube, 1212 - elbow, 122 - header pipeline, 130 - protection plate, 140 - guide plate, 150 - ash hopper, 150a - ash outlet, 160 - flap valve, 170 - induced draft fan. DETAILED DESCRIPTION
[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0029] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative positional relationship, movement condition and the like between components in a certain specific posture, and if the specific posture changes, the directional indications also change accordingly.
[0030] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal connection of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0031] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.
[0032] The applicant of the present application finds that the header pipe of the evaporator of the flue boiler is often damaged and leaks. After the applicant analyzes, the evaporator includes a plurality of heat exchange pipes and a plurality of header pipes, and one header pipe simultaneously communicates a plurality of heat exchange pipes. The header pipe is arranged at both ends of the heat exchange pipe, and the heat exchange pipe mainly performs heat exchange. Due to the serious environmental protection situation, the sintering machine raw material needs to add the solid waste which cannot be used in the factory area. Because the solid waste contains alkali, the dust content in the flue is greatly increased, which causes the gap between each heat exchange pipe of the windward surface of the evaporator to be basically blocked by dust. As shown in Figure 5 , thereby changing the route of the flue gas, so that most of the flue gas flows to both ends of the heat exchange pipe, and the header pipe is located at both ends of the heat exchange pipe. Therefore, the dust in the flue gas continuously erodes the surface of the header pipe, so that the surface of the header pipe is continuously abraded, the wall of the header pipe becomes thinner and thinner, causing the header pipe to be damaged. After the header pipe is worn out, the liquid in the header pipe will leak.
[0033] On the basis of finding the above problems and analyzing the causes of the above problems, the applicant of the present application designs the flue boiler of the present application. The flue boiler provided in the embodiments of the present application can at least solve the technical problem that the header pipe of the evaporator of the flue boiler is often damaged to a certain extent.
[0034] The present application will be described below in conjunction with the accompanying drawings and specific embodiments:
[0035] As Figure 1 , Figure 2 and Figure 4As shown, the flue boiler 100 comprises a furnace shell 110, an evaporator 120 and a shield plate 130. The furnace shell 110 has a mounting cavity 110a, and an air inlet 110b and an air outlet 110c which are in communication with the mounting cavity 110a. The evaporator 120 is mounted in the mounting cavity 110a, and the heat exchange pipe 121 of the evaporator 120 is oppositely arranged with the air inlet 110b. The shield plate 130 is mounted on the evaporator 120 and / or the furnace shell 110, and is arranged at the front side of the header pipe 122 of the evaporator 120 in the direction from the evaporator 120 to the air inlet 110b, and at least part of the projection of the header pipe 122 is located on the shield plate 130.
[0036] The structure of the flue boiler 100 is known to those skilled in the art, and it usually further comprises a superheater which is also mounted in the mounting cavity 110a, and the superheater is located at the side of the evaporator 120 close to the air inlet 110b. When the flue boiler 100 is in working state, the flue gas of the sintering machine air bellow enters the furnace shell 110 through the air inlet 110b, and then enters the superheater and the evaporator 120 in sequence, and the flue gas enters the next process after heat exchange in the evaporator 120. In some embodiments, the flue boiler 100 further comprises a desuperheater, a steam collecting header, a blowdown flash tank and the like, which are not limited in the present application.
[0037] The furnace shell 110 functions to form a flow channel for flue gas and support the evaporator 120, the superheater and the like located therein. Specifically, the furnace shell 110 has the mounting cavity 110a, and the air inlet 110b and the air outlet 110c which are in communication with the mounting cavity 110a, and the mounting cavity 110a, the air inlet 110b and the air outlet 110c form the flow channel, and the evaporator 120 is located in the mounting cavity 110a.
[0038] The heat exchange pipe 121 of the evaporator 120 is oppositely arranged with the air inlet 110b, so that the flue gas entering the air inlet 110b can directly act on the heat exchange pipe 121 and exchange heat with the liquid in the heat exchange pipe 121, thereby ensuring the efficiency of heat exchange.
[0039] The shield plate 130 can be mounted on the evaporator 120, or mounted on the furnace shell 110, or mounted on both the evaporator 120 and the furnace shell 110. It is easy to understand that the shield plate 130 is located in the mounting cavity 110a. Figure 1The direction of X in the figure is the direction from the evaporator 120 to the air inlet 110b. In the direction from the evaporator 120 to the air inlet 110b, the protection plate 130 is arranged at the front side of the header pipe 122 of the evaporator 120, and at least part of the projection of the header pipe 122 is located on the protection plate 130. In this way, the flue gas entering from the air inlet 110b passes through the gap between the heat exchange pipes 121 and exchanges heat with the heat exchange pipes 121. When the gap between the heat exchange pipes 121 is blocked by an ash layer or the like, the flue gas flows along the surface of the heat exchange pipes 121 to the ends of the heat exchange pipes 121. Due to the presence of the protection plate 130, the flue gas at least partially blows on the protection plate 130, and at least part of the header pipe 122 is shielded by the protection plate 130. The protection plate 130 provides protection to at least part of the header pipe 122. The protection plate 130 replaces the header pipe 122 to be worn by the dust in the flue gas, thereby protecting the header pipe 122, prolonging the service life of the header pipe 122, and reducing the risk of liquid leakage.
[0040] In order to ensure the service life of the protection plate 130, the protection plate 130 can be made of wear-resistant and high-temperature-resistant materials, such as high-hardness alloy or ceramic composite material. In addition, the protection plate 130 can be designed to be relatively thick.
[0041] In some embodiments, the protection plate 130 can be detachably installed on the evaporator 120 and / or the furnace shell 110, so as to facilitate replacement of the protection plate 130 after wear.
[0042] In some embodiments, in the direction from the evaporator 120 to the air inlet 110b, the projection of the header pipe 122 is located on the protection plate 130. In this way, in the direction from the air inlet 110b to the evaporator 120, the protection plate 130 completely shields the header pipe 122, thereby protecting the header pipe 122 and prolonging the service life of the header pipe 122.
[0043] In some embodiments, the heat exchange pipe 121 includes a finned tube 1211 and an elbow pipe 1212. The elbow pipe 1212 is arranged between the finned tube 1211 and the header pipe 122, and is connected to the finned tube 1211 and the header pipe 122. In the direction from the evaporator 120 to the air inlet 110b, at least part of the projection of the elbow pipe 1212 is located on the protection plate 130.
[0044] The finned tube 1211 includes a heat exchange tube and a plurality of fins arranged on the surface of the heat exchange tube. The fins can increase the outer surface area of the heat exchange tube, so as to improve the heat exchange efficiency. Moreover, the fins can protect the heat exchange tube to some extent, and reduce the abrasion rate of the heat exchange tube. The elbow pipe 1212 connects the finned tube 1211 and the header pipe 122. When the gap between the heat exchange pipes 121 is blocked by ash layer or the like, and the flue gas flows along the surface of the heat exchange pipes 121 to the two ends of the evaporator 120, the elbow pipe 1212 will also be abraded by the dust, and has the risk of oil leakage. In these embodiments, in the direction from the evaporator 120 to the air inlet 110b, at least part of the projection of the elbow pipe 1212 is located on the protective plate 130. In this way, the flue gas entering from the air inlet 110b passes through the gap between the heat exchange pipes 121, and exchanges heat with the heat exchange pipes 121. When the gap between the heat exchange pipes 121 is blocked by ash layer or the like, and the flue gas flows along the surface of the heat exchange pipes 121 to the two ends of the heat exchange pipes 121, due to the existence of the protective plate 130, the flue gas is at least partially blown on the protective plate 130, and at least part of the elbow pipe 1212 is shielded by the protective plate 130. The protective plate 130 provides protection for at least part of the elbow pipe 1212. The protective plate 130 replaces the elbow pipe 1212 to be abraded by the dust in the flue gas, so as to protect the elbow pipe 1212, prolong the service life of the elbow pipe 1212, and reduce the risk of oil leakage of the elbow pipe 1212.
[0045] In some embodiments, in the direction from the evaporator 120 to the air inlet 110b, the projection of the elbow pipe 1212 is entirely located on the protective plate 130. In this way, in the direction from the air inlet 110b to the evaporator 120, the protective plate 130 completely shields the elbow pipe 1212, and provides protection for each part of the elbow pipe 1212, so as to prolong the service life of the elbow pipe 1212.
[0046] In some embodiments, in the direction from the evaporator 120 to the air inlet 110b, the evaporator 120 has a plurality of header pipes 122 arranged at intervals. In these embodiments, one protective plate 130 is arranged, and the protective plate 130 is located on the front side of the header pipe 122 closest to the air inlet 110b. Since the header pipe 122 closest to the air inlet 110b first contacts the high-flow flue gas, and has the greatest risk of abrasion, when only one protective plate 130 is arranged, the header pipe 122 closest to the air inlet 110b can be preferentially protected. This design helps to reduce the amount of the protective plate 130, and reduce the cost.
[0047] In some embodiments, the evaporator 120 has a plurality of header pipes 122 arranged at intervals in the direction from the evaporator 120 to the air inlet 110b; the flue boiler 100 is provided with a plurality of protective plates 130, and each protective plate 130 is arranged at the front side of each header pipe 122. Each protective plate 130 is arranged at the front side of each header pipe 122 to shield each header pipe 122, thereby improving the overall reliability and durability of the flue boiler 100 and ensuring the heat exchange efficiency of the evaporator 120 and the stable operation of the flue boiler 100.
[0048] The end surface of the protective plate 130 facing the air inlet 110b is a windward surface, and the windward surface of the protective plate 130 can be designed to be streamlined to ensure smooth flue gas flow while taking into account the protection effect and heat exchange efficiency. If the windward surface is designed to be streamlined, the surface processing precision of the protective plate 130 is relatively high, which increases the production cost of the flue boiler 100. For example, as shown in FIG. 1, in some embodiments, the lower end of the protective plate 130 is inclined toward the header pipe 122 at an angle of 10° to 30°. The protective plate 130 is a flat plate, which simplifies the processing procedure, and the angle of 10° to 30° of the lower end inclined toward the header pipe 122 can guide the flue gas flow to ensure smooth flue gas flow and to a certain extent, avoid the local wear of the protective plate 130 from being intensified. Figure 3
[0049] In some embodiments, the flue boiler 100 further comprises a flow guide plate 140, and the flow guide plate 140 is installed on the evaporator 120 and / or the furnace shell 110. The flow guide plate 140 is located below the side of the evaporator 120 close to the air inlet 110b.
[0050] The flow guide plate 140 can be installed on the evaporator 120, or installed on the furnace shell 110, or installed on both the evaporator 120 and the furnace shell 110. The flow guide plate 140 is located below the evaporator and on the side of the evaporator 120 close to the air inlet 110b, as shown in FIG. 1. Figure 2 After the flue gas passes through the protective plate 130, it reaches the flow guide plate 140 and flows downward along the flow guide plate 140. In this way, at least part of the flue gas flows downward under the guidance of the protective plate 130, thereby moving away from the header pipe 122 and to a certain extent, slowing down the wear of the lower end of the header pipe 122, thereby prolonging the service life of the header pipe 122.
[0051] In some embodiments, as shown in FIG. 1, the lower end of the flow guide plate 140 is inclined toward the air outlet 110c at an angle of 10° to 30°. The flow guide plate 140 is a flat plate, which simplifies the processing procedure, and the angle of 10° to 30° of the lower end inclined toward the air outlet 110c can guide the flue gas flow to ensure smooth flue gas flow. Figure 3 In some embodiments, as shown in FIG. 1, the lower end of the flow guide plate 140 is inclined toward the air outlet 110c at an angle of 10° to 30°. The flow guide plate 140 is a flat plate, which simplifies the processing procedure, and the angle of 10° to 30° of the lower end inclined toward the air outlet 110c can guide the flue gas flow to ensure smooth flue gas flow.
[0052] like Figure 4 As shown, in some embodiments, both ends of the guide plate 140 extend beyond the manifold 122 along its length. This design ensures that the flue gas at all points along the length of the manifold 122 is guided by the guide plate 140, and that all points along the length of the manifold 122 are protected to a certain extent by the guide plate 140, reducing the risk of localized wear caused by flue gas scouring and improving the durability of the manifold 122.
[0053] In some embodiments, such as Figure 3 As shown, along the direction from the evaporator 120 to the air inlet 110b, the projections of the protective plate 130 and the guide plate 140 have an overlapping area. This design can reduce the amount of flue gas flowing through the gap between the protective plate 130 and the guide plate 140 in the height direction, ensuring that most of the flue gas flows downward along the guide plate 140.
[0054] In some embodiments, the flue gas boiler 100 further includes an ash hopper 150, which is disposed below the evaporator 120, with the guide plate 140 and / or the protective plate 130 located above the ash hopper 150. When dust in the flue gas impacts the guide plate 140 and the protective plate 130, its kinetic energy decreases, and it falls under gravity. With the ash hopper, the dust can fall into the ash hopper 150 and be collected. The ash hopper is conical, with a larger upper end and a smaller lower end. The upper end has an ash inlet communicating with the mounting cavity 110a. The guide plate 140 and / or the protective plate 130 are located above the ash inlet. The lower end has an ash outlet 150a communicating with the ash inlet, through which dust is discharged.
[0055] In some embodiments, the flue boiler 100 further includes a flap valve 160 disposed at the ash outlet 150a of the ash hopper 150. With this design, the flap valve 160 can control the opening and closing of the ash outlet 150a. When the amount of dust in the ash hopper 150 reaches a certain level, the flap valve 160 is opened, allowing the dust to be discharged through the ash outlet 150a. When the amount of dust in the ash hopper 150 is low, the flap valve 160 is closed to prevent flue gas from being discharged from the ash outlet 150a, thus avoiding impact on heat exchange efficiency.
[0056] In some embodiments, the flue gas boiler 100 further includes an induced draft fan 170 disposed at the outlet 110c. The induced draft fan 170 guides the flue gas to flow in the direction from the inlet 110b to the outlet 110c, thereby increasing the flue gas movement rate and ensuring heat exchange efficiency.
[0057] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate different embodiments or examples described in the specification.
[0058] In addition, the technical solutions among various embodiments can be combined with each other, but it must be based on the fact that a person skilled in the art can realize the combination, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.
[0059] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.
Claims
1. A flue boiler, characterized in that The application relates to a boiler (100) comprising: a furnace shell (110) having a mounting cavity (110a) and an air inlet (110b) and an air outlet (110c) communicating with the mounting cavity (110a); an evaporator (120) mounted in the mounting cavity (110a), wherein a heat exchange pipe (121) of the evaporator (120) is oppositely arranged with the air inlet (110b); a protection plate (130) mounted on the evaporator (120) and / or the furnace shell (110), wherein the protection plate (130) is arranged on a front side of a header pipe (122) of the evaporator (120) along a direction from the evaporator (120) to the air inlet (110b), and at least a part of a projection of the header pipe (122) is located on the protection plate (130).
2. The flue boiler according to claim 1, characterized in that The projection of the header pipe (122) is entirely located on the protection plate (130) along the direction from the evaporator (120) to the air inlet (110b).
3. A flue boiler according to any of claims 1-2, characterised in that The heat exchange pipe (121) comprises a finned tube (1211) and a bend pipe (1212), wherein the bend pipe (1212) is arranged between the finned tube (1211) and the header pipe (122) and communicates with the finned tube (1211) and the header pipe (122), and at least a part of a projection of the bend pipe (1212) is located on the protection plate (130) along the direction from the evaporator (120) to the air inlet (110b).
4. The flue boiler according to claim 3, characterized in that The projection of the bend pipe (1212) is entirely located on the protection plate (130) along the direction from the evaporator (120) to the air inlet (110b).
5. A flue boiler according to any of claims 1-2, characterised in that The evaporator (120) has a plurality of header pipes (122) arranged at intervals along the direction from the evaporator (120) to the air inlet (110b), and the boiler (100) is provided with a plurality of protection plates (130), wherein each of the protection plates (130) is arranged on a front side of a corresponding header pipe (122).
6. A flue boiler according to any of claims 1-2, characterised in that The lower end of the protection plate (130) is inclined towards the header pipe (122).
7. A flue boiler according to any of claims 1-2, characterised in that The boiler (100) further comprises a flow guide plate (140) mounted on the evaporator (120) and / or the furnace shell (110), wherein the flow guide plate (140) is arranged below a side of the evaporator (120) close to the air inlet (110b).
8. The flue boiler according to claim 7, characterized in that Both ends of the flow guide plate (140) protrude from the header pipe (122) along the length direction of the header pipe (122).
9. The flue boiler according to claim 7, characterized in that The boiler (100) further comprises an ash hopper (150) arranged below the evaporator (120), and the flow guide plate (140) and / or the protection plate (130) are arranged above the ash hopper (150).
10. The flue boiler according to claim 9, characterized in that The boiler (100) further comprises a flap valve (160) arranged at an ash outlet (150a) of the ash hopper (150).