Ash collecting device of biomass boiler
By designing an ash collection device in a membrane wall boiler and optimizing flue gas flow using an arc-shaped ash collection plate and a top baffle, the problem of difficult ash collection and cleaning was solved, achieving efficient ash collection and improved heat transfer efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG NORTH GREEN TECHNOLOGY CO LTD
- Filing Date
- 2025-04-24
- Publication Date
- 2026-04-21
AI Technical Summary
The collection and cleaning of flue ash in existing membrane wall boilers is difficult, especially in small gas or biomass boilers. Uneven flue gas velocity makes it difficult for particles to settle, and ash is easy to clog or corrode the tube wall. Furthermore, slag and ash accumulation are difficult to clean, affecting heat transfer efficiency and increasing energy consumption.
Design an ash collection device including an arc-shaped ash collection plate and a top baffle. It utilizes the flow of flue gas to create a low-speed zone to allow the ash to settle, and the ash slides down to the collection box through a vibrating end. The combined structure of the arc-shaped ash collection plate and the baffle optimizes the flow of flue gas and enhances the ash collection effect.
It achieves efficient collection and cleaning of soot, reduces ash and slag accumulation on pipe walls, improves heat transfer efficiency, reduces energy consumption, and simplifies the cleaning process.
Smart Images
Figure CN224150959U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of flue gas ash collection technology for membrane wall boilers, and particularly relates to an ash collection device for biomass boilers. Background Technology
[0002] For small gas-fired or biomass boilers, existing membrane wall boilers present challenges in collecting and cleaning flue ash. On the one hand, the structure of membrane wall boilers results in uneven distribution of flue gas velocity. The flue of membrane wall boilers is usually composed of closely arranged water-cooled wall tubes with smooth surfaces and small gaps, which can easily lead to excessively high flue gas velocity in some areas or the formation of eddies, affecting the uniform settling of dust. As a result, in the high-speed zone of flue gas flow, particles are carried by the airflow and are difficult to settle; in the low-speed zone of flue gas flow, ash accumulates and may block the flue or corrode the tube walls.
[0003] On the other hand, ash and slag buildup on the pipe walls can lead to the formation of low-melting-point compounds from alkali metals such as potassium, sodium, and chlorine in biomass ash at high temperatures. These compounds adhere to the surface of the membrane wall pipe, forming slag or sintered ash. This results in reduced heat transfer efficiency, increased energy consumption, and makes cleaning difficult. Using mechanical tools for cleaning can also easily damage the pipe walls. Summary of the Invention
[0004] The purpose of this utility model embodiment is to provide an ash collection device for a biomass boiler, aiming to solve the technical problem of difficulty in collecting and cleaning flue ash in the prior art of membrane wall boilers.
[0005] The present invention is implemented as follows:
[0006] An ash collection device for a biomass boiler is fixed at the flue gas vent at the bottom of an inner membrane wall. The device includes an arc-shaped ash collection plate and a top baffle. The ash collection plate includes a vibrating end and an ash collection section. The bottom of the ash collection section is a first fixed end, and the top of the ash collection section is a second fixed end. The first fixed end penetrates the wall of the lower manifold and is welded to the wall of the lower manifold in a sealed manner. The portion of the ash collection plate inside the lower manifold is the vibrating end. One end of the top baffle is suspended, and the other end is fixed to the bottom of the inner membrane wall panel. The suspended free end faces the ash collection section of the ash collection plate. The thickness of the arc-shaped ash collection plate and the top baffle is ≤0.5 mm. The dust accumulated in the ash collection section slides down the slope of the ash collection section and enters a collection box at the bottom of the boiler.
[0007] Furthermore, the outer membrane wall is formed by alternating welding of a first water pipe and a first wall panel, and the inner membrane wall is formed by a second water pipe and a second wall panel. The first water pipe, the second water pipe, and the first wall panel are connected to the lower manifold, and the bottom end of the second wall panel does not contact the lower manifold, thus forming the smoke vent.
[0008] Furthermore, between the ash collection section and the top baffle, an intermediate baffle is welded to the outside of the second water pipe in the inner mode, with the intermediate baffle and the top baffle arranged alternately.
[0009] Furthermore, the angle between the intermediate baffle and the vertical direction is 25 degrees to 45 degrees.
[0010] Furthermore, the dust collection section of the dust collection plate is wrapped around the bottom inner side of the outer membrane wall, and the vibration end is a number of slender strips of the dust collection plate extending downwards from the bottom of the dust collection section to the collection pipe.
[0011] Furthermore, the elongated slats have at least one spiral in the lower manifold portion.
[0012] Furthermore, the second fixed end at the top of the ash collection section is higher than the bottom end of the second wall panel of the inner mold wall.
[0013] The positive effects of this invention are as follows: Because the free end of the top baffle is suspended directly opposite the ash collection section of the ash collection plate, a region where the flue gas passage narrows abruptly is formed at the flue gas vent, and then the flue gas passage widens again. This creates a low-speed zone for flue gas flow after quickly passing through this narrowing zone. The ash settles and accumulates in this low-speed zone, eventually falling and accumulating at the top of the top baffle or in the lower middle part of the ash collection section. Since small gas-fired or biomass boilers are intermittently started and stopped according to heat demand, frequent start-stop operations by a thermostat are not feasible. During ignition or extinguishing, the flue gas flow is intermittent with the combustion cycle, and the airflow in the flue exhibits "pulse-like" fluctuations. This causes soot to fall and accumulate at the top of the top baffle or in the lower middle part of the ash collection section. The soot falling at the top of the top baffle will also slide down into the lower middle part of the ash collection section due to vibration and finally into the collection box. In addition, the part located in the lower manifold is the vibrating end, which can transmit the vibration generated by the impact of the water flow in the lower manifold to the ash collection section, causing the ash collection section to shake off the soot and drop it into the collection box. Attached Figure Description
[0014] Figure 1 This is a front view of an ash collection device for a biomass boiler according to this utility model;
[0015] Figure 2 yes Figure 1 The enlarged view of point N of the ash collection device of the biomass boiler of this utility model is shown in the figure.
[0016] Legend: 1—Outer membrane wall, 101—First water pipe, 102—First wall panel, 2—Inner membrane wall, 201—Second water pipe, 202—Second wall panel, 203—Bottom end of wall panel, 3—Dust collection plate, 301—Vibration end, 302—First fixed end, 303—Second fixed end, 304—Intermediate baffle, 305—Top baffle, 4—Collection box, 5—Lower manifold, 6—Water inlet pipe. Detailed Implementation
[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments:
[0018] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0020] like Figure 1 The diagram shows the structure of an ash collection device for a biomass boiler according to an embodiment of this utility model. The ash collection device is fixed at the flue gas vent at the bottom of the inner membrane wall and includes an arc-shaped ash collection plate 3 and a top baffle 305. The ash collection plate 3 includes a vibrating end 301 and an ash collection section. The bottom of the ash collection section is a first fixed end 302, and the top of the ash collection section is a second fixed end 303. The first fixed end 302 penetrates the wall of the lower manifold 5 and is welded to the wall of the lower manifold 5 in a sealed manner. The part of the ash collection plate 3 that passes through the lower manifold 5 and is located inside the lower manifold 5 is the vibrating end 301. One end of the top baffle 305 is suspended, and the other end is fixed to the bottom end 203 of the inner membrane wall. The suspended free end is directly opposite the ash collection section of the ash collection plate 3. The thickness of the arc-shaped ash collection plate 3 and the top baffle 305 is ≤0.5 mm. The dust accumulated in the ash collection section slides down the slope of the ash collection section and enters the collection box 4 at the bottom of the boiler.
[0021] In this embodiment of the invention, the outer membrane wall 1 is formed by alternating welding of a first water pipe 101 and a first wall panel 102, and the inner membrane wall is formed by a second water pipe 201 and a second wall panel 202. The first water pipe 101, the second water pipe 201, and the first wall panel 102 are connected to the lower manifold 5. The bottom end of the second wall panel 202 does not contact the lower manifold 5, forming the flue gas passage. Since the free end of the top baffle 305 is directly opposite the ash collection section of the ash collection plate 3, a region with a sudden decrease in channel width is formed at the flue gas passage, and then the flue gas channel widens again. Thus, after quickly passing through the region with a sudden decrease in channel width, a low-speed zone of flue gas flow is formed. The soot settles and accumulates in the low-speed zone of flue gas flow, and then falls and accumulates on the top baffle. At the top of baffle 305 or the lower middle part of the ash collection section, because small gas or biomass boilers start and stop intermittently according to heat demand, such as by controlling the burner to frequently ignite or shut down through a thermostat, the flue gas flow is generated intermittently with the combustion cycle, and there is a "pulse-like" fluctuation in the airflow in the flue. This causes the soot to fall and accumulate at the top of baffle 305 or the lower middle part of the ash collection section. The soot falling at the top of baffle 305 will also slide down into the lower middle part of the ash collection section under the action of vibration and finally slide into the collection box 4. In addition, the part located in the lower manifold is the vibrating end. The vibrating end can transmit the vibration formed by the impact of the water flow in the lower manifold to the ash collection section, so that the ash collection section shakes the soot off and falls into the collection box through vibration.
[0022] Preferably, between the ash collection section and the top baffle 305, an intermediate baffle 304 is welded to the outside of the second water pipe in the inner mode, and the intermediate baffle 304 and the top baffle 305 are arranged alternately. This arrangement can form a low-speed zone for flue gas flow between the intermediate baffle 304 and the ash collection section of the ash collection plate 3. The flue gas settles and accumulates in the low-speed zone for flue gas flow, and then falls and accumulates in the middle and lower part of the ash collection section, and then slides into the middle and lower part of the ash collection section and finally slides into the collection box 4.
[0023] Preferably, the angle between the intermediate baffle 304 and the vertical direction is 25 degrees to 45 degrees.
[0024] Preferably, the dust collection section of the dust collection plate 3 surrounds the bottom inner side of the outer membrane wall 1, and the vibration end 301 consists of several slender strips of the dust collection plate 3 extending downwards from the bottom of the dust collection section into the collection pipe.
[0025] Preferably, the slender slats have at least one spiral in the lower manifold section to increase the contact surface with water in the lower manifold, thereby generating more vibrations when water flows through the slender slats.
[0026] The spiral here should be understood as a thin strip twisted into a shape similar to a twist drill.
[0027] Preferably, the top baffle 305 is evenly distributed along the outer circumference of the inner membrane wall.
[0028] Preferably, the angle between the top baffle 305 and the second wall panel of the inner membrane wall is 30 degrees to 50 degrees.
[0029] Preferably, the second fixed end 303 at the top of the ash collection section is higher than the bottom end 203 of the second wall panel 202 of the inner mode wall 2.
[0030] The foregoing has broadly outlined some aspects and features of the various embodiments and should be interpreted as merely illustrative of potential applications. Other beneficial results can be obtained by applying the disclosed information in different ways or by combining aspects of the disclosed embodiments. Further aspects and a more complete understanding can be obtained based on the detailed description of exemplary embodiments with reference to the accompanying drawings, within the scope defined by the claims.
[0031] The above embodiments provide a detailed description of the present invention. Of course, the above description is not intended to limit the present invention, nor is the present invention limited to the examples described above. Any changes, modifications, additions, reductions, or substitutions made by those skilled in the art within the scope of the present invention are also within the protection scope of the present invention.
Claims
1. A biomass boiler ash collection device, characterized by, The ash collection device is fixed at the smoke vent at the bottom of the inner membrane wall and includes an arc-shaped ash collection plate and a top baffle. The ash collection plate includes a vibrating end and an ash collection section. The bottom of the ash collection section is the first fixed end, and the top of the ash collection section is the second fixed end. The first fixed end penetrates the pipe wall of the lower manifold and is welded to the pipe wall of the lower manifold in a sealed manner. The part of the ash collection plate that passes through the lower manifold and is located inside the lower manifold is the vibrating end. One end of the top baffle is suspended in the air, and the other end is fixed to the bottom end of the inner membrane wall panel. The suspended free end is directly opposite the dust collection section of the dust collection plate. The thickness of the arc-shaped dust collection plate and the top baffle is ≤0.5 mm. The dust accumulated in the ash collection section slides down the slope of the ash collection section and enters the collection box at the bottom of the boiler.
2. The ash collection device for a biomass boiler according to claim 1, characterized in that, The outer membrane wall is formed by alternating welding of a first water pipe and a first wall panel, and the inner membrane wall is formed by a second water pipe and a second wall panel. The first water pipe, the second water pipe, and the first wall panel are connected to the lower manifold, and the bottom end of the second wall panel does not contact the lower manifold, thus forming the smoke vent.
3. The ash collection device of a biomass boiler according to claim 2, characterized in that Between the ash collection section and the top baffle, an intermediate baffle is welded to the outside of the second water pipe in the inner mode, and the intermediate baffle and the top baffle are arranged alternately.
4. The ash collection device of a biomass boiler according to claim 3, characterized in that The angle between the intermediate baffle and the vertical direction is 25 degrees to 45 degrees.
5. The ash collection device of a biomass boiler according to any one of claims 1 to 4, characterized in that, The dust collection section of the dust collection plate is wrapped around the bottom inner side of the outer membrane wall, and the vibration end is a number of slender strips of the dust collection plate extending downwards from the bottom of the dust collection section to the collection pipe.
6. The ash collection device of a biomass boiler according to claim 5, characterized in that The slender strip has at least one spiral in the lower manifold section.
7. The ash collection apparatus of a biomass boiler according to claim 6, characterized in that The second fixed end at the top of the ash collection section is higher than the bottom end of the second wall panel of the inner mold wall.