A coal powder screening and separation device
By designing conical rotating screen and annular screen structures, the problems of low screening efficiency and short lifespan in pulverized coal separation equipment were solved, achieving efficient screening and stable equipment operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENGHONG REFINING & CHEM (LIANYUNGANG) CO LTD
- Filing Date
- 2026-04-24
- Publication Date
- 2026-06-02
AI Technical Summary
Existing coal powder separation technologies suffer from low screening efficiency and short screen lifespan, especially in dry coal powder gasification processes, where coal powder accumulates on the screen surface and does not make sufficient contact, leading to unstable equipment operation.
The rotating screen is designed with a conical structure and is tilted by a drive assembly. An annular screen is added to the outer periphery to increase the screening area and path, decompose the impact force, and reduce screen damage. At the same time, the annular screen on the outer periphery of the rotating screen prevents foreign objects from leaking out.
It improves the efficiency of coal powder screening, extends the service life of the screen, ensures stable operation of the equipment, and enhances the screening quality.
Smart Images
Figure CN122124973A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of dry coal gasification technology, and in particular to a coal powder screening and separation device. Background Technology
[0002] In dry pulverized coal gasification, after the raw coal is ground into powder by a coal mill, it usually needs to be separated and collected by pulverized coal separation equipment to meet the feed requirements of subsequent gasification processes. In actual production, pulverized coal often contains foreign matter such as fibers, lumpy impurities, and pulverized coal flakes. If such foreign matter enters the gasifier along with qualified pulverized coal, it can easily cause blockage of the coal conveying pipeline, leading to fluctuations in coal flow and thus affecting the operating efficiency of the gasifier and the stability of the system.
[0003] Existing coal powder separation technologies mostly employ a transmission mechanism to drive a circular screen for rotary screening. The screen traps larger foreign objects in the coal powder, thus separating the coal powder from impurities. However, this type of coal powder screening and separation equipment still has some shortcomings. For example, the drive mechanism rotates the screen, and the coal powder diffuses along the screen surface under centrifugal force. This can lead to coal powder accumulation on the screen surface, a short residence path, and insufficient contact with the screen openings, resulting in low overall screening efficiency. Furthermore, the screen directly bears the impact load of falling coal powder, with the force concentrated in a localized area. After long-term operation, this can easily lead to screen deformation and damage, resulting in a shorter equipment lifespan.
[0004] Therefore, there is an urgent need for a coal powder screening and separation device to solve the above-mentioned technical problems. Summary of the Invention
[0005] The purpose of this invention is to provide a coal powder screening and separation device to improve the efficiency of coal powder screening and separation, while extending the service life of the screen.
[0006] To achieve this objective, the present invention adopts the following technical solution:
[0007] This invention provides a coal powder screening and separation device, comprising: a shell assembly with a coal powder inlet at the upper end and a coal powder outlet at the lower end; a drive assembly installed outside the shell assembly; the output shaft of the drive assembly passing through the interior of the shell assembly along a first direction; the first direction being a vertical direction; a rotating screen disposed inside the shell assembly; the rotating screen having a conical structure, and the diameter of the rotating screen increasing from top to bottom; the rotating screen being drively connected to the output shaft; the drive assembly being capable of driving the rotating screen to rotate around its own axis; in the first direction, the orthographic projection of the coal powder inlet is located within the outer contour of the orthographic projection of the rotating screen; a first annular screen disposed around the outer periphery of the rotating screen and connected to the rotating screen; in a second direction, the orthographic projection of the first annular screen at least partially coincides with the orthographic projection of the rotating screen; the second direction being a horizontal direction.
[0008] In some embodiments, the angle between the surface of the rotating screen and the axis of the output shaft is a first angle; the angle range of the first angle is 30° to 60°.
[0009] In some embodiments, the first annular screen includes a first connecting end connected to the rotating screen and a first free end located above the rotating screen; a first annular blocking portion is provided around the first free end; in the first direction, the orthographic projection of the first annular blocking portion at least partially coincides with the orthographic projection of the rotating screen.
[0010] In some embodiments, the housing assembly includes a housing body and a top plate fastened to the upper end of the housing body; the pulverized coal inlet is opened in the top plate; the rotating screen is disposed inside the housing body; the pulverized coal screening and separation device further includes a second annular screen; the second annular screen is disposed between the top plate and the rotating screen, and is connected to the top plate; the diameter of the second annular screen is smaller than the diameter of the first annular screen, and the two are coaxially arranged; in the second direction, the orthographic projection of the second annular screen at least partially coincides with the orthographic projection of the first annular screen; the outer peripheral wall of the second annular screen and the inner peripheral wall of the first annular screen form an annular movement gap.
[0011] In some embodiments, the second annular screen includes a second connecting end connected to the top plate and a second free end located between the top plate and the rotating screen; a second annular blocking portion is provided around the second free end; the outer peripheral wall of the second annular screen and the inner peripheral wall of the first annular screen form an annular movement gap; in the first direction, the orthographic projection of the second annular blocking portion at least partially coincides with the orthographic projection of the annular movement gap.
[0012] In some embodiments, a plurality of comb teeth are arranged at intervals on the rotating screen; the extending direction of the comb teeth is set at an angle to the surface of the rotating screen.
[0013] In some embodiments, the housing assembly includes a first region and a second region arranged from top to bottom; the pulverized coal inlet is connected to the upper side of the first region; the rotating screen is disposed in the first region; the size of the second region decreases from top to bottom in the second direction; and the pulverized coal outlet is connected to the lower side of the second region.
[0014] In some embodiments, the rotating screen has a plurality of screening holes; the screening holes are made by a stamping process.
[0015] In some embodiments, the rotating screen has a carburized layer on its surface; the thickness of the carburized layer is 0.5 mm to 1 mm.
[0016] In some embodiments, a maintenance opening is further provided at the upper end of the housing assembly; in the first direction, the orthographic projection of the maintenance opening is located within the outer contour of the orthographic projection of the rotating screen.
[0017] The beneficial effects of this invention are:
[0018] This invention provides a coal powder screening and separation device. A drive assembly is installed outside the housing assembly, and this drive assembly is connected to a rotating screen inside the housing assembly. This allows the drive assembly to drive the rotating screen to rotate around its own axis, thus achieving the coal powder screening action. Simultaneously, the rotating screen is designed as a conical structure, wider at the bottom and narrower at the top, with the screen surface (i.e., the screening working surface) inclined. This allows the coal powder to be screened, entering through the coal powder inlet at the top of the housing assembly, to fall onto the rotating screen surface and automatically slide along the inclined surface under gravity, preventing the coal powder from being trapped on the screen due to weaker centrifugal force near the rotation center. The screen is piled up at the center to ensure screening efficiency. Furthermore, because the rotating screen is angled, the screening area is increased within the same radial dimension, extending the movement path of the coal powder on the screen surface and ensuring full contact between the coal powder and the screen surface, further improving screening efficiency. Simultaneously, the angled rotating screen surface decomposes the impact force of falling coal powder into a tangential component along the screen surface and a normal component perpendicular to the screen surface. Only the normal component directly impacts the screen surface, while the tangential component is converted into the power for coal powder sliding, thereby reducing the impact load on the rotating screen, minimizing the risk of screen deformation and breakage, and extending the service life of the rotating screen. Furthermore, because a first annular screen is provided on the outer periphery of the rotating screen, and in the second direction, the orthographic projection of the first annular screen at least partially coincides with the orthographic projection of the rotating screen, a corner convergence area is formed between the first annular screen and the rotating screen. Under the action of gravity and centrifugal force, coal powder will eventually accumulate at this corner convergence area. This corner convergence area is located on the outer periphery of the rotating screen and is subjected to the strongest centrifugal force, thus further improving the screening efficiency of coal powder. Moreover, because the first annular screen is provided on the outer periphery of the rotating screen, it can, to a certain extent, block foreign objects after screening, preventing leakage of foreign objects from the gap between the rotating screen and the shell assembly, thereby improving the screening quality of the aforementioned coal powder screening and separation device. Attached Figure Description
[0019] Figure 1 This is a structural diagram of a coal powder screening and separation device provided in a specific embodiment of the present invention;
[0020] Figure 2 This is a partial structural diagram of a coal powder screening and separation device provided in a specific embodiment of the present invention.
[0021] In the picture:
[0022] 1. Shell assembly; 11. Shell body; 111. Pulverized coal outlet; 12. Top plate; 121. Pulverized coal inlet; 122. Maintenance port; 2. Output shaft; 3. Rotary screen; 4. First annular screen; 41. First connecting end; 42. First free end; 43. First annular blocking part; 5. Second annular screen; 51. Second connecting end; 52. Second free end; 53. Second annular blocking part; 6. Comb teeth;
[0023] X1, first direction; X2, second direction; a1, first included angle; a2, second included angle; S1, first region; S2, second region. Detailed Implementation
[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.
[0025] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0027] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.
[0028] like Figure 1 As shown in the figure, this embodiment provides a coal powder screening and separation device, which includes a housing assembly 1, a drive assembly (not shown in the figure), a rotating screen 3, and a first annular screen 4.
[0029] The aforementioned shell assembly 1 may be a cylindrical shell structure, a rectangular shell structure, or an irregularly shaped shell structure (e.g., the upper half of the shell assembly 1 is a cylindrical shell structure, and the lower half is a rectangular shell structure). A pulverized coal inlet 121 is provided at the upper end of the shell assembly 1, and a pulverized coal outlet 111 is provided at the lower end. It is easy to understand that after the raw coal is ground into powder by the coal mill, it enters the interior of the shell assembly 1 (or the interior of the pulverized coal screening and separation device) through the pulverized coal inlet 121, and the pulverized coal after screening and separation can be discharged through the pulverized coal outlet 111.
[0030] The aforementioned drive assembly is mounted on the outside of housing assembly 1. This drive assembly includes, for example, a drive element (e.g., a rotary motor), a transmission structure (e.g., a reduction gear set), and an output shaft 2. The output shaft 2 of this drive assembly passes through the interior of housing assembly 1 along a first direction X1. Here, the first direction X1 is the vertical direction.
[0031] The aforementioned rotating screen 3 is disposed inside the housing assembly 1. The rotating screen 3 has a conical structure, and its diameter increases from top to bottom; that is, it is a cone-shaped structure with a smaller top and a larger bottom. In other words, the center of the rotating screen 3 is higher than its outer periphery, causing the screen surface (i.e., the screening working surface) to be inclined. The rotating screen 3 is driven by the output shaft 2 of the drive assembly, which can drive the rotating screen 3 to rotate around its own axis. In other words, the center of the rotating screen 3 is driven by the output shaft 2 of the drive assembly, or the axis of the rotating screen 3 coincides with the axis of the output shaft 2 of the drive assembly. Here, the rotating screen 3 can be directly connected to the output shaft 2 of the drive assembly (e.g., by welding or bolting), or it can be connected to the output shaft 2 of the drive assembly through other adapter components (e.g., adapter seats). In the first direction X1, the orthographic projection of the coal powder inlet 121 at the upper end of the housing assembly 1 is located within the outer contour of the orthographic projection of the rotary screen 3, so that the coal powder to be screened entering the housing assembly 1 through the coal powder inlet 121 can fall onto the screen surface of the rotary screen 3 for screening.
[0032] It is easy to understand that the aforementioned rotary screen 3 has multiple screening holes, which are manufactured using a stamping process. By employing a stamping process to manufacture the screening holes, the need for wire mesh weaving is eliminated, thereby improving the overall structural strength of the rotary screen 3 and extending its service life. For example, the screening holes can be circular, which ensures the pulverized coal passing area while shortening the perimeter of the screening holes, preventing the formation of angular structures that easily lead to stress concentration, and further improving the overall structural strength of the rotary screen 3.
[0033] Furthermore, the surface of the rotary screen 3 (i.e., the screening working surface) is provided with a carburized layer, meaning that the surface of the rotary screen 3 is treated with a carburizing process to form a carburized layer. The thickness of this carburized layer is 0.5mm to 1mm. For example, the thickness of the carburized layer is 0.5mm; or 0.6mm; or 0.75mm; or 0.8mm; or 1mm. This design improves the wear resistance and structural strength of the rotary screen 3, further extending its service life.
[0034] The aforementioned first annular screen 4 is disposed around the outer periphery of the rotating screen 3 and is connected to the rotating screen 3. In the second direction X2, the orthographic projection of the first annular screen 4 at least partially coincides with the orthographic projection of the rotating screen 3; here, the second direction X2 is a horizontal direction. In other words, the mesh surface of the first annular screen 4 and the mesh surface of the rotating screen 3 are set at an angle, and a corner convergence area can be formed between them. For example, combined with… Figure 1 , Figure 2 As shown, the angle between the surface of the rotating screen 3 and the axis of the output shaft 2 of the drive assembly is the first included angle α1, and the angle between the surface of the first annular screen 4 and the surface of the rotating screen 3 is the second included angle α2. The angle of the second included angle α2 is equal to the angle of the first included angle α1. Similarly, the first annular screen 4 also has multiple screening holes, which can be specifically set with reference to the screening holes on the rotating screen 3 described above, and will not be repeated here.
[0035] Therefore, the coal powder screening and separation device provided in this embodiment, by setting a drive component outside the shell assembly 1, and connecting the drive component to the rotating screen 3 inside the shell assembly 1, enables the drive component to drive the rotating screen 3 to rotate around its own axis, thereby realizing the coal powder screening action; at the same time, the rotating screen 3 is set as a conical structure with a smaller top and a larger bottom, so that the screen surface (i.e., the screening working surface) of the rotating screen 3 is inclined. This allows the coal powder to be screened entering from the coal powder inlet 121 at the upper end of the shell assembly 1 to fall onto the screen surface of the rotating screen 3 and automatically slide along the inclined screen surface under the action of gravity, avoiding the weak centrifugal force near the rotation center area. The pulverized coal accumulates at the center of the screen, ensuring screening efficiency. Furthermore, because the rotating screen 3 has an inclined surface, the screening area can be increased within the same radial dimension, extending the movement path of the pulverized coal on the screen surface and allowing it to fully contact the screen surface for screening, further improving screening efficiency. At the same time, the inclined rotating screen 3 can decompose the impact force of the falling pulverized coal into a tangential component along the screen surface and a normal component perpendicular to the screen surface. Only the normal component directly impacts the screen surface, while the tangential component is converted into the power for pulverized coal sliding, thereby reducing the impact load on the rotating screen 3, reducing the risk of screen deformation and breakage, and extending the service life of the rotating screen 3. Furthermore, because a first annular screen 4 is provided on the outer periphery of the rotating screen 3, and the orthographic projection of the first annular screen 4 at least partially coincides with the orthographic projection of the rotating screen 3 in the second direction X2, a corner convergence area is formed between the first annular screen 4 and the rotating screen 3. Under the action of gravity and centrifugal force, coal powder will eventually gather at this corner convergence area. This corner convergence area is located on the outer periphery of the rotating screen 3 and is subjected to the strongest centrifugal force, thus further improving the screening efficiency of coal powder. Moreover, because the first annular screen 4 is provided on the outer periphery of the rotating screen 3, it can, to a certain extent, block foreign objects after screening, preventing foreign objects from leaking from the gap between the rotating screen 3 and the housing assembly 1, thereby improving the screening quality of the aforementioned coal powder screening and separation device.
[0036] In some embodiments, such as Figure 1As shown, the angle between the surface of the rotating screen 3 and the axis of the output shaft 2 of the drive assembly is a first included angle α1, which ranges from 30° to 60°. For example, the first included angle α1 between the surface of the rotating screen 3 and the axis of the output shaft 2 of the drive assembly is 30°; or 40°; or 45°; or 55°; or 60°. This arrangement ensures that the angle between the surface of the rotating screen 3 and the axis of the output shaft 2 of the drive assembly is within a suitable range, preventing the angle from being too large or too small, which could lead to a decrease in screening efficiency or quality.
[0037] In some embodiments, such as Figure 2 As shown, the aforementioned first annular screen 4 includes a first connecting end 41 connected to the rotating screen 3 and a first free end 42 located above the rotating screen 3. A first annular blocking portion 43 is provided around the first free end 42 of the first annular screen 4. In the first direction X1, the orthographic projection of the first annular blocking portion 43 at least partially coincides with the orthographic projection of the rotating screen 3. With this arrangement, when the screened foreign matter is about to cross the first annular screen 4 and leak through the gap between the rotating screen 3 and the housing assembly 1, the first annular blocking portion 43 can play a further blocking role, improving the blocking effect on the screened foreign matter and improving the screening quality of the aforementioned coal powder screening and separation device.
[0038] In some embodiments, such as Figure 1As shown, the aforementioned housing assembly 1 includes a housing body 11 and a top plate 12 fastened to the upper end of the housing body 11. A pulverized coal inlet 121 is opened in the top plate 12, and a rotating screen 3 is disposed inside the housing body 11. The aforementioned pulverized coal screening and separation device also includes a second annular screen 5. This second annular screen 5 is disposed between the top plate 12 and the rotating screen 3, and is connected to the top plate 12. The diameter of the second annular screen 5 is smaller than the diameter of the first annular screen, and the two are coaxially arranged; in other words, the first annular screen 4 is fitted inside the second annular screen 5. In the second direction X2, the orthographic projection of the second annular screen 5 at least partially coincides with the orthographic projection of the first annular screen 4. The outer peripheral wall of the second annular screen 5 and the inner peripheral wall of the first annular screen 4 form an annular movement gap. With the above configuration, the first annular screen 4 and the second annular screen 5 can be used to block foreign objects after screening simultaneously, and an annular movement gap is formed between the two. Even if foreign objects can enter the annular movement gap, they will continuously collide with the side wall of the annular movement gap (i.e., the outer peripheral wall of the second annular screen 5 and the inner peripheral wall of the first annular screen 4), and their kinetic energy will be continuously consumed. This prevents foreign objects from overturning the first annular screen 4 and leaking through the gap between the rotating screen 3 and the housing assembly 1, further improving the blocking effect on foreign objects after screening and improving the screening quality of the above-mentioned coal powder screening and separation device.
[0039] In some embodiments, such as Figure 2 As shown, the second annular screen 5 includes a second connecting end 51 connected to the top plate 12 and a second free end 52 located between the top plate 12 and the rotating screen 3. A second annular blocking portion 53 is provided around the second free end 52 of the second annular screen 5. In the first direction X1, the orthographic projection of the second annular blocking portion 53 at least partially coincides with the orthographic projection of the annular movement gap. With this arrangement, the second annular blocking portion 53 can be used to block foreign objects after screening from entering the annular movement gap, preventing foreign objects from crossing the first annular screen 4 and leaking from the gap between the rotating screen 3 and the housing assembly 1, further improving the blocking effect on foreign objects after screening and improving the screening quality of the above-mentioned coal powder screening and separation device.
[0040] In some embodiments, such as Figure 1 , Figure 2 As shown, multiple comb-shaped components 6 are arranged at intervals on the rotating screen 3. The comb-shaped components 6 are cylindrical rod-shaped structures or strip-shaped plate-shaped structures, etc. The extending direction of the comb-shaped components 6 is set at an angle to the mesh surface of the rotating screen 3. For example, the extending direction of the comb-shaped components 6 is parallel to the aforementioned first direction X1; or, the extending direction of the comb-shaped components 6 is perpendicular to the mesh surface of the rotating screen 3. Through this arrangement, the comb-shaped components 6 can intercept and clean fibrous impurities in the coal powder to be screened, improving the screening quality. Simultaneously, it can prevent fibrous impurities from accumulating in the corner convergence area formed by the first annular screen 4 and the rotating screen 3, indirectly improving screening efficiency.
[0041] In some embodiments, such as Figure 1 As shown, the aforementioned shell assembly 1 includes a first region S1 and a second region S2 arranged from top to bottom. The pulverized coal inlet 121 communicates with the upper side of the first region S1, and the rotating screen 3 is disposed in the first region S1. The second region S2 has dimensions decreasing from top to bottom in the second direction X2, and the pulverized coal outlet 111 communicates with the lower side of the second region S2. In other words, the second region S2 of the shell assembly 1 has a conical structure that is larger at the top and smaller at the bottom, and the pulverized coal outlet 111 is located at the smaller end of this conical structure. This arrangement facilitates the rapid discharge of sifted pulverized coal and prevents pulverized coal accumulation inside the shell assembly 1.
[0042] In some embodiments, such as Figure 1 As shown, a maintenance port 122 is also provided at the upper end of the housing assembly 1. In the first direction X1, the orthographic projection of the maintenance port 122 is located within the outer contour of the orthographic projection of the rotary screen 3. With this arrangement, the operator can observe the operation of the rotary screen 3 and the accumulation of foreign objects through the maintenance port, so as to perform timely maintenance and cleaning of the rotary screen 3, thereby improving the practicality of the above-mentioned coal powder screening and separation device.
[0043] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A coal powder screening and separation device, characterized in that, include: The shell assembly (1) has a pulverized coal inlet (121) at the upper end and a pulverized coal outlet (111) at the lower end. A drive assembly is installed outside the housing assembly (1); the output shaft (2) of the drive assembly passes through the interior of the housing assembly (1) along a first direction (X1); the first direction (X1) is a vertical direction; A rotating screen (3) is disposed inside the housing assembly (1); the rotating screen (3) has a conical structure, and the diameter of the rotating screen (3) increases from top to bottom; the rotating screen (3) is connected to the output shaft (2) in a transmission connection; the driving assembly can drive the rotating screen (3) to rotate around its own axis; in the first direction (X1), the orthographic projection of the coal powder inlet (121) is located within the outer contour of the orthographic projection of the rotating screen (3); A first annular screen (4) is arranged around the outer periphery of the rotating screen (3) and connected to the rotating screen (3); in a second direction (X2), the orthographic projection of the first annular screen (4) at least partially coincides with the orthographic projection of the rotating screen (3); the second direction (X2) is a horizontal direction.
2. The coal powder screening and separation device according to claim 1, characterized in that, The angle between the surface of the rotating screen (3) and the axis of the output shaft (2) is the first included angle (a1); the angle range of the first included angle (a1) is 30°~60°.
3. The coal powder screening and separation device according to claim 1, characterized in that, The first annular screen (4) includes a first connecting end (41) connected to the rotating screen (3) and a first free end (42) located above the rotating screen (3). A first annular blocking portion (43) is provided around the first free end (42); in the first direction (X1), the orthographic projection of the first annular blocking portion (43) at least partially coincides with the orthographic projection of the rotating screen (3).
4. The coal powder screening and separation device according to claim 1, characterized in that, The shell assembly (1) includes a shell body (11) and a top plate (12) fastened to the upper end of the shell body (11); the pulverized coal inlet (121) is opened on the top plate (12); the rotating screen (3) is disposed inside the shell body (11); The coal powder screening and separation device further includes a second annular screen (5); the second annular screen (5) is disposed between the top plate (12) and the rotating screen (3), and is connected to the top plate (12); the diameter of the second annular screen (5) is smaller than the diameter of the first annular screen, and the two are coaxially arranged; in the second direction (X2), the orthographic projection of the second annular screen (5) at least partially coincides with the orthographic projection of the first annular screen (4); the outer peripheral wall of the second annular screen (5) and the inner peripheral wall of the first annular screen (4) form an annular movement gap.
5. The coal powder screening and separation device according to claim 4, characterized in that, The second annular screen (5) includes a second connecting end (51) connected to the top plate (12) and a second free end (52) located between the top plate (12) and the rotating screen (3). A second annular blocking portion (53) is provided around the second free end (52); in the first direction (X1), the orthographic projection of the second annular blocking portion (53) at least partially coincides with the orthographic projection of the annular movement gap.
6. The coal powder screening and separation device according to any one of claims 1 to 5, characterized in that, Multiple comb teeth (6) are arranged at intervals on the rotating screen (3); the extending direction of the comb teeth (6) is set at an angle to the screen surface of the rotating screen (3).
7. The coal powder screening and separation device according to any one of claims 1 to 5, characterized in that, The housing assembly (1) includes a first region (S1) and a second region (S2) arranged from top to bottom; the pulverized coal inlet (121) is connected to the upper side of the first region (S1); the rotating screen (3) is disposed in the first region (S1). The size of the second region (S2) in the second direction (X2) decreases from top to bottom; the pulverized coal outlet (111) is connected to the lower side of the second region (S2).
8. The coal powder screening and separation device according to any one of claims 1 to 5, characterized in that, The rotating screen (3) has multiple screening holes; the screening holes are made by a stamping process.
9. The coal powder screening and separation device according to any one of claims 1 to 5, characterized in that, The rotating screen (3) has a carburized layer on its surface; the thickness of the carburized layer is 0.5 mm to 1 mm.
10. The coal powder screening and separation device according to any one of claims 1 to 5, characterized in that, A maintenance port (122) is also provided at the upper end of the housing assembly (1); in the first direction (X1), the orthographic projection of the maintenance port (122) is located within the outer contour of the orthographic projection of the rotating screen (3).