A pipeline for conveying pulverized coal in boilers
By using a ceramic-rubber composite liner and flow guide strip design, combined with anti-clogging components, the problem of easy clogging in pulverized coal conveying pipelines is solved, achieving efficient and stable pulverized coal conveying and automatic unclogging function, thus reducing energy consumption and maintenance costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU INTERNAI MASCH MFG CO LTD
- Filing Date
- 2025-08-22
- Publication Date
- 2026-07-31
AI Technical Summary
Existing coal powder conveying pipelines are prone to blockage due to coal powder deposition during long-distance, high-capacity transportation. Existing anti-blockage measures, such as increasing airflow speed, increase energy consumption, and the lining plate is prone to coal powder adhesion. Fixed ash removal ports have a delayed response and limited effectiveness.
It adopts a ceramic-rubber composite liner and flow guide strip design, combined with anti-clogging components. Utilizing the high hardness of ceramic and the toughness of rubber, the flow guide strip generates swirling flow to reduce friction, and the anti-clogging components achieve automatic unclogging through a counterweight mechanism.
It effectively prevents coal dust deposition, reduces energy consumption, improves conveying efficiency, reduces maintenance frequency, ensures stable system operation, and reduces downtime.
Smart Images
Figure CN224580295U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of pulverized coal conveying technology, specifically relating to a pipeline for conveying pulverized coal in a boiler. Background Technology
[0002] Pneumatic conveying of pulverized coal is a critical component of coal-fired boiler systems, and its operational stability directly impacts combustion efficiency and system reliability. During long-distance, high-capacity conveying, pulverized coal particles tend to deposit at the bottom of the pipeline, especially during system start-up and shutdown, load fluctuations, or insufficient conveying airflow velocity. Under these conditions, pulverized coal gradually accumulates due to gravity, forming caking or even completely blocking the pipeline, leading to conveying interruptions, abnormally high system pressure, and in severe cases, requiring shutdown for manual cleaning, resulting in decreased production efficiency and increased maintenance costs.
[0003] Currently, to prevent coal dust from depositing in conveying pipelines, methods such as increasing airflow velocity, optimizing pipeline layout angles, adding liners, or setting up ash removal ports are commonly used. However, increasing airflow velocity significantly increases energy consumption and equipment wear; while ordinary metal or polymer liners have some wear-resistant properties, fine coal dust particles easily adhere to their surfaces, especially at high humidity levels, making adsorption more pronounced and failing to fundamentally prevent deposition; and fixed ash removal ports require periodic manual operation, cannot achieve real-time, automatic clogging, and have delayed response and limited clogging removal effectiveness.
[0004] Therefore, a pipeline for conveying pulverized coal in boilers is proposed to address the current shortcomings. Utility Model Content
[0005] This utility model provides a pipeline for conveying pulverized coal in boilers, which aims to solve the problems of easy blockage, low conveying efficiency, frequent maintenance and unstable operation caused by the inability to effectively prevent pulverized coal deposition and caking in existing pulverized coal conveying pipelines.
[0006] To achieve the above objectives, the technical solution adopted by this utility model is: to provide a pipeline for conveying pulverized coal in a boiler, comprising:
[0007] The pipeline body has an inlet end connected to the pipeline body at one end and an outlet end connected to the pipeline body at the other end.
[0008] The composite liner is coaxially nested inside the pipe body, with its outer wall tightly fitted to the inner wall of the pipe body.
[0009] The guide strip extends in a spiral shape along the inner wall of the composite liner to guide and lift the pulverized coal.
[0010] The anti-clogging section is located at the bottom of the pipe body near the inlet end and is used to remove coal dust deposited at the bottom of the composite liner.
[0011] Preferably, the pipe body is a hollow cylindrical structure with openings at both ends.
[0012] Preferably, the composite liner is made of a ceramic-rubber composite liner.
[0013] Composite liner combines the high hardness of ceramics with the high toughness of rubber: ceramics can effectively resist long-term erosion and wear from coal dust particles, extending the service life of the pipeline; rubber can absorb the impact energy of particles, reduce pipeline vibration and noise, and prevent the ceramic layer from brittlely fracturing under heavy impact; in addition, the surface of the composite liner is smooth and does not easily adhere to coal dust, which can reduce the friction and adsorption force between particles and the pipe wall, and work with the guide strip to maintain high-speed and stable swirling flow, reducing flow resistance and the risk of coal dust deposition. At the same time, it facilitates the discharge of the blown-up accumulated powder during the unblocking process, avoiding secondary adhesion.
[0014] Preferably, the cross-section of the guide strip is a trapezoidal or arc-shaped raised strip structure, and the surface of the guide strip is coated with a self-lubricating ceramic coating.
[0015] This type of guide bar can smoothly guide and change the direction of airflow, effectively reducing the generation of eddies and thus reducing the flow resistance of pulverized coal airflow. At the same time, the self-lubricating ceramic coating on the surface of the guide bar further reduces its surface friction coefficient, which can reduce the adhesion of pulverized coal particles to the surface of the guide bar and prevent the formation of the starting point for ash accumulation. In addition, it reduces the erosion and wear of the guide bar itself by high-velocity pulverized coal particles, thereby extending the service life of this key component.
[0016] Preferably, the spiral angle of the guide strip is 15°-45°, and the ratio of the spiral pitch to the pipe body diameter is 1:8-1:10.
[0017] Preferably, the anti-clogging part includes:
[0018] The self-cleaning tank has a long, open-top structure and is set along the length of the pipe body and connected to the inside of the pipe body.
[0019] The self-cleaning baffle is installed inside the composite liner and is adapted to the self-cleaning tank. One end of the baffle is rotatably connected to the self-cleaning tank via a rotating shaft.
[0020] The counterweight is fixedly installed at the bottom of the self-cleaning baffle near the rotating shaft.
[0021] Preferably, the shape of the self-cleaning baffle matches the inner wall contour of the composite liner, and it is provided with a guide plate adapted to the shape of the guide strip.
[0022] Preferably, the rotating shaft is located at one end of the self-cleaning tank near the inlet.
[0023] The anti-clogging unit achieves automatic detection and removal of deposited coal dust through close coordination between its mechanical structure and the pipeline flow field. The self-cleaning tank provides temporary storage space for coal dust and serves as the mounting base for moving parts. The self-cleaning baffle, as the actuating element, ensures the continuity and stability of the flow field during normal operation by matching its contour with the inner wall of the composite liner and the smooth connection of the guide plate on it with the guide strip. The rotating shaft is located near the inlet end, and together with the counterweight fixed to the bottom of the baffle near the rotating shaft end, they form an automatic triggering mechanism based on gravity torque balance. This mechanism realizes the automatic start and stop of the unclogging action. That is, the weight of the accumulated ash triggers the self-cleaning baffle to open and release a high-speed impact flow. After unclogging, the counterweight can automatically reset it, thereby reducing manual intervention and ensuring the continuous smooth flow of the pipeline.
[0024] The present invention has the following advantages due to the adoption of the above technical solution:
[0025] 1. This utility model adopts a ceramic-rubber composite liner, which utilizes the high hardness and wear resistance of the ceramic component to significantly resist the erosion and wear of coal powder particles. At the same time, the elasticity and toughness of the rubber component absorbs impact energy, reduces pipeline vibration and noise, and prevents brittle materials from breaking, thereby improving the overall durability and reliability of the pipeline.
[0026] 2. The smooth surface of the composite liner reduces the adsorption and friction between coal powder particles and the pipe wall, making it especially suitable for fine particles with high humidity, ensuring smooth coal powder transportation; combined with the swirling effect generated by the guide strip, it maintains a high airflow velocity, reduces energy loss, and further inhibits coal powder deposition.
[0027] 3. The spiral design of the guide strip of this utility model forces the coal powder airflow to form a strong swirling flow. Through centrifugal action, the particles are evenly distributed and spiral forward along the pipe wall, avoiding gravity settling. The self-lubricating coating and trapezoidal or arc-shaped cross section of the guide strip further reduce the friction coefficient, reduce wear and adhesion, and ensure the continuous and stable flow field.
[0028] 4. The anti-clogging part of this utility model sets the unclogging threshold through the counterweight mechanism. When the dust accumulation is severe, the self-cleaning baffle is automatically triggered to open, and the dust is removed by high-speed airflow impact without external intervention. After unclogging, it automatically resets to restore the integrity of the flow field, reduce downtime, and improve the continuous operation capability of the system.
[0029] 5. The components of this utility model work together to prevent blockage during normal operation and automatically clear blockages in case of abnormalities. This effectively copes with changes in operating conditions such as start-up, shutdown, or low load, reducing maintenance frequency and costs, and meeting the requirements for high efficiency and safety in boiler pulverized coal conveying.
[0030] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description
[0031] Figure 1 A schematic diagram of the structure of a pipeline for conveying pulverized coal in a boiler, provided as an embodiment of this utility model. Figure 1 ;
[0032] Figure 2 An exploded view of a pipeline for conveying pulverized coal in a boiler, provided as an embodiment of this utility model;
[0033] Figure 3 A schematic diagram of the internal structure of a pipeline for conveying pulverized coal in a boiler, provided for an embodiment of this utility model;
[0034] Figure 4 yes Figure 3 A magnified view of a portion of point A in the middle.
[0035] Figure 5 for Figure 3 The diagram shows a top view of a pipeline used for conveying pulverized coal in a boiler.
[0036] Figure 6 yes Figure 5 Sectional view at point BB.
[0037] Figure 7 yes Figure 6 A magnified view of a section at point C.
[0038] Explanation of reference numerals in the attached figures:
[0039] 1. Pipeline body; 11. Inlet end; 12. Outlet end;
[0040] 2. Composite liner; 3. Flow guide strip;
[0041] 4. Anti-clogging section; 41. Self-cleaning tank; 42. Self-cleaning baffle; 43. Rotating shaft; 44. Counterweight; 421. Guide plate. Detailed Implementation
[0042] To make the technical problem to be solved, the technical solution, and the beneficial effects 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.
[0043] This utility model discloses a pipeline for conveying pulverized coal in a boiler, comprising:
[0044] Pipe body 1 is a hollow cylindrical structure with openings at both ends, forming the main flow channel for pulverized coal pneumatic conveying and connecting other equipment in the boiler system; at the same time, pipe body 1 forms the outermost pressure-bearing and support structure and provides the installation foundation for the internal structure.
[0045] One end of the pipe body 1 is provided with an inlet end 11 that communicates with the pipe body 1, and the other end is provided with an outlet end 12 that communicates with the pipe body 1.
[0046] The composite liner 2 is coaxially nested inside the pipe body 1, with both ends extending to both ends of the pipe body 1, and its outer wall is tightly fitted with the inner wall of the pipe body 1.
[0047] In this embodiment, the composite liner 2 is made of a ceramic-rubber composite liner. The ceramic component provides extremely high surface hardness, effectively resisting long-term erosion and wear from coal dust particles, thus effectively extending the service life of the pipeline. The rubber component has good elasticity and toughness, which can absorb the impact energy of coal dust particles, reducing the vibration and noise of the pipeline, while preventing the brittle ceramic from shattering under heavy impact.
[0048] Moreover, the surface of the composite liner 2 is smooth and does not easily adhere to coal powder, which greatly reduces the adsorption and friction between coal powder particles, especially fine particles with a certain degree of moisture, and the wall of the composite liner 2.
[0049] Meanwhile, the swirling synergy generated by the composite liner 2 and the guide strip 3, with its smooth wall surface ensuring low resistance for the spiral-forward coal powder flow, allows particles to slide and roll smoothly, reduces flow energy loss, maintains a high airflow velocity, and further reduces the probability of coal powder deposition.
[0050] In addition, when the self-cleaning baffle 42 is opened, the smooth composite liner 2 wall surface allows the blown coal dust to be quickly carried away when the high-speed airflow impacts the bottom coal dust, thereby preventing the coal dust from adhering again to the composite liner 2 wall around the self-cleaning baffle 42 or downstream, ensuring the thoroughness and effectiveness of each cleaning action.
[0051] The guide strip 3 extends in a spiral shape along the inner wall of the composite liner 2 to guide and lift the pulverized coal.
[0052] In this embodiment, the helical angle of the guide strip 3 is 15°-45°, and the ratio of its pitch to the pipe diameter of the pipe body 1 is 1:8-1:10.
[0053] During implementation, when the pulverized coal airflow passes through the guide bar 3, it forces the linearly moving pulverized coal airflow to change from linear motion to rotational motion, forming a strong vortex.
[0054] The centrifugal force generated by the swirling flow causes the coal powder particles to be thrown towards the wall of the composite liner 2 and move along the spiral trajectory of the guide strip 3, thus preventing the particles from settling directly to the bottom of the composite liner 2 pipe under gravity.
[0055] Furthermore, the cross-section of the guide strip 3 is a trapezoidal or arc-shaped raised strip structure, and the surface of the guide strip 3 is coated with a self-lubricating ceramic coating.
[0056] The trapezoidal or arc-shaped cross-section of the guide strip 3 can smoothly guide the airflow and reduce flow resistance. The self-lubricating ceramic coating further reduces its coefficient of friction, reduces the wear of the guide strip 3 itself, and reduces the adhesion between the coal powder and the wall of the guide strip 3.
[0057] The anti-clogging section 4 is located at the bottom of the pipe body 1 near the inlet end 11 and is used to remove coal dust deposited at the bottom of the composite liner 2.
[0058] Anti-clogging section 4 includes:
[0059] The self-cleaning tank 41 has a long groove-shaped structure with an opening at the top, and is set along the length of the pipe body 1 and communicates with the interior of the pipe body 1.
[0060] The self-cleaning tank 41 allows for the temporary accumulation of a small amount of coal dust under abnormal conditions, preventing large-area caking of coal dust at the bottom of the flat composite liner 2. It also provides installation and movement space for the self-cleaning baffle 42, allowing it to rotate and oscillate.
[0061] The self-cleaning baffle 42 is installed inside the composite liner 2 and is adapted to the self-cleaning tank 41. One end of the baffle is rotatably connected to the self-cleaning tank 41 via a rotating shaft 43.
[0062] In this embodiment, the self-cleaning baffle 42 has a double-layer structure, is set corresponding to the pipe body 1 and the composite liner 2, and is made of the same material as the pipe body 1 and the composite liner 2.
[0063] The shape of the self-cleaning baffle 42 matches the inner wall contour of the composite liner 2, and the self-cleaning baffle 42 is provided with a guide plate 421 that matches the shape of the guide strip 3.
[0064] When the pulverized coal airflow is normal, the guide plate 421 on the self-cleaning baffle 42 is smoothly connected to the guide strip 3, ensuring the continuity and stability of the swirling field and preventing the generation of eddies or additional resistance.
[0065] When the dust accumulation is severe, the self-cleaning baffle 42, as an openable movable part, releases the accumulated dust by rotation, and is the actuator for the unblocking action.
[0066] The rotating shaft 43 is located at the end of the self-cleaning tank 41 near the inlet end 11, serving as the rotation pivot of the self-cleaning baffle 42. It provides a reliable fulcrum for the rotation of the self-cleaning baffle 42, ensuring that the end of the self-cleaning baffle 42 away from the inlet end 11 can only open in one direction (downward and inward).
[0067] The counterweight 44 is fixedly installed at the bottom of the self-cleaning baffle 42 near the rotating shaft 43.
[0068] When in use, the force of gravity generates a torque that causes the self-cleaning baffle 42 to rotate upward around the pivot 43 and close. When there is no dust accumulation or the airflow is normal, the self-cleaning baffle 42 maintains a closed tendency, thus preserving the integrity of the inner wall of the composite liner 2.
[0069] In this embodiment, the weight of the counterweight 44 sets the trigger threshold for the unclogging action. When the downward torque generated by the weight of the coal dust accumulated on the self-cleaning baffle 42 exceeds the restoring torque generated by the counterweight 44, the self-cleaning baffle 42 is triggered to open downward.
[0070] In practice, multiple anti-clogging units 4 can be installed at intervals according to the length of the pipeline, or the length of the self-cleaning tank 41 can be extended to improve the cleaning effect.
[0071] In specific implementation of this utility model:
[0072] 1) Routine transportation and congestion prevention phase:
[0073] When the pulverized coal gas flows into the pipeline body 1 from the inlet end 11 at the normal design flow rate, the pipeline enters a high-efficiency anti-clogging conveying state.
[0074] Swirl generation and pulverized coal transport: The pulverized coal airflow comes into contact with the guide strips 3 on the inner wall of the composite liner 2. The spiral structure of the guide strips 3 forces the linearly moving pulverized coal airflow to transform into a high-speed rotating swirling flow. The centrifugal force generated by the swirling flow evenly throws the pulverized coal particles toward the pipe wall.
[0075] Synergistic anti-clogging of the composite liner 2 wall: Coal powder particles thrown onto the wall of the composite liner 2 spiral forward along the trajectory of the guide strip 3 under the action of centrifugal force. At this time, the smooth wall of the composite liner 2 ensures low resistance to the spiraling coal powder flow, allowing the particles to slide and roll forward smoothly, greatly overcoming the influence of gravity and avoiding static deposition of particles at the bottom of the composite liner 2 pipe.
[0076] Continuity and stability of the flow field: During this process, the self-cleaning baffle 42 of the anti-clogging section 4 is in a closed state, and the guide plate 421 on it is smoothly connected with the guide strip 3, which ensures the continuity and stability of the spiral flow field, so that the swirling flow can pass through the area without interference and with low resistance, and finally uniformly transport the coal powder to the outlet end 12.
[0077] 2) Abnormal Dust Accumulation and Automatic Unblocking Stage
[0078] When the airflow speed drops sharply due to system start-up, shutdown, or low-load operation, the swirling intensity weakens, and pulverized coal begins to deposit at the bottom of the composite liner 2.
[0079] Slight deposition: When the pulverized coal gas flow resumes, the renewed enhanced vortex can entrain and remove the slightly deposited pulverized coal.
[0080] Heavy deposition: A large amount of coal powder accumulates on the self-cleaning baffle 42. As the weight of the coal powder increases, the torque (downward turning torque) that causes the self-cleaning baffle 42 to open also gradually increases.
[0081] Triggering the unblocking action: When the downward torque generated by the weight of the accumulated dust exceeds the restoring torque generated by the counterweight 44, the self-cleaning baffle 42 rotates downward and inward around the pivot 43 to open.
[0082] High-speed airflow impact clearing: The opening of the self-cleaning baffle 42 instantly forms a local high-speed discharge channel at the bottom of the composite liner 2. The high-speed airflow behind it preferentially passes through this channel, forming a strong impact flow that quickly blows away, peels off, and transports the accumulated coal dust to the downstream mainstream area of the pipeline.
[0083] 3) Automatic reset and restoration to normal state:
[0084] After the accumulated dust in the self-cleaning tank 41 is removed, the weight of the accumulated dust acting on the self-cleaning baffle 42 disappears, and the downward torque disappears. At this time, the restoring torque generated by the gravity of the counterweight 44 drives the self-cleaning baffle 42 to automatically rotate upward until it is completely reset and tightly adheres to the inner wall of the composite liner 2 again. The guide plate 421 on its surface smoothly connects with the guide strip 3 again. The internal flow field of the composite liner 2 is instantly restored to complete, and the pipeline returns to normal operation, waiting for the next cycle.
[0085] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A pipe for pulverized coal conveying of a boiler, characterized in that, include: The pipeline body (1) has an inlet end (11) connected to the pipeline body (1) at one end and an outlet end (12) connected to the pipeline body (1) at the other end. The composite liner (2) is coaxially nested inside the pipe body (1), and its outer wall is tightly fitted with the inner wall of the pipe body (1). The guide strip (3) extends spirally along the inner wall of the composite liner (2) to guide and lift the coal powder. The anti-clogging part (4) is located at the bottom of the pipe body (1) near the inlet end (11) and is used to remove coal dust deposited at the bottom of the composite liner (2).
2. A duct for the transport of pulverized coal to a boiler as claimed in claim 1, characterized in that: The pipe body (1) is a hollow cylindrical structure with openings at both ends.
3. A duct for the transport of pulverized coal to a boiler as claimed in claim 1, characterized in that: The composite liner (2) is made of ceramic-rubber composite liner.
4. A duct for the transport of pulverized coal to a boiler as claimed in claim 1, characterized in that: The cross-section of the guide strip (3) is a trapezoidal or arc-shaped raised strip structure, and the surface of the guide strip (3) is coated with a self-lubricating ceramic coating.
5. A duct for the transport of pulverized coal to a boiler as claimed in claim 4, characterized in that: The spiral angle of the guide strip (3) is 15°-45°, and the ratio of the pitch to the pipe diameter of the pipe body (1) is 1:8-1:
10.
6. A duct for the transport of pulverized coal to a boiler as claimed in claim 1, characterized in that, The anti-clogging part (4) includes: The self-cleaning tank (41) has a long groove-shaped structure with an opening at the top, and is set along the length of the pipe body (1) and communicates with the inside of the pipe body (1). A self-cleaning baffle (42) is installed inside the composite liner (2) and is adapted to the self-cleaning tank (41). One end of the baffle is rotatably connected to the self-cleaning tank (41) via a rotating shaft (43). The counterweight (44) is fixedly installed at the bottom of the self-cleaning baffle (42) near the rotating shaft (43).
7. A duct for the transport of pulverized coal to a boiler as claimed in claim 6, characterized in that: The shape of the self-cleaning baffle (42) matches the inner wall contour of the composite liner (2), and a guide plate (421) adapted to the shape of the guide strip (3) is provided on it.
8. A duct for the transport of pulverized coal to a boiler as claimed in claim 6, characterized in that: The rotating shaft (43) is located at one end of the self-cleaning tank (41) near the inlet end (11).