Pyrite continuous drying system based on waste heat recovery and control method thereof

Abstract

The application discloses a pyrite continuous drying system based on waste heat recovery and a control method thereof, and belongs to the technical field of pyrite drying. The system mainly solves the problem that the existing drying equipment cannot dynamically adjust the drying process according to the material humidity and temperature field changes, and cannot adapt to different working conditions. The system comprises a cylinder body and a heat exchange unit rotatably installed on a rack, the inner cavity of the cylinder body is divided into multiple adjustment zones along the axial direction, an angle-adjustable scoop plate unit and an adjustment unit are arranged in each adjustment zone, and a temperature and humidity detection unit and a control unit are arranged. The control unit independently controls the scoop plate of each adjustment zone to a target angle according to the detected material humidity and the temperature of each zone. The application can adaptively adjust the angle of the scoop plate in different zones according to the real-time changing material humidity and the temperature field changing along the axial direction of the cylinder body, dynamically optimizes the drying process, and improves the adaptability to different working conditions.

Description

Technical Field

[0001] This invention relates to the field of pyrite drying technology, specifically to a continuous pyrite drying system based on waste heat recovery and its control method. Background Technology

[0002] Rotary drum dryers are commonly used equipment for drying pyrite. Inside the drum of the dryer, there are heat exchange tubes that can rotate with it. Waste heat carriers from subsequent processes (such as roasting processes) (such as sulfur dioxide gas at 600℃-900℃ generated in the roasting process) flow inside the heat exchange tubes. Lifting plates distributed on the inner wall of the drum lift the material, and the material and the waste heat carrier are dried through heat exchange.

[0003] In actual operation, as the pyrite exchanges heat with the waste heat carrier, a significant temperature gradient exists along the axial direction of the dryer's cylinder. Simultaneously, the moisture content of the pyrite entering the dryer varies depending on its source and the weather. Since the fixed-angle lifting plates cannot dynamically adjust to these real-time temperature parameters and material characteristics, the drying process cannot be dynamically optimized, thus limiting the final drying quality.

[0004] A search revealed that patent CN202709679U discloses a "Drying Device for Pyrite Ore," which utilizes the waste heat from sulfuric acid production to dry pyrite ore; patent CN223484715U discloses a "Novel High-Efficiency Mineral Drying Equipment," which features fixed-angle lifting plates on the inner wall of the cylinder. The aforementioned prior art cannot dynamically adjust the angle of the lifting plates based on real-time changes in temperature parameters and material characteristics.

[0005] Therefore, how to dynamically optimize the drying process based on the real-time changes in material humidity and the temperature field along the cylinder axis to improve adaptability to different working conditions is a technical problem that urgently needs to be solved. Summary of the Invention

[0006] To address the aforementioned shortcomings of existing technologies, this invention proposes a continuous drying system for pyrite based on waste heat recovery and its control method. This invention can dynamically optimize the drying process based on the real-time changes in material humidity and the temperature field along the axial direction of the cylinder, ensuring that the drying process is always in an optimal state and improving adaptability to different working conditions.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A continuous pyrite drying system based on waste heat recovery includes a cylinder rotatably mounted on a frame and a heat exchange unit that rotates with the cylinder. The heat exchange unit contains a waste heat carrier from subsequent processes. The inner cavity of the cylinder is divided into multiple adjustment zones along the axial direction. The system also includes: The lifting plate units are arranged along the axial direction of the cylinder in each adjustment zone, and each lifting plate unit includes multiple lifting plates distributed circumferentially along the cylinder. Adjustment units are installed along the axial direction of the cylinder in each adjustment zone. Each adjustment unit is used to adjust the angle of the lifting plate in the corresponding adjustment zone. The temperature and humidity detection unit includes temperature sensors arranged along the axial direction of the cylinder in each adjustment zone and a humidity sensor installed at the feed end of the cylinder. The control unit, based on the detection information from the humidity sensor and the temperature sensor in each adjustment zone, controls the adjustment unit in each adjustment zone to adjust the measuring plate in each adjustment zone to the target angle.

[0008] Preferably, the adjustment unit includes an angle sensor for feedback of the angle of the measuring plate in each adjustment zone, and the control unit performs closed-loop control based on the feedback signal from the angle sensor.

[0009] Preferably, the adjustment unit further includes: An annular body is fitted onto the outer wall of the cylindrical body; A driving component, disposed on the outer wall of the cylinder, is used to drive the ring body to rotate around the outer wall of the cylinder; Multiple adjusting pins are provided along the circumference of the ring body; Multiple swing rods are provided along the circumference of the cylinder. The upper part of the swing rod is provided with an adjustment elongated hole for cooperating with the adjustment pin. The middle part of the swing rod is pivotally connected to the outer wall of the cylinder. The lower part of the swing rod is connected to the lifting plate after passing through the clearance hole provided on the cylinder.

[0010] Preferably, the adjustment unit further includes a scar removal shovel, and multiple scar removal shovels are provided along the circumference of the cylinder. Each scar removal shovel slides against the inner wall of the cylinder along the circumference of the cylinder. Each scar removal shovel is provided with a through hole, and the swing rod is provided in the through hole.

[0011] Preferably, a plurality of limiting ribs are provided circumferentially inside the cylinder, with both ends of each limiting rib connected to the inner wall of the cylinder, and a sliding gap provided between the middle of each limiting rib and the inner wall of the cylinder, and the cleaning shovel is provided in the sliding gap.

[0012] Preferably, it further includes a dispersion unit, which includes: Two support frames are respectively located at the feed end and discharge end of the cylinder, and the lower end of the support frames is located on the machine frame; A dispersion plate is provided in the lower part of the inner cavity of the cylinder. The dispersion plate extends along the axial direction of the cylinder. The dispersion plate is an arc-shaped plate with the convex surface facing upward. The dispersion plate is provided with multiple hollow holes. The suspension component is adjustable in length, with its upper end movably connected to the support frame and its lower end movably connected to the dispersion plate.

[0013] Preferably, the dispersion unit further includes a distance sensor, which is used to provide feedback on the distance between the highest point of the concave surface of the dispersion plate and the bottom of the inner wall of the cylinder, and the control unit performs closed-loop control based on the feedback signal from the distance sensor.

[0014] Preferably, the heat exchange unit includes: The first hot box includes a first annular box body and a first annular box cover. The first annular box body is disposed at the feed end of the cylinder. The first annular box cover is rotatably disposed on the end face of the first annular box body. The first annular box cover is connected to the frame through a first connecting frame. The first annular box cover is provided with a hot air pipe and a cold air pipe. Both the hot air pipe and the cold air pipe are connected to the interior of the first annular box body. The second heat exchange box includes a second annular box body and a second annular box cover. The second annular box body is disposed at the discharge end of the cylinder. The second annular box cover is rotatably disposed on the end face of the second annular box body. The second annular box cover is connected to the frame through a second connecting frame. The second annular box cover is provided with a discharge pipe. Multiple heat exchange tubes are provided along the circumference of the cylinder. The heat exchange tubes and the lifting plates are spaced apart. The heat exchange tubes are used to connect the inner cavity of the first annular box and the inner cavity of the second annular box.

[0015] Preferably, the feed end of the cylinder is provided with a first guide groove for receiving pyrite from the feed conveyor. The lower end of the first guide groove is provided with two partition grooves, and a clearance area is provided between the two partition grooves. The suspension member is provided in the clearance area. The lower ends of the two partition grooves extend to the top of the dispersion plate.

[0016] A control method for a continuous pyrite drying system based on waste heat recovery, comprising the following steps: S1. The initial humidity of the pyrite entering the cylinder is detected in real time by the humidity sensor, and the control unit determines the humidity level of the current feed humidity according to the preset humidity threshold range. S2. The control unit sends a control command to the suspension component according to the humidity level and a preset humidity height mapping rule, so as to raise or lower the dispersion plate to the target height. S3. The drying temperature in each adjustment zone is collected in real time by the temperature sensors arranged in each adjustment zone, and the control unit determines the temperature level of each adjustment zone according to the preset temperature threshold range. S4. The control unit sends control commands to the adjustment units in each adjustment zone according to the humidity level and the temperature level of each adjustment zone, and according to the preset temperature and humidity angle mapping rules, so as to adjust the plate unit in each adjustment zone to the target angle.

[0017] The beneficial effects of this invention are as follows: 1. Compared to existing drying systems that rely solely on waste heat and lack dynamic adjustment, this invention divides the inner cavity of the drying drum into multiple adjustment zones and incorporates temperature and humidity detection, adjustment, and control units. This allows for independent adjustment of the target angle of the lifting plates in each zone based on real-time monitoring of the feed humidity and the drying temperature of each zone. Thus, regardless of fluctuations in drying temperature or changes in raw material humidity, the system automatically optimizes the material distribution and residence time in each zone, achieving adaptive control of the drying process, dynamically optimizing the drying process, improving adaptability to different operating conditions, and enhancing the drying effect.

[0018] 2. By setting up an adjustment unit including a ring, a driving component, an adjusting pin, and a swing arm, the present invention achieves synchronous and reliable adjustment of the angle of all the measuring plates in each zone during continuous operation of the system, which saves power and improves adjustment efficiency.

[0019] 3. By setting a cleaning shovel on the swing arm and making the cleaning shovel slide in cooperation with the inner wall of the cylinder, the swing arm can drive the cleaning shovel to move, automatically removing the material adhering to the inner wall of the cylinder. This ensures the free movement space of the lifting plate and the continuous and effective material lifting capacity, reduces the number of downtime cleanings, and improves the continuity of system operation.

[0020] 4. This invention, by setting an adjustable-height dispersing plate, can actively adjust the force of the material falling onto the inner wall of the cylinder according to the feed moisture content. The higher the material moisture content, the lower the height of the dispersing plate needs to be. The lower the height of the dispersing plate, the weaker the force of the high-moisture material falling onto the inner wall of the cylinder, thus reducing the binding force between the high-moisture material and the inner wall of the cylinder, thereby reducing the risk of scaling. This helps to reduce the difficulty of scaling removal with the scaling removal shovel, further reducing the number of downtime cleanings and ensuring the continuity of system operation.

[0021] 5. The control method of this invention divides the feed humidity into different levels and combines them with the temperature levels of each zone. By querying the preset temperature and humidity angle mapping rules, it accurately selects the optimal lifting plate angle for each adjustment zone. This control strategy transforms complex drying process experience into quantitative control logic, realizing refined and automated management of the drying process and ensuring optimized drying effects under various complex operating conditions. Attached Figure Description

[0022] Figure 1 It is a three-dimensional continuous drying system for pyrite based on waste heat recovery. Figure 1 ; Figure 2 It is a three-dimensional continuous drying system for pyrite based on waste heat recovery. Figure 2 ; Figure 3 This is a front view of a continuous pyrite drying system based on waste heat recovery; Figure 4 It is a three-dimensional diagram of a continuous pyrite drying system based on waste heat recovery after removing the first guide groove, the second guide groove, the first end cover and the second end cover. Figure 5 yes Figure 4 A magnified view of a section at point A in the middle; Figure 6 yes Figure 4 The front view from direction B in the middle; Figure 7 It is a three-dimensional assembly diagram of the cylinder, lifting plate unit, adjusting unit and sealing structure; Figure 8 yes Figure 7 A magnified view of a section at point C; Figure 9 It is a three-dimensional assembly diagram of the cylinder, lifting plate unit and adjustment unit after removing the sealing structure, cleaning scraper and limiting ribs; Figure 10 yes Figure 9 A magnified view of a section at point D; Figure 11 This is a 3D assembly diagram of the adjustment unit and the copying unit; Figure 12 It is a 3D assembly diagram of the heat exchange unit and the frame; Figure 13 It is a 3D assembly diagram of the distributed units and the rack; Figure 14 This is a three-dimensional view of the first guide groove; Figure 15 This is a 3D view of the second guide groove; Figure 16 This is a three-dimensional view of the first end cap; Figure 17 This is a three-dimensional view of the second end cap; Figure 18 This is a block diagram of the control principle.

[0023] Explanation of reference numerals in the attached figures: 1-Rack; 2-Cylinder body; 21-Allowing hole; 22-First guide groove; 221-Divider groove; 222-Allowing area; 223-First frame; 23-Second guide groove; 231-Second frame; 24-First end cover; 241-Feed window; 242-First clearance hole; 243-Connecting frame; 25-Second end cover; 251-Second clearance hole; 252-Discharge window; 26-Sealing structure; 261-Sealing cover; 262-Guide rod; 263-Guide seat; 264-Compression spring; 3-Heat exchange unit; 31-First heat header; 311-First annular housing; 312-First annular housing cover; 313-Hot air pipe; 314-Cold air pipe; 315-First connecting frame; 32-Second heat header; 321-Second annular housing; 322-Second annular housing cover; 323-Drain pipe; 324-Second connecting frame; 33-Heat exchange tube; 4-Reverse engineering unit; 41-Reverse engineering; 5-Adjusting unit; 51-Ring body; 52-Driver; 521-Mounting base; 53-Adjusting pin; 54-Swing rod; 541-Adjusting elongated hole; 55-Angle sensor; 56-Scar removal scraper; 561-Through hole; 57-Limiting rib; 571-Sliding gap; 61-Temperature sensor; 62-Humidity sensor; 7-Control unit; 8-Dispersion unit; 81-Support frame; 82-Dispersion plate; 821-Hollow hole; 83-Suspension component; 84-Distance sensor. Detailed Implementation

[0024] To better understand the present invention, further explanation is provided below with reference to the accompanying drawings.

[0025] Example 1: This embodiment describes a continuous pyrite drying system based on waste heat recovery. See [link to relevant documentation]. Figure 4 It includes a cylinder 2 rotatably mounted on a frame 1 and a heat exchange unit 3 that rotates with the cylinder 2. The heat exchange unit 3 is equipped with a waste heat carrier from subsequent processes. In this embodiment, the waste heat carrier from subsequent processes specifically includes roasting flue gas from a roasting furnace.

[0026] The core improvement of this embodiment lies in dividing the inner cavity of the cylinder 2 into multiple adjustment zones along the axial direction. In this embodiment, three adjustment zones are divided along the axial direction of the cylinder 2 from the feed end to the discharge end. See [link to relevant documentation] Figure 3 The cylinder 2 is set at an inclination, with the high end of the cylinder 2 being the feed end and the low end being the discharge end.

[0027] See Figure 7 The system also includes a lifting plate unit 4, which is arranged along the axial direction of the cylinder 2 within each adjustment zone. See [link / reference] Figure 11 Each lifting plate unit 4 includes 12 lifting plates 41 evenly distributed along the circumference of the cylinder 2.

[0028] See Figure 4 The system also includes adjustment units 5, which are arranged along the axial direction of the cylinder 2 in each adjustment zone. Each adjustment unit 5 is used to independently adjust the angle of the lifting plate 41 in the corresponding adjustment zone. The angle of the lifting plate 41 refers to the angle between the lifting plate 41 and the tangent direction of the cylinder 2.

[0029] The system also includes a temperature and humidity detection unit, which includes a temperature sensor 61 arranged along the axial direction of the cylinder 2 in each adjustment zone (for detecting the drying temperature of each adjustment zone) and a humidity sensor 62 set at the feed end of the cylinder 2 (for real-time detection of the initial humidity of the pyrite entering the cylinder 2).

[0030] See Figure 18 The system also includes a control unit 7, which is electrically connected to the temperature sensor 61, the humidity sensor 62, and each adjustment unit 5. Based on the detection information from the humidity sensor 62 and the temperature sensor 61 in each adjustment zone, the control unit 7 controls the adjustment units 5 in each adjustment zone to adjust the lifting plates 41 in each adjustment zone to their respective independent target angles according to a preset control strategy.

[0031] The working principle is as follows: Pyrite enters cylinder 2 from the feed end, and the drive unit (motor and gear structure) on the frame 1 drives cylinder 2 to rotate around its own axis. Roasting flue gas flows inside cylinder 2 through heat exchange unit 3, heating the air and material inside. Humidity sensor 62 detects the initial humidity of the pyrite entering cylinder 2, and temperature sensors 61 in each adjustment zone detect the current drying temperature of that zone. Control unit 7 integrates this information to determine the appropriate angle of the lifting plates 41 for each adjustment zone, and then drives the corresponding adjustment unit 5 to adjust the angle of all lifting plates 41 in that zone.

[0032] For example, near the feed end of cylinder 2, the drying temperature and material moisture content are highest. Adjusting the angle of the lifting plates 41 to a smaller angle (the smaller the angle, the flatter the lifting plates 41) reduces the material's lifting height, decreases the force with which it reaches the inner wall of cylinder 2, and reduces adhesion, thus lowering the risk of scaling. In the middle of cylinder 2, the drying temperature and material moisture content are lower. At this point, increasing the angle of the lifting plates 41 increases the material's lifting height, allowing for full contact with hot air and extending its residence time in the air, thus enhancing drying. Near the discharge end of cylinder 2, the drying temperature and material moisture content are lowest. Lowering the angle of the lifting plates 41 reduces the material's lifting height, allowing it to flow quickly, reducing dust and preventing over-drying. This achieves refined and adaptive control of the drying process.

[0033] Based on the above working principle, it can be seen that the drying system of this embodiment has the following advantages: This embodiment transforms static equipment into a dynamic adaptive system by using "zoning" and "online adjustment" and establishing a closed loop of "detection-control-execution". This method of independently adjusting the angle of the lifting plates 41 in each adjustment zone of the cylinder 2 based on real-time humidity and temperature information enables refined and adaptive control of the drying process.

[0034] Example 2: This embodiment provides a preferred implementation of the adjustment unit 5 in Embodiment 1.

[0035] See Figure 11 The adjustment unit 5 includes a ring 51, a driving component 52, an adjusting pin 53, and a rocker arm 54. (See also...) Figure 9 The ring 51 is fitted onto the outer wall of the cylinder 2 and can rotate relative to the cylinder 2. (See also...) Figure 10 A driving component 52 is disposed on the outer wall of the cylinder 2 and is used to drive the ring 51 to rotate around the outer wall of the cylinder 2. The driving component 52 is preferably a telescopic component (such as an electric push rod). One end of the telescopic component is pivotally connected to the ring 51, and the other end of the telescopic component is pivotally connected to the mounting seat 521 fixedly installed on the outer wall of the cylinder 2. Twelve adjusting pins 53 are provided along the circumference of the ring 51. Twelve swing rods 54 are provided along the circumference of the cylinder 2. The upper part of the swing rod 54 is provided with an adjusting elongated hole 541 for cooperating with the adjusting pins 53. The middle part of the swing rod 54 is pivotally connected to the outer wall of the cylinder 2 through a pivot. The lower part of the swing rod 54 is fixedly connected to the lifting plate 41 after passing through the clearance hole 21 provided on the cylinder 2.

[0036] See Figure 5 To reduce material leakage from the cylinder 2 through the clearance hole 21 to the outside of the cylinder 2, a sealing structure 26 is installed on the cylinder 2. The sealing structure 26 includes arc-shaped sealing covers 261 located on both sides of the swing direction of the swing rod 54. Both sealing covers 261 abut against the swing rod 54 at their ends near the swing rod 54, and arc-shaped guide rods 262 are welded and fixed to the other ends of both sealing covers 261. The guide rods 262 slide in cooperation with guide seats 263 welded and fixed to the outer wall of the cylinder 2 along the circumference of the cylinder 2. A compression spring 264 is fitted on the guide rod 262, providing a driving force to the sealing covers 261 to keep them in contact with the swing rod 54. When the swing rod 54 swings around its pivot, the two sealing covers 261 remain in contact with the swing rod 54, thus maintaining the cover over the clearance hole 21, thereby reducing material leakage from the cylinder 2 to the outside of the cylinder 2 through the clearance hole 21.

[0037] To accurately achieve online adjustment of the lifting plate 41, the adjustment unit 5 also includes an angle sensor 55, used to provide feedback on the actual angle of the lifting plate 41 in each adjustment zone (this angle can be indirectly obtained by detecting the rotation angle of the swing arm 54; in this case, the angle sensor 55 can be coaxially mounted on a pivot in the adjustment unit 5, see [reference]). Figure 5 or Figure 10 The control unit 7 performs closed-loop control based on the feedback signal from the angle sensor 55.

[0038] The working principle is as follows: When the angle of the lifting plate 41 in a certain adjustment zone needs to be adjusted, the control unit 7 issues a command to control the drive component 52 (telescopic component) of the corresponding adjustment zone to rotate the ring 51 around the cylinder 2 by an angle. The rotation of the ring 51 causes the adjusting pin 53 on it to make a circular motion. The adjusting pin 53 slides in the adjusting elongated hole 541 of the swing rod 54, thereby forcing the swing rod 54 to swing together with the pivot in its middle about the axis of the pivot. The swing of the swing rod 54 causes the lifting plate 41 connected to its lower part to swing inside the cylinder 2, thereby changing the tangential direction of the lifting plate 41 relative to the cylinder 2, that is, changing the lifting angle. At the same time, the angle sensor 55 detects the actual angle of the lifting plate 41 in real time and feeds it back to the control unit 7. The control unit 7 compares the feedback value with the target angle. If there is a deviation, it continues to control the drive component 52 to fine-tune until the preset target angle is reached.

[0039] Based on the above working principle, it can be seen that Embodiment 2 has the following advantages: In this embodiment, the adjustment unit 5 cleverly converts the linear motion of the drive member 52 into the rotational motion of the ring body 51. Through the cooperation of the adjustment pin 53 and the adjustment elongated hole 541, it is further converted into the swinging motion of the swing rod 54, thereby changing the angle of the lifting plate 41. This design only requires one power source, the drive member 52, to drive all the circumferentially distributed swing rods 54 to swing, thereby simultaneously adjusting the angle of all the circumferentially distributed lifting plates 41. This improves the synchronization of adjustment, increases the adjustment efficiency, and helps to save energy.

[0040] The introduction of angle sensor 55 enables the adjustment unit 5 to provide feedback on the adjustment angle of the copy plate 41, allowing the control unit 7 to perform closed-loop control based on the feedback signal from angle sensor 55, thereby improving the accuracy and reliability of the angle adjustment of the copy plate 41.

[0041] Example 3: This embodiment adds a scar-removing function to Embodiment 2. See also... Figure 7 and Figure 8 The adjusting unit 5 also includes a cleaning shovel 56. Twelve cleaning shovels 56 are arranged along the circumference of the cylinder 2. Each cleaning shovel 56 slides against the inner wall of the cylinder 2 along the circumference of the cylinder 2. Each cleaning shovel 56 has a through hole 561, and a swing rod 54 passes through the through hole 561. When the swing rod 54 swings, it will drive the cleaning shovel 56 to move along the circumference of the cylinder 2, thereby removing the material scale on the inner wall of the cylinder 2.

[0042] See Figure 7 and Figure 8To guide and limit the cleaning spatula 56 and prevent it from leaving the inner wall of the cylinder 2, multiple limiting ribs 57 are provided circumferentially inside the cylinder 2. The two ends of each limiting rib 57 are welded and fixed to the inner wall of the cylinder 2, and a sliding gap 571 is left between the middle of each limiting rib 57 and the inner wall of the cylinder 2. The cleaning spatula 56 is accommodated in the sliding gap 571 and can slide within the sliding gap 571 circumferentially around the cylinder 2.

[0043] The working principle is as follows: When the swing arm 54 in the adjusting unit 5 swings, it drives the cleaning shovel 56 to move circumferentially along the inner wall of the cylinder 2, thereby removing material buildup on the inner wall of the cylinder 2 and clearing away accumulated material that may obstruct the movement of the swing arm 54. At the same time, the cleaning shovel 56 slides in the sliding gap 571 between the limiting rib 57 and the inner wall of the cylinder 2, so that the surface of the cleaning shovel 56 is also scraped by the limiting rib 57, realizing the self-cleaning of the cleaning shovel 56. Furthermore, the limiting rib 57 set on the inner wall of the cylinder 2 can also lift up the bottom material close to the inner wall of the cylinder 2, helping the bottom material to dry.

[0044] Based on the above working principle, it can be seen that the improvement of this embodiment has the following advantages: This embodiment integrates the scar removal function with the angle adjustment function of the lifting plate 41. The driving force of the scar removal shovel 56 comes directly from the swing arm 54 of the lifting plate 41, without the need for an additional power source, achieving a linkage effect of "adjustment equals scar removal". The above-mentioned "adjustment equals scar removal" design not only solves the problem of scar formation on the inner wall of the cylinder 2, but also ensures the flexibility of the angle adjustment of the lifting plate 41.

[0045] Furthermore, the scar-removing shovel 56 is not only guided and limited by the limiting rib 57, but also scraped by the limiting rib 57, thus achieving self-cleaning of the scar-removing shovel 56; the limiting rib 57 can also lift up the bottom material close to the inside of the cylinder 2, helping the bottom material to dry.

[0046] Example 4 This embodiment adds a distributed adjustment function based on any one of embodiments 1-3.

[0047] See Figure 4 or Figure 6 or Figure 13The system also includes a dispersion unit 8. The dispersion unit 8 includes two support frames 81, two suspension members 83, and a dispersion plate 82. The two support frames 81 are respectively located outside the feed end and discharge end of the cylinder 2, with the lower end of the support frames 81 fixed to the frame 1. The dispersion plate 82 is located in the lower part of the inner cavity of the cylinder 2, extending along the axial direction of the cylinder 2. The dispersion plate 82 is a convex-facing arc-shaped plate with multiple perforated holes 821 for hot air circulation. The length of the suspension member 83 is adjustable. The suspension member 83 can specifically be a telescopic rod (such as an electric push rod or a hydraulic cylinder). The upper end of the telescopic rod is movably connected to the support frame 81 (e.g., hook connection), and the lower end of the telescopic rod is movably connected to the dispersion plate 82 (e.g., hook connection).

[0048] The working principle is as follows: When the material entering the cylinder 2 is under high humidity conditions (humidity > 10%), the length of the suspension component 83 is increased, and the dispersing plate 82 is adjusted to a lower position. That is, the distance from the highest point of the concave surface of the dispersing plate 82 to the bottom of the inner wall of the cylinder is (0.1~0.2)R, where R is the radius of the cylinder. After the dispersing plate 82 is lowered, the distance that the high-humidity material falls from the dispersing plate 82 to the inner wall of the cylinder 2 is shortened. The force of the high-humidity material falling onto the inner wall of the cylinder 2 with a shorter falling distance is reduced, which weakens the bonding force between the high-humidity material and the inner wall of the cylinder 2, thereby reducing the risk of scaling.

[0049] When the material entering the cylinder 2 is in a medium-moisture condition (humidity of 5% to 10%), the dispersing plate 82 is adjusted to the middle position, i.e., the distance is (0.3~0.4)R. At this time, the risk of scaling of medium-moisture material is reduced compared with high-moisture material (because the viscosity of medium-moisture material is reduced). Appropriately increasing the distance from the dispersing plate 82 to the inner wall of the cylinder 2 can increase the contact area between the medium-moisture material and the hot airflow, thus accelerating drying.

[0050] When the material entering the cylinder 2 is under low-humidity conditions (humidity <5%), the dispersing plate 82 is adjusted to a high position, i.e., the distance is (0.5~0.6)R. At this time, the risk of scaling of the low-humidity material is further reduced, and the distance from the dispersing plate 82 to the inner wall of the cylinder 2 can be appropriately increased, which can further increase the contact area between the low-humidity material and the hot airflow, and further accelerate the drying process.

[0051] When the material is lifted by the lifting plates 41 inside the cylinder 2, it falls onto the dispersing plates 82 for further dispersion, allowing for more thorough contact between the material and the hot air, thus improving the drying effect. Furthermore, the dispersing plates 82 cushion the material during its descent, reducing the contact force between the material and the inner wall of the cylinder 2. This reduces the risk of scaling and also minimizes impact wear on the cylinder 2, extending its service life.

[0052] Because the upper end of the suspension component 83 is movably connected to the support frame 81, and the lower end of the suspension component 83 is movably connected to the dispersing plate 82, the dispersing plate 82 can swing inside the cylinder 2. This allows the dispersing plate 82 to cushion the impact of materials, thus reducing the impact and extending the service life of the dispersing unit 8. The swinging motion of the dispersing plate 82 makes the trajectory of the material sliding off the dispersing plate 82 more flexible, resulting in a larger dispersion range and further enhancing the contact area between the dispersed material and the hot airflow, thereby improving the drying effect.

[0053] Based on the above working principle, it can be seen that this embodiment has the following effects: In this embodiment, the dispersing plate 82 is designed with adjustable height and linked to humidity detection. This allows for proactive adjustment of the material's falling height during the initial drying stage, optimizing the initial contact conditions between the material and the waste heat carrier and creating favorable conditions for subsequent efficient drying. When the material has high humidity, the falling height is reduced to decrease the risk of scaling; when the humidity is medium or low, the falling height is increased to accelerate drying.

[0054] To precisely control the height of the dispersing plate 82, the dispersing unit 8 also includes a distance sensor 84 (such as a laser rangefinder or ultrasonic rangefinder) to provide real-time feedback on the distance between the highest point of the concave surface of the dispersing plate 82 and the bottom of the inner wall of the cylinder 2. The distance sensor 84 can be installed on the dispersing plate 82 near the feed end of the cylinder 2, and its signal line can be led out along the suspension member 83. The control unit 7 performs closed-loop control on the extension and retraction of the suspension member 83 based on the feedback signal from the distance sensor 84 to ensure that the dispersing plate 82 accurately reaches the target height.

[0055] Example 5: This embodiment describes the structure of the heat exchange unit 3 in detail, based on embodiment 4.

[0056] See Figure 4 and Figure 12 The heat exchange unit 3 includes a first heat exchange box 31 located at the feed end of the cylinder 2, a second heat exchange box 32 located at the discharge end of the cylinder 2, and 12 heat exchange tubes 33 arranged along the circumference of the cylinder 2.

[0057] See Figure 4 The first thermal connector 31 includes a first annular housing 311 and a first annular cover 312. The first annular housing 311 is fixedly installed at the feed end of the cylinder 2 and rotates with the cylinder 2. A first annular groove is provided on the inner circumference of the front end of the first annular housing 311. The first annular cover 312 is rotatably fitted in the first annular groove, and the first annular cover 312 is fixedly assembled with the frame 1 through a first connecting bracket 315. To improve the sealing performance of the first thermal connector 31, a graphite sealing gasket is installed on the groove wall of the first annular groove to fill the gap between the first annular cover 312 and the first annular groove.

[0058] See Figure 4 A hot air pipe 313 and a cold air pipe 314 are welded and fixed to the first annular cover 312, both of which connect to the interior of the first annular box 311. The hot air pipe 313 is connected to the waste heat carrier (roasting flue gas) of subsequent processes (such as a roasting furnace), and the cold air pipe 314 can be connected to the atmosphere or a cold air source to regulate the flue gas temperature. A temperature measuring element (such as a temperature sensor) is also fixedly installed on the first annular cover 312 to detect the temperature inside the first annular box 311.

[0059] See Figure 12 The second heat exchanger 32 includes a second annular housing 321 and a second annular cover 322. The second annular housing 321 is fixedly installed at the discharge end of the cylinder 2. A second annular groove is provided on the inner circumference of the rear end of the second annular housing 321. The second annular cover 322 is rotatably fitted in the second annular groove. The second annular cover 322 is fixedly assembled with the frame 1 through a second connecting bracket 324. To improve the sealing performance of the second heat exchanger 32, a graphite sealing gasket is installed on the groove wall of the second annular groove to fill the gap between the second annular cover 322 and the second annular groove.

[0060] See Figure 12 The end face of the second annular box cover 322 is welded and fixed with a discharge pipe 323, which is used to pass the heat-exchanged flue gas to the subsequent flue gas treatment system. For example, the roasting flue gas from the roasting furnace is sulfur dioxide flue gas. After the drying system has used up the heat of the sulfur dioxide flue gas, the sulfur dioxide flue gas is passed to the subsequent flue gas treatment system, which is the acid production system, through the discharge pipe 323.

[0061] See Figure 6 Twelve heat exchange tubes 33 are arranged alternately with twelve circumferentially distributed lifting plates 41. (See also...) Figure 12 The two ends of the heat exchange tube 33 are respectively connected to the inner cavity of the first annular box 311 and the inner cavity of the second annular box 321. The temperature sensor 61 in Embodiment 1 can be installed on the heat exchange tube 33, or the temperature sensor 61 can be directly installed on the cylinder wall of the cylinder 2.

[0062] The working principle is as follows: The roasting flue gas from the roasting furnace enters the first annular box 311 through the hot gas pipe 313, and then disperses into 12 heat exchange tubes 33. The heat exchange tubes 33 exchange heat with the material inside the cylinder 2 while rotating with the cylinder 2, and finally converge into the second annular box 321 and are discharged from the exhaust pipe 323.

[0063] When the temperature of the roasting flue gas is too high, such as exceeding 800°C, it is necessary to supplement with cold air for regulation. The cold air enters the first annular chamber 311 through the cold air pipe 314 and mixes with the roasting flue gas. Since the cylinder 2 rotates together with the first annular chamber 311, the roasting flue gas and cold air entering the first annular chamber 311 can mix more thoroughly, making the hot air supplied to the multiple heat exchange tubes 33 more uniform.

[0064] Based on the above working principle, it can be seen that this embodiment has the following advantages: In this embodiment, the heat exchange unit 3 achieves stable introduction and extraction of the waste heat carrier while the cylinder 2 is rotating, resulting in a compact structure. Furthermore, the rotational motion of the cylinder 2 assists in mixing the waste heat carrier and cold air located inside the first heat header 31, improving the uniformity of heating.

[0065] Example 6: This embodiment, based on embodiment 4 or 5, provides the feeding and discharging structure of cylinder 2.

[0066] See Figure 1 or Figure 14 The cylinder 2 has a first guide groove 22 at its feed end for receiving pyrite from a feed conveyor (such as a screw conveyor or belt conveyor). A first frame 223 is fixedly installed on the bottom surface of the first guide groove 22, and the first frame 223 is installed on the ground. The lower end of the first guide groove 22 has two integrally formed partition grooves 221, with a clearance area 222 between them. A suspension member 83 passes through the clearance area 222. The lower ends of both partition grooves 221 extend above the dispersing plate 82, evenly guiding the material to both sides of the dispersing plate 82. A humidity sensor 62 is installed inside the first guide groove 22 to detect the humidity of the incoming material.

[0067] See Figure 2 or Figure 15 The discharge end of the cylinder 2 is provided with a second guide groove 23, which is used to guide the dried pyrite to the unloading conveyor (such as a screw conveyor or belt conveyor). The bottom surface of the second guide groove 23 is fixedly installed with a second frame 231, which is also fixedly installed on the ground.

[0068] See Figure 1 or Figure 16 The feed end of the cylinder 2 is also provided with a first end cover 24, on which a feed window 241 is provided, through which a first guide groove 22 passes. The first end cover 24 is fixedly installed on the first frame 223 below the first guide groove 22 by a connecting bracket 243, so that the first end cover 24 will not rotate with the cylinder 2. The upper part of the first end cover 24 is provided with a first clearance hole 242, through which the suspension member 83 located at the feed end of the cylinder 2 passes.

[0069] See Figure 2 or Figure 17 The discharge end of the cylinder 2 is provided with a second end cap 25, which is fixedly connected to the second annular box cover 322. Because the second annular box cover 322 does not rotate with the cylinder 2, the second end cap 25 located on the second annular box cover 322 also does not rotate with the cylinder 2. The upper part of the second end cap 25 is provided with a second clearance hole 251, through which the suspension member 83 located at the discharge end of the cylinder 2 passes. The lower part of the second end cap 25 is provided with a discharge window 252, and a second guide groove 23 is provided below the discharge window 252. The dried material falls from the discharge window 252 and enters the second guide groove 23.

[0070] The working principle is as follows: The pyrite from the feed conveyor falls into the first guide trough 22. The pyrite in the first guide trough 22 falls into the dispersing plate 82 through the two partition troughs 221 at its lower end. The pyrite on the dispersing plate 82 slides down the arc of the dispersing plate 82 into the cylinder 2. The pyrite in the cylinder 2 is dried. When the pyrite reaches the discharge end of the cylinder 2, it falls into the second guide trough 23 through the discharge window 252. Then it slides down from the second guide trough 23 onto the unloading conveyor, which transports it to the subsequent process.

[0071] Based on the above working principle, it can be seen that this embodiment has the following advantages: Two dividing grooves 221 are provided at the lower end of the first guide groove 22, forming a clearance area 222 in the middle for the suspension member 83 to pass through. This design cleverly utilizes the limited space, avoids interference with the suspension member 83, and at the same time, the two dividing grooves 221 guide the flow, ensuring that the material can fall evenly on both sides of the dispersing plate 82, resulting in a compact structure.

[0072] Example 7: This embodiment provides a control method for a continuous drying system for pyrite based on waste heat recovery, which is implemented based on a drying system as described in Embodiments 4, 5, or 6.

[0073] This control method includes the following steps: S1. The initial humidity of the pyrite entering the cylinder 2 is detected in real time by the humidity sensor 62. The control unit 7 determines the humidity level of the current feed humidity according to the preset humidity threshold range.

[0074] If the humidity is >10%, it is considered a high humidity condition; if the humidity is 5% ~ 10%, it is considered a medium humidity condition; if the humidity is <5%, it is considered a low humidity condition.

[0075] S2 and control unit 7, based on the humidity level determined by S1, send control commands to suspension component 83 according to the preset "humidity height mapping rule" to raise and lower the dispersion plate 82 to the target height.

[0076] The "humidity height mapping rule" is as follows: Under high humidity conditions, the dispersion plate 82 is adjusted to a low position, that is, the distance between the highest point of the concave surface of the dispersion plate 82 and the bottom of the inner wall of the cylinder 2 is (0.1~0.2)R, where R is the radius of the cylinder 2.

[0077] Under medium humidity conditions, the dispersion plate 82 is adjusted to the middle position, i.e., the distance is (0.3~0.4)R.

[0078] Under low humidity conditions, the dispersion plate 82 is adjusted to a high position, i.e., the distance is (0.5~0.6)R.

[0079] S3. The drying temperature in each adjustment zone is collected in real time by temperature sensors 61 arranged in each adjustment zone. The control unit 7 independently determines the temperature level of each adjustment zone according to the preset temperature threshold range.

[0080] If the temperature is >600℃, it is determined to be a high temperature zone; if the temperature is between 300℃ and 600℃, it is determined to be a medium temperature zone; if the temperature is <300℃, it is determined to be a low temperature zone.

[0081] S4 and control unit 7, based on the humidity level obtained in S1 and the temperature level of each adjustment zone obtained in S3, send independent control commands to the adjustment unit 5 of each adjustment zone according to the preset "temperature, humidity and angle mapping rules" to adjust the reading plate 41 in each adjustment zone to its respective target angle.

[0082] The "Temperature and Humidity Angle Mapping Rule" is a rule that combines humidity and temperature levels and maps them to a specific 41° angle range on a reverse-reading board, as follows: For high-temperature areas under high humidity conditions, the angle of the lifting plate should be adjusted to 15°~20°. For the medium temperature range under high humidity conditions, the angle of the lifting plate should be adjusted to 40°~45°. For the low-temperature zone under high humidity conditions, the angle of the lifting plate should be adjusted to 25°~30°. For the high-temperature zone under medium humidity conditions, the angle of the lifting plate should be adjusted to 25°~30°. For the medium temperature range under medium humidity conditions, the angle of the lifting plate should be adjusted to 40°~45°. For the low-temperature zone under medium humidity conditions, the angle of the lifting plate 41 should be adjusted to 15°~20°. For high-temperature zones under low-humidity conditions, the angle of the lifting plate should be adjusted to 30°~35°. For medium temperature range under low humidity conditions, the angle of the lifting plate should be adjusted to 40°~45°. For low-temperature zones under low-humidity conditions, the angle of the lifting plate 41 should be adjusted to 10°~15°.

[0083] In the above temperature and humidity angle mapping rules, under the same humidity conditions, the temperature field distribution along the axis of the cylinder 2 is successively a high-temperature zone, a medium-temperature zone, and a low-temperature zone. Correspondingly, the material has high humidity and high surface viscosity in the initial stage of drying. At this time, the material in the initial stage of drying is located in the high-temperature zone environment. Compared with the medium-temperature zone and the low-temperature zone, the high-temperature zone uses lifting plates 41 with smaller angles to achieve low throwing and low spraying, reducing the contact force between the material and the inner wall of the cylinder 2, and reducing the residence time of the material in the air (the smaller the angle of the lifting plate 41, the lower the height of the material thrown, and the shorter the residence time of the material in the air), preventing the material from sticking to the wall and forming scale. In the middle stage of drying, the surface of the material is dry and the particles are loose. The material in the middle stage of drying is located in the medium-temperature zone. In this area, the internal moisture of the material migrates to the surface. Compared with the high-temperature zone, the lifting plates 41 with larger angles can throw the material at high altitudes, enhancing heat exchange. In the final stage of drying, the material is basically dried. The material in the final stage of drying is located in the low-temperature zone. Compared with the medium-temperature zone, reducing the angle of the lifting plates 41 can reduce dust.

[0084] In the high-temperature zone, the lifting plate angle 41° increases sequentially for high-humidity, medium-humidity, and low-humidity conditions. This is because high-humidity materials have the highest moisture content and viscosity, while medium-humidity and low-humidity materials have relatively lower moisture content and viscosity. Reducing the lifting plate angle 41° for high-humidity materials can lower the risk of wall adhesion and scaling, while increasing the lifting plate angle 41° for medium-humidity and low-humidity materials can balance heat exchange and reduce scaling.

[0085] In the low-temperature zone, the lifting plate angle 41 decreases sequentially for high-humidity conditions, medium-humidity conditions, and low-humidity conditions. This is to allow low-humidity materials to pass through more quickly, avoid over-drying, and reduce dust generated by low-humidity materials. It also allows high-humidity materials to dry more thoroughly, and medium-humidity materials to achieve both drying and dust reduction.

[0086] Through the above control method, it can be seen that this embodiment has the following advantages: The control method in this embodiment uses humidity as a global variable and temperature as a local variable to coordinate the control of the dispersing plate 82 and the lifting plate 41, forming a predictive and adaptive control strategy. This dynamically optimizes the height of the dispersing plate 82 and the lifting angle of the lifting plates 41 in each zone, ensuring the entire drying process is always in optimal working condition, thus achieving efficient, energy-saving, and stable drying operations. This control method uses discretized and graded humidity and temperature parameters, which reduces the complexity of control and better reflects the actual conditions of industrial sites.

Claims

1. A continuous pyrite drying system based on waste heat recovery, comprising a cylinder rotatably mounted on a frame and a heat exchange unit rotating with the cylinder, wherein the heat exchange unit contains a waste heat carrier from subsequent processes, and the inner wall of the cylinder is provided with lifting plates, characterized in that, The inner cavity of the cylinder is divided into multiple adjustment zones along the axial direction, and also includes: The lifting plate units are arranged along the axial direction of the cylinder in each adjustment zone, and each lifting plate unit includes multiple lifting plates distributed circumferentially along the cylinder. Adjustment units are arranged along the axial direction of the cylinder in each adjustment zone. Each adjustment unit is used to adjust the angle of the lifting plate in the corresponding adjustment zone. The temperature and humidity detection unit includes temperature sensors arranged along the axial direction of the cylinder in each adjustment zone and a humidity sensor installed at the feed end of the cylinder. The control unit, based on the detection information from the humidity sensor and the temperature sensor in each adjustment zone, controls the adjustment unit in each adjustment zone to adjust the measuring plate in each adjustment zone to the target angle.

2. The continuous pyrite drying system based on waste heat recovery according to claim 1, characterized in that, The adjustment unit includes an angle sensor for feedback of the angle of the measuring plate in each adjustment zone, and the control unit performs closed-loop control based on the feedback signal from the angle sensor.

3. The continuous pyrite drying system based on waste heat recovery according to claim 2, characterized in that, The adjustment unit further includes: An annular body is fitted onto the outer wall of the cylindrical body; A driving component, disposed on the outer wall of the cylinder, is used to drive the ring body to rotate around the outer wall of the cylinder; Multiple adjusting pins are provided along the circumference of the ring body; Multiple swing rods are provided along the circumference of the cylinder. The upper part of the swing rod is provided with an adjustment elongated hole for cooperating with the adjustment pin. The middle part of the swing rod is pivotally connected to the outer wall of the cylinder. The lower part of the swing rod is connected to the lifting plate after passing through the clearance hole provided on the cylinder.

4. The continuous pyrite drying system based on waste heat recovery according to claim 3, characterized in that, The adjustment unit also includes a scar removal shovel, which has multiple shovels arranged along the circumference of the cylinder. Each shovel slides along the circumference of the cylinder and is engaged with the inner wall of the cylinder. Each shovel has a through hole, and the swing rod is arranged in the through hole.

5. The continuous pyrite drying system based on waste heat recovery according to claim 4, characterized in that, Multiple limiting ribs are provided circumferentially inside the cylinder. The two ends of each limiting rib are connected to the inner wall of the cylinder. A sliding gap is provided between the middle of each limiting rib and the inner wall of the cylinder. The cleaning shovel is provided in the sliding gap.

6. The continuous pyrite drying system based on waste heat recovery according to claim 1, characterized in that, It also includes a distributed unit, which includes: Two support frames are respectively located at the feed end and discharge end of the cylinder, and the lower end of the support frames is located on the machine frame; A dispersion plate is provided in the lower part of the inner cavity of the cylinder. The dispersion plate extends along the axial direction of the cylinder. The dispersion plate is an arc-shaped plate with the convex surface facing upward. The dispersion plate is provided with multiple hollow holes. The suspension component is adjustable in length, with its upper end movably connected to the support frame and its lower end movably connected to the dispersion plate.

7. The continuous pyrite drying system based on waste heat recovery according to claim 6, characterized in that, The dispersion unit also includes a distance sensor, which is used to provide feedback on the distance between the highest point of the concave surface of the dispersion plate and the bottom of the inner wall of the cylinder. The control unit performs closed-loop control based on the feedback signal from the distance sensor.

8. The continuous pyrite drying system based on waste heat recovery according to claim 6, characterized in that, The heat exchange unit includes: The first hot box includes a first annular box body and a first annular box cover. The first annular box body is disposed at the feed end of the cylinder. The first annular box cover is rotatably disposed on the end face of the first annular box body. The first annular box cover is connected to the frame through a first connecting frame. The first annular box cover is provided with a hot air pipe and a cold air pipe. Both the hot air pipe and the cold air pipe are connected to the interior of the first annular box body. The second heat exchange box includes a second annular box body and a second annular box cover. The second annular box body is disposed at the discharge end of the cylinder. The second annular box cover is rotatably disposed on the end face of the second annular box body. The second annular box cover is connected to the frame through a second connecting frame. The second annular box cover is provided with a discharge pipe. Multiple heat exchange tubes are provided along the circumference of the cylinder. The heat exchange tubes and the lifting plates are spaced apart. The heat exchange tubes are used to connect the inner cavity of the first annular box and the inner cavity of the second annular box.

9. The continuous pyrite drying system based on waste heat recovery according to claim 8, characterized in that, The feed end of the cylinder is provided with a first guide groove, which is used to receive pyrite from the feed conveyor. The lower end of the first guide groove is provided with two partition grooves, and a clearance area is provided between the two partition grooves. The suspension component is provided in the clearance area. The lower ends of the two partition grooves extend to the top of the dispersion plate.

10. A control method for a continuous pyrite drying system based on waste heat recovery, characterized in that, The continuous pyrite drying system based on waste heat recovery as described in any one of claims 6-9 includes the following steps: S1. The initial humidity of the pyrite entering the cylinder is detected in real time by the humidity sensor, and the control unit determines the humidity level of the current feed humidity according to the preset humidity threshold range. S2. The control unit sends a control command to the suspension component according to the humidity level and a preset humidity height mapping rule, so as to raise or lower the dispersion plate to the target height. S3. The drying temperature in each adjustment zone is collected in real time by the temperature sensors arranged in each adjustment zone, and the control unit determines the temperature level of each adjustment zone according to the preset temperature threshold range. S4. The control unit sends control commands to the adjustment units in each adjustment zone according to the humidity level and the temperature level of each adjustment zone, and according to the preset temperature and humidity angle mapping rules, so as to adjust the plate unit in each adjustment zone to the target angle.

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