A rotary dryer for drying particulate material

Abstract

This invention relates to the field of dryer technology, specifically to a rotary dryer for granular materials, comprising a support frame, a main cylinder, and a screening cylinder. The main cylinder is inclined on the support frame and can rotate around its own axis. A lifting section is provided inside the main cylinder, comprising multiple lifting plates evenly distributed on the inner circumferential wall of the main cylinder, the lifting plates having an L-shaped structure. The screening cylinder is located inside the main cylinder and coaxial with it, and has screening holes, with the hole diameter gradually increasing in the rotation direction of the main cylinder. This rotary dryer for granular materials, by incorporating a screening cylinder within the main cylinder, achieves material grading and staggered descent. Larger particle sizes result in longer rotation paths, higher lifting heights, later descent times, and longer contact time with hot air, thus improving the uniformity of material descent and the stability of material drying quality.

Description

Technical Field

[0001] This invention relates to the field of dryer technology, and more specifically to a rotary dryer for granular materials. Background Technology

[0002] Granular materials (such as ammonium sulfate and fertilizer granules) often contain a certain amount of moisture during production and need to be dried to reduce their moisture content in order to ensure the material's storage stability, performance, and subsequent processing quality. Rotary dryers, with their advantages of large processing capacity and continuous operation capability, have become the mainstream equipment for drying granular materials, especially in the drying of large quantities of granular materials such as ammonium sulfate. They typically use hot air generated from natural gas combustion as the heat source to achieve efficient and large-scale drying.

[0003] During operation, material enters the drum from the feed end and rotates with the drum. L-shaped lifting plates continuously tumble and drop the material, allowing it to come into contact with the hot air entering the drum. Heat exchange removes moisture from the material, and the dried material exits from the discharge port. This continuous feeding and drum rotation enables large-scale continuous production. However, in existing rotary dryers, during drum rotation, a large amount of material tumbled by the L-shaped lifting plates is often thrown back down during the lifting phase. The concentrated and short descent path of the material results in some material being discharged before it is fully dried, affecting the stability of the drying quality. Summary of the Invention

[0004] This invention provides a rotary dryer for granular materials to solve the problem that in existing rotary dryers, during the rotation of the drum, the material lifted by the L-shaped lifting plates is often thrown down in large quantities during the lifting stage. The material falls along a concentrated path and for a short time, resulting in some material being discharged before it is fully dried, which affects the stability of the drying quality.

[0005] The present invention provides a rotary dryer for granular materials, comprising a support frame, a main cylinder, and a screening cylinder. The main cylinder is inclinedly mounted on the support frame and can rotate around its own axis. A feed cylinder and a discharge cylinder are rotatably connected to both ends of the main cylinder, with the feed cylinder located above the discharge cylinder. The feed cylinder has a feed inlet and an air outlet, and the discharge cylinder has a discharge outlet and an air inlet. A lifting section is provided inside the main cylinder, arranged along the axial direction of the main cylinder. The lifting section includes multiple lifting plates and multiple... The lifting plates are evenly distributed on the inner circumferential wall of the main cylinder, and the lifting plates have an L-shaped structure. The screening cylinder is located inside the main cylinder and is coaxial with the main cylinder. The two ends of the screening cylinder are connected to the feed cylinder and the discharge cylinder, respectively. In the radial direction of the main cylinder, there is a gap between the lifting plates and the screening cylinder. The screening cylinder has an arc-shaped structure. During the rotation of the main cylinder, the arc length traversed by the lifting plates from the start to the end of the throwing process is called the throwing section, and the screening cylinder is located on the throwing section. Screening holes are opened on the screening cylinder, and the diameter of the screening holes gradually increases in the rotation direction of the main cylinder.

[0006] Furthermore, the lifting plate includes a long side plate and a short side plate. The long side plate is arranged along the radial direction of the cylinder and fixedly installed inside the cylinder. Multiple filter holes are opened on the long side plate. The short side plate is arranged in the circumferential direction of the cylinder and fixedly connected to the long side plate. Multiple discharge holes are opened on the short side plate. The diameter of the filter holes is smaller than the diameter of the discharge holes, and the diameter of the discharge holes is smaller than the diameter of any screening hole.

[0007] Furthermore, multiple lifting sections are provided; multiple guide sections are also provided inside the main cylinder, and the multiple guide sections and multiple lifting sections are arranged sequentially in the axial direction of the main cylinder, and the guide sections and lifting sections are alternately distributed in the axial direction of the main cylinder; the guide section includes multiple guide plates, which are evenly distributed on the inner circumferential wall of the main cylinder, and the guide plates are spiral plates.

[0008] Furthermore, the main cylinder also includes a rotating shaft and a support cylinder. The rotating shaft is coaxial with the main cylinder, and its two ends are connected to the feed cylinder and the discharge cylinder, respectively. The support cylinder has an arc-shaped structure and is coaxial with the main cylinder. The support cylinder and the screening cylinder are evenly distributed around the axis of the main cylinder and connected end to end in sequence. The support cylinder includes multiple support rings, which are spaced apart in the axial direction of the main cylinder. Multiple support groups are provided in the axial direction of the rotating shaft. Each support group includes multiple support rods, which are evenly distributed in the circumferential direction of the rotating shaft. Each support group corresponds to a support ring. In each support group, at least one support rod is connected to the corresponding support ring, and in each support group, at least one support rod is connected to the screening cylinder.

[0009] Furthermore, both the support ring and the screening cylinder are equipped with rotatable rollers that contact the main cylinder body.

[0010] Furthermore, each support ring is provided with a wind baffle, which is arranged along the radial direction of the main cylinder and located between the main cylinder and the support ring.

[0011] Furthermore, the rotating shaft is rotatably mounted on the feed cylinder via the first elastic element. The rotation direction of the main cylinder is called forward rotation, and the first elastic element makes the rotating shaft always have a tendency to reverse the direction around the axis of the main cylinder.

[0012] Furthermore, the screening cylinder is equipped with multiple back thrust groups, which are arranged sequentially in the axial direction of the screening cylinder and located on one side near the bottom of the main cylinder. Each back thrust group includes multiple back thrust plates, which are evenly distributed around the axis of the screening cylinder and are spiral plates. When the screening cylinder rotates forward, the back thrust plates can cause the material on them to move towards the side closer to the feed inlet.

[0013] Furthermore, a motor is installed on the support frame, and a gear is connected to the output shaft of the motor via a reducer; a gear ring is coaxially and fixedly installed on the main cylinder body, and the gear ring meshes with the gear.

[0014] Furthermore, it also includes multiple support components, which are arranged sequentially in the axial direction of the main cylinder. Each support component includes a support platform, a rotating ring, and two support wheels. The support platform and the bracket are both set on the ground, and the two support wheels are rotatably mounted on the support platform. The rotating ring is coaxially arranged with the main cylinder and fixedly connected to the main cylinder. The rotating ring also rotates and cooperates with the two support wheels.

[0015] The beneficial effects of this invention are as follows: A rotary dryer for granular materials, by incorporating a screening cylinder within the main drum, allows smaller particles to pass through the screening holes first. Medium-sized particles must move to the corresponding screening hole size before falling, while the largest particles must rotate a longer distance until reaching the matching screening hole before falling and colliding with the material below. This process breaks down the larger particles, facilitating drying and ultimately achieving material grading and staggered falling. Larger particles have a longer rotation path, a higher lifting height, and a later falling time, resulting in longer contact time with hot air, thus improving the uniformity of material falling and the stability of material drying quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a schematic diagram of the overall structure of an embodiment of a rotary dryer for granular materials according to the present invention;

[0018] Figure 2 This is a front view of the overall structure of an embodiment of a rotary dryer for granular materials according to the present invention;

[0019] Figure 3 This is a schematic diagram of a partial structure of an embodiment of a rotary dryer for granular materials according to the present invention;

[0020] Figure 4 for Figure 3 Sectional view at point A in the middle;

[0021] Figure 5 for Figure 3 The front view of the structure shown;

[0022] Figure 6 for Figure 5 A cross-sectional view along the BB direction;

[0023] Figure 7 for Figure 6 A magnified view of point C in the middle.

[0024] In the diagram: 100, bracket; 110, motor; 120, gear; 130, support platform; 140, rotating ring; 150, support wheel; 200, main cylinder; 201, gear ring; 210, feed cylinder; 211, feed inlet; 212, air outlet; 220, discharge cylinder; 221, discharge outlet; 222, air inlet; 230, lifting plate; 231, long side plate; 232, short side plate; 233, filter hole; 234, discharge hole; 240, guide plate; 250, rotating shaft; 260, support ring; 261, support rod; 262, roller; 263, wind baffle; 270, reverse thrust plate; 300, screening cylinder; 301, screening hole. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] An embodiment of the rotary dryer for granular materials according to the present invention, such as... Figures 1 to 7 As shown.

[0027] A rotary dryer for granular materials includes a support frame 100, a main cylinder 200, and a screening cylinder 300. The support frame 100 is fixedly mounted on the ground. The main cylinder 200 is inclined on the support frame 100 and can rotate around its own axis. A feed cylinder 210 and a discharge cylinder 220 are rotatably connected to both ends of the main cylinder 200, respectively. The feed cylinder 210 is located above the discharge cylinder 220 and has a feed inlet 211 and an air outlet 212. The discharge cylinder 220 has a discharge outlet 221 and an air inlet 222. A lifting section is provided inside the main cylinder 200, arranged along the axial direction of the main cylinder 200. The lifting section includes multiple lifting plates 230, which are evenly distributed on the inner circumferential wall of the main cylinder 200 and have an L-shaped structure.

[0028] The screening cylinder 300 is located inside the main cylinder 200 and is coaxial with it. Both ends of the screening cylinder 300 are connected to the feed cylinder 210 and the discharge cylinder 220, respectively. A gap exists between the lifting plate 230 and the screening cylinder 300 in the radial direction of the main cylinder 200. The screening cylinder 300 has an arc-shaped structure. During one revolution of the main cylinder 200, the arc length traversed by the lifting plate 230 from the start to the end of the throwing motion is called the throwing section, and the screening cylinder 300 is located on the throwing section. Screening holes 301 are provided on the screening cylinder 300, and the diameter of the screening holes 301 gradually increases in the rotation direction of the main cylinder 200.

[0029] The support frame 100 is equipped with a motor 110, and a gear 120 is connected to the output shaft of the motor 110 via a reducer. A gear ring 201 is coaxially and fixedly mounted on the outer side of the main cylinder 200, and the gear ring 201 meshes with the gear 120. In use, starting the motor 110 causes it to drive the gear ring 201 to rotate via the gear 120, thereby causing the main cylinder 200 to rotate.

[0030] In this embodiment, a screening cylinder 300 is installed inside the main cylinder 200. During use, material is fed into the main cylinder 200 from the feed inlet 211, and hot air is fed into the main cylinder 200 from the air inlet 222. The hot air flows inside the main cylinder 200 and is finally discharged from the air outlet 212 of the feed cylinder 210, forming a stable airflow. Then, the main cylinder 200 is driven to rotate. The rotation of the main cylinder 200 will drive the lifting plate 230 to rotate synchronously. During the rotation of the lifting plate 230, the material at the bottom of the main cylinder 200 is scraped up and lifted, and gradually moved to the top as the main cylinder 200 rotates, preventing the material from accumulating at the bottom.

[0031] When the lifting plate 230 rotates to the throwing section, the material is gradually thrown away from the lifting plate 230 and falls onto the corresponding screening cylinder 300. Since the diameter of the screening holes 301 on the screening cylinder 300 gradually increases along the rotation direction of the main cylinder 200, when the material falls onto the screening cylinder 300, the material that can pass through the screening holes 301 will fall from the screening holes 301, while the material that cannot pass through the screening holes 301 will fall back along the screening cylinder 300 and be driven by other lifting plates 230 on the rear side until the diameter of the material reaches the screening hole 301 on the screening cylinder 300 that allows it to pass through.

[0032] In other words, smaller particles will preferentially pass through screening holes 301. Medium-sized particles need to move to the corresponding screening hole 301 to fall, while the largest particles need to rotate a longer distance until they reach the matching screening hole 301 before falling and colliding with the materials below, breaking up the larger particles for easier drying. This ultimately achieves material grading and staggered falling. Larger particles have a longer rotation distance, a higher lifting height, and a later falling time, resulting in longer contact time with hot air, which improves the uniformity of material falling and the stability of material drying quality. It should be noted that smaller particles will also fall through the larger screening holes 301, but larger particles can only fall through the larger screening holes 301.

[0033] The material falling to the bottom of the main cylinder 200 will move from the feed inlet 211 to the discharge outlet 221 along the inclined direction. During the movement, the material will also be lifted, screened and fallen again by the rotating lifting plate 230, repeating the heat exchange process, and finally discharged from the discharge outlet 221 of the discharge cylinder 220 to complete the drying.

[0034] In a further embodiment, the lifting plate 230 includes a long side plate 231 and a short side plate 232. The long side plate 231 is arranged along the radial direction of the main cylinder 200 and fixedly installed inside the main cylinder 200. The long side plate 231 has a plurality of filter holes 233. The short side plate 232 is arranged in the circumferential direction of the main cylinder 200 and fixedly connected to the long side plate 231. The short side plate 232 has a plurality of discharge holes 234. The diameter of the filter holes 233 is smaller than the diameter of the discharge holes 234. The diameter of the discharge holes 234 is smaller than the diameter of any screening hole 301.

[0035] During operation, the material cannot completely fill the gap between the two lifting plates 230. Therefore, some hot air easily passes through the portion of the gap where there is no material, resulting in ineffective heat exchange and wasted heat. To address this, filter holes 233 are provided on the long side plate 231 of the lifting plate 230. As the main cylinder 200 rotates the lifting plate 230, smaller particles enter the space between the two lifting plates through the filter holes 233 and exchange heat with the hot air passing between them, improving the effective utilization rate of the hot air. A discharge hole 234 is provided on the short side plate 232 of the lifting plate 230 to facilitate the smooth flow of material up and down from the lifting plate 230.

[0036] In a further embodiment, multiple lifting sections are provided. Multiple guide sections are also provided within the main cylinder 200, and these guide sections and lifting sections are sequentially arranged in the axial direction of the main cylinder 200, with the guide sections and lifting sections alternating sequentially in the axial direction of the main cylinder 200. Each guide section includes multiple guide plates 240, which are evenly distributed on the inner circumferential wall surface of the main cylinder 200, and the guide plates 240 are spiral plates.

[0037] This embodiment uses multiple lifting sections and multiple guiding sections to work together, so that when the material is in the lifting section, it will be continuously lifted, screened and fallen, and when the material is in the guiding section, it will be guided by the guide plate 240 to continue to move along the axial direction of the main cylinder 200 towards the side closer to the discharge port 221, so as to avoid the material from being stuck or jammed in the main cylinder 200.

[0038] In a further embodiment, a rotating shaft 250 and a support cylinder are also provided inside the main cylinder 200. The rotating shaft 250 is coaxially arranged with the main cylinder 200, and its two ends are connected to the feed cylinder 210 and the discharge cylinder 220, respectively. The support cylinder has an arc-shaped structure and is coaxial with the main cylinder 200. The support cylinder and the screening cylinder 300 are evenly distributed around the axis of the main cylinder 200 and connected end to end in sequence. The support cylinder includes multiple support rings 260, which are spaced apart in the axial direction of the main cylinder 200.

[0039] Multiple support groups are provided in the axial direction of the rotating shaft 250. Each support group includes multiple support rods 261, specifically, three support rods 261 are provided. The multiple support rods 261 are evenly distributed in the circumferential direction of the rotating shaft 250. Each support group is correspondingly set with a support ring 260. In each support group, at least one support rod 261 is connected to its corresponding support ring 260, and in each support group, at least one support rod 261 is connected to the screening cylinder 300.

[0040] Furthermore, both the support ring 260 and the screening cylinder 300 are equipped with rotatable rollers 262, which contact the main cylinder 200. By setting the rollers 262, the main cylinder 200 is supported while the friction between the two is reduced.

[0041] Furthermore, each support ring 260 is provided with a wind baffle 263, which is arranged along the radial direction of the main cylinder 200 and located between the main cylinder 200 and the support ring 260.

[0042] After the material falls from the throwing section, when the lifting plate 230 rotates to the side of the support ring 260, there is almost no material left on it. Therefore, even if hot air passes through here, it cannot dry the material. Therefore, the baffle plate 263 is set to block the hot air so that the hot air can flow elsewhere to increase the effective utilization rate of the hot air.

[0043] In a further embodiment, the rotating shaft 250 is rotatably mounted on the feed cylinder 210 via a first elastic element. The rotation direction of the main cylinder 200 is referred to as forward rotation. The first elastic element ensures that the rotating shaft 250 always has a tendency to reverse the direction around the axis of the main cylinder 200. The first elastic element is a torsion spring.

[0044] By setting the first elastic element, when there is material between the lifting plate 230 and the screening cylinder 300 during use, the main cylinder 200 will drive the lifting plate 230 to rotate, which will drive the screening cylinder 300 to rotate synchronously through friction, so that the screening cylinder 300 rotates in the forward direction. After the lifting plate 230 disengages from the screening hole 301, the screening cylinder 300 will reverse and reset under the action of the torsion spring. During this process, the rotating shaft 250 will drive the screening cylinder 300 and other structures to rotate back and forth, assisting the material between the two to fall and preventing the main cylinder 200 from jamming.

[0045] Furthermore, the screening cylinder 300 is provided with multiple back thrust groups. The multiple back thrust groups are arranged sequentially in the axial direction of the screening cylinder 300 and located on one side near the bottom of the main cylinder 200. The back thrust group includes multiple back thrust plates 270. The multiple back thrust plates 270 are evenly distributed around the axis of the screening cylinder 300 and are spiral plates. When the screening cylinder 300 rotates forward, the back thrust plates 270 can cause the material on them to move towards the side closer to the feed port 211.

[0046] By setting up the push plate 270, during the forward rotation of the screening cylinder 300, which causes the torsion spring to store energy, the material falling on the push plate 270 will be pushed back under its spiral guidance, moving towards the side closer to the feed inlet 211. This increases the time the material stays in the main cylinder 200, prolongs the drying time, and ensures the drying quality of the material. When the torsion spring releases and drives the screening cylinder 300 to reverse and reset, most of the material on the screening cylinder 300 will detach due to its shaking. Therefore, there will be less material on the push plate 270, and consequently, less material can be pushed by the push plate 270 towards the side closer to the discharge outlet 221 during the reverse rotation of the screening cylinder 300, which will not affect the normal drying process.

[0047] Furthermore, a rotary dryer for granular materials also includes multiple support components, which are sequentially arranged in the axial direction of the main cylinder 200. Each support component includes a support platform 130, a rotating ring 140, and two support wheels 150. The support platform 130 is fixedly mounted on the ground, and both support wheels 150 are rotatably mounted on the support platform 130. The rotating ring 140 is coaxially arranged with and fixedly connected to the main cylinder 200, and simultaneously rotates with the two support wheels 150. By providing these support components, the main cylinder 200 is supported.

[0048] Based on the above embodiments, the specific working process is as follows:

[0049] In operation, material is fed into the main cylinder 200 from the feed inlet 211, and hot air is fed into the main cylinder 200 from the air inlet 222. The hot air flows within the main cylinder 200 and is finally discharged from the air outlet 212 of the feed cylinder 210, forming a stable airflow. The main cylinder 200 is then driven to rotate, which in turn drives the lifting plates 230 to rotate synchronously. During the rotation of the lifting plates 230, the material at the bottom of the main cylinder 200 is scraped and lifted, gradually moving towards the top as the main cylinder 200 rotates, preventing material from accumulating at the bottom.

[0050] When the lifting plate 230 rotates to the throwing section, the material is gradually thrown away from the lifting plate 230 and falls onto the corresponding screening cylinder 300. Since the diameter of the screening holes 301 on the screening cylinder 300 gradually increases along the rotation direction of the main cylinder 200, when the material falls onto the screening cylinder 300, the material that can pass through the screening holes 301 will fall from the screening holes 301, while the material that cannot pass through the screening holes 301 will fall back along the screening cylinder 300 and be driven by other lifting plates 230 on the rear side until the diameter of the material reaches the screening hole 301 on the screening cylinder 300 that allows it to pass through.

[0051] In other words, smaller particles will preferentially pass through screening holes 301. Medium-sized particles need to move to the corresponding screening hole 301 to fall, while the largest particles need to rotate a longer distance until they reach the matching screening hole 301 before falling and colliding with the materials below, breaking up the larger particles for easier drying. This ultimately achieves material grading and staggered falling. Larger particles have a longer rotation distance, a higher lifting height, and a later falling time, resulting in longer contact time with hot air, which improves the uniformity of material falling and the stability of material drying quality. It should be noted that smaller particles will also fall through the larger screening holes 301, but larger particles can only fall through the larger screening holes 301.

[0052] Furthermore, during the rotation of the lifting plates 230 driven by the main cylinder 200, relatively small particles will enter between the two lifting plates 230 through the filter holes 233 and exchange heat with the hot air passing between the lifting plates 230, thereby improving the effective utilization rate of the hot air. A discharge hole 234 is provided on the short side plate 232 of the lifting plate 230 to facilitate the smooth falling of materials from the lifting plate 230.

[0053] When material exists between the lifting plate 230 and the screening cylinder 300, the main cylinder 200, while driving the lifting plate 230 to rotate, will cause the screening cylinder 300 to rotate synchronously through friction, making the screening cylinder 300 rotate forward. After the lifting plate 230 disengages from the screening hole 301, the screening cylinder 300 will reverse and reset under the action of the torsion spring. During this process, the rotating shaft 250 will drive the screening cylinder 300 and other structures to rotate back and forth, assisting the material between them to fall and preventing the main cylinder 200 from jamming. During the process of the screening cylinder 300 being driven to rotate forward and the torsion spring storing force, the material falling on the push plate 270 will be pushed back under its spiral guidance, moving towards the side closer to the feed inlet 211, increasing the time the material stays in the main cylinder 200, extending the drying time of the material, and ensuring the drying quality of the material. When the torsion spring releases and drives the screening cylinder 300 to reverse and reset, most of the material on the screening cylinder 300 is dislodged by its shaking. Therefore, there is less material on the push plate 270. Consequently, the material that can be pushed by the push plate 270 to move closer to the discharge port 221 when the screening cylinder 300 reverses is also less, which will not affect the normal drying process.

[0054] The material falling to the bottom of the main cylinder 200 will move from the feed inlet 211 to the discharge outlet 221 along the inclined direction. During the movement, the material will also be lifted, screened and fallen again by the rotating lifting plate 230, repeating the heat exchange process, and finally discharged from the discharge outlet 221 of the discharge cylinder 220 to complete the drying.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rotary dryer for granular materials, characterized in that: It includes a support frame, a main cylinder, and a screening cylinder; the main cylinder is inclined on the support frame and can rotate around its own axis. The two ends of the main cylinder are respectively rotatably connected to a feed cylinder and a discharge cylinder. The feed cylinder is located above the discharge cylinder and has a feed inlet and an air outlet. The discharge cylinder has a discharge outlet and an air inlet; a lifting section is provided inside the main cylinder and is arranged along the axis of the main cylinder. The lifting section includes multiple lifting plates, which are evenly distributed on the inner circumferential wall of the main cylinder. The lifting plates have an L-shaped structure. The screening cylinder is located inside the main cylinder and is coaxial with it. Both ends of the screening cylinder are connected to the feed cylinder and discharge cylinder, respectively. A gap exists between the lifting plates and the screening cylinder in the radial direction of the main cylinder. The screening cylinder has an arc-shaped structure. During one revolution of the main cylinder, the arc length traversed by the lifting plates from the start to the end of the throwing motion is called the throwing segment, and the screening cylinder is located on this segment. Screening holes are provided on the screening cylinder, and the diameter of the screening holes gradually increases in the direction of rotation of the main cylinder. The lifting plates include long side plates and short side plates. The long side plates are arranged along the radial direction of the cylinder and fixedly installed inside the cylinder, with multiple filter holes on them. The short side plates are arranged in the circumferential direction of the cylinder and fixedly connected to the long side plates, with multiple discharge holes on them. The diameter of the filter holes is smaller than the diameter of the discharge holes, and the diameter of the discharge holes is smaller than the diameter of any screening hole. The main cylinder also contains... The system is equipped with a rotating shaft and a support cylinder. The rotating shaft is coaxial with the main cylinder, and its two ends are connected to the feed cylinder and discharge cylinder, respectively. The support cylinder is arc-shaped and coaxial with the main cylinder. The support cylinder and the screening cylinder are evenly distributed around the axis of the main cylinder and connected end to end. The support cylinder includes multiple support rings, which are spaced apart in the axial direction of the main cylinder. Multiple support groups are provided in the axial direction of the rotating shaft. Each support group includes multiple support rods, which are evenly distributed in the circumferential direction of the rotating shaft. Each support group corresponds to a support ring. In each support group, at least one support rod is connected to its corresponding support ring, and in each support group, at least one support rod is connected to the screening cylinder. Each support ring is equipped with a baffle plate, which is arranged in the radial direction of the main cylinder and located between the main cylinder and the support ring.

2. The rotary dryer for granular materials according to claim 1, characterized in that: There are multiple lifting sections; multiple guide sections are also provided inside the main cylinder. The multiple guide sections and multiple lifting sections are arranged sequentially in the axial direction of the main cylinder, and the guide sections and lifting sections are alternately distributed in the axial direction of the main cylinder. The guide section includes multiple guide plates, which are evenly distributed on the inner circumferential wall of the main cylinder. The guide plates are spiral plates.

3. The rotary dryer for granular materials according to claim 1, characterized in that: Both the support ring and the screening cylinder are equipped with rotatable rollers that contact the main cylinder body.

4. A rotary dryer for granular materials according to claim 1, characterized in that: The rotating shaft is rotatably mounted on the feed cylinder via the first elastic element. The rotation direction of the main cylinder is called forward rotation. The first elastic element makes the rotating shaft always have a tendency to reverse the direction around the axis of the main cylinder.

5. A rotary dryer for granular materials according to claim 4, characterized in that: The screening cylinder is equipped with multiple back thrust groups, which are arranged sequentially in the axial direction of the screening cylinder and located on one side near the bottom of the main cylinder. Each back thrust group includes multiple back thrust plates, which are evenly distributed around the axis of the screening cylinder and are spiral plates. When the screening cylinder rotates forward, the back thrust plates can cause the material on them to move towards the side closer to the feed inlet.

6. A rotary dryer for granular materials according to claim 1, characterized in that: A motor is mounted on the support frame, and a gear is connected to the output shaft of the motor via a reducer; a gear ring is coaxially and fixedly mounted on the main cylinder body, and the gear ring meshes with the gear.

7. A rotary dryer for granular materials according to claim 1, characterized in that: It also includes multiple support components, which are arranged sequentially in the axial direction of the main cylinder. Each support component includes a support platform, a rotating ring, and two support wheels. The support platform and the bracket are both set on the ground. The two support wheels are rotatably mounted on the support platform. The rotating ring is coaxially arranged with the main cylinder and fixed to the main cylinder. The rotating ring also rotates and cooperates with the two support wheels.

Images