Potato screening structure and screening method
By setting up a step-by-step screening chamber and a driving device in the potato screening device, step-by-step screening of potatoes is realized, which solves the problem of low screening accuracy in the existing technology, improves screening accuracy, simplifies the structure, and facilitates cleaning.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YUNNAN AGRICULTURAL UNIVERSITY
- Filing Date
- 2026-02-28
- Publication Date
- 2026-04-28
AI Technical Summary
In existing potato screening devices, some smaller potatoes are discharged through larger holes during the screening process, resulting in low screening accuracy.
A potato screening structure was designed, which includes a screening barrel with multiple screening chambers inside an inclined setting. The screening holes of each chamber gradually increase in size. The connection and isolation between adjacent chambers are controlled by an isolation device. The lower baffle is opened sequentially by a driving device to achieve step-by-step screening.
It improves the accuracy of potato screening, ensuring that smaller potatoes are fully screened in the previous compartment before entering the next compartment, preventing smaller potatoes from being discharged through larger holes. The simple structure is suitable for small-batch screening and is easy to clean.
Smart Images
Figure CN121927809A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of potato screening technology, specifically relating to a potato screening structure and screening method. Background Technology
[0002] The potato is a perennial herbaceous plant with edible tubers. It is the world's fourth most important food crop, after wheat, rice, and corn. Potatoes are also known as foreign yams, sweet potatoes, and other names. In some southern provinces, they are also called "winter potatoes" because they are often planted in winter after the autumn rice harvest. When selling or saving potatoes for seed, they are sorted according to size. This standardized management based on size maximizes economic benefits.
[0003] Patent CN216965261U discloses a screening device for potato processing. The mesh screening barrel has progressively larger apertures from right to left. Potatoes are fed into the mesh screening barrel. The output end of the support base rotates and drives the rotating shaft to rotate via a pulley. Finally, the cross plate drives the mesh screening barrel to rotate. The rotation of the mesh screening barrel causes the potatoes inside to roll from right to left. Potatoes of different sizes will be discharged through different apertures on the mesh screening barrel. Finally, the screening work is completed through the front side of the guide frame and the left side of the mesh screening barrel.
[0004] However, during the screening process, some smaller potatoes may be discharged through the larger holes, resulting in generally low screening accuracy. Summary of the Invention
[0005] The purpose of this invention is to provide a potato screening structure and screening method that can increase the screening accuracy of potatoes.
[0006] To achieve the above objectives, the present invention provides the following technical solution: a potato screening structure, comprising: Main support; A screening bucket is rotatably connected to the main support. The screening bucket is tilted and has a screening cavity that extends through both ends of the screening bucket. The screening cavity is divided into several screening sub-cavities from top to bottom. Each screening sub-cavity has several screening holes on its side wall. The screening holes of the upper screening sub-cavities are smaller than the screening holes of the adjacent lower screening sub-cavities. A support rod, one end of which is fixedly connected to the main support via a connecting bracket, and the other end of which is inserted into the screening chamber; An isolation device is provided between adjacent screening chambers, the isolation device comprising: An upper baffle, which is fixed to the support rod; A lower baffle is disposed below the upper baffle and is hinged to the support rod. The lower baffle has an open state and a closed state. When the lower baffle is open, the lower parts of adjacent screening chambers are connected. When the lower baffle is closed, the adjacent screening chambers are isolated. A driving device is used to switch the lower baffle between an open state and a closed state; A rotating device is used to drive the screening bucket to rotate.
[0007] Furthermore, the driving device includes: A telescopic structure corresponding to each of the lower baffles, the telescopic structure includes a telescopic rod and a push rod, the support rod is provided with a telescopic groove corresponding to the lower baffle, the telescopic rod is installed in the telescopic groove, the side wall of the telescopic groove is provided with a first side groove, the telescopic rod is fixed with a first protrusion extending out of the first side groove, one end of the push rod is hinged to the first protrusion, and the other end is hinged to the corresponding lower baffle; A moving device, which is used to move the telescopic rod.
[0008] Furthermore, the telescopic structure also includes a telescopic spring. One end of the telescopic rod is provided with a groove with an opening facing the lower baffle. One end of the telescopic spring is inserted into the groove, and the other end abuts against the inner wall of the telescopic slide. The side wall of the telescopic slide is also provided with a second side groove. A second protrusion extending out of the second side groove is fixed on the telescopic rod. A second extension rod extending out of the screening cavity is fixed on the second protrusion. One end of the second extension rod extending out of the screening cavity is provided with an abutment surface. The moving device includes a drive motor, which is fixed on the connecting bracket. The drive motor shaft is provided with drive cams that correspond one-to-one with the contact surfaces. The drive motor drives the drive cams to rotate, causing the lower baffles near the inlet of the screening chamber to open sequentially from the lower baffles near the outlet of the screening chamber.
[0009] Furthermore, a second side groove is provided on the side wall of the telescopic chute, and a second protrusion extending out of the second side groove is fixed on the telescopic rod, and a second extension rod extending out of the screening cavity is fixed on the second protrusion. The moving device is configured as an electric push rod corresponding to each of the second extension rods. The electric push rod is fixed on the connecting bracket, and the push rod end of the electric push rod is connected to the corresponding second extension rod.
[0010] Furthermore, a connecting rod is fixed on the support rod, and a connecting bolt that is threadedly connected to the connecting bracket is threaded through the connecting rod.
[0011] Furthermore, a support crossbar is fixed on the main bracket, a sliding groove is provided in the support crossbar, an adjusting screw is rotatably connected in the sliding groove, a sliding block is installed in the sliding groove, an adjusting internal thread hole is provided in the sliding block, the adjusting screw is threadedly connected to the adjusting internal thread hole, and the connecting bracket is fixedly connected to the sliding block.
[0012] Furthermore, a connecting block is fixed to the end of the electric push rod, and the connecting block is provided with an upward-facing slot. A plug block that is inserted into the slot is fixed on the second extension rod.
[0013] Furthermore, a sliding side groove is provided on the side wall of the sliding groove, and a fastening bolt that is threadedly connected to the sliding block is inserted into the sliding side groove.
[0014] Furthermore, the main support is provided with a screening channel corresponding to the screening chamber, and the inlet of the screening channel is located below the corresponding screening chamber.
[0015] A potato screening method was also disclosed, including the following steps: S1, Feeding and Initial Movement: Pour the potatoes to be sorted into the high end of the sorting bin; The potatoes tumbled continuously inside the screening bin and slowly moved towards the lower end. S2, First-level screening: The potatoes first enter the first screening chamber, where the screening holes are the smallest. The screening bucket rotates continuously, and the potatoes tumble inside. The smallest potatoes fall through the sieve holes during the tumbling process. The remaining potatoes remain in the sorting chamber; S3, segmented release and step-by-step screening: The control drive device causes the lower baffle to open sequentially from the inlet to the outlet at set times. Open the first lower baffle: When the potatoes in the first compartment have been fully sorted, the drive device is activated, pushing the first lower baffle from the "closed state" to the "open state"; Material flow: After the first lower baffle is opened, the remaining potatoes in the first screening chamber flow into the second screening chamber through the space below the opened lower baffle. S4, Second-stage screening: The screening holes in the second compartment are larger than those in the first. Potatoes remaining here continue to tumble, and medium-sized potatoes fall through the screening holes in this section. S5, Cyclic Process: Subsequently, the drive device opens the second and third lower baffles in sequence, and each compartment repeats the above process of "retention screening - opening baffle - feeding to the next level - continuing screening"; S6, Final Product Outflow: Potatoes of the largest size cannot pass through any sieve holes and eventually flow out from the bottom of the screening bucket.
[0016] Compared with the prior art, the beneficial effects of the present invention are: (1) By setting up an isolation device, adjacent screening chambers can be connected or isolated, so that potatoes can be fully screened in the previous screening chamber before entering the next screening chamber. Smaller potatoes will not be discharged from larger holes, which can increase the screening accuracy of potatoes. (2) A single drive motor can open the lower baffle from the inlet of the screening chamber to the outlet of the screening chamber in sequence, making the structure simpler and suitable for small-batch screening. (3) When the inside of the screening barrel needs to be cleaned, the adjusting screw can be unscrewed first to separate the connecting rod and the connecting bracket. Then, the adjusting screw is rotated to move the sliding block, thereby moving the connecting bracket laterally. In this way, the connecting bracket will not block the support rod from moving out of the screening barrel, so that the upper baffle and the lower baffle can be moved out of the screening barrel together, making it convenient to clean the inside of the screening barrel. (4) The extension and retraction of the electric push rod can drive the corresponding second extension rod to extend and retract through the connecting block, thereby realizing the opening and closing of the lower baffle. When the inside of the screening barrel needs to be cleaned, it is only necessary to move the connecting bracket laterally and the insert block moves laterally out of the slot, thereby separating the electric push rod from the second extension rod, which can realize the individual control of each lower baffle. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the potato screening structure of the present invention; Figure 2 for Figure 1 A magnified view of a section at point I; Figure 3 for Figure 1 Top view; Figure 4 for Figure 3 Cross-sectional view at point AA; Figure 5 for Figure 4 Enlarged view of a section at point II; Figure 6 for Figure 4 A magnified view of a section at point III; Figure 7 This is a schematic diagram of the connection structure of the upper baffle, lower baffle, and support rod. Figure 8 for Figure 7 A magnified view of a section at point IV in the middle; Figure 9 This is a schematic diagram of another embodiment of the potato screening structure of the present invention; Figure 10 for Figure 9 A magnified view of the middle V section.
[0018] In the diagram: 1. Main support; 2. Screening barrel; 3. Screening chamber; 4. Screening hole; 5. Support rod; 6. Connecting support; 7. Upper baffle; 8. Lower baffle; 9. Telescopic rod; 10. Push rod; 11. Telescopic slide groove; 12. First side groove; 13. First protrusion; 14. Telescopic spring; 15. Groove; 16. Second side groove; 17. Second protrusion; 18. Second extension rod; 19. Abutment surface; 20. Drive motor; 21. Drive cam; 22. Electric push rod; 23. Connecting rod; 24. Connecting bolt; 25. Support crossbar; 26. Sliding groove; 27. Adjusting screw; 28. Sliding block; 29. Connecting block; 30. Slot; 31. Sliding side groove; 32. Fastening bolt; 33. Screening channel; 34. Insert block; 35. Adjusting internal thread hole; 36. Rotating device. Detailed Implementation
[0019] 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.
[0020] Please see Figures 1-10 This invention provides a technical solution for potato screening structure and screening method.
[0021] A potato screening structure, comprising: Main support 1; Screening barrel 2 is rotatably connected to main support 1. Screening barrel 2 is tilted. Screening chamber 3 is provided inside screening barrel 2, which passes through both ends of it. Screening chamber 3 is divided into several screening sub-chambers from top to bottom. Each screening sub-chamber has several screening holes 4 on its side wall. The screening holes 4 of the upper screening sub-chamber are smaller than the screening holes 4 of the adjacent lower screening sub-chamber. Support rod 5, one end of which is fixedly connected to main support 1 via connecting bracket 6, and the other end is inserted into screening chamber 3; An isolation device is provided between adjacent screening chambers. The isolation device includes: Upper baffle 7 is fixed on support rod 5; The lower baffle 8 is located below the upper baffle 7. The lower baffle 8 is hinged to the support rod 5. The lower baffle 8 has an open state and a closed state. When it is open, the lower parts of adjacent screening chambers are connected. When it is closed, adjacent screening chambers are isolated. The drive unit is used to switch the lower baffle 8 between the open and closed states; A rotating device is used to drive the screening bucket to rotate.
[0022] By setting up an isolation device, adjacent screening chambers can be connected or isolated, allowing potatoes to be fully screened in the previous screening chamber before entering the next screening chamber, preventing smaller potatoes from being discharged through larger holes.
[0023] The following is one embodiment of the driving device, which includes: The telescopic structure corresponds one-to-one with the lower baffle 8. The telescopic structure includes a telescopic rod 9 and a push rod 10. The support rod 5 is provided with a telescopic groove 11 corresponding to the lower baffle 8. The telescopic rod 9 is installed in the telescopic groove 11. The side wall of the telescopic groove 11 is provided with a first side groove 12. A first protrusion 13 extending out of the first side groove 12 is fixed on the telescopic rod 9. One end of the push rod 10 is hinged to the first protrusion 13, and the other end is hinged to the corresponding lower baffle 8. A moving device is used to move the telescopic rod 9.
[0024] The moving device drives the telescopic rod 9 to move, and the telescopic rod 9 drives the lower baffle 8 to rotate relative to the support rod 5 via the push rod 10. Figure 7 The diagram shown is a structural schematic of the first lower baffle 8 when it is open. The lower baffle 8 is generally opened to about 60°.
[0025] Furthermore, the telescopic structure also includes a telescopic spring 14. One end of the telescopic rod 9 is provided with a groove 15 with an opening facing the lower baffle 8. One end of the telescopic spring 14 is inserted into the groove 15, and the other end abuts against the inner wall of the telescopic slide 11. The side wall of the telescopic slide 11 is also provided with a second side groove 16. A second protrusion 17 extending out of the second side groove 16 is fixed on the telescopic rod 9. A second extension rod 18 extending out of the screening chamber 3 is fixed on the second protrusion 17. One end of the second extension rod 18 extending out of the screening chamber 3 is provided with an abutment surface 19. The moving device includes a drive motor 20, which is fixed on the connecting bracket 6. The drive motor 20 has a drive cam 21 on its rotating shaft that corresponds one-to-one with the contact surface 19. The drive motor 20 drives the drive cam 21 to rotate, so that the lower baffle 8 near the inlet of the screening chamber 3 to the lower baffle 8 near the outlet of the screening chamber 3 are opened in sequence.
[0026] Initially, all lower baffles 8 are closed under the action of springs. Potatoes tumble and are sieved out in the first screening chamber. The smallest potatoes fall through the sieve holes during the tumbling process in the first screening chamber. After the potatoes are screened in the first screening chamber, the drive motor 20 drives each drive cam 21 to rotate simultaneously. The first drive cam 21 first abuts against the contact surface 19 of the first second extension rod 18. The first drive cam 21 pushes the first second extension rod 18 to move. The first second extension rod 18 is connected to the first telescopic rod 9 and the first... The push rod 10 drives the first lower baffle 8 to open (at this time, the first telescopic spring 14 is in a compressed state), and the remaining potatoes in the first compartment will enter the second screening compartment. Medium-sized potatoes will be screened out in the second screening compartment. Similarly, after the potatoes in the second screening compartment are screened, the drive motor 20 drives the second drive cam 21 to abut against the contact surface 19 of the second extension rod 18, pushing the second lower baffle 8 to open, and the potatoes in the second screening compartment enter the next screening compartment for screening.
[0027] A single drive motor 20 can sequentially open the lower baffle 8 from the inlet of the screening chamber 3 to the outlet of the screening chamber 3, resulting in a simpler structure suitable for small-batch screening.
[0028] like Figure 5 As shown, a connecting rod 23 is fixed to the support rod 5, and a connecting bolt 24, which is threaded onto the connecting rod 23, is threaded to the connecting bracket 6. The support rod 5 is fixed to the connecting bracket 6 by the connecting bolt 24.
[0029] like Figure 5 As shown, a support crossbar 25 is fixed on the main bracket 1. A sliding groove 26 is provided in the support crossbar 25. An adjusting screw 27 is rotatably connected in the sliding groove 26. A sliding block 28 is installed in the sliding groove 26. An adjusting internal thread hole 35 is provided in the sliding block 28. The adjusting screw 27 is threadedly connected to the adjusting internal thread hole 35. The connecting bracket 6 is fixedly connected to the sliding block 28.
[0030] Rotating the adjusting screw 27 can drive the sliding block 28 to move laterally within the sliding groove 26. When the inside of the screening barrel 2 needs to be cleaned, the support rod 5 and other components need to be moved out of the screening barrel 2. At this time, the adjusting screw 27 can be unscrewed first to separate the connecting rod 23 and the connecting bracket 6. Then, rotating the adjusting screw 27 will drive the sliding block 28 to move, thereby driving the connecting bracket 6 to move laterally. In this way, the connecting bracket 6 will not block the support rod 5 from moving out of the screening barrel 2, thereby allowing the upper baffle 7 and the lower baffle 8 to be moved out of the screening barrel 2 together, facilitating the cleaning of the inside of the screening barrel 2.
[0031] like Figure 5As shown, a sliding side groove 31 is provided on the side wall of the sliding groove 26, and a fastening bolt 32 that is threadedly connected to the sliding block 28 is inserted into the sliding side groove 31. When the sliding block 28 does not need to move, the fastening bolt 32 can be tightened to make the sliding block 28 more securely fixed.
[0032] like Figure 8 As shown, the main support 1 has a screening channel 33 corresponding to the screening chamber, and the inlet of the screening channel 33 is located below the corresponding screening chamber. The screening channel 33 can receive the screened potatoes and then output the potatoes.
[0033] like Figure 9 and Figure 10 As shown, another type of moving device is provided. The side wall of the telescopic chute 11 is also provided with a second side groove 16. A second protrusion 17 extending out of the second side groove 16 is fixed on the telescopic rod 9. A second extension rod 18 extending out of the screening cavity 3 is fixed on the second protrusion 17. The moving device is configured as an electric push rod 22 corresponding to the second extension rod 18. The electric push rod 22 is fixed on the connecting bracket 6, and the push rod end of the electric push rod 22 is connected to the corresponding second extension rod 18.
[0034] The electric push rod 22 has a connecting block 29 fixed to its push rod end. The connecting block 29 has an upward-facing slot 30. The second extension rod 18 has a plug block 34 that is inserted into the slot 30.
[0035] The extension and retraction of the electric push rod 22 can drive the corresponding second extension rod 18 to extend and retract via the connecting block 29, thereby opening and closing the lower baffle 8. When the interior of the screening tank 2 needs to be cleaned, simply move the connecting bracket 6 laterally, and the insert block 34 will move laterally out of the slot 30, thus separating the electric push rod 22 from the second extension rod 18.
[0036] The rotating device 36 is an existing device, and its specific structure will not be described in detail.
[0037] A potato screening method was also disclosed, including the following steps: S1, Feeding and Initial Movement: Pour the potatoes to be screened into the upper part (imported) of screening bucket 2; Because the screening bucket 2 is tilted and rotating, the potatoes tumble continuously inside the screening bucket and slowly move towards the lower end (outlet). S2, First-level screening: The potatoes first enter the first screening chamber, where the screening holes (4) are the smallest. The screening drum rotates continuously, and the potatoes tumble inside. The smallest potatoes (smaller than the sieve openings) fall through the sieve openings during the tumbling process. The remaining potatoes remain in the sorting chamber; S3, segmented release and step-by-step screening: The control drive device causes the lower baffle 8 to open sequentially from the inlet to the outlet direction at set times. Open the first lower baffle 8: When the potatoes in the first screening chamber have been fully screened, the drive device is activated, pushing the first lower baffle 8 from the "closed state" to the "open state"; Material flow: After the first lower baffle 8 is opened, the remaining potatoes in the first compartment flow into the second screening compartment through the space below the opened lower baffle 8. S4, Second-stage screening: The screening holes 4 of the second compartment are larger than the first. Potatoes remaining here continue to tumble, and medium-sized potatoes fall through the screening holes of this section. S5, Cyclic Process: Subsequently, the drive device opens the second and third lower baffles 8 in sequence, and each compartment repeats the above process of "retention screening - opening baffle - feeding to the next level - continuing screening"; S6, Final Product Outflow: Potatoes of the largest size cannot pass through any sieve holes and eventually flow out from the bottom of the screening bucket.
[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A potato screening structure, characterized in that, include: Main support; A screening bucket is rotatably connected to the main support. The screening bucket is tilted and has a screening cavity that extends through both ends of the screening bucket. The screening cavity is divided into several screening sub-cavities from top to bottom. Each screening sub-cavity has several screening holes on its side wall. The screening holes of the upper screening sub-cavities are smaller than the screening holes of the adjacent lower screening sub-cavities. A support rod, one end of which is fixedly connected to the main support via a connecting bracket, and the other end of which is inserted into the screening chamber; An isolation device is provided between adjacent screening chambers, the isolation device comprising: An upper baffle, which is fixed to the support rod; A lower baffle is disposed below the upper baffle and is hinged to the support rod. The lower baffle has an open state and a closed state. When the lower baffle is open, the lower parts of adjacent screening chambers are connected. When the lower baffle is closed, the adjacent screening chambers are isolated. A driving device is used to switch the lower baffle between an open state and a closed state; A rotating device is used to drive the screening bucket to rotate.
2. The potato screening structure according to claim 1, characterized in that, The driving device includes: A telescopic structure corresponding to each of the lower baffles, the telescopic structure includes a telescopic rod and a push rod, the support rod is provided with a telescopic groove corresponding to the lower baffle, the telescopic rod is installed in the telescopic groove, the side wall of the telescopic groove is provided with a first side groove, the telescopic rod is fixed with a first protrusion extending out of the first side groove, one end of the push rod is hinged to the first protrusion, and the other end is hinged to the corresponding lower baffle; A mobile device for moving the telescopic rod.
3. The potato screening structure according to claim 2, characterized in that, The telescopic structure also includes a telescopic spring. One end of the telescopic rod is provided with a groove with an opening facing the lower baffle. One end of the telescopic spring is inserted into the groove, and the other end abuts against the inner wall of the telescopic slide. The side wall of the telescopic slide is also provided with a second side groove. A second protrusion extending out of the second side groove is fixed on the telescopic rod. A second extension rod extending out of the screening cavity is fixed on the second protrusion. One end of the second extension rod extending out of the screening cavity is provided with an abutment surface. The moving device includes a drive motor, which is fixed on the connecting bracket. The drive motor shaft is provided with drive cams that correspond one-to-one with the contact surfaces. The drive motor drives the drive cams to rotate, causing the lower baffles near the inlet of the screening chamber to open sequentially from the lower baffles near the outlet of the screening chamber.
4. The potato screening structure according to claim 2, characterized in that, The side wall of the telescopic chute is also provided with a second side groove, and a second protrusion extending out of the second side groove is fixed on the telescopic rod, and a second extension rod extending out of the screening cavity is fixed on the second protrusion. The moving device is configured as an electric push rod corresponding to each of the second extension rods. The electric push rod is fixed on the connecting bracket, and the push rod end of the electric push rod is connected to the corresponding second extension rod.
5. The potato screening structure according to claim 1, characterized in that, A connecting rod is fixed on the support rod, and a connecting bolt that is threaded onto the connecting rod and connected to the connecting bracket is threaded through the connecting rod.
6. The potato screening structure according to claim 5, characterized in that, A support crossbar is fixed on the main bracket. A sliding groove is provided in the support crossbar. An adjusting screw is rotatably connected in the sliding groove. A sliding block is installed in the sliding groove. An adjusting internal thread hole is provided in the sliding block. The adjusting screw is threadedly connected to the adjusting internal thread hole. The connecting bracket is fixedly connected to the sliding block.
7. The potato screening structure according to claim 4, characterized in that, The electric push rod has a connecting block fixed to its push rod end, and the connecting block has an upward-facing slot. The second extension rod has a plug block that is inserted into the slot.
8. The potato screening structure according to claim 6, characterized in that, The sliding groove has a sliding side groove on its side wall, and a fastening bolt that is threadedly connected to the sliding block is inserted into the sliding side groove.
9. The potato screening structure according to claim 1, characterized in that, The main support is provided with a screening channel corresponding to the screening chamber, and the inlet of the screening channel is located below the corresponding screening chamber.
10. A method for screening potatoes, characterized in that, Includes the following steps: S1, Feeding and Initial Movement: Pour the potatoes to be screened into the high end of the screening bin; The potatoes tumbled continuously inside the screening bin and slowly moved towards the lower end. S2, First-level screening: The potatoes first enter the first screening chamber, where the screening holes are the smallest. The screening bucket rotates continuously, and the potatoes tumble inside. The smallest potatoes fall through the sieve holes during the tumbling process. The remaining potatoes remain in the sorting chamber; S3, segmented release and step-by-step screening: The control drive device causes the lower baffle to open sequentially from the inlet to the outlet at set times. Open the first lower baffle: When the potatoes in the first compartment have been fully sorted, the drive device is activated, pushing the first lower baffle from the "closed state" to the "open state"; Material flow: After the first lower baffle is opened, the remaining potatoes in the first screening chamber flow into the second screening chamber through the space below the opened lower baffle. S4, Second-stage screening: The screening holes in the second compartment are larger than those in the first. Potatoes remaining here continue to tumble, and medium-sized potatoes fall through the screening holes in this section. S5, Cyclic Process: Subsequently, the drive device opens the second and third lower baffles in sequence, and each compartment repeats the above process of "retention screening - opening baffle - feeding to the next level - continuing screening"; S6, Final Product Outflow: Potatoes of the largest size cannot pass through any sieve holes and eventually flow out from the bottom of the screening bucket.