Needle belt type electrostatic separation device for separating residual films in straw feed

Abstract

The invention discloses a needle belt type electrostatic separation device for separating plastic film residues in straw feed, and belongs to the technical field of agricultural material separation, the needle belt type electrostatic separation device comprises a first metal type conveying belt and a second metal type conveying belt, and electrode supports are symmetrically arranged on the two sides of the first metal type conveying belt and the two sides of the second metal type conveying belt; electret discharge rods are arranged above the first metal type conveying belt and the second metal type conveying belt through the electrode supports respectively, residual film collecting boxes are arranged on the lower surfaces of the tail ends of the first metal type conveying belt and the second metal type conveying belt, and static brushes are arranged in the residual film collecting boxes. A feeding device is arranged above the head end of the first metal type conveying belt, a turnover device is arranged at the tail end of the first metal type conveying belt, and a straw feed collecting box is arranged below the tail end of the second metal type conveying belt. By the adoption of the structure, efficient separation of residual films and straw feed is achieved, and the separation efficiency and the overall separation rate are improved.

Description

Technical Field

[0001] This invention relates to the technical field of agricultural material separation, and in particular to a needle-belt electrostatic separation device for separating residual film from straw feed. Background Technology

[0002] In recent years, the continuous development of animal husbandry has driven the increasing demand for feed, prompting various local livestock enterprises to actively utilize straw as feed. However, due to the widespread application of drip irrigation technology, straw feed is easily mixed with impurities such as broken plastic film (residual film) during harvesting and transportation. If these hay bales containing residual film are mixed into livestock feed after being broken up and crushed, and are accidentally ingested by ruminants such as cattle and sheep, it may cause indigestion, poisoning, stunted growth, or even death, posing a significant threat to livestock safety. Currently, the removal of residual film from straw feed mainly relies on manual labor, which is inefficient and costly, severely restricting the development of animal husbandry. Solving the problem of removing residual film from straw feed is of paramount importance to livestock enterprises. Summary of the Invention

[0003] The purpose of this invention is to provide a needle-belt electrostatic separation device for separating residual film from straw feed, thereby reducing manual labor, achieving efficient separation of residual film and straw feed, and improving the separation efficiency and overall separation rate of residual film and straw feed.

[0004] To achieve the above objectives, the present invention provides a needle-belt type electrostatic separation device for separating residual film from straw feed, comprising a first support frame and a second support frame. Both the first and second support frames include a base plate, and a high-voltage electrostatic generator is disposed on the upper surface of the base plate. A first metal conveyor belt is disposed above the first support frame, and a second metal conveyor belt is disposed above the second support frame. Electrode supports are symmetrically disposed on both sides of the first and second metal conveyor belts. Electret discharge rods are respectively disposed above the first and second metal conveyor belts through the electrode supports. A residual film collection box is disposed on the lower surface of the end of both the first and second metal conveyor belts, and an electrostatic brush is disposed inside the residual film collection box. A feeding device is provided above the first end of the first metal conveyor belt, and a turning device is provided at the end of the first metal conveyor belt. A straw feed collection box is provided below the end of the second metal conveyor belt.

[0005] Preferably, the heights of the first support frame and the second support frame are adjustable. By adjusting the heights of the first support frame and the second support frame, the beginning end of the second metal conveyor belt is positioned below the end end of the first metal conveyor belt.

[0006] Preferably, the feeding device includes a feeding box, and a material leveling device is provided below the feeding box.

[0007] Preferably, the material leveling device includes a rubber roller with a spiral groove on its outer surface. Both ends of the rubber roller are connected to a large pulley via bearing seats. The large pulley at either end is connected to a small pulley, which is connected to a DC brushless motor. The rubber roller is connected to a pressure plate.

[0008] Preferably, the electret discharge rod includes a shell, a groove is provided on the upper part of the shell, a heat sink is provided inside the shell, a positioning groove is provided below the heat sink, a copper conductive plate is provided through the positioning groove, and a plurality of tungsten carbide corona needles are arranged in an array below the copper conductive plate.

[0009] Preferably, the motor bracket includes several bolts, and the electret discharge rod is connected to the bolts via a groove on the upper part of the outer shell.

[0010] Preferably, the electret discharge rod is connected to the negative electrode of the high-voltage electrostatic generator.

[0011] Preferably, both the first and second metal conveyor belts are grounded.

[0012] Therefore, the present invention employs the above-described needle-type electrostatic separation device for separating residual film from straw feed, which has the following advantages: (1) In this invention, the material is charged by electret discharge rod and grounded by metal conveyor belt, so as to achieve efficient separation of residual film and straw feed. It has low energy consumption and low manufacturing cost of a single unit.

[0013] (2) In this invention, the material spreading device spreads the material into a single layer, which solves the problem of the residual film being wrapped by straw. The secondary separation is achieved by the flipping device, which improves the thoroughness of the separation.

[0014] (3) In this invention, the heavy labor of traditional residual film removal work is greatly reduced, the separation efficiency of residual film and straw feed is improved, the overall separation rate is high, which has an important impact on the economic benefits of breeding enterprises and is conducive to the development of agricultural economy.

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a needle-type electrostatic separation device for separating residual film in straw feed according to the present invention; Figure 2This is a schematic diagram of the uniforming device structure of a needle-type electrostatic separation device for separating residual film in straw feed according to the present invention; Figure 3 This is a schematic diagram of the electret discharge rod structure of a needle-belt electrostatic separation device for separating residual film in straw feed according to the present invention; Figure 4 This is a schematic diagram showing the connection between the motor support and the electret discharge rod in a needle-type electrostatic separation device for separating residual film in straw feed according to the present invention. Figure 5 This is a schematic diagram of the feeding device of a needle-type electrostatic separation device for separating residual film in straw feed according to the present invention; Figure 6 This is a schematic diagram of a needle-type electrostatic separation device for separating residual film in straw feed according to the present invention; Figure 7 This is a schematic diagram of the effective electric field region in a needle-type electrostatic separation device for separating residual film in straw feed according to the present invention; Figure 8 This is a schematic diagram of the force analysis of straw feed and residual film in a needle-type electrostatic separation device for separating residual film in straw feed according to the present invention; Reference numerals: 1. First support frame; 2. Second support frame; 3. Base plate; 4. High-voltage electrostatic generator; 5. First metal conveyor belt; 6. Second metal conveyor belt; 7. Electrode support; 8. Electret discharge rod; 9. Residual film collection box; 10. Electrostatic brush; 11. Feeding box; 12. Rubber roller; 13. Pressing plate; 14. Bearing seat; 15. Large pulley; 16. Small pulley; 17. DC brushless motor; 18. Housing; 19. Heat sink; 20. Positioning groove; 21. Copper guide plate; 22. Tungsten carbide corona needle; 23. Bolt; 24. Tilting device; 25. Straw feed collection box. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Specific model specifications need to be selected and determined according to the actual specifications of the device, etc. The specific selection calculation method adopts existing technology in the art, and therefore will not be described in detail.

[0018] Example like Figures 1-4As shown, this invention provides a needle-belt type electrostatic separation device for separating residual film in straw feed, including a first support frame 1 and a second support frame 2. Both the first support frame 1 and the second support frame 2 include a base plate 3. A high-voltage electrostatic generator 4 is disposed on the upper surface of the base plate 3. A first metal conveyor belt 5 is disposed above the first support frame 1, and a second metal conveyor belt 6 is disposed above the second support frame 2. The heights of the first support frame 1 and the second support frame 2 are adjustable. By adjusting the heights of the first support frame 1 and the second support frame 2, the first end of the second metal conveyor belt 6 is positioned below the end of the first metal conveyor belt 5. A feeding device is provided above the first end of a metal conveyor belt 5. The feeding device includes a feeding box 11. A material leveling device is provided below the feeding box 11. The material leveling device includes a rubber roller 12 with a diameter of 300 mm and a length of 880 mm. The outer surface of the rubber roller 12 is provided with a spiral groove of rubber with a depth of 2 mm. Both ends of the rubber roller 12 are connected to a large pulley 15 through a bearing seat 14. The large pulley 15 at any end is connected to a small pulley 16. The small pulley 16 is connected to a DC brushless motor 17. The rubber roller 12 is connected to a pressure plate 13. The distance between the rubber roller 12 and the pressure plate 13 is adjustable from 5 to 15 mm. Electrode supports 7 are symmetrically arranged on both sides of the first metal conveyor belt 5 and the second metal conveyor belt 6. Electret discharge rods 8 are respectively arranged above the first metal conveyor belt 5 and the second metal conveyor belt 6 through the electrode supports 7. The electret discharge rod 8 includes a shell 18, a groove is provided on the upper part of the shell 18, a heat sink 19 is provided inside the shell 18, a positioning groove 20 with a width of 10 mm is provided below the heat sink 19, a copper conductor plate 21 with a thickness of 0.5 mm is provided through the positioning groove 20, and several tungsten steel corona needles 22 with an arrayed cone angle of 12° and a needle length of 14 mm and a needle spacing of 20 mm are provided below the copper conductor plate 21. The motor support includes several bolts 23. The electret discharge rod 8 is connected to the bolts 23 through the groove on the upper part of the shell 18 to achieve a sliding groove connection. The electret discharge rod 8 is connected to the negative terminal of the high voltage electrostatic generator 4. The high voltage electrostatic generator 4 is connected to the copper conductor plate 21 through a wire to increase the high voltage power supply and is sealed with resin glue to enhance the high voltage protection performance and improve the corrosion resistance. The lower surface of the ends of the first metal conveyor belt 5 and the second metal conveyor belt 6 are both provided with residual film collection boxes 9, and electrostatic brushes 10 are provided inside the residual film collection boxes 9; the end of the first metal conveyor belt 5 is provided with a turning device 24; the lower end of the second metal conveyor belt 6 is provided with a straw feed collection box 25; both the first metal conveyor belt 5 and the second metal conveyor belt 6 are grounded.

[0019] like Figures 5-7As shown, during the operation of the device, the crushed straw feed mixture is placed into the feeding box 11. Under the combined action of the rubber roller 12 and the pressing plate 13, the material is evenly dispersed in a single layer on the upper surface of the first metal conveyor belt 5, so that the material can enter the corona charging area of ​​the electret discharge rod 8 evenly and continuously. Figure 7 The central sector-shaped region is the effective electric field area for separating straw feed and residual film. Near the electret discharge rod 8, the strong electric field accelerates free electrons, causing them to collide with air molecules. The free electrons are quickly captured by the air molecules, forming stable negative ions. These negative ions move towards the first metallic conveyor belt 5 under the action of the electric field and randomly enter the surface of the mixture. At the same time, the material is polarized under the action of the electric field, making the material as a whole negatively charged. Due to the differences in conductivity and material properties between straw feed and residual film, the highly conductive straw feed can quickly conduct the charge to the ground. Under the influence of gravity and inertia, the material is thrown out of the first metal conveyor belt 5 at the end of the return zone and onto the second metal conveyor belt 6. The residual film, which has poor conductivity, transfers charge slowly and therefore adheres to the first metal conveyor belt 5. It is then collected into the residual film collection box 9 by the electrostatic brush 10. After the first residual film separation, the mixed material may still have residue. After the material is turned over by the turning device 24, it enters the second metal conveyor belt 6 to achieve secondary separation of the residual film. Finally, the straw feed is thrown into the straw feed collection box 25.

[0020] like Figure 8 As shown, a force analysis was performed on the straw feed and residual film. The forces acting on the materials include mirror forces. ,gravity Centrifugal force and air resistance .

[0021] Mirror force The material in the electric field is adsorbed onto the surface of the metal conveyor belt, and the charge of the material is... It is proportional to the square of, that is: (1) in, Represents the vacuum permittivity. Represents the equivalent radius of the material; The force of gravity acting on the material is: (2) in, m Represents material quality. Represents gravitational acceleration; The centrifugal force experienced by the material as it travels along the metal conveyor belt in the return zone at the end. for: (3) in, v Represents material velocity. R The radius of the drive roller of the metal conveyor belt; Air resistance experienced by the material for: (4) in, Represents the projected area of ​​the material. Represents the drag coefficient. Represents air density; air resistance Calculated to be approximately N Compared to other forces, it is negligible.

[0022] Analyzing the critical release condition of straw feed, when the straw feed reaches the bottom of the drive roller of the metal conveyor belt, the vertical component of gravity reaches its maximum, while the magnitudes of the mirror force and centrifugal force remain constant. The release condition of the straw feed at this point can be expressed as: (5) After being charged, the residual film carries a large amount of negative charge on its surface, and this accumulated charge is not easily dissipated. Under the influence of mirror force, the residual film tends to be adsorbed onto the grounding electrode surface and is eventually collected by an electrostatic brush into the residual film collection box. During this process, the residual film is most likely to detach at the bottom of the metal conveyor belt drive roller. To ensure that the residual film does not detach from the metal conveyor belt, the following conditions must be met: (6) During the movement of residual film and straw feed, the mirror force plays a dominant role, and the mirror force mainly depends on the charge acquired by the material. To ensure that the charge meets the critical desorption value, the expressions of each force are substituted into equations (5) and (6) to obtain the critical charge of residual film and straw feed. With quality Relationship: (7) The lower limit of the residual film charge threshold and the upper limit of the straw feed charge threshold were determined by equation (7). Due to the differences in material properties between straw feed and residual film, the amount of charge they carry is significantly different. During the separation process, the actual measured charge of the residual film is higher than the set lower limit of the residual film charge threshold. At this time, the image force plays a dominant role, causing the residual film to adhere to the surface of the metal conveyor belt. However, the actual measured charge of the straw feed is close to zero, far below the upper limit of the straw feed charge threshold. At this time, the combined force of gravity and centrifugal force plays a dominant role, causing the straw feed to fall off.

[0023] Therefore, the present invention employs the above-mentioned needle-belt electrostatic separation device for separating residual film from straw feed. By charging the material with electret discharge rods and combining it with the grounding design of the metal conveyor belt, the manual labor is reduced, and efficient separation of residual film and straw feed is achieved. It has low energy consumption, low manufacturing cost per unit, and improves the separation efficiency and overall separation rate of residual film and straw feed.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A needle-belt electrostatic separation device for separating residual film from straw feed, characterized in that: The system includes a first support frame and a second support frame, both of which include a base plate. A high-voltage electrostatic generator is mounted on the upper surface of the base plate. A first metal conveyor belt is mounted above the first support frame, and a second metal conveyor belt is mounted above the second support frame. Electrode supports are symmetrically arranged on both sides of the first and second metal conveyor belts. Electret discharge rods are respectively mounted above the first and second metal conveyor belts via the electrode supports. A residual film collection box is mounted on the lower surface of the ends of both the first and second metal conveyor belts, and an electrostatic brush is installed inside the residual film collection box. A feeding device is provided above the first end of the first metal conveyor belt, and a turning device is provided at the end of the first metal conveyor belt. A straw feed collection box is provided below the end of the second metal conveyor belt.

2. The needle-belt electrostatic separation device for separating residual film in straw feed according to claim 1, characterized in that: The heights of the first support frame and the second support frame are adjustable. By adjusting the heights of the first support frame and the second support frame, the beginning end of the second metal conveyor belt is positioned below the end end of the first metal conveyor belt.

3. The needle-belt electrostatic separation device for separating residual film in straw feed according to claim 1, characterized in that: The feeding device includes a feeding box, and a material leveling device is provided below the feeding box.

4. A needle-belt electrostatic separation device for separating residual film in straw feed according to claim 3, characterized in that: The material leveling device includes a rubber roller with a spiral groove on its outer surface. Both ends of the rubber roller are connected to a large pulley via bearing seats. The large pulley at either end is connected to a small pulley, which is connected to a DC brushless motor. The rubber roller is connected to a pressure plate.

5. A needle-type electrostatic separator for separating residual film from straw feed according to claim 1, characterized in that: The electret discharge rod includes a shell, a groove is provided on the upper part of the shell, a heat sink is provided inside the shell, a positioning groove is provided below the heat sink, a copper conductive plate is provided through the positioning groove, and a plurality of tungsten carbide corona needles are arranged in an array below the copper conductive plate.

6. A needle-belt electrostatic separation device for separating residual film in straw feed according to claim 5, characterized in that: The motor bracket includes several bolts, and the electret discharge rod is connected to the bolts via a groove on the upper part of the outer shell.

7. A needle-belt electrostatic separation device for separating residual film in straw feed according to claim 6, characterized in that: The electret discharge rod is connected to the negative terminal of the high-voltage electrostatic generator.

8. A needle-belt electrostatic separation device for separating residual film in straw feed according to claim 1, characterized in that: Both the first and second metal conveyor belts are grounded.

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