A screening device for heavy calcium carbonate particles

Abstract

The application discloses a screening device for heavy calcium carbonate particles, and relates to the technical field of screening, which comprises a frame body, an outer cover installed on the frame body, a support frame fixedly installed in the outer cover, a double-screen assembly rotatably installed on the support frame, and a primary screen assembly rotatably installed in the double-screen assembly, and a tumbling assembly matched with the primary screen assembly is installed on the support frame. Advantages are as follows: the heavy calcium carbonate particle screening device realizes two-stage screening through reverse rotation of double rollers, utilizes the staggered effect to diffuse materials and improves the efficiency; a driving motor is provided to drive a filter plate to scatter the accumulated materials of the inner roller, so that the diffusion of the materials is accelerated; a gas injection rotating pipe with fins is used to further diffuse the materials through pulse blowing, and dust is sucked and discharged at the same time; the rotating pipe is controlled to rotate at variable speed through gas injection pressure, and an elastic expansion rod cooperates with a counterweight ball to knock and vibrate, so that the rotating pipe is prevented from being blocked.

Description

Technical Field

[0001] This invention relates to the field of screening technology, and more particularly to a screening device for heavy calcium carbonate particles. Background Technology

[0002] To address the current problems of poor adhesion and bonding strength, poor workability, and lack of environmental performance in architectural coatings, the key lies in the compatibility of the particle size distribution and shape of the filler particles with the base material. Research is being conducted on key technologies for the preparation of new heavy calcium carbonate particle filler materials for architectural coatings. The research focuses on particle size and distribution, particle shape control technology, crushing and grading combination processes, intelligent control and other means to implement precise control of particle size in multiple process stages, which significantly improves the uniformity of particle distribution in products of the same specification.

[0003] The screening process for heavy calcium carbonate particles is a core step in calcium carbonate production, directly affecting product quality indicators such as particle size distribution, especially particle size distribution range, particle shape, and application performance. CN110238026B discloses a drum screen, which includes two opposing screen cylinder mounting seats. A cylindrical screen cylinder is installed between the two mounting seats. Several strip-shaped inlet scrapers are installed on the inner wall of the inlet end of the screen cylinder, and several strip-shaped outlet scrapers are installed on the inner wall of the outlet end of the screen cylinder. The inlet and outlet scrapers extend spirally along the inner wall of the screen cylinder, with opposite directions of rotation. One side of the inlet and outlet scrapers is in close contact with the inner wall of the screen cylinder, while the other side is suspended. The front and rear ends of the suspended sides of the inlet and outlet scrapers twist in opposite directions.

[0004] The aforementioned drum screen is equipped with inlet and outlet scrapers, which increases the drop of the banana taro as it rotates in the screen cylinder, making it easier to separate the mud from the surface of the banana taro. The inlet and outlet scrapers rotate in opposite directions. When the screen cylinder rotates in a specific direction, the inlet and outlet scrapers work together to push the banana taro towards the middle of the screen cylinder, extending the mud removal time of the banana taro in the screen cylinder. When the mud removal is completed, when the screen cylinder rotates in the opposite direction, the outlet scraper can push the banana taro out of the screen cylinder, effectively controlling the mud removal time and making the mud removal effect better. The front and rear ends of the suspended sides of the inlet and outlet scrapers twist in opposite directions, which guides the banana taro and prevents it from getting stuck when moving between adjacent inlet or outlet scrapers.

[0005] However, when the aforementioned drum screen is used for calcium carbonate screening, the varying sizes of the calcium carbonate make it easy for it to get stuck in the screen. This necessitates the use of a vibrating device to strike the screen and dislodge the stuck calcium carbonate. This method severely impacts the screening efficiency. Furthermore, impurities in the calcium carbonate are also screened along with it, resulting in a large amount of dust in the screened calcium carbonate, affecting its quality. Additionally, using the drum screen's rotation to move the calcium carbonate leads to accumulation within the screen, preventing rapid material diffusion. Therefore, a longer drum screen is required, further reducing screening efficiency and increasing the equipment's footprint.

[0006] Therefore, a new type of screening device for heavy calcium carbonate particles can be used to overcome the shortcomings of the existing technology. Summary of the Invention

[0007] The purpose of this invention is to solve the problems existing in the prior art by proposing a screening device for heavy calcium carbonate particles.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A screening device for heavy calcium carbonate particles includes a frame, an outer cover mounted on the frame, and a support frame fixedly mounted inside the outer cover. It also includes a secondary screening assembly rotatably mounted on the support frame and a primary screening assembly rotatably mounted inside the secondary screening assembly. A tumbling assembly that cooperates with the primary screening assembly is mounted on the support frame.

[0010] The support frame is equipped with a first drive assembly that cooperates with the secondary screening assembly, a second drive assembly that cooperates with the primary screening assembly, and a third drive assembly that cooperates with the tumbling assembly. A feeding hopper that cooperates with the secondary screening assembly is fixedly installed on the support frame.

[0011] The primary screening assembly includes an inner drum screen, an air guide roller is fixedly installed on the outside of the inner drum screen, one end of the air guide roller is connected to an external air source, and multiple auxiliary feeding mechanisms are installed inside the air guide roller. The secondary screening assembly includes an outer drum screen.

[0012] Preferably, the first drive assembly consists of a first drive motor and a transmission wheel. The support frame is rotatably mounted with a plurality of limiting wheels that cooperate with the outer drum screen. The transmission wheel is installed between the outer drum screen and the first drive motor to transmit power from the first drive motor, thereby driving the outer drum screen to rotate.

[0013] Preferably, the tumbling assembly includes two brackets fixedly mounted on a support frame, and a rotating shaft is rotatably mounted on both brackets. The third drive assembly includes a third drive motor fixedly mounted on one of the brackets, with the drive end of the third drive motor fixedly connected to the rotating shaft, and a filter plate fixedly mounted on the rotating shaft.

[0014] Preferably, the second drive assembly consists of a second drive motor and a transmission track mechanism, wherein the second drive motor drives the transmission track to rotate, thereby driving the inner drum screen to rotate.

[0015] Preferably, the air guide roller, outer roller screen, and inner roller screen are all consistent with the support frame and are all inclined, with the diameter of the higher side of the air guide roller being larger than the diameter of the lower side.

[0016] Preferably, the inner drum screen has multiple material distribution plates fixedly installed inside, and each material distribution plate has a certain degree of elasticity.

[0017] Preferably, the auxiliary feeding mechanism includes a first connecting pipe and a second connecting pipe fixedly installed inside the air guide roller. The end of the first connecting pipe is arc-shaped and matches the inner drum screen. The second connecting pipe passes through and extends out of the air guide roller. A rotating pipe is rotatably installed between the first connecting pipe and the second connecting pipe. The rotating pipe is equipped with an air blowing negative pressure structure, a vibration structure, and a driving structure.

[0018] Preferably, the blowing negative pressure structure includes an air guide hole with two air guide ports on the rotating tube. The air guide holes are opened at an angle, with the air guide port inside the rotating tube being higher than the air guide port outside the rotating tube. The air guide holes are located on the lower half of the rotating tube.

[0019] Preferably, the vibration structure includes multiple elastic telescopic rods fixedly installed outside the rotating tube, and a counterweight ball is fixedly installed at the telescopic end of each elastic telescopic rod.

[0020] Preferably, the drive structure includes multiple drive fins fixedly mounted on the rotating tube, each drive fin forming a 60-degree angle with the rotating tube.

[0021] Compared with existing technologies, the advantages of this invention are:

[0022] 1. This screening device for heavy calcium carbonate particles can perform two-stage screening of calcium carbonate by setting an inner drum screen and an outer drum screen. The inner drum screen and the outer drum screen rotate in opposite directions. The calcium carbonate falling from the inner drum screen into the outer drum screen will be misaligned, making the calcium carbonate more diffusely distributed in the outer drum screen, which has the advantage of improving screening efficiency.

[0023] 2. This screening device for heavy calcium carbonate particles uses a third drive motor to rotate the filter plate during calcium carbonate screening. This disperses the calcium carbonate accumulated inside the inner drum screen, reduces the amount of calcium carbonate accumulated inside the inner drum screen, and allows the material inside the calcium carbonate pile to diffuse rapidly, thereby improving the calcium carbonate screening efficiency.

[0024] 3. This screening device for heavy calcium carbonate particles uses a rotating tube with drive fins to rotate during calcium carbonate screening. Air is injected to make the rotating tube rotate, and air guide holes are provided on the rotating tube. When the air guide holes face the air injection direction, the injected gas enters the inner drum screen through the air guide holes, blowing and dispersing the calcium carbonate pile. Due to the rotation of the rotating tube, pulsed airflow is generated, resulting in better dispersion. When the air guide holes face away from the air injection direction, the air velocity at the air guide holes is low, creating negative pressure. This draws dust from the calcium carbonate in the inner drum screen into the rotating tube and discharges it with the airflow, effectively cleaning the dust.

[0025] 4. This screening device for heavy calcium carbonate particles uses multiple elastic telescopic rods and counterweight balls on the rotating tube during calcium carbonate screening. The rotation speed of the rotating tube is controlled by the air injection pressure, thereby achieving variable speed rotation of the rotating tube. The variable speed rotation generates different centrifugal forces, which cause the elastic telescopic rods and counterweight balls to work together to knock and vibrate the rotating tube, squeezing out the calcium carbonate material stuck in the rotating tube and effectively reducing the probability of blockage. Attached Figure Description

[0026] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0027] Figure 1 This is a schematic diagram of the structure of a screening device for heavy calcium carbonate particles proposed in this invention.

[0028] Figure 2 for Figure 1 Detailed structural diagram after the outer casing has been cut open;

[0029] Figure 3 for Figure 2 Detailed schematic diagram of the planar structure of the intermediate support frame and the secondary screening assembly;

[0030] Figure 4 for Figure 3 Detailed schematic diagram of the three-dimensional structure;

[0031] Figure 5 for Figure 4 Detailed schematic diagram of the structure after rotation at a certain angle;

[0032] Figure 6 for Figure 5 Detailed schematic diagram of the structure after rotation at a certain angle;

[0033] Figure 7 for Figure 6 Detailed enlarged structural diagram of section A;

[0034] Figure 8 for Figure 5 Detailed schematic diagram of the enlarged structure of the tumbling component;

[0035] Figure 9 for Figure 5 Detailed schematic diagram of the enlarged structure of the primary and intermediate screening components;

[0036] Figure 10 for Figure 9 Detailed schematic diagram of the planar structure along one of the angles;

[0037] Figure 11 for Figure 9 Detailed schematic diagram of the structure of the central air guide roller after a portion has been cut open;

[0038] Figure 12 for Figure 11 Enlarged schematic diagram of the auxiliary feeding mechanism;

[0039] Figure 13 for Figure 12 Detailed schematic diagram of the planar structure along one of the angles;

[0040] Figure 14 for Figure 12 Detailed schematic diagram of the structure after cutting open the first connecting pipe, the rotating pipe and the second connecting pipe.

[0041] In the diagram: 1 Support frame, 2 Secondary screening assembly, 3 First drive assembly, 4 Second drive assembly, 5 Third drive assembly, 6 Feed hopper, 7 Primary screening assembly, 8 Baffle, 9 First drive motor, 10 Limiting wheel, 11 Tumbling assembly, 12 Bracket, 13 Third drive motor, 14 Rotating shaft, 15 Filter plate, 16 Inner drum screen, 17 Air guide drum, 18 Material distribution plate, 19 Auxiliary feeding mechanism, 20 First connecting pipe, 21 Rotating pipe, 22 Transmission fins, 23 Second connecting pipe, 24 Air guide hole, 25 Elastic telescopic rod, 26 Counterweight ball, 27 Frame, 28 Outer cover, 29 Hydraulic rod, 30 Feed pipe, 31 Feed hopper. Detailed Implementation

[0042] 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.

[0043] Example 1: Refer to Figures 1-8A screening device for heavy calcium carbonate particles includes a frame 27, an outer cover 28 mounted on the frame 27, and a support frame 1 fixedly mounted inside the outer cover 28. It also includes a secondary screening assembly 2 rotatably mounted on the support frame 1 and a primary screening assembly 7 rotatably mounted inside the secondary screening assembly 2. A tumbling assembly 11 that cooperates with the primary screening assembly 7 is mounted on the support frame 1.

[0044] Multiple hydraulic rods 29 are fixedly installed on the frame 27. The telescopic end of each hydraulic rod 29 is rotatably connected to the outer cover 28. The outer cover 28 is fixedly installed with a feed hopper 31 that cooperates with the screening assembly 2. The feed hopper 31 is fixedly connected to a feed pipe 30. The tilt angle of the outer cover 28 is adjusted by the hydraulic rods 29 to change the feeding speed. The smaller the tilt angle, the slower the feeding, and the larger the tilt angle, the faster the feeding.

[0045] A support plate is fixedly installed on the outer cover 28, and a support column for supporting the feed hopper 31 is fixedly installed on the support plate. The support column and the support plate are located below the feed hopper 31.

[0046] The support frame 1 is equipped with a first drive assembly 3 that cooperates with the secondary screening assembly 2, a second drive assembly 4 that cooperates with the primary screening assembly 7, and a third drive assembly 5 that cooperates with the tumbling assembly 11. The support frame 1 is also fixedly equipped with a feeding hopper 6 that cooperates with the secondary screening assembly 2.

[0047] The first drive assembly 3 consists of a first drive motor 9 and a transmission wheel. Multiple limiting wheels 10 that cooperate with the outer drum screen are rotatably mounted on the support frame 1. The transmission wheel is installed between the outer drum screen and the first drive motor 9 to transmit the power from the first drive motor 9, thereby driving the outer drum screen to rotate.

[0048] The outer drum screen is set to rotate counterclockwise. As the outer drum screen rotates, the calcium carbonate that has been screened once inside the outer drum screen will rotate along the inner wall of the outer drum screen until the weight of the calcium carbonate is greater than the friction between the calcium carbonate and the outer drum screen. Then the calcium carbonate adhering to the outer drum screen will fall off, thus exposing the calcium carbonate inside the calcium carbonate pile for screening.

[0049] As the screening process proceeds, the calcium carbonate will slide down the outer drum screen until it is discharged from the discharge port of the outer drum screen. The calcium carbonate that has been screened by the outer drum screen will be discharged from the feed hopper 6.

[0050] Example 2: This example differs from Example 1 in that: (Refer to...) Figures 1-5 , Figures 8-14The primary screening component 7 includes an inner drum screen 16, an air guide roller 17 is fixedly installed on the outside of the inner drum screen 16, one end of the air guide roller 17 is connected to an external air source, and multiple auxiliary feeding mechanisms 19 are installed inside the air guide roller 17. The secondary screening component 2 includes an outer drum screen.

[0051] The tumbling assembly 11 includes two brackets 12 fixedly mounted on the support frame 1. A rotating shaft 14 is rotatably mounted on both brackets 12. The third drive assembly 5 includes a third drive motor 13 fixedly mounted on one of the brackets 12. The drive end of the third drive motor 13 is fixedly connected to the rotating shaft 14. A filter plate 15 is fixedly mounted on the rotating shaft 14.

[0052] During the screening process, the third drive motor 13 is started. The rotation of the drive end of the third drive motor 13 will drive the rotating shaft 14 fixedly connected to it to rotate. The rotation of the rotating shaft 14 will drive the filter plate 15 fixedly connected to it to rotate. The bottom of the filter plate 15 is in contact with the inside of the inner drum screen 16. Through the rotation of the filter plate 15, not only can the calcium carbonate pile in the inner drum screen 16 be broken up, but also large particles of calcium carbonate stuck on the inner drum screen 16 can be scraped off, which can effectively reduce the probability of the primary screening component 7 being blocked.

[0053] The second drive assembly 4 consists of a second drive motor and a transmission track mechanism. The second drive motor drives the transmission track to rotate, which in turn drives the inner drum screen 16 to rotate. The rotation of the drive end of the second drive motor will drive the inner drum screen 16 to rotate through the transmission track. The rotation direction of the inner drum screen 16 is opposite to the rotation direction of the outer drum screen. Here, it is set to be the opposite of the above, which is clockwise rotation.

[0054] When the inner drum screen 16 and the outer drum screen rotate in opposite directions, the calcium carbonate screened out from the inner drum screen 16 will form a reverse relative motion with the inner wall of the outer drum screen, generating shearing force and collision force, which can quickly break up materials such as calcium carbonate that are prone to caking, avoid the formation of a material layer on the screen surface, and make it easier for fine particles to pass through the screen holes.

[0055] Reverse rotation changes the movement trajectory of calcium carbonate in the outer drum screen, causing it to move forward slowly in a spiral shape instead of sliding out quickly in the same direction as the drum. This prolongs the contact time between calcium carbonate and the screen surface, reduces the probability of mixing coarse and fine particles, and ensures the grading effect of two-stage screening.

[0056] The reverse relative motion creates a continuous frictional cleaning effect on the screen surface, which can reduce the situation where calcium carbonate particles get stuck in the screen holes. It is especially suitable for materials such as calcium carbonate that are easy to adhere to and clog, thus reducing the frequency of downtime for cleaning.

[0057] The air guide roller 17, the outer roller screen, and the inner roller screen 16 are all consistent with the support frame 1 and are all inclined. The diameter of the higher side of the air guide roller 17 is larger than the diameter of the lower side.

[0058] Since the size of the air injection end is larger than that of the air outlet end, according to the Venturi effect in fluid mechanics, when the airflow flows in the gradually narrowing air guide drum 17, the reduced cross-sectional area will increase the flow velocity and reduce the static pressure. The high-speed airflow can form a stronger impact force, quickly blowing away the calcium carbonate clumps accumulated in the inner drum screen 16, avoiding agglomeration and hindering the screening, and improving the screening efficiency.

[0059] The reduction in static pressure caused by the reduced diameter of the air guide roller 17 will create a stable negative pressure zone at the air outlet and its surroundings. Combined with the rotation of the rotating tube 21, the negative pressure zone can efficiently adsorb the dust generated during the calcium carbonate screening process, reduce the adhesion of dust on the screen surface, reduce the probability of screen hole blockage, and improve the working environment.

[0060] The tapered structure of the air guide roller 17 can guide the airflow to accelerate smoothly and avoid turbulence caused by sudden changes in pipe diameter. For the design of pulse blowing, a stable high-speed airflow can make the blowing diffusion effect more uniform, while ensuring the continuity of negative pressure dust removal and improving the reliability of airflow-assisted screening.

[0061] Multiple material distribution plates 18 are fixedly installed inside the inner drum screen 16, and each material distribution plate 18 has a certain degree of elasticity. When the inner drum screen 16 rotates, the inclined material distribution plates 18 will bring the bottom calcium carbonate to the upper part of the inner drum screen 16 and then drop it, so that the calcium carbonate changes from accumulation and sliding to air throwing, which greatly increases the contact area between calcium carbonate and the screen surface, and fine particles can pass through the screen holes more fully, reducing the situation of coarse and fine particles being mixed during screening.

[0062] During the process of lifting and feeding calcium carbonate, the feed plate 18 will impact and shear the agglomerated calcium carbonate, breaking the material into loose particles, preventing large pieces of calcium carbonate from clogging the screen holes, and reducing the probability of calcium carbonate adhering to the inner wall of the inner drum screen 16.

[0063] The auxiliary feeding mechanism 19 includes a first connecting pipe 20 and a second connecting pipe 23 fixedly installed inside the air guide roller 17. The end of the first connecting pipe 20 is arc-shaped (this design is for better connection with the inner drum screen 16) and matches the inner drum screen 16. The second connecting pipe 23 passes through and extends out of the air guide roller 17. A rotating pipe 21 is rotatably installed between the first connecting pipe 20 and the second connecting pipe 23. The rotating pipe 21 is equipped with an air blowing negative pressure structure, a vibration structure and a drive structure.

[0064] The air blowing negative pressure structure includes an air guide hole 24 with two air guide ports on the rotating tube 21. The air guide hole 24 is opened at an angle, with the air guide port inside the rotating tube 21 being higher than the air guide port outside the rotating tube 21. The air guide hole 24 is located on the lower half of the rotating tube 21.

[0065] When the air guide hole 24 is facing the air injection direction, the injected gas enters the inner drum screen 16 through the air guide hole 24 and blows and diffuses the calcium carbonate pile. Due to the rotation of the rotating tube 21, the airflow entering the air guide hole 24 is unstable and will generate pulse blowing, which will have a better blowing effect.

[0066] Calcium carbonate particles are fine and easily adhere to each other, which can easily get stuck in the sieve holes and form bridges, leading to a decrease in the effective opening rate of the sieve holes. Directional pulsed airflow can directly impact the stuck particles in the sieve holes and use the airflow impact force to blow them out of the sieve holes, avoiding the reduction in screening efficiency caused by clogging and reducing the frequency of downtime for manual cleaning.

[0067] For fine calcium carbonate particles that are attached to the surface of coarse particles or stuck in the gaps of the material layer, the airflow can generate a peeling and pushing effect, separating the fine particles from the coarse particles and pushing the fine particles through the screen holes quickly, avoiding the fine particles being carried away by the coarse particles and improving the classification accuracy of the two-stage screening.

[0068] When the air guide hole 24 is facing away from the air injection direction, the wind speed at the air guide hole 24 is low, which will generate negative pressure, sucking the dust in the calcium carbonate inside the inner drum screen 16 into the rotating tube 21 and expelling it with the airflow, thus playing a role in cleaning dust.

[0069] During the blowing process, the dust attached to the calcium carbonate can be blown off. Then, the calcium carbonate dust generated during screening is carried out from the inner drum screen 16 by negative pressure. The dust is collected in conjunction with the subsequent dust removal device, which reduces the accumulation of dust on the inner wall of the drum and the surface of the screen. This reduces the wear of dust on the transmission parts of the equipment and improves the dust pollution problem in the field.

[0070] In addition, negative pressure can also absorb calcium carbonate in the inner drum screen 16, accelerate the passage speed of calcium carbonate, and thus improve the screening of calcium carbonate.

[0071] The drive structure includes multiple drive fins 22 fixedly mounted on the rotating tube 21, with each drive fin 22 forming a 60-degree angle with the rotating tube 21;

[0072] The vibration structure includes multiple elastic telescopic rods 25 fixedly installed outside the rotating tube 21, and a counterweight ball 26 is fixedly installed at the telescopic end of each elastic telescopic rod 25.

[0073] Since there is a risk of the screen holes of the rotating tube 21 being blocked, the calcium carbonate particles passing through the inner drum screen 16 can pass through the rotating tube 21. However, there is a possibility that the calcium carbonate may rotate and deviate within the rotating tube 21, causing it to get stuck inside (the calcium carbonate particles are irregular, and their lateral dimensions will change after deviation, resulting in a probability of them getting stuck inside the rotating tube 21). In this case, by using unstable air injection, the rotating tube 21 is driven to rotate by the resistance of the transmission fins 22. Due to the unstable airflow, the rotation speed of the rotating tube 21 is unstable, and the resulting centrifugal force is also unstable. At this time, the centrifugal force generated by the counterweight ball 26 is different, so the difference between the centrifugal force of the counterweight ball 26 and the elastic force of the elastic telescopic rod 25 will change. When the centrifugal force is less than the elastic force, the counterweight ball 26 will compress the elastic telescopic rod 25 to the extreme under the action of the elastic force, generating an impact force on the rotating tube 21. Through the impact, the calcium carbonate stuck in the rotating tube 21 will rotate. Combined with the centrifugal force of the rotating tube 21 itself, the calcium carbonate will also rotate, thus allowing the calcium carbonate to detach from the rotating tube 21.

[0074] When the centrifugal force is greater than the elastic force, the counterweight ball 26 will cause the elastic telescopic rod 25 to stretch to its limit. In this way, the centrifugal force will be transmitted to the rotating tube 21 through the elastic telescopic rod 25. The stretching will cause the rotating tube 21 to deform slightly, expanding the inner diameter of the rotating tube 21, making it easier for the calcium carbonate inside the rotating tube 21 to fall out.

[0075] The specific operating steps of this device are as follows:

[0076] First, calcium carbonate is introduced into the feed hopper 31 through the feed pipe 30, and then enters the inner drum screen 16 on the higher side through the feed hopper 31. Then, the first drive motor 9, the second drive motor and the third drive motor 13 are started.

[0077] The rotation of the second drive motor drives the inner drum screen 16 to rotate via the transmission belt. The rotation of the third drive motor 13 drives the rotating shaft 14 fixedly connected to it to rotate. The rotation of the rotating shaft 14 drives the filter plate 15 fixedly connected to it to rotate. The drive of the first drive motor 9 drives the outer drum screen to rotate via the transmission wheel. The rotation direction of the inner drum screen 16 is opposite to the rotation direction of the outer drum screen.

[0078] The calcium carbonate that falls through the inner drum screen 16 will fall onto the outer drum screen. As the outer drum screen rotates, the calcium carbonate that has already been screened once by the inner drum screen 16 will rotate along the inner wall of the outer drum screen until the weight of the calcium carbonate is greater than the friction between the calcium carbonate and the outer drum screen. Then the calcium carbonate adhering to the outer drum screen will fall off, thus exposing the calcium carbonate inside the calcium carbonate pile and allowing for screening of the calcium carbonate inside.

[0079] As the screening process proceeds, the calcium carbonate will slide down the outer drum screen until it is discharged from the discharge port of the outer drum screen. The calcium carbonate after being screened by the outer drum screen will be discharged from the feed hopper 6.

[0080] When screening inside the inner drum screen 16, the bottom of the filter plate 15 is in contact with the inside of the inner drum screen 16. By rotating the filter plate 15, not only can the calcium carbonate pile inside the inner drum screen 16 be broken up, but also large particles of calcium carbonate stuck on the inner drum screen 16 can be scraped off, which can effectively reduce the probability of the primary screening component 7 being blocked.

[0081] At the same time, air is injected into the air inlet of the air guide roller 17 through an external air source. The airflow will blow onto the transmission fins 22. Due to the inclined design of the transmission fins 22, the resistance between each transmission fin 22 and the airflow is different. Therefore, the resistance difference is used to drive the rotating tube 21 to rotate.

[0082] First, stabilize the gas injection. When the rotation speed of the rotating tube 21 is stable, and the air guide hole 24 on the rotating tube 21 is facing the gas injection direction, the injected gas enters the inner drum screen 16 through the air guide hole 24 to blow and diffuse the calcium carbonate pile. Because the rotating tube 21 rotates, the airflow entering the air guide hole 24 is unstable and will generate pulse blowing, which will have a better blowing effect.

[0083] When the air guide hole 24 is facing away from the air injection direction, the wind speed at the air guide hole 24 is low, which will generate negative pressure, sucking the dust in the calcium carbonate inside the inner drum screen 16 into the rotating tube 21 and expelling it with the airflow, thus playing a role in cleaning dust.

[0084] During the blowing process, the dust attached to the calcium carbonate can be blown off. Then, the calcium carbonate dust generated during screening is carried out from the inner drum screen 16 by negative pressure. The dust is collected in conjunction with the subsequent dust removal device, which reduces the accumulation of dust on the inner wall of the drum and the surface of the screen. This reduces the wear of dust on the transmission parts of the equipment and solves the dust pollution problem in the field.

[0085] In addition, negative pressure can also absorb calcium carbonate in the inner drum screen 16, accelerate the passage speed of calcium carbonate, and thus improve the screening of calcium carbonate.

[0086] After running for a period of time, the stable gas injection and unstable gas injection alternate. During unstable gas injection, the rotation speed of the rotating tube 21 is unstable due to the unstable airflow, and the resulting centrifugal force is also unstable. At this time, the centrifugal force generated by the counterweight ball 26 is different, so the difference between the centrifugal force of the counterweight ball 26 and the elastic force of the elastic telescopic rod 25 will change. When the centrifugal force is less than the elastic force, the counterweight ball 26 will compress the elastic telescopic rod 25 to the extreme under the action of the elastic force, generating an impact force on the rotating tube 21. Through the impact, the calcium carbonate stuck in the rotating tube 21 will rotate. Combined with the centrifugal force of the rotating tube 21 itself, the calcium carbonate itself will also rotate, thus detaching the calcium carbonate from the rotating tube 21.

[0087] When the centrifugal force is greater than the elastic force, the counterweight ball 26 will cause the elastic telescopic rod 25 to stretch to its limit. In this way, the centrifugal force will be transmitted to the rotating tube 21 through the elastic telescopic rod 25. The stretching will cause the rotating tube 21 to deform slightly, expanding the inner diameter of the rotating tube 21, making it easier for the calcium carbonate inside the rotating tube 21 to fall out.

[0088] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A screening device for heavy calcium carbonate particles, comprising a frame (27), an outer cover (28) mounted on the frame (27), and a support frame (1) fixedly mounted inside the outer cover (28), characterized in that, It also includes a secondary screening assembly (2) rotatably mounted on a support frame (1) and a primary screening assembly (7) rotatably mounted inside the secondary screening assembly (2), and a tumbling assembly (11) that cooperates with the primary screening assembly (7) is installed on the support frame (1). The support frame (1) is equipped with a first drive assembly (3) that cooperates with the secondary screening assembly (2), a second drive assembly (4) that cooperates with the primary screening assembly (7), and a third drive assembly (5) that cooperates with the tumbling assembly (11). The support frame (1) is also equipped with a feeding hopper (6) that cooperates with the secondary screening assembly (2). The primary screening component (7) includes an inner drum screen (16), an air guide roller (17) is fixedly installed on the outside of the inner drum screen (16), one end of the air guide roller (17) is connected to an external air source, and multiple auxiliary feeding mechanisms (19) are installed inside the air guide roller (17). The secondary screening component (2) includes an outer drum screen. The auxiliary feeding mechanism (19) includes a first connecting pipe (20) and a second connecting pipe (23) fixedly installed inside the air guide roller (17). The end of the first connecting pipe (20) is arc-shaped and matches the inner drum screen (16). The second connecting pipe (23) passes through and extends out of the air guide roller (17). A rotating pipe (21) is rotatably installed between the first connecting pipe (20) and the second connecting pipe (23). The rotating pipe (21) is equipped with a blowing negative pressure structure, a vibration structure and a driving structure. The blowing negative pressure structure includes an air guide hole (24) with two air guide ports on the rotating tube (21). The air guide hole (24) is opened at an angle, with the air guide port inside the rotating tube (21) being higher than the air guide port outside the rotating tube (21). The air guide hole (24) is located on the lower half of the rotating tube (21). The vibration structure includes multiple elastic telescopic rods (25) fixedly installed outside the rotating tube (21), and a counterweight ball (26) is fixedly installed at the telescopic end of each elastic telescopic rod (25). The drive structure includes multiple drive fins (22) fixedly mounted on the rotating tube (21), each drive fin (22) forming a 60-degree angle with the rotating tube (21).

2. The screening device for heavy calcium carbonate particles according to claim 1, characterized in that, The first drive assembly (3) consists of a first drive motor (9) and a transmission wheel. Multiple limiting wheels (10) that cooperate with the outer drum screen are rotatably mounted on the support frame (1). The transmission wheel is installed between the outer drum screen and the first drive motor (9) to transmit the power on the first drive motor (9) and thus drive the outer drum screen to rotate.

3. The screening device for heavy calcium carbonate particles according to claim 1, characterized in that, The tumbling assembly (11) includes two brackets (12) fixedly installed on the support frame (1), and a rotating shaft (14) is rotatably installed on both brackets (12). The third drive assembly (5) includes a third drive motor (13) fixedly installed on one of the brackets (12), and the drive end of the third drive motor (13) is fixedly connected to the rotating shaft (14). A filter plate (15) is fixedly installed on the rotating shaft (14).

4. The screening device for heavy calcium carbonate particles according to claim 1, characterized in that, The second drive assembly (4) consists of a second drive motor and a transmission track mechanism. The second drive motor drives the transmission track to rotate, thereby driving the inner drum screen (16) to rotate.

5. The screening device for heavy calcium carbonate particles according to claim 1, characterized in that, The air guide roller (17), outer roller screen and inner roller screen (16) are all consistent with the support frame (1) and are all inclined. The diameter of the higher side of the air guide roller (17) is larger than the diameter of the lower side.

6. The screening device for heavy calcium carbonate particles according to claim 1, characterized in that, The inner drum screen (16) has multiple material distribution plates (18) fixedly installed inside, and each material distribution plate (18) has a certain degree of elasticity.

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