Screening device for high-viscosity bentonite production and production process

Abstract

The invention relates to the technical field of screening devices, and discloses a screening device for high-viscosity bentonite production and a production technology.The screening device for high-viscosity bentonite production comprises a rack, multiple sets of vibration isolation springs are arranged at the bottom of the rack, a bottom plate is arranged at the bottoms of the vibration isolation springs, and a discharging port is formed in the bottom of the rack; a feeding port and a vibration motor are arranged at the top of the rack, and a plurality of screening units are arranged in the rack. Each screening unit comprises supporting frames arranged on the two sides of the rack, the pair of supporting frames has a height difference, an impurity outlet is formed in the side wall of the rack and located in one side of the lower supporting frame, a screening frame is jointly erected on the pair of supporting frames, and a screening net is arranged in the screening frame; the hammering unit is arranged on the rack, the screening net moves downwards under the action of gravity after being blocked, the hammering unit is excited to hammer the bottom of the screening net after the screening net reaches a triggering position, viscous materials blocked in screening holes are effectively removed through high-frequency and high-strength impact, and the hole blocking rate is remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of screening devices, and in particular to a screening device and a production process for producing high-viscosity bentonite. Background Art

[0002] Bentonite production screening equipment is used to separate particles of different sizes in bentonite raw materials. It uses a vibrating motor to drive the multi-layer screening unit, using screens of different apertures to achieve graded screening.

[0003] Patent publication number CN110152992A discloses a screening machine, comprising a processing box, a screening box arranged in the processing box, and a receiving box arranged below the screening box, wherein a first screen frame is provided in the receiving box, a supporting assembly cooperating with the first screen frame is provided in the processing box, a hydraulic rod for driving the receiving box to perform lifting movements is provided at the bottom of the processing box, a first connecting plate is provided above the receiving box, a stirring assembly is provided on the first connecting plate, a movable plate is provided above the stirring assembly, a water storage chamber is provided in the movable plate, a plurality of water spray holes are provided at the bottom of the water storage chamber, a through groove cooperating with the movable plate is provided on the rising side wall of the processing box, and the movable plate can move along the inner wall of the through groove.

[0004] The existing technology has the following defects: Existing high-viscosity bentonite screening devices have many technical defects: First, the screening efficiency is low. Traditional screens are mostly straight-hole structures with a single aperture, which can easily form bridging of the apertures or clogging of the inner wall due to the viscosity of the material, resulting in obstructed screening. In addition, there is a lack of grading design, making it difficult to achieve accurate separation of products of different particle sizes. Second, the blockage clearing capacity is insufficient, and most of the devices rely on manual cleaning or simple vibration clearing. The clearing action cannot be adaptively triggered according to the degree of blockage. The single impact force is limited, making it difficult to break the adsorptive blockage of sticky materials. Frequent shutdowns for cleaning seriously affect continuity. Summary of the Invention

[0005] In view of the above problems in the prior art, a screening device for high-viscosity bentonite production is proposed.

[0006] One aspect of the present application provides a screening device for high-viscosity bentonite production, the purpose of which is to reduce the clogging of bentonite powder on the screening net.

[0007] The technical solution of the present invention is: a screening device for high-viscosity bentonite production, comprising a frame, a plurality of groups of vibration isolation springs are arranged at the bottom of the frame, a bottom plate is arranged at the bottom of the vibration isolation springs, a discharge port is arranged at the bottom of the frame, a feed port and a vibration motor are arranged at the top of the frame, and a plurality of screening units are arranged in the frame; Each of the screening units includes support frames arranged on both sides of the frame, a pair of support frames having a height difference, a debris outlet opening formed on the side wall of the frame and located on one side of the lower support frame, a screening frame is mounted on the pair of support frames, and limiting holes are provided on both sides of the screening frame, limiting columns matching the limiting holes are provided on the support frames, and the limiting columns slide in the limiting holes, a plurality of compression springs are provided between each support frame and the screening frame, and a screening net is provided in the screening frame; It also includes a hammer unit, which is arranged on the frame. When the screening net is blocked by material, it moves downward due to gravity. When it reaches the trigger position, the hammer unit is stimulated to hammer the bottom of the screening net.

[0008] Furthermore, the hammer unit includes a pair of splints arranged on the side walls of the frame, a hammer block is arranged between the pair of splints, a support rod 1 is arranged on both sides of the hammer block, a guide block is arranged on the support rod 1, a guide groove is provided on the splint, the guide block slides in the guide groove, a tension spring is connected to the support rod 1, and the other end of the tension spring is fixed to the splint, and a rotating rod 1 and a rotating rod 2 are also rotatably arranged between the pair of splints, a vortex cam and a gear 1 are fixed on the rotating rod 1, the edge of the vortex cam is in contact with the wall of the support rod 1, a gear 2 is fixed on the rotating rod 2, and the gear 2 is meshed with the gear 1, and a tooth column is vertically arranged on the screening frame, and the tooth column is meshed with the gear 2.

[0009] Furthermore, an impact beam is provided at the bottom of the screening frame, the bottom of the impact beam is arc-shaped, and the top of the hammer block fits the impact beam.

[0010] Furthermore, an impact cavity is provided inside the hammer block, and an impact block is slidably provided in the impact cavity.

[0011] Furthermore, a material guide plate is provided above the screening frame, and the material guide plate is distributed along the edge of the screening frame.

[0012] Furthermore, the screening net is provided with screening holes, which are a 120° inverted cone expansion, a cylindrical section and a 60° forward cone contraction from top to bottom.

[0013] Furthermore, the depth ratio of the inverted cone expansion opening, the cylindrical section and the forward cone contraction opening is 1:0.15:0.35.

[0014] Furthermore, the guide groove is inclined by 1°-3°.

[0015] Furthermore, the tooth column is connected to the impact beam.

[0016] Another aspect of the present invention provides a process for producing high-viscosity bentonite, comprising the following steps: Step 1: The raw ore is crushed to a particle size of ≤50mm by a jaw crusher, and then the metal impurities (iron content ≤0.1%) are removed by a permanent magnetic drum remover. After pretreatment, the material is conveyed to the drying section by a belt conveyor; Step 2: Use a rotary kiln and introduce 200-300℃ hot air for countercurrent drying to reduce the moisture content from 25% to ≤15%. After drying, the material temperature is less than 60℃. Step 3: The hammer crusher crushes the material to ≤10mm and feeds it to the Raymond mill via a bucket elevator. The powder fineness is controlled to 100-200 mesh by adjusting the grinding roller pressure (0.8-1.2MPa) and the classifier speed (120-200rpm). Step 4: Use a screening device designed for high-viscosity bentonite production. The upper 20-mesh screen intercepts unbroken particles, and the lower 200-mesh screen separates the target fine powder. Step 5: Evenly spray 3% to 5% sodium carbonate solution in a dual-shaft differential speed mixer (speed 45 / 30 rpm), and introduce 0.4 MPa saturated steam to maintain the reaction temperature at 85°C for 30 minutes; Step 6: Flash dryer uses 250°C hot air for instant dehydration (residence time <15 seconds), with the outlet material moisture content ≤8%. The final sieve is then passed through a 325-mesh air sieve, with the ultrafine powder content exceeding 70%.

[0017] Beneficial effects of the present invention: Through the stepped aperture design of the multi-layer screening unit, the three-section composite structure of the screening hole (inverted cone expansion to destroy bridging, cylindrical section for precise grading, and positive cone contraction to accelerate discharge), and the adjustable exciting force of the vibration motor, efficient grading and screening of high-viscosity bentonite is achieved. This not only solves the problems of easy clogging and low screening efficiency of traditional screens, but also ensures the purity of products of different particle sizes, and significantly improves screening efficiency.

[0018] Through the mechanical linkage trigger structure of the hammer unit (the coordinated action of the tooth column, gear, and vortex cam) and the secondary impact design of the hammer block (the impact chamber and the impact block form a continuous impact force), it can automatically respond when the screening mesh is blocked. Through high-frequency and high-intensity impact, it can effectively remove sticky materials stuck in the screen holes, reduce the need for manual cleaning, significantly reduce the blockage rate, and ensure continuous and stable operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A perspective view of a screening device for producing high-viscosity bentonite according to the present invention; Figure 2 It is a top view of the screening device for producing high-viscosity bentonite of the present invention; Figure 3 For the present invention Figure 2 Cross-sectional view at AA in the middle; Figure 4 A three-dimensional diagram of a screening unit in a screening device for producing high-viscosity bentonite according to the present invention; Figure 5 It is a top view of a screening unit in a screening device for producing high-viscosity bentonite according to the present invention; Figure 6 For the present invention Figure 5 Cross-sectional view at the middle BB; Figure 7 An exploded view of a screening unit in a screening device for producing high-viscosity bentonite according to the present invention; Figure 8 For the present invention Figure 5 Partial cutaway image of ; Figure 9 A three-dimensional diagram of a hammer unit in a screening device for producing high-viscosity bentonite according to the present invention; Figure 10 This is a top view of a hammer unit in a screening device for producing high-viscosity bentonite according to the present invention; Figure 11 For the present invention Figure 10 Cross-sectional view at CC; Figure 12 An exploded view of a hammer unit in a screening device for producing high-viscosity bentonite according to the present invention; Figure 13 This is a vertical cross-sectional view of the screening holes in the screening device for producing high-viscosity bentonite according to the present invention.

[0020] In the picture: 1. Frame; 2. Vibration isolation spring; 3. Bottom plate; 4. Discharge port; 5. Feed port; 6. Vibration motor; 7. Support frame; 8. Discharge port; 9. Screening frame; 10. Limiting hole; 11. Limiting column; 12. Compression spring; 13. Screening net; 14. Clamp; 15. Hammer block; 16. Support rod 1; 17. Guide block; 18. Guide groove; 19. Tension spring; 20. Rotating rod 1; 21. Rotating rod 2; 22. Vortex cam; 23. Gear 1; 24. Gear 2; 25. Gear column; 26. Impact beam; 27. Impact chamber; 28. Impact block; 29. ​​Guide plate; 30. Screening hole; 31. Inverted cone expansion; 32. Cylindrical section; 33. Positive cone contraction. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] Example 1, with reference to Figures 1-13, which is the first embodiment of the present invention, provides a screening device for high-viscosity bentonite production, including a frame 1, a plurality of groups of vibration isolation springs 2 are arranged at the bottom of the frame 1, a bottom plate 3 is arranged at the bottom of the vibration isolation spring 2, a discharge port 4 is arranged at the bottom of the frame 1, a feed port 5 and a vibration motor 6 are arranged at the top of the frame 1, and a plurality of screening units are arranged in the frame 1; each screening unit includes a support frame 7 arranged on both sides of the frame 1, a pair of support frames 7 have a height difference, and a side wall of the frame 1 is provided with a miscellaneous outlet 8 and the miscellaneous outlet 8 is located at a relatively high position. On one side of the low support frame 7, a pair of support frames 7 are jointly provided with a screening frame 9, and limiting holes 10 are provided on both sides of the screening frame 9. Limiting columns 11 matching the limiting holes 10 are provided on the support frame 7, and the limiting columns 11 slide in the limiting holes 10. A plurality of compression springs 12 are provided between each support frame 7 and the screening frame 9, and a screening net 13 is provided in the screening frame 9; it also includes a hammer unit, which is provided on the frame 1. After the screening net 13 is blocked by material, it moves downward due to gravity. After reaching the trigger position, the hammer unit is stimulated to hammer the bottom of the screening net 13.

[0023] Specifically, frame 1 is constructed from high-strength steel to ensure stability under long-term vibration conditions. Four sets of vibration isolation springs 2 connect the four corners of frame 1 to a base plate 3, which is secured to the ground using embedded or expansion bolts. The vibration isolation springs 2 are made from a fatigue-resistant alloy, effectively absorbing vibration energy and reducing vibration interference with the ground and surrounding equipment during operation.

[0024] The feed port 5 is provided with a feed hopper. Each vibration motor 6 consists of a driving motor and an eccentric wheel fixed at both ends of the motor main shaft. The two motors rotate in opposite directions. By adjusting the eccentric distance of the eccentric wheel, the exciting force can be changed to adapt to the screening requirements of bentonite with different viscosities.

[0025] Two screening units are vertically arranged within the frame 1, arranged sequentially from top to bottom. The aperture of the screening mesh 13 of each screening unit gradually decreases, achieving graded screening of the bentonite. The support frame 7 of each screening unit is an L-shaped angle steel structure fixed to the inner wall of the frame 1. The height difference between the pair of support frames 7 of the same screening unit forms an inclination angle of 5°-15° (the angle can be adjusted according to the fluidity of the material). The screening frame 9 is a rectangular frame structure with elongated limiting holes 10 on its two side frames. The limiting posts 11 on the support frame 7 pass through the limiting holes 10, allowing the screening frame 9 to slide up and down along the limiting posts 11 and to swing slightly back and forth.

[0026] The screening mesh 13 is made of a wear-resistant punching plate and is detachably mounted in the screening frame 9 by bolts, so as to facilitate the replacement of screens with different apertures or maintenance and cleaning at a later stage.

[0027] A debris outlet 8 is provided on the lower side of each screening unit corresponding to the side wall of the frame 1. A reversible baffle is installed at the debris outlet 8. The baffle is connected to the frame 1 through a hinge, and the opening angle can be adjusted according to the discharge amount of the screened material; an inclined material guide trough is provided below the debris outlet 8, and the end of the material guide trough is connected to the waste collection box or the return material conveyor belt.

[0028] The bottom of the frame 1 is a funnel-shaped hopper, and a discharge port 4 is set at the bottom of the hopper. A gate valve is installed at the discharge port 4 to control the discharge speed of qualified materials after screening. The inner wall of the hopper is paved with wear-resistant rubber sheets to reduce the adhesion residue of bentonite due to its viscosity.

[0029] Reference Figures 8-12 The hammer unit includes a pair of splints 14 arranged on the side walls of the frame 1, a hammer block 15 is arranged between the pair of splints 14, a support rod 16 is arranged on both sides of the hammer block 15, a guide block 17 is arranged on the support rod 16, a guide groove 18 is provided on the splint 14, the guide block 17 slides in the guide groove 18, a tension spring 19 is connected to the support rod 16, and the other end of the tension spring 19 is fixed to the splint 14, and a rotating rod 20 and a rotating rod 2 21 are also rotatably arranged between the pair of splints 14, a vortex cam 22 and a gear 1 23 are fixed on the rotating rod 1 20, the edge of the vortex cam 22 is in contact with the rod wall of the support rod 16, and a gear 2 24 is fixed on the rotating rod 21, which meshes with the gear 1 23, and a tooth column 25 is vertically arranged on the screening frame 9, which meshes with the gear 2 24.

[0030] Specifically, a pair of clamping plates 14 are cut from steel plates of appropriate thickness and fixed in a vertical, parallel position on the sidewalls of the frame 1, corresponding to the center of the screening unit. The inner edges of the clamping plates 14 are polished to prevent sharp angles from abrading other components. The clamping plates 14 are fixed together by 3-5 parallel bolts, which pass through the clamping plates 14 and are locked with double nuts to ensure a stable spacing between the two clamping plates 14. Rubber washers are installed at the connection holes between the bolts and the clamping plates 14 to cushion the rigid collision between the bolts and the clamping plates 14 during vibration, reducing abnormal noise and wear.

[0031] The hammer block 15 is a rectangular parallelepiped structure, which is forged in one piece with a high-strength alloy material. A detachable rubber hammer head is embedded in the top (the end facing the screening mesh 13). The rubber material ensures the hammering force while avoiding deformation caused by hard impact on the screening mesh 13.

[0032] Cylindrical support rods 16 are symmetrically welded on both sides of the hammer block 15, and a guide block 17 (made of wear-resistant cast iron) is vertically fixed to the middle section of the support rod 16. The cross-section of the guide block 17 matches the guide groove 18 on the splint 14 to ensure that the guide block 17 can slide smoothly along the vertical guide groove 18, limiting the hammer block 15 to only make linear motion in the up and down directions to avoid deviation.

[0033] A pull ring is welded to the middle of the support rod 16, one end of the tension spring 19 is hooked on the pull ring, and the other end is connected through a hanging column fixed to the upper part of the splint 14; the tension spring 19 is made of high-strength spring steel and is in a slightly stretched state in its natural state. It always applies an upward pulling force to the hammer block 15, so that the hammer block 15 is normally maintained in the upper position of the guide groove 18.

[0034] A rotating rod 1 20 and a rotating rod 21 are horizontally arranged between a pair of splints 14. Both rods are connected to the splints 14 through deep groove ball bearings. The outer ring of the bearing has an interference fit with the mounting hole on the splint 14, and the inner ring has a clearance fit with the rotating rod, ensuring flexible rotation without obvious radial shaking.

[0035] Rotating rod 1 (20) is secured to the shaft by a volute cam (22) and gear (23). Both are keyed and welded to the rotating rod to prevent relative rotation. The edge of volute cam (22) is a continuous clockwise spiral line, its contour gradually extending outward from the starting point near the rotating rod (i.e., increasing distance from the center of rotation). The edge is polished to reduce friction with support rod 1 (16). Gear (23) is a spur gear with a tooth count determined by the required transmission ratio.

[0036] Gear 24 is fixedly mounted on the shaft of rotating rod 21 and is also secured to the rotating rod via a key. Gear 24 meshes with Gear 1 23, with the same module and pressure angle to ensure smooth transmission. Gear 24 has fewer teeth than Gear 1 23 (creating a speed-increasing transmission), allowing the volute cam 22 to achieve a faster rotation speed.

[0037] Preferably, the guide groove 18 is inclined at 1°-3°, so as to prevent the powder from snapping back to its original position after being subjected to a vertical impact force.

[0038] Reference Figure 8 A striking beam 26 is provided at the bottom of the screening frame 9. The bottom of the striking beam 26 is arc-shaped. The top of the hammer block 15 fits the striking beam 26. The tooth column 25 is connected to the striking beam 26. When arranged in this way, the impact force is transmitted to the screening net 13 through the striking beam 26, so that the entire screening net 13 is evenly stressed, avoiding deformation of the screening net 13 caused by concentrated force.

[0039] Reference Figure 10-11 An impact cavity 27 is provided inside the hammer block 15 , and an impact block 28 is slidably provided in the impact cavity 27 .

[0040] Specifically, the hammer block 15 is constructed from a solid alloy block, with a cylindrical impact cavity 27 machined vertically (aligned with the direction of the hammering). The axis of the impact cavity 27 coincides with the central axis of the hammer block 15, ensuring coaxial transmission of the impact force. An elastic cushion, made of highly elastic polyurethane or nitrile rubber, is embedded in the bottom of the impact cavity 27 (away from the hammering end). When the impact block 28 returns to its original position, the cushion absorbs the kinetic energy of its fall, reducing noise and component wear. The impact block 28 is a cylindrical solid structure made of a high-density alloy (such as tungsten alloy). Its density is higher than that of the hammer block 15 itself, allowing it to generate greater inertial impact force within the same volume.

[0041] First impact: The rubber hammer head on the top of the hammer block 15 hits the bottom of the screening mesh 13. At this time, the movement of the hammer block 15 stops abruptly, but the impact block 28 continues to slide upward in the impact cavity 27 due to inertia. Due to the high density and strong inertia of the impact block 28, its sliding speed will not disappear immediately due to the stop of the hammer block 15.

[0042] Secondary impact: The impact block 28 moves rapidly upward along the inner wall of the impact chamber 27 until its top strikes the stopper of the impact chamber 27 (i.e., the top of the impact chamber 27), generating a second impact force. This impact force is transmitted to the screening mesh 13 through the hammer block 15, forming a continuous impact in the same direction as the first impact with extremely short intervals.

[0043] Reset process: After the second impact, the impact block 28 slides downward along the impact cavity 27 under the force of gravity and the elastic reaction force of the buffer pad, returns to the initial position (the bottom of the impact cavity 27), and waits for the next hammering action.

[0044] Reference Figure 3 A material guide plate 29 is provided above the screening frame 9. The material guide plate 29 is distributed along the edge of the screening frame 9 and is used to guide the powder located at the edge to the screening net 13 for screening.

[0045] Reference Figure 5 and Figure 13 The screening net 13 is provided with screening holes 30, which are, from top to bottom, a 120° inverted cone expansion 31, a cylindrical section 32, and a 60° forward cone contraction 33. The depth ratio of the inverted cone expansion 31, the cylindrical section 32, and the forward cone contraction 33 is 1:0.15:0.35.

[0046] Specifically, the inverted cone flare 31, located on the upper surface of the screening mesh 13, is the first channel for bentonite particles to enter the sieve apertures. Its 120° inverted cone angle ensures the aperture's wideness while also creating lateral shear forces on the particles through the inclined inner wall. When high-viscosity bentonite particles form a "bridge" at the aperture due to their viscosity (the particles adsorb and support each other, forming a blockage), the 120° cone disrupts this balance, causing the bridging particles to slide or disperse along the cone surface. The entrance diameter is designed to be 1.8d (d is the target sieve aperture diameter), which increases the entrance area by 2.25 times compared to traditional sieve apertures of equal diameter. This reduces localized particle accumulation at the aperture and allows more dispersed or small agglomerated particles to enter smoothly.

[0047] Depth and Surface Treatment: The depth of the 31 sections of the inverted cone flare accounts for 67% of the total depth of the three sections (based on a depth ratio of 1:0.15:0.35, the total depth is 1 + 0.15 + 0.35 = 1.5 units, with the inverted cone section accounting for 1 unit). The sufficiently long cone surface provides a buffering transition space for particles. The inner wall is mirror-polished (roughness Ra ≤ 0.8μm) to reduce the adhesion of bentonite due to viscosity. Combined with the vibration of the screening mesh 13, the remaining particles at the aperture slide back along the cone surface to the surface of the screening mesh 13 for re-screening.

[0048] The diameter of cylindrical section 32 is the target sieve aperture diameter d. Only bentonite particles with a diameter less than or equal to d can pass through, directly determining the particle size purity of the sieved product. Its depth is only 0.15 units (10% of the total depth). This short design reduces the retention time of highly sticky particles within the aperture. If sticky particles remain in a straight aperture for too long, they can easily adhere to the aperture wall due to vibration and compression, causing blockage. The short cylindrical section 32 allows qualified particles to pass quickly, reducing the risk of clogging.

[0049] The positive conical converging port 33, located at the bottom of the sieve aperture, features a 60° taper angle, gradually narrowing from the end of the cylindrical section 32 (diameter d) to an outlet diameter of 0.9d (an outlet converging ratio of 0.9). This converging structure exploits the "Venturi effect": as particles and air flow pass through the converging channel, the flow velocity increases as the cross-sectional area decreases, creating a downward thrust that quickly propels highly viscous particles out of the sieve aperture and reduces adhesion to the aperture walls. The 60° angle ensures a high flow rate while preventing "stuck" (particles trapped by a sharp angle) caused by a narrower angle.

[0050] Depth and Connection: The depth of the tapered constriction 33 is 0.35 units (23.3% of the total depth). The long constriction path allows for a steady increase in flow velocity, preventing particle breakage caused by sudden impacts. The connection with the cylindrical section 32 is achieved with a 0.1d radius arc transition, eliminating stress concentration caused by right angles and preventing particle accumulation in this dead corner.

[0051] Working principle of the present invention: When the screening mesh 13 is blocked and powder accumulates, the overall weight of the screening frame 9 increases, the compression spring 12 is compressed, and the screening frame 9 moves downward along the limiting column 11, synchronously driving the gear column 25 to move downward.

[0052] Transmission triggering: When tooth column 25 moves downward, driving gear 2 24 clockwise; gear 2 24 drives the meshing gear 1 23 counterclockwise, which in turn drives volute cam 22 counterclockwise along with rotating rod 1 20. At this point, the edge of volute cam 22 gradually contacts and compresses the wall of support rod 1 16. As the cam rotates, the radius of its contact point with support rod 1 16 gradually increases, forcing support rod 1 16 to slide downward along guide slot 18, overcoming the tension of tension spring 19 and driving hammer block 15 downward synchronously (tension spring 19 is further stretched, storing elastic potential energy).

[0053] Instantaneous hammering: When vortex cam 22 rotates to the edge position farthest from the center of rotation (i.e., the trigger position), support rod 16 is squeezed to the lowest end of guide slot 18 (at this point, tension spring 19 is stretched to its maximum). Subsequently, vortex cam 22 continues to rotate, and the radius of the contact point between its edge and support rod 16 suddenly decreases, eliminating the squeezing force on support rod 16. Tension spring 19 instantly releases its elastic potential energy, driving support rod 16 and hammer block 15 upward along guide slot 18 at high speed. The rubber hammer head at the top of hammer block 15 precisely strikes the bottom of screening mesh 13, generating a strong impact force that shakes off the high-viscosity bentonite particles stuck in the sieve holes, clearing the blockage.

[0054] Circular reset: After the hammering is completed, if the screening mesh 13 is still blocked (the screening frame 9 has not been reset), the tooth column 25 continues to drive the gear transmission, the vortex cam 22 continues to rotate, and the above-mentioned "squeeze-release-hammer" process is repeated; if the blockage is cleared, the screening frame 9 is reset upward under the elastic force of the compression spring 12, the tooth column 25 moves upward, driving the gear to rotate in the opposite direction, the vortex cam 22 is reset, and the hammer block 15 returns to its initial position under the action of the tension spring 19, waiting for the next trigger.

[0055] Example 2 is the second embodiment of the present invention, which provides: a high-viscosity bentonite production process, a screening device used in the production of high-viscosity bentonite, comprising the following steps: Step 1: The raw ore is crushed to a particle size of ≤50mm by a jaw crusher, and then the metal impurities (iron content ≤0.1%) are removed by a permanent magnetic drum remover. After pretreatment, the material is conveyed to the drying section by a belt conveyor; Step 2: Use a rotary kiln and introduce 300℃ hot air for countercurrent drying to reduce the moisture content from 25% to ≤15%. The material temperature after drying is less than 60℃. Step 3: The hammer crusher crushes the material to ≤10mm and feeds it to the Raymond mill via a bucket elevator. The powder fineness is controlled to 100-200 mesh by adjusting the grinding roller pressure (0.8MPa) and the classifier speed (200rpm). Step 4: Using a screening device for high-viscosity bentonite production, the upper 20-mesh screening net 13 intercepts unbroken particles, and the lower 200-mesh screening net 13 separates the target fine powder; Step 5: Evenly spray 5% sodium carbonate solution in a dual-shaft differential speed mixer (speed 45 / 30 rpm), and introduce 0.4 MPa saturated steam to maintain the reaction temperature at 85°C for 30 minutes; Step 6: Flash dryer uses 250°C hot air for instant dehydration (residence time <15 seconds), with the outlet material moisture content ≤8%. The final sieve is then passed through a 325-mesh air sieve, with the ultrafine powder content exceeding 70%.

[0056] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A screening device for producing high-viscosity bentonite, comprising a frame (1), a plurality of groups of vibration isolation springs (2) being provided at the bottom of the frame (1), a bottom plate (3) being provided at the bottom of the vibration isolation springs (2), a discharge port (4) being provided at the bottom of the frame (1), and a feed port (5) and a vibration motor (6) being provided at the top of the frame (1), characterized in that: A plurality of screening units are arranged in the frame (1); Each of the screening units comprises support frames (7) arranged on both sides of the frame (1), the two support frames (7) having a height difference, a debris outlet (8) being provided on the side wall of the frame (1) and the debris outlet (8) being located on one side of the lower support frame (7), a screening frame (9) being provided on a pair of support frames (7), limiting holes (10) being provided on both sides of the screening frame (9), limiting columns (11) matching the limiting holes (10) being provided on the support frames (7), the limiting columns (11) sliding in the limiting holes (10), a plurality of compression springs (12) being provided between each support frame (7) and the screening frame (9), and a screening net (13) being provided in the screening frame (9); It also includes a hammer unit, which is arranged on the frame (1). After the screening net (13) is blocked by material, it moves downward due to gravity. After reaching the trigger position, the hammer unit is stimulated to hammer the bottom of the screening net (13).

2. The screening device for high-viscosity bentonite production according to claim 1, characterized in that: The hammer unit comprises a pair of clamps (14) arranged on the side walls of the frame (1), a hammer block (15) is arranged between the pair of clamps (14), a support rod (16) is arranged on both sides of the hammer block (15), a guide block (17) is arranged on the support rod (16), a guide groove (18) is provided on the clamp (14), the guide block (17) slides in the guide groove (18), a tension spring (19) is connected to the support rod (16), and the other end of the tension spring (19) is fixed to the clamp (14). A pair of clamping plates (14) are provided between a rotating rod (20) and a rotating rod (21) for rotation. A vortex cam (22) and a gear (23) are fixed on the rotating rod (20). The edge of the vortex cam (22) is in contact with the wall of the supporting rod (16). A gear (24) is fixed on the rotating rod (21). The gear (24) is meshed with the gear (23). A tooth column (25) is vertically provided on the screening frame (9). The tooth column (25) is meshed with the gear (24).

3. The screening device for high-viscosity bentonite production according to claim 2, characterized in that: An impact beam (26) is provided at the bottom of the screening frame (9), the bottom of the impact beam (26) is arc-shaped, and the top of the hammer block (15) is in contact with the impact beam (26).

4. The screening device for high-viscosity bentonite production according to claim 2, characterized in that: An impact cavity (27) is provided inside the hammer block (15), and an impact block (28) is slidably provided inside the impact cavity (27).

5. The screening device for high-viscosity bentonite production according to claim 1, characterized in that: A material guide plate (29) is provided above the screening frame (9), and the material guide plate (29) is distributed along the edge of the screening frame (9).

6. The screening device for high-viscosity bentonite production according to claim 1, characterized in that: The screening net (13) is provided with screening holes (30), which are, from top to bottom, a 120° inverted cone expansion opening (31), a cylindrical section (32), and a 60° forward cone contraction opening (33).

7. The screening device for high-viscosity bentonite production according to claim 6, characterized in that: The depth ratio of the inverted cone expansion opening (31), the cylindrical section (32) and the forward cone contraction opening (33) is 1:0.15:0.

35.

8. The screening device for high-viscosity bentonite production according to claim 2, characterized in that: The guide groove (18) is inclined at 1°-3°.

9. The screening device for high-viscosity bentonite production according to claim 3, characterized in that: The tooth column (25) is connected to the impact beam (26).

10. A process for producing high-viscosity bentonite, using the screening device for producing high-viscosity bentonite according to claim 2, characterized in that: The following steps are involved: Step 1: The raw ore is crushed to a particle size of ≤50mm by a jaw crusher, and then the metal impurities (iron content ≤0.1%) are removed by a permanent magnetic drum remover. After pretreatment, the material is conveyed to the drying section by a belt conveyor; Step 2: Use a rotary kiln and introduce 200-300℃ hot air for countercurrent drying to reduce the moisture content from 25% to ≤15%. After drying, the material temperature is less than 60℃. Step 3: The hammer crusher crushes the material to ≤10mm, and then feeds it into the Raymond mill through the bucket elevator. By adjusting the grinding roller pressure (0.8-1.2MPa) and the classifier speed (120-200rpm), the powder fineness is controlled to 100-200 mesh; Step 4: Using a screening device for high-viscosity bentonite production, the upper 20-mesh screening net (13) intercepts unbroken particles, and the lower 200-mesh screening net (13) separates the target fine powder; Step 5: Evenly spray 3% to 5% sodium carbonate solution in a dual-shaft differential speed mixer (speed 45 / 30 rpm), and introduce 0.4 MPa saturated steam to maintain the reaction temperature at 85°C for 30 minutes; Step 6: Flash dryer uses 250℃ hot air for instant dehydration (residence time <15 seconds), the moisture content of the outlet material is ≤8%, and then it is screened through a 325 mesh air sieve, and the proportion of ultrafine powder is >70%.

Images