Multistage pre-classifying device for limestone granules

Abstract

The utility model relates to the technical field of screening equipment, especially limestone particle grading multistage pre -screening device for a kind of, including: mounting bracket, pull frame and screen, two ends of two the mounting bracket are fixedly connected with support spring, the top end of four the support spring is fixedly connected with frame body, frame body is inclined design, the output end of frame body is respectively provided with three the discharge gate, the inner wall of mounting bracket is respectively slidably connected with two the pull frame, pull frame located above length is greater than pull frame located below, and two the parallel with frame body, the pull frame of utility model adopts pull formula structure design, screen is installed in the mounting hole of pull frame, when replacing screen, device main frame does not need to be disassembled, only need to carry out operation by pulling square bar to remove positioning, hold handle and pull out pull frame, save the cumbersome step of traditional device disassembly protection structure, remove upper component.

Description

Technical Field

[0001] This utility model relates to the field of screening equipment technology, and in particular to a multi-stage pre-screening device for limestone particle grading. Background Technology

[0002] In the limestone processing industry, particle size classification is a crucial preliminary step for subsequent deep processing (such as building material production and chemical raw material preparation). Screening devices are needed to separate limestone particles of different sizes to meet the precision requirements of various applications. Currently, most limestone screening equipment used in the industry has a fixed frame structure. In existing fixed-frame screening devices, the screens are mostly fixed directly to the main frame of the device by welding or multiple sets of complex bolts. Replacing the screen requires first dismantling the outer protective structure of the device, and then removing each bolt fixing the screen (some welded screens even require cutting and separation). The operation is cumbersome, and a single replacement typically takes 2-4 hours. Since limestone processing is mostly a continuous production line, prolonged downtime will lead to a decrease in the overall production line's capacity, increasing the company's time and labor costs. Furthermore, some devices require multiple sets of screens to be stacked within the same frame to achieve multi-stage screening. Replacing the lower screen requires removing the upper screen first, further extending the replacement cycle and reducing equipment utilization.

[0003] Therefore, it is necessary to provide a new multi-stage pre-screening device for limestone particle classification to solve the above-mentioned technical problems. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a multi-stage pre-screening device for limestone particle grading.

[0005] The multi-stage pre-screening device for limestone particle grading provided by this utility model includes: a mounting frame, a pull-out frame, and a screen. Support springs are fixedly connected to both ends of the two mounting frames, and a frame body is fixedly connected to the top of the four support springs. The frame body is inclined, and three discharge ports are respectively opened at the output end of the frame body. Two pull-out frames are slidably connected to the inner wall of the mounting frame. The upper pull-out frame is longer than the lower pull-out frame, and the two pull-out frames are parallel to the frame body. Two mounting holes are opened inside the pull-out frames, and screens are installed inside the mounting holes respectively. The aperture of the upper screen is larger than the aperture of the lower screen.

[0006] Preferably, the screen and the pull-out frame are fixedly connected by bolts.

[0007] Preferably, the pull-out frame has air passages symmetrically opened on both sides of the mounting hole along its length. An air bag is fixedly connected inside the air passage, and the two air passages are interconnected. An air valve is installed on one side of the pull-out frame, and the air valve is connected to one of the air passages.

[0008] Preferably, the pull-out frame has a first slot and a second slot respectively located at the highest point of the frame.

[0009] Preferably, a groove is provided at the highest point of the frame on the side of the pull-out frame, a slide plate is slidably connected to the inner wall of the groove, a square rod is fixedly connected to the middle of the slide plate, one end of the square rod extends out of the groove and engages with one of the first slots, a limit spring is fixedly connected between the groove and the slide plate, and the other end of the square rod extends out of the pull-out frame.

[0010] Preferably, a handle is installed on one side of the pull-out frame, and connection holes are provided at the bottom of the two mounting brackets.

[0011] Compared with related technologies, the multi-stage pre-screening device for limestone particle grading provided by this utility model has the following beneficial effects: The device features a pull-out frame design, with the screen installed in the mounting holes within the frame. Screen replacement requires no disassembly of the main frame; simply pull the square rod to release the positioning and grasp the handle to pull out the frame. This eliminates the cumbersome steps of disassembling the protective structure and removing upper components required in traditional devices. Furthermore, the screen and pull-out frame are secured with bolts, and the inflatable / deflatable airbag allows for rapid switching, further simplifying the assembly and disassembly process. A single screen replacement can be completed in 30-60 minutes, a 75% improvement in efficiency compared to the 2-4 hour replacement cycle of traditional devices. This design effectively reduces downtime in continuous limestone production lines, minimizing production losses and labor costs due to downtime, and significantly improving equipment utilization. Attached Figure Description

[0012] Figure 1 A schematic diagram of the structure of the multi-stage pre-screening device for limestone particle grading provided by this utility model; Figure 2 for Figure 1 The diagram shows the internal structure of the frame. Figure 3 for Figure 1 The diagram shows the structure of the mounting holes; Figure 4 for Figure 1 The diagram shows the structure of the airway; Figure 5 for Figure 1 The diagram shows a partially enlarged cross-sectional view of the mounting bracket.

[0013] The following are labeled in the diagram: 1. Mounting bracket; 2. Support spring; 3. Frame; 4. Discharge port; 5. Pull-out frame; 6. Screen; 7. Mounting hole; 8. Air passage; 9. Airbag; 10. Valve nozzle; 11. First slot; 12. Second slot; 13. Groove; 14. Slide plate; 15. Square rod; 16. Limiting spring. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0015] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0016] Please see Figures 1 to 5 A multi-stage pre-screening device for limestone particle grading includes: a mounting frame 1, a pull-out frame 5, and a screen 6. Supporting springs 2 are fixedly connected to both ends of the two mounting frames 1. A frame body 3 is fixedly connected to the top of the four supporting springs 2. A vibration motor is installed at the bottom of the frame body 3. The frame body 3 is inclined, and three discharge ports 4 are respectively opened at the output end of the frame body 3. Two pull-out frames 5 are slidably connected to the inner wall of the mounting frame 1. The upper pull-out frame 5 is longer than the lower pull-out frame 5, and the two pull-out frames 5 are parallel to the frame body 3. Two mounting holes 7 are opened inside the pull-out frames 5, and screens 6 are installed inside the mounting holes 7 respectively. The aperture of the upper screen 6 is larger than that of the lower screen 6. The screens 6 are fixedly connected to the pull-out frames 5 by bolts. A handle is installed on one side of the pull-out frames 5. Connection holes are opened at the bottom ends of the two mounting frames 1.

[0017] It should be noted that the handle is used to facilitate the left and right movement of the pull-out frame 5, and the connecting hole is used to install the entire device.

[0018] Please see Figure 3 .to Figure 4 The pull-out frame 5 has air passages 8 symmetrically opened on both sides of the mounting hole 7 along its length. An air bag 9 is fixedly connected inside the air passage 8. The two air passages 8 are interconnected. An air valve 10 is installed on one side of the pull-out frame 5. The air valve 10 is connected to one of the air passages 8.

[0019] It should be noted that the airbag 9 is inflated to prevent leakage from the frame 3.

[0020] Please see Figures 3 to 5 The pull-out frame 5 has a first slot 11 and a second slot 12 at the highest point of the frame 3. The highest point of the frame 3 has a groove 13 at the side of the pull-out frame 5. A slide plate 14 is slidably connected to the inner wall of the groove 13. A square rod 15 is fixedly connected to the middle of the slide plate 14. One end of the square rod 15 extends out of the groove 13 and engages with one of the first slots 11. A limit spring 16 is fixedly connected between the groove 13 and the slide plate 14. The other end of the square rod 15 extends out of the pull-out frame 5.

[0021] It should be noted that: in the initial state, the square rod 15 is inserted into the first slot 11. When the screen 6 needs to be replaced, simply pull the square rod 15 to insert it into the second slot 12.

[0022] The working principle of the multi-stage pre-screening device for limestone particle grading provided by this utility model is as follows: I. Initial state of the device and its structural fit In the device, two mounting frames 1 provide elastic support to the inclined frame 3 via four support springs 2 fixedly connected to their ends. A vibration motor is installed at the bottom of the frame 3, providing power for the vibrating screening. This structure together lays the foundation for subsequent efficient screening. Two pull-out frames 5 are slidably connected to the inner wall of the frame 3. Because the upper pull-out frame 5 is longer than the lower pull-out frame 5, and both are parallel to the frame 3, they enable the orderly division of the grading screening area. The pull-out design of the pull-out frames 5 aims to accelerate the replacement efficiency of the screen 6. The pull-out frames 5 can be removed for screen operation without disassembling the entire device, significantly reducing downtime and improving overall operating efficiency. The pull-out frame 5 engages with the positioning structure of the frame 3 via the first slot 11 and the second slot 12: Within the groove 13 on the side of the pull-out frame 5 at the highest point of the frame 3, the limiting spring 16 pushes the sliding plate 14, causing the square rod 15 fixed in the middle of the sliding plate 14 to extend out of the groove 13 and engage with the first slot 11 or the second slot 12 of the pull-out frame 5. This stably fixes the pull-out frame 5 within the frame 3, preventing displacement due to vibration of the frame 3 during screening. Simultaneously, the handle on one side of the pull-out frame 5 facilitates subsequent pull-out operations, and the connection hole at the bottom of the mounting frame 1 can be used for the fixed installation of the entire device with external equipment. II. Preparation of sieves before screening Two mounting holes 7 inside the pull-out frame 5 are used to install the screen 6. The screen 6 is fixed to the pull-out frame 5 with bolts to ensure that the screen 6 is stable during the vibration screening process of the frame 3 and to prevent the screen 6 from loosening or falling off due to vibration. In addition, the aperture of the screen 6 in the upper pull-out frame 5 is larger than that in the lower pull-out frame 5, forming a multi-stage screening gradient from coarse to fine to meet the grading requirements of limestone particles of different sizes. In addition, air bladders 9 are fixed inside the air channels 8 symmetrically opened on both sides of the mounting hole 7 in the pull-out frame 5. The two air channels 8 are interconnected, and the valve 10 on one side of the pull-out frame 5 is connected to one of the air channels 8. Before installing the screen 6, air can be injected into the air channel 8 through the valve 10 to inflate the air bladder 9. The core function of the inflated air bladder 9 is to fill the gap between the screen 6 and the mounting hole 7 of the pull-out frame 5, preventing limestone particles from leaking out of the gap during the vibrating screening process of the frame 3, thus ensuring screening accuracy and material utilization. If it is necessary to disassemble or replace the screen 6, air can be released through the valve 10 to shrink the air bladder 9, making operation easier. III. Limestone Particle Grading and Screening Process Particle feeding and preliminary screening: The limestone particles to be graded are fed into the frame 3 from the highest end. Because the frame 3 is inclined, and the vibration motor installed at the bottom of the frame 3 is activated, it drives the frame 3 to vibrate. The support spring 2 provides cushioning, keeping the frame 3 in a stable and efficient vibration state. Under the combined action of gravity and vibration, the particles slide down the inclined frame 3 and first come into contact with the coarse-mesh screen 6 in the upper pull-out frame 5. Multi-stage screening and particle separation: Limestone particles with a diameter smaller than the aperture of the upper screen 6 pass through the screen 6 under the vibration of the frame 3 and fall onto the fine-aperture screen 6 in the lower pull-out frame 5; while particles with a diameter larger than the aperture of the upper screen 6 continue to slide along the surface of the upper screen 6 and are finally discharged from the first discharge port 4 corresponding to the output end of the frame 3, completing the first stage of coarse screening. Secondary fine screening: Particles falling onto the lower fine-mesh screen 6 are continuously vibrated by the frame 3. Particles with a diameter smaller than the aperture of the lower screen 6 pass through the screen 6, slide along the bottom of the frame 3, and are discharged from the second discharge port 4 corresponding to the output end of the frame 3. Particles with a diameter larger than the aperture of the lower screen 6 but smaller than the aperture of the upper screen 6 slide along the surface of the lower screen 6 and are discharged from the third discharge port 4 corresponding to the output end of the frame 3, thus achieving secondary fine classification of limestone particles. IV. Post-screening operations, including detailed screen replacement procedures. After the screening operation is completed, first turn off the vibration motor at the bottom of frame 3. After frame 3 stops vibrating, if it is necessary to clean or replace screen 6, the specific operation procedure is as follows: Pull-out frame removal operation: The operator holds the handle on one side of the pull-out frame 5 corresponding to the screen to be replaced with both hands, and simultaneously pulls the square rod 15 out of one end of the pull-out frame 5 with their fingers or a tool, causing the square rod 15 to move into the groove 13. During this process, the limiting spring 16 is compressed until the square rod 15 is completely disengaged from the first slot 11 or the second slot 12 on the pull-out frame 5, releasing the fixing restriction between the pull-out frame 5 and the frame body 3. While keeping the square rod 15 pulled, slowly slide the pull-out frame 5 outward along the inner wall of the frame body 3 until the pull-out frame 5 is completely detached from the frame body 3, and place it stably on the pre-prepared operating platform. This process fully demonstrates the design advantages of the pull-out frame 5, eliminating the need for complex disassembly, quickly removing the pull-out frame 5, saving time for subsequent screen replacements, and reducing downtime losses. Removing the old screen: First, locate the bolts securing the screen 6 to the pull-out frame 5. Using a suitable wrench, such as an open-end wrench or a box wrench, rotate the bolts clockwise to remove them one by one. Place the removed bolts in a dedicated storage box to prevent loss. After all bolts have been removed, gently lift the edge of the screen 6 and remove it from the mounting hole 7 of the pull-out frame 5. If the old screen 6 is slightly stuck to the pull-out frame 5 due to long-term vibration, gently pry the edge of the screen 6 to avoid forcibly pulling and damaging the pull-out frame 5 or the mounting hole 7. Then, release the air through the valve 10 on one side of the pull-out frame 5. Press down the air core of the valve 10 to slowly release the gas from the air passage 8. Observe the state of the air bag 9 until it is fully contracted and flush with the inner wall of the pull-out frame 5. New Screen Installation: Select a new screen 6 that matches the pull-out frame 5 and has an aperture that meets the screening requirements. Lay the new screen 6 flat above the mounting holes 7 of the pull-out frame 5. Adjust the position of the screen 6 to ensure that the edge of the screen 6 is aligned with the edge of the mounting hole 7, without any offset or wrinkles. After alignment, take the bolt from the storage box and pass the bolt through the mounting holes 7 on the edge of the screen 6 and the corresponding screw holes on the pull-out frame 5. Use a wrench to rotate the bolt counterclockwise to initially tighten the bolt. After all the bolts are initially fixed, tighten them in a diagonal order, such as first tightening the upper left bolt, then the lower right bolt, then the upper right bolt, and finally the lower left bolt, until all the bolts are fully tightened, ensuring that the screen 6 and the pull-out frame 5 fit tightly without any signs of looseness. Inflation and Fixing of the Airbag: Use an air pump or manual air pump connected to the valve 10 on one side of the pull-out frame 5 to slowly inflate the air passage 8. Observe the expansion of the airbag 9 during inflation. You can feel the degree of inflation of the airbag 9 by touching the corresponding position on the outside of the pull-out frame 5. When the airbag 9 inflates to the point of tight contact with the edge of the screen 6, and there is no obvious deformation when you gently press the screen 6, stop inflation, disconnect the air pump from the valve 10, and check whether the valve 10 is leaking. You can apply soapy water to the valve 10 and observe whether air bubbles are generated. At this time, the airbag 9 tightly fills the gaps, effectively preventing particle leakage when the frame 3 vibrates later. Pull-out frame reset: After the new screen 6 is installed, the operator holds the handle of the pull-out frame 5 again, aligns the pull-out frame 5 with the inner wall slide of the frame 3, and slowly pushes the pull-out frame 5 into the frame 3. During the pushing process, keep the pull-out frame 5 parallel to the frame 3 to avoid jamming. When the pull-out frame 5 is pushed to the initial fixed position, release the restriction on the square rod 15. At this time, the limit spring 16 pushes the slide plate 14 under the action of elasticity, driving the square rod 15 to move towards the pull-out frame 5 until the square rod 15 automatically engages with the first slot 11 or the second slot 12 on the pull-out frame 5. After hearing a "click" sound, gently pull the handle of the pull-out frame 5 to confirm that the pull-out frame 5 is stable and fixed without loosening. Post-replacement inspection: After all operations are completed, start the vibration motor at the bottom of frame 3 and let the device run unloaded for 1-2 minutes. Observe whether the newly installed screen 6 is loose or displaced, listen to the operating sound of the device to see if it is normal, without abnormal friction sounds or noises, and at the same time check whether there is particle leakage in frame 3 and verify the sealing effect of airbag 9. If everything is normal, turn off the vibration motor and proceed to the next round of limestone particle screening. If screen 6 is found to be loose, making abnormal noises or particle leakage, the above steps need to be repeated to re-check and adjust the installation status of screen 6 and the inflation status of airbag 9.

[0023] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A multi-stage pre-screening device for limestone particle grading, characterized in that, include: Mounting bracket (1), both ends of the two mounting brackets (1) are fixedly connected to support springs (2), and the top of the four support springs (2) are fixedly connected to a frame (3). The frame (3) is designed to be inclined, and the output end of the frame (3) is provided with three discharge ports (4). The inner wall of the mounting bracket (1) is slidably connected to two of the pull-out frames (5), the upper pull-out frame (5) is longer than the lower pull-out frame (5), and the two pull-out frames (5) are parallel to the frame (3). The screen (6) and the pull-out frame (5) have two mounting holes (7) inside. The screen (6) is installed in the mounting holes (7) respectively. The aperture of the upper screen (6) is larger than that of the lower screen (6).

2. The multi-stage pre-screening device for limestone particle grading according to claim 1, characterized in that, The screen (6) and the pull-out frame (5) are fixedly connected by bolts.

3. The multi-stage pre-screening device for limestone particle grading according to claim 1, characterized in that, The pull-out frame (5) has air passages (8) symmetrically opened on both sides of the mounting hole (7) along its length. An air bag (9) is fixedly connected inside the air passage (8). The two air passages (8) are interconnected. An air valve (10) is installed on one side of the pull-out frame (5). The air valve (10) is connected to one of the air passages (8).

4. The multi-stage pre-screening device for limestone particle grading according to claim 1, characterized in that, The pull-out frame (5) is located at the highest point of the frame (3) and has a first slot (11) and a second slot (12).

5. The multi-stage pre-screening device for limestone particle grading according to claim 4, characterized in that, The highest point of the frame (3) is located on the side of the pull-out frame (5) with a groove (13). A slide plate (14) is slidably connected to the inner wall of the groove (13). A square rod (15) is fixedly connected to the middle of the slide plate (14). One end of the square rod (15) extends out of the groove (13) and engages with one of the first slots (11). A limit spring (16) is fixedly connected between the groove (13) and the slide plate (14). The other end of the square rod (15) extends out of the pull-out frame (5).

6. The multi-stage pre-screening device for limestone particle grading according to claim 1, characterized in that, A handle is installed on one side of the pull-out frame (5), and connection holes are provided at the bottom of the two mounting brackets (1).

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