Coal grindability index determination sample preparation equipment and method

Abstract

The invention discloses sample preparation equipment for determining a grindability index of coal, and relates to the technical field of coal sample testing. Comprising a treatment box, a discharging hopper is fixed to the bottom of the treatment box, a smashing mechanism and a screening mechanism are arranged in the treatment box, and a dust removal assembly is arranged on the back face of the treatment box; and the crushing mechanism comprises two interval adjusting frames, the two interval adjusting frames are symmetrically distributed on the left side and the right side of the treatment box, and the front ends and the rear ends of the two interval adjusting frames are fixedly connected with limiting mounting plates. By arranging the crushing mechanism capable of adjusting the distance, the crushing granularity is accurately controlled, the adjusting screw rod is driven to rotate through the double-shaft motor, the two distance adjusting frames can be driven to move reversely, then the distance between the two crushing rollers is accurately adjusted, a coal sample can be gradually crushed to the target granularity of 1.25 mm, and the crushing efficiency is greatly improved. A sample meeting the granularity requirement is provided for determining the grindability index of the coal, and the influence of granularity deviation on the accuracy of a detection result is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal sample testing, in particular to a coal grindability index determination sample preparation equipment and method. BACKGROUND

[0002] In the field of coal grindability index determination, the particle size uniformity and preparation efficiency of the sample directly affect the accuracy of the detection result and the efficiency of the detection work.

[0003] However, the spacing between the crushing rollers of most existing equipment is fixed and cannot be adjusted, making it difficult to accurately crush the coal sample to the specified target particle size, resulting in a large particle size deviation of the prepared sample, which in turn interferes with the authenticity of the grindability index determination result. In addition, a large amount of dust is generated during the crushing of the coal sample, and the traditional equipment is not equipped with a high-efficiency dust removal component, resulting in the spread of dust to the operating environment, endangering the health of the operators, and also affecting the service life of the equipment due to the attachment of dust to the equipment components. SUMMARY

[0004] The purpose of the present application is to provide a coal grindability index determination sample preparation equipment and method to solve the problems raised in the background.

[0005] To achieve the above purpose, the present application provides the following technical solution: a coal grindability index determination sample preparation equipment, comprising a treatment box, a discharge hopper fixed to the bottom of the treatment box, a crushing mechanism and a screening mechanism arranged inside the treatment box, and a dust removal component arranged on the back of the treatment box. The crushing mechanism comprises two spacing adjustment frames symmetrically distributed on the left and right sides of the treatment box, and a limiting installation plate fixedly connected to the front and rear ends of the two spacing adjustment frames, one end of the limiting installation plate extending into the interior of the treatment box, and a rotating shaft rotatably connected between the limiting installation plates corresponding in position, the rotating shaft being fixedly provided with a crushing roller, adjusting screws rotatably connected to the left and right sides of the treatment box, the screw thread directions on the surfaces of the two adjusting screws being opposite to each other, a threaded hole matching the adjusting screw being formed on the surface of the spacing adjustment frame, the spacing adjustment frame being threadedly connected to the surface of the adjusting screw through the threaded hole, two limiting guide holes being formed on the left and right sides of the treatment box, the limiting guide holes corresponding in position to the limiting installation plates and matching in size to the limiting installation plates, and the limiting installation plate being slidably connected to the inner walls of the limiting guide holes.

[0006] Preferably, the upper surface of the four limiting installation plates is respectively fixedly connected with two first installation racks and two second installation racks, the surface of the first installation rack is fixedly connected with a driving motor, the rotating shaft of the driving motor is fixedly connected with a driving shaft rod, the driving shaft rod is rotatably arranged between the first installation rack and the second installation rack, and the surface of the driving shaft rod is fixedly connected with a driving synchronous wheel, one end surface of the rotating shaft is fixedly connected with a driven synchronous wheel, and a transmission belt is arranged between the driving synchronous wheel and the driven synchronous wheel.

[0007] Preferably, the upper surface of the processing box is fixedly connected with a U-shaped frame at the middle position, the lower surface of the U-shaped frame is fixedly provided with a protection box, the inside of the protection box is fixedly installed with a double-shaft motor, both ends of the double-shaft motor are fixedly connected with extension shafts, the end portions of the extension shafts extend to the outside of the U-shaped frame, and are fixedly connected with a first synchronous wheel, the end portion of the adjusting screw is fixedly connected with a second synchronous wheel, and a synchronous belt is arranged between the first synchronous wheel and the second synchronous wheel.

[0008] Preferably, the dust removal assembly comprises a dust collecting box fixedly connected to the back of the processing box, a driving gear, a driven gear and a support frame fixedly connected to the surface of the second installation rack, the end portion of the support frame is fixedly connected with a wind guide cylinder, the end portion of the wind guide cylinder is fixedly embedded with a conical accelerating pipe, the driving gear is fixedly connected to one end of the driving shaft rod away from the driving motor, the driven gear is rotatably connected to the surface of the second installation rack, and the driving gear is engaged with the driven gear, the central shaft position of the driven gear is fixedly connected with a linkage shaft, one end of the linkage shaft away from the driven gear extends to the inside of the wind guide cylinder, and is fixedly connected with a wind guide impeller.

[0009] Preferably, the output end of the conical accelerating pipe is fixedly connected with an air inlet pipe connector, the air suction end of the wind guide impeller corresponds in position to the air inlet pipe connector, the surface of the air inlet pipe connector is fixedly embedded with an air suction hose, one end of the air suction hose away from the air inlet pipe connector extends to the inside of the dust collecting box, the inside of the dust collecting box is fixedly provided with a filter screen, and the air suction end of the air suction hose is located above the filter screen.

[0010] Preferably, a plurality of air outlet holes are formed in one end of the wind guide cylinder away from the conical accelerating pipe, the positions of the air outlet holes correspond to the air outlet ends of the wind guide impeller, the surface of the dust collecting box is provided with a blow-off port, and a side baffle is mounted on the outside of the blow-off port through bolts.

[0011] Preferably, the inner wall of the processing box is provided with a dust suction port, the inner wall of the dust suction port is fixedly connected with a grating net cover, the dust suction port is located below the two crushing rollers, and the position of the dust suction port corresponds to the dust collecting box, and the dust suction port communicates the inside of the processing box with the inside of the dust collecting box.

[0012] Preferably, the screening mechanism comprises an arc-shaped screen plate arranged inside the treatment box, the arc-shaped screen plate is in the shape of a middle arch, and the arc-shaped screen plate is located directly below the two crushing rollers, the left and right ends of the arc-shaped screen plate are fixedly connected with material guiding rubber belts, one end of the material guiding rubber belt away from the arc-shaped screen plate is fixedly connected with the inner side wall of the treatment box, and the left and right sides of the treatment box are both provided with rectangular screening holes, the positions of the rectangular screening holes correspond to the positions of the material guiding rubber belts, the left and right sides of the treatment box are both fixedly connected with collecting boxes, and the positions of the collecting boxes correspond to the positions of the rectangular screening holes.

[0013] Preferably, the front surface of the treatment box is fixedly provided with a rotary motor, the output end of the rotary motor extends to the inside of the treatment box, and the output end is fixedly connected with a movable rod, the middle surface of the movable rod is fixedly connected with a rotary cam, the rotary cam is located directly below the arc-shaped screen plate, and the rotary cam is overlapped with the surface of the arc-shaped screen plate, and the surface of the rotary cam is provided with a wear-resistant rubber layer.

[0014] Compared with the prior art, the present application has the following beneficial effects: By arranging the crushing mechanism with adjustable spacing, the crushing particle size can be accurately controlled, the double-shaft motor drives the adjusting screw rod to rotate, which can drive the two spacing adjusting frames to move in opposite directions, thereby accurately adjusting the spacing of the two crushing rollers, the coal sample can be gradually crushed to a target particle size of 1.25 mm, and a sample meeting the particle size requirement can be provided for the grindability index determination of coal, so that the accuracy of the detection result is not affected by the particle size deviation.

[0015] By arranging the screening mechanism inside the treatment box, efficient screening and separation of the coal sample can be realized, the arc-shaped screen plate with a middle arch is used, and the rotary cam driven by the rotary motor can make the arc-shaped screen plate vibrate stably, so that the coal sample with a qualified size can smoothly pass through the arc-shaped screen plate and enter the discharge hopper, and the unqualified coal sample can slide along the material guiding rubber belt and enter the collecting boxes on the two sides of the treatment box under the action of vibration, thereby realizing efficient separation of the qualified and unqualified coal samples and further ensuring the uniformity of the sample particle size.

[0016] The driving motor of the crushing mechanism can drive the crushing rollers to rotate while driving the air guide impeller to rotate through the meshing transmission of the driving gear and the driven gear, thereby realizing the dust removal function without the need to separately configure a power source for dust removal; the dust removal assembly can process dust in real time during the sample preparation process, the air guide impeller rotates at high speed to generate negative pressure, dust generated during the crushing of the coal sample in the treatment box is sucked into the dust collection box through the dust suction port, the dust is effectively prevented from spreading to the operating environment, the harm of the dust to the operator is reduced, and the dust adhered to the equipment is prevented from affecting the service life. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a front view structural schematic diagram of the present application. Figure 2 is a schematic view of the rear view structure of the present application; Figure 3 is a schematic view of the top view structure of the present application; Figure 4 is a schematic view of the front view structure of the present application; Figure 5 is a schematic view of the front view structure of the processing box of the present application; Figure 6 is a schematic view of the side view structure of the present application; Figure 7 is a schematic view of the enlarged structure at A in the figure; Figure 6 is a schematic view of the enlarged structure at B in the figure. Figure 8 is a schematic view of the enlarged structure at B in the figure. Figure 6 is a schematic view of the enlarged structure at B in the figure.

[0018] Figure: 1, processing box; 2, discharge hopper; 3, crushing mechanism; 4, screening mechanism; 5, dust removal assembly; 301, spacing adjusting frame; 302, limiting installation plate; 303, rotating shaft; 304, crushing roller; 305, adjusting screw; 306, first installation frame; 307, second installation frame; 308, driving motor; 309, driving shaft; 310, driving synchronous wheel; 311, driven synchronous wheel; 312, transmission belt; 313, U-shaped frame; 314, protection box; 315, extension shaft; 316, first synchronous wheel; 317, second synchronous wheel; 318, synchronous belt; 401, arc-shaped screen plate; 402, material guiding rubber belt; 403, rectangular screening hole; 404, collection box; 405, rotating motor; 406, movable rod; 407, rotating cam; 501, dust collection box; 502, driving gear; 503, driven gear; 504, air duct; 505, conical accelerating pipe; 506, linkage shaft; 507, air guiding impeller; 508, air inlet pipe connector; 509, air suction hose; 510, filter screen plate; 511, air outlet hole; 512, side baffle; 513, dust suction port; 514, grating cover. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0020] Please refer to Figures 1-8The application provides a technical scheme: a coal grindability index determination sample preparation equipment which is composed of a treatment box 1, a discharge hopper 2, a crushing mechanism 3, a screening mechanism 4 and a dust removal assembly 5.

[0021] The crushing mechanism 3 comprises spacing adjustment frames 301 and limiting installation plates 302; the two spacing adjustment frames 301 are symmetrically arranged on the left and right sides of the treatment box 1 and are located at the outer positions of the left and right side walls of the treatment box 1. One limiting installation plate 302 is fixedly connected to each spacing adjustment frame 301 at the front and rear ends, and the end of the limiting installation plate 302 away from the spacing adjustment frame 301 extends through the side wall of the treatment box 1 to the inside of the treatment box 1.

[0022] In the inside of the treatment box 1, a rotating shaft 303 is rotationally connected between the limiting installation plates 302 at the front and rear positions, that is, one rotating shaft 303 is connected between the two limiting installation plates 302 at the front end of the inside of the treatment box 1, and one rotating shaft 303 is also connected between the two limiting installation plates 302 at the rear end. A crushing roller 304 is fixedly arranged on the rotating shaft 303, and the crushing roller 304 is completely located in the inside of the treatment box 1. The two crushing rollers 304 are symmetrically arranged on the left and right sides. With the rotation of the rotating shaft 303, the crushing rollers 304 can rotate synchronously, so as to crush the coal sample.

[0023] Adjusting screws 305 are rotationally connected to the left and right side walls of the treatment box 1, and the two adjusting screws 305 are located at the outer sides of the left and right side walls of the treatment box 1 and are on the same side as the spacing adjustment frames 301. Threaded holes matched with the adjusting screws 305 are formed in the surfaces of the spacing adjustment frames 301, the adjusting screws 305 pass through the threaded holes to be threadedly connected with the spacing adjustment frames 301. In particular, the screw thread directions on the surfaces of the two adjusting screws 305 are opposite to each other. When the adjusting screws 305 rotate, the left and right spacing adjustment frames 301 can be driven to move in opposite directions, so as to adjust the spacing between the two crushing rollers 304 and meet the requirements of different crushing particle sizes.

[0024] The upper surfaces of the four limiting installation plates 302 are respectively fixedly connected with two first installation racks 306 and two second installation racks 307, specifically, one first installation rack 306 is fixedly arranged on the upper surface of each of the left two limiting installation plates 302, and one second installation rack 307 is fixedly arranged on the upper surface of each of the right two limiting installation plates 302, and the first installation rack 306 and the second installation rack 307 are both located above the outer side of the treatment box 1 and do not affect the coal sample treatment inside the treatment box 1. The driving motor 308 is fixedly connected to the surface of the first installation rack 306, the rotating shaft of the driving motor 308 is fixedly connected with the driving shaft rod 309, and the two ends of the driving shaft rod 309 are respectively rotationally arranged on the first installation rack 306 and the second installation rack 307, that is, one end of the driving shaft rod 309 is rotationally connected with the first installation rack 306, and the other end is rotationally connected with the second installation rack 307, so that the driving shaft rod 309 can stably rotate under the driving of the driving motor 308.

[0025] The driving synchronous wheel 310 is fixedly connected to the surface of the driving shaft rod 309 and located between the first installation rack 306 and the second installation rack 307; the driven synchronous wheel 311 is fixedly connected to the surface of the end of the rotating shaft 303 extending out of the inside of the treatment box 1 (one end of the rotating shaft 303 is rotationally connected with the limiting installation plate 302, and the other end extends to the outside of the limiting installation plate 302). The driving synchronous wheel 310 corresponds to the position of the driven synchronous wheel 311, and a transmission belt 312 is installed between the two. When the driving shaft rod 309 drives the driving synchronous wheel 310 to rotate, the driven synchronous wheel 311 and the rotating shaft 303 can be driven to rotate synchronously through the transmission of the transmission belt 312, so as to finally realize the rotation of the crushing roller 304 and complete the coal sample crushing action.

[0026] The U-shaped frame 313 is fixedly connected to the middle position of the upper surface of the treatment box 1, and the lower surface is fixedly provided with a protection box 314, which is completely located inside the U-shaped frame 313 and directly above the upper surface of the treatment box 1 and does not directly contact with the internal structure of the treatment box 1. A double-shaft motor is fixedly installed in the inside of the protection box 314, and the two ends of the double-shaft motor are fixedly connected with extension shafts 315, one end of the extension shaft 315 away from the double-shaft motor extends through the side wall of the protection box 314 to the outside of the U-shaped frame 313, and the end of the extension shaft 315 is fixedly connected with a first synchronous wheel 316. A second synchronous wheel 317 is fixedly connected to the end of the adjusting screw 305 away from the side wall of the treatment box 1, the positions of the first synchronous wheel 316 and the second synchronous wheel 317 correspond, and a synchronous belt 318 is installed therebetween. When the double-shaft motor starts, the extension shaft 315 and the first synchronous wheel 316 are driven to rotate, and the second synchronous wheel 317 and the adjusting screw 305 can be driven to rotate synchronously through the transmission of the synchronous belt 318, so as to realize the movement of the spacing adjusting frame 301 and the adjustment of the spacing of the crushing roller 304.

[0027] The screening mechanism 4 is used for particle size screening of the crushed coal sample, and includes an arc-shaped screen plate 401 arranged inside the treatment box 1 and located directly below the two crushing rollers 304, so as to ensure that the crushed coal sample falling from the crushing rollers 304 can completely fall on the arc-shaped screen plate 401. The arc-shaped screen plate 401 is in a shape of arching in the middle, that is, the middle part is higher than the left and right ends, and such a structural design facilitates the sliding of the unqualified coal sample to the two sides. The left and right ends of the arc-shaped screen plate 401 are fixedly connected with guide rubber belts 402, one end of each guide rubber belt 402 away from the arc-shaped screen plate 401 is fixedly connected with the inner side wall of the treatment box 1, and the guide rubber belts 402 are in an inclined state and gradually incline downward from the end of the arc-shaped screen plate 401 to the inner side wall of the treatment box 1, thereby providing guidance for the sliding of the unqualified coal sample.

[0028] Rectangular screening holes 403 are formed in the left and right side walls of the treatment box 1, the positions of the rectangular screening holes 403 correspond to the guide rubber belts 402, and the inlet end of each rectangular screening hole 403 is connected with the end of the corresponding guide rubber belt 402, so that the unqualified coal sample sliding along the guide rubber belt 402 can smoothly pass through the rectangular screening hole 403 and be discharged from the inside of the treatment box 1. Collection boxes 404 are fixedly connected to the outer sides of the left and right side walls of the treatment box 1, and the opening positions of the collection boxes 404 correspond to the rectangular screening holes 403, for receiving the unqualified coal sample discharged from the rectangular screening holes 403. The side surface of each collection box 404 is rotatably provided with a movable door plate, and the movable door plate can be opened or closed by rotating, so as to facilitate the subsequent taking out of the unqualified coal sample in the collection box 404 and re-feeding into the treatment box 1 for secondary crushing.

[0029] A rotary motor 405 is fixedly installed on the front outer side of the treatment box 1, the output end of the rotary motor 405 extends to the inside of the treatment box 1 through the front side wall of the treatment box 1, and is fixedly connected with a movable rod 406. The movable rod 406 is located inside the treatment box 1 and directly below the arc-shaped screen plate 401, and the middle surface of the movable rod 406 is fixedly connected with a rotary cam 407, and the surface of the rotary cam 407 is lapped with the lower surface of the arc-shaped screen plate 401. When the rotary motor 405 is started, the movable rod 406 and the rotary cam 407 are synchronously rotated, and due to the eccentric structure of the rotary cam 407, the arc-shaped screen plate 401 can be repeatedly pushed upward during the rotation, so that the arc-shaped screen plate 401 generates a continuous vibration effect, improves the coal sample screening efficiency, and avoids the coal sample from blocking the screen holes. In addition, the surface of the rotary cam 407 is provided with a wear-resistant rubber layer, which can reduce the friction loss between the rotary cam 407 and the arc-shaped screen plate 401 and prolong the service life of the components.

[0030] The dust removal assembly 5 is used for collecting dust generated in the sample preparation process, preventing dust from spreading and polluting the environment, and includes a dust collection box 501. The dust collection box 501 is fixedly connected to the back outside of the treatment box 1, and the position of the dust collection box 501 corresponds to the position below the crushing rollers 304 inside the treatment box 1. The inner wall (back side wall) of the treatment box 1 is provided with a dust suction port 513 below the two crushing rollers 304, and the position of the dust suction port 513 corresponds to the position of the dust collection box 501. The dust suction port 513 completely penetrates the back side wall of the treatment box 1, and the inside of the treatment box 1 is connected to the inside of the dust collection box 501, so that the dust in the treatment box 1 can enter the dust collection box 501 through the dust suction port 513. The inner wall of the dust suction port 513 is fixedly connected with a grid mesh cover 514, which can prevent larger coal samples from entering the dust collection box 501 and only allow dust to pass through, avoiding blockage of the subsequent pipeline.

[0031] The surface of the second mounting frame 307 is fixedly connected with a support frame, which extends in a horizontal state away from the treatment box 1. The air duct 504 is fixedly connected to the end of the support frame, and the air duct 504 is placed horizontally. One end of the air duct 504 is fixedly embedded with a conical accelerating pipe 505. The small-diameter end of the conical accelerating pipe 505 faces the inside of the air duct 504, and the large-diameter end faces the outside. This conical structure can accelerate the airflow entering the air duct 504 and improve the dust removal effect.

[0032] The driving gear 502 is fixedly connected to the end of the driving shaft 309 away from the driving motor 308, i.e., one end of the driving shaft 309 is connected to the driving motor 308, and the other end extends to the outside of the second mounting frame 307 and is provided with the driving gear 502. The driven gear 503 is rotatably connected to the surface of the second mounting frame 307, and the driven gear 503 is engaged with the driving gear 502, so that when the driving shaft 309 rotates, the driving gear 502 can be driven to rotate synchronously, and the driven gear 503 can be driven to rotate in the opposite direction. The center shaft of the driven gear 503 is fixedly connected with a linkage shaft 506. One end of the linkage shaft 506 extends to the inside of the air duct 504 through the side wall of the air duct 504, and the other end of the linkage shaft 506 is fixedly connected with a wind guide impeller 507. The wind guide impeller 507 is completely located in the air duct 504, and corresponds to the position of the conical accelerating pipe 505. When the driven gear 503 rotates, the linkage shaft 506 can drive the wind guide impeller 507 to rotate at high speed in the air duct 504, generating a negative pressure airflow.

[0033] An air inlet pipe connector 508 is fixedly connected to the air inlet end of the conical accelerator tube 505. The air inlet pipe connector 508 corresponds to the air intake end of the guide impeller 507, ensuring that the negative pressure generated by the guide impeller 507 can effectively act on the air inlet pipe connector 508. An air intake hose 509 is fixedly embedded on the surface of the air inlet pipe connector 508. The end of the air intake hose 509 away from the air inlet pipe connector 508 extends into the interior of the dust collection box 501, and the air inlet end of the air intake hose 509 is located above the filter screen plate 510 inside the dust collection box 501. The filter plate 510 is fixedly installed inside the dust collection box 501, dividing the interior of the dust collection box 501 into upper and lower spaces. The lower space is connected to the suction port 513, and the upper space is connected to the suction hose 509. The filter plate 510 can filter the dust entering the dust collection box 501, so that the dust is retained in the lower space of the dust collection box 501, and the purified airflow enters the upper space and enters the air guide duct 504 through the suction hose 509.

[0034] Several exhaust holes 511 are provided at the end of the air guide duct 504 away from the conical acceleration tube 505. The exhaust holes 511 are evenly distributed on the end side wall of the air guide duct 504, and the position of the exhaust holes 511 corresponds to the air outlet end of the air guide impeller 507. The purified airflow accelerated by the air guide impeller 507 can be discharged to the outside of the equipment through the exhaust holes 511. A drain port is provided on the surface of the dust collection box 501. The drain port is located on the lower side of the dust collection box 501 and communicates with the lower internal space of the dust collection box 501. A side baffle 512 is bolted to the outside of the drain port. When it is necessary to clean the dust collected inside the dust collection box 501, the bolts can be removed to open the side baffle 512 and the dust can be discharged through the drain port.

[0035] A sample preparation device for determining the grindability index of coal includes the following steps: S1. Equipment Start-up and Initial Preparation: First, start the two drive motors 308 to rotate in opposite directions. The drive motors 308 drive the drive shaft 309 to rotate. The drive synchronous pulley 310 on the drive shaft 309 drives the driven synchronous pulley 311 and the rotating shaft 303 to rotate through the transmission belt 312. This causes the two crushing rollers 304 to rotate inwards towards each other, preparing for the crushing of the coal sample.

[0036] S2. Dust collection system synchronously starts: While the drive motor 308 drives the drive shaft 309 to rotate, the drive gear 502 at the end of the drive shaft 309 rotates synchronously, which drives the driven gear 503 to rotate. The driven gear 503 drives the guide impeller 507 to rotate at high speed inside the guide tube 504 through the linkage shaft 506. The rotation of the guide impeller 507 generates negative pressure airflow, which creates a negative pressure effect inside the dust collection box 501 through the air inlet pipe connector 508 and the suction hose 509, allowing the dust inside the treatment box 1 to enter the dust collection box 501 through the dust suction port 513.

[0037] S3. Coal Sample Input and Crushing Size Adjustment: Several pre-treated coal samples (processed to 6mm) are input from the top of the processing box 1. Under gravity, the coal samples fall between two crushing rollers 304 and are crushed by the inwardly rotating crushing rollers 304. Then, the dual-shaft motor inside the protective box 314 is activated. The dual-shaft motor drives the extension shafts 315 at both ends to rotate. The first synchronous pulley 316 on the extension shaft 315 drives the second synchronous pulley 317 and the adjusting screw 305 to rotate via the synchronous belt 318. This causes the two left and right spacing adjustment frames 301 to move in opposite directions, gradually bringing the two crushing rollers 304 closer together. The spacing between the crushing rollers 304 is adjusted until the coal sample is crushed to the target particle size.

[0038] S4. Coal Sample Screening and Separation: The crushed coal sample falls between the crushing rollers 304 and onto the arc-shaped screen plate 401 below. The sieve holes of the arc-shaped screen plate 401 only allow qualified coal samples smaller than the target particle size to pass through. After passing through the sieve holes, the qualified coal samples fall to the bottom of the processing box 1 and are finally discharged through the discharge hopper 2, completing the collection of qualified samples. At the same time, the rotary motor 405 on the front of the processing box 1 is started. The rotary motor 405 drives the movable rod 406 to rotate, and the rotary cam 407 on the movable rod 406 rotates synchronously. Due to the eccentric structure of the rotary cam 407, it repeatedly pushes the arc-shaped screen plate 401 upward during the rotation, causing the arc-shaped screen plate 401 to vibrate continuously. Unqualified coal samples larger than the target particle size slide to the left and right ends along the arched surface of the arc-shaped screen plate 401 under the action of vibration. Guided by the guide rubber belt 402, they are discharged from the processing box 1 through the rectangular screening holes 403 and fall into the collection boxes 404 on both sides.

[0039] S5. Recycling of Non-compliant Coal Samples: After one screening cycle, turn off the rotary motor 405 and the dual-shaft motor, open the movable door panel on the side of the collection box 404, and remove the non-compliant coal sample from the collection box 404. Then, restart the drive motor 308 and the dual-shaft motor, adjust the spacing of the crushing rollers 304 to a suitable position, and reintroduce the removed non-compliant coal sample from the top of the processing box 1, repeating the above crushing and screening process. Repeat this cycle multiple times until there are no coal sample residues larger than the target particle size remaining on the surface of the arc-shaped screen plate 401, ensuring that all input coal samples are processed to the qualified particle size, thus completing the entire sample preparation process for the coal grindability index determination.

Claims

1. A sample preparation device for determining the grindability index of coal, comprising a processing box (1), wherein a discharge hopper (2) is fixed at the bottom of the processing box (1), characterized in that: The processing box (1) is equipped with a crushing mechanism (3) and a screening mechanism (4) inside, and a dust removal component (5) is provided on the back of the processing box (1). The crushing mechanism (3) includes two spacing adjustment frames (301), which are symmetrically distributed on the left and right sides of the processing box (1). Each of the two spacing adjustment frames (301) has a fixed mounting plate (302) at both its front and rear ends. One end of the mounting plate (302) extends into the interior of the processing box (1), and a rotating shaft (303) is rotatably connected between the two corresponding mounting plates (302). A crushing roller (304) is fixedly mounted on the rotating shaft (303). Adjustment rollers are rotatably connected to both the left and right sides of the processing box (1). The screw (305) has two adjusting screws (305) with opposite thread directions. The surface of the spacing adjustment bracket (301) is provided with a threaded hole that matches the adjusting screw (305). The spacing adjustment bracket (301) is threadedly connected to the surface of the adjusting screw (305) through the threaded hole. Two limiting guide holes are provided on both the left and right sides of the processing box (1). The position of the limiting guide hole corresponds to the limiting mounting plate (302), and the size of the limiting guide hole matches the limiting mounting plate (302). The limiting mounting plate (302) is slidably connected to the inner wall of the limiting guide hole.

2. The sample preparation equipment for determining the grindability index of coal according to claim 1, characterized in that: Two first mounting brackets (306) and two second mounting brackets (307) are fixedly connected to the upper surfaces of the four limiting mounting plates (302). A drive motor (308) is fixedly connected to the surface of the first mounting bracket (306). A drive shaft (309) is fixedly connected to the rotating shaft of the drive motor (308). The drive shaft (309) is rotatably disposed between the first mounting bracket (306) and the second mounting bracket (307). A drive synchronous pulley (310) is fixedly connected to the surface of the drive shaft (309). A driven synchronous pulley (311) is fixedly connected to one end surface of the rotating shaft (303). A transmission belt (312) is installed between the drive synchronous pulley (310) and the driven synchronous pulley (311).

3. The sample preparation equipment for determining the grindability index of coal according to claim 2, characterized in that: A U-shaped frame (313) is fixedly connected to the middle of the upper surface of the processing box (1). A protective box (314) is fixedly installed on the lower surface of the U-shaped frame (313). A dual-axis motor is fixedly installed inside the protective box (314). Both ends of the dual-axis motor are fixedly connected to an extension shaft (315). The end of the extension shaft (315) extends to the outside of the U-shaped frame (313) and is fixedly connected to a first synchronous pulley (316). The end of the adjusting screw (305) is fixedly connected to a second synchronous pulley (317). A synchronous belt (318) is installed between the first synchronous pulley (316) and the second synchronous pulley (317).

4. The sample preparation equipment for determining the grindability index of coal according to claim 3, characterized in that: The dust removal assembly (5) includes a dust collection box (501) fixedly connected to the back of the processing box (1), a drive gear (502), a driven gear (503), and a support frame fixedly connected to the surface of the second mounting bracket (307). The end of the support frame is fixedly connected to a guide tube (504), and the end of the guide tube (504) is fixedly embedded with a conical acceleration tube (505). The drive gear (502) is fixedly connected to the end of the drive shaft (309) away from the drive motor (308). The driven gear (503) is rotatably connected to the surface of the second mounting bracket (307), and the drive gear (502) meshes with the driven gear (503). The central shaft of the driven gear (503) is fixedly connected to a linkage shaft (506). The end of the linkage shaft (506) away from the driven gear (503) extends into the interior of the guide tube (504) and is fixedly connected to a guide impeller (507).

5. The sample preparation equipment for determining the grindability index of coal according to claim 4, characterized in that: The output end of the conical acceleration tube (505) is fixedly connected to an air inlet pipe connector (508). The air intake end of the guide impeller (507) corresponds to the position of the air inlet pipe connector (508). An air intake hose (509) is fixedly embedded on the surface of the air inlet pipe connector (508). The end of the air intake hose (509) away from the air inlet pipe connector (508) extends into the interior of the dust collection box (501). A filter screen plate (510) is fixed inside the dust collection box (501). The air intake end of the air intake hose (509) is located above the filter screen plate (510).

6. The sample preparation equipment for determining the grindability index of coal according to claim 5, characterized in that: The air guide tube (504) has several exhaust holes (511) at the end away from the conical acceleration tube (505). The position of the exhaust holes (511) corresponds to the air outlet of the air guide impeller (507). The surface of the dust collection box (501) has a drain port. A side baffle (512) is installed on the outside of the drain port by bolts.

7. The sample preparation equipment for determining the grindability index of coal according to claim 6, characterized in that: The inner wall of the processing box (1) is provided with a dust suction port (513). A grid cover (514) is fixedly connected to the inner wall of the dust suction port (513). The dust suction port (513) is located below the two crushing rollers (304), and the position of the dust suction port (513) corresponds to the dust collection box (501). The dust suction port (513) connects the processing box (1) and the inside of the dust collection box (501).

8. The sample preparation equipment for determining the grindability index of coal according to claim 7, characterized in that: The screening mechanism (4) includes an arc-shaped screen plate (401) set inside the processing box (1). The arc-shaped screen plate (401) is arched in the middle and is located directly below the two crushing rollers (304). The left and right ends of the arc-shaped screen plate (401) are fixedly connected to the guide rubber belt (402). The end of the guide rubber belt (402) away from the arc-shaped screen plate (401) is fixedly connected to the inner wall of the processing box (1). The left and right sides of the processing box (1) are provided with rectangular screening holes (403). The position of the rectangular screening holes (403) corresponds to the position of the guide rubber belt (402). The two sides of the processing box (1) are fixedly connected with collection boxes (404). The position of the collection boxes (404) corresponds to the position of the rectangular screening holes (403). The side of the collection box (404) is rotatably provided with a movable door panel.

9. The sample preparation equipment for determining the grindability index of coal according to claim 8, characterized in that: A rotary motor (405) is fixedly installed on the front of the processing box (1). The output end of the rotary motor (405) extends into the interior of the processing box (1) and is fixedly connected to a movable rod (406). A rotary cam (407) is fixedly connected to the middle surface of the movable rod (406). The rotary cam (407) is located directly below the arc-shaped screen plate (401) and overlaps with the surface of the arc-shaped screen plate (401). The surface of the rotary cam (407) is provided with a wear-resistant rubber layer.

10. A method for preparing a sample for determining the grindability index of coal, used to implement the sample preparation equipment for determining the grindability index of coal as described in any one of claims 1-9, characterized in that: S1. First, start the two drive motors so that the rotating shafts of the two drive motors rotate in opposite directions, thereby driving the two crushing rollers to rotate inwards towards each other. Then, put several coal samples smaller than 6mm from the top of the processing box between the two crushing rollers inside. S1. The drive motor drives the drive gear and the driven gear to rotate simultaneously through the drive shaft, which in turn drives the air guide impeller to rotate at high speed inside the air guide tube. The air guide impeller generates negative pressure airflow, and the suction hose generates negative pressure inside the dust collection box, which then sucks up and collects the dust generated inside the processing box through the dust suction port. S3. Then, the dual-shaft motor drives the two adjusting screws to rotate, and the adjusting screws drive the two spacing adjustment frames to move in opposite directions, thereby adjusting the spacing between the two crushing rollers so that the two crushing rollers are close together, thus crushing and producing a 1.25mm coal sample. S4. The sieve holes of the arc-shaped screen plate retain coal samples larger than 1.25mm on its surface, while coal samples smaller than 1.25mm pass through the arc-shaped screen plate and fall into the discharge hopper at the bottom of the processing box for discharge. At the same time, the rotary motor is started to drive the movable rod to rotate, which in turn drives the rotary cam to repeatedly push the arc-shaped screen plate upward during the rotation process, so that the arc-shaped screen plate generates a vibration effect, which can vibrate the unqualified coal samples to the collection boxes on both sides of the processing box. S5. Remove the coal samples that do not meet the size requirements from the collection box and put them back into the processing box for subsequent multiple crushing processes until there are no coal samples larger than 1.25mm on the surface of the arc screen plate.

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