A coal mine screening device for coal mining

Abstract

The present application relates to the technical field of coal mine screening, and specifically discloses a coal mine screening device for coal mining, which comprises a rack, a screening unit, a driving unit and a dredging unit. The dredging unit is arranged between two layers of screen meshes, and the paddle thereof is periodically reciprocatingly rotated under the driving of the driving member to continuously stir the material on the second screen mesh, effectively breaking the arching effect of small coal blocks and ensuring the smoothness of the screening channel. A flow channel and a jet groove are arranged in the rotating shaft and the paddle of the dredging unit, and when the paddle is rotated to the optimal angle perpendicular to the screen mesh, the gas supply member instantaneously sprays a gas flow to the mesh hole, powerfully removing foreign matters and sticky coal sludge stuck in the mesh hole and effectively solving the problem of screen mesh blockage. Meanwhile, the capillary water film formed between the sticky coal sludge and the surface of the screen mesh is broken, the separation and shedding of water are accelerated, the water content of the small coal blocks screened finally is effectively reduced, and the quality of the coal product is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal mine screening, more particularly, it relates to a coal mine screening device for coal mining. BACKGROUND

[0002] When the existing coal mine screening device processes high-humidity sticky coal slime, the water in the coal slime is easy to form a capillary water film on the surface of the screen, resulting in strong adsorption, causing fine coal particles to adhere to the screen and agglomerate with other particulate materials, causing serious screen hole blockage, which not only greatly reduces the screening efficiency and processing capacity, but also causes the product coal to have a high water content, affecting the quality of the coal, and increasing the load of the subsequent dewatering process.

[0003] Secondly, the traditional knocking and vibrating unblocking method has poor effect and is easy to damage the screen, especially when processing double-layer screens, it is difficult to meet the unblocking needs of each layer of screen surface, and the material on the lower layer of screen is easy to accumulate and compact due to arching effect, hindering the screening of qualified particles and the separation of impurities, affecting the classification accuracy and recovery rate. SUMMARY

[0004] In order to overcome the above technical problems, the present application provides a coal mine screening device for coal mining.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] A coal mine screening device for coal mining, comprising:

[0007] A rack, one side of the top of which is provided with a receiving hopper;

[0008] A screening unit, which is arranged below the receiving hopper and comprises a screening frame, both ends of the screening frame are hingedly connected to the rack through suspension rods, and the screening frame is provided with first and second screens arranged in parallel in an up-down direction.

[0009] A drive unit arranged on the rack for driving the screening frame to reciprocate;

[0010] A dredging unit arranged between the first and second screens, comprising rotating shafts arranged at equal intervals in the screening frame, a paddle is mounted on each rotating shaft, a flow channel is formed in each rotating shaft, and a gas injection groove is formed in each paddle and communicates with the flow channel; the inner wall of the screening frame is provided with a driving member for driving each rotating shaft to rotate reciprocally and a gas supply member for supplying gas to the flow channel of each rotating shaft.

[0011] As a further scheme of the present application, the downwardly inclined end of the first screen is connected with a first discharge chute, and the downwardly inclined end of the second screen is connected with a second discharge chute.

[0012] As a further scheme of the present application: the driving unit comprises a driving motor fixed on the frame and a crankshaft rotatably installed on the frame, the driving motor output end is connected with the crankshaft through a transmission belt, and a connecting rod is rotatably connected on the crankshaft journal, and the connecting rod far from the crankshaft is hingedly connected with the bottom of the screening frame.

[0013] As a further scheme of the present application: the driving unit comprises a driving motor fixed on the frame and a crankshaft rotatably installed on the frame, the driving motor output end is connected with the crankshaft through a transmission belt, and a connecting rod is rotatably connected on the crankshaft journal, and the connecting rod far from the crankshaft is hingedly connected with the bottom of the screening frame.

[0014] As a further scheme of the present application: the driving unit comprises a driving motor fixed on the frame and a crankshaft rotatably installed on the frame, the driving motor output end is connected with the crankshaft through a transmission belt, and a connecting rod is rotatably connected on the crankshaft journal, and the connecting rod far from the crankshaft is hingedly connected with the bottom of the screening frame.

[0015] As a further scheme of the present application: the driving unit comprises a driving motor fixed on the frame and a crankshaft rotatably installed on the frame, the driving motor output end is connected with the crankshaft through a transmission belt, and a connecting rod is rotatably connected on the crankshaft journal, and the connecting rod far from the crankshaft is hingedly connected with the bottom of the screening frame.

[0016] The second air chamber is provided with a flexible bag piece on the side facing the first discharge outlet of the first discharge chute, and a guide plate for guiding the coal blocks is arranged on the screening frame; a piston plate is slidably arranged in the first air chamber, and the piston plate is fixedly connected with the rack through a push-pull rod.

[0017] As a further scheme of the present application: the driving unit comprises a driving motor fixed on the frame and a crankshaft rotatably installed on the frame, the driving motor output end is connected with the crankshaft through a transmission belt, and a connecting rod is rotatably connected on the crankshaft journal, and the connecting rod far from the crankshaft is hingedly connected with the bottom of the screening frame.

[0018] As a further scheme of the present application: the driving unit comprises a driving motor fixed on the frame and a crankshaft rotatably installed on the frame, the driving motor output end is connected with the crankshaft through a transmission belt, and a connecting rod is rotatably connected on the crankshaft journal, and the connecting rod far from the crankshaft is hingedly connected with the bottom of the screening frame.

[0019] As a further scheme of the present application: the driving unit comprises a driving motor fixed on the frame and a crankshaft rotatably installed on the frame, the driving motor output end is connected with the crankshaft through a transmission belt, and a connecting rod is rotatably connected on the crankshaft journal, and the connecting rod far from the crankshaft is hingedly connected with the bottom of the screening frame.

[0020] As a further scheme of the present application: the driving unit comprises a driving motor fixed on the frame and a crankshaft rotatably installed on the frame, the driving motor output end is connected with the crankshaft through a transmission belt, and a connecting rod is rotatably connected on the crankshaft journal, and the connecting rod far from the crankshaft is hingedly connected with the bottom of the screening frame.

[0021] The beneficial effects of the present application are as follows:

[0022] The dredging unit arranged between the two layers of screens, with the paddle periodically reciprocating under the driving of the driving member, continuously stirs the material on the second screen, effectively breaking the arching effect of small coal blocks, preventing the accumulation and compaction of the material on the screen surface, and ensuring the smoothness of the screening channel.

[0023] The flow channel and the air jet groove are arranged in the rotating shaft and the paddle, when the paddle rotates to the optimal angle perpendicular to the screen, the gas supply member instantaneously sprays air flow to the mesh hole to achieve point blasting type blockage removal, and strongly removes the foreign matter and sticky coal slurry stuck in the mesh hole, effectively solving the screen blockage; the air flow sprayed by the air jet groove not only serves for dredging, but also effectively breaks the capillary water film formed between the sticky coal slurry and the screen surface, accelerates the separation and shedding of water, so that the water content of the small coal blocks finally screened is effectively reduced, not only improving the quality of the coal product, but also reducing the load of the subsequent dehydration process. BRIEF DESCRIPTION OF DRAWINGS

[0024] The present application will be further described below in conjunction with the drawings.

[0025] Figure 1 is a perspective view of the present application;

[0026] Figure 2 is another perspective view of the present application;

[0027] Figure 3 is a structural view of the screening unit and the dredging unit in the present application;

[0028] Figure 4 is an internal cross-sectional view of the screening frame in the present application;

[0029] Figure 5 is Figure 4 is an enlarged view of A in the present application;

[0030] Figure 6 is a structural view of the rotating shaft and the gas supply member in the present application;

[0031] Figure 7 is a structural view of the first discharging unit and the dredging unit in the present application;

[0032] Figure 8 is a structural view of the pushing member in the present application;

[0033] Figure 9 is a structural view of the dust suction unit in the present application;

[0034] Figure 10 is another structural view of the dust suction unit in the present application;

[0035] Figure 11 The connection structure of the rack in the present application is shown in the schematic view.

[0036] In the figure:

[0037] 100, frame; 110, material receiving hopper;

[0038] 200, material screening unit; 210, material screening frame; 211, guide plate; 220, suspension rod; 230, air pipe; 240, first screen; 250, second screen; 260, first discharge chute; 270, second discharge chute; 280, pushing member; 281, first air chamber; 282, second air chamber; 283, partition plate; 284, notch; 285, flexible bag piece; 286, push-pull rod; 287, piston plate; 288, tension spring;

[0039] 300, drive unit; 310, drive motor; 320, crankshaft; 330, transmission belt; 340, connecting rod;

[0040] 400, dredging unit; 410, rotating shaft; 411, flow channel; 412, through hole; 420, push plate; 421, air jet groove; 430, gear; 440, air supply frame; 450, rack; 460, air supply member; 461, sleeve; 462, annular air cavity; 463, through groove; 470, guide wheel; 480, pull cable;

[0041] 500, dust suction unit; 510, cylinder; 520, negative pressure chamber; 530, dust suction port; 540, rotating disc; 550, sliding cavity; 560, sealing plate; 570, dust collection chamber; 580, filter screen. DETAILED DESCRIPTION

[0042] The subject matter described herein will now be discussed with reference to example implementations. It should be understood that discussions of these implementations are merely provided to enable those skilled in the art to better understand so as to be able to implement the subject matter described herein, and variations of elements discussed can be made by one skilled in the art, without departing from the scope of the present specification. Various processes or components can be omitted, substituted, or added according to desired implementations. Additionally, features described with respect to some examples can be combined in other examples.

[0043] Referring to Figure 1 , Figure 2 and Figure 3 , the present application discloses a coal screening device for coal mining, comprising a frame 100, a material screening unit 200, a drive unit 300, and a dredging unit 400.

[0044] The rack 100 is provided with a receiving hopper 110 on one side of the top, and the screening unit 200 is arranged below the receiving hopper 110 and comprises a screening frame 210, both ends of the screening frame 210 are hinged to the rack 100 through a suspension rod 220, and the screening frame 210 is respectively provided with a first screen 240 and a second screen 250 which are arranged in parallel in an up-down manner; the driving unit 300 is arranged on the rack 100 and is used for driving the screening frame 210 to reciprocally shake;

[0045] Please refer to Figure 4 、 Figure 5 and Figure 6 , the dredging unit 400 is arranged between the first screen 240 and the second screen 250 and comprises a rotating shaft 410 which is arranged equidistantly in the screening frame 210, the rotating shaft 410 is provided with a push plate 420, the rotating shaft 410 is provided with a flow channel 411, and the push plate 420 is provided with a jet groove 421 which is in communication with the flow channel 411; the inner wall of the screening frame 210 is provided with a driving member which drives each rotating shaft 410 to reciprocally rotate and a gas supply member 460 which supplies gas to the flow channel 411 of the rotating shaft 410;

[0046] Specifically, the coal blocks are put into the receiving hopper 110, the screening frame 210 which is suspended below the suspension rod 220 is driven by the driving unit 300 to reciprocally shake, so that the coal blocks are screened, the coal blocks fall onto the first screen 240, the first screen 240 has relatively large mesh holes, small-particle coal blocks and heavy impurities such as gravel pass through the first screen 240 and fall onto the second screen 250, and large-particle coal blocks are retained on the mesh surface of the first screen 240, the second screen 250 has relatively small mesh holes and can intercept small-particle coal blocks, and the gravel passes through the second screen 250 and is discharged from the bottom of the screening frame 210, so that the coal blocks are classified and screened and the impurities are removed;

[0047] In the reciprocating shaking process of the screening frame 210, the driving member synchronously drives each rotating shaft 410 to reciprocally rotate in the region between the first screen 240 and the second screen 250, when the push plate 420 is rotated to be perpendicular to the first screen 240 and the second screen 250, the gas supply passage between the gas supply member 460 and the flow channel 411 is open, so that the airflow passes through the flow channel 411 and is sprayed from the jet grooves 421 of the two push plates 420, the mesh holes of the first screen 240 and the second screen 250 are respectively jet-dredged, the coal blocks and foreign matters are prevented from causing blockage, the capillary water film formed between the sticky and wet coal slurry and the screen surface is broken, and the water content of the coal blocks is reduced; when the push plate 420 is rotated to an angle which is not perpendicular to the first screen 240 and the second screen 250, the gas supply passage between the gas supply member 460 and the flow channel 411 is closed, at this time, the circumferential pushing action of the push plate 420 is used to turn over the coal blocks above the second screen 250, so that the coal blocks are prevented from being concentrated and accumulated, and the rapid separation of small-particle coal blocks and impurities is promoted.

[0048] The design goal of the present application is to solve the two key problems of "sticky slime clogging the screen holes" and "material agglomeration leading to unclear separation" which lead to the failure of traditional screening;

[0049] The main function of the first screen 240 is to preliminarily classify and separate "ultra-large particles" from "small and medium particle mixture". The material retained on the first screen 240 may indeed contain large coal blocks and large impurities, but this part of the material can usually be processed by manual or other means (such as visual sorting) or enter different crushing cycles. The present application focuses on optimizing the fine separation of small and medium particle mixture on the second screen.

[0050] The second screen 240 and the dredging unit 400 are the core technical solutions of the present application. The dredging unit 400, which is arranged between the two layers of screens, continuously turns the material on the second screen through the periodic reciprocating rotation of the paddle 420, thereby breaking the arching effect and static accumulation of the material, allowing the wrapped particles (small coal blocks and small impurities) of different densities to redistribute and move relatively. Under the combined action of continuous turning and screen body shaking, coal blocks with smaller density tend to move to the surface, while impurities with larger density have more opportunities to contact the screen holes and fall.

[0051] The present device is suitable for classifying and screening coal and ore mixtures after coarse or medium crushing. In actual application, the aperture of the first screen 240 can be set according to the size of the ultra-large material to be separated (such as particle size greater than 50mm), and its main role is to separate this part of the material for subsequent concentrated processing or re-crushing. The aperture of the second screen 250 is set according to the target particle size of the small particle clean coal (for example, 6-25mm);

[0052] The material falling into the second screen 250 is a mixture containing target particle size clean coal and impurities of similar particle size. Due to the density difference between coal and gangue and the presence of sticky slime, traditional screens are prone to clogging and incomplete separation at this stage. The present application aims to overcome this problem through the synergistic action of the dredging unit 400: the continuous turning of the paddle 420 not only prevents material accumulation, but also creates a dynamic sorting environment on the screen surface, allowing larger density impurity particles to have more opportunities to contact the screen holes and pass through. At the same time, the regular strong air jet can effectively break the small slime clumps formed by water, release the wrapped impurities, and destroy the capillary water film adhesion between the slime and the screen. Therefore, the present device can effectively improve the separation efficiency of coal and impurities within the same particle size range while achieving particle size classification, ultimately ensuring the purity of small particle coal blocks discharged from the second discharge chute (270).

[0053] In addition, the poking plate 420 of the dredging unit 400 is periodically reciprocatingly rotated, and in the non-perpendicular state, it does not continuously block the falling of the materials, and the interval design ensures the smooth passing of the materials between the two layers of screens.

[0054] It should be noted that the poking plate 420 of the dredging unit 400 arranged between the two layers of screens is periodically reciprocatingly rotated under the driving of the driving member, continuously stirs the materials on the second screen 250, effectively breaks the arching effect of the small coal blocks, prevents the accumulation and compaction of the materials on the screen surface, and ensures the smoothness of the screening channel;

[0055] The flow channel 411 and the air jet groove 421 are arranged in the rotating shaft 410 and the poking plate 420, when the poking plate 420 is rotated to the optimal angle perpendicular to the screen, the air supply member 460 instantaneously sprays air flow to the mesh hole to achieve the point blasting type unblocking, and strongly removes the foreign matters and wet coal slurry stuck in the mesh hole, effectively solves the screen jamming; the air flow sprayed by the air jet groove 421 not only dredges, but also effectively breaks the capillary water film formed between the wet coal slurry and the screen surface, accelerates the separation and falling of the water, effectively reduces the water content of the small coal blocks finally screened out, improves the quality of the coal products, and reduces the load of the subsequent dehydration process;

[0056] In an embodiment, please refer to Figure 3 and Figure 4 , the downwardly inclined one end of the first screen 240 is connected with the first discharge chute 260, and the downwardly inclined one end of the second screen 250 is connected with the second discharge chute 270.

[0057] Specifically, the large coal blocks retained on the screen surface of the first screen 240 can slide along the inclined first screen 240 to the first discharge chute 260 under the action of inertia, and the small coal blocks retained on the screen surface of the second screen 250 can slide along the inclined second screen 250 to the second discharge chute 270 under the action of inertia, and the discharge angles of the first discharge chute 260 and the second discharge chute 270 do not interfere with each other, so that the screening of the coal blocks of different particle sizes can be realized.

[0058] It should be noted that by independently configuring the first discharge chute 260 and the second discharge chute 270 for the first screen 240 and the second screen 250 respectively, the large coal blocks and the small coal blocks after classification can be collected and discharged along the paths that do not interfere with each other, avoiding the mixing and cross contamination of the materials of different particle sizes at the outlet, ensuring the high purity of the screened products, and realizing the seamless connection and continuous operation from screening to collection;

[0059] The screen is designed to be downwardly inclined, so that the mechanical energy generated by the reciprocating shaking of the screening frame 210 is converted into driving force for the forward sliding of the materials, and the coal blocks can automatically and smoothly slide to the corresponding discharge chute under the action of inertia; the discharge angles of the first discharge chute 260 and the second discharge chute 270 do not interfere with each other, avoiding the structural congestion problem caused by the concentrated discharge port of the traditional multi-layer screening machine.

[0060] Further, referring to Figure 1 and Figure 2 , the driving unit 300 includes a driving motor 310 fixed to the rack 100 and a crankshaft 320 rotatably installed on the rack 100, the output end of the driving motor 310 is drivingly connected with the crankshaft 320 through a transmission belt 330, and the crankshaft 320 is rotatably connected with a connecting rod 340 on the journal thereof, and the end of the connecting rod 340 away from the crankshaft 320 is hingedly connected with the bottom of the screening frame 210;

[0061] Specifically, under the driving of the transmission belt 330, the driving motor 310 drives the crankshaft 320 to rotate, thereby driving the connecting rod 340 to reciprocatingly swing up and down, and further driving the screening frame 210 to swing back and forth with the suspension rod 220 as the fulcrum, so as to realize the continuous screening of the coal blocks.

[0062] Notably, the driving motor 310 drives the crankshaft 320 to rotate at a constant speed through the transmission belt 330, and the connecting rod 340 converts the rotary motion into reciprocating shaking of the screening frame 210, so as to generate a stable and periodic exciting force, so that the materials on the screen obtain consistent throwing and sliding motion, effectively avoiding the uneven screening force or local accumulation phenomenon, and providing effective guarantee for high-precision and high-efficiency screening.

[0063] In yet another embodiment, referring to Figure 4 and Figure 5 , the driving member includes a gear 430 coaxially sleeved on each rotating shaft 410 and a rack 450 slidingly installed in the screening frame 210, and the rack 450 is drivingly engaged with each gear 430;

[0064] Specifically, when the screening frame 210 reciprocatingly shakes relative to the rack 100, the rack 450 and the screening frame 210 can be driven to reciprocatingly slide relative to each other, so as to drive each rotating shaft 410 to synchronously reciprocate through the meshing transmission of the rack 450 and the corresponding gear 430, so as to realize the periodic air jet dredging of the first screen 240 and the second screen 250 and the periodic turning of the coal blocks above the second screen 250.

[0065] It should be noted that the driving member directly utilizes the relative displacement between the sieve frame 210 and the rack 100 to drive the rack 450 to slide relative to the sieve frame 210, and a common rack 450 is used to engage all the gears 430 on the rotating shafts 410 to ensure that the rotating angles and speeds of all the rotating shafts 410 and the paddles 420 thereon are completely consistent, thereby ensuring that the loosening and turning effects on the first screen 240 and the second screen 250 are uniform and have no dead angle, and the screening efficiency is prevented from being reduced due to inconsistent actions in individual areas.

[0066] The uniform and reciprocating shaking of the sieve frame 210 is converted into the periodic forward and reverse reciprocating rotation of the rotating shafts 410 through the rack and pinion mechanism, so that the paddles 420 are automatically and seamlessly switched between the two states of vertical alignment with the screen jet loosening and inclined material turning.

[0067] Further, referring to Figure 5 and Figure 11 , a cable 480 is connected between one end of the rack 450 and the rack 100, a guide wheel 470 that rolls in contact with the cable 480 is rotatably installed on one side of the sieve frame 210, and a tension spring 288 connected with the rack 450 is arranged at the end of the sieve frame 210 away from the cable 480;

[0068] Specifically, the rack 450 is pulled by the cable 480 on the rack 100, when the sieve frame 210 shakes towards the end away from the cable 480, the cable 480 can pull the rack 450 in the opposite direction of the shaking of the sieve frame 210, and at the same time the tension spring is stretched to store energy, so that the rack 450 and the sieve frame 210 slide relative to each other to drive the rotating shafts 410 to rotate to one side; when the sieve frame 210 shakes towards the end close to the cable 480, the tension spring at the other end can automatically pull the rack 450 back, thereby driving the rotating shafts 410 to rotate to the other side; such reciprocation can realize the reciprocating rotation of the rotating shafts 410.

[0069] It is worth noting that only the traction of the cable 480 and the tension spring can feedback the reciprocating movement of the rack 450 from the shaking of the main body of the sieve frame 210, the cable 480 changes direction through the guide wheel 470, linearly converts the horizontal displacement of the sieve frame 210 into the linear motion of the rack 450, and cooperates with the stable rebound force provided by the tension spring to ensure that the reciprocating stroke of the rack 450 strictly corresponds to the shaking amplitude and frequency of the sieve frame 210, so that the reciprocating rotation angle of the rotating shafts 410 is fixed and the rhythm is stable, thereby ensuring that the jet loosening and material turning actions of the paddles 420 can be alternately performed at the preset optimal period, and the effect is uniform and consistent;

[0070] The cable 480 provides a one-way pulling force, and the tension spring provides a reverse spring force, which together provide a balanced driving force for the bidirectional movement of the rack 450, avoiding dead points or jamming of the mechanism when reversing, and making the entire transmission process smoother.

[0071] Further, referring to Figure 7 and Figure 8 , the first discharge chute 260 is provided with a pushing member 280 away from one side of the discharge outlet, the pushing member 280 includes a first air chamber 281 and a second air chamber 282, and a partition plate 283 is arranged between the first air chamber 281 and the second air chamber 282, and a slot 284 is formed in one end of the partition plate 283 to communicate the first air chamber 281 and the second air chamber 282; the second air chamber 282 is provided with a flexible bladder 285 on the side facing the discharge outlet of the first discharge chute 260, and the screening frame 210 is provided with a guide plate 211 for guiding the coal blocks; a piston plate 287 is slidably embedded in the first air chamber 281, and the piston plate 287 is fixedly connected with the rack 450 through a push-pull rod 286;

[0072] Referring to Figure 5 and Figure 11 , one end of the rack 450 is connected with the rack 100 through the cable 480, and the other end is connected with the screening frame 210 through the tension spring, so as to realize the reciprocating movement thereof; at the same time, the middle part or appropriate position of the rack is fixedly connected with the piston plate 287 of the pushing member 280 through the push-pull rod 286, so as to transmit the reciprocating movement of the rack to the pushing member.

[0073] Specifically, when the rack 450 slides towards one side of the first discharge chute 260, the piston plate 287 can be pushed to slide along the first air chamber 281 through the push-pull rod 286, so as to extrude the gas in the first air chamber 281 by the piston plate 287, and then the gas enters the second air chamber 282 through the slot 284, and then the gas pressure in the second air chamber 282 increases, so as to make the flexible bladder 285 expand to push the coal blocks in the first discharge chute 260 out of the discharge outlet thereof;

[0074] When the rack 450 slides away from one side of the first discharge chute 260, the piston plate 287 can be pulled to slide along the first air chamber 281 through the push-pull rod 286, so as to make the first air chamber 281 produce negative pressure, and then the gas in the second air chamber 282 flows back to the first air chamber 281 through the slot 284, and then the gas pressure in the second air chamber 282 decreases, so as to make the flexible bladder 285 retract into the second air chamber 282, and then the space in the first discharge chute 260 for accommodating the coal blocks is generated again, and the coal blocks on the screen surface of the first screen 240 can be guided by the guide plate 211 to be discharged into the space again, so as to realize the periodic active discharge of the coal blocks in the first discharge chute 260, and avoid the accumulation and retention of the coal blocks.

[0075] Notably, the power source of the pushing member 280 is directly taken from the reciprocating movement of the rack 450, and for the problem that large coal lumps may be retained in the first discharge chute 260 due to large friction and poor flowability, this design optimizes passive inertial sliding to active periodic pneumatic pushing; when the flexible bladder 285 is inflated by air pressure, it can generate an effective pushing force to force the coal lumps to the outlet, avoiding blockage and accumulation of the discharge outlet, and ensuring the continuous smoothness of the discharge path of large particle materials; the flexible bladder 285 is in large-area and flexible contact with the coal lumps when it is inflated, and the pushing force is uniform, avoiding the possible breakage of the coal lumps (maintaining the quality of the coal lumps) or the hard impact and wear of the chute body caused by a rigid push rod.

[0076] The pushing action is synchronously controlled by the movement process of the rack 450, and the pushing frequency is completely synchronized with the shaking frequency of the screening frame 210 and the operation frequency of the dredging unit 400. The beats of pushing (bladder inflation) and preparing (bladder contraction) are automatically alternated, the guide plate 211 ensures that the coal lumps can accurately fall into the space left by the bladder after contraction, and the whole process has high automation degree and closely cooperates with the upstream screening process, so that the process is smooth and efficient.

[0077] In addition, please refer to Figure 6 , the air supply member 460 includes a sleeve 461 fixedly arranged in the screening frame 210, the sleeve 461 is in rotary sealing connection with one end of the rotating shaft 410, the sleeve 461 is provided with an annular air cavity 462, the inner wall of the annular air cavity 462 is provided with two groups of through grooves 463 distributed in an up-down manner, and the rotating shaft 410 is provided with two groups of through holes 412 matched with the through grooves 463;

[0078] Specifically, the annular air cavity 462 of each air supply member 460 is supplied with air by an external air source, when the rotating shaft 410 is rotated to be perpendicular to the first screen 240 and the second screen 250, the through holes 412 are just aligned with the corresponding through grooves 463, so that the annular air cavity 462 is in communication with the flow channel 411, and the airflow in the annular air cavity 462 can enter the flow channel 411 through the through grooves 463 and the through holes 412, and then the airflow is sprayed out from the two side air injection grooves 421, so as to realize the effects of air injection dredging and water film breaking of the first screen 240 and the second screen 250;

[0079] When the rotating shaft 410 is rotated to other angles, the through holes 412 and the through grooves 463 are staggered with each other, at this time the annular air cavity 462 is no longer in communication with the flow channel 411, so as to avoid that when the coal lumps are turned over, the airflow is accidentally sprayed out from the air injection groove 421 to sweep the impurities that have not been separated from the small coal lumps to the second discharge chute 270.

[0080] It should be noted that the air supply member 460 controls the opening and closing of the air path by the rotation angle of the rotating shaft 410, and only when the dial plate 420 is rotated to the optimal unblocking angle perpendicular to the first screen 240 and the second screen 250, the through hole 412 on the rotating shaft 410 is aligned with the through slot 463 on the sleeve 461, and the airflow is sprayed out, ensuring that the airflow spraying and unblocking demand are perfectly matched in time and space, realizing accurate and efficient point clearing and film breaking;

[0081] When the dial plate 420 is at the angle of turning the material, the air path is automatically cut off, effectively preventing the accidental spraying of airflow during the turning process, thereby avoiding blowing the fine impurities that have not been separated on the second screen 250 into the finished small particle coal (second discharge chute 270), eliminating cross interference, and thus ensuring the purity of the small particle coal.

[0082] In further embodiments, please refer to Figure 1 and Figure 9 , further comprising a dust suction unit 500 located between the receiving hopper 110 and the screening frame 210, the dust suction unit 500 comprising a cylinder 510 fixed to the rack 100, a negative pressure chamber 520 is arranged in the cylinder 510, a dust suction port 530 is opened on the side of the negative pressure chamber 520 facing the discharge port of the receiving hopper 110, and a dust collection chamber 570 is also opened in the cylinder 510 and communicates with the negative pressure chamber 520.

[0083] Specifically, when the coal blocks in the receiving hopper 110 fall to the first screen 240, the negative pressure chamber 520 generates negative pressure at the dust suction port 530, so that the light dust mixed in the coal blocks can be sucked into the negative pressure chamber 520, and then the dust is collected and recycled into the dust collection chamber 570, avoiding dust generation during the screening process of the coal blocks.

[0084] Notably, the dust suction unit 500 is arranged in the path of the coal blocks falling, and the negative pressure chamber 520 captures the source at the moment of dust generation, avoiding the spread and escape of dust inside the screening equipment, and improving the working environment.

[0085] When the coal blocks fall from the receiving hopper 110, the surrounding air flows, the dust suction unit 500 directly faces the falling track at the dust suction port 530, so that the negative pressure can efficiently separate the light dust from the heavier coal blocks and suck them into the dust collection chamber 570, thereby removing a large amount of light dust before screening, reducing air pollution during screening, indirectly reducing the load of the unblocking unit 400, reducing the risk of the screen being blocked by sticky dust, and helping to improve the purity of the final collected coal product.

[0086] Further, please refer to Figure 9The negative pressure bin 520 is eccentrically installed with a rotating disc 540 at one end of which a transmission belt 330 is in transmission connection, and a plurality of slide cavities 550 extending in the radial direction are formed in the circumferential direction of the rotating disc 540, and the slide cavities 550 are slidably embedded with sealing plates 560;

[0087] Specifically, the rotating disc 540 is synchronously driven to rotate by the driving motor 310 in the driving unit 300, when the rotating disc 540 rotates, the sealing plates 560 in the slide cavities 550 can be adaptively extended and retracted under the action of centrifugal force and gravity, when the sealing plates 560 are thrown out, the sealing plates 560 are sealingly attached to the inner wall of the negative pressure bin 520, so as to form a negative pressure chamber in the negative pressure bin 520, and further generate negative pressure at the dust suction port 530 to achieve the suction effect of dust, with the rotation of the rotating disc 540, the airflow carrying dust is pushed by the sealing plates 560 to the side away from the dust suction port 530, and the sealing plates 560 gradually retract into the corresponding slide cavities 550 under the limitation of the inner wall of the negative pressure bin 520, when the sealing plates 560 are rotated to be upwardly inclined, the sealing plates 560 can be automatically slid into the corresponding slide cavities 550, and then the airflow carrying dust can be thrown into the dust collection bin 570, the airflow is discharged from the dust collection bin 570 to the outside, and the dust is retained in the dust collection bin 570.

[0088] It should be noted that the power source of the dust collection unit 500 directly reuses the driving motor 310 for driving the screen, when the rotating disc 540 rotates at high speed, the sealing plates 560 are automatically thrown out under the action of centrifugal force, and form dynamic sealing with the inner wall of the negative pressure bin 520, so as to form a high negative pressure chamber at the side of the dust suction port 530 instantaneously, and generate strong suction force, the dust-containing airflow sucked in is forced to be pushed to the dust collection bin 570 by the rotating sealing plates 560, when the sealing plates 560 are rotated to be upwardly inclined, they are automatically retracted under the action of gravity, and the airflow carrying dust is thrown into the dust collection bin 570, due to the sudden expansion of space, the sudden drop of flow rate, and the inertia of dust itself, efficient gas-solid separation is achieved, dust is collected, and purified air is discharged.

[0089] Further, please refer to Figure 2 and Figure 10 The material screening frame 210 is provided with a gas supply frame 440 in communication with each gas supply member 460, and a gas pipe 230 is connected between the gas supply frame 440 and the dust collection bin 570, and a filter screen 580 is arranged at the connection between the gas pipe 230 and the dust collection bin 570;

[0090] Specifically, the air flow in the dust collection bin 570 is used to supply air to the air supply frame 440 and each air supply member 460 through the air pipe 230, and the dust is intercepted and filtered through the filter screen 580, and then the clean gas enters the air pipe 230; when the air flow channel between the air supply member 460 and the rotating shaft 410 is closed, the air flow in the dust collection bin 570 escapes from the filter screen 580 to the external environment, so that the air pressure in the dust collection bin 570 is always maintained within a stable range, thereby avoiding hidden dangers caused by excessive air pressure in the dust collection bin 570.

[0091] When the system is designed, the air permeation resistance of the filter screen 580 is matched with the conduction resistance of the air flow channel; when the air flow channel is opened, the air supply path resistance is reduced, and the air flow in the dust collection bin 570 flows to the air supply member 460 under the action of the air pressure difference through the air pipe 230, thereby ensuring the instantaneous air flow intensity required for jet cleaning, and the existence of the filter screen 580 will not cause insufficient air supply.

[0092] It should be noted that the air flow discharged from the dust collection bin 570 after completing dust separation is recovered through the air pipe 230 and used as the air source of the jet groove 421 of the dredging unit 400, thereby realizing the secondary utilization of the internal air flow of the equipment and converting the waste gas originally discharged into the environment into a valuable functional performance source.

[0093] Through the connection of the air pipe 230, the dust collection unit 500 not only takes charge of dust removal, but also provides the air source for the dredging unit 400; when the air path of the dredging unit 400 is closed, the recovered air flow cannot enter the air supply frame 440, at this time, the filter screen 580 forms an automatic pressure relief channel to allow the air flow to escape, thereby ensuring that the internal air pressure of the dust collection bin 570 is always maintained within a safe range, and avoiding possible safety hazards caused by excessive air pressure accumulation.

[0094] The filter screen 580 arranged before the air flow enters the air pipe 230 can effectively intercept the fine dust that may escape, ensure that the recovered gas is relatively clean, prevent the dust from entering the annular air cavity 462, the flow channel 411 and the jet groove 421 and other air paths of the air supply member 460, and avoid possible blockage or wear caused thereby.

[0095] The specific embodiments of the present application are described above, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative and not limiting, and those skilled in the art can make many forms under the inspiration of the present application, which all belong to the protection of the present application.

Claims

1. A coal mine screening apparatus for use in coal mining, characterised in that, The utility model relates to a coal screening and conveying device, which comprises a rack (100) provided with a receiving hopper (110) on one side of the top thereof, a screening unit (200) arranged below the receiving hopper (110) and comprising a screening frame (210) hingedly connected to the rack (100) at both ends thereof through suspension rods (220), the screening frame (210) being provided with a first screen (240) and a second screen (250) arranged in parallel in an up-down manner respectively, a driving unit (300) arranged on the rack (100) and used for driving the screening frame (210) to reciprocatingly shake, and a dredging unit (400) arranged between the first screen (240) and the second screen (250) and comprising rotating shafts (410) arranged at equal intervals in the screening frame (210), the rotating shafts (410) being provided with push plates (420) mounted thereon, the rotating shafts (410) being provided with flow channels (411) formed therein, and the push plates (420) being provided with air injection grooves (421) formed therein and communicated with the flow channels (411), the inner wall of the screening frame (210) being provided with driving members used for driving the rotating shafts (410) to reciprocatingly rotate and air supply members (460) used for supplying air to the flow channels (411) of the rotating shafts (410), the first screen (240) being connected with a first discharge chute (260) at one end thereof which is inclined downward, the second screen (250) being connected with a second discharge chute (270) at one end thereof which is inclined downward, the driving members comprising gears (430) coaxially sleeved on the rotating shafts (410) and a rack (450) slidingly mounted in the screening frame (210) and in meshing transmission with the gears (430), the first discharge chute (260) being provided with a pushing member (280) on the side thereof away from a discharge outlet, the pushing member (280) comprising a first air chamber (281) and a second air chamber (282), a partition plate (283) being arranged between the first air chamber (281) and the second air chamber (282), the partition plate (283) being provided with a notch (284) formed at one end thereof and communicated with the first air chamber (281) and the second air chamber (282), the second air chamber (282) being provided with a flexible bag piece (285) on the side thereof facing the discharge outlet of the first discharge chute (260), the screening frame (210) being provided with a guide plate (211) used for guiding coal blocks, and the first air chamber (281) being slidingly embedded with a piston plate (287), the piston plate (287) being fixedly connected with the rack (450) through a push-pull rod (286), the driving unit (300) comprising a driving motor (310) fixed to the rack (100) and a crankshaft (320) rotationally mounted to the rack (100), the driving motor (310) being in transmission connection with the crankshaft (320) through a transmission belt (330), the crankshaft (320) being provided with a connecting rod (340) rotationally connected to the shaft journal thereof, and the connecting rod (340) being hingedly connected with the bottom of the screening frame (210) at the end thereof away from the crankshaft (320). ​ ​ ​ ​ ​ ​ ​ ​ 2. The coal mine screening apparatus for coal mining according to claim 1, characterized in that, ​ 3. The coal mine screening apparatus for coal mining according to claim 1, characterized in that, The rack (100) is connected with one end of the rack (450) through a cable (480), one side of the screening frame (210) is rotatably installed with a guide wheel (470) in rolling contact with the cable (480), and the end of the screening frame (210) away from the cable (480) is provided with a tension spring connected with the rack (450).

4. The coal screening apparatus for coal mining as claimed in claim 1, wherein, The air supply part (460) includes a sleeve shell (461) fixedly arranged in the screening frame (210), the sleeve shell (461) is rotatably and sealingly connected with one end of the rotating shaft (410), the sleeve shell (461) is provided with an annular air cavity (462) therein, the inner wall of the annular air cavity (462) is provided with two groups of through grooves (463) distributed in an up-down manner, and the rotating shaft (410) is provided with two groups of through holes (412) matched with the through grooves (463).

5. The coal screening apparatus for coal mining as claimed in claim 1, wherein, Further comprising a dust suction unit (500) between the receiving hopper (110) and the screening frame (210), the dust suction unit (500) includes a cylinder (510) fixed to the rack (100), the cylinder (510) is provided with a negative pressure bin (520) therein, the negative pressure bin (520) is provided with a dust suction port (530) on the side facing the discharge port of the receiving hopper (110), and the cylinder (510) is further provided with a dust collection bin (570) in communication with the negative pressure bin (520).

6. A coal mine screening apparatus for use in coal mining according to claim 5, characterised in that, The negative pressure bin (520) is provided with a rotating disc (540) eccentrically rotatable therein, one end of the rotating disc (540) is in transmission connection with the transmission belt (330), and the rotating disc (540) is provided with a plurality of radially extending sliding cavities (550) in the inner periphery.

7. A coal mine screening apparatus for use in coal mining according to claim 5, characterized in that, The screening frame (210) is provided with a gas supply frame (440) in communication with each air supply part (460), the gas supply frame (440) and the dust collection bin (570) are connected through a gas pipe (230), and the gas pipe (230) is provided with a filter screen (580) at the connection with the dust collection bin (570).

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