A screening system for coal mixtures

Abstract

This application discloses a screening system for coal mixtures, including a pretreatment device, a first conveying device, a vibrating screening device, a scraper conveyor device, and a crusher device. The pretreatment device pretreats the coal mixture; the vibrating screening device screens the pretreated coal mixture to obtain a first mixture and a second mixture. The vibrating screening device includes a screening inlet, a first outlet, and a second outlet. The screening inlet is connected to the conveying outlet. The first outlet is connected to a collecting device to transfer the first mixture thereto. The second outlet is connected to the scraper conveyor device to transfer the second mixture thereto. The scraper conveyor device transfers the second mixture from the scraper inlet to the scraper outlet. The crusher device is connected to the scraper outlet to crush the second mixture. This solution can improve the utilization rate of effective components in coal.

Description

Technical Field

[0001] This application generally relates to the field of coal mining technology. More specifically, this application relates to a screening system for coal mixtures. Background Technology

[0002] Raw coal refers to the original coal product extracted from underground mines, without washing, screening, or processing. It retains the physical state and compositional characteristics naturally formed during the mining process. It is the initial form in the coal production chain and can be further processed into products such as clean coal, lump coal, and fine coal through washing and screening. Raw coal is not a single substance but a complex mixture containing useful components (organic matter) and useless impurities (inorganic matter). Specifically, organic matter consists of complex organic compounds formed from plant remains through geological processes (coalification), which may include fixed carbon, volatile components, and inherent moisture. Inorganic matter may include gangue, sulfides (such as pyrite), and carbonates (such as calcite). Gangue is often the main impurity in coal, and it may include quartz, feldspar, clay minerals, and mica. Gangue in coal increases transportation costs and reduces calorific value, therefore, it is necessary to separate gangue and other impurities.

[0003] In existing gangue separation processes, after coal is sorted in the screening workshop and by the jigging machine, many fine-grained impurities (such as gangue) remain. The sorting accuracy is low, and the separation effect on fine-grained coal is poor. The screened coal contains a significant amount of gangue (e.g., the gangue content may exceed 5%). Furthermore, the coal containing gangue has a large particle size, which subsequent coal washing plants cannot crush, resulting in the ineffective utilization of large particles and wasted coal resources, thus increasing production costs.

[0004] In view of this, there is an urgent need to provide a screening system for coal mixtures in order to reduce impurities such as gangue in coal and improve the utilization rate of effective components in coal. Utility Model Content

[0005] In order to at least solve one or more of the technical problems mentioned above, this application proposes a screening system for coal mixtures in one aspect.

[0006] In a first aspect, this application provides a screening system for a coal mixture, the screening system including a collection device, the screening system comprising: a pretreatment device, a first conveying device, a vibrating screening device, a scraper conveyor device, and a crusher device; wherein, the pretreatment device is used to pretreat the coal mixture; the first conveying device includes a conveying inlet and a conveying outlet, wherein the conveying inlet is connected to the outlet of the pretreatment device for conveying the pretreated coal mixture; the vibrating screening device is used to screen the pretreated coal mixture to obtain a first mixture and a second mixture, wherein the vibrating screen... The selection device includes a screening inlet, a first outlet, and a second outlet. The screening inlet is connected to the conveying outlet. The first outlet is connected to the collecting device for transferring a first mixture to the collecting device. The second outlet is connected to the scraper conveyor for transferring a second mixture to the scraper conveyor. The scraper conveyor includes a scraper inlet and a scraper outlet. The scraper inlet is connected to the second outlet, and the scraper conveyor is used to transfer the second mixture from the scraper inlet to the scraper outlet. The crusher is connected to the scraper outlet for crushing the second mixture.

[0007] In some embodiments, the pretreatment apparatus includes a first screening device for preliminary screening of the coal mixture, wherein the first screening device includes a first screening outlet and a second screening outlet; after the coal mixture is preliminarily screened by the first screening device, a first coal mixture and a first impurity mixture are obtained, wherein the first coal mixture is discharged from the first screening outlet and the first impurity mixture is discharged from the second screening outlet.

[0008] In some embodiments, the pretreatment apparatus further includes a second screening device, the inlet of which is connected to a second screening outlet, the second screening device being used to screen the first impurity mixture to obtain a second coal mixture and a second impurity mixture.

[0009] In some embodiments, the second screening device includes a jig device.

[0010] In some embodiments, the pretreatment apparatus further includes a crusher connected to the second screening device for crushing the second coal mixture and the second impurity mixture.

[0011] In some embodiments, the pretreatment apparatus further includes a lifting device and a dewatering device, wherein the lifting device is connected to the output port of the crusher device and the input port of the dewatering device, for conveying the crushed second coal mixture and the second impurity mixture to the dewatering device, and the dewatering device is used to dewater the crushed second coal mixture and the second impurity mixture.

[0012] In some embodiments, the first conveying device includes a gangue transfer conveyor belt.

[0013] The screening system for coal mixtures described above, through the pretreatment device and vibrating screening device, can reduce the content of impurities such as gangue in coal, thereby increasing the content of effective components in the coal. Furthermore, the inclusion of a crusher device can crush larger coal particles containing gangue, thereby further increasing the content of effective components in the coal. Attached Figure Description

[0014] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, and the same or corresponding reference numerals denote the same or corresponding parts, wherein:

[0015] Figure 1 An exemplary block diagram of a screening system for coal mixtures according to some embodiments of this application is shown;

[0016] Figure 2 Exemplary block diagrams of screening systems for coal mixtures according to other embodiments of this application are shown. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] It should be understood that the terms "comprising" and "including" used in the specification and claims of this application indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0019] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this specification and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0020] As used in this specification and claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0021] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0022] Exemplary application scenarios.

[0023] Figure 1 Exemplary block diagrams of screening systems for coal mixtures according to some embodiments of this application are shown. Figure 2 Exemplary block diagrams of screening systems for coal mixtures, representing other embodiments of this application, are shown. Figure 1 and Figure 2As shown, the screening system includes a collection device, comprising: a pretreatment device, a first conveying device, a vibrating screening device, a scraper conveyor, and a crusher. The pretreatment device is used to pretreat the coal mixture. The first conveying device includes a conveying inlet and a conveying outlet, wherein the conveying inlet is connected to the outlet of the pretreatment device for conveying the pretreated coal mixture. The vibrating screening device is used to screen the pretreated coal mixture to obtain a first mixture and a second mixture. The vibrating screening device includes a screening inlet, a first conveying device, a vibrating screening device, a scraper conveyor, and a crusher. The system includes a first discharge port and a second discharge port, with the screening inlet connected to the conveying discharge port. The first discharge port is connected to the collecting device for transferring a first mixture to the collecting device. The second discharge port is connected to the scraper conveyor for transferring a second mixture to the scraper conveyor. The scraper conveyor includes a scraper inlet and a scraper outlet, with the scraper inlet connected to the second discharge port. The scraper conveyor is used to convey the second mixture from the scraper inlet to the scraper outlet. A crusher is connected to the scraper outlet for crushing the second mixture. In some embodiments, the first conveying device includes a gangue transfer conveyor belt.

[0024] In some embodiments, the pretreatment device can pretreat the coal mixture. It is understood that the coal mixture may include a coal matrix (e.g., organic matter) and impurities, such as gangue, sulfides, and carbonates. After pretreatment, the coal mixture can be pre-screened to obtain a pre-screened coal mixture, which is the pre-treated coal mixture. It is understood that even after pretreatment, the coal mixture still contains a significant amount of gangue and large coal lumps, which may also contain gangue.

[0025] In some embodiments, the first conveying device may include a gangue transfer belt conveyor, whose conveying inlet may be connected to the outlet of the pretreatment device and whose conveying outlet may be connected to the screening inlet of the vibrating screening device, which can convey the pretreated coal mixture to the vibrating screening device.

[0026] In some embodiments, the screening inlet of the vibrating screening device can be connected to the conveying outlet of the first conveying device, and can accept the pre-treated coal mixture.

[0027] In some embodiments, the vibrating screening device may consist of a screen body (e.g., a frame that carries materials), a vibration source (e.g., a vibrating motor, an eccentric shaft, etc., which can provide vibration power), a screen mesh (e.g., a mesh structure with different aperture sizes, which can determine the screening particle size), a support device, etc.

[0028] When the vibrating screening device is in operation, the vibration source drives the screen body to perform periodic reciprocating vibrations (such as up-and-down, back-and-forth, or rotational vibrations), causing the coal mixture falling on the screen surface to jump and slide. At this time, coal mixture particles smaller than the screen mesh size pass through the mesh and become undersize material; coal mixture particles larger than the mesh size remain on the screen surface and move towards the discharge end with the vibration, becoming oversize material. In this way, coal mixtures of different particle sizes can be separated.

[0029] After the vibrating screening device screens the pretreated coal mixture, it can obtain a first mixture and a second mixture. The first mixture can be the aforementioned undersize material, and the second mixture can be the aforementioned oversize material. Further, the first mixture can be discharged into a collecting device through a first outlet, and the second mixture can be discharged into a scraper conveyor device through a second outlet.

[0030] In some embodiments, the collection device may be a raw coal bunker, which may be used to store sorted raw coal or clean coal.

[0031] In some embodiments, the scraper conveyor device may consist of a trough, a scraper chain (which may be composed of scrapers and chain connected together and is key to traction and conveying of materials), a drive device (such as a motor, reducer, etc., which provides power), and a tensioning device (which can maintain chain tension).

[0032] In some embodiments, the second mixture can be conveyed from the scraper inlet into the base trough of the scraper conveyor. When the scraper conveyor is in operation, the drive unit drives the scraper chain to circulate within the trough. When the second mixture falls onto the trough, the scraper chain, through the thrust of the scrapers, propels the second mixture forward along the trough, eventually reaching the scraper outlet for discharge. Compared to a conveyor belt, this method directly pushes the second mixture within the trough using scrapers, rather than relying on the friction of a conveyor belt.

[0033] In some embodiments, the aforementioned second mixture can be conveyed to a crusher through a scraper discharge port. After crushing by the crusher, the crushed second mixture is conveyed to a gangue bin, which can be used to store gangue. Preferably, the gangue bin can include a modified gangue bin, which can realize the green disposal and resource utilization of gangue. In some embodiments, the material processed by the modified gangue bin can be conveyed to a coal feeder. It is understood that the modified gangue bin can further improve the utilization rate of coal.

[0034] The solution described in this application, through the installation of a pretreatment device and a vibrating screening device, can reduce the content of impurities such as gangue in the first mixture, thereby increasing the content of effective components in the coal. Furthermore, the installation of a crusher device can crush larger coal particles containing gangue, thereby increasing the content of effective components in the coal.

[0035] In some embodiments, the pretreatment apparatus includes a first screening device for preliminary screening of the coal mixture, wherein the first screening device includes a first screening outlet and a second screening outlet; after the coal mixture is preliminarily screened by the first screening device, a first coal mixture and a first impurity mixture are obtained, wherein the first coal mixture is discharged from the first screening outlet and the first impurity mixture is discharged from the second screening outlet.

[0036] Specifically, the pretreatment device may include a first screening device, which can be used to perform preliminary screening of the coal mixture.

[0037] In some embodiments, the first screening device may include a grading vibration device, which can grade raw coal or gangue into different products according to particle size through multiple layers of screens and high-frequency vibration, providing a particle size basis for subsequent sorting or processing. In some embodiments, the grading vibration device may include multiple layers of screen frames, such as 2-4 layers of screen frames stacked on top of each other, each layer of screen frames may be inclined. Further, each layer of screen frame may be equipped with screens of different aperture sizes, and the screen apertures of the screens may gradually decrease from top to bottom.

[0038] Furthermore, the grading vibration device can also be equipped with a vibration motor, which generates high-frequency and low-amplitude vibrations, causing the coal mixture to jump forward on the screen. Larger particles that cannot pass through the screen are discharged towards the outlet. It is understood that the upper screen can intercept the largest particles (e.g., larger than 50mm in diameter) of the coal mixture, the middle screen can intercept medium-sized particles (e.g., 25mm-50mm in diameter), and the lower screen can intercept finer particles (e.g., 13mm-25mm in diameter). Particles that pass through the lower screen are the undersize particles, which are the finest (e.g., less than 13mm in diameter).

[0039] It is understood that the first coal mixture may include the aforementioned undersize material, and the aforementioned first coal mixture may be conveyed to a collecting device. The first impurity mixture may include the coal mixture intercepted by the upper screen, the coal mixture intercepted by the middle screen, and the coal mixture intercepted by the lower screen.

[0040] In some embodiments, the first screening device includes a first screening outlet and a second screening outlet, wherein the undersize material (i.e., the first coal mixture) can be discharged from the first screening outlet, and the first impurity mixture can be discharged through the second screening outlet.

[0041] In some embodiments, the pretreatment apparatus further includes a second screening device, the inlet of which is connected to a second screening outlet, the second screening device being used to screen the first impurity mixture to obtain a second coal mixture and a second impurity mixture. In some embodiments, the second screening device includes a jig.

[0042] In some embodiments, the second screening device may include a jig device, wherein, due to the different densities of coal and gangue, their settling velocities in water are different, the jig device can use vertically alternating water flow (e.g., pulsating water flow) to cause the coal bulk and gangue in the coal mixture to separate on the screen surface: the less dense coal (e.g., 1.3-1.4 g / cm³) will float, and the more dense gangue (e.g., 2.5-2.8 g / cm³) will sink, thereby achieving separation.

[0043] Specifically, the jig apparatus may include a moving screen mechanism, a sorting tank, a discharge device, a drive system, and a control system. The moving screen mechanism may include a screen plate, which can be used to carry a first impurity mixture and create a sorting space. The screen plate may be driven by a hydraulic cylinder or a crank-connecting rod to perform up-and-down reciprocating motion. In some embodiments, the sorting tank may hold circulating water, and its water level is adjustable. The discharge device may include a clean coal end and a gangue end. The clean coal end can discharge a second coal mixture, and the gangue end can discharge a second impurity mixture. The aforementioned second coal mixture may include clean coal, which can be conveyed to a collection device. In some embodiments, the second impurity mixture may include gangue.

[0044] When the jig is in operation, the screen plate rises rapidly, and the first impurity mixture is floated up by the water flow. Under the action of gravity, the low-density second coal mixture (e.g., clean coal) floats to the top of the material layer, while the high-density second impurity mixture (e.g., gangue) sinks to the bottom of the screen plate. Further, the screen plate slowly descends, and the water flow penetrates downwards: fine particles of the second coal mixture pass through the screen holes with the water flow, becoming passable material, while large pieces of clean coal remain suspended in the middle layer, and the second impurity mixture adheres closely to the screen plate. During the screen plate movement, a horizontal water flow is injected laterally into the trough: this washes away the light particles mixed in the second impurity mixture, preventing clean coal from being entrained by the second impurity mixture.

[0045] In some embodiments, after the second screening device (e.g., a jig) screens the first impurity mixture, a second coal mixture and a second impurity mixture can be obtained.

[0046] By installing a jig, larger coal blocks and gangue can be separated, thus improving the sorting efficiency.

[0047] In some embodiments, the pretreatment apparatus further includes a crusher connected to the second screening device for crushing the second coal mixture and the second impurity mixture.

[0048] In some embodiments, the pretreatment apparatus may further include a crusher device, which may be connected to a second screening device and may be used to crush the second coal mixture and the second impurity mixture.

[0049] Specifically, the crushing device can include a double-toothed roll crusher or a hammer crusher, etc. After passing through the crushing device, the second coal mixture and the second impurity mixture can be crushed into particles of the same or similar size. In addition, coal containing fine gangue is often wrapped with gangue or cemented with gangue. Crushing separates the coal from the gangue, which facilitates subsequent sorting and recovery of residual coal.

[0050] By setting up a crusher device, the second coal mixture and the second impurity mixture can be crushed to a uniform particle size, thereby facilitating the accuracy of subsequent sorting.

[0051] In some embodiments, the pretreatment apparatus further includes a lifting device and a dewatering device, wherein the lifting device is connected to the output port of the crusher device and the input port of the dewatering device, for conveying the crushed second coal mixture and the second impurity mixture to the dewatering device, and the dewatering device is used to dewater the crushed second coal mixture and the second impurity mixture.

[0052] It is understandable that since the dewatering device, raw coal bunker, clean coal bunker, and gangue bunker are all located at higher positions, while the aforementioned first screening device, second screening device, and crusher device are all located at lower positions, when transporting the crusher device to the dewatering device, the lifting device also needs to lift it to a higher height when transporting the crushed second coal mixture and second impurity mixture.

[0053] In some embodiments, the lifting device may include a bucket elevator that can vertically lift the crushed second coal mixture and the second impurity mixture and convey them to a dewatering device.

[0054] In some embodiments, the dewatering device may include a dewatering screen, which can dewater the aforementioned crushed second coal mixture and second impurity mixture. It is understood that the aforementioned second coal mixture and second impurity mixture absorb a large amount of water after passing through the jig, and therefore this water needs to be removed.

[0055] By installing a dewatering device, the weight of the second coal mixture and the second impurity mixture can be reduced, which facilitates subsequent transportation and reduces transportation costs.

[0056] In some embodiments, after dehydrating the second coal mixture and the second impurity mixture, a pretreated coal mixture can be obtained.

[0057] In summary, by incorporating pretreatment and vibrating screening devices, the content of impurities such as gangue in coal can be reduced, thereby increasing the content of effective components in the coal. Furthermore, by installing a crusher, larger coal pieces containing gangue can be crushed, which can further increase the content of effective components in the coal.

[0058] While numerous embodiments of this application have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will arise for those skilled in the art without departing from the spirit and intent of this application. It should be understood that various alternatives to the embodiments of this application described herein may be employed in the practice of this application. The appended claims are intended to define the scope of protection of this application and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A screening system for a coal mixture, the screening system comprising a collection device, characterised in that, The screening system includes: a pretreatment device, a first conveying device, a vibrating screening device, a scraper conveyor device, and a crusher device; wherein... The pretreatment device is used to pretreat the coal mixture; The first conveying device includes a conveying inlet and a conveying outlet, wherein the conveying inlet is connected to the outlet of the pretreatment device and is used to convey the pretreated coal mixture; The vibrating screening device is used to screen the pretreated coal mixture to obtain a first mixture and a second mixture. The vibrating screening device includes a screening inlet, a first outlet, and a second outlet. The screening inlet is connected to the conveying outlet; The first discharge port is connected to the collecting device and is used to transfer the first mixture to the collecting device; The second discharge port is connected to the scraper conveyor device and is used to transfer the second mixture into the scraper conveyor device; The scraper conveyor includes a scraper inlet and a scraper outlet. The scraper inlet is connected to the second outlet. The scraper conveyor is used to convey the second mixture from the scraper inlet to the scraper outlet. The crusher device is connected to the scraper discharge port and is used to crush the second mixture.

2. The screening system of claim 1, wherein, The pretreatment device includes a first screening device for preliminary screening of the coal mixture, wherein the first screening device includes a first screening outlet and a second screening outlet; after the coal mixture is preliminarily screened by the first screening device, a first coal mixture and a first impurity mixture are obtained, wherein the first coal mixture is discharged from the first screening outlet and the first impurity mixture is discharged from the second screening outlet.

3. The screening system of claim 2, wherein, The pretreatment device further includes a second screening device, the inlet of which is connected to the outlet of the second screening device. The second screening device is used to screen the first impurity mixture to obtain a second coal mixture and a second impurity mixture.

4. The screening system of claim 3, wherein, The second screening device includes a jig device.

5. The screening system of claim 3, wherein, The pretreatment device further includes a crusher device connected to the second screening device, used to crush the second coal mixture and the second impurity mixture.

6. The screening system of claim 4, wherein, The pretreatment device further includes a lifting device and a dewatering device, wherein the lifting device is connected to the output port of the crusher device and the input port of the dewatering device, for conveying the crushed second coal mixture and the second impurity mixture to the dewatering device, and the dewatering device is used to dewater the crushed second coal mixture and the second impurity mixture.

7. The screening system according to any one of claims 1 to 6, characterized in that, The first conveying device includes a gangue transfer conveyor belt.

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