A diversified coal blending device and method for producing washed fine coal and screened fine coal

Abstract

The present application relates to the technical field of coal blending, in particular to a diversified coal blending equipment and method for producing washed fine coal and screened fine coal. In order to effectively solve the problem that the yield and quality of washed fine coal and screened fine coal are greatly affected by the moisture change of fine raw coal, the diversified coal blending equipment for producing washed fine coal and screened fine coal is provided. The coal blending scraper is provided with a first discharge port and a second discharge port. The first discharge port is communicated with a general chute of a Y-shaped chute. One of the branch chutes of the Y-shaped chute is connected with a screened fine coal belt, and the other branch chute is connected with a desliming screen. The oversize material outlet of the desliming screen is connected with a dense medium cyclone. The undersize material outlet of the desliming screen is connected with the screened fine coal belt after dehydration. The second discharge port is connected with the feed inlet of a desliming screen. The oversize material outlet of the desliming screen is connected with the feed inlet of the desliming screen. The undersize material outlet of the desliming screen is connected with the screened fine coal belt. The equipment ensures the yield and quality balance of washed fine coal and screened fine coal to a certain extent.

Description

Technical Field

[0001] This invention relates to the field of coal blending technology, specifically to a diversified coal blending equipment and method for producing washed fine coal and screened fine coal. Background Technology

[0002] Based on market and user demand, thermal coal preparation plants typically need to produce two types of fine coal products simultaneously: washed fine coal and screened fine coal. The traditional process involves the raw coal being de-pulverized by a de-pulverizing screen. The undersize from the de-pulverizing screen is sold as screened fine coal, while the oversize from the de-pulverizing screen is further processed by a desliming screen. The undersize from the desliming screen is then dewatered by a dewatering centrifuge and sold as screened fine coal. The oversize from the desliming screen is then separated into washed fine coal by a heavy medium cyclone separator. However, in actual production, the yield and quality of washed fine coal and screened fine coal produced by this single de-pulverizing and desliming series-connected coal blending process are significantly affected by changes in the moisture content of the raw coal. Specifically, when the moisture content of the raw coal... When the moisture content is too high (around 10% or more), the desliming screen becomes severely clogged, requiring frequent maintenance and cleaning. Simultaneously, its desliming effect is poor, resulting in more material on the screen and a larger amount of coal entering the desliming screen and the heavy medium cyclone separator for both products. This leads to poor desliming and heavy medium separation, easily causing excessive ash content or coal carried in the gangue in the produced washed coal. Conversely, when the moisture content of the raw coal is too low (around 8% or less), the desliming effect is too good, resulting in less material on the screen and a smaller amount of coal entering the desliming screen and the heavy medium cyclone separator for both products. This leads to insufficient raw material entering the heavy medium cyclone separator, resulting in insufficient washed coal production to meet production needs, and an imbalance in the yield and quality of screened and washed coal. Summary of the Invention

[0003] In order to solve the problem that the yield and quality of washed and screened coal produced by traditional coal blending processes are greatly affected by the changes in the moisture content of the raw coal, this invention provides a diversified coal blending equipment and method for producing washed and screened coal.

[0004] This invention is achieved using the following technical solution: A diversified coal blending equipment for producing washed and screened fine coal includes a raw coal conveyor belt, a coal blending scraper conveyor, a Y-shaped chute consisting of a main chute and two branch chutes, a desliming screen, a dewatering centrifuge, a two-product heavy medium cyclone separator, and a screened fine coal conveyor belt. The tail end of the raw coal conveyor belt is connected to the feed inlet of the coal blending scraper conveyor. The coal blending scraper conveyor has two discharge ports, designated as a first discharge port and a second discharge port. The first discharge port is connected to the main chute port of the Y-shaped chute via a first gate. The two branch chutes of the Y-shaped chute are respectively equipped with a third gate and a second gate. The fourth gate, with the port of the chute of the third gate connected to the screen conveyor belt, and the port of the chute of the fourth gate connected to the feed inlet of the desliming screen, the discharge port of the desliming screen connected to the feed inlet of the two-product heavy medium cyclone, and the discharge port of the desliming screen connected to the screen conveyor belt after passing through the dewatering centrifuge. The second gate is provided at the second discharge port, and the outlet of the second gate is connected to the feed inlet of the powdering screen. The discharge port of the powdering screen is connected to the feed inlet of the desliming screen, and the discharge port of the powdering screen is connected to the feed inlet of the desliming screen. The discharge port of the powdering screen is connected to the screen conveyor belt.

[0005] The working process includes the following three situations: 1) When the moisture content of the raw coal on the conveyor belt is too high, the first gate is fully opened, the fourth gate is fully opened, the second gate is closed, and the opening degree of the third gate is controlled according to the amount of coal on the conveyor belt and the target screening value of the coal. After the raw coal passes through the first gate, part of the raw coal passes through the main chute of the Y-shaped chute and the branch chute equipped with the third gate and then directly enters the conveyor belt. The other part of the raw coal passes through the main chute of the Y-shaped chute. 1) After passing through a chute equipped with a third gate, the material enters the desliming screen. After desliming, the undersize material is dewatered by a dewatering centrifuge and then enters the end-of-line conveyor belt. The oversize material from the desliming screen is separated by a two-product heavy medium cyclone separator to produce washed coal product. 2) When the moisture content of the raw coal on the end-of-line conveyor belt is appropriate, the first, third, and fourth gates are closed, and the second gate is opened. The raw coal enters the pulverizing screen through the second gate. After pulverizing, the undersize material enters the end-of-line conveyor belt, and the oversize material from the pulverizing screen enters the end-of-line conveyor belt. In the desliming screen, the undersize material after desliming is dewatered by a dewatering centrifuge and then enters the end-of-line conveyor belt. The oversize material of the desliming screen is separated by a two-product heavy medium cyclone separator to generate washed coal product; 3) When the moisture content of the raw coal on the end-of-line conveyor belt is low, the fourth and second gates are opened, and the third gate is closed. The opening degree of the first gate is controlled according to the amount of coal on the end-of-line conveyor belt and the target screening value of the coal. A portion of the raw coal enters the desliming screen after passing through the first and fourth gates. After the mud screen deslims, the undersize material is dewatered by a dewatering centrifuge and then enters the end belt of the screen. The oversize material of the desliming screen is separated by a two-product heavy medium cyclone separator to produce washed fine coal product. Another part of the raw coal passes through the second gate and enters the pulverizing screen. After pulverizing by the pulverizing screen, the undersize material enters the end belt of the screen. The oversize material of the pulverizing screen enters the desliming screen. After desliming by the desliming screen, the undersize material is dewatered by a dewatering centrifuge and then enters the end belt of the screen. The oversize material of the desliming screen is separated by a two-product heavy medium cyclone separator to produce washed fine coal product.

[0006] The beneficial effects of this invention are as follows: 1) This equipment can effectively avoid the situation where the amount of coal entering the heavy medium cyclone of the two products is too much or too little, and to a certain extent ensures the yield and quality balance of washed coal and screened coal; 2) This equipment can realize continuous and stable coal blending operation, which is more flexible than the traditional coal blending process and is more adaptable to changes in the moisture content of raw coal and market changes; 3) It effectively reduces the problem of severe screen clogging of the de-pulverizing screen and effectively reduces the subsequent maintenance and cleaning work of the de-pulverizing screen. Attached Figure Description

[0007] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0010] In the diagram: 1—Powdered raw coal conveyor belt, 2—Coal blending scraper conveyor, 3—Y-type chute, 4—De-pulverizing screen, 5—Desliming screen, 6—Two-product heavy medium cyclone separator, 7—Screen end conveyor belt, 8—Belt scale, 9—First gate, 10—Second gate, 11—Third gate, 12—Fourth gate, 13—Centrifugal dewatering machine, 14—Moisture analyzer. Detailed Implementation

[0011] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0012] In this description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0013] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0014] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0015] like Figure 1As shown, a diversified coal blending equipment for producing washed and screened coal fines includes a raw coal conveyor belt 1, a coal blending scraper conveyor 2, a Y-shaped chute 3 consisting of a main chute and two branch chutes, a de-pulverizing screen 4, a desliming screen 5, a dewatering centrifuge 13, a two-product heavy medium cyclone 6, and a screened coal conveyor belt 7. The tail end of the raw coal conveyor belt 1 is connected to the feed inlet of the coal blending scraper conveyor 2. The coal blending scraper conveyor 2 has two discharge ports, designated as a first discharge port and a second discharge port. The first discharge port is connected to the main chute port of the Y-shaped chute 3 via a first gate 9. The two branch chutes of the Y-shaped chute 3 are respectively equipped with a third gate 11 and a fourth gate 12. A gate 12 is provided, with the port of the chute of the third gate 11 connected to the screen conveyor belt 7. The port of the chute of the fourth gate 12 is connected to the feed inlet of the desliming screen 5. The discharge port of the oversize material of the desliming screen 5 is connected to the feed inlet of the two-product heavy medium cyclone 6. The discharge port of the undersize material of the desliming screen 5 is connected to the screen conveyor belt 7 after passing through the dewatering centrifuge 13. A second gate 10 is provided at the second discharge port. The outlet of the second gate 10 is connected to the feed inlet of the powdering screen 4. The discharge port of the oversize material of the powdering screen 4 is connected to the feed inlet of the desliming screen 5. The discharge port of the undersize material of the powdering screen 4 is connected to the screen conveyor belt 7.

[0016] The working process includes the following three situations: 1) When the moisture content of the raw coal on the raw coal conveyor belt 1 is too high, the first gate 9 is fully opened, the fourth gate 12 is fully opened, the second gate 10 is closed, and the opening degree of the third gate 11 is controlled according to the amount of coal on the screening conveyor belt 7 and the target screening value of the screening coal. After the raw coal passes through the first gate 9, part of the raw coal passes through the main chute of the Y-shaped chute 3, which has a branch chute equipped with the third gate 11, and then directly enters the screening conveyor belt 7. Another part of the raw coal passes through the main chute of the Y-shaped chute 3, which has a branch chute equipped with the third gate 11, and then directly enters the screening conveyor belt 7. After passing through the chute of the third gate 11, the material enters the desliming screen 5. After desliming by the desliming screen 5, the undersize material is dewatered by the dewatering centrifuge 13 and then enters the screen end belt 7. The oversize material of the desliming screen 5 is separated by the two-product heavy medium hydrocyclone 6 to generate washed coal product; 2) When the moisture content of the raw coal on the raw coal conveyor 1 is moderate, the first gate 9, the third gate 11, and the fourth gate 12 are closed, and the second gate 10 is opened. The raw coal enters the pulverizing screen 4 from the second gate 10. After pulverizing by the pulverizing screen 4, the undersize material enters the screen end belt 7, and the oversize material of the pulverizing screen 4 enters the desliming screen 7. In the mud screen 5, after desliming by the desliming screen 5, the undersize material is dewatered by the dewatering centrifuge 13 and then enters the screen end belt 7. The oversize material of the desliming screen 5 is separated by the two-product heavy medium cyclone 6 to generate washed fine coal product; 3) When the moisture content of the fine raw coal on the fine raw coal belt 1 is low, the fourth gate 12 and the second gate 10 are opened, and the third gate 11 is closed. The opening degree of the first gate 9 is controlled according to the amount of coal on the screen end belt 7 and the target screening value of the fine coal. A portion of the fine raw coal enters the desliming screen 5 after passing through the first gate 9 and the fourth gate 12, and after desliming... After the mud screen 5 deslims, the undersize material is dewatered by the dewatering centrifuge 13 and then enters the end screen belt 7. The oversize material of the desliming screen 5 is separated by the two-product heavy medium cyclone 6 to generate washed fine coal product. Another part of the raw coal passes through the second gate 10 and enters the pulverizing screen 4. After pulverizing by the pulverizing screen 4, the undersize material enters the end screen belt 7. The oversize material of the pulverizing screen 4 enters the desliming screen 5. After desliming by the desliming screen 5, the undersize material is dewatered by the dewatering centrifuge 13 and then enters the end screen belt 7. The oversize material of the desliming screen 5 is separated by the two-product heavy medium cyclone 6 to generate washed fine coal product.

[0017] In practice, the screening belt 7 is equipped with a belt scale 8 to facilitate real-time monitoring of the screening coal output.

[0018] In practice, the raw coal conveyor belt 1 is equipped with a moisture meter 14 to facilitate observation of the moisture content of the raw coal.

[0019] In practice, the first gate 9, the second gate 10, the third gate 11, and the fourth gate 12 are all electrically controlled gates, which facilitates the control of the gate opening degree.

[0020] In practice, pull-wire sensors are installed on the first gate 9, the second gate 10, the third gate 11, and the fourth gate 12 to facilitate real-time detection of the gate opening.

[0021] The equipment can also automate coal blending. In specific implementation, the equipment also includes a controller. The output terminals of the belt scale 8 and the moisture analyzer 14 are all connected to the input terminal of the controller. The controller controls the opening of the gate according to the following conditions: 1) When the moisture content of the raw coal on the raw coal belt 1 is too high, the controller controls the first gate 9 to be fully open, the fourth gate 12 to be fully open, and the second gate 10 to be closed. The opening of the third gate 11 is controlled according to the amount of coal on the screen belt 7 detected by the belt scale 8 and the set target screening value of the screen coal; 2) When the moisture content of the raw coal on the raw coal belt 1 is moderate, the first gate 9, the third gate 11, and the fourth gate 12 are closed, and the second gate 10 is open; 3) When the moisture content of the raw coal on the raw coal belt 1 is too low, the fourth gate 12 and the second gate 10 are fully open, the third gate 11 is closed, and the opening of the first gate 9 is controlled according to the amount of coal on the screen belt 7 detected by the belt scale 8 and the set target screening value of the screen coal.

[0022] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A diversified coal blending method for producing washed fine coal and screened fine coal, characterized in that, This method is achieved through the following coal blending equipment, which includes a raw coal conveyor belt (1), a coal blending scraper (2), a Y-shaped chute (3) consisting of a main chute and two sub-chutes, a de-pulping screen (4), a desliming screen (5), a dewatering centrifuge (13), a two-product heavy medium cyclone separator (6), and a screen end belt (7). The tail end of the raw coal conveyor belt (1) is connected to the feed inlet of the coal blending scraper (2). The coal blending scraper (2) has two discharge ports, namely the first discharge port and the second discharge port. The first discharge port is connected to the main chute of the Y-shaped chute (3). The port is connected through the first gate (9). The two sub-sluices of the Y-shaped chute (3) are respectively equipped with a third gate (11) and a fourth gate (12). The port of the sub-sluice with the third gate (11) is connected to the screen belt (7), and the port of the sub-sluice with the fourth gate (12) is connected to the feed port of the desliming screen (5). The discharge port of the oversize material of the desliming screen (5) is connected to the feed port of the two-product heavy medium cyclone (6). The discharge port of the undersize material of the desliming screen (5) is connected to the screen belt (7) after passing through the dewatering centrifuge (13). A second gate (10) is provided at the second discharge port. The outlet of the second gate (10) is connected to the inlet of the de-pulverizing screen (4). The outlet of the oversize material of the de-pulverizing screen (4) is connected to the inlet of the desliming screen (5). The outlet of the undersize material of the de-pulverizing screen (4) is connected to the screen end belt (7). This method includes the following three situations: 1) When the moisture content of the raw coal on the raw coal belt (1) is too high, the first gate (9) is fully opened, the fourth gate (12) is fully opened, the second gate (10) is closed, and the opening degree of the third gate (11) is determined according to the screen end. 1) The amount of coal on the final conveyor belt (7) and the target screening value of the final coal are controlled; 2) When the moisture content of the final raw coal on the final raw coal conveyor belt (1) is moderate, the first gate (9), the third gate (11), and the fourth gate (12) are closed, and the second gate (10) is opened; 3) When the moisture content of the final raw coal on the final raw coal conveyor belt (1) is low, the fourth gate (12), the second gate (10) are opened, and the third gate (11) is closed. The opening degree of the first gate (9) is controlled according to the amount of coal on the final conveyor belt (7) and the target screening value of the final coal.

2. The diversified coal blending method for producing washed fine coal and screened fine coal according to claim 1, characterized in that, The sieve belt (7) is equipped with a belt scale (8).

3. The diversified coal blending method for producing washed fine coal and screened fine coal according to claim 2, characterized in that, The raw coal conveyor belt (1) is equipped with a moisture analyzer (14).

4. The diversified coal blending method for producing washed fine coal and screened fine coal according to claim 3, characterized in that, The first gate (9), the second gate (10), the third gate (11), and the fourth gate (12) are all electrically controlled gates.

5. A diversified coal blending method for producing washed fine coal and screened fine coal according to claim 4, characterized in that, The device also includes a controller. The output of the belt scale (8) and the output of the moisture analyzer (14) are both connected to the input of the controller. The controller controls the opening of the gate according to the following conditions: 1) When the moisture content of the raw coal on the raw coal belt (1) is too high, the controller controls the first gate (9) to be fully open, the fourth gate (12) to be fully open, and the second gate (10) to be closed. The opening of the third gate (11) is based on the amount of coal on the screened coal belt (7) detected by the belt scale (8) and the set target screening of the screened coal. 1) The value is controlled; 2) When the moisture content of the raw coal on the raw coal conveyor belt (1) is moderate, the first gate (9), the third gate (11), and the fourth gate (12) are closed, and the second gate (10) is opened; 3) When the moisture content of the raw coal on the raw coal conveyor belt (1) is low, the fourth gate (12) and the second gate (10) are fully opened, and the third gate (11) is closed. The opening degree of the first gate (9) is controlled according to the amount of coal on the screened coal conveyor belt (7) detected by the belt scale (8) and the set target screening value of the screened coal.

6. A diversified coal blending method for producing washed fine coal and screened fine coal according to claim 1, 2, 3, 4, or 5, characterized in that, Pull-wire sensors are installed on the first gate (9), the second gate (10), the third gate (11), and the fourth gate (12).

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