Air curtain-negative pressure coupling circulating dust removal system for open pit coal mine crushing station

Abstract

The invention relates to an air curtain-negative pressure coupling circulating dust removal system for an open pit coal mine crushing station, and belongs to the technical field of dust prevention and control. Comprising a dust isolation device, a dust falling device and an air curtain dust control device which are arranged on a mine truck coal unloading channel. The dust isolation device comprises a dust blocking curtain arranged at the top of the coal unloading channel and dust blocking plates arranged on the two sides of the dust blocking curtain; the dust falling device comprises a dust remover arranged outside the coal unloading channel, a dust suction hood arranged in the channel and a negative pressure dust suction pipeline; the air curtain dust control device comprises an air supercharger arranged outside the coal unloading channel, air curtain generators arranged on the two sides of the channel and an air compression pipeline. The air outlet of the dust remover is provided with an air supercharger communicated to the compressed air pipeline, and air flow treated by the dust remover is conveyed to the air curtain generator through the compressed air pipeline under the action of the air supercharger to form circulating air flow. The dust removal system solves the problem of serious dust pollution in the production process of the primary crushing station, and dust treatment is carried out by utilizing airflow circulation to prevent dust diffusion from influencing the surrounding environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of dust prevention and control, and relates to an air curtain-negative pressure coupled circulation dust removal system for an open-pit coal mine crushing station. Background Art

[0002] As an important way of coal mining, open-pit coal mines play a key role in the coal production process. At the operation site of an open-pit coal mine, large dump trucks with a load capacity of 120 - 300 tons (hereinafter referred to as mining trucks) are mainly relied on to undertake the coal transfer task. These mining trucks, like steel giants, shuttle between the mining pit and the primary crushing station, continuously transporting large chunks of coal from the bottom of the mining pit to the primary crushing station. At the primary crushing station, after the coal is finely crushed by the bottom crusher of the station, it is then transported to the screening and crushing workshop (washing and dressing workshop) through an efficient belt transportation system for further deep processing. In this series of processes, the primary crushing station has achieved a major transition from intermittent production to continuous production, greatly improving the efficiency of coal production.

[0003] However, during the process of coal transfer and crushing, the problem of dust pollution has become a major problem faced by open-pit coal mines. When 120 - 300 tons of coal are dumped from a mining truck into a 10.5-meter-deep and 350-cubic-meter coal unloading pit within just 30 seconds, a series of chain reactions will be triggered. A large number of coal blocks and coal dust strongly squeeze the air at the bottom of the pit, forming an upward strong impact high-speed air flow. This air flow, like an invisible giant hand, raises the coal dust deposited around the pit and the coal dust in the dumped coal body, instantly forming an instantaneous high-intensity and high-concentration dust-containing air flow.

[0004] These dust-containing air flows do not stay near the coal unloading pit. They will deposit again around the coal unloading pit, or diffuse and deposit again in the surrounding areas with the help of the natural wind. The diffusion range of the dust is extensive, not only causing serious impacts on the surrounding ecological environment, damaging the local vegetation and soil structure, but also seriously polluting the air quality and threatening the physical health of the surrounding residents.

[0005] To address this dust pollution problem, the mining side has taken a series of measures. As Figure 1 shown, a top-covered protective shed is built above the pit. This measure has a certain dust isolation effect to a certain extent. The protective shed can effectively block the dust in the north and east directions, reducing the dust emission in these directions by about 50%. However, the protective shed is not omnipotent. It still cannot effectively block the large amount of dust diffusing from the air flow channels between the mining trucks and the protective shed on the south and west coal unloading channels. This is mainly because the air flow channels in the south and west directions are relatively complex, and the air flow movement is difficult to fully control, resulting in a large amount of dust still being able to escape.

[0006] To further control dust, the mine operator once installed a micro-mist system on the top inside the protective shed. The micro-mist system attempts to adsorb and settle dust by spraying fine water mist particles. However, the actual effect is not obvious. After actual testing, the dust reduction efficiency is only 35.8%. Moreover, the spray system cannot be used normally in autumn and winter. In autumn and winter, the temperature is relatively low, and the water mist is prone to freezing, resulting in the abnormal operation of the spray system and further restricting its dust reduction effect.

[0007] The dust pollution problem in open-pit coal mines needs to be solved urgently. Although the existing control measures have alleviated the problem to a certain extent, there are still many deficiencies. In the future, it is necessary to further explore more effective dust control technologies and methods to reduce dust pollution, protect the surrounding ecological environment and the health of residents, and achieve the green and sustainable development of open-pit coal mines. Summary of the Invention

[0008] In view of this, the purpose of the present invention is to provide an air curtain-negative pressure coupled circulation dust removal system for open-pit coal mine crushing stations, to solve the serious dust pollution in the production process of primary crushing stations, use air flow circulation to handle dust, and prevent dust from spreading and affecting the surrounding environment.

[0009] To achieve the above purpose, the present invention provides the following technical solutions:

[0010] An air curtain-negative pressure coupled circulation dust removal system for open-pit coal mine crushing stations, comprising a dust isolation device, a dust reduction device and an air curtain dust control device arranged on the coal unloading channel of the mining truck;

[0011] The dust isolation device includes 3 dust-proof curtains arranged on the top of the coal unloading channel and dust-proof plates on both sides thereof;

[0012] The dust reduction device includes a dust collector arranged outside the coal unloading channel and a dust suction hood arranged inside the coal unloading channel. The dust collector is connected to the dust suction hood through a negative pressure dust extraction pipeline;

[0013] The air curtain dust control device includes an air booster arranged outside the coal unloading channel and air curtain generators arranged on both sides of the coal unloading channel; the air curtain generators are connected to the air curtain generators through compressed air pipelines;

[0014] An air booster for connecting the air outlet of the dust collector to the compressed air pipeline is provided. The air flow processed by the dust collector is transported to the air curtain generator through the compressed air pipeline under the action of the air booster to form a circulating air flow.

[0015] Optionally, the 3 dust-proof curtains are arranged on the top of the coal unloading channel from inside to outside, and the lengths of the 3 dust-proof curtains decrease in sequence from inside to outside.

[0016] Optionally, the included angle between the bottom connection line of the three dust-proof curtains and the horizontal direction is the same as the inclination angle of the car body when unloading coal.

[0017] Optionally, the inclination angle is 40°-50°.

[0018] Optionally, the dust-proof curtain is cut from waste belts.

[0019] Optionally, the dust suction hood includes a first dust suction hood arranged at the top of the coal unloading passage, second dust suction hoods on both sides of the coal unloading passage, and a third dust suction hood inside the crushing plant building.

[0020] Optionally, an electric control air valve is provided on the negative pressure dust extraction pipeline.

[0021] Optionally, an electric control air valve is provided on the compressed air pipeline.

[0022] Optionally, a transfer device for collecting dust is provided at the bottom of the dust collector, and the transfer device conveys the collected dust to the production system through a screw conveyor.

[0023] Optionally, a detection device for detecting the air flow quality is further provided at the air outlet of the dust collector.

[0024] The beneficial effects of the present invention are as follows:

[0025] The present invention solves the serious dust pollution in the production process of the primary crushing station, is particularly suitable for dust control in the low temperature and strong wind weather of minus 20 degrees in the north, and at the same time addresses the supervision problem of the organized emission of dust-containing air flow. The dust removal system of the present invention collects and treats a large amount of dust generated instantaneously when a large dump truck in an open-pit coal mine unloads coal at the primary crushing station, and uses the treated clean air for the air flow control at the coal unloading port, and uses the air flow cycle to treat dust to prevent dust from spreading and affecting the surrounding environment. Fundamentally reducing the dust generated by the impact during coal unloading of mining trucks in open-pit coal mines, realizing the recycling of air, and reducing the emission pressure. Before treatment, the total dust concentration was tested by a third-party professional testing agency at the coal unloading port, and the total dust concentration was 241.95 mg / m 3 . After opening the dust removal system for dust treatment, the dust concentration at the same position was 32.68 mg / m 3 , and the dust reduction efficiency was 86.49%. After the device was built, it reduced the dust pollution of the air, alleviated the impact on the surrounding ecological environment, protected the physical and mental health of the operating personnel, and saved the cost of flushing and depositing dust in the coal mine.

[0026] Through the "isolation - reduction - control" three - level linkage design, the present invention combines closed dust isolation, negative pressure suction and air curtain circulation to achieve a closed - loop treatment of dust source suppression (isolation), efficient capture (reduction) and diffusion blocking (control). It reduces the pressure of environmental protection supervision. The air flow after being treated by the dust collector is pressurized by a fan and then returned to the air curtain, realizing the recycling of air containing dust, and at the same time alleviating the supervision pressure brought by organized emissions.

[0027] Other advantages, objectives and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0029] Figure 1 is the original steel structure workshop at the top of the primary crushing station;

[0030] Figure 2 is the schematic diagram of the dust isolation device;

[0031] Figure 3 is the schematic diagram of the dust reduction device;

[0032] Figure 4 is the schematic diagram of the air curtain dust control device.

[0033] Reference numerals:

[0034] 1 dust curtain, 2 dust baffle, 3 dust collector, 4 dust suction hood, 5 negative pressure dust extraction pipeline, 6 air booster, 7 air curtain generator, 8 compressed air pipeline, 9 electric control air valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention schematically. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0036] Among them, the attached drawings are only for illustrative purposes, showing only schematic diagrams rather than physical drawings, and should not be construed as a limitation on the present invention; in order to better illustrate the embodiments of the present invention, some components in the attached drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the attached drawings may be omitted.

[0037] In the attached drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the attached drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the attached drawings are only for illustrative purposes and should not be construed as a limitation on the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0038] Please refer to Figures 2 to 4 , which is an air curtain-negative pressure coupled circulating dust removal system for an open-pit coal mine crushing station, including a dust isolation device, a dust reduction device and an air curtain dust control device arranged on the coal unloading passage of the mining truck.

[0039] The dust isolation device includes three dust-proof curtains 1 arranged on the top of the coal unloading passage and dust-proof plates 2 on both sides thereof. Among them, the three dust-proof curtains 1 are arranged on the top of the coal unloading passage from the inside to the outside, and the lengths of the three dust-proof curtains 1 decrease in sequence from the inside to the outside. The included angle between the bottom connection line of the three dust-proof curtains 1 and the horizontal direction is the same as the inclination angle of the car hopper when unloading coal, so as to prevent the dust-containing air flow from rushing out from the top of the mining truck; the inclination angle is 40° - 50°, preferably 45.6°. The dust-proof curtain 1 is cut from waste belts and can meet the requirements of antistatic, flame retardant and wear resistance.

[0040] The dust reduction device includes a dust collector 3 arranged outside the coal unloading passage and a horn-shaped dust suction hood 4 arranged inside the coal unloading passage. The dust collector 3 is connected to the dust suction hood 4 through a negative pressure dust extraction pipeline 5. The air curtain dust control device includes an air booster 6 arranged outside the coal unloading passage and air curtain generators 7 arranged on both sides of the coal unloading passage; the air curtain generators 7 are connected to the air curtain generators 7 through a compressed air pipeline 8. Electric control air valves 9 are arranged on both the negative pressure dust extraction pipeline 5 and the compressed air pipeline 8.

[0041] Since the air sucked by the dust suction hood 4 cannot distinguish whether it is the dust-laden air flow from the coal unloading pit or the clean air from the outside, it is necessary to control the air flow to reduce the entry of external air into the dust collector 3 and prevent the dust collector 3 from sucking fresh air for useless work. Therefore, in the present invention, air curtain generators 7 are respectively arranged on both sides of the coal unloading passage to form strip-shaped air outlets, which blow towards the sides of the self-unloading truck body to form an air curtain, preventing the dust in the coal unloading pit from escaping along both sides of the vehicle body. According to the current "Emission Standard of Pollutants for the Coal Industry" (GB 20426-2006), after the dust collector 3 extracts the dust-laden air flow and then discharges it, it belongs to organized emission. It is necessary to install a detection device at the discharge port and also apply for a pollution discharge permit, which will increase the project volume and complexity. Therefore, in this dust removal system, the air flow processed by the dust collector 3 is transported to the air curtain device after increasing the air flow pressure through a fan. Finally, the recycling of the air flow is realized, and the regulatory pressure brought by organized emission is also avoided.

[0042] The dust collector 3 can be selected from a wet dust reduction device and a dry dust collector 3. Since most large open-pit coal mines are in the north, and the winter temperature is as low as minus 30 degrees, it is difficult to implement the wet dust reduction device. Therefore, in some embodiments of the present invention, the dust collector 3 is preferably a dry dust collector 3. By placing a large dry dust collector 3 at a suitable position outside the coal unloading passage, and then extending the air inlet to both sides, the top of the maintenance passage and the steel structure workshop, and adding a set of dust suction hoods 4 near the center of the steel structure workshop, a flared design is adopted to expand the negative pressure coverage range to perform all-round dust removal and prevent dust from escaping.

[0043] In some embodiments of the present invention, the dust suction hood 4 in the dust reduction device includes a first dust suction hood 4 arranged at the top of the coal unloading passage, a second dust suction hood 4 on both sides of the coal unloading passage, and a third dust suction hood 4 inside the crushing station workshop.

[0044] In other embodiments of the present invention, in order to improve the utilization efficiency of resources and avoid clean pollution, a transfer device for collecting dust is provided at the bottom of the dust collector 3. The transfer device transports the regularly collected dust to the production system through a screw conveyor. A detection device for detecting the air flow quality is also provided at the air outlet of the dust collector 3.

[0045] In other embodiments of the present invention, an air booster 6 communicating with the compressed air pipeline 8 is provided at the air outlet of the dust collector 3. The air flow processed by the dust collector 3 is transported to the air curtain generator 7 through the compressed air pipeline 8 under the action of the air booster 6 to form a circulating air flow.

[0046] First, the present invention seals the upper part of the coal unloading pit by setting up a dust isolation device, leaving only the access channels for mining trucks to unload coal. At the same time, multiple dust-proof curtains 1 are installed above the self-unloading truck passage to block most of the dust from escaping. Then, dust suction ports (dust suction hoods 4) of the dry dust collector 3 are installed at appropriate positions inside the closed workshop, on the top and both sides of the mining truck passage to form a negative pressure area for sucking dust. Finally, the clean air after treatment is pressurized by a fan and returned to the air outlets on both outermost sides of the mining truck passage to blow against the mining truck body, forming an air curtain. A one-way air flow towards the closed workshop is formed through the high-pressure air flow to further reduce the outward diffusion of dust.

[0047] Since the two coal unloading channels are not used simultaneously during production, electric control air valves 9 are installed on both the negative pressure dust extraction pipes 5 and the compressed air pipes 8 leading to the two coal unloading channels. The air extraction pipe above the non-coal unloading channel is closed during production to increase the system's dust extraction volume and reduce energy consumption.

[0048] The treatment air volume of the dust collector 3 is related to the size of the coal unloading pit and the coal unloading volume. Calculated based on the dust source point control wind speed of 1 m / s at the dust generation point, combined with the coal body volume air volume Q1: 148 m 3 , the coal flow induced air volume Q2: 160.6 m 3 and the coal unloading time of 20 s, the determined treatment air volume is 137548 m 3 / h. Considering a safety factor of 1.1, the treatment air volume selected for the bag filter dust collector 3 is 150,000 m 3 / h.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An air curtain - negative pressure coupled cyclic dust removal system for an open - pit coal mine crushing station, characterized in that: It includes a dust isolation device, a dust suppression device and an air curtain dust control device installed on the coal unloading channel of the mining truck; The dust isolation device includes three dust curtains (1) installed on the top of the coal unloading channel and dust baffle plates (2) on both sides thereof; The dust suppression device includes a dust collector (3) installed outside the coal unloading channel and a dust suction hood (4) installed inside the coal unloading channel. The dust collector (3) is connected to the dust suction hood (4) through a negative pressure dust extraction pipeline (5); The air curtain dust control device includes an air booster (6) installed outside the coal unloading channel and air curtain generators (7) installed on both sides of the coal unloading channel; the air curtain generators (7) are connected to the air curtain generators (7) through a compressed air pipeline (8); An air booster (6) communicating with the compressed air pipeline (8) is provided at the air outlet of the dust collector (3). The air flow processed by the dust collector (3) is transported to the air curtain generator (7) through the compressed air pipeline (8) under the action of the air booster (6) to form a circulating air flow.

2. The air curtain - negative pressure coupled cyclic dust removal system for the open - pit coal mine crusher station according to claim 1, wherein: The three dust curtains (1) are arranged from inside to outside on the top of the coal unloading channel, and the lengths of the three dust curtains (1) decrease sequentially from inside to outside.

3. The air curtain - negative pressure coupled circulating dust removal system for the open - pit coal mine crushing station according to claim 2, wherein: The included angle between the bottom connection line of the three dust curtains (1) and the horizontal direction is consistent with the inclination angle of the car hopper when unloading coal.

4. The air curtain-negative pressure coupled cyclic dust removal system for an opencast coal mine crusher station according to claim 3, characterized in that: The inclination angle is 40° - 50°.

5. The air curtain-negative pressure coupled cyclic dust removal system for open-pit coal mine crushing station according to claim 3, wherein: The dust curtain (1) is cut from waste belts.

6. The air curtain - negative pressure coupled cyclic dust removal system for open - pit coal mine crushing station according to claim 1, wherein: The dust suction hood (4) includes a first dust suction hood (4) installed on the top of the coal unloading channel, a second dust suction hood (4) on both sides of the coal unloading channel and a third dust suction hood (4) inside the crushing plant building.

7. The air curtain - negative pressure coupled circulating dust removal system for the open - pit coal mine crusher station according to claim 1, wherein: An electric control air valve (9) is provided on the negative pressure dust extraction pipeline (5).

8. The air curtain - negative pressure coupled circulating dust removal system for open - pit coal mine crushing station according to claim 1, wherein: An electric control air valve (9) is provided on the compressed air pipeline (8).

9. The air curtain - negative pressure coupled cyclic dust removal system for open - pit coal mine crushing station according to claim 1, wherein: A transfer device for collecting dust is provided at the bottom of the dust collector (3), and the collected dust is transported to the production system through a screw conveyor by the transfer device.

10. The air curtain - negative pressure coupled cyclic dust removal system for an open - pit coal mine crusher station according to claim 1, wherein: A detection device for detecting the air flow quality is further provided at the air outlet of the dust collector (3).

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