What Is a Coal Yard?

Coal yard refers to the place where coal is piled, and it is usually an auxiliary facility of a coal-fired power plant or a steel plant. With the continuous improvement of China's coal production capacity, the stricter national environmental protection policy, and the continuous increase in people's awareness of environmental protection, the open-air coal storage methods previously used by coal production companies have not met the requirements and must be fully enclosed in accordance with the actual needs of enterprises. Only in a coal storage yard can a company ensure good economic, environmental and social benefits.

With the continuous improvement of China's coal production capacity, the strict national environmental protection policy, and the continuous awareness of people's environmental protection

Trestle-type coal storage yard is one of the simplest and common fully enclosed coal storage yards. The general layout is: the top of the coal yard is the unloading trestle, the bottom is the coal receiving pit and the coal return tunnel, and the height is generally 15-20. m, the outside is a fully enclosed grid storage structure coal storage shed. The coal storage shed is equipped with ventilation, spray dust reduction facilities and safety exits. If the gas content of coal is high, it also has gas monitoring and monitoring and drainage facilities. When working, the coal is unloaded into the coal storage yard by the coal unloading trestle and coal discharging equipment at the top. When the coal is returned, the coal is transported out of the coal storage site through a coal feeder and a coal return belt conveyor located in the coal return tunnel. . The advantages of this type of coal storage yard are: simple structure, low investment, and little influence by engineering geological conditions; the disadvantages are: If the raw materials are stored in coal, the dust will fall when the coal unloading trestle falls, which will cause the entire coal storage shed The internal environment is polluted and the working conditions of the workers are bad; The bulldozer is needed to assist the operation when returning the coal, which is not only inefficient, but also the crushing of the bulldozer on the coal is serious, which easily causes the secondary crushing of the coal; ^]

Overflow window coal storage yards are widely used in the coal industry. The specific layout is as follows: the entire coal storage yard is circular, and the middle of the coal storage yard is a cylindrical coal falling tube. There are overflow coal windows at different heights of the tube wall. The top of the falling coal tube is a coal discharging device and the bottom is It is a common coal receiving pit and coal return tunnel. The diameter of the falling coal tube is usually 6m or 8m, and the height can reach more than 40 meters. The exterior is a fully enclosed coal storage structure coal storage shed. The coal storage shed is equipped with ventilation, spray dust reduction facilities and safety exits. If the gas content of coal is high, gas monitoring, monitoring and drainage facilities are also provided. When unloading coal, the coal first falls into the falling coal barrel, and then flows into the coal storage yard through the overflow coal window located on the wall of the falling coal barrel. When returning coal, it is the same as the ordinary trestle-type coal storage yard. Coal feeders and coal return belt conveyors in the coal return tunnel transport coal out of the coal storage yard. The advantages of this type of coal storage yard are: coal flows to the coal storage yard through the overflow coal window on the wall of the falling coal barrel, which plays a certain role in suppressing dust and reducing coal dust pollution; Small area, little influence by engineering geological conditions, beautiful appearance. The disadvantages are: bulldozer auxiliary operation is needed when returning coal, and the degree of automation is low, which easily causes the coal to be crushed twice due to the rolling of the bulldozer, and the production cost is high ^[3]

With the continuous improvement of coal enterprises' requirements for automated production, silo coal storage has been widely used in China. The general layout is: the top of the silo is equipped with a silo belt conveyor and unloading equipment, and the bottom of the silo is a coal feeder and a return coal belt conveyor. An air cannon is provided on the outer wall of the hopper. The diameter of the silo is usually 8 m, 10m, 12m, 15m, 18m, 21m, 30m, the height is 1.5 to 2 times the diameter, the maximum diameter of the silo can reach 40m, and the storage capacity of a single silo can reach 30,000t. When unloading coal, the coal is discharged into the silo by a distribution belt conveyor and a discharging device located on the top of the silo. When coal is returned, it is completed by a coal feeder and a coal return belt conveyor provided at the bottom of the silo. . The advantages of this coal storage method are: small footprint, high degree of automation, low production costs, and minimal pollution to the surrounding environment; the disadvantages are: the load per unit area of the silo foundation is large, so it is affected by engineering geology The impact of the conditions is obvious. If the geological conditions are poor, the cost of basic treatment is high; arch accidents and warehouse blocking accidents are prone to occur ^[3]

Slot-type coal storage yards can be divided into semi-underground and full-underground. The specific layout method is completely determined by the specific terrain and geological conditions. The general layout is: the top of the tank is a fully enclosed coal storage shed and coal unloading trestle, the bottom is a coal return tunnel, coal feeder and belt conveyor, and the entire coal storage yard is in a "V" shape. In order to reduce the investment in civil construction, the terrain conditions are used as much as possible as the inclined walls on both sides of the tank. When working, the coal is unloaded into the tank by the coal unloading trestle and coal unloading equipment at the top of the tank, and the coal return operation is completed by the coal feeder and the belt conveyor provided at the bottom. The advantages of this coal storage yard are: large coal storage, high degree of automation, and good environmental protection effect; disadvantages are: affected by terrain conditions, low probability of use, large amount of underground engineering, high investment ^[2]

The stacker-reclaimer coal storage plant is a highly mechanized coal storage method that can store, transfer, and homogenize materials. In recent years, it has been widely used in large-scale coking plants, ports and docks, and thermal power plants in China. According to the shape of the coal storage yard, it can be divided into two types: long and circular stockyards. The maximum diameter of the circular stockyard can reach 120m. The stacker and reclaimer series mainly include: circular stockyard mixing stacker reclaimer, long stockyard mixing stacker reclaimer, arm bucket wheel stacker reclaimer, arm bucket wheel reclaimer, bridge bucket Wheel reclaimer.

The circular stockyard mixing stacker and reclaimer is mainly composed of a swingable cantilever stacker, a center pillar, a bridge scraper (scraper) reclaimer, and an electronic control system. The long stockyard mixing stacker and reclaimer is mainly composed of a side cantilever stacker, a bridge scraper (side scraper) reclaimer, and an electronic control system. Generally, the layout is: the outside of the coal storage yard is a fully enclosed coal storage shed, and the inside is a stacker and reclaimer. When working, the coal is discharged into the coal storage yard through the loading system and stacker, and the coal return operation is completed by the reclaimer and the discharge belt conveyor when returning the coal. The advantages of this coal storage yard are: small amount of civil engineering, short construction cycle, large coal storage, high degree of automation; disadvantages: large amount of mechanical equipment maintenance work, large investment in mechanical equipment ^[2]

The problem that must be considered during the lump coal storage is how to prevent the secondary crushing of lump coal. Common storage methods include cylindrical silos, square silos, and inverted cone silos. When using a silo to store lump coal, a spiral chute must be laid on the inner wall of the silo to make the lump coal fall into the silo along the spiral chute, thereby reducing the height of falling coal and reducing the breakage of lump coal. When coal is coal, one side of the square warehouse is usually made into a sloped concrete warehouse wall, so that lump coal is dropped into the square warehouse along the inclined warehouse wall, thereby reducing the height of coal fall; inverted cone coal warehouses are generally used underground or It is a semi-underground layout, which allows lump coal to fall into the coal bunker along the inclined silo wall, which can also reduce the fragmentation of lump coal ^[3]

Each type of coal storage yard has its own strengths. In the specific selection process, comprehensive consideration should be given to engineering geological conditions, automation degree, design scale and investment, and the type of coal storage yard suitable for the enterprise itself should be selected ^[3] .