A coal charging car for improving the coal charging density of a top-charged coke oven

Abstract

The present application belongs to the technical field of coking process, and particularly relates to a coal charging car for improving the coal charging density of top-charged coke oven, comprising a spiral dense coal feeder; the spiral dense coal feeder comprises a shell and a spiral blade; the shell is provided with a material conveying cavity, and a feeding port and a discharging port communicated with the material conveying cavity; the spiral blade is attached to a rotating shaft and arranged in the material conveying cavity; wherein the material conveying cavity is divided into multiple sections along the axial direction, comprising a variable-diameter section, multiple variable-pitch sections and multiple exhaust sections; along the material conveying direction, the variable-pitch sections are arranged behind the variable-diameter section, and the exhaust sections are arranged between the variable-diameter section and the first variable-pitch section, and between any two adjacent variable-pitch sections. The coal charging car can not only improve the bulk specific gravity of the coal charged into the coke oven, increase the yield and improve the quality, but also effectively suppress the coal dust pollution of tar and the dust accumulation problem of the heat exchange chamber of the heat recovery coke oven, and has low energy consumption.

Description

Technical Field

[0001] This invention belongs to the field of coking process technology, specifically relating to a coal charging car for improving the coal charging density of top-charging coke ovens. Background Technology

[0002] Currently, most coking ovens use a hot-charging intermittent production process. The commonly used technologies during the charging process include side charging, where the side-tamping coal car pushes the tamped coal cake into the carbonization chamber, and top charging, where the top-charging coal car adds loose coal from the coal hopper into the carbonization chamber in a free-fall manner.

[0003] The density of the coal cake added to the carbonization chamber via the tamping side loading is generally 1.1 t / m³. 3 Despite the gaps around the coal cake in the carbonization chamber, the effective bulk density of the coal in the chamber can still reach 0.93 t / m³. 3 The effective volumetric density of coal added to the carbonization chamber by top-loading is currently only 0.76 t / m³. 3 The increase in the effective bulk density of coking coal not only increases output but also allows for the use of more inexpensive, weakly caking coal in coking blends, thereby reducing the amount of prime coking coal used and producing higher quality coke products. This results in lower blend coal costs, increased enterprise profits, and the conservation of valuable, non-renewable prime coking coal resources for the country.

[0004] However, the investment in tamped coke ovens is significantly higher than that of top-charged coke ovens, and their operating and maintenance costs remain high. Furthermore, because the side furnace doors are open during coal charging, various sealing and dust removal measures must be implemented, which not only increases energy consumption considerably but also still causes varying degrees of pollution, especially noise pollution. At the same time, tamped coke ovens have an extremely short lifespan, only one-third to one-half that of top-charged coke ovens, effectively increasing the unit investment. This short lifespan also leads to repeated construction investments, and the reprocessing of materials further increases pollution. Summary of the Invention

[0005] To address the shortcomings in this field, the present invention provides a coal charging car for improving the coal charging density of top-loading coke ovens. Under the premise of ensuring normal coal charging, the coal charging car has the advantages of increasing the bulk density of coal and increasing the proportion of coal pile in the coke oven carbonization chamber, thus effectively overcoming many of the disadvantages of tamping coke ovens from the source.

[0006] Specifically, the present invention provides the following technical solution:

[0007] A coal charging car for improving the coal charging density of a top-loading coke oven includes a spiral dense coal feeder;

[0008] The spiral coal feeder includes a housing and spiral blades; the housing has a material conveying cavity and an inlet and an outlet communicating with the material conveying cavity; the spiral blades are attached to a rotating shaft and disposed in the material conveying cavity;

[0009] The material conveying chamber is divided into multiple sections along the axial direction, including a variable diameter section, multiple variable pitch sections, and multiple exhaust sections.

[0010] Along the material conveying direction, the variable pitch section is located after the variable diameter section, and the exhaust section is located between the variable diameter section and the first variable pitch section, as well as between any two adjacent variable pitch sections;

[0011] In the variable diameter section, the diameter of the spiral blades and the diameter of the shell gradually decrease along the material conveying direction;

[0012] In any of the variable pitch sections, the pitch of the helical blades gradually decreases along the material conveying direction;

[0013] No spiral blades are provided in any of the exhaust sections, and an exhaust port for exhaust is provided on the housing.

[0014] Preferably, the coal loading car also includes a coal hopper, the bottom outlet of which is connected to the feed inlet of the spiral feeder.

[0015] In this invention, the bottom outlet of the coal hopper of the coal charging car is connected to the feed inlet of the spiral feeder. The material conveying chamber at the feed inlet contains constant-diameter, constant-pitch spiral blades, which first feed the receiving coal into the variable-diameter section. In the variable-diameter section, due to the reduced cross-sectional area, the raw coal is initially compressed before entering the exhaust section to remove some air from the coal gaps. Then, it enters the variable-pitch section, where the reduced pitch causes the coal to be continuously compressed again during transport. The compressed air is then expelled through the exhaust holes in the exhaust section, causing the loose coal to form a granular structure, increasing its density and thus increasing the coal loading capacity. Coal is a poor conductor of heat; increasing the effective bulk density improves the heat transfer effect of the coal. Increasing the amount of coal in the carbonization chamber not only increases coke production but also effectively improves coke quality, reduces production costs, and creates better overall benefits for the enterprise. Through practical experience, this invention has shown that coal fed into the furnace through the inlet has a low effective volumetric density in the carbonization chamber. Initially, using a variable-diameter section to reduce the shell cross-sectional area for compression results in higher compression efficiency and lower energy consumption compared to using a variable-pitch screw. Furthermore, the subsequent alternating use of multiple variable-pitch screw sections and multiple exhaust sections allows for more efficient removal of air between coal particles during the compression process, preventing the compressed coal from rebounding after decompression. This, in turn, promotes an increase in the density of the coal fed into the furnace while reducing energy consumption.

[0016] Meanwhile, the coal charging car provided by this invention, which improves the coal charging density of top-charging coke ovens, avoids the defects of tamping coke ovens, such as high noise and air pollution, large maintenance volume and short service life, and overcomes many disadvantages of tamping coke ovens from the source; moreover, it can effectively improve the problem of coal dust flying after the loose coal material is pushed into the coke oven carbonization chamber during conventional top-charging coke oven charging, and effectively reduce the toluene insoluble matter in coal tar.

[0017] Furthermore, coke ovens larger than 7m, especially 7.63m coke ovens, suffer from excessive shrinkage during the coking process, leading to a larger top space and higher temperature. This results in severe cracking of high-carbon hydrocarbons in the raw coal gas, causing two intractable consequences: first, severe graphite buildup in the charging holes and riser pipes, requiring frequent cleaning; second, the complete depletion of high-quality light tar, which can purify the coal gas and remove naphthalene, necessitating the expensive purchase of light oil for naphthalene removal. With the coal charging car of this invention, the increased density of the coal entering the furnace significantly reduces shrinkage during coking, inevitably leading to a substantial improvement in the temperature of the top space. This effectively resolves the severe cracking of high-carbon hydrocarbons in the raw coal gas, thus eliminating both intractable consequences.

[0018] Preferably, in the variable diameter section, the pitch of the helical blades remains unchanged along the material conveying direction.

[0019] Preferably, along the material conveying direction, the maximum pitch of the helical blades in the first variable pitch section is the same as the pitch of the helical blades in the variable diameter section.

[0020] Preferably, along the material conveying direction, the minimum pitch of the helical blades in the preceding variable pitch section is the same as the maximum pitch of the helical blades in the following variable pitch section.

[0021] The pitch of the variable diameter section is kept continuous with that of the first variable pitch section and the adjacent variable pitch sections, which can ensure a smoother compression process of the coal entering the furnace and avoid the drawbacks of large pressure fluctuations causing blockage of the material conveying chamber and increased energy consumption.

[0022] Preferably, the lengths of the variable pitch sections decrease sequentially along the material conveying direction. As the variable pitch sections compress the coal entering the furnace, its density continuously increases, and the pressure for further compression of the coal also continuously increases. Gradually reducing the length of the variable pitch sections allows for more effective exhaust compression in conjunction with adjacent exhaust sections, thereby better increasing the density of the coal entering the furnace and reducing energy consumption.

[0023] Preferably, the length of each exhaust section decreases sequentially along the material conveying direction. As the variable pitch section compresses the coal entering the furnace, its density continuously increases, and the amount of gas discharged gradually decreases. Therefore, the length of the exhaust section can be gradually reduced accordingly, thereby avoiding wasted space.

[0024] This invention does not impose special restrictions on parameters such as the reduction range of the shell diameter in the variable diameter section and the pitch in the variable pitch section. Depending on the coal quality and the user's requirements for the density of the coal entering the furnace, the shell diameter or pitch can be gradually reduced in inverse proportion to the increase in density.

[0025] This invention also provides the application of the coal charging car of the aforementioned top-charged coke oven in a heat exchange coke oven. Applying the coal charging car of this invention to a heat exchange coke oven can not only improve the output and quality of the heat recovery coke oven, but also solve the problem of dust accumulation in the heat exchange chamber. In heat exchange coke ovens, due to the negative pressure conditions, the fine particles of loose coal entering the furnace are easily lifted and enter the combustion chamber through the gas crossing holes, resulting in increasing dust accumulation in the heat exchange chamber, requiring frequent cleaning; otherwise, it increases resistance and affects heat transfer and normal operation. Using the coal charging car of this invention, air in the gaps between the incoming coal can be squeezed out, and the originally loose free particles can be compressed into a high-density granular structure, thereby effectively curbing coal dust from flying and solving the defect of frequent dust cleaning of the heat exchange chamber caused by coal dust entering the combustion system.

[0026] In summary, the coal charging car for the top-charging coke oven provided by this invention can not only increase the proportion of coal entering the coke oven, thereby increasing output and improving quality, but also effectively curb the problems of coal dust pollution of tar in conventional coke ovens and dust accumulation in the heat exchange chamber of heat recovery coke ovens.

[0027] The coal charging car for the top-charging coke oven provided by this invention has the same operational complexity as conventional top-charging technology, but is much lower than tamping coal charging technology. As production capacity and quality are improved simultaneously, its unit investment is lower than that of conventional top-charging coke oven technology, and the coke oven life is not affected. Its investment is also far lower than that of tamping coal charging technology. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the coal charging car of the top-charged coke oven in Example 1;

[0029] Among them, 1 is the discharge port; 2 is the rotating shaft; 3 is the spiral blade; 4 is the shell; 5 is the exhaust port; 6 is the feed port; 7 is the coal hopper; 8 is the power input end; 9 is the constant pitch and constant diameter section; 10 is the variable diameter section; 11 is the variable pitch section; and 12 is the exhaust section.

[0030] Figure 2 This is a schematic diagram of coal loading using the coal loading car of Example 1. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments, but it is not intended to limit the scope of the present invention.

[0032] Example 1

[0033] See Figure 1The coal charging car of the top-loading coke oven includes a spiral dense feeder and a coal hopper 7. The spiral dense feeder is installed at the feed port below the coal hopper 7.

[0034] The spiral coal feeder includes a housing 4 and a rotating shaft 2; the housing 4 has a material conveying cavity and an inlet 6 and an outlet 1 communicating with the material conveying cavity; the rotating shaft 2 is rotatably disposed in the material conveying cavity;

[0035] The material conveying chamber is divided into multiple sections along the axial direction. From the inlet 6 to the outlet 1, it includes a constant-pitch, constant-diameter section 9 (located below the coal hopper 7), a variable-diameter section 10, and three variable-pitch sections 11. An exhaust section 12 is provided between the variable-diameter section 10 and an adjacent variable-pitch section 11, and an exhaust section 12 is provided between any two adjacent variable-pitch sections 11. More specifically:

[0036] 1) A spiral blade 3 is arranged around the rotating shaft in the constant pitch and constant diameter section 9. The pitch and diameter of the spiral blade 3 remain unchanged along the material conveying direction; and the diameter of the shell 4 remains unchanged along the material conveying direction.

[0037] 2) A spiral blade 3 is arranged around the rotating shaft 2 in the variable diameter section 10. The diameter of the spiral blade 3 and the diameter of the shell 4 gradually decrease synchronously along the material conveying direction (that is, the gap between the outer edge of the spiral blade and the shell remains unchanged along the material conveying direction).

[0038] Furthermore, in the variable diameter section 10, the pitch of the spiral blade 3 remains unchanged along the material conveying direction.

[0039] 3) A spiral blade 3 is arranged around the rotating shaft 2 in any of the variable pitch sections 11, and the pitch of the spiral blade 3 gradually decreases along the material conveying direction;

[0040] Furthermore, along the material conveying direction, the length of each variable pitch section 11 decreases sequentially; the maximum pitch of the helical blade 3 in the first variable pitch section 11 is the same as the pitch of the helical blade 3 in the variable diameter section 10; the maximum pitch of the helical blade 3 in the second variable pitch section 11 is the same as the minimum pitch of the helical blade 3 in the first variable pitch section 11, and so on.

[0041] 4) No spiral blades 3 are provided on the rotating shaft 2 in any of the exhaust sections 12, and an exhaust hole 5 for exhaust is provided on the housing 4;

[0042] Furthermore, along the material conveying direction, the length of each exhaust section 12 decreases sequentially.

[0043] like Figure 2 As shown, during coal loading, the coal charging car of the top-loading coke oven is moved above the carbonization chamber of the coal to be loaded. A guide pipe is installed below the discharge port to guide the densified coal into the carbonization chamber.

[0044] The variable frequency motor is started, and the coal in the coal hopper falls into the spiral feeder through the feed inlet. In the spiral feeder, the loose coal is gradually compressed, and the air squeezed out is discharged through the exhaust holes on the shell. As its density increases, the air is gradually discharged and the coal is formed into granules, which then fall into the coke oven carbonization chamber through the guide tube from the discharge outlet.

[0045] Compared with conventional constant-distance, constant-diameter top-charged coal, the effective bulk density of the coal in Example 1 is significantly increased (5-10% higher, or even higher), while energy consumption is low. The increased coal density not only achieves the goal of increasing the proportion of coal entering the coke oven carbonization chamber, thereby increasing output and improving quality, but also effectively curbs the problems of coal dust contamination of tar in conventional coke ovens and dust accumulation in the heat exchange chambers of heat recovery coke ovens.

[0046] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A coal charging car for increasing the coal charging density of a top-loading coke oven, characterized in that, The coal feeder comprises a housing and a spiral blade; the housing has a material conveying cavity, an inlet and an outlet communicating with the material conveying cavity; the spiral blade is attached to a rotating shaft and arranged in the material conveying cavity. The material conveying cavity is divided into multiple sections along the axial direction, including a variable-diameter section, multiple variable-pitch sections and multiple exhaust sections. The variable-pitch sections are arranged behind the variable-diameter section along the material conveying direction; the exhaust sections are arranged between the variable-diameter section and the first variable-pitch section, and between any two adjacent variable-pitch sections. The diameter of the spiral blade in the variable-diameter section gradually decreases along the material conveying direction. The pitch of the spiral blade in any variable-pitch section gradually decreases along the material conveying direction. No spiral blade is arranged in any exhaust section, and exhaust holes are arranged on the housing for exhaust. The length of each variable-pitch section gradually decreases along the material conveying direction, and the length of each exhaust section gradually decreases along the material conveying direction. In the variable-diameter section, the pitch of the spiral blade is constant along the material conveying direction.

2. The coal charging car for improving the coal charging density of a top-charged coke oven according to claim 1, characterized by The maximum pitch of the spiral blade in the first variable-pitch section is the same as the pitch of the spiral blade in the variable-diameter section along the material conveying direction.

3. The coal charging car for increasing the coal charging density of a top-charged coke oven according to claim 1 or 2, characterized by The minimum pitch of the spiral blade in the previous variable-pitch section is the same as the maximum pitch of the spiral blade in the next variable-pitch section along the material conveying direction.

4. The coal charging car for increasing the coal charging density of a top-charged coke oven according to claim 1 or 2, characterized by ​

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