Countercurrent Carbon Calcination Furnace

Abstract

The present invention relates to a countercurrent carbon calcining furnace, which belongs to the field of high-temperature calcination of carbon materials. It comprises two material tanks arranged side by side, two fire channels connected to each other in opposite directions are arranged side by side on one side of the two material tanks, symmetrically arranged internal volatile component connecting channels are arranged on the top of the material tanks, symmetrically arranged external volatile component connecting channels are arranged on the top of both sides of the material tanks, symmetrically arranged volatile component vertical channels are arranged on the outer sides of the two material tanks, the bottom of the volatile component vertical channels is connected to the volatile component horizontal channel, and the volatile component horizontal channel is connected to the fire channel through the volatile component inlet channel; a preheating air channel is arranged at the bottom of the fire channel, and the preheating air channel is connected to the fire channel through the preheating air inlet channel. The preheated air enters the connected fire channel through the preheating air channel. The present invention adopts a new countercurrent calcining furnace to heat the carbon material at high temperature by indirect heating, and finally reaches qualified physical and chemical indicators. It mainly solves the problems of severe deformation, short life, need for external fuel, and unstable indicators of calcined coke in the current needle coke calcining furnace.

Description

Technical Field

[0001] The invention relates to a counter-current carbon calcining furnace and belongs to the field of high-temperature calcination of carbon materials. Background Art

[0002] In recent years, with the rapid development of negative electrode lithium battery materials in the carbon industry and the recovery of the ultra-high power graphite electrode market, needle coke, as an important raw material, has also been in short supply.

[0003] Traditionally, needle coke is calcined in a brick kiln, which directly heats the raw coke to remove moisture and volatiles, increase the true density of needle coke, and reduce specific resistance, thereby meeting the production requirements of high-quality electrodes and negative electrodes. The biggest disadvantage of using a rotary kiln to calcine needle coke is excessive burnout, with a general burnout rate of ≥10%. Due to the high price of calcined needle coke, this part of the burnout is wasted. For example, for a calcined rotary kiln with an annual output of 50,000 tons, the direct loss from burnout alone is more than 100 million yuan per year, which is a very alarming figure.

[0004] In addition to rotary kilns, some companies also use pot-type calciners to calcine needle coke. Due to the indirect heating method, the burn-out rate is generally ≤3%, which to a certain extent solves the problem of excessive burn-out rate. However, since the calcination temperature of needle coke is generally above 1500°C, it exceeds the empirical maximum temperature of traditional structure and silica brick calcining furnaces. As a result, the furnace is severely deformed and the poor sealing leads to air leakage and material leakage, which greatly shortens the theoretical design life of the calcining furnace. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a countercurrent carbon calcining furnace, which uses a new countercurrent calcining furnace to heat the carbon material at high temperature by indirect heating, and finally achieves qualified physical and chemical indicators. It mainly solves the problems of severe deformation, short life, need for external fuel, and unstable indicators of calcined coke in the current needle coke calcining furnace.

[0006] The countercurrent carbon calcining furnace of the present invention comprises two material tanks arranged side by side, two fire channels connected to each other in opposite directions are arranged side by side on both sides of the two material tanks, symmetrically arranged internal volatile component connecting channels of the material tanks are arranged on the top of the material tanks, symmetrically arranged external volatile component connecting channels of the material tanks are arranged on the top of both sides of the material tanks, symmetrically arranged volatile component vertical channels are arranged on the outside of the two material tanks, the bottom of the volatile component vertical channels is connected to the volatile component horizontal channel, and the volatile component horizontal channel is connected to the fire channel through the volatile component inlet channel;

[0007] A preheating air passage is provided at the bottom of the fire passage, and the preheating air passage is connected to the fire passage through the preheating air inlet passage. The preheated air enters the connected fire passage through the preheating air passage.

[0008] Working process or working principle:

[0009] After the volatiles in the countercurrent calcining furnace material tank escape from the top material layer, they enter the volatile connecting channel inside the material tank and the volatile connecting channel outside the material tank. Under the action of negative pressure, they pass downward through the volatile vertical channel, and then, after passing through the volatile horizontal channel, they enter from the volatile inlet channel and then enter the fire channel.

[0010] The preheated air passes through the bottom preheated air duct and then enters the fire duct through the preheated air inlet duct.

[0011] The preheated air and volatile matter are isolated before entering the flue, in order to force the volatile matter and preheated air to be premixed in the first-layer fire channel and then fully burned. The released heat is used as the main heat input item for calcining needle coke.

[0012] Preferably, a volatile cleaning channel is provided at the bottom of the volatile vertical channel, the volatile cleaning channel is provided below the volatile horizontal channel, and a cleaning door is provided at the end of the volatile cleaning channel.

[0013] Preferably, a pull plate combination brick is provided at the connection between the volatile component inlet channel and the fire channel to adjust the amount of volatile components entering the fire channel.

[0014] Preferably, the volatile matter inlet passage and the air inlet passage are separated by partition bricks.

[0015] Preferably, a negative pressure pull brick is provided on one side of the fire channel to adjust the negative pressure in the fire channel.

[0016] Preferably, the end of the left fire channel on the top floor is connected to the left flue through the left connecting channel, and the end of the right fire channel on the top floor is connected to the right flue through the right connecting channel. The left flue end and the right flue end are connected to the collecting outlet. The fire channel is connected to the flue through the connecting channel, and the two flue ends are connected to the collecting outlet.

[0017] Preferably, at least two groups of fire channels are arranged side by side in the vertical direction, adjacent fire channels are connected in sequence, the preheating air channel is arranged at the bottom of the lowest fire channel, and the uppermost fire channel is connected to the flue through a connecting channel.

[0018] Preferably, at least two layers of preheating air ducts are provided, and each layer of preheating air ducts is connected to the fire duct through a preheating air inlet duct.

[0019] Preferably, a sealing section is provided on the volatile component vertical channel to reinforce the sealing connection channel and the volatile component vertical channel, thereby ensuring the sealing connection between the volatile component vertical channel and the connection channel to avoid deformation, and effectively ensuring the sealing effect of the junction.

[0020] Preferably, the sealing section is a combined special-shaped brick staggered masonry structure.

[0021] Preferably, a volatile cleaning channel is provided at the bottom of the volatile vertical channel, and the volatile cleaning channel is provided below the volatile horizontal channel.

[0022] Preferably, the top of the fire channel is symmetrically connected to the flue via connecting channels on both sides, and the ends of the two flue are connected to a collecting outlet.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Structurally, the present invention adopts a two-way reversible fire channel and concealed collecting flue structures on both sides. Since the flue gas is evenly distributed to both sides of the furnace body, the resistance loss in the flue is small, and the cross-sectional area of ​​the flue is correspondingly reduced. Therefore, the protruding flue structure on one side of the traditional furnace type can be optimized into concealed flues on both sides. The furnace body structure is simple, the operating space is larger, and the control of negative pressure and temperature is more convenient and accurate. With the two-way fire channel structure, there is no need to design a complex volatile component connection channel on the furnace top. It is only necessary to connect the volatile component vertical channel of the material tank on one side with the fire inlet at the bottom of the two fire channels. The material tank and the fire channel correspond one-to-one through the volatile component vertical channel, which ensures that the amount of volatile components entering each fire channel during normal production is basically constant, the temperature fluctuation of the calcination zone is small, and no frequent manual adjustment is required, which effectively ensures the stability of the indicators of calcined coke.

[0025] 2. The furnace bottom adopts three layers of preheating air ducts, which can significantly increase the preheating air temperature and effectively increase the temperature of the calcining zone without adding external fuel. The end of the air duct is directly connected to the first layer of the bottom fire channel, and the air and volatiles are separated by partition bricks at the entrance to ensure that the volatiles and combustion-supporting air are premixed and burned in the fire channel. The fire channel can adopt an eight-layer elevated fire channel structure, and the negative pressure resistance loss along the fire channel is small. The low negative pressure operation can reduce the air leakage of the furnace and increase the temperature of the calcining zone.

[0026] 3. By using high thermal conductivity and high strength magnesium materials in the calcining zone, the service life of the furnace is effectively extended. Due to the increase in the thermal conductivity of the calcining zone material and the small temperature difference on both sides of the material tank, the maximum temperature of the fire channel can be appropriately reduced and the discharge amount can be increased. The direct benefit of lowering the maximum calcining temperature is that the furnace life is extended and it is possible to use it without adding external fuel. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is one of the structural schematic diagrams of an embodiment of the present invention,

[0028] Figure 2 This is a second structural diagram of an embodiment of the present invention.

[0029] Figure 3 yes Figure 1 BB cross-sectional structure diagram,

[0030] Figure 4 yes Figure 1 AA cross-sectional structure diagram,

[0031] Figure 5 yes Figure 1Schematic diagram of CC cross-section structure,

[0032] Figure 6 It is a structural schematic diagram of a combined special-shaped brick staggered masonry structure.

[0033] In the figure: 1. The volatile matter connecting channel inside the tank on the right; 2. The volatile matter connecting channel outside the tank on the right; 3. The flue on the right; 4. The sealing section on the right; 5. The vertical channel of volatile matter on the right; 6. The material tank on the right; 7. The horizontal channel of volatile matter on the right; 8. The flue on the left; 9. The material tank on the left; 10. The vertical channel of volatile matter on the left; 11. The horizontal channel of volatile matter on the left; 12. The connecting channel on the right; 13. The fire channel on the right; 14. The pull plate combination brick on the right; 15. The volatile matter entrance channel on the right; 16. The partition brick on the right; 17. The preheated air entrance channel on the right; 18. The preheated air channel on the right; 19. The negative pressure pull plate brick on the left; 20. The volatile matter cleaning channel on the right. DETAILED DESCRIPTION

[0034] The technical solution in the embodiment of the present invention will be further clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present invention:

[0035] Example 1

[0036] like Figure 1 to Figure 6 As shown, the countercurrent carbon calcining furnace described in the present invention includes two material tanks arranged side by side, two fire channels connected to each other in opposite directions are arranged side by side on both sides of the two material tanks, the two fire channels are symmetrically arranged, the top of the material tank is symmetrically provided with a connecting channel for volatile components inside the material tank, the top of both sides of the material tank is symmetrically provided with a connecting channel for volatile components outside the material tank, the outer sides of the two material tanks are symmetrically provided with vertical channels for volatile components, the bottom of the vertical channels for volatile components are connected to the horizontal channel for volatile components, and the horizontal channel for volatile components is connected to the fire channel through the volatile component inlet channel.

[0037] The material tank includes a left material tank 9 and a right material tank 6. The top of the left material tank is provided with a left material tank internal volatile component connecting channel, the top of the left side of the left material tank is provided with a left tank external volatile component connecting channel, the left side of the left material tank is provided with a left volatile component vertical channel, the left tank external volatile component connecting channel and the left tank internal volatile component connecting channel are connected to the left volatile component vertical channel 10, and the bottom of the left volatile component vertical channel is connected to the left volatile component horizontal channel 11; the left volatile component horizontal channel 11 is connected to the left fire channel through the left volatile component inlet channel.

[0038] A right-side material tank internal volatile component connecting channel 1 is provided at the top of the right-side material tank, a right-side tank external volatile component connecting channel 2 is provided at the top of the right-side material tank, a right-side material tank is provided with a right-side volatile component vertical channel 5 on the right side, the right-side tank external volatile component connecting channel and the right-side tank internal volatile component connecting channel are connected to the right-side volatile component vertical channel, and the bottom of the right-side volatile component vertical channel is connected to the right-side volatile component horizontal channel 7; the right-side volatile component horizontal channel 7 is connected to the right-side fire channel 13 through the right-side volatile component inlet channel 15.

[0039] A preheating air passage is provided at the bottom of the fire passage, and the preheating air passage is connected to the fire passage through the preheating air inlet passage. A left preheating air passage is provided at the bottom of the left fire passage, and the left preheating air passage is connected to the left fire passage through the left preheating air inlet passage. A right preheating air passage is provided at the bottom of the right fire passage, and the right preheating air passage is connected to the right fire passage through the right preheating air inlet passage.

[0040] A sealing section is provided on the volatile component vertical channel, which is used to reinforce the sealing of the connecting channel and the volatile component vertical channel. A left sealing section is provided on the left volatile component vertical channel, which is used to reinforce the sealing of the left connecting channel and the left volatile component vertical channel. A right sealing section 4 is provided on the right volatile component vertical channel, which is used to reinforce the sealing of the right connecting channel and the right volatile component vertical channel. In order to prevent the right volatile component vertical channel 5, the left volatile component vertical channel 10 and the connecting channel 12 from being poorly sealed and severely deformed at the intersection, sealing sections are provided in the volatile component vertical channels on both sides. The sealing sections adopt a combined special-shaped brick staggered masonry structure, which can effectively ensure the sealing effect of the junction.

[0041] like Figure 6 As shown, the sealing section is a combined special-shaped brick staggered masonry structure. A volatile cleaning channel is provided at the bottom of the volatile vertical channel, and the volatile cleaning channel is provided below the volatile horizontal channel. A cleaning door is provided at the end of the volatile cleaning channel. A left volatile cleaning channel is provided at the bottom of the left volatile vertical channel, and the left volatile cleaning channel is provided below the left volatile horizontal channel, and a left cleaning door is provided at the end of the left volatile cleaning channel. A right volatile cleaning channel 20 is provided at the bottom of the right volatile vertical channel, and the right volatile cleaning channel is provided below the right volatile horizontal channel, and a right cleaning door is provided at the end of the right volatile cleaning channel.

[0042] like Figure 2 As shown, a pull plate combination brick is provided between the volatile component inlet and the fire channel, which is used to adjust the amount of volatile components entering the fire channel. A left pull plate combination brick is provided between the left volatile component inlet and the left fire channel, which is used to adjust the amount of volatile components entering the left fire channel. A right pull plate combination brick 14 is provided between the right volatile component inlet and the right fire channel, which is used to adjust the amount of volatile components entering the right fire channel. The right pull plate combination brick 14 adjusts the amount of volatile components by changing the flow section.

[0043] The volatile matter inlet duct and the air inlet duct are separated by a partition brick. The left volatile matter inlet duct and the left air inlet duct are separated by a left partition brick. The right volatile matter inlet duct and the right air inlet duct are separated by a right partition brick.

[0044] like Figure 2 As shown, a negative pressure pull plate brick is provided on one side of the fire channel to adjust the negative pressure in the fire channel. A left negative pressure pull plate brick 19 is provided on one side of the left fire channel to adjust the negative pressure in the left fire channel. A right negative pressure pull plate brick is provided on one side of the right fire channel to adjust the negative pressure in the right fire channel. The left negative pressure pull plate brick 19 adjusts the negative pressure by changing the flow cross section.

[0045] The two sides of the top of the fire channel are symmetrically connected to the flue through the connecting channel, and the ends of the two flues are connected to the collection outlet. The flue includes a left flue 8 and a right flue 3. The end of the left fire channel on the top layer is connected to the left flue through the left connecting channel, and the end of the right fire channel 13 on the top layer is connected to the right flue through the right connecting channel 12. The ends of the left flue and the right flue are connected to the collection outlet, and the collection outlet is connected to a waste heat recovery device to further recover the heat of the high-temperature flue gas discharged from the collection outlet. The waste heat recovery device can use an existing waste heat recovery device, such as a conventional heat exchanger.

[0046] At least two groups of fire channels are arranged side by side in the vertical direction, and adjacent fire channels are connected in sequence. The preheating air channel is set at the bottom of the lowest fire channel, and the uppermost fire channel is connected to the flue through a connecting channel. The directions of adjacent fire channels are opposite. The fire channel can adopt an eight-layer elevated fire channel structure. The negative pressure resistance loss along the fire channel is small. The low negative pressure operation can reduce the air leakage of the furnace and increase the temperature of the calcining zone. The left fire channel and the right fire channel are arranged symmetrically with 8 layers each. The 8 layers of the left fire channel are connected in sequence, and the 8 layers of the right fire channel are connected in sequence.

[0047] At least two layers of preheating air ducts are provided, and each layer of preheating air ducts is connected to the fire duct through the preheating air inlet duct. An appropriate number of preheating air duct layers can be provided as needed.

[0048] Working process or working principle:

[0049] After the volatiles in the countercurrent calciner charge tank escape from the top material layer,

[0050] A part of the volatiles enters the volatiles connecting channel inside the left tank and the volatiles connecting channel outside the left tank. Under the action of negative pressure, it passes downward through the volatiles vertical channel on the left, and then passes through the volatiles horizontal channel on the left; enters the left fire channel through the volatiles entrance channel on the left, passes through the left fire channel on the 8th floor in sequence, and enters the left flue through the left connecting channel;

[0051] The preheated air passes through the left preheated air duct at the bottom and then enters the left fire duct through the left preheated air inlet duct. The preheated air enters the left fire duct through the first-floor entrance at the bottom of the left fire duct in the tank room.

[0052] The left side partition bricks are used to separate the left side volatile matter inlet channel and the left side preheated air inlet channel. The preheated air and volatile matter are in an isolated state before entering the fire channel. The purpose is to force the volatile matter and preheated air to be premixed and fully burned in the first layer of the fire channel. The released heat is used as the main heat input item for calcining needle coke.

[0053] The high-temperature flue gas after combustion turns back upward and enters the left flue through the left connecting channel at the end of the left fire channel on the top floor. The high-temperature flue gas is connected to the waste heat recovery device through the collecting outlet to recover the waste heat. The waste heat recovery device can be a flue gas utilization device.

[0054] A part of the volatiles enters the right tank internal volatiles connecting channel and the right tank external volatiles connecting channel, and under the action of negative pressure, passes downward through the right volatiles vertical channel, and then passes through the right volatiles horizontal channel; enters the right fire channel through the right volatiles entrance channel, passes through the right fire channel on the 8th floor in sequence, and enters the right smoke channel through the right connecting channel;

[0055] The preheated air passes through the right preheated air duct at the bottom and then enters the right fire duct through the right preheated air inlet duct. The preheated air enters the right fire duct through the first-floor entrance at the bottom of the right fire duct in the tank room.

[0056] The right side partition bricks are used to separate the right side volatile matter inlet channel and the right side preheated air inlet channel. The preheated air and volatile matter are in an isolated state before entering the fire channel. The purpose is to force the volatile matter and preheated air to be premixed and fully burned in the first layer of the fire channel. The released heat is used as the main heat input item for calcining needle coke.

[0057] The high-temperature flue gas after combustion turns back upward and enters the right flue through the right connecting channel at the end of the top fire channel. The high-temperature flue gas is connected to the waste heat recovery device through the collecting outlet to recover the waste heat. The waste heat recovery device can be a flue gas utilization device.

[0058] In order to prevent the right volatile component vertical channel 5, the left volatile component vertical channel 10 and the connecting channel 12 from being poorly sealed and severely deformed at the intersection, sealing sections are set in the volatile component vertical channels on both sides, the left volatile component vertical channel is set in the left sealing section, and the right sealing section 4 is set in the right volatile component vertical channel. The sealing sections adopt a combined special-shaped brick staggered masonry structure, which can effectively ensure the sealing effect of the junction. A volatile component cleaning channel is set at the bottom of the volatile component vertical channel, the purpose of which is to discharge the solid coke that falls off when cleaning the volatile component vertical channel. The volatile component cleaning channel can be equipped with a cleaning door at the exit as needed.

[0059] The negative pressure of the fire channel in the furnace is adjusted by the negative pressure pull-plate bricks, and the distribution of the volatile components entering the fire channel is adjusted by the pull-plate combination bricks 14.

[0060] The description of the direction and relative position relationship of the structure in the present invention, such as the description of front, back, left, right, up, and down, does not constitute a limitation of the present invention, but is only for the convenience of description.

Claims

1. A countercurrent carbon calcining furnace, characterized in that: It comprises two material tanks arranged side by side, two fire channels connected to each other in opposite directions are arranged side by side on both sides of the two material tanks, symmetrically arranged internal volatile component connecting channels on the top of the material tanks, symmetrically arranged external volatile component connecting channels on the top of both sides of the material tanks, symmetrically arranged volatile component vertical channels on the outside of the two material tanks, the bottom of the volatile component vertical channels is connected to the volatile component horizontal channel, and the volatile component horizontal channel is connected to the fire channel through the volatile component inlet channel; A preheating air passage is provided at the bottom of the fire passage, and the preheating air passage is connected to the fire passage through a preheating air inlet passage; The volatile matter inlet channel and the air inlet channel are separated by partition bricks; the preheated air and volatile matter are isolated before entering the fire channel, which can force the volatile matter and preheated air to be premixed in the first-layer fire channel and then fully burned. The released heat is used as the main heat input item for calcining needle coke. The end of the left fire channel on the top floor is connected to the left flue via the left connecting channel, the end of the right fire channel (13) on the top floor is connected to the right flue via the right connecting channel (12), and the end of the left flue and the end of the right flue are connected to a collecting outlet; At least two groups of fire channels are arranged side by side in the vertical direction, and adjacent fire channels are connected in sequence. The preheating air channel is arranged at the bottom of the lowest fire channel, and the uppermost fire channel is connected to the flue through a connecting channel. The preheating air duct is provided with at least two layers, and the preheating air duct is connected to the fire duct through the preheating air inlet duct; A volatile cleaning channel is provided at the bottom of the volatile vertical channel, the volatile cleaning channel is provided below the volatile horizontal channel, and a cleaning door is provided at the end of the volatile cleaning channel; A pull plate combination brick is provided between the connection point between the volatile matter inlet channel and the fire channel, which is used to adjust the amount of volatile matter entering the fire channel.

2. The counter-current carbon calcining furnace according to claim 1, characterized in that: A negative pressure pull brick is provided on one side of the fire channel to adjust the negative pressure in the fire channel.

3. The counter-current carbon calcining furnace according to claim 1 or 2, characterized in that: A sealing section is provided on the volatile component vertical channel for reinforcing the sealing connecting channel and the volatile component vertical channel.

4. The counter-current carbon calcining furnace according to claim 3, characterized in that: The sealing section is a combined special-shaped brick staggered masonry structure.

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