Vertical continuous carbonization-graphitization integrated furnace

Abstract

A vertical continuous carbonization-graphitization integrated furnace, used for carbonization treatment and graphitization treatment of continuous production of graphite negative electrode materials, and comprising a graphitization furnace, a furnace cover, a feeding pipe, a positive electrode, a negative electrode, a furnace chamber graphitization zone, a feeding device, an auxiliary exhaust pipe, a heating member, and a main exhaust pipe. A hollow structure of the graphitization furnace forms a furnace chamber, the furnace cover covers the furnace chamber, the feeding device is connected to the furnace chamber by means of the feeding pipe, the graphitization zone is formed in the furnace chamber by means of the positive and negative electrode pair, the auxiliary exhaust pipe is inserted into the feeding pipe, and the auxiliary exhaust pipe recovers thermal energy from high-temperature off-gas for reuse in the carbonization process; and the heating member supplements heating to the carbonization furnace, a graphitization heat preservation zone, a gradient cooling zone, and a discharger are sequentially communicated below the furnace chamber graphitization zone, an air-tight seal is formed in a discharge port of the discharger, and the main exhaust pipe and the auxiliary exhaust pipe are configured in a slightly positive pressure state to discharge the off-gas in the furnace chamber, thereby achieving self-oxygen isolation of a system. In addition, the present application integrates the carbonization treatment and the graphitization treatment, thus achieving low cost and low energy consumption.

Description

Vertical continuous carbonization graphitization integrated furnace TECHNICAL FIELD

[0001] The present application relates to the field of battery negative electrode materials, and particularly relates to a vertical continuous carbonization graphitization integrated furnace. BACKGROUND

[0002] Lithium ion battery is a kind of secondary battery, at present, researchers are actively developing lithium ion batteries with better large current charge and discharge performance and higher safety for electric vehicles. Lithium ion battery has excellent performance in small size, light weight, no pollution, fast charge and discharge, long cycle life and the like. However, the commonly used negative electrode materials include artificial graphite, natural graphite and mesocarbon microbeads, which are essentially graphite-based negative electrode materials. At present, the actual delithiation capacity of graphite-based negative electrode materials in half-batteries has approached the theoretical limit, but it still cannot meet the demand of high energy density batteries. The common process of graphite-based negative electrode materials is to grind artificial graphite or natural graphite into powder with a particle size meeting the requirements, and then to perform shaping treatment on the powder. After the carbon powder is shaped, it needs to be sequentially subjected to carbonization treatment in a pre-carbonization furnace and graphitization treatment in a graphitization furnace. The pre-carbonization treatment is performed in a pre-carbonization furnace, and the graphitization treatment is performed in a graphitization furnace. The existing pre-carbonization treatment and graphitization treatment are performed separately, and the pre-carbonization treatment is usually performed in a horizontal pre-carbonization furnace, while the graphitization treatment is performed in a vertical graphitization furnace. In the process of graphitization treatment, the material needs to be transferred from the horizontal structure to the vertical structure for feeding, and the coordination and consistency of the two are poor, and the sealing of the material is prone to failure, which leaves safety hazards. At the same time, in the existing vertical graphitization furnace, the exhaust of flue gas needs to be performed by introducing a large amount of inert gas (usually nitrogen) into the furnace chamber and the furnace bottom to increase the gas pressure in the furnace and then to exhaust the flue gas. The introduction of inert gas is not only to push the flue gas out, but also to prevent oxygen in the air from entering the graphitization furnace to cause adverse reactions. This way of introducing inert gas not only increases the operation cost, but also causes the carbon powder in the graphitization furnace to be scattered and washed away from the exhaust pipe due to the introduction of inert gas. In addition, the impurities in the upper part of the existing vertical graphitization furnace will be enriched on the surface of the material in the furnace chamber and form a coking board, which will cause safety hazards.

[0003] Therefore, there is an urgent need for an equipment integrating carbonization treatment and graphitization treatment of graphite negative electrode materials, which does not need to introduce inert gas for oxygen isolation and has high safety.

[0004] CONTENT

[0005] The present application aims to provide a vertical continuous carbonization graphitization integrated furnace which integrates carbonization treatment and graphitization treatment of graphite negative electrode materials, does not need to introduce inert gas for oxygen isolation, and has high safety.

[0006] To achieve the above object, the application provides a vertical continuous carbonization graphitization integrated furnace for carbonization treatment and graphitization treatment of continuous production of graphite negative electrode material, which comprises a feeding device, a carbonization furnace and a graphitization furnace which are sequentially connected in communication and present a hollow vertical integrated structure from top to bottom, the graphitization furnace comprises a graphite positive electrode, a secondary exhaust pipe, a primary exhaust pipe, a graphite negative electrode and a furnace top, a furnace cover and a furnace chamber which are arranged from top to bottom, the furnace chamber comprises a furnace chamber cavity gas buffer zone, a furnace chamber graphitization zone, a furnace chamber graphitization heat preservation zone, a gradient cooling zone and an oxygen isolation discharging zone which are arranged from top to bottom, the secondary exhaust pipe and the primary exhaust pipe are in communication with the furnace chamber cavity gas buffer zone, the graphite positive electrode and the graphite negative electrode extend into the furnace chamber at a certain distance, and the graphite positive electrode and the graphite negative electrode form the furnace chamber graphitization zone in the interval region in the furnace chamber.

[0007] Preferably, the feeding device is a group of hoppers which are uniformly distributed around the graphite positive electrode.

[0008] Preferably, the feeding device is a group of hoppers which are uniformly distributed around the graphite positive electrode, and the group of hoppers comprises 2-6 hoppers.

[0009] Preferably, the feeding device is a group of hoppers which are uniformly distributed around the graphite positive electrode; and the bottom of each hopper is provided with at least one discharging pipe with a valve, and the discharging pipe is in communication with the carbonization furnace.

[0010] Preferably, the carbonization furnace is a hollow cylinder with a diameter of 350-480 mm, vertically penetrates the furnace cover of the graphitization furnace and is in communication with the furnace chamber of the graphitization furnace.

[0011] Preferably, the feeding port of the carbonization furnace is in communication with the discharging pipe of the feeding device.

[0012] Preferably, the discharging port of the carbonization furnace is in communication with the graphitization furnace.

[0013] Preferably, the discharging port of the carbonization furnace is 100-270 mm lower than the furnace cover of the graphitization furnace.

[0014] Preferably, the graphite positive electrode presents a vertical center penetrating through the furnace cover and reaching the upper part of the furnace chamber graphitization zone.

[0015] Preferably, the graphite positive electrode is in a cylindrical structure.

[0016] Preferably, the diameter of the graphite positive electrode is 600-800 mm.

[0017] Preferably, the graphite positive electrode is provided with an automatic tensioning and automatic lifting mechanical gripper which is in an insulating state.

[0018] Preferably, the graphite positive electrode is provided with a cooling device.

[0019] Preferably, an insulation oxygen-sealing device is provided at the contact between the graphite positive electrode and the furnace cover.

[0020] Preferably, the inner diameter of the auxiliary exhaust pipe is 100-150 mm, and the outer diameter is 150-220 mm.

[0021] Preferably, the auxiliary exhaust pipe vertically passes through the center of the carbonization furnace; the upper opening of the auxiliary exhaust pipe penetrates out of the carbonization furnace and is connected to the pipeline of the external tail gas treatment system; the lower opening of the auxiliary exhaust pipe is 100-200 mm lower than the lower opening of the carbonization furnace.

[0022] Preferably, 4-8 rows of perforations with a diameter of 1-3 mm are provided on the pipe wall of the portion of the auxiliary exhaust pipe inside the carbonization furnace.

[0023] Preferably, the auxiliary exhaust pipe is provided with a flue gas differential pressure automatic detection device and a flue gas flow automatic regulating valve.

[0024] Preferably, the thickness of the furnace cover is 900-1300 mm.

[0025] Preferably, the furnace cover comprises, from top to bottom, a steel layer, a first insulation layer, a second insulation layer, a third insulation layer, a first refractory insulation layer, a second refractory insulation layer, and a third refractory insulation layer, which are sequentially stacked.

[0026] Preferably, the furnace cavity gas buffer zone is arranged below the furnace cover; the height of the furnace cavity gas buffer zone is 200-400 mm, and the diameter is 2700-3000 mm.

[0027] Preferably, the main exhaust pipe is arranged below the furnace cover, with the inner opening connected to the furnace cavity gas buffer zone and the outer opening connected to the pipeline of the external tail gas treatment system.

[0028] Preferably, the main exhaust pipe is provided with a flue gas differential pressure automatic detection device and a flue gas flow automatic regulating valve.

[0029] Preferably, the inner diameter of the main exhaust pipe is 280-330 mm, and the outer diameter is 380-430 mm.

[0030] Preferably, the main exhaust pipe is sequentially provided, from inside to outside, with a refractory insulation layer, an insulation layer, and a steel layer outside the furnace wall.

[0031] Preferably, the main exhaust pipe is provided with an insulation and anti-thermal expansion and cold contraction device.

[0032] Preferably, the lower part of the furnace cavity gas buffer zone is provided with a furnace graphitization preheating zone.

[0033] Preferably, the height of the furnace graphitization preheating zone is 230-860 mm, and the diameter is 2700-3000 mm.

[0034] Preferably, the lower part of the furnace cavity gas buffer zone is provided with a furnace graphitization preheating zone; the furnace graphitization zone is arranged below the furnace graphitization preheating zone, and has a V-like structure, with the upper part having a diameter of 2700-3000 mm, the lower part having a diameter of 800-1200 mm, and the height being 1070-1700 mm.

[0035] Preferably, the graphite negative electrode is arranged below the furnace graphitization zone.

[0036] Preferably, the graphite negative electrode is provided with a circular discharging passage with a diameter of 800-1200 mm.

[0037] Preferably, the graphite negative electrode is provided with a circular discharging passage, and the circular discharging passage of the graphite negative electrode and the circular discharging passage of the furnace graphitization zone are the same vertical center.

[0038] Preferably, the height of the graphite negative electrode is 1300-1800 mm.

[0039] Preferably, the lower end of the graphite negative electrode is provided with a graphite negative electrode lead-out; the graphite negative electrode lead-out is one of a circular graphite column with a diameter of 600-800 mm or a square graphite column with a side length of 600-800 mm; the graphite negative electrode lead-out extends to the outside of the furnace shell by 600-1300 mm; an insulation oxygen-proof and waterproof seal is arranged between the graphite negative electrode lead-out and the furnace shell; and the graphite negative electrode lead-out is further provided with a cooling device.

[0040] Preferably, the furnace graphitization heat preservation zone is arranged below the graphite negative electrode; the furnace graphitization heat preservation zone is provided with a circular discharging passage with a diameter of 800-1200 mm; the graphite negative electrode is provided with a circular discharging passage; and the circular discharging passage of the furnace graphitization heat preservation zone and the circular discharging passage of the graphite negative electrode are in communication.

[0041] Preferably, the furnace graphitization heat preservation zone is provided with a circular discharging passage; the graphite negative electrode is provided with a circular discharging passage; and the circular discharging passage of the furnace graphitization heat preservation zone and the circular discharging passage of the graphite negative electrode are the same vertical center.

[0042] Preferably, the height of the furnace graphitization heat preservation zone is 1300-2300 mm.

[0043] Preferably, the gradient cooling zone is arranged below the hearth graphitization holding zone, the gradient cooling zone is provided with a circular discharge channel with a diameter of 800-1200 mm; the hearth graphitization holding zone is provided with a circular discharge channel; the circular discharge channel of the gradient cooling zone is vertically aligned with the discharge channel of the hearth graphitization holding zone, and the area of the gradient cooling zone is 8-30 square meters.

[0044] Preferably, the oxygen isolation discharge zone is sequentially provided with a cooling type disc feeder, a first can, a first gas sealing mechanism, a second can, and a second gas sealing mechanism from top to bottom; the second can is provided with a vacuum exhaust device; the volume of the first can is 1.0-2.0 cubic meters, and the volume of the second can is 1.2-2.2 cubic meters; the outlet of the first can is in communication with the inlet of the second can of the second can through the first gas sealing mechanism, and the outlet of the second can is provided with a second gas sealing mechanism which can be opened and closed; when the second gas sealing mechanism is opened, the material in the second can falls out through the outlet of the second can; when the second gas sealing mechanism is closed, the outlet of the second can is closed in airtight manner, and then the vacuum exhaust device is opened to exhaust the air in the second can; the furnace bottom mechanical gas sealing mechanism of the present application does not need to use inert gas, thereby avoiding the negative effects caused by the introduction of inert gas in the prior art, such as the powder in the graphitization furnace being washed away and the heat being taken away.

[0045] Preferably, the furnace wall of the graphitization furnace comprises, from outside to inside, a steel layer, a first holding layer, a second holding layer, a third holding layer, a first refractory insulation layer, a second refractory insulation layer, and a third refractory insulation layer.

[0046] Preferably, the outermost layer of the graphitization furnace is a steel shell, and the outer diameter of the steel shell is 4600-5600 mm.

[0047] Preferably, the vertical distance from the graphite positive electrode to the graphite negative electrode is D, the vertical distance from the graphite positive electrode to the furnace wall of the hearth is H, and 0.8≤(D / H)≤1.6.

[0048] Preferably, the carbonization furnace is a hollow cylinder, and the periphery of the hollow cylinder is provided with a heat source with a temperature of 500-1650℃; the outer side of the heat source with a temperature of 500-1600℃ is provided with a refractory layer, an insulation layer, and a holding layer.

[0049] Preferably, the carbonization furnace is a hollow cylinder, and an annular cavity is formed between the hollow cylinder and the auxiliary exhaust pipe, and the annular cavity forms a discharge channel; the hearth cavity gas buffer zone is provided below a hearth graphitization preheating zone, and the discharge channel is in communication with the hearth graphitization preheating zone.

[0050] Preferably, the distance between the auxiliary exhaust pipe and the center of the graphite positive electrode is 700-1100 mm.

[0051] Preferably, the outlet of the auxiliary exhaust pipe and the main exhaust pipe is provided with an automatic regulating device for differential pressure of 0-25 Pa, forming a self-oxygen isolation at the top of the furnace.

[0052] Preferably, the thickness of the steel layer in the furnace wall of the graphitization furnace is 14-20 mm.

[0053] Preferably, the thermal conductivity of the first insulation layer in the furnace wall of the graphitization furnace is not more than 0.025 W / (m.K).

[0054] Preferably, the thermal conductivity of the second insulation layer in the furnace wall of the graphitization furnace is not more than 0.15 W / (m.K).

[0055] Preferably, the thermal conductivity of the third insulation layer in the furnace wall of the graphitization furnace is not more than 1.2 W / (m.K).

[0056] Preferably, the service temperature of the first refractory insulation layer in the furnace wall of the graphitization furnace is not lower than 1650℃.

[0057] Preferably, the service temperature of the second refractory insulation layer in the furnace wall of the graphitization furnace is not lower than 3000℃.

[0058] Preferably, the service temperature of the third refractory insulation layer in the furnace wall of the graphitization furnace is not lower than 3300℃.

[0059] Preferably, the temperature of the hearth graphitization zone is 2800-3300℃.

[0060] Preferably, the temperature of the hearth graphitization insulation zone decreases from 3300-2800℃ to 2200-1800℃ from top to bottom.

[0061] Preferably, the temperature of the gradient cooling zone decreases from 2200-1800℃ to 160-100℃ from top to bottom.

[0062] Preferably, the temperature of the oxygen isolation and discharging zone decreases from 160-100℃ to 80-40℃ from top to bottom.

[0063] Preferably, the hearth cavity gas buffer zone is formed by the part of the discharging channel extending into the hearth, which is not filled with materials.

[0064] Preferably, the gradient cooling zone is provided with a rotary scraper; the rotation speed of the rotary scraper is 2-20 r / min.

[0065] Preferably, the total direct current power of the graphitization furnace is set to 400-2700 kw.

[0066] Preferably, the vertical continuous carbonization and graphitization integrated furnace of the present application comprises:

[0067] a graphitization furnace, which is vertically structured and has a hollow structure penetrating from top to bottom, forming a hearth, the upper opening of the hearth forming an upper cavity, and the lower opening of the hearth forming a lower cavity;

[0068] a furnace cover, which covers and seals the upper cavity;

[0069] a carbonization furnace, which is a hollow cylinder, forming a feeding pipe, the lower end of the feeding pipe being insulated and sealed through the furnace cover and extending into the hearth, and the upper end of the feeding pipe protruding out of the furnace cover;

[0070] a graphite positive electrode, the lower end of which is insulated and sealed through the furnace cover and extends into the hearth;

[0071] a graphite negative electrode, which is insulated and sealed through the lower cavity from outside the graphitization furnace;

[0072] a hearth graphitization zone, which is formed between the graphite positive electrode and the graphite negative electrode in the hearth, for the graphitization of materials;

[0073] a feeding device, which is located above the furnace cover and communicates with the upper end of the feeding pipe;

[0074] a secondary exhaust pipe, which is suspended in the feeding pipe, both ends of the secondary exhaust pipe protruding out of the feeding pipe, and a plurality of exhaust holes being provided through the wall of the secondary exhaust pipe; the secondary exhaust pipe functions to perform micro-positive pressure exhaust, including exhausting the air and moisture carried by the materials during feeding, and to recycle the heat energy of the high-temperature flue gas generated during graphitization for carbonization treatment;

[0075] a heating element, which generates heat after being electrified, and is in heat exchange with the feeding pipe, and transfers heat to the materials in the feeding pipe for carbonization treatment;

[0076] a main exhaust pipe, which communicates with the hearth cavity gas buffer zone and is connected above the hearth graphitization zone;

[0077] a hearth graphitization heat preservation zone, which is formed by the downward extension of the lower cavity in the graphitization furnace, for heat preservation of materials.

[0078] a gradient cooling zone, the hearth graphitization zone downwardly extending to form the gradient cooling zone for cooling the material;

[0079] an oxygen isolation material discharging zone, a discharger being arranged in the oxygen isolation material discharging zone, a discharging inlet of the discharger being communicated with the gradient cooling zone, a first gas sealing mechanism being arranged at a discharging outlet of the discharger and being openable and closable, the material in the discharger falling out of the discharging outlet when the first gas sealing mechanism is opened, and the discharging outlet being closed in airtight manner when the first gas sealing mechanism is closed;

[0080] the feeding device, the feeding pipe, the hearth cavity gas buffer zone, the hearth graphitization zone, the hearth graphitization insulation zone, the gradient cooling zone and the discharger being communicated with each other from top to bottom to form a processing channel for carbonization and graphitization of the material, the material moving downwardly in the processing channel by gravity, the hearth cavity gas buffer zone and the auxiliary exhaust pipe forming an auxiliary flue gas discharge channel with a micro-positive pressure higher than the atmospheric pressure by closing the first gas sealing mechanism, the hearth cavity gas buffer zone and the main exhaust pipe forming a main flue gas discharge channel with a micro-positive pressure higher than the atmospheric pressure, the micro-positive pressure being ΔP, 0<ΔP<25 Pa, so that the air outside cannot enter the furnace, the top of the furnace is self-oxygen-isolated, and the negative effects such as the powder material being washed away and the heat energy being taken away in the graphite furnace caused by the inert gas being introduced for oxygen isolation in the prior art are avoided.

[0081] Compared with the prior art, the application has the following positive beneficial effects: (1) The feeding pipe of the application is in communication with the feeding device, and the heating member is in heat exchange with the feeding pipe, so that the heating member can perform carbonization treatment on the material entering the feeding pipe through heat transfer; the carbonized material falls into the graphite zone of the hearth and is subjected to graphitization treatment; therefore, the application integrates carbonization treatment and graphitization treatment of the graphite negative electrode material, effectively solves the technical problems of poor coordination and consistency caused by separate carbonization treatment and graphitization treatment in the prior art, and also solves the technical problems of poor sealing and potential safety hazards caused by separate treatment, and the by-pass exhaust pipe can exchange the heat energy of high-temperature flue gas to provide carbonization treatment, and the high-temperature material after carbonization directly enters the graphitization furnace, which has remarkable energy-saving effect. (2) By controlling the temperature of the heating member and adjusting the exhaust valves of the main and by-pass exhaust pipes, the following three aspects can be controlled: a. The temperature of the upper end of the feeding pipe of the application is controlled below 300 DEG C, so that the water vapor and air entrained in the material entering the upper end region can enter the by-pass exhaust pipe through the exhaust hole and be discharged, ensuring the drying and air-free entering of the material, avoiding the negative effects of C+O2=CO2 or C+H2O=CO+H2; b. The temperature of the middle part of the feeding pipe of the application is controlled below 1300 DEG C, and the temperature of the lower part is controlled below 1700 DEG C, ensuring that the material is subjected to carbonization treatment in the middle and lower parts of the feeding pipe in a water vapor-free and air-free environment, effectively avoiding the occurrence of the adverse situation of rich and coking, and eliminating the safety hazards caused by rich and coking.(3) In the implementation of the present application, the temperature inside the graphitization furnace is higher than the temperature outside the graphitization furnace, and the discharge outlet is provided with a first gas closing mechanism that can be opened and closed. Therefore, according to the closing of the first gas closing mechanism and the Clapeyron equation: PV = nRT, the gas pressure inside the graphitization furnace is higher than the atmospheric pressure outside. By controlling the volume and temperature of each cavity, as well as the diameter of the auxiliary exhaust pipe and the main exhaust pipe, the gas pressure inside the graphitization furnace is slightly higher than the atmospheric pressure outside, that is, the gas pressure inside the graphitization furnace is slightly higher than the atmospheric pressure outside, forming a micro-positive pressure. Then, the furnace cavity gas buffer zone and the auxiliary exhaust pipe form a micro-positive pressure auxiliary flue gas discharge channel with a pressure value higher than the atmospheric pressure outside, and the furnace cavity gas buffer zone and the main exhaust pipe form a micro-positive pressure main flue gas discharge channel with a pressure value higher than the atmospheric pressure outside. The pressure value of the micro-positive pressure is ΔP, 0 < ΔP < 25 Pa. Therefore, the flue gas inside the graphitization furnace is discharged from the main flue gas discharge channel and the auxiliary flue gas discharge channel under the action of micro-positive pressure, and the water vapor and air in the feeding pipe are also discharged through the auxiliary exhaust pipe provided therein, avoiding the water vapor and air from continuing to flow into the furnace 1a with the material and causing adverse reactions and adverse consequences. Since it is micro-positive pressure, the amount of material in the graphitization furnace carried by micro-positive pressure under the action of its own gravity is greatly reduced, effectively solving the technical defect of the prior art that inert gas needs to be introduced to isolate oxygen in the air and then push the flue gas in the graphitization furnace out. Not only does it reduce the operating cost, but it also greatly reduces the amount of carbon powder in the graphitization furnace that is scattered and washed away from the exhaust pipe.(4) The feeding device, the feeding pipe, the carbonization zone of the carbonization furnace, the flue gas buffer zone of the furnace cavity of the graphitization furnace, the graphitization zone of the furnace, the graphitization heat preservation zone of the furnace, the gradient cooling zone, and the discharger are sequentially connected to form a processing channel for material carbonization and graphitization treatment, so that the material can continuously slide and move in the processing channel under its own gravity, and the carbonization and graphitization treatment can be continuously carried out, greatly improving the production efficiency.

[0082] Preferably, in the vertical continuous carbonization and graphitization integrated furnace of the present application, the graphite positive electrode and the graphite negative electrode are vertically arranged.

[0083] Preferably, in the vertical continuous carbonization and graphitization integrated furnace of the present application, the graphite positive electrode vertically passes through the center of the furnace cover.

[0084] Preferably, in the vertical continuous carbonization and graphitization integrated furnace of the present application, the graphite positive electrode vertically passes through the center of the furnace cover.

[0085] Preferably, in the vertical continuous carbonization and graphitization integrated furnace of the present application, the upper part of the furnace cavity is a cylindrical cavity, the lower part of the furnace cavity is an inverted circular conical cavity, and the graphite positive electrode extends into the cylindrical cavity.

[0086] Preferably, in the vertical continuous carbonization and graphitization integrated furnace, a sealed heating cavity is formed in the furnace cover, and an insulation and sealed heating element is inserted into the furnace cover and extends into the heating cavity to provide supplemental heating for the carbonization furnace.

[0087] Preferably, in the vertical continuous carbonization and graphitization integrated furnace, the heating element is located at the center of the heating cavity.

[0088] Preferably, in the vertical continuous carbonization and graphitization integrated furnace, the graphite positive electrode is uniformly distributed on the furnace cover as the center of the feeding pipe.

[0089] Preferably, in the vertical continuous carbonization and graphitization integrated furnace, the feeding device has a cavity structure with a large upper part and a small lower part, and the lower end of the feeding device extends towards the feeding pipe to form a discharging pipe in communication with the feeding pipe.

[0090] Preferably, the vertical continuous carbonization and graphitization integrated furnace further comprises a first hopper, which has a funnel structure, and a sealed first hopper inlet of the first hopper is in communication with the discharging outlet, and a first air closing mechanism is arranged at the first hopper outlet; when the first air closing mechanism is opened, the material in the discharger falls out through the first hopper outlet; and when the first air closing mechanism is closed, the first hopper outlet is closed in airtight manner.

[0091] Preferably, the vertical continuous carbonization and graphitization integrated furnace further comprises a second hopper, which has a funnel structure, and the first hopper outlet is in communication with a second hopper inlet of the second hopper through the first air closing mechanism, and a second air closing mechanism is arranged at a second hopper outlet of the second hopper; when the second air closing mechanism is opened, the material in the second hopper falls out through the second hopper outlet; and when the second air closing mechanism is closed, the second hopper outlet is closed in airtight manner.

[0092] Preferably, in the vertical continuous carbonization and graphitization integrated furnace, a third air closing mechanism is arranged on the discharging pipe, and when the third air closing mechanism is opened, the material in the feeding device enters the feeding pipe from the discharging pipe; and when the third air closing mechanism is closed, the feeding device is airtightly isolated from the feeding pipe.

[0093] Preferably, in the vertical continuous carbonization and graphitization integrated furnace, the part of the feeding pipe extending into the furnace chamber forms a furnace cavity gas buffer zone without filling material. BRIEF DESCRIPTION OF DRAWINGS

[0094] FIG. 1 is a schematic view of the cross-sectional structure of the vertical continuous carbonization and graphitization integrated furnace.

[0095] Figure 2 is a schematic view of the cross-section of the cover of the furnace of the present application.

[0096] Figure 3 is a schematic view of the inlet pipe of the furnace of the present application.

[0097] Figure 4 is a schematic view of the cross-section of the cover of the furnace of the present application. DETAILED DESCRIPTION

[0098] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with specific implementation examples and the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. The specific embodiments of the present application will be described in detail below in combination with the accompanying drawings. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many different ways than those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited to the specific embodiments disclosed below. The embodiments of the present application will now be described with reference to the accompanying drawings, wherein like reference numerals represent like elements.

[0099] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0100] As shown in FIG. 1-3, the vertical continuous carbonization graphitization integrated furnace 100 of the present application is used for the carbonization treatment and graphitization treatment of the continuous production of graphite negative electrode material. The vertical continuous carbonization graphitization integrated furnace 100 of the present application includes a feeding device, a carbonization furnace and a graphitization furnace which are sequentially connected and communicated from top to bottom and present a hollow vertical integrated structure. The graphitization furnace of the present application for the graphitization treatment of graphite negative electrode material includes a graphite positive electrode 4, a secondary exhaust pipe 8, a main exhaust pipe 10, a graphite negative electrode 5, and a furnace top, a furnace cover 2 and a furnace chamber 1a which are arranged from top to bottom. The furnace chamber 1a of the present application includes a furnace chamber cavity gas buffer zone 1d, a furnace chamber graphitization zone 6, a furnace chamber graphitization heat preservation zone 11, a gradient cooling zone 12 and an oxygen isolation discharging zone which are arranged from top to bottom. The secondary exhaust pipe 8 and the main exhaust pipe 10 of the present application are communicated with the furnace chamber cavity flue gas buffer zone 1b. The graphite positive electrode 4 and the graphite negative electrode 5 of the present application extend into the furnace chamber at a certain distance, and the interval region of the graphite positive electrode 4 and the graphite negative electrode 5 in the furnace chamber 1a forms the furnace chamber graphitization zone 6. The carbonization furnace of the present application is a hollow cylindrical structure, and the hollow cylinder forms a feeding pipe 3, that is, the feeding pipe 3 forms the carbonization furnace of the present application. The heat energy of the carbonization furnace is converted back by the high-temperature flue gas overflowed from the graphitization and provided by the secondary exhaust pipe 8, and is supplemented and adjusted by the heating element 9. The carbonization furnace structure formed by the feeding pipe 3 of the present application is simple and practical, so that the carbonization treatment and the graphitization treatment can be integrated on one furnace body, effectively realizing the purpose of continuous carbonization and graphitization. The feeding pipe 3 of the carbonization furnace of the present application vertically penetrates the furnace cover 2 of the graphitization furnace and is connected and communicated with the furnace chamber 1a of the graphitization furnace. As can be seen, the carbonization treatment and graphitization treatment of the graphite negative electrode material are integrated in the present application, effectively solving the technical problems of poor coordination and consistency caused by the carbonization treatment and graphitization treatment separated into two devices for processing in the prior art, and also solving the technical problems of material docking sealing failure and safety hidden danger caused by separate processing, and the secondary exhaust pipe 8 can exchange the heat energy of the high-temperature flue gas to provide carbonization treatment and high-temperature material after carbonization directly entering the graphitization furnace, which has remarkable energy-saving effect.

[0101] Continuing as shown in FIG. 1-3, in particular, the vertical continuous carbonization graphitization integrated furnace 100 of the present application, including the graphitization furnace 1, the furnace cover 2, the feeding pipe 3, the graphite positive electrode 4, the graphite negative electrode 5, the furnace chamber graphitization area 6, the feeding device 7, the auxiliary exhaust pipe 8, the heating element 9, the main exhaust pipe 10, the furnace chamber graphitization heat preservation area 11, the gradient cooling area 12 and the oxygen isolation discharging area. The graphitization furnace 1 of the present application is in a vertical structure, which is in a hollow structure from top to bottom, forming a furnace chamber 1a, the upper opening of the furnace chamber 1a forms an upper cavity 1b, and the lower opening of the furnace chamber 1a forms a lower cavity 1c. The furnace cover 2 of the present application is arranged at the upper cavity 1b of the furnace chamber 1a, and the furnace cover 2 seals the upper cavity 1b. The lower end of the feeding pipe 3 of the present application is insulated and sealed through the furnace cover 2 and extends into the furnace chamber 1a, and the upper end of the feeding pipe 3 protrudes out of the furnace cover 2. The lower end of the graphite positive electrode 4 of the present application is insulated and sealed through the furnace cover 2 and extends into the furnace chamber 1a; the graphite negative electrode 5 is insulated and sealed through the lower cavity 1c outside the graphitization furnace 1, so that the insertion end of the graphite negative electrode 5 is embedded in the area between the graphite positive electrode 4 and the graphite negative electrode 5 in the graphitization furnace 1, which forms the furnace chamber graphitization area 6 for material graphitization in the furnace chamber 1a; in the implementation of the present application, the temperature gradient of the furnace chamber graphitization area 6 from top to bottom is 2000-3300℃. The feeding device 7 of the present application is located above the furnace cover 2, that is, the feeding device of the present application is located at the highest position, the feeding device 7 is in communication with the upper end of the feeding pipe 3, and the communication is that the material of the feeding device 7 can directly enter the feeding pipe 3 under the action of its own gravity; in particular, the side wall of the feeding pipe 3 is provided with a feeding port 3a, and the feeding device 7 is connected with the feeding port 3a through a flange, so that the feeding device 7 is in airtight communication with the feeding pipe 3. The auxiliary exhaust pipe 8 of the present application is suspended in the feeding pipe 3, and the two ends of the auxiliary exhaust pipe 8 protrude out of the feeding pipe 3, so that the two ends of the auxiliary exhaust pipe 8 are exposed out of the feeding pipe 3, and a plurality of exhaust holes 81 are provided through the wall of the auxiliary exhaust pipe 8 (see FIG. 3). The heating element 9 of the present application generates heat after being connected to the outside, and the heating element 9 is in heat exchange with the feeding pipe 3, that is, the heat generated by the heating element 9 after being connected to the outside is transferred to the feeding pipe 3. The heating element 9 of the present application transfers heat to the feeding pipe 3, so that the material entering the feeding pipe 3 from the feeding device 7 is subjected to carbonization treatment, thereby realizing carbonization treatment of the material in the feeding pipe 3. The main exhaust pipe 10 of the present application is in communication with the furnace chamber 1a and is connected at the furnace chamber cavity smoke buffer area 1b above the furnace chamber graphitization area 6, and the main exhaust pipe 10 is located above the furnace chamber graphitization area 6, so as to facilitate the exhaust of the smoke in the furnace chamber 1a during the graphitization process. The lower cavity 1c of the furnace chamber 1a of the present application extends downward in the graphitization furnace 1 to form the furnace chamber graphitization heat preservation area 11 for heat preservation of the material; in the implementation of the present application, the temperature gradient of the furnace chamber graphitization heat preservation area 11 from top to bottom is 3300-1800℃.The graphite furnace insulation zone 11 extends downward to form a gradient cooling zone 12 for cooling the material. The gradient cooling zone 12 extends downward to form an oxygen isolation discharge zone for isolating oxygen from entering, and a discharger 13 is arranged in the oxygen isolation discharge zone. In the implementation of the present application, the temperature gradient of the gradient cooling zone 12 from top to bottom is 1800-1600C. The discharge inlet of the discharger 13 of the present application is in communication with the gradient cooling zone 12, and a first air closing mechanism 14 that can be opened and closed is arranged at the discharge outlet of the discharger. Specifically, the bottom of the gradient cooling zone 12 is inserted into the platform of the discharger 13 by a certain depth, and the platform of the discharger 12 is a cavity structure. When the first air closing mechanism 14 of the present application is opened, the material in the discharger 14 falls out of the discharge outlet; when the first air closing mechanism 14 is closed, the discharge outlet is closed in airtight manner, so that external air cannot enter the graphite furnace 1a through the discharge outlet, and the material in the discharger 14 cannot fall out. The feeding device 7, the feeding pipe 3, the graphite furnace 1a, the graphite furnace insulation zone 11, the gradient cooling zone 12, and the discharger 13 of the present application are in communication with each other to form a processing channel for carbonization and graphitization of the material, and the material moves downward in the processing channel by gravity. At the same time, the graphite furnace 1a and the auxiliary exhaust pipe 8 form a secondary flue gas discharge channel with a micro-positive pressure higher than the atmospheric pressure by closing the first air closing mechanism 14, the graphite furnace 1a and the main exhaust pipe 10 form a main flue gas discharge channel with a micro-positive pressure higher than the atmospheric pressure, and the micro-positive pressure value ΔP is 0<ΔP<25Pa. Therefore, external air cannot enter the furnace, the top of the furnace is self-oxygen-isolated, and the negative effects such as powder being washed away and heat being taken away caused by the introduction of inert gas for oxygen isolation in the prior art are avoided.

[0102] In combination with FIGS. 1-3, the feeding pipe 3 is in communication with the feeding device 7, and the heating element 9 is in heat exchange with the feeding pipe 3, so that the heating element 3 can perform carbonization treatment on the material entering the carbonization furnace formed by the feeding pipe 3 by heat transfer; the carbonized material falls into the graphite furnace insulation zone 6 of the graphite furnace 1a to perform graphitization treatment; therefore, the present application integrates carbonization treatment and graphitization treatment of the graphite negative electrode material, effectively solves the technical problems of poor coordination and consistency caused by separate carbonization treatment and graphitization treatment in the prior art, and also solves the technical problems of poor sealing and safety hazards caused by separate treatment.

[0103] In combination with Figs. 1-3, in the implementation of the present application, by controlling the temperature of the heating element 9, the following three aspects of control can be carried out: a. The temperature of the upper end of the inlet pipe 3 of the present application is controlled below 300°C, so that the water vapor and air entrained in the material entering the upper end region of the inlet pipe 3 can be effectively discharged through the exhaust hole 81 into the auxiliary exhaust pipe 8, ensuring the drying of the material and the entry of air, avoiding the negative effects of C+O2=CO2 or C+H2O=CO+H2; b. The temperature of the middle part of the inlet pipe 3 of the present application is controlled below 1300°C and the temperature of the lower part is controlled below 1700°C, ensuring that the material is carbonized in the middle and lower parts of the inlet pipe 3 in a water vapor-free and air-free environment, effectively avoiding the occurrence of the undesirable situation of rich coking and eliminating the safety hazards caused by rich coking.

[0104] In combination with Figs. 1-3, in the implementation of the present application, the temperature inside the graphitization furnace 1 is higher than the temperature outside the graphitization furnace 1, and the discharge outlet is provided with a first air closing mechanism 14 that can be opened and closed, so that according to the closure of the first air closing mechanism 14 and the Clapeyron equation: PV=nRT, the air pressure inside the graphitization furnace 1 will be higher than the atmospheric pressure outside, by controlling the volume and temperature of each chamber and the diameter of the auxiliary exhaust pipe 8 and the main exhaust pipe 10, the air pressure inside the graphitization furnace 1 is slightly higher than the atmospheric pressure outside, i.e. the air pressure inside the graphitization furnace 1 is slightly higher than the atmospheric pressure outside; thereby forming a micro-positive pressure auxiliary flue gas discharge channel with a pressure value higher than the atmospheric pressure outside between the furnace chamber 1a and the auxiliary exhaust pipe 8, and a micro-positive pressure main flue gas discharge channel with a pressure value higher than the atmospheric pressure outside between the furnace chamber 1a and the main exhaust pipe 10, the pressure value of the micro-positive pressure is 0<△P<25 Pa; therefore, the flue gas inside the graphitization furnace 1 will be discharged from the main flue gas discharge channel and the auxiliary flue gas discharge channel under the push of the micro-positive pressure, at the same time, the water vapor and air inside the inlet pipe 3 will also be discharged through the auxiliary exhaust pipe 8 provided therein, avoiding the water vapor and air continuing to flow with the material to the furnace chamber 1a to produce adverse reactions and adverse consequences; because it is a micro-positive pressure and a multi-pipe low flow rate flue gas push, the amount of material inside the graphitization furnace 1 carried away by the micro-positive pressure low flow rate flue gas under the action of its own gravity is greatly reduced, effectively solving the technical defect in the prior art that inert gas needs to be introduced into the top and bottom of the graphitization furnace to isolate oxygen and water vapor in the air, not only reducing the operating cost, but also greatly reducing the heat loss of the graphitization furnace and the amount of carbon powder being washed away from the exhaust pipe.

[0105] Continuing to combine the shown in FIG. 1-3, the present application from top to bottom in turn connected to the feeding device 7, feeding pipe 3, hearth 1a, hearth graphitization heat preservation zone 11, gradient cooling zone 12 and discharge device 13 form for material carbonization and graphitization processing processing channel, so that the material in the processing channel by gravity can be continuous down the move, and then can be continuous carbonization and graphitization processing, greatly improving the production efficiency.

[0106] The following will be further described in detail in combination with FIG. 1-4 on the vertical continuous carbonization and graphitization integrated furnace of the present application:

[0107] As shown in FIG. 1 and FIG. 2, specifically, the graphite positive electrode 4 and the graphite negative electrode 5 of the present application are vertically arranged; by vertically arranging the graphite positive electrode 4 and the graphite negative electrode 5, the hearth graphitization zone 6 formed between the two is more regular in space, and at the same time, the temperature formed in the hearth graphitization zone after the graphite positive electrode 4 and the graphite negative electrode 5 are energized is more uniform, thereby improving the graphitization processing effect on the material. More specifically, in order to further improve the effect of graphitization processing, the graphite positive electrode 4 of the present application passes through the center of the furnace cover 2 vertically; preferably, the vertical distance from the graphite positive electrode 4 to the graphite negative electrode 5 is D, and the vertical distance from the graphite positive electrode 4 to the wall of the hearth 1a is H, 1≤(D / H)≤1.6. Further, the graphite positive electrode 4 of the present application passes through the furnace cover 2 slidingly; without the creative labor of those skilled in the art, the vertical distance D from the graphite positive electrode 4 to the graphite negative electrode 5 can be adjusted by the depth of the graphite positive electrode 4 extending into the hearth 1a according to the actual needs. Preferably, in order to facilitate manufacturing and utilize the material to slide down by its own gravity, the upper part of the hearth 1a is a cylindrical cavity, and the lower part of the hearth 1a is an inverted conical cavity, and the graphite positive electrode 4 extends into the cylindrical cavity.

[0108] As shown in FIG. 1, specifically, a sealed heating cavity 15 is further provided in the furnace cover 2 of the present application, and the heating element 9 is inserted into the furnace cover 2 and extends into the heating cavity 15 in an insulated and sealed manner. The heat generated by the energized heating element 9 is transferred to the feeding pipe 3 through the heating cavity 15. Since the heating element 9 is surrounded by the heating cavity 15, and the heating cavity 15 has a closed space, the heat generated by the energized heating element 9 can be more uniformly and wrappedly transferred to the feeding pipe 3 for water vapor removal, air removal and carbonization treatment. Compared with the direct contact of the heating element 9 with the feeding pipe for heat transfer, the heat transfer effect and the uniformity of heating are better, and thus the water vapor removal, air removal and carbonization treatment are better. In order to further improve the water vapor removal, air removal and carbonization treatment, preferably, the heating element 9 of the present application is located at the center of the heating cavity 15.

[0109] As shown in Fig. 1, in order to improve the air tightness of the furnace bottom of the present application, to prevent air from entering the hearth 1a from the furnace bottom. The present application also includes a first ladle 16, which is in the form of a funnel structure, and the discharge outlet of the discharger 13 is in sealed butt joint communication with the first ladle inlet of the first ladle 16. The first air closing mechanism 14 is arranged at the first ladle outlet of the first ladle 16; when the first air closing mechanism 14 is opened, the material in the discharger 13 falls out through the first ladle outlet of the first ladle 16; when the first air closing mechanism 14 is closed, the first ladle outlet of the first ladle 16 is in air-tight closed state, thereby preventing air from entering from the first ladle outlet under the condition that the hearth 1a is in a slightly positive pressure state. In order to further improve the air tightness of the furnace bottom of the present application, to prevent air from entering the hearth 1a from the furnace bottom, more specifically, the present application also includes a second ladle 17, which is in the form of a funnel structure, and the first ladle outlet of the first ladle 16 is in communication with the second ladle inlet of the second ladle 17 through the first air closing mechanism 14. The second air closing mechanism 18 is arranged at the second ladle outlet of the second ladle 17 of the present application, which can be opened and closed. When discharging is needed, the first air closing mechanism 14 is opened, the material in the first ladle 16 enters the second ladle 17, the second air closing mechanism 18 is opened at the same time, and the first air closing mechanism 14 is closed, the material in the second ladle 17 falls out from the second ladle outlet; of course, when continuous discharging is needed, the second air closing mechanism 18 and the first air closing mechanism 14 can be opened at the same time. However, when discharging is not needed, the second air closing mechanism 18 and the first air closing mechanism 14 are closed at the same time, thereby realizing double-layer air tightness of the furnace bottom, preventing air from entering the hearth 1a from the furnace bottom. Specifically, the volume of the first ladle 16 of the present application is 1.0-2.0 cubic meters. The volume of the second ladle 17 of the present application is 1.2-2.2 cubic meters. Preferably, the first air closing mechanism 14 and the second air closing mechanism 18 of the present application are completely the same in structure and type, and existing pneumatic plug valve mechanism or rotary ball valve mechanism (i.e., faucet-like structure) can be selected. As known from the above, the furnace bottom of the present application adopts mechanical air closing and oxygen isolation, without the need to use inert gas, thereby avoiding the negative effects such as the powder in the graphitization furnace being washed away and heat energy being taken away caused by the introduction of inert gas in the prior art.

[0110] As shown in FIG. 1 and FIG. 2, in particular, in order to improve the efficiency of the carbonization treatment of the present application, and to improve the effect of the graphitization treatment of the material in the hearth 1a, the inlet pipe 3 of the present application is uniformly distributed on the furnace cover 2 with the graphite positive electrode 4 as the center. At the same time, the inlet device 7 of the present application has a cavity structure with a large upper part and a small lower part, the lower end of the inlet device 7 extends to the inlet pipe 3 to form a lower discharge pipe 7a in communication with the inlet pipe 3, the lower discharge pipe 7a is in communication with the inlet port 3a of the inlet pipe 3 through a flange, thereby forming the inclined downward arrangement of the lower discharge pipe 7a, and further enabling the material in the inlet device 7 to easily slide into the inlet pipe 3 through the inclined arrangement of the lower discharge pipe 7a under the action of its own gravity. More specifically, the lower discharge pipe 7a of the present application is provided with a third air closing mechanism 7b which can be opened and closed, when the third air closing mechanism 7b is opened, the material in the inlet device 7 enters the inlet pipe 3 from the lower discharge pipe 7a; when the third air closing mechanism 7b is closed, the inlet device 7 is in airtight isolation with the inlet pipe 3. The third air closing mechanism 7b of the present application is preferably a valve formed by the existing pneumatic gate valve mechanism, of course, other existing structures can also be used to form a valve, thereby becoming the third air closing mechanism 7b.

[0111] As shown in FIG. 1, in order to improve the effect of the carbonization treatment of the present application and facilitate the quick discharge of flue gas from the main exhaust pipe 10 and the auxiliary exhaust pipe 8, the part of the inlet pipe 3 of the present application extending into the hearth 1a forms a hearth cavity gas buffer zone 1d which is not filled with material. The hearth cavity gas buffer zone 1d of the present application is located at the uppermost part of the hearth 1a, due to the fact that it is not filled with material and under the action of the high temperature of the hearth 1a, the gas pressure in the hearth cavity gas buffer zone 1d is more easily formed into a slight positive pressure, thereby enabling the flue gas in the hearth 1a to be more quickly and conveniently discharged from the main exhaust pipe 10 and the auxiliary exhaust pipe 8. In particular, the height of the hearth cavity gas buffer zone 1d is 200-400 mm; in implementation, the temperature of the hearth cavity gas buffer zone 1d is controlled at 1350-1700℃, which is conducive to preventing impurities from accumulating and coking in the graphitization furnace 1.

[0112] As shown in FIG. 1 and FIG. 4, in particular, the furnace cover 2 of the present application comprises, from top to bottom, a steel layer 21, a first heat preservation layer 22, a second heat preservation layer 23, a third heat preservation layer 24, a first refractory insulation layer 25, a second refractory insulation layer 26 and a third refractory insulation layer 27 which are sequentially stacked; the thickness of the furnace cover 2 is 900-1300 mm. In particular, the thermal conductivity coefficient of the first heat preservation layer 22 is not greater than 0.025 W / (m.K) (i.e., 0.025 watt / meter·degree Celsius), the thermal conductivity coefficient of the second heat preservation layer 23 is not greater than 0.15 W / (m.K), and the thermal conductivity coefficient of the third heat preservation layer 24 is not greater than 1.2 W / (m.K).

[0113] In combination with the drawings 1-4, specifically: the graphite positive electrode 4 of the application is in the shape of a cylinder, the diameter of the graphite positive electrode 4 is 600-800 mm. The diameter of the upper cavity opening 1b of the hearth 1a of the application is 2700-3000 mm, and the diameter of the lower cavity opening 1c is 800-1200 mm. The distance between the feeding pipe 3 and the graphite positive electrode 4 is 500-600 mm; more specifically, the inner diameter of the feeding pipe 3 is 350-450 mm. The bottom opening of the auxiliary exhaust pipe 8 is 100-200 mm lower than the bottom opening of the feeding pipe 3; more specifically, the outer diameter of the auxiliary exhaust pipe 8 is 160-260 mm; further, the hole diameter of the exhaust hole 81 of the auxiliary exhaust pipe 8 is 2-3 mm.

[0114] In combination with the drawings 1-4, specifically: the volume of the graphitization holding zone 11 of the hearth of the application is 1.5-3.0 cubic meters. The volume of the gradient cooling zone 12 is 1.5-5.0 cubic meters, and the area of the gradient cooling zone 12 is 8-30 square meters.

[0115] As shown in Figure 1, specifically, the discharger 13 of the application is a rotary scraper discharger; the number of the scraper 13a of the discharger 13 is 1-4, the inner diameter of the scraper rotation track is 800-1650 mm and is adjustable; the outer diameter of the scraper rotation track is not greater than 1800 mm, and the rotation speed of the scraper is 0-15 rpm and is adjustable.

[0116] As shown in Figure 1, specifically, the application is provided with four feeding devices 7, each of which is provided with an auxiliary exhaust pipe 8 for recycling the heat energy of the high-temperature flue gas overflowing from the graphitization furnace to the carbonization treatment, and at the same time, for guiding the air and moisture carried in during the feeding of the carbonization furnace to be discharged outside to avoid causing carbon loss (2C+O2=2CO and C+H2O=H2+CO).

[0117] Specifically, the graphitization furnace 1 of the application is sequentially composed of a refractory heat-insulating first layer, a refractory heat-insulating second layer, a refractory heat-insulating third layer, a refractory heat-insulating fourth layer, a holding first layer, a holding second layer, a holding third layer, and a steel shell. The service temperature of the refractory heat-insulating first layer of the graphitization furnace 1 is not lower than 3300℃, the service temperature of the refractory heat-insulating second layer is not lower than 3000℃, the service temperature of the refractory heat-insulating third layer is not lower than 1800℃, and the service temperature of the refractory heat-insulating fourth layer is not lower than 1650℃; further, in the manufacture of the graphitization furnace 1, the refractory bricks of the same refractory heat-insulating layer or the holding bricks of the same holding layer are all designed and built according to the non-joint design; the refractory bricks of different refractory heat-insulating layers or the holding bricks of different holding layers are all designed and built according to the staggered joint design, which is beneficial to energy saving and improving the service life of the application.

[0118] In combination with the drawings 1-4, the vertical continuous carbonization and graphitization integrated furnace 100 of the application is implemented as follows:

[0119] Example 1:

[0120] The present application is set up as follows, four feeding devices 7 are set up. The diameter of the graphite positive electrode 4 is 600 mm. The diameter of the upper cavity opening 1b of the furnace chamber 1a is 2700 mm, and the diameter of the lower cavity opening 1c is 800 mm. The distance between the feeding pipe 3 and the graphite positive electrode 4 is 550 mm; the inner diameter of the feeding pipe 3 is 400 mm; the bottom opening of the feeding pipe 3 is 200 mm lower than the bottom surface of the furnace cover 2; the height of the preheating zone of the furnace chamber is 400 mm; the height of the graphitization zone is 1500 mm. The bottom opening of the auxiliary exhaust pipe 8 is 100 mm lower than the bottom opening of the feeding pipe 3. The pressure value of the slight positive pressure is 0 < ΔP < 10 Pa; the temperature control of the upper end of the feeding pipe 3 is lower than 300℃, the temperature control of the middle part of the feeding pipe 3 is lower than 1300℃, and the temperature control of the lower part of the feeding pipe 3 is lower than 1700℃. The thickness of the furnace cover 2 is 1000 mm; the heating element 9 and the heating cavity 15 are arranged at the second refractory insulation layer 26 and the third refractory insulation layer 27 of the furnace cover 2, and the temperature of the heating cavity 15 is controlled at 1350-1650℃ and is adjustable; the thermal conductivity coefficient of the first insulation layer 22 is not greater than 0.025 W / (m.K), the thermal conductivity coefficient of the second insulation layer 23 is not greater than 0.15 W / (m.K), and the thermal conductivity coefficient of the third insulation layer 24 is not greater than 1.2 W / (m.K). The height of the gas buffer zone 1d of the furnace chamber cavity is 230 mm. The inner diameter of the main exhaust pipe 10 is 300 mm. The volume of the graphitization insulation zone 11 of the furnace chamber is 2.0 cubic meters. The volume of the gradient cooling zone 12 is 2.0 cubic meters, and the cooling area is 18 square meters; the distance between the bottom of the gradient cooling zone 12 and the platform of the discharger 13 is 230 mm; the inner diameter of the gradient cooling zone is 800 mm, and the diameter of the platform of the discharger 13 is 1700 mm. The number of the scrapers 13a of the discharger 13 is set to 2 and is symmetrically arranged, the inner diameter of the scraper rotating track is set to 1000-1650 mm and is adjustable; the outer diameter of the scraper rotating track is not greater than 1800 mm, and the rotating speed of the scraper is set to 0-15 rpm and is adjustable. The volume of the first ladle 16 is 2.0 cubic meters. The volume of the second ladle 17 is 2.2 cubic meters, and the temperature gradient of the material in the second ladle 17 from top to bottom is 100-40℃.

[0121] According to the continuous operation of the above-mentioned example 1 for one year, the vertical continuous carbonization and graphitization integrated furnace 100 of the present application does not have the problem of impurity enrichment and coking; the slight positive pressure self-oxygen isolation of the furnace top and the mechanical oxygen isolation of the furnace bottom are safe, simple, and low in investment and operation cost; the loss rate of the carbon powder flushed away in the furnace is about 0.6%; and the power consumption per ton of product is 3100 kwh. Compared with the existing carbonization treatment and graphitization treatment split type furnace, the loss rate of the carbon powder flushed away is greatly reduced, and the energy saving effect is remarkable, and basically 15% of the energy consumption can be saved.

[0122] Compared with the carbonization and graphitization split furnace, the energy saving is more than 15%.

[0123] Embodiment 2:

[0124] The application is set as follows: four feeding devices 7 are set. The diameter of the graphite positive electrode 4 is 800 mm. The diameter of the upper cavity opening 1b of the hearth 1a is 3000 mm, and the diameter of the lower cavity opening 1c is 1000 mm. The distance between the feeding pipe 3 and the graphite positive electrode 4 is 600 mm; the inner diameter of the feeding pipe 3 is 400 mm; the bottom opening of the feeding pipe 3 is 200 mm lower than the bottom surface of the furnace cover 2. The bottom opening of the auxiliary exhaust pipe 8 is 100 mm lower than the bottom opening of the feeding pipe 3. The pressure value of the micro-positive pressure is 0<△P<15 Pa; the temperature control of the upper end of the feeding pipe 3 is lower than 300℃, the temperature control of the middle part of the feeding pipe 3 is lower than 1300℃, and the temperature control of the lower part of the feeding pipe 3 is lower than 1700℃. The thickness of the furnace cover 2 is 1200 mm; the heating element 9 and the heating cavity 15 are arranged at the second refractory insulation layer 26 and the third refractory insulation layer 27 of the furnace cover 2, and the temperature control of the heating cavity 15 is 1350-1650℃ and adjustable; the thermal conductivity coefficient of the first insulation layer 22 is not more than 0.025 W / (m.K), the thermal conductivity coefficient of the second insulation layer 23 is not more than 0.15 W / (m.K), and the thermal conductivity coefficient of the third insulation layer 24 is not more than 1.2 W / (m.K). The height of the hearth cavity gas buffer zone 1d is 260 mm. The inner diameter of the main exhaust pipe 10 is 330 mm. The volume of the graphitization insulation zone 11 of the hearth is 2.0 cubic meters. The volume of the gradient cooling zone 12 is 2.2 cubic meters, and the cooling area is 22 square meters; the distance between the bottom of the gradient cooling zone 12 and the platform of the discharger 13 is 230 mm; the inner diameter of the gradient cooling zone is 800 mm, and the diameter of the platform of the discharger 13 is 1700 mm. The number of the scrapers 13a of the discharger 13 is set to 2 and arranged symmetrically; the inner diameter of the scraper rotation track is set to 1000-1550 mm and adjustable; the outer diameter of the scraper rotation track is not more than 1800 mm, and the rotation speed of the scraper is set to 0-15 r / min and adjustable. The volume of the first ladle 16 is 2.0 cubic meters. The volume of the second ladle 17 is 2.2 cubic meters, and the temperature gradient of the material in the second ladle 17 from top to bottom is 100-40℃.

[0125] After the continuous operation of the above-mentioned embodiment 2 for one year, the vertical continuous carbonization and graphitization integrated furnace 100 of the application does not have the problem of impurity enrichment and coking; the micro-positive pressure self-oxygen isolation of the furnace top and the mechanical oxygen isolation of the furnace bottom are safe, simple, and low in investment and operation cost; the loss rate of the carbon powder flushed away in the furnace is about 0.5%; and the power consumption per ton of product is 3075 kwh. Compared with the existing carbonization and graphitization split furnace, the loss rate of the carbon powder flushed away is greatly reduced, and the high-temperature flue gas overflowed during the graphitization is reused to the carbonization treatment through the auxiliary exhaust pipe, which has a remarkable energy saving effect and can basically save 15% of the energy consumption.

[0126] Comparative Example 1

[0127] In this comparative example, the carbonization and graphitization processes are completed separately, and nitrogen is used as input to replace the slight positive pressure of the furnace top, and the mechanical isolation of the furnace bottom, and the by-pass exhaust pipe is closed, and the existing kiln exhaust port is set to slight negative pressure. The final carbon powder loss rate is 6.5%; the power consumption for producing the same quality of product per ton is 3675kwh, which is more than 550kwh higher than that of Example 1; and after 15 days of continuous operation, the impurity enrichment and coking of the material in the upper part of the furnace occur.

[0128] Comparison table of experimental results of Example 1-2 and Comparative Example 1

[0129] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims. Meanwhile, the above disclosure is only for the preferred embodiments of the present application, and of course cannot limit the scope of the present application, and equivalent changes made within the scope of the present patent are still within the scope of the present application.

Claims

1. A vertical continuous graphitization furnace for carbonization and graphitization of graphite negative electrode material, characterized in that, The application relates to a vertical integrated structure of a feeding device, a carbonization furnace and a graphitization furnace which are sequentially connected in communication from top to bottom, wherein the graphitization furnace comprises a graphite positive electrode, a secondary exhaust pipe, a main exhaust pipe, a graphite negative electrode, a furnace top, a furnace cover and a furnace chamber arranged from top to bottom, the furnace chamber comprises a furnace chamber cavity gas buffer zone, a furnace chamber graphitization zone, a furnace chamber graphitization heat preservation zone, a gradient cooling zone and an oxygen isolation discharging zone arranged from top to bottom, the secondary exhaust pipe and the main exhaust pipe are in communication with the furnace chamber cavity gas buffer zone, the graphite positive electrode and the graphite negative electrode extend into the furnace chamber at a certain distance, and the graphite positive electrode and the graphite negative electrode form the furnace chamber graphitization zone in the interval region in the furnace chamber.

2. The vertical continuous carbonization graphitization integrated furnace according to claim 1, wherein The feeding device comprises any one of the following features (A) to (C): (A) the feeding device is a group of hoppers which are uniformly distributed around the graphite positive electrode; (B) the feeding device is a group of hoppers which are uniformly distributed around the graphite positive electrode, and the group of hoppers is composed of 2-6 hoppers; (C) the feeding device is a group of hoppers which are uniformly distributed around the graphite positive electrode, and the bottom of the hopper is provided with at least one discharging pipe with a valve, and the discharging pipe is in communication with the carbonization furnace.

3. The vertical continuous carbonization graphitization integrated furnace according to claim 1, wherein The carbonization furnace comprises any one of the following features (I) to (IV): (I) the carbonization furnace is a hollow cylinder with a diameter of 350-480 mm, vertically penetrates the furnace cover of the graphitization furnace, and is in communication with the furnace chamber of the graphitization furnace; (II) the feeding port of the carbonization furnace is in communication with the feeding device; (III) the discharging port of the carbonization furnace is in communication with the graphitization furnace; (IV) the discharging port of the carbonization furnace is 100-270 mm lower than the furnace cover of the graphitization furnace.

4. The vertical continuous carbonization graphitization integrated furnace according to claim 1, wherein The graphitization furnace comprises any one of the following features (1) to (32): (1) the graphite positive electrode vertically penetrates the center of the furnace cover, and reaches the upper part of the furnace chamber graphitization zone; (2) the graphite positive electrode is in a cylindrical structure; (3) the diameter of the graphite positive electrode is 600-800 mm; (4) the graphite positive electrode is provided with an automatic tensioning and automatic lifting mechanical gripper which is in insulation; (5) the graphite positive electrode is provided with a cooling device; (6) an insulation oxygen isolation sealing device is arranged at the contact position between the graphite positive electrode and the furnace cover; (7) the inner diameter of the secondary exhaust pipe is 100-150 mm, and the outer diameter is 150-220 mm; (8) the secondary exhaust pipe vertically penetrates the center of the carbonization furnace, the upper port of the secondary exhaust pipe penetrates out of the carbonization furnace, and is in communication with the pipeline of an external tail gas treatment system; and the lower port of the secondary exhaust pipe is 100-200 mm lower than the discharging port of the carbonization furnace; (9) 4-8 rows of perforations with a diameter of 1-3 mm are arranged on the pipe wall of the part of the secondary exhaust pipe in the carbonization furnace; (10) the secondary exhaust pipe is provided with a flue gas differential pressure automatic detection device and a flue gas flow automatic regulating valve; (11) the thickness of the furnace cover is 900-1300 mm; (12) the furnace cover comprises, from top to bottom, a steel layer, a first heat preservation layer, a second heat preservation layer, a third heat preservation layer, a first refractory insulation layer, a second refractory insulation layer, and a third refractory insulation layer arranged in sequence; (13) the furnace cavity gas buffer zone is arranged below the furnace cover; the height of the furnace cavity gas buffer zone is 200-400 mm, and the diameter is 2700-3000 mm; (14) the main exhaust pipe is arranged below the furnace cover, and the inner opening is in communication with the furnace cavity gas buffer zone, and the outer opening is in communication with the pipeline of the external tail gas treatment system; (15) the main exhaust pipe is provided with a flue gas differential pressure automatic detection device and a flue gas flow automatic regulating valve; (16) the inner diameter of the main exhaust pipe is 280-330 mm, and the outer diameter is 380-430 mm; (17) the outer periphery of the main exhaust pipe is sequentially provided, from inside to outside, with a refractory insulation layer, a heat preservation layer, and a steel layer outside the furnace wall; (18) the main exhaust pipe is provided with an insulation and anti-thermal expansion and cold contraction device; (19) the furnace cavity gas buffer zone is provided below with a furnace graphitization preheating zone; the height of the furnace graphitization preheating zone is 230-860 mm, and the diameter is 2700-3000 mm; (20) the furnace cavity gas buffer zone is provided below with a furnace graphitization preheating zone; the furnace graphitization zone is arranged below the furnace graphitization preheating zone and has a V-like structure, with an upper diameter of 2700-3000 mm, a lower diameter of 800-1200 mm, and a height of 1070-1700 mm; (21) the graphite negative electrode is arranged below the furnace graphitization zone; (22) the graphite negative electrode is provided with a circular discharging passage with a diameter of 800-1200 mm; (23) the graphite negative electrode is provided with a circular discharging passage; the circular discharging passage of the graphite negative electrode and the circular discharging passage of the furnace graphitization zone are the same vertical center; (24) the height of the graphite negative electrode is 1300-1800 mm; (25) the lower end of the graphite negative electrode is provided with a graphite negative electrode lead-out; the graphite negative electrode lead-out is one of a circular graphite column with a diameter of 600-800 mm or a square graphite column with a side length of 600-800 mm; the graphite negative electrode lead-out extends to outside the furnace shell by 600-1300 mm; an insulation oxygen-proof and waterproof seal is arranged between the graphite negative electrode lead-out and the furnace shell; the graphite negative electrode lead-out is further provided with a cooling device; (26) the furnace graphitization heat preservation zone is arranged below the graphite negative electrode; the furnace graphitization heat preservation zone is provided with a circular discharging passage with a diameter of 800-1200 mm; the graphite negative electrode is provided with a circular discharging passage; the circular discharging passage of the furnace graphitization heat preservation zone is in communication with the circular discharging passage of the graphite negative electrode; (27) the furnace graphitization heat preservation zone is provided with a circular discharging passage; the graphite negative electrode is provided with a circular discharging passage; the circular discharging passage of the furnace graphitization heat preservation zone and the circular discharging passage of the graphite negative electrode are the same vertical center; (28) the height of the furnace graphitization heat preservation zone is 1300-2300 mm; (29) the gradient cooling zone is arranged below the hearth graphitization holding zone, the gradient cooling zone is provided with a circular discharge channel with a diameter of 800-1200 mm; the hearth graphitization holding zone is provided with a circular discharge channel; the circular discharge channel of the gradient cooling zone is vertically aligned with the discharge channel of the hearth graphitization holding zone, and the area of the gradient cooling zone is 8-30 square meters; (30) the oxygen isolation discharge zone is sequentially provided from top to bottom with a cooling type disc feeder, a first can, a first gas sealing mechanism, a second can, and a second gas sealing mechanism; the second can is provided with a vacuum pumping and exhausting device; the volume of the first can is 1.0-2.0 cubic meters, and the volume of the second can is 1.2-2.2 cubic meters; the outlet of the first can is communicated with the inlet of the second can of the second can through the first gas sealing mechanism, and the outlet of the second can is provided with a second gas sealing mechanism which can be opened and closed; when the second gas sealing mechanism is opened, the material in the second can falls out through the outlet of the second can; when the second gas sealing mechanism is closed, the outlet of the second can is closed in airtight manner, and then the vacuum pumping and exhausting device is opened to exhaust the air in the second can; (31) the wall of the graphitization furnace comprises, from outside to inside, a steel layer, a first holding layer, a second holding layer, a third holding layer, a first refractory insulation layer, a second refractory insulation layer, and a third refractory insulation layer; (32) the outermost layer of the graphitization furnace is a steel shell, and the outer diameter of the steel shell is 4600-5600 mm.

5. The vertical continuous carbonization graphitization integrated furnace according to claim 1, wherein The vertical distance from the graphite positive electrode to the graphite negative electrode is D, and the vertical distance from the graphite positive electrode to the wall of the hearth is H, and 0.8≤(D / H)≤1.

6.

6. The vertical continuous carbonization graphitization integrated furnace according to claim 3 or 4, wherein At least one of the following features (a)-(c) is included: (a) the carbonization furnace is a hollow cylinder, and a 500-1650℃ heat source is arranged outside the hollow cylinder; a refractory layer, an insulation layer, and a holding layer are arranged outside the 500-1650℃ heat source; (b) the carbonization furnace is a hollow cylinder, and an annular cavity is formed between the hollow cylinder and the auxiliary exhaust pipe, and the annular cavity forms a discharge channel; a hearth graphitization preheating zone is arranged below the hearth cavity gas buffer zone, and the discharge channel is connected with the hearth graphitization preheating zone; (c) the distance between the auxiliary exhaust pipe and the center of the graphite positive electrode is 700-1100 mm.

7. The vertical continuous carbonization graphitization integrated furnace according to claim 1, wherein The outlets of the auxiliary exhaust pipe and the main exhaust pipe are provided with an automatic control device with a gas differential pressure of 0 Pa to 25 Pa, forming a self-oxygen isolation furnace top.

8. The vertical continuous carbonization graphitization integrated furnace according to claim 4, wherein At least one of the following features (i)-(xi) is included: (i) the thickness of the steel layer is 14-20 mm; (ii) the thermal conductivity of the first holding layer is not greater than 0.025 W / (m.K); (iii) the thermal conductivity of the second holding layer is not greater than 0.15 W / (m.K); (iv) the thermal conductivity of the third holding layer is not greater than 1.2 W / (m.K); (v) the service temperature of the first refractory insulation layer is not lower than 1650℃; (v) the second refractory heat-insulating layer has a service temperature of not less than 3000℃; (vi) the third refractory heat-insulating layer has a service temperature of not less than 3300℃; (vii) the temperature of the hearth graphitization zone is 2800-3300℃; (viii) the temperature of the hearth graphitization heat-insulating zone is 3300-2800℃ to 2200-1800℃ from top to bottom, decreasing in gradient; (ix) the temperature of the gradient cooling zone is 2200-1800℃ to 160-100℃ from top to bottom, decreasing in gradient; (xi) the temperature of the oxygen-isolating downfeed zone is 160-100℃ to 80-40℃ from top to bottom, decreasing in gradient; 9. The vertical continuous carbonization graphitization integrated furnace according to claim 6, wherein at least comprising any one of the following features ① to ②: ① the hearth cavity gas buffer zone is formed by the part of the downfeed channel extending into the hearth and not filled with material to form a cavity; ② the gradient cooling zone is provided with a rotary scraper; the rotary scraper has a rotating speed of 2-20 r / min.

10. The vertical continuous carbonization graphitization integrated furnace according to claim 1, wherein the total direct current power of the graphitization furnace is 400-2700 kw.

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