Anti-crusting vertical continuous graphitization furnace and anti-crusting method

Abstract

The invention discloses an anti-crusting vertical continuous graphitization furnace and an anti-crusting method in the technical field of graphitization furnaces, the top of the graphitization furnace is provided with an exhaust hole and a blanking pipe, and the bottom of the graphitization furnace is provided with a discharge pipe; a vertical graphite electrode is arranged in the graphitization furnace, and the bottom end of the graphite electrode is positioned on the lower edge of the high-temperature heating area; an exhaust pipe is arranged on the graphitization furnace and is used for exhausting ash steam in the high-temperature heating area to the outside of the furnace so as to prevent the ash steam from condensing and crusting in the low-temperature area.

Description

Technical Field

[0001] The invention relates to the technical field of graphitization furnaces, and in particular to an anti-crusting vertical continuous graphitization furnace and an anti-crusting method. Background Art

[0002] The carbonaceous raw materials can be subjected to high temperature heat treatment to perfect their atomic structure and transform them into graphite carbon with a three-dimensional regular and ordered structure of graphite, thereby achieving the purpose of graphitization.

[0003] Graphite has very high melting and boiling points, and its melting point is much higher than the boiling point of the impurities it contains. In the process of high-temperature graphitization, in addition to the lattice transformation of carbon atoms, various impurities also evaporate into gas at high temperatures. With the reduction of impurities and the increase of fixed carbon content, the purity of graphite increases, and its application value also increases.

[0004] The vertical continuous graphitization furnace transmits electricity to the graphitization furnace through graphite electrodes, and uses the resistance of the carbon raw material itself to convert the electrical energy entering the furnace into thermal energy. Its characteristics are continuous production, improved product quality, improved working conditions, controllable waste emissions, energy consumption is reduced by at least 50% compared with the Acheson graphitization furnace, and the temperature in the furnace can exceed 2500℃.

[0005] The common vertical continuous graphitization furnace structure is divided into four areas from top to bottom: preheating zone, sub-high temperature heating zone, high temperature heating zone and cooling zone. The carbon raw material is added from the top feed pipe and is continuously heated to 2500-3000℃ during the entire falling process to achieve high temperature graphitization of the carbon raw material. After graphitization in the high temperature heating zone is completed, the material enters the cooling zone at the bottom of the furnace for cooling and discharge. The ash of the carbon raw material is evaporated into gas at a high temperature of more than 2500℃ in the high temperature heating zone. Due to the buoyancy, the ash gas will naturally rise, penetrate the sub-high temperature heating zone and the preheating zone in turn, and then gather at the top of the furnace, and be sucked out of the furnace by the exhaust hole at the top.

[0006] At present, the problem of producing high-purity graphite in vertical continuous graphitization furnace is that the production of high-purity graphite has very high requirements for raw materials, including the impurity content and particle size of the raw materials. In particular, the particle size requirement is very fine, which makes the air permeability of the material layer in the furnace very poor, and the pressure of the gas evaporated from the high temperature in the furnace continues to rise until it is successfully discharged.

[0007] The ash vapor evaporated from the high temperature heating zone rises naturally and needs to pass through the secondary high temperature heating zone before it can be discharged. During the penetration process, the high temperature ash vapor will cool down when it encounters the secondary high temperature carbon raw material, condense from gaseous state to solid state, and form a hard shell layer occupying the entire cross section of the furnace in the secondary high temperature area.

[0008] This hard shell layer is very harmful. It prevents the smooth discharge of impurity evaporation gas, causing the gas pressure in the furnace to continue to rise, which can easily make the operating pressure in the furnace too high, resulting in increased equipment investment. Especially when discharging materials at the bottom of the graphitization furnace, the material layer drops as a whole, and the hard shell layer drops with it. Uneven sedimentation will always occur, and the hard shell layer will be damaged by force. High-pressure gas will be suddenly released from the damaged hard shell layer, causing "spraying" to cause material leakage, posing a threat to the safe operation of the graphitization furnace and causing safety accidents.

[0009] In summary, when producing high-purity graphite in the existing vertical continuous graphitization furnace, the ash vapor will be cooled in the sub-high temperature zone and will be agglomerated with the fine powdered raw material to form a hard shell layer occupying the entire furnace cross-section in the sub-high temperature zone, hindering the smooth discharge of impurity evaporation gas. Summary of the invention

[0010] The object of the present invention is to provide an anti-crusting vertical continuous graphitization furnace and an anti-crusting method, so as to solve the technical problem in the prior art that when producing high-purity graphite in the vertical continuous graphitization furnace, ash vapor will be cooled in the sub-high temperature zone and agglomerated with the fine powder raw material to form a hard shell layer occupying the entire cross-section of the furnace in the sub-high temperature zone, thereby hindering the smooth discharge of impurity evaporation gas.

[0011] In order to solve the above technical problems, the present invention specifically provides an anti-crusting vertical continuous graphitization furnace, wherein the top of the graphitization furnace is provided with an exhaust hole and a feed pipe, and the bottom of the graphitization furnace is provided with a discharge pipe;

[0012] A vertical graphite electrode is arranged in the graphitization furnace, and the bottom end of the graphite electrode is located at the lower edge of the high-temperature heating zone;

[0013] The graphitization furnace is provided with an exhaust pipe, which is used to exhaust the ash vapor in the high-temperature heating zone to the outside of the furnace to prevent the ash vapor from condensing and condensing in the low-temperature zone.

[0014] As a preferred solution of the present invention, the graphitization furnace is divided into a preheating zone, a sub-high temperature heating zone and a high temperature heating zone from top to bottom, and the discharge pipe is installed at the bottom of the high temperature heating zone;

[0015] The exhaust pipe is installed at the bottom of the high-temperature heating zone to form a downward air flow velocity field in the furnace body;

[0016] The zero-speed interface between the downward airflow velocity field and the upward airflow velocity field formed by the exhaust hole is located on the interface between the sub-high temperature heating zone and the high temperature heating zone.

[0017] As a preferred solution of the present invention, the graphitization furnace is composed of a preheating zone, a sub-high temperature heating zone, a high temperature heating zone and a cooling zone from top to bottom, and the discharge pipe is installed at the bottom of the cooling zone;

[0018] The exhaust pipe is installed on the side wall of the high-temperature heating zone, and one end of the exhaust pipe located in the high-temperature heating zone is connected to a wire mesh filter cartridge to extract ash vapor and intercept powdered materials.

[0019] As a preferred solution of the present invention, the wire mesh filter cartridge is made of graphite.

[0020] In order to solve the above technical problems, the present invention further provides a method for preventing crusting of a vertical continuous graphitization furnace, using the above-mentioned vertical continuous graphitization furnace for preventing crusting, including the following two situations:

[0021] If the exhaust pipe is installed at the bottom of the high temperature heating zone, then:

[0022] The fan connected to the exhaust pipe is started to form a downward air flow velocity field in the furnace;

[0023] Control the exhaust pressure of the exhaust pipe, and then control the zero-speed interface between the downward airflow velocity field and the upward airflow velocity field formed by the exhaust hole to be located at the interface between the sub-high temperature heating zone and the high temperature heating zone, so that the ash vapor in the high temperature zone flows downward, penetrates the high temperature zone and is discharged out of the furnace;

[0024] If the exhaust pipe is installed on the side of the high temperature heating zone, then:

[0025] Start the fan connected to the exhaust pipe, so that the wire mesh filter cylinder located in the high-temperature heating zone can suck the ash vapor generated in the high-temperature heating zone out of the furnace to prevent crusting in the furnace; and effectively intercept fine powder materials.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] During the graphitization process, the exhaust pipe extracts the ash vapor in the high-temperature heating zone to the outside of the furnace. The ash vapor does not need to penetrate upward into the secondary high-temperature heating zone and the preheating zone to prevent the ash vapor from condensing and condensing in the low-temperature zone, so that the operating pressure in the furnace is stable, and the spraying accident caused by the damage of the hard shell layer due to the force is avoided, so as to maintain the safe operation of the graphitization furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0029] Figure 1 This is a schematic diagram of the structure when the exhaust pipe is located at the bottom of the furnace in an embodiment of the present invention;

[0030] Figure 2 It is a structural schematic diagram of an embodiment of the present invention when the exhaust pipe is located at the furnace side;

[0031] Figure 3 It is a schematic diagram of the structure of the air extraction pipe and the wire mesh filter cartridge in an embodiment of the present invention.

[0032] The numbers in the figure represent the following:

[0033] 1-graphitizing furnace, 2-exhaust hole, 3-feeding pipe, 4-discharge pipe, 5-graphite electrode, 6-exhaust pipe, 7-preheating zone, 8-secondary high temperature heating zone, 9-high temperature heating zone, 10-cooling zone, 11-wire mesh filter cartridge, 12-zero speed interface. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The present invention specifically provides an anti-crusting vertical continuous graphitization furnace, wherein the top of the graphitization furnace 1 is provided with an exhaust hole 2 and a feed pipe 3, and the bottom of the graphitization furnace 1 is provided with a discharge pipe 4;

[0036] A vertical graphite electrode 5 is arranged in the graphitization furnace 1, and the bottom end of the graphite electrode 5 is located at the lower edge of the high-temperature heating zone 9;

[0037] The graphitization furnace 1 is provided with an exhaust pipe 6, which is used to exhaust the ash vapor in the high-temperature heating zone 9 to the outside of the furnace to prevent the ash vapor from condensing and condensing in the low-temperature zone.

[0038] The working principle of the vertical continuous graphitization furnace is as follows:

[0039] The carbonaceous raw material is added from the top discharge pipe 3, and the discharge rate is controlled by the discharge speed of the bottom discharge pipe 4, thereby controlling the graphitization time of the carbonaceous raw material.

[0040] The carbonaceous raw material falls slowly in the furnace by its own gravity. During the whole falling process, it passes through the preheating zone 7, the sub-high temperature heating zone 8 and the high temperature heating zone 9 in sequence and is continuously heated to 2500-3000°C to realize high temperature graphitization of the carbonaceous raw material.

[0041] In the preheating zone 7 and the secondary high temperature heating zone 8, the carbonaceous raw materials are dried and calcined, and the moisture and volatile gases generated by evaporation naturally rise due to buoyancy and gather at the top of the furnace, and are sucked out of the furnace by the exhaust hole 2 at the top.

[0042] The temperature in the high-temperature heating zone 9 exceeds 2500°C, and the ash of the carbon raw material (containing silicate minerals of potassium, sodium, magnesium, calcium, aluminum, and iron) is evaporated into gas at high temperature. Due to the buoyancy, the ash gas will naturally rise, penetrate the secondary high-temperature heating zone 8 and the preheating zone 7 in turn, and then gather at the top of the furnace, and be sucked out of the furnace by the exhaust hole 2 at the top.

[0043] After graphitization is completed in the high temperature heating zone 9, the material is directly discharged from the furnace for cooling, or discharged after cooling in the furnace bottom cooling zone 10, depending on the specific situation.

[0044] During the graphitization process, the exhaust pipe 6 is used to extract the ash vapor in the high-temperature heating zone 9 to the outside of the furnace. The ash vapor does not need to penetrate upward into the secondary high-temperature heating zone 8 and the preheating zone 7 to prevent the ash vapor from condensing and condensing in the low-temperature zone, so as to stabilize the operating pressure in the furnace and avoid material spraying accidents caused by damage to the hard shell layer due to stress, thereby maintaining the safe operation of the graphitization furnace 1.

[0045] As a preferred embodiment of the present invention, the graphitization furnace 1 includes a preheating zone 7, a sub-high temperature heating zone 8 and a high temperature heating zone 9 from top to bottom, and the discharge pipe 4 is installed at the bottom of the high temperature heating zone 9;

[0046] The exhaust pipe 6 is installed at the bottom of the high temperature heating zone 9 to form a downward air flow velocity field in the furnace body;

[0047] The zero-velocity boundary surface 12 between the downward airflow velocity field and the upward airflow velocity field formed by the exhaust hole 2 is located on the boundary surface between the sub-high temperature heating zone 8 and the high temperature heating zone 9 .

[0048] In this way, the ash vapor in the high temperature zone can flow downward and penetrate the high temperature zone, rather than penetrating the medium and low temperature zones to be condensed and crusted. This solution requires direct discharge from the high temperature zone and cooling outside the furnace, otherwise the ash vapor will still crust in the cooling zone 10.

[0049] As a preferred embodiment of the present invention, the graphitization furnace 1 includes a preheating zone 7, a sub-high temperature heating zone 8, a high temperature heating zone 9 and a cooling zone 10 from top to bottom, and the discharge pipe 4 is installed at the bottom of the cooling zone 10;

[0050] The exhaust pipe 6 is installed on the side wall of the high temperature heating zone 9. One end of the exhaust pipe 6 located in the high temperature heating zone 9 is connected to a wire mesh filter cartridge 11 to extract the ash vapor generated in the high temperature heating zone 9 out of the furnace to prevent crusting in the furnace.

[0051] At the same time, the dense wire mesh effectively intercepts fine powder materials to avoid the "material leakage" of raw materials and products caused by suction negative pressure.

[0052] As a preferred solution of the present invention, the wire mesh filter cartridge 11 needs to operate stably at a very high temperature, and the material selected is high temperature resistant graphite.

[0053] In order to solve the above technical problems, the present invention further provides a method for preventing crusting of a vertical continuous graphitization furnace, using the above-mentioned vertical continuous graphitization furnace for preventing crusting, including the following two situations:

[0054] If the exhaust pipe 6 is installed at the bottom of the high temperature heating zone 9, then:

[0055] The fan connected to the exhaust pipe 6 is started to form a downward air flow velocity field in the furnace;

[0056] Control the exhaust pressure of the exhaust pipe 6, and then control the zero-speed interface of the downward airflow velocity field and the upward airflow velocity field formed by the exhaust hole 2 to be located at the interface between the sub-high temperature heating zone 8 and the high temperature heating zone 9, so that the ash vapor in the high temperature zone flows downward, penetrates the high temperature zone and is discharged out of the furnace;

[0057] If the exhaust pipe 6 is installed on the side of the high temperature heating zone 9, then:

[0058] Start the fan connected to the exhaust pipe 6, so that the wire mesh filter cartridge 11 located in the high-temperature heating zone 9 can suck the ash vapor generated in the high-temperature heating zone 9 out of the furnace to prevent crusting in the furnace; and effectively intercept the fine powder material.

[0059] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A vertical continuous graphitization furnace for preventing encrustation, characterized in that: The top of the graphitization furnace (1) is provided with an exhaust hole (2) and a feed pipe (3), and the bottom of the graphitization furnace (1) is provided with a discharge pipe (4); A vertical graphite electrode (5) is arranged in the graphitization furnace (1), and the bottom end of the graphite electrode (5) is located at the lower edge of the high-temperature heating zone (9); The graphitization furnace (1) is provided with an exhaust pipe (6), and the exhaust pipe (6) is used to exhaust the ash vapor in the high-temperature heating zone (9) to the outside of the furnace to prevent the ash vapor from condensing and forming a crust in the low-temperature zone.

2. The anti-crusting vertical continuous graphitization furnace according to claim 1, characterized in that: The graphitization furnace (1) includes a preheating zone (7), a secondary high temperature heating zone (8) and a high temperature heating zone (9) from top to bottom, and the discharge pipe (4) is installed at the bottom of the high temperature heating zone (9); The exhaust pipe (6) is installed at the bottom of the high-temperature heating zone (9) to form a downward air flow velocity field in the furnace body; The zero-speed boundary surface (12) between the downward airflow velocity field and the upward airflow velocity field formed by the exhaust hole (2) is located at the boundary surface between the sub-high temperature heating zone (8) and the high temperature heating zone (9).

3. The anti-crusting vertical continuous graphitization furnace according to claim 1, characterized in that: The graphitization furnace (1) includes, from top to bottom, a preheating zone (7), a secondary high temperature heating zone (8), a high temperature heating zone (9) and a cooling zone (10), and the discharge pipe (4) is installed at the bottom of the cooling zone (10); The exhaust pipe (6) is installed on the side wall of the high-temperature heating zone (9), and one end of the exhaust pipe (6) located in the high-temperature heating zone (9) is connected to a wire mesh filter cartridge (11) to extract ash vapor and intercept powdered materials.

4. The anti-crusting vertical continuous graphitization furnace according to claim 3, characterized in that: The wire mesh filter cartridge (11) is made of graphite.

5. A method for preventing crusting in a vertical continuous graphitization furnace, characterized in that: The use of an anti-crusting vertical continuous graphitization furnace according to any one of claims 1 to 4 includes the following two situations: If the exhaust pipe (6) is installed at the bottom of the high-temperature heating zone (9), then: Starting a fan connected to the exhaust pipe (6) to form a downward air flow velocity field in the furnace; Controlling the exhaust pressure of the exhaust pipe (6), thereby controlling the zero-speed interface between the downward airflow velocity field and the upward airflow velocity field formed by the exhaust hole (2) to be located at the interface between the sub-high temperature heating zone (8) and the high temperature heating zone (9), so that the ash vapor in the high temperature heating zone flows downward, penetrates the high temperature heating zone and is discharged out of the furnace; If the exhaust pipe (6) is installed on the side of the high-temperature heating zone (9), then: The fan connected to the exhaust pipe (6) is started to make the wire mesh filter cartridge (11) located in the high temperature heating zone (9) suck the ash vapor generated in the high temperature heating zone (9) out of the furnace to prevent crusting in the furnace; And effectively intercept fine powder materials.

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