Roasting furnace for carbon products and roasting control method

Abstract

The invention discloses a roasting furnace for carbon products and a roasting control method, and the roasting furnace for the carbon products comprises a furnace body which is divided into a plurality of roasting areas in the direction from a product inlet to a product outlet of the furnace body; the carrying device is partially arranged in the furnace body and is used for conveying the carbon products from the product inlet of the furnace body to the product outlet of the furnace body; the multiple heating devices are arranged on the inner side wall of the furnace body at intervals, each roasting area is provided with at least one heating device, and the heating temperatures of the heating devices arranged in different roasting areas are different. The technical problem that large energy loss is caused by roasting temperature control is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of roasting, and particularly relates to a roasting furnace for carbon products and a roasting control method. Background Art

[0002] After roasting carbon products, their mechanical strength, heat resistance, corrosion resistance, and good thermal and electrical conductivity can be further improved to meet the needs of use and further thermal processing. According to different application requirements, carbon products can be divided into various types, such as carbon blocks, electrodes, carbon resistors, etc., and their roasting temperatures and process conditions are also different. When roasting carbon products, different roasting stages require different roasting temperatures, and temperature control has a great impact on the roasting quality.

[0003] In the prior art, it is necessary to bury carbon products at a fixed position and control the overall temperature inside the roasting furnace to meet the different roasting temperatures required by carbon products at different roasting stages. Since the roasting temperatures required in different roasting stages vary greatly and frequent temperature rises and falls are needed, the control of the roasting temperature causes large energy losses, which in turn increases the enterprise cost. Therefore, the large energy loss caused by the control of the roasting temperature is a technical problem to be solved urgently. Summary of the Invention

[0004] The embodiments of the present invention provide a roasting furnace for carbon products and a roasting control method, which solve the technical problem of large energy losses caused by the control of the roasting temperature.

[0005] In a first aspect, the embodiments of the present invention provide a roasting furnace for carbon products, including: a furnace body, which is divided into multiple roasting zones in the direction from the product inlet to the product outlet of the furnace body; a conveying device, partially arranged inside the furnace body, for transporting carbon products from the product inlet of the furnace body to the product outlet of the furnace body; and a plurality of heating devices, which are arranged at intervals on the inner sidewall of the furnace body, at least one heating device is arranged in each roasting zone, and the heating temperatures of the heating devices arranged in different roasting zones are different.

[0006] In combination with the first aspect of the present invention, in some embodiments, the conveying device includes: an inner track, arranged at the inner bottom of the furnace body, and the inner track extends from the product inlet of the furnace body to the product outlet of the furnace body; an outer track, arranged outside the furnace body, one end of the outer track is connected to one end of the inner track, and the other end of the outer track is connected to the other end of the inner track; and a kiln car, which is movably arranged on the inner track and the outer track.

[0007] In connection with the first aspect of the present invention, in some embodiments, each of the roasting zones is provided with one of the heating devices, and the rated power of the heating wires of the heating devices provided in different roasting zones is the same. The number of heating wires of the heating devices provided in the roasting zones near the product inlet and the product outlet is lower than the number of heating wires of the heating devices provided in the roasting zones near the middle position inside the furnace body; or each of the roasting zones is provided with one of the heating devices, and the number of heating wires of the heating devices provided in different roasting zones is the same. The rated power of the heating wires of the heating devices provided in the roasting zones near the product inlet and the product outlet is lower than the rated power of the heating wires of the heating devices provided in the roasting zones near the middle position inside the furnace body.

[0008] In connection with the first aspect of the present invention, in some embodiments, the heating wires of the heating device provided in at least one of the roasting zones include a plurality. A part of the heating wires of the heating device is disposed on the first inner sidewall of the furnace body, and another part of the heating wires of the heating device is disposed on the second inner sidewall of the furnace body. The first inner sidewall and the second inner sidewall are located on opposite sides of the inner track.

[0009] In connection with the first aspect of the present invention, in some embodiments, it further includes: a gas supply device, which is communicated with the furnace body and is used for supplying an inert gas into the furnace body; the gas supply device includes: a first pipeline, the outlet of the first pipeline is connected to the first gas inlet of the furnace body; a second pipeline, the inlet of the second pipeline is connected to the first gas outlet of the furnace body; a circulation sub-device, the first outlet of the circulation sub-device is connected to the first inlet of the first pipeline, and the inlet of the circulation sub-device is connected to the outlet of the second pipeline; a first gas source, which is connected to the second inlet of the first pipeline; wherein, the gas in the furnace body flows through the furnace body, the second pipeline, the circulation sub-device and the first pipeline in sequence.

[0010] In connection with the first aspect of the present invention, in some embodiments, it further includes: a heat-conducting gasket, which is disposed on the bearing surface of the kiln car, and the bearing surface is used for bearing the carbon product.

[0011] In combination with the first aspect of the present invention, in some embodiments, the furnace body includes a first furnace zone and a second furnace zone. The plurality of roasting zones are located in the first furnace zone. The first furnace zone is close to the product outlet of the furnace body, and the second furnace zone is close to the product inlet of the furnace body. The first gas inlet of the furnace body, the first gas outlet of the furnace body, and the plurality of heating devices are located in the first furnace zone. The roasting furnace further includes: a third pipeline, the outlet of which is connected to the second gas inlet of the furnace body; a fourth pipeline, the inlet of which is connected to the second gas outlet of the furnace body; a gas combustion device, the outlet of which is connected to the inlet of the third pipeline, and the inlet of which is connected to the outlet of the fourth pipeline. Wherein, the gas in the second furnace zone sequentially flows through the second furnace zone, the fourth pipeline, the gas combustion device, and the third pipeline. The second gas inlet and the second gas outlet of the furnace body are located in the second furnace zone.

[0012] In combination with the first aspect of the present invention, in some embodiments, it further includes: a fifth pipeline, the inlet of which is connected to the second outlet of the circulation sub-device, and the outlet of which is arranged on the side wall between the first furnace zone and the second furnace zone.

[0013] In combination with the first aspect of the present invention, in some embodiments, it further includes: a damper, which is arranged in the furnace body and divides the space in the furnace body into the first furnace zone and the second furnace zone.

[0014] In a second aspect, an embodiment of the present invention provides a roasting control method for carbon products, which is applied to the roasting furnace for carbon products as described in any one of the first aspects. The method includes: when roasting the carbon products, obtaining the target partition temperature of each roasting zone in the furnace body; based on the target partition temperature of each roasting zone in the plurality of roasting zones, controlling the plurality of heating devices so that the temperature of each roasting zone in the plurality of roasting zones reaches the corresponding target partition temperature; after the temperature of each roasting zone in the plurality of roasting zones reaches the corresponding target partition temperature, repeating at intervals of a preset duration, and controlling the carrier device to move the carbon products at a preset distance.

[0015] One or more technical solutions provided by the embodiments of the present invention at least achieve the following technical effects or advantages:

[0016] The baking furnace for carbon products provided by the embodiments of the present invention includes: a furnace body, which is divided into multiple baking zones in the direction from the product inlet to the product outlet of the furnace body; a conveying device, partially arranged inside the furnace body, for transporting the carbon products from the product inlet of the furnace body to the product outlet of the furnace body; and a plurality of heating devices, which are arranged at intervals on the inner side wall of the furnace body, at least one heating device is arranged in each baking zone, and the heating temperatures of the heating devices arranged in different baking zones are different. Since the conveying device can move the carbon products, and the heating devices can control the temperature inside the furnace body of the furnace in zones, the carbon products can be moved to different baking zones of the furnace body at different baking stages to meet the required baking temperature of the carbon products. By controlling in zones, the overall control of the temperature inside the baking furnace is avoided, and thus the energy consumption loss caused by frequent temperature rise and fall due to overall temperature control is avoided. Therefore, the energy loss caused by the control of the baking temperature is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 Schematic diagram of the baking furnace for carbon products in the embodiments of the present invention;

[0019] Figure 2 Schematic diagram of the gas supply device in the embodiments of the present invention;

[0020] Figure 3 Schematic diagram of the kiln car in the embodiments of the present invention;

[0021] Figure 4 Schematic diagram of the first furnace zone and the second furnace zone in the embodiments of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0023] In the present invention, descriptions such as "first", "second", etc. are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. Additionally, the technical solutions between various embodiments may be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or is unachievable, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0024] Figure 1 It is a schematic diagram of a roasting furnace for carbon products in an embodiment of the present invention, where Figure 1 (a) is the front view of the roasting furnace for carbon products, Figure 1 (b) is the side view of the roasting furnace for carbon products. Specifically, the side view may refer to the view in the direction from the product inlet to the product outlet of the furnace body 10, and the front view may refer to the view in the direction perpendicular to the above direction. Referring Figure 1 As shown, a roasting furnace for carbon products provided by an embodiment of the present invention includes: a furnace body 10, which is divided into multiple roasting zones in the direction from the product inlet to the product outlet of the furnace body 10; a conveying device 20, partially arranged inside the furnace body 10, for transporting carbon products from the product inlet of the furnace body 10 to the product outlet of the furnace body 10; and a plurality of heating devices 30, spaced apart and arranged on the inner sidewall of the furnace body 10, with at least one heating device 30 provided in each roasting zone, and the heating temperatures of the heating devices 30 provided in different roasting zones are different.

[0025] In some embodiments, the conveying device 20 may include: an inner track, arranged at the inner bottom of the furnace body 10, and the inner track extends from the product inlet of the furnace body 10 to the product outlet of the furnace body 10; an outer track, arranged outside the furnace body 10, one end of the outer track is connected to one end of the inner track, and the other end of the outer track is connected to the other end of the inner track; and a kiln car 210, movably arranged on the inner track and the outer track.

[0026] It should be noted that the carbon products may be placed on the bearing surface of the kiln car 210. Specifically, one kiln car 210 may transport one carbon product, or one kiln car 210 may transport multiple carbon products. The actual length of the kiln car 210 may be determined according to the actual situation. The kiln car 210 may be one or more.

[0027] In some embodiments, each roasting zone is provided with a heating device 30. The rated power of the heating wire of the heating devices 30 provided in different roasting zones is the same, and the number of heating wires of the heating devices 30 provided in the roasting zones near the product inlet and the product outlet is lower than that of the heating devices 30 provided in the roasting zones near the middle position inside the furnace body 10; or each roasting zone is provided with a heating device 30, the number of heating wires of the heating devices 30 provided in different roasting zones is the same, and the rated power of the heating wire of the heating devices 30 provided in the roasting zones near the product inlet and the product outlet is lower than that of the heating devices 30 provided in the roasting zones near the middle position inside the furnace body 10.

[0028] It should be noted that when roasting carbon products, it is necessary to first raise the temperature and then lower the temperature. Therefore, the above restrictions on the number of heating wires and the rated power of the heating wire are to achieve a temperature rise first and then a temperature drop in the roasting zones from the product inlet to the product outlet, so as to meet the roasting requirements of carbon products and improve the roasting quality of carbon products.

[0029] In some embodiments, the heating wire of the heating device 30 provided in at least one roasting zone includes a plurality of wires. A part of the heating wires of the heating device 30 is arranged on the first inner side wall of the furnace body 10, and another part of the heating wires of the heating device 30 is arranged on the second inner side wall of the furnace body 10. The first inner side wall and the second inner side wall are located on opposite sides of the inner track.

[0030] It should be noted that arranging the heating wires on the first inner side wall and the second inner side wall respectively can ensure that the temperatures of different parts of the carbon product change evenly, thereby improving the roasting quality.

[0031] In some embodiments, the roasting furnace for carbon products may further include: a gas supply device, which is connected to the furnace body 10 and is used to supply inert gas into the furnace body 10; the gas supply device may include: a first pipeline 410, the outlet of the first pipeline 410 is connected to the first gas inlet of the furnace body 10; a second pipeline 420, the inlet of the second pipeline 420 is connected to the first gas outlet of the furnace body 10; a circulation sub-device 430, the first outlet of the circulation sub-device 430 is connected to the first inlet of the first pipeline 410, and the inlet of the circulation sub-device 430 is connected to the outlet of the second pipeline 420; a first gas source 440, which is connected to the second inlet of the first pipeline 410; wherein, the gas in the furnace body 10 flows through the furnace body 10, the second pipeline 420, the circulation sub-device 430, and the first pipeline 410 in sequence.

[0032] Reference Figure 2 as shown Figure 2It is a schematic diagram of the gas supply device in the embodiment of the present invention. The first gas inlet of the furnace body 10 can be arranged at the bottom of the furnace body 10 near the product outlet, and the first gas outlet of the furnace body 10 can be arranged at the bottom of the furnace body 10 near the product inlet. It should be noted that if the inert gas inside the furnace body 10 is insufficient, the first gas source 440 can release a part of the internal inert gas to supplement the inert gas inside the furnace body 10. The inert gas released by the first gas source 440 flows through the first pipeline 410, the furnace body 10, the second pipeline 420, and the circulation sub-device 430 in sequence. Among them, the circulation sub-device 430 can be a device composed of a fan, which is used to form a negative pressure to circulate the gas inside the furnace body 10.

[0033] It should be noted that during the roasting process, if the carbon product is in direct contact with oxygen, especially at high temperatures, oxygen will chemically react with the carbon material, resulting in oxidation. This oxidation reaction will consume the carbon material and reduce its quality and performance. Therefore, the embodiment of the present invention limits the gas supply device to supply inert gas to the furnace body 10 to isolate the carbon product from oxygen, thereby avoiding the oxidation of the carbon product and improving the roasting quality of the carbon product.

[0034] In some embodiments, the roasting furnace for carbon products may further include: a heat-conducting gasket 40, which is arranged on the bearing surface of the kiln car 210, and the bearing surface is used to bear the carbon product.

[0035] It should be noted that the heat-conducting gasket 40 can accelerate the heat transfer efficiency at the bottom position of the carbon product, realize uniform temperature change at different positions of the carbon product, and thus improve the roasting quality of the carbon product. In addition, as shown in Figure 3 shown Figure 3 It is a schematic diagram of the kiln car in the embodiment of the present invention. The bearing surface of the kiln car 210 can be a block-shaped refractory material with gaps to strengthen gas circulation, thereby strengthening heat conduction, making the temperature change uniformly at different positions of the carbon product, and improving the roasting quality of the carbon product.

[0036] In some embodiments, the furnace body 10 may include a first furnace zone 110 and a second furnace zone 120. A plurality of roasting zones are located in the first furnace zone 110. The first furnace zone 110 is close to the product outlet of the furnace body 10, and the second furnace zone 120 is close to the product inlet of the furnace body 10. The first gas inlet of the furnace body 10, the first gas outlet of the furnace body 10, and a plurality of heating devices 30 are located in the first furnace zone 110. The roasting furnace may further include: a third pipeline 50, the outlet of the third pipeline 50 is connected to the second gas inlet of the furnace body 10; a fourth pipeline 60, the inlet of the fourth pipeline 60 is connected to the second gas outlet of the furnace body 10; a gas combustion device 70, the outlet of the gas combustion device 70 is connected to the inlet of the third pipeline 50, and the inlet of the gas combustion device 70 is connected to the outlet of the fourth pipeline 60; wherein, the gas in the second furnace zone 120 sequentially flows through the second furnace zone 120, the fourth pipeline 60, the gas combustion device 70, and the third pipeline 50; the second gas inlet of the furnace body 10 and the second gas outlet of the furnace body 10 are located in the second furnace zone 120.

[0037] It should be noted that in the case where the furnace body 10 is not divided into the first furnace zone 110 and the second furnace zone 120, then the plurality of roasting zones may refer to the entire furnace zone or a part of the furnace zone. In the case where the furnace body 10 is divided into the first furnace zone 110 and the second furnace zone 120, then the plurality of roasting zones may refer to those obtained by further subdividing the first furnace zone 110.

[0038] Reference Figure 4 shown in Figure 4 is a schematic diagram of the first furnace zone and the second furnace zone in the embodiment of the present invention. The gas flow directions of the first furnace zone and the second furnace zone can be referred to Figure 4 shown. The second gas inlet of the furnace body 10 may be provided at the bottom of the furnace body 10 near the product outlet, and the second gas outlet of the furnace body 10 may be provided at the bottom of the furnace body 10 near the product inlet. It should be noted that as the roasting progresses, the position of the carbon product first passes through the second furnace zone 120 and then through the first furnace zone 110. The gas combustion device 70 may include a second gas source, and the second gas source may be used to store combustible gas, such as natural gas. By burning the gas inside the gas combustion device 70, the gas temperature in the third pipeline 50 can be increased, thereby increasing the gas temperature in the second furnace zone 120, and thus realizing the control of the roasting temperature of the carbon product. In addition, the second furnace zone 120 corresponds to the initial stage of roasting. At this time, a large amount of volatile components in the carbon product will be precipitated, and some of the volatile components in the carbon product are combustible. The gas combustion device 70 utilizes the volatile components in the carbon product to provide energy for roasting temperature control, reduces the consumption of combustible gas, and thus realizes the beneficial effect of energy conservation.

[0039] It should be noted that the gas combustion device 70 may further include a gas circulation module and a combustion module.

[0040] Among them, the second gas source is arranged inside the combustion module. The gas circulation module can be a module composed of a fan, which is used to circulate the gas in the second furnace zone 120, and suck the gas in the second furnace zone 120 into the combustion module through the gas circulation module.

[0041] In some embodiments, the roasting furnace for carbon products may further include: a fifth pipeline 80. The inlet of the fifth pipeline 80 is connected to the second outlet of the circulation sub-device 430, and the outlet of the fifth pipeline 80 is arranged on the side wall between the first furnace zone 110 and the second furnace zone 120.

[0042] In some embodiments, the third pipeline 50 can be wound around the fifth pipeline 80 to achieve gas heat exchange.

[0043] It should be noted that part of the gas flowing out of the outlet of the fifth pipeline 80 enters the first furnace zone 110, and part enters the second furnace zone 120. The gas flowing out of the fifth pipeline 80 can form an air curtain to separate the gas in the first furnace zone 110 and the second furnace zone 120, thus preventing the oxygen in the second furnace zone 120 from entering the first furnace zone 110, and further preventing the carbon products in the first furnace zone 110 from being oxidized, and improving the roasting quality of the carbon products.

[0044] In some embodiments, the roasting furnace for carbon products may further include: a gate plate, which is arranged inside the furnace body 10 and divides the space inside the furnace body 10 into the first furnace zone 110 and the second furnace zone 120. It should be noted that the gate plate can also separate the gas in the first furnace zone 110 and the second furnace zone 120.

[0045] It should be noted that both the gate plate or the fifth pipeline 80 are used to block the gas flow between the first furnace zone 110 and the second furnace zone 120, and the position of the gate plate or the fifth pipeline 80 can be set at the position corresponding to the temperature inside the furnace body being less than 500°C.

[0046] It should be noted that in the prior art, the carbon products need to be buried in a fixed position, and the overall temperature inside the roasting furnace is controlled to meet the different roasting temperatures required by the carbon products at different roasting stages. Since the carbon products are buried in a fixed position, the carbon products can only be roasted batch by batch, and the roasting time is long. In contrast, in the embodiments of the present invention, the carbon products can be moved, and the temperature inside the furnace can be controlled in zones, realizing continuous roasting, without the need to frequently control the temperature rise and fall, thus reducing the waiting time for the temperature rise and fall, and further improving the roasting efficiency of the carbon products.

[0047] For example, suppose there are carbon products numbered 1 - 10 that need to be baked. The prior art requires batch baking. The first batch can be carbon products numbered 1 - 5. After the baking of 1 - 5 is completed, the baking of carbon products numbered 6 - 10 can start. In contrast, in the embodiment of the present invention, first, carbon products numbered 1 - 5 are baked. After the conveying device 20 removes the 5th carbon product from the first outlet of the furnace body 10, that is, when the 5th one is baked, at this time, the 6th one enters the furnace, and the 2nd - 6th ones are baked simultaneously. Each time one carbon product is removed, one carbon product can be moved in, realizing continuous baking.

[0048] It should be noted that the baking of carbon products is a key process in the production of carbon products for aluminum use, which determines the levels of key indicators such as the resistivity, strength, and gas reactivity of carbon products. The baking process has the highest energy consumption ratio in the whole process. The existing carbon product baking has long used open baking furnaces as the main equipment, and the large-scale energy-saving technology of baking furnaces has reached a principle bottleneck, with the following problems: (1) Due to the thermal process system of repeated heating and cooling, the energy consumption level of the step-by-step intermittent heating furnace is difficult to further reduce; (2) The flue wall material box is too long and deep, the flue temperature distribution is uneven, and the temperature difference within the same flue wall is 50 °C; there are problems such as flue creep deformation and air leakage, and the repeated charging and discharging of the material box cause damage, making it difficult to maintain the baking quality; (3) The heating position changes with the baking curve, resulting in an unfixed flue gas emission position, making it difficult to achieve centralized treatment of flue gas purification and difficult to utilize the flue gas waste heat; (4) The open and mobile working surface is difficult to improve the automation level, improve the working environment, and reduce the labor intensity; (5) The production capacity of metallurgical furnaces is restricted by indicators such as the project floor area and the plant span and is difficult to further improve; (6) To prevent the oxidation of carbon products, the existing baking uses methods such as carbon burial to protect carbon products, uses flues to isolate the flame, heats the filling material through thermal radiation, and then heats the carbon products, which additionally increases the consumption of thermal energy. The embodiment of the present invention, in order to overcome the deficiencies such as the repeated heating and cooling thermal process system and low thermal energy utilization rate in the prior art, adopts segmented precise control of the furnace atmosphere, prevents the oxidation of carbon products, makes full use of the volatile components released by the products, reduces the heat loss such as heat storage and heat release of traditional baking furnaces, effectively reduces the energy consumption of carbon product baking, and improves the baking heating method for the homogeneity of carbon products.

[0049] It should be noted that the roasting stage includes a stage where volatiles in the carbon product are precipitated in large quantities and a stage where the carbon product is prevented from oxidation. The heating method in the stage where volatiles are precipitated in large quantities can be high-temperature flue gas heating, and the carbon product is prevented from oxidation by electric heating under the protection of inert gas, so that the carbon product is heated to about 1080°C in the room temperature stage, and then taken out of the furnace after being cooled to 300°C, completing the roasting heat treatment of the carbon product. In addition, the carrier 20 can be built of refractory materials, and a thermally conductive gasket 40 is placed on the carrier 20. The thermally conductive gasket 40 can be a high thermal conductivity material such as a graphite plate or a carbon plate, and the carbon product is placed on the thermally conductive gasket 40. Under the action of the carrier 20, the carbon product enters the furnace body 10 from one end of the furnace, and after passing through the stage where volatiles are precipitated in large quantities and the stage where the product is prevented from oxidation, it is transported out from the end of the furnace. Secondly, in the stage of large-scale precipitation of volatiles in carbon products, this temperature point is before 500℃, and the flue gas is introduced from the flue gas inlet of the 500℃ temperature section through the flue gas circulation system, and discharged to the flue gas outlet of the normal temperature section under the action of negative pressure. The flue gas discharge takes away the volatiles at the same time and enters the flue gas circulation and waste heat utilization system. The volatiles precipitated from the carbon products and the flue gas enter the flue gas circulation and waste heat utilization system under the action of negative pressure. Under the action of natural gas and other fuels, the flue gas containing volatiles burns to generate heat, heating the flue gas to above 550℃. The heated high-temperature flue gas enters the furnace through the flue gas circulation system and participates in the heating of carbon products. The stage of preventing oxidation of carbon products mainly includes two parts: heating and cooling. The whole process is protected by inert atmosphere. Carbon products do not need to be protected by fillers to prevent anodic oxidation. The heating method is flame insulation heating (electric heating, fire wall or fire channel heating, etc.). In the stage of preventing oxidation of carbon products, in the stage of inert atmosphere protection and heating, the inert gas enters from the inert gas inlet at the tail of the heating device 30, and under the action of negative pressure, it passes through the cooling section and the high temperature section to reach a temperature of 500°C, and is discharged through the inert gas outlet and merged into the circulation sub-device 430. In the stage of preventing oxidation of carbon products, the inert atmosphere is produced by the first gas source 440, which can be an inert gas such as N2 and argon, and the purity of the inert gas is above 99.9%. The inert gas discharged from the furnace can be recycled after being purified and dust-removed by the inert gas circulation system, and participates in the atmosphere protection to prevent the oxidation of the product. The insufficient part is prepared by the first gas source 440 and supplied to the inert gas circulation system. Between the stage of large-scale precipitation of volatiles in carbon products and the stage of preventing oxidation of carbon products, an inert gas curtain or gate is used to separate, and at the same time, it is ensured that the heat of the carbon product prevention oxidation stage can be radiated into the stage of large-scale precipitation of volatiles in carbon products. Through the above scheme, the resistivity of the carbon product treated by the embodiment of the present invention reaches 55μΩ·m, there is no oxidation on the surface, the roasting energy consumption is reduced to below 1.7GJ / t, and the temperature deviation in the high-temperature furnace is less than 10°C.The embodiment of the present invention realizes the roasting heat treatment of carbon products without filler protection, adopts segmented precise atmosphere control to prevent oxidation of carbon products, fully utilizes volatile matter precipitated from the products, reduces heat loss such as heat storage and release of traditional roasting furnaces, effectively reduces roasting energy consumption, and achieves the purpose of improving the quality and reducing the cost of roasting carbon products, providing a technical path for energy saving and consumption reduction of electrolytic aluminum.

[0050] The following is further described by way of examples:

[0051] Embodiment 1:

[0052] In the stage of large-scale precipitation of volatiles in carbon products, the temperature is 500°C. The heating method in this stage is high-temperature flue gas heating (corresponding to the second furnace area 120). The 600°C high-temperature flue gas flows through the second furnace area 120, the fourth pipeline 60, the gas combustion device 70 and the third pipeline 50 in sequence. Under the action of negative pressure, it is drawn out from the flue gas outlet at the furnace head position, and the volatiles are taken out to the gas combustion device 70 at the same time. The mixed gas discharged from the furnace is heated to 600°C through the flue gas circulation and waste heat utilization system and then circulated in the heating device 30; in the stage of preventing oxidation of carbon products, electric heating is used under the protection of inert gas to prevent oxidation of the products. The heating method is flame-muffle heating (electric heating , fire wall or fire channel, etc.), the inert atmosphere is produced by a gas generating device, which can be an inert gas such as N2, argon, etc., and the purity of the inert gas is above 99.99%; under the action of negative pressure, the inert gas passes through the cooling section via the high temperature section to reach a temperature of 500°C, is discharged through the inert gas outlet, and merged into the inert gas circulation recovery system. The carbon products do not need to be protected by fillers during the entire roasting process, so that the carbon products are heated to about 1080°C in the room temperature stage, and are taken out of the furnace after being cooled to 300°C. The temperature deviation in the high temperature section furnace is less than 10°C, the resistivity of the carbon products is 55μΩ·m, there is no oxidation on the surface, and the roasting energy consumption is reduced to 1.7GJ / t.

[0053] Embodiment 2:

[0054] During the stage when a large amount of volatile matter is released from the carbon product, at the temperature of 490 °C, the heating method in this stage is heating with high-temperature flue gas. At 560 °C, under the action of negative pressure, the high-temperature flue gas is led out from the flue gas outlet at the furnace head position, and at the same time, the volatile matter generated by the green product is carried out of the second furnace zone 120. The mixed gas discharged from the furnace is heated to 560 °C through the flue gas circulation and waste heat utilization system and then circulates in the second furnace zone 120; during the stage of preventing oxidation of the carbon product, electric heating is adopted under the protection of inert gas to prevent the product from being oxidized. The heating method is muffle heating (such as electric heating, fire wall or flue heating, etc.). The inert atmosphere is produced by a gas generating device and can be inert gases such as N2 and argon, and the purity of the inert gas is above 99.99%; under the action of negative pressure, the inert gas reaches the temperature of 490 °C from the cooling section through the high-temperature section and is discharged through the inert gas outlet and then incorporated into the inert gas circulation and recovery system. During the entire roasting process, the carbon product does not require protection by filler. The carbon product is heated from room temperature to about 1050 °C, cooled to 300 °C and then discharged from the furnace. The temperature deviation in the high-temperature section of the furnace is less than 10 °C. The resistivity of the carbon product reaches 57 μΩ·m, and there is no oxidation phenomenon on the surface. The roasting energy consumption is reduced to 1.5 GJ / t.

[0055] Example 3:

[0056] During the stage when a large amount of volatile matter is released from the carbon product, at the temperature of 450 °C, the heating method in this stage is heating with high-temperature flue gas. At 580 °C, under the action of negative pressure, the high-temperature flue gas is led out from the flue gas outlet at the furnace head position, and at the same time, the volatile matter generated by the green product is carried out of the second furnace zone 120. The mixed gas discharged from the furnace is heated to 580 °C through the flue gas circulation and waste heat utilization system and then circulates in the second furnace zone 120; during the stage of preventing oxidation of the carbon product, electric heating is adopted under the protection of inert gas to prevent the product from being oxidized. The heating method is muffle heating (such as electric heating, fire wall or flue heating, etc.). The inert atmosphere is produced by a gas generating device and can be inert gases such as N2 and argon, and the purity of the inert gas is above 99.99%; under the action of negative pressure, the inert gas reaches the temperature of 450 °C from the cooling section through the high-temperature section and is discharged through the inert gas outlet and then incorporated into the inert gas circulation and recovery system. During the entire roasting process, the carbon product does not require protection by filler. The carbon product is heated from room temperature to about 1060 °C, cooled to 300 °C and then discharged from the furnace. The temperature deviation in the high-temperature section of the furnace is ≤10 °C. The resistivity of the carbon product reaches 56.5 μΩ·m, and there is no oxidation phenomenon on the surface. The roasting energy consumption is reduced to 1.6 GJ / t.

[0057] Example 4:

[0058] During the stage of a large amount of volatile matter evolving from the carbon product, at the temperature of 490°C, the heating method in this stage is heating with high-temperature flue gas. At 580°C, under the action of negative pressure, the high-temperature flue gas is led out from the flue gas outlet at the furnace head position, and at the same time, the volatile matter generated by the green product is carried out of the second furnace zone 120. The mixed gas discharged from the furnace is heated to 580°C through the flue gas circulation and waste heat utilization system and then circulates in the second furnace zone 120; during the stage of preventing oxidation of the carbon product, under the protection of inert gas, electric heating is adopted to prevent the product from oxidation, and the heating method is muffle heating (such as electric heating, fire wall or flue heating, etc.). The inert atmosphere is produced by a gas generating device and can be inert gases such as N2 and argon, and the purity of the inert gas is above 99.99%. Under the action of negative pressure, the inert gas reaches the temperature of 490°C from the cooling section through the high-temperature section and is discharged through the inert gas outlet and then incorporated into the inert gas circulation and recovery system. During the entire roasting process, the carbon product does not need to be protected by a filler. The carbon product is heated from room temperature to about 1070°C, cooled to 300°C and then discharged from the furnace. The temperature deviation in the high-temperature section of the furnace is less than 10°C, the resistivity of the carbon product reaches 56.5 μΩ·m, there is no oxidation phenomenon on the surface, and the roasting energy consumption is reduced to 1.63 GJ / t.

[0059] The roasting furnace for carbon products provided by the embodiment of the present invention includes: a furnace body 10, which is divided into multiple roasting zones in the direction from the product inlet to the product outlet of the furnace body 10; a conveying device 20, partially arranged in the furnace body 10, and used to convey the carbon product from the product inlet of the furnace body 10 to the product outlet of the furnace body 10; a plurality of heating devices 30, which are arranged at intervals on the inner side wall of the furnace body 10, at least one heating device 30 is arranged in each roasting zone, and the heating temperatures of the heating devices 30 arranged in different roasting zones are different. Since the conveying device 20 can move the carbon product, and the heating device 30 can control the temperature in the furnace of the furnace body 10 in zones, the carbon product can be moved to different roasting zones of the furnace body 10 at different roasting stages to meet the required roasting temperature of the carbon product. By controlling in zones, the overall control of the temperature in the furnace of the roasting furnace is avoided, and thus the energy consumption loss caused by frequent temperature rise and fall due to overall temperature control is also avoided. Therefore, the energy loss caused by roasting temperature control is reduced.

[0060] Based on the same inventive concept, the embodiment of the present invention provides a roasting control method for carbon products, which is applied to the roasting furnace for carbon products in any one of the above embodiments. The method includes: when roasting the carbon product, obtaining the target partition temperature of each roasting zone in the furnace body 10; based on the target partition temperature of each roasting zone in the plurality of roasting zones, controlling the plurality of heating devices 30 so that the temperature of each roasting zone in the plurality of roasting zones reaches the corresponding target partition temperature; after the temperature of each roasting zone in the plurality of roasting zones reaches the corresponding target partition temperature, repeat at intervals of a preset time length, and control the conveying device 20 to move the carbon product according to a preset distance.

[0061] It should be understood that for more implementation details of the baking control method of the carbon products in the embodiments of the present invention, reference may be made to the aforementioned baking furnace of the carbon products. For the sake of brevity of the specification, they will not be elaborated herein.

[0062] The above are only the embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A carbon product roasting furnace, characterized in that: include: A furnace body, wherein a direction from a product inlet to a product outlet of the furnace body is divided into a plurality of roasting zones; A carrying device, partly disposed in the furnace body, for transporting the carbon product from the product inlet of the furnace body to the product outlet of the furnace body; A plurality of heating devices are arranged at intervals on the inner wall of the furnace body, each of the roasting zones is provided with at least one heating device, and the heating temperatures of the heating devices arranged in different roasting zones are different.

2. The carbon product roasting furnace according to claim 1, characterized in that: The carrying device comprises: An inner track is arranged at the inner bottom of the furnace body, and the inner track extends from the product inlet of the furnace body to the product outlet of the furnace body; An outer rail is arranged outside the furnace body, one end of the outer rail is connected to one end of the inner rail, and the other end of the outer rail is connected to the other end of the inner rail; The kiln car is movably arranged on the inner track and the outer track.

3. The carbon product roasting furnace according to claim 2, characterized in that: Each of the roasting zones is provided with a heating device, the rated powers of the heating wires of the heating devices provided in different roasting zones are the same, and the number of heating wires of the heating devices provided in the roasting zones near the product inlet and the product outlet is lower than the number of heating wires of the heating devices provided in the roasting zones near the middle section of the furnace body; or Each of the roasting zones is provided with a heating device, and the number of heating wires of the heating devices arranged in different roasting zones is the same. The rated power of the heating wires of the heating devices arranged in the roasting zones near the product inlet and the product outlet is lower than the rated power of the heating wires of the heating devices arranged in the roasting zone near the middle section of the furnace body.

4. The carbon product roasting furnace according to claim 3, characterized in that: The heating device arranged in at least one of the roasting zones includes a plurality of heating wires, a portion of the heating wires of the heating device is arranged on the first inner wall of the furnace body, and another portion of the heating wires of the heating device is arranged on the second inner wall of the furnace body, and the first inner wall and the second inner wall are located on opposite sides of the inner track.

5. The carbon product roasting furnace according to any one of claims 1 to 4, characterized in that: Also includes: A gas supply device, connected to the furnace body, for providing inert gas into the furnace body; The air supply device comprises: a first pipeline, wherein an outlet of the first pipeline is connected to a first gas inlet of the furnace body; a second pipeline, wherein an inlet of the second pipeline is connected to a first gas outlet of the furnace body; a circulation sub-device, wherein a first outlet of the circulation sub-device is connected to a first inlet of the first pipeline, and an inlet of the circulation sub-device is connected to an outlet of the second pipeline; a first gas source connected to the second inlet of the first pipeline; The gas in the furnace body flows through the furnace body, the second pipeline, the circulation sub-device and the first pipeline in sequence.

6. The carbon product roasting furnace according to claim 2, characterized in that: Also includes: A heat-conducting gasket is arranged on the bearing surface of the kiln car, and the bearing surface is used to bear the carbon product.

7. The carbon product roasting furnace according to claim 5, characterized in that: The furnace body comprises a first furnace zone and a second furnace zone, the plurality of roasting zones are located in the first furnace zone, the first furnace zone is close to the product outlet of the furnace body, and the second furnace zone is close to the product inlet of the furnace body; the first gas inlet of the furnace body, the first gas outlet of the furnace body and the plurality of heating devices are located in the first furnace zone; the roasting furnace further comprises: a third pipeline, wherein an outlet of the third pipeline is connected to a second gas inlet of the furnace body; a fourth pipeline, wherein an inlet of the fourth pipeline is connected to a second gas outlet of the furnace body; A gas combustion device, wherein the outlet of the gas combustion device is connected to the inlet of the third pipeline, and the inlet of the gas combustion device is connected to the outlet of the fourth pipeline; wherein the gas in the second furnace zone flows through the second furnace zone, the fourth pipeline, the gas combustion device and the third pipeline in sequence; the second gas inlet of the furnace body and the second gas outlet of the furnace body are located in the second furnace zone.

8. The carbon product roasting furnace according to claim 7, characterized in that: Also includes: A fifth pipeline, the inlet of which is connected to the second outlet of the circulation sub-device, and the outlet of which is arranged on the side wall between the first furnace zone and the second furnace zone.

9. The carbon product roasting furnace according to claim 7, characterized in that: Also includes: The gate plate is arranged in the furnace body, and divides the space in the furnace body into the first furnace area and the second furnace area.

10. A method for controlling the roasting of carbon products, applied to a roasting furnace for carbon products as claimed in any one of claims 1 to 9, characterized in that: The method comprises: When the carbon product is roasted, obtaining a target zone temperature of each roasting zone in the plurality of roasting zones of the furnace body; Based on the target partition temperature of each of the plurality of roasting zones, controlling the plurality of heating devices so that the temperature of each of the plurality of roasting zones reaches the corresponding target partition temperature; After the temperature of each of the multiple roasting zones reaches the corresponding target zone temperature, the preset interval is repeated, and the carrier is controlled to move the carbon product according to a preset distance.

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