A method of roasting in a rotating hearth furnace

Abstract

The embodiment of the present application provides a rotary hearth furnace baking method, and relates to the field of metallurgy.The rotary hearth furnace baking method comprises igniting a hot blast furnace;starting a rotary hearth combustion-supporting fan, converting high-temperature air generated in the hot blast furnace into low-temperature combustion-supporting air by using a heat exchanger;carrying out drying treatment on rotary hearth refractory by using the low-temperature combustion-supporting air, and adjusting a baking time according to a rotary hearth furnace baking temperature rising curve table;carrying out low-temperature baking on the rotary hearth furnace, and adjusting a baking progress according to the rotary hearth furnace baking temperature rising curve table;igniting a furnace body burner, and carrying out high-temperature baking on the rotary hearth furnace.The low-temperature combustion-supporting air is used to carry out drying treatment on the rotary hearth refractory, so that the rotary hearth refractory is prevented from being dried excessively;the temperature of the rotary hearth furnace and the flow of the low-temperature combustion-supporting air are adjusted strictly according to the rotary hearth furnace baking temperature rising curve table, so that the baking temperature and the baking quality are controlled, the rotary hearth refractory can be dried better, then the furnace body burner is ignited, and the high-temperature baking is carried out on the rotary hearth furnace, so that the baking operation of the rotary hearth furnace is better completed.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and more specifically, to a method for baking a rotary hearth furnace. Background Technology

[0002] In the existing technology of the metallurgical field, how to properly dry a newly built rotary hearth furnace to ensure its smooth commissioning is a difficult problem. This is mainly reflected in the fact that whether the temperature and time are properly controlled during the furnace drying process determines the quality and service life of the refractory materials in the subsequent production of the rotary hearth furnace. If the temperature is too low and the time is too short, the moisture in the refractory materials may not be dried enough to meet the requirements; if the temperature is too high and the time is too long, the refractory materials may be over-dried and directly rejected.

[0003] Existing rotary hearth furnaces have problems with controlling the drying time and temperature, resulting in either insufficient or excessive drying of refractory materials. Summary of the Invention

[0004] This invention provides a method for drying a rotary hearth furnace, which can better control the drying time and temperature, ensuring that the refractory material can be dried well during the drying process, thereby better completing the drying operation of the rotary hearth furnace.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] An embodiment of the present invention provides a method for drying a rotary hearth furnace, comprising:

[0007] Light the hot air furnace;

[0008] Start the rotary hearth furnace combustion air blower and use a heat exchanger to convert the high-temperature air generated inside the hot blast furnace into low-temperature combustion air.

[0009] The refractory material of the rotary hearth furnace is dried using the low-temperature combustion air, and the drying time is adjusted according to the rotary hearth furnace drying temperature rise curve.

[0010] The rotary hearth furnace is subjected to low-temperature drying, and the drying progress is adjusted according to the rotary hearth furnace drying temperature rise curve table;

[0011] Ignite the furnace burners to heat the rotary hearth furnace at high temperature.

[0012] Optionally, the step of starting the rotary hearth furnace combustion air fan and using a heat exchanger to convert the high-temperature air generated inside the hot blast furnace into low-temperature combustion air includes:

[0013] After the combustion fan is started, the fan speed is gradually accelerated to the rated speed. During the acceleration process, the fan current data is monitored. After the fan speed and current are constant, the fan outlet valve is opened and the inlet valve is gradually opened so that the fan pressure reaches the process requirements. The flue gas after the furnace is dried is discharged by the rotary hearth furnace flipping machine.

[0014] Optionally, the temperature range of the low-temperature combustion air entering the rotary hearth furnace is between 145°C and 155°C.

[0015] Optionally, the step of performing low-temperature baking on the rotary hearth furnace and adjusting the baking progress according to the rotary hearth furnace baking temperature rise curve table includes:

[0016] The amount of gas and combustion air in the hot blast stove are manually adjusted based on the temperature of the hot blast stove and the air preheating temperature of the rotary hearth furnace.

[0017] Optionally, the step of performing low-temperature baking on the rotary hearth furnace and adjusting the baking progress according to the rotary hearth furnace baking temperature rise curve table further includes:

[0018] The preheating air flow and temperature of the rotary hearth furnace are controlled by a heat exchanger, and the hot air after the furnace is dried is discharged by the rotary hearth furnace flipping machine.

[0019] Optionally, the furnace temperature range of the rotary hearth furnace during the low-temperature baking stage is between 150°C and 300°C.

[0020] Optionally, the step of igniting the furnace burners to perform high-temperature furnace baking of the rotary hearth furnace includes:

[0021] The gas in the furnace burner is ignited by an open flame, thereby gradually igniting the furnace burner to bake the rotary hearth furnace.

[0022] Optionally, the rotary hearth furnace includes a heating zone, a reduction zone one, a reduction zone two, a reduction zone three, a reduction zone four, and a reduction zone five connected in sequence, and the step of igniting the furnace burners to perform high-temperature furnace baking of the rotary hearth furnace further includes:

[0023] The ignition sequence of the rotary hearth furnace starts with the inner and outer burners of the fifth reduction zone, and then proceeds alternately to the fourth reduction zone, the third reduction zone, the second reduction zone, the first reduction zone, and the heating zone.

[0024] Optionally, the temperature range of the rotary hearth furnace during the high-temperature baking stage is between 300℃ and 1250℃.

[0025] Optionally, the step of igniting the hot blast stove includes:

[0026] The coke oven gas is ignited by a firewood and kerosene, and then the blast furnace gas is ignited. The high-temperature flue gas from the hot blast stove is discharged through the flue gas vent pipe.

[0027] The beneficial effects of the rotary hearth furnace baking method according to embodiments of the present invention include, for example:

[0028] The rotary hearth furnace drying method includes: igniting the hot blast stove; starting the rotary hearth furnace combustion fan and using a heat exchanger to convert the high-temperature air generated inside the hot blast stove into low-temperature combustion air; using the low-temperature combustion air to dry the refractory material of the rotary hearth furnace and adjusting the drying time according to the rotary hearth furnace drying temperature rise curve; performing low-temperature drying on the rotary hearth furnace and adjusting the drying progress according to the rotary hearth furnace drying temperature rise curve; and igniting the furnace burners to perform high-temperature drying on the rotary hearth furnace. In this rotary hearth furnace drying method, the hot blast stove generates high-temperature air, which is then converted into low-temperature combustion air via a heat exchanger. This low-temperature combustion air is used to dry the refractory material in the rotary hearth furnace, preventing over-drying. During the drying process, the furnace temperature and the flow rate of the low-temperature combustion air are strictly adjusted according to the rotary hearth furnace drying temperature rise curve to ensure control over the drying temperature and quality, resulting in better drying of the refractory material. Then, the furnace burners are ignited to perform high-temperature drying of the rotary hearth furnace, thus better completing the drying operation. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the rotary hearth furnace and hot blast stove provided in this embodiment;

[0031] Figure 2 The initial hot blast stove baking temperature rise curve provided in this embodiment;

[0032] Figure 3 The temperature rise curve of the first rotary hearth furnace baking provided in this embodiment.

[0033] Icons: 10-Hot air furnace; 20-Rotary hearth furnace; 21-Reduction stage 1; 22-Reduction stage 2; 23-Reduction stage 3; 24-Reduction stage 4; 25-Reduction stage 5; 26-Heating stage. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0036] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0037] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0038] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0039] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0040] In the existing technology of the metallurgical field, how to properly dry a newly built rotary hearth furnace to ensure its smooth commissioning is a difficult problem. This is mainly reflected in the fact that whether the temperature and time are properly controlled during the furnace drying process determines the quality and service life of the refractory materials in the subsequent production of the rotary hearth furnace. If the temperature is too low and the time is too short, the moisture in the refractory materials may not be dried enough and will not meet the requirements; if the temperature is too high and the time is too long, the refractory materials may be over-dried and directly rejected.

[0041] Existing rotary hearth furnaces have problems with controlling the drying time and temperature, resulting in either insufficient or excessive drying of refractory materials.

[0042] Please refer to Figures 1-3 This embodiment provides a method for drying a rotary hearth furnace, which can effectively improve the technical problems mentioned above, better control the drying time and temperature, and ensure that the refractory material can be dried well during the drying process, thereby better completing the drying operation of the rotary hearth furnace 20.

[0043] Please refer to Figures 1-3 This embodiment provides a method for drying a rotary hearth furnace, including:

[0044] S1: Ignite hot air furnace 10;

[0045] Specifically, the hot blast stove 10 is connected to the combustion fan of the rotary hearth furnace 20, coke oven gas, and blast furnace gas. After confirming that the ignition conditions are met, the hot blast stove 10 for drying green pellets is ignited and heated. For the first ignition, firewood and kerosene are used to ignite the coke oven gas in the furnace, and then the blast furnace gas is ignited. The ignition operation is carried out in accordance with the operating procedures of the hot blast stove 10. The high-temperature flue gas of the hot blast stove 10 is discharged through the flue gas vent pipe, and the furnace temperature gradually rises.

[0046] S2: Start the combustion air blower of the rotary hearth furnace 20 and use the heat exchanger to convert the high-temperature air generated inside the hot blast furnace 10 into low-temperature combustion air;

[0047] Specifically, after the hot blast stove 10 is burning normally, prepare to start the combustion air blower of the rotary hearth furnace 20. Before starting the combustion air blower of the rotary hearth furnace 20, check the inlet and outlet valves of the blower. After the inlet and outlet valves of the blower are completely closed, press the jog button on the control box next to the machine to prepare to start the combustion air blower of the rotary hearth furnace 20.

[0048] After the combustion blower is started, the blower speed is gradually accelerated to the rated speed. During the acceleration process, the current data of the blower is monitored. After the blower speed and current are constant, the blower outlet valve is opened and the inlet valve is gradually opened so that the blower pressure reaches the process requirements. The flue gas after the furnace is dried is discharged by the rotary hearth furnace 20 flip-top machine.

[0049] More often, when the pressure of the blower meets the process requirements, the preheated combustion air of the rotary hearth furnace 20 enters the furnace chamber of the rotary hearth furnace 20 at 150°C for furnace drying.

[0050] It should also be noted that during the stage of preheating the combustion air into the rotary hearth furnace 20, no requirements are placed on the temperature change of the rotary hearth furnace 20.

[0051] S3: Use low-temperature combustion air to dry the refractory material of rotary hearth furnace 20, and adjust the drying time according to the temperature rise curve of rotary hearth furnace 20.

[0052] Specifically, the preheating air flow and temperature of the rotary hearth furnace 20 are controlled by a heat exchanger, and the hot air after the furnace is dried is discharged by the rotary hearth furnace 20 flipping machine.

[0053] In this embodiment, the refractory material in the rotary hearth furnace 20 is dried for five days using low-temperature combustion air obtained through heat exchange. In other embodiments, the specific drying time is strictly determined according to the furnace temperature rise curve table.

[0054] More often, the temperature range of the low-temperature combustion air entering the rotary hearth furnace 20 is between 145℃ and 155℃.

[0055] S4: Perform low-temperature drying on the rotary hearth furnace 20, and adjust the drying progress according to the temperature rise curve of the rotary hearth furnace 20.

[0056] Specifically, during the low-temperature baking stage, the furnace temperature of the rotary hearth furnace 20 is between 150℃ and 300℃. The gas volume and combustion air volume of the hot blast stove 10 are manually adjusted according to the temperature of the hot blast stove 10 and the air preheating temperature of the rotary hearth furnace 20. The baking temperature of the rotary hearth furnace 20 is controlled by adjusting the preheating air flow and temperature through a heat exchanger. The hot air after baking the rotary hearth furnace 20 is discharged by the rotary hearth furnace 20 flipping machine.

[0057] Furthermore, if the dust removal in the exhaust duct of the rotary hearth furnace 20 and the waste heat boiler are ready for trial use, the hot air after drying the rotary hearth furnace 20 can also be discharged by the dust collector.

[0058] S5: Ignite the furnace burner to perform high-temperature baking of the rotary hearth furnace 20;

[0059] Specifically, an open flame is used to ignite the gas in the furnace burner, thereby igniting the gas and gradually igniting the furnace burner to bake the rotary hearth furnace 20.

[0060] In this embodiment, the rotary hearth furnace 20 includes a heating zone, a reduction zone 1, a reduction zone 2, a reduction zone 3, a reduction zone 4, and a reduction zone 5 connected in sequence.

[0061] It should be noted that, since the temperature range required for the rotary hearth furnace 20 during the high-temperature baking stage is between 300℃ and 1250℃, in order to ensure that the hot air temperature inside the hot blast stove 10 meets the temperature requirements for the high-temperature baking stage, the burners of the rotary hearth furnace 20 need to be ignited for high-temperature baking. Before ignition, the rotary hearth furnace 20 needs to meet the following conditions:

[0062] (1) The gas pipeline of the rotary hearth furnace 20 has passed the air tightness test. All valves are closed and the gas of the rotary hearth furnace 20 has been sent to the valve in front of the furnace. Nitrogen is ready for purging and replacement. Compressed air, cooling water and other media can be used normally.

[0063] (2) The relevant equipment of the rotary hearth furnace 20 has been tested and run normally. The mechanical, electrical and instrumentation systems have been debugged without any abnormalities and all equipment is in operation.

[0064] (3) The automatic control system of the rotary hearth furnace is normal, and the central control operation interface is clear and in normal operation.

[0065] (4) The water circulation system of the rotary hearth furnace 20 is operating normally, the water seal tank is full of water and meets the requirement of continuous water injection:

[0066] (5) The waste heat boiler has been commissioned and is ready to supply flue gas;

[0067] (6) All instruments, valves, dust collectors and dust collection fans in the flue can be put into normal operation.

[0068] After all the above conditions are met, the gas pipeline is replaced with nitrogen according to the gas operation post specifications. After confirming that the replacement is qualified, the gas is introduced and the furnace burner is gradually ignited for the rotary hearth furnace 20 baking.

[0069] More importantly, since the ignition temperature range of coke oven gas is between 750℃ and 800℃, when the hot air in the hot blast stove 10 is at 300℃, the burners in the furnace body cannot be directly ignited. In this case, an open flame such as an ignition rod is needed to ignite the gas in the burners. The specific operation for igniting the burners is as follows:

[0070] (1) According to the operating procedure for the 20th gas inlet of the rotary hearth furnace, the air in the gas pipeline is replaced with nitrogen before the gas is introduced according to the gas ignition operating procedure.

[0071] (2) Adjust the automatic flow control valve for combustion air to ensure that its opening is about 30%;

[0072] (3) The gas flow regulating valve is opened by the central control through the instrument to a degree of about 30%, and the manual air valve in front of the burner is opened to a degree of about 25%.

[0073] (4) Insert the ignition rod (torch) into the burner through the ignition hole, ensuring that it is not blown out by the combustion air. Open the butterfly valve at the top of the gas pipeline to 35%, and then slowly open the secondary butterfly valve at the bottom of the gas pipeline to about 25%. Observe whether the gas in the burner is ignited. If it is not ignited, retest the ignition gas and then re-ignite it.

[0074] (5) After the burner is lit, the gas butterfly valve and air butterfly valve in front of the burner are opened slowly at the same time. Observe and confirm that the burner flame is bright blue and sprays out. The rest of the burners are lit in the same way to raise the furnace temperature and the furnace is baked according to the furnace baking curve. The high temperature flue gas generated during furnace baking must be discharged from the dust removal fan through the waste heat boiler. The lit burners are arranged in an intermittent cross manner to ensure uniform heating.

[0075] (6) The ignition sequence principle starts from the inner and outer burners of the fifth reduction zone, and then proceeds in a cross manner to the fourth reduction zone, the third reduction zone, the second reduction zone, the first reduction zone and the heating zone. During the furnace baking process, the ignition time and ignition sequence of each burner can be adjusted according to the heating requirements and actual conditions.

[0076] (7) The burner's hot-state adjustment is carried out after holding at 1250℃. When the furnace temperature reaches 1250℃, it is held for 10 hours. The target values ​​for furnace temperature control in each section when the furnace temperature reaches 1250℃ are: Reduction Section 5 25: 1230-1260℃; Reduction Section 4 24: 1230-1260℃; Reduction Section 3 23:

[0077] 1210-1230℃; Reduction Stage 22: 1180-1210℃; Reduction Stage 1: 1150-1180℃;

[0078] Heating section 26: 1100-1150℃.

[0079] Specifically, this rotary hearth furnace baking method strictly follows the baking curve to control the temperature rise. Before the furnace temperature of the rotary hearth furnace 20 reaches 300℃, the temperature is regulated by the hot air temperature and flow rate, thereby controlling the temperature difference between each section of the rotary hearth furnace 20 within ±50℃. When the furnace temperature of the rotary hearth furnace 20 is above 300℃, the furnace burners are already ignited. The gas and air flow rates are manually adjusted using the flow regulating valves of each section, and the burner activation sequence is marked.

[0080] It should also be noted that after the temperature inside the rotary hearth furnace 20 reaches 300℃, except for the heating section 26, one burner is ignited in each zone of the outer ring of the reduction section. According to the temperature change inside the rotary hearth furnace 20, the burners are ignited and heated gradually in a staggered and intermittent manner until all burners are ignited. During this process, the manual valve in front of the burners is fully open, and the electric regulating valves for gas and air in each zone are opened by 1% to 2%. After the temperature can no longer rise, the opening of the electric regulating valves for gas and air in each zone is gradually increased (each increase should not exceed 2%, or the temperature increase should not exceed 5℃ per hour) until they are fully open. During this process, the furnace temperature is strictly controlled according to the temperature rise curve.

[0081] Specifically, the reference temperature of the heating curve is the average temperature on both sides of each zone. When the temperature difference between the two sides is large, the air and gas flow rates need to be adjusted in time to reduce the temperature difference.

[0082] The furnace temperature and flue gas temperature are measured every hour. The furnace pressure at the discharge end is controlled at 0 to -5 Pa, and the furnace pressure at the feed end is controlled at approximately -10 to -13 Pa (depending on whether there is positive pressure at the burner). The flow rate, pressure, and temperature of various energy media (including coal gas, compressed air, and combustion air) are recorded every hour. The burner combustion status is checked at least 6 times per shift, and adjustments and confirmations are made immediately if any abnormalities are found.

[0083] In addition, the rotary hearth furnace needs to be cooled down after high-temperature baking at 20°C. The specific cooling operation is as follows:

[0084] Cooling sequence: heating section 26 → reduction section 1 21 → reduction section 2 22 → reduction section 3 23 → reduction section 4 24 and reduction section 5 25. When the furnace temperature drops below 600℃, the final shutdown is carried out. The shutdown process is carried out by adjusting the gas and air regulating valves in each zone to reduce the flow rate, and finally closing all manual valves in front of the furnace.

[0085] When the furnace temperature drops to 150℃, open the rotary hearth furnace 20 flip-top machine, turn off the exhaust fan, open the furnace door for natural cooling, and set the shutdown time for the combustion fan according to the production and maintenance schedule.

[0086] When the furnace temperature drops to 20℃~40℃, the masonry can be inspected inside the furnace. Expansion joints should be filled with LYGX-512 ceramic fiber blankets, with a focus on filling the expansion joints at the furnace bottom. After the expansion joints at the furnace bottom are filled and repaired, fiber blankets and magnesia are laid to complete the furnace drying process.

[0087] In summary, the embodiments of the present invention provide a method for drying a rotary hearth furnace. This method includes igniting a hot blast stove 10; starting the combustion air blower of the rotary hearth furnace 20 and using a heat exchanger to convert the high-temperature air generated inside the hot blast stove 10 into low-temperature combustion air; using the low-temperature combustion air to dry the refractory material of the rotary hearth furnace 20 and adjusting the drying time according to the temperature rise curve of the rotary hearth furnace 20; performing low-temperature drying on the rotary hearth furnace 20 and adjusting the drying progress according to the temperature rise curve of the rotary hearth furnace 20; and igniting the furnace burners to perform high-temperature drying on the rotary hearth furnace 20. In this rotary hearth furnace drying method, the hot blast stove generates high-temperature air at 10 o'clock. The high-temperature air is converted into low-temperature combustion air through a heat exchanger. The low-temperature combustion air is used to dry the refractory material in the rotary hearth furnace 20, avoiding over-drying. During the drying process of the rotary hearth furnace 20, the drying temperature and the flow rate of the low-temperature combustion air are strictly adjusted according to the drying temperature rise curve of the rotary hearth furnace 20 to ensure control over the drying temperature and drying quality, so as to better dry the refractory material. Then, the furnace burner is ignited to carry out high-temperature drying of the rotary hearth furnace 20, thereby better completing the drying operation of the rotary hearth furnace 20.

[0088] This rotary hearth furnace baking method can effectively solve the problems of inappropriate baking time and uneven temperature, and can reduce the circumferential temperature difference of the rotary hearth furnace 20 to within 3℃.

[0089] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for drying a rotary hearth furnace, characterized in that, include: Ignite the hot air furnace (10); Start the combustion air blower of the rotary hearth furnace (20) and use the heat exchanger to convert the high temperature air generated inside the hot blast furnace (10) into low temperature combustion air; wherein, after starting the combustion air blower, the blower speed is gradually accelerated to the rated speed, and the current data of the blower is monitored during the acceleration process. After the blower speed and current are constant, the blower outlet valve is opened and the inlet valve is gradually opened so that the blower pressure reaches the process requirements. The flue gas after the furnace is dried is discharged by the rotary hearth furnace (20) flipping machine; The refractory material of the rotary hearth furnace (20) is dried using the low-temperature combustion air, and the drying time is adjusted according to the temperature rise curve of the rotary hearth furnace (20). The rotary hearth furnace (20) is subjected to low-temperature baking, and the baking progress is adjusted according to the baking temperature rise curve of the rotary hearth furnace (20); wherein, the gas volume and combustion air volume of the hot blast stove (10) are manually adjusted according to the temperature of the hot blast stove (10) and the air preheating temperature of the rotary hearth furnace (20), and the preheating air flow rate and preheating air temperature of the rotary hearth furnace (20) are controlled by the heat exchanger. The hot air after baking is discharged by the rotary hearth furnace (20) flipping machine. The furnace temperature range of the rotary hearth furnace (20) during the low-temperature baking stage is between 150℃ and 300℃; Ignite the furnace burner to perform high-temperature baking on the rotary hearth furnace (20); The rotary hearth furnace (20) includes a heating zone, a reduction zone 1, a reduction zone 2, a reduction zone 3, a reduction zone 4, and a reduction zone 5 connected in sequence. The step of igniting the furnace burner to perform high-temperature furnace baking on the rotary hearth furnace (20) further includes: The ignition sequence of the rotary hearth furnace (20) starts from the inner and outer burners of the fifth reduction zone, and then proceeds alternately to the fourth reduction zone, the third reduction zone, the second reduction zone, the first reduction zone, and the heating zone. The temperature range of the rotary hearth furnace (20) during the high-temperature baking stage is between 300℃ and 1250℃.

2. The rotary hearth furnace drying method according to claim 1, characterized in that, The temperature range of the low-temperature combustion air entering the rotary hearth furnace (20) is between 145°C and 155°C.

3. The rotary hearth furnace drying method according to claim 1, characterized in that, The step of igniting the furnace burner to perform high-temperature furnace baking of the rotary hearth furnace (20) includes: The gas in the furnace burner is ignited by an open flame, thereby gradually igniting the furnace burner to bake the rotary hearth furnace (20).

4. The rotary hearth furnace drying method according to claim 1, characterized in that, The step of igniting the hot air furnace (10) includes: The coke oven gas is ignited by firewood and kerosene, and then the blast furnace gas is ignited. The high-temperature flue gas of the hot blast stove (10) is discharged through the flue gas vent pipe.

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