Vacuum chamber refractory brick baking method and device

Abstract

The invention relates to the technical field of vacuum metallurgy, in particular to a vacuum chamber refractory brick baking method and device. The vacuum chamber refractory brick baking method comprises the steps of obtaining the internal temperature of a vacuum chamber, and controlling the current frequency, the gas flow and the oxygen flow of the baking device in an interlocking mode based on the internal temperature of the vacuum chamber. A vacuum chamber refractory brick baking device comprises a thermocouple temperature sensor, a baking device, a fan system and a control system. The control system is used for integrally controlling the working states of the vacuum chamber, the thermocouple temperature sensor, the baking device and the fan system, so as to automatically control the gas flow, the oxygen flow and the current frequency of a fan motor in the fan system according to the temperature detected by the thermocouple temperature sensor; therefore, interlocking control over the current frequency, the gas flow and the oxygen flow of the fan motor is achieved, and the bottom of the vacuum chamber and the side wall of the lower portion of the vacuum chamber can be effectively baked.

Description

Technical Field

[0001] The invention relates to the technical field of vacuum metallurgy, and in particular to a method and a device for baking refractory bricks in a vacuum chamber. Background Art

[0002] In the field of steel production, especially for the production of high-quality steel, vacuum treatment technology has become an important means to improve steel quality and develop new varieties.

[0003] In the prior art, the RH vacuum treatment system is one of the most important equipment for improving the quality of steelmaking and achieving high-purity steel grades. The RH vacuum treatment system includes a baking device and a vacuum chamber, which is mainly used for decarburization, dehydrogenation, deoxidation, and desulfurization of molten steel, removal of inclusions and fine-tuning of components, purification of molten steel, and process operations to improve the quality of molten steel. The vacuum chamber has a processing position and a standby position. The vacuum chamber is produced at the processing position, and the vacuum chamber is hoisted and baked at the standby position to dry and preheat the refractory bricks for standby use. After the refractory bricks in the vacuum chamber are laid, they need to be baked using a baking device before being placed on the processing position to dry and heat the refractory bricks. After the baking and preheating are completed, the vacuum chamber is transferred from the standby position to the processing position by replacing the trolley.

[0004] The vacuum chamber works in a high temperature environment, and the performance of its refractory material directly affects the effect of vacuum treatment and the service life of the refractory material. In order to ensure production quality and production capacity, the vacuum chamber needs to be replaced every 2.5 days.

[0005] In actual production, molten steel circulates repeatedly under vacuum, flushing and soaking the refractory bricks. Experience shows that the bottom or lower side wall of the vacuum chamber often causes steel modification and casting machine interruption accidents due to nodules or perforations in the steel structure.

[0006] Through the investigation and analysis of the on-site vacuum chamber perforation accident, it was concluded that there were serious problems with the baking quality of the refractory bricks in the perforated area. The main manifestations were the low temperature of the refractory bricks at the bottom of the vacuum chamber, and the serious nodules on the lower side walls of the vacuum chamber during the production process, which affected the alloy yield. Sometimes poor baking of the bottom refractory material will lead to poor dehydrogenation of heavy rail steel, which requires steel modification. The bottom refractory material temperature is low, and under the high-temperature immersion and scouring of molten steel, the erosion resistance, high-temperature compression resistance, and high-temperature flexural strength of the refractory bricks are reduced, resulting in peeling and pitting of the working layer bricks at the bottom of the vacuum chamber, and cracking of the working layer bricks on the lower side walls of the vacuum chamber. With the increase in the number of uses, molten steel gradually penetrates into the brick joints, eventually causing perforation of the bottom or lower side walls of the vacuum chamber, resulting in casting machine interruption and steel modification accidents.

[0007] Since the vacuum chamber is 6.7 meters high and the flame of the ignition burner is 1.5 meters, the refractory bricks in the upper and middle parts of the vacuum chamber can reach a relatively high temperature to meet the production requirements of the vacuum line. However, the refractory bricks in the lower side walls of the vacuum chamber and the bottom of the vacuum chamber are baked at a relatively low temperature, especially after the overhaul of the bottom of the vacuum chamber and the lower side walls, the baking temperature of the refractory bricks is even lower.

[0008] In view of the above problems, the prior art usually adjusts the structure and position of the baking device. The existing baking device usually uses a baking burner as a gas input device, cools with cooling water and adopts an internal mixing burner structure. When used on site, the gas and oxygen flow rates of the baking vacuum chamber are manually adjusted, and the baking is continued until the vacuum chamber needs to be replaced. The existing baking device has the following problems: (1) Insufficient heating power at the bottom of the vacuum chamber. The air volume of the ignition burner cannot be adjusted, the current frequency of the fan motor is always controlled at a fixed frequency, the air volume of the fan remains unchanged, and the flame of the burner baking in the standby position remains at a certain length, which cannot transfer the heat and flame of the upper part of the vacuum chamber to the lower part of the vacuum chamber and the refractory bricks at the bottom. (2) Manually set parameters, poor control effect, and energy waste. The gas flow rate, oxygen flow rate, and fan frequency cannot be adjusted according to the specific conditions of the vacuum chamber baking. The refractory bricks in the middle and upper part of the vacuum chamber can reach a higher temperature and meet the production requirements of vacuum production; but the baking temperature of the refractory bricks of the lower side wall of the vacuum chamber and the bottom of the vacuum chamber is relatively low, especially the vacuum chamber after overhaul at the bottom and bottom. When a vacuum chamber that is not properly baked is put into production, the dehydrogenation effect of the heavy rail is poor, which leads to steel modification. In addition, the magnesia-chrome bricks at the bottom and lower side walls of the corresponding vacuum chamber that are in contact with molten steel crack and pit, and the life of the refractory material is reduced. (3) This vacuum chamber baking method affects the effective baking of the refractory bricks at the lower side walls and bottom of the vacuum chamber, and the actual temperature cannot meet the requirements of continuous production of the vacuum chamber. It will also lead to steel modification and casting machine interruption accidents.

[0009] Based on this, it is particularly important to develop a new method and device for baking refractory bricks in a vacuum chamber. Summary of the invention

[0010] In view of this, the present invention proposes a method and device for baking refractory bricks in a vacuum chamber, which can at least solve the technical problem that the existing refractory bricks in the vacuum chamber have poor baking effect before being put into use and the actual temperature cannot meet the continuous production requirements of the vacuum chamber.

[0011] The first aspect of the present invention provides a method for baking refractory bricks in a vacuum chamber, comprising: Get the temperature inside the vacuum chamber; The fan motor current frequency, gas flow and oxygen flow of the baking device are controlled based on the temperature interlock inside the vacuum chamber.

[0012] In some embodiments, controlling the fan motor current frequency, gas flow rate and oxygen flow rate of the baking device based on the internal temperature interlock of the vacuum chamber includes: Based on the temperature inside the vacuum chamber being in each of the multiple stages, the current frequency of the fan motor, the gas flow rate and the oxygen flow rate of the baking device are controlled accordingly.

[0013] In some embodiments, the multiple stages are three stages, the first stage is 600° C. to 900° C., the second stage is 900° C. to 1200° C., and the third stage is above 1200° C. The current frequency, gas flow rate, and oxygen flow rate corresponding to the second stage are respectively greater than the current frequency, gas flow rate, and oxygen flow rate corresponding to the first stage, and the current frequency, gas flow rate, and oxygen flow rate corresponding to the third stage are respectively less than the current frequency, gas flow rate, and oxygen flow rate corresponding to the first and second stages.

[0014] In some embodiments, if the temperature inside the vacuum chamber is in the first stage, the gas flow rate is controlled to be 200-260 NM 3 / h, oxygen flow rate is 180~230NM 3 / h, the current frequency is 30~35Hz.

[0015] In some embodiments, if the temperature inside the vacuum chamber is in the second stage, the gas flow rate is controlled to be 280~300NM 3 / h, oxygen flow rate is 250~270NM 3 / h, the current frequency is 45~50Hz.

[0016] In some embodiments, if the temperature inside the vacuum chamber is in the third stage, the gas flow rate is controlled to be 150-200 NM. 3 / h, oxygen flow rate is 135~180NM 3 / h, the current frequency is 25~30Hz.

[0017] A second aspect of the present invention provides a vacuum chamber refractory brick baking device, comprising a thermocouple temperature sensor, a baking device, a fan system and a control system; Thermocouple temperature sensors are set inside the vacuum chamber to monitor the temperature changes in the vacuum chamber in real time; The baking device includes a baking burner, a gas supply pipeline, an oxygen supply pipeline and a mixer; flow meters are provided on the gas supply pipeline and the oxygen supply pipeline; The fan system includes a fan motor, a fan impeller, a frequency controller and an air duct; The control system is used to integrate and control the working status of the vacuum chamber, thermocouple temperature sensor, baking device and fan system, and realize automatic detection of gas flow and oxygen flow through flow meter according to the temperature detected by the thermocouple temperature sensor, and control of the current frequency of the fan motor through frequency controller.

[0018] In some embodiments, the control system is configured to: The gas flow rate, oxygen flow rate and current frequency are controlled accordingly based on the temperature detected by the thermocouple temperature sensor in each of the first stage, the second stage and the third stage; wherein the first stage is 600℃~900℃, the second stage is 900℃~1200℃, and the third stage is above 1200℃; the gas flow rate and oxygen flow rate corresponding to the third stage are respectively smaller than the gas flow rate and oxygen flow rate corresponding to the first stage and the second stage; the current frequency corresponding to the second stage is greater than the current frequency corresponding to the first stage and the third stage.

[0019] In some embodiments, the control system is configured to: If the temperature detected by the thermocouple temperature sensor is in the first stage, control the gas flow rate to 200-260NM 3 / h, oxygen flow rate is 180~230NM 3 / h, current frequency is 30~35Hz; If the temperature detected by the thermocouple temperature sensor is in the second stage, control the gas flow rate to 280~300NM 3 / h, oxygen flow rate is 250~270NM 3 / h, current frequency is 45~50Hz; If the temperature detected by the thermocouple temperature sensor is in the third stage, control the gas flow rate to 150~200NM 3 / h, oxygen flow rate is 135~180NM 3 / h, the current frequency is 25~30Hz.

[0020] In some embodiments, multiple thermocouple temperature sensors are arranged in sequence along the vertical direction; the control system detects and controls the gas flow and oxygen flow through a flow meter according to the average temperature value detected by the multiple thermocouple temperature sensors, and controls the current frequency of the fan motor through a frequency controller.

[0021] The beneficial effects of the present invention are as follows: the present application controls the current frequency, gas flow rate and oxygen flow rate based on the temperature interlock inside the vacuum chamber, thereby "adjusting" the flame length of the baking device, and can effectively bake the bottom of the vacuum chamber and the lower side wall of the vacuum chamber. The vacuum chamber baked in this way can fully meet the needs of continuous production, avoiding the low temperature of the refractory bricks at the bottom and side walls of the vacuum chamber, cracking, pitting, perforation of magnesia-chrome bricks inside the vacuum chamber, steel modification, and pouring interruption caused by the original baking method, and improving the life of the refractory bricks at the bottom of the vacuum chamber, the life of the refractory bricks on the lower side walls of the vacuum chamber, and saving energy consumption, with significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A diagram showing the coordination between a vacuum chamber refractory brick baking device and a vacuum chamber provided in one embodiment of the present invention; Figure 2 A diagram showing the coordination of a baking cover and a baking burner of a baking device provided in one embodiment of the present invention.

[0024] Description of reference numerals: 1. Vacuum chamber; 2. Replacement trolley; 3. Baking device; 301. Baking burner; 302. Gas supply pipeline; 303. Oxygen supply pipeline; 304. Mechanical cantilever; 305. Baking cover; 4. Thermocouple temperature sensor. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0026] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. The subsequent embodiments will not explain this one by one.

[0027] The first aspect of the present invention provides a method for baking refractory bricks in a vacuum chamber, comprising: Get the temperature inside the vacuum chamber; The fan motor current frequency, gas flow and oxygen flow of the baking device are controlled based on the temperature interlock inside the vacuum chamber.

[0028] The present application controls the current frequency, gas flow and oxygen flow of the fan motor based on the temperature interlock inside the vacuum chamber, thereby "adjusting" the flame length of the baking device, and can effectively bake the bottom of the vacuum chamber and the lower side walls of the vacuum chamber. The vacuum chamber baked in this way can fully meet the continuous production needs, avoiding the low temperature of the refractory bricks on the bottom and side walls of the vacuum chamber, cracking, pitting, and perforation of the magnesia-chrome bricks inside the vacuum chamber caused by the original baking method, and the steel modification and pouring interruption accidents are avoided. The service life of the refractory bricks at the bottom of the vacuum chamber and the service life of the refractory bricks on the lower side walls of the vacuum chamber are improved, and energy consumption is saved, with significant economic and social benefits.

[0029] In some embodiments, controlling the current frequency, gas flow rate, and oxygen flow rate of the baking device based on the internal temperature of the vacuum chamber interlock includes: Based on the temperature inside the vacuum chamber being in each of the multiple stages, the current frequency of the fan motor, the gas flow rate and the oxygen flow rate of the baking device are controlled accordingly.

[0030] The present application can achieve more precise control and thus improve baking efficiency by dividing the temperature of the vacuum chamber into multiple stages and adjusting the current frequency, gas flow rate and oxygen flow rate according to the temperature requirements of each stage. This staged control helps ensure that the baking conditions of each stage are optimal, thereby shortening the overall baking time. The current frequency and gas flow rate can be adjusted according to actual needs to avoid energy waste.

[0031] In some embodiments, the multiple stages are divided into three stages according to the temperature inside the vacuum chamber, the first stage is 600°C to 900°C, the second stage is 900°C to 1200°C, and the third stage is above 1200°C. As the temperature rises, the various gas molecules in the vacuum chamber will accelerate their movement, which can effectively bake the refractory bricks. The current frequency, gas flow rate and oxygen flow rate corresponding to the second stage are respectively greater than the current frequency, gas flow rate and oxygen flow rate corresponding to the first stage, and the current frequency, gas flow rate and oxygen flow rate corresponding to the third stage are respectively less than the current frequency, gas flow rate and oxygen flow rate corresponding to the first and second stages.

[0032] Specifically, in the first stage, the vacuum chamber is hoisted from the off-line preheating station to the standby position, and the baking device mainly bakes the middle and upper parts of the vacuum chamber until the temperature inside the vacuum chamber reaches about 900°C, while the lower part of the vacuum chamber has not yet reached the required temperature for baking. At this time, in the second stage, the gas flow, oxygen flow and fan motor current frequency are all controlled to increase, which can increase the air supply volume, transfer the heat and burner flame of the upper part of the vacuum chamber to the bottom and lower part of the vacuum chamber, and effectively bake the lower part of the vacuum chamber and the refractory bricks at the bottom until the temperature inside the vacuum chamber reaches about 1200°C. In the third stage, the interior of the vacuum chamber has approached or reached its operating temperature. At this time, reducing the current frequency, gas flow and oxygen flow for insulation can reduce energy consumption, prolong the residence time of heat in the vacuum chamber, and achieve a good insulation effect, so that the vacuum chamber is insulated and ready for use.

[0033] In some embodiments, if the temperature inside the vacuum chamber is in the first stage, the gas flow rate is controlled to be 200-260 NM 3 / h, oxygen flow rate is 180~230NM 3 / h, the current frequency is 30~35Hz. In the first stage, the gas flow rate is 200~260NM 3 / h, oxygen flow rate is 180~230NM 3 / h, the current frequency is 30~35Hz, which is helpful to bake the middle and upper part of the vacuum chamber, and helps the refractory bricks of the vacuum chamber gradually adapt to environmental changes and reduce the generation of thermal stress.

[0034] In some embodiments, if the vacuum chamber temperature is in the second stage, the gas flow rate is controlled to be 280-300 NM. 3 / h, oxygen flow rate is 250~270NM 3 / h, the current frequency is 45~50Hz. In the second stage, the gas flow, oxygen flow and the current frequency of the fan motor are all controlled to be higher than that in the first stage, which can increase the air supply, transfer the heat and burner flame of the upper part of the vacuum chamber to the bottom and lower part of the vacuum chamber, and effectively bake the lower part of the vacuum chamber and the refractory bricks at the bottom.

[0035] In some embodiments, if the vacuum chamber temperature is at the third stage, the gas flow rate is controlled to be 150-200 NM. 3 / h, oxygen flow rate is 135~180NM 3 / h, the current frequency is 25~30Hz, so as to slow down the heating rate and reduce energy consumption after the vacuum chamber temperature meets the preset requirements, so as to carry out subsequent insulation standby.

[0036] The second aspect of the present invention provides a vacuum chamber 1 refractory brick baking device 3, such as Figure 1As shown, the vacuum chamber 1 is transferred to the standby position by the replacement trolley 2 for baking, and the refractory brick baking device 3 of the vacuum chamber 1 includes a thermocouple temperature sensor 4, a baking device 3, a fan system and a control system.

[0037] Thermocouple temperature sensor 4 is arranged inside vacuum chamber 1 to monitor temperature change inside vacuum chamber 1 in real time and ensure that temperature is controlled at key temperature points such as 600°C to 900°C, above 900°C and 1200°C.

[0038] The baking device 3 includes a baking burner 301, a gas supply pipeline 302, an oxygen supply pipeline 303 and a mixer (not shown in the figure). The baking burner 301 is used to spray a mixture of fuel and air to generate flames for heating. The baking burner 301 is usually installed on the furnace wall steel plate, and the baking burner 301 brick is installed on the furnace body through the opening. Attention should be paid to the sealing during installation to ensure that there is no leakage at the connection. The gas and oxygen supply pipelines are responsible for transporting gas and oxygen to the burner. Flow meters are provided on the gas supply pipeline 302 and the oxygen supply pipeline 303, which are used to detect and control the gas flow and oxygen flow respectively to ensure that the ratio of gas and oxygen is appropriate during the baking process. The mixer is used to mix the gas and oxygen evenly to form a gas mixture suitable for combustion.

[0039] The fan system includes a fan motor, a fan impeller, a frequency controller and an air duct. The fan motor is used to drive the fan impeller to rotate. The frequency controller is used to adjust the operating frequency of the fan motor, thereby controlling the speed of the fan impeller. The air duct is the channel for gas flow in the fan system, which is responsible for guiding the airflow generated by the fan impeller into the vacuum chamber 1.

[0040] The control system is used to integrate and control the working states of the vacuum chamber 1, the thermocouple temperature sensor 4, the baking device 3 and the fan system, and realize automatic detection and control of the gas flow and oxygen flow through the flow meter according to the temperature detected by the thermocouple temperature sensor 4, and control of the current frequency of the fan motor through the frequency controller.

[0041] The present application can effectively implement the above-mentioned method of baking refractory bricks in the vacuum chamber 1 by setting up a thermocouple temperature sensor 4, a baking device 3, a fan system and a control system, that is, it can interlock and control the current frequency, gas flow and oxygen flow according to the internal temperature of the vacuum chamber 1, and then "adjust" the flame length of the baking device 3. It can effectively bake the bottom of the vacuum chamber 1 and the lower side wall of the vacuum chamber 1. By accurately controlling the heating rate and temperature distribution, the thermal stress caused by temperature fluctuations is reduced and the service life of the equipment is extended.

[0042] In some embodiments, the control system is configured to: Based on the temperature detected by the thermocouple temperature sensor 4 in each of the first stage, the second stage and the third stage, the gas flow rate, the oxygen flow rate and the current frequency are controlled accordingly; wherein, the first stage is 600℃~900℃, the second stage is 900℃~1200℃, and the third stage is above 1200℃; the gas flow rate and the oxygen flow rate corresponding to the third stage are respectively smaller than the gas flow rate and the oxygen flow rate corresponding to the first stage and the second stage; the current frequency corresponding to the second stage is larger than the current frequency corresponding to the first stage and the third stage.

[0043] In some embodiments, the control system is configured to: If the temperature detected by the thermocouple temperature sensor 4 is in the first stage, the gas flow rate is controlled to be 200-260 NM3 / h, the oxygen flow rate is 180-230 NM3 / h, and the current frequency is 30-35 Hz; If the temperature detected by the thermocouple temperature sensor 4 is in the second stage, the gas flow rate is controlled to be 280~300NM3 / h, the oxygen flow rate is 250~270NM3 / h, and the current frequency is 45~50Hz; If the temperature detected by the thermocouple temperature sensor 4 is in the third stage, the gas flow rate is controlled to be 150-200 NM3 / h, the oxygen flow rate is controlled to be 135-180 NM3 / h, and the current frequency is controlled to be 25-30 Hz.

[0044] In some embodiments, a plurality of thermocouple temperature sensors 4 are arranged in sequence along the vertical direction; the plurality of thermocouple temperature sensors 4 are arranged spaced upward from the bottom of the vacuum chamber 1. The control system detects and controls the gas flow and oxygen flow through a flow meter according to the average value of the temperature detected by the plurality of thermocouple temperature sensors 4, and controls the current frequency of the motor through a frequency controller. By arranging a plurality of thermocouple temperature sensors 4 at different heights of the vacuum chamber 1, the temperature distribution in the vacuum chamber 1 can be monitored more comprehensively. Taking the average value of the plurality of thermocouple temperature sensors 4 as the control basis can reduce the measurement error of a single thermocouple temperature sensor 4 due to factors such as position and environment, thereby improving the accuracy of the overall measurement.

[0045] In some embodiments, Figure 2 As shown, the baking device 3 of the vacuum chamber 1 further includes a baking cover 305, which is movably arranged through a mechanical cantilever 304 and is used to seal and cooperate with the upper part of the vacuum chamber 1 to provide a good heat preservation function for the vacuum chamber 1 and prevent heat loss. The nozzle of the baking burner 301 passes through the baking cover 305 and is located in the middle of the baking cover 305. It is convenient to spray flames into the vacuum chamber 1 to bake the refractory bricks of the vacuum chamber 1.

[0046] In some embodiments, the refractory brick baking device 3 of the vacuum chamber 1 also includes a control machine, and the control system is arranged on the control machine. The control machine is provided with a user interaction interface, so that the operator can easily set parameters, monitor the process and obtain feedback information. Specifically, the control machine is a microcomputer, which has storage and memory functions, and can perform baking tests and track and record relevant data in a program-designed manner to monitor the baking quality of the bottom and side walls of the vacuum chamber 1; the control machine can track the test life of the bottom and lower side walls of the vacuum chamber 1, and optimize the program interlocking according to the tracking data to form a fixed operation mode. The present application can significantly improve the baking quality of refractory bricks and extend the service life of equipment through the intelligent management of the control machine, while achieving efficient use of energy and environmental protection.

[0047] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for baking refractory bricks in a vacuum chamber, characterized in that: include: Get the temperature inside the vacuum chamber; The fan motor current frequency, gas flow rate and oxygen flow rate of the baking device are interlocked and controlled based on the internal temperature of the vacuum chamber.

2. The method for baking refractory bricks in a vacuum chamber according to claim 1, characterized in that: The fan motor current frequency, gas flow rate and oxygen flow rate of the baking device are controlled based on the temperature interlock inside the vacuum chamber, including: Based on the temperature inside the vacuum chamber being in each of the multiple stages, the current frequency of the fan motor, the gas flow rate and the oxygen flow rate of the baking device are controlled accordingly.

3. The method for baking refractory bricks in a vacuum chamber according to claim 2, characterized in that: The multiple stages are three stages, the first stage is 600℃~900℃, the second stage is 900℃~1200℃, and the third stage is above 1200℃; the current frequency, gas flow rate and oxygen flow rate corresponding to the second stage are respectively greater than the current frequency, gas flow rate and oxygen flow rate corresponding to the first stage, and the current frequency, gas flow rate and oxygen flow rate corresponding to the third stage are respectively less than the current frequency, gas flow rate and oxygen flow rate corresponding to the first and second stages.

4. The method for baking refractory bricks in a vacuum chamber according to claim 3, characterized in that: If the temperature inside the vacuum chamber is in the first stage, control the gas flow rate to 200-260NM 3 / h, oxygen flow rate is 180~230NM 3 / h, the current frequency is 30~35Hz.

5. The method for baking refractory bricks in a vacuum chamber according to claim 3, characterized in that: If the temperature inside the vacuum chamber is in the second stage, control the gas flow rate to 280~300NM 3 / h, oxygen flow rate is 250~270NM 3 / h, the current frequency is 45~50Hz.

6. The method for baking refractory bricks in a vacuum chamber according to claim 3, characterized in that: If the temperature inside the vacuum chamber is in the third stage, control the gas flow rate to 150~200NM 3 / h, oxygen flow rate is 135~180NM 3 / h, the current frequency is 25~30Hz.

7. A vacuum chamber refractory brick baking device, characterized in that: Including thermocouple temperature sensor, baking device, fan system and control system; The thermocouple temperature sensor is arranged inside the vacuum chamber to monitor the temperature change inside the vacuum chamber in real time; The baking device comprises a baking burner, a gas supply pipeline, an oxygen supply pipeline and a mixer; the gas supply pipeline and the oxygen supply pipeline are both provided with flow meters; The fan system includes a fan motor, a fan impeller, a frequency controller and an air duct; The control system is used to integrate and control the working states of the vacuum chamber, the thermocouple temperature sensor, the baking device and the fan system, and realize automatic detection and control of the gas flow and the oxygen flow through the flow meter according to the temperature detected by the thermocouple temperature sensor, and control of the current frequency of the fan motor through the frequency controller.

8. The vacuum chamber refractory brick baking device according to claim 7, characterized in that: The control system is configured as follows: Based on the temperature detected by the thermocouple temperature sensor in each of the first stage, the second stage and the third stage, the gas flow rate, the oxygen flow rate and the current frequency are controlled accordingly; wherein, the first stage is 600°C~900°C, the second stage is 900°C~1200°C, and the third stage is above 1200°C; the gas flow rate and oxygen flow rate corresponding to the third stage are respectively smaller than the gas flow rate and oxygen flow rate corresponding to the first stage and the second stage; the current frequency corresponding to the second stage is greater than the current frequency corresponding to the first stage and the third stage.

9. The vacuum chamber refractory brick baking device according to claim 8, characterized in that: The control system is configured as follows: If the temperature detected by the thermocouple temperature sensor is in the first stage, the gas flow rate is controlled to be 200-260 NM 3 / h, oxygen flow rate is 180~230NM 3 / h, current frequency is 30~35Hz; If the temperature detected by the thermocouple temperature sensor is in the second stage, the gas flow rate is controlled to be 280~300NM 3 / h, oxygen flow rate is 250~270NM 3 / h, current frequency is 45~50Hz; If the temperature detected by the thermocouple temperature sensor is in the third stage, the gas flow rate is controlled to be 150~200NM 3 / h, oxygen flow rate is 135~180NM 3 / h, the current frequency is 25~30Hz.

10. The vacuum chamber refractory brick baking device according to claim 7, characterized in that: The thermocouple temperature sensors are arranged in a plurality in sequence along the vertical direction; The control system detects and controls the gas flow and oxygen flow through the flow meter according to the average value of the temperatures detected by the plurality of thermocouple temperature sensors, and controls the current frequency of the blower motor through the frequency controller.

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