Method for realizing rapid blow-in of blast furnace by utilizing microwaves

Abstract

The invention relates to the technical field of blast furnace ironmaking, in particular to a method for achieving rapid blow-in of a blast furnace through microwaves. The method specifically comprises the following steps that S1, microwave generators and waveguide tubes are installed on an iron notch, a tuyere, a bosh, the lower portion of a furnace body and the upper portion of the furnace body of the blast furnace, and an inner cavity of the furnace body serves as a heating cavity; s2, thermocouples are installed at the upper portion, the tuyere and the iron notch of the blast furnace and used for measuring the temperature of materials in the blast furnace; s3, after oven baking leakage testing is finished, charging is conducted, coke is filled below a bosh, light-load materials are filled from the bosh to the lower portion of the oven body, and normal materials are filled above the middle of the oven body; s4, all microwave generators are started to heat materials in the furnace, and the temperature of furnace charge on the middle-upper portion of the furnace body is controlled to be smaller than the temperature of furnace charge from the lower portion of the furnace body to the hearth; s5, during heating, steam or nitrogen is introduced into the furnace top for cooling; and S6, after the furnace burden is heated to a preset state, the microwave generator is turned off, and air supply blow-in is carried out. The device has the advantages of high heating speed, high efficiency and no pollution.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace ironmaking, and in particular to a method for realizing rapid opening of a blast furnace by utilizing microwaves. Background Art

[0002] Blow-up marks the beginning of a blast furnace's lifespan. Newly built and overhauled blast furnaces undergo a recovery process. The success of each recovery process directly impacts the efficiency and economics of the start-up, and even the subsequent smooth operation of the blast furnace. Blast-furnace start-up is a crucial step in ironmaking, directly impacting the furnace's production efficiency and lifespan.

[0003] At present, due to the temperature tolerance limit of the charging equipment on the furnace top, blast furnaces are generally started with cold materials. Sintered ore, pelletized ore, coke and solvent are composed of furnace charges in a certain proportion. The charges are added into the furnace from the furnace top, and hot air is blown into the blast furnace tuyere. When the charge contacts and moves with the hot air in the blast furnace, heat transfer and redox reaction occur to produce coal gas. The coal gas moves upward and leaves the blast furnace from the riser. During the reaction, the blast furnace material melts and drips into molten iron and slag, and the liquid slag iron is discharged from the blast furnace from the iron mouth.

[0004] The primary task during the initial furnace start-up phase is heating the furnace and charge to normal production conditions. This process requires significant heat and time. Generally, furnace start-ups for major or medium-sized repairs are difficult, and recovery takes a long time. Therefore, achieving rapid furnace start-up has long been a technical challenge for ironmakers. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a method for quickly starting a blast furnace using microwaves, which can achieve rapid furnace start-up and has the advantages of fast heating speed, high efficiency and no pollution.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for rapidly starting a blast furnace using microwaves comprises the following steps:

[0008] S1: Microwave generators and waveguides are installed at the iron mouth, tuyere, bosh, lower part of the furnace body and upper part of the furnace body of the blast furnace, and the inner cavity of the furnace body serves as the heating cavity.

[0009] S2: Thermocouples are installed on the upper part of the blast furnace, at the tuyere and the iron mouth to measure the material temperature in the furnace.

[0010] S3: After the furnace leak test is completed, the material is loaded. Coke is filled below the furnace bosh, light-load material is filled from the furnace bosh to the lower part of the furnace body, and normal material is filled above the middle of the furnace body.

[0011] S4: Turn on all microwave generators to heat the materials in the furnace, and control the temperature of the materials in the upper and middle parts of the furnace body to be lower than the temperature of the materials from the lower part of the furnace body to the furnace cylinder.

[0012] When the temperature of the thermocouple on the upper part of the furnace body reaches 150-200℃, turn off the microwave generator on the upper part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 400-600℃, turn off the microwave generator at the lower part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 600-800℃, turn off the microwave generators at the tuyere and bosh; when the temperature of the thermocouple at the iron mouth reaches 800-1000℃, turn off the microwave generator at the iron mouth.

[0013] S5: While heating, steam or nitrogen is passed through the furnace top to cool it down.

[0014] S6: When the charge is heated to a predetermined state, the microwave generator is turned off, the microwave generator and the waveguide are removed, and their mounting holes are repaired, and the furnace is opened with air supply.

[0015] Furthermore, in S1, microwave generators and waveguide tubes are installed at all iron mouths; 4 to 8 tuyere are selected to install microwave generators and waveguide tubes, and these 4 to 8 tuyere are evenly distributed around the circumference; 4 to 8 microwave generators and waveguide tubes are evenly distributed around the circumference of the furnace bosh, the lower part of the furnace body, and the upper part of the furnace body; all microwave generators are equipped with separate control switches.

[0016] Furthermore, in S2, thermocouples are inserted into the furnace through the iron mouth, the tuyere, the static pressure hole at the lower part of the furnace body, and the static pressure hole at the upper part of the furnace body respectively.

[0017] Furthermore, in S3, normal material refers to the charge load and structure during normal smelting of the blast furnace. The total coke ratio of the start-up charge is reduced by 40-60% according to the normal start-up charge, and the basicity of the start-up charge is 0.7-0.9; the coke load of the light load charge is reduced by 0.2-0.4 compared with the normal charge; the sintered ore, pelletized ore and coke in the start-up charge are selected at the upper limit level of the quality standard for blast furnace materials of each volume.

[0018] Furthermore, in S4, the microwave frequency from the furnace body to the furnace waist is 915~1500MHz, and the power is 100~150kW; the microwave frequency from the furnace belly to the furnace hearth is: 1500~2450MHz, and the power is: 150~200kW.

[0019] Furthermore, in S4, the charge in the upper middle portion of the furnace body is heated to 200-600°C.

[0020] Furthermore, in S4, the charge from the lower part of the furnace body to the hearth is heated to 610-1000°C.

[0021] Furthermore, in S5, the steam temperature is 160-190°C, the pressure is 0.6-0.8 MPa, and the flow rate is 50-100 m 3 / h.

[0022] Furthermore, in S5, the nitrogen temperature is 20-40°C, the pressure is 0.4-0.6 MPa, and the flow rate is 100-200 m 3 / h.

[0023] Furthermore, in S5, the furnace top temperature is ensured to be less than 350°C.

[0024] Compared with the existing method, the present invention has the following beneficial effects:

[0025] 1. The present invention utilizes the advantages of microwave heating, such as fast speed, high efficiency, and zero pollution, to preheat the furnace hearth and charge in advance, achieving rapid furnace start-up and recovery, greatly shortening furnace start-up time and improving furnace start-up efficiency. At the same time, the present invention can also reduce environmental pollution, with good economic and social benefits.

[0026] 2. In this invention, the microwave frequency and power gradually increase from the furnace body to the hearth. The predetermined temperature for heating the charge during the start-up process also increases gradually from the furnace body to the hearth. The charge in the upper middle section of the furnace body is heated to approximately 200-600°C, while the charge from the lower section of the furnace body to the hearth is heated to approximately 600-1000°C. The heating temperature of each section of charge is close to the charge temperature of the blast furnace's block and soft melting zones during normal operation. This is the key to saving start-up time with microwave preheating.

[0027] 3. This invention fills the furnace below the bosh with coke, the lower portion of the furnace body with light-loaded charge from the bosh to the lower portion, and the middle portion of the furnace body with normal charge. Using microwaves to preheat the furnace allows the charge to reach normal production conditions as quickly as possible. This allows the charge structure to be similar to that of short- to medium-term wind-down charge, significantly reducing the coke ratio of the charge and avoiding complex charge structure and distribution control.

[0028] 4. The microwave frequency from the furnace body to the waist of the present invention is 915-1500 MHz, with a power of 100-150 kW; the microwave frequency from the bosh to the hearth is 1500-2450 MHz, with a power of 150-200 kW. The microwave frequency and power are determined by the heating load at each location. As the preheating temperature of the charge increases from the upper part of the furnace body to the hearth, the heating load gradually increases. The base power is selected based on industrial testing.

[0029] 5. Based on the temperature distribution characteristics of various zones within the blast furnace, the present invention creatively introduces microwaves to preheat the start-up charge to a semi-production state, overcoming the drawback of the blast furnace charging system's inability to add preheated charge. By pre-setting microwave generating and temperature measurement systems throughout the blast furnace, the start-up charge preheating temperature is precisely controlled, significantly reducing the start-up charge coke ratio while greatly shortening the start-up time and improving start-up efficiency. Furthermore, the present invention can reduce environmental pollution and offer excellent economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure and process principle of the present invention. DETAILED DESCRIPTION

[0031] The present invention discloses a method for rapidly starting a blast furnace using microwaves. Those skilled in the art may refer to the contents of this document and appropriately improve the process parameters to achieve this. It should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0032] A method for rapidly starting a blast furnace using microwaves comprises the following steps:

[0033] S1: Microwave generators and waveguides are installed at the iron mouth, tuyere, bosh, lower part of the furnace body and upper part of the furnace body of the blast furnace, and the inner cavity of the furnace body serves as the heating cavity.

[0034] All iron mouths are equipped with microwave generators and waveguide tubes; 4 to 8 tuyere are selected to install microwave generators and waveguide tubes, and these 4 to 8 tuyere are evenly distributed around the circumference; 4 to 8 microwave generators and waveguide tubes are evenly distributed around the circumference of the furnace bosh, the lower part of the furnace body, and the upper part of the furnace body; all microwave generators are equipped with separate control switches.

[0035] S2: Install thermocouples at the upper part of the blast furnace, at the tuyere, and at the taphole to measure the charge temperature. Insert the thermocouples into the furnace through the taphole, tuyere, static pressure hole at the lower part of the furnace, and static pressure hole at the upper part of the furnace.

[0036] S3: After the furnace leak test is completed, charging begins. Coke is placed below the bosh, light-loaded charge is placed from the bosh to the lower part of the furnace shaft, and normal charge is placed above the middle of the furnace shaft. Normal charge represents the charge load and structure during normal smelting. The start-up charge has a 40-60% lower total coke ratio than the normal start-up charge, and a basicity of 0.7-0.9. The light-loaded charge has a 0.2-0.4 lower coke load than the normal charge. The sinter, pellets, and coke in the start-up charge should be at the upper limit of the quality standards for blast furnace materials of their respective volumes.

[0037] S4: Turn on all microwave generators to heat the materials in the furnace, and control the temperature of the materials in the upper and middle parts of the furnace body to be lower than the temperature of the materials from the lower part of the furnace body to the furnace cylinder.

[0038] When the temperature of the thermocouple on the upper part of the furnace body reaches 150-200℃, turn off the microwave generator on the upper part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 400-600℃, turn off the microwave generator at the lower part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 600-800℃, turn off the microwave generators at the tuyere and bosh; when the temperature of the thermocouple at the iron mouth reaches 800-1000℃, turn off the microwave generator at the iron mouth.

[0039] The microwave frequency from the furnace body to the furnace waist is 915~1500MHz, and the power is 100~150kW; the microwave frequency from the furnace belly to the furnace hearth is 1500~2450MHz, and the power is 150~200kW.

[0040] Heat the charge in the upper part of the furnace body to 200-600℃.

[0041] Heat the charge from the lower part of the furnace body to the hearth to 610-1000℃.

[0042] S5: While heating, steam or nitrogen is passed through the furnace top to cool it down, ensuring that the furnace top temperature is less than 350℃ to protect the furnace top equipment.

[0043] Steam temperature 160~190℃, pressure 0.6~0.8MPa, flow rate 50~100m 3 / h. Nitrogen temperature 20~40℃, pressure 0.4~0.6MPa, flow rate 100~200m 3 / h.

[0044] S6: When the charge is heated to a predetermined state, the microwave generator is turned off, the microwave generator and the waveguide are removed, and their mounting holes are repaired, and the furnace is opened with air supply.

[0045] Since the furnace body and charge are preheated in advance, the blast furnace can achieve rapid air addition, speeding up the smelting process and achieving the purpose of rapid furnace start-up.

[0046] Example 1: Take a 4000m 3 The present invention will be described in detail by taking the start-up of a blast furnace as an example.

[0047] 1. Implementation Background

[0048] In order to speed up the blast furnace start-up process, improve production efficiency and reduce energy consumption, the microwave preheating method is used to carry out the furnace start-up operation.

[0049] 2. Implementation Preparation

[0050] At 4000m 3 Microwave generators and waveguides are installed at the iron mouth, tuyere, bosh, lower part of the furnace body and upper part of the furnace body, and the inner cavity of the furnace body serves as a heating cavity.

[0051] 4000m 3There are four iron mouths in the blast furnace in the east, west, south and north directions, and all of them are equipped with microwave generators and waveguide tubes; four tuyere are selected to install microwave generators and waveguide tubes, and these four tuyere are evenly distributed around the circumference; four microwave generators and waveguide tubes are evenly installed around the bosh, the lower part of the furnace body and the upper part of the furnace body; all microwave generators are equipped with separate control switches.

[0052] Thermocouples are installed at the upper part of the blast furnace, at the tuyere, and at the taphole to measure the charge temperature. The thermocouples are inserted into the furnace through the taphole, tuyere, static pressure hole at the lower part of the furnace, and static pressure hole at the upper part of the furnace.

[0053] 3. Loading process

[0054] After the furnace leak test is complete, charging begins. Coke is placed below the bosh, light-load charge is placed from the bosh to the lower portion of the furnace shaft, and normal charge is placed above the middle portion of the furnace shaft. Normal charge represents the charge load and structure during normal blast furnace smelting. The start-up charge has a 40-60% lower total coke ratio and a basicity of 0.7-0.9. The light-load charge has a 0.2-0.4 lower coke load than the normal charge. The sinter, pellets, and coke in the start-up charge should meet the upper limits of the quality standards for blast furnace materials of their respective volumes.

[0055] The starting charge is made of clinker materials such as sintered ore and pellets, and the coke is fully dry coke. The impurity and moisture content of the starting charge is strictly controlled to ensure that its quality meets the requirements. The coke CSR must be ≥65%, M40 ≥85%, and M10 ≤6.5%. The sintering RDI+3.15 must be ≥70%, the drum index must be ≥80%, and the pellet compressive strength must be ≥3000N.

[0056] 4. Microwave heating

[0057] The microwave generators in the furnace and body are turned on. The microwaves generated by the microwave generators are transmitted to the furnace via waveguides, heating the materials inside. Based on the temperature measured by the thermocouples, the frequency, power, and heating time of the microwaves at each location are adjusted in real time. The microwave frequency and power gradually increase from the furnace body to the furnace, and the predetermined temperature for heating the materials also gradually increases from the furnace body to the furnace body. The details are as follows:

[0058] When the temperature of the thermocouple on the upper part of the furnace body reaches 150-200℃, turn off the microwave generator on the upper part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 400-600℃, turn off the microwave generator at the lower part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 600-800℃, turn off the microwave generators at the tuyere and bosh; when the temperature of the thermocouple at the iron mouth reaches 800-1000℃, turn off the microwave generator at the iron mouth.

[0059] The microwave frequency from the furnace body to the furnace waist is 915~1500MHz, and the power is 100~150kW; the microwave frequency from the furnace belly to the furnace hearth is 1500~2450MHz, and the power is 150~200kW.

[0060] Heat the charge in the upper part of the furnace body to 200-600℃. Heat the charge from the lower part of the furnace body to the hearth to 610-1000℃.

[0061] 5. Protection measures

[0062] While heating, steam is passed through the furnace top to cool it down, ensuring that the furnace top temperature is less than 350℃ and protecting the furnace top equipment.

[0063] Steam temperature 160~190℃, pressure 0.6~0.8MPa, flow rate 50~100m 3 / h.

[0064] 6. Supply air and start the furnace

[0065] When the charge is heated to a predetermined state, the microwave generator is turned off and air is supplied to open the furnace.

[0066] During the implementation process, it is necessary to closely monitor the temperature data measured by the thermocouple and promptly adjust the parameters of the microwave generator to ensure that the charge is evenly heated and reaches the predetermined temperature requirement. At the same time, pay attention to the flow rate of steam or nitrogen to fully protect the furnace top equipment.

[0067] The furnace start-up time in this embodiment is 10 hours, while the traditional method takes more than 48 hours. Compared with the traditional furnace start-up method, the present invention overcomes the disadvantage of the blast furnace charging system being unable to add preheated materials. By pre-setting the microwave generation system and temperature measurement system in various parts of the blast furnace body, the preheating temperature of the start-up charge is accurately controlled, significantly reducing the coke ratio of the start-up charge while greatly shortening the furnace start-up time and improving the furnace start-up efficiency. At the same time, the present invention can also reduce environmental pollution and has good economic and social benefits.

[0068] Example 2: Taking a 3200m 3 The present invention will be described in detail by taking the start-up of a blast furnace as an example.

[0069] 1. Implementation Background

[0070] In order to speed up the blast furnace start-up process, improve production efficiency and reduce energy consumption, the microwave preheating method is used to carry out the furnace start-up operation.

[0071] 2. Implementation Preparation

[0072] At 3200m 3 Microwave generators and waveguides are installed at the taphole, tuyere, bosh, lower part of the furnace body, and upper part of the furnace body. The furnace cavity serves as the heating chamber. The microwave generators in these areas are each equipped with separate control switches.

[0073] 3200m 3There are four iron mouths in the blast furnace in the east, west, south and north directions, and all of them are equipped with microwave generators and waveguide tubes; four tuyere are selected to install microwave generators and waveguide tubes, and these four tuyere are evenly distributed around the circumference; four microwave generators and waveguide tubes are evenly installed around the bosh, the lower part of the furnace body and the upper part of the furnace body; all microwave generators are equipped with separate control switches.

[0074] Thermocouples are installed at the upper part of the blast furnace, at the tuyere, and at the taphole to measure the charge temperature. The thermocouples are inserted into the furnace through the taphole, tuyere, static pressure hole at the lower part of the furnace, and static pressure hole at the upper part of the furnace.

[0075] 3. Loading process

[0076] After the furnace leak test is complete, charging begins. Coke is placed below the bosh, light-load charge is placed from the bosh to the lower portion of the furnace shaft, and normal charge is placed above the middle portion of the furnace shaft. Normal charge represents the charge load and structure during normal blast furnace smelting. The start-up charge has a 40-60% lower total coke ratio and a basicity of 0.7-0.9. The light-load charge has a 0.2-0.4 lower coke load than the normal charge. The sinter, pellets, and coke in the start-up charge should meet the upper limits of the quality standards for blast furnace materials of their respective volumes.

[0077] The starting charge is made of clinker materials such as sintered ore and pellets, and the coke is fully dry coke. The impurity and moisture content of the starting charge is strictly controlled to ensure that its quality meets the requirements. The coke CSR must be ≥65%, M40 ≥85%, and M10 ≤6.5%. The sintering RDI+3.15 must be ≥70%, the drum index must be ≥80%, and the pellet compressive strength must be ≥3000N.

[0078] 4. Microwave heating

[0079] The microwave generators in the furnace and body are turned on. The microwaves generated by the microwave generators are transmitted to the furnace via waveguides, heating the materials inside. Based on the temperature measured by the thermocouples, the frequency, power, and heating time of the microwaves at each location are adjusted in real time. The microwave frequency and power gradually increase from the furnace body to the furnace, and the predetermined temperature for heating the materials also gradually increases from the furnace body to the furnace body. The details are as follows:

[0080] When the temperature of the thermocouple on the upper part of the furnace body reaches 150-200℃, turn off the microwave generator on the upper part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 400-600℃, turn off the microwave generator at the lower part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 600-800℃, turn off the microwave generators at the tuyere and bosh; when the temperature of the thermocouple at the iron mouth reaches 800-1000℃, turn off the microwave generator at the iron mouth.

[0081] The microwave frequency from the furnace body to the furnace waist is 915~1500MHz, and the power is 100~150kW; the microwave frequency from the furnace belly to the furnace hearth is 1500~2450MHz, and the power is 150~200kW.

[0082] Heat the charge in the upper part of the furnace body to 200-600℃. Heat the charge from the lower part of the furnace body to the hearth to 610-1000℃.

[0083] 5. Protection measures

[0084] While heating, nitrogen is passed through the furnace top to cool it down, ensuring that the furnace top temperature is less than 350℃ and protecting the furnace top equipment.

[0085] Nitrogen temperature 20~40℃, pressure 0.4~0.6MPa, flow rate 100~200m 3 / h.

[0086] 6. Supply air and start the furnace

[0087] When the charge is heated to a predetermined state, the microwave generator is turned off and air is supplied to open the furnace.

[0088] During the implementation process, it is necessary to closely monitor the temperature data measured by the thermocouple and promptly adjust the parameters of the microwave generator to ensure that the charge is evenly heated and reaches the predetermined temperature requirement. At the same time, pay attention to the flow rate of steam or nitrogen to fully protect the furnace top equipment.

[0089] The furnace start-up time in this embodiment is 8 hours, while the traditional method takes more than 48 hours. Compared with the traditional furnace start-up method, the present invention overcomes the disadvantage of the blast furnace charging system being unable to add preheated materials. By pre-setting the microwave generation system and temperature measurement system in various parts of the blast furnace body, the preheating temperature of the start-up charge is accurately controlled, significantly reducing the coke ratio of the start-up charge while greatly shortening the furnace start-up time and improving the furnace start-up efficiency. At the same time, the present invention can also reduce environmental pollution and has good economic and social benefits.

[0090] Example 3: Taking a 4700m 3 The present invention will be described in detail by taking the start-up of a blast furnace as an example.

[0091] 1. Implementation Background

[0092] In order to speed up the blast furnace start-up process, improve production efficiency and reduce energy consumption, the microwave preheating method is used to carry out the furnace start-up operation.

[0093] 2. Implementation Preparation

[0094] At 4700m 3 Microwave generators and waveguides are installed at the taphole, tuyere, bosh, lower part of the furnace body, and upper part of the furnace body. The furnace cavity serves as the heating chamber. The microwave generators in these areas are each equipped with separate control switches.

[0095] 4700m 3There are four iron holes in the blast furnace in the east, west, south and north directions, and all of them are equipped with microwave generators and waveguide tubes; 6 tuyere are selected to install microwave generators and waveguide tubes, and these 6 tuyere are evenly distributed around the circumference; 4 microwave generators and waveguide tubes are evenly installed around the bosh, the lower part of the furnace body and the upper part of the furnace body; all microwave generators are equipped with separate control switches.

[0096] Thermocouples are installed at the upper part of the blast furnace, at the tuyere, and at the taphole to measure the charge temperature. The thermocouples are inserted into the furnace through the taphole, tuyere, static pressure hole at the lower part of the furnace, and static pressure hole at the upper part of the furnace.

[0097] 3. Loading process

[0098] After the furnace leak test is complete, charging begins. Coke is placed below the bosh, light-load charge is placed from the bosh to the lower portion of the furnace shaft, and normal charge is placed above the middle portion of the furnace shaft. Normal charge represents the charge load and structure during normal blast furnace smelting. The start-up charge has a 40-60% lower total coke ratio and a basicity of 0.7-0.9. The light-load charge has a 0.2-0.4 lower coke load than the normal charge. The sinter, pellets, and coke in the start-up charge should meet the upper limits of the quality standards for blast furnace materials of their respective volumes.

[0099] The starting charge is made of clinker materials such as sintered ore and pellets, and the coke is fully dry coke. The impurity and moisture content of the starting charge is strictly controlled to ensure that its quality meets the requirements. The coke CSR must be ≥65%, M40 ≥85%, and M10 ≤6.5%. The sintering RDI+3.15 must be ≥70%, the drum index must be ≥80%, and the pellet compressive strength must be ≥3000N.

[0100] 4. Microwave heating

[0101] The microwave generators in the furnace and body are turned on. The microwaves generated by the microwave generators are transmitted to the furnace via waveguides, heating the materials inside. Based on the temperature measured by the thermocouples, the frequency, power, and heating time of the microwaves at each location are adjusted in real time. The microwave frequency and power gradually increase from the furnace body to the furnace, and the predetermined temperature for heating the materials also gradually increases from the furnace body to the furnace body. The details are as follows:

[0102] When the temperature of the thermocouple on the upper part of the furnace body reaches 150-200℃, turn off the microwave generator on the upper part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 400-600℃, turn off the microwave generator at the lower part of the furnace body; when the temperature of the thermocouple at the tuyere reaches 600-800℃, turn off the microwave generators at the tuyere and bosh; when the temperature of the thermocouple at the iron mouth reaches 800-1000℃, turn off the microwave generator at the iron mouth.

[0103] The microwave frequency from the furnace body to the furnace waist is 915~1500MHz, and the power is 100~150kW; the microwave frequency from the furnace belly to the furnace hearth is 1500~2450MHz, and the power is 150~200kW.

[0104] Heat the charge in the upper part of the furnace body to 200-600℃. Heat the charge from the lower part of the furnace body to the hearth to 610-1000℃.

[0105] 5. Protection measures

[0106] While heating, steam is passed through the furnace top to cool it down, ensuring that the furnace top temperature is less than 350℃ and protecting the furnace top equipment.

[0107] Steam temperature 160~190℃, pressure 0.6~0.8MPa, flow rate 50~100m 3 / h.

[0108] 6. Supply air and start the furnace

[0109] When the charge is heated to a predetermined state, the microwave generator is turned off and air is supplied to open the furnace.

[0110] During the implementation process, it is necessary to closely monitor the temperature data measured by the thermocouple and promptly adjust the parameters of the microwave generator to ensure that the charge is evenly heated and reaches the predetermined temperature requirement. At the same time, pay attention to the flow rate of steam or nitrogen to fully protect the furnace top equipment.

[0111] The furnace start-up time in this embodiment is 12 hours, while the traditional method takes more than 48 hours. Compared with the traditional furnace start-up method, the present invention overcomes the disadvantage of the blast furnace charging system being unable to add preheated materials. By pre-setting the microwave generation system and temperature measurement system in various parts of the blast furnace body, the preheating temperature of the start-up charge is accurately controlled, significantly reducing the coke ratio of the start-up charge while greatly shortening the furnace start-up time and improving the furnace start-up efficiency. At the same time, the present invention can also reduce environmental pollution and has good economic and social benefits.

[0112] The present invention utilizes the advantages of microwave heating, such as fast speed, high efficiency, and zero pollution, to preheat the furnace hearth and charge in advance, achieving rapid furnace start-up and recovery, significantly shortening furnace start-up time and improving furnace start-up efficiency. Furthermore, the present invention can reduce environmental pollution and has good economic and social benefits.

[0113] The present invention utilizes the advantages of microwave heating, such as fast speed, high efficiency, and zero pollution, to preheat the furnace hearth and charge in advance, achieving rapid furnace start-up and recovery, significantly shortening furnace start-up time and improving furnace start-up efficiency. Furthermore, the present invention can reduce environmental pollution and has good economic and social benefits.

[0114] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for rapidly opening a blast furnace using microwaves, characterized in that: The specific steps include: S1: Microwave generators and waveguides are installed at the iron mouth, tuyere, bosh, lower part of the furnace body and upper part of the furnace body of the blast furnace, and the inner cavity of the furnace body serves as the heating cavity; S2: Thermocouples are installed on the upper part of the blast furnace, at the tuyere and the iron mouth to measure the material temperature in the furnace; S3: After the furnace leak test is completed, the furnace is charged with coke below the bosh, light-load material is filled from the bosh to the lower part of the furnace body, and normal material is filled above the middle of the furnace body; S4: Turn on all microwave generators to heat the materials in the furnace, and control the temperature of the materials in the upper part of the furnace body to be lower than the temperature of the materials in the lower part of the furnace body to the furnace cylinder; When the temperature of the thermocouple on the upper part of the furnace reaches 150-200°C, turn off the microwave generator on the upper part of the furnace; When the temperature of the tuyere thermocouple reaches 400-600℃, turn off the microwave generator at the bottom of the furnace; When the temperature of the tuyere thermocouple reaches 600-800℃, turn off the microwave generators at the tuyere and bosh; When the taphole thermocouple temperature reaches the range of 800-1000℃, turn off the microwave generator at the taphole; S5: While heating, steam or nitrogen is passed through the furnace top to cool it down; S6: When the charge is heated to a predetermined state, the microwave generator is turned off, the microwave generator and the waveguide are removed, and their mounting holes are repaired, and the furnace is opened with air supply.

2. The method for rapidly opening a blast furnace using microwaves according to claim 1, wherein: In S1, microwave generators and waveguides are installed at all iron mouths; 4 to 8 tuyere are selected to install microwave generators and waveguides, and these 4 to 8 tuyere are evenly distributed around the circumference; 4 to 8 microwave generators and waveguides are evenly distributed around the circumference of the furnace bosh, the lower part of the furnace body, and the upper part of the furnace body; all microwave generators are equipped with separate control switches.

3. The method for rapidly opening a blast furnace using microwaves according to claim 1, wherein: In S2, thermocouples are inserted into the furnace through the iron mouth, tuyere, static pressure hole at the lower part of the furnace body, and static pressure hole at the upper part of the furnace body respectively.

4. The method for rapidly opening a blast furnace using microwaves according to claim 1, wherein: In S3, the normal charge is the charge load and structure during the normal smelting period before the blast furnace overhaul. The total coke ratio of the charge for starting the furnace is reduced by 40-60% according to the cold charge, and the basicity of the charge is 0.7-0.

9. The coke load of light-load material is 0.2-0.4 lower than that of normal material; The sintered ore, pelletized ore and coke in the starting charge shall be selected at the upper limit level of the quality standard for blast furnace materials of each volume.

5. The method for rapidly opening a blast furnace using microwaves according to claim 1, wherein: In S4, the microwave frequency from the furnace body to the furnace waist is 915~1500MHz, and the power is 100~150kW; the microwave frequency from the furnace belly to the furnace hearth is: 1500~2450MHz, and the power is: 150~200kW.

6. The method for rapidly opening a blast furnace using microwaves according to claim 1, wherein: In S4, the charge in the upper middle portion of the furnace body is heated to 200-600°C.

7. The method for rapidly opening a blast furnace using microwaves according to claim 1, wherein: In S4, the charge from the lower part of the furnace body to the hearth is heated to 610-1000°C.

8. The method for rapidly opening a blast furnace using microwaves according to claim 1, wherein: In S5, the steam temperature is 160-190°C, the pressure is 0.6-0.8 MPa, and the flow rate is 50-100 m 3 / h.

9. The method for rapidly opening a blast furnace using microwaves according to claim 1, wherein: In S5, the nitrogen temperature is 20-40°C, the pressure is 0.4-0.6 MPa, and the flow rate is 100-200 m 3 / h.

10. The method for rapidly opening a blast furnace using microwaves according to claim 1, wherein: In S5, ensure that the furnace top temperature is less than 350°C.

Images