Blast furnace baking and blowing-in method
By laying coils and setting air ducts at the bottom of the blast furnace, the problem that hot air is difficult to fully dry the furnace bottom and iron mouth areas is solved, efficient hot air utilization and furnace cylinder heating are achieved, the air spraying time of the iron mouth is extended, and the production efficiency and product quality are improved.
Patent Information
- Application Number
- CN202510034188.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-09
- Publication Date
- 2025-05-02
AI Technical Summary
During the blast furnace drying process, the equivalent diameter of the lower hot air passage is smaller than the upper part, causing the hot air to tend to flow upward, thus unable to fully dry the furnace cylinder, furnace bottom, and iron mouth area with the thickest resistance. After the furnace is opened and air supply, the furnace bottom, iron mouth and furnace cylinder area are difficult to be quickly heated by high-temperature gas.
Coils are laid at the bottom of the blast furnace, and a first interval is formed by welding brackets, and air ducts are arranged so that the hot air is evenly distributed to the bottom of the furnace. The multiple air outlets are communicated with the coil through the furnace transverse tube and the riser, and hot air guide plates are welded on the furnace transverse tube to form a second interval to guide the distribution of the hot air to the furnace wall. When the furnace is turned on, the coil is buried by the bottom-laying coke, and the gas passes through the bottom-laying coke and enters the coil and is discharged, changing the gas flow path to heat the bottom-laying coke.
By laying coils and setting air ducts at the bottom of the blast furnace, the distance between the hot air and the bottom is effectively controlled, the heat exchange efficiency is improved, the air spraying time of the iron mouth is extended, and the temperature of the furnace cylinder and the first iron is improved by changing the gas flow path, and the production efficiency and product quality are improved.
Smart Images
Figure CN119913304A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of blast furnaces, and in particular to a blast furnace baking and opening method. Background Art
[0002] Purpose of blast furnace baking: There is a lot of moisture in the blast furnace body and pipelines during the masonry process, and the blast furnace is always in a high temperature state after it is put into production. In order to ensure the service life of the refractory materials after the blast furnace is put into production, the refractory materials must be baked before the blast furnace is put into production, and the moisture must be slowly dried to give the refractory materials and equipment sufficient preheating expansion. Blast furnace baking is to blow hot air from the tuyere, and use the temperature of the hot air to gradually heat up the moisture in the body, and finally discharge it from the exhaust hole of the blast furnace itself in the form of water vapor. However, due to the design characteristics of the blast furnace itself, during the baking process, the equivalent diameter of the lower hot air channel is much smaller than that of the upper part, so the hot air from the baking furnace tends to flow upward and be discharged from the top of the furnace rather than downward from the iron mouth. This results in the furnace hearth, furnace bottom, and iron mouth areas where the refractory materials are thickest not having sufficient hot air for drying, and the baking goal can only be achieved through a longer baking time. In addition, after the furnace is opened and air is supplied, a large amount of hot air needs to be directed from the tuyere to the furnace bottom to quickly heat the furnace bottom, taphole, and hearth area, and the fully heated coke in the upper part is sent down to heat the hearth to provide good fluidity for the generated slag iron, laying a good foundation for the smooth outflow of the first iron. In the past, when there was no furnace bottom coil, after the furnace was opened and air was supplied, the hot air entering the lower part was directly discharged from the taphole, and the bottom coke below the taphole was a "dead zone" for gas flow and was difficult to be quickly heated by high-temperature gas. Summary of the invention
[0003] The purpose of the present invention is to provide a blast furnace baking and opening method to solve the problems existing in the above-mentioned prior art, which can effectively improve the heat utilization rate of hot air in the furnace baking process and effectively prolong the iron mouth empty spraying time.
[0004] To achieve the above object, the present invention provides the following solutions:
[0005] The present invention provides a blast furnace baking and opening method, comprising the following steps:
[0006] S1: laying a coil on the bottom of a blast furnace, welding a bracket at the bottom of the coil to form a first gap between the coil and the bottom of the blast furnace, providing an air duct at the lower half of the coil, and opening a plurality of tuyere in the circumferential direction of the top of the blast furnace wall, one tuyere being connected to a vertical pipe in the furnace through a horizontal pipe in the furnace, and then connected to the coil through a vertical pipe in the furnace, welding a hot air guide plate on the horizontal pipe in the furnace, and forming a second gap between the circumference of the hot air guide plate and the blast furnace wall;
[0007] S2: hot air is blown into each of the tuyere, and the hot air enters the coil at the bottom of the blast furnace through the horizontal pipe and the vertical pipe in the furnace, and the hot air is blown to the bottom of the blast furnace from the air duct at the lower half of the coil, so as to strengthen the heat exchange effect between the hot air and the bottom of the blast furnace, and the hot air flows upward after drying the bottom of the blast furnace, and the hot air guide plate forces the rising hot air to be distributed to the furnace wall, so as to strengthen the heat exchange between the hot air and the blast furnace wall to be dried;
[0008] S3: Preparation before furnace opening: the hot air guide plate, the horizontal pipe in the furnace, and the vertical pipe in the furnace are cut off, and the furnace bottom coil is left. The connecting pipe is extended from the blast furnace iron mouth into the blast furnace and welded to the coil and connected, and the upper half of the coil is coated with refractory material;
[0009] S4: Charging and furnace opening process, charging into the blast furnace. After charging, the coil is buried by the bottom coke. The furnace is opened for air supply. The coal gas entering the furnace passes through the bottom coke and enters the air duct of the coil, and then is discharged from the connecting pipe passing through the iron mouth, so that the bottom coke can be effectively heated, thereby increasing the furnace temperature and the temperature of the first iron.
[0010] Preferably, in step S1, the coiled pipe laid at the bottom of the blast furnace is a double-layer octagonal ring pipe welded with seamless steel pipes, the outer ring pipe is connected to the inner ring pipe, the outer ring pipe is 10-20% of the hearth diameter away from the protective bricks of the blast furnace wall, and the inner ring pipe is 30-40% of the hearth diameter away from the center of the blast furnace.
[0011] Preferably, in step S1, the first interval is 400-600 mm, and the second interval is 300-500 mm.
[0012] Preferably, in step S1, four rows of air ducts with a diameter of 20-40 mm are arranged on the lower half of the coil, and the air ducts include a plurality of ventilation holes, and the spacing between adjacent ventilation holes in the axial direction of the coil is 300 mm.
[0013] Preferably, in step S1, the number of the tuyere is 8, each of the tuyere is evenly distributed in the circumferential direction of the blast furnace wall, the number of the horizontal pipes in the furnace is 8, and one end of the horizontal pipe in the furnace connected to the tuyere is provided with a bell mouth, the number of the vertical pipes in the furnace is 8, and the bottom end of the vertical pipe in the furnace is connected to the inner ring pipe of the coil.
[0014] Preferably, in step S3, a refractory coating with a thickness of 10 to 20 mm is laid on the upper half of the coil.
[0015] Compared with the prior art, the present invention has achieved the following technical effects:
[0016] The present invention provides a method for baking and opening a blast furnace. By laying a coil at the bottom of the blast furnace and setting a bracket to form a first interval, the distance between the hot air and the bottom of the furnace can be effectively controlled, and the thermal shock can be reduced or the heating effect can be enhanced as needed. The air duct is arranged to facilitate the uniform distribution of the hot air to the bottom of the furnace, thereby improving the heat exchange efficiency. A plurality of air ports are connected to the coil through a horizontal pipe and a vertical pipe in the furnace to ensure the smooth transportation of the hot air. A hot air guide plate is welded on the horizontal pipe in the furnace to form a second interval, which can guide the hot air to be distributed to the furnace wall and enhance the drying effect of the furnace wall. The function of the hot air guide plate enables the hot air to be distributed to the furnace wall after drying the furnace bottom, further improving the utilization efficiency of the hot air and enhancing the drying effect of the furnace wall. After loading, the coil is buried by the bottom coke. When the furnace is opened and the air is supplied, the coal gas passes through the bottom coke into the coil and then is discharged, which changes the flow path of the coal gas, so that the bottom coke is effectively heated, thereby increasing the temperature of the furnace cylinder and the temperature of the first iron, which is conducive to improving production efficiency and product quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] 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 will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0018] Figure 1 A front cross-sectional view of a blast furnace in the blast furnace baking and opening method provided by the present invention;
[0019] Figure 2 for Figure 1 A top view of
[0020] Figure 3 for Figure 2 The cross-sectional view shown in AA;
[0021] In the figure: 1. coil; 2. inner ring pipe; 3. outer ring pipe; 4. bracket; 5. air duct; 6. air outlet; 7. horizontal pipe in the furnace; 8. vertical pipe in the furnace; 9. hot air guide plate; 10. refractory coating; 11. connecting pipe; 12. blast furnace wall; 13. blast furnace bottom; 14. blast furnace iron mouth. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0023] The purpose of the present invention is to provide a blast furnace baking and opening method to solve the problems existing in the above-mentioned prior art, which can effectively improve the heat utilization rate of hot air in the furnace baking process and effectively prolong the iron mouth empty spraying time.
[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0025] The present invention provides a blast furnace baking and opening method, comprising the following steps:
[0026] S1: Coil 1 is laid on the bottom 13 of the blast furnace, and a first interval is formed between the coil 1 and the bottom 13 of the blast furnace by welding a bracket 4 at the bottom of the coil 1. The lower half of the coil 1 is provided with an air duct 5. A plurality of tuyere 6 is provided on the top circumferential direction of the blast furnace wall 12. One tuyere 6 is connected to a vertical pipe 8 in the furnace through a horizontal pipe 7 in the furnace, and then connected to the coil 1 through a vertical pipe 8 in the furnace. A hot air guide plate 9 is welded on the horizontal pipe 7 in the furnace, and a second interval is formed between the circumference of the hot air guide plate 9 and the blast furnace wall 12. By laying the coil 1 on the bottom 13 of the blast furnace and setting the bracket 4 to form the first interval, the distance between the hot air and the furnace bottom can be effectively controlled, and the thermal shock can be reduced or the heating effect can be enhanced as needed. The air duct 5 is provided to facilitate the uniform distribution of hot air to the furnace bottom and improve the heat exchange efficiency. Multiple tuyere 6 are connected to the coil 1 through the horizontal pipe 7 and the vertical pipe in the furnace to ensure the smooth transportation of hot air. A hot air guide plate 9 is welded on the horizontal pipe 7 in the furnace to form a second interval, which can guide the hot air to be distributed to the furnace wall and enhance the drying effect of the furnace wall.
[0027] S2: Hot air is blown in from each tuyere 6, and the hot air enters the coil 1 of the blast furnace bottom 13 through the furnace horizontal pipe 7 and the furnace vertical pipe 8, and the hot air is blown to the blast furnace bottom 13 from the air duct 5 in the lower half of the coil 1, thereby strengthening the heat exchange effect between the hot air and the blast furnace bottom 13, and the hot air flows upward after drying the blast furnace bottom 13, and the hot air guide plate 9 forces the rising hot air to be distributed to the furnace wall, thereby strengthening the heat exchange between the hot air and the blast furnace wall 12 to be dried, and the hot air blown in from the tuyere 6 can enter the coil 1 through the furnace horizontal pipe 7 and the vertical pipe in an orderly manner, and then blown to the furnace bottom from the air duct 5, thereby greatly improving the heat exchange effect between the hot air and the furnace bottom. The function of the hot air guide plate 9 enables the hot air to be distributed to the furnace wall after drying the furnace bottom, thereby further improving the utilization efficiency of the hot air and strengthening the drying effect of the furnace wall.
[0028] S3: Preparation before opening the furnace; cut off the hot air guide plate 9, the horizontal pipe 7 in the furnace, and the vertical pipe 8 in the furnace, leaving the furnace bottom coil 1, extend the connecting pipe 11 from the blast furnace iron mouth 14 into the blast furnace and weld and connect with the coil 1, apply refractory material on the upper half of the coil 1, cut off the hot air guide plate 9, the horizontal pipe 7 and the vertical pipe in the furnace before opening the furnace, simplify the device structure, and avoid unnecessary obstruction to the air flow during the furnace opening process. Connecting the connecting pipe 11 from the iron mouth to the coil 1 and applying refractory material on the upper half of the coil 1 can effectively resist the slag iron dripping from the upper part during the furnace opening process, prolong the iron mouth empty spraying time, and fully heat the furnace cylinder and iron mouth area.
[0029] S4: Charging and furnace opening process, charging the blast furnace. After charging, the coil 1 is buried by the bottom coke. When the furnace is opened and air is supplied, the gas entering the furnace body passes through the bottom coke and enters the air duct 5 of the coil 1 and is then discharged from the connecting pipe 11 passing through the iron mouth, so that the bottom coke can be effectively heated, thereby increasing the furnace body temperature and the temperature of the first iron. After charging, the coil 1 is buried by the bottom coke. When the furnace is opened and air is supplied, the gas passes through the bottom coke and enters the coil 1 and is then discharged, which changes the flow path of the gas, so that the bottom coke is effectively heated, thereby increasing the furnace body temperature and the temperature of the first iron, which is beneficial to improving production efficiency and product quality.
[0030] In a preferred solution, in step S1, the coil 1 laid on the blast furnace bottom 13 is a double-layer octagonal annular tube welded with seamless steel pipes, the outer annular tube 3 is connected to the inner annular tube 2, the outer annular tube 3 is 10-20% of the hearth diameter from the protective bricks of the blast furnace wall 12, and the inner annular tube is 30-40% of the hearth diameter from the center of the blast furnace, and the double-layer octagonal annular tube structure is adopted to increase the flow path and distribution range of the hot air. The outer annular tube 3 and the inner annular tube 2 are reasonably positioned, which can better heat and dry different areas of the hearth and improve the effect of baking and opening the furnace.
[0031] In a preferred solution, in step S1, the first interval is 400-600 mm, and the second interval is 300-500 mm. Reasonable setting of the first interval can adjust the degree of thermal impact of hot air on the furnace bottom or enhance the heating effect of the bottom coke according to actual conditions. The setting of the second interval ensures that the hot air guide plate 9 can effectively guide the hot air to the furnace wall, thereby improving the heat exchange efficiency between the hot air and the furnace wall.
[0032] In a preferred scheme, in step S1, 4 rows of air ducts 5 with a diameter of 20 to 40 mm are set in the lower half of the coil 1, and the air ducts 5 include a plurality of ventilation holes. The spacing between adjacent ventilation holes in the axial direction of the coil 1 is 300 mm. By setting 4 rows of air ducts 5 with specific diameters and reasonably controlling the spacing between the ventilation holes, the hot air can be blown to the bottom of the furnace more evenly, thereby further improving the heat exchange effect and the uniformity of furnace baking and furnace opening.
[0033] In a preferred solution, in step S1, the number of tuyere 6 is 8, each tuyere 6 is evenly distributed in the circumferential direction of the blast furnace wall 12, the number of the furnace transverse pipes 7 is 8, and one end of the furnace transverse pipe 7 connected to the tuyere 6 is provided with a bell mouth, the number of the furnace vertical pipes 8 is 8, and the bottom end of the furnace vertical pipe 8 is connected to the inner ring pipe of the coil 1, and the 8 evenly distributed tuyere 6 and the corresponding furnace transverse pipes 7 and vertical pipes can ensure that the hot air enters the coil 1 evenly, improving the stability and effect of the furnace drying and opening. The setting of the bell mouth facilitates the docking of the tuyere 6 with the furnace transverse pipe 7, ensuring the smooth transportation of the hot air.
[0034] In a preferred scheme, in step S3, a refractory coating 10 with a thickness of 10 to 20 mm is laid on the upper half of the coil 1. Laying the refractory coating 10 on the upper half of the coil 1 can effectively resist the slag dripping from the upper part during the furnace opening process, extend the service life of the coil 1, and ensure the smooth progress of the furnace baking and furnace opening process.
[0035] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.
Claims
1. A blast furnace baking and opening method, characterized in that: The following steps are involved: S1: laying a coil on the bottom of a blast furnace, welding a bracket at the bottom of the coil to form a first gap between the coil and the bottom of the blast furnace, providing an air duct at the lower half of the coil, and opening a plurality of tuyere in the circumferential direction of the top of the blast furnace wall, one tuyere being connected to a vertical pipe in the furnace through a horizontal pipe in the furnace, and then connected to the coil through a vertical pipe in the furnace, welding a hot air guide plate on the horizontal pipe in the furnace, and forming a second gap between the circumference of the hot air guide plate and the blast furnace wall; S2: hot air is blown into each of the tuyere, and the hot air enters the coil at the bottom of the blast furnace through the horizontal pipe and the vertical pipe in the furnace, and the hot air is blown to the bottom of the blast furnace from the air duct at the lower half of the coil, so as to strengthen the heat exchange effect between the hot air and the bottom of the blast furnace, and the hot air flows upward after drying the bottom of the blast furnace, and the hot air guide plate forces the rising hot air to be distributed to the furnace wall, so as to strengthen the heat exchange between the hot air and the blast furnace wall to be dried; S3: Preparation before furnace opening: the hot air guide plate, the horizontal pipe in the furnace, and the vertical pipe in the furnace are cut off, and the furnace bottom coil is left. The connecting pipe is extended from the blast furnace iron mouth into the blast furnace and welded to the coil and connected, and a refractory coating is applied to the upper half of the coil; S4: Charging and furnace opening process, charging into the blast furnace. After charging, the coil is buried by the bottom coke of the furnace. The furnace is opened for air supply. The coal gas entering the furnace passes through the bottom coke and enters the air duct of the coil, and is then discharged from the connecting pipe passing through the iron mouth, so that the bottom coke can be effectively heated, thereby increasing the temperature of the furnace and the temperature of the first iron.
2. The blast furnace baking and opening method according to claim 1, characterized in that: In step S1, the coil pipe laid at the bottom of the blast furnace is a double-layer octagonal ring pipe welded with seamless steel pipes, the outer ring pipe is connected to the inner ring pipe, the outer ring pipe is 10-20% of the hearth diameter away from the protective bricks of the blast furnace wall, and the inner ring pipe is 30-40% of the hearth diameter away from the center of the blast furnace.
3. The blast furnace baking and opening method according to claim 2, characterized in that: In step S1, the first interval is 400-600 mm, and the second interval is 300-500 mm.
4. The blast furnace baking and opening method according to claim 3, characterized in that: In step S1, four rows of air ducts with a diameter of 20-40 mm are arranged at the lower half of the coil, the air ducts include a plurality of ventilation holes, and the spacing between adjacent ventilation holes in the axial direction of the coil is 300 mm.
5. The blast furnace baking and opening method according to claim 4, characterized in that: In step S1, the number of the tuyere is 8, and each of the tuyere is evenly distributed in the circumferential direction of the blast furnace wall. The number of the horizontal pipes in the furnace is 8, and a bell mouth is provided at one end of the horizontal pipe in the furnace connected to the tuyere. The number of the vertical pipes in the furnace is 8, and the bottom end of the vertical pipe in the furnace is connected to the inner ring pipe of the coil.
6. The blast furnace baking and opening method according to claim 5, characterized in that: In step S3, a refractory coating with a thickness of 10 to 20 mm is laid on the upper half of the coil.