Ironmaking process for fast treatment of suspended material in blast furnace

Abstract

The application discloses a kind of iron-making methods for quickly processing blast furnace suspension material, and steel industry blast furnace iron-making technical field.The core scheme of the method is to carry out through hole transformation to the waist part of blast furnace, open a through hole at the suitable position of blast furnace waist ring, avoid the original cooling system of blast furnace, furnace lining reinforcement structure and monitoring equipment at hole opening position, simultaneously weld a length of 5.5 meters sealing sleeve at the position of through hole, the included angle between sleeve and horizontal plane is 45°, sealing sleeve is fixedly connected with through hole by using high-temperature-resistant steel sealing flange, disturbance rod is placed therein, and sealing locking device is matched and set, the complete sealing of hole opening is maintained under non-suspension material processing state, the high-temperature and high-pressure smelting environment in blast furnace is ensured not to be affected, and problems such as gas leakage and heat loss are eliminated, so as to ensure the sealing and safety of blast furnace during normal production.The purpose of the application is to fundamentally optimize the suspension material processing efficiency and minimize the influence of suspension material on blast furnace production.

Description

Technical Field

[0001] This invention belongs to the field of blast furnace ironmaking technology in the iron and steel industry, and particularly relates to an ironmaking method for rapidly processing suspended charge in blast furnaces. Background Technology

[0002] Blast furnace ironmaking is a core production link in the modern steel industry. Its operational stability and smoothness directly determine ironmaking efficiency, energy consumption indicators, and equipment lifespan. Charge suspension, the most common and highly dangerous serious production failure in blast furnace smelting, refers to the loss of normal descent momentum of the charge inside the blast furnace, causing it to stagnate and unable to descend smoothly. This interrupts the blast furnace smelting process. If not handled promptly or properly, it can lead to a series of problems such as continuous deterioration of furnace conditions, furnace temperature imbalance, and accelerated furnace lining erosion. In severe cases, it can even cause major safety and production accidents such as hearth freezing and equipment damage, resulting in huge economic losses for steel companies.

[0003] From the perspective of the blast furnace's internal structure and smelting mechanism, the waist area is a crucial transitional zone between the furnace body and belly, and is also the core distribution area of ​​the blast furnace's softening zone. In this area, the burden has undergone initial heating and reduction, beginning to form viscous initial slag. The permeability of the burden layer decreases significantly, making the distribution of gas flow highly susceptible to imbalance, thus making it a high-risk area for burden hanging. Current industry practices for handling blast furnace burden hanging primarily rely on passive adjustments such as reducing blast pressure, stopping fuel injection, lowering blast temperature, and adjusting blast ventilation to allow the burden to slide off under its own weight. However, these traditional methods have significant limitations: First, the processing cycle is long, often taking tens of minutes or even longer from the discovery of suspended material to the effective adjustment of parameters, during which the blast furnace is shut down and awaiting recovery, resulting in huge capacity losses; second, the control is not targeted, only adjusting the overall airflow and pressure parameters of the blast furnace, and cannot directly act on the core area where suspended material occurs, with extremely poor treatment effect on stubborn suspended material, suspended material in the furnace waist and belly, and often multiple adjustments still cannot eliminate the suspended material; third, it is easy to cause secondary failures, as large-scale adjustments to blast furnace air pressure, air temperature and other parameters will disrupt the original thermal and slagging regimes in the furnace, leading to fluctuations in furnace conditions and increasing the risk of secondary accidents such as furnace cooling and material collapse; fourth, it has a significant impact on equipment, as repeated venting and charging will produce violent fluctuations in furnace pressure, aggravating the damage to the furnace lining and the wear and tear on equipment such as cooling walls, and shortening the overall service life of the blast furnace.

[0004] As the steel industry transforms towards higher efficiency, greener practices, and smarter operations, higher demands are placed on the continuity and stability of blast furnace production. Traditional methods of handling suspended charge can no longer meet the refined production needs of modern large blast furnaces. Currently, the industry lacks an active suspension charge handling technology that can directly target the location of suspended charge, provide rapid and precise intervention, and have minimal impact on furnace conditions and equipment. Therefore, developing a simple, responsive, and efficient rapid suspension charge handling method for blast furnaces to address the pain points of existing technologies is of significant practical importance and engineering application value for ensuring the long-term stable operation of blast furnaces and improving ironmaking production efficiency. Summary of the Invention

[0005] This invention addresses the shortcomings of existing blast furnace charge handling technologies, such as long processing cycles, poor targeting, and susceptibility to furnace condition fluctuations. It provides a method for rapidly handling blast furnace charge by disturbing the airflow in the furnace waist area. By pre-setting special openings in the blast furnace waist area and using disturbance rods with cooling functions, the charge can be quickly released, fundamentally optimizing the charge handling efficiency and minimizing the impact of charge on blast furnace production.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This invention discloses a rapid ironmaking method for handling suspended charge in blast furnaces, comprising:

[0008] The blast furnace waist section is modified by creating a through hole. A through hole with a diameter of 750-850 cm is opened at a suitable position in the circumferential direction of the blast furnace waist. The opening position avoids the original cooling system, furnace lining reinforcement structure and monitoring equipment of the blast furnace. At the same time, a sealing sleeve with a length of 5-6 meters is welded at the through hole position. The sleeve has an angle of 40-50° with the horizontal plane. The sealing sleeve is fixedly connected to the through hole using a high-temperature resistant steel sealing flange. A disturbance rod is placed in it. At the same time, a sealing and locking device is installed to keep the opening completely sealed under non-suspended material treatment conditions. This ensures that the high temperature and high pressure smelting environment inside the blast furnace is not affected, and prevents problems such as gas leakage and heat loss. It also ensures the sealing and safety of the blast furnace during normal production.

[0009] The main body of the disturbance rod is made of high-strength, high-temperature resistant, and thermal shock resistant alloy steel. It has excellent structural strength and high-temperature resistance, and can withstand the high-temperature environment of more than 1000°C in the blast furnace waist and the extrusion force of the material layer. The front end of the disturbance rod is designed with a conical structure.

[0010] A nitrogen and water combined cooling mode is used to provide full-process cooling protection for the disturbance rod. The disturbance rod is equipped with a double-layer cooling channel. The inner layer is a cooling water circulation channel and the outer layer is a nitrogen purging channel. Cooling water enters from the end of the disturbance rod, flows through the entire rod body along the internal channel, and is discharged. The continuous water circulation quickly removes the high-temperature heat absorbed by the disturbance rod, preventing the rod body from deforming or softening due to high temperature. Nitrogen gas is introduced from the end and sprayed out from the front conical end along the outer channel. On the one hand, it forms a nitrogen gas film, which further isolates the high temperature in the furnace from the radiative heat transfer to the rod body and improves the cooling effect. On the other hand, the nitrogen gas can purge the front end of the disturbance rod, cleaning the adhering slag and dust, preventing the slag from clogging the cooling channel. At the same time, as an inert gas, nitrogen gas will not participate in the chemical reaction of blast furnace smelting after entering the furnace, and will not destroy the reducing atmosphere and thermal regime in the furnace.

[0011] Furthermore, a through hole with a diameter of 800 cm is opened at a suitable position in the waist ring of the blast furnace.

[0012] Furthermore, a 5.5-meter-long sealing sleeve is welded at the location of the through hole.

[0013] Furthermore, the sleeve makes a 45° angle with the horizontal plane.

[0014] Furthermore, after the disturbance rod penetrates into the furnace, it directly disrupts the unbalanced gas flow distribution in the furnace waist and belly through controllable reciprocating movement and small-amplitude rotation, thereby breaking the force balance of the suspended material layer.

[0015] Furthermore, by utilizing the thrust of the airflow generated by nitrogen injection, the stagnant furnace charge is further dispersed, quickly restoring the uniform distribution of gas flow and the downward momentum of the charge within the furnace, thereby achieving rapid relief of the suspended charge.

[0016] Furthermore, after the furnace charge resumes its normal downward flow and the blast furnace pressure difference and gas flow parameters return to stability, the disturbance rod is slowly withdrawn from the furnace, the furnace waist opening sealing device is closed, and the cooling system is then shut down to complete the entire suspended charge handling process.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are as follows: Detailed Implementation

[0018] The core technical solution of this invention is as follows: First, the through hole in the blast furnace waist is modified. A through hole with a diameter of 800 cm is opened at a suitable position in the circumferential direction of the blast furnace waist. The opening position avoids the original cooling system, furnace lining reinforcement structure and monitoring equipment of the blast furnace. At the same time, a sealing sleeve with a length of 5.5 meters is welded at the through hole position. The sleeve makes an angle of 45° with the horizontal plane. The sealing sleeve is fixedly connected to the through hole using a high-temperature resistant steel sealing flange. A disturbance rod is placed in it. At the same time, a sealing and locking device is set up to keep the opening completely sealed in the non-suspended material treatment state, ensuring that the high temperature and high pressure smelting environment inside the blast furnace is not affected, eliminating problems such as gas leakage and heat loss, and ensuring the sealing and safety of the blast furnace during normal production.

[0019] The core processing device is a 5-meter-long specialized disturbance rod. The main body of the disturbance rod is made of high-strength, high-temperature resistant, and thermal shock resistant alloy steel, possessing excellent structural strength and high-temperature resistance. It can withstand the high-temperature environment of over 1000°C in the blast furnace waist and the extrusion force of the material layer. The front end of the disturbance rod is designed with a conical structure, and the angle of the conical end has been optimized. This design effectively reduces the resistance encountered by the disturbance rod when it penetrates into the blast furnace, and efficiently breaks up locally stuck or stagnant material during its advancement. This facilitates the smooth and rapid advancement of the disturbance rod into the blast furnace, avoiding mechanical damage to the furnace lining.

[0020] To ensure the structural stability and service life of the disturbance rod in the high-temperature furnace environment, this invention employs a nitrogen and water composite cooling mode for full-process cooling protection of the disturbance rod. The disturbance rod has a double-layer cooling channel: an inner cooling water circulation channel and an outer nitrogen purging channel. Cooling water enters from the end of the disturbance rod, flows through the entire rod body along the internal channel, and then exits. This continuous water circulation quickly removes the high-temperature heat absorbed by the disturbance rod, preventing deformation and softening due to high temperatures. Nitrogen gas enters from the end and exits from the conical tip of the outer channel. This forms a nitrogen gas film, further isolating the rod from radiative heat transfer from the high furnace temperature, improving the cooling effect. Furthermore, the nitrogen gas purges the front end of the disturbance rod, cleaning adhering slag and dust, preventing slag blockage of the cooling channel. As an inert gas, nitrogen does not participate in the blast furnace smelting chemical reactions and does not disrupt the reducing atmosphere and thermal regime within the furnace.

[0021] During normal blast furnace production, the disturbance rod is fixed inside a sleeve welded to the outside of the furnace. When a suspended charge accident occurs during blast furnace operation, the suspended charge handling process of this invention is immediately activated: First, the disturbance rod cooling system is turned on, and cooling water circulation and nitrogen purging are started. After the disturbance rod cooling system is running stably, the sealing and locking device of the furnace waist opening is opened, and the 5-meter-long disturbance rod is steadily pushed into the blast furnace at a horizontal angle of 45° through the furnace waist through hole by a hydraulic pushing device. The front conical structure breaks through the suspended charge layer and penetrates into the core area where the suspended charge occurs. After the disturbance rod penetrates into the furnace, through controllable reciprocating movement and small-amplitude rotation, it directly disrupts the unbalanced gas flow distribution in the furnace waist and belly, breaks the force balance of the suspended charge layer, and at the same time, with the help of the gas flow thrust generated by the nitrogen injection, it further disperses the stagnant charge, quickly restores the uniform distribution of gas flow in the furnace and the downward momentum of the charge, and achieves rapid relief of the suspended charge.

[0022] After the furnace charge resumes its normal downward flow and the blast furnace pressure differential and gas flow parameters stabilize, the disturbance rod is slowly withdrawn from the furnace, the furnace waist opening sealing device is closed, and the cooling system is then shut down, completing the entire suspended charge treatment process. This invention eliminates the need for significant adjustments to the overall blast furnace operating parameters, allowing for direct and precise application to the location where suspended charge occurs. The entire treatment process can be completed in a short time, significantly reducing the time required for suspended charge treatment and minimizing blast furnace downtime losses. Simultaneously, the composite cooling system ensures the durability of the device, and the inert nitrogen purging does not interfere with normal smelting reactions within the furnace, avoiding problems such as furnace condition fluctuations and equipment wear caused by traditional methods. The operation is simple, safe, and reliable, suitable for rapid suspended charge treatment in blast furnaces of various volumes, effectively improving the stability and economy of blast furnace ironmaking production.

[0023] The technical solution of the present invention will be described in detail below with reference to the embodiments.

[0024] Example 1

[0025] Production accidents caused by blast furnace suspension due to chaotic airflow caused by low blast furnace temperature can be addressed using the technology of this invention for 2000m³ blast furnaces. 3 The treatment of suspended materials in the blast furnace has yielded good results.

[0026] Example 2

[0027] Poor blast furnace tapping conditions and insufficient iron production lead to chaotic airflow and subsequent blast furnace charge suspension accidents. This invention addresses this issue in a 3000m³ blast furnace. 3 By addressing the blast furnace condition, the time required to reduce blast was significantly shortened.

[0028] Example 3

[0029] Changes in the quality of raw materials and fuels in the blast furnace, coupled with the operator's failure to respond promptly, led to airflow disruptions and ultimately, a production accident involving blast furnace charge suspension. This invention addresses this issue in a 4000m³ blast furnace. 3The blast furnace condition was addressed, and the blast furnace recovered quickly with minimal impact on production.

[0030] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A rapid ironmaking method for handling suspended charge in blast furnaces, characterized in that, include: The blast furnace waist section is modified by creating a through hole. A through hole with a diameter of 750-850 cm is opened at a suitable position in the circumferential direction of the blast furnace waist. The opening position avoids the original cooling system, furnace lining reinforcement structure and monitoring equipment of the blast furnace. At the same time, a sealing sleeve with a length of 5-6 meters is welded at the through hole position. The sleeve has an angle of 40-50° with the horizontal plane. The sealing sleeve is fixedly connected to the through hole using a high-temperature resistant steel sealing flange. A disturbance rod is placed in it. At the same time, a sealing and locking device is installed to keep the opening completely sealed under non-suspended material treatment conditions. This ensures that the high temperature and high pressure smelting environment inside the blast furnace is not affected, and prevents problems such as gas leakage and heat loss. It also ensures the sealing and safety of the blast furnace during normal production. The main body of the disturbance rod is made of high-strength, high-temperature resistant, and thermal shock resistant alloy steel. It has excellent structural strength and high-temperature resistance, and can withstand the high-temperature environment of more than 1000°C in the blast furnace waist and the extrusion force of the material layer. The front end of the disturbance rod is designed with a conical structure. A nitrogen and water combined cooling mode is used to provide full-process cooling protection for the disturbance rod. The disturbance rod is equipped with a double-layer cooling channel. The inner layer is a cooling water circulation channel and the outer layer is a nitrogen purging channel. Cooling water enters from the end of the disturbance rod, flows through the entire rod body along the internal channel, and is discharged. The continuous water circulation quickly removes the high-temperature heat absorbed by the disturbance rod, preventing the rod body from deforming or softening due to high temperature. Nitrogen gas is introduced from the end and sprayed out from the front conical end along the outer channel. On the one hand, it forms a nitrogen gas film, which further isolates the high temperature in the furnace from the radiative heat transfer to the rod body and improves the cooling effect. On the other hand, the nitrogen gas can purge the front end of the disturbance rod, cleaning the adhering slag and dust, preventing the slag from clogging the cooling channel. At the same time, as an inert gas, nitrogen gas will not participate in the chemical reaction of blast furnace smelting after entering the furnace, and will not destroy the reducing atmosphere and thermal regime in the furnace.

2. The ironmaking method for rapidly processing suspended blast furnace charge according to claim 1, characterized in that, A through hole with a diameter of 800 cm is opened at a suitable position on the waist ring of the blast furnace.

3. The ironmaking method for rapidly processing suspended blast furnace charge according to claim 1, characterized in that, Weld a 5.5-meter-long sealing sleeve at the location of the through hole.

4. The ironmaking method for rapidly processing suspended blast furnace charge according to claim 1, characterized in that, The sleeve makes an angle of 45° with the horizontal plane.

5. The ironmaking method for rapidly processing suspended blast furnace charge according to claim 1, characterized in that, After the disturbance rod is inserted into the furnace, it directly disrupts the unbalanced gas flow distribution in the furnace waist and belly through controllable reciprocating movement and small-amplitude rotation, breaking the force balance of the suspended material layer.

6. The ironmaking method for rapidly processing suspended blast furnace charge according to claim 1, characterized in that, By utilizing the thrust of the airflow generated by nitrogen injection, the stagnant furnace charge is further dispersed, quickly restoring the uniform distribution of gas flow and the downward momentum of the charge, thus achieving rapid relief of the suspended charge.

7. The ironmaking method for rapidly processing suspended blast furnace charge according to claim 1, characterized in that, Once the furnace charge resumes its normal downward flow and the blast furnace pressure differential and gas flow parameters return to stability, the disturbance rod is slowly withdrawn from the furnace, the furnace waist opening sealing device is closed, and the cooling system is then shut down to complete the entire suspended charge handling process.