Device and method for improving activity of rotary area of tuyere of blast furnace

Abstract

The invention relates to a system and a method for improving activity of a tuyere rotation area of a blast furnace. The system comprises a hot air furnace, a hot air bustle pipe, a compressor and an oxygen bustle pipe, wherein the oxygen bustle pipe comprises an annular pipe and a plurality of branch pipes extending downwards from the annular pipe, and each branch pipe is provided with an electromagnetic valve and connected with an oxygen spray gun through a pressure-resistant hose; the oxygen spray gun and the pulverized coal injection spray gun are symmetrically and oppositely arranged on the two sides of the tuyere; the compressor is used for pressurizing oxygen provided by an external oxygen source to 1.8 MPa and then inputting the oxygen into the oxygen bustle pipe; and the hot blast stove is used for heating the oxygen-enriched air to 1100-1300 DEG C and then conveying the oxygen-enriched air to the tuyere through the bustle pipe. On the basis that oxygen-enriched hot air is provided by a hot-blast stove and a bustle pipe for a traditional blast-furnace tuyere, medium-pressure high oxygen (pure oxygen) blown to a tuyere convolute area is added, so that the activity of the blast-furnace tuyere convolute area is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of blast furnace ironmaking, and in particular relates to a device and a method for improving the activity of a blast furnace tuyere raceway. Background Art

[0002] As a basic industry in my country, the steel industry occupies an important position in the national economy. The blast furnace is a very important component of the smelting process and is the core link in the entire system. Solid raw materials such as iron ore, coke and solvent are fed into the blast furnace in batches from the top of the blast furnace. Hot air is fed into the furnace through the blast furnace tuyere and enters the channel where the coal powder and coke react. An evacuated and pear-shaped space is formed in front of each tuyere, which is usually called the tuyere whirlpool. The tuyere whirlpool is both the area where reducing gas is generated and the area where blast furnace heat is generated. The coal gas generated in the tuyere whirlpool forms the initial coal gas flow of the blast furnace. Its distribution can not only affect the descent of the upper charge, but also reflect the combustion of coke. It also determines the size of the dead material column of the blast furnace as well as the liquid permeability and gas permeability. Therefore, an active tuyere whirlpool is the basis for the smooth operation of the furnace and plays a vital role in the smelting process.

[0003] In the actual operation of blast furnace, people usually change the diameter of tuyere or adjust the blast furnace charging system to achieve the purpose of activating the tuyere raceway of blast furnace. The above methods either need to be handled by stopping the blast furnace or take a long period to achieve the purpose, and the cost is high. Summary of the invention

[0004] The present invention aims to provide a system and method for improving the activity of the blast furnace tuyere raceway zone, so as to solve the technical problems of long cycle and high cost of active blast furnace tuyere raceway zone in the prior art.

[0005] To achieve the first aspect of the above-mentioned purpose, the present invention adopts the following technical solution:

[0006] A system for improving the activity of a blast furnace tuyere raceway, comprising a hot blast stove, a hot blast shroud pipe, a compressor and an oxygen shroud pipe:

[0007] The oxygen surrounding pipe includes an annular pipe and a plurality of branch pipes extending obliquely downward from the annular pipe, wherein the branch pipes are evenly spaced and distributed along the circumference of the annular pipe and are connected to the annular pipe;

[0008] Each branch pipe is equipped with a solenoid valve and connected to the oxygen spray gun through a hose with a pressure resistance of ≥2.5MPa;

[0009] The oxygen spray gun and the coal powder injection spray gun are symmetrically arranged on both sides of the tuyere; the compressor is used to pressurize the oxygen provided by the external oxygen source to 1.8MPa and then transport it to the oxygen enclosure pipe through the pipeline;

[0010] The hot blast stove is used to heat the oxygen-enriched air to 1100 - 1300 °C and then transport it to the tuyere through the hot blast loop pipe.

[0011] Further, the solenoid valves on each branch pipe are connected to the controller, and the controller adjusts the opening degree of the solenoid valves according to the blast furnace data.

[0012] Further, the branch pipes extend downward from the annular pipe at an inclination angle of 15° - 45°, and the spacing between them evenly distributed circumferentially along the annular pipe is 0.5 - 2 meters.

[0013] Further, the included angle between the oxygen lance and the pulverized coal injection lance and the axis of the air pipe is 10° - 90°.

[0014] To achieve the second aspect of the above object, the present invention adopts the following technical solutions:

[0015] A method for improving the activity of the raceway in the blast furnace tuyere, characterized by comprising the following steps:

[0016] Oxygen pressurization and distribution: Pressurize oxygen to 1.8 MPa through a compressor and input it into the annular pipe of the oxygen loop pipe. The oxygen loop pipe includes an annular pipe and a number of branch pipes extending downward from the annular pipe at an inclination angle of 15° - 45°, and the branch pipes are evenly distributed circumferentially along the annular pipe;

[0017] Dynamic injection control: Adjust the oxygen flow rate through the solenoid valves on each branch pipe, so that the oxygen is transported to the oxygen lance through a hose with a pressure resistance of ≥ 2.5 MPa;

[0018] Coordinated injection operation: Arrange the oxygen lance and the pulverized coal injection lance symmetrically and oppositely on both sides of the tuyere, and the included angle between the two and the axis of the air pipe is 10° - 90°, and synchronously inject oxygen and pulverized coal into the raceway;

[0019] Oxygen-enriched hot blast supply: Heat the oxygen-enriched air to 1100 - 1300 °C through the hot blast stove and transport it to the tuyere through the hot blast loop pipe.

[0020] Further, it also includes:

[0021] Real-time monitor the temperature, pressure and gas composition in the raceway, and dynamically adjust at least one of the following parameters through the controller:

[0022] a. The opening degree of the solenoid valve to control the oxygen flow rate;

[0023] b. The output pressure of the compressor to adjust the oxygen injection speed;

[0024] c. The ratio of the pulverized coal injection rate to the oxygen injection rate.

[0025] Further, it also includes:

[0026] A pressure sensor is set in the oxygen pipeline to monitor the oxygen pressure in real time;

[0027] The compressor dynamically adjusts the output pressure according to the real-time monitored oxygen pressure value, and controls the oxygen pressure between 1.8 Mpa and 2.0 MPa.

[0028] Based on the traditional blast furnace tuyere where the oxygen-enriched hot air is provided by the hot blast stove and the hot blast loop pipe, the present invention increases the injection of medium-pressure high-purity oxygen (pure oxygen) into the tuyere raceway to improve the activity of the tuyere raceway in the blast furnace. Brief Description of the Drawings

[0029] Figure 1 It is a block diagram of the blast furnace oxygen supply system of the present invention. Detailed Embodiments

[0030] To further illustrate the embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used to explain the operating principle of the embodiments in combination with the relevant descriptions in the specification. With reference to these contents, those of ordinary skill in the art should be able to understand other possible embodiments and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0031] The present invention will be further described below in conjunction with the drawings and specific embodiments.

[0032] As Figure 1 shown, the present invention provides a system for improving the activity of the tuyere raceway in the blast furnace. Based on the traditional blast furnace tuyere where the oxygen-enriched hot air is provided by the hot blast stove and the hot blast loop pipe, a compressor and an oxygen loop pipe are added to inject medium-pressure high-purity oxygen (pure oxygen) into the tuyere raceway to improve the activity of the tuyere raceway in the blast furnace.

[0033] The oxygen loop pipe includes an annular pipe and a plurality of branch pipes extending downward from the annular pipe at an inclination angle of 15° to 45°. The branch pipes are evenly spaced along the circumferential direction of the annular pipe (the spacing is 0.5 to 2 meters) and are connected to the annular pipe.

[0034] Solenoid valves are arranged on each branch pipe and are connected to the oxygen lance through a pressure-resistant hose (pressure resistance ≥ 2.5 MPa);

[0035] The oxygen lance and the pulverized coal injection lance are symmetrically arranged opposite to each other on both sides of the tuyere, and the included angle between the two and the axis of the air duct is 10° to 90°;

[0036] The compressor is connected to the oxygen production station through the first oxygen pipeline, and is used to pressurize the oxygen (pure oxygen) to 1.8 MPa and then input it into the oxygen loop pipe. After passing through the oxygen loop pipe and the oxygen lance, high-pressure oxygen is directly injected into the tuyere and acts on the center of the raceway, which can accurately strengthen the combustion of pulverized coal.

[0037] The solenoid valves on each branch pipe are connected to the controller, and the controller adjusts the opening degree of the solenoid valves according to the temperature data in the raceway. Specifically, the controller controls the opening degree and adjustment frequency of the solenoid valves according to the needs of blast furnace production. The essence of the controller is a matrix, which can control the solenoid valves of all oxygen branch pipes in the whole blast furnace and independently control the opening degree and opening degree adjustment frequency of each solenoid valve.

[0038] The oxygen output from the oxygen production station is mixed with the cold air blown by the blower station in the cold air pipeline to form oxygen-enriched air.

[0039] The oxygen-enriched air is heated to 1100 - 1300 °C by the hot blast stove and then transported to the tuyere through the hot blast loop pipe, acting on the whole tuyere to maintain the basic oxygen concentration and heat.

[0040] The present invention also provides a method for improving the activity of the raceway in the blast furnace tuyere. Its basic principle is: pressurize part of the oxygen to make it have higher energy and directly act on the basis of the present invention that the oxygen-enriched hot air is provided by the hot blast stove and the hot blast loop pipe in the traditional blast furnace tuyere, and increase the injection of medium-pressure high-oxygen (pure oxygen) into the raceway to improve the activity of the raceway in the blast furnace tuyere, so that the central gas flow develops, reduces the volume of the dead stock column, and increases its gas permeability and liquid permeability. It includes the following steps:

[0041] ① Oxygen pressurization and distribution: Pressurize the oxygen to 1.8 MPa through a compressor and input it into the annular pipe of the oxygen loop pipe through a pressure-resistant pipeline. The oxygen loop pipe includes an annular pipe and several branch pipes extending downward at an inclination angle of 15° - 45° from the annular pipe. The branch pipes are evenly spaced along the circumferential direction of the annular pipe (spacing 0.5 - 2 meters);

[0042] ② Dynamic injection control: Adjust the oxygen flow rate through the solenoid valves on each branch pipe so that the oxygen is transported to the oxygen lance through a pressure-resistant hose (pressure resistance ≥ 2.5 MPa);

[0043] ③ Cooperative injection operation: Arrange the oxygen lance and the pulverized coal injection lance symmetrically and oppositely on both sides of the tuyere. The included angle between the two and the axis of the air duct is 10° - 90°, and oxygen and pulverized coal are injected into the raceway synchronously;

[0044] ④ Oxygen-enriched hot air supply: Heat the oxygen-enriched air to 1100 - 1300 °C through the hot blast stove and then transport it to the tuyere through the hot blast loop pipe.

[0045] The activity of the raceway in the blast furnace tuyere can be improved by adjusting at least one of the steps ① - ③, and its implementation method is:

[0046] Real-time monitor the temperature, pressure and gas composition in the raceway, and dynamically adjust at least one of the following parameters through the controller:

[0047] a. The opening degree of the solenoid valve to control the oxygen flow rate;

[0048] b. Adjust the output pressure of the compressor to regulate the oxygen injection rate;

[0049] c. The ratio of the pulverized coal injection rate to the oxygen injection rate, such as adjusting the oxygen-to-coal ratio between 0.8 and 1.2 m 3 / kg.

[0050] The above method further includes:

[0051] ⑤ Install a pressure sensor in the oxygen pipeline to monitor the oxygen pressure in real time; the compressor dynamically adjusts the output pressure according to the real-time monitored oxygen pressure value, and controls the oxygen pressure between 1.8 Mpa and 2.0 MPa. This method can prevent pipeline rupture or lance damage caused by overpressure.

[0052] Through the above safety control, the stability of the furnace condition can be improved.

[0053] Although the present invention has been specifically shown and described in connection with the preferred embodiments, those skilled in the art should understand that various changes can be made to the present invention in terms of form and details without departing from the spirit and scope of the present invention defined by the appended claims, and all such changes are within the protection scope of the present invention.

Claims

1. A system for improving the activity of the raceway in a blast furnace, characterized in that, It includes a hot blast stove, a hot blast manifold, a compressor and an oxygen manifold: The oxygen manifold includes an annular pipe and a plurality of branch pipes that extend obliquely downward from the annular pipe. The branch pipes are evenly spaced circumferentially along the annular pipe and communicate with the annular pipe; Solenoid valves are arranged on each branch pipe and are connected to oxygen lances through hoses with a pressure resistance ≥ 2.5 MPa; The reducing gas lance and the pulverized coal injection lance are symmetrically arranged opposite each other on both sides of the tuyere; The compressor is used to pressurize the oxygen provided by an external oxygen source to 1.8 MPa and then transport it to the oxygen manifold through a pipeline; The hot blast stove is used to heat the oxygen-rich air to 1100 - 1300 °C and then transport it to the tuyere through the hot blast manifold.

2. The system according to claim 1, wherein The solenoid valves on each branch pipe are connected to a controller, and the controller adjusts the opening degree of the solenoid valves according to the blast furnace data.

3. The system according to claim 1, wherein The branch pipes extend obliquely downward from the annular pipe at an inclination angle of 15° - 45°, and the spacing of the uniform circumferential distribution along the annular pipe is 0.5 - 2 meters.

4. The system according to claim 1, characterized in that, The included angles between the oxygen lance, the pulverized coal injection lance and the axis of the air duct are 10° - 90°.

5. A method for improving the activity of the raceway in a blast furnace, characterized in that, It includes the following steps: Oxygen pressurization and distribution: Pressurize the oxygen to 1.8 MPa through a compressor and input it into the annular pipe of the oxygen manifold. The oxygen manifold includes an annular pipe and a plurality of branch pipes that extend obliquely downward from the annular pipe at an inclination angle of 15° - 45°. The branch pipes are evenly spaced circumferentially; Dynamic injection control: Adjust the oxygen flow rate through the solenoid valves on each branch pipe so that the oxygen is transported to the oxygen lance through a hose with a pressure resistance ≥ 2.5 MPa; Coordinated injection operation: Arrange the oxygen lance and the pulverized coal injection lance symmetrically opposite each other on both sides of the tuyere, and the included angles between them and the axis of the air duct are 10° - 90°. Synchronously inject oxygen and pulverized coal into the raceway; Oxygen-rich hot blast supply: Heat the oxygen-rich air to 1100 - 1300 °C through the hot blast stove and then transport it to the tuyere through the hot blast manifold.

6. The method according to claim 5, wherein It also includes: Real-time monitor the temperature, pressure and gas composition of the raceway, and dynamically adjust at least one of the following parameters through the controller: a. The opening degree of the solenoid valve to control the oxygen flow rate; b. The output pressure of the compressor to adjust the oxygen injection speed; c. The ratio of the pulverized coal injection rate to the oxygen injection rate.

7. The method according to claim 5, wherein It also includes: Install a pressure sensor in the oxygen pipeline to monitor the oxygen pressure in real time; The compressor dynamically adjusts the output pressure according to the real-time monitored oxygen pressure value and controls the oxygen pressure between 1.8 Mpa - 2.0 MPa.

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