Two-section type reducing gas injection reacting furnace

Abstract

The invention relates to a two-section type reducing gas injection reacting furnace. The reacting furnace comprises a reacting furnace main body, a gas heating furnace and a gas controller, the reaction furnace main body comprises a reactor, a material box, a hearth, a furnace shell, a bottom blowing pipeline, a side blowing pipeline, a reactor top cover and an exhaust pipeline, the reactor is arranged in the hearth, the hearth is wrapped by the furnace shell, the material box is arranged in the reactor, and the side blowing pipeline on the reaction furnace main body is connected with the gas heating furnace through a metal hose. The bottom blowing pipeline is connected with a gas controller through a metal hose; a gas inlet pipeline on the gas heating furnace is connected with the gas controller through a metal hose; the scheme is suitable for coal gas components in any ratio, and the reduction process under different conditions can be simulated by regulating and controlling the coal gas components.

Description

Technical Field

[0001] The invention relates to a reactor, in particular to a two-stage reducing gas injection reactor, which is used for simulating oxygen blast furnace reducing atmosphere to test the reducibility of furnace charge and belongs to the field of blast furnace ironmaking experimental equipment. Background Art

[0002] Ironmaking is the process with the highest carbon consumption in the entire steel production process. 70% of carbon consumption is generated in the ironmaking process, and nearly two tons of carbon dioxide are emitted for every ton of iron produced. The carbon utilization efficiency of traditional ironmaking blast furnaces is only 65.5%, and the unused carbon is carried away by the blast furnace gas. Therefore, in order to reduce carbon consumption in the ironmaking process, it is necessary to improve the carbon utilization rate and reduce carbon dioxide emissions by reusing the carbon in the blast furnace output gas.

[0003] In traditional blast furnace smelting, the output gas contains nearly 50% to 55% nitrogen. To effectively use the carbon in the blast furnace output gas, nitrogen and carbon dioxide must be removed to avoid the cyclic accumulation of nitrogen and carbon dioxide. Under the current conditions, it is not economical to achieve the recycling of nitrogen and carbon dioxide after denitrification. Only by achieving full oxygen smelting can the output gas after carbon dioxide is removed be reused, achieving 100% utilization of carbon resources and achieving the goal of minimum carbon consumption in the ironmaking process.

[0004] In recent years, low-carbon ironmaking has been a hot academic topic in the metallurgical industry, among which oxygen blast furnaces have been studied more. However, the research methods currently used in the study of the influence of oxygen blast furnace combined with top gas circulation process on the performance of blast furnace charge are limited to numerical simulation and traditional metallurgical performance reduction furnace. The traditional metallurgical performance furnace can only refer to the national standard GB / T 13241-2017 to test the reducibility of charge under the conditions of oxygen blast furnace-top gas circulation. The problem is that it can only adjust the atmosphere of reducing gas, while the oxygen blast furnace-top gas circulation often considers the simultaneous injection of reducing gas at the tuyere and the furnace body, and studies the influence of the injection system of tuyere and furnace body on the performance of charge; at the same time, it is necessary to consider the difference in the influence of the injection of reducing gas on the charge in the lateral direction, that is, the influence of the injection parameters on the injection depth, but the existing reduction furnaces cannot realize this research test.

[0005] The patent literature was searched with the keywords "reduction furnace" and "oxygen blast furnace experimental equipment", but no similar cases were found. Some engineering application case papers were retrieved with the side-blowing reduction furnace, such as the paper "Application of a new device for side-blowing reduction furnace baking", which introduces the structure of an industrial side-blowing reduction furnace, which is fundamentally different from the combination of bottom blowing and side blowing in the present invention, and the shape and material are also quite different; Patent application No. 202021461467.3 discloses a circular bottom plate reduction furnace, which is equipped with multiple nozzles to spray reducing gas, but is not equipped with a bottom blowing process; therefore, a new solution is urgently needed to solve the above technical problems. Summary of the invention

[0006] The present invention aims at the problems existing in the prior art and provides a two-stage reducing gas injection reactor. The purpose of this technical solution is to simulate the oxygen blast furnace-top gas circulation process, and to carry out a reduction test on the charge by simultaneously injecting reducing gas from the furnace bottom and the furnace body.

[0007] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a two-stage reducing gas injection reactor, including a reactor body, a gas heating furnace, and a gas controller; the reactor body includes a reactor, a material box, a furnace, a furnace shell, a bottom blowing pipeline, a side blowing pipeline, a reactor top cover, and an exhaust pipeline. The side blowing pipeline is connected to the gas heating furnace through a metal hose, and the bottom blowing pipeline is connected to the gas controller through a metal hose. The reactor is placed in the furnace, and the outside of the furnace is wrapped with a furnace shell; the gas heating furnace includes a heating reaction tube, a heating furnace, and an air intake pipeline. The air intake pipeline is connected to the gas controller through a metal hose, and the heating reaction tube is placed in the heating furnace; the gas controller includes a gas mixing tank and a gas flow meter, and the gas mixing tank is connected to the flow meter through a stainless steel pipe. Using the reactor, the gas composition of the top gas circulation is simulated for gas distribution, and the gas ratio and flow are controlled by the gas flow meter. After being fully mixed by the gas mixing tank, it is sprayed at the bottom and side to reduce the ore.

[0008] Furthermore, the reactor is an isosceles triangular prism made of GH3044 high temperature alloy steel, with a height of 1320 mm, an isosceles triangle base of 290 mm, and an isosceles triangle waist length of 406 mm; the reactor is provided with a reactor top cover on the upper part, and an exhaust pipe is welded on the top cover. The purpose of this design is to intercept a section of the charge in the blast furnace shaft, observe the reduction state of this section of the charge to simulate the charge state of the entire blast furnace shaft.

[0009] Furthermore, the material boxes are placed in the reactor, a total of 7, are isosceles triangular prisms, made of GH3044 high-temperature alloy steel, 150 mm in height, with 8 mm holes evenly distributed on the material box wall for ventilation, and 2 material box lifting rods are welded on it to facilitate lifting out of the reactor; the bottom material box is filled with alumina balls with a particle size of 20 mm, and the 6 material boxes above the bottom material box are used to hold iron ore and coke.

[0010] Furthermore, the furnace is formed of mullite crystal fiber, which is composed of four parts, each of which is connected with a thermal insulation gradient; the four parts of the top corner, the bottom edge, and the two beveled edges form a hollow column, each of which is connected with a thermal insulation gradient, and the two beveled edges are respectively embedded with three sections of electric furnace wire for heating the reactor. The electric furnace wire is HRE type with a diameter of 2.5mm; each temperature zone is 6.88 ohms, and the surface load is 1.28w / cm 2 .

[0011] Furthermore, the furnace shell, bottom blowing pipe, side blowing pipe and exhaust pipe are all made of 304 stainless steel, the bottom blowing pipe has a diameter of 50 mm, the side blowing pipe has a diameter of 11 mm, the exhaust pipe has a diameter of 25 mm and a height of 300 mm; the bottom blowing pipe is located at the bottom center of the reactor, the side blowing pipe is located at a height of 710 mm of the reactor, and the exhaust pipe is located at the upper center of the reactor.

[0012] Furthermore, the reactor top cover is 4 mm thick, and there is a graphite pad inside the top cover, which is shaped like a hollow triangle with a bottom of 438 mm and a height of 560 mm. The width of the pad is 30 mm, and the graphite pad can prevent gas leakage.

[0013] Furthermore, the gas heating furnace includes a heating reaction tube, a heating furnace, and an air intake pipe. The heating reaction tube is made of 310S stainless steel and contains alumina balls with a height of 2 / 3 and a diameter of 20 mm. The heating reaction tube is placed in the heating furnace. The heating furnace is integrally formed with mullite crystal fiber. The air intake pipe is made of 304 stainless steel and has a diameter of 11 mm.

[0014] Furthermore, the gas controller includes a large mixing tank, a small mixing tank, and a gas flow meter. The large mixing tank has 4 air inlets, which are connected to the 4 gas flow meters through stainless steel pipes. The small mixing tank has 5 air inlets, which are connected to the 5 gas flow meters through stainless steel pipes.

[0015] Furthermore, the large and small gas mixing tanks include an air inlet, a gas mixing chamber, and an air outlet pipe. The gas mixing tank is made of stainless steel. The air inlet is located on the lower side wall of the gas mixing tank. The air outlet pipe is inserted into the gas mixing chamber and is 50 to 150 mm away from the bottom of the gas mixing chamber.

[0016] Compared with the prior art, the present invention has the following advantages: the technical solution can realize two-stage injection of reducing gas, simulating the process of injecting gas at the bottom and the body of the oxygen blast furnace-top gas circulation process. The solution is applicable to any ratio of gas components, and the reduction process under different conditions can be simulated by adjusting the gas composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 A top view of the reactor body of the present invention;

[0019] Figure 3 It is a schematic diagram of the reactor of the present invention;

[0020] Figure 4 This is a schematic diagram of the furnace structure of the reactor of the present invention;

[0021] Figure 5This is a schematic diagram of the electric furnace wire structure of the reaction furnace of the present invention.

[0022] Figure 6 This is a schematic diagram of the structure of the graphite pad on the reactor top cover of the present invention;

[0023] Figure 7 It is a schematic diagram of the structure of the material box of the present invention.

[0024] Explanation of the numbers in the figure: 1-exhaust duct; 2-reactor; 3-furnace shell; 4-reactor furnace; 5-reactor body; 6-material box; 7-side blowing duct; 8-reactor alumina balls; 9-bottom blowing duct; 10-air inlet duct; 11-gas heating reaction tube; 12-gas heating furnace; 13-gas heating furnace; 14-gas heating alumina balls; 15-gas flow meter; 16-gas controller; 17-mixing tank; 18-thermocouple; 19-electric furnace wire; 20-graphite gasket; 21-material box lifting rod. DETAILED DESCRIPTION

[0025] In order to deepen the understanding of the present invention, the present embodiment is described in detail below with reference to the accompanying drawings.

[0026] Example 1: Please refer to Figure 1-6 A two-stage reducing gas injection reactor comprises a reactor body 5, a gas heating furnace 12 and a gas controller 16; the side blowing pipe 7 on the reactor body 5 is connected to the gas heating furnace 12 through a metal hose, the bottom blowing pipe 9 is connected to the gas controller 16 through a metal hose, and the air inlet pipe 10 on the gas heating furnace 12 is connected to the gas controller 16 through a metal hose.

[0027] See also Figure 1-Figure 2 The main body of the reactor includes a reactor 2, a material box 6, a reactor furnace 4, a furnace shell 3, a bottom blowing pipe 9, a side blowing pipe 7, a reactor top cover, and an exhaust pipe 10. The side blowing pipe 7 is connected to the gas heating furnace 12 through a metal hose, and the bottom blowing pipe is connected to the gas controller through a metal hose. The reactor is placed in the furnace, and the furnace 4 is wrapped by the furnace shell 3 outside; the gas heating furnace includes a heating reaction tube, a heating furnace, and an air intake pipe. The air intake pipe is connected to the gas controller through a metal hose, and the heating reaction tube is placed in the heating furnace; the gas controller includes a gas mixing tank and a gas flow meter, and the gas mixing tank is connected to the flow meter through a stainless steel pipe. Using this reactor, the gas composition of the top gas circulation gas is simulated for gas distribution, and the gas ratio and flow are controlled by the gas flow meter. After being fully mixed by the gas mixing tank, it is sprayed at the bottom and side to reduce the ore.

[0028] See also Figure 3The reactor 2 is an isosceles triangular prism made of GH3044 high temperature alloy steel, with a height of 1320mm, an isosceles triangle base of 290mm, and an isosceles triangle waist length of 406mm; the reactor has a reactor top cover on the top of which an exhaust pipe is welded. The purpose of this design is to intercept a section of the charge in the blast furnace shaft and observe the reduction state of this section of the charge to simulate the charge state of the entire blast furnace shaft.

[0029] See also Figure 7 The material box 6 is placed in the reactor, a total of 7, is an isosceles triangular prism, made of GH3044 high-temperature alloy steel, 150mm high, and has 8mm holes evenly distributed on the wall of the material box for ventilation. Two material box lifting rods are welded on it to facilitate lifting from the reactor; the bottom material box is filled with alumina balls with a particle size of 20mm, and the 6 material boxes above the bottom material box are used to hold iron ore and coke.

[0030] See also Figure 4 , Figure 5 The furnace is formed of mullite crystal fiber, and is composed of four parts, each of which is connected with a thermal insulation gradient; the four parts of the top corner, the bottom edge, and the two beveled edges form a hollow column, each of which is connected with a thermal insulation gradient, and the two beveled edges are respectively embedded with three sections of electric furnace wire for heating the reactor. The electric furnace wire is HRE type with a diameter of 2.5mm; each temperature zone is 6.88 ohms, and the surface load is 1.28w / cm 2 .

[0031] The furnace shell 3, bottom blowing pipe 9, side blowing pipe 7 and exhaust pipe 1 are all made of 304 stainless steel, the bottom blowing pipe has a diameter of 50 mm, the side blowing pipe has a diameter of 11 mm, the exhaust pipe has a diameter of 25 mm and a height of 300 mm; the bottom blowing pipe is located at the bottom center of the reactor, the side blowing pipe is located at a height of 710 mm of the reactor, and the exhaust pipe is located at the upper center of the reactor.

[0032] See also Figure 5 The reactor top cover has a thickness of 4 mm, and there is a graphite pad inside the top cover, which is shaped like a hollow triangle with a bottom edge of 438 mm and a height of 560 mm. The side width of the pad is 30 mm. The graphite pad can prevent gas leakage.

[0033] The gas heating furnace includes a heating reaction tube, a heating furnace, and an air intake pipe. The heating reaction tube is made of 310S stainless steel and contains alumina balls with a height of 2 / 3 and a diameter of 20 mm. The heating reaction tube is placed in the heating furnace. The heating furnace is integrally formed with mullite crystal fiber. The air intake pipe is made of 304 stainless steel and has a diameter of 11 mm.

[0034] The gas controller includes a large gas mixing tank, a small gas mixing tank, and a gas flow meter. The large gas mixing tank has 4 air inlets, which are connected to the 4 gas flow meters through stainless steel pipes. The small gas mixing tank has 5 air inlets, which are connected to the 5 gas flow meters through stainless steel pipes.

[0035] The large and small gas mixing tanks include an air inlet, a gas mixing chamber, and an air outlet pipe. The gas mixing tank is made of stainless steel. The air inlet is located on the lower side wall of the gas mixing tank. The air outlet pipe is inserted into the gas mixing chamber and is 50 to 150 mm away from the bottom of the gas mixing chamber.

[0036] Embodiment 2:

[0037] The reactor alumina balls 8 are loaded into the material box 6 and placed in the bottom layer of the reactor 2. Then, the mixture of sintered ore, lump ore and pellet ore is loaded into the material box 6 and placed in the reactor 2 from bottom to top. Nitrogen is blown into the bottom blowing pipe 9 through the gas controller 16 at a flow rate of 5L / min. At the same time, the reactor body 5 begins to heat up to 1100°C. After the heating is completed, the temperature is kept constant. The simulated reducing gas composition is configured by the gas flow meter 15 on the gas controller 16 as follows: CO (82L / min), CO2 (21L / min), H2 (8L / min), and N2 (126L / min). It is blown into the reactor 2 from the bottom blowing pipe 9 for 90 minutes. The temperature change is observed through the thermocouple 18 during the reduction process. The exhaust gas is discharged through the exhaust pipe 1. After the reduction is completed, the CO, CO2, and H2 flow meters are turned off, and the N2 flow rate is adjusted to 5L / min, and the mixture is cooled to room temperature. After cooling, the material box 6 is successively taken out of the reactor 2. The alumina ball layer at the bottom of the reactor 2 does not need to be taken out. The quality and composition of the reduced charge are tested to calculate its reduction degree.

[0038] Embodiment 3:

[0039] Load the reactor alumina balls 8 into the material box 6 and put it into the bottom layer of the reactor 2. Then load the mixture of sintered ore, lump ore and pellet ore into the material box 6 and put it into the reactor 2 from bottom to top. Blow nitrogen from the bottom blowing pipe 9 and the side blowing pipe 7 through the gas controller 16, with a flow rate of 5L / min each. At the same time, the reactor body 5 and the gas heating furnace 12 begin to heat up, the reactor body 5 is heated to 1100°C, and the gas heating furnace 12 is heated to 900°C; after the heating is completed, the temperature is kept constant, and the gas flow meter 15 on the gas controller 16 is configured to simulate the reducing gas composition. The reducing gas in the bottom blowing pipe 9 is: CO (110L / min), CO2 (24L / min), H2 (30L / min), N2 (17L / min), and the reducing gas in the measuring blowing pipe 7 is: CO (56L / min) in), H2 (18L / min), N2 (5L / min), are blown into the reactor 2 from the bottom blowing pipe 9 and the measuring blowing pipe 7. The reduction time is 60min. During the reduction process, the temperature change is observed by the thermocouple 18. The exhaust gas is discharged through the exhaust pipe 1. After the reduction is completed, the CO, CO2, and H2 flowmeters are turned off. At the same time, the N2 flow rate of the bottom blowing pipe 9 and the side blowing pipe 7 is adjusted to 5L / min, and the mixture is cooled to room temperature. After cooling, the material box 6 is successively taken out of the reactor 2. The alumina ball layer at the bottom of the reactor 2 can be left intact. The quality and composition of the reduced charge are tested to calculate its reduction degree.

[0040] It should be noted that the above embodiments are not intended to limit the protection scope of the present invention, and equivalent changes or substitutions made on the basis of the above technical solutions all fall within the protection scope of the claims of the present invention.

Claims

1. A two-stage reducing gas injection reactor, characterized in that: The reactor includes a reactor body, a gas heating furnace and a gas controller; the reactor body includes a reactor, a material box, a furnace, a furnace shell, a bottom blowing pipe, a side blowing pipe, a reactor top cover and an exhaust pipe, the reactor is placed in the furnace, the outside of the furnace is wrapped with a furnace shell, the material box is arranged in the reactor, the side blowing pipe on the reactor body is connected to the gas heating furnace through a metal hose, the bottom blowing pipe is connected to the gas controller through a metal hose, and the air intake pipe on the gas heating furnace is connected to the gas controller through a metal hose.

2. The two-stage reducing gas injection reactor according to claim 1, characterized in that: The reactor is an isosceles triangular columnar body, with a reactor top cover on the upper part of the reactor, and an exhaust pipe welded on the top cover.

3. The two-stage reducing gas injection reactor according to claim 2 is characterized in that: The material boxes are placed in the reactor, a total of 7, in the shape of isosceles triangular prisms, with 8mm holes evenly distributed on the wall of the material boxes for ventilation, and 2 material box lifting rods welded on them for easy lifting out of the reactor; the bottom material box is filled with alumina balls with a particle size of 20mm, and the 6 material boxes above the bottom material box are used to hold iron ore and coke.

4. The two-stage reducing gas injection reactor according to claim 3 is characterized in that: The furnace is formed in one piece by mullite crystal fiber, and is composed of four parts, each of which is connected with a thermal insulation gradient; the furnace is composed of a top corner, a bottom edge, and two beveled edges to form a hollow columnar body, each of which is connected with a thermal insulation gradient, and the two beveled edges are respectively embedded with three sections of electric furnace wire for heating the reactor.

5. The two-stage reducing gas injection reactor according to claim 3 or 4, characterized in that: The furnace shell, bottom blowing pipe, side blowing pipe and exhaust pipe are all made of 304 stainless steel. The bottom blowing pipe has a diameter of 50 mm, the side blowing pipe has a diameter of 11 mm, the exhaust pipe has a diameter of 25 mm and a height of 300 mm. The bottom blowing pipe is located at the bottom center of the reactor, the side blowing pipe is located at a height of 710 mm of the reactor, and the exhaust pipe is located at the upper center of the reactor.

6. The two-stage reducing gas injection reactor according to claim 5, characterized in that: The reactor top cover has a thickness of 4 mm and a graphite pad is arranged inside the top cover in the shape of a hollow triangle.

7. The two-stage reducing gas injection reactor according to claim 6, characterized in that: The gas heating furnace comprises a heating reaction tube, a heating furnace, and an air intake pipe. The heating reaction tube is made of 310S stainless steel and contains alumina balls of 2 / 3 height and 20 mm diameter. The heating reaction tube is placed in the heating furnace, and the heating furnace is integrally formed with mullite crystal fiber.

8. The two-stage reducing gas injection reactor according to claim 1, characterized in that: The gas controller includes a large gas mixing tank, a small gas mixing tank and a gas flow meter, wherein the large gas mixing tank has 4 gas inlets connected to the 4 gas flow meters through stainless steel pipes, and the small gas mixing tank has 5 gas inlets connected to the 5 gas flow meters through stainless steel pipes.

9. A two-stage reducing gas injection reactor according to claim 8, characterized in that: The large and small gas mixing tanks both include an air inlet, a gas mixing chamber and an air outlet pipe. The gas mixing tank is made of stainless steel. The air inlet is located on the lower side wall of the gas mixing tank. The air outlet pipe is inserted into the gas mixing chamber and is 50 to 150 mm away from the bottom of the gas mixing chamber.

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