Hydrogen-based shaft furnace oxidized pellet load reduction experiment device

Abstract

The invention discloses a hydrogen-based shaft furnace oxidized pellet load reduction experiment device, and relates to the technical field of hydrogen-based shaft furnace reduction. According to the device, by simulating the actual production condition in the hydrogen-based shaft furnace, the requirement for the reduction process that the atmosphere is complex (H2 + CO + CH4 + N2 + H2O + CO2) and the material layer pressure is borne in the reduction and material descending process is met, the load in the reduction process can be adjusted, the pressure in the pressurization reduction process is gradually increased from 0 kpa to 147 kpa, and the reduction effect is good. A bonding experiment result after high-temperature load reduction is convenient to sample through the design of a horn mouth, so that the convenience of a simulation experiment is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen-based vertical furnace reduction, in particular to a hydrogen-based vertical furnace oxidized pellet load reduction experimental device. Background Art

[0002] The output of hydrogen-based shaft furnace reduction process accounts for more than 70% of the output of direct reduced iron. Compared with the traditional blast furnace process, it has the advantages of fast reduction speed, stable product quality, high degree of automation, and clean ingredients. With the development of natural gas resources in my country, the transformation and integration of the coke industry, the centralized recycling of coke oven gas, and the maturity of coal-to-gas technology, some regions in my country have the conditions to develop hydrogen-based shaft furnace reduction process. In particular, coal-to-gas and semi-coke-to-gas have become conventional technologies in the chemical industry, solving the problem of "no price-appropriate reducing gas available" in hydrogen-based shaft furnace reduction process. Hydrogen metallurgical processes represented by hydrogen-based shaft furnace direct reduction technology have become the inevitable path for the future steel industry. The bonding behavior of oxidized pellets during the reduction process is one of the problems faced by hydrogen-based shaft furnace processes. The reduction temperature of the hydrogen-based shaft furnace is below the softening temperature of the pellets, but during the reduction process of the pellets, fibrous metallic iron and low-melting-point substances will be generated. The low-melting-point substances will generate liquid phases at local high temperatures and eventually cause the direct reduced iron to bond, which will directly affect the forward movement of the shaft furnace charge and the distribution of the airflow and temperature field in the furnace. Therefore, in order to find out the adhesion during the reduction process of hydrogen-based shaft furnace oxidized pellets and how to effectively avoid adhesion, it is necessary to clarify the bonding reaction mechanism of direct reduced iron in hydrogen-based shaft furnaces and carry out high-temperature load reduction of oxidized pellets. This study can provide theoretical reference and technical support for the production and application of hydrogen-based shaft furnace direct reduced iron, which is of great significance for achieving cost reduction, efficiency improvement, energy conservation and emission reduction in hydrogen-based shaft furnace ironmaking systems.

[0003] There are currently two solutions for high temperature load reduction of oxidized pellets: 1. Determination of agglomeration properties of iron ore pellets for direct reduction of furnace charge (national standard GB / T 24237-2009) Experimental equipment such as Figure 1 As shown, the reducing gas is composed of hydrogen, carbon monoxide, carbon dioxide and nitrogen. The reduction test tube is a double-layer test tube made of heat-resistant non-oxidizing metal. The pressurization during the reaction is achieved by compressed air in a cylinder. Before the experiment begins, nitrogen is passed through the reduction test tube to increase the temperature at a fixed flow rate. After the sample reaches a fixed temperature, the reducing gas is switched to perform isothermal reduction on the test sample, and a constant pressure is applied after 1 hour of reduction. 2. The experimental equipment for the high-temperature load reduction of iron ore soft-melting dripping performance (national standard GB / T 34211-2017) is as follows Figure 2As shown, the reducing gas is composed of carbon monoxide and nitrogen. The charge is in a graphite crucible. The reaction process is pressurized by compressed air in a cylinder. The pressure is applied before the experiment starts and the pressure is constant during the entire reduction process. At the same time, nitrogen is passed through the reduction test tube to increase the temperature at a fixed flow rate. After the sample reaches a temperature of 500°C, the reducing gas is switched to perform variable temperature reduction on the test sample.

[0004] Under the actual working conditions of the vertical furnace, the reducing atmosphere is more complicated, and the reducing gas contains (H2+CO+CH4+N2+H2O+CO2). The experimental equipment for the determination of the agglomeration of iron ore pellets for direct reduction of furnace charge (national standard GB / T 24237-2009) cannot approach the actual composition of the vertical furnace due to the simple atmosphere. It is difficult to take the pellets after high-temperature load reduction, which affects the subsequent experimental results. The static pressure of the material layer received by the oxidized pellets in the vertical furnace gradually increases during the reduction process. The pressure application process of this equipment is a fixed load and cannot simulate the actual working conditions in the vertical furnace. Not only does it have the same disadvantages as the former, such as a single atmosphere and constant load, but also because a graphite crucible is used as a reaction container, the graphite material itself has an impact on the reduction process. The H2O produced after H2 reduction will also react with the C in the graphite under high temperature conditions, accelerating the consumption of graphite accessories and increasing costs.

[0005] Therefore, a new solution to the above problems needs to be proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a hydrogen-based vertical furnace oxidized pellet load reduction experimental device, which has solved the technical problems raised in the background technology.

[0007] To achieve the above-mentioned object, the present invention provides the following technical solutions: a hydrogen-based vertical furnace oxidation pellet load reduction experimental device, comprising a temperature control device, a high-temperature electric furnace, a water vapor generator, a peristaltic pump, a gas flow meter and a high-purity gas storage and output component;

[0008] The temperature control device is used to monitor and control the temperature during the experiment to ensure that the reduction reaction is carried out within the set range;

[0009] A high-temperature electric furnace is provided on one side of the temperature control device, and the high-temperature electric furnace is used to provide a heating function;

[0010] A steam generator is provided on one side of the high-temperature electric furnace away from the temperature control device, and the steam generator is used to generate steam to provide steam components in the hydrogen environment required for the reduction process, which helps to promote the reduction reaction;

[0011] A peristaltic pump is provided on one side of the water vapor generator away from the high-temperature electric furnace, and the peristaltic pump is used to continuously deliver high-purity gas into the water vapor generator;

[0012] A gas flow meter is provided on the side of the peristaltic pump away from the steam generator, and the gas flow meter is used to measure and control the gas flow to ensure that the inflow of hydrogen and other gases meets the experimental requirements;

[0013] A high-purity gas storage and output component is arranged on a side of the gas flow meter away from the peristaltic pump. The high-purity gas storage and output component is used for atmosphere control in the reduction reaction to ensure the purity of the experimental environment.

[0014] Furthermore, a silicon-molybdenum rod and a gas-solid reaction tube are arranged on the inner side of the high-temperature electric furnace. The silicon-molybdenum rod is arranged around the gas-solid reaction tube. The silicon-molybdenum rod serves as a heating source for the high-temperature electric furnace. The silicon-molybdenum rod is used to heat the high-temperature electric furnace to a required high temperature. The gas-solid reaction tube is used to provide a dedicated reaction area, allowing the gas to fully contact the solid sample for a reduction reaction.

[0015] Furthermore, a load-applying assembly is provided at the top of the gas-solid reaction tube, and the load-applying assembly is used to apply loads to fillers and corundum balls. The fillers include pelletized ore samples, and the corundum balls are used to help evenly distribute heat and reduce direct contact between the sample and the heating element to prevent overheating or heat loss.

[0016] Furthermore, a material layer thermocouple is arranged inside the load applying component, and the material layer thermocouple is used to monitor the temperature of the material layer where the experimental sample is located in real time, so as to perform precise temperature control.

[0017] Furthermore, high-purity gas is stored inside the high-purity gas storage and output assembly, and the high-purity gas includes at least N, CO, CO, CH and H.

[0018] Furthermore, the gas-solid reaction tube includes a main tube, an air inlet, a reaction tube outer layer, a reaction tube inner layer, a bell mouth, a porous sieve plate and an air outlet, an air inlet is opened on one side of the top end of the main tube, and an air outlet is opened on the other side of the top end of the main tube. The reaction tube outer layer is arranged on the outside of the main tube, and the reaction tube inner layer is arranged on the inside of the main tube. The bottom end of the reaction tube inner layer is a bell mouth, and the inner side of the bell mouth is fixedly connected with a porous sieve plate.

[0019] Further, the load applying assembly includes a cylinder, a pressure rod, a cylinder connector and a thermocouple hole;

[0020] A pressure rod is arranged on the inner side of the cylinder, a cylinder connector is arranged on the top of the cylinder, and a thermocouple hole is opened on the top of the pressure rod.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The device of the present invention simulates the actual production conditions in a hydrogen-based vertical furnace to meet the requirements of a complex atmosphere (H2+CO+CH4+N2+H2O+CO2), and the reduction process in which the material is subjected to the layer pressure during reduction and material descent. The load during the reduction process is adjustable, and the pressure during the pressurized reduction process can be gradually increased from 0 kPa to 147 kPa. The bonding test results after high-temperature load reduction are convenient for sampling through the bell-mouth design, which greatly improves the convenience of the simulation experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0024] Figure 1 It is a hybrid multi-objective optimization integrated feature selection structure diagram of the present invention;

[0025] Figure 2 This is a structural diagram of the data preprocessing module of the present invention;

[0026] Figure 3 This is a schematic diagram of the feature subset merging and deduplication process of the present invention.

[0027] 1. Temperature control device; 2. Silicon-molybdenum rod; 3. Agglomerate sample; 4. High-temperature electric furnace; 5. Material layer thermocouple; 6. Corundum ball; 7. Steam generator; 8. Peristaltic pump; 9. Gas flow meter; 10. High-purity gas storage and output assembly; 11. Air inlet; 12. Outer layer of reaction tube; 13. Inner layer of reaction tube; 14. Bell mouth; 15. Porous sieve plate; 16. Air outlet; 17. Cylinder; 18. Pressure rod; 19. Cylinder connector; 20. Thermocouple hole. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0029] See also Figure 1 , a hydrogen-based vertical furnace oxidation pellet load reduction experimental device, comprising a temperature control device 1, a high-temperature electric furnace 4, a steam generator 7, a peristaltic pump 8, a gas flow meter 9 and a high-purity gas storage and output component 10;

[0030] The temperature control device 1 is used to monitor and control the temperature during the experiment to ensure that the reduction reaction is carried out within the set range;

[0031] A high-temperature electric furnace 4 is provided on one side of the temperature control device 1, and the high-temperature electric furnace 4 is used to provide a heating function;

[0032] A water vapor generator 7 is provided on the side of the high temperature electric furnace 4 away from the temperature control device 1. The water vapor generator 7 is used to generate steam to provide steam components in the hydrogen environment required for the reduction process, which helps to promote the reduction reaction;

[0033] A peristaltic pump 8 is provided on the side of the water vapor generator 7 away from the high-temperature electric furnace 4, and the peristaltic pump 8 is used to continuously deliver high-purity gas into the water vapor generator 7;

[0034] A gas flow meter 9 is provided on the side of the peristaltic pump 8 away from the steam generator 7, and the gas flow meter 9 is used to measure and control the gas flow to ensure that the inflow of hydrogen and other gases meets the experimental requirements;

[0035] A high-purity gas storage and output assembly 10 is provided on the side of the gas flow meter 9 away from the peristaltic pump 8. The high-purity gas storage and output assembly 10 is used for atmosphere control in the reduction reaction to ensure the purity of the experimental environment.

[0036] The inner side of the high-temperature electric furnace 4 is provided with a silicon-molybdenum rod 2 and a gas-solid reaction tube. The silicon-molybdenum rod 2 is arranged around the gas-solid reaction tube. The silicon-molybdenum rod 2 serves as a heating source for the high-temperature electric furnace 4. The silicon-molybdenum rod 2 is used to heat the high-temperature electric furnace 4 to the required high temperature. The gas-solid reaction tube is used to provide a dedicated reaction area to allow the gas to fully contact the solid sample for a reduction reaction.

[0037] A load-applying assembly is provided at the top of the gas-solid reaction tube, and the load-applying assembly is used to apply load to the filler and the corundum ball 6. The filler includes a pelletized ore sample 3, and the corundum ball 6 is used to help evenly distribute heat and reduce direct contact between the sample and the heating element to prevent overheating or heat loss.

[0038] A material layer thermocouple 5 is arranged inside the load applying component, and the material layer thermocouple 5 is used to monitor the temperature of the material layer where the experimental sample is located in real time, so as to perform accurate temperature control.

[0039] The high-purity gas storage and output assembly 10 stores high-purity gas inside, and the high-purity gas includes at least N2, CO, CO2, CH4 and H2.

[0040] See also Figure 2The gas-solid reaction tube comprises a main body tube, an air inlet 11, a reaction tube outer layer 12, a reaction tube inner layer 13, a bell mouth 14, a porous sieve plate 15 and an air outlet 16. An air inlet 11 is provided on one side of the top of the main body tube, and an air outlet 16 is provided on the other side of the top of the main body tube. The reaction tube outer layer 12 is provided on the outside of the main body tube, and the reaction tube inner layer 13 is provided on the inside of the main body tube. The bottom end of the reaction tube inner layer 13 is a bell mouth 14, and the inner side of the bell mouth 14 is fixedly connected with a porous sieve plate 15.

[0041] The working principle of the gas-solid reaction tube is as follows:

[0042] Gas enters the reaction tube through the gas inlet 11. This gas is usually hydrogen or other gas in a reducing atmosphere, the purpose of which is to react with the solid sample.

[0043] The outer layer 12 of the reaction tube has a heat insulating or protective function, which helps to keep the temperature inside the reaction tube stable and prevents external heat sources from affecting the experimental results.

[0044] The inner layer 13 of the reaction tube is the main area for gas-solid reaction, and the inner surface is usually designed to enhance the contact between gas and solid sample. The solid sample is placed in this area.

[0045] Gas distribution and flow: The design of the bell mouth 14 helps to evenly distribute the gas to the inner layer 13 of the reaction tube, thereby ensuring the uniformity and stability of the gas flow.

[0046] The porous sieve plate 15 is used to provide uniform gas distribution while supporting the distribution of solid samples. Its porous structure allows the gas to pass smoothly, ensuring good contact between the solid sample and the gas.

[0047] See also Figure 3 , the load applying assembly includes a cylinder 17, a pressure rod 18, a cylinder connector 19 and a thermocouple hole 20;

[0048] A pressure rod 18 is disposed inside the cylinder 17 , a cylinder connector 19 is disposed at the top of the cylinder, and a thermocouple hole 20 is opened at the top of the pressure rod.

[0049] The cylinder 17 is the main component for applying the load. It pushes the piston downward through the internal gas pressure, thereby applying the load to the sample in the reaction tube.

[0050] The pressure rod 18 connects the cylinder 17 and the sample, and ensures that the load is evenly applied by transmitting the force of the cylinder 17 to the sample. The design of the pressure rod ensures the accuracy and stability of the load application.

[0051] The cylinder connector 19 is used to fixedly connect the cylinder 17 to the pressure rod 18 or other mechanical parts, ensuring that the movement of the cylinder 17 can be effectively transmitted to the sample and maintaining the structural stability of the device.

[0052] The thermocouple hole 20 is used to monitor the temperature of the load application area, which is very important to ensure that the experiment is carried out under the set temperature conditions, especially in a high temperature environment to avoid the temperature affecting the load application effect.

[0053] The overall working principle of a hydrogen-based shaft furnace oxidation pellet load reduction experimental device is as follows:

[0054] Preparation:

[0055] The pellet sample 3 is placed on the corundum ball 6 in the high-temperature electric furnace 4, and the material layer thermocouple 5 is connected to ensure that the temperature of the sample can be monitored in real time.

[0056] The peristaltic pump 8 is started to deliver water into the steam generator 7 to generate the required steam.

[0057] Heating and atmosphere control:

[0058] The high temperature electric furnace 4 is turned on, and the pellet sample 3 is heated by the silicon-molybdenum rod 2 .

[0059] The temperature control device 1 is responsible for adjusting and maintaining the temperature inside the high-temperature electric furnace 4 .

[0060] The high-purity gas in the high-purity gas storage and output assembly 10 is adjusted in flow by the gas flow meter 9 and enters the high-temperature electric furnace 4, and the hydrogen and steam together form a reducing atmosphere.

[0061] Reduction reaction:

[0062] Under high temperature and reducing atmosphere, the pellet sample 3 undergoes a reduction reaction, and hydrogen as a reducing agent reacts with the oxides in the sample to produce a reduction product.

[0063] The material layer thermocouple 5 continuously monitors the temperature change of the sample to ensure that the reaction proceeds within the required temperature range.

[0064] Data Collection and Analysis:

[0065] During the experiment, record the temperature, gas flow rate and other relevant data.

[0066] The reduction performance of the pelletized ore samples was analyzed based on the experimental results, including reduction degree, reduction rate, etc.

[0067] The hydrogen-based vertical furnace oxidation pellet load reduction experimental device simulates the reduction behavior of minerals in the actual metallurgical process by precisely controlling the temperature, gas flow and reducing atmosphere. The heating silicon molybdenum rod 2 and the high-temperature electric furnace 4 provide a high-temperature environment, the steam generator 7 and the peristaltic pump 8 maintain the stability of the reducing atmosphere, and the gas flow meter 9 and the high-purity gas ensure the reduction reaction. Through the coordination of these components, the behavior of pellets in the high-temperature reduction process can be systematically studied.

[0068] The whole material of the gas-solid reaction tube is made of a double-layer heat-resistant metal that is not easily deformed at high temperatures. The gas is introduced from the outer layer of the reaction tube, and after being preheated by the side wall, it is introduced into the bottom of the reaction tube from the bottom of the reaction tube. A porous base is provided at the bottom of the reaction tube to even out the experimental reaction gas flow. The experimental sample is placed above the base, and the side wall at the material layer position is provided with a trumpet-shaped chamfer, that is, the inner diameter of the bottom is larger than the upper diameter of the material layer. After the high-temperature load reduction is completed, the load-applying component is convenient for sampling the experimental results to avoid distortion of the experimental results caused by sampling difficulties. The load-applying part is mainly composed of a pressure rod 18, a cylinder 17 and an air compressor. The cylinder 17 is on both sides of the pressure rod 18, and is connected by metal in the middle. The air compressor is turned on to compress the air to give pressure to the cylinder 17, and the cylinder 17 drives the pressure rod 18 to give pressure to the material layer.

[0069] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A hydrogen-based shaft furnace oxidation pellet load reduction experimental device, characterized in that: It comprises a temperature control device (1), a high-temperature electric furnace (4), a water vapor generator (7), a peristaltic pump (8), a gas flow meter (9) and a high-purity gas storage and output component (10); The temperature control device (1) is used to monitor and control the temperature during the experiment to ensure that the reduction reaction is carried out within a set range; A high-temperature electric furnace (4) is provided on one side of the temperature control device (1), and the high-temperature electric furnace (4) is used to provide a heating function; A water vapor generator (7) is provided on a side of the high-temperature electric furnace (4) away from the temperature control device (1), and the water vapor generator (7) is used to generate steam to provide steam components in the hydrogen environment required for the reduction process, thereby helping to promote the reduction reaction; A peristaltic pump (8) is provided on a side of the water vapor generator (7) away from the high-temperature electric furnace (4), and the peristaltic pump (8) is used to continuously deliver high-purity gas into the water vapor generator (7); A gas flow meter (9) is provided on the side of the peristaltic pump (8) away from the water vapor generator (7), and the gas flow meter (9) is used to measure and control the gas flow to ensure that the inflow of hydrogen and other gases meets the experimental requirements; A high-purity gas storage and output assembly (10) is provided on the side of the gas flow meter (9) away from the peristaltic pump (8). The high-purity gas storage and output assembly (10) is used for atmosphere control in the reduction reaction to ensure the purity of the experimental environment.

2. A hydrogen-based shaft furnace oxidized pellet load reduction experimental device according to claim 1, characterized in that: A silicon-molybdenum rod (2) and a gas-solid reaction tube are arranged on the inner side of the high-temperature electric furnace (4). The silicon-molybdenum rod (2) is arranged around the gas-solid reaction tube. The silicon-molybdenum rod (2) serves as a heating source for the high-temperature electric furnace (4). The silicon-molybdenum rod (2) is used to heat the high-temperature electric furnace (4) to a required high temperature. The gas-solid reaction tube is used to provide a dedicated reaction area to allow the gas to fully contact the solid sample for a reduction reaction.

3. A hydrogen-based shaft furnace oxidation pellet load reduction experimental device according to claim 2, characterized in that: A load-applying assembly is provided at the top of the gas-solid reaction tube, and the load-applying assembly is used to apply a load to a filler and a corundum ball (6), wherein the filler includes a pelletized ore sample (3), and the corundum ball (6) is used to help evenly distribute heat and reduce direct contact between the sample and the heating element to prevent overheating or heat loss.

4. A hydrogen-based shaft furnace oxidized pellet load reduction experimental device according to claim 3, characterized in that: A material layer thermocouple (5) is arranged inside the load applying component, and the material layer thermocouple (5) is used to monitor the temperature of the material layer where the experimental sample is located in real time, so as to perform accurate temperature control.

5. The hydrogen-based shaft furnace oxidized pellet load reduction experimental device according to claim 1 is characterized by: The high-purity gas storage and output component (10) stores high-purity gas inside, and the high-purity gas includes at least N2, CO, CO2, CH4 and H2.

6. The hydrogen-based shaft furnace oxidized pellet load reduction experimental device according to claim 2 is characterized by: The gas-solid reaction tube comprises a main body tube, an air inlet (11), a reaction tube outer layer (12), a reaction tube inner layer (13), a bell mouth (14), a porous sieve plate (15) and an air outlet (16); an air inlet (11) is provided on one side of the top end of the main body tube, an air outlet (16) is provided on the other side of the top end of the main body tube, the reaction tube outer layer (12) is provided on the outside of the main body tube, the reaction tube inner layer (13) is provided on the inside of the main body tube, the bottom end of the reaction tube inner layer (13) is a bell mouth (14), and the inner side of the bell mouth (14) is fixedly connected with the porous sieve plate (15).

7. The hydrogen-based shaft furnace oxidation pellet load reduction experimental device according to claim 4 is characterized by: The load-applying assembly comprises a cylinder (17), a pressure rod (18), a cylinder connector (19) and a thermocouple hole (20); A pressure rod (18) is arranged on the inner side of the cylinder (17), a cylinder connector (19) is arranged on the top of the cylinder, and a thermocouple hole (20) is opened on the top of the pressure rod.

Images