Electric heating moving bed pure hydrogen reduction iron device

Abstract

The utility model provides an electric heating moving bed pure hydrogen reduction iron device, which is characterized in that a stock bin is connected with the upper part of one side of an electric heating moving bed through a pipeline, and a temperature rising resistor is arranged in the electric heating moving bed and is connected with a temperature control system; the other side of the heat exchanger is connected with a gas recovery device, and meanwhile, the heat exchanger is respectively connected with a hydrogen storage tank and the lower part of the electric heating moving bed up and down through a pipeline; a steam-water separation device and a circulating fan are sequentially connected between the heat exchanger and the electric heating moving bed through pipelines; an electric heating rotary blow-off valve is arranged at the bottom of the electric heating moving bed, and reacted spherical materials are discharged out of the moving bed through the rotary blow-off valve and enter a material recovery device. By using the device, materials and hydrogen can be fully mixed and contacted, the iron ore reduction reaction is efficiently completed under the action of high temperature, and the whole process is simple to operate and convenient to control.

Description

Technical Field

[0001] This utility model belongs to the field of metallurgical technology, and in particular relates to an experimental device for the reduction of iron with pure hydrogen in an electrically heated moving bed. Background Technology

[0002] Hydrogen metallurgy technology uses hydrogen as a reducing agent to replace carbon reduction, which can reduce pollutant and carbon dioxide emissions at the source. Currently, depending on the type of reactor, the reduction ironmaking process is mainly divided into vertical furnace process and fluidized bed process. Compared with vertical furnace process and fluidized bed process, moving bed has the advantages of high efficiency, energy saving and high efficiency.

[0003] Electrically heated moving beds offer advantages such as uniform heating, efficient reaction, continuous operation, and flexible control.

[0004] An electrically heated moving bed, a specialized piece of equipment, combines the technical features of electric heating and moving beds. It is commonly used in scenarios requiring uniform heating and material circulation, such as in the chemical, pharmaceutical, and metallurgical industries. The electrically heated moving bed utilizes internal electric heating elements, such as resistance wires or electric heating tubes, which are heated by electric current, thus transferring heat to the material within the bed. The moving bed consists of two parts: the upper part is a pipe containing granular material, and the lower part is the material bed area containing air inlets, fans, and heating equipment. Material is added through the upper feed inlet and, propelled by airflow and heated by the heating equipment, circulates within the bed. The material rises continuously under the influence of the airflow, receiving heating as it ascends. When the material reaches the top, some is discharged, while the bed gradually descends, forming a continuously circulating and renewed bed.

[0005] Patent document "An Apparatus and Method for Direct Reduction" (CN200580017740.5) discloses a technical solution that uses a two-stage fluidized bed to reduce solid iron ore oxides. In the first fluidized bed, heat is generated through the reaction of solid carbonaceous materials and oxygen-containing gas. In the second fluidized bed, the metal-containing raw material is reduced, and heat is supplied to the second fluidized bed through the hot exhaust gas stream and entrained solids flowing from the first fluidized bed. This method, using a fluidized bed for direct reduction, suffers from problems such as poor preheating of the ore powder, the need to provide the heat required for reduction through the combustion of carbonaceous fuels resulting in carbon dioxide emissions, and low heat utilization efficiency.

[0006] The patent document "A Hydrogen Vertical Shaft Furnace Ironmaking System and Method Using Electrical Heating" (CN202110053605.7) discloses a vertical shaft furnace with a microwave heating section, an intermediate section, an induction heating section, and a cooling section. By controlling the metallization rate of iron-containing charge at different heights within the furnace, microwave heating and induction heating provide the necessary heat for the reduction reaction. However, this vertical shaft furnace system cannot directly process fine ore, and the reduction process of iron oxide pellets suffers from disadvantages such as high mass transfer resistance, low heat transfer, and low reduction efficiency.

[0007] CN109913606A discloses a coal-to-hydrogen vertical shaft furnace ironmaking system and process based on induction heating. This system uses inexpensive lignite to produce pure hydrogen through direct reduction, significantly reducing carbon emissions. Induction heating raises hydrogen to a high temperature and provides supplementary induction heating to the furnace body, greatly shortening reduction time, increasing capacity, reducing the amount of gas fed into the furnace, and saving production costs. However, this method involves preheating H2 to approximately 900°C outside the furnace before introducing the high-temperature H2 into the furnace. Due to the high permeability of H2 to metals at high temperatures, both the heating equipment and the pipelines transporting H2 are prone to material failure and H2 diffusion leakage, posing significant safety hazards.

[0008] Based on the above analysis and the results of relevant patent searches, most current research on hydrogen reduction of iron uses vertical furnaces or fluidized beds. There are few reports on existing moving bed hydrogen reduction of iron, and there are even fewer reports on pure electric heating. Therefore, we have invented an experimental device for electric heating moving bed pure hydrogen reduction of iron to provide strong experimental support for subsequent hydrogen metallurgy engineering in steel plants. Utility Model Content

[0009] The purpose of this invention is to overcome the above-mentioned problems and shortcomings and provide an electrically heated moving bed pure hydrogen reduction iron device with advantages such as uniform heating temperature control, high efficiency reaction, continuous operation and flexible control.

[0010] The objective of this utility model is achieved as follows:

[0011] An electric heating moving bed pure hydrogen reduction iron device includes an electric heating moving bed, a silo, valves, pipelines, a temperature control system, a heating resistor, a circulating fan, a gas-water separation device, a hydrogen storage tank, a heat exchanger, a gas recovery device, a rotary discharge valve, and a material recovery device.

[0012] The silo is connected to the upper part of one side of the electrically heated moving bed via a pipeline. The electrically heated moving bed is equipped with a heating resistor, which is connected to the temperature control system. The other side of the upper part of the electrically heated moving bed is connected to a heat exchanger, and the other side of the heat exchanger is connected to a gas recovery device. At the same time, the heat exchanger is connected to a hydrogen storage tank and the lower part of the electrically heated moving bed via pipelines. The heat exchanger and the electrically heated moving bed are connected in sequence to a gas-liquid separator and a circulating fan via pipelines. An electrically heated rotary discharge valve is installed at the bottom of the electrically heated moving bed. The spherical material after the reaction is discharged from the moving bed through the rotary discharge valve and enters the material recovery device.

[0013] Furthermore, valves are installed between the silo and the electrically heated moving bed, and between the hydrogen storage tank and the heat exchanger.

[0014] Furthermore, the hopper is positioned above the electrically heated moving bed.

[0015] Furthermore, the heat exchanger is a shell-and-tube heat exchanger.

[0016] The beneficial effects of this utility model are as follows:

[0017] 1. Uniform heating and precise temperature control: The use of a heating resistance electric heating method can ensure the temperature of the material in the bed. The uniformity of the internal temperature of the moving bed is controlled by adjusting the voltage. At the same time, the temperature data is fed back to the temperature control system through the internal temperature controller of the heating resistance, which can accurately record the current temperature of the moving bed and avoid local overheating or undercooling.

[0018] 2. Highly efficient and pollution-free reaction: Hydrogen enters from the bottom of the moving bed, while iron ore powder enters from the top. The moving bed design allows for thorough mixing and contact of the materials, enabling efficient iron ore reduction under high temperature. The heat generated by the resistance system completes the reduction reaction between iron ore and hydrogen. The entire reaction process produces no toxic, harmful, or greenhouse gas emissions.

[0019] 3. The system can operate continuously: The electrically heated moving bed can continuously feed and discharge materials, realizing continuous production and improving production efficiency;

[0020] 4. Flexible control: By adjusting the heating temperature and heating rate through the temperature control system, and controlling the hydrogen flow rate, this experimental device can flexibly control the reaction process of hydrogen reducing iron ore powder solidification material. The whole process is simple to operate and easy to control. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the electrically heated moving bed pure hydrogen reduction iron device of this utility model.

[0022] In the diagram, 1 is an electrically heated moving bed, 2 is a silo, 3 is a valve, 4 is a pipeline, 5 is a temperature control system, 6 is a heating resistor, 7 is a circulating fan, 8 is a gas-water separator, 9 is a hydrogen storage tank, 10 is a heat exchanger, 11 is a gas recovery device, 12 is a rotary discharge valve, and 13 is a material recovery device. Detailed Implementation

[0023] The present invention will be further described below through embodiments.

[0024] An electric heating moving bed pure hydrogen reduction iron device includes an electric heating moving bed 1, a silo 2, valves 3, pipelines 4, a temperature control system 5, a heating resistor 6, a circulating fan 7, a gas-water separation device 8, a hydrogen storage tank 9, a heat exchanger 10, a gas recovery device 11, a rotary discharge valve 12, and a material recovery device 13.

[0025] The silo 2 is connected to the upper part of one side of the electrically heated moving bed 1 via a pipe 4. The electrically heated moving bed 1 is equipped with a heating resistor 6, which is connected to the temperature control system 5. The other side of the upper part of the electrically heated moving bed 1 is connected to a heat exchanger 10, and the other side of the heat exchanger 10 is connected to a gas recovery device 11. At the same time, the heat exchanger 10 is connected to the hydrogen storage tank 9 and the lower part of the electrically heated moving bed 1 via pipes 4. The heat exchanger 10 and the electrically heated moving bed 1 are connected in sequence via pipes 4 to a gas-water separator 8 and a circulating fan 7. The bottom of the electrically heated moving bed 1 is equipped with an electrically heated rotary discharge valve 12. The spherical material after the reaction is discharged from the moving bed 1 through the rotary discharge valve 12 and enters the material recovery device 13.

[0026] The silo 2 contains uniformly sized iron ore powder solidified material with a diameter of 1-6 mm. The amount of iron ore powder solidified material flowing into the electrically heated moving bed 1 is controlled by valve 3. The electrically heated moving bed 1 moves the material from the feed port to the discharge port through a drive device. The maximum material height inside the moving bed must not exceed the height of the rapid heating resistor 6. The temperature range of the reduction reaction inside the moving bed is 750-850℃, and the reaction time of the material inside the moving bed is 40-60 minutes.

[0027] The temperature control system 5 controls the temperature of the heating resistor 6 by adjusting the voltage. The heating resistor 6, located inside the moving bed, consists of a temperature controller and a precision resistor. The temperature controller monitors the resistor temperature in real time according to temperature requirements. The precision resistor uses materials with good conductivity and stability, and can be, but is not limited to, nickel-cobalt resistors. A circulating fan 7 is connected to the fluidized bed on one side and to the gas-water separator 8 on the other side via a pipeline. The circulating fan 7 extracts the high-temperature gas from inside the electrically heated moving bed 1, which then passes through the gas-water separator 8 and enters the heat exchanger 10. A gas recovery device 11 is connected to the heat exchanger 10 to recover the low-temperature gas after heat exchange. The heat exchanger 10 is a shell-and-tube heat exchanger, characterized by its robust structure and resistance to high temperatures and pressures. The main function of the heat exchanger 10 is to absorb the heat from the high-temperature flue gas after the reaction and simultaneously heat the hydrogen in the hydrogen storage tank 9. The hydrogen in the hydrogen storage tank 9 has a purity of 98-99.99%. Its flow rate is controlled by valve 3, and after being heated by the heat exchanger 10, it enters the bottom of the electrically heated moving bed 1 through the pipeline system 4. Inside the electrically heated moving bed 1, hydrogen gas and uniformly sized spherical iron ore powder solidified material undergo a reduction reaction under the high temperature of the heating resistor 6. The spherical material after the reaction is discharged from the moving bed through the rotary discharge valve 12 and enters the material recovery device 13. The rotary discharge valve 12 is used to discharge the material inside the moving bed, and the material recovery device 13 recovers the material that has completed the reaction.

[0028] A smelting method using an electrically heated moving bed pure hydrogen reduction iron device, wherein a silo 2 contains agglomerated iron ore powder of uniform size with a diameter of 1-6 mm, and a valve 3 controls the amount of agglomerated iron ore powder flowing into an electrically heated moving bed 1, wherein a drive device moves the material from the feed inlet to the discharge outlet of the electrically heated moving bed 1 for smelting, wherein the maximum height of the agglomerated iron ore powder inside the electrically heated moving bed 1 shall not exceed the height of the heating resistor 6 installed inside the electrically heated moving bed 1, the temperature range of the reduction reaction in the moving bed is 750-850℃, and the reaction time of the material in the moving bed is 40-60 min.

[0029] The utility model device was used to conduct experimental research on the solidified iron ore powder of different particle sizes and its properties. The metallization rate of the solidified iron ore powder after the experiment was tested. The main process parameters and properties of the reduced iron of this utility model are shown in Table 1.

[0030] Main process parameters and properties of reduced iron in this utility model

[0031]

[0032] In order to illustrate this utility model, the present utility model has been properly and sufficiently described above through embodiments. The above embodiments are only used to illustrate this utility model and are not intended to limit it. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this utility model. Any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of this utility model. The patent protection scope of this utility model should be defined by the claims.

Claims

1. An electrically heated moving bed pure hydrogen direct reduced iron plant, characterized in that, Includes an electrically heated moving bed (1), a silo (2), valves (3), pipes (4), a temperature control system (5), a heating resistor (6), a circulating fan (7), a gas-water separator (8), a hydrogen storage tank (9), a heat exchanger (10), a gas recovery device (11), a rotary discharge valve (12), and a material recovery device (13); The silo (2) is connected to the upper part of one side of the electric heating moving bed (1) through the pipe (4). The electric heating moving bed (1) is equipped with a heating resistor (6), which is connected to the temperature control system (5). The other side of the upper part of the electric heating moving bed (1) is connected to a heat exchanger (10), and the other side of the heat exchanger (10) is connected to a gas recovery device (11). At the same time, the heat exchanger (10) is connected to the hydrogen storage tank (9) and the lower part of the electric heating moving bed (1) through the pipe (4). The heat exchanger (10) and the electric heating moving bed (1) are connected in sequence through the pipe (4) to the gas-water separator (8) and the circulating fan (7). The bottom of the electric heating moving bed (1) is equipped with an electric heating rotary discharge valve (12). The spherical material after the reaction is discharged from the moving bed (1) through the rotary discharge valve (12) and enters the material recovery device (13).

2. The electrically heated moving bed pure hydrogen reduction iron apparatus according to claim 1, characterized in that, Valves (3) are installed between the silo (2) and the electrically heated moving bed (1), and between the hydrogen storage tank (9) and the heat exchanger (10).

3. The apparatus of claim 1, wherein the apparatus is characterized by: The hopper (2) is located above the electrically heated moving bed (1).

4. The apparatus of claim 1, wherein the apparatus is an electrically heated moving bed pure hydrogen reduction iron plant. The heat exchanger (10) is a shell-and-tube heat exchanger.

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