Reducing gas preparation and treatment system for gas-based shaft furnace

Abstract

The invention discloses a gas-based shaft furnace reducing gas preparation and treatment system, and relates to the technical field of direct reduction ironmaking in ferrous metallurgy. In the gas-based shaft furnace reducing gas preparation and treatment system, a pretreatment unit is used for carrying out desulfurization treatment on first furnace top separated gas and preheated first natural gas and then mixing the desulfurized first natural gas with standby water vapor formed after liquid water is filtered out on the basis of a gas-liquid mixture, so that reforming raw material mixed gas is formed; the public preheating unit is used for receiving the waste heat of the flue gas output by the reforming furnace unit so as to preheat the received combustion-supporting air, the first natural gas, the make-up water and the reforming raw material mixed gas in sections; preheating the make-up water to form a gas-liquid mixture; and the reforming furnace unit is used for receiving the preheated reforming raw material mixed gas, the preheated combustion-supporting air, the second furnace top separated gas and the second natural gas so as to heat the reforming raw material mixed gas through heat generated by combustion to form reducing gas. The gas-based shaft furnace reducing gas preparation and treatment system can be simplified, and raw material consumption and energy waste are reduced.

Description

Technical Field

[0001] This application relates to the field of direct reduction ironmaking technology in iron and steel metallurgy, and more specifically to a vertical shaft furnace system with self-circulating reducing gas, which is particularly suitable for the preparation and treatment of reducing gas with low energy consumption and low CO2 emissions. Background Technology

[0002] Under the "dual carbon" target, the steel industry urgently needs to replace the traditional blast furnace ironmaking process. To this end, a gas-based vertical shaft furnace reducing gas preparation and treatment system based on direct reduction ironmaking technologies (such as MIDREX and HYL) has been designed. In the gas-based vertical shaft furnace reducing gas preparation and treatment system, reducing gas including H2 and CO is used to produce direct reduced iron (DRI) in the gas-based vertical shaft furnace, which can significantly reduce CO2 emissions.

[0003] Among them, how to simplify the gas-based vertical shaft furnace reducing gas preparation and processing system, reduce the raw material consumption in the gas-based vertical shaft furnace reducing gas preparation and processing system, and at the same time reduce the energy waste in the gas-based vertical shaft furnace reducing gas preparation and processing system are still technical problems that need to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, in order to solve the above-mentioned technical problems, this application provides a gas-based vertical shaft furnace reducing gas preparation and processing system, which includes a gas-based vertical shaft furnace unit, a pretreatment unit, a common preheating unit and a reformer unit; The gas-based vertical shaft furnace unit is connected to the reformer unit and is used to receive the reducing gas output from the reformer unit and separate the furnace top gas into the first furnace top gas and the second furnace top gas. The pretreatment unit is connected to the gas-based vertical furnace unit and the common preheating unit respectively. It is used to desulfurize the first natural gas after the first furnace top gas and the first natural gas after the common preheating unit are preheated, and then mix it with the steam to be used after filtering out liquid water based on the gas-liquid mixture to form a reforming feedstock mixture for preparing reducing gas. The common preheating unit is connected to the reformer unit and is used to receive the waste heat of the flue gas output from the reformer unit to preheat the received combustion air, first natural gas, makeup water and reforming feed gas mixture in stages; wherein, the makeup water forms a gas-liquid mixture after preheating. The reformer unit is used to receive preheated reforming feed gas mixture, preheated combustion air, second top gas separator and second natural gas, so that the combustion air, second top gas separator and second natural gas are mixed and burned to form flue gas, and the heat generated by combustion heats the reforming feed gas mixture to form reducing gas.

[0005] Beneficial Effects: Unlike existing technologies, this application offers at least three beneficial effects. First, it can recover a portion of the CO2 from the first furnace top gas separator as raw material for reducing gas preparation. This avoids the need for complex CO2 removal equipment, simplifying the gas-based vertical shaft furnace reducing gas preparation and processing system, and also reduces raw material consumption and CO2 emissions. Second, it can recover waste heat from the flue gas to preheat the combustion air, first natural gas, makeup water, and reforming feedstock mixture in stages. This enables tiered energy utilization and reduces energy waste in the gas-based vertical shaft furnace reducing gas preparation and processing system. Third, it can recover the remaining H2 and CO from the second furnace top gas separator as fuel, reducing fuel consumption and thus reducing energy waste and CO2 emissions. In summary, this application simplifies the gas-based vertical shaft furnace reducing gas preparation and processing system, reduces raw material consumption in the system, and simultaneously reduces energy waste. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the gas-based vertical shaft furnace reducing gas preparation and processing system of this application; Figure 2 This is a schematic diagram of the gas-based vertical shaft furnace reducing gas preparation and processing system of this application; Figure 3 yes Figure 2 An enlarged schematic diagram of the area near the central public preheating unit; Figure 4 yes Figure 3 A schematic diagram of the structure of the air blower unit; Figure 5 yes Figure 2 Enlarged schematic diagram of region Q1 in the middle; Figure 6 yes Figure 2 Enlarged schematic diagram of region Q2 in the middle area; Figure 7 yes Figure 2 Enlarged schematic diagram of a gas-fired vertical shaft furnace unit; Figure 8 yes Figure 2 An enlarged schematic diagram of the area near the gas-liquid separator from the intermediate filter; Figure 9 yes Figure 2 Enlarged schematic diagram of the area near the mixer and humidifier; Figure 10 yes Figure 2 Enlarged schematic diagram of the intermediate reformer unit; Figure 11 yes Figure 10 Enlarged schematic diagram of the central region Q3; Figure 12 yes Figure 10 Enlarged schematic diagram of the central region Q4.

[0007] Explanation of reference numerals in the attached figures: Gas-based vertical shaft furnace reducing gas preparation and processing system 10; Gas-based vertical shaft furnace unit 100; Pretreatment unit 200; Common preheating unit 300; Reformer unit 400; Reaction chamber 401; Combustion chamber 402; Vaporization and mixing unit 500; Natural gas supply unit 600; Air blower unit 700; Air blower 710; Reducing gas F1; Furnace top gas A1; First furnace top gas separator A11; Second furnace top gas separator A12; First natural gas B11; Second natural gas B12; Make-up water H1; Gas-liquid mixture H2; Steam to be used H3; Reforming feedstock mixture C1; Flue gas E1; Combustion air G1; Premixed gas AB; Gas-based vertical shaft furnace 110; dust removal assembly 120; quench cooler 121; venturi tube 122; desliming device 123; dehydration assembly 130; cooling tower 131; dehydrator 132; compressor 210; hydrogenation reactor 220; mixer 230; desulfurization tower assembly 240; desulfurization adsorption tower 241; humidifier 250; cooler 260; gas-liquid separation device 270; filter 280; Flue gas induced draft unit 310; flue gas induced draft fan 311; heat exchanger 320; heat exchange tube 321; combustion air preheating section 322; makeup water preheating section 323; natural gas preheating section 324; raw material gas preheating section 325; combustion air reheating section 326; makeup water supply device 510; boiler drum device 520; water supply end 521; return supply end 522; steam supply end 523; water inlet end 524. Detailed Implementation

[0008] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0009] It should be noted that in this application, any character combination consisting of any characters x1 and x2, such as x1~x2, represents a value that is not less than x1 and not greater than x2.

[0010] Please see Figure 1 The gas-based vertical shaft furnace reducing gas preparation and processing system 10 of this application includes a gas-based vertical shaft furnace unit 100, a pretreatment unit 200, a common preheating unit 300, and a reformer unit 400.

[0011] The gas-based vertical shaft furnace unit 100 is connected to the reformer unit 400 and is used to receive the reducing gas F1 output by the reformer unit 400 and separate the furnace top gas A1 into the first furnace top gas A11 and the second furnace top gas A12.

[0012] The pretreatment unit 200 is connected to the gas-based vertical furnace unit 100 and the common preheating unit 300, respectively. It is used to desulfurize the first furnace top gas A11 and the first natural gas B11 preheated by the common preheating unit 300, and then mix it with the water vapor H3 formed after filtering out liquid water from the gas-liquid mixture H2 to form the reforming feedstock mixture C1 for preparing reducing gas F1.

[0013] The common preheating unit 300 is connected to the reformer unit 400 and is used to receive the waste heat of the flue gas E1 output by the reformer unit 400 to preheat the received combustion air G1, first natural gas B11, makeup water H1 and reforming feedstock mixture C1 in stages. Among them, the makeup water H1 forms a gas-liquid mixture H2 after preheating.

[0014] The reformer unit 400 is used to receive the preheated reforming feed gas mixture C1, the preheated combustion air G1, the second top gas A12, and the second natural gas B12, so that the combustion air G1, the second top gas A12, and the second natural gas B12 are mixed and burned to form flue gas E1, and the heat generated by the combustion heats the reforming feed gas mixture C1 to form reducing gas F1.

[0015] The above method offers at least three beneficial effects. First, it allows for the recovery of a portion of the CO2 from the first top gas separator A11 as raw material for preparing reducing gas F1. This avoids the need for complex CO2 removal equipment, simplifying the gas-based vertical shaft furnace reducing gas preparation and processing system 10, and reducing raw material consumption and CO2 emissions. Second, it allows for the recovery of waste heat from flue gas E1, enabling staged preheating of combustion air G1, first natural gas B11, makeup water H1, and reforming feedstock mixture C1. This achieves tiered energy utilization, reducing energy waste in the gas-based vertical shaft furnace reducing gas preparation and processing system 10. Third, it allows for the recovery of remaining H2 and CO from the second top gas separator A12 as fuel, reducing fuel consumption and further reducing energy waste and CO2 emissions. In summary, this application simplifies the gas-based vertical shaft furnace reducing gas preparation and processing system 10, reduces raw material consumption, and minimizes energy waste.

[0016] For example, and not limited to, the makeup water H1 can be demineralized water. This can prevent or reduce scaling in subsequent pipelines or equipment, as well as prevent or reduce blockages and ensure the purity of the steam H3 to be used, thereby improving the reforming reaction in the subsequent reformer unit 400.

[0017] Optionally, combined Figure 1 See Figures 2 to 6 As shown, the gas-based vertical shaft furnace unit 100 includes a gasification coordination unit 500, a natural gas supply unit 600, and an air blowing unit 700.

[0018] The vaporization mixing unit 500 is connected to the common preheating unit 300 and the pretreatment unit 200 respectively. It is used to provide supplementary water H1 to the common preheating unit 300, receive the gas-liquid mixture H2 returned after preheating by the supplementary water H1, and filter out the liquid water in the gas-liquid mixture H2 to form water vapor H3 to be output to the pretreatment unit 200.

[0019] The natural gas supply unit 600 is connected to the common preheating unit 300 and the reformer unit 400 respectively, and is used to separately supply the first natural gas B11 and the second natural gas B12. The first natural gas B11 is output to the common preheating unit 300, and the second natural gas B12 is output to the reformer unit 400.

[0020] The air blower unit 700 is connected to the common preheating unit 300 and is used to draw in combustion air G1 to provide combustion air G1 to be output to the common preheating unit 300.

[0021] By filtering out liquid water from the gas-liquid mixture H2 in the above manner, the service life of downstream pipelines or equipment can be improved, and the damage of liquid water to the reforming catalyst in the reformer unit 400 can be avoided.

[0022] Optionally, combined Figure 1 See Figures 2 to 4 As shown, the air blower unit 700 can draw in combustion air G1 through the air blower 710. For example, and not as a limitation, the air blower unit 700 can employ two air blowers 710 connected in parallel. One of the two air blowers 710 connected in parallel can be configured in a tooling state, and the other can be configured in a standby state.

[0023] Optionally, combined Figure 1 See Figures 2 to 3 , Figures 10 to 12 As shown, the common preheating unit 300 includes a combustion air preheating section 322, a makeup water preheating section 323, a natural gas preheating section 324, a raw material gas preheating section 325, and a combustion air reheating section 326, which are segmented and arranged in the opposite direction to the flow of flue gas E1.

[0024] The two ends of the combustion air preheating section 322 are connected to the output end of the air blower unit 700 and the input end of the combustion air reheating section 326, respectively, and are used to preheat the combustion air G1 and output it to the combustion air reheating section 326.

[0025] The two ends of the supplementary water preheating section 323 are respectively connected to the water supply end 521 and the return end 522 of the vaporization coordination unit 500. It is used to preheat the supplementary water H1 output from the water supply end 521 so that the supplementary water H1 forms a gas-liquid mixture H2 and is returned to the vaporization coordination unit 500 through the return end 522.

[0026] The two ends of the natural gas preheating section 324 are connected to the natural gas supply unit 600 and the pretreatment unit 200, respectively, and are used to preheat the first natural gas B11 and output it to the pretreatment unit 200.

[0027] The feed gas preheating section 325 is connected to the pretreatment unit 200 and the reaction chamber 401 of the reformer unit 400, respectively, and is used to preheat the reforming feed gas mixture C1 and output it to the reaction chamber 401 of the reformer unit 400.

[0028] The output end of the combustion air reheat section 326 is connected to the combustion chamber 402 of the reformer unit 400, and is used to preheat the combustion air G1 again and output it to the combustion chamber 402 of the reformer unit 400.

[0029] The combustion chamber 402 of the reformer unit 400 is also used to receive the second top gas A12 and the second natural gas B12, so that the combustion air G1, the second top gas A12 and the second natural gas B12 are mixed and burned to form flue gas E1, and the heat generated by the combustion heats the reforming raw material mixture C1 in the reaction chamber 401 to form reducing gas F1.

[0030] The above method has at least two beneficial effects. First, by utilizing the combustion air preheating section 322, makeup water preheating section 323, natural gas preheating section 324, feed gas preheating section 325, and combustion air reheating section 326 arranged in the opposite direction of flue gas E1, the waste heat of flue gas E1 can be extracted in stages to achieve tiered energy utilization, thus improving the heat recovery rate. Second, by preheating the combustion air preheating section 322, makeup water preheating section 323, natural gas preheating section 324, feed gas preheating section 325, and combustion air reheating section 326 separately, the floor space occupied by the common preheating unit 300 can be reduced.

[0031] For example, and not limited to, the combustion air preheating section 322 preheats the combustion air G1 to 200°C~250°C. The makeup water preheating section 323 preheats the makeup water H1 to 120°C~150°C. The natural gas preheating section 324 preheats the first natural gas B11 to 350°C~400°C. The feedstock gas preheating section 325 preheats the reforming feedstock mixture C1 to 500°C~600°C. The combustion air reheating section 326 preheats the combustion air G1 to 500°C~600°C.

[0032] Optionally, the above method has at least the following two beneficial effects. First, it ensures that the reforming feed gas mixture C1 within the reformer unit 400 undergoes a more efficient reforming reaction to form reducing gas F1 with a volume fraction of hydrogen and carbon monoxide of not less than 85%. Second, it enables the desulfurization treatment of the first furnace top gas A11 and the first natural gas B11 to be carried out under better operating conditions.

[0033] Optionally, combined Figure 1 See Figures 2 to 3 , Figures 10 to 12 As shown, the vaporization unit 500 includes a water supply device 510 and a boiler drum device 520. The common preheating unit 300 includes a flue gas induced draft unit 310 and a heat exchanger 320.

[0034] A makeup water supply device 510 is connected to the water inlet 524 of the boiler drum assembly 520 to provide makeup water H1 to the boiler drum assembly 520. A water supply end 521 and a return end 522 are located in the boiler drum assembly 520. The steam supply end 523 of the boiler drum assembly 520 is connected to the pretreatment unit 200 to output steam H3 to be used to the humidifier 250. The input end of the heat exchange tubes 321 of the heat exchanger 320 is connected to the combustion chamber 402 of the reformer unit 400 to receive the waste heat of the flue gas E1 output by the reformer unit 400 when the flue gas E1 flows through it. A flue gas induced draft unit 310 is connected to the output end of the heat exchange tubes 321 of the heat exchanger 320 to drive the flue gas E1 through the heat exchange tubes 321 of the heat exchanger 320. An air blower unit 700 is used to draw in combustion air G1 to provide combustion air G1 to the combustion air preheating section 322. The combustion air preheating section 322, the makeup water preheating section 323, the natural gas preheating section 324, the raw material gas preheating section 325, and the combustion air reheating section 326 are thermally connected to the heat exchange tubes 321 of the heat exchanger 320, respectively.

[0035] In the above manner, the flue gas E1 is driven by the flue gas induced draft unit 310 to flow through the heat exchange tubes 321 of the heat exchanger 320, thereby enhancing the heat exchange efficiency. It should be noted that the boiler drum unit 520 is used to recover the gas-liquid mixture H2 output from the makeup water preheating section 323 through the recovery end, and to filter out the liquid water in the gas-liquid mixture H2 to form steam H3 to be used, which is then output from the steam delivery end 523 to the pretreatment unit 200.

[0036] Optionally, the waste heat of flue gas E1 is received by the heat exchange tube 321 of heat exchanger 320, so that the waste heat of flue gas E1 drops from 1000℃~1200℃ before entering the heat exchange tube 321 to 200℃~250℃ when exiting the heat exchange tube 321.

[0037] Optionally, such as Figure 3As shown, the flue gas induced draft unit 310 can drive the flue gas E1 to flow through the heat exchange tubes 321 of the heat exchanger 320 via the flue gas induced draft fan 311. For example, and not as a limitation, the flue gas induced draft unit 310 can employ two flue gas induced draft fans 311 connected in parallel. One of the two parallel flue gas induced draft fans 311 can be configured in a working state, and the other can be configured in a standby state.

[0038] Optionally, combined Figure 1 See Figure 2 and Figure 7 , Figures 10 to 12 As shown, the gas-based vertical shaft furnace unit 100 includes a gas-based vertical shaft furnace 110, a dust removal assembly 120, and a dehydration assembly 130.

[0039] The gas-based shaft furnace 110 is connected to the reaction chamber 401 of the reformer unit 400, and is used to receive the reducing gas F1 output from the reformer unit 400 to reduce iron ore to metallic iron and output the top gas A1. The dust removal assembly 120 is connected to the gas-based shaft furnace 110, and is used to receive the top gas A1 output from the gas-based shaft furnace 110 and remove dust from the top gas A1. The dehydration assembly 130 is connected to the dust removal assembly 120, and is used to receive the top gas A1 after dust removal and dehydrate the top gas A1.

[0040] The dehydrated top gas A1 is output separately to form the first top gas A11 and the second top gas A12. The pretreatment unit 200 is connected to the dehydration assembly 130 to receive the first top gas A11. The combustion chamber 402 of the reformer unit 400 is connected to the gas-based vertical shaft furnace unit 100 and the natural gas supply unit 600 to receive the second top gas A12 and the second natural gas B12.

[0041] In this manner, the dust removal component 120 removes dust from the furnace top gas A1, and the dehydration component 130 dehydrates the dust-removed furnace top gas A1, thus ensuring the normal operation of the pretreatment unit 200. For example, it can prevent or reduce clogging of the subsequent compressor 210 and the desulfurization tower component 240.

[0042] Optionally, combined Figure 1 See Figure 2 and Figure 7 , Figures 10 to 12 As shown, the dust removal assembly 120 includes a quench cooler 121, a venturi tube 122, and a sludge remover 123.

[0043] The quench cooler 121 is connected to the gas-based vertical shaft furnace 110 and is used to receive the furnace top gas A1 output from the gas-based vertical shaft furnace 110 and reduce the temperature of the furnace top gas A1 to a first preset temperature, the difference between the first preset temperature and the dew point temperature of water being 5℃~10℃. The venturi tube 122 is connected to the quench gas and is used to receive the furnace top gas A1 reduced to the first preset temperature, allowing the furnace top gas A1 to pass through a throat and receive water mist sprayed into the throat, so that the dust in the furnace top gas A1 collides with the water particles in the water mist and is adsorbed by the water particles. The desliming unit 123 is connected to the venturi tube 122 and is used to collect the water particles adsorbed with dust. The dewatering assembly 130 is connected to the desliming unit 123 to receive the furnace top gas A1 after passing through the desliming unit 123.

[0044] In this way, the quench cooler 121 can rapidly reduce the furnace top gas A1 to near the dew point temperature, thereby avoiding or slowing down the vaporization of water particles and promoting the agglomeration of dust on the water particles. The venturi tube 122 uses water particles in the water mist to adsorb dust, resulting in high dust removal efficiency. The desliming device 123 can collect the water particles adsorbed with dust.

[0045] Optionally, combined Figure 1 See Figure 2 and Figure 7 , Figures 10 to 12 As shown, the dehydration assembly 130 includes a cooling tower 131 and a dehydrator 132.

[0046] Cooling tower 131 is connected to desliming unit 123 to receive the furnace top gas A1 after passing through desliming unit 123, and to cool the furnace top gas A1 and absorb some of the mechanical water in the furnace top gas A1. Dehydrator 132 is connected to cooling tower 131 to receive the furnace top gas A1 after being processed by cooling tower 131 and to dehydrate the furnace top gas A1.

[0047] The top gas A1 after passing through the dehydrator 132 is output separately to form the first top gas A11 and the second top gas A12. The pretreatment unit 200 is connected to the dehydrator 132 to receive the first top gas A11. The combustion chamber 402 of the reformer unit 400 is connected to the dehydrator 132 to receive the second top gas A12.

[0048] Using the above method, the combination of cooling tower 131 and dehydrating gas can effectively remove mechanical water from the furnace top gas A1. This mechanical water can be suspended water particles, mist, or condensate.

[0049] Optionally, combined Figure 1 See Figures 2 to 12 As shown, the pretreatment unit 200 includes a compressor 210, a hydrogenation reactor 220, a mixer 230, a desulfurization tower assembly 240, and a humidifier 250.

[0050] Compressor 210 is connected to dehydrator 132 for receiving and compressing the first top gas A11. Hydrogenation reactor 220 is connected to natural gas supply unit 600 for receiving first natural gas B11 and adding hydrogen to it to convert organic sulfur in the natural gas B11 into inorganic sulfur. Mixer 230 is connected to compressor 210 and hydrogenation reactor 220 to receive the first top gas A11 after passing through compressor 210 and the first natural gas B11 after passing through hydrogenation reactor 220, respectively, to form premixed gas AB. Desulfurization tower assembly 240 is connected to mixer 230 for receiving and desulfurizing premixed gas AB to remove inorganic sulfur. The humidifier 250 is connected to the desulfurization tower assembly 240, the vaporization mixing unit 500 and the common preheating unit 300 respectively. It is used to mix the premixed gas AB after desulfurization with the water vapor H3 to be used to form the reforming raw material mixed gas C1 and output it to the common preheating unit 300.

[0051] The above methods have at least the following three beneficial effects.

[0052] Firstly, the hydrogenation reactor 220 converts organic sulfur into inorganic sulfur, and the desulfurization tower ensures that the total sulfur content in the subsequently output premixed gas AB is ≤1 mg / Nm3. This protects the reforming catalyst within the reaction chamber 401 of the reformer unit 400. It should be noted that the reforming catalyst is the catalyst that catalyzes the reforming reaction of the reforming feedstock mixture C1 to generate reducing gas F1. It is described in existing technical records and will not be elaborated upon here.

[0053] Secondly, the water vapor H3 injected into the premixed gas AB by the humidifier 250 can adjust the composition of the reforming feed gas C1, so that the volume ratio of H2O to CO2 in the reforming feed gas C1 is 0.90~0.95, which can improve the quality of the reducing gas F1 generated in the reaction chamber 401 of the reformer unit 400.

[0054] Thirdly, the compressor 210 compresses the first top gas A11, which can increase the gas pressure of the first top gas A11 to 250 kPa~260 kPa, providing the pressure conditions for the reforming reaction.

[0055] Optionally, combined Figure 1 See Figures 2 to 12 As shown, the hydrogenation reactor 220 can be a cobalt-molybdenum catalytic hydrogenation reactor 220, but is not limited thereto. Optionally, the compressor 210 can be a screw compressor 210 and / or a centrifugal compressor 210.

[0056] For example, and not as a limitation, in one example, compressor 210 employs two centrifugal compressors connected in parallel. One of the two centrifugal compressors can be configured in a tooling state, and the other can be configured in a standby state.

[0057] As an example, and not a limitation, in another example, compressor 210 employs a parallel two-screw compressor. One of the parallel two-screw compressors can be configured in a tooling state, and the other can be configured in a standby state.

[0058] Optionally, combined Figure 1 See Figures 2 to 12 As shown, the desulfurization tower assembly 240 may include multiple desulfurization adsorption towers 241 connected in parallel. It should be noted that in other alternative examples, the desulfurization tower assembly 240 may also include multiple desulfurization adsorption towers 241 connected in series.

[0059] For example, and not as a limitation, the desulfurization tower assembly 240 may employ two desulfurization adsorption towers 241 connected in parallel, one of which may be configured as a working unit and the other as a standby unit.

[0060] Optionally, combined Figure 1 See Figures 2 to 12 As shown, the pretreatment unit 200 may further include a cooler 260, a gas-liquid separator 270, and a filter 280, with the filter 280, compressor 210, cooler 260, and gas-liquid separator 270 connected in sequence. The filter 280 is connected to a dehydrator 132 for receiving the first top gas separator A11 and filtering out solid particles from it. This avoids or reduces clogging of the subsequent compressor 210 and desulfurization tower assembly 240.

[0061] Thus, the cooler 260 and the gas-liquid separator 270 work together to further separate the residual mechanical water in the first furnace top gas separator A11.

[0062] Optionally, the dust removal component 120 reduces the pressure of the furnace top gas A1 from 80 kPa to 100 kPa to 65 kPa to 85 kPa, reduces the temperature of the furnace top gas A1 from 350°C to 40°C to 50°C, increases the volume fraction of CO and H2 in the furnace top gas A1 from 55% to 60% to 70% to 75%, maintains the volume ratio of CO to H2 in the furnace top gas A1 at 2.0:1 to 2.8:1, reduces the volume fraction of H2O in the furnace top gas A1 from 18% to 22% to 4% to 6%, and reduces the dust content in the furnace top gas A1 from 5 g / Nm3 to 10 g / Nm3 to 5 mg / Nm3 to 10 mg / Nm3.

[0063] Compressor 210 is used to increase the pressure of the first top gas A11 from 65 kPa to 85 kPa to 250 kPa to 260 kPa. The pressure of the steam to be used is 240 kPa to 250 kPa. The volume ratio of H2O to CO2 in the reforming feed gas mixture C1 is 0.90 to 0.95. The volume ratio of CO2 to CH4 in the reforming feed gas mixture C1 is 0.80 to 0.85. The volume fraction of the first top gas A11 from the outflow gas-based vertical shaft furnace unit 100 in the top gas A1 after exiting the dehydrator 132 is 60% to 70%. The volume fraction of the second top gas A12 from the outflow gas-based vertical shaft furnace unit 100 in the top gas A1 after exiting the dehydrated gas is 30% to 40%.

[0064] The reducing gas F1 output from reformer unit 400 contains CO and H2 at a volume fraction of 85%~90%, a CO to H2 volume ratio of 1.6~2.0, H2O at a volume fraction of 4%~6%, CH4 content ≤1%, a pressure of 200 kPa~220 kPa, and a temperature of 800℃~1000℃.

[0065] It should be noted that, through the above method, the first top gas A11 of the gas-based vertical shaft furnace unit 100 accounts for 60%~70% of the volume fraction of the top gas A1 after the dehydrator 132. The second top gas A12 of the gas-based vertical shaft furnace unit 100 accounts for 30%~40% of the volume fraction of the top gas A1 after the dehydrated gas. This balances the production of reducing gas F1 with energy consumption.

[0066] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A gas-based vertical shaft furnace reducing gas preparation and processing system, characterized in that, The gas-based vertical shaft furnace reducing gas preparation and processing system includes a gas-based vertical shaft furnace unit, a pretreatment unit, a common preheating unit, and a reforming furnace unit; The gas-based vertical furnace unit is connected to the reformer unit and is used to receive the reducing gas output from the reformer unit and separate the furnace top gas into a first furnace top gas and a second furnace top gas. The pretreatment unit is connected to the gas-based vertical furnace unit and the common preheating unit, respectively. It is used to desulfurize the first gas from the top of the furnace and the first natural gas preheated by the common preheating unit, and then mix it with the steam to be used after filtering out liquid water from the gas-liquid mixture to form a reforming feedstock mixture for preparing the reducing gas. The common preheating unit is connected to the reformer unit and is used to receive the waste heat of the flue gas output by the reformer unit to preheat the received combustion air, first natural gas, makeup water and the reforming feed gas mixture in stages; wherein, the makeup water forms the gas-liquid mixture after preheating. The reformer unit is used to receive the preheated reforming feed gas mixture, the preheated combustion air, the second top gas distributor, and the second natural gas, so that the combustion air, the second top gas distributor, and the second natural gas are mixed and burned to form the flue gas, and the heat generated by the combustion is used to heat the reforming feed gas mixture to form the reducing gas.

2. The gas-based vertical shaft furnace reducing gas preparation and processing system according to claim 1, characterized in that, The gas-based vertical furnace unit includes a vaporization coordination unit, a natural gas supply unit, and an air blowing unit; The vaporization unit is connected to the common preheating unit and the pretreatment unit respectively, and is used to provide makeup water to the common preheating unit, receive the gas-liquid mixture returned after preheating by the makeup water, and filter out the liquid water in the gas-liquid mixture to form water vapor to be output to the pretreatment unit. The natural gas supply unit is connected to the common preheating unit and the reformer unit respectively, and is used to supply the first natural gas and the second natural gas separately; the first natural gas is output to the common preheating unit, and the second natural gas is output to the reformer unit; The air blower unit is connected to the common preheating unit and is used to draw in combustion air to provide the combustion air to the common preheating unit.

3. The gas-based vertical shaft furnace reducing gas preparation and treatment system according to claim 2, characterized in that, The common preheating unit includes a combustion air preheating section, a makeup water preheating section, a natural gas preheating section, a raw material gas preheating section, and a combustion air reheating section, which are segmented and arranged in the opposite direction to the flow of the flue gas. The two ends of the combustion air preheating section are respectively connected to the output end of the air blower unit and the input end of the combustion air reheating section, and are used to preheat the combustion air and output it to the combustion air reheating section. The two ends of the supplementary water preheating section are respectively connected to the water supply end and the return end of the vaporization combination unit, and are used to preheat the supplementary water output from the water supply end so that the supplementary water forms the gas-liquid mixture and is returned to the vaporization combination unit through the return end. The two ends of the natural gas preheating section are respectively connected to the natural gas supply unit and the pretreatment unit, and are used to preheat the first natural gas and output it to the pretreatment unit; The feed gas preheating section is connected to the reaction chambers of the pretreatment unit and the reformer unit, respectively, and is used to preheat the reforming feed gas mixture and output it to the reaction chamber of the reformer unit. The output end of the combustion air reheat section is connected to the combustion chamber of the reformer unit, and is used to preheat the combustion air again and output it to the combustion chamber of the reformer unit. The combustion chamber of the reformer unit is also used to receive the second top gas and the second natural gas, so that the combustion air, the second top gas and the second natural gas are mixed and burned to form the flue gas, and the heat generated by the combustion heats the reforming feed gas mixture in the reaction chamber to form the reducing gas.

4. The gas-based vertical shaft furnace reducing gas preparation and treatment system according to claim 3, characterized in that, The combustion air preheating section preheats the combustion air to 200°C~250°C; the makeup water preheating section preheats the makeup water to 120°C~150°C; the natural gas preheating section preheats the first natural gas to 350°C~400°C; the feed gas preheating section preheats the reforming feed gas mixture to 500°C~600°C; and the combustion air reheating section preheats the combustion air to 500°C~600°C.

5. The gas-based vertical shaft furnace reducing gas preparation and treatment system according to claim 3, characterized in that, The vaporization unit includes a water supply device and a boiler drum device; the common preheating unit includes a flue gas induced draft unit and a heat exchanger. The supplementary water supply device is connected to the water inlet of the boiler drum device and is used to provide supplementary water to the boiler drum device; the water supply end and the return end are provided on the boiler drum device; The steam delivery end of the boiler drum device is connected to the pretreatment unit to output the steam to be used to the humidifier; The inlet end of the heat exchange tube of the heat exchanger is connected to the combustion chamber of the reformer unit to receive the waste heat of the flue gas output by the reformer unit when the flue gas flows through it. The flue gas induced draft unit is connected to the output end of the heat exchange tube of the heat exchanger and is used to drive the flue gas to flow through the heat exchange tube of the heat exchanger. The air blower unit is used to draw in the combustion air and provide the combustion air to the combustion air preheating section; the combustion air preheating section, the makeup water preheating section, the natural gas preheating section, the raw material gas preheating section and the combustion air reheating section are respectively thermally connected to the heat exchange tubes of the heat exchanger.

6. The gas-based vertical shaft furnace reducing gas preparation and treatment system according to claim 2, characterized in that, The gas-based vertical furnace unit includes: A gas-based vertical shaft furnace is connected to the reaction chamber of the reforming furnace unit and is used to receive the reducing gas output from the reforming furnace unit to reduce iron ore into metallic iron and output the furnace top gas. A dust removal assembly, connected to the gas-based vertical furnace, is used to receive the furnace top gas output from the gas-based vertical furnace and remove dust from the furnace top gas. And a dehydration component, connected to the dust removal component, for receiving the furnace top gas after dust removal and dehydrating the furnace top gas; The dehydrated top gas is output separately to form a first top gas distribution and a second top gas distribution; the pretreatment unit is connected to the dehydration assembly to receive the first top gas distribution. The combustion chamber of the reformer unit is connected to the gas-based vertical furnace unit and the natural gas supply unit, respectively, to receive the second top gas and the second natural gas.

7. The gas-based vertical shaft furnace reducing gas preparation and treatment system according to claim 6, characterized in that, The dust removal component includes: A quencher, connected to the gas-based vertical furnace, is used to receive the furnace top gas output from the gas-based vertical furnace and reduce the temperature of the furnace top gas to a first preset temperature, wherein the difference between the first preset temperature and the dew point temperature of water is 5℃~10℃. A venturi tube, connected to the quenching gas, is used to receive the furnace top gas that has been reduced to the first preset temperature, allowing the furnace top gas to pass through a throat and receive water mist sprayed into the throat, so that the dust in the furnace top gas collides with the water particles in the water mist and is adsorbed by the water particles. And a desliming device, connected to the venturi tube, for collecting water particles adsorbed with dust; The dewatering component is connected to the desliming device to receive the furnace top gas after it has passed through the desliming device.

8. The gas-based vertical shaft furnace reducing gas preparation and treatment system according to claim 7, characterized in that, The dehydration component includes: A cooling tower, connected to the desliming device, is used to receive the furnace top gas after passing through the desliming device, and to cool the furnace top gas and absorb some of the mechanical water in the furnace top gas. And a dehydrator, connected to the cooling tower, for receiving the furnace top gas after it has been processed by the cooling tower and for dehydrating the furnace top gas; The top gas after passing through the dehydrator is output separately to form a first top gas distribution and a second top gas distribution; the pretreatment unit is connected to the dehydrator to receive the first top gas distribution; the combustion chamber of the reformer unit is connected to the dehydrator to receive the second top gas distribution.

9. The gas-based vertical shaft furnace reducing gas preparation and treatment system according to claim 8, characterized in that, The preprocessing unit includes: A compressor, connected to the dehydrator, is used to receive the first top gas distribution and compress the first top gas distribution; A hydrogenation reactor, connected to the natural gas supply unit, is used to receive the first natural gas and add hydrogen to the first natural gas to convert organic sulfur in the first natural gas into inorganic sulfur. A mixer is connected to the compressor and the hydrogenation reactor respectively to receive the first top gas from the compressor and the first natural gas from the hydrogenation reactor to form a premixed gas. A desulfurization tower assembly, connected to the mixer, is used to receive the premixed gas and desulfurize the premixed gas; A humidifier is connected to the desulfurization tower assembly, the vaporization mixing unit, and the common preheating unit, respectively, for mixing the desulfurized premixed gas with the steam to be used to form the reforming feed gas mixture and outputting it to the common preheating unit.

10. The gas-based vertical shaft furnace reducing gas preparation and processing system according to claim 9, characterized in that, The dust removal component reduces the pressure of the gas at the top of the furnace from 80 kPa to 100 kPa to 65 kPa to 85 kPa, reduces the temperature of the gas at the top of the furnace from 350°C to 40°C to 50°C, increases the volume fraction of CO and H2 in the gas at the top of the furnace from 55% to 60% to 70% to 75%, maintains the volume ratio of CO to H2 in the gas at the top of the furnace at 2.0:1 to 2.8:1, reduces the volume fraction of H2O in the gas at the top of the furnace from 18% to 22% to 4% to 6%, and reduces the dust content in the gas at the top of the furnace from 5 g / Nm3 to 10 g / Nm3 to 5 mg / Nm3 to 10 mg / Nm3. The compressor is used to increase the pressure of the first top gas separator to 250 kPa to 260 kPa; the pressure of the steam to be used is 240 kPa to 250 kPa; the volume ratio of H2O to CO2 in the reforming feed gas mixture is 0.90 to 0.95; the volume ratio of CO2 to CH4 in the reforming feed gas mixture is 0.80 to 0.85; the volume fraction of the first top gas separator flowing out of the gas-based vertical shaft furnace unit in the top gas after flowing out of the dehydrator is 60% to 70%; the volume fraction of the second top gas separator flowing out of the gas-based vertical shaft furnace unit in the top gas after flowing out of the dehydrated gas is 30% to 40%; the volume fraction of CO and H2 in the reducing gas output from the reformer unit is not less than 85%.

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