Transfer system and method for hot delivery of oxidized pellets for direct reduction to hydrogen-based shaft furnace
By adopting a ring cooler and a heat transfer system designed with insulation design in hydrogen-based vertical furnace production, the problem of heat loss of high-temperature oxidized pellets is solved, the thermal efficiency is improved, and the energy-saving and carbon reduction goal of hydrogen-based vertical furnace production is achieved.
Patent Information
- Application Number
- CN202411575930.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-06
- Publication Date
- 2025-01-03
AI Technical Summary
During the hydrogen-based vertical furnace production process, most of the heat of high-temperature oxidized pellets is converted into low-value hot water or steam during the transmission process, resulting in a reduced thermal efficiency. It is necessary to develop an effective heat delivery system to prevent heat loss.
Adopt a transport system including ring cooler, hot-loading transport vehicle, hydrogen-based vertical furnace buffer tank and vertical lifting device. Through a two-stage medium and high-temperature ring cooler and insulation design, efficient thermal transport of oxidized pellets is achieved to ensure heat and return directly to the main process of steel metallurgy.
It improves the waste heat utilization efficiency of oxidized pellets, reduces the consumption of external heat sources by hydrogen-based vertical furnaces, achieves the energy-saving and carbon reduction goals in the steel production process, and achieves environmentally friendly and efficient production conditions.
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Figure CN119242879A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a heat transfer system and method, in particular to a transfer system and method for heat transfer of oxidized pellets for direct reduction to a hydrogen-based vertical furnace. Background Art
[0002] Hydrogen metallurgy, which replaces carbon with hydrogen, has become one of the effective ways for steel companies to optimize their energy structure and process flow and achieve green, low-carbon and sustainable development. From "replacing coke with coal and coke with gas" to "replacing carbon with hydrogen and reducing carbon with hydrogen", the iron ore smelting process has changed from reducing the dependence on coke and coking coal to focusing on reducing carbon emissions, and then to the ultimate goal of near-zero carbon emissions, gradually forming the current direct reduction iron production technology route with hydrogen-based vertical furnaces as the core. From the perspective of the future development of the steel industry and the transformation of the energy structure, the full hydrogen direct reduction process is an important route to achieve near-zero carbon emissions in the steel industry.
[0003] At present, the oxidized pellets for hydrogen-based vertical furnace production are produced by the chain grate-rotary kiln method, the vertical furnace method, or the belt roaster method. They are all cooled to room temperature by air cooling, stored in silos, and then loaded into the top of the vertical furnace through conveyor belts and raw material lifting devices. In this way, most of the high-value heat contained in the high-temperature oxidized pellets (generally at a temperature of 900℃ to 1100℃) that come out of the furnace is converted into low-value hot water, steam or environmental heat, resulting in a decrease in the thermal efficiency of the pelletizing process. Therefore, it is very necessary to develop a transfer system and method for directly reducing oxidized pellets to the hydrogen-based vertical furnace. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide a transfer system for directly reducing oxidized pellets to a hydrogen-based vertical furnace, which can effectively prevent the heat loss of high-temperature oxidized pellets; the present invention also provides a transfer method for directly reducing oxidized pellets to a hydrogen-based vertical furnace.
[0005] In order to solve the above technical problems, the technical solution adopted by the system of the present invention is: it includes a ring cooler, a hot charging transport vehicle, a hydrogen-based vertical furnace buffer bin, a quantitative feeding belt conveyor and a vertical lifting device; the ring cooler is connected to the hydrogen-based vertical furnace buffer bin through the hot charging transport vehicle, the hydrogen-based vertical furnace buffer bin is connected to the vertical lifting device through the quantitative feeding belt conveyor, and the vertical lifting device is connected to the pellet entrance of the hydrogen-based vertical furnace; the ring cooler is a two-stage medium and high temperature ring cooler, including a ring cooling buffer bin and a normal unloading chute, and the ring cooling buffer bin and the normal unloading chute are both provided with insulation; the hot charging transport vehicle is provided with a silo, and the silo is provided with insulation; the hydrogen-based vertical furnace buffer bin is provided with insulation; the quantitative feeding belt conveyor is provided with a sealed insulation cover.
[0006] Furthermore, the inner layer of the silo of the annular cooling buffer silo is made of wear-resistant surfacing material, and the outer layer of the silo is made of thermal insulation material; the normal unloading chute is provided with an insulation cover.
[0007] Furthermore, the silo includes a silo body and a sealed silo cover, the silo body is provided with an inner lining; the inner layer of the inner lining is an impact-resistant wear-resistant surfacing material, and the outer layer of the inner lining is a thermal insulation material; the silo cover seals the inward part of the silo cover and is provided with thermal insulation material.
[0008] Furthermore, the hydrogen-based vertical furnace buffer bin is provided with an inner lining; the inner layer of the inner lining is an impact-resistant wear-resistant surfacing material, and the outer layer is a thermal insulation material.
[0009] In order to solve the above technical problems, the method of the present invention adopts the above transfer system, and the technical solution adopted includes the following steps: 1) the high-temperature oxidized pellets enter the annular cooler, and are sent to the silo of the hot-loading transport vehicle through the annular cooling buffer bin and the normal unloading chute; 2) The hot-charged transport vehicle delivers the oxidized pellets in the silo to the hydrogen-based vertical furnace buffer silo; 3) The hydrogen-based vertical furnace buffer bin delivers the oxidized pellets to the vertical lifting device through a quantitative feeding belt conveyor; 4) The vertical lifting device delivers the oxidized pellets into the hydrogen-based vertical furnace.
[0010] Furthermore, in step 1), the temperature of the high-temperature oxidized pellets entering the ring cooler is 900°C to 1100°C, and the temperature of the oxidized pellets entering the ring cooling buffer bin is 400°C to 600°C.
[0011] Furthermore, in step 3), the discharge temperature of the hydrogen-based vertical furnace buffer bin is 200°C to 400°C.
[0012] Furthermore, in step 4), the temperature of the oxidized pellets entering the hydrogen-based vertical furnace is 100°C to 400°C.
[0013] The beneficial effects of the above technical solution are: the system and method of the present invention adopts a two-stage medium-high temperature ring cooler, and insulates each device for hot delivery, so as to realize hot loading and hot delivery of oxidized pellets under hot conditions, and the temperature of the hot pellets entering the hydrogen-based vertical furnace is between 100°C and 400°C. In order to prevent the heat loss of high-temperature oxidized pellets, the system and method of the present invention directly returns as much waste heat contained in the hot oxidized pellets as possible to the main process of iron and steel metallurgy, improves the waste heat utilization efficiency of oxidized pellets, and reduces the additional heat energy supplement required for the hydrogen-based vertical furnace, so as to further achieve energy conservation and carbon reduction in the direct reduction iron production process, and achieve environmental protection and high efficiency goals; it can realize the continuous operation of pellet ore-hydrogen-based vertical furnace production, realize the recovery and utilization of heat in the medium and low temperature section of the ring cooling of pellet production, and reduce the consumption of external heat sources by the hydrogen-based vertical furnace. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0015] Figure 1 It is a schematic diagram of the structure of the system of the present invention.
[0016] In the figure: 1-cooling stage 1 of the annular cooler; 2-cooling stage 2 of the annular cooler; 3-annular cooler buffer bin; 4-accident discharge control valve; 5-accident discharge chute; 6-normal discharge chute; 7-hot charging transport vehicle; 8-hydrogen-based vertical furnace buffer bin; 9-adjusting gate; 10-quantitative feeding belt conveyor; 11-high temperature resistant hot conveying belt; 12-reciprocating hopper; 13-vertical lifting device. DETAILED DESCRIPTION
[0017] Figure 1 As shown, the transfer system for hot delivery of oxidized pellets for direct reduction to a hydrogen-based vertical furnace comprises a ring cooler, a hot-charging transport vehicle 7, a hydrogen-based vertical furnace buffer bin 8, a quantitative feeding belt conveyor 10 and a vertical lifting device 13; the ring cooler is connected to the hydrogen-based vertical furnace buffer bin 8 through the hot-charging transport vehicle 7, the hydrogen-based vertical furnace buffer bin 8 is connected to the vertical lifting device 13 through the quantitative feeding belt conveyor 10, and the vertical lifting device 13 is connected to the pellet inlet of the hydrogen-based vertical furnace.
[0018] Figure 1 As shown, the transfer system of the direct reduction oxidized pellets hot to the hydrogen-based vertical furnace, the annular cooler is a two-stage medium-high temperature annular cooler, which reduces the low temperature section compared with the traditional three-stage annular cooler, including annular cooler cooling section 1, annular cooler cooling section 2, annular cooling buffer bin 3 and normal unloading chute 6. The upper part of the annular cooler cooling section 1 is provided with a receiving opening for receiving the high-temperature roasted pellets after roasting; the lower part of the annular cooler cooling section 1 is provided with a blast-type air-blowing cooling device, and the upper part is provided with an annular cooling high-temperature gas collection hood. The annular cooler cooling section 2 receives the high-temperature pellets from section 1; the lower part of the annular cooler cooling section 2 is provided with a blast-type air-blowing cooling device, and the upper part is provided with an annular cooling high-temperature gas collection hood. The end of the cooling section 2 of the annular cooler is equipped with an annular cooling unloading chute system; the annular cooling unloading chute system includes an annular cooling buffer bin 3 and an unloading chute; the annular cooling buffer bin 3 receives hot pellets from the cooling section 2 of the annular cooler; the unloading chute includes an emergency unloading chute 5 and a normal unloading chute 6, the emergency unloading chute 5 is provided with an emergency unloading control valve 4, and the normal unloading chute 6 is provided with a normal unloading control valve. The annular cooling buffer bin 3 is provided with insulation, and the insulation structure is: the inner layer of the bin body of the annular cooling buffer bin 3 is wear-resistant surfacing material, and the outer layer of the bin body is thermal insulation material. The normal unloading chute 6 is provided with insulation, and the insulation structure is: the normal unloading chute 6 is provided with an insulation cover.
[0019] Figure 1As shown, the transfer system of the oxidized pellets for direct reduction is hot transported to the hydrogen-based vertical furnace. The hot-loading transport vehicle 7 is provided with a silo, which includes a silo body and a sealed silo cover. The silo is provided with insulation, and the insulation structure is: the silo body is provided with an inner lining; the inner layer of the inner lining is an impact-resistant wear-resistant surfacing material, and the outer layer of the inner lining is a thermal insulation material; the silo cover seals the inward part of the silo cover and is provided with thermal insulation material.
[0020] Figure 1 As shown, the transfer system of the oxidized pellets for direct reduction is hot transported to the hydrogen-based vertical furnace. The outlet of the hydrogen-based vertical furnace buffer bin 8 is provided with an adjusting gate 9 to control the discharge flow; the hydrogen-based vertical furnace buffer bin 8 is provided with insulation, and the insulation structure is: the hydrogen-based vertical furnace buffer bin 8 is provided with a lining; the inner layer of the lining is an impact-resistant wear-resistant surfacing material, and the outer layer is a thermal insulation material, and the top sealing cover is provided with a thermal insulation lining; the circular cylinder of this buffer bin is made of Q235B-Q345B / C / D / E steel plate, etc.
[0021] Figure 1 As shown, the transfer system of the direct reduction oxidized pellets is hot transported to the hydrogen-based vertical furnace. The quantitative feeding belt conveyor 10 is a variable frequency speed regulating quantitative feeding belt conveyor. The heat-resistant conveying belt 11 of the quantitative feeding belt conveyor 10 can withstand temperatures of 600°C and below; the quantitative feeding belt conveyor 10 is provided with a sealed heat-insulating cover.
[0022] Figure 1 As shown, the transfer system of the direct reduction oxidized pellets is hot transported to the hydrogen-based vertical furnace, and the vertical lifting device 13 is provided with a reciprocating hopper 12, and the heat-resistant temperature of the reciprocating hopper 12 can reach 500°C.
[0023] Figure 1 As shown, the method for transferring the oxidized pellets for direct reduction to the hydrogen-based vertical furnace is as follows. The components of the transferred high-temperature oxidized pellets are iron-containing raw materials and auxiliary materials such as iron ore powder, composite binder, dust ash and return ore. After the components are mixed, water is added to the disc pelletizer to make balls. The balls are sieved to select qualified balls with a particle size of 8mm to 16mm. The qualified balls are preheated and then enter the roasting kiln to be roasted and oxidized at a temperature of 1250±20℃ to produce finished oxidized pellets. The mass ratio of the iron ore powder, composite binder, dust ash and return ore is 92:1.2:5:1.8. The finished oxidized pellets are transferred using the following steps: 1) The high-temperature oxidized pellets at 900℃~1100℃ are discharged into the ring cooler through the inclined chute, and are cooled to 400℃~600℃ through two-stage high-temperature blast cooling of the ring cooler cooling stage 1 and the ring cooler cooling stage 2, and then enter the ring cooling buffer bin 3; and then sent to the silo of the hot loading transport vehicle 7 through the normal unloading chute 6; if there is a production abnormality in the next process of the ring cooling buffer bin 3, the oxidized pellets can be discharged through the emergency unloading chute 5 and the emergency unloading control valve 4 for separate stacking treatment; 2) The hot-loading transport vehicle 7 delivers the oxidized pellets in the silo to the hydrogen-based vertical furnace buffer silo 8; 3) The discharge temperature of the hydrogen-based vertical furnace buffer bin 8 is 200°C to 400°C, and the oxidized pellets are fed into the vertical lifting device 13 through the quantitative feeding belt conveyor 10; 4) The vertical lifting device 13 delivers the oxidized pellets into the hydrogen-based vertical furnace. The temperature of the oxidized pellets entering the hydrogen-based vertical furnace is 100°C to 400°C. The hot oxidized pellets enter the hydrogen-based vertical furnace and react with the reducing gas rising from the lower part of the hydrogen-based vertical furnace, which can further reduce the consumption of the external heating furnace gas.
Claims
1. A transfer system for hot delivery of oxidation pellets for direct reduction to a hydrogen-based shaft furnace, characterized in that: The invention comprises a ring cooler, a hot-charging transport vehicle (7), a hydrogen-based vertical furnace buffer bin (8), a quantitative feeding belt conveyor (10) and a vertical lifting device (13); the ring cooler is connected to the hydrogen-based vertical furnace buffer bin (8) via the hot-charging transport vehicle (7); the hydrogen-based vertical furnace buffer bin (8) is connected to the vertical lifting device (13) via the quantitative feeding belt conveyor (10); the vertical lifting device (13) is connected to the pellet inlet of the hydrogen-based vertical furnace; the ring cooler is a two-stage medium-high temperature ring cooler, comprising a ring cooling buffer bin (3) and a normal unloading chute (6); both the ring cooling buffer bin (3) and the normal unloading chute (6) are provided with thermal insulation; the hot-charging transport vehicle (7) is provided with a silo, and the silo is provided with thermal insulation; the hydrogen-based vertical furnace buffer bin (8) is provided with thermal insulation; the quantitative feeding belt conveyor (10) is provided with a sealed thermal insulation cover.
2. The system for transferring oxidized pellets for direct reduction to a hydrogen-based shaft furnace according to claim 1, characterized in that: The inner layer of the annular cooling buffer bin (3) is made of wear-resistant cladding material, and the outer layer of the bin is made of thermal insulation material; the normal unloading chute (6) is provided with a thermal insulation cover.
3. The system for transferring oxidized pellets for direct reduction to a hydrogen-based shaft furnace according to claim 1, characterized in that: The silo includes a silo body and a sealed silo cover, the silo body is provided with an inner lining; the inner layer of the inner lining is an impact-resistant wear-resistant surfacing material, and the outer layer of the inner lining is a thermal insulation material; the silo cover seals the silo cover, and the inner part thereof is provided with a thermal insulation material.
4. The system for transferring oxidized pellets for direct reduction to a hydrogen-based shaft furnace according to claim 1, 2 or 3, characterized in that: The hydrogen-based vertical furnace buffer bin (8) is provided with an inner lining; the inner layer of the inner lining is an impact-resistant wear-resistant surfacing material, and the outer layer is a thermal insulation material.
5. A method for transferring oxidation pellets for direct reduction to a hydrogen-based shaft furnace using a transfer system according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: 1) high temperature oxidized pellets enter a ring cooler and are sent to a silo of a hot loading transport vehicle (7) via a ring cooling buffer bin (3) and a normal unloading chute (6); 2) The hot-loading transport vehicle (7) transports the oxidized pellets in the silo into the hydrogen-based vertical furnace buffer silo (8); 3) The hydrogen-based vertical furnace buffer bin (8) delivers the oxidized pellets to the vertical lifting device (13) via a quantitative feeding belt conveyor (10); 4) The vertical lifting device (13) delivers the oxidized pellets into the hydrogen-based vertical furnace.
6. The method for transferring oxidized pellets for direct reduction to a hydrogen-based shaft furnace according to claim 5, characterized in that: In the step 1), the temperature of the high-temperature oxidized pellets entering the ring cooler is 900°C to 1100°C, and the temperature of the oxidized pellets entering the ring cooling buffer bin (3) is 400°C to 600°C.
7. The method for transferring oxidized pellets for direct reduction to a hydrogen-based shaft furnace according to claim 5, characterized in that: In the step 3), the discharge temperature of the hydrogen-based vertical furnace buffer bin (8) is 200° C. to 400° C.
8. The method for transferring oxidized pellets for direct reduction to a hydrogen-based shaft furnace according to claim 5, 6 or 7, characterized in that: In the step 4), the temperature of the oxidized pellets entering the hydrogen-based vertical furnace is 100°C to 400°C.