SRV furnace gas preheating recovery device for Hismelt ironmaking process
By combining a multi-stage cyclone preheating device and a circulating fan, direct heat exchange between gas and materials in the Hismelt ironmaking process is achieved, solving the problem of low efficiency in traditional sensible heat recovery and improving the economic efficiency of the ironmaking process.
Patent Information
- Application Number
- CN202422925011.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-11-29
AI Technical Summary
In the traditional Hismelt ironmaking process, the sensible heat recovery efficiency of SRV furnace gas is low, resulting in poor economic efficiency, and the steam by-products cannot be directly used for the main process production.
A multi-stage cyclone preheating device and a circulating fan are used to achieve direct heat exchange between coal gas and materials through gas-solid two-phase flow. The circulating fan is used to stabilize the coal gas flow rate and improve the sensible heat recovery efficiency of the coal gas.
Improved sensible heat recovery efficiency, reduced gas temperature, and significantly enhanced material preheating effect improve the economics of the ironmaking process.
Smart Images
Figure CN223496510U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technology of sensible heat recovery of blast furnace gas, and in particular to a preheating and recovery device for SRV furnace gas in the Hismelt blast furnace process. Background Technology
[0002] The Hismelt ironmaking process can directly smelt iron ore powder and other suitable iron-containing raw materials, using pulverized coal as the reducing agent and heat source for the system. The core technology of the traditional Hismelt smelting reduction process is the smelting reduction furnace (SRV), which can be divided into upper and lower sections. In the high-temperature molten iron pool in the lower part of the smelting reduction furnace, carbon can be melted in the molten iron at a high temperature of 1450°C, and the carbon melted in the molten iron can then react with incandescent iron oxides; in the upper part of the smelting reduction furnace, the 1200°C hot air blown in undergoes an exothermic oxidation combustion reaction of CO and H2 with the furnace's own gas.
[0003] The CO produced in the molten iron pool, the H2 produced from the volatilization and decomposition of coal, and the N2 from the injected material carrier form a mixed gas. The strongly escaping rising gas further causes the high-temperature liquid slag and iron to form a mixed "spring." The heat energy generated by the exothermic oxidation reaction in the upper part of the molten reduction furnace increases the temperature of the slag-iron mixed "spring" through conduction and radiation. The heated slag-iron mixed "spring" falls back to the lower part of the molten iron pool, providing the necessary heat energy for the reaction. The continuous injection of ore powder, coal, and flux into the molten iron pool maintains the continuity of the reaction.
[0004] The traditional Hismelt ironmaking process utilizes SRV furnace gas sensible heat recovery technology, which recovers a portion of the sensible heat through a vaporization flue and waste heat boiler, followed by dust removal from the gas. While the vaporization flue and waste heat boiler recover a certain amount of steam, this steam is a byproduct and cannot be directly used in the main production process, resulting in poor economic efficiency. Summary of the Invention
[0005] Purpose of this utility model: The purpose of this utility model is to provide an SRV furnace gas preheating and recovery device for Hismelt ironmaking process, which can directly exchange heat between the gas and the raw materials, improve the recovery efficiency of sensible heat of SRV furnace gas, and improve economic efficiency.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A Hismelt ironmaking process SRV furnace gas preheating and recovery device is characterized by comprising an SRV furnace, an iron ore powder silo, a multi-stage cyclone preheating device, and a circulating fan. The outlet of the iron ore powder silo is connected to the material inlet of the multi-stage cyclone preheating device. The furnace top gas outlet of the SRV furnace is connected to the gas inlet of the multi-stage cyclone preheating device. The gas outlet of the multi-stage cyclone preheating device is connected to the gas user pipeline and the air inlet of the circulating fan, respectively. The air outlet of the circulating fan is connected to the gas inlet of the multi-stage cyclone preheating device.
[0008] Furthermore, the multi-stage cyclone preheating device includes a first-stage cyclone dust collector, a second-stage cyclone dust collector, a third-stage cyclone dust collector, a first mixer, a second mixer, and a third mixer. The gas inlet of the first mixer is connected to the gas outlet at the top of the SRV furnace. The material inlet of the first mixer is connected to the material outlet of the second-stage cyclone dust collector. The material outlet of the first mixer is connected to the material inlet of the first-stage cyclone dust collector. The gas outlet of the first-stage cyclone dust collector is connected to the gas inlet of the second mixer. The material inlet of the second mixer is connected to the material outlet of the third-stage cyclone dust collector. The material outlet of the second mixer is connected to the material inlet of the second-stage cyclone dust collector. The gas outlet of the second-stage cyclone dust collector is connected to the gas inlet of the third mixer. The material inlet of the third mixer is connected to the outlet of the iron ore powder silo. The material outlet of the third mixer is connected to the material inlet of the third-stage cyclone dust collector. The gas outlet of the third-stage cyclone dust collector is connected to both the gas user pipeline and the air inlet of the circulating fan. The air outlet of the circulating fan is connected to the gas inlet of the first mixer.
[0009] Furthermore, the material outlets of the first-stage cyclone dust collector, the second-stage cyclone dust collector, and the third-stage cyclone dust collector are all equipped with airlock valves.
[0010] Furthermore, pressure sensors are installed at the gas inlets of the first mixer, the second mixer, and the third mixer.
[0011] Furthermore, a gas dust removal device is installed on the connecting pipeline between the gas outlet of the third-stage cyclone dust collector and the gas user pipeline and the air inlet of the circulating fan.
[0012] Furthermore, a pressure sensor is provided at the outlet of the third-stage cyclone dust collector.
[0013] Furthermore, the iron ore powder silo is equipped with a metering device at its outlet.
[0014] Furthermore, the outlet of the iron ore powder silo is equipped with an airlock valve.
[0015] Beneficial effects: The device uses a multi-stage cyclone to enable direct heat exchange between the material and the coal gas through gas-solid two-phase flow; by setting up a circulating fan to circulate part of the coal gas, the two-phase flow operation is stabilized. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the SRV furnace gas preheating and recovery unit in the Hismelt ironmaking process.
[0017] In the diagram: 1-Iron ore powder silo; 2-Metering device; 3-Airlock valve; 4-Third mixer; 5-Pressure sensor; 6-Second-stage cyclone dust collector; 7-First mixer; 8-SRV furnace; 9-Third-stage cyclone dust collector; 10-Second mixer; 11-First-stage cyclone dust collector; 12-Gas dust removal device; 13-Valve; 14-Gas user pipeline; 15-Circulating fan. Detailed Implementation
[0018] The present invention will be further explained below with reference to the accompanying drawings.
[0019] like Figure 1 As shown, this utility model discloses an SRV furnace gas preheating and recovery device for the Hismelt ironmaking process, comprising an SRV furnace 8, an iron ore powder silo 1, a multi-stage cyclone preheating device, and a circulating fan 15. The outlet of the iron ore powder silo 1 is connected to the material inlet of the multi-stage cyclone preheating device. The furnace top gas outlet of the SRV furnace 8 is connected to the gas inlet of the multi-stage cyclone preheating device. The gas outlet of the multi-stage cyclone preheating device is connected to both a gas user pipeline 14 and the air inlet 15 of the circulating fan. The air outlet of the circulating fan 15 is connected to the gas inlet of the multi-stage cyclone preheating device. The gas user pipeline 14 is connected to a gas storage tank or a gas combustion device, and the gas user pipeline 14 is equipped with a valve 13.
[0020] In this embodiment, the multi-stage cyclone preheating device includes a first-stage cyclone dust collector 11, a second-stage cyclone dust collector 6, a third-stage cyclone dust collector 9, a first mixer 7, a second mixer 10, and a third mixer 4. The gas inlet of the first mixer 7 is connected to the gas outlet at the top of the SRV furnace 8. The material inlet of the first mixer 7 is connected to the material outlet of the second-stage cyclone dust collector 6. The material outlet of the first mixer 7 is connected to the material inlet of the first-stage cyclone dust collector 11. The gas outlet of the first-stage cyclone dust collector 11 is connected to the gas inlet of the second mixer 10. The material outlet of the second mixer 10... The inlet is connected to the material outlet of the third-stage cyclone dust collector 9, the material outlet of the second mixer 10 is connected to the material inlet of the second-stage cyclone dust collector 6, the gas outlet of the second-stage cyclone dust collector 6 is connected to the gas inlet of the third mixer 10, the material inlet of the third mixer 10 is connected to the outlet of the iron ore powder silo 1, the material outlet of the third mixer 10 is connected to the material inlet of the third-stage cyclone dust collector 9, the gas outlet of the third-stage cyclone dust collector 9 is connected to the gas user pipeline 14 and the air inlet of the circulating fan 15 respectively, and the air outlet of the circulating fan 15 is connected to the gas inlet of the first mixer 7.
[0021] To maintain a certain air pressure in the conveying pipeline and prevent gas or dust leakage, the material outlets of the first-stage cyclone dust collector 11, the second-stage cyclone dust collector 6, and the third-stage cyclone dust collector 9 are all equipped with airlock valves 3.
[0022] To improve the accuracy of material supply from the iron ore powder silo 1, a metering device is installed at the outlet of the iron ore powder silo 1. At the same time, to prevent gas or dust leakage, an airlock valve is also installed at the outlet of the iron ore powder silo 1.
[0023] To filter out dust contained in the gas after heat exchange, a gas dust removal device 12 is installed on the connecting pipeline between the gas outlet of the third-stage cyclone dust collector 9 and the gas user pipeline 14 and the air inlet of the circulating fan 15. A pressure sensor 5 is installed at the outlet of the third-stage cyclone dust collector 9.
[0024] The materials (iron ore powder and dolomite powder) stored in the iron ore powder silo 1 pass through the metering device 2 and the airlock valve 3, and then enter the third mixer 4 before the third-stage cyclone dust collector 9. This process thoroughly mixes the gas and materials into a gas-solid two-phase flow. After entering the third-stage cyclone dust collector 9, most of the material is collected and discharged from the material outlet at the bottom of the third-stage cyclone dust collector 9. The discharged material then passes through the second mixer 10 and is thoroughly mixed with the gas entering the second-stage cyclone dust collector 6. After entering the second-stage cyclone dust collector 6, most of the material is collected and discharged from the material outlet at the bottom of the second-stage cyclone dust collector 6. The discharged material is thoroughly mixed with the gas exiting the top gas outlet of the SRV furnace 8 and entering the first-stage cyclone dust collector 11 through the first mixer 7. After entering the first-stage cyclone dust collector 11 with the gas, most of the material is collected and discharged from the material outlet at the bottom of the first-stage cyclone dust collector. During the process of the material sequentially passing through the third-stage cyclone dust collector 9, the second-stage cyclone dust collector 6, and the first-stage cyclone dust collector 11, in a gas-solid two-phase flow state, the material and gas undergo sufficient countercurrent heat exchange, resulting in a decrease in gas temperature and an increase in mineral powder temperature. The preheated material is supplied to other processes. The gas temperature exiting the third-stage cyclone dust collector is reduced by approximately 150℃ to 200℃, and then enters the gas dust removal device 12 to filter dust from the gas. The clean gas passes through valve 13 to the gas user pipeline 14, where it is stored in a gas storage cabinet or used by a gas combustion device.
[0025] Gas-solid two-phase flow has certain requirements for the stability of the gas flow rate. If the gas-solid ratio is too high or the gas velocity is too low, material may settle in the pipeline, disrupting the effective formation of the gas-solid two-phase flow. The gas generation in SRV furnace 8 is not very stable. In order to ensure the stable and reliable formation of the two-phase flow and improve the stability of the gas-solid two-phase flow in the system, a portion of the gas filtered by the gas dust collector 12 is pressurized by the circulating fan 15 and recirculated to the gas inlet of the first mixer 7 to mix with the top gas of SRV furnace 8. The gas-solid mixing effect of the three cyclone dust collectors is judged by the pressure sensors 5 installed at the inlets of the first mixer 7, the second mixer 10, and the third mixer 4, as well as the outlet of the third-stage cyclone dust collector, thereby adjusting the gas flow rate recirculated back through the circulating fan 15 and improving the operational stability of the system.
[0026] The SRV furnace 9 produces gas continuously. By adjusting the opening of valve 13, the pressure of the gas at the top of the SRV reduction furnace can be controlled at 60-80 kPa to coordinate the production of the SRV furnace 9. Under the pressure at the top of the SRV furnace 9, the gas passes through a three-stage cyclone dust collector, a gas dust removal system, and valve 13, and is then stored in a gas storage device or supplied to the gas combustion device.
[0027] This preheating and recovery system allows the material to exchange heat with hot coal gas at nearly 1200°C from the top of the SRV furnace, preheating the material from ambient temperature to 600-700°C for use in other processes. The coal gas temperature is reduced from 1200°C to 150-200°C (before the coal gas dust removal device is installed), so that most of the sensible heat of the coal gas is recovered.
[0028] This system can adjust the contact time between the material and the gas by increasing or decreasing the number of cyclone dust collector stages according to the actual situation, so that the temperature of the gas is reduced to a suitable temperature before entering the gas dust removal system.
[0029] In order to ensure that the material mixes stably and reliably with the gas in this system and that the gas-solid two-phase flow is stable, the particle size of the material needs to be adjusted to ≤3mm.
[0030] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. A preheating and recovery device for SRV furnace gas in the Hismelt ironmaking process, characterized in that: It includes an SRV furnace, an iron ore powder silo, a multi-stage cyclone preheating device, and a circulating fan. The outlet of the iron ore powder silo is connected to the material inlet of the multi-stage cyclone preheating device. The gas outlet at the top of the SRV furnace is connected to the gas inlet of the multi-stage cyclone preheating device. The gas outlet of the multi-stage cyclone preheating device is connected to the gas user pipeline and the air inlet of the circulating fan, respectively. The air outlet of the circulating fan is connected to the gas inlet of the multi-stage cyclone preheating device.
2. The SRV furnace gas preheating and recovery device for the Hismelt ironmaking process according to claim 1, characterized in that: The multi-stage cyclone preheating device includes a first-stage cyclone dust collector, a second-stage cyclone dust collector, a third-stage cyclone dust collector, a first mixer, a second mixer, and a third mixer. The gas inlet of the first mixer is connected to the gas outlet at the top of the SRV furnace. The material inlet of the first mixer is connected to the material outlet of the second-stage cyclone dust collector. The material outlet of the first mixer is connected to the material inlet of the first-stage cyclone dust collector. The gas outlet of the first-stage cyclone dust collector is connected to the gas inlet of the second mixer. The material inlet of the second mixer is connected to the material outlet of the third-stage cyclone dust collector. The material outlet of the second mixer is connected to the material inlet of the second-stage cyclone dust collector. The gas outlet of the second-stage cyclone dust collector is connected to the gas inlet of the third mixer. The material inlet of the third mixer is connected to the outlet of the iron ore powder silo. The material outlet of the third mixer is connected to the material inlet of the third-stage cyclone dust collector. The gas outlet of the third-stage cyclone dust collector is connected to both the gas user pipeline and the air inlet of the circulating fan. The air outlet of the circulating fan is connected to the gas inlet of the first mixer.
3. The SRV furnace gas preheating and recovery device for the Hismelt ironmaking process according to claim 2, characterized in that: The material outlets of the first-stage cyclone dust collector, the second-stage cyclone dust collector, and the third-stage cyclone dust collector are all equipped with airlock valves.
4. The SRV furnace gas preheating and recovery device for the Hismelt ironmaking process according to claim 2, characterized in that: Pressure sensors are installed at the gas inlets of the first mixer, the second mixer, and the third mixer.
5. The SRV furnace gas preheating and recovery device for the Hismelt ironmaking process according to claim 2, characterized in that: A gas dust removal device is installed on the connecting pipeline between the gas outlet of the third-stage cyclone dust collector and the gas user pipeline and the air inlet of the circulating fan.
6. The SRV furnace gas preheating and recovery device for the Hismelt ironmaking process according to claim 5, characterized in that: The outlet of the third-stage cyclone dust collector is equipped with a pressure sensor.
7. The SRV furnace gas preheating and recovery device for the Hismelt ironmaking process according to claim 1, characterized in that: The iron ore powder silo is equipped with a metering device at its discharge port.
8. The SRV furnace gas preheating and recovery device for the Hismelt ironmaking process according to claim 1, characterized in that: The iron ore powder silo is equipped with an airlock valve at its discharge port.