Furnace top gas circulation shaft furnace system

Abstract

The utility model discloses a furnace top gas circulation shaft furnace system. The device at least comprises a shaft furnace (1); a furnace top gas loop (101) and a hydrogen loop (103) which are independent are arranged on the shaft furnace, a plurality of furnace top gas nozzles (102) are arranged on the furnace top gas loop (101), and a plurality of hydrogen nozzles (104) are arranged on the hydrogen loop (103); the CO-rich gas supplementing unit (3), the furnace top gas pressurizing unit (4) and the furnace top gas heating unit (5) are sequentially connected through a pipeline; an outlet of the furnace top gas heating unit (5) is communicated with the furnace top gas loop (101) through a pipeline; the hydrogen supply unit (6), the hydrogen pressurizing unit (7) and the hydrogen heating unit (8) are sequentially connected through a pipeline; and an outlet of the hydrogen heating unit (8) is communicated with the hydrogen loop (103) through a pipeline. The technological process is simple, and efficient, high-hydrogen, low-consumption and low-carbon production of the shaft furnace can be achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of furnace top gas circulation shaft furnace systems. BACKGROUND

[0002] In direct reduction iron-making process, shaft furnace iron-making is currently the mainstream process, and shaft furnace is mainly divided into Hill and MIDREX two processes. The main components of reducing gas used in the two processes are hydrogen and CO mixed gas, only the proportion of the two gases is different, but the two processes are mixed into the furnace by spraying.

[0003] Although hydrogen and CO are both reducing gases, their thermodynamic and kinetic reduction characteristics are very different, mainly in that: hydrogen reacts with iron oxide as a reducing agent is an endothermic reaction, and the higher the temperature, the stronger the reactivity, so hydrogen as a reducing agent needs a lot of heat supplement. The reaction of CO as a reducing agent and main iron oxide is an exothermic reaction, and the reactivity becomes weaker as the temperature rises. Based on the difference in characteristics of hydrogen and CO, the current shaft furnace production process mainly has the following problems: 1) hydrogen and CO mixed into the shaft furnace, due to the opposite characteristics of the two, the utilization rate of hydrogen and CO is not very high; 2) hydrogen and CO are mixed and heated to the same temperature, without developing different preheating strategies according to the reaction characteristics of hydrogen and CO; 3) without extending the reaction height of hydrogen according to the lighter characteristics of hydrogen, hydrogen and CO have the same reaction height in the shaft furnace. SUMMARY

[0004] To overcome the above-mentioned defects, the purpose of the utility model is to provide a kind of furnace top gas circulation shaft furnace system.

[0005] To achieve the above-mentioned purpose, the hydrogen direct blowing and furnace top gas circulation shaft furnace system of the utility model at least includes a shaft furnace (1); an independent furnace top gas ring (101) and a hydrogen ring (103) are arranged on the shaft furnace, a plurality of furnace top gas nozzles (102) are arranged on the furnace top gas ring (101), and a plurality of hydrogen nozzles (104) are arranged on the hydrogen ring (103);

[0006] It also includes a CO-rich gas supplement unit (3), a furnace top gas pressurizing unit (4) and a furnace top gas heating unit (5) connected in sequence by pipeline; the outlet of the furnace top gas heating unit (5) is communicated with the furnace top gas ring (101) by pipeline.

[0007] It also includes a hydrogen supply unit (6), a hydrogen pressurizing unit (7) and a hydrogen heating unit (8) connected in sequence by pipeline; the outlet of the hydrogen heating unit (8) is communicated with the hydrogen ring (103) by pipeline.

[0008] Further, the furnace top gas treatment unit is arranged on the exhaust pipe.

[0009] Further, the exhaust branch pipe is connected to the pipeline between the CO-rich gas supplement unit (3) and the furnace top gas pressurizing unit (4).

[0010] Further, the furnace top gas ring (101) is arranged above the hydrogen gas ring (103).

[0011] Further, the CO-rich gas supplement unit (3) supplements pure CO gas or CO-rich mixed gas.

[0012] Further, the hydrogen gas supply unit (6) supplies pure hydrogen gas or hydrogen-rich mixed gas.

[0013] Further, the furnace top gas treatment unit (2) comprises a cooling, dehydration, dust removal, desulfurization and CO2 removal process unit.

[0014] Further, the furnace top gas heating unit (5) adopts a medium or medium-high temperature heater, and the hydrogen gas heating unit (8) adopts a high temperature heater.

[0015] Further, the furnace top gas ring (101) and the hydrogen gas ring (103) are arranged inside the furnace shell of the shaft furnace or in the form of a surrounding pipe outside the furnace shell.

[0016] The furnace top gas nozzle (102) and the hydrogen gas nozzle (104) are independently arranged in one row or in multiple rows.

[0017] The utility model discloses a different reduction characteristic of CO and hydrogen gas, through setting up two sets of independent blowing system of entering the furnace, and setting up independent CO and hydrogen gas ring on the shaft furnace, makes CO and hydrogen gas enter the furnace at suitable parts of the shaft furnace respectively, improves the utilization efficiency of CO and hydrogen gas, and the utilization efficiency of two is improved by setting up different heating temperature of CO and hydrogen gas, reduces the investment. The utility model discloses simple process flow, and the furnace top gas generated in the process can be closed loop repeatedly used, improves the production efficiency of the shaft furnace, realizes the efficient, high hydrogen, low consumption, low carbon production of the shaft furnace. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the process flow schematic diagram of the utility model.

[0019] In the drawing: 1, shaft furnace;2, furnace top gas treatment unit;3, CO-rich gas supplement unit;4, furnace top gas pressurizing unit;

[0020] 5. Furnace top gas heating unit; 6. Hydrogen supply unit; 7. Hydrogen pressurization unit; 8. Hydrogen heating unit.

[0021] 101. Furnace top gas ring pipe; 102. Furnace top gas nozzle; 103. Hydrogen ring pipe; 104. Hydrogen nozzle. Detailed Implementation

[0022] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0023] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] like Figure 1 As shown, this embodiment of a hydrogen direct-blowing and top gas circulation vertical furnace process includes a vertical furnace (1), a top gas treatment unit (2), a CO-rich gas replenishment unit (3), a top gas pressurization unit (4), a top gas heating unit (5), a hydrogen supply unit (6), a hydrogen pressurization unit (7), a hydrogen heating unit (8), and connecting pipes, control valves, shut-off valves, and supporting testing facilities between each piece of equipment. The vertical furnace (1) is equipped with an independent top gas circulation channel (101) and a hydrogen circulation channel (103). Several top gas nozzles (102) are provided on the top gas circulation channel (101), and several hydrogen nozzles (104) are provided on the hydrogen circulation channel (103).

[0027] One of the embodiments of the present embodiment is: the top gas generated by the shaft furnace (1) is subjected to process treatment such as cooling, dehydration, dust removal, CO2 removal, etc. in the top gas treatment unit (2) to become qualified clean top gas, is subjected to CO enrichment in the CO-rich gas supplement unit (3) to supplement the consumed CO in the shaft furnace and improve the CO content in the circulating top gas, is pressurized in the top gas pressurizing unit (4) to raise the top gas to a suitable injection pressure, and is raised to medium or medium-high temperature in the top gas heating unit (5); the top gas is injected into the shaft furnace (1) through the upper top gas ring channel (101) and the top gas injection port (103) to form a closed-loop circulating injection of the top gas in the shaft furnace; the CO moves upward in the shaft furnace and reacts with the ore to release heat, the temperature of the ore rises and moves downward, and the hydrogen gas at the lower part is subjected to a reduction reaction.

[0028] The hydrogen gas supply unit (6) raises the hydrogen gas to a suitable injection pressure in the hydrogen gas pressurizing unit (7), raises the hydrogen gas to a suitable high temperature in the hydrogen gas heating unit (8), and is injected into the shaft furnace (1) to move upward and is subjected to a reduction reaction with the high-temperature ore moving downward, thereby further completely reducing the ore.

[0029] The present utility model uses the different reduction characteristics of CO and hydrogen gas, sets two independent injection systems into the shaft furnace, makes the CO and hydrogen gas enter the shaft furnace at suitable positions, improves the utilization efficiency of the CO and hydrogen gas, sets different heating temperatures of the CO and hydrogen gas to improve the utilization efficiency of the two and reduce the equipment investment. The process flow of the present utility model is simple, the top gas generated in the process flow can be recycled in a closed loop, the production efficiency of the shaft furnace is improved, and efficient, high-hydrogen, low-consumption and low-carbon production of the shaft furnace is realized.

[0030] As an improvement of the above-mentioned embodiment, the top gas ring channel (101) is located at the upper part of the hydrogen gas ring channel (103). A plurality of top gas injection ports (102) are arranged on the top gas ring channel (101), and a plurality of hydrogen gas injection ports (104) are arranged on the hydrogen gas ring channel (103).

[0031] The gas supplemented by the CO-rich gas supplement unit (3) is pure CO gas or a mixed gas rich in CO.

[0032] The gas supplied by the hydrogen gas supply unit (6) is pure hydrogen gas or a mixed gas rich in hydrogen gas.

[0033] As an improvement of the above-mentioned embodiment, the top gas treatment unit (2) can include process units such as cooling, dehydration, dust removal, CO2 removal, etc. The process units can be freely combined according to the characteristics of the top gas and the process flow of the shaft furnace, and other treatment processes such as but not limited to desulfurization can be added as needed.

[0034] The furnace top gas heating unit (5) and the hydrogen gas heating unit (8) can be heated by the heat recovered from the furnace top gas, by an independent heat source, or by a combination of the two.

[0035] The furnace top gas heating unit (5) uses a medium or medium-high temperature heater, and the hydrogen gas heating unit (8) uses a high temperature heater.

[0036] As an improvement of the above embodiment, the furnace top gas ring (101) and the hydrogen gas ring (103) can be arranged inside the furnace shell of the shaft furnace (1), or arranged in the form of a surrounding pipe outside the furnace shell of the shaft furnace (1).

[0037] As an improvement of the above embodiment, the furnace top gas nozzle (102) and the hydrogen gas nozzle (104) can be arranged in one or more rows, and the number of nozzles can be evenly distributed, and the shape of the nozzle can be set according to the process requirements.

[0038] The utility model has been described in detail in combination with the drawings, but the utility model is not limited to the above-mentioned embodiments, and various changes can be made within the knowledge range of those skilled in the art without departing from the purpose of the utility model.

[0039] In the description of the present specification, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0040] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited to this, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the utility model, which should be covered in the protection scope of the utility model. Therefore, the protection scope of the utility model should be subject to the protection scope of the claims.

Claims

1. A top gas circulation vertical furnace system, characterized in that, It includes at least a vertical furnace (1); the vertical furnace is provided with an independent furnace top gas ring channel (101) and a hydrogen ring channel (103), the furnace top gas ring channel (101) is provided with a number of furnace top gas nozzles (102), and the hydrogen ring channel (103) is provided with a number of hydrogen nozzles (104). It also includes a CO-rich gas replenishment unit (3), a furnace top gas pressurization unit (4), and a furnace top gas heating unit (5) connected in sequence by pipelines; the outlet of the furnace top gas heating unit (5) is connected to the furnace top gas loop (101) by a pipeline; It also includes a hydrogen supply unit (6), a hydrogen pressurization unit (7), and a hydrogen heating unit (8) connected in sequence by pipelines; the outlet of the hydrogen heating unit (8) is connected to the hydrogen loop (103) by a pipeline.

2. The furnace top gas circulation vertical furnace system as described in claim 1, characterized in that, It also includes a furnace top gas treatment unit; the furnace top gas treatment unit is used to treat the furnace top gas discharged from the furnace top and then discharge it through the exhaust pipe.

3. The furnace top gas circulation vertical furnace system as described in claim 2, characterized in that, The exhaust pipe is provided with an exhaust branch pipe, which is connected to the pipeline between the CO rich gas replenishment unit (3) and the furnace top gas pressurization unit (4).

4. The furnace top gas circulation vertical furnace system as described in claim 1, characterized in that, The furnace top gas ring channel (101) is located above the hydrogen ring channel (103).

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