Hydrogen direct blowing and top gas circulating shaft furnace system and process

Abstract

The invention discloses a hydrogen direct blowing and top gas circulation shaft furnace system and process. 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 invention relates to a vertical furnace system and process for direct hydrogen blowing and top gas circulation. Background Art

[0002] In the direct reduction ironmaking process, vertical furnace ironmaking is currently the mainstream process, and the vertical furnace is mainly divided into two major processes: Hill and MIDREX. The main components of the reducing gas used in these two processes are a mixture of hydrogen and CO, but the proportions of the two gases are different. However, both processes spray the mixture of the two gases into the furnace.

[0003] Although both hydrogen and CO are reducing gases, their thermodynamic and kinetic reduction characteristics are very different, mainly manifested in: the reaction of hydrogen as a reducing agent and iron oxide is an endothermic reaction, and the higher the temperature, the stronger the reactivity, so hydrogen as a reducing agent requires a large amount of heat supplement; CO as a reducing agent and the main iron oxide reaction is an exothermic reaction, and the reactivity weakens as the temperature rises. Based on the different characteristics of hydrogen and CO, the current vertical furnace production process has the following main problems: 1) Hydrogen and CO are mixed into the vertical furnace, and due to their opposite characteristics, the utilization rate of hydrogen and CO is not very high; 2) Hydrogen and CO are mixed and heated to the same temperature, and different preheating strategies are not formulated according to the reaction characteristics of hydrogen and CO; 3) The hydrogen reaction height is not extended based on the lighter nature of hydrogen, and hydrogen and CO have the same reaction height in the vertical furnace. Summary of the invention

[0004] In order to overcome the above-mentioned defects, the object of the present invention is to provide a vertical furnace system and process with hydrogen direct blowing and top gas circulation.

[0005] To achieve the above-mentioned object, the present invention provides a hydrogen direct blowing and top gas circulation vertical furnace system, which comprises at least a vertical furnace (1); an independent top gas ring channel (101) and a hydrogen ring channel (103) are arranged on the vertical furnace; a plurality of top gas nozzles (102) are arranged on the top gas ring channel (101); and a plurality of hydrogen nozzles (104) are arranged on the hydrogen ring channel (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) which are sequentially connected via pipelines; the outlet of the furnace top gas heating unit (5) is connected to the furnace top gas ring channel (101) via a pipeline;

[0007] It also includes a hydrogen supply unit (6), a hydrogen pressurizing unit (7), and a hydrogen heating unit (8) which are connected in sequence through pipelines; the outlet of the hydrogen heating unit (8) is connected to the hydrogen ring channel (103) through a pipeline.

[0008] Furthermore, it also includes a furnace top gas processing unit; the furnace top gas processing unit is used to process the furnace top gas discharged from the furnace top and then discharge it through the exhaust pipe.

[0009] Furthermore, an exhaust branch pipe is provided on the exhaust pipe, and 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] Furthermore, the furnace top gas ring channel (101) is located above the hydrogen ring channel (103).

[0011] Furthermore, the gas supplemented by the CO-rich gas supplementation unit (3) is pure CO gas or a mixed gas rich in CO.

[0012] Furthermore, the gas supplied by the hydrogen supply unit (6) is pure hydrogen or a mixed gas rich in hydrogen.

[0013] Furthermore, the furnace top gas processing unit (2) includes cooling, dehydration, dust removal, desulfurization, and CO2 removal process units.

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

[0015] Furthermore, the furnace top gas ring channel (101) and the hydrogen ring channel (103) are arranged inside the furnace shell of the vertical furnace or outside the furnace shell in the form of surrounding pipes;

[0016] Furthermore, the gas treated by the top gas treatment unit (2) may be partially or completely mixed with the hydrogen-rich gas from the hydrogen supply unit (6) to form a mixed gas which is sprayed into the vertical furnace (1);

[0017] The furnace top gas nozzles (102) and hydrogen nozzles (104) are independently arranged in an upper and lower row, or arranged in multiple rows in the upper and lower rows, and the number of nozzles is evenly distributed.

[0018] To achieve the above-mentioned object, the present invention provides a hydrogen direct blowing and top gas circulation vertical furnace process, wherein the hydrogen direct blowing and top gas circulation vertical furnace system comprises a vertical furnace (1), a top gas processing unit (2), a CO-rich gas supplement unit (3), a top gas pressurizing unit (4), a top gas heating unit (5), a hydrogen supply unit (6), a hydrogen pressurizing unit (7), and a hydrogen heating unit (8); the process comprises:

[0019] 1) The top gas generated by the vertical furnace (1) is treated by a top gas treatment unit;

[0020] The treated furnace top gas is output to the furnace top gas pressurizing unit together with the CO-rich gas supplement unit (3);

[0021] After the pressure is applied, the top gas is raised to a suitable injection temperature by a top gas heating unit;

[0022] The gas is injected from the furnace top gas ring channel into the vertical furnace (1), forming a circulation injection of the vertical furnace top gas;

[0023] 2) The hydrogen supply unit outputs to the hydrogen pressurizing unit;

[0024] The pressurized hydrogen is raised to a suitable injection temperature through a hydrogen heating unit (8) and then injected into the vertical furnace (1) from a hydrogen ring channel (103).

[0025] The present invention utilizes the different reduction characteristics of CO and hydrogen, and sets two independent furnace injection systems, and sets independent CO and hydrogen loops on the vertical furnace, so that CO and hydrogen enter the furnace at appropriate positions of the vertical furnace, respectively, to improve the utilization efficiency of CO and hydrogen, and to improve the utilization efficiency of both and reduce investment by setting different heating temperatures of CO and hydrogen. The process flow of the present invention is simple, and the top gas generated in the process can be closed-loop reused, thereby improving the production efficiency of the vertical furnace and realizing high-efficiency, high-hydrogen, low-consumption, and low-carbon production in the vertical furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the process flow of the present invention.

[0027] In the figure: 1. Vertical furnace; 2. Top gas treatment unit; 3. CO-rich gas supplement unit; 4. Top gas pressurization unit;

[0028] 5. Furnace top gas heating unit; 6. Hydrogen supply unit; 7. Hydrogen pressurizing unit; 8. Hydrogen heating unit.

[0029] 101. Furnace top gas ring pipe; 102. Furnace top gas nozzle; 103. Hydrogen gas ring pipe; 104. Hydrogen gas nozzle. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0032] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] like Figure 1 As shown, a hydrogen direct blowing and top gas circulation vertical furnace process of this embodiment comprises a vertical furnace (1), a top gas processing unit (2), a CO-rich gas supplement unit (3), a top gas pressurizing unit (4), a top gas heating unit (5), a hydrogen supply unit (6), a hydrogen pressurizing unit (7), a hydrogen heating unit (8), and connecting pipelines, control valves, cut-off valves, and matching detection facilities between various devices. The vertical furnace (1) is provided with an independent top gas ring channel (101) and a hydrogen ring channel (103), a plurality of top gas nozzles (102) are provided on the top gas ring channel (101), and a plurality of hydrogen nozzles (104) are provided on the hydrogen ring channel (103).

[0035] The implementation method of one of the embodiments is as follows: the top gas generated by the vertical furnace (1) → the top gas treatment unit (2) performs cooling, dehydration, dust removal, CO2 removal and other process treatments to become qualified clean top gas → the CO-enriched gas replenishment unit (3) performs CO enrichment to replenish the CO consumed in the vertical furnace and increase the CO content in the circulating top gas → the top gas pressurizing unit (4) pressurizes the top gas to raise the top gas to a suitable injection pressure → the top gas heating unit (5) raises the top gas to a medium or medium-high temperature → injects into the vertical furnace (1) through the upper top gas ring channel (101) and the top gas nozzle (103), forming a closed-loop circulation injection of the vertical furnace top gas. CO enters the furnace and moves upward, reacts with the ore, releases heat, and the ore temperature rises and moves downward, and undergoes a reduction reaction with the hydrogen at the bottom.

[0036] The hydrogen supply unit (6) → the hydrogen pressurizing unit (7) raises the hydrogen to a suitable injection pressure → the hydrogen heating unit (8) raises the hydrogen to a suitable high temperature → the hydrogen is injected into the vertical furnace (1) through the lower furnace top gas ring channel (102) and the furnace top gas nozzle (104) to move upward, and react with the high-temperature ore moving downward to further completely reduce the ore.

[0037] The present invention uses the different reduction characteristics of CO and hydrogen, and sets two independent furnace injection systems to allow CO and hydrogen to enter the furnace at appropriate positions of the vertical furnace, thereby improving the utilization efficiency of CO and hydrogen. By setting different heating temperatures for CO and hydrogen, the utilization efficiency of the two can be improved and equipment investment can be reduced. The process flow of the present invention is simple, and the top gas generated in the process can be recycled in a closed loop, thereby improving the production efficiency of the vertical furnace and achieving high-efficiency, high-hydrogen, low-consumption, and low-carbon production in the vertical furnace.

[0038] As an improvement of the above embodiment, the furnace top gas ring channel (101) is located above the hydrogen ring channel (103). A plurality of furnace top gas nozzles (102) are arranged on the furnace top gas ring channel (101), and a plurality of hydrogen nozzles (104) are arranged on the hydrogen ring channel (103).

[0039] The gas supplemented by the CO-rich gas supplementing unit (3) is pure CO gas or a mixed gas rich in CO.

[0040] The gas supplied by the hydrogen supply unit (6) is pure hydrogen or a mixed gas rich in hydrogen.

[0041] As an improvement of the above embodiment, the above-mentioned top gas treatment unit (2) may include process units such as cooling, dehydration, dust removal, and CO2 removal. Each process unit may be freely combined according to the characteristics of the top gas and the needs of the vertical furnace process flow, and other treatment processes may also be added as needed, such as but not limited to desulfurization.

[0042] The above-mentioned top gas heating unit (5) and hydrogen heating unit (8) can be heated by heat recovered from the top gas just leaving the vertical furnace, or by an independent heat source, or by a combination of the two.

[0043] The furnace top gas heating unit (5) adopts a medium temperature or medium-high temperature heater, and the hydrogen heating unit (8) adopts a high temperature heater.

[0044] As an improvement of the above embodiment, the furnace top gas ring duct (101) and the hydrogen ring duct (103) can be arranged inside the furnace shell of the vertical furnace (1), or can be arranged outside the furnace shell of the vertical furnace (1) in the form of a surrounding pipe.

[0045] As an improvement to the above embodiment, the furnace top gas nozzles (102) and hydrogen nozzles (104) are independently arranged in an upper and lower row, or multiple rows are arranged in the upper and lower rows, with a number of nozzles evenly distributed and the shape of the nozzles set according to process requirements.

[0046] The present invention is described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. Many other changes and modifications that do not depart from the concept and scope of the present invention should be regarded as the protection scope of the present invention.

[0047] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0048] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A vertical furnace system with hydrogen direct blowing and top gas circulation, characterized in that: At least comprising a vertical furnace (1); an independent furnace top gas ring channel (101) and a hydrogen ring channel (103) are arranged on the vertical furnace; a plurality of furnace top gas nozzles (102) are arranged on the furnace top gas ring channel (101); and a plurality of hydrogen nozzles (104) are arranged on the hydrogen ring channel (103); 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) which are sequentially connected via pipelines; the outlet of the furnace top gas heating unit (5) is connected to the furnace top gas ring channel (101) via a pipeline; It also includes a hydrogen supply unit (6), a hydrogen pressurizing unit (7), and a hydrogen heating unit (8) which are connected in sequence through pipelines; the outlet of the hydrogen heating unit (8) is connected to the hydrogen ring channel (103) through a pipeline.

2. The hydrogen direct blowing and top gas circulation vertical furnace system according to claim 1, characterized in that: It also includes a furnace top gas processing unit; the furnace top gas processing unit is used to process the furnace top gas discharged from the furnace top and then discharge it through the exhaust pipe.

3. The hydrogen direct blowing and top gas circulation vertical furnace system according to claim 2, characterized in that: An exhaust branch pipe is provided on the exhaust pipe, and 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).

4. The hydrogen direct blowing and top gas circulation vertical furnace system according to claim 1, characterized in that: The furnace top gas ring channel (101) is located above the hydrogen ring channel (103).

5. The hydrogen direct blowing and top gas circulation vertical furnace system according to claim 1, characterized in that: The gas supplemented by the CO-rich gas supplement unit (3) is pure CO gas or a mixed gas rich in CO.

6. The hydrogen direct blowing and top gas circulation vertical furnace system according to claim 1, characterized in that: The gas supplied by the hydrogen supply unit (6) is pure hydrogen or a mixed gas rich in hydrogen.

7. The hydrogen direct blowing and top gas circulation vertical furnace system according to claim 2, characterized in that: The furnace top gas processing unit (2) comprises cooling, dehydration, dust removal, desulfurization and CO2 removal process units.

8. The hydrogen direct blowing and top gas circulation vertical furnace system according to claim 1, characterized in that: The furnace top gas heating unit (5) adopts a medium temperature or medium-high temperature heater, and the hydrogen heating unit (8) adopts a high temperature heater.

9. The hydrogen direct blowing and top gas circulation vertical furnace system according to claim 1, characterized in that: The furnace top gas ring channel (101) and the hydrogen ring channel (103) are arranged inside the furnace shell of the vertical furnace or outside the furnace shell in the form of surrounding pipes; The furnace top gas nozzles (102) and hydrogen nozzles (104) are independently arranged in an upper and lower row, or arranged in multiple rows in the upper and lower rows, and the number of nozzles is evenly distributed.

10. A vertical furnace process with hydrogen direct blowing and top gas circulation, characterized in that: The hydrogen direct blowing and top gas circulation vertical furnace system comprises a vertical furnace (1), a top gas processing unit (2), a CO-rich gas supplement unit (3), a top gas pressurizing unit (4), a top gas heating unit (5), a hydrogen supply unit (6), a hydrogen pressurizing unit (7), and a hydrogen heating unit (8); the process comprises: 1) The top gas generated by the vertical furnace (1) is treated by a top gas treatment unit; The treated furnace top gas is output to the furnace top gas pressurizing unit together with the CO-rich gas supplement unit (3); After the pressure is applied, the top gas is raised to a suitable injection temperature by a top gas heating unit; The gas is injected from the furnace top gas ring channel into the vertical furnace (1), forming a circulation injection of the vertical furnace top gas; 2) The hydrogen supply unit outputs to the hydrogen pressurizing unit; The pressurized hydrogen is raised to a suitable injection temperature through a hydrogen heating unit (8) and then injected into the vertical furnace (1) from a hydrogen ring channel (103).

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