Electricity-carbon mixed heat reduction furnace

Abstract

The utility model discloses an electricity-carbon mixed heat reduction furnace, and belongs to the technical field of reduction furnaces. Comprising a furnace body, an electric heating device and a gas combustion heating device, a reduction chamber is arranged on the lower portion of the furnace body, a pre-reduction chamber is arranged in the middle, a drying chamber is arranged on the upper portion, and the electric heating device is arranged on the lower portion of the pre-reduction chamber; a discharge port is formed in the lower part of the reduction chamber, a residual gas combustion cavity is formed in the joint of the pre-reduction chamber and the drying chamber, a flue gas chamber is arranged at the upper part of the drying chamber, a receiving bin and a flue gas outlet are formed in the top of the drying chamber, and the flue gas outlet is communicated with the flue gas chamber; the gas combustion heating device comprises a plurality of oxygen-containing gas nozzles which surround the reduction chamber and blow oxygen-containing gas to the middle of the reduction chamber. The technical problem that due to the fact that the furnace temperature below a high-temperature air nozzle of a traditional blast furnace type reduction furnace is low and a hearth of a submerged arc furnace type reduction furnace is shallow, reducing gas overflows out of the charge level when the reducing gas cannot be pre-reduced with metal oxide in time is solved.

Description

Technical Field

[0001] This utility model relates to the field of reduction furnace technology, and in particular to an electric carbon mixed-heat reduction furnace. Background Technology

[0002] The working principle of the reduction furnace is to reduce metal oxides to metals through high temperature and reducing environment. The specific process is as follows: First, the reducing agent and metal oxides enter the furnace and generate a high temperature environment through electric heating or carbon heating. When carbon is used as a reducing agent, carbon and metal oxides undergo redox reaction in a high temperature environment to generate metal (gaseous, solid or liquid) and carbon monoxide. The generated metal is collected and extracted through the transfer device in the furnace, and the generated carbon monoxide is either recovered as raw coal gas or burned directly on the surface of the furnace material. Existing reduction furnaces have the following problems: (1) Existing blast furnace-type reduction furnaces only use carbon as a heating agent. The furnace temperature below the high temperature air nozzle is low, making it difficult to reduce metals and resulting in low metal yield. (2) Existing electric arc furnaces use electricity as a heat source to heat the furnace charge and charcoal as a reducing agent. Due to the shallow furnace chamber, a large amount of reducing gas generated during the reduction process not only fails to be pre-reduced with metal oxides but also overflows from the charge surface and is burned, resulting in energy waste and increased charcoal content. Moreover, the high-temperature reducing gas at thousands of degrees can only be used after cooling and purification, resulting in low efficiency and high cost of secondary utilization.

[0003] Therefore, it is necessary to modify the existing reduction furnace and invent an electric-carbon mixed-heat reduction furnace, that is, a reduction furnace that heats the molten charge by inputting electrical energy and burning the gas generated in the reduction process of the reduction furnace, in order to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide an electric carbon mixed-heat reduction furnace to address the above-mentioned problems, thereby solving the technical problems of traditional reduction furnaces where the furnace temperature below the high-temperature air nozzle is low and the furnace chamber is shallow, resulting in insufficient time for the reducing gas to pre-reduce the metal oxide.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] An electric carbon-coal mixed-heat reduction furnace includes a furnace body, an electric heating device, and a gas combustion heating device. The lower part of the furnace body is configured as a reduction chamber, the middle part as a pre-reduction chamber, and the upper part as a drying chamber. The electric heating device is located in the lower part of the pre-reduction chamber. A discharge port is provided in the lower part of the reduction chamber. A residual gas combustion chamber is provided at the connection between the pre-reduction chamber and the drying chamber. A flue gas chamber is provided in the upper part of the drying chamber. A receiving bin and a flue gas outlet are provided at the top of the drying chamber. The flue gas outlet communicates with the flue gas chamber. The gas combustion heating device includes a plurality of oxygen-containing gas nozzles, which surround the reduction chamber and blow oxygen-containing gas towards the center of the reduction chamber.

[0007] Furthermore, an annular heat-resistant grating is provided at the connection between the pre-reduction chamber and the drying chamber, and a heat-resistant feed pipe is provided on the inner wall of the annular heat-resistant grating. The annular heat-resistant grating, the heat-resistant feed pipe, and the upper part of the inner wall of the pre-reduction chamber form an open residual gas combustion chamber.

[0008] Furthermore, the furnace body is also provided with an air duct that passes through the residual gas combustion chamber, and an electric valve is installed on the air duct.

[0009] Furthermore, the lower part of the receiving hopper is inserted into the drying chamber, and the lower part of the receiving hopper, the top plate of the drying chamber, and the inner wall of the drying chamber form an open flue gas chamber.

[0010] Furthermore, a material level measuring instrument is installed on the upper part of the receiving hopper.

[0011] Furthermore, the electric heating device includes a lifting device, a first electrode, and a second electrode. The lower end of the first electrode passes through the lower part of the pre-reduction chamber and is inserted into the reduction chamber. The second electrode is located at the bottom of the reduction chamber. The lifting device controls the lifting movement of the first electrode.

[0012] Furthermore, an arched cavity is provided in the middle of the furnace body, which extends horizontally into the pre-reduction chamber. The lower end of the first electrode extends into the pre-reduction chamber from the bottom surface of the arched cavity, and the upper end of the first electrode is located in the arched cavity and connected to the lifting device.

[0013] Furthermore, a high-temperature resistant crossbeam is provided at the bottom of the arched cavity, and an electrode sealing sleeve is provided in the middle of the high-temperature crossbeam. The lower end of the first electrode is sealed and inserted into the electrode sealing sleeve. A sealing felt is provided in the gap between the inner wall of the electrode sealing sleeve and the outer wall of the first electrode. A movable cover plate is provided on the upper end face of the high-temperature crossbeam. The movable cover plate is located on both sides of the electrode sealing sleeve. A heat-insulating material layer fixed by heat-resistant bolts is provided on the lower end face of the movable cover plate.

[0014] Furthermore, the furnace wall is provided with a refractory material layer, a high-temperature insulation layer and an outer shell layer from the inside out.

[0015] Due to the adoption of the above technical solution, the beneficial effects of this utility model are as follows:

[0016] 1. This invention, by installing an electric heating device at the bottom of the reduction chamber, effectively increases the furnace temperature below the high-temperature air nozzle, making the reduction process more uniform and efficient. Simultaneously, the oxygen-containing gas nozzle blows oxygen-containing gas into the lower part of the reduction chamber, enhancing the intensity and efficiency of the reduction reaction. Furthermore, the exothermic reaction of reducing gases generated during the oxygen-containing combustion process heats the furnace charge in the pre-reduction chamber to high temperatures, even the melting point, significantly saving energy. In addition, oxygen-containing combustion reduces the partial pressure of reducing gases such as CO, which is beneficial for improving the solid-state reduction rate and reducing the overall energy consumption per unit product. A residual gas combustion chamber is installed at the connection between the pre-reduction chamber and the drying chamber to further ignite and heat the remaining reducing gases for raw material drying, preventing the overflow of unused reducing gases onto the material surface. The design of the annular heat-resistant grating and heat-resistant feed pipe optimizes the flow path of the high-temperature gases generated by combustion, improving the utilization rate of reducing gases, reducing the amount of charcoal required, and reducing the cost of secondary utilization. This addresses the technical problems of traditional blast furnace reduction furnaces, where the furnace temperature below the high-temperature air nozzle is low, and the shallow furnace of submerged arc furnace reduction furnaces, which prevent the reducing gas from having enough time to pre-reduce the metal oxides.

[0017] 2. This utility model utilizes a hybrid electric-carbon heating method, which rationally utilizes both electrical energy and the thermal energy of carbon, thereby improving energy efficiency. Furthermore, the inclusion of an electrode sealing sleeve, sealing felt, insulation material layer, and movable cover plate effectively reduces heat loss, further lowering energy consumption and achieving the goal of energy conservation and emission reduction.

[0018] 3. The reduction furnace wall of this utility model is sequentially composed of a refractory material layer, a high-temperature insulation layer, and an outer shell layer from the inside out. This multi-layered structural design can effectively resist high temperatures and chemical corrosion, improving the stability and service life of the equipment. By installing a material level measuring instrument at the top of the receiving hopper, the material level can be monitored in real time, facilitating timely adjustments to the feed rate by operators and preventing the reduction process from being affected by excessively high or low material levels. Attached Figure Description

[0019] Figure 1 This is a front sectional view of the present invention;

[0020] Figure 2 This is a side sectional view of the present invention;

[0021] Figure 3 This is a cross-sectional view of the bottom structure of the arched cavity of this utility model.

[0022] In the attached diagram, 1-furnace body, 2-electric heating device, 3-gas combustion heating device, 4-reduction chamber, 5-pre-reduction chamber, 6-drying chamber, 7-discharge port, 8-residual gas combustion chamber, 9-flue gas chamber, 10-receiving bin, 11-flue gas outlet, 12-oxygen-containing gas nozzle, 13-annular heat-resistant grating plate, 14-heat-resistant feeding pipe, 15-air duct, 16-electric valve, 17-material level measuring instrument, 18-lifting device, 19-first electrode, 20-second electrode, 21-arched cavity, 22-high temperature resistant crossbeam, 23-electrode sealing sleeve, 24-sealing felt, 25-heat insulation material layer, 26-movable cover plate, 27-refractory material layer, 28-high temperature insulation layer, 29-outer shell layer, 30-conductor, 31-clamp. Detailed Implementation

[0023] The specific implementation of the utility model will be further described below with reference to the accompanying drawings.

[0024] In the description of this utility model, it should be understood that the terms "center", "length", "width", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", 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.

[0025] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] Please see Figures 1 to 3An electric carbon-coal mixed-heat reduction furnace is characterized by comprising a furnace body 1, an electric heating device 2, and a gas combustion heating device 3. The lower part of the furnace body 1 is configured as a reduction chamber 4, the middle part as a pre-reduction chamber 5, and the upper part as a drying chamber 6. The electric heating device 2 is located in the lower part of the reduction chamber 4. A discharge port 7 is provided in the lower part of the reduction chamber 4. A residual gas combustion chamber 8 is provided at the connection between the pre-reduction chamber 5 and the drying chamber 6. A flue gas chamber 9 is provided in the upper part of the drying chamber 6. A receiving bin 10 and a flue gas outlet 11 are provided at the top of the drying chamber 6, and the flue gas outlet 11 communicates with the flue gas chamber 9. The gas combustion heating device 3 includes several oxygen-containing gas nozzles 12, which surround the reduction chamber 4 and blow oxygen-containing gas into the center of the reduction chamber 4. Specifically, the furnace body 1 wall is provided with a refractory material layer 27, a high-temperature insulation layer 28, and an outer shell layer 29 from the inside out. The cross-section of the furnace body 1 is circular, rectangular, or elliptical.

[0028] In this embodiment, an annular heat-resistant grating plate 13 is provided at the connection between the pre-reduction chamber 5 and the drying chamber 6, and a heat-resistant feed pipe 14 is provided on the inner wall of the annular heat-resistant grating plate 13. The annular heat-resistant grating plate 13, the heat-resistant feed pipe 14, and the upper part of the inner wall of the pre-reduction chamber 5 form an open residual gas combustion chamber 8. The use of the annular heat-resistant grating plate 13 can prevent blocky materials from passing through, while allowing gas to rise.

[0029] In this embodiment, the furnace body 1 is also provided with an air duct 15 that passes through the residual gas combustion chamber 8, and an electric valve 16 is provided on the air duct 15. By setting up the air duct of the residual gas combustion chamber 8, an appropriate amount of air can be introduced into the residual gas combustion chamber 8 as needed to facilitate the combustion of the gas in the residual gas combustion chamber 8.

[0030] In this embodiment, the lower part of the receiving hopper 10 is inserted into the drying chamber 6, and the lower part of the receiving hopper 10, the top plate of the drying chamber 6, and the inner wall of the drying chamber 6 form an open flue gas chamber 9. By providing the flue gas chamber 9, the exhaust of flue gas can be smoother and easier.

[0031] In this embodiment, a material level measuring instrument 17 is installed on the upper part of the receiving hopper 10. By installing the material level measuring instrument 17 on the upper part of the receiving hopper 10, the material level can be monitored in real time, which makes it convenient for operators to adjust the feed rate in a timely manner and avoid affecting the normal operation of the reduction process due to the material level being too high or too low.

[0032] In this embodiment, the electric heating device 2 includes a lifting device 18, a first electrode 19, and a second electrode 20. The lower end of the first electrode 19 is inserted into the reduction chamber 4, and the second electrode 20 is located at the bottom of the reduction chamber 4. The lifting device 18 controls the lifting movement of the first electrode 19. Specifically, an arched cavity 21 is provided in the middle of the furnace body 1, which is horizontally inserted into the pre-reduction chamber 5. The lower end of the first electrode 19 enters the reduction chamber 4 from the bottom surface of the arched cavity 21, and the upper end of the first electrode 19 is located in the arched cavity 21 and connected to the lifting device 18. A high-temperature resistant crossbeam 22 is provided at the bottom of the arched cavity 21, and an electrode sealing sleeve 23 is provided in the middle of the high-temperature resistant crossbeam 22. The lower end of the first electrode 19 is sealed and inserted into the electrode sealing sleeve 23. A sealing felt 24 is provided in the gap between the inner wall of the electrode sealing sleeve 23 and the outer wall of the first electrode 19. A movable cover plate 26 is provided on the upper end face of the high-temperature crossbeam 22. The movable cover plate 26 is located on both sides of the electrode sealing sleeve 23. A heat-insulating material layer 25 fixed by heat-resistant bolts is provided on the lower end face of the movable cover plate 26. It should also be noted that the electrode sealing sleeve 23 is made of high-temperature resistant ceramic, and the movable cover plate 26 is made of high-temperature resistant steel plate. The lifting device 18 is a conventional telescopic cylinder structure. A horizontally extending conductor 30 is provided at the telescopic end of the lifting device 18. A clamp 31 is provided at the end of the conductor 30 and electrically connected to the first electrode 19.

[0033] The above description is a detailed description of the preferred embodiments of the present utility model. However, the embodiments are not intended to limit the scope of the patent application of the present utility model. All equivalent changes or modifications made under the technical spirit of the present utility model should fall within the patent scope covered by the present utility model.

Claims

1. An electrically heated carbon-mixed reduction furnace, characterized by: The application relates to a rotary kiln for producing iron powder, which comprises a rotary kiln body (1), an electric heating device (2) and a gas combustion heating device (3), wherein the lower part of the rotary kiln body (1) is provided with a reduction chamber (4), the middle part is provided with a pre-reduction chamber (5), and the upper part is provided with a drying chamber (6); the electric heating device (2) is arranged at the lower part of the pre-reduction chamber (5); the lower part of the reduction chamber (4) is provided with a discharge port (7); the connecting part of the pre-reduction chamber (5) and the drying chamber (6) is provided with a residual gas combustion cavity (8); the upper part of the drying chamber (6) is provided with a material receiving bin (10) and a flue gas outlet (11), and the flue gas outlet (11) is communicated with the flue gas chamber (9); the gas combustion heating device (3) comprises a plurality of oxygen-containing gas nozzles (12) which surround the reduction chamber (4) and blow oxygen-containing gas into the middle part of the reduction chamber (4).

2. The electrically heated carbon-mixed reduction furnace according to claim 1, characterized by: The connecting part of the pre-reduction chamber (5) and the drying chamber (6) is provided with an annular heat-resistant grid plate (13), the inner wall of the annular heat-resistant grid plate (13) is provided with a heat-resistant downcomer (14), and the annular heat-resistant grid plate (13), the heat-resistant downcomer (14) and the upper part of the inner wall of the pre-reduction chamber (5) form the open residual gas combustion cavity (8).

3. An electrically heated carbon-mixed reduction furnace according to claim 2, characterized in that: The rotary kiln body (1) is further provided with a wind pipe (15) which passes through the residual gas combustion cavity (8), and the wind pipe (15) is provided with an electric valve (16).

4. The electrically heated carbon-mixed reduction furnace according to claim 1, characterized by: The lower part of the material receiving bin (10) is inserted into the drying chamber (6), and the lower part of the material receiving bin (10), the top plate of the drying chamber (6) and the inner wall of the drying chamber (6) form the open flue gas chamber (9).

5. An electrically heated carbon-mixed reduction furnace according to claim 4, characterized in that: The upper part of the material receiving bin (10) is provided with a material level measuring instrument (17).

6. The electrically heated carbon-mixed reduction furnace according to claim 1, characterized by: The electric heating device (2) comprises a lifting device (18), a first electrode (19) and a second electrode (20), the lower end of the first electrode (19) is inserted into the reduction chamber (4) through the lower part of the pre-reduction chamber (5), the second electrode (20) is located at the bottom of the reduction chamber (4), and the lifting device (18) controls the lifting movement of the first electrode (19).

7. An electrically heated carbon-mixed reduction furnace according to claim 6, characterized in that: The middle part of the rotary kiln body (1) is provided with an arch-shaped cavity (21) which penetrates into the pre-reduction chamber (5) horizontally, the lower end of the first electrode (19) penetrates into the pre-reduction chamber (5) from the bottom surface of the arch-shaped cavity (21), and the upper end of the first electrode (19) is located in the arch-shaped cavity (21) and connected with the lifting device (18).

8. An electrically heated carbon-mixed reduction furnace according to claim 7, characterized in that: The bottom of the arched cavity (21) is provided with a high-temperature-resistant crossbeam (22), the middle of the high-temperature-resistant crossbeam (22) is provided with an electrode sealing sleeve (23), the lower end of the first electrode (19) is sealingly inserted into the electrode sealing sleeve (23), and the gap between the inner wall of the electrode sealing sleeve (23) and the outer wall of the first electrode (19) is provided with sealing felt (24); the upper end surface of the high-temperature-resistant crossbeam (22) is provided with a movable cover plate (26), the movable cover plate (26) is located on the two sides of the electrode sealing sleeve (23), and the lower end surface of the movable cover plate (26) is provided with a heat-resistant bolt-fixed heat insulation material layer (25).

9. The electrically heated carbon-mixed reduction furnace according to claim 1, characterized by: The wall of the furnace body (1) is sequentially provided with a refractory material layer (27), a high-temperature insulation layer (28) and an outer shell layer (29) from inside to outside.

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