Arrangement structure of gas-based direct reduction iron shaft furnace and electric arc furnace

Abstract

The invention belongs to the technical field of steelmaking, and particularly relates to a gas-based direct reduction iron shaft furnace and electric arc furnace arrangement structure which comprises a shaft furnace and an electric arc furnace, the shaft furnace and the electric arc furnace are both arranged in the same plant workshop, and a lower distributor of the shaft furnace is communicated with the electric arc furnace through a hot-state direct reduction iron conveying device. Compared with the prior art, the arrangement structure of the gas-based direct reduction iron shaft furnace and the electric arc furnace has the advantages that the gas-based direct reduction iron shaft furnace and the electric arc furnace are arranged in the same workshop, the distance between the shaft furnace and the electric arc furnace is minimized, and conditions are created for ultra-short distance conveying of hot-state direct reduction iron.

Description

Technical Field

[0001] The invention belongs to the technical field of steelmaking, and in particular relates to an arrangement structure of a gas-based direct-reduction iron vertical furnace and an electric arc furnace. Background Art

[0002] Domestic direct reduced iron production is in its infancy, and short-process steelmaking has achieved great development. Combined with the current situation of domestic scrap steel resources, electric arc furnace production with direct reduced iron and scrap steel as mixed raw materials will achieve great development in the future. Currently, two sets of gas-based direct reduced iron production equipment have been introduced in Hesteel and Baosteel, and no domestic gas-based direct reduced iron vertical furnace has been put into production.

[0003] From a foreign perspective, Iran and India are major producers of direct reduced iron, with Iran mainly using gas-based methods and India mainly using coal-based methods. Regardless of whether it is gas-based or coal-based, almost all of the direct reduced iron produced is transported to the electric arc furnace workshop after becoming cold. This method has low technical difficulty and is easy to implement, but it cannot utilize the physical sensible heat of direct reduced iron and has poor energy-saving performance. For every 100°C increase in hot direct reduced iron, the power consumption of electric arc furnace smelting can be reduced by about 30kwh. When 600-700°C hot delivery to the electric arc furnace is achieved, the smelting power consumption can be reduced by 180-210kwh, and the smelting cost per ton of steel is reduced by about 90-105 yuan. It can be seen that the use of hot direct reduced iron for electric arc furnace smelting is more competitive in the market.

[0004] In recent years, researchers at home and abroad have studied a series of hot direct reduced iron transportation technologies and devices. There are two main categories, one is pneumatic transportation and the other is mechanical transportation. Among them, pneumatic transportation has been commercially applied, but its investment and operating costs are relatively large, which is not conducive to low-cost production. Mechanical transportation includes chain conveyor transportation, screw feeder transportation, horizontal vibrator transportation, scraper transportation, roller transportation, etc. These methods do not realize the arrangement of the vertical furnace and the electric arc furnace in the same workshop, so the transportation distance is long, the heat loss of hot direct reduced iron is relatively large, the equipment is more complicated, and the existing mechanical transportation device does not consider the impact on the dust hood of the electric arc furnace in actual application.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The present invention provides a gas-based direct reduction iron vertical furnace and an electric arc furnace arrangement structure to solve the technical problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A gas-based direct reduced iron vertical furnace and electric arc furnace arrangement structure comprises a vertical furnace and an electric arc furnace, wherein the vertical furnace and the electric arc furnace are both arranged in the same workshop, and a lower distributor of the vertical furnace is connected to the electric arc furnace through a hot direct reduced iron conveying device.

[0009] Preferably, the hot direct reduced iron conveying device comprises a fixed chute system and a mobile chute system; one end of the fixed chute system is connected to the vertical furnace, and the other end is connected to the mobile chute system;

[0010] The mobile chute system comprises a mobile trolley and a double-layer chute. The double-layer chute is arranged on the mobile trolley. One end of the double-layer chute is connected to the fixed chute system, and the other end is connected to the charging port of the electric arc furnace.

[0011] Preferably, the inner tube of the double-layer slide pipe is connected to a nitrogen inerting tube.

[0012] Preferably, circulating cooling water is passed between the inner tube and the outer tube of the double-layer slide pipe.

[0013] Preferably, a rectangular fireproof baffle is provided on the double-layer slide pipe, and the rectangular fireproof baffle cooperates with the opening of the dust removal hood outside the electric arc furnace to form a closed space in the dust removal hood.

[0014] Preferably, the rectangular fire baffle is provided with refractory heat-insulating fibers on one side close to the electric arc furnace.

[0015] Preferably, wear-resistant blocks are welded on the inner surface of the inner tube of the double-layer slide pipe.

[0016] Preferably, the lower distributor of the vertical furnace is also connected to a cooling tank and / or a hot buffer tank.

[0017] Preferably, the factory workshop includes an arc furnace span, a vertical furnace span, a refining span and a molten steel receiving span that are adjacent to each other in sequence;

[0018] The electric arc furnace is arranged in the electric arc furnace span, and the vertical furnace is arranged in the vertical furnace span;

[0019] A refining furnace is arranged in the refining span.

[0020] Preferably, a scrap steel continuous feeding device is provided in the electric arc furnace span, and the scrap steel continuous feeding device is arranged parallel to or perpendicular to the electric arc furnace span, and the scrap steel continuous feeding device transports the scrap steel into the electric arc furnace.

[0021] Compared with the prior art, the present invention provides a gas-based direct reduction iron vertical furnace and an electric arc furnace arrangement structure, which has the following beneficial effects:

[0022] 1. The present invention provides a gas-based direct reduced iron vertical furnace and electric arc furnace arrangement structure, which arranges the gas-based direct reduced iron vertical furnace and the electric arc furnace in the same workshop, thereby minimizing the distance between the vertical furnace and the electric arc furnace, and creating conditions for ultra-short distance transportation of hot direct reduced iron.

[0023] 2. The present invention provides a gas-based direct reduced iron vertical furnace and an electric arc furnace arrangement structure, in which hot direct reduced iron is transported by a chute, the equipment is simple, and the transportation is fast. In particular, the second section of the chute creatively adopts a mobile trolley structure, which is different from other chute structures and can be well matched with the dust cover of the electric arc furnace. The dust cover of the electric arc furnace has a small opening, which can better achieve sealing and does not affect the environmental protection and production convenience of the electric arc furnace.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A plan view of the same workshop layout of a gas-based direct reduction iron vertical furnace and an electric arc furnace layout structure provided by the present invention;

[0027] Figure 2 A vertical view of the same workshop arrangement of a gas-based direct reduction iron vertical furnace and an electric arc furnace arrangement structure provided by the present invention;

[0028] Figure 3 A structural layout diagram of a hot direct reduction conveying device in a gas-based direct reduction iron vertical furnace and an electric arc furnace arrangement structure provided by the present invention.

[0029] In the figure:

[0030] 1. Electric arc furnace; 2. Vertical furnace; 3. Hot direct reduced iron conveying device; 4. Direct reduced iron hot briquetting system; 5. Scrap steel continuous feeding device; 6. LF refining furnace; 7. VD refining furnace; 11. Dust hood; 21. Cooling tank; 22. Hot buffer tank; 31. Fixed chute system; 32. Mobile chute system; 311. Fixed upper nitrogen seal and cooling water device; 312. Fixed double-layer chute; 313. Fixed lower nitrogen seal pipe; 314. Fixed lower cooling water pipe; 321. Mobile upper nitrogen seal and cooling water device; 322. Double-layer chute; 323. Nitrogen inerting pipe; 325. Mobile lower cooling water pipe; 324. Rectangular fire baffle; 326. Mobile trolley; 100. Electric arc furnace span; 200. Vertical furnace span; 300. Refining span; 400. Molten steel receiving span. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0032] like Figure 1-3 As shown, an embodiment of the present invention provides a gas-based direct reduced iron vertical furnace 2 and an electric arc furnace 1 arrangement structure, comprising a vertical furnace 2 and an electric arc furnace 1, wherein the vertical furnace 2 and the electric arc furnace 1 are both arranged in the same factory workshop, and the lower distributor of the vertical furnace 2 is connected to the electric arc furnace 1 through a hot direct reduced iron conveying device 3.

[0033] In the above embodiment, the present invention arranges the gas-based direct reduced iron vertical furnace 2 and the electric arc furnace 1 in the same workshop, thereby minimizing the distance between the vertical furnace 2 and the electric arc furnace 1, and creating conditions for ultra-short distance transportation of hot direct reduced iron. At the same time, the direct reduced iron at 600-700°C is hot transported to the electric furnace, reducing the smelting power consumption by 180-210 kwh, and reducing the smelting cost of a ton of steel by about 90-105 yuan.

[0034] In the above embodiment of the present invention, from the perspective of process layout, the factory workshop is equipped with an arc furnace span 100, a vertical furnace span 200, a refining span 300, and a molten steel receiving span 400. The arc furnace span 100 is mainly arranged with an arc furnace 1 and a scrap steel continuous feeding device 5, wherein the scrap steel feeding device can be arranged parallel to or perpendicular to the arc furnace span 100. The vertical furnace span 200 is arranged with a vertical furnace 2 near the arc furnace 1, and a direct reduced iron hot briquetting system 4 is arranged near the vertical furnace 2. The refining span 300 is mainly arranged with an LF refining furnace 6 and a VD refining furnace 7.

[0035] In the actual production process, the scrap steel required by the electric arc furnace 1 is added to the electric arc furnace 1 through the scrap steel continuous feeding device 5, and the hot direct reduced iron is added to the electric arc furnace 1 through the hot direct reduced iron conveying device 3. The molten steel smelted in the electric arc furnace 1 is poured into a ladle, transported to the molten steel receiving span 400 by a ladle car, and transferred to the ladle car of the refining furnace by a crane. The molten steel refined by the refining furnace (including the LF refining furnace 6 and the VD refining furnace 7) is transferred to the ladle turntable of the continuous casting machine and cast into ingots by the continuous casting machine.

[0036] The detailed conveying process and method of hot direct reduced iron are as follows: the green balls of the vertical furnace 2 are added into the vertical furnace 2 from the belt conveyor above the vertical furnace span 200, and are reduced into metal pellets in the vertical furnace 2. The temperature of the metal pellets at the outlet of the vertical furnace is about 600-700°C, and can be sent to the hot direct reduced iron conveying device 3, the cooling tank 21, and / or the hot buffer tank 22 through the distributor at the lower part of the vertical furnace. During normal production, the hot direct reduced iron conveying device 3 is conveyed into the electric arc furnace 1. When the electric arc furnace 1 is in the non-smelting time, the hot DRI can enter the hot buffer tank 22 of the device and be conveyed to the direct reduced iron hot briquetting system 4 for briquetting. The briquetting direct reduced iron can be added back into the electric arc furnace 1.

[0037] In a preferred embodiment of the present invention, the hot direct reduced iron conveying device 3 includes a fixed chute system 31 and a mobile chute system 32; one end of the fixed chute system 31 is connected to the vertical furnace 2, and the other end is connected to the mobile chute system 32;

[0038] The mobile chute system 32 includes a mobile trolley 326 and a double-layer chute 322 . The double-layer chute 322 is arranged on the mobile trolley 326 . One end of the double-layer chute 322 is connected to the fixed chute system 31 , and the other end is connected to the charging port of the electric arc furnace 1 .

[0039] The specific fixed slide pipe system 31 mainly includes a fixed upper nitrogen sealing and cooling water device 311, a fixed double-layer slide pipe 312, a fixed lower nitrogen sealing pipe 313, and a fixed lower cooling water pipe 314.

[0040] The fixed double-layered slide pipe 312 adopts a double-layered sleeve structure, and the inner and outer sleeves are both made of heat-resistant stainless steel, wherein the inner surface of the inner sleeve is welded with wear-resistant blocks, and a circle of annular nitrogen holes is set at the gap between the upper and lower wear-resistant blocks. A fixed upper nitrogen seal and cooling water device 311 is set on the upper part of the slide pipe. The fixed upper nitrogen seal and cooling water device 311 is a concentric tube structure, and nitrogen is passed inside the concentric tube, which is connected to the inner tube of the fixed double-layered slide pipe 312. The nitrogen passed in can provide inert protection for hot DRI. The outer tube of the fixed upper nitrogen seal and cooling water device 311 is connected to the outer tube of the fixed double-layered slide pipe 312, and cooling water is passed in to water-cool the fixed double-layered slide pipe 312 to ensure the strength of the fixed double-layered slide pipe 312. A fixed lower nitrogen sealing pipe 313 is provided at the lower part of the fixed double-layered slide pipe 312, and the fixed lower nitrogen sealing pipe 313 is connected to the annular nitrogen hole of the inner tube of the fixed double-layered slide pipe 312, and nitrogen is blown into the fixed double-layered slide pipe 312 to form an air curtain to prevent air from entering the slide pipe to oxidize DRI. A fixed lower cooling water pipe 314 is provided at the lower part of the fixed double-layered slide pipe 312, and is connected to the outer tube of the fixed double-layered slide pipe 312, and forms a loop with the mobile upper nitrogen sealing and cooling water device 321 to water-cool the fixed double-layered slide pipe 312.

[0041] The mobile slide pipe system 32 mainly includes a mobile upper nitrogen sealing ring and cooling water device, a double-layer slide pipe 322, a nitrogen inerting pipe 323, a mobile lower cooling water pipe 325, a rectangular fire baffle 324, and a mobile trolley 326.

[0042] The double-layer slide pipe 322 adopts a double-layer casing structure, and the inner and outer casings are both made of heat-resistant stainless steel. The inner surface of the inner casing is welded with wear-resistant blocks, and a mobile upper nitrogen seal and cooling water device 321, a nitrogen inerting pipe 323, and a mobile lower cooling water pipe 325 are respectively arranged at the upper, middle, and lower parts. The upper part of the double-layer slide pipe 322 is provided with a mobile upper nitrogen seal and cooling water device 321 connected to the annular nitrogen hole of the inner casing of the double-layer slide pipe 322, and nitrogen is blown in to form an air curtain to prevent air from entering the slide pipe to oxidize DRI. The nitrogen inerting pipe 323 is connected to the inner casing of the double-layer slide pipe 322, and nitrogen is passed in to inertize DRI. The lower part of the slide pipe is provided with a mobile lower cooling water pipe 325, which is communicated with the outer pipe of the double-layer slide pipe 322, and forms a loop with the cooling pipe of the mobile upper nitrogen seal and cooling water device 321 to water-cool the casing.

[0043] The rectangular fire baffle 324 is arranged on the double-layer chute 322, and cooperates with the opening of the dust hood 11 outside the electric arc furnace 1 to form an enclosed space for the dust hood 11. The side close to the trolley is made of welded steel plates and channel steels, and the side close to the electric arc furnace 1 is inlaid with refractory insulation fibers. The rectangular fire baffle 324 cooperates with the opening of the dust hood 11 to form a closed dust hood 11.

[0044] The mobile trolley 326 is equipped with a transmission mechanism. The upper welded bracket of the mobile trolley 326 is used to connect the double-layer slide pipe 322. The mobile trolley 326 is responsible for the transportation of the double-layer slide pipe 322 between the feeding position and the standby position.

[0045] In the present invention, the mobile slide pipe system 32 adopts a mobile trolley 326 structure, which is different from other slide pipe structures and can achieve a good match with the dust cover 11. The opening of the dust cover 11 is small, which can better achieve sealing and does not affect the environmental protection of the electric furnace. In addition, the double-layer slide pipe 322 adopts water cooling, which has a good cooling effect and is conducive to extending the service life of the slide pipe. At the same time, the double-layer slide pipe 322 adopts a double-layer casing design, and a wear-resistant lining is welded inside to extend the service life of the slide pipe; and an annular nitrogen sealing air curtain is set to prevent DRI secondary oxidation.

[0046] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0047] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0048] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

Claims

1. A gas-based direct reduction iron vertical furnace and electric arc furnace arrangement structure, characterized in that: It comprises a vertical furnace and an electric arc furnace, wherein the vertical furnace and the electric arc furnace are both arranged in the same workshop, and the lower distributor of the vertical furnace is connected with the electric arc furnace through a hot direct reduced iron conveying device.

2. The arrangement structure of a gas-based direct reduced iron vertical furnace and an electric arc furnace according to claim 1, characterized in that: The hot direct reduced iron conveying device comprises a fixed chute system and a mobile chute system; one end of the fixed chute system is connected to the vertical furnace, and the other end is connected to the mobile chute system; The mobile chute system comprises a mobile trolley and a double-layer chute. The double-layer chute is arranged on the mobile trolley. One end of the double-layer chute is connected to the fixed chute system, and the other end is connected to the charging port of the electric arc furnace.

3. The arrangement structure of a gas-based direct reduction iron vertical furnace and an electric arc furnace according to claim 2, characterized in that: The inner tube of the double-layer slide pipe is connected with a nitrogen inerting tube.

4. The arrangement structure of a gas-based direct reduction iron vertical furnace and an electric arc furnace according to claim 3, characterized in that: Circulating cooling water is passed between the inner tube and the outer tube of the double-layer slide pipe.

5. The arrangement structure of a gas-based direct-reduction iron vertical furnace and an electric arc furnace according to claim 4, characterized in that: A rectangular fireproof baffle is arranged on the double-layer slide pipe, and the rectangular fireproof baffle cooperates with the opening of the dust removal hood outside the electric arc furnace to form a closed space in the dust removal hood.

6. The arrangement structure of a gas-based direct reduction iron vertical furnace and an electric arc furnace according to claim 5, characterized in that: The rectangular fire baffle is provided with refractory heat-insulating fibers on one side close to the electric arc furnace.

7. The arrangement structure of a gas-based direct-reduction iron vertical furnace and an electric arc furnace according to claim 6, characterized in that: A wear-resistant block is welded on the inner surface of the inner tube of the double-layer slide pipe.

8. The arrangement structure of a gas-based direct-reduction iron vertical furnace and an electric arc furnace according to claim 7, characterized in that: The lower distributor of the vertical furnace is also connected to a cooling tank and / or a hot buffer tank.

9. The arrangement structure of a gas-based direct-reduction iron vertical furnace and an electric arc furnace according to claim 8, characterized in that: The workshop includes the electric arc furnace span, the vertical furnace span, the refining span and the molten steel receiving span which are adjacent to each other in sequence; The electric arc furnace is arranged in the electric arc furnace span, and the vertical furnace is arranged in the vertical furnace span; A refining furnace is arranged in the refining span.

10. The arrangement structure of a gas-based direct-reduction iron vertical furnace and an electric arc furnace according to claim 9, characterized in that: A scrap steel continuous feeding device is arranged in the electric arc furnace span, and the scrap steel continuous feeding device is arranged parallel to or perpendicular to the electric arc furnace span, and the scrap steel continuous feeding device transports the scrap steel into the electric arc furnace.

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