Reduction furnace

Abstract

The utility model provides a reduction furnace which comprises a furnace body, a feed port and a smoke outlet are arranged on the furnace body, a hearth comprises a reduction area, the reduction area comprises a metal layer area, and the metal layer area is arranged close to a furnace bottom; the static slag layer area is arranged on the side, away from the furnace bottom, of the metal layer area; the foam slag layer area is arranged on the side, away from the metal layer area, of the static slag layer area; the reduction furnace further comprises a plurality of secondary combustion guns, one ends of the secondary combustion guns are fixed to the furnace wall of the side, away from the static slag layer area, of the foam slag layer area, and nozzles of at least part of the secondary combustion guns are located in the foam slag layer area. And the multiple primary combustion guns are fixed to the furnace wall, and spray heads of at least part of the primary combustion guns are located in the foam slag layer area. Therefore, the secondary combustion rate of the fuel is improved, the utilization rate of secondary combustion heat is improved, the fuel consumption is reduced, the gas yield is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of reduction furnaces, in particular to a reduction furnace. Background Art

[0002] When iron ore is smelted and reduced to produce molten iron, in order to ensure the reduction effect, a strong reducing atmosphere is required in the furnace of the reduction furnace. The reduction is an endothermic reaction, so a large amount of heat needs to be absorbed during the reaction, and the heat is mainly provided by the combustion of coal. The coal gas combustion utilization rate in the reduction furnace in the related art is low, resulting in high fuel consumption, large coal gas output, and high production costs. Therefore, the current reduction furnace needs to be further improved. Utility Model Content

[0003] The utility model aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] The utility model proposes a reduction furnace, the reduction furnace comprises a furnace body, the furnace body comprises a furnace bottom, a furnace wall and a furnace top, the furnace bottom, the furnace wall and the furnace top define a furnace, the furnace body is provided with a feed port and a smoke outlet, the furnace chamber comprises a reduction zone, the reduction zone comprises: a metal layer area, the metal layer area is arranged close to the furnace bottom; a static slag layer area, the static slag layer area is arranged on the side of the metal layer area away from the furnace bottom; a foam slag layer area, the foam slag layer area is arranged on the side of the static slag layer area away from the metal layer area; the reduction furnace also comprises: a plurality of secondary combustion guns, one end of the plurality of secondary combustion guns is fixed on the furnace wall on the side of the foam slag layer area away from the static slag layer area, at least part of the nozzles of the secondary combustion guns are located in the foam slag layer area; a plurality of primary combustion guns, the plurality of primary combustion guns are fixed on the furnace wall, at least part of the nozzles of the primary combustion guns are located in the foam slag layer area. Thus, the secondary combustion rate of the fuel is improved, the utilization rate of the secondary combustion heat is improved, the fuel consumption is reduced, the coal gas output is reduced, and the production cost is reduced.

[0005] The reduction furnace proposed by the utility model also has the following additional technical features:

[0006] According to some embodiments of the utility model, a plurality of the secondary combustion guns are fixed to the furnace wall via water-cooled gun stocks, thereby reducing the temperature of the secondary combustion guns and increasing the service life of the secondary combustion guns.

[0007] According to some embodiments of the utility model, in the horizontal direction, the spacing between the plurality of secondary combustion guns is the same, and the nozzles of the secondary combustion guns are all located in the foam slag layer area, thereby increasing the oxygen content and uniformity in the furnace and improving the secondary combustion rate of the fuel.

[0008] According to some embodiments of the utility model, the angle between the gun body of the secondary combustion gun and the furnace wall is α, and satisfies: 45°≤α≤60°. Thus, the nozzle of the secondary combustion gun is obliquely inserted into the foam slag layer, improving the utilization rate of the secondary combustion heat.

[0009] According to some embodiments of the present invention, it further comprises: a plurality of reducing agent spray guns, wherein the plurality of reducing agent spray guns are fixed on the furnace wall and are suitable for spraying reducing agent into the static slag layer area.

[0010] According to some embodiments of the utility model, the reducing agent spray gun and the primary combustion gun are arranged alternately at the same height of the reduction furnace, thereby improving the uniformity of the reducing agent, fuel and combustion-supporting air in the furnace and improving the efficiency of the reduction reaction.

[0011] According to some embodiments of the utility model, the furnace further comprises a front bed area, a retaining wall is arranged between the front bed area and the reduction area, the free end of the retaining wall is spaced apart from the furnace bottom, and a slag discharge port is arranged on the furnace wall of the front bed area. Thus, the slag can enter the front bed area for slag-iron separation, thereby reducing the iron content in the slag.

[0012] According to some embodiments of the present invention, the furnace body further comprises a first metal discharge port and a second metal discharge port, and the first metal discharge port and the second metal discharge port are arranged on the furnace wall of the metal layer area, thereby reducing the probability of reducing gas entering the front bed area.

[0013] According to some embodiments of the present invention, the reduction furnace further includes a first electrode and a second electrode, and the first electrode and the second electrode are located in the front bed area so as to be suitable for heating the front bed area.

[0014] According to some embodiments of the utility model, a charging port and a first smoke outlet are provided on the furnace top of the reduction zone, and a second smoke outlet is provided on the furnace top of the front bed zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0016] Figure 1 The schematic diagram of the structure of a reduction furnace of an embodiment of the utility model is shown.

[0017] Figure 2 Shows Figure 1 Cross-section of the reduction furnace.

[0018] Reference numerals:

[0019] 1: reduction furnace; 11: furnace bottom; 12: furnace wall; 13: furnace roof; 131: feed port; 132: first flue gas outlet; 133: second flue gas outlet; 20: reduction zone: 21: metal layer area; 22: static slag area; 23: foam slag layer area; 14: secondary combustion gun; 15: primary combustion gun; 16: reducing agent spray gun; 30: front bed area; 17: retaining wall; 111: first metal discharge port; 112: second metal discharge port; 181: first electrode; 182: second electrode; 121: slag discharge port; 122: accident discharge port; 123: foam slag overflow port. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0021] In the reduction furnace of the related art, the secondary combustion mainly occurs in the area above the slag surface of the furnace. The heat of the secondary combustion can only be replenished into the molten pool by thermal radiation, and a large amount of heat is discharged with the coal gas (the coal gas temperature is above 1800℃), resulting in a heat utilization rate of only about 50%. Moreover, the secondary combustion rate is low, about 40%-50%, resulting in large fuel consumption and large amount of coal gas.

[0022] The utility model proposes a reduction furnace 1, referring to Figure 1The reduction furnace 1 includes a furnace body, the furnace body includes a furnace bottom 11, a furnace wall 12 and a furnace top 13, the furnace bottom 11, the furnace wall 12 and the furnace top 13 define a furnace, the furnace body is provided with a feed port 131 and a flue gas outlet, the furnace includes a reduction zone 20, the reduction zone 20 includes: a metal layer area 21, the metal layer area 21 is arranged close to the furnace bottom 11; a static slag layer area 22, the static slag layer area 22 is arranged on the side of the metal layer area 21 away from the furnace bottom 11; a foam slag layer area 23, the foam slag layer area 23 is arranged on the side of the static slag layer area 22 away from the metal layer area 21; the furnace body also includes: a plurality of secondary combustion guns 14, one end of each of the secondary combustion guns 14 is fixed on the furnace wall 12 on the side of the foam slag layer area 23 away from the static slag layer area 22, and at least part of the nozzles of the secondary combustion guns 14 are located in the foam slag layer area 23; a plurality of primary combustion guns 15, each of the primary combustion guns 15 is fixed on the furnace wall 12, and at least part of the nozzles of the primary combustion guns 15 are located in the foam slag layer area 23. Thus, the secondary combustion rate of the fuel is improved, the utilization rate of the secondary combustion heat is improved, the fuel consumption is reduced, the gas output is reduced, and the production cost is reduced.

[0023] In the reduction furnace 1 proposed in the utility model, iron-containing materials and reducing agents can enter the furnace through the feed port 131 for reduction reaction, and the fuel and primary air are sprayed into the molten pool through the primary combustion gun 15 to burn and supplement heat. After combustion and reduction, molten iron, slag and primary coal gas are obtained. The primary coal gas foams the slag layer during the escape process, and the oxygen-rich air sprayed by the secondary combustion gun 14 and the raw coal gas burn in the foamy slag layer. The molten iron formed by reduction is located at the bottom of the furnace, and above the molten iron are a static slag layer and a foamy slag layer, respectively. The area in the furnace where the molten iron is located forms a metal layer area 21, the area where the static slag layer is located forms a static slag layer area 22, and the area where the foamy slag layer is located forms a foamy slag layer area 23. The primary combustion gun 15 of the reduction furnace 1 can spray oxygen-rich air into the furnace. Specifically, refer to Figure 2 The primary combustion gun 15 is fixed on the furnace wall 12 near the furnace bottom 11, and the nozzle is horizontally inserted into the foamed slag layer to spray oxygen-enriched air into the area of ​​the foamed slag layer close to the metal layer. The secondary combustion gun 14 is fixed on the furnace wall 12 on the side of the foamed slag layer area 23 away from the static slag layer area 22, and the nozzle is obliquely inserted into the foamed slag layer to spray pure oxygen into the foamed slag layer, thereby improving the secondary combustion rate inside the furnace. The heat generated by the combustion can be fed back to the molten pool through the heated high-temperature slag, iron, solid materials, etc., thereby improving the utilization rate of the secondary combustion heat, reducing fuel consumption, reducing gas production, and reducing production costs.

[0024] The reduction furnace 1 provided by the utility model has a secondary combustion rate greater than or equal to 70%, a secondary combustion heat utilization rate greater than or equal to 80%, and a temperature of the flue gas discharged from the flue gas outlet less than or equal to 1700°C.

[0025] According to some embodiments of the utility model, during the production of molten iron by smelting reduction of iron ore, in the height direction of the reduction furnace 1, the height of the metal layer area 21 can be 500mm-800mm, the height of the static slag layer area 22 can be 300mm-500mm, the height of the foamed slag layer area 23 can be 2m-3m, and the total height of the furnace is greater than or equal to 6m.

[0026] As an example, the height of the metal layer region 21 may be 500 mm, 600 mm, 700 mm, 800 mm, etc., or may be a range consisting of any of the above values.

[0027] As an example, the height of the static slag layer area 22 may be 300 mm, 400 mm, 500 mm, etc., or may be a range consisting of any of the above values.

[0028] As an example, the height of the foamed slag layer area 23 may be 2 m, 2.2 m, 2.4 m, 2.6 m, 2.8 m or 3 m, etc., or may be a range consisting of any of the above values.

[0029] According to some embodiments of the present invention, the primary combustion gun 15 is used to spray fuel and combustion-supporting air. Specifically, the combustion-supporting air can be oxygen-enriched air.

[0030] According to some embodiments of the present invention, the concentration of oxygen in the oxygen-enriched air is 50%-80%, for example, 50%, 60%, 70% or 80%, or a range of any of the above values.

[0031] According to some embodiments of the present invention, the spraying speed of the primary combustion gun 15 can be 80m / s-150m / s. For example, it can be 80m / s, 100m / s, 120m / s, 140m / s or 150m / s, or can be a range of any of the above values. Thus, the probability of the nozzle of the primary combustion gun 15 being blocked is reduced.

[0032] According to some embodiments of the present invention, the oxygen excess coefficient of the primary combustion gun 15 may be 0.5-0.55.

[0033] According to some embodiments of the present invention, the secondary combustion gun 14 is used to spray pure oxygen.

[0034] According to some embodiments of the present invention, the spraying speed of the secondary combustion gun 14 may be greater than or equal to 200 m / s, and the spraying pressure may be 0.1 MPa-0.5 MPa.

[0035] According to some embodiments of the present invention, a plurality of the secondary combustion guns 14 are fixed to the furnace wall 12 via water-cooled gun stocks, thereby reducing the temperature of the secondary combustion guns 14 and increasing the service life of the secondary combustion guns 14.

[0036] According to some embodiments of the present invention, reference Figure 2 In the horizontal direction, the spacing between the plurality of secondary combustion guns 14 is the same, and the nozzles of the secondary combustion guns 14 are all located in the foamed slag layer area 23. Thus, oxygen can be evenly sprayed into the entire foamed slag layer to improve the secondary combustion rate.

[0037] According to some embodiments of the utility model, the angle between the gun body of the secondary combustion gun 14 and the furnace wall 12 is α, and satisfies: 45°≤α≤60°. Specifically, the secondary combustion gun 14 is obliquely inserted into the foam slag layer, and oxygen is sprayed into the foam slag layer, so that the heat generated by the secondary combustion can be replenished into the molten pool through the heated high-temperature slag, iron, solid materials, etc., thereby improving the secondary combustion rate inside the furnace, improving the utilization rate of the secondary combustion heat, reducing fuel consumption, reducing gas production, and reducing production costs.

[0038] According to some embodiments of the present invention, reference Figure 2 The reduction furnace 1 may further include: a plurality of reducing agent spray guns 16, which are fixed on the furnace wall 12 and are suitable for spraying reducing agent to the static slag layer area 22. Specifically, one end of the reducing agent spray gun 16 is fixed on the furnace wall 12 and is arranged horizontally, and the reducing agent spray gun 16 sprays reducing agent to the foam slag layer area 23 close to the static slag layer area 22 to improve the reduction efficiency of iron oxide and improve the yield of metallic iron.

[0039] According to some embodiments of the utility model, the reducing agent spray gun 16 and the primary combustion gun 15 are arranged alternately at the same height of the reduction furnace 1. For example, they can be arranged in the order of one reducing agent spray gun 16, one primary combustion gun 15, one reducing agent spray gun 16, and one primary combustion gun 15. Or they can be arranged in the order of one reducing agent spray gun 16, two primary combustion guns 15, one reducing agent spray gun 16, and two primary combustion guns 15. Thus, the uniformity of the distribution of reducing agent and oxygen in the furnace is improved, the efficiency of the reduction reaction is improved, and the production efficiency is improved.

[0040] According to some embodiments of the present invention, reference Figure 1The furnace also includes a front bed area 30, a retaining wall 17 is arranged between the front bed area 30 and the reduction area 20, the free end of the retaining wall 17 is spaced from the furnace bottom 11, the furnace bottom 11 is provided with a metal discharge port, and the furnace wall 12 of the reduction area 20 is provided with a slag discharge port 121. Specifically, the reducing agent reduces the iron oxide into molten iron in the reduction area 20, and the slag enters the front bed area 30 and stands still. Due to the high density of iron, the iron can be deposited on the furnace bottom 11 by standing still, so as to further separate the slag and iron, reduce the iron content in the slag, and improve the production efficiency. By arranging the retaining wall 17 in the reduction area 20 and the front bed area 30, the influence of the reducing agent spray gun 16, the primary combustion gun 15 and the secondary combustion gun 14 in the reduction area 20 on the standing process of the front bed area 30 during the injection process can be reduced, and the probability of the reducing agent entering the front bed area 30 can be reduced.

[0041] According to some embodiments of the present invention, reference Figure 1 The front bed area 20 is also provided with an emergency discharge port 122 to discharge the slag during a power outage and prevent the slag from staying in the reduction furnace 1 for a long time.

[0042] According to some embodiments of the present invention, reference Figure 1 The metal discharge port includes a first metal discharge port 111 and a second metal discharge port 112 , the first metal discharge port 111 is located in the reduction zone 20 , and the second metal discharge port 112 is located in the front bed zone 30 .

[0043] According to some embodiments of the present invention, in the height direction of the reduction furnace 1, the distance between the free end of the retaining wall 17 and the reducing agent spray gun 16 is 200 mm-300 mm. For example, it can be 200 mm, 220 mm, 240 mm, 260 mm, 280 mm or 300 mm, or can be a range composed of any of the above values.

[0044] It should be noted that the free end of the retaining wall 17 refers to the lowermost end of the retaining wall 17, and the distance between the free end of the retaining wall 17 and the reducing agent spray gun 16 refers to the distance between the lowermost end of the retaining wall 17 and the reducing agent spray gun 16 in the height direction of the reduction furnace 1. The reducing agent spray gun 16 is placed horizontally.

[0045] According to some embodiments of the present invention, the residence time of the slag in the front bed area 30 may be 10 min-30 min.

[0046] According to some embodiments of the present invention, reference Figure 1The reduction furnace 1 further includes a first electrode 181 and a second electrode 182, and the first electrode 181 and the second electrode 182 are located in the front bed area 30 to heat the front bed area 30. Thus, the front bed area 30 is kept warm by the first electrode 181 and the second electrode 182, thereby reducing the risk of slag solidification and improving separation efficiency.

[0047] According to some embodiments of the present invention, the smoke outlet includes a first smoke outlet 132 and a second smoke outlet 133. The first smoke outlet 132 is provided on the furnace roof 13 of the reduction zone 20, and the second smoke outlet 133 is provided on the furnace roof 13 of the front bed zone 30. Thus, smoke can be discharged from the reduction furnace 1 through the first smoke outlet 132 and the second smoke outlet 133.

[0048] According to some embodiments of the present invention, reference Figure 1 A foam slag overflow port 123 may also be provided on the furnace wall 12 of the reduction zone 20 . When the foam slag content in the furnace is high, it can be discharged through the foam slag overflow port 123 .

[0049] According to some embodiments of the present invention, the furnace wall 12 of the static slag layer area 22 and the foamed slag layer area 23 may adopt a water-cooled slag hanging structure.

[0050] According to some embodiments of the present invention, the furnace wall 12 of the metal layer area 21 may be made of refractory bricks.

[0051] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A reduction furnace, characterized in that: The furnace body comprises a furnace bottom, a furnace wall and a furnace top, the furnace bottom, the furnace wall and the furnace top define a furnace chamber, the furnace body is provided with a feed inlet and a smoke outlet, the furnace chamber comprises a reduction zone, and the reduction zone comprises: A metal layer region, wherein the metal layer region is arranged close to the furnace bottom; A static slag layer area, wherein the static slag layer area is arranged on a side of the metal layer area away from the furnace bottom; A foamed slag layer region, wherein the foamed slag layer region is arranged on a side of the static slag layer region away from the metal layer region; The reduction furnace also includes: A plurality of secondary combustion guns, one end of each of the secondary combustion guns being fixed on the furnace wall on the side of the foamed slag layer region away from the static slag layer region, and at least some of the nozzles of the secondary combustion guns being located in the foamed slag layer region; A plurality of primary combustion guns are fixed on the furnace wall, and at least some of the nozzles of the primary combustion guns are located in the foam slag layer area.

2. The reduction furnace according to claim 1, characterized in that: A plurality of the secondary combustion guns are fixed on the furnace wall via water-cooled gun stocks.

3. The reduction furnace according to claim 2, characterized in that: In the horizontal direction, the intervals between the plurality of secondary combustion guns are the same, and the nozzles of the secondary combustion guns are all located in the foamed slag layer area.

4. The reduction furnace according to claim 3, characterized in that: The angle between the gun body of the secondary combustion gun and the furnace wall is α, and satisfies: 45°≤α≤60°.

5. The reduction furnace according to any one of claims 1 to 4, characterized in that: Also includes: A plurality of reducing agent spray guns are fixed on the furnace wall and are suitable for spraying reducing agent toward the static slag layer area.

6. The reduction furnace according to claim 5, characterized in that: The reducing agent spray guns and the primary combustion guns are arranged alternately at the same height of the reduction furnace.

7. The reduction furnace according to claim 5, characterized in that: The furnace also includes a front bed area, a retaining wall is arranged between the front bed area and the reduction area, the free end of the retaining wall is spaced apart from the furnace bottom, and a slag discharge port is arranged on the furnace wall of the front bed area.

8. The reduction furnace according to claim 7, characterized in that: The furnace body further includes a first metal discharge port and a second metal discharge port, and the first metal discharge port and the second metal discharge port are arranged on the furnace wall of the metal layer area.

9. The reduction furnace according to claim 7, characterized in that: The invention also includes a first electrode and a second electrode, wherein the first electrode and the second electrode are located in the front bed area so as to be suitable for heating the front bed area.

10. The reduction furnace according to claim 7, characterized in that: The smoke outlet comprises a first smoke outlet and a second smoke outlet. The first smoke outlet is arranged on the furnace top of the reduction zone, and the second smoke outlet is arranged on the furnace top of the front bed zone.

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