KR100803983B1 - Apparatus for manufacturing molten irons and method for manufacturing molten irons - Google Patents

Abstract

An apparatus for manufacturing molten irons and a method for manufacturing molten irons are provided to produce hydrogen using sensible heat of reduction gas exhausted from a melter gasifier. An apparatus for manufacturing molten irons includes: at least one reduction furnace for reducing iron ores to manufacture reduced irons; a melter gasifier(60) which is connected to the reduction furnace, into which the reduced irons and a lump carbonaceous material are charged, into which oxygen is blown, and which manufactures molten irons; a reduction gas supply pipe(70) for cooling reduction gas exhausted from the melter gasifier to supply the cooled reduction gas into the at least one reduction furnace; and a reformer(10) for generating reformed gas by reforming hydrocarbon-containing gas by heat emitted while cooling the reduction gas. The reformer includes a supply pipe(105), a reforming pipe, and an exhaust pipe(103). The reforming pipe is installed in the reduction gas supply pipe and includes one end(101a) and the other end(101b). The exhaust pipe is connected to the one end of the reforming pipe while the supply pipe is connected to the other end of the reforming pipe.

Description

Apparatus for manufacturing molten iron and method for manufacturing molten iron {APPARATUS FOR MANUFACTURING MOLTEN IRONS AND METHOD FOR MANUFACTURING MOLTEN IRONS}

1 is a view schematically showing a molten iron manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic view illustrating an enlarged part II of FIG. 1.

3 is a view schematically showing a molten iron manufacturing apparatus according to another embodiment of the present invention.

The present invention relates to an apparatus for producing molten iron and a method for producing molten iron, and more particularly, to an apparatus for producing molten iron and a method for producing molten iron using sensible heat of reducing gas discharged from a molten gasifier.

The steel industry is a key industry that supplies basic materials to the entire industry, such as automobiles, shipbuilding, home appliances, and construction. Steel mills, which play a pivotal role in the steel industry, manufacture molten pig iron, molten iron, using iron ore and coal as raw materials.

In order to solve the problems of the blast furnace method, many countries around the world are putting a lot of effort into the development of the molten reduction steelmaking method. In the molten reduction steelmaking method, molten iron is produced in a molten gas furnace using direct coal as a fuel and a reducing agent, and iron ore directly as an iron source. Here, oxygen is blown into the melt gasifier to combust the coal packed bed in the melt gasifier. Oxygen is converted to high-temperature reducing gas and sent to a reduction furnace to reduce iron ore and discharged to the outside.

When the temperature of the reducing gas discharged from the molten gasifier is too high, it adds a thermal burden to the auxiliary equipment, and iron ore adheres to the inside of the reduction furnace, thereby deteriorating breathability. Therefore, the temperature of the reducing gas should be lowered appropriately and supplied to the reduction furnace.

On the other hand, various apparatuses are used in steel mills for steel production, and hydrogen is required to operate these apparatuses. In order to produce large quantities of hydrogen, a liquid natural gas steam reformer is used. Reactors included in the LNG steam reformer need to be kept at a high temperature for reforming and therefore require an additional heat source. Therefore, since the reactor must have an additional heat source, there is a problem that the energy efficiency is lowered.

The present invention is to solve the above problems, to provide a molten iron manufacturing apparatus for producing hydrogen by using the sensible heat of the reducing gas discharged from the molten gasifier.

In addition, the present invention is to provide a molten iron manufacturing method for producing hydrogen using the sensible heat of the reducing gas discharged from the molten gasifier.

In the molten iron manufacturing apparatus according to an embodiment of the present invention, i) at least one reduction furnace for reducing iron ore to reduce iron, ii) is connected to a reduction furnace is charged with reduced iron, the bulk carbon is charged, oxygen is blown A molten gasification furnace for producing molten iron, iii) a reducing gas supply pipe for cooling the reducing gas generated and discharged from the molten gasifier and supplying it to one or more reduction furnaces, and iv) a hydrocarbon-containing gas by the heat released while cooling the reducing gas. A reformer that generates a reformed gas by reforming.

The reformer may include a reforming pipe installed inside the reducing gas supply pipe to absorb the heat to generate the reformed gas. The hydrocarbon-containing gas may flow in the reforming pipe, and the hydrocarbon-containing gas may flow in a direction parallel to the direction in which the reducing gas flows.

The reformer may further include a discharge pipe connected to one end of the reforming pipe to discharge the reformed gas. The reformed gas can be fed to one or more reduction furnaces via a discharge pipe. The discharge pipe may be connected to the reducing gas supply pipe to supply the reformed gas to the reducing gas supply pipe. The reforming gas may include hydrogen or carbon monoxide.

The reformer may further include i) a discharge pipe connected to one end of the reforming pipe to discharge the reformed gas, and ii) a supply pipe connected to the other end of the reforming pipe to supply the hydrocarbon-containing gas. The other end of the reforming tube may be located closer to the melt gasifier than one end of the reforming tube. The reforming pipe may be located near the reducing gas outlet to the melt gasifier.

The hydrocarbon containing gas may contain water. The reforming gas may comprise hydrogen. The reducing gas may be cooled to 700 ° C. to 900 ° C. by the reformer. The reduction furnace may be a fluidized bed reduction furnace or a packed bed reduction furnace.

The method for manufacturing molten iron according to an embodiment of the present invention includes the steps of: i) charging iron ore into one or more reduction furnaces to produce reduced iron, and ii) charging the bulk coal material into a molten gasifier to form a coal-filled layer inside the molten gasifier. Forming, iii) charging reduced iron into the melt gasifier, iv) blowing oxygen into the melt gasifier to melt the reduced iron, and v) cooling the reduced gas generated in the melt gasifier to And supplying the above-mentioned reduction furnace, and vi) generating a reformed gas by reforming a hydrocarbon-containing gas by using heat released during cooling of the reducing gas.

The molten iron manufacturing method according to an embodiment of the present invention may further include the step of supplying the reformed gas to one or more reduction furnace. The reformed gas may be combined with the reducing gas and fed to the reduction furnace. The reforming gas may include hydrogen or carbon monoxide. In the step of producing the reformed gas, the hydrocarbon-containing gas may include moisture. The reforming gas may include hydrogen. In the step of supplying the reducing gas to one or more reduction furnaces, the reducing gas may be supplied by cooling to 700 ℃ to 900 ℃. In the step of producing reduced iron, the reducing furnace may be a fluidized bed reduction furnace or packed bed reduction furnace.

DETAILED DESCRIPTION Embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As can be easily understood by those skilled in the art, the embodiments described below may be modified in various forms without departing from the concept and scope of the present invention. Where possible the same or similar parts are represented with the same reference numerals in the drawings.

All terms including technical terms and scientific terms used below have the same meaning as those commonly understood by those skilled in the art. Terms defined in advance are additionally interpreted to have a meaning consistent with the related technical literature and the presently disclosed contents, and are not interpreted in an ideal or very formal sense unless defined.

Figure 1 schematically shows a molten iron manufacturing apparatus 100 according to an embodiment of the present invention.

As shown in FIG. 1, the apparatus for manufacturing molten iron 100 includes a plurality of flow reduction reactors 20, a melt gasifier 60, a reducing gas supply pipe 70, and a reformer 10. In addition, the compacted material manufacturing apparatus 40, the high temperature uniform pressure-reducing device 50, and the compacted material storage tank 52 may be further included as needed.

The molten iron manufacturing apparatus 100 manufactures molten iron by directly using iron ore and coal collected from a mountain region. First, iron ore is supplied to the flow reduction path 20 to flow iron ore in the flow reduction path (20). Iron ore may be used as iron ore, and if necessary, side materials may be used. A fluidized bed is formed inside the fluid reduction path 20 to reduce iron ore. The flow reduction path 20 includes a first flow reduction path 201, a second flow reduction path 203, a third flow reduction path 205, and a fourth flow reduction path 207. Although four flow reduction reactors are shown in FIG. 1, one or more flow reduction reactors may be used. In addition, although the flow reduction path is shown in FIG. 1, this is for illustrating the present invention and the present invention is not limited thereto. Therefore, other kinds of reduction furnaces may be used.

The first flow reduction path 201 preheats the iron ore with reducing gas discharged from the second flow reduction path 203. The second flow reduction path 203 and the third flow reduction path 205 preliminarily reduce the preheated iron ore. The fourth flow reduction reactor 207 finally converts the preliminarily reduced iron ore into reduced iron.

Iron ore is reduced and heated while passing through the fluid reduction path (20). The reducing gas generated and discharged from the melt gasifier 60 is supplied to the flow reduction path 20 through the reducing gas supply pipe 70. Therefore, iron ore may be reduced by reducing gas in the flow reduction reactor 20 to be produced with reduced iron. Reduced iron is manufactured into compacted material by the compacted material manufacturing apparatus 40.

The compacted material manufacturing apparatus 40 includes the charging hopper 401, a pair of roll 403, the crusher 405, and the storage tank 407. In addition, other devices may be further included as necessary. The charging hopper 401 stores the reduced iron. The reduced iron is press-molded in strip form while charging from the charging hopper 401 into the pair of rolls 403. The reduced iron thus compacted and molded is crushed in the crusher 405 and stored in the storage tank 407.

The reduced iron stored in the storage tank 407 is transferred to the melt gasifier (60). The high temperature uniform pressure-reducing apparatus 50 controls the pressure between both ends, and feeds the compacted material manufactured by the compacted material manufacturing apparatus 40 to the melt gasifier 60. The storage tank 52 temporarily stores the compacted material and charges the compacted material into the melt gasifier 60.

The bulk carbonaceous material is charged into the melting gasifier 60 to form a coal filling layer therein. The bulk coal material includes lump coal or coal briquettes. Coal briquettes are manufactured by press-molding fine coal. In addition, coke may be charged as needed. An air vent 80 is provided on the outer wall of the melt gasifier 60 to blow in oxygen. Oxygen is blown into the coal packed bed to form a combustion zone, and the bulk coal ash is burned in the combustion zone to generate reducing gas. The compacted material is melted by the combustion of the bulk carbon material and molten iron is produced and discharged to the outside.

The temperature of the reducing gas supplied to the flow reduction path 20 through the reducing gas supply pipe 70 is as high as 1000 ℃. Therefore, it is preferable to cool the reducing gas and adjust the temperature to 700 ° C. to 900 ° C. and then supply the reduced gas to the flow reduction reactor 20. When the temperature of the reducing gas is less than 700 ° C., the reduction rate of the iron ore flowing in the flow reduction path 20 is lowered. In addition, when the temperature of the reducing gas exceeds 900 ℃, iron ore flowing in the flow reduction path 20 may be adhered to the flow reduction path 20 to deteriorate breathability. Therefore, it is preferable to cool the reducing gas in the above-described temperature range.

As shown in FIG. 1, the apparatus for manufacturing molten iron 100 includes a reformer 10. The reformer 10 reforms the hydrocarbon-containing gas to generate a reformed gas. The reformer 10 requires a heat source to reform the hydrocarbon containing gas. Therefore, by supplying heat emitted from the reducing gas discharged through the reducing gas supply pipe 70 to the reformer 10, the hydrocarbon-containing gas may be reformed and the reducing gas may be cooled.

To this end, as shown in FIG. 1, the reformer 10 is installed in the reducing gas supply pipe 70. The reformer 10 includes discharge pipes 1031 and 1033 for discharging the reformed gas. The discharge pipes 1031 and 1033 include a first discharge pipe 1031 and a second discharge pipe 1033. Since the 1st valve 1031 and the 2nd valve 1033 are provided in the 1st discharge pipe 1031 and the 2nd discharge pipe 1033, respectively, it can adjust to the supply direction of reformed gas. Since the rest of the reformer 10 can be easily understood by those skilled in the art, detailed description thereof will be omitted.

When the first valve 1031 is opened and the second valve 1033 is closed, the reformed gas may be supplied to the flow reduction path 20 through the first discharge pipe 1031. Since the first discharge pipe 1031 is connected to the reducing gas supply pipe 70, the reformed gas is supplied to the reducing gas supply pipe 70. The reformed gas is combined with the reducing gas in the reducing gas supply pipe 70 and supplied to the flow reducing path 20. Since the reformed gas contains a component capable of reducing iron ore, the reduction rate of iron ore can be improved. Although the first discharge pipe 1031 is illustrated in communication with the reducing gas supply pipe 70 in FIG. 1, the first discharge pipe 1031 may be directly connected to the flow reduction path 20.

On the other hand, when the first valve 1031 is closed and the second valve 1033 is opened, the reformed gas can be supplied to the outside via the second discharge pipe 1033. Since the reformed gas contains hydrogen, it can be supplied to a device that requires hydrogen in the steelworks.

In addition, both the first valve 1031 and the second valve 1033 may be opened to simultaneously supply the reformed gas to the flow reduction path 20 and to the outside. In addition, when the molten iron manufacturing apparatus 100 does not operate, both the first valve 1031 and the second valve 1033 may be closed and the operation of the reformer 10 may be stopped.

FIG. 2 is a schematic enlarged view of a portion II of FIG. 1. In FIG. 1, the II part is shown to be located on the left side of the melt gasifier 60, but the position of the II part is not limited thereto, and may be in the vicinity of the melt gasifier 60. Therefore, the portion II is shown in the upper portion of the melt gasifier 60 as shown in FIG.

As shown in FIG. 2, the reformer 10 includes a supply pipe 105, a reforming pipe 101, and a discharge pipe 103. The reforming pipe 101 is installed inside the reducing gas supply pipe 70 and includes one end 101a and the other end 101b. The discharge pipe 103 is connected to one end 101a of the reforming pipe 101, and the supply pipe 105 is connected to the other end of the reforming pipe 101. The supply pipe 105 supplies a hydrocarbon-containing gas to the reforming pipe 101. The hydrocarbon-containing gas includes a hydrocarbon and moisture (H ₂ O) as shown in FIG. Examples of hydrocarbons include LNG.

The hydrocarbon-containing gas supplied along the arrow direction (left direction) in FIG. 2 flows into the reforming pipe 101 and flows along the reforming pipe 101 in the arrow direction (upward direction). In this case, as shown by the plurality of arrows, the reforming pipe 101 absorbs the heat released from the reducing gas. Therefore, the hydrocarbon-containing gas flowing through the reforming pipe 101 is reformed by an endothermic reaction as shown in the following formula (1). That is, the water contained in the hydrocarbon-containing gas reacts with water to produce a reformed gas containing hydrogen and carbon monoxide.

CH ₄ + H ₂ O → 3H ₂ + CO 230 KJ / mol

At the same time, the reducing gas is cooled while losing heat to the reforming pipe 101. Therefore, it is possible to supply the reducing gas which is cooled and the temperature is appropriately adjusted to the flow reduction path 20 (shown in FIG. 1, hereinafter same).

As shown in the arrow direction (right direction) of FIG. 2, the reformed gas generated in the reforming pipe 101 is discharged to the outside through the discharge pipe 103. Since the reformed gas contains hydrogen (H ₂ ), it can be usefully supplied to the steelworks. In addition, since the reformed gas contains carbon monoxide (CO) in addition to hydrogen (H ₂ ), the reforming gas is excellent in reducing power. Therefore, the reformed gas may be supplied to the flow reduction path 20 to increase the reduction rate of iron ore.

As the reducing gas flows, its retained heat gradually decreases. That is, the reducing gas has a high calorific value when discharged through the reducing gas outlet 601 of the molten gas furnace 60, but the calorific value gradually decreases while flowing inside the reducing gas supply pipe 70. Therefore, as shown in FIG. 2, when the hydrocarbon-containing gas flows in a direction parallel to the direction in which the reducing gas flows (upward direction), the hydrocarbon-containing gas is brought into the reforming pipe 101 while contacting the reducing gas having a high calorific value. do. Accordingly, the hydrocarbon-containing gas can be reformed by sufficiently absorbing the sensible heat of the reducing gas, and the reducing gas can be appropriately cooled while sufficiently providing the sensible heat.

In other words, since the other end 101b of the reforming pipe 101 is located closer to the molten gasifier 60 than the one end 101a of the reforming pipe 101, the hydrocarbon-containing gas is well cooled as described above. Can be modified well. In particular, since the reforming pipe 101 is located near the reducing gas outlet 601, the cooling effect of the high temperature reducing gas can be increased.

Figure 3 schematically shows a molten iron manufacturing apparatus 200 according to another embodiment of the present invention. Since the apparatus for manufacturing molten iron 200 shown in FIG. 3 is similar to the apparatus for manufacturing molten iron 100 shown in FIG. 1, the same reference numerals are used for the same parts, and detailed description thereof will be omitted.

As shown in FIG. 3, the apparatus for manufacturing molten iron 200 includes one packed bed reduction furnace 55. Although not shown in FIG. 3, the apparatus for manufacturing molten iron may include a packed-bed reduction furnace and a fluidized-bed reduction furnace together. Further, the apparatus for manufacturing molten iron may include a plurality of packed bed reduction furnaces. Iron ore is charged into the packed-bed reduction reactor 55, and the reducing gas generated from the melt gasifier 60 is supplied to the packed-bed reduction reactor 55 through the reducing gas supply pipe 70. The reformer 10 may be used to improve the reducing power of the reducing gas. A packed bed is formed in the packed bed reduction furnace 55 to convert iron ore into reduced iron. The reduced iron is charged into the melt gasifier 60 and melted by the coal-filled layer formed by the bulk coal material. This method can be used to produce molten iron.

As described above, by using the sensible heat of the reducing gas discharged from the molten gasifier, the reformed gas may be manufactured and cooled at the same time. Therefore, it is possible to optimize the reduction rate of iron ore by means of a reducing gas whose temperature is appropriately controlled, while producing a large amount of hydrogen using a reformer.

Although the present invention has been described above, it will be readily understood by those skilled in the art that various modifications and variations are possible without departing from the spirit and scope of the claims set out below.

Claims (20)

At least one reduction furnace for reducing iron ore to produce reduced iron, A molten gasification furnace connected with the reduction furnace to charge the reduced iron, the bulk carbon material is charged, and the oxygen is blown to produce molten iron, A reducing gas supply pipe for cooling the reducing gas generated and discharged from the molten gasifier to supply the at least one reducing furnace, and A reformer for generating a reformed gas by reforming a hydrocarbon-containing gas by heat released while cooling the reducing gas. Iron manufacturing apparatus comprising a. The method of claim 1, The reformer is installed in the reducing gas supply pipe molten iron manufacturing apparatus including a reforming pipe for generating a reformed gas by absorbing the heat. The method of claim 2, And a hydrocarbon-containing gas flows inside the reforming pipe, and the hydrocarbon-containing gas flows in a direction parallel to a direction in which the reducing gas flows. The method of claim 2, The reformer further includes a discharge pipe connected to one end of the reforming pipe to discharge the reformed gas, and supplies the reformed gas to the at least one reduction furnace through the discharge pipe. The method of claim 4, wherein The discharge pipe is connected to the reducing gas supply pipe for manufacturing molten iron for supplying the reformed gas to the reducing gas supply pipe. The method of claim 4, wherein The reforming gas is molten iron manufacturing apparatus containing hydrogen or carbon monoxide. The method of claim 2, The reformer, A discharge pipe connected to one end of the reforming pipe to discharge the reformed gas, and A supply pipe connected to the other end of the reforming pipe to supply the hydrocarbon-containing gas; More, And the other end of the reforming pipe is located closer to the molten gasifier than one end of the reforming pipe. The method of claim 2, The reforming pipe is molten iron manufacturing apparatus located in the vicinity of the reducing gas discharge port of the molten gasifier. The method of claim 1, The hydrocarbon-containing gas is molten iron manufacturing apparatus containing water. The method of claim 9, The reforming gas manufacturing apparatus for molten iron containing hydrogen. The method of claim 1, The molten iron manufacturing apparatus for cooling the reducing gas to 700 ℃ to 900 ℃ by the reformer. The method of claim 1, The reduction furnace is a molten iron manufacturing apparatus is a fluidized bed reduction furnace or packed bed reduction furnace. Charging iron ore into one or more reduction furnaces to produce reduced iron, Charging a lumped carbonaceous material into a molten gasifier to form a coal filling layer inside the molten gasifier; Charging the reduced iron into the melt gasifier; Manufacturing molten iron by injecting oxygen into the molten gasifier to melt the reduced iron; Cooling the reducing gas generated in the molten gasifier to supply the at least one reducing furnace, and Generating a reformed gas by reforming a hydrocarbon-containing gas by using heat released during cooling of the reducing gas; Iron manufacturing method comprising a. The method of claim 13, And supplying the reformed gas to the one or more reduction furnaces. The method of claim 14, The molten iron manufacturing method for supplying the reformed gas to the reducing furnace combined with the reducing gas. The method of claim 13, The reforming gas is a molten iron manufacturing method containing hydrogen or carbon monoxide. The method of claim 13, In the step of producing the reformed gas, the hydrocarbon-containing gas manufacturing method containing molten iron. The method of claim 16, The reforming gas is a molten iron manufacturing method containing hydrogen. The method of claim 13, In the step of supplying the reducing gas to the at least one reduction furnace, molten iron manufacturing method for cooling the reducing gas to 700 ℃ to 900 ℃ supplied. The method of claim 13, In the step of producing the reduced iron, the reduction furnace is a molten iron manufacturing method is a fluidized bed reduction furnace or packed-bed reduction furnace.

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