KR101690741B1 - Recycle apparatus for unreacted gas and method thereof - Google Patents

Recycle apparatus for unreacted gas and method thereof Download PDF

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Publication number
KR101690741B1
KR101690741B1 KR1020150140719A KR20150140719A KR101690741B1 KR 101690741 B1 KR101690741 B1 KR 101690741B1 KR 1020150140719 A KR1020150140719 A KR 1020150140719A KR 20150140719 A KR20150140719 A KR 20150140719A KR 101690741 B1 KR101690741 B1 KR 101690741B1
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South Korea
Prior art keywords
heat exchanger
unreacted gas
compressor
discharged
temperature
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KR1020150140719A
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Korean (ko)
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김남일
이민정
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한국과학기술원
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/52—Manufacture of steel in electric furnaces
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/56—Manufacture of steel by other methods
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
    • F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C2100/00—Exhaust gas
    • C21C2100/04—Recirculation of the exhaust gas
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C2100/00—Exhaust gas
    • C21C2100/06—Energy from waste gas used in other processes
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C2200/00—Recycling of waste material

Abstract

According to an embodiment of the present invention, a recycle apparatus for unreacted gas generated by an iron-manufacturing system, comprises: a first heat exchanger; a second heat exchanger; and a compressor. After at least a part of the unreacted gas passes through the first heat exchanger, the second heat exchanger, and the compressor, a part of the unreacted gas passes through the first heat exchanger again to flow into the iron-manufacturing system again. The unreacted high temperature gas which has flown from the iron-manufacturing system, exchanges heat with the low temperature unreacted gas which has flowed from the compressor in the first heat exchanger. The unreacted gas, which has flowed from the iron-manufacturing system to the first heat exchanger, radiates heat and is discharged to the second heat exchanger. The unreacted gas, which has flowed into the second heat exchanger, exchanges heat with fuel or an oxidizing agent in the second heat exchanger. The unreacted gas, which has flowed into the second heat exchanger, radiates heat and is discharged to the compressor. The unreacted gas, which has flowed into the compressor, is compressed and discharged to the first heat exchanger. The heat of the unreacted gas, which has flowed from the compressor to the first heat exchanger, is absorbed, and the unreacted gas is discharged to the iron-manufacturing system. The heat of the fuel or the oxidizing agent, which has flowed into the second heat exchanger, is absorbed; and the fuel or the oxidizing agent is discharged to the iron-manufacturing system. The present invention aims to provide a recycle apparatus for unreacted gas and a method thereof, which is able to satisfy various required temperature conditions and simultaneously collect and reuse both heat energy and chemical energy of unreacted gas.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a recycle apparatus for recycling an unreacted gas, a recycle method, an electric arc furnace having the recycle apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus for recycling unreacted gases, and more particularly, to a high-efficiency energy utilization system capable of simultaneously recovering thermal energy and chemical energy of unreacted gases.

When iron oxide such as magnetite is melted at a high temperature in a general steel making process, pure iron is obtained by introducing hydrocarbons such as coke into the melting furnace so that oxygen bonded with iron is combined with carbon. The electric arc furnace is a melting facility for producing steel by dissolving iron scrap (scrap iron) of various qualities by generating a high-power arc, and likewise hydrocarbons are injected when iron scrap is melted. In this process, a large amount of unreacted gas such as CO is generated, and the unreacted gas is burned and discharged into the air without using the energy of the unreacted gas again. In addition, in particular, in the case of electric arc furnaces, the use of large amounts of electricity is a burden on the national power supply and demand. Therefore, there is a need for a device capable of recovering the energy of the unreacted gas again.

In order to solve such a problem, there is a method of preheating the iron scrap 124 by using the sensible heat of the high-temperature exhaust gas discharged from the electric arc furnace body 1 shown in FIG. 1. In this case, Temperature exhaust gas containing unreacted gas discharged from the body of the main body 1 and the exhaust gas is brought into contact with the iron scrap 124 filled in the iron scrap preheater 5, To the outside.

However, steel scrap has various composition and quality. Especially, it is in contact with various machine oils or treated with coating materials, so it is inevitable that harmful harmful substances (dioxins, furans, etc.) It is becoming a target. Therefore, at present, in Korea, the steel scrap is directly charged by opening the top of the electric arc without performing any pretreatment including the preheating of the iron scrap. This is because the cooling and reheating are repeated due to the discharge of the high temperature thermal energy in the electric arc, It is difficult to expect energy and electric energy savings.

In addition, as shown in FIG. 2, the scrap is heated by using the heat of combustion of the additional fuel and the oxidizer, thereby reducing the burden of using the electric power of the scrap and discharging the various odor-inducing substances generated in the scrap heating process through the high temperature melting furnace So that odor can be removed together. In this case, in addition to a large amount of CO generated in general, the generation of unreacted gases such as CO and H2 increases due to the additional supplied fuel. The preheated oxygen and fuel are supplied to the recovery combustion device 220 and the combustion is generated in the recovery combustion space 221 to completely combust the exhaust gas and to be introduced into the second internal space 213 of the recovery device body 210 There is a method in which oxygen and fuel are preheated by heat exchange with exhaust gas that has been completely burned and then preheated in the preheating chamber 125 to preheat the iron scrap 124 stored in the preheating chamber 125. In this case, The temperature of the exhaust gas is lowered to the ignition temperature or lower, so that the combustion performance is lowered and a separate ignition source is required.

3, there is a method in which the unreacted gas is directly introduced into the steel scrap preheater 400 by using the compressor 50 and then combusted to reuse the chemical energy of the unreacted gas. However, Since the discharge temperature of the temperature of the reaction gas is a high temperature of 1000 K or more, there are many practical difficulties in using the compressor 50 at the temperature. Therefore, the temperature of the unreacted gas must be lowered, but this causes a considerable amount of sensible heat loss. The calorific value of the unreacted gas is lower than that of the conventional fuel, and the sensible heat loss greatly reduces the improvement in the efficiency that can be expected with the unreacted gas. Also, in order to smoothly burn unreacted gas having a low calorific value, there is a problem that the temperature of the unreacted gas just before being input to the scrap preheater 400 must be raised again. Further, when the unreacted gas is burned at an excessively high temperature, it is required to regulate an appropriate temperature range since the CO is released and CO is generated again when the unreacted gas is burned at an excessively high temperature .

Therefore, it is necessary to develop a recirculating apparatus for unreacted gas which can simultaneously recover thermal energy and chemical energy of unreacted gas while satisfying various required temperature conditions and reuse it.

Korean Patent Publication No. 10-2014-0131608

An object of the present invention is to provide an apparatus and a method for recycling unreacted gases which can simultaneously recover heat energy and chemical energy of unreacted gases while satisfying various required temperature conditions.

An apparatus for recycling unreacted gas generated in a steel making system according to an embodiment of the present invention includes a first heat exchanger; A second heat exchanger; Wherein at least a portion of the unreacted gas passes through the first heat exchanger, the second heat exchanger and the compressor, passes through the first heat exchanger again and flows into the steel making system, The unreacted gas at a high temperature introduced from the iron-making system and the unreacted gas at a low temperature introduced from the compressor are heat-exchanged in the first heat exchanger, and the unreacted gas introduced into the first heat exchanger in the iron- The unreacted gas flowing into the second heat exchanger is heat-exchanged with the fuel or the oxidant introduced into the second heat exchanger, and the unreacted gas introduced into the second heat exchanger is radiated, Wherein the unreacted gas introduced into the compressor is compressed by the compressor and discharged to the first heat exchanger, In the compressor, the unreacted gas introduced into the first heat exchanger is absorbed and discharged to the steel making system, and the fuel or the oxidizer introduced into the second heat exchanger absorbs heat and is discharged to the steel making system.

Further, an electric arc furnace equipped with a recirculation device for unreacted gas according to an embodiment of the present invention includes: a melting furnace; Iron scrap preheating system; A first heat exchanger; A second heat exchanger; And at least a portion of the unreacted gas generated in the melting furnace passes through the first heat exchanger, the second heat exchanger, and the compressor, passes through the first heat exchanger again, Wherein the high temperature unreacted gas introduced into the melting furnace and the low temperature unreacted gas introduced from the compressor are heat-exchanged in the first heat exchanger, and the high temperature unreacted gas introduced into the first heat exchanger The unreacted gas is radiated and discharged to the second heat exchanger, the unreacted gas introduced into the second heat exchanger and the fuel or the oxidant are heat-exchanged in the second heat exchanger, and the unreacted gas And the unreacted gas introduced into the compressor is compressed in the compressor to be discharged to the first heat exchanger The unreacted gas flowing into the first heat exchanger in the compressor is absorbed and discharged to the steel scrap preheater, and the fuel or oxidizer introduced into the second heat exchanger absorbs heat and is discharged to the steel scrap preheater do.

The method for recycling unreacted gas, which re-introduces at least a part of the unreacted gas generated in the iron manufacturing system according to the embodiment of the present invention into the steel making system, is characterized in that the unreacted gas introduced at the high- Exchanging the unreacted gas in the first heat exchanger; The unreacted gas flowing into the first heat exchanger in the steelmaking system is discharged to the second heat exchanger; Exchanging the unreacted gas and the fuel or the oxidant introduced into the second heat exchanger in the second heat exchanger; The unreacted gas flowing into the second heat exchanger is discharged to the compressor; Wherein the unreacted gas introduced into the compressor is compressed in the compressor and discharged to the first heat exchanger, and the unreacted gas introduced into the first heat exchanger in the compressor is absorbed and discharged to the steel making system; And a step in which the fuel or the oxidant introduced into the second heat exchanger is absorbed and discharged to the steel making system, and at least a part of the unreacted gas is introduced into the first heat exchanger, the second heat exchanger, Passes through the first heat exchanger, and then flows back into the steel making system.

A method of operating an electric arc furnace having an unreacted gas recirculating device for introducing at least a part of unreacted gas generated in a melting furnace according to an embodiment of the present invention into an iron scrap preheater, The unreacted gas and the low-temperature unreacted gas introduced from the compressor are heat-exchanged in the first heat exchanger; And discharging the unreacted gas flowing into the first heat exchanger in the melting furnace to the second heat exchanger; Exchanging the unreacted gas and the fuel or the oxidant introduced into the second heat exchanger in the second heat exchanger; The unreacted gas flowing into the second heat exchanger is discharged to the compressor; The unreacted gas introduced into the compressor is compressed in a compressor and discharged to the first heat exchanger, and the unreacted gas introduced into the first heat exchanger in the compressor is absorbed and discharged to the scrap preheater; And the fuel or the oxidant introduced into the second heat exchanger is absorbed and discharged to the scrap preheating apparatus, and at least a part of the unreacted gas is discharged to the first heat exchanger, the second heat exchanger, Passes through the first heat exchanger, and flows into the steel scrap preheater.

The recycling apparatus for the unreacted gas according to the embodiment of the present invention has the effect of simultaneously recovering the thermal energy and the chemical energy of the unreacted gas while satisfying various required temperature conditions and reusing it.

Figs. 1 to 3 are views showing an electric arc furnace for recovering energy of an unreacted gas. Fig.
4 is a view showing an apparatus for recycling unreacted gas according to an embodiment of the present invention.
5 is a Ts diagram for explaining heat exchange occurring in the recirculating apparatus for unreacted gas according to an embodiment of the present invention shown in FIG.
FIG. 6 is a view for explaining a recirculation method of unreacted gas according to an embodiment of the present invention shown in FIG.
7 is a view showing an apparatus for recycling unreacted gas according to still another embodiment of the present invention.
Fig. 8 is a Ts diagram for explaining heat exchange occurring in the recirculating apparatus of unreacted gas according to another embodiment of the present invention shown in Fig. 7; Fig.
9 is a view for explaining a recirculation method of unreacted gas according to another embodiment of the present invention shown in FIG.
10 is a view showing an apparatus for recycling unreacted gas according to still another embodiment of the present invention.
Fig. 11 is a Ts diagram for explaining heat exchange occurring in the recycling apparatus for unreacted gas according to another embodiment of the present invention shown in Fig. 10; Fig.
12 is a view showing an electric arc furnace equipped with an apparatus for recycling unreacted gas according to an embodiment of the present invention.
FIG. 13 is a view for explaining an operation method of an electric arc furnace equipped with a recirculating apparatus for an unreacted gas according to an embodiment of the present invention shown in FIG. 12;
14 is a view showing an electric arc furnace equipped with an apparatus for recycling unreacted gas according to still another embodiment of the present invention.
FIG. 15 is a view for explaining an operation method of an electric arc furnace equipped with a recirculation apparatus for an unreacted gas according to still another embodiment of the present invention shown in FIG. 14;
16 is a view showing an electric arc furnace equipped with an apparatus for recycling unreacted gas according to still another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, particular advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements are assigned the same number as much as possible even if they are displayed on different drawings. Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 4 is a view showing an apparatus for recycling unreacted gas according to an embodiment of the present invention.

As shown in FIG. 4, the non-reacted gas recycling apparatus 100 according to an embodiment of the present invention may include a first heat exchanger 10 and a compressor 50.

The first heat exchanger 10 according to an embodiment of the present invention may include a first fluid path for guiding the first fluid and a second fluid path for guiding the second fluid, 2 fluid may be formed so that the contact surface of the first fluid path and the second fluid path is large.

The compressor 50 according to an embodiment of the present invention may be a general compressor and may pressurize the first fluid or the second fluid.

FIG. 5 is a Ts diagram for explaining heat exchange occurring in a recirculating apparatus of unreacted gas according to an embodiment of the present invention shown in FIG. 4, and FIG. 6 is a cross- Fig. 3 is a view for explaining a recirculation method of the reaction gas. Fig.

4 and 5, an unreacted gas recycling apparatus 100 according to an embodiment of the present invention is a system in which unreacted gas generated in a steel making system 200 is introduced into the first heat exchanger 10 and / After passing through the compressor 50, it may pass back to the first heat exchanger and back into the iron making system 200. 6, the high temperature unreacted gas introduced from the iron manufacturing system 200 and the low temperature unreacted gas introduced from the compressor 50 perform heat exchange in the first heat exchanger 10 (S110) , The unreacted gas introduced into the compressor 50 may be compressed in the compressor 50 (S130).

Specifically, unreacted gas having a high discharge temperature (T 0 ) is introduced into the first heat exchanger (10) from the steel making system (200) by being sucked through the compressor (50) (S100). When the high temperature unreacted gas is heat-exchanged with the low temperature unreacted gas introduced into the first heat exchanger 10 from the compressor 50 (S110), the temperature of the unreacted gas is released to the first temperature T 1 , The unreacted gas is discharged to the compressor 50 (S120).

When the unreacted gas at the first temperature T 1 flowing into the compressor 50 from the first heat exchanger 10 is adiabatically compressed, the temperature of the unreacted gas again rises to the second temperature T 2 , The reaction gas is discharged again to the first heat exchanger 10 (S130). At this time, the temperature of the unreacted gas can be increased to a second temperature (T 2 ) which is equal to or lower than the maximum temperature at which the compressor (50) can operate.

The unreacted gas at the second temperature (T 2 ) which is the low temperature introduced from the compressor (50) into the first heat exchanger (10) is discharged from the high-temperature system (200) When T 0) of the non-reacted gas and the heat exchange (S140), the heat absorption and then the unreacted gas temperature is increased again, the unreacted gas is again discharged to the steel system (200) (S150). At this time, since the temperature of the unreacted gas flowing back to the steelmaking system 200 is increased to the level of the high exhaust temperature (T 0 ), the sensible heat loss of the unreacted gas can be minimized. At this time, if the temperature of the unreacted gas flowing back to the iron making system 200 is equal to or higher than the minimum igniting temperature, additional energy consumption for maintaining the flame can be minimized. As described above, the temperature of the unreacted gas is lowered to a temperature at which the compressor (50) can operate by using the first heat exchanger (10) in a temperature range in which the compressor (50) The sensible heat loss of the unreacted gas flowing into the steel making system 200 can be minimized and the temperature can be raised again to the ignition enabling temperature. Therefore, by using a complex Brayton cycle consisting of a two-step constant-pressure process, a one-step adiabatic compression process and a heat exchange with a fuel or an oxidizing agent between the unreacted gases as described above, the heat energy of the unreacted gas All of the chemical energy can be recirculated. As described above, under the condition that the pressure rise of the compressor is not large, a substantial object can be achieved by only heat exchange between the unreacted gas flowing into the compressor and the unreacted gas discharged from the compressor.

7 is a view showing an apparatus for recycling unreacted gas according to still another embodiment of the present invention. As shown in FIG. 7, the non-reacted gas recycling apparatus 100 according to another embodiment of the present invention may further include a second heat exchanger 20.

The first heat exchanger 10 and the second heat exchanger 20 according to another embodiment of the present invention include a first fluid path for guiding the first fluid and a second fluid path for guiding the second fluid And may be formed such that the contact surface of the first fluid path and the second fluid path is large so that heat exchange between the first fluid and the second fluid can occur well.

The compressor 50 according to another embodiment of the present invention may be a general compressor and may pressurize the first fluid or the second fluid.

FIG. 8 is a Ts diagram for explaining heat exchange occurring in the recirculating apparatus of unreacted gas according to another embodiment of the present invention shown in FIG. 7, and FIG. 9 is a view showing another embodiment of the present invention shown in FIG. 7 FIG. 2 is a view for explaining a recirculation method of an unreacted gas according to the present invention.

7 and 8, an unreacted gas recycling apparatus 100 according to another embodiment of the present invention is a system in which unreacted gas generated in a steel making system 200 is introduced into a first heat exchanger 10, The second heat exchanger 20 and the compressor 50, and then flows back to the steel making system 200 through the first heat exchanger. Specifically, as shown in FIG. 9, the high temperature unreacted gas introduced from the iron manufacturing system 200 and the low temperature unreacted gas introduced from the compressor 50 perform heat exchange in the first heat exchanger 10 (S210) The unreacted gas introduced into the second heat exchanger 20 and the fuel or the oxidant undergo heat exchange in the second heat exchanger 20 at step S230 and the unreacted gas introduced into the compressor 50 is compressed (S250).

Specifically, unreacted gas having a high exhaust temperature T 0 is introduced into the first heat exchanger 10 from the steel making system 200 through the compressor 50 (S200). When the high temperature unreacted gas is heat-exchanged with the low temperature unreacted gas introduced into the first heat exchanger 10 from the compressor 50 (S210), the temperature of the unreacted gas is discharged to the first temperature T 1 , And the unreacted gas is discharged to the second heat exchanger 20 (S220).

The unreacted gas at the first temperature T 1 flowing into the second heat exchanger 20 from the first heat exchanger 10 is further heat-exchanged with the fuel or the oxidant introduced from the outside into the second heat exchanger 20 The temperature of the unreacted gas is lowered to the second temperature T 2 , and the unreacted gas is discharged to the compressor 50 (S240).

When the unreacted gas at the second temperature (T 2 ) introduced into the compressor (50) from the second heat exchanger (20) is adiabatically compressed, the temperature of the unreacted gas again rises to the first temperature (T 1 ) The reaction gas is discharged again to the first heat exchanger 10 (S250). At this time, the temperature of the unreacted gas can be increased to the first temperature (T 1 ) which is equal to or lower than the maximum temperature at which the compressor (50) can operate.

The unreacted gas of the low temperature first temperature T 1 flowing from the compressor 50 into the first heat exchanger 10 is discharged at a high temperature exhaust temperature T 0 ) (S260), the endothermic loss of the unreacted gas is minimized by increasing the temperature of the unreacted gas to the level of the exhaust temperature (T 0 ) The gas is discharged to the steel making system 200 again (S270). At this time, if the temperature of the unreacted gas flowing back to the iron making system 200 is equal to or higher than the minimum igniting temperature, additional energy consumption for maintaining the flame can be minimized.

When the fuel or the oxidant introduced from the outside into the second heat exchanger 20 is heat-exchanged with the unreacted gas introduced into the second heat exchanger 20 from the first heat exchanger 10, After the temperature rises, the fuel or oxidant is discharged to the iron making system 200. At this time, the fluid that is introduced into the second heat exchanger 20 and absorbs heat may be either a fuel or an oxidant, or a fluid in which a fuel and an oxidant are mixed.

Thus, the heat energy of the unreacted gas is transferred to the fuel or the oxidant introduced into the steel making system 200 by using the second heat exchanger 20 and the compressor 50 in the temperature range in which the compressor 50 can operate The temperature of the unreacted gas is lowered to a temperature at which the compressor 50 can be operated by using the first heat exchanger 10 and the unreacted gas is introduced into the steel making system 200 The sensible heat loss of the unreacted gas can be minimized by raising the temperature of the unreacted gas flowing into the steel making system 200 again. Therefore, by using a complex Brayton cycle consisting of a two-step constant-pressure process, a one-step adiabatic compression process and a heat exchange with a fuel or an oxidizing agent between the unreacted gases as described above, the heat energy of the unreacted gas All of the chemical energy can be recirculated. As described above, under the condition that the pressure rise of the compressor is not small, not only the heat exchange between the unreacted gas introduced into the compressor and the unreacted gas discharged from the compressor, but also the heat energy of the unreacted gas corresponding to the pressure rise of the compressor, There is an advantage that can be used for preheating.

10 is a view showing an apparatus for recycling unreacted gas according to still another embodiment of the present invention.

As shown in FIG. 10, the non-reacted gas recycling apparatus 100 according to another embodiment of the present invention may further include a third heat exchanger 30.

11 is a T-s diagram for explaining heat exchange occurring in a recirculating apparatus of unreacted gas according to another embodiment of the present invention shown in Fig.

10 and 11, an unreacted gas recycling apparatus 100 according to another embodiment of the present invention is a system in which unreacted gas generated in a steel making system 200 is introduced into a first heat exchanger 10, The second heat exchanger 20, the compressor 50 and the third heat exchanger 30 and then flowed back to the iron making system 200 through the first heat exchanger. At this time, the high-temperature unreacted gas introduced from the iron-making system 200 and the low-temperature unreacted gas introduced from the compressor 50 undergo heat exchange in the first heat exchanger 10 and flow into the second heat exchanger 20 The unreacted gas and the fuel or the oxidant are heat-exchanged in the second heat exchanger 20 and the unreacted gas introduced into the compressor 50 is compressed in the compressor 50 and the unreacted gas introduced into the third heat exchanger 30 The reaction gas and the fuel or the oxidizing agent can perform heat exchange in the third heat exchanger (30).

More specifically, unreacted gas having a high temperature exhaust temperature (T 0 ), which is sucked through the compressor (50) and introduced into the first heat exchanger (10) in the steel making system (200), is introduced into the first heat exchanger The unreacted gas is discharged to the second heat exchanger 20 after the temperature of the unreacted gas is lowered to the first temperature T 1 , and then the unreacted gas is discharged to the second heat exchanger 20.

The unreacted gas at the first temperature T 1 flowing into the second heat exchanger 20 from the first heat exchanger 10 is further heat-exchanged with the fuel or the oxidant introduced from the outside into the second heat exchanger 20 The temperature of the unreacted gas is lowered to the second temperature T 2 , and then the unreacted gas is discharged to the compressor 50.

When the unreacted gas of the second temperature (T 2 ) flowing into the compressor (50) from the second heat exchanger (20) is adiabatically compressed, the temperature of the unreacted gas is increased to the third temperature (T 3 ) Gas is discharged to the third heat exchanger (30). At this time, the third temperature T 3 may be equal to or lower than the maximum temperature at which the compressor 50 can operate.

When the unreacted gas at the third temperature T 3 flowing into the third heat exchanger 30 from the compressor 50 is further heat-exchanged with the fuel or the oxidant introduced from the outside into the third heat exchanger 20, Or the heat is released to bring the temperature of the unreacted gas to the first temperature T 1 , and then the unreacted gas is discharged to the first heat exchanger 10. At this time, when the third temperature T 3 is higher than the first temperature T 1 which is the temperature of the fuel or the oxidant flowing into the third heat exchanger 30, the temperature of the unreacted gas is released, a first temperature (T 1) to be lowered, and the third temperature (T 3) a first temperature (T 1), if lower than, the temperature is the first temperature of the unreacted gas, the unreacted gas is endothermic (T 1) . In FIG. 11, for example, the third temperature T 3 is higher than the first temperature T 1 .

The unreacted gas at the first temperature (T 1 ), which is the low temperature introduced from the third heat exchanger (30) into the first heat exchanger (10), is introduced into the first heat exchanger (10) Upon heat exchange with the unreacted gas at the discharge temperature (T 0 ), the temperature of the unreacted gas is increased again after the heat is absorbed, and then the unreacted gas is discharged to the steel making system 200 again. At this time, since the temperature of the unreacted gas flowing back into the steel making system 200 is increased to the level of the high temperature discharge temperature (T 0 ), the sensible heat loss of the unreacted gas can be minimized, If equal to or greater than the minimum possible temperature, additional energy consumption for flame retention can be minimized.

When the fuel or the oxidant introduced from the outside into the second heat exchanger 20 is heat-exchanged with the unreacted gas introduced into the second heat exchanger 20 from the first heat exchanger 10, After the temperature rises, the fuel or oxidant is discharged to the iron making system 200.

When the fuel or the oxidant introduced from the outside into the third heat exchanger 30 is heat-exchanged with the unreacted gas introduced into the third heat exchanger 30 from the compressor 50, the temperature of the fuel or the oxidant Is brought to the third temperature (T 3 ), and then the fuel or oxidant is discharged to the steel making system 200. At this time, when the first temperature T 1 is higher than the third temperature T 3 , the fuel or the oxidant dissipates so that the temperature of the fuel or oxidizer is lowered to the first temperature T 1 , T 3 ) is lower than the first temperature (T 1 ), the fuel or the oxidant is absorbed, and the temperature of the fuel or the oxidant is increased to the first temperature (T 1 ).

As described above, the thermal energy of the unreacted gas is supplied to the steelmaking system 200 using the second heat exchanger 20, the third heat exchanger 30, and the compressor 50 in a temperature range in which the compressor 50 can operate. The temperature of the fuel or the oxidizer can be increased by transferring the unreacted gas or the unreacted gas through the first heat exchanger 10 and the temperature of the unreacted gas is lowered to a temperature at which the compressor 50 can be operated using the first heat exchanger 10, The sensible heat loss of the unreacted gas can be minimized and the additional energy consumption for maintaining the flame can be minimized when the temperature is equal to or higher than the ignitable temperature. Therefore, by using a complex Brayton cycle consisting of a two-step constant-pressure process, a one-step adiabatic compression process and a heat exchange with a fuel or an oxidizing agent between the unreacted gases as described above, the heat energy of the unreacted gas All of the chemical energy can be recirculated. When the second heat exchanger and the third heat exchanger are used, there is an advantage that both the fuel and the oxidant can be preheated.

In the above description, the unreacted gas having passed through the second heat exchanger 20 flows into the third heat exchanger 30 through the compressor 50. However, the unreacted gas passing through the second heat exchanger 20 Gas may flow into the third heat exchanger 30 and heat-exchange with the fuel or the oxidant, and then may be introduced into the compressor 50. [

In the above, the iron making system 200 may be a melting furnace, and may be a steel making apparatus including a melting furnace and an auxiliary apparatus. In addition, the oxidant may be conventional air or oxygen introduced to assist combustion of the fuel.

12 is a view showing an electric arc furnace equipped with an apparatus for recycling unreacted gas according to an embodiment of the present invention. 12, an electric arc furnace 1000 provided with an unreacted gas recycling apparatus 100 according to an embodiment of the present invention includes an unreacted gas recycling apparatus 100, a melting furnace 300, A scrap preheater 400 may be included.

The unreacted gas recycle apparatus 100 of the electric arc furnace 1000 according to an embodiment of the present invention may include a first heat exchanger 10 and a compressor 50. [ The first heat exchanger 10 may include a first fluid path for guiding the first fluid and a second fluid path for guiding the second fluid, and heat exchange between the first fluid and the second fluid may well occur So that the contact surface of the first fluid path and the second fluid path is large.

The compressor 50 according to an embodiment of the present invention may be a general compressor and may pressurize the first fluid or the second fluid.

FIG. 13 is a view for explaining an operation method of an electric arc furnace equipped with a recirculating apparatus for an unreacted gas according to an embodiment of the present invention shown in FIG. 12;

12, at least part of the unreacted gas generated in the melting furnace 300 is introduced into the first heat exchanger 10 and the compressor 50 Passes through the first heat exchanger 10, and can flow back into the iron scrap preheater 400. Specifically, as shown in FIG. 13, the high-temperature unreacted gas introduced from the melting furnace 300 and the low-temperature unreacted gas introduced from the compressor 50 heat-exchange in the first heat exchanger 10 (S310) The unreacted gas introduced into the compressor 50 may be compressed in the compressor 50 (S330).

Specifically, the unreacted gas having a high discharge temperature is introduced into the first heat exchanger 10 from the melting furnace 300 through the compressor 50 (S300). When the high-temperature unreacted gas is heat-exchanged with the low-temperature unreacted gas introduced into the first heat exchanger 10 from the compressor 50 (S310), the temperature of the unreacted gas is reduced to the first temperature, Unreacted gas is discharged to the compressor 50 (S320).

When the unreacted gas at the first temperature flowing into the compressor 50 from the first heat exchanger 10 is adiabatically compressed, the temperature of the unreacted gas again rises to the second temperature, and then the unreacted gas is returned to the first heat exchanger (Step S330). At this time, the temperature of the unreacted gas can be increased to a second temperature that is equal to or lower than a maximum temperature at which the compressor 50 can operate.

The unreacted gas at the second temperature, which is the low temperature introduced from the compressor 50 into the first heat exchanger 10, is introduced into the first heat exchanger 10 from the steel making system 200, After the heat exchange (S340), the temperature of the unreacted gas is increased again after the endothermic reaction, and then the unreacted gas is discharged to the iron scrap preheater 400 (S350). At this time, the temperature of the unreacted gas flowing into the steel scrap preheater 400 may be equal to or higher than the minimum temperature at which the unreacted gas can ignite.

As described above, the temperature of the unreacted gas is lowered to a temperature at which the compressor (50) can operate by using the first heat exchanger (10) in a temperature range in which the compressor (50) The temperature of the unreacted gas flowing into the iron scrap preheater 400 can be raised again to the ignition temperature by re-performing the heat exchange just before entering the preheating device 400. Therefore, by using a complex Brayton cycle consisting of a two-step constant-pressure process, a one-step adiabatic compression process and a heat exchange with a fuel or an oxidizing agent between the unreacted gases as described above, the heat energy of the unreacted gas All of the chemical energy can be recirculated. As described above, under the condition that the pressure rise of the compressor is not large, a substantial object can be achieved by only heat exchange between the unreacted gas flowing into the compressor and the unreacted gas discharged from the compressor.

14 is a view showing an electric arc furnace equipped with an apparatus for recycling unreacted gas according to still another embodiment of the present invention. As shown in FIG. 14, the unreacted gas recycling apparatus 100 of the electric arcade 1000 according to another embodiment of the present invention may further include a third heat exchanger 10.

FIG. 15 is a view for explaining an operation method of an electric arc furnace equipped with a recirculation apparatus for an unreacted gas according to still another embodiment of the present invention shown in FIG. 14;

14, in an electric arc furnace 1000 according to another embodiment of the present invention, at least a part of the unreacted gas generated in the melting furnace 300 is introduced into the first heat exchanger 10, After passing through the heat exchanger 20 and the compressor 50, it may pass through the first heat exchanger again and flow into the iron scrap preheater 400 again. 15, the high temperature unreacted gas introduced from the melting furnace 300 and the low temperature unreacted gas introduced from the compressor 50 perform heat exchange in the first heat exchanger 10 (S410) The unreacted gas introduced into the second heat exchanger 20 and the fuel or the oxidant undergo heat exchange in the second heat exchanger 20 at step S430 and the unreacted gas introduced into the compressor 50 is compressed in the compressor 50 (S450).

Specifically, unreacted gas having a high discharge temperature is drawn into the first heat exchanger 10 from the melting furnace 300 through the compressor 50 (S400). When the high temperature unreacted gas is heat-exchanged with the low temperature unreacted gas introduced into the first heat exchanger 10 from the compressor 50 (S410), the temperature of the unreacted gas is reduced to the first temperature by heat radiation, Unreacted gas is discharged to the second heat exchanger 20 (S420).

When the unreacted gas of the first temperature flowing from the first heat exchanger 10 to the second heat exchanger 20 is further heat-exchanged with the fuel or the oxidant introduced from the outside into the second heat exchanger 20 (S430) The temperature of the unreacted gas is lowered to the second temperature, and the unreacted gas is discharged to the compressor 50 (S440).

When the unreacted gas at the second temperature flowing into the compressor 50 from the second heat exchanger 20 is adiabatically compressed, the temperature of the unreacted gas again rises to the first temperature, and then the unreacted gas is returned to the first heat exchanger (S450). At this time, the temperature of the unreacted gas can be increased to a first temperature which is equal to or lower than a maximum temperature at which the compressor 50 can operate.

The unreacted gas having the first temperature introduced from the compressor 50 into the first heat exchanger 10 flows into the first heat exchanger 10 from the iron manufacturing system 200 and the unreacted gas After the heat exchange (S460), the temperature of the unreacted gas is increased again after the heat absorption, and then the unreacted gas is discharged to the iron scrap preheater 400 (S470). At this time, the temperature of the unreacted gas flowing into the steel scrap preheater 400 may be equal to or higher than the minimum temperature at which the unreacted gas can ignite.

When the fuel or the oxidant introduced from the outside into the second heat exchanger 20 is heat-exchanged with the unreacted gas introduced into the second heat exchanger 20 from the first heat exchanger 10, After the temperature rises, the fuel or oxidant is discharged to the iron scrap preheater 400. At this time, the fluid that is introduced into the second heat exchanger 20 and absorbs heat may be either a fuel or an oxidant, or a fluid in which a fuel and an oxidant are mixed.

As described above, the heat energy of the unreacted gas is supplied to the fuel or the oxidizing agent introduced into the iron scrap preheater 400 by using the second heat exchanger 20 and the compressor 50 in a temperature range in which the compressor 50 can operate. The temperature of the unreacted gas is lowered to a temperature at which the operation of the compressor 50 can be performed by using the first heat exchanger 10 and the unreacted gas is supplied to the iron scrap preheater 400, the temperature of the unreacted gas flowing into the iron scrap preheater 400 can be raised again to the ignitable temperature. Therefore, by using a complex Brayton cycle consisting of a two-step constant-pressure process, a one-step adiabatic compression process and a heat exchange with a fuel or an oxidizing agent between the unreacted gases as described above, the heat energy of the unreacted gas All of the chemical energy can be recirculated. As described above, under the condition that the pressure rise of the compressor is not small, not only the heat exchange between the unreacted gas introduced into the compressor and the unreacted gas discharged from the compressor, but also the heat energy of the unreacted gas corresponding to the pressure rise of the compressor, There is an advantage that can be used for preheating.

16 is a view showing an electric arc furnace equipped with an apparatus for recycling unreacted gas according to still another embodiment of the present invention.

As shown in FIG. 16, the non-reacted gas recycling apparatus 100 according to another embodiment of the present invention may further include a third heat exchanger 30.

16, in an electric arc furnace 1000 according to another embodiment of the present invention, at least a part of the unreacted gas generated in the melting furnace 300 is introduced into the first heat exchanger 10, The steam may pass through the first heat exchanger 20, the compressor 50, and the third heat exchanger 30, and then may pass through the first heat exchanger and may be introduced into the iron scrap preheater 400. At this time, the high-temperature unreacted gas introduced from the melting furnace 300 and the low-temperature unreacted gas introduced from the compressor 50 heat-exchange in the first heat exchanger 10, The unreacted gas and the fuel or the oxidant are heat-exchanged in the second heat exchanger 20 and the unreacted gas introduced into the compressor 50 is compressed in the compressor 50 and the unreacted gas introduced into the third heat exchanger 30 The gas and the fuel or the oxidant can heat-exchange in the third heat exchanger.

More specifically, the unreacted gas at a high temperature, which is sucked through the compressor 50 and introduced into the first heat exchanger 10 from the melting furnace 300, is introduced into the first heat exchanger 10 from the compressor 50 When the heat is exchanged with the unreacted gas at a low temperature, the temperature of the unreacted gas is reduced to the first temperature, and the unreacted gas is discharged to the second heat exchanger 20.

When the unreacted gas at the first temperature flowing from the first heat exchanger 10 to the second heat exchanger 20 is further heat-exchanged with the fuel or the oxidant introduced into the second heat exchanger 20 from the outside, The temperature of the unreacted gas is further lowered to the second temperature, and then the unreacted gas is discharged to the compressor (50).

When the unreacted gas of the second temperature flowing into the compressor 50 from the second heat exchanger 20 is adiabatically compressed, the temperature of the unreacted gas is increased to the third temperature, and then the unreacted gas is introduced into the third heat exchanger 30 ). At this time, the third temperature may be equal to or lower than the maximum temperature at which the compressor 50 can operate.

When the unreacted gas of the third temperature flowing into the third heat exchanger 30 from the compressor 50 is further heat-exchanged with the fuel or the oxidant introduced into the third heat exchanger 20 from the outside, After the temperature of the reaction gas reaches the first temperature, the unreacted gas is discharged to the first heat exchanger (10). At this time, when the third temperature is higher than the first temperature, which is the temperature of the fuel or the oxidant flowing into the third heat exchanger 30, the temperature of the unreacted gas is lowered to the first temperature, When the third temperature is lower than the first temperature, the unreacted gas absorbs heat, and the temperature of the unreacted gas becomes higher to the first temperature.

The unreacted gas of the first temperature flowing from the third heat exchanger 30 into the first heat exchanger 10 is not reacted with the high temperature exhaust temperature flowing into the first heat exchanger 10 from the melting furnace 300, After the heat exchange with the gas, the temperature of the unreacted gas is increased again by the heat absorption, and then the unreacted gas is discharged to the iron scrap preheater 400. At this time, the temperature of the unreacted gas flowing into the steel scrap preheater 400 may be equal to or higher than the minimum temperature at which the unreacted gas can ignite.

When the fuel or the oxidant introduced from the outside into the second heat exchanger 20 is heat-exchanged with the unreacted gas introduced into the second heat exchanger 20 from the first heat exchanger 10, After the temperature rises, the fuel or oxidant is discharged to the iron scrap preheater 400.

When the fuel or the oxidant introduced from the outside into the third heat exchanger 30 is heat-exchanged with the unreacted gas introduced into the third heat exchanger 30 from the compressor 50, the temperature of the fuel or the oxidant The fuel or the oxidant is discharged to the iron scrap preheater 400. In this case, At this time, when the first temperature is higher than the third temperature, the temperature of the fuel or oxidizer is lowered to the first temperature by dissipating the fuel or the oxidant, and when the third temperature is lower than the first temperature, So that the temperature of the fuel or the oxidizer is increased to the first temperature.

As described above, the heat energy of the unreacted gas is supplied to the scrap heat preheating device 400 (400) by using the second heat exchanger 20, the third heat exchanger 30 and the compressor 50 in a temperature range in which the compressor 50 can operate. The temperature of the unreacted gas is lowered to a temperature at which the operation of the compressor 50 can be performed by using the first heat exchanger 10, The temperature of the unreacted gas can be raised again to the ignitable temperature by performing heat exchange again immediately before the reaction gas is introduced into the iron scrap preheater 400. [ Therefore, by using a complex Brayton cycle consisting of a two-step constant-pressure process, a one-step adiabatic compression process and a heat exchange with a fuel or an oxidizing agent between the unreacted gases as described above, the heat energy of the unreacted gas All of the chemical energy can be recirculated. When the second heat exchanger and the third heat exchanger are used, there is an advantage that both the fuel and the oxidant can be preheated.

In the above description, the unreacted gas having passed through the second heat exchanger 20 flows into the third heat exchanger 30 through the compressor 50. However, the unreacted gas passing through the second heat exchanger 20 Gas may flow into the third heat exchanger 30 and heat-exchange with the fuel or the oxidant, and then may be introduced into the compressor 50. [

The oxidant may be conventional air or oxygen introduced to assist combustion of the fuel.

The electric arc furnace 1000 equipped with the recycling apparatus 100 for the unreacted gas according to the embodiment of the present invention may further include the exhaust gas heat recovery apparatus 500 and the fan 600. [

Specifically, as shown in FIGS. 12, 14 and 16, the exhaust gas heat recovery apparatus 500 is an apparatus for recovering thermal energy of a high-temperature exhaust gas discharged from a melting furnace 300, To the fuel or oxidizing agent introduced into the preheating device (400). Therefore, the temperature of the fuel or the oxidant flowing into the second heat exchanger 20 of Fig. 14 is raised to the second temperature in advance, or the temperature of the fuel or the oxidant introduced into the third heat exchanger 30 of Fig. 1 < / RTI > temperature.

Thereafter, the exhaust gas is burned and purified, and then discharged through the fan 600 to the outside.

As described above, the electric arc furnace 1000 equipped with the recirculation apparatus 100 for unreacted gas according to the embodiment of the present invention is capable of preventing the smell gas generated in the iron scrap preheater 400 from being discharged to the outside, So that it is possible to remove odors.

The features, structures, effects and the like described in the embodiments are included in one embodiment of the present invention, and are not necessarily limited to only one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments can be combined and modified by other persons having ordinary skill in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

10: first heat exchanger
20: second heat exchanger
30: Third heat exchanger
50: Compressor
100: Recirculating device of unreacted gas
200: Steel system
300: melting furnace
400: Iron scrap preheating device
500: Flue gas heat recovery unit
600: Fan

Claims (28)

In an apparatus for recycling unreacted gas generated in a steel making system,
A first heat exchanger;
A second heat exchanger; And
A compressor,
After at least a portion of the unreacted gas has passed through the first heat exchanger, the second heat exchanger and the compressor, the second heat exchanger is re-
Wherein the high-temperature unreacted gas introduced from the iron-making system and the low-temperature unreacted gas introduced from the compressor heat-exchange in the first heat exchanger,
The unreacted gas flowing into the first heat exchanger in the steel making system is discharged to the second heat exchanger,
The unreacted gas flowing into the second heat exchanger and the fuel or the oxidant are heat-exchanged in the second heat exchanger,
The unreacted gas flowing into the second heat exchanger is discharged to the compressor,
The unreacted gas introduced into the compressor is compressed in the compressor and discharged to the first heat exchanger,
The unreacted gas flowing into the first heat exchanger in the compressor is absorbed and discharged to the steel making system,
Wherein the fuel or the oxidant introduced into the second heat exchanger is absorbed and discharged to the steel making system,
An apparatus for recycling unreacted gases. delete delete delete The method according to claim 1,
A third heat exchanger,
At least a portion of the unreacted gas passes through the third heat exchanger, passes through the first heat exchanger again,
Wherein the unreacted gas introduced into the third heat exchanger and the fuel or the oxidant are heat-exchanged in the third heat exchanger,
An apparatus for recycling unreacted gases. 6. The method of claim 5,
The unreacted gas flowing into the first heat exchanger in the steel making system is discharged to the second heat exchanger,
The unreacted gas flowing into the second heat exchanger is discharged to the compressor,
The unreacted gas introduced into the compressor is compressed and discharged to the third heat exchanger,
The unreacted gas introduced into the third heat exchanger is absorbed or radiated and discharged to the first heat exchanger,
The unreacted gas flowing into the first heat exchanger in the third heat exchanger is absorbed and discharged to the steel making system,
The fuel or the oxidant introduced into the second heat exchanger absorbs heat and is discharged to the steel making system,
Wherein the fuel or the oxidant introduced into the third heat exchanger is radiated or absorbed and discharged to the iron-
An apparatus for recycling unreacted gases. 7. The method according to any one of claims 1, 5, or 6,
Wherein a temperature of the unreacted gas discharged from the compressor is equal to or lower than a maximum temperature at which the compressor can operate,
An apparatus for recycling unreacted gases. 7. The method according to any one of claims 1, 5, or 6,
Wherein the temperature of the unreacted gas discharged into the iron-making system is equal to or higher than the minimum igniting temperature,
An apparatus for recycling unreacted gases. An electric arc furnace equipped with a recirculating device for unreacted gas,
Melting furnace;
Iron scrap preheating system;
A first heat exchanger;
A second heat exchanger; And
A compressor,
Wherein at least a part of the unreacted gas generated in the melting furnace passes through the first heat exchanger, the second heat exchanger and the compressor, passes through the first heat exchanger and flows into the iron scrap preheater,
The unreacted gas at a high temperature flowing in the melting furnace and the unreacted gas at a low temperature flowing in the compressor are heat-exchanged in the first heat exchanger,
The unreacted gas flowing into the first heat exchanger in the melting furnace is discharged to the second heat exchanger,
The unreacted gas flowing into the second heat exchanger and the fuel or the oxidant are heat-exchanged in the second heat exchanger,
The unreacted gas flowing into the second heat exchanger is discharged to the compressor,
The unreacted gas introduced into the compressor is compressed in the compressor and discharged to the first heat exchanger,
The unreacted gas flowing into the first heat exchanger in the compressor is absorbed and discharged to the scrap preheating device,
Wherein the fuel or oxidizer introduced into the second heat exchanger absorbs heat and is discharged to the scrap preheater.
Electric arc. delete delete delete 10. The method of claim 9,
A third heat exchanger,
At least a portion of the unreacted gas passes through the third heat exchanger, passes through the first heat exchanger again,
Wherein the unreacted gas introduced into the third heat exchanger and the fuel or the oxidant are heat-exchanged in the third heat exchanger,
Electric arc. 14. The method of claim 13,
The unreacted gas flowing into the first heat exchanger in the melting furnace is discharged to the second heat exchanger,
The unreacted gas flowing into the second heat exchanger is discharged to the compressor,
The unreacted gas introduced into the compressor is compressed and discharged to the third heat exchanger,
Wherein the unreacted gas introduced into the third heat exchanger from the compressor is discharged to the first heat exchanger by absorbing or dissipating heat,
The unreacted gas flowing into the first heat exchanger in the third heat exchanger is absorbed and discharged to the scrap preheating device,
The fuel or the oxidant flowing into the second heat exchanger is absorbed and discharged to the scrap preheater,
Wherein the fuel or the oxidant introduced into the third heat exchanger is radiated or absorbed and discharged to the iron scrap preheater,
Electric arc. The method according to any one of claims 9, 13, or 14,
Wherein a temperature of the unreacted gas discharged from the compressor is equal to or lower than a maximum temperature at which the compressor can operate,
Electric arc. The method according to any one of claims 9, 13, or 14,
Wherein the temperature of the unreacted gas discharged to the iron scrap preheater is equal to or higher than the minimum ignitable temperature,
Electric arc. A method for recycling an unreacted gas which re-introduces at least a portion of unreacted gas generated in a steel making system into a steelmaking system,
Reacting the high-temperature unreacted gas introduced from the iron-making system and the low-temperature unreacted gas introduced from the compressor with heat in a first heat exchanger;
The unreacted gas flowing into the first heat exchanger in the steelmaking system is discharged to the second heat exchanger;
Exchanging the unreacted gas and the fuel or the oxidant introduced into the second heat exchanger in the second heat exchanger;
The unreacted gas flowing into the second heat exchanger is discharged to the compressor;
The unreacted gas introduced into the compressor is compressed in the compressor and discharged to the first heat exchanger;
Reacting gas flowing into the first heat exchanger in the compressor is absorbed and discharged to the steel making system; And
Wherein the fuel or the oxidant introduced into the second heat exchanger is absorbed and discharged to the steel making system,
Wherein at least a portion of the unreacted gas passes through the first heat exchanger, the second heat exchanger and the compressor and then flows back to the ironing system through the first heat exchanger,
And recirculating the unreacted gas. delete delete delete 18. The method of claim 17,
Wherein a temperature of the unreacted gas discharged from the compressor is equal to or lower than a maximum temperature at which the compressor can operate,
And recirculating the unreacted gas. 18. The method of claim 17,
Wherein the temperature of the unreacted gas discharged into the iron-making system is equal to or higher than the minimum igniting temperature,
And recirculating the unreacted gas. A method of operating an electric arc furnace equipped with a recirculation device for an unreacted gas for introducing at least a part of unreacted gas generated in a melting furnace into an iron scrap preheater,
Reacting the high-temperature unreacted gas introduced from the melting furnace and the low-temperature unreacted gas introduced from the compressor in a first heat exchanger;
The unreacted gas flowing into the first heat exchanger in the melting furnace is discharged to the second heat exchanger;
Exchanging the unreacted gas and the fuel or the oxidant introduced into the second heat exchanger in the second heat exchanger;
The unreacted gas flowing into the second heat exchanger is radiated and discharged to the compressor;
The unreacted gas introduced into the compressor is compressed by the compressor and discharged to the first heat exchanger;
The unreacted gas flowing into the first heat exchanger in the compressor is absorbed and discharged to the scrap preheating device; And
And the fuel or the oxidant introduced into the second heat exchanger is absorbed and discharged to the scrap preheating device,
Wherein at least a portion of the unreacted gas passes through the first heat exchanger, the second heat exchanger, and the compressor, passes through the first heat exchanger, and flows into the iron scrap preheater.
Operation method of electric arc furnace. delete delete delete 24. The method of claim 23,
Wherein a temperature of the unreacted gas discharged from the compressor is equal to or lower than a maximum temperature at which the compressor can operate,
Operation method of electric arc furnace. 24. The method of claim 23,
Wherein the temperature of the unreacted gas discharged to the iron scrap preheater is equal to or higher than the minimum ignitable temperature,
Operation method of electric arc furnace.
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US4416689A (en) * 1980-10-15 1983-11-22 Asea Ab Process for the manufacture of crude iron and energy-rich gases
JPH1151584A (en) * 1997-07-30 1999-02-26 Kawasaki Heavy Ind Ltd Heat collector
KR20140131608A (en) 2013-05-02 2014-11-14 한국에너지기술연구원 Electric arc furnace with simultaneous scrap preheating and waste chemical energy recuperation system and it's operation method
JP2014227588A (en) * 2013-05-24 2014-12-08 新日鉄住金エンジニアリング株式会社 Apparatus for producing direct-reduced iron and method of producing direct-reduced iron
KR20150105068A (en) * 2014-03-07 2015-09-16 주식회사 에스에이씨 Electric arc furnaces and method for preheating scrap in lectric arc furnaces

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Publication number Priority date Publication date Assignee Title
US4416689A (en) * 1980-10-15 1983-11-22 Asea Ab Process for the manufacture of crude iron and energy-rich gases
JPH1151584A (en) * 1997-07-30 1999-02-26 Kawasaki Heavy Ind Ltd Heat collector
KR20140131608A (en) 2013-05-02 2014-11-14 한국에너지기술연구원 Electric arc furnace with simultaneous scrap preheating and waste chemical energy recuperation system and it's operation method
JP2014227588A (en) * 2013-05-24 2014-12-08 新日鉄住金エンジニアリング株式会社 Apparatus for producing direct-reduced iron and method of producing direct-reduced iron
KR20150105068A (en) * 2014-03-07 2015-09-16 주식회사 에스에이씨 Electric arc furnaces and method for preheating scrap in lectric arc furnaces

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Publication number Priority date Publication date Assignee Title
KR20230043481A (en) * 2021-09-24 2023-03-31 이화여자대학교 산학협력단 Thermochemical redox cycle producing hydrogen combined with bottoming cycle
KR102614862B1 (en) 2021-09-24 2023-12-19 이화여자대학교 산학협력단 Thermochemical redox cycle producing hydrogen combined with bottoming cycle

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