1
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
APPARATUS FOR DECOMPOSING TAR,
APPARATUS FOR PRODUCING MOLTEN IRON,
AND METHOD FOR PRODUCING MOLTEN
IRON;
POSCO, A CORPORATION ORGANIZED AND
EXISTING UNDER THE LAWS OF REPUBLIC
OF KOREA, WHOSE ADDRESS IS
(GOEDONG-DONG) 6261, DONGHAEAN-RO
NAM-GU, POHANG-SI GYEONGSANGBUK-DO
37859, REPUBLIC OF KOREA
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE INVENTION
AND THE MANNER IN WHICH IT IS TO BE
PERFORMED.
2
【DESCRIPTION】
【Invention Title】
APPARATUS FOR DECOMPOSING TAR, APPARATUS FOR
PRODUCING MOLTEN IRON, AND METHOD FOR PRODUCING MOLTEN
5 IRON
【Technical Field】
The present invention relates to an apparatus and a method for
manufacturing molten iron.
【Background Art】
10 Because a blast furnace process for producing molten iron causes a lot
of problems such as environmental pollution, researches are being conducted
on a direct iron ore smelting reduction process which is to be substituted for the
blast furnace process. The direct iron ore smelting reduction process
manufactures molten iron by directly using coal as fuel and a reducing agent and
15 directly using iron ore as an iron source.
The molten iron is manufactured by inputting the reduced iron ore and
the coal into a melting and gasifying furnace and melting the reduced iron ore.
A reducing furnace is used to reduce iron ore. The iron ore comes into contact
with reducing gas blown into the reducing furnace while flowing in the reducing
20 furnace. Therefore, the iron ore is converted into reduced iron and then
discharged from the reducing furnace. The reduced iron discharged from the
reducing furnace is inputted into the melting and gasifying furnace.
3
Meanwhile, tar, which is produced during a process of manufacturing
molten iron, is hydrocarbon in which carbon and hydrogen are complicatedly
bonded in the form of a chain or a benzene ring, and the amount of tar is about
15 to 20% of the amount of coal inputted into the melting and gasifying furnace.
5 If the tar remains as it is, the amount of reducing gas, which is produced in the
melting and gasifying furnace and supplied into the reducing furnace, is
insufficient, and as a result, it is necessary to decompose most of the tar into
reducing gas such as CO, H2, and CH4.
In a case in which the melting and gasifying furnace is configured to
10 decompose the tar therein, a dome space having a significant volume needs to
be provided at an upper side of the melting and gasifying furnace, and a large
amount of oxygen for combustion needs to be used to ensure a temperature of
the dome space. In addition, a gas cooling and circulating device needs to be
provided to adjust a temperature of the reducing gas to be supplied to the
15 connected reducing furnace, and as a result, there is a problem in that a
significant loss of energy occurs.
【DISCLOSURE】
【Technical Problem】
The present invention has been made in an effort to provide an
20 apparatus for decomposing tar and an apparatus and a method for
manufacturing molten iron, which are capable of reducing a size of a melting and
gasifying furnace for manufacturing molten iron, reducing a loss of coal and
energy, and increasing the amount of produced gas, thereby improving
4
economic feasibility.
【Technical Solution】
An exemplary embodiment of the present invention provides an
apparatus for manufacturing molten iron, the apparatus including: one or more
5 reducing furnaces which manufacture reduced iron by reducing ore; an input
device which inputs coal and the reduced iron discharged from the reducing
furnace into a melting and gasifying furnace; the melting and gasifying furnace
which combusts the coal supplied from the input device by using oxygen, and
melts the reduced iron by using combustion heat to manufacture molten iron;
10 and a tar decomposition furnace which is connected to the melting and gasifying
furnace, and decomposes a tar component included in gas discharged from the
melting and gasifying furnace.
The apparatus may include a uniform-pressure input device which is
connected to the tar decomposition furnace and inputs high-temperature
15 reduced iron or high-temperature reduced agglomerates into the tar
decomposition furnace.
The apparatus may include a partial combustion furnace which combusts
a part of gas discharged from the melting and gasifying furnace, and inputs the
gas into the tar decomposition furnace.
20 The apparatus may include: an oxygen blowing conduit which blows
oxygen into the partial combustion furnace; and a steam blowing conduit which
blows steam into the partial combustion furnace.
The apparatus may include an exhaust heat boiler which is connected to
5
the steam blowing conduit, and manufactures the steam by using sensible heat
of exhaust gas discharged from the reducing furnace.
The apparatus may include a uniform-pressure discharge device which is
connected to the tar decomposition furnace, and discharges high-temperature
5 reduced iron or high-temperature reduced agglomerates from the tar
decomposition furnace.
The tar decomposition furnace may include therein a filling layer which is
formed of the high-temperature reduced iron or the high-temperature reduced
agglomerates inputted by the uniform-pressure input device.
10 The apparatus may include a partial combustion furnace which combusts
a part of gas discharged from the melting and gasifying furnace, and inputs the
gas into the tar decomposition furnace.
The apparatus may include: an oxygen blowing conduit which blows
oxygen into the partial combustion furnace; and a steam blowing conduit which
15 blows steam into the partial combustion furnace.
The apparatus may include an exhaust heat boiler which manufactures
the steam by using sensible heat of exhaust gas discharged from the reducing
furnace, and is connected to the steam blowing conduit.
The apparatus may include a uniform-pressure discharge device which is
20 connected to the tar decomposition furnace, and discharges high-temperature
reduced iron or high-temperature reduced agglomerates from the tar
decomposition furnace.
The tar decomposition furnace may include therein a filling layer which is
formed of the high-temperature reduced iron or the high-temperature reduced
6
agglomerates inputted by the uniform-pressure input device.
The apparatus may include a uniform-pressure discharge device which is
connected to the tar decomposition furnace, and discharges high-temperature
reduced iron or high-temperature reduced agglomerates from the tar
5 decomposition furnace.
The tar decomposition furnace may include therein a filling layer which is
formed of the high-temperature reduced iron or the high-temperature reduced
agglomerates inputted by the uniform-pressure input device.
The apparatus may include: a high-temperature cyclone which separates
10 dust in gas discharged from the melting and gasifying furnace; and a gas conduit
which inputs the gas, from which the dust is separated, into the partial
combustion furnace.
The apparatus may include a differential pressure meter which is
connected to the tar decomposition furnace to monitor a level of pores in the
15 filling layer.
The apparatus may include a cooling device which cools the
high-temperature reduced iron discharged from the tar decomposition furnace.
The apparatus may further include: a high-temperature agglomeration
device which agglomerates reduced iron discharged from the reducing furnace;
20 and a conveying device which conveys high-temperature reduced agglomerates,
which are agglomerated by the high-temperature agglomeration device, to the
input device.
Another exemplary embodiment of the present invention provides an
apparatus for decomposing tar, the apparatus including: a tar decomposition
7
furnace which includes therein a filling layer formed of high-temperature reduced
iron or high-temperature reduced agglomerates, and decomposes a tar
component; a uniform-pressure input device which is connected to the tar
decomposition furnace, and inputs the high-temperature reduced iron or the
5 high-temperature reduced agglomerates into the tar decomposition furnace; a
partial combustion furnace which combusts a part of gas, and inputs the gas into
the tar decomposition furnace; and a uniform-pressure discharge device which is
connected to the tar decomposition furnace, and discharges high-temperature
reduced iron or high-temperature reduced agglomerates from the tar
10 decomposition furnace.
The apparatus may further include: an oxygen blowing conduit which
blows oxygen into the partial combustion furnace; and a steam blowing conduit
which blows steam into the partial combustion furnace.
The apparatus may further include an exhaust heat boiler which is
15 connected to the steam blowing conduit, and manufactures the steam by using
sensible heat of exhaust gas.
Still another exemplary embodiment of the present invention provides a
method of manufacturing molten iron, the method including: manufacturing
reduced iron by inputting ore into one or more reducing furnaces; inputting the
20 reduced iron and coal into a melting and gasifying furnace; manufacturing
molten iron by combusting the coal with oxygen and melting the reduced iron
with combustion heat; inputting gas discharged from the melting and gasifying
furnace into a tar decomposition furnace; and decomposing a tar component
included in the gas in the tar decomposition furnace.
8
The decomposing of the tar component may include: inputting the
reduced iron discharged from the reducing furnace and forming a reduced iron
filling layer in the tar decomposition furnace; and effectively decomposing a tar
component contained in the gas into reducing gas components by inputting the
5 gas discharged from the melting and gasifying furnace and allowing the gas to
pass through the reduced iron filling layer.
A constant volume of the reduced iron filling layer may be maintained as
an equal amount of reduced iron is continuously supplied into and discharged
from the tar decomposition furnace.
10 The method may further include combusting, in a partial combustion
furnace, a part of the gas discharged from the melting and gasifying furnace
before the inputting of the gas into the tar decomposition furnace.
The method may further include: blowing oxygen into the partial
combustion furnace through an oxygen blowing conduit before the combusting
15 of the part of the gas in the partial combustion furnace; and blowing steam into
the partial combustion furnace through a steam blowing conduit.
The method may include adjusting a ratio of oxygen and steam blown
into the partial combustion furnace provided in the tar decomposition furnace so
that the reducing gas, which is discharged from the tar decomposition furnace
20 when the decomposition of tar is completed, is maintained at a temperature of
700 to 800°C.
The steam in the blowing of the steam may be manufactured, by an
exhaust heat boiler, by using sensible heat of exhaust gas discharged from the
reducing furnace.
9
The decomposing of the tar component may include discharging
high-temperature reduced iron or high-temperature reduced agglomerates from
the tar decomposition furnace by a uniform-pressure discharge device.
The method may include cooling the high-temperature reduced iron
5 discharged from the tar decomposition furnace by a cooling device and inputting
the cooled high-temperature reduced iron back into the reducing furnace.
The method may further include: separating dust in high-temperature
reducing gas, which is discharged from the melting and gasifying furnace, by a
high-temperature cyclone connected to the melting and gasifying furnace; and
10 inputting the dust, which is separated by the high-temperature cyclone, back into
the melting and gasifying furnace by a dust burner connected to the melting and
gasifying furnace.
The method may further include supplying a part of the high-temperature
reducing gas into the reducing furnace and discharging the remaining part of the
15 high-temperature reducing gas to the outside in order to maintain a pressure in
the melting and gasifying furnace.
The method may further include: agglomerating reduced iron, which is
discharged from the reducing furnace, by a high-temperature agglomeration
device connected to the reducing furnace after the manufacturing of the reduced
20 iron; and conveying high-temperature reduced agglomerates agglomerated by
the high-temperature agglomeration device to the melting and gasifying furnace
by a conveying device.
【Advantageous Effects】
10
According to the present invention, it is possible to reduce a size of the
melting and gasifying furnace for manufacturing molten iron, reduce a loss of
coal and energy, increase the amount of produced gas, thereby improving
economic feasibility.
5 【Description of the Drawings】
FIG. 1 is a view schematically illustrating an apparatus for decomposing
tar according to an exemplary embodiment of the present invention.
FIG. 2 is a view schematically illustrating an apparatus for manufacturing
molten iron which is provided with the apparatus for decomposing tar according
10 to the exemplary embodiment of the present invention.
FIG. 3 is a view schematically illustrating the apparatus for
manufacturing molten iron which is provided with the apparatus for decomposing
tar according to the exemplary embodiment of the present invention.
FIG. 4 is a view illustrating an experimental result of measuring the
15 amount of gas, a change in temperature, and a change in composition at front
and rear ends of the apparatus for decomposing tar according to the exemplary
embodiment of the present invention.
【Mode for Invention】
Hereinafter, exemplary embodiments of the present invention will be
20 described in detail with reference to the accompanying drawings so that those
skilled in the technical field to which the present invention pertains may easily
carry out the exemplary embodiments. The present invention may be
implemented in various different ways, and is not limited to the exemplary
11
embodiments described herein.
A part irrelevant to the description will be omitted to clearly describe the
present invention, and the same or similar constituent elements will be
designated by the same reference numerals throughout the specification.
5 In addition, each configuration illustrated in the drawings is arbitrarily
shown for understanding and ease of description, but the present invention is not
limited thereto. In the drawings, some portions are enlarged for clear
expressions.
In addition, unless explicitly described to the contrary, the word
10 "comprise" and variations such as "comprises" or "comprising", will be
understood to imply the inclusion of stated elements but not the exclusion of any
other elements.
Then, an apparatus for decomposing tar according to an exemplary
embodiment of the present invention will be described in detail with reference to
15 the drawings.
FIG. 1 is a view schematically illustrating an apparatus for decomposing
tar according to an exemplary embodiment of the present invention.
Gas, which is inputted into a high-temperature cyclone 50, is separated
from dust at a rear end of the high-temperature cyclone 50, and the gas
20 separated from the dust is inputted into a partial combustion furnace 2 through a
gas conduit 1. The partial combustion furnace 2 is provided with an oxygen
blowing conduit 3 and a steam blowing conduit 4, and oxygen and steam are
blown into the partial combustion furnace 2 through the oxygen blowing conduit
3 and the steam blowing conduit 4, such that a part of the gas inputted into the
12
partial combustion furnace 2 is combusted by the oxygen, and also mixed with
the steam. The gas, which is partially combusted by the oxygen and mixed with
the steam, is inputted into a tar decomposition furnace 6 from a lower side of the
tar decomposition furnace 6 through a gas conduit 5.
5 A high-temperature reduced iron conveying device 7 and a
uniform-pressure input device 8 connected therewith are provided at an upper
side of the tar decomposition furnace 6 so that high-temperature reduced iron
may be inputted into the tar decomposition furnace 6 from a normal-pressure
place to a high-pressure place, such that the high-temperature reduced iron is
10 supplied into the tar decomposition furnace 6 so that a high-temperature
reduced iron filling layer is formed in the tar decomposition furnace 6.
The gas, which is inputted into the lower side of the tar decomposition
furnace 6, raises the high-temperature reduced iron filling layer, and in this
process, a tar component included in the gas reacts with steam, CO2, and the
15 like and is decomposed into CO, H2, CH4, and the like by using the reduced iron
as a catalyst. The gas in which the included tar is decomposed is discharged
from the upper side of the tar decomposition furnace 6 through a gas conduit 9,
the gas may be maintained at a temperature of about 700 to 800°C, and the
temperature of the gas is adjusted by adjusting a ratio of oxygen and steam to
20 be blown into the partial combustion furnace 2.
Meanwhile, pores of the reduced iron filling layer in the tar decomposition
furnace 6 are clogged by a significant amount of carbon produced during the
process of decomposing the tar and by dust included in the inputted gas, and a
function of the reduced iron, which serves as a catalyst for decomposing tar,
13
severely deteriorates if a degree to which the pores are clogged reaches a
certain or higher level. To prevent the deterioration, at the lower side of the tar
decomposition furnace 6, there are provided a first uniform-pressure discharge
device 10 which may discharge the reduced iron in the reduced iron filling layer
5 in the tar decomposition furnace 6 from a high-pressure place to a
normal-pressure place, and a conveying device 11 which conveys the
discharged high-temperature reduced iron.
The high-temperature reduced iron is supplied from the uniform-pressure
input device 8 as much as the high-temperature reduced iron is discharged from
10 the first uniform-pressure discharge device 10, such that the high-temperature
reduced iron filling layer having a constant volume may be maintained in the tar
decomposition furnace 6, and the pores may be constantly maintained in the
high-temperature reduced iron filling layer. Meanwhile, a differential pressure
meter 12 is provided at upper and lower sides of the tar decomposition furnace 6
15 in order to monitor a level of pores in the high-temperature reduced iron filling
layer.
Next, an apparatus for manufacturing molten iron which is provided with
the apparatus for decomposing tar according to the exemplary embodiment of
the present invention will be described in detail with reference to FIG. 2. A
20 detailed description of the constituent elements, which are identical to the
constituent elements of the apparatus for decomposing tar according to the
exemplary embodiment described with reference to FIG. 1, will be omitted.
FIG. 2 is a view schematically illustrating the apparatus for
manufacturing molten iron which is provided with the apparatus for decomposing
14
tar according to the exemplary embodiment of the present invention.
The apparatus for manufacturing molten iron illustrated in FIG. 2 may be
configured by applying the apparatus for decomposing tar illustrated in FIG. 1.
The apparatus 100 for manufacturing molten iron includes a reducing
5 furnace 20 which reduces lump ore, an input device 25 which inputs coal and
reduced iron discharged from the reducing furnace, and a melting and gasifying
furnace 40 which combusts the coal supplied from the input device 25 by using
oxygen, and melts the reduced iron by using combustion heat to manufacture
molten iron.
10 High-temperature reducing gas to be supplied into the reducing furnace
20 is manufactured in the melting and gasifying furnace 40. In addition, the
high-temperature reducing gas discharged from the melting and gasifying
furnace 40 passes through the high-temperature cyclone 50, and the gas
inputted into the high-temperature cyclone 50 is separated from dust at a rear
15 end of the high-temperature cyclone 50. The dust, which is separated by the
high-temperature cyclone 50, is inputted back into the melting and gasifying
furnace 40 by a dust burner 51.
An exhaust heat recovery boiler 30 is installed at a rear end of the
reducing furnace 20 to produce steam by using sensible heat of exhaust gas
20 discharged from an upper side of the reducing furnace 20 after the ore is
reduced in the reducing furnace 20, and the steam is supplied into the partial
combustion furnace 2 through the steam blowing conduit 4.
In addition, a part of the reduced iron is inputted to a reduced iron branch
conduit 21 from an input conduit 23 through which the reduced iron is inputted
15
into the melting and gasifying furnace 40 from the reducing furnace 20, and the
part of the reduced iron is discharged by a second uniform-pressure discharge
device 22. The reduced high-temperature reduced iron is conveyed to the
uniform-pressure input device 8 at the upper side of the tar decomposition
5 furnace 6 by the conveying device 7.
Meanwhile, the high-temperature reduced iron, which is discharged from
the tar decomposition furnace 6 by the first uniform-pressure discharge device
10, is conveyed to a cooling device 13 by the conveying device 11, cooled to
room temperature, inputted into the reducing furnace 20 together with lump ore,
10 and then reused as a raw material for manufacturing molten iron.
In addition, the reducing gas discharged from the tar decomposition
furnace 6 is maintained at a temperature of about 700 to 800°C, such that the
reducing gas is supplied into the reducing furnace 20 through a reducing gas
conduit 52 without being separately cooled, and a part of the reducing gas is
15 inputted to a separate gas conduit 53 in order to maintain a constant pressure in
the melting and gasifying furnace 40, and discharged to the outside after being
cleaned and cooled by a first dust collecting device 55.
Exhaust gas, which is discharged from the upper side of the reducing
furnace 20 after the ore is reduced, is cleaned and cooled while passing through
20 a second dust collecting device 56, mixed with the gas discharged from a rear
end of the first dust collecting device 55 in order to maintain a pressure in the
melting and gasifying furnace 40, and then discharged to the outside from the
apparatus for manufacturing molten iron.
As described above, a tar decomposition facility is configured outside the
16
melting and gasifying furnace 40, such that the melting and gasifying furnace 40
of the apparatus for manufacturing molten iron according to the present
invention may have a volume of about 30 to 40% of a volume of a dome portion
of the melting and gasifying furnace 40 of an apparatus for manufacturing molten
5 iron in which the tar decomposition facility is configured inside the melting and
gasifying furnace 40. Therefore, the amount of oxygen for combustion, which is
used to ensure a temperature of a dome space, is reduced, and it is possible to
prevent a loss caused by a function of coal due to a high temperature in the
dome space.
10 In addition, a cooling circulation line for controlling a temperature of the
reducing gas is not required unlike the apparatus for manufacturing molten iron
in which the tar decomposition facility is configured inside the melting and
gasifying furnace 40, and as a result, it is possible to reduce costs required to
manufacture the apparatus, and it is possible to prevent a loss of energy caused
15 by cooling.
Next, an apparatus for manufacturing molten iron which is provided with
the apparatus for decomposing tar according to the exemplary embodiment of
the present invention will be described in detail with reference to FIG. 3. A
detailed description of the constituent elements, which are identical to the
20 constituent elements of the apparatus for decomposing tar according to the
exemplary embodiment described with reference to FIG. 1, will be omitted.
FIG. 3 is a view schematically illustrating the apparatus for
manufacturing molten iron which is provided with the apparatus for decomposing
tar according to the exemplary embodiment of the present invention.
17
The apparatus for manufacturing molten iron illustrated in FIG. 3 may be
configured by applying the apparatus for decomposing tar illustrated in FIG. 1.
An apparatus 100 for manufacturing molten iron includes a multi-stage
reducing furnace 20 which reduces iron-containing ore powder, a
5 high-temperature agglomeration device 36 which agglomerates reduced iron
powder discharged from the multi-stage reducing furnace 20, a conveying
device 37 which conveys high-temperature reduced agglomerates agglomerated
by the high-temperature agglomeration device 36, an input device 25 which
inputs coal and the high-temperature reduced agglomerates conveyed by the
10 conveying device 37, and a melting and gasifying furnace 40 which combusts
the coal supplied from the input device 25 by using oxygen, and melts the
high-temperature reduced agglomerates by using combustion heat to
manufacture molten iron.
Some high-temperature reduced agglomerates are separated from the
15 high-temperature reduced agglomerates conveying device 37 and conveyed to
the uniform-pressure input device 8 at the upper side of the tar decomposition
furnace 6 by the conveying device 7. Meanwhile, the high-temperature
reduced agglomerates, which are discharged from the tar decomposition
furnace 6 by the first uniform-pressure discharge device 10, are conveyed by the
20 conveying device 14, inputted into the melting and gasifying furnace 40 by the
high-temperature reduced agglomerate conveying device 37, and then used as
a raw manufacturing material.
In addition, the reducing gas discharged from the tar decomposition
furnace 6 is maintained at a temperature of about 700 to 800°C, such that the
18
reducing gas is supplied into the multi-stage reducing furnace 20 through the
reducing gas conduit 52 without being separately cooled, and a part of the
reducing gas is inputted to the separate gas conduit 53 in order to maintain a
constant pressure in the melting and gasifying furnace 40, and discharged to the
5 outside after being cleaned and cooled by the first dust collecting device 55.
Hereinafter, an effect of the apparatus for decomposing tar according to
the present invention will be described with reference to an example in which the
apparatus for decomposing tar according to the present invention is applied to
an apparatus for manufacturing 600,000 tons of molten iron per year by directly
10 using coal. FIG. 4 is a view illustrating an experimental result of measuring the
amount of gas, a change in temperature, and a change in composition at front
and rear ends of the apparatus for decomposing tar according to the exemplary
embodiment of the present invention.
Referring to a table in FIG. 4, in a case in which coal containing a volatile
15 component of 28% is directly used in a melting furnace, tar of 35.6 g per gas of 1
Nm3
is included in the gas ① which is discharged from the melting and
gasifying furnace and then inputted into the partial combustion furnace 2.
However, after the gas passes through the tar decomposition furnace 6 (②), the
amount of tar is greatly decreased to about 0.8 g per gas of 1 Nm3
, which shows
20 that the apparatus for decomposing tar according to the present invention
effectively decomposes the tar.
In addition, it can be confirmed that in the gas ② after the gas passes
19
through the tar decomposition furnace 6, the amount of CO2 is increased from
0.67% to 5.74%, the amount of H2 is increased from 21.3% to 21.87%, the
amount of CH4 is increased from 5.02% to 7.94%, the amount of H2O is
increased from 0.25% to 1.76%, and the amount of NH3 is increased from
5 20.11% to 32.97%. The reason is that the carbon component and the
hydrogen component in the tar are decomposed into gas components such as
CO, CO2, H2, H2O, and CH4 by oxygen and steam supplied for decomposing the
tar. Further, the steam is used to decompose the tar, and as a result, in
comparison with an apparatus for manufacturing molten iron (Comparative
10 Example) that uses only oxygen to decompose tar, the amount of produced gas
is increased by about 10% even though the same amount of coal is used.
Further, the apparatus for decomposing tar according to the present
invention uses the reduced iron as a catalyst to decompose the tar at a
temperature lower than a temperature in the related art, and as a result, as
15 shown in the table in FIG. 4, the gas ② discharged from the apparatus for
decomposing tar has a temperature of about 775°C, and thus the gas may be
supplied directly into the reducing furnace without separately adjusting the
temperature thereof.
While this invention has been described in connection with what is
20 presently considered to be practical exemplary embodiments, it is to be
understood that the invention is not limited to the disclosed embodiments, but,
on the contrary, is intended to cover various modifications and equivalent
arrangements included within the spirit and scope of the appended claims.
20

2: Partial combustion furnace 6: Tar decomposition furnace
8: Uniform-pressure input device
10, 22: Uniform-pressure discharge device
5 20: Reducing furnace 30: Exhaust heat recovery boiler
40: Melting and gasifying furnace 50: High-temperature cyclone
21
We Claim :
【Claim 1】
An apparatus for manufacturing molten iron, the apparatus comprising:
5 one or more reducing furnaces which manufacture reduced iron by
reducing ore;
an input device which inputs coal and the reduced iron discharged from
the reducing furnace into a melting and gasifying furnace;
the melting and gasifying furnace which combusts the coal supplied from
10 the input device by using oxygen, and melts the reduced iron by using
combustion heat to manufacture molten iron; and
a tar decomposition furnace which is connected to the melting and
gasifying furnace, and decomposes a tar component included in gas discharged
from the melting and gasifying furnace.
15
【Claim 2】
The apparatus of claim 1, comprising:
a uniform-pressure input device which is connected to the tar
decomposition furnace and inputs high-temperature reduced iron or
20 high-temperature reduced agglomerates into the tar decomposition furnace.
22
【Claim 3】
The apparatus of claim 1, comprising:
a partial combustion furnace which combusts a part of gas discharged
from the melting and gasifying furnace, and inputs the gas into the tar
5 decomposition furnace.
【Claim 4】
The apparatus of claim 1, comprising:
an oxygen blowing conduit which blows oxygen into the partial
10 combustion furnace; and
a steam blowing conduit which blows steam into the partial combustion
furnace.
【Claim 5】
15 The apparatus of claim 4, comprising:
an exhaust heat boiler which is connected to the steam blowing conduit,
and manufactures the steam by using sensible heat of exhaust gas discharged
from the reducing furnace.
20 【Claim 6】
The apparatus of claim 1, comprising:
a uniform-pressure discharge device which is connected to the tar
23
decomposition furnace, and discharges high-temperature reduced iron or
high-temperature reduced agglomerates from the tar decomposition furnace.
【Claim 7】
5 The apparatus of claim 1, wherein:
the tar decomposition furnace includes therein a filling layer which is
formed of the high-temperature reduced iron or the high-temperature reduced
agglomerates inputted by the uniform-pressure input device.
10 【Claim 8】
The apparatus of claim 2, comprising:
a partial combustion furnace which combusts a part of gas discharged
from the melting and gasifying furnace, and inputs the gas into the tar
decomposition furnace.
15
【Claim 9】
The apparatus of claim 8, comprising:
an oxygen blowing conduit which blows oxygen into the partial
combustion furnace; and
20 a steam blowing conduit which blows steam into the partial combustion
furnace.
24
【Claim 10】
The apparatus of claim 9, comprising:
an exhaust heat boiler which manufactures the steam by using sensible
heat of exhaust gas discharged from the reducing furnace, and is connected to
5 the steam blowing conduit.
【Claim 11】
The apparatus of claim 2, comprising:
a uniform-pressure discharge device which is connected to the tar
10 decomposition furnace, and discharges high-temperature reduced iron or
high-temperature reduced agglomerates from the tar decomposition furnace.
【Claim 12】
The apparatus of claim 2, wherein:
15 the tar decomposition furnace includes therein a filling layer which is
formed of the high-temperature reduced iron or the high-temperature reduced
agglomerates inputted by the uniform-pressure input device.
【Claim 13】
20 The apparatus of claim 10, comprising:
a uniform-pressure discharge device which is connected to the tar
decomposition furnace, and discharges high-temperature reduced iron or
25
high-temperature reduced agglomerates from the tar decomposition furnace.
【Claim 14】
The apparatus of claim 13, wherein:
5 the tar decomposition furnace includes therein a filling layer which is
formed of the high-temperature reduced iron or the high-temperature reduced
agglomerates inputted by the uniform-pressure input device.
【Claim 15】
10 The apparatus of claim 14, comprising:
a high-temperature cyclone which separates dust in gas discharged from
the melting and gasifying furnace; and
a gas conduit which inputs the gas, from which the dust is separated, into
the partial combustion furnace.
15
【Claim 16】
The apparatus of claim 15, comprising:
a differential pressure meter which is connected to the tar decomposition
furnace to monitor a level of pores in the filling layer.
20
【Claim 17】
The apparatus of claim 16, comprising:
26
a cooling device which cools the high-temperature reduced iron
discharged from the tar decomposition furnace.
【Claim 18】
5 The apparatus of claim 17, further comprising:
a high-temperature agglomeration device which agglomerates reduced
iron discharged from the reducing furnace; and a conveying device which
conveys high-temperature reduced agglomerates, which are agglomerated by
the high-temperature agglomeration device, to the input device.
10
【Claim 19】
An apparatus for decomposing tar, the apparatus comprising:
a tar decomposition furnace which includes therein a filling layer formed
of high-temperature reduced iron or high-temperature reduced agglomerates,
15 and decomposes a tar component;
a uniform-pressure input device which is connected to the tar
decomposition furnace, and inputs the high-temperature reduced iron or the
high-temperature reduced agglomerates into the tar decomposition furnace;
a partial combustion furnace which combusts a part of gas, and inputs
20 the gas into the tar decomposition furnace; and
a uniform-pressure discharge device which is connected to the tar
decomposition furnace, and discharges high-temperature reduced iron or
high-temperature reduced agglomerates from the tar decomposition furnace.
27
【Claim 20】
The apparatus of claim 19, further comprising:
an oxygen blowing conduit which blows oxygen into the partial
5 combustion furnace; and
a steam blowing conduit which blows steam into the partial combustion
furnace.
【Claim 21】
10 The apparatus of claim 20, further comprising:
an exhaust heat boiler which is connected to the steam blowing conduit,
and manufactures the steam by using sensible heat of exhaust gas.
【Claim 22】
15 A method of manufacturing molten iron, the method comprising:
manufacturing reduced iron by inputting ore into one or more reducing
furnaces;
inputting the reduced iron and coal into a melting and gasifying furnace;
manufacturing molten iron by combusting the coal with oxygen and
20 melting the reduced iron with combustion heat;
inputting gas discharged from the melting and gasifying furnace into a tar
decomposition furnace; and
28
decomposing a tar component included in the gas in the tar
decomposition furnace.
【Claim 23】
5 The method of claim 22, wherein:
the decomposing of the tar component includes:
inputting the reduced iron discharged from the reducing furnace and
forming a reduced iron filling layer in the tar decomposition furnace; and
effectively decomposing a tar component contained in the gas into
10 reducing gas components by inputting the gas discharged from the melting and
gasifying furnace and allowing the gas to pass through the reduced iron filling
layer.
【Claim 24】
15 The method of claim 23, wherein:
a constant volume of the reduced iron filling layer is maintained as an
equal amount of reduced iron is continuously supplied into and discharged from
the tar decomposition furnace.
20 【Claim 25】
The method of claim 24, further comprising:
combusting, in a partial combustion furnace, a part of the gas discharged
29
from the melting and gasifying furnace before the inputting of the gas into the tar
decomposition furnace.
【Claim 26】
5 The method of claim 25, further comprising:
blowing oxygen into the partial combustion furnace through an oxygen
blowing conduit before the combusting of the part of the gas in the partial
combustion furnace; and
blowing steam into the partial combustion furnace through a steam
10 blowing conduit.
【Claim 27】
The method of claim 26, comprising:
adjusting a ratio of oxygen and steam blown into the partial combustion
15 furnace provided in the tar decomposition furnace so that the reducing gas,
which is discharged from the tar decomposition furnace when decomposition of
tar is completed, is maintained at a temperature of 700 to 800°C.
【Claim 28】
20 The method of claim 27, wherein:
the steam in the blowing of the steam is manufactured, by an exhaust
heat boiler, by using sensible heat of exhaust gas discharged from the reducing
30
furnace.
【Claim 29】
The method of claim 25, wherein:
5 the decomposing of the tar component includes discharging
high-temperature reduced iron or high-temperature reduced agglomerates from
the tar decomposition furnace by a uniform-pressure discharge device.
【Claim 30】
10 The method of claim 29, comprising:
cooling the high-temperature reduced iron discharged from the tar
decomposition furnace by a cooling device and inputting the cooled
high-temperature reduced iron back into the reducing furnace.
15 【Claim 31】
The method of claim 30, further comprising:
separating dust in high-temperature reducing gas, which is discharged
from the melting and gasifying furnace, by a high-temperature cyclone
connected to the melting and gasifying furnace; and
20 inputting the dust, which is separated by the high-temperature cyclone,
back into the melting and gasifying furnace by a dust burner connected to the
melting and gasifying furnace.
31
【Claim 32】
The method of claim 31, further comprising:
supplying a part of the high-temperature reducing gas into the reducing
5 furnace and discharging the remaining part of the high-temperature reducing gas
to the outside in order to maintain a pressure in the melting and gasifying
furnace.
【Claim 33】
10 The method of claim 32, further comprising:
agglomerating reduced iron, which is discharged from the reducing
furnace, by a high-temperature agglomeration device connected to the reducing
furnace after the manufacturing of the reduced iron; and
conveying high-temperature reduced agglomerates agglomerated by the
15 high-temperature agglomeration device to the melting and gasifying furnace by a
conveying device.