U.S. patent application number 14/428558 was filed with the patent office on 2015-08-13 for pulverized-coal injection device, blast furnace facility provided with the same, and pulverized-coal supplying method.
This patent application is currently assigned to MITSUBISHI HEAVY INDUSTRIES, LTD.. The applicant listed for this patent is MITSUBISHI HEAVY INDUSTRIES, LTD.. Invention is credited to Tsutomu Hamada, Keiichi Nakagawa, Takeshi Okada, Setsuo Omoto, Masakazu Sakaguchi.
Application Number | 20150225804 14/428558 |
Document ID | / |
Family ID | 50341260 |
Filed Date | 2015-08-13 |
United States Patent
Application |
20150225804 |
Kind Code |
A1 |
Sakaguchi; Masakazu ; et
al. |
August 13, 2015 |
PULVERIZED-COAL INJECTION DEVICE, BLAST FURNACE FACILITY PROVIDED
WITH THE SAME, AND PULVERIZED-COAL SUPPLYING METHOD
Abstract
A pulverized-coal injection device is configured so as to inject
pulverized coal from a tuyere of a blast-furnace main unit)
together with heated, compressed injection air, and upgraded coal
that has a self-heating property and that is upgraded from
low-grade coal is used as a raw material for the pulverized coal.
In addition, a heat exchanger is provided as a heat transporting
unit for transporting heat due to a self-heating effect of this
upgraded coal to a site requiring heat. This heat exchanger heats
intake air by using the heat due to the self-heating effect of the
upgraded coal that passes through the pulverized-coal supplying
pipe to perform heat exchange with, for example, air that is taken
into an injection-air feeding device. Furthermore, a deactivating
unit for deactivating the upgraded coal such that a predetermined
level of the self-heating effect thereof is retained may be
provided.
Inventors: |
Sakaguchi; Masakazu; (Tokyo,
JP) ; Hamada; Tsutomu; (Tokyo, JP) ; Okada;
Takeshi; (Tokyo, JP) ; Omoto; Setsuo; (Tokyo,
JP) ; Nakagawa; Keiichi; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI HEAVY INDUSTRIES, LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
MITSUBISHI HEAVY INDUSTRIES,
LTD.
Tokyo
JP
|
Family ID: |
50341260 |
Appl. No.: |
14/428558 |
Filed: |
September 10, 2013 |
PCT Filed: |
September 10, 2013 |
PCT NO: |
PCT/JP2013/074404 |
371 Date: |
March 16, 2015 |
Current U.S.
Class: |
266/47 ; 266/216;
266/265 |
Current CPC
Class: |
C21B 7/16 20130101; C21B
5/003 20130101; C21B 2100/66 20170501; C21B 7/163 20130101 |
International
Class: |
C21B 5/00 20060101
C21B005/00; C21B 7/16 20060101 C21B007/16 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 20, 2012 |
JP |
2012-207274 |
Claims
1. A pulverized-coal injection device configured so as to inject
pulverized coal from a tuyere of a blast-furnace main unit together
with heated, compressed injection air, wherein upgraded coal that
has a self-heating property and that is upgraded from low-grade
coal is used as a raw material for the pulverized coal.
2. A pulverized-coal injection device according to claim 1,
comprising: a heat transporting unit for transporting heat due to a
self-heating effect of the upgraded coal to a site requiring
heat.
3. A pulverized-coal injection device according to claim 2, wherein
the heat transporting unit is configured so as to subject the
injection air, before being compressed, to heat exchange with the
upgraded coal.
4. A pulverized-coal injection device according to claim 2, wherein
the heat transporting unit is configured so as to transport the
heat of the upgraded coal to a upgrading device that upgrades the
low-grade coal.
5. A pulverized-coal injection device according to claim 1, further
comprising: a deactivating unit for deactivating the upgraded coal
such that a predetermined level of a self-heating effect thereof is
retained.
6. A pulverized-coal injection device according to claim 1,
comprising: a mixing portion for mixing pulverized coal constituted
of the upgraded coal and pulverized coal constituted of generally
used raw coal, wherein the pulverized coal constituted of the raw
coal is dried at the mixing portion and a downstream side thereof
by using a self-heating effect of the upgraded coal.
7. A blast furnace facility comprising a pulverized-coal injection
device according to claim 1.
8. A pulverized-coal supplying method for injecting pulverized coal
from a tuyere of a blast-furnace main unit together with heated,
compressed injection air, the pulverized-coal supplying method
comprising: using upgraded coal upgraded from low-grade coal as a
raw material for the pulverized coal; and transporting heat due to
a self-heating effect of the upgraded coal to a site requiring heat
and utilizing the heat thereat.
9. A pulverized-coal supplying method according to claim 8, further
comprising: deactivating the upgraded coal such that a
predetermined level of the self-heating effect thereof is
retained.
10. A pulverized-coal supplying method for injecting pulverized
coal from a tuyere of a blast-furnace main unit together with
heated, compressed injection air, the pulverized-coal supplying
method comprising: mixing pulverized coal constituted of upgraded
coal upgraded from low-grade coal and pulverized coal constituted
of generally used raw coal; and drying the pulverized coal
constituted of the raw coal by means of a self-heating effect of
the upgraded coal.
11. A pulverized-coal injection device according to claim 2,
further comprising: a deactivating unit for deactivating the
upgraded coal such that a predetermined level of a self-heating
effect thereof is retained.
12. A pulverized-coal injection device according to claim 3,
further comprising: a deactivating unit for deactivating the
upgraded coal such that a predetermined level of a self-heating
effect thereof is retained.
13. A pulverized-coal injection device according to claim 4,
further comprising: a deactivating unit for deactivating the
upgraded coal such that a predetermined level of a self-heating
effect thereof is retained.
Description
TECHNICAL FIELD
[0001] The present invention relates to a pulverized-coal injection
device, a blast furnace facility provided with the same, and a
pulverized-coal supplying method.
BACKGROUND ART
[0002] Pulverized-coal injection (PCI; Pulverized Coal Injection)
employed to supply a supplemental fuel for a blast furnace facility
is a low-cost supplemental-fuel supplying method that is an
alternative to heavy-oil injection that had been employed until the
1970s. Important requirements for pulverized coal (PCI coal) used
for blast furnace injection include low moisture content, low
volatile matter content, excellent combustibility, a combustion
speed as fast as that of heavy oil, low combustion residues such as
uncombusted carbon, ash, or the like, a heat of combustion equal to
or greater than 6500 kcal/kg, low sulfur and phosphorus contents,
and so forth.
[0003] In order to meet these requirements, as described in Patent
Literature 1, relatively high-quality, expensive raw coal, such as
bituminous coal or the like, is currently used as a raw material
for PCI coal. Such raw coal is pulverized into a predetermined
grain size by using a pulverizer, thus being turned into pulverized
coal, and is transported to and stored in a storage tank installed
in the vicinity of a blast-furnace main unit by means of gas-flow
transportation that uses high-pressure air, nitrogen, or the like.
Then, the pulverized coal is injected into the blast-furnace main
unit, to be combusted therein, from a tuyere provided at a lower
portion of the blast-furnace main unit together with hot air
consisting of heated high-pressure air.
CITATION LIST
Patent Literature
{PTL 1} Japanese Unexamined Patent Application, Publication No.
2012-173241
SUMMARY OF INVENTION
Technical Problem
[0004] However, as described above, because high-quality, expensive
raw coal is necessary as the raw material for PCI coal to be
injected into the interior of the blast-furnace main unit as a
supplemental fuel, the operating cost of the blast furnace facility
is increased, and, as a result, the manufacturing cost of pig iron
is increased.
[0005] In addition, although pulverized coal is injected into the
blast furnace together with compressed air, the compressed air must
be preheated to about 1200.degree. C. by means of a burner or the
like so that the furnace interior is not cooled by the compressed
air at the time of this injection. A large amount of fuel, such as
heavy oil or the like, is required to achieve this, and this has
also caused an increase in the operating cost of the blast furnace
facility.
[0006] The present invention has been conceived in light of the
above-described circumstances, and an object thereof is to provide
a pulverized-coal injection device with which the manufacturing
cost of pig iron can be reduced by reducing the operating cost of a
blast furnace facility, to provide a blast furnace facility
provided with this pulverized-coal injection device, and to provide
a pulverized-coal supplying method.
Solution to Problem
[0007] In order to solve the above-described problems, the present
invention employs the following solutions.
[0008] Specifically, a pulverized-coal injection device according
to a first aspect of the present invention is a pulverized-coal
injection device configured so as to inject pulverized coal from a
tuyere of a blast-furnace main unit together with heated,
compressed injection air, wherein upgraded coal that has a
self-heating property and that is upgraded from low-grade coal is
used as a raw material for the pulverized coal.
[0009] With this pulverized-coal injection device, because the
upgraded coal that is considerably more inexpensive than generally
used raw coal such as bituminous coal or the like is used as the
raw material of the pulverized coal to be injected into the
interior of the blast-furnace main unit as the supplemental fuel,
the manufacturing cost of pig iron can be reduced by reducing the
operating cost of the blast furnace facility by reducing the cost
of the supplemental fuel.
[0010] In addition, it is possible to contribute to energy saving
by effectively utilizing the heat of the upgraded coal at other
sites requiring heat.
[0011] In the pulverized-coal injection device according to the
first aspect of the present invention, it is preferable that the
above-described configuration include a heat transporting unit for
transporting heat due to a self-heating effect of the upgraded coal
to a site requiring heat.
[0012] In the case in which the above-described configuration is
employed, because the heat due to the self-heating effect of the
upgraded coal is transported to sites requiring heat by means of
the heat transporting unit, fuel, power, or the like consumed to
generate heat at these sites can be reduced; by doing so, the
operating cost of the blast furnace facility can be reduced, and,
consequently, the manufacturing cost of pig iron can be
reduced.
[0013] In addition, because the upgraded coal is cooled by
transporting the heat of the upgraded coal by means of the heat
transporting unit, it is possible to prevent spontaneous combustion
of the upgraded coal.
[0014] In the pulverized-coal injection device according to the
first aspect of the present invention, it is preferable that, in
the above-described configuration, the heat transporting unit be
configured so as to subject the injection air, before being
compressed, to heat exchange with the upgraded coal.
[0015] With the above-described configuration, the injection air is
appropriately heated by undergoing heat exchange with the upgraded
coal before being heated by a special heating means. Because of
this, it is possible to reduce the energy used for further heating
the injection air. In particular, because cold injection air,
before being compressed, is subjected to heat exchange with the
upgraded coal, it is possible to increase the cooling effect on the
upgraded coal, to also increase the generation rate of the heat of
compression of the injection air, and, accordingly, to reduce the
energy required to heat the injection air.
[0016] In the pulverized-coal injection device according to the
first aspect of the present invention, it is preferable that, in
the above-described configuration, the heat transporting unit be
configured so as to transport the heat of the upgraded coal to an
upgrading device that upgrades the low-grade coal.
[0017] With the above-described configuration, because a portion of
heat required at the upgrading device that upgrades low-grade coal
is provided by the heat of the upgraded coal, it is possible to
reduce the energy consumed at the upgrading device.
[0018] In the pulverized-coal injection device according to the
first aspect of the present invention, it is preferable that the
above-described configuration include a deactivating unit for
deactivating the upgraded coal such that a predetermined level of
the self-heating effect thereof is retained.
[0019] With the above-described configuration, because the
self-heating effect of the upgraded coal is reduced, the need to
transport the upgraded coal in a nitrogen atmosphere so as to
prevent spontaneous combustion thereof is reduced, and the
utilization rate of the nitrogen supplying device can be reduced.
Because of this, the operating cost of the blast furnace facility
can be reduced, and, consequently, the manufacturing cost of pig
iron can be reduced.
[0020] In the pulverized-coal injection device according to the
first aspect of the present invention, it is preferable that the
above-described configuration include a mixing portion for mixing
pulverized coal constituted of the upgraded coal and pulverized
coal constituted of generally used raw coal, wherein the pulverized
coal constituted of the raw coal is dried at the mixing portion and
a downstream side thereof by using the self-heating effect of the
upgraded coal.
[0021] In the case in which the above-described configuration is
employed, the pulverized coal constituted of the raw coal is dried
by the heat of the upgraded coal having a self-heating property
when the pulverized coal constituted of the raw coal having greater
moisture content than the upgraded coal is mixed with the
pulverized coal constituted of the upgraded coal. Because of this,
it is possible to partially omit or simplify the step of drying the
raw coal. By doing so, the manufacturing cost of pig iron can be
reduced by reducing the operating cost of the blast furnace
facility by reducing equipment, energy, personnel, or the like
involved in the drying step.
[0022] A blast furnace facility according to a second aspect of the
present invention is provided with a pulverized-coal injection
device having any one of above-described configurations.
[0023] With this blast furnace facility, because inexpensive
upgraded coal is used as the pulverized coal to be injected into
the interior of the blast-furnace main unit as the supplemental
fuel, the manufacturing cost of pig iron can be reduced by reducing
the operating cost of the blast furnace facility by reducing the
cost of the supplemental fuel, and, also, the heat generated when
the upgraded coal exhibits self heating can effectively be
utilized.
[0024] In addition, a pulverized-coal supplying method according to
a third aspect of the present invention is a pulverized-coal
supplying method for injecting pulverized coal from a tuyere of a
blast-furnace main unit together with heated, compressed injection
air, the pulverized-coal supplying method including using upgraded
coal upgraded from low-grade coal as a raw material for the
pulverized coal, and transporting heat due to a self-heating effect
of the upgraded coal to a site requiring heat and utilizing the
heat thereat.
[0025] With this pulverized-coal supplying method, because the
pulverized coal to be injected into the interior of the
blast-furnace main unit as the supplemental fuel is inexpensive
upgraded coal, the manufacturing cost of pig iron can be reduced by
reducing the cost of the supplemental fuel. Moreover, by
transporting the heat due to the self-heating effect of the
upgraded coal to sites requiring heat, thus effectively utilizing
the heat, the operating cost of the blast furnace facility can be
reduced by reducing fuel, power, or the like consumed to generate
heat at these sites, and, consequently, the manufacturing cost of
pig iron can be reduced.
[0026] In addition, in the pulverized-coal supplying method
according to the third aspect of the present invention, it is
preferable that the above-described method include deactivating the
upgraded coal such that a predetermined level of the self-heating
effect thereof is retained.
[0027] With the above-described method, because the self-heating
effect of the upgraded coal is reduced, the need to transport the
upgraded coal in a nitrogen atmosphere so as to prevent spontaneous
combustion thereof is reduced, and the utilization rate of the
nitrogen supplying device can be reduced. Because of this, the
operating cost of the blast furnace facility can be reduced, and,
consequently, the manufacturing cost of pig iron can be
reduced.
[0028] A pulverized-coal supplying method according to a fourth
aspect of the present invention is a pulverized-coal supplying
method for injecting pulverized coal from a tuyere of a
blast-furnace main unit together with heated, compressed injection
air, the pulverized-coal supplying method including mixing
pulverized coal constituted of upgraded coal upgraded from
low-grade coal and pulverized coal constituted of generally used
raw coal, and drying the pulverized coal constituted of the raw
coal by means of a self-heating effect of the upgraded coal.
[0029] With the above-described pulverized-coal supplying method,
because the pulverized coal constituted of the raw coal is dried by
the heat of the upgraded coal having a self-heating property when
the pulverized coal constituted of the raw coal having a greater
moisture content than the upgraded coal is mixed with the
pulverized coal constituted of the upgraded coal, it is possible to
partially omit or simplify the step of drying the raw coal. By
doing so, the manufacturing cost of pig iron can be reduced by
reducing the operating cost of the blast furnace facility by
reducing equipment, energy, personnel, or the like involved in the
drying step.
Advantageous Effects of Invention
[0030] As described above, with a pulverized-coal injection device,
a blast furnace facility provided with the same, and a
pulverized-coal supplying method according to the present
invention, the manufacturing cost of pig iron can be reduced by
reducing the operating cost of the blast furnace facility.
BRIEF DESCRIPTION OF DRAWINGS
[0031] FIG. 1 is a diagram showing, in outline, the configuration
of a blast furnace facility provided with a pulverized-coal
injection device according to a first embodiment of the present
invention.
[0032] FIG. 2 is a diagram showing, in outline, the configuration
of a blast furnace facility provided with a pulverized-coal
injection device according to a second embodiment of the present
invention.
[0033] FIG. 3 is a diagram showing, in outline, the configuration
of a blast furnace facility provided with a pulverized-coal
injection device according to a third embodiment of the present
invention.
[0034] FIG. 4 is a diagram showing, in outline, the configuration
of a blast furnace facility provided with a pulverized-coal
injection device according to a fourth embodiment of the present
invention.
[0035] FIG. 5 is a diagram showing, in outline, the configuration
of a blast furnace facility provided with a pulverized-coal
injection device according to a fifth embodiment of the present
invention.
DESCRIPTION OF EMBODIMENTS
[0036] A plurality of embodiments of the present invention will be
described below based on FIGS. 1 to 5.
First Embodiment
[0037] FIG. 1 is a diagram showing, in outline, the configuration
of a blast furnace facility 1A provided with a pulverized-coal
injection device 5A according to a first embodiment of the present
invention. This blast furnace facility 1A is provided with a
blast-furnace main unit 2, a fixed-quantity raw-material supplying
device 3, a charging conveyor 4, and a pulverized-coal injection
device 5A.
[0038] The blast-furnace main unit 2 has a general structure in
which a furnace top hopper 7 is provided at a top portion, and a
tuyere 8 and a tap hole 9 are provided at a lower portion. A
blowpipe 11 is connected to the tuyere 8, and an injection lance 12
is connected to this blowpipe 11 so as to join therewith at an
angle.
[0039] The charging conveyor 4 is installed so as to rise from the
vicinity of a base portion of the blast-furnace main unit 2 to the
furnace top hopper 7, a transport-direction downstream end (top end
portion) of this charging conveyor 4 is positioned directly above
the furnace top hopper 7, and the fixed-quantity raw-material
supplying device 3 is installed at a portion directly above a
transport-direction upstream end (bottom end portion) thereof.
[0040] The fixed-quantity raw-material supplying device 3 supplies
raw materials, such as iron ore, which is the main raw material of
pig iron 14, to be smelted in the blast-furnace main unit 2, coke
that serves as fuel and a reducing agent, and limestone that serves
as a scavenger, to the charging conveyor 4 at a constant supplying
speed; these raw materials are charged into the blast-furnace main
unit 2 from the furnace top hopper 7 by means of the charging
conveyor 4; and the smelted pig iron 14 is accumulated at a bottom
portion of the blast-furnace main unit 2. The smelted pig iron 14
is removed from the tap hole 9.
[0041] On the other hand, the pulverized-coal injection device 5A
injects pulverized coal (PCI coal), which is a supplemental fuel,
from the tuyere 8 (blowpipe 11) of the blast-furnace main unit 2
together with the injection air, which has been heated and
compressed to form hot air, so as to increase the temperature in
the blast-furnace main unit 2. This pulverized-coal injection
device 5A is provided with a upgrading device 16, a charging line
17, a nitrogen-gas feeding device 18, a cyclone separator 19, a
storage tank 21, a pulverized-coal supplying pipe 22, an
injection-air feeding device 23, and so forth.
[0042] The upgrading device 16 and the cyclone separator 19 are
connected by the charging line 17, and the nitrogen-gas feeding
device 18 is connected at an upstream portion of the charging line
17. In addition, the storage tank 21 and the injection lance 12 are
connected by the pulverized-coal supplying pipe 22. Furthermore,
the injection air in the form of hot air generated at the
injection-air feeding device 23 is supplied to the blowpipe 11.
[0043] Because the upgrading device 16 has a known configuration, a
detailed description thereof will be omitted; however, in outline,
it is a device that upgrades the properties of low-grade coal, such
as inexpensive subbituminous coal, brown coal, or the like, into
properties suitable as a supplemental fuel for the blast-furnace
main unit 2 and, also, that generates supplemental-fuel pulverized
coal (PCI coal) by pulverizing the upgraded coal. At this upgrading
device 16, low-grade coal input from a receiving hopper 24 is
cooled after the low-grade coal is subjected multiple times to
drying and heating processing to remove moisture and volatile
components therein, and is pulverized by a mill into the
supplemental-fuel pulverized coal.
[0044] The injection-air feeding device 23 is a device that
compresses the air taken in from an air intake pipe 25 by means of
a compressor (not shown), that also heats this air to about
1200.degree. C. by means of a heater or a burner (not shown), and
that generates high-temperature, high-pressure, dry injection air
for pulverized coal injection.
[0045] An intermediate portion of the air intake pipe 25 is molded
into, for example, a spiral shape that goes around multiple times
in the area surrounding the pulverized-coal supplying pipe 22, and
this spiral portion serves as a heat exchanger 25a. This heat
exchanger 25a serves as a heat transporting unit for transporting
the heat due to the self-heating effect of the upgraded coal that
passes through the interior of the pulverized-coal supplying pipe
22 to a site requiring heat, in this embodiment, for example, the
injection-air feeding device 23.
[0046] With the pulverized-coal injection device 5A configured as
described above, the pulverized coal constituted of the upgraded
coal upgraded by the upgrading device 16 from low-grade coal is
sent to the charging line 17, is mixed with nitrogen gas fed by the
nitrogen-gas feeding device 18, forms a solid-gas two-phase flow,
and is fed to the cyclone separator 19 in an inert atmosphere of
nitrogen gas. The cyclone separator 19 is a type of centrifugal
separator that separates and deaerates nitrogen gas from the
pulverized coal by means of a centrifugal force, and the nitrogen
gas is released to the exterior or collected. Subsequently, the
pulverized coal is accumulated in the storage tank 21, and a
required amount thereof is supplied to the injection lance 12 from
the pulverized-coal supplying pipe 22.
[0047] On the other hand, with the air (external air) that is taken
in from the air intake pipe 25 and supplied to the injection-air
feeding device 23, the temperature thereof is increased when
passing through the heat exchanger 25a, which is formed in an
intermediate portion of the air intake pipe 25, by undergoing heat
exchange with the heat due to the self-heating effect of the
pulverized coal constituted of the upgraded coal that precipitates
in the interior of the pulverized-coal supplying pipe 22 at a
relatively low speed, and, while possessing this heat, the air is
supplied to the injection-air feeding device 23, where the air is
further compressed and heated into high-temperature, high-pressure
hot air of about 1200.degree. C. In other words, the injection air
undergoes heat exchange with the upgraded coal before being
compressed and heated at the injection-air feeding device 23.
[0048] Then, the pulverized coal (upgraded coal) supplied to the
injection lance 12 is mixed with the injection air supplied to the
blowpipe 11, the pulverized coal is ignited and combusted by coming
into contact with the high-temperature injection air in the form of
hot air and forms flames at the tip of the blowpipe 11 which, in
turn, form a raceway, and thus, coke charged into the blast-furnace
main unit 2 is combusted. By doing so, iron ore charged together
with the coke forms pig iron (molten iron) 14 by undergoing
reduction and is removed from the tap hole 9.
[0049] With the pulverized-coal injection device 5A configured as
described above, pulverized coal constituted of upgraded coal that
has a self-heating property and that is upgraded from low-grade
coal is used as the pulverized coal to be injected from the tuyere
8 of the blast-furnace main unit 2 together with the heated and
compressed injection air. Because the cost of the upgraded coal is
considerably lower than generally used raw coal, such as bituminous
coal or the like, the manufacturing cost of pig iron can be reduced
by reducing the operating cost of the blast furnace facility 1A by
reducing the cost of the supplemental fuel. In addition, it is
possible to contribute to energy saving by effectively utilizing
the heat of the upgraded coal at other sites requiring heat.
[0050] In addition, in this embodiment, as an example of the heat
transporting unit for transporting the heat due to the self-heating
effect of the pulverized coal generated from the upgraded coal to
other sites requiring heat, the heat exchanger 25a is provided in
the intermediate portion of the air intake pipe 25 through the air
to be taken into the injection-air feeding device 23 passes, and
this air that passes through the interior thereof undergoes heat
exchange with the pulverized coal that passes through the interior
of the pulverized-coal supplying pipe 22. Therefore, the injection
air is appropriately heated by undergoing heat exchange with the
pulverized coal before being injected.
[0051] Because of this, it is possible to contribute to reducing
the manufacturing cost of pig iron by reducing the operating cost
of the blast furnace facility 1A by achieving a considerable saving
in terms of energy such as fuel, power, or the like to be consumed
for further heating the injection air at the injection-air feeding
device 23. In addition, because the upgraded coal is cooled by
transporting the heat of the upgraded coal that passes through the
interior of the pulverized-coal supplying pipe 22 by means of the
heat exchanger 25a, it is possible to prevent spontaneous
combustion of the upgraded coal.
[0052] In particular, because cold injection air is subjected to
heat exchange with the upgraded coal before being compressed at the
injection-air feeding device 23, it is possible to increase the
cooling effect on the upgraded coal at the pulverized-coal
supplying pipe 22, to also increase the generation rate of the heat
of compression of the injection air, and thus, to reduce the energy
for heating the injection air.
Second Embodiment
[0053] FIG. 2 is a diagram showing, in outline, the configuration
of a blast furnace facility 1B provided with a pulverized-coal
injection device 5B according to a second embodiment of the present
invention.
[0054] The pulverized-coal injection device 5B differs from the
pulverized-coal injection device 5A of the first embodiment (FIG.
1) in that a heat transporting pipe 32 (heat transporting unit)
that extends from the upgrading device 16 is provided, and this
heat transporting pipe 32 is disposed so as to return to the
upgrading device 16 again after going around multiple times in the
area surrounding the pulverized-coal supplying pipe 22. This
portion of the heat transporting pipe 32 that goes around also
serves as a heat exchanger 32a that is similar to the heat
exchanger 25a of the pulverized-coal injection device 5A of the
first embodiment. At the interior of the heat transporting pipe 32,
fluid that serves as a heating medium is circulated. Because the
configurations of other portions are the same as those in the
pulverized-coal injection device 5A according to the first
embodiment, the same reference signs are assigned to the respective
portions, and descriptions thereof will be omitted.
[0055] The heating medium that flows through the interiors of the
heat transporting pipe 32 and the heat exchanger 32a transports the
heat due to the self-heating effect of the updated coal that passes
through the interior of the pulverized-coal supplying pipe 22 to
the updating device 16. At the updating device 16, this heat is
used, for example, in a step of drying the low-grade coal. By doing
so, it is possible to reduce the energy consumed to dry the
low-grade coal.
Third Embodiment
[0056] FIG. 3 is a diagram showing, in outline, the configuration
of a blast furnace facility 1C provided with a pulverized-coal
injection device 5C according to a third embodiment of the present
invention.
[0057] The pulverized-coal injection device 5C differs from the
pulverized-coal injection device 5A of the first embodiment (FIG.
1) only in that a deactivation device 42 (deactivating unit) is
interposed at the downstream side of the updating device 16, and,
because the configurations of other portions are the same as those
in the pulverized-coal injection device 5A, the same reference
signs are assigned to the respective portions, and descriptions
thereof will be omitted.
[0058] At the deactivation device 42, the updated coal updated from
low-grade coal by the updating device 16 is deactivated such that a
predetermined level of the self-heating effect thereof is retained.
As a specific deactivating method, coal that is cooled after being
subjected to dry distillation at 300.degree. C. to 500.degree. C.
at the updating device 16 is exposed to a processing-gas atmosphere
containing oxygen at the deactivation device 42, and thus,
processing of oxygen adsorbing (permeating) to the surface and the
interior thereof is performed. By adjusting the adsorption level of
oxygen, it is possible to adjust the level of the self-heating
effect of the updated coal.
[0059] In this embodiment, the level of processing at the
deactivation device 42 is set such that the updated coal that is
sent out to the charging line 17 after completing the deactivating
processing at the deactivation device 42 retains a certain level of
self-heating effect.
[0060] Because the self-heating effect of the updated coal can be
reduced by providing such a deactivation device 42, it is possible
to eliminate the need to transport the updated coal in a nitrogen
atmosphere so as to prevent spontaneous combustion thereof or to
reduce the amount of nitrogen gas used. Therefore, the rate of
operation of the nitrogen-gas feeding device 18 can be reduced, the
operating cost of the blast furnace facility 1C can be reduced,
and, consequently, the manufacturing cost of pig iron can be
reduced.
Fourth Embodiment
[0061] FIG. 4 is a diagram showing, in outline, the configuration
of a blast furnace facility 1D provided with a pulverized-coal
injection device 5D according to a fourth embodiment of the present
invention.
[0062] The pulverized-coal injection device 5D differs from the
pulverized-coal injection device 5A of the first embodiment (FIG.
1) in that, as opposed to the pulverized-coal injection device 5A
in which only the pulverized coal constituted of the updated coal
updated at the updating device 16 is supplied to the blast-furnace
main unit 2, in this pulverized-coal injection device 5D, a mixture
of the pulverized coal constituted of the updated coal and
pulverized coal constituted of generally used raw coal is supplied
to the blast-furnace main unit 2.
[0063] The pulverized-coal injection device 5D is provided with two
cyclone separators 19A and 19B, a mixing pipe 52 (mixing portion)
is provided at a downstream portion thereof, and this mixing pipe
52 is connected to the storage tank 21. Because the configurations
of other portions are the same as those in the pulverized-coal
injection device 5A, the same reference signs are assigned to the
respective portions and descriptions thereof will be omitted.
[0064] In this pulverized-coal injection device 5D, the pulverized
coal constituted of the updated coal updated at the updating device
16 is supplied to the cyclone separator 19A from the charging line
17. In addition, the pulverized coal constituted of the raw coal is
supplied to the cyclone separator 19B from a supplying device (not
shown). Then, the two types of pulverized coal are mixed in the
mixing pipe 52 and are accumulated in the storage tank 21.
Subsequently, the two types of pulverized coal in the mixed state
are supplied to the blast-furnace main unit 2 via the
pulverized-coal supplying pipe 22 together with the injection air
in the form of hot air that is supplied from the injection-air
feeding device 23.
[0065] In the above-described configuration, because the pulverized
coal constituted of the updated coal and the pulverized coal
constituted of the raw coal are mixed in the mixing pipe 52, the
moisture contained in the pulverized coal constituted of the raw
coal is dried by the self-heating effect of the pulverized coal
constituted of the updated coal at the interiors of the mixing pipe
52, the storage tank 21 at the downstream side thereof, and the
pulverized-coal supplying pipe 22.
[0066] Because of this, it is possible to partially omit or
simplify a step of drying the pulverized coal constituted of the
raw coal or the raw coal itself. By doing so, the manufacturing
cost of pig iron can be reduced by reducing the operating cost of
the blast furnace facility 1D by reducing equipment, energy,
personnel, or the like involved in the step of drying the raw
coal.
Fifth Embodiment
[0067] FIG. 5 is a diagram showing, in outline, the configuration
of a blast furnace facility 1E provided with a pulverized-coal
injection device 5E according to a fifth embodiment of the present
invention.
[0068] This pulverized-coal injection device 5E is the
pulverized-coal injection device 5D of the fourth embodiment (FIG.
4) provided with the deactivation device 42 that is provided in the
pulverized-coal injection device 5C of the third embodiment (FIG.
3). With this deactivation device 42, the upgraded coal upgraded
from low-grade coal by the upgrading device 16 is deactivated such
that the predetermined level of the self-heating effect thereof is
retained. The configurations of other portions are the same as
those in the pulverized-coal injection device 5D.
[0069] Because the upgraded coal loses its self-heating property
when completely deactivated, the deactivation device 42 does not
completely deactivate the upgraded coal, and the moisture contained
in the pulverized coal constituted of the raw coal is dried by self
heating of the pulverized coal constituted of the upgraded coal
while the pulverized coal constituted of the upgraded coal and the
pulverized coal constituted of the raw coal are supplied to the
blast-furnace main unit 2 from the mixing pipe 52 by passing
through the pulverized-coal supplying pipe 22.
[0070] With this pulverized-coal injection device 5E, the
manufacturing cost of pig iron can be reduced by reducing the
operating cost of the blast furnace facility 1E by reducing
equipment, energy, personnel, or the like involved in the step of
drying the raw coal by partially omitting or simplifying the step
of drying the raw coal.
[0071] In addition, because the self-heating effect of the upgraded
coal can be reduced by using the deactivation device 42, it is
possible to eliminate the need to transport the upgraded coal in a
nitrogen atmosphere so as to prevent spontaneous combustion thereof
or to reduce the amount of nitrogen gas used. Therefore, the rate
of operation of the nitrogen-gas feeding device 18 can be reduced,
the operating cost of the blast furnace facility 1E can also be
reduced in this respect, and, consequently, it is possible to
contribute to reducing the manufacturing cost of pig iron.
[0072] As has been described above, with the pulverized-coal
injection devices 5A to 5E and the pulverized-coal injection method
according to the individual embodiments described above, the
manufacturing cost of pig iron can be reduced by reducing the
operating cost of the blast furnace facility 1A to 1E.
[0073] The present invention is not limited only to the
configurations of the individual embodiments described above;
appropriate modifications and improvements can be incorporated
within a range that does not depart from the scope of the present
invention, and embodiments in which such modifications and
improvements are incorporated are also encompassed in the range
claimed by the present invention.
[0074] For example, the destination to which heat due to the
self-heating property of upgraded coal is transported need not
necessarily be the interior of the blast furnace facility, and the
heat may be transported to an adjacent plant or other equipment. In
addition, it is permissible to appropriately combine the
configurations of the individual embodiments or the like.
REFERENCE SIGNS LIST
[0075] 1A, 1B, 1C, 1D, 1E blast furnace facility [0076] 2
blast-furnace main unit [0077] 3 fixed-quantity raw-material
supplying device [0078] 4 charging conveyor [0079] 5A, 5B, 5C, 5D,
5E pulverized-coal injection device [0080] 7 furnace top hopper
[0081] 8 tuyere [0082] 9 tap hole [0083] 11 blowpipe [0084] 12
injection lance [0085] 14 pig iron [0086] 16 upgrading device
[0087] 17 charging line [0088] 18 nitrogen-gas feeding device
[0089] 19, 19A, 19B cyclone separator [0090] 21 storage tank [0091]
22 pulverized-coal supplying pipe [0092] 23 injection-air feeding
device [0093] 24 receiving hopper [0094] 25 air intake pipe [0095]
25a heat exchanger (heat transporting unit) [0096] 32 heat
transporting pipe (heat transporting unit) [0097] 32a heat
exchanger (heat transporting unit) [0098] 42 deactivation device
(deactivating unit) [0099] 52 mixing pipe (mixing portion)
* * * * *