FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. Title of the Invention
METHOD FOR MANUFACTURING COAL BRIQUETTES AND APPARATUS FOR
MANUFACTURING COAL BRIQUETTES
2. Applicant(s)
Name Nationality Address
POSCO Korean (Goedong-dong) 6261 Donghaean-ro,
Nam-gu, Pohang-si Gyeongsangbuk-do
37859, Republic of Korea
3. Preamble to the description
The following specification particularly describes the invention and the manner in which it is to be
performed.
2
【DESCRIPTION】
【Invention Title】
METHOD FOR MANUFACTURING COAL BRIQUETTES AND
APPARATUS FOR MANUFACTURING COAL BRIQUETTES
5 【Technical Field】
The present invention relates to a method and an apparatus for
manufacturing briquette coal. Particularly, the present invention relates
to a method and an apparatus for manufacturing briquette coal with a
reduced deviation of cold strength.
10 【Background Art】
In a direct iron ore smelting reduction process, a reducing furnace
for reducing iron ore and a melting and gasifying furnace for melting the
reduced iron ore are used. When the melting and gasifying furnace melts
the iron ore, briquette coal, as a heat source for melting the iron ore, is
15 inputted into the melting and gasifying furnace. Here, the reduced iron is
melted in the melting and gasifying furnace, converted into molten iron and
slag, and then discharged to the outside. The briquette coal inputted into
the melting and gasifying furnace forms a coal-packed bed. Oxygen is
injected through a tuyere installed in the melting and gasifying furnace,
20 and then combusts the coal-packed bed to generate combustion gas.
The combustion gas is converted into high-temperature reducing gas while
moving upward through the coal-packed bed. The high-temperature
reducing gas is discharged to the outside of the melting and gasifying
3
furnace and supplied as reducing gas to a reducing furnace.
Manufactured briquette coal is piled up outdoors because a large
amount of briquette coal is required to manufacture a large amount of
molten iron. In this case, it is necessary to increase cold strength of the
briquette coal because the briquette coal 5 may be broken by external
impact. In addition, in a case in which a deviation of cold strength of the
briquette coal is large, an operational variation may occur in the melting
and gasifying furnace, and as a result, it is necessary to reduce the
deviation of cold strength of the briquette coal.
10 【DISCLOSURE】
【Technical Problem】
The present invention has been made in an effort to provide a
method and an apparatus for manufacturing briquette coal with excellent
cold strength and a reduced deviation of cold strength.
15 【Technical Solution】
An exemplary embodiment of the present invention provides a
method of manufacturing briquette coal, the method including: preparing
coal; drying the coal; measuring the moisture content of the dried coal
after drying the coal; providing a mixture by mixing one or more of the
20 dried coal, a curing agent, and a binder; and molding the mixture to
manufacture the briquette coal. In the providing of the mixture, moisture
may be added so that a moisture content reaches a preset target value of
the moisture content from the moisture content measured in the
4
measuring of the moisture after drying the coal.
The method may further include measuring the moisture content of
the prepared coal before drying the coal prior to the drying of the coal.
In the drying of the coal, the coal may be dried so that the moisture
in an amount of 4 to 7 wt% is contained with respect to 5 the total amount of
coal of 100 wt%. Otherwise, the coal may be dried so that the moisture
in an amount of 5 to 8 wt% is contained in the coal.
The target value may include the moisture in an amount of 6 to 8
wt% with respect to the total amount of coal of 100 wt%. More
10 specifically, the moisture in an amount of 7 to 8 wt% may be included.
The providing of the mixture by mixing one or more of the dried
coal, the curing agent, and the binder may include providing a first mixture
by mixing the dried coal and the curing agent, and providing a second
mixture by mixing the first mixture and the binder, and in the providing of
15 the second mixture, the moisture may be added so that the moisture
content reaches a preset target value of the moisture content from the
measured moisture content.
The method may further include crushing the coal subsequent to
the preparing of the coal.
20 Another exemplary embodiment of the present invention provides
an apparatus for manufacturing briquette coal, the apparatus including: a
coal storage tank which stores coal; a dryer which is connected to the coal
storage tank, and dries the coal; a dryer-rear-end moisture measuring
5
device which is installed at a rear end of the dryer; a curing agent storage
tank which stores a curing agent; a binder storage tank which stores a
binder; a mixer which provides a mixture by mixing the dried coal provided
from the dryer, the curing agent provided from the curing agent storage
tank, and the binder provided from the binder 5 storage tank; a moisture
supply nozzle which is installed in the mixer; a control unit which receives
a signal from the dryer-rear-end moisture measuring device, and controls
the moisture supply nozzle so that the moisture content reaches a preset
target value; and a molding device which is supplied with the mixture from
10 the mixer, and molds the mixture.
A plurality of moisture supply nozzles may be installed in the mixer.
The apparatus may further include a dryer-front-end moisture
measuring device which is installed at a front end of the dryer.
The apparatus may further include a dryer control unit which
15 receives a signal from the dryer-front-end moisture measuring device, and
controls a heat quantity of the dryer so that the moisture content reaches 5
to 8 wt% with respect to the total amount of coal of 100 wt%.
The mixer may include a first mixer and a second mixer, the first
mixer may be connected to the curing agent storage tank, the second
20 mixer may be connected to the binder storage tank, and the moisture
supply device may be installed on the second mixer.
The apparatus may further include a crusher for crushing the coal
between the coal storage tank and the dryer.
6
The control unit may control the target value so that the moisture is
included in an amount of 6 to 8 wt% with respect to the total amount of
coal of 100 wt%.
【Advantageous Effects】
It is possible to reduce a deviation of cold 5 strength of the briquette
coal by maintaining a constant moisture content of the coal. In addition, it
is possible to reduce fuel costs of the melting and gasifying furnace for
producing molten iron by minimizing a rapid deviation of cold strength
caused by a variation of moisture.
10 【Description of the Drawings】
FIG. 1 is a schematic flowchart of a method of manufacturing
briquette coal according to an exemplary embodiment of the present
invention.
FIG. 2 is a schematic view of an apparatus for manufacturing
15 briquette coal according to the exemplary embodiment of the present
invention.
FIG. 3 is a schematic view of an apparatus for manufacturing
briquette coal according to another exemplary embodiment of the present
invention.
20 FIG. 4 is a schematic view of a molten iron manufacturing device
using the briquette coal manufactured by the method of FIG. 1.
FIG. 5 is a schematic view of another molten iron manufacturing
device using the briquette coal manufactured by the method of FIG. 1.
7
【Mode for Invention】
The terms first, second, third, and the like are used to describe
various portions, components, regions, layers, and/or sections, but the
present invention is not limited thereto. These terms are used only to
distinguish any portion, component, region, 5 layer, or section from other
portions, components, regions, layers, or sections. Therefore, a first
portion, component, region, layer, or section to be described below may
be referred to as a second portion, component, region, layer, or section
without departing from the scope of the present invention.
10 The technical terms used herein are used merely for the purpose
of describing a specific exemplary embodiment, and not intended to limit
the present invention. Singular expressions used herein include plural
expressions unless they have definitely opposite meanings. The terms
"comprises" and/or "comprising" used in the specification specify particular
15 features, regions, integers, steps, operations, elements, and/or
components, but do not preclude the presence or addition of other
features, regions, integers, steps, operations, elements, and/or
components thereof.
Unless otherwise defined, all terms used herein including technical
20 or scientific terms have the same meanings as meanings which are
generally understood by those skilled in the art. Terms, which are usually
used and defined in dictionaries, shall be construed that they have
meanings matching those in the context of a related art, and shall not be
8
construed in ideal or excessively formal meanings unless they are clearly
defined in the present application.
The present invention will be described more fully hereinafter with
reference to the accompanying drawings, in which exemplary
embodiments of the invention are shown. 5 As those skilled in the art
would realize, the described embodiments may be modified in various
different ways, all without departing from the spirit or scope of the present
invention.
FIG. 1 schematically illustrates a flowchart of a method of
10 manufacturing briquette coal according to an exemplary embodiment of
the present invention. The flowchart of the method of manufacturing
briquette coal as illustrated in FIG. 1 is merely for exemplifying the present
invention, and the present invention is not limited thereto. Therefore, the
method of manufacturing briquette coal may be variously changed.
15 As illustrated in FIG. 1, the method of manufacturing briquette coal
includes preparing coal (S10), drying the coal (S20), measuring the
moisture content of the dried coal (S30), providing a mixture by mixing one
or more of the dried coal, a curing agent, and a binder (S40), and
manufacturing briquette coal by molding the mixture (S50). In the
20 providing of the mixture (S40), the moisture is added so that a moisture
content reaches a preset target value. In addition, the method of
manufacturing briquette coal may further include other steps, as
necessary.
9
First, in step S10, coal is prepared. In general, in accordance
with a carbonization degree, the coal is classified into peat with the carbon
content of about 60%, lignite and brown coal with the carbon content of
about 70%, subbituminous coal with the carbon content of about 70% to
80%, bituminous coal with the carbon content of 5 about 80% to 90%, and
anthracite with the carbon content of 90% or more. The type of coal is
not particularly limited, and a single type of coal may be used, or various
types of coal may be mixed and then used.
Crushing the coal may be included subsequent to step S10. To
10 reduce a deviation of quality, the coal may be crushed so that a grain size
of particles of the crushed coal is constant, and according to a specific
criterion, the coal may be crushed so that the coal in an amount of 90 wt%
to 100 wt% has a grain size of 5 mm or less.
Next, in step S20, the coal is dried. In the drying of the coal, the
15 coal may be dried so that the moisture in an amount of 4 to 7 wt% is
contained with respect to the total amount of coal of 100 wt%. Otherwise,
the coal may be dried so that the moisture in an amount of 5 to 8 wt% is
contained in the coal.
Specifically, prior to step S20, measuring a moisture content of the
20 coal prepared in step S10 before drying the coal may be included. The
moisture content of the dried coal may be adjusted by adjusting a drying
heat quantity or a drying time in step S20 based on the moisture content
measured in the measuring of the moisture content of the coal before
10
drying the coal. In the following step S30, the drying heat quantity or the
drying time may also be adjusted based on feedback about the measured
moisture content.
As a method of measuring the moisture content of the coal
prepared in the measuring of the moisture content 5 of the coal before
drying the coal, a method of using a microwave-emission type moisture
measuring device may be used or a method of manually and directly
obtaining a sample of coal and manually measuring the moisture may be
used. The method of using the microwave-emission type moisture
10 measuring device may measure the moisture in real time, but has a
problem in that this method is sensitive to a condition such as a grain size
of the coal and density of the coal and thus reliability is not high. In
addition, in a case in which the moisture is manually measured, a
deviation occurs between operators, and a workload of the operator is
15 caused. Therefore, a deviation of the moisture content of the coal is
increased in a case in which no moisture is added in the following step
S40 after the coal is dried in step S20.
Next, step S30 is a step of measuring the moisture content of the
dried coal after drying the coal. Specifically, as a method of measuring
20 the moisture in the dried coal, a continuous microwave-emission type
measuring device, which is widely utilized as a typical moisture measuring
device, may be used or a method of obtaining a sample of the dried coal
manually by the operator, inputting the sample into a dryer, and then
11
periodically measuring the moisture may be used.
Next, in step S40, one or more of the dried coal, a curing agent,
and a binder are mixed to provide a mixture.
As a curing agent, CaO, Ca(OH)2, MgO, Mg(OH)2, Na2O, NaOH,
K2O, KOH, and the like may be used. The amount 5 of curing agent with
respect to the total amount of mixture may be 1 wt% to 5 wt%. If the
amount of curing agent is too small, the binder and the curing agent are
not coupled well, and as a result, strength of the manufactured briquette
coal cannot be sufficiently increased. In addition, if the amount of curing
10 agent is too large, the amount of ash in the briquette coal is increased,
and as a result, heat required to melt the reduced iron is not sufficiently
generated in the melting and gasifying furnace. Therefore, the amount of
curing agent is adjusted to the aforementioned range.
As the binder, molasses, raw sugar, cellulose, starch, bitumen, or
15 the like may be used. The binder may be mixed in an amount of 3 wt% to
15 wt% with respect to the total amount of mixture. If the amount of
binder is too small, strength of the briquette coal may deteriorate. In
addition, if the amount of binder is too large, a problem of attachment
occurs when the powdered coal and the binder are mixed. Therefore, the
20 amount of binder is adjusted to the aforementioned range.
In step S40, the moisture is added so that a moisture content
reaches a preset target value. Specifically, based on the moisture
content measured in step S30, a moisture supplement is added so that the
12
moisture content reaches the preset target value. In this case, the preset
target value may include moisture in the amount of 6 to 8 wt% with respect
to the total amount of coal of 100 wt%. More specifically, the moisture in
an amount of 7 to 8 wt% is included. If the moisture content of the coal is
too small, sufficient cold strength cannot be exhibited. 5 In addition, if the
moisture content of the coal is too large, there may occur problems in that
the coal cannot be normally supplied from a supply device to forming rolls,
and low-density pockmarked briquette coal is formed, or the briquette coal
is attached to the forming rolls. Therefore, the target value is adjusted to
10 the aforementioned range.
Step S40 may include providing a first mixture by mixing the dried
coal and the curing agent, and providing a second mixture by mixing the
first mixture and the binder. Since the mixing steps are divided into the
two steps, it is possible to more uniformly manufacture the mixture.
15 In the case in which the mixing processes are performed in step
S40 including the two divided steps, the moisture may be added in the
providing of the second mixture in order to further reduce a deviation of
the moisture content of the coal.
Finally, in step S50, the mixture is molded to manufacture the
20 briquette coal. In the case in which the mixing processes are performed
in step S40 including the two divided steps, the second mixture is molded
to manufacture the briquette coal. Although not illustrated in FIG. 1, the
mixture is inputted between a pair of rolls rotating in the opposite
13
directions, such that the briquette coal in the form of a pocket or a strip
may be manufactured. As a result, it is possible to manufacture the
briquette coal having excellent hot strength and excellent cold strength.
FIG. 2 schematically illustrates an apparatus for manufacturing
briquette coal according to the exemplary embodiment 5 of the present
invention. The apparatus for manufacturing briquette coal as illustrated in
FIG. 2 is merely for exemplifying the present invention, and the present
invention is not limited thereto. Therefore, the apparatus for
manufacturing briquette coal may be variously changed.
10 As illustrated in FIG. 2, the apparatus for manufacturing briquette
coal includes a coal storage tank 10 which stores coal, a dryer 40 which is
connected to the coal storage tank 10 and dries the coal, a dryer-rear-end
moisture measuring device 50 which is installed at a rear end of the dryer
40, a curing agent storage tank 20 which stores a curing agent, a binder
15 storage tank 30 which stores a binder, a mixer 60 which provides a
mixture by mixing the dried coal provided from the dryer 40, the curing
agent provided from the curing agent storage tank 20, and the binder
provided from the binder storage tank 30, a moisture supply nozzle 70
which is installed in the mixer 60, a control unit 80 which receives a signal
20 from the dryer-rear-end moisture measuring device 50 and controls the
moisture supply nozzle 70 so that a moisture content reaches a preset
target value, and a molding device 90 which is supplied with the mixture
from the mixer 60 and molds the mixture. Because specific structures
14
and operating methods of the respective devices included in the apparatus
for manufacturing briquette coal in FIG. 2 may be easily understood by
those skilled in the art to which the present invention pertains, a detailed
description thereof will be omitted.
The coal storage tank 10 stores coal. 5 In general, in accordance
with a carbonization degree, the coal is classified into peat with the carbon
content of about 60%, lignite and brown coal with the carbon content of
about 70%, subbituminous coal with the carbon content of about 70% to
80%, bituminous coal with the carbon content of about 80% to 90%, and
10 anthracite with the carbon content of 90% or more. The type of coal is
not particularly limited, and a single type of coal may be used, or various
types of coal may be mixed and then used.
A crusher may be further installed between the coal storage tank
10 and the dryer 40. To reduce a deviation of quality, the crusher may
15 crush the coal so that a grain size of particles of the crushed coal is
constant, and according to a specific criterion, the coal may be crushed so
that the coal in an amount of 90 wt% to 100 wt% has a grain size of 5 mm
or less.
The dryer 40 is connected to the coal storage tank 10, and dries
20 the coal supplied from the coal storage tank 10. In the case in which the
crusher is installed between the coal storage tank 10 and the dryer 40, the
dryer 40 dries the coal supplied from the crusher.
A dryer-front-end moisture measuring device for measuring the
15
moisture content of the stored coal may be further installed at a front end
of the dryer 40, and a dryer control unit for controlling a heat quantity of
the dryer 40 may be further installed. The dryer control unit receives a
signal from the dryer-front-end moisture measuring device and may
control the heat quantity of the dryer so that the 5 moisture in an amount of
5 to 8 wt% is contained with respect to the total amount of coal of 100 wt%.
The dryer control unit may control the heat quantity of the dryer 40 based
on feedback from the dryer-rear-end moisture measuring device 50 to be
described below together with the dryer-front-end moisture measuring
10 device.
The dryer-rear-end moisture measuring device 50 for measuring
the moisture content of the dried coal is installed at the rear end of the
dryer 40. As the dryer-rear-end moisture measuring device 50, a
continuous microwave-emission type moisture meter which is typically and
15 widely utilized to measure the moisture, a continuous moisture meter
using infrared rays or neutron, or a method of obtaining a sample manually
by an operator and measuring the moisture by the dryer may be used, but
the present invention is not particularly limited thereto. The moisture
content measured by the dryer-rear-end moisture measuring device 50 is
20 transmitted to the control unit 80, and the control unit 80 receives a signal
from the dryer-rear-end moisture measuring device 50 and controls the
moisture supply nozzle 70 so that the moisture content reaches the preset
target value. In this case, the target value may include moisture in an
16
amount of 6 to 8 wt% with respect to the total amount of coal of 100 wt%.
The mixer 60 provides the mixture by mixing the dried coal
provided from the dryer 40, the curing agent provided from the curing
agent storage tank 20, and the binder provided from the binder storage
tank 30. In addition, the moisture supply 5 nozzle 70 is installed in the
mixer 60, and the moisture supply nozzle 70 adds the moisture so that the
moisture content of the coal reaches the target value. A plurality of
moisture supply nozzles 70 may be installed to uniformly supply the
moisture to the coal in the mixer 60.
10 The mixer 60 may include a first mixer 61 which provides the first
mixture by mixing the dried coal provided from the dryer 40 and the curing
agent provided from the curing agent storage tank 20, and a second mixer
62 which provides the second mixture by mixing the first mixture provided
from the first mixer 61 and the binder provided from the binder storage
15 tank 30. Therefore, the first mixer 61 is connected to the curing agent
storage tank 20, and the second mixer 62 is connected to the binder
storage tank 30.
FIG. 3 schematically illustrates an apparatus for manufacturing
briquette coal according to another exemplary embodiment of the present
20 invention, and illustrates an example in which the mixer 60 includes the
first mixer 61 and the second mixer 62. In the case in which the mixer 60
includes the first mixer 61 and the second mixer 62, the moisture supply
nozzle 70 may be installed in the second mixer 62 in order to further
17
reduce a deviation of the moisture content of the coal.
The molding device 90 is supplied with the mixture from the mixer
60 and molds the mixture. Specifically, the molding device 90 includes
the pair of rolls rotating in the opposite directions, and the mixture is
inputted between the pair of rolls, such that the 5 mixture may be molded in
the form of a pocket or a strip.
FIG. 4 schematically illustrates a molten iron manufacturing device
100 using the briquette coal manufactured by the method of FIG. 1. A
structure of the molten iron manufacturing device 100 in FIG. 4 is merely
10 for exemplifying the present invention, and the present invention is not
limited thereto. Therefore, the molten iron manufacturing device 100 in
FIG. 4 may be modified to have various forms.
The molten iron manufacturing device 100 in FIG. 4 includes a
melting and gasifying furnace 110 and a reducing furnace 120. Other
15 devices may be included in addition to the furnaces, as necessary. Iron
ore is inputted into and reduced in the reducing furnace 120. The iron
ore inputted into the reducing furnace 120 is dried in advance, and then
used to manufacture reduced iron while passing through the reducing
furnace 120. The reducing furnace 120 is a packed-bed reducing furnace,
20 and the reducing furnace 120 is supplied with the reducing gas from the
melting and gasifying furnace 110.
Since the briquette coal manufactured by the manufacturing
method of FIG. 1 is inputted into the melting and gasifying furnace 110, a
18
coal-packed bed is formed in the melting and gasifying furnace 110. A
dome portion 101 is formed at an upper side of the melting and gasifying
furnace 110. That is, the dome portion 101 has a space wider than the
remaining portion of the melting and gasifying furnace 110, and hightemperature
reducing gas is present in 5 this space. Therefore, the
briquette coal, which is inputted into the dome portion 101, may be easily
powdered by high-temperature reducing gas. The char generated by the
thermal decomposition reaction of the briquette coal is moved to the lower
side of the melting and gasifying furnace 110 and exothermically reacts
10 with oxygen supplied through a tuyere 130. As a result, the briquette coal
may be used as a heat source for maintaining the melting and gasifying
furnace 110 at a high temperature. Meanwhile, the char provides
breathability, and as a result, a large amount of gas generated at the lower
side of the melting and gasifying furnace 110 and the reduced iron
15 supplied from the reducing furnace 120 may more easily and uniformly
pass through the entire coal-packed bed in the melting and gasifying
furnace 110. A rapid deviation of cold strength of the briquette coal
manufactured by the manufacturing method in FIG. 1, which is caused by
a variation of moisture, is minimized, and as a result, it is possible to
20 reduce fuel costs in the melting and gasifying furnace 110.
In addition to the briquette coal, a lump carbon material or cokes
may be inputted into the melting and gasifying furnace 110, as necessary.
The tuyere 130 is installed in an outer wall of the melting and gasifying
19
furnace 110, and oxygen is injected through the tuyere 30. The oxygen is
injected to the coal-packed bed, and a combustion zone is formed. The
briquette coal may be combusted in the combustion zone to generate
reducing gas.
FIG. 5 schematically illustrates a molten iron 5 manufacturing device
200 using the briquette coal manufactured by the method of FIG. 1. A
structure of the molten iron manufacturing device 200 in FIG. 5 is merely
for exemplifying the present invention, and the present invention is not
limited thereto. Therefore, the molten iron manufacturing device 200 in
10 FIG. 5 may be modified to various forms. Because the structure of the
molten iron manufacturing device 200 of FIG. 5 is similar to the structure
of the molten iron manufacturing device 100 of FIG. 4, the same
constituent elements are designated by the same reference numerals, and
a detailed description thereof will be omitted.
15 As illustrated in FIG. 5, the molten iron manufacturing device 200
includes a melting and gasifying furnace 110, a reducing furnace 122, a
reduced iron compression device 140, and a compressed and reduced
iron storage tank 150. Here, the compressed and reduced iron storage
tank 150 may be omitted.
20 The manufactured briquette coal is inputted into the melting and
gasifying furnace 110. Here, the briquette coal generates reducing gas in
the melting and gasifying furnace 110, and the generated reducing gas is
supplied to the fluidized-bed reducing furnace. Fine iron ore is supplied
20
to a plurality of reducing furnaces 122 having fluidized beds, and flows by
reducing gas supplied to the reducing furnaces 122 from the melting and
gasifying furnace 110, such that the reduced iron is manufactured. The
reduced iron is compressed by the reduced iron compression device 140,
and then stored in the compressed and reduced 5 iron storage tank 150.
The compressed and reduced iron is supplied to the melting and gasifying
furnace 110 from the compressed and reduced iron storage tank 150 and
melted in the melting and gasifying furnace 110. The briquette coal is
supplied to the melting and gasifying furnace 110 and converted into char
10 having breathability, and as a result, a large amount of gas generated at a
lower side of the melting and gasifying furnace 110 and the compressed
reduced iron more easily and uniformly pass through a coal-packed bed in
the melting and gasifying furnace 110, such that molten iron with high
quality may be manufactured.
15 The following examples illustrate the present invention in more
detail. However, the following Examples are preferred examples of the
present invention, and the present invention is not limited to the following
Examples.
Example
20 The moisture content of the prepared coal was measured in real
time by using the microwave-emission type moisture measuring device,
and the coal was dried while the heat quantity was adjusted in accordance
with the measured result. In this case, the heat quantity was adjusted so
21
that the moisture content was proximate to 6.5 wt% with respect to the
total amount of coal of 100 wt%. The moisture content of the dried coal
was measured in real time by using the microwave-emission type moisture
measuring device, CaO, as the curing agent, in an amount of 3 wt% with
respect to the total amount of the mixture of 5 100 wt% and molasses, as
the binder, in an amount of 10 wt% with respect to the total amount of the
mixture of 100 wt% were mixed with the dried coal, and the moisture was
supplied through the moisture supply nozzle based on the result of
measuring the moisture content of the dried coal while mixing the binder
10 so that the target value of the moisture content became 7.5 wt% with
respect to the total amount of coal of 100 wt%. The mixture was
compressed by a roll press, such that the briquette coal having a briquette
shape was manufactured.
Samples were collected for each step, the moisture content was
15 measured, and the results are shown in the following Table 1.
(Table 1)
Moisture Content
of Raw Coal
(wt%)
Moisture Content of Coal
Immediately after Drying
(wt%)
Moisture Content of
Coal before Molding
(wt%)
Sample
1
7.5 5.10 7.42
Sample
2
8.9 6.84 7.53
22
Sample
3
8.3 6.07 7.48
Sample
4
8.0 5.29 7.45
Sample
5
9.0 7.03 7.61
As shown in Table 1, it can be seen that a deviation of the
moisture content of the coal is relatively large immediately after the coal is
dried, but a deviation of the moisture content of the coal is relatively small
before the mixture is molded after the moisture 5 is added during the
process of mixing the binder.
Comparative Example
The moisture content of the prepared coal was measured in real
time by using the microwave-emission type moisture measuring device,
10 and the coal was dried while the heat quantity was adjusted in accordance
with the measured result. In this case, the heat quantity was adjusted so
that the moisture content was proximate to 7.5 wt% with respect to the
total amount of coal of 100 wt%. CaO, as the curing agent, in an amount
of 3 wt% with respect to the total amount of the mixture of 100 wt% and
15 molasses, as the binder, in an amount of 10 wt% with respect to the total
amount of the mixture of 100 wt% were mixed with the dried coal. The
mixture was compressed by a roll press, such that the briquette coal
23
having a briquette shape was manufactured.
Samples were collected for each step, the moisture content was
measured, and the results are shown in the following Table 2.
(Table 2)
Moisture Content
of Raw Coal
(wt%)
Moisture Content of Coal
Immediately after Drying
(wt%)
Moisture Content of
Coal before Molding
(wt%)
Sample
1
8.6 7.5 7.40
Sample
2
9.1 7.2 7.69
Sample
3
7.5 7.0 7.10
Sample
4
7.9 6.9 7.03
Sample
5
7.7 8.0 7.82
5
As shown in Table 2, it can be seen that an average value of the
moisture content of the coal before molding the mixture is similar to that of
the Example, but a deviation of the moisture content is relatively larger
than that of the Example.
24
Experimental Example: Evaluation of Cold Strength
Five manufactured briquette coals of the Example and five
manufactured briquette coals of Comparative Example were arbitrarily
selected, and a maximum load was measured until the briquette coal was
destroyed when an upper portion of the briquette 5 coal was pressed at a
constant rate in a state in which a lower portion of the briquette coal was
fixed, and the result is shown in the following Table 3.
(Table 3)
Example
(kgf)
331 325 340 314 309
Comparative Example
(kgf)
345 366 310 286 301
10 As shown in Table 3, it can be confirmed that average values of
cold strength of the briquette coal manufactured by the Example and the
Comparative Example are similar to each other, but a deviation of cold
strength of the briquette coal manufactured by the Example is small, but a
deviation of cold strength of the briquette coal manufactured by the
15 Comparative Example is large.
The present invention is not limited to the exemplary embodiments
disclosed above but will be implemented in various different forms, and
those skilled in the art will understand that the present invention may be
implemented in any other specific form without changing the technical
25
spirit or an essential feature of the present invention. Therefore, it should
be understood that the above-described exemplary embodiments are
illustrative in all aspects and do not limit the present invention.

10: Coal storage tank 5 20: Curing agent storage
tank
30: Binder storage tank 40: Dryer
50: Dryer-rear-end moisture measuring device 60: Mixer
61: First mixer 62: Second mixer
10 70: Moisture supply nozzle 80: Control unit
90: Molding device 110: Melting and gasifying
furnace
120, 122: Reducing furnace 130: Tuyere
140: Reduced iron compression device
15 150: Compressed and reduced iron storage tank
100, 200: Molten iron manufacturing device 101: Dome portion
26
WE CLAIM:
【Claim 1】
A method of manufacturing briquette coal, the method comprising:
preparing coal;
5 drying the coal;
measuring a moisture content of the dried coal after drying the
coal;
providing a mixture by mixing one or more of the dried coal, a
curing agent, and a binder; and
10 molding the mixture to manufacture the briquette coal,
wherein in the providing of the mixture, moisture is added so that a
moisture content reaches a preset target value of the moisture content
from the moisture content measured in the measuring of the moisture after
drying the coal.
15
【Claim 2】
The method of claim 1, further comprising:
measuring a moisture content of the prepared coal before drying
the coal prior to the drying of the coal.
20
【Claim 3】
The method of claim 1, wherein:
the drying of the coal dries the coal so that the moisture in an
27
amount of 5 to 8 wt% is contained with respect to the total amount of coal
of 100 wt%.
【Claim 4】
The 5 method of claim 1, wherein:
the target value includes the moisture in an amount of 6 to 8 wt%
with respect to the total amount of coal of 100 wt%.
【Claim 5】
10 The method of claim 1, wherein:
the providing of the mixture by mixing one or more of the dried coal,
the curing agent, and the binder includes providing a first mixture by
mixing the dried coal and the curing agent, and providing a second mixture
by mixing the first mixture and the binder, and
15 in the providing of the second mixture, the moisture is added so
that the moisture content reaches a preset target value of the moisture
content from the measured moisture content.
【Claim 6】
20 The method of claim 1, further comprising:
crushing the coal subsequent to the preparing of the coal.
【Claim 7】
28
An apparatus for manufacturing briquette coal, the apparatus
comprising:
a coal storage tank which stores coal;
a dryer which is connected to the coal storage tank, and dries the
5 coal;
a dryer-rear-end moisture measuring device which is installed at a
rear end of the dryer;
a curing agent storage tank which stores a curing agent;
a binder storage tank which stores a binder;
10 a mixer which provides a mixture by mixing the dried coal provided
from the dryer, the curing agent provided from the curing agent storage
tank, and the binder provided from the binder storage tank;
a moisture supply nozzle which is installed in the mixer;
a control unit which receives a signal from the dryer-rear-end
15 moisture measuring device, and controls the moisture supply nozzle so
that the moisture content reaches a preset target value; and
a molding device which is supplied with the mixture from the mixer,
and molds the mixture.
20 【Claim 8】
The apparatus of claim 7, wherein:
the plurality of moisture supply nozzles is installed in the mixer.
29
【Claim 9】
The apparatus of claim 7, further comprising:
a dryer-front-end moisture measuring device which is installed at a
front end of the dryer.
5
【Claim 10】
The apparatus of claim 9, further comprising:
a dryer control unit which receives a signal from the dryer-front-end
moisture measuring device, and controls a heat quantity of the dryer so
10 that the moisture content reaches 5 to 8 wt% with respect to the total
amount of coal of 100 wt%.
【Claim 11】
The apparatus of claim 7, wherein:
15 the mixer includes a first mixer and a second mixer,
the first mixer is connected to the curing agent storage tank,
the second mixer is connected to the binder storage tank, and
the moisture supply device is installed on the second mixer.
20 【Claim 12】
The apparatus of claim 7, further comprising:
a crusher for crushing the coal between the coal storage tank and
the dryer.
30
【Claim 13】
The apparatus of claim 7, wherein:
the control unit controls the target value so that the moisture is
contained in an amount of 6 to 8 wt% with respect 5 to the total amount of
coal of 100 wt%.