CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent
Application No. 10-2014-0154764 filed in the Korean Intellectual Property Office
on November 7, 2014, the entire contents of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to an emptying standpipe discharging
device of molten iron facilities. More particularly, the present invention relates
to an emptying standpipe discharging device of molten iron facilities that may be
used when a fluidized-reduction furnace is idle in a gas-solid reaction process
using fluidized-reduction furnaces of two or more stages connected by a
standpipe, in which productivity of a process may be increased by minimizing a
loss of a charged material in the fluidized-reduction furnace, a clogging
phenomenon caused by a solid during normal operations may be solved, and a
powder flow disturbance phenomenon by a gas backflow may be effectively
solved when the fluidized-reduction furnace is idle by at least one valve and gas
purging pipe to the emptying standpipe.
(b) Description of the Related Art
3
In general, a blast furnace method is a mainstream of molten iron
production equipment thus far, and the blast furnace method, having a
characteristic of only using raw materials having hardness of at least a
predetermined level and grain size that can ensure ventilation in the furnace,
must use a coke in which a specific raw coal is processed as a carbon source
used as a fuel and a reducing agent.
Also, sintered ores or pellets that have gone through a successive
agglomeration process such as sintering and pellet palletizing as a pretreatment
process are mainly used as iron sources, and resultantly, a cost increase
depending on construction of subsidiary facilities and environmental pollution
generated in the subsidiary facilities must be solved.
Accordingly, the development of molten iron facilities as a new
institutional line process that produces molten irons by directly using fine coals
as the fuel and the reducing agent and directly using powder ores, which
account for more than 80 % of the world’s ore production, as iron sources, has
been spurred on all over the world.
FIG. 1 shows a representative example of molten iron facilities directly
using the fine coal and the powder ores.
Referring to FIG. 1, the molten iron facilities include fluidized-reduction
furnaces 31, 32, and 33 of three stages reducing the powder iron ore while
forming a fluidized bed and a melting gas furnace 10 in which a coal packed
bed is formed.
The powder ores at room temperature charged in the (pre)fluidized4
reduction furnace 33 of the uppermost stage are contacted with a high
temperature reducing gas (an air flow) supplied from a melting gas furnace 10
while passing through the fluidized-reduction furnaces 31, 32, and 33 of three
stages, thereby being switched to reduced powder ores at a high temperature,
in which an elevated temperature and 60 % or more reduction are made, and
are then discharged.
The reduced powder ores are hot-formed through an agglomeration
device 20, continuously charged in the melting gas furnace 10 in which a coal
packed bed is formed, and are melted in the coal packed bed thereby being
switched into the molten iron and are then discharged outside the melting gas
furnace 10. The fine coal of an agglomerate form is continuously supplied to
the melting gas furnace 10 such that a coal packed bed of a predetermined
height is formed inside the furnace, oxygen is supplied through a plurality of
tuyeres mounted to a lower portion of an outer wall of the coal packed bed, and
a combustion gas generated while the coal is combusted in the coal packed bed
is switched into a high-temperature reduction flow while rising through the coal
packed bed and is discharged outside the melting gas furnace 10, thereby
being supplied to the fluidized-reduction furnaces 31, 32, and 33 of three stages.
The movement of the ore passing through the fluidized-reduction
furnaces 31, 32, and 33 of three stages between the fluidized-reduction
furnaces 31, 32, and 33 is done through standpipes 41 and 42 connecting the
upper end and the lower end of the fluidized-reduction furnaces 31, 32, and 33.
The high temperature reduction gas flow formed from the lower fluidized5
reduction furnace to the upper fluidized-reduction furnace by a pressure
difference between the upper and lower ends and an ore flow formed from the
upper fluidized-reduction furnace to the lower fluidized-reduction furnace by
gravity cross each other in the standpipes 41 and 42. On the other hand, a
non-powder reduced ore continuously discharged from the lowest fluidizedreduction
furnace is discharged through an ore charge pipe, and the discharged
non-powder reduced ore is charged into the melting gas furnace 10 by a
conveyor due to the portion of the high temperature reduction gas supplied to
the fluidized-reduction furnaces of three stages when the discharging position of
the lowest fluidized-reduction furnace is low depending on a height difference
between a discharging position of the lowest fluidized-reduction furnace and the
upper position of the melting gas furnace and is charged inside the melting gas
furnace 10 by gravity of the non-powder reduction ore when the discharging
position of the lowest fluidized-reduction furnace is high.
Compared with a conventional process, the manufacturing process of
the molten iron facilities using the fine coal and the powder iron ore has
advantages that the powder iron ore is used instead of lump ore and the fine
coal is used instead of the coke, and there is a point that pausing and restarting
of the equipment are simple as a characteristic of the process. However,
careful attention is required in the deactivation of the device due to the nature of
the process in which the powder iron ore is used as a raw material. That is,
the fluidization of the fluidized bed must be continuously maintained when the
fluidized-reduction furnace is deactivated in the operating status that is
6
performed with the stage in which the fluidized bed is formed by the reduction
gas supplied under each fluidized-reduction furnace.
If the supply of the reduction gas is stopped in the deactivation of the
fluidized-reduction furnace such that the powder iron ore that was fluidized
comes down just on the bottom of the fluidized-reduction furnace, a nozzle of a
distribution plate installed for a purpose of uniform gas flow under the fluidizedreduction
furnace is clogged such that a condition that the restart is difficult is
generated if a large amount of maintenance work is performed.
Also, since a powder iron ore outlet of each fluidized-reduction furnace
is positioned on the fluidized bed, the discharging of the powder iron ore from
the powder iron ore outlet has a limitation, and even though the discharging is
completed until the powder iron ore is not discharged any longer from the
powder iron ore outlet, a significant amount of powder iron ore still remains from
the gas distribution plate inside the fluidized-reduction furnace to the powder
iron ore outlet, and if the fluidization of the remaining powder iron ore is also
stopped in this state, the problem of the clogging phenomena of the gas
distribution plate appears as above.
Accordingly, currently, the flow of the reduction gas is still maintained
such that a form that the powder iron ore is discharged from the fluidizedreduction
furnace through a remaining powder iron ore discharging pipe directly
on the gas distribution plate, not the conventional powder iron ore outlet, in the
state that the fluidization of the powder iron ore is maintained in each fluidizedreduction
furnace. In this case, the ore charge pipe that is always operated
7
with an opened state on the operation is closed by a valve, and the ore that is
operated while forming the fluidized bed in each fluidized-reduction furnace is
not moved to the other fluidized-reduction furnaces and is discharged. In this
case, since the discharged powder iron ore is the ore that the reduction reaction
is not yet finished with, the discharged powder iron ore is charged into the
melting gas furnace of a following process and is discarded. In this case, since
the discarded powder iron ore is at a high temperature, a water-cooling
treatment must be essentially performed, thereby a discarding cost due to
sludge generation and a process water purification cost are additionally
generated.
The above information disclosed in this Background section is only for
enhancement of understanding of the background of the invention and therefore
it may contain information that does not form the prior art that is already known
in this country to a person of ordinary skill in the art.
SUMMARY OF THE INVENTION
The present invention provides an emptying standpipe discharging
device of molten iron facilities increasing usage efficiency of the raw ore and the
productivity of the molten iron facilities by sequentially reducing the nonreduced
and remaining powder iron ore of the fluidized-reduction furnace from
the uppermost fluidized-reduction furnace to the lowermost fluidized-reduction
furnace and supplying it to the melting gas furnace without discarding it to
maximally suppress the amount of the lost powder iron ore when the fluidizedreduction
furnace of the molten iron facilities directly using the fine coal and the
8
powder iron ore is deactivated.
According to an exemplary embodiment of the present invention, an
emptying standpipe discharging device of molten iron facilities includes
fluidized-reduction furnaces of multiple stages reducing a powder iron ore while
forming a fluidized bed,
a melting gas furnace supplying a reduction gas required for the
reduction of the powder ores in the fluidized-reduction furnaces of the multiple
stages and formed with a coal packed bed,
standpipes respectively connecting the fluidized-reduction furnaces of
the multiple stages and including a standpipe control valve for moving the ore
and a high temperature reduction gas passing through the fluidized-reduction
furnaces of the multiple stages between the fluidized-reduction furnaces, and
emptying standpipes installed between the fluidized-reduction furnaces
of the multiple stages to connect the fluidized-reduction furnaces of the multiple
stages and sequentially discharging a non-reduction remaining powder iron ore
of the fluidized-reduction furnace of the multiple stages from an uppermost
fluidized-reduction furnace to a lowermost fluidized-reduction furnace when the
fluidized-reduction furnace of the molten iron facilities is idle.
The emptying standpipe may be connected with the same height as an
ore outlet directly on the upper fluidized-reduction furnace distribution plate
among the fluidized-reduction furnaces of the multiple stages and an ore
charging hole of the lower fluidized-reduction furnace among the fluidizedreduction
furnaces of the multiple stages.
9
The emptying standpipes may be installed with an angle of more than
45 degrees with a ground surface for a smooth flow of the ore discharging
inside the pipe.
An upper emptying standpipe control valve to control close/open of the
emptying standpipe may be respectively installed on the emptying standpipe.
A lower emptying standpipe control valve to control the open/close of
the emptying standpipe may be respectively installed under the emptying
standpipe.
The upper emptying standpipe control valve may be installed at a
position of more than 1/4 of an entire length from an entrance of the emptying
standpipe.
The lower emptying standpipe control valve may be installed within 1 m
from an exit of the emptying standpipe.
At least one upper gas purging pipe for the upper control valve and at
least one lower gas purging pipe for the upper control valve for performing a
gas purge to the emptying standpipe may be respectively installed on and under
the upper emptying standpipe control valve in the emptying standpipe.
At least one upper gas purging pipe for the lower control valve and at
least one lower gas purging pipe for the lower control valve for performing the
gas purge to the emptying standpipe may be respectively installed on and under
the lower emptying standpipe control valve in the emptying standpipe.
According to the exemplary embodiment of the present invention, when
the fluidized-reduction furnace of the molten iron facilities directly using the fine
10
coal and the powder iron ore is idle, the non-reduction remaining powder iron
ore of the fluidized-reduction furnace is not discarded, but is sequentially
reduced from the uppermost fluidized-reduction furnace to the lowermost
fluidized-reduction furnace to be supplied to the melting gas furnace, and
thereby the amount of the lost powder iron ore is maximally suppressed such
that the usage efficiency and the productivity of the molten iron facilities may be
increased.
Also, by using the emptying stand pipe, since the ore may be moved
from the uppermost fluidized-reduction furnace to the lowermost fluidizedreduction
furnace by a height 100 shown in FIG. 4, without the water cooling
treatment in the deactivation of the fluidized-reduction furnace, the production
may be increased, and the water deterioration of the process water is not
generated since the water-cooling process is not performed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a molten iron facility according to a
conventional art.
FIG. 2 is a schematic diagram of an emptying standpipe discharging
device of a molten iron facility according to a first exemplary embodiment of the
present invention.
FIG. 3 is a schematic diagram of an emptying standpipe discharging
device of a molten iron facility according to a second exemplary embodiment of
the present invention.
FIG. 4 is a partial enlarged view of FIG. 3.
11
DETAILED DESCRIPTION OF THE EMBODIMENTS
The present invention will be described more fully hereinafter with
reference to the accompanying drawings, in which exemplary embodiments of
the invention are shown so as to be easily understood by the person with
ordinary skill in the art. As is easily understood by the person with ordinary
skill in the art to which the present invention pertains, the exemplary
embodiments which will be described below may be variously modified without
departing from the spirit and the scope of the present invention. If possible,
the same or similar portions are represented by using the same reference
numeral in the drawings.
The terminologies used hereinafter are set forth just to illustrate a
specific exemplary embodiment but not to limit the present invention. It must
be noted that, as used in the specification and the appended claims, the
singular forms include plural references unless the context clearly dictates
otherwise. It will be further understood that the terms "comprises", when used
in this specification, specify the presence of stated properties, regions, integers,
steps, operations, elements, and/or components, but do not preclude the
presence or addition of one or more other properties, regions, integers, steps,
operations, elements, components, and/or groups.
All terms including technical terms and scientific terms used herein have
the same meaning as the meaning generally understood by the person with
ordinary skill in the art to which the present invention pertains. The
terminologies that are defined previously are further understood to have the
12
meaning that coincides with relating technical documents and the contents that
are disclosed currently, but are not to be interpreted as the ideal or very official
meaning unless it is defined.
FIG. 2 is a schematic diagram of an emptying standpipe discharging
device of a molten iron facility according to a first exemplary embodiment of the
present invention, and FIG. 3 is a schematic diagram of an emptying standpipe
discharging device of a molten iron facility according to a second exemplary
embodiment of the present invention.
Referring to FIG. 2 to FIG. 4, an emptying standpipe discharging device
of molten iron facilities according to the first and the second exemplary
embodiments of the present invention includes
fluidized-reduction furnaces 31, 32, and 33 of multiple stages reducing a
powder iron ore while forming a fluidized bed,
a melting gas furnace 10 supplying a reduction gas required for the
reduction of the powder ores in the fluidized-reduction furnaces 31, 32, and 33
of the multiple stages and formed with a coal packed bed,
standpipes 41 and 42 respectively connecting the fluidized-reduction
furnaces 31, 32, and 33 of the multiple stages and moving the ore and a high
temperature reduction gas passing through the fluidized-reduction furnaces 31,
32, and 33 of the multiple stages between the fluidized-reduction furnaces, and
emptying standpipes 51 and 52 installed between the fluidized-reduction
furnaces 31, 32, and 33 of the multiple stages to connect the fluidized-reduction
furnaces of the multiple stages and sequentially discharging a non-reduction
13
remaining powder iron ore of the fluidized-reduction furnace of the multiple
stages from an uppermost fluidized-reduction furnace 33 to a lowermost
fluidized-reduction furnace 31 when the fluidized-reduction furnace of the
molten iron facilities is idle.
The fluidized-reduction furnace may be configured with the multiple
stages of two, three, or more stages.
Standpipe control valves 43 and 44 may be respectively installed to the
standpipes 41 and 42 to control the open/closing of the standpipes 41 and 42.
Also, the emptying standpipes 51 and 52 may be connected with the
same height as an ore outlet directly on the upper fluidized-reduction furnace
distribution plate of the multiple stage fluidized-reduction furnaces and an ore
charging hole of the lower fluidized-reduction furnace among the multiple stage
fluidized-reduction furnaces.
The emptying standpipes 51 and 52 may be installed with an angle of
more than 45 degree with a ground surface for a smooth flow of the ore
discharging inside the pipe.
Also, on the emptying standpipes 51 and 52, as shown in FIG. 2, upper
emptying standpipe control valves 53 and 54 may be respectively installed to
control the open/close of the emptying standpipes 51 and 52.
Also, on and under the emptying standpipe 51 and 52, as shown in FIG.
3 and FIG. 4, upper emptying standpipe control valves 53 and 54 and lower
emptying standpipe control valves 55 and 56 for the close/open of the emptying
standpipe 51 and 52 may be respectively installed.
14
When normally operating, the control valves 53 and 54 of the upper
emptying standpipe and the lower emptying standpipe control valves 55 and 56
are all closed so that the ores are stacked inside the fluidized-reduction furnace
to not generate clogging.
The upper emptying standpipe control valves 53 and 54 must be
installed to be as close as possible at the entrance of the emptying standpipe
51 and 52 and are installed at the position of more than 1/4 of the entire length
from the entrance of the emptying standpipes 51 and 52, thereby maximally
suppressing the phenomena that the ore is stacked on the upper emptying
standpipe control valve 53 and 54 to be clogged when closing the upper
emptying standpipe control valves 53 and 54. If the upper emptying standpipe
control valves 53 and 54 are installed at the position of less than 1/4 of the
entire length from the entrance of the emptying standpipes 51 and 52, the
particles are stacked inside the reactor in the normal operation such that the
standpipe may be blocked, an additional gas purge system must be provided to
prevent this.
Also, the lower emptying standpipe control valves 55 and 56 are also
installed to be as close as possible to the outlet of the emptying standpipes 51
and 52 for the ore to be stacked on the lower emptying standpipe control valves
55 and 56 when closing the lower emptying standpipe control valves 55 and 56
in the ore flow failure, and they are installed within 1 m from the outlet of the
emptying standpipes 51 and 52 for the ore to be maximally stacked on the lower
emptying standpipe control valves 55 and 56 when the lower emptying
15
standpipe control valves 55 and 56 are closed.
Also, in the emptying standpipes 51 and 52, at least one of lower gas
purging pipes 63 and 64 for the upper control valve and at least one of upper
gas purging pipes 61 and 62 for the upper control valve to perform the gas
purge to the emptying standpipe 51 and 52 may be respectively installed on and
under the upper emptying standpipe control valves.
Further, in the emptying standpipe 51 and 52, at least one of upper gas
purging pipes 65 and 66 for the lower control valve and at least one of lower
gas purging pipes 67 and 68 for the lower control valve to perform the gas
purge to the emptying standpipe 51 and 52 may be installed on and under the
lower emptying standpipe control valves 55 and 56.
In FIG. 4, four gas purging pipes are respectively installed at the
emptying standpipes 51 and 52, however the number of gas purging pipes is
not limited thereto, and the number may be appropriately determined depending
on the length of the emptying standpipes 51 and 52 and the distance between
the upper emptying standpipe control valves 53 and 54 and the lower emptying
standpipe control valves 55 and 56.
Accordingly, by using the upper gas purging pipes 61 and 62 for the
upper control valve, the lower gas purging pipes 63 and 64 for the upper control
valve, the upper gas purging pipes 65 and 66 for the lower control valve, and
the lower gas purging pipes 67 and 68 for the lower control valve, the clogging
may be quickly solved by the valve operation and the gas purge when the
emptying standpipes 51 and 52 are clogged.
16
Next, the operation of the emptying standpipe discharging device of the
molten iron facilities according to the second exemplary embodiment of the
present invention will be described with reference to FIG. 3 and FIG. 4.
Firstly, when the fluidized-reduction furnace of the molten iron facilities
is deactivated, the standpipe valves 43 and 44 of the conventional overflow
shape are closed to prevent the ore flow from the uppermost fluidized-reduction
furnace 33 to the middle fluidized-reduction furnace 32 among the multiple
stages of the fluidized-reduction furnaces, and the upper emptying standpipe
control valve 54 and the lower emptying standpipe control valve 56 are opened
for the ore to be flow through the upper emptying standpipe 52.
Thus, the ores that were conventionally discarded by the water-cooling
treatment by the height 100 shown in FIG. 4 flows to the middle fluidizedreduction
furnace 32 among the multiple stages of fluidized-reduction furnaces
positioned under the uppermost fluidized-reduction furnace 33.
If the ore flow fails, the ore may be sufficiently filled on the lower
emptying standpipe control valve 56 through a cyclic operation of the lower
emptying standpipe control valve 56, and then may be decreased to the middle
fluidized-reduction furnace 32 among the multiple stage fluidized-reduction
furnaces by its own weight.
Through the process as described above, the uppermost fluidizedreduction
furnace 33 among the multiple stage fluidized-reduction furnaces may
be empty, and the middle fluidized-reduction furnace 32 may be empty by the
same method by using the lower emptying stand pipe 51 and the upper
17
emptying standpipe control valve 53 and the lower emptying standpipe control
valve 56.
Here, since the lower emptying standpipe control valves 55 and 56 are
not required when the flow of the ore is smooth, the lower emptying standpipe
control valves 55 and 56 may be omitted as in FIG. 2, however the upper
emptying standpipe control valves 53 and 54 are essential to prevent the
clogging in the normal operation. Also, if the flow failure is not solved in the
operation of the emptying standpipes 51 and 52 and the clogging is generated,
the flow failure may be solved by using the valve operation and the gas purge.
That is, by using the upper gas purging pipes 61 and 62 for the upper
control valve, the lower gas purging pipes 63 and 64 for the upper control valve,
the upper gas purging pipes 65 and 66 for the lower control valve, and the lower
gas purging pipes 67 and 68 for the lower control valve, the clogging may be
quickly solved by using the valve operation and the gas purge when the
emptying standpipes 51 and 52 are clogged.
For example, when the front end of the upper emptying standpipe
control valve 54 of FIG. 4 is blocked, the upper emptying standpipe control
valve 54 is closed and then a high pressure gas is blown through the upper gas
purging pipe 62 for the upper control valve positioned on the upper emptying
standpipe control valve 54, thereby solving the clogging of the front end of the
upper emptying standpipe control valve 54. In this way, the clogging of the
rear end of the upper emptying standpipe control valve 54, the front and rear
ends of the upper emptying standpipe control valve 53, and the front and rear
18
ends of the lower emptying standpipe control valve 55 and 56 may also be
solved by using the valve operation and the gas purging pipe.
While this invention has been described in connection with what is
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.

10: melting gas furnace
20: agglomeration device
31, 32, 33: fluidized-reduction furnace
41, 42: standpipe
43, 44: standpipe control valve
51, 52: emptying standpipe
53, 54: upper emptying standpipe control valve
55, 56: lower emptying standpipe control valve
61, 62: upper gas purging pipe for an upper control valve
63, 64: lower gas purging pipe for an upper control valve
65, 66: upper gas purging pipe for a lower control valve
67, 68: lower gas purging pipe for a lower control valve

WHAT IS CLAIMED IS:
1. An emptying standpipe discharging device of molten iron
facilities includes:
fluidized-reduction furnaces of multiple stages reducing a powder iron
ore while forming a fluidized bed;
a melting gas furnace supplying a reduction gas required for the
reduction of the powder ores in the fluidized-reduction furnaces of the multiple
stages and formed with a coal packed bed;
standpipes respectively connecting the fluidized-reduction furnaces of
the multiple stages and including a standpipe control valve for moving the ore
and a high temperature reduction gas passing through the fluidized-reduction
furnaces of the multiple stages between the fluidized-reduction furnaces; and
emptying standpipes installed between the fluidized-reduction furnaces
of the multiple stages to connect the fluidized-reduction furnaces of the multiple
stages and sequentially discharging a non-reduction remaining powder iron ore
of the fluidized-reduction furnace of the multiple stages from an uppermost
fluidized-reduction furnace to a lowermost fluidized-reduction furnace when the
fluidized-reduction furnace of the molten iron facilities is idle.
2. The emptying standpipe discharging device of claim 1, wherein
the emptying standpipe is connected with the same height as an ore
outlet directly on the upper fluidized-reduction furnace distribution plate among
20
the fluidized-reduction furnaces of the multiple stages and an ore charging hole
of the lower fluidized-reduction furnace among the fluidized-reduction furnaces
of the multiple stages.
3. The emptying standpipe discharging device of claim 1 or claim 2,
wherein the emptying standpipes are installed with an angle of more than 45
degrees with a ground surface for a smooth flow of the ore discharging inside
the pipe.
4. The emptying standpipe discharging device of claim 3, wherein
an upper emptying standpipe control valve to control close/open of the
emptying standpipe is respectively installed on the emptying standpipe.
5. The emptying standpipe discharging device of claim 4, wherein
a lower emptying standpipe control valve to control the open/close of the
emptying standpipe is respectively installed under the emptying standpipe.
6. The emptying standpipe discharging device of claim 4, wherein
the upper emptying standpipe control valve is installed at a position of
more than 1/4 of an entire length from an entrance of the emptying standpipe.
7. The emptying standpipe discharging device of claim 5, wherein
the lower emptying standpipe control valve is installed within 1 m from
21
an exit of the emptying standpipe.
8. The emptying standpipe discharging device of claim 6, wherein
at least one upper gas purging pipe for the upper control valve and at
least one lower gas purging pipe for the upper control valve for performing a
gas purge to the emptying standpipe are respectively installed on and under the
upper emptying standpipe control valve in the emptying standpipe.
9. The emptying standpipe discharging device of claim 7, wherein
at least one upper gas purging pipe for the lower control valve and at
least one lower gas purging pipe for the lower control valve for performing the
gas purge to the emptying standpipe are respectively installed on and under the
lower emptying standpipe control valve in the emptying standpipe.