Technical Field
5 The present invention relates to internal structures of a fluidized bed reduction
furnace for reduction of iron ore powder, and more particularly,' to a column structure for
supporting a distribution plate in a fluidized bed reduction furnace for the FMEX process,
which is a new iron production process. •
Background Art
10 In the modern steel production, an indirect method is used, in which molten iron
prepared at first is subjected to decarbonization, to produce steel. The. molten iron is
produced by a blast furnace method, in which coke is used as fuel.
FIG 1 illustrates a diagram for describing a method for producing iron by the
blast furnace method schematically, wherein iron ore passes through a pretreatment
15 process in which the .iron ore is crushed, concentrated, briquetted of iron ore .powder,
' sintered, to form hard-pellets that are lumps of a predetermined size chargeable into the
blast furnace, when coke from flaming coal is used as fuel, The pellets and the coke aire
charged into the blast furnace, and fired to produce the molten iron.
.Though the blast furnace method is used as the best method for mass production-20 of iron presently, the blast furnace method costs high due to complicated process, and •
requirements foT additional separate large sized equipment for sintering and coke
production, and causes a problem of discharging sulfur oxides SOx, nitrides NOx, carbon
dioxide CO2, and the like, which are environment pollution substances, from the sintered
steel and coke production.
25 In order to solve the problems of the blast furnace method, equipment is
developed by POSCO, a Korean steel production company, in which natural state fron ore
powder is reduced directly by fluidized bed reaction without the pretreatment of the iron

ore and the coke production process, of which patent was filed with Korean patent
application No. 10-1995-41931, patented with a Korean Patent registration No. 10-
236160, of which process is .named as FENEX process, and the equipment is constructed,
and put into test operation, recently.
5 . FIG 2 illustrates a diagram of the FINEX process, an iron production process,
having the present invention applied thereto schematically, FIG 3 illustrates a section of a key portion of the fiuidized bed reduction furnace in FIG. 2 in detail, FIG 4 illustrates a section across a line I-I in FIG 3, FIG 5 illustrates a perspective view of columns in the fiuidized bed reduction furnace in FIG. 3, and FIG 6 illustrates a perspective view of a
10 distribution plate in the fiuidized bed reduction furnace in FIG 3, for reference. ■
The FINEX process is a new iron production process for producing the molten iron economically, in which iron ore powder having a wide grain size distribution is reduced step by step through many stages of the fiuidized bed reduction furnaces 1, and charges into a melting furnace 2 together with 8 ~ 50mm sized briquette eoal, to form
15 molten iron, wherein iron ore powder with a grain size of about' 8mm is passed through many stages of fiuidized bed reduction furnaces 1, to change into reduced iron ore, formed into pellets (HCI; Hot Compact Iron), and charged into the melting furnace, to produce the molten irqn.
The fiuidized bed reduction furnace 1 is provided with a body 11 having a gas
20 • supply opening 11 a in a lower portion for supplying a reductive gas, a plurality of vertical columns 12 each constructed of blocks in an inside space of the body, and a distribution plate 13 supported on the columns by a plurality of blocks uniformly. The column 12 simply supports' the distribution plate 13, and the distribution plate 13 distributes high temperature, high pressure reductive gas supplied to the inside space of the body 11
25 through the gas supply opening 11a, to fiuidize and reduce the iron ore, wherein, because the columns 12 and the distribution plate 13 can not, but be exposed to the high temperature, high pressure reductive gas in the inside.space of the body 11, the columns

• 12.and the distribution plate 13 are formed of a refractory material which has good chemical resistance, good thermal shock resistance, good mechanical strength, and good abrasion resistance, and so on.
In the meantime, the columns 12 and the distribution plate 13 have a plurality of 5 pass through holes 12a and 13a respectively, for smooth flow and pass of the gas for fluidizing and reducing the iron ore powder.
Since the columns 12 and the distribution plate 13 are structures of a reaction furnace which is not for small sized experimental equipment, but for full scale commercial production equipment, the material of the columns 12 and the distribution 10 plate 13 is' required to have no chemical reaction with the reductive gas and various components of the iron ore in the vicinity of 600 ~ 1000°C which is a main service temperature of the columns 12 and the distribution plate 13 during service, good abrasion resistance in a high temperature, high speed fluidized condition of the iron ore powder, and good thermal impact resistance enough to endure fast temperature rise and drop 15 following re-operation of the equipment because cracks occur, not in a continuous operation, but in an intermittent operation.
Moreover, since the columns 12 and the distribution plate 13 are required to be formed in various shapes of structures depending on design of the equipment, the material' of the columns 12 and the distribution plate 13 is required to have no fixed form to enable 20 formation'to any shape, and, since most of the equipment is large sized construction,the material of the columns 12 and the distribution plate 13 is required to have no deformation of the structure during curing and drying even after formation, or explosion during formation.
For formation of the columns 12 and the distribution plate 13 of the fluidized bed
25 reduction furnace 1 described thus, after preparing refractory composition for formation
of the same, the columns 12 and the distribution plate 13 are constructed respectively,
wherein, though the columns 12 and the distribution plate 13 may be formed by forming

the blocks of the refractory composition, and building up the blocks in the inside space of the body 11 in a fashion of general brick laying as shown in drawings of embodiments, different from this, after construction of molds in the inside space of the body 11," the refractory composition is mixed with bonding agent, and the like, the same as mixing 5 • general concrete, and filled, and set in the molds, to form the columns 12 and the distribution plate 13.
The plurality of pass through holes 12a and 13a are provided in the columns 12 and the distribution plate 13 respectively at the time of construction of the columns 12 and the distribution plate 13 of the prepared refractory composition for, as described 10 before, smooth flow and pass of the high temperature, high pressure reductive gas.
However, because the FINEX equipment is recently constructed, and put into test
operation, the column 12 that is constructed in the body 11 of the fluidized bed reduction
• furnace for supporting the distribution plate 13 has no provision for a case the column 12
is exposed to the reductive gas, and the iron ore powder contained in the reductive gas, at
15 all. Consequently, there are a primary problem in that the column 12 is corroded by the
high temperature, high, pressure reductive gas, as well as eroded by flow of fine iron ore
powder intensively, and a secondary problem in that an operation rate of the fluidized bed
reduction furnace 1 drops significantly due to frequent repair of the fluidized bed
reduction furnace 1 caused by the primary problem.
20 Disclosure of Invention
An object of the present invention is to provide a column for supporting a
distribution plate in a fluidized bed reduction furnace for reducing iron ore powder, which
has a good chemical resistance, a good thermal impact resistance, and a good abrasion
resistance, such that the column is not involved in corrosion or erosion due to exposure to
25 'reductive gas and iron ore powder in the reductive gas.
To achieve the object of the present invention, the present invention provides a column structure for supporting a distribution plate in a fluidized bed reduction furnace

for reducing iron ore powder comprising a body having a gas supply opening in a lower portion for receiving a reductive gas, columns in an inside space of the body each constructed of blocks of refractory, and a distribution plate supported on the columns uniformly having a plurality of pass through holes, wherein each of the columns includes 5 a plurality of stainless steel bands placed on, and fastened to an outside circumference thereof, partially.
The column includes the bands each placed on a particular portion of the column through pass through holes in a state the column is constructed by building up blocks of . refractory, and band being fastened to the column as opposite ends of the band are 10 connected directly, or with a connecting bar.
The column includes the bands each placed on the block before building up the
blocks of refractory, and band becomes in a state fastened to the column as the column is
constructed by building up the blocks having the bands fastened thereto in a state opposite
ends of the band placed on the block is connected directly, or with a separate connecting
15 bar.
The band is formed of SUS310S having molybdenum added to general stainless steel SUS304S. Brief Description of the Accompanying Drawings
The accompanying drawings, which are included to provide a further 20 understanding of the invention, illustrate embodiments. In the drawings;
FIG 1 illustrates a diagram for describing a method for producing iron by using a blast furnace method, schematically;
FIG 2 illustrates a diagram of the FINEX process having the present invention
applied thereto, schematically;
25 FIG. 3 illustrates a section of a key portion of the fiuidized bed reduction furnace
in FIG 2 in detail;
FIG 4 illustrates a-sect'on across a line I-I in FIG 3;

FIG 5 illustrates a perspective view of columns in the fluidized bed reduction furnace in FIG. 3;
FIG 6 illustrates a perspective view of a distribution plate in the fluidized bed
reduction furnace in FIG 3, for reference;
5 FIG. 7 illustrates a front view of key portion having the present invention.applied
to a column in a state the column is constructed of blocks in the fluidized bed reduction furnace in FIG 3;
FIG 8 illustrates a section across a line II-II in FIG 7 showing an embodiment of
a band of the present invention fastened to blocks of the column;
10 FIG 9 illustrates a section across a line EH-III in FIG 7 showing another
embodiment of a band of the present invention fastened to blocks of the column;
FIG 10 illustrates a section across a line IV-IV in FIG 7 showing another embodiment of a band of the present invention fastened to blocks of the column;
FIG 11 illustrates front and plan views each showing a state in which a band .of . 15 the present invention is fastened to a block of a column in accordance with a preferred embodiment of the present invention;
FIG 12 illustrates front and plan views each showing a state in which a band of
the present invention is fastened to a block of a column in accordance with another
preferred embodiment of the present invention; and
20 FIG. 12 illustrates front and plan views each showing a state in which a band of
the present invention is fastened to a block of a column in accordance with another preferred embodiment of the present invention. Best Mode for Carrying Out the Invention
In order to achieve above objects, in a fluidized bed reduction furnace for
25 fluidized bed reaction of iron ore powder of the present invention includes a body having
a gas supply opening in a lower portion for supplying a reductive gas, a plurality of
vertical columns in an inside space of the body, and a distribution plate supported on the

columns such that many portions thereof are supported and balance at the same time, wherein each of the columns has a plurality of pass through holes, the column includes a plurality of stainless steel bands placed on, and fastened to an outside circumference thereof, partially.-5 • The present invention will be described in more detail with reference to FIGS. 7 to 10 which are provided as embodiments in detail.
FIG. 7 illustrates a front view of key portion having the present invention applied to a column in a state the column is constructed of blocks in the fiuidized bed reduction furnace in FIG. 3, FIG. 8 illustrates a section across a line II-II in FIG. 7 showing an
10 embodiment of a band of the present invention fastened to blocks of the column, FIG. 9 illustrates a section across a line Hi-Ill in FIG. 7 showing another embodiment of a band, of the present invention fastened to blocks of the column, and FIG. 10 illustrates a section across a line' IV-IV in FIG 7 showing another embodiment of a band of the present invention fastened to blocks of the column.
15 The column 12 of the present invention, provided for supporting a distribution
plate of the fiuidized bed reaction furnace 1, includes a plurality of bands 14 of stainless steel placed on an outside circumference of the column 12. It is preferable that the stainless steel of the band is SUS310S having molybdenum added to general stainless steel SUS304S. Because the SUS310S has a good abrasion resistance, is not corroded
20 even in a CO gas environment, has a wear rate of ASTM C708 below ,1 cm3, and is very much suitable to a position that requires abrasion resistance.
Moreover, it is preferable that the band 14 is placed on the outside circumference
of the column 12 through pass through holes 12a in the column 12. That is, as shown in
' FIG. 8, by placing the band 14 around a particular portion of the column 12 by using two
25 pass through holes 12a, and welding opposite ends of the band 14, the band 14 can be fastened in a state the band 14 is placed on the outside circumference of the column 12, Or, as shown in FIG. 9, by connecting opposite ends of the band 14 with a connection bar

15 through another pass through hole 12a in a state the band 14 is placed around a particular portion of the column 12, the band 14 can be fastened in a state the band 14 is placed around the particular portion of the column 12. Or, as shown in FIG. 10, by connecting each of opposite ends of one band 14 placed around a particular portion of (he 5 column 12 through one pass through hole 12a, and the other band 14 placed around the other particular portion of the column 12 through the other'pass through hole 12a with connecting bars 15, the bands 14 can be fastened in a state the bands 14 are placed around the particular portions of the column 12.
According to this, if the fluidized bed reduction furnace 1 is put into operation as
10 an equipment of the FINEX process in a state the column 12 of the fluidized bed reduction furnace 1 of the present invention is applied thereto, a high pressure, and high temperature reductive gas is supplied to an inside space of the body 11, distributed in the . space, flows, and is reduced. In this instance, though the column 12, in the space of the body 11, is always exposed to the high pressure, and high temperature reductive gas so as
15 to be in an reductive gas environment, such that the column 12 is under the influence of corrosion, thermal impact, abrasion, and so on of the reductive gas and the iron ore powder therein, the column 12 has a good corrosion resistance, a good thermal impact resistance, a good abrasion resistance, and so on, because the particular portions of the outside circumference of the column-12 have the bands 14 of stainless steel placed
20 thereon.
In the meantime, the stainless steel of the band is SUS310S having molybdenum added to general stainless steel SUS304S. Because the SUS310S has a good abrasion resistance at an elevated temperature, a good corrosion even in a reductive gas environment containing iron ore powder, and a wear rate of ASTM C708 below 1cm3, the
25 band 14 is very much suitable to the column of the present invention.
There are no detailed references on where, and how the bands 14 are placed on the column 12 to surround the outside of the column 12. What is only required is placing

the bands on necessary portions. That is, as described in the embodiments, the band 14 may be fastened to a completed column. 12 having the pass through hole 12, or, as shown in FIGS. 11 ~ 13, the bands 14 may be placed on an outside of the block 12b in advance before the blocks 12b are placed to construct the column 12. In the latter case, it is 5 • apparent that, even if the column 12 is constructed of blocks 12b having the band 14 placed thereon, the bands 14 are fastened to the column 14 in a state the bands 14 are placed on a circumference of the column 12.
Moreover, in the case the bands 14 are fastened to the column. 14 in a state the bands 14 are placed on a circumference of the column 12, if the fastening is made more
10 than one places, fastening structures of the bands 14 are not necessarily required to be the same throughout entire section of the column 12, but the structures •shown in FIGS. 8 to 10 may be applied in a mix. Industrial Applicability
The plurality of bands of stainless steel placed on an outside circumference of the
15 columns of the fluidized bed reduction furnace make the columns to have a better chemical resistance, a better thermal impact resistance, and a better abrasion resistance, such that the refractory of the columns is not degraded for a long time even if the refractory is in the high temperature, and high speed reductive gas environment containing iron ore powder during the FINEX process is carried out, thereby permitting
20 long lasting secure operation.

WE CLAIM:
1. A column structure for supporting a distribution plate in a fluidized bed reduction furnace for reducing iron ore powder comprising a body having a gas supply opening in a lower portion for receiving a reductive gas, columns in an inside space of the body each constructed of blocks of refractory, and a distribution plate supported on the columns uniformly having a plurality of pass through holes, wherein each of the columns comprise a plurality of stainless steel bands placed on, and fastened to an outside circumference thereof, partially.
2. The column structure as claimed in claim 1, wherein the band is formed of SUS310S having molybdenum added to general stainless steel SUS304S.
3. The column structure as claimed in claim 1 or 2, wherein the column comprises the bands each placed on a particular portion of the column through pass through holes in a state the column is constructed by building up blocks of refractory, and band being fastened to the column as opposite ends of the band are connected directly, or with a connecting bar.
4. The column structure as claimed in claim 1 or 2, wherein the column comprises the bands each placed on the block before building up the blocks of refractory, and band becomes in a state fastened to the column as the column is constructed by building up the blocks having the bands fastened thereto in a state opposite ends of the band placed on the block is connected directly, or with a separate connecting bar.

ABSTRACT

Support Frame Structure for Supporting Dispersion Plate in Fluid Layer Reduction Furnace for Reduction of Iron Ore
Support frame structure for supporting dispersion plate in fluid layer reduction furnace for reduction of iron ore is hereby disclosed. A column structure for supporting a distribution plate in a fluidized bed reduction furnace for reducing iron ore powder comprising a body having a gas supply opening in a lower portion for receiving a reductive gas, columns in an inside space of the body each constructed of blocks of refractory, and a distribution plate supported on the columns uniformly having a plurality of pass through holes, wherein each of the columns comprise a plurality of stainless steel bands placed on, and fastened to an outside circumference thereof, partially.