BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a precision method of short-term
relining, constructing or reconstructing a blast furnace. Particularly, the method
realizes significant shortening and simplification of the relining or construction
process and reduction in cost.
2. Description of the Related Art
Conventionally, relining of a blast furnace is carried out by successively
disassembling the blast furnace from top to bottom and thereafter successively assembling
the blast furnace from the bottom to the top in reverse. In the disassembling and
assembling operation, a furnace top crane is installed in the vicinity of the top
of the blast furnace. However, the lifting capacity of the usual furnace top crane
is only about 60 through 100 tons. Therefore, the disassembling and assembling operation
requires dividing the blast furnace (hereinafter referred to as "shell") and its
firebricks into a number of small units. Further, a time period as long as 120 to
150 days is required to complete relining. Further, work at a high elevation in
the furnace is needed, posing a problem of safety. This is also a problem in newly
constructing a blast furnace.
Japanese Patent Publication No. 39322/1978 proposes a method in which
a blast furnace is divided into several sections or blocks extending from a furnace
top portion to a furnace bottom portion, the divided blocks are successively assembled
from the furnace top portion to the furnace bottom portion by the so-called "lift-up"
method, and finally the furnace bottom portion is fixed onto a foundation of the
blast furnace along with a furnace bottom base plate. Further, the respective divided
blocks are preconstructed at a location other than the foundation of the blast furnace.
Further, the assembling operation is carried out by utilizing an attached framework
for constructing the blast furnace installed above the furnace tower.
Japanese Patent Publication No. 43404/1985 proposes a method in which
a projected deck is attached to a furnace framework installed above the blast furnace
tower, and a forwardly and rearwardly movable carriage is arranged on the deck.
In the disassembling operation, the blast furnace is divided into several ring-like
blocks from a furnace top portion to a furnace bottom portion. Blocks above the
projected deck are moved out of the furnace by utilizing the carriage while successively
conveying them down. Meanwhile, blocks below the deck are moved out of the furnace
similarly by the carriage while successively conveying them up. Further, in relining
the blast furnace is assembled by similarly utilizing the carriage on the projected
deck in reverse of the disassembling procedure. This is a so-called "center drawing"
Japanese Patent Laid-Open No. 87907/1978 proposes a method of utilizing
an operation floor installed at a furnace framework above the furnace tower similar
to Japanese Patent Publication No. 43404/1985. In disassembling, portions above
a tuyere portion are moved out of the furnace by utilizing a carriage while successively
conveying them down. Meanwhile, portions below the tuyere portion are disassembled
separately by bulldozers or the like. Further, in relining of the blast furnace,
the portions below the tuyere portion are installed by conveying them down from
the operation floor and portions above the tuyere portion are bonded while successively
conveying them up. However, in this case, the assembling operation is carried out
only in respect of the shell.
In all of the above-described conventional methods, no consideration
is given to the delicacy of the complicated integral sections that comprise the
shell, the brittle firebrick and the structure for maintaining the firebrick in
place, or the warping or strain imposed upon the firebrick portions, or to the danger
of deformation of the shell, which is caused by newly moving, assembling and placing
the heavy divided blast furnace segments. Therefore, cracks are caused at bond portions
of laid bricks owing to warping or strain or deformation of the shell in the moving
and assembling operation. When the warping or the like is considerable, laid bricks
tend to collapse. Further, there are problems of malfunction or destruction of attached
measuring instruments and piping, and failure in bonding the separate integral blast
furnace segments, which are sometimes called "ring-like blocks," or simply "blocks."
In the apparatus of Japanese Patent Publication No. 39322/1978, a
problem is presented in which a jacking-up operation by hydraulic jacks installed
at a furnace bottom base plate is indispensable in assembling or moving the furnace
bottom. This requires the equipment and the operation to be complicated.
Further, according to Japanese Patent Publication No. 43404/1985 and
Japanese Patent Laid-Open No. 87907/1978, the respective sections or blocks need
to be removed and carried by utilizing the operation floor installed at the furnace
framework above the furnace tower. Therefore, the operation is complicated and the
investment cost is increased.
The applicants have previously developed a method of short-term relining
or construction of a blast furnace capable of resolving the above-described problems,
and have disclosed the method in Japanese Patent Laid-Open No. 143521/1997. Therein
the occurrence of warping or straining of brickwork portions is effectively prevented,
and roundness is essentially ensured in moving and assembling divided blocks. In
this method, there is no need of jacking-up in moving and assembling the furnace
bottom; all of the respective blocks are moved and hung up at the furnace foundation
level and no operation floor or crane is needed. The existing furnace is disassembled
and another blast furnace is reconstructed on the foundation thereof, or a totally
new blast furnace is constructed. The method comprises the following steps:
- 1. The furnace is divided into several ring-like blocks from the furnace top
portion to the furnace bottom portion.
- 2. The blocks are constructed at a location other than the foundation of the
- 3. Blocks other than the furnace bottom block are provided with means for preventing
warping or straining of the brickwork portions and means for deforming the shell.
- 4. In respect of the furnace bottom block, bricks are laid on a furnace bottom
plate installed at a lower end thereof.
- 5. Blocks other than the furnace bottom block are moved onto the foundation
of the blast furnace by horizontal transfer.
- 6. Blocks other than the furnace bottom block moved onto the foundation of the
blast furnace, are successively lifted up from the furnace top portion by the lift-up
method and are bonded together to thereby constitute upper blocks.
- 7. The furnace bottom block is moved and installed onto the foundation by horizontal
transfer at the blast furnace foundation level.
- 8. The furnace bottom block and the upper blocks are bonded together.
Occurrence of warping or straining at brickwork portions in moving,
hanging up and bonding, can effectively be prevented. Further, the roundness of
the furnace can substantially be ensured. Further, in assembling the respective
blocks, when the entire brick-layers, electric instrumentation, piping, drying of
the bricks and coating of the equipment and other steps are carried out, the relining
or construction term can significantly be shortened to about 70 to 90 days. That
is, simplification of relining or construction operation, as well as reduction in
relining or construction cost, can be achieved.
Integrated iron and steel works, in recent times, tend to provide
a production system in which extra facilities are not provided and the operational
rate of aggregated facilities is promoted. Therefore, in blast furnaces which are
limited to one or two furnaces in the entire iron and steel works, further shortening
of the relining or the construction period is desired. However, according to the
above-described methods, further shortening of this period is difficult to achieve.
Many related facilities are installed around a blast furnace, and this becomes a
troublesome and time-consuming operation in which existing attached facilities need
to be temporarily removed and later installed again. That is, according to the relining
and constructing methods disclosed previously, particularly in relining a blast
furnace, a problem arises in which heavy integrated blast furnace segments cannot
often be moved safely and smoothly onto a foundation of a blast furnace.
SUMMARY OF THE INVENTION
We have resolved the above-described problems by dividing the blast
furnace into a plurality of very heavy generally cylindrical blast furnace segments,
and by utilizing the casting floor that is present in the existing blast furnace
as a floor for transferring the ring-like segments successively onto the foundation
of the blast furnace. The casting floor is an operation floor located in a casting
floor building that is provided with a molten pig iron trough for guiding molten
pig iron to a pig iron receiving vessel, such as a torpedo car, arranged outside
of the furnace.
The casting floor building is normally not provided with complicated
and troublesome attached facilities for removal or installation of heavy components.
Therefore, a super-heavy-weight article such as a blast furnace segment with its
integrated shell, brickwork and associated components may normally only be mounted
or transferred at the inside of the casting floor building. When the usual existing
crane is used for the purpose, total destruction of the integrated segment is sometimes
caused in the unloading operation alone, since excessive impact is applied to the
shell and delicate brickwork. The crane cannot be stopped accurately at an exact
predetermined position and the heavy ring-like segment and its shell and brickwork
cannot be safely and precisely positioned on the casting floor.
Hence, we have been engaged in development of a novel grounding apparatus
capable of safely and precisely positioning the ring-like block on the casting floor.
We have now created a novel grounding apparatus integrated with a
jack system utilizing rod-type lift jacks and a sliding apparatus installed with
intermittently movable hydraulic cylinders, which for the first time enable the
operator to safely and precisely mount the very heavy blast furnace segments gently
upon the casting floor.
Thus, safe transfer of the blast furnace segment, utilizing the casting
floor building, is now made feasible. Therefore, short-term relining or construction
or reconstruction of a blast furnace, utilizing the casting floor building, is realized
for the first time.
We have provided a method of short-term relining or construction of
a blast furnace, or disassembling an existing furnace and reconstructing a blast
furnace on its foundation, or constructing a totally new blast furnace. Our method
comprises the steps of:
- dividing the blast furnace into a plurality of generally cylindrical segments
extending from a furnace top portion to a furnace bottom portion;
- constructing each of the blast furnace segments at a location other than the
foundation of the blast furnace;
- installing attached facilities including staves and other attachments at each
of the blast furnace segments while constructing them;
- jacking up each of the blast furnace segments to the casting floor level in
the casting floor building by use of a grounding apparatus that extends between
the inside and the outside of the casting floor building;
- laterally moving each of the generally cylindrical blast furnace segments already
jacked up at the casting floor level, and mounting each of the blast furnace segments
on a movable carriage installed on the casting floor;
- transferring each of the blast furnace segments to a furnace center position
of the blast furnace by laterally transferring the movable carriage on rails laid
on the casting floor;
- supportively hanging each of the integrated blast furnace segments by a plurality
of jacks positioned at the top portion of the blast furnace tower at the furnace
center position of the blast furnace;
- temporarily removing the rails at the furnace center position of the blast furnace
and lowering each of the integrated blast furnace segments to position them on the
foundation of the blast furnace to thereby form a lower portion of the furnace positioned
below the casting floor;
- successively lifting up from the furnace top portion each of the integrated
blast furnace segments from the furnace center position of the blast furnace for
positioning a portion of the blast furnace above the casting floor level, using
the jacks attached to the furnace tower and bonding together the successive blast
furnace segments to form the upper portions of the blast furnace; and bonding the
upper portions of the blast furnace with the lower portion of the blast furnace
after forming the upper portions of the furnace;
- and removing the rails from the furnace center position of the blast furnace.
The following beneficial operations accordingly provide important
advantages achieved by the invention:
- I. Welding an shell of each blast furnace segment by one-side welding from outside
- II. Lifting up the blast furnace segments, combined with the bonding operation
when the weld height of the one-side welding procedure reaches one-third of the
plate thickness of the shell of the blast furnace segment, and carrying out the
remaining welding after completing the lifting-up operation.
- III. Extending ring-like shell reinforcement members through the centers of
the blast furnace segments to horizontally span the shell surrounding the outer
periphery of the integrated blast furnace segments, and engaging such shell reinforcement
members with furnace inner structures, for attaching to the shell a stave which
is highly useful in accelerating the construction process.
Further, according to this invention, there is provided an apparatus
for relining or constructing or reconstructing a blast furnace, comprising:
- a steel structure that extends to the inside and to the outside of the casting
- a movable base mounted on rails cooperating with the steel structure, which
base is movable between the inside and outside of the casting floor building;
- a moving apparatus for controlling movement of the movable base in a horizontal
direction, and having hydraulic cylinders that are movable intermittently along
the rails; and
- a grounding apparatus for grounding individual integrated blast furnace segments,
having a hanging base movable up and down under forces exerted by a plurality of
sets of rod-type lift jacks installed at the moving base and installed with hanging
pieces for supportively hanging the integrated blast furnace segments.
These and other features of the invention will be further described
in detail, and in the drawings, which show selected forms of the apparatus and the
method, but which are not intended to define or to limit the scope of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
- Fig. 1 is a vertical sectional view of an existing blast furnace before disassembling
- Fig. 2 is a view showing the blast furnace after being separated into a plurality
of integrated segments A', B', C', D', E' and F' in accordance with this invention;
- Fig. 3 is a view showing a procedure for separating the lowest stage segment
F' of the Fig. 2 blast furnace in disassembling the blast furnace;
- Fig. 4 is a view showing a procedure of dividing and moving out an upper stage
integrated segment E' of the Fig. 2 furnace in disassembling it;
- Fig. 5 is a view showing an initial step in a procedure for relining or reconstructing
the blast furnace, by moving into the casting floor of the casting house a lowest
stage blast furnace segment F and delivering it to a foundation of the furnace;
- Fig. 6 is a view showing a procedure for moving in successively a plurality
of integrated blast furnace segments and positioning them at upper stages of the
- Figs. 7A and 7B show a grounding apparatus according to the invention, in which
Fig. 7A is a side view and Fig. 7B is a plan view;
- Figs. 8A, 8B and 8C are views showing a procedure for hanging up a blast furnace
segment C at an upper stage of the furnace, outside of the casting floor building,
by grounding apparatus according to the invention;
- Figs. 9A, 9B and 9C are views showing a procedure for horizontally moving the
furnace segment C at an upper stage of a furnace, from outside of the casting floor
building to inside the casting floor building, by grounding apparatus according
to the invention;
- Figs. 10A, 10B and 10C are views showing intermittent moving type hydraulic
cylinders useful in achieving horizontal transfer of an integrated blast furnace
segment such as segment C of Figs. 9A, 9B and 9C;
- Fig. 11 is a front view of a moving apparatus for fixing and releasing a hydraulic
cylinder to and from a hanging structure in accordance with this invention;
- Figs. 12A and 12B are views showing a preferred structure for smoothly moving
a moving base on a hanging structure in accordance with this invention, in which
Fig. 12A shows the use of rollers and Fig. 12B shows the use of a shoe;
- Fig. 13 is a view showing a procedure for mounting an integrated blast furnace
segment at an upper stage of a furnace onto a movement carriage above the casting
floor by a grounding apparatus according to the invention;
- Fig. 14 is a view showing an example of a usable route for transferring and
grounding an integrated blast furnace segment on a casting floor at a furnace center
- Fig. 15 is an explanatory view showing points of bonding an upper furnace portion
A B C D E to a lower furnace portion F;
- Fig. 16 is an explanatory view showing an inside portion of an integrated blast
furnace segment in accordance with this invention, mounted with brick supporting
members, brick holding members and deformation prevention members;
- Fig. 17 is an explanatory view showing points of bonding divided furnace segments
- Fig. 18 is an explanatory view showing preferable points of welding to perform
- Fig. 19 is an explanatory view showing points of attaching shell reinforcement
members to an shell of an integrated furnace segment; and
- Fig. 20 is a view showing attachment of shell reinforcement members to the shell
of Fig. 19.
A specific explanation will be given of a specific preferred relining
operation of a blast furnace in accordance with the invention. Specific terms have
been used for ease and clarity of explanation; they are not intended to define or
to limit the scope of the invention, which is defined in the appended claims.
Prior to relining of a blast furnace, the existing blast furnace needs
to be disassembled. The method of disassembling the blast furnace is not particularly
limited. Any disassembling methods which have been carried out conventionally can
be used. However, working at a high elevation poses a problem of safety and should
First, an explanation will be given of a preferable method of disassembling
a blast furnace.
Fig. 1 is a vertical sectional view of a complete blast furnace. In
the drawing, numeral 1 designates a furnace, numeral 2 designates a bustle pipe,
numeral 3 designates a furnace tower, numeral 4 designates a casting floor and numeral
41 designates a casting floor building.
As shown by Fig. 2, the furnace 1 is cut along a plurality of horizontal
planes to divide it into a plurality of ring-like integrated blast furnace segments
A', B', C', D', E' and F'. Each of the segments is kept integrated with the furnace
bricks, the cooling facilities, the shell and sundry appurtenances. It is preferable
to make a face cut between the furnace bottom block F' and the block E' just above
it, flush with the level of the cast floor surface 4A.
First, as shown by Fig. 3, the upper segments A', B', C', D', E' excluding
the furnace bottom segment F', are hung up by a plurality of lifting rods 5 of a
plurality of hydraulic jacks, which are used in a substantial number and attached
to the furnace tower 3. Thereafter, a plurality of transfer rails 6 (Fig. 3) are
laid on the upper face of the lowest blast furnace segment F' and upon the casting
floor surface 4A. A movement carriage 7 is arranged upon the transfer rails.
Next, the upper blast furnace segments are lowered by actuating the
lift rods 5, and are placed on the rails 6 at the upper face of the lowest segment
F'. The segment E' is separated from the remaining upper segments A', B', C' and
D'. Further, as indicated by the arrow appearing in Fig. 4, the segment E' is horizontally
moved on the rails, moved to an end portion of the casting floor and moved out of
the casting floor building. Further, in separating the segment E' from the remaining
ones of the upper segments, prior to the lifting operation, an shell cutting line
capable of withstanding the weight of the segment E' is left, the segment E' is
grounded on the rails at the upper face of the lowest segment F', and the segment
E' is separated and cut.
These procedures are repeated and the segments E', D', C', B' and
A' are successively disassembled and moved out. When the shell portion at the furnace
top portion can be reutilized without major repair work, it can be reutilized without
being moved out.
In disassembling the lowest segment F', a plurality of cut lines in
the vertical direction are produced in the shell to thereby divide the lowest segment
F' into a plurality of separate portions. The lowest segment F' is removed at the
foundation level or hung up above the casting floor and removed in a manner similar
to the upper segments. Bricks at the furnace bottom of the lowest segment F' are
exposed to the outside after disassembling the shell. Therefore, the furnace bottom
bricks are disassembled from outside by use of a large-sized disassembling machine
and are thereafter lifted above the casting floor and removed.
After disassembling the existing furnace in this way, the blast furnace
is ready to be newly reconstructed on its own foundation.
The furnace is relined or constructed as a plurality of integrated
blast furnace segments. Each of the segments is previously separately constructed
and is integrated in a ring-like shape. It may be constructed at a location remote
from the foundation of the blast furnace. The example shown in the drawings is a
case in which the furnace is assembled from six separate integrated blast furnace
segments designated A, B, C, D, E and F. In assembling each of the segments, an
shell is provided with an attached cooling facility of staves, cooling plates and
so on, and castable refractory is flowed or stamped between the shell and the staves.
Preferably, the inside of the furnace is finished drying at this stage. In supporting
each of the segments, a space in which a moving facility can enter a lower portion
thereof is maintained. Further, divided segments of the shell are aligned with lines
dividing the staves.
Further, in assembling the respective segments, bricks can be laid
on their inner faces along therewith. Because deformation of the shell is prevented
by shell reinforcement members according to this invention, even when a portion
or all of the bricks remain to be laid, transfer and bonding of the respective segments
are nevertheless practical and feasible.
Further, in respect of the shape of the segment, although a ring-like
shape is most preferable, other shapes may be used as necessary or desired.
Turning now to the assembly method, following the arrow appearing
in Fig. 5, the lowest stage segment F constituting a portion of the furnace at and
below the casting floor level, is moved to the vicinity of the casting floor building,
mounted on the casting floor, thereafter moved horizontally on the rails laid on
the casting floor, moved to the furnace center position of the blast furnace and
thereafter hung from above as heretofore described as a unit.
Successively, the individual blast furnace segments (A, B, C, D and
E) constituting the portions of the furnace to be located above the casting floor
level, are moved to the vicinity of the casting floor building, mounted on the casting
floor, thereafter moved horizontally on the rails laid on the casting floor, moved
to the furnace center position of the blast furnace, lifted up successively from
the furnace top portion, and bonded together. Fig. 6 shows the block C being moved
according to the arrows.
It has been difficult to safely and precisely mount an integrated
blast furnace segment having a weight exceeding 1000 tons on the casting floor by
using a fixed-type crane, such as a tower crane or a mobile-type crane such as a
In these cranes wires or cables are used as load supporting means.
However, it is extremely difficult to horizontally move a heavy segment having extreme
weight, since there are differences of elongations and lengths of the respective
wires or cables. When the load cannot be controlled horizontally, varying forces
are produced in unloading the segment, wherein a high load is locally applied and
the delicate integrated segment may be damaged or even destroyed.
With these cranes, the mechanism of moving the load up and down is
driven by rotating a wire drum by a motor. Stoppage accuracy, particularly in moving
down, is poor. When the stoppage accuracy in moving down is not precisely controllable,
impact is often applied in moving down the load, and the integrated segment may
quickly be damaged or destroyed.
Further, particularly in the case of a gate type crane, its horizontal
moving means uses driving wheels powered by a motor. Its stoppage accuracy in travelling
is also poor. The load cannot be accurately stopped at a predetermined position,
which results in a hindrance to the later steps, as will be readily appreciated.
Fig. 7A is a vertical sectional view of a novel grounding apparatus
according to the invention, and Fig. 7B is a horizontal sectional view thereof.
Numeral 10 designates a hanging structure which extends inside and
outside of the casting floor building. Numeral 11 (Fig. 7A) designates a slide rail
installed on the hanging structure 10 and a moving base 12 is horizontally movable
along the hanging structure 10. Numeral 13 designates a hydraulic cylinder intermittently
movable on the slide rail 11, numeral 14 designates a rod type lift jack, numeral
15 designates a hanging base and numeral 16 designates a hanger.
Hanging up the segment is shown in Figs. 8A, 8B and 8C. First, the
moving base 12 is on standby and is positioned outside of the casting floor building.
The segment C, which with the other segments was constructed at a location other
than the foundation of the blast furnace, is transported to the site by a trailer
(Fig. 8A). The segment C is engaged by the hangers 16, lifted upwardly (Fig. 8B)
and hung above the casting floor level (Fig. 8C). Further, the hangers 16 are attached
to the hanging base 15 with the front ends thereof free. Engagement thereof is carried
out freely in accordance with the size of each respective segment. After the segment
C is engaged with the hangers 16, the hanging base 15 is lifted up by a jack system
which provides equal distance and synchronized strokes at the respective hanging
points, and with synchronous control of the positions and altitudes of the respective
hanging points, such that the jack strokes for each of the respective hanging points
are equal to each other. Therefore, each individual blast furnace segment always
maintains a horizontal attitude without deviation of the hung load throughout each
raising and lowering operation.
Horizontally moving the thus lifted heavy integrated segment is shown
in Figs. 9A, 9B and 9C. The segment C is hung above and beside the casting floor
(Fig. 9A), horizontally moved toward a location above the casting floor, (Fig. 9B)
and lowered onto the casting floor (Fig. 9C). The horizontal movement is carried
out by moving the hydraulic cylinders 13 intermittently on the slide rails 11. In
that manner, the horizontal movement (Fig. 9B) can be carried out smoothly and with
excellent stoppage accuracy. The hydraulic cylinder 13 is provided with a structure
capable of being freely fixed to and released from the hanging structure 10.
As shown by Fig. 10A, the hydraulic cylinder 13 is fixed to the hanging
structure 10 with the cylinder rod 13a in a mostly contracted condition. The cylinder
rod 13a can be gradually extended to make the movable supportin base 12 approach
the casting floor in that amount (Fig. 10B). When the cylinder rod 13a is fully
extended, the connection of the hydraulic cylinder 13 to the hanging structure 10
is released and the cylinder rod 13a is contracted. Then, as shown by Fig. 10C,
on this occasion, the hydraulic cylinder 13 itself is moved toward the movable base
12 by that amount. When the hydraulic cylinder 13 maximally approaches the movable
base 12, the hydraulic cylinder 13 is affixed again to the hanging structure 10.
By repeating that operation, the movable supporting base 12 is smoothly moved under
precise control in a succession of steps onto the casting floor.
Further, converse to extracting the cylinder rod 13a, by retracting
the cylinder rod 13a, the movable supporting base 12 can also be moved accurately
in the opposite direction.
The hydraulic cylinder 13 is fixed to or released from its associated
slide rail 11 by using a structure shown by Fig. 11. In Fig. 11, numeral 17 generally
designates the movable apparatus, numeral 18 designates a lock pin, numeral 19 designates
a cylinder for driving the lock pin, numeral 20 designates a rotary lever and numeral
21 designates a lock hole of the lock pin 18 installed in the hanging structure
12. In pushing the movable base 12, when the lock pin 18 is driven by the driving
cylinder 19 and fitted into the lock hole 21, the movable apparatus 17 and accordingly,
the hydraulic cylinder 13 is fixed to the hanging structure 10. Meanwhile, when
the hydraulic cylinder 13 is pulled back, the driving cylinder 19 may be driven
again and engagement of the lock pin 18 with the lock hole 21 may be released.
Upon this occasion, control of the respective hydraulic cylinders
is carried out synchronously by a single hydraulic unit. Therefore, there is no
lack of uniformity in the moving speed of the movable base between the respective
slide rails. Further, extremely precise speed adjustment can be carried out in respect
of the hydraulic cylinder by simply adjusting the amount of oil it contains. Therefore,
compared with the conventional style in which wheels are driven by a motor, the
travel stoppage accuracy of this apparatus is remarkably precise. Accordingly, movement
of the movable base and accordingly the segment C to a predetermined position can
be carried out extremely accurately.
Figs. 12A and 12B show a specific structure for smoothly moving the
moving base on the hanging structure. Rollers are used in Fig. 12A and a shoe is
used in Fig. 12B. In the drawings, the reference number 10a designates a rail-receiving
hanging structure on which the slide rail 11 is installed. The reference number
10b designates a hanging structure on which the moving base 12 is devised to be
mounted and horizontally moved. Further, numeral 22 designates rollers and numeral
23 designates a shoe and by interposing these between the slide rail 11 and the
hanging structure 10b, the moving base 12 can be moved smoothly horizontally. In
this case, a hard material is generally used for the roller and a resin-species
used for the shoe.
Any heavy segment which has been moved horizontally to a predetermined
position on the casting floor, is readily supportively hung by the above-described
jack system and is mounted on the moving carriage 7 installed on the casting floor
(Fig. 13). In the hanging operation, according to the jack system of the invention,
the integrated blast furnace segment can be hung down while maintaining a horizontal
attitude. Accordingly, there is no concern that interference will be produced in
the hanging down operation, or that a high load will be applied locally, or that
the integrated segment will be damaged. Further, the stoppage accuracy of downward
movement is extremely excellent.
The segment mounted on the moving carriage 7 is transferred to a furnace
center position 50 (Fig. 14) by moving on the rails 6 for transfer, as shown by
the arrow in Fig. 14. Although as moving means, a method using the rollers 22 or
the shoe 23 shown by Figs. 12A and 12B is particularly preferable, compared with
the hanging operation from outside of the casting floor building to inside the casting
floor building, less precision is needed and therefore, a wheel type carriage may
be used. Further, Fig. 14 relates to movement of the segment on the casting floor.
Direction of movement may be changed by a moving turntable 52 (Fig. 14). However,
this is only an example and direction change is not necessarily needed.
With the creation of such a grounding apparatus, a heavy yet delicate
blast furnace segment constructed at a location other than the foundation of the
blast furnace can be safely and precisely grounded on the casting floor. As a result,
short-term relining or construction of a blast furnace, utilizing the casting floor,
has been achieved.
As shown by Fig. 15, after transferring the final segment E to the
furnace center position, the rails at the furnace center portion are removed, the
upper portions A-E of the furnace are hung down and the upper portions of the furnace
and the lower portion F of the furnace are bonded together to thereby finish relining
of the blast furnace. The time for relining can be shortened to 60 to 70 days.
It is preferable for the invention to provide the blast furnace segments
with means for preventing warping or straining of bricklaying portions and for preventing
deformation of the shell. According to a preferred embodiment, in respect of upper
segments A-E except the furnace bottom portion F, there are provided at least brick
supporting portions at a lower end of the segment and/or brick holding portions
at an upper end thereof. It is further preferable to install deformation preventing
members at some or all of the upper and lower ends and the inside of the segment.
Further, when staves are utilized as means for preventing warping
or straining at such a bricklaying portion and/or means for preventing deformation
of an shell, such staves are preferably utilized.
Further, in respect of the furnace bottom portion block F, a furnace
bottom plate is installed at the bottom, essentially preventing warping or straining
and deformation of the shell. Therefore, there is no particular need of installing
brick supporting members, brick holding members and deformation preventive members.
Fig. 16 shows a preferred embodiment of a blast furnace segment provided
with brick supporting members, brick holding members and deformation preventive
members. In the drawing, numeral 27 designates an shell, numeral 28 designates a
stave, numeral 29 designates castable refractory injected between the shell 27 and
the stave 28, numeral 30 designates firebricks, numeral 31 designates a cooling
plate, numeral 32 designates a cooling plate pipe, numeral 33 designates a stave
connecting pipe, numeral 34 designates a brick holding metal piece and numeral 35
designates monolithic refractory interposed at bond portions among the respective
blocks. According to this example, the cooling plates 31 are installed at a central
portion and a lower end of the block and the cooling plate 31 at the lower end also
serves to support the bricks. Further, the brick holding metal piece 34 is provided
with high bending rigidity since the shape is a doughnut shape. Therefore, by installing
such a doughnut plate at an upper end of the segment, the doughnut plate functions
not only as a brick holding member but also as a deformation preventive member.
This example is a case in which the cooling plate 31 at the lower end serves to
support bricks and the brick holding metal piece 34 serves as the deformation preventive
member. Even when these members are installed respectively and individually, there
poses no problem.
By installing such brick supporting members, brick holding members
and deformation preventive members at the blast furnace segment, occurrence of warping
or straining at bricklaying portions can effectively be prevented in carrying, hanging
up and welding the respective segments. At the same time, prevention of deformation
of the shell of the segment is essentially ensured. Further, when the bricks are
not laid in a blast furnace segment, the brickholding metal pieces are not necessarily
needed. However, it is further advantageous to install the brick holding metal pieces
for preventing deformation.
According to the invention, bonding of the respective segments is
carried out by one side welding of the shell from outside of the furnace and therefore,
welding within the furnace is not needed. Further, it is important to align the
bonding face of the staves with a face bonding the shell on the spot. In this case,
as shown by Fig. 17, to provide one-side welding of the shell, grooves for one-side
welding are provided at a lower end of the shell 27 of the upper segment and an
upper end of the shell 27 of the lower segment and welding is carried out from outside.
In this way, according to the invention, filling gaps among the segments and bonding
the shell can be carried out from outside of the furnace and therefore, processing
in the furnace can significantly be reduced, which is preferable for reasons of
safety, saving of construction expense and shortening of the term.
As shown by Fig. 18, it is preferable to lift up the blast furnace
segment at a time when the weld height of the one side welding of the shell from
outside of the furnace is completed to the extent of at least 1/3 of the plate thickness
of the shell, and to carry out the remaining welding operation after completing
the lift-up operation. The plate thickness of the shell is designed to withstand
the inner pressure in operating the blast furnace and accordingly, the bond portion
in hanging up the shell does not need a dimension of the weld portion which is equal
to the thickness of the shell. Therefore, in lifting up the segment, a weld height
only to avoid breaking the weld under the lifting up operation is sufficient. According
to stress analysis it has been found that the weld height needs to be at least 1/3
of the plate thickness of the shell. Further, at the lower portion of the furnace,
the shell is comparatively thick and accordingly, the weld height is sufficient
when it reaches about 1/3 of the plate thickness of the shell. The thickness of
the shell at an upper portion of the furnace is usually less than that in the lower
portion of the furnace and accordingly the weld height is preferably equal to or
more than 1/2 of the plate thickness of the shell. In Fig. 18, the numeral 36 designates
a weld metal and numeral 37 designates a backing metal. As a result, the time for
welding the segments can significantly be shortened, the standby time period before
lifting up a successive segment can be halved and accordingly, shortening of the
relining or construction term can be achieved.
Further, with the purpose of preventing deformation of the shell surrounding
the outer periphery of a constructed ring-like segment, the ring-like shell reinforcement
members passing through the center of the segment are attached to span horizontally.
In this case, it is preferable to engage an end portion of the shell reinforcement
member with an end portion of a metal piece on the inner side of the furnace for
attaching the stave to the shell. As a result, removal of the shell reinforcement
member from the segment is facilitated and the relining term can be shortened by
Fig. 19 is a vertical fragmented sectional view of a blast furnace
segment. The shell portion 27 is at the outer periphery, the stave 28 for cooling
the furnace is engaged with an attachment metal piece 38, and bricks are laid on
the inner side of the stave 28. The shell reinforcement member 39 is installed simultaneously
with the stave 28. An end portion of an shell reinforcement member 39 in a rod-like
shape may be engaged with a furnace inner side of the stave attachment metal piece
38 (for example, a bolt) by a turnbuckle 40 or a weld joint (not illustrated). Further,
positions for engaging the shell reinforcement member 39 are disposed at both ends
thereof and opposed to each other at an angle of 180 degrees relative to the center
of the ring as shown in Fig. 20. Although in this example the number of shell reinforcement
members 39 is 4, the number is not limited but may be at least one. After the block
has been installed, the rod-like shell reinforcement member 39 may be removed by
drawing the shell reinforcement member 39 by rotating the screw portion of the turnbuckle
40 or cutting the periphery of the weld joint by a simple cutter. In this way, the
rod-like shell reinforcement member 39 can be removed at a position not directly
related to the shell portion 27 and therefore, the shell portion 27 is not damaged
or destroyed. Further, the engagement is carried out by simple means and therefore
the shell reinforcement member 39 can easily be removed.
Although we have primarily referred to relining the blast furnace,
the method is naturally applicable similarly to cases of rebuilding or newly constructing
a blast furnace, as previously described.
In this way, according to the invention, an integrated blast furnace
segment constructed at a location other than the foundation of the blast furnace
can safely and precisely be grounded on the casting floor. In the relining or construction
or reconstruction of a blast furnace utilizing the casting floor, significant acceleration
of construction can be achieved with significantly reduced expense.
Particularly, in relining a blast furnace, the troublesome and time-consuming
operation of removing existing attached facilities can be saved. Warping or straining
of brickwork portions can effectively be prevented. Deformation of the shell of
the furnace can be prevented during transport, hanging and bonding operations. Further,
by welding the shells in position from outside the furnace, dangerous working procedures
at an elevated location, or within the furnace, can be significantly avoided.