[Technical Field]
5 [0001]
The present invention relates to a method and device for measuring refractories remaining amount of a molten steel ladle that are capable of simply and accurately measuring a refractories remaining amount of a molten
steel ladle used for conveying a molten steel in a steelmaking plant.
10 [Background Art]
[0002]
A molten steel ladle used for conveying a molten steel to a continuous
casting facility or the like in a steelmaking plant has a structure in which an
internal surface of a bottomed cylindrical iron shell is lined with refractories,
15 and is a large-sized structure having an inside diameter and height of several
meters. It is unavoidable that the refractories on the internal surface of the
ladle are gradually damaged by coming into contact with a high temperature
molten steel. The damaged refractories are mended by periodic repair.
[0003]
20 For performing the above mend rationally, it is desirable to accurately
grasp a refractories remaining amount on the occasion of periodic repair.
For this reason, it is also conceivable to use a method of measuring a profile
of refractories in a converter as described in, for example, Patent Document 1
for the above purpose. However, a laser scanner described in Patent
25 Document 1 is a large-sized and extremely highly-priced device, so that it is
not easy to install it additionally for measuring a refractories remaining
amount of a molten steel ladle. Thus, there has been employed a method in
2
which a plumb bob (weight) is suspended from a top end of a molten steel
ladle to set a reference line, and a worker measures a distance to a surface of
refractories from the plumb bob. However, even the above method has
required complicated work such that a table lifter used in order for a worker to
5 mount on is disposed on a ladle bottom portion, and has further caused a
problem that a lot of time is required also for the measuring work by a
worker.
[0G04]
Further, as shown in FIG. 1, there has been also attempted a method in
10 which a laser distance meter 2 is disposed on an outer edge of a top portion of
a molten steel ladle 1 and measures a distance to a surface of refractories 3
while performing a scan in the horizontal direction and the vertical direction,
and thereby a refractories remaining amount is obtained. The above method
has an advantage in that the relatively lower-priced laser distance meter 2 can
15 be used. However, it is not easy to accurately set a measurement reference
point on which the laser distance meter 2 is disposed, so that there is a
problem that a measurement error is increased. Particularly, for grasping a
time-dependent transition of a damage state, the measurement is desirably
performed in a manner that the measurement reference point is set the same in
20 each periodic repair. However, according to the above-described method, a
mark of the measurement reference point added to an iron shell of the molten
steel ladle 1 disappears due to damage to the iron shell, slug adhesion, or the
like, and thus it is difficult to repeatedly perform the measurement with the
same measurement reference point.
25 [0005]
Meanwhile, in Patent Document 2, there has been described a method
3
of measuring a profile of refractories on an internal surface of a molten steel
ladle by using an electro-optical distance meter with a time pulse method
disposed on a bottom surface of the molten steel ladle. Here, the origin of
coordinates of the electro-optical distance meter is determined by measuring a
5 distance to an attachable/detachable reference position indicator disposed on
an outer edge of a top portion of the molten steel ladle. According to the
above method, it is possible to repeatedly perform the measurement with the
substantially same measurement reference point. However, in the above
method, processes of attaching at least three sets of reference position
10 indicators and measuring a distance to each of the reference point indicators
are needed, and thus there is a problem that the measuring work is
complicated.
[Prior Art Document]
[Patent Document]
15 [0006]
[Patent Document 1] Japanese Laid-open Patent Publication No. 2007-291435
[Patent Document 2] Japanese Laid-open Patent Publication No. H6-160074
[Summary]
[Technical Problem]
20 [0007]
Thus, an object of the present invention is, in order to solve the
above-described problem and measure a refractories remaining amount of a
molten steel ladle by using a laser distance meter, to provide a method and
device for measuring refractories remaining amount of a molten steel ladle
25 that facilitate measurement with the same measurement reference point and
allow the refractories remaining amount of the molten steel ladle to be
4
accurately grasped.
[Solution to Problem]
[0008]
In order to solve the above-described object, according to one aspect
5 of the present invention, there is provided a method for measuring refractories
remaining amount of a molten steel ladle including: disposing a supporting
member on a bottom surface of the molten steel ladle with first and second
well bricks formed in the bottom surface set as a position reference; setting a
measurement reference point of a laser distance meter disposed on the
10 supporting member based on a third well brick formed in the bottom surface
or a predetermined portion of the supporting member; and measuring a
distance to a surface of refractories on an internal surface of the molten steel
ladle while moving a measurement point of the laser distance meter in a
circumferential direction and a vertical direction of the molten steel ladle and
15 obtaining a refractories remaining amount.
[0009]
Further, in order to solve the above-described object, according to
another aspect of the present invention, there is provided a device for
measuring refractories remaining amount of a molten steeHadle including: a
20 supporting member disposed on a bottom surface of the molten steel ladle
with first and second well bricks formed in the bottom surface set as a
position reference; and a laser distance meter provided on the supporting
member so as to allow a measurement point to be moved in a circumferential
direction and a vertical direction of the molten steel ladle, in which a
25 measurement reference point of the laser distance meter is set based on a third
well brick formed in the bottom surface or a predetermined portion of the
5
supporting member.
[0010]
Optionally, each of the first and second well bricks (as well as the
third well brick in the case of being formed) may be either a teeming well
5 brick or a bottom blowing well brick. Further, the supporting member may
include three leg parts having respective tips thereof supported by three points .
including the first and the second well bricks, a main body supported by the
leg parts, and a support post provided upright on a top portion of the main
body, and the laser distance meter may also be mounted on a platform that is
10 disposed on a top end of the support post and is rotatable in at least the
circumferential direction of the molten steel ladle. Reference pins to be
inserted into the first and the second well bricks respectively may also be
provided on tip portions of two of the leg parts, and two of the leg parts may
also each have a level adjuster in order to make the support post perpendicular
15 to the bottom surface of the molten steel ladle. The platform may also be
tiltable in the vertical direction of the molten steel ladle. Further, the
platform may also be an electric turntable being * disposed to be
ascendable/descendable from/to the main body and rotatable in a horizontal
direction of the molten steel ladle.
20 [Effect of the Invention]
[0011]
According to the present invention, on the supporting member
disposed based on the two well bricks formed in the bottom surface of the
molten steel ladle, the laser distance meter is disposed based on still another
25 well brick or a predetermined portion of the supporting member, and by
performing a scan by the above laser distance meter, the measurement of the
6
refractories remaining amount of the molten steel ladle is performed. The
well bricks are formed in a manner to penetrate through an iron shell of the
molten steel ladle, so that even though the lining refractories are damaged, the
positions of the well bricks do not change. Thus, it is possible to easily
5 secure the same measurement reference point.
[0012]
Furthermore, according to the present invention, it is possible to
perform the measurement by using the relatively lower-priced laser distance
meter. Further, by using an electric turntable as the platform, for example, it
10 is also possible to automatically execute the setting of positions in the
circumferential direction and the vertical direction of a measurement point of
the laser distance meter and the measurement. In this manner, it is possible
to simply and accurately measure the refractories remaining amount of the
molten steel ladle, and it becomes possible to rationally mend a damaged
15 portion.
[Brief Description of Drawings]
[0013]
[FIG. 1] FIG. 1 is an explanatory view of a conventional technique;
[FIG. 2] FIG. 2 is a perspective view showing a refractories remaining
20 amount measuring device according to a first embodiment of the present
invention;
[FIG. 3] FIG. 3 is a plan view of a molten steel ladle on which the
refractories remaining amount measuring device according to the first
embodiment of the present invention is disposed;
25 [FIG. 4] FIG. 4 is a graph showing one example of measured results;
[FIG. 5] FIG. 5 is a graph showing a change in refractories remaining
7
amount in each periodic repair; and
[FIG. 6] FIG. 6 is a plan view of a molten steel ladle on which a
refractories remaining amount measuring device according to a second
embodiment of the present invention is disposed.
5 [Description of Embodiments]
[0014]
Preferred embodiments of the present invention will be explained in
detail with reference to the attached drawings below. Incidentally, in the
present description and drawings, components having practically the same
10 functional structures are denoted by the same reference numerals and symbols
to thereby omit repeated explanation.
[0015]
(First Embodiment)
Hereinafter, a first embodiment of the present invention will be
15 explained.
FIG. 2 is a perspective view of a refractories remaining amount
measuring device according to this embodiment. The refractories remaining
amount measuring device includes leg parts 11, 12, and 13, a main body 10,
and a support post 14 as a supporting member. The main body 10 is
20 supported by the three leg parts 11, 12, and 13. Inside the main body 10, a
control device, a communication device, and so on may also be housed. The
support post 14 is provided upright on a top portion of the main body 10. A
laser distance meter 2 is mounted on a platform 15 disposed on a top end of
the support post 14.
25 [0016]
FIG. 3 is a plan view of a molten steel ladle on which the refractories
8
remaining amount measuring device according to this embodiment is
disposed. As shown in FIG. 3, in this embodiment, in a bottom surface of a
molten steel ladle 1, two teeming well bricks 4a and 4b, (which will be
sometimes referred to as teeming well bricks 4 generically, hereinafter), and a
5 bottom blowing well brick 5 are formed. The teeming well bricks 4 each are
a drain hole for letting a molten steel in the molten steel ladle 1 flow down to
a tundish or the like therethrough and are each provided with a sliding nozzle
brick. Further, the bottom blowing well brick 5 is a hole for injecting an
oxide gas or the like into the molten steel ladle 1 therethrough. Note that in
10 the present description, the holes formed in the bottom surface of the molten
steel ladle 1 as above are referred to as well bricks. Thus, in the bottom
surface of the molten steel ladle 1, another type of well brick may also be
provided. Further, in FIG. 3, the bottom blowing well brick 5 is positioned
in the middle between the two teeming well bricks 4a and 4b, but the
15 positions and the number of the teeming well bricks 4 and the bottom blowing
well brick 5 are not limited to this.
[0017]
These teeming well bricks 4 and bottom blowing well brick 5 are
formed in a manner to penetrate through refractories 3 on the bottom surface
20 and an iron shell of the bottom surface, so that their positions in the horizontal
direction do not change regardless of a damage state of the refractories 3 on
the bottom surface and the existence or absence of slug adhesion. Thus, in
the present invention, reference pins 16 provided on tips of the two leg parts
11 and 12 of the refractories remaining amount measuring device respectively
25 are inserted into the two teeming well bricks 4a and 4b. The leg parts 11 and
12 each have rigidity, and further the respective leg parts and the main body
9
10 are rigidly coupled. For this reason, the two points of the tips on which
the reference pins 16 are provided are fixed, thereby making it possible to fix
the position of the main body 10. The shape of the reference pin 16 may
also be a conical shape so that the reference pins 16 can be fitted into the
5 teeming well bricks 4 to fix the positions of the tips of the two leg parts 11
and 12. On the other hand, a tip of the other leg part 13 is placed on the
bottom surface of the molten steel ladle 1.
[0018]
As is clear from the principle of triangulation, coordinates of three
10 points are needed in order to specify a reference point. For that reason, by
only the two teeming well bricks 4a and 4b, the position of the main body 10
is fixed, but a measurement reference point by the laser distance meter 2
cannot be determined. Thus, in this embodiment, the bottom blowing well
. brick 5 is further used. More specifically, as shown in FIG. 3, a laser axis of
15 the laser distance meter 2 is arranged to pass through the bottom blowing well
brick 5. For example, a laser of the laser distance meter 2 is emitted
diagonally downward onto the bottom blowing well brick 5, and in the state,
the emitting direction of the laser is directed to the horizontal direction, and
thereby the measurement reference point based on the bottom blowing well
20 brick 5 is set. In this manner, in this embodiment, the two teeming well
bricks 4a and 4b and the single bottom blowing well brick 5 are utilized, and
thereby the measurement reference point is set.
[0019]
Incidentally, as will be explained also in a later-described second
25 embodiment, in the embodiments of the present invention, the roles of the
teeming well bricks 4 and the bottom blowing well brick 5 are exchangeable.
10
For example, the reference pin 16 may also be inserted into each of the
teeming well brick 4a and the bottom blowing well brick 5. In the above
case, the laser distance meter 2 can be disposed so that, for example, the laser
axis may pass through the teeming well brick 4b. Further, the well bricks to
5 be used as a reference are not limited to the teeming well bricks 4 and the
bottom blowing well brick 5. For example, another type of well brick
provided in the bottom surface of the molten steel ladle 1 can also be used
similarly to the teeming well bricks 4 and the bottom blowing well brick 5 in
the above-described example.
10 [0020]
The bottom surface of the molten steel ladle 1 is not necessarily flat
due to adhesion of a slug or the like, so that, for example, a manual rotary
level adjuster 17 is provided on the tip of at least the two leg parts and a level
gauge 18 is disposed on the main body 10, and by adjusting the level adjuster
15 17 while referring the level gauge 18, the main body 10 is desirably disposed
horizontally. Thereby, the support post 14 is provided vertically, namely
perpendicularly to the bottom surface (being horizontal) of the molten steel
ladle 1.
[0021]
20 The platform 15 disposed on the top end of the support post 14 is
rotatable in at least the circumferential direction of the molten steel ladle 1.
The platform 15 may also be further tiltable in the vertical direction of the
molten steel ladle 1. Further, the platform 15 may also be an electric
turntable being disposed to be ascendable/descendable from/to the main body
25 10 and rotatable in the horizontal direction of the molten steel ladle 1. In
order to allow the platform 15 to ascend/descend from/to the main body 10,
11
for example, the support post 14 may also have an extensible structure.
[0022]
On the occasion of the measurement, a rotation angle in the
circumferential direction and a tilt angle in the vertical direction (or a position
5 in the vertical direction) of the platform 15 are set beforehand and the laser
distance meter 2 mounted on the platform 15 emits a laser beam onto an
internal circumferential surface of the molten steel ladle 1 to measure a
distance to a surface of the refractories 3. The setting of the angles and the
measurement of the distance may also be automated. Measurement data can
10 be output in a manner to correspond to the positions in the circumferential
direction and the vertical direction of a measurement point, for example.
The laser distance meter 2 can desirably measure, for example, the distance to
the surface of the refractories 3 with the accuracy of ± 1.5 mm or so. As the
laser distance meter 2 as above, for example, one supplied commercially by
15 MURAKAMI GIKEN CO., LTD. with a model number of LDS can be used.
[0023]
Intervals between the measurement points defined by the angle in the
circumferential direction and the angle in the vertical direction are only
necessary to be set appropriately. Further, the measurement is preferably
20 performed by rotating the laser distance meter 2 360° in the circumferential
direction. FIG. 4 is a view showing one example of measurement results.
FIG. 4 shows the result of which the distance to the surface of the refractories
3 at a certain position in the circumferential direction from the center of the
molten steel ladle 1 (the disposed position of the laser distance meter 2) is
25 measured at each of measurement points corresponding to ten equal parts into
which the molten steel ladle 1 is divided in the vertical direction. Each black
12
circle indicates the distance to the surface of the refractories 3 in an initial
state, and each white circle indicates the distance to the surface of the
refractories 3 measured at the time of a certain periodic repair. As long as
the measurement is performed in each periodic repair in this manner, a
5 damage state of the refractories 3 at each area can be grasped with time.
Furthermore, in this embodiment, as described previously, it is possible to use
the same measurement reference point in each measurement.
[0024]
FIG. 5 is a graph showing a change in remaining amount of the
10 refractories 3 at a certain measurement point in the case when four periodic
repairs are performed between an overall repair and a subsequent overall
repair by using a conventional technique with the remaining amount at the
time of the initial overall repair set as zero. The solid line indicates a
reference value of the remaining amount, and the dashed line indicates an
15 actual measured value.
[0025]
In this example, a mend by spraying unshaped refractories is
performed three times in "middle 2," "middle 3," and "addition" to recover
the remaining amount of the refractories 3. In these repairs, based on
20 experience of a worker, an appropriate amount of unshaped refractories was
sprayed onto an area determined to be damaged remarkably based on visual
observation of the worker. However, as shown in the drawing, the remaining
amount of the refractories 3 after the mends exceeds the reference value, and
it is found that actually, the mend is performed excessively.
25 [0026]
As described above, the repair of the refractories by using the
13
conventional technique has sometimes resulted in the excessive mend from a
long-term perspective. However, according to this embodiment, in each
periodic repair, the measurement based on the same reference point is
performed, and thereby with high accuracy, the refractories remaining amount
5 at each of the measurement points is grasped with time. For that reason, it is
possible to keep the mend within a rational range, and there is an advantage in
that a reduction in cost can be achieved.
[0027]
(Second Embodiment)
10 Next, a second embodiment of the present invention will be explained.
FIG. 6 is a plan view of a molten steel ladle on which a refractories
remaining amount measuring device according to this embodiment is
disposed. As shown in FIG. 6, in this embodiment, in a bottom surface of a
molten steel ladle 1, a teeming well brick 4 and a bottom blowing well brick 5
15 are formed.
[0028]
In this embodiment, unlike the above-described first embodiment,
reference pins 16 provided on tips of two leg parts 11 and 12 of the
refractories remaining amount measuring device respectively are inserted into
20 the teeming well brick 4 and the bottom blowing well brick 5 respectively,
and thereby the position of a main body 10 is fixed.
[0029]
Further, in this embodiment, as a disposition reference of a laser
distance meter 2, a level adjuster 17 provided on a tip of a leg part 13 is used.
25 More specifically, as shown in FIG. 6, a laser axis of the laser distance meter 2
is designed to pass through the level adjuster 17. For example, a laser of the
14
laser distance meter 2 is emitted diagonally downward onto the level adjuster
17, and in the state, the emitting direction of the laser is directed to the
horizontal direction, and thereby a measurement reference point based on the
level adjuster 17 is set. In this manner, in this embodiment, the
5 measurement reference point is set based on the teeming well brick 4, the
bottom blowing well brick 5, and the level adjuster 17 being a predetermined
portion of a supporting member.
[0030]
Incidentally, the portion of the supporting member to be used as the
10 reference is not limited to the level adjuster 17 in the above-described
example. As long as the portion used as the reference is the portion having a
fixed positional relationship with the leg parts 11 and 12 (rigidly coupled to
these members, for example) of the supporting member, any portion of the
supporting member can be used as the reference of the measurement. For
15 example, it may also be designed that a mark of a reference position is added
to a surface of any one of the main body 10 and the leg parts 11, 12, and 13,
and to the position of the mark, a laser emitted from the laser distance meter 2
is applied, and thereby the measurement reference point is set.
[0031]
20 This embodiment is applicable to the case where only the two well
bricks are provided in the bottom surface of the molten steel ladle 1 as is the
above-described example, for example. Further, even in the case where
three or more of the well bricks are provided in the bottom surface of the
molten steel ladle 1, if it is easier to use a predetermined portion of the
25 supporting member as the reference in terms of the work, this embodiment is
applicable.
15
[0032]
As has been explained above, according to the embodiments of the
present invention, when measuring the refractories remaining amount of the
molten steel ladle, the measurement with the same measurement reference
5 point is facilitated, and it is possible to grasp the refractories remaining
amount of the molten steel ladle accurately.
[0033]
In the foregoing, the preferred embodiments of the present invention
have been described in detail with reference to the attached drawings, but the
10 present invention is not limited to such examples. It is apparent that a
person having common knowledge in the technical field to which the present
invention belongs is able to devise various variation or modification examples
within the range of technical ideas described in the claims, and it should be
understood that such examples belong to the technical scope of the present
15 invention as a matter of course.
[Reference Signs List]
[0034]
1 molten steel ladle
2 laser distance meter
20 3 refractories
4 well brick
5 bottom blowing hole
10 main body
11 leg part
25 12 leg part
13 leg part
16
14 support post
15 platform
16 reference pin
17 level adjuster
5 18 level gauge

17
[CLAIMS]
[Claim 1]
A method for measuring refractories remaining amount of a molten steel ladle, comprising:
5 disposing a supporting member on a bottom surface of the molten
steel ladle with first and second well bricks formed in the bottom surface set
as a position reference;
setting a measurement reference point of a laser distance meter
disposed on the supporting member based on a third well brick formed in the
10 bottom surface or a predetermined portion of the supporting member; and
measuring a distance to a surface of refractories on an internal surface
of the molten steel ladle while moving a measurement point of the laser
distance meter in a circumferential direction and a vertical direction of the
molten steel ladle and obtaining a refractories remaining amount.
15 [Claim 2]
The method for measuring refractories remaining amount of the
molten steel ladle according to claim 1, fijrther comprising:
setting a measurement reference point of the laser distance meter
based on the third well brick, wherein
20 each of the first, second, and third well bricks is either a teeming well
brick or a bottom blowing well brick.
[Claim 3]
The method for measuring refractories remaining amount of the
molten steel ladle according to claim 1, further comprising:
25 setting a measurement reference point of the laser distance meter
based on the predetermined portion of the supporting member, wherein
18
each of the first and second well bricks is either a teeming well brick
or a bottom blowing well brick.
[Claim 4]
A device for measuring refractories remaining amount of a molten
5 steel ladle, comprising:
a supporting member disposed on a bottom surface of the molten steel
ladle with first and second well bricks formed in the bottom surface set as a
position reference; and
a laser distance meter provided on the supporting member so as to
10 allow a measurement point to be moved in a circumferential direction and a
vertical direction of the molten steel ladle, wherein
a measurement reference point of the laser distance meter is set based
on a third well brick formed in the bottom surface or a predetermined portion
of the supporting member. •
15 [Claim 5]
The device for measuring refractories remaining amount of the molten
steel ladle according to claim 4, wherein
the measurement reference point of the laser distance meter is set
based on the third well brick, and
20 each of the first, second, and third well bricks is either a teeming well
brick or a bottom blowing well brick.
[Claim 6]
The device for measuring refractories remaining amount of the molten
steel ladle according to claim 4, wherein
25 the measurement reference point of the laser distance meter is set
based on the predetermined portion of the supporting member, and
19
each of the first and second well bricks is either a teeming well brick
or a bottom blowing well brick.
[Claim 7]
The device for measuring refractories remaining amount of the molten
5 steel ladle according to claim 4, wherein
the supporting member includes:
three leg parts having respective tips thereof supported by
three points including the first and second well bricks;
a main body supported by the leg parts; and
10 a support post provided upright on a top portion of the main
body, and
the laser distance meter is mounted on a platform that is disposed on a
top end of the support post and is rotatable in at least the circumferential
direction of the molten steel ladle.
15 [Claim 8]
The device for measuring refractories remaining amount of the molten
steel ladle according to claim 7, wherein
reference pins to be inserted into the first and second well bricks
respectively are provided on tip portions of two of the leg parts.
20 [Claim 9]
The device for measuring refractories remaining amount of the molten
steel ladle according to claim 7, wherein
two of the leg parts each have a level adjuster in order to make the
support post perpendicular to the bottom surface of the molten steel ladle.
25 [Claim 10]
The device for measuring refractories remaining amount of the molten
20
steel ladle according to claim 7, wherein
the platform is tiltable in a vertical direction of the molten steel ladle.
[Claim 11]
The device for measuring refiractories remaining amount of the molten
5 steel ladle according to claim 7, wherein
the platform is an electric turntable being disposed to be
ascendable/descendable fi:om/to the main body and rotatable in a horizontal
direction of the molten steel ladle.