TECHNICAL FIELD
[0001] The present invention relates to a molten metal ladle.
BACKGROUND OF THE INVENTION
[0002] Heretofore, transportation of aluminum or like molten metal has been conducted in
such a manner that the molten metal is first removed from a furnace and poured into
a molten metal ladle in a foundry, and then transferred to a manufacturing site inside
or outside the foundry using a fork lift, etc. Patent Document 1 discloses an example
of such a molten metal ladle.
[0003] As shown in Fig. 4, the molten metal ladle 100 disclosed in Patent Document 1 comprises
a ladle body 102 having a molten metal discharging tube 101, and a lid 104 covering
an opening 103 provided on top of the ladle body 102. As shown in the figure, the
ladle body 102 has a cross-sectional structure wherein an outer covering 105 formed
of a steel plate is provided on the outermost side, and a lining layer 108 formed
of a heat-insulating member 106 and a refractory member 107 is provided inside the
outer covering 105.
[0004] When the molten metal ladle 100 is repeatedly used to transport molten metal, scales,
slag and the like adhere to the innermost surface of the lining layer 108 in the ladle
body 102. If the scales, slag and the like that adhere to the innermost surface of
the lining layer 108 fall into the molten metal, problems occur, such as a lowering
of the purity of the molten metal. Therefore, the scales, slag, etc., have to be removed
periodically or when they adhere. A method wherein scales, slag and the like are scratched
off using a scraper or like tool is employed as a means for removing the scales, slag
and the like adhered to the innermost surface of the lining layer 108.
[Patent Document 1]
Japanese Unexamined Patent Publication No. 2000-106935
SUMMARY OF THE INVENTION
[Problem to be Solved by the Invention]
[0005] However, it is difficult to clean the lining layer 108 disposed in the ladle body
of the molten metal ladle of Patent Document 1. Specifically, because the innermost
surface 108b of the upper portion lining layer 108a provided on the inner surface
of the top end 102a of the ladle body 102 is horizontal, the operator has to put his
or her head into the opening 103 or use a mirror to check the adhesion and removal
of the scales, slag, etc., to or from the innermost surface 108b. This makes checking
adhesion and/or removal of the scales, slag, etc., troublesome. Furthermore, when
the innermost surface 108b of the upper portion lining layer 108a or area near the
upper corner 109 of the lining layer 108 is cleaned, the edge of the opening 103 interferes
with the scraper or like removing tool. This adversely affects the cleaning and removing
operation and makes complete removal of scales, slag, etc., difficult.
[0006] An object of the present invention is to solve the above problem and provide a molten
metal ladle in which scales, slag and the like that adhere to the lining layer can
be easily and reliably removed.
[Means for Solving the Problem]
[0007] The object of the present invention can be achieved by a molten metal ladle comprising
a bottomed tubular ladle body having an opening in the top, wherein the ladle body
has an upper ladle portion and a lower ladle portion, the upper ladle portion being
connected to the top end of the lower ladle portion, a lining layer being provided
inside the upper ladle portion and the lower ladle portion, and the innermost surface
of the lining layer in the upper ladle portion being formed as an inclined plane with
its opening area becoming smaller from the top end of the lining layer of the lower
ladle portion toward the edge of the opening.
[0008] In this molten metal ladle, it is preferable that the inclined plane have a fixed
inclination angle from the top end of the lining layer of the lower ladle portion
to the edge of the opening as seen in a vertical sectional view.
[0009] It is also preferable that the lining layer be formed of a heat-insulating member
and a refractory member.
EFFECT OF THE INVENTION
[0010] The present invention provides a molten metal ladle in which scales, slag, etc.,
that adhere to the surface of the lining layer can be easily and reliably removed.
BRIEF DESCRIPTION OF DRAWINGS
[0011]
Fig. 1(a) shows a cross-sectional view of a molten metal ladle according to one embodiment
of the present invention, and Fig. 1 (b) shows a cross-sectional view of Fig. 1(a)
taken along the line A-A.
Fig. 2 is a cross-sectional view of a molten metal ladle according to another embodiment
of the present invention.
Fig. 3 is a cross-sectional view of a molten metal ladle according to still another
embodiment of the present invention.
Fig. 4 is a cross-sectional view of a known molten metal ladle.
[Explanation of reference numerals]
[0012]
- 1
- molten metal ladle
- 10
- ladle body
- 11
- lower ladle portion
- 12
- upper ladle portion
- 13
- opening
- 14
- outer covering
- 15
- heat-insulating member
- 16
- refractory member
- 17
- lower portion lining layer
- 17a
- innermost surface
- 18
- upper portion lining layer
- 18a
- innermost surface
- 19
- lid lining layer
- 20
- connecting portion
- 30
- molten metal discharging tube
- 31
- pressurizing member
- 32
- lid
- 33
- foot
- 33a
- fork pockets
BEST MODE FOR CARRYING OUT THE INVENTION
[0013] The molten metal ladle of the present invention is explained in detail below with
reference to the attached drawings. Fig. 1(a) is a cross-sectional view of a molten
metal ladle according to one embodiment of the present invention and Fig. 1 (b) is
a cross-sectional view of Fig. 1(a) taken along the line A-A.
[0014] As shown in Fig. 1, the molten metal ladle 1 is a ladle from which molten metal is
discharged by the application of pressure. The molten metal ladle 1 comprises a ladle
body 10, a molten metal discharging tube 30, a pressurizing member 31, a lid 32, and
a pair of feet 33,33.
[0015] The ladle body 10 has a tubular form with a circular shape as seen in a horizontal
sectional view, and comprises a lower ladle portion 11 and an upper ladle portion
12. The lower ladle portion 11 is a bottomed cylinder having a constant outer diameter,
and its upper end is in contact with the upper ladle portion 12. On top of the upper
ladle portion 12, an opening 13 having a diameter smaller than the inside diameter
of the bottom surface of the lower ladle portion 11 is formed. The upper ladle portion
12 has a tapered external form, i.e., its horizontal sectional area becomes smaller
from the top of the lower ladle portion 11 toward the upper portion. Note that, the
lower ladle portion 11 and the upper ladle portion 12 may be formed in a united manner
or formed independently and then connected using a connecting member.
[0016] The cross-sectional structure of the lower ladle portion 11 is such that an outer
covering 14 formed of a steel plate is provided on the outside, and a lower portion
lining layer 17 formed of a heat-insulating member 15 and a refractory member 16 and
having a shape similar to the outer covering 14 is provided along the outer covering
14. The upper ladle portion 12 has the same cross-sectional structure as the same
as that of the lower ladle portion 11, wherein an outer covering 14 formed of a steel
plate is provided on the outside, and an upper portion lining layer 18 formed of a
heat-insulating member 15 and a refractory member 16 and having a shape similar to
the outer covering 14 is formed on the inside of the outer covering 14. The innermost
surface 18a of the upper portion lining layer 18 is formed as an inclined plane wherein
the opening area becomes smaller from the top of the innermost surface 17a of the
lower portion lining layer 17 toward the edge of the opening 13. This inclined plane
is formed so as to have a fixed inclination angle from the upper end of the innermost
surface 17a of the lower portion lining layer 17 toward the edge of the opening 13
in the longitudinal sectional view of Fig. 1.
[0017] Here, insulating firebricks, ceramic fiber felt, mortar, etc., can be used as materials
for the heat-insulating member 15. Refractory bricks, castable refractory, plastic
refractory, etc., can be used as materials for the refractory member 16.
[0018] One end 30a of the molten metal discharging tube 30 is open to the inside of the
ladle body 10 in the vicinity of the bottom surface, and the other end 30b is open
to the outside of the ladle body 10.
[0019] The pressurizing member 31 projects obliquely upward from the ladle body 10, and
comprises a compressed air inlet 31a. A means for supplying compressed air (such as
a compressor), which is not shown in the figure, is connected to the compressed air
inlet 31a. Teeming is conducted by applying pressure to the inside of the ladle body
10 using compressed air so that molten metal is discharged from the molten metal discharging
tube 30. Note that the inside the ladle body 10 also may be pressurized using a compressed
inert gas instead of compressed air.
[0020] An openable and closable lid 32 is provided on top of the ladle body 10 so as to
cover the opening 13 of the ladle body 10. The cross-sectional structure of the lid
32 is such that an outer covering 14 formed of a steel plate is provided on the outermost
side, and a lid lining layer 19 comprising a heat-insulating member 15 and a refractory
member 16 is provided inside the outer covering 14.
[0021] A pair of feet 33,33 are provided on the bottom surface of the ladle body 10 in such
a manner that one foot 33 is parallel to the other foot 33. A fork pocket 33a into
which the fork portion of a forklift can be inserted is formed in each foot 33, so
that molten metal ladle 1 can be transported by a forklift.
[0022] A method for cleaning and removing the scales, slage, etc., that adhere to the upper
portion lining layer 18 and the lower portion lining layer 17 of the molten metal
ladle 1 of the above-described structure is explained below. First, the operator of
the removal operation opens the lid 32, and checks the adhesion condition of scales,
slag, etc., to the upper portion lining layer 18 and the lower portion lining layer
17, etc., from the opening 13 of the upper portion of the ladle body 10.
[0023] Subsequently, scales, slag, etc., that adhere to the upper portion lining layer 18
and the lower portion lining layer 17 are removed using a scraper or like removing
tool. Specifically, scales, slag, etc., that adhere to the innermost surfaces 18a,
17a of the upper portion lining layer 18 and the lower portion lining layer 17a are
scratched off by inserting a scraper or like removing tool into the ladle body 10
from the opening 13.
[0024] Because the innermost surface 18a of the upper portion lining layer 18 in the upper
ladle portion 12 is formed as an inclined plane wherein the opening area becomes smaller
from the top end of the innermost surface 17a of the lower portion lining layer 17
toward the edge of the opening 13, the operator who removes the scales, slag, etc.,
does not have to check the adhesion condition by inserting his or her head into the
opening 13 during the removal operation. This allows the operator to reliably remove
scales, slag, etc., from outside the opening 13 in a comfortable position while checking
the adhesion/removal condition of all of surfaces 18a, 17a of the upper portion lining
layer 18 and the lower portion lining layer 17. Furthermore, when the innermost surface
18a of the upper portion lining layer 18 or the area near the connecting portion 20
between the innermost surface 18a of the upper portion lining layer 18 and the innermost
surface 17a of the lower portion lining layer 17 is cleaned, the operator can handle
a scraper or like removing tool without interference from the edge of the opening
13, and this simplifies the removal operation.
[0025] Because the innermost surface 18a of the upper portion lining layer 18 in the upper
ladle portion 12 is formed as an inclined plane wherein the opening area decreases
from the top end of the innermost surface 17a of the lower portion lining layer 17
toward the edge of the opening 13, when molten metal is placed in the lower ladle
portion 11, a space is formed between the surface of the molten metal and the inner
surface of the lid 32. This effectively prevents adhesion of the molten metal to the
inner surface of the lid 32, even if the molten metal splashes in the ladle body 10
when transporting the molten metal ladle 1 or pouring the molten metal.
[0026] Furthermore, because the innermost surface 18a of the upper portion lining layer
18, which forms an inclined plane, has a fixed inclination angle from the top end
of the innermost surface 17a of the lower portion lining layer 17 toward the edge
of the opening 13 as shown in the cross-sectional view of Fig. 1 (b), adhesion and
removal of scales, slag, etc., to or from the innermost surface 18a can be easily
checked. When the scales, slag, etc., that adhere to the innermost surface 18a of
the upper portion lining layer 18 are removed, the operator can remove the scales,
slag, etc., without drastically changing the holding position of a scraper or like
removing tool, and therefore the removal operation can be conducted quickly.
[0027] In the upper ladle portion 12, because the upper portion lining layer 18 is provided
in such a manner that the innermost surface 18a of the upper portion lining layer
18 forms an inclined plane wherein the opening area decreases from the top end of
the innermost surface 17a of the lower portion lining layer 17 toward the edge of
the opening 13, it is possible to effectively prevent dropping of the refractory member
16, such as a refractory brick, that forms the upper portion lining layer 18. In other
words, because a part of the weight of each refractory member 16 is supported by a
refractory member 16 immediately below, the tensile load in the gravity direction
generated in the lining surface of the refractory member 16 is reduced, and therefore
dropping of the refractory member 16 can be effectively prevented.
[0028] Here, it is preferable that the angle
θ between the inclined line of the innermost surface 18a of the upper portion lining
layer 18 and the line connecting the connecting portion 20 to the edge of the opening
13 be such that the scraper will not be caught by the edge of the opening 13 when
the scales, slag, etc., that adhere to the innermost surface 18a are removed using
a straight scraper as shown in the cross-sectional view of Fig. 1(b). The inclination
angle is preferably, for example, 5° to 30° .
[0029] One embodiment of the present invention is described above; however, the scope of
the present invention is not limited to this. For example, in the present embodiment,
the upper ladle portion 12 has a tapered external form, but the external form of the
upper ladle portion 12 is not limited as long as the innermost surface 18a of the
upper portion lining layer 18 provided inside the upper ladle portion 12 is formed
as an inclined plane wherein the opening area decreases from the top end of the lower
portion lining layer 17 toward the edge of the opening 13, and the external form may
be tubular having a consistent outer diameter in the height direction.
[0030] Furthermore, in the present embodiment, a pressurizing-type molten metal ladle is
employed as the molten metal ladle 1, wherein teeming is conducted by pressurizing
the inside of the ladle body 10 by sending compressed air, etc., therein so as to
discharge the molten metal stored in the ladle body 10 to the outside. However, it
is also possible to employ a tilting molten metal ladle as shown in Fig. 2 by which
molten metal can be discharged from the discharging port 51 by tilting the molten
metal ladle.
[0031] In the present embodiment, the innermost surface 18a of the upper portion lining
layer 18 is formed as an inclined plane having a fixed inclination angle from the
top end of the innermost surface 17a of the lower portion lining layer 17 to the edge
of the opening 13 as shown in the cross-sectional view of Fig. 1(b). However, it is
also possible to form the innermost surface 18a of the upper portion lining layer
18 as an inclined plane having a smooth curve connecting the innermost layer 17a of
the lower portion lining layer 17 with the edge of the opening 13 as shown in the
cross-sectional view of Fig. 3.