EP1832363A1

EP1832363A1 - Molten metal ladle

Info

Publication number: EP1832363A1
Application number: EP05793202A
Authority: EP
Inventors: Kiyohumi Daiki Aluminium Industry Co. Ltd. KAWAI; Katsuyoshi c/o Nippon Crucible Co. Ltd. MUKAI; Toshiyuki c/o Chuo Ceramic Co. Ltd. MATSUMOTO
Original assignee: Nippon Crucible Co Ltd; Daiki Aluminium Industry Co Ltd
Current assignee: Nippon Crucible Co Ltd; Daiki Aluminium Industry Co Ltd
Priority date: 2004-12-28
Filing date: 2005-10-14
Publication date: 2007-09-12
Also published as: JP2006181615A; CN101065202A; JP3903321B2; EP1832363A4; WO2006070522A1; US20090065987A1

Abstract

An object of the present invention is to provide a molten metal ladle in which scales, slag, etc., that adhere to the lining surface can be removed easily and reliably.

The present invention provides a molten metal ladle provided with a bottomed tubular ladle body having an opening on the top, wherein the ladle body (10) has an upper ladle portion (12) and a lower ladle portion (11); the upper ladle portion (12) being connected to the top end of the lower ladle portion (11); lining layers (17,18) being provided inside the upper ladle portion (12) and lower ladle portion (11); and the innermost surface of the lining layer (18) of the upper ladle portion (12) being formed as an inclined plane wherein the opening area decreases from the top of the lining layer (17) of the lower ladle portion (11) toward the edge of the opening (13).

Description

TECHNICAL FIELD

The present invention relates to a molten metal ladle.

BACKGROUND OF THE INVENTION

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.
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.
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]

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.
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]

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.
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.
It is also preferable that the lining layer be formed of a heat-insulating member and a refractory member.

EFFECT OF THE INVENTION

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

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]

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

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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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° .
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.
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.
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.

Claims

A molten metal ladle comprising a bottomed tubular ladle body and an opening in an upper portion thereof;
the ladle body being provided with an upper ladle portion and a lower ladle portion;
the upper ladle portion being connected to the top end of the lower ladle portion;
the upper ladle portion and the lower ladle portion each being provided with a lining layer inside thereof;
the innermost surface of the lining layer of the upper ladle portion being formed as an inclined plane having an opening area decreasing from the top end of the lining layer of the lower ladle portion to the edge of the opening.
A molten metal ladle according to claim 1, wherein the inclined plane has a fixed inclination angle, as seen in a longitudinal sectional view, from the top end of the lining layer of the lower ladle portion to the edge of the opening.
A molten metal ladle according to claim 1 or 2, wherein the lining layer is formed of a heat-insulating member and a refractory member.