WO1997026100A1

WO1997026100A1 - Method of casting molten metal in a belt caster including belt brushing and coolant removal and associated belt casters

Info

Publication number: WO1997026100A1
Application number: PCT/US1997/000323
Authority: WO
Inventors: Wilhelm F. Lauener
Original assignee: Larex Ag; Aluminum Company Of America
Priority date: 1996-01-16
Filing date: 1997-01-09
Publication date: 1997-07-24
Also published as: AU1574697A

Abstract

A method of casting molten metal into a metal product in a mold of a belt caster having at least one movable belt including brushing the belt of the belt caster. The belt can be brushed before or after or at both times before and after the belt is passed through a casting zone including the mold. The invention also includes a method of casting molten metal including cooling the belt with a coolant as the belt passes through a casting zone and subsequently removing excess coolant remaining on the belt after the belt passes through the casting zone. A belt caster including brushes and/or coolant removal apparatus is also disclosed.

Description

METHOD OF CASTING MOLTEN METAL IN A BELT CASTER INCLUDING BELT BRUSHING AND COOLANT REMOVAL AND ASSOCIATED BELT CASTERS Background of the Invention This invention relates to a method of casting molten metal in a belt caster including belt brushing and coolant removal and associated belt casters.

Belt casters are known machines which cast molten metal into metal products. Belt casters include a pair of movable opposed belts and a pair of opposed side dams which define a mold for casting therein the molten metal into a metal product. As the belts are passed through a casting zone including the mold, the belts are cooled by coolant from cooling boxes or other coolant supply means.

One type of belt caster is disclosed in my United States Patent No. 4,964,456, the disclosure of which is incorporated by reference herein. A belt is unwound from a top coil, passed through a casting zone including a mold where the molten metal is cast into a metal product and then wound onto a lower coil. While in the casting zone, the belt is cooled by coolant supplied from a cooling box.

With all belt casters, it is desired to produce a metal product having good surface qualities. Also, it is desired to maintain the belt so that it has a long useful life. What is needed, therefore, are methods related to the maintenance of the belt during casting and associated apparatus that will accomplish the objective of proper maintenance of the belt. Proper maintenance of the belt will lead to the production of a better metal product and will also lead to a longer useful life for the belt. S πrmarv of the Invention

The invention has met or exceeded the above¬ mentioned needs as well as others. A method of casting molten metal into a metal product in a mold of a belt caster includes brushing the belt. The belt can be brushed before or after or at both times before and after the belt is passed through the casting zone. The invention also includes a method of casting molten metal including cooling the belt with a coolant as the belt passes through a casting zone and subsequently removing excess coolant remaining on the belt after the belt passes through the casting zone. A metal product and an aluminum product made by the methods of the invention are also disclosed.

A belt caster including brushes and/or coolant removal means are also provided.

Brief Description of the Drawings A full understanding of the invention can be gained from the following description of the preferred embodiment when read in conjunction with the accompanying drawings in which:

Figure 1 is a schematic side elevational view of an open-end belt caster showing the brushes and coolant removal means of the invention.

Figure 2 is a top plan view of one embodiment of the coolant removal means and the belt of the belt caster.

Figure 3 is a front elevational view of the coolant removal means and belt shown in Figure 2. Figure 4 is a top plan view of another embodiment of the coolant removal means and the belt of the belt caster.

Figure 5 is a front elevational view of the coolant removal means- and belt shown in Figure 4.

Figure 6 is a schematic side elevational view of the oil removal means of the invention.

Figure 7 is a top plan view of the oil removal means and belt shown in Figure 6.

Detailed Description As used herein, the term "metal product", means primarily clad or unclad strip or slab made substantially of one or more metals, including without limitation, aluminum and aluminum alloys and can alβo include, in a broader sense, clad or unclad bar, foil or rod.

Referring now particularly to Figure 1, an open-end belt caster 20 is shown. The caster 20 includes a pair of movable opposed belts 22, 23 which together with a pair of movable side dams (not shown) move through a casting zone Z. The belts 22, 23 and side dams define a mold 26 in the casting zone Z for casting a molten metal 28 into a metal product 30. As can be seen, the molten metal 28 solidifies into a metal product 30 in the mold 26. The belts 22, 23 are cooled by coolant C from respective cooling boxes 32, 33 as the belts 22, 23 are passed through the casting zone Z. The metal product 30 is then moved out of mold 26 at casting speed for further processing, such as hot rolling. The molten metal 28 iβ delivered to the mold 26 from a nozzle 34 that receives molten metal 28 from a trough 36 leading from a furnace 38.

The belts 22, 23 are moved through the caβting zone Z by unwinding them from respective top coils 40, 41 and moving them around respective pulleys 42, 43. After pasβing through the casting zone Z, the belts 22, 23 then pass over respective pulleys 44, 45 and are wound on respective lower coils 46, 47. The belts 22, 23 are preferably made of steel and most preferably 0.4% carbon βteel and can have any desired length and width and are preferably bare, i.e., not coated with any coating material. Typically, the belts 22, 23 are from 0.25 mm to 0.75 mm thick. Each belt 22, 23 has a casting surface 22a, 23a which iβ adj cent to the solidifying molten metal 28 in the casting zone Z and a cooling surface 22b, 23b which is opposite the casting surface 22a, 23a, the cooling surface 22b, 23b being struck by the coolant C flowing from the cooling boxes 32, 33.

In accordance with the invention, the casting surfaces 22a, 23a of each belt 22, 23 are brushed by respective brushing means 60, 61 preferably before being unwound from coils 40, 41 and at minimum, before the belts 22, 23 enter the casting zone Z. The brushes 60, 61 remove any excess oil or other dirt or particulate matter from the casting surface 22a, 23a before the casting surface 22a, 23a is contacted by the molten metal 28 in the mold 26. The brushes 60, 61 preferably extend substantially across the entire width of the belt 22. A substantially clean, dirt and particulate-free caβting surface 22a, 23a enhances the surface quality of the metal product 30 cast in the mold 26 because undesired particulate matter on the belts 22, 23 can undesirably limit heat tranβfer through the belt thus adverβely effecting surface quality.

The brushing means 60, 61 are preferably positioned so that the brush 60, 61 can engage against the belt 22, 23 while the belt 22, 23 is supported by the coil 60, 61 as the belt 22, 23 is being unwound therefrom. The brushes 60, 61 are applied to the belt 22, 23 with a force great enough to remove undesired particles yet not so great as to mar, mark, or otherwise permanently damage the belt 22, 23 or remove any of the basic material of the belt. The brushes can be a powered rotary brush that is driven by an electric motor (not shown) for example. If rotatable, it is preferred, but not necessary, to rotate the brushes 60, 61 in a direction A opposite of the movement of the belt 22, 23 (arrow B) in order to avoid redepositing the dirt onto the belt 22, 23. The brush 60, 61 can alβo be non-rotatable and thus act to wipe dirt and oil from the belt 22, 23. The brushes 60, 61 can have bristles or not have bristles and can be made of any suitable material that will remove the undesired materials from the belt 22, 23 while at the same time not doing damage to the belt 22, 23 such as marring or marking the belt 22, 23. Such materials include metal, plastic, fabric, paper and combinations of the above.

It will be understood that when the term "brushing" or "brushes" are used herein, theβe terms encompass both brushing and wiping. Once the belts 22, 23 pass through the casting zone Z, it is desirable to brush the cooling surfaces 22b, 23b thereof in order to remove dissolved solids or other particulate matter from the coolant C which may be preβent on the cooling surfaces 22b, 23b. As can be seen in Figure 1, the brushes 66, 67 are positioned to brush the cooling surfaceβ 22b, 23b before another wrap of the belt iβ wound onto the coils 46, 47.

In accordance with another aspect of the invention, once the belts 22, 23 are passed through the casting zone Z, excess coolant C delivered from cooling boxes 32, 33 remaining on the cooling surfaces 22b, 23b of the respective belts 22, 23 is also removed before the belts 22, 23 are wound onto lower coils 46, 47. Removal of the excess coolant will resiβt rusting of the belt 22, 23 once the belts 22, 23 are wrapped onto lower coils 46, 47.

Figure 1 βhows schematically respective coolant removal means 70, 71 for removing exceβs coolant C from the cooling surfaces 22b, 23b after the belts 22, 23 are passed through the casting zone Z. Figures 2-3 βhow one embodiment of a coolant removal meanβ 70. This embodiment is a dryer 72 which directβ hot air HA (preferably at leaβt 600°F.) onto the cooling surface 22b of belt 22 in order to evaporate excess coolant C therefrom. It will be appreciated that the dryer 72 iβ constructed and arranged to introduce hot air HA substantially across the entire width of the belt 22.

Figures 4-5 show an alternate embodiment which utilizes a vacuum means 74 including a hose 76 for removing excess coolant C from the cooling surface 22a after the belt 22 is passed through the casting zone Z. The removed excess coolant iβ then properly disposed of, for example, into the municipal sewage; system. Once again, it will be appreciated that the vacuum means 74 is preferably constructed and arranged so that it extends substantially across the entire width of the belt 22.

Figures 6 and 7 show another aspect of the invention. A steel strip 94 used for the belt is shipped by the manufacturer on a coil 95. The manufacturer, before shipping, usually applies an oil O (Figure 10) to the belt surfaces in order to resist rusting of the strip during shipping. It has been found that this oil 0, if allowed to remain on the strip that is used for the belt during casting, produces undesired effects such as surface irregularities or other effects similar to the effects caused by undesired particulate matter discussed above. It is desired to remove this oil 0 before using the metal strip as the belt in the belt caster. Figures 6 and 7 show a vapor degreasing apparatus 96 that can remove the oil from the steel strip. A take-up coil 97 is provided in order to rewind the steel strip 94. Tension is maintained on the strip 94 by a brake 98. This will insure tight wrapping of the steel strip onto the take-up coil.

Although the invention has been shown in use with an open-end belt- caster, it will be appreciated that the brushing means and coolant removal means can be used with other belt-type casters, such aβ an endless belt caster. It will be appreciated that a method of casting molten metal in a belt caster has been shown in which the belt is bruβhed and the excess coolant removed. The metal product made by the methods of the invention will exhibit better surface quality than metal products made previously. In addition, removal of the excess coolant will resist rusting of the belt surface.

While specific embodiments of the invention have been diβcloβed, it will be appreciated by those skilled in the art that various modifications and alterations to those details could be developed in light of the overall teachings of the discloβure. Accordingly, the particular arrangements diβcloβed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.

Claims

- C L A M S

1. A method of caβting molten metal into a metal product in a mold of a belt caβter having at least one movable belt, said method comprising brushing said belt.

2. The method of claim 1, including brushing said belt before said belt pasβeβ through a caβting zone including βaid mold.

3. The method of claim 2, including brushing βaid belt after said belt passes through said casting zone.

4. The method of claim 1, including brushing said belt after said belt passes through said casting zone.

5. The method of claim 1, including brushing said belt with a force that is sufficient to remove undesired materials therefrom, but not so forceful as to permanently damage said belt.

6. The method of claim 1, including unwinding said belt from a firβt coil; passing βaid belt through a caβting zone including a mold; and winding βaid belt onto a second coil.

7. The method of claim 6, including brushing βaid belt just before said belt is unwound from said first coil.

8. The method of claim 6, including brushing said belt after said belt has passed through βaid caβting zone while βaid belt is supported by said second coil.

9. The method of claim 1, including before using said belt to cast said molten metal, removing oil from said belt.

10. The method of claim 9, including removing said oil by vapor degreasing.

11. The method of claim 1, including casting molten aluminum into an aluminum product .

12. A metal product made by the method of claim 1.

13. An aluminum product made by the method of claim 11.

14. A method of casting molten metal into a metal product in a mold of a belt caster having at least one movable belt, said method comprising cooling βaid belt with a coolant as said belt paββeβ through a casting zone including βaid mold and subsequently removing excesβ coolant remaining on said belt after said belt passes through said casting zone.

15. The method of claim 14, including removing said excesβ coolant by drying βaid belt.

16. The method of claim 14, including removing βaid excess coolant by vacuuming said belt.

17. The method of claim 14, including after removing βaid excess coolant, winding said belt onto a coil.

18. The method of claim 17, including before coiling said belt onto said coil, brushing said belt.

19. The method of claim 14, including before using said belt to cast molten metal, removing oil from βaid belt.

20. The method of claim 14, including removing βaid oil by vapor degreasing.

21. The method of claim 14, including caβting molten aluminum into an aluminum product.

22. A metal product made by the method of claim 14.

23. An aluminum product made by the method of claim 21.

24. A method of casting molten metal into a metal product in a mold of a belt caster having at least one movable belt having a casting surface and a cooling surface, said method comprising: brushing βaid caβting βurface before said belt passes through a casting zone including said mold; cooling said cooling surface with a coolant as said belt passes through said casting zone; and after passing said belt through said casting zone, removing excesβ coolant remaining on βaid cooling surface.

25. The method of claim 24, including winding said belt onto a coil after said belt passes through said casting zone.

26. The method of claim 25, including brushing βaid cooling βurface after said belt has passed through said caβting zone and while βaid belt iβ supported by βaid second coil.

27. The method of claim 24, including before uβing βaid belt to cast said molten metal, removing oil from said belt.

28. The method of claim 27, including removing said oil by vapor degreasing.

29. The method of claim 24, including casting molten aluminum into an aluminum product.

30. A metal product made by the method of claim 24.

31. An aluminum product made by the method of claim 29.

32. A belt caster having at leaβt one movable belt for caβting a molten metal into a metal product in a mold, said belt caster including at least one brush operatively associated with said belt.

33. The belt caster of claim 32, wherein said brush iβ a rotary brush.

34. The belt caster of claim 32, wherein said brush is a non-rotating brush.

35. The belt caster of claim 32, wherein said brush iβ made from a material selected from the group conβiβting of metal, plastic, fabric and paper.

36. The belt caster of claim 32, including a first brush for brushing said belt before βaid belt passes through a casting zone including said mold; and a βecond brush for brushing said belt after βaid belt passes through said casting zone.

37. The belt caster of claim 32, wherein said belt caster is an open-end belt caster.

38. A belt caster having at least one movable belt for casting a molten metal into a metal product in a mold, said belt caster including means for supplying a coolant to said belt as said belt passes through a casting zone including said mold and meanβ for removing excess coolant remaining on said belt after said belt passes through said casting zone.

39. The belt caster of claim 37, wherein said removing meanβ iβ a belt dryer.

40. The belt caster of claim 37, wherein said removing means is a vacuum.

41. The belt caster of claim 37, wherein said belt caster is an open-end belt caster.