NZ202545A - Float for indicating molten metal levels - Google Patents
Float for indicating molten metal levelsInfo
- Publication number
- NZ202545A NZ202545A NZ202545A NZ20254582A NZ202545A NZ 202545 A NZ202545 A NZ 202545A NZ 202545 A NZ202545 A NZ 202545A NZ 20254582 A NZ20254582 A NZ 20254582A NZ 202545 A NZ202545 A NZ 202545A
- Authority
- NZ
- New Zealand
- Prior art keywords
- float
- molten metal
- area
- lower section
- level
- Prior art date
Links
- 229910052751 metal Inorganic materials 0.000 title claims description 59
- 239000002184 metal Substances 0.000 title claims description 59
- 239000011819 refractory material Substances 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052919 magnesium silicate Inorganic materials 0.000 claims description 3
- 235000019792 magnesium silicate Nutrition 0.000 claims description 3
- 239000000391 magnesium silicate Substances 0.000 claims description 3
- 238000010276 construction Methods 0.000 claims description 2
- 239000006260 foam Substances 0.000 claims description 2
- 239000011521 glass Substances 0.000 claims description 2
- 239000011435 rock Substances 0.000 claims description 2
- 239000004411 aluminium Substances 0.000 claims 1
- 239000003795 chemical substances by application Substances 0.000 claims 1
- 238000005266 casting Methods 0.000 description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 239000002826 coolant Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000005672 electromagnetic field Effects 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 230000005499 meniscus Effects 0.000 description 1
- 238000005058 metal casting Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/103—Distributing the molten metal, e.g. using runners, floats, distributors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/16—Controlling or regulating processes or operations
- B22D11/18—Controlling or regulating processes or operations for pouring
- B22D11/181—Controlling or regulating processes or operations for pouring responsive to molten metal level or slag level
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Level Indicators Using A Float (AREA)
- Continuous Casting (AREA)
Description
20254
Priority D=t.(s): <0. WSfrfW.. .«?. '•
Complete Specification Filed: I?. rJI;S? Class: On.T.aSlCfe
|i\9 i*irt< 1986... ;Publication Date: ;P.O. Journal, No: • • • ■ ;Hl $. ;NEW ZEALAND ;The Patents Act, 1953 COMPLETE. £p££(Pl£ firTlOH ;"MOLTEN METAL FLOAT" ;/ ^ •(* ?^N0V;i932
WE, KAISER ALUMINUM & CHEMICAL CORPORATION, a Corporation organized and existing under the laws of the State of Delaware, United States of America, of 300 Lakeside Drive, Oakland, California 94643, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:-
(followed by page la)
GetSTS—6-5"©"8—
202545
Background of the Invention
This invention relates to an improved float for accurately sensing the level of a molten metal surface. The float is particularly suitable in molten metal level control systems for vertical DC (direct chill) casting and vertical 5 EM (electromagnetic) casting of metals such as aluminum, magnesium and their alloys.
DC casting generally comprises directing molten metal into the feed end of a water cooled, open ended tubular mold and withdrawing solidified or partially solid-10 ified metal out of the discharge end of the mold. Coolant, usually water, is directed onto the surfaces of the metal exiting the discharge end of the mold and this application of coolant effects most of the solidification. At the start of the cast, when molten metal is first introduced into the 15 mold, the discharge end thereof is blocked off with a downwardly moveable bottom block which supports the ingot or billet in its downward descent during casting.
EM casting is very similar to DC casting except that instead of a mold controlling the shape of the molten 20 metal until it solidifies, the shape of the molten metal is controlled by the pressure developed by an electromagnetic field which is generated by an annular inductor surrounding the molten metal. In the EM casting process essentially all solidification is effected by the application of coolant to 25 the metal surface at the discharge end of the inductor.
Controlling the molten metal level within the metal shaping means, whether it be a mold or an electromagnetic field is very important in vertical continuous casting processes. For accurate head control it has been found most 30 advantageous to utilize a float device which is operatively connected to a level sensor such as the linear displacement transducer described in U.S. patent 4,498,521. ~
In the process described and claimed in
; , -V
- lo—
MOLTEN METAL FLOAT
the above application the signal from the transducer is used to regulate the flow of molten metal to the mold or inductor which thereby controls the level of molten metal.
However, in the past accurate positioning of the 5 float has been difficult due to the variability of the molten metal meniscus. For example, if a float is pushed down into the molten metal it will frequently not return to the same precise position when the added thrust is removed and the float is allowed to rise by its natural buoyancy. Similar 10 results occur when the float is partially raised out of the molten metal. Because of this inability of the float to return to the same position each time, accurate molten metal level control has been difficult when the float is used to sense the metal level. This is particularly critical with 15 EM casting because slight molten metal head changes can significantly change the dimensions of the ingot or billet being cast. Changes in the surface tension of molten metal due to changes in temperature, composition and the like can aggravate this problem.
It is against this background that the present invention was developed.
Description of the Invention
This invention relates to an improved molten metal float which when positioned on a molten metal surface consist-25 ently has the same relative position with respect to the surface of the molten metal.
In accordance with this invention the float is provided with an upper portion which has an essentially flat lower surface adapted to rest on a molten metal surface and 30 a lower section comprising an element which projects from the flat areas of the upper portion of the float into the body of the molten metal. The area of the essentially flat surface of the upper portion in contact with the molten metal should be at least 10%, preferably at least 257o of the 35 area of the float facing the molten metal surface. The element projecting into the molten metal displaces an amount
20254
of metal having a weight essentially equal to the total weight of the float and any force applied to the float by attachments thereto.
In a preferred embodiment the float is used as a 5 skimming device to prevent the incorporation of oxides or dross into the metal being cast. In this case the float is generally annular or ringlike in nature so that when molten metal is introduced into the inner portion of the float the oxides which are on the surface or which rise to the surface 10 during casting are contained by the float. In this preferred embodiment, the element projecting into the molten metal ensures that the oxides or dross do not escape from the float during casting. To effectively skim, the lower section should project at least 0.5 inch preferably at least 15 1.0 inch into the molten metal. Although the shape of the element projecting into the molten metal is not critical, excessive projections, e.g. 3 inches or more, into the molten metal are not desirable.
Reference is made to the drawings which illustrate 20 embodiments of the invention. Figure 1 is a perspective view partially in section of a preferred float of the invention. Figure 2 is a cross sectional view in elevation of the float of the invention installed in an electromagnetic casting assembly. Figures 3 and 4 represent other 25 embodiments of the invention. In the drawings all corresponding parts are numbered the same.
Figure 1 shows a perspective view partially in section of a preferred float 10 which comprises an upper section or collar 11 with an essentially flat lower surface 30 12 and a lower section or projecting element 13. The volume of projecting element 13 is equal to the volume of molten metal it displaces so that the flat surface 12 of collar 11 rests on the molten metal surface. The weight of the metal displaced by element 13 should be equal to the 35 weight of the float and any force applied to the float by
\
202545
attachments thereto. The area of the flat surface 12 must be at least 10%, preferably at least 25%, of the total area of the float projected downwardly onto the molten metal surface.
Figure 2 illustrates a preferred float 10 in asso-5 ciation with an EM casting assembly 20, which comprises an inductor 21, a water jacket 22 and a refractory down spout 23 which is adapted to feed molten metal to the interior or inner space of the annular inductor 21. A bottom block 24 is also associated with the assembly 20 and at the start of 10 the cast is positioned within the inductor to vertically — support the molten metal therein while the electromagnetic-ally induced pressure against the molten metal controls the lateral spread of the metal until it solidifies into its final shape. The inductor 21 is provided with a plurality 15 of holes or conduits 25 through which water from the water jacket passes for the application thereof onto the ingot or billet which exits from the discharge end of the inductor. The float 11 is provided with rods 26 and 27 to support the float during noncasting periods when no molten metal is 20 within the inductor 20. Preferably, one of the rods 26 or 27 is operatively connected to a linear displacement transducer (not shown) or its equivalent which will generate a signal representing the molten metal level 28 on which the float 10 rests. The signal from the transducer can be used 25 to control the flow of molten metal from a source such as a trough through a refractory lined down spout 23. (See such use described in U.S. patent 4,498,521 Takeda et al.
provided wherein the relative positions of the flat bottomed collars 11 and the projecting elements 13 have been changed in comparison with the embodiment shown in Figure 1.
density much less than the density of the molten metal and 35 which is sufficiently resistant to the molten metal and the
In Figures 3 and 4 alternative float designs are
The float is made from a material which has a
surrounding harsh environment to provide a reasonably long service life. Suitable materials of construction include lightweight refractories such as a fibrous magnesium silicate, glass rock foam, foamed refractories and the like. A 5 preferred material is fibrous magnesium silicate sold under the trademark MariniteC^/.
It is obvious that various modifications and improvements can be made to the invention without departing from the spirit of the invention and the scope of the ap-10 pended claims.
*54$
Claims (6)
1. A molten metal float" for sensing a molten metal level comprising an upper section which has an essentially flat under surface that rests on the molten metal surface and a lower section that is submerged beneath the level of the molten metal, the apparatus construction being such that in use the area of the flat under surface is at least 107. of the area of an image of the float projected downwardly and the volume of the lower section of the float submerged beneath the level of the molten metal displacing a volume of molten metal essentially equal in weight to the weight of the float and any vertical force applied to the float by attachments thereto.
2, The float of claim 1 wherein the area of the flat under surface is at least 25% of the area of the image projected downwardly. 15
3. The float of claim 1 wherein the float is formed from a lightweight refractory material resistant to molten aluminium and selected from the group containing fibrous magnesium silicate, glass rock foam and foamed refractories.
4. The float of claim 1 wherein the lower section thereof projects into molten metal at least 0.5 inch but less than 3 inches from the flat surface of the upper 20 section.
5. The float of claim 4 wherein the lower section projects at least 1.0 inch from the flat surface of the upper section. -7- 202545
6. A float as claimed in any one of claims 1 to 5 substantially as hereinbefore described with reference to any of the accompanying drawings. /(Lariat. - By Hie/Their authorised Agent A. J. PARK & SON Per. / // V . on
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US32945781A | 1981-12-10 | 1981-12-10 |
Publications (1)
Publication Number | Publication Date |
---|---|
NZ202545A true NZ202545A (en) | 1986-05-09 |
Family
ID=23285486
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NZ202545A NZ202545A (en) | 1981-12-10 | 1982-11-18 | Float for indicating molten metal levels |
Country Status (16)
Country | Link |
---|---|
JP (1) | JPS58105017A (en) |
KR (1) | KR840002675A (en) |
AU (1) | AU550044B2 (en) |
BR (1) | BR8207113A (en) |
CA (1) | CA1200976A (en) |
CH (1) | CH658721A5 (en) |
DE (2) | DE3243650A1 (en) |
ES (1) | ES278758Y (en) |
FR (1) | FR2517996B1 (en) |
GB (1) | GB2112135B (en) |
IN (1) | IN157323B (en) |
IT (1) | IT1207968B (en) |
NL (1) | NL8204770A (en) |
NZ (1) | NZ202545A (en) |
PT (1) | PT75944B (en) |
SE (1) | SE458641B (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2176611B (en) * | 1985-06-20 | 1989-07-19 | Thor Ceramics Ltd | Constant temperature probe |
US5074174A (en) * | 1989-09-02 | 1991-12-24 | Dae Sam Co., Ltd. | Socket wrench |
GB9409183D0 (en) * | 1994-05-07 | 1994-06-29 | British Steel Plc | Continuous casting molds |
EP1337369A4 (en) * | 2000-10-27 | 2004-06-23 | Univ Ohio State | Method and apparatus for controlling standing surface wave and turbulence in continuous casting vessel |
DE10146600B4 (en) * | 2001-09-21 | 2006-09-14 | Paus, Hans J., Prof. Dr. | Device for growing crystals from the melt |
CN110883319A (en) * | 2019-10-14 | 2020-03-17 | 北京理工大学 | Casting method of aluminum-lithium alloy composite ingot |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB744639A (en) * | 1953-06-29 | 1956-02-08 | Kent Ltd G | Improvements in floats for use in measuring instruments |
US2968847A (en) * | 1959-01-16 | 1961-01-24 | Aluminum Co Of America | Skimmer apparatus for fluxing light metals |
DE1780523A1 (en) * | 1968-09-25 | 1971-08-26 | Wolfgang Mueller | Device for monitoring the minimum amount of brake fluid permitted in a brake circuit of hydraulic motor vehicle brakes |
US3752217A (en) * | 1971-08-13 | 1973-08-14 | Olin Corp | Float-distributor for direct chill casting |
-
1982
- 1982-11-17 GB GB08232744A patent/GB2112135B/en not_active Expired
- 1982-11-18 CA CA000415912A patent/CA1200976A/en not_active Expired
- 1982-11-18 NZ NZ202545A patent/NZ202545A/en unknown
- 1982-11-22 IN IN1356/CAL/82A patent/IN157323B/en unknown
- 1982-11-25 DE DE19823243650 patent/DE3243650A1/en not_active Withdrawn
- 1982-11-25 DE DE19828233113U patent/DE8233113U1/en not_active Expired
- 1982-12-06 PT PT75944A patent/PT75944B/en unknown
- 1982-12-07 CH CH7118/82A patent/CH658721A5/en not_active IP Right Cessation
- 1982-12-08 KR KR1019820005498A patent/KR840002675A/en unknown
- 1982-12-08 BR BR8207113A patent/BR8207113A/en unknown
- 1982-12-09 SE SE8207039A patent/SE458641B/en not_active IP Right Cessation
- 1982-12-09 JP JP57216257A patent/JPS58105017A/en active Granted
- 1982-12-09 ES ES1982278758U patent/ES278758Y/en not_active Expired
- 1982-12-09 FR FR8220630A patent/FR2517996B1/en not_active Expired
- 1982-12-09 AU AU91703/82A patent/AU550044B2/en not_active Ceased
- 1982-12-09 NL NL8204770A patent/NL8204770A/en not_active Application Discontinuation
- 1982-12-10 IT IT8224682A patent/IT1207968B/en active
Also Published As
Publication number | Publication date |
---|---|
DE8233113U1 (en) | 1983-03-10 |
ES278758U (en) | 1984-10-16 |
PT75944B (en) | 1985-12-09 |
SE458641B (en) | 1989-04-17 |
FR2517996A1 (en) | 1983-06-17 |
IN157323B (en) | 1986-03-01 |
BR8207113A (en) | 1983-10-11 |
GB2112135B (en) | 1985-11-20 |
JPS58105017A (en) | 1983-06-22 |
DE3243650A1 (en) | 1983-06-23 |
IT8224682A0 (en) | 1982-12-10 |
IT1207968B (en) | 1989-06-01 |
PT75944A (en) | 1983-01-01 |
AU9170382A (en) | 1983-06-16 |
JPH0259406B2 (en) | 1990-12-12 |
SE8207039D0 (en) | 1982-12-09 |
NL8204770A (en) | 1983-07-01 |
KR840002675A (en) | 1984-07-16 |
GB2112135A (en) | 1983-07-13 |
SE8207039L (en) | 1983-06-11 |
CH658721A5 (en) | 1986-11-28 |
AU550044B2 (en) | 1986-02-27 |
CA1200976A (en) | 1986-02-25 |
FR2517996B1 (en) | 1987-04-24 |
ES278758Y (en) | 1985-04-16 |
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