CA2097261C - Process for treating molten metal during casting operation using a filter and filter for implementing the process - Google Patents
Process for treating molten metal during casting operation using a filter and filter for implementing the process Download PDFInfo
- Publication number
- CA2097261C CA2097261C CA002097261A CA2097261A CA2097261C CA 2097261 C CA2097261 C CA 2097261C CA 002097261 A CA002097261 A CA 002097261A CA 2097261 A CA2097261 A CA 2097261A CA 2097261 C CA2097261 C CA 2097261C
- Authority
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- Canada
- Prior art keywords
- cavity
- molten metal
- treating
- filtering
- inoculating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 114
- 239000002184 metal Substances 0.000 title claims abstract description 114
- 238000000034 method Methods 0.000 title claims description 19
- 230000008569 process Effects 0.000 title claims description 19
- 238000005266 casting Methods 0.000 title description 10
- 239000000463 material Substances 0.000 claims abstract description 96
- 229910052500 inorganic mineral Inorganic materials 0.000 claims abstract description 9
- 239000011707 mineral Substances 0.000 claims abstract description 9
- 238000001914 filtration Methods 0.000 claims description 58
- 238000011282 treatment Methods 0.000 claims description 36
- 239000007787 solid Substances 0.000 claims description 14
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 10
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 6
- 229910045601 alloy Inorganic materials 0.000 claims description 6
- 239000000956 alloy Substances 0.000 claims description 6
- 239000011777 magnesium Substances 0.000 claims description 6
- 230000002093 peripheral effect Effects 0.000 claims description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 claims description 5
- 229910002804 graphite Inorganic materials 0.000 claims description 5
- 239000010439 graphite Substances 0.000 claims description 5
- 229910052749 magnesium Inorganic materials 0.000 claims description 5
- 229910052710 silicon Inorganic materials 0.000 claims description 5
- 239000010703 silicon Substances 0.000 claims description 5
- 229910052712 strontium Inorganic materials 0.000 claims description 5
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 claims description 5
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 4
- 229910000640 Fe alloy Inorganic materials 0.000 claims description 4
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 4
- 239000000654 additive Substances 0.000 claims description 4
- 230000000996 additive effect Effects 0.000 claims description 4
- 150000001553 barium compounds Chemical class 0.000 claims description 4
- 229910052791 calcium Inorganic materials 0.000 claims description 4
- 239000011575 calcium Substances 0.000 claims description 4
- 150000002642 lithium compounds Chemical class 0.000 claims description 4
- 150000002681 magnesium compounds Chemical class 0.000 claims description 4
- -1 rare earths Chemical compound 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 4
- 230000000476 thermogenic effect Effects 0.000 claims description 4
- 229910052726 zirconium Inorganic materials 0.000 claims description 4
- 229940043430 calcium compound Drugs 0.000 claims description 3
- 150000001674 calcium compounds Chemical class 0.000 claims description 3
- 238000007670 refining Methods 0.000 claims description 3
- 229910001338 liquidmetal Inorganic materials 0.000 abstract description 26
- 150000002739 metals Chemical class 0.000 abstract 1
- 239000003795 chemical substances by application Substances 0.000 description 8
- 239000011819 refractory material Substances 0.000 description 4
- 238000011144 upstream manufacturing Methods 0.000 description 4
- 238000011081 inoculation Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- 239000005997 Calcium carbide Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- CLZWAWBPWVRRGI-UHFFFAOYSA-N tert-butyl 2-[2-[2-[2-[bis[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]amino]-5-bromophenoxy]ethoxy]-4-methyl-n-[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]anilino]acetate Chemical compound CC1=CC=C(N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)C(OCCOC=2C(=CC=C(Br)C=2)N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)=C1 CLZWAWBPWVRRGI-UHFFFAOYSA-N 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910017082 Fe-Si Inorganic materials 0.000 description 1
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 1
- 229910017133 Fe—Si Inorganic materials 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 210000003717 douglas' pouch Anatomy 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 1
- 239000002054 inoculum Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 235000010603 pastilles Nutrition 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 238000012809 post-inoculation Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/01—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements
- B01D29/03—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements self-supporting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/50—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition
- B01D29/56—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in series connection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
- B22C9/086—Filters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
- B22D1/007—Treatment of the fused masses in the supply runners
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2201/00—Details relating to filtering apparatus
- B01D2201/18—Filters characterised by the openings or pores
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/10—Making spheroidal graphite cast-iron
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
- Filtering Materials (AREA)
Abstract
A filter for molten metal comprises a series of at least two refractory mineral material plates which define between them one or more cavities. The plates each comprise a series of holes through which the liquid metal passes and by which the liquid metal is filtered. At least one of the cavities contains a material for treating the metal, for example a material for inoculating the liquid metal. The filter is used among other things to filter and treat molten metals simultaneously and to improve the quality of the metal.
Description
_ CA 02097261 1998-OS-06 PROCESS FOR TREATING MOLTEN METAL DURING A CASTING
OPERATION USING A FILTER AND FILTER FOR IMPLEMENTING THE
PROCESS
BACKGROUND OF THE INVENTION
Field of the invention The present invention concerns a process for treating a molten metal during a casting operation into a mold using a filter, the process including the step, prior to casting the molten metal, of placing a material for treating said metal at a point or_ the channel adapted to guide said metal to the filter.
The invention also concerns a filter for implementing the process in accordance with the invention.
Description of the prior art The treatment agents are usually merely placed in the channels for the molten metal, which is time-consuming.
It is also known to distribute products for treating the metal by placing the treatment products in destructible sachets which are disposed in a corner or a cul-de-sac of the channels for the metal upstream of the filter; this process has the drawback that it does not guarantee that all of the metal comes into contact with the treatment agents.
Because of turbulence caused by the flow of the metal in the casting channels the destructible sachets are sometimes dislodged from where they are placed and travel upstream into the funnel into which the molten metal is poured. This results in wastage of the unused treatment material and rejection of the cast parts because the metal is insufficiently treated. Also the molten metal does not enter fully into contact with the treatment material and the metal cast in the mold may not be homogeneous.
OPERATION USING A FILTER AND FILTER FOR IMPLEMENTING THE
PROCESS
BACKGROUND OF THE INVENTION
Field of the invention The present invention concerns a process for treating a molten metal during a casting operation into a mold using a filter, the process including the step, prior to casting the molten metal, of placing a material for treating said metal at a point or_ the channel adapted to guide said metal to the filter.
The invention also concerns a filter for implementing the process in accordance with the invention.
Description of the prior art The treatment agents are usually merely placed in the channels for the molten metal, which is time-consuming.
It is also known to distribute products for treating the metal by placing the treatment products in destructible sachets which are disposed in a corner or a cul-de-sac of the channels for the metal upstream of the filter; this process has the drawback that it does not guarantee that all of the metal comes into contact with the treatment agents.
Because of turbulence caused by the flow of the metal in the casting channels the destructible sachets are sometimes dislodged from where they are placed and travel upstream into the funnel into which the molten metal is poured. This results in wastage of the unused treatment material and rejection of the cast parts because the metal is insufficiently treated. Also the molten metal does not enter fully into contact with the treatment material and the metal cast in the mold may not be homogeneous.
It is also known to treat the liquid metal by placing on the upstream side of the filter pastilles of treatments products held together by a binder or by pressing and/or sintering and/or molding them: once again, there is no guarantee that all of the metal has been treated. Also, this represents a further handling operation.
An object of the present invention is to remedy of the aforementioned type whereby all of the cast molten metal is treated as regularly and as homogeneously as possible and the treatment material is entirely used to treat said metal.
Another object of the invention is to propose a filter for implementing said process.
SUMMARY OF THE INVENTION
An apparatus for filtering and treating molten metal adapted to implement a process for simultaneously filtering and treating a molten metal during an operation to cast said molten metal into a mold, said apparatus comprising a series of at least two refractory mineral material filtering plates in contact with each other at their periphery and defining between them at least one cavity, said filtering plates each having a series of filtering holes through which said molten metal flows and by which said molten metal is filtered, the dimensions of the filtering holes and the number of the filtering plates being selected so as to eliminate from the molten metal solid inclusions likely to affect the quality of the cast metal, said apparatus containing within said at least one cavity an inorganic treatment material for treating said molten metal flowing through the cavity, said treating material being in the form of one of solid compressed or molded or sintered treating plate positioned in said at least one cavity and extending over substantially the length and the width of said at least one cavity, said treating plate having when viewed in the direction of metal flow, a shape such that one or more passage holes are arranged in or around said treating (or inoculating) plate for said molten metal to pass through said passage holes and through said apparatus.
In this way it is certain that the treatment material will not be expelled from the cavity by turbulence caused by the flow of the molten metal, as it is retained between two plates, and that it will all be used to threat the metal. This eliminates any risk of rejection of the cast parts because of defective treatment of the metal.
Furthermore, all of the molten metal passing through the filter is brought into contact with the treatment material and this contact takes place within the cavity of the filter where the metal travels at a lower speed than in the channels.
It has been found that metal cast by the process of the invention has a better distribution of the treatment product and improved treatment homogeneity as compared with the prior art processes.
Without wishing to claim that this is the only possible explanation of this unexpected and surprising result, it is thought that he result is due to the very slow speed at which the metal travels in the filter cavity compared to the much higher speeds at which it passes through the holes in the plates. This causes energetic and very regular mixing of the untreated metal reaching the interior of the cavity at high speed and the already treated metal remaining in this cavity before it is evacuated through the holes in the second plate, this. mixing continuing throughout the duration of casting.
Combined with the fact that the treatment product is trapped within the cavity and cannot be expelled from it under any circumstances, this mixing probably explains the very regular distribution of the treatment product in the metal of the cast part and the excellent homogeneity of the result of treating said metal within said part.
An apparatus for filtering and inoculating molten metal adapted to implement a process for simultaneously filtering and inoculating a molten metal during an operation to cast said molten metal into a mold, said apparatus comprising a series of at least two refractory mineral material filtering plates in contract with each other at their periphery and defining between them at least one cavity, said filtering plates each having a series of filtering holes through which said molten metal flows and by which said molten metal is filtered, the dimensions of the filtering holes and the number of the filtering plates being selected so as to eliminate from the molten metal solid inclusions likely to affect the quality of the cast metal, said apparatus containing within said at least one cavity an inorganic inoculating material for inoculating said molten metal flowing through the cavity said inoculating material being in the form of one of solid compressed or molded or sintered inoculating plate positioned in said at least one cavity and extending over substantially the length and the width of said at least one cavity, said inoculating plate having when viewed in the direction of metal flow, a shape such that one or_ more passage S holes are arranged in or around said treating (or inoculating) plate for said molten metal to pass through said passage holes and through said apparatus.
This enables the preparation of prefabricated filters containing a predetermined dose of the treatment product:
filters of this kind are highly suited to mass production, facilitate the work of the casting shop and reduce the problems associated with management of consumable materials and products for such shops.
In one beneficial embodiment of the invention the filter comprises at least two plates joined together along their periphery, the cavity formed between said two plates is filed with said powdered treatment material and said holes in said plates are blocked k.~y a film of a material adapted to melt, carbonize or calcine in contact with the molten metal to be treated, said film being disposed on the inside or the outside surface of each plate.
In this way the treatment material can be easily sealed by an insulated film of this kind against moisture in the atmosphere so that it remains perfectly dry, enabling problem-free storage of prefabricated filters.
The filters are used to eliminate from the liquid metal any solid inclusions such as metal oxides likely to affect the quality of the metal which is cast into a container such as a mold or a mold for ingot.
The effectiveness of any such filter depends essentially on the diameter of the holes and the number of plates constituting it. The smaller the diameter of the holes the greater the ability of the filter to hold back fine inclusions and the more effective the filter action.
If the holes have a diameter less than 1 mm filtration takes a very long time (because the liquid metal passes through holes this size with great difficulty) and the holes rapidly clog.
If the number of plates is increased the cost of the filter is increased.
In one advantageous embodiment of the invention said treatment material is an inoculating material in 5 plate form optionally comprising one or more holes for said liquid metal to pass through.
This inoculating material improves the characteristics of the metal.
Thus the inoculating material makes it possible to increase very significantly the effectiveness of the filter by virtue of a barrage effect. Also, the cavities in the filter plates form receptacles which are particularly well suited to receiving the inoculating material with the result that use of this material does not require any modification of the filter.
When the liquid metal enters the filter it laps the surface of this plate which treats the metal with the aim of improving it.
In one advantageous embodiment of the invention at least the side of said plate adjacent the bottom of the cavity comprises a series of recesses.
These recesses increase the area of contact between the liquid metal and the inoculating material which increases the effectiveness of the inoculation reaction.
In one embodiment of the filter in accordance with the invention said inoculating material is in the form of spaced bars extending across substantially all of the length and the width of a cavity.
Such bars are simple to manufacture and also make it possible to obtain a large area of contact between the inoculating material and the liquid metal without impeding the passage of the latter through the filter.
In another embodiment of the invention at least one of the cavities is filled with a filter material.
This filter material comprises refractory fibers, for example, and further increases the effectiveness of filtration.
The inoculating material is preferably selected from the following substances: alloys of iron, magnesium and magnesium compounds, calcium and its compounds, lithium compounds, strontium and barium compounds, silicon, zirconium, aluminum, rare earth, graphite and carbon.
- Other features and advantages of the invention will emerge from the following description given by way of non-limiting example and with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a view in cross-section on the line I-I
in figure 2 of a two-stage filter in a first embodiment of the present invention.
Figure 2 is a plan view of the filter from figure 1.
Figure 3 is a view similar to figure 1 of a filter comprising only one cavity.
Figure 2 is a view to a larger scale and in cross-section-of a filter in a second embodiment of the present invention.
Figure 5 is a view similar to figure 4 comprising two adjoining half-views of respective variants of the filter shown in said figure.
Figure 6 is a view in cross-section on the line VI-VI in figure 7.
Figure 7 is a plan view with the top plate removed comprising two adjoining half-views of respective variants of a third embodiment of the present invention.
Figure 8 is a view in cross-section of a fourth embodiment of the filter in accordance with the invention.
Figure 9 is a partially cut away plan view of the filter from figure 8.
Figure 10 is a view in cross-section of a fifth embodiment of the filter.
Figure 11 is a plan view of the filter from figure 10.
Figure 12 is a partial view in cross-section of a sixth embodiment.
Figure 7 is a view in cross-section of a seventh - embodiment.
DETAILED DESCRIPTION OF THE INVENTION
As shown in the figures, the process with which the invention is concerned for treating molten metal during an operation of casting it in a mold using a filter 1, la, lb, lc, ld, le comprises the step, prior to casting the molten metal, of placing a material 12, 22, 23, 24 for treating said metal at a point on the channel -adapted to guide said metal to said filter.
In the process of the invention a filter 1, la, lb, lc, ld, le for liquid metal is used which comprises a series of at least two refractory mineral material plates 2, 2a, 2b in contact with each other at their periphery and defining between them one or more cavities 4, 5, 6, each plate 2, 2a; 2b comprising a series of holes 3, 3a, 3b through which the liquid metal passes and by which it is filtered, and the treatment material 12, 22, 23, 24 is introduced into at least one of the cavities 4, 5, 6 before the filter 1, la, lb, lc, ld, le is placed in a mold (not shown) such as a cylindrical sleeve.
The treatment material 12, 22, 23, 24 is selected from desulphurizing, thermogenic, inoculating, spheroidizing, recarburizing, refining and modifying products and additive alloys.
The weight of the treatment material 12, 22, 23, 24 may vary between approximately 0.001% and 1°s of the weight of the liquid metal depending on the nature of the treatment to be applied.
The filter la shown in figure 1 comprises three plates 2, 2a, 2b. The plates 2 and 2a each have a projecting peripheral rim 11 adapted to come into contact with the respective adjacent plate 2a, 2b which is thus spaced from it to form a respective cavity 4, 5. The plate 2b has no such rim, as this would increase the height of the filter 1 with no benefit.
The upper plate, which is normally on the upstream side, has progressively increasing diameter holes 3, 3a, 3b in it. The plates 2a, 2b also have holes in them, of the same diameter or different diameters. The holes in the intermediate plate 2a are arranged in a quincunx arrangement relative to the holes in the outer plates 2 and 2b. The holes 3, 3a, 3b may be non-circular. -In the known way the plates 2, 2a, 2b are made from a ceramic refractory mineral material such as silica, for example, and are able to withstand the temperature of the cast metal without distortion.
The filter 1 shown in figure 2 comprises a plate 2 with holes 3 of substantially the same diameter.
The filter lb shown in figure 3 comprises two plates 2a whose peripheral edges 11 are adjacent and fastened together by an adhesive 10. The heights of the rims 11 are shown the same but they could be different.
The two plates delimit a cavity 6.
Figures 4 and 5 on the one hand and figures 6 and 7 on the other hand respectively show a filter lc, ld comprising two plates 2a in contact at their peripheral edge 11 to delimit a cavity 6.
In the embodiment shown in figures 8 through 12 the liquid metal filter comprises three refractory material plates 2, 2a, 2b in contact with each other at their periphery and defining between them a plurality of _ CA 02097261 1998-OS-06 cavities 5, 6, 7. The plates 2, 2a, 2b each comprise a series of holes 3 through which the liquid metal passes and by which it is filtered as it passes through the filter in the direction of the arrow D.
As shown in figures 1 through 12, and in accordance with the invention, at least one of the cavities 4, 5, 6 of the filter 1, la, lb, lc, ld, le contains a material for treating the molten metal.
In the embodiment of figures 1, 3, 4 and 5 the treatment material 12 is in powder form and is retained by a film 13 of a material adapted to melt, carbonize or calcine in contact with the liquid metal to be treated.
The particle size of the powder material is selected in accordance with the required treatment conditions.
The film 13 of a material adapted to melt, carbonize or calcine in contact with the metal to be treated is an aluminum or paper or plastics material or composite film, for example.
In the embodiment of figures 1 and 3 the treatment material 12 is contained in sachets 8, 8a, 8b made from said film 13 and placed in said cavity 4, 5, 6.
The cavities 4 and 5 in figure 1 each contain a respective sachet 8, 8a which fills the respective cavity 4, 5 partially or almost completely. The sachets 8, 8a may be identical or have different capacities.
The cavity 6 in figure 3 contains a sachet 8b disposed eccentrically in said cavity 6, for example.
In the embodiment of figures 4 and 5 the cavity 6 formed between the two plates 2a is filled with powdered treatment material 12 and the holes 3 in the plates 2a are blocked by a film 13 of the aforementioned type disposed on the inside or outside surface of each plate 2a.
In the figure 4 example a film 13 is fixed (for example glued) to the inside surface of the upper plate.
Another film 13 is fixed to the outside surface of the lower plate, the holes 3 being filled with treatment material 12.
5 In the figure 5 example the films 13 are fixed to the inside surfaces of the plates in the lefthand half-view and to the outside surfaces of the plates in the righthand half-view. This latter case represents the - maximum volume of treatment material 12 that can be 10 contained in the filter lc.
In the embodiment of figures 6 and 7 the powdered treatment material 12 is pressed or sintered to form plates 14a, 14b or bars. The dimensions of the plates 14a, 14b or-bars are less than or equal to the inside dimensions of the cavity 6 so that as soon as casting begins the plates or bars can move inside the cavity 6 due to the turbulence caused by the arrival of the molten metal in the cavity 6.
The lefthand half-view shows, by way of example, a hexagonal contour plate 14a whereas the righthand half view shows an annular plate 14b. Plates 14a, 14b of this kind are pressed with a binder such as stearate or the like, for example; the treatment material 12 prepared in crystallized form, for example, can also be bound together under high pressure. The plate 14a includes a central hole 15 through which the metal passes. It could comprise other holes of various shapes and sizes.
The treatment materials may be desulphurizing agents, for example magnesium and/or calcium carbide, and/or thermogenic agents, for example calcium carbide, and/or inoculation and/or post-inoculation agents and/or spheroidizing agents, for example magnesium and/or rare earths and/or ferrosilicomagnesium, and/or additive alloy agents, for example molybdenum, boron, silicon, ferrosilicon, manganese, chromium, titanium, ferroaluminium, silicomishmetal alloys, recarburizing agents, for example based on carbon or graphite, or fluxes for modifying the structure of the metal, such as sodium, phosphorous, boron, titanium, strontium, etc salts.
Figures 8 through 13 show other embodiments of the invention in which the treatment material is a material 22, 23, 24 for inoculating the liquid metal. In the example shown in figure 8 the cavities 5, 6 each contain an inoculating material 22.
In the case of figures 8 and 9 the inoculating material 22 is in the form of a plate comprising holes 25 through which the liquid metal passes and extending over substantially all of the length and the width of the cavity 5 or 6.
The side of each plate 22 adjacent the bottom of the cavity 5 or 6 further comprises a series of recesses 26 made up of a series of parallel dihedra.
In the figure 8 example the other side of the plate 22 also comprises recesses 27. Figures 8 and 9 also show that the holes 25 in the inoculating material plate 22 have a larger cross-section than the holes 3 in the refractory material plates 2, 2a, 2b.
When the liquid metal (steel or cast iron) passes through the filter le shown in figure 8 it first comes into contact with the upper surface of the inoculating material plate 22, passes through the holes 25 in this and then fills the recesses 26 on the lower surface of the plate 22, thereafter flowing through the filter holes 3 in the plate 2.
Because the holes 3 are smaller than the holes 25 in the inoculating material plates 22 the metal fills the recesses 26 which achieves a large area of contact between the liquid metal and the inoculating material which is beneficial to the metal treatment reaction.
An object of the present invention is to remedy of the aforementioned type whereby all of the cast molten metal is treated as regularly and as homogeneously as possible and the treatment material is entirely used to treat said metal.
Another object of the invention is to propose a filter for implementing said process.
SUMMARY OF THE INVENTION
An apparatus for filtering and treating molten metal adapted to implement a process for simultaneously filtering and treating a molten metal during an operation to cast said molten metal into a mold, said apparatus comprising a series of at least two refractory mineral material filtering plates in contact with each other at their periphery and defining between them at least one cavity, said filtering plates each having a series of filtering holes through which said molten metal flows and by which said molten metal is filtered, the dimensions of the filtering holes and the number of the filtering plates being selected so as to eliminate from the molten metal solid inclusions likely to affect the quality of the cast metal, said apparatus containing within said at least one cavity an inorganic treatment material for treating said molten metal flowing through the cavity, said treating material being in the form of one of solid compressed or molded or sintered treating plate positioned in said at least one cavity and extending over substantially the length and the width of said at least one cavity, said treating plate having when viewed in the direction of metal flow, a shape such that one or more passage holes are arranged in or around said treating (or inoculating) plate for said molten metal to pass through said passage holes and through said apparatus.
In this way it is certain that the treatment material will not be expelled from the cavity by turbulence caused by the flow of the molten metal, as it is retained between two plates, and that it will all be used to threat the metal. This eliminates any risk of rejection of the cast parts because of defective treatment of the metal.
Furthermore, all of the molten metal passing through the filter is brought into contact with the treatment material and this contact takes place within the cavity of the filter where the metal travels at a lower speed than in the channels.
It has been found that metal cast by the process of the invention has a better distribution of the treatment product and improved treatment homogeneity as compared with the prior art processes.
Without wishing to claim that this is the only possible explanation of this unexpected and surprising result, it is thought that he result is due to the very slow speed at which the metal travels in the filter cavity compared to the much higher speeds at which it passes through the holes in the plates. This causes energetic and very regular mixing of the untreated metal reaching the interior of the cavity at high speed and the already treated metal remaining in this cavity before it is evacuated through the holes in the second plate, this. mixing continuing throughout the duration of casting.
Combined with the fact that the treatment product is trapped within the cavity and cannot be expelled from it under any circumstances, this mixing probably explains the very regular distribution of the treatment product in the metal of the cast part and the excellent homogeneity of the result of treating said metal within said part.
An apparatus for filtering and inoculating molten metal adapted to implement a process for simultaneously filtering and inoculating a molten metal during an operation to cast said molten metal into a mold, said apparatus comprising a series of at least two refractory mineral material filtering plates in contract with each other at their periphery and defining between them at least one cavity, said filtering plates each having a series of filtering holes through which said molten metal flows and by which said molten metal is filtered, the dimensions of the filtering holes and the number of the filtering plates being selected so as to eliminate from the molten metal solid inclusions likely to affect the quality of the cast metal, said apparatus containing within said at least one cavity an inorganic inoculating material for inoculating said molten metal flowing through the cavity said inoculating material being in the form of one of solid compressed or molded or sintered inoculating plate positioned in said at least one cavity and extending over substantially the length and the width of said at least one cavity, said inoculating plate having when viewed in the direction of metal flow, a shape such that one or_ more passage S holes are arranged in or around said treating (or inoculating) plate for said molten metal to pass through said passage holes and through said apparatus.
This enables the preparation of prefabricated filters containing a predetermined dose of the treatment product:
filters of this kind are highly suited to mass production, facilitate the work of the casting shop and reduce the problems associated with management of consumable materials and products for such shops.
In one beneficial embodiment of the invention the filter comprises at least two plates joined together along their periphery, the cavity formed between said two plates is filed with said powdered treatment material and said holes in said plates are blocked k.~y a film of a material adapted to melt, carbonize or calcine in contact with the molten metal to be treated, said film being disposed on the inside or the outside surface of each plate.
In this way the treatment material can be easily sealed by an insulated film of this kind against moisture in the atmosphere so that it remains perfectly dry, enabling problem-free storage of prefabricated filters.
The filters are used to eliminate from the liquid metal any solid inclusions such as metal oxides likely to affect the quality of the metal which is cast into a container such as a mold or a mold for ingot.
The effectiveness of any such filter depends essentially on the diameter of the holes and the number of plates constituting it. The smaller the diameter of the holes the greater the ability of the filter to hold back fine inclusions and the more effective the filter action.
If the holes have a diameter less than 1 mm filtration takes a very long time (because the liquid metal passes through holes this size with great difficulty) and the holes rapidly clog.
If the number of plates is increased the cost of the filter is increased.
In one advantageous embodiment of the invention said treatment material is an inoculating material in 5 plate form optionally comprising one or more holes for said liquid metal to pass through.
This inoculating material improves the characteristics of the metal.
Thus the inoculating material makes it possible to increase very significantly the effectiveness of the filter by virtue of a barrage effect. Also, the cavities in the filter plates form receptacles which are particularly well suited to receiving the inoculating material with the result that use of this material does not require any modification of the filter.
When the liquid metal enters the filter it laps the surface of this plate which treats the metal with the aim of improving it.
In one advantageous embodiment of the invention at least the side of said plate adjacent the bottom of the cavity comprises a series of recesses.
These recesses increase the area of contact between the liquid metal and the inoculating material which increases the effectiveness of the inoculation reaction.
In one embodiment of the filter in accordance with the invention said inoculating material is in the form of spaced bars extending across substantially all of the length and the width of a cavity.
Such bars are simple to manufacture and also make it possible to obtain a large area of contact between the inoculating material and the liquid metal without impeding the passage of the latter through the filter.
In another embodiment of the invention at least one of the cavities is filled with a filter material.
This filter material comprises refractory fibers, for example, and further increases the effectiveness of filtration.
The inoculating material is preferably selected from the following substances: alloys of iron, magnesium and magnesium compounds, calcium and its compounds, lithium compounds, strontium and barium compounds, silicon, zirconium, aluminum, rare earth, graphite and carbon.
- Other features and advantages of the invention will emerge from the following description given by way of non-limiting example and with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a view in cross-section on the line I-I
in figure 2 of a two-stage filter in a first embodiment of the present invention.
Figure 2 is a plan view of the filter from figure 1.
Figure 3 is a view similar to figure 1 of a filter comprising only one cavity.
Figure 2 is a view to a larger scale and in cross-section-of a filter in a second embodiment of the present invention.
Figure 5 is a view similar to figure 4 comprising two adjoining half-views of respective variants of the filter shown in said figure.
Figure 6 is a view in cross-section on the line VI-VI in figure 7.
Figure 7 is a plan view with the top plate removed comprising two adjoining half-views of respective variants of a third embodiment of the present invention.
Figure 8 is a view in cross-section of a fourth embodiment of the filter in accordance with the invention.
Figure 9 is a partially cut away plan view of the filter from figure 8.
Figure 10 is a view in cross-section of a fifth embodiment of the filter.
Figure 11 is a plan view of the filter from figure 10.
Figure 12 is a partial view in cross-section of a sixth embodiment.
Figure 7 is a view in cross-section of a seventh - embodiment.
DETAILED DESCRIPTION OF THE INVENTION
As shown in the figures, the process with which the invention is concerned for treating molten metal during an operation of casting it in a mold using a filter 1, la, lb, lc, ld, le comprises the step, prior to casting the molten metal, of placing a material 12, 22, 23, 24 for treating said metal at a point on the channel -adapted to guide said metal to said filter.
In the process of the invention a filter 1, la, lb, lc, ld, le for liquid metal is used which comprises a series of at least two refractory mineral material plates 2, 2a, 2b in contact with each other at their periphery and defining between them one or more cavities 4, 5, 6, each plate 2, 2a; 2b comprising a series of holes 3, 3a, 3b through which the liquid metal passes and by which it is filtered, and the treatment material 12, 22, 23, 24 is introduced into at least one of the cavities 4, 5, 6 before the filter 1, la, lb, lc, ld, le is placed in a mold (not shown) such as a cylindrical sleeve.
The treatment material 12, 22, 23, 24 is selected from desulphurizing, thermogenic, inoculating, spheroidizing, recarburizing, refining and modifying products and additive alloys.
The weight of the treatment material 12, 22, 23, 24 may vary between approximately 0.001% and 1°s of the weight of the liquid metal depending on the nature of the treatment to be applied.
The filter la shown in figure 1 comprises three plates 2, 2a, 2b. The plates 2 and 2a each have a projecting peripheral rim 11 adapted to come into contact with the respective adjacent plate 2a, 2b which is thus spaced from it to form a respective cavity 4, 5. The plate 2b has no such rim, as this would increase the height of the filter 1 with no benefit.
The upper plate, which is normally on the upstream side, has progressively increasing diameter holes 3, 3a, 3b in it. The plates 2a, 2b also have holes in them, of the same diameter or different diameters. The holes in the intermediate plate 2a are arranged in a quincunx arrangement relative to the holes in the outer plates 2 and 2b. The holes 3, 3a, 3b may be non-circular. -In the known way the plates 2, 2a, 2b are made from a ceramic refractory mineral material such as silica, for example, and are able to withstand the temperature of the cast metal without distortion.
The filter 1 shown in figure 2 comprises a plate 2 with holes 3 of substantially the same diameter.
The filter lb shown in figure 3 comprises two plates 2a whose peripheral edges 11 are adjacent and fastened together by an adhesive 10. The heights of the rims 11 are shown the same but they could be different.
The two plates delimit a cavity 6.
Figures 4 and 5 on the one hand and figures 6 and 7 on the other hand respectively show a filter lc, ld comprising two plates 2a in contact at their peripheral edge 11 to delimit a cavity 6.
In the embodiment shown in figures 8 through 12 the liquid metal filter comprises three refractory material plates 2, 2a, 2b in contact with each other at their periphery and defining between them a plurality of _ CA 02097261 1998-OS-06 cavities 5, 6, 7. The plates 2, 2a, 2b each comprise a series of holes 3 through which the liquid metal passes and by which it is filtered as it passes through the filter in the direction of the arrow D.
As shown in figures 1 through 12, and in accordance with the invention, at least one of the cavities 4, 5, 6 of the filter 1, la, lb, lc, ld, le contains a material for treating the molten metal.
In the embodiment of figures 1, 3, 4 and 5 the treatment material 12 is in powder form and is retained by a film 13 of a material adapted to melt, carbonize or calcine in contact with the liquid metal to be treated.
The particle size of the powder material is selected in accordance with the required treatment conditions.
The film 13 of a material adapted to melt, carbonize or calcine in contact with the metal to be treated is an aluminum or paper or plastics material or composite film, for example.
In the embodiment of figures 1 and 3 the treatment material 12 is contained in sachets 8, 8a, 8b made from said film 13 and placed in said cavity 4, 5, 6.
The cavities 4 and 5 in figure 1 each contain a respective sachet 8, 8a which fills the respective cavity 4, 5 partially or almost completely. The sachets 8, 8a may be identical or have different capacities.
The cavity 6 in figure 3 contains a sachet 8b disposed eccentrically in said cavity 6, for example.
In the embodiment of figures 4 and 5 the cavity 6 formed between the two plates 2a is filled with powdered treatment material 12 and the holes 3 in the plates 2a are blocked by a film 13 of the aforementioned type disposed on the inside or outside surface of each plate 2a.
In the figure 4 example a film 13 is fixed (for example glued) to the inside surface of the upper plate.
Another film 13 is fixed to the outside surface of the lower plate, the holes 3 being filled with treatment material 12.
5 In the figure 5 example the films 13 are fixed to the inside surfaces of the plates in the lefthand half-view and to the outside surfaces of the plates in the righthand half-view. This latter case represents the - maximum volume of treatment material 12 that can be 10 contained in the filter lc.
In the embodiment of figures 6 and 7 the powdered treatment material 12 is pressed or sintered to form plates 14a, 14b or bars. The dimensions of the plates 14a, 14b or-bars are less than or equal to the inside dimensions of the cavity 6 so that as soon as casting begins the plates or bars can move inside the cavity 6 due to the turbulence caused by the arrival of the molten metal in the cavity 6.
The lefthand half-view shows, by way of example, a hexagonal contour plate 14a whereas the righthand half view shows an annular plate 14b. Plates 14a, 14b of this kind are pressed with a binder such as stearate or the like, for example; the treatment material 12 prepared in crystallized form, for example, can also be bound together under high pressure. The plate 14a includes a central hole 15 through which the metal passes. It could comprise other holes of various shapes and sizes.
The treatment materials may be desulphurizing agents, for example magnesium and/or calcium carbide, and/or thermogenic agents, for example calcium carbide, and/or inoculation and/or post-inoculation agents and/or spheroidizing agents, for example magnesium and/or rare earths and/or ferrosilicomagnesium, and/or additive alloy agents, for example molybdenum, boron, silicon, ferrosilicon, manganese, chromium, titanium, ferroaluminium, silicomishmetal alloys, recarburizing agents, for example based on carbon or graphite, or fluxes for modifying the structure of the metal, such as sodium, phosphorous, boron, titanium, strontium, etc salts.
Figures 8 through 13 show other embodiments of the invention in which the treatment material is a material 22, 23, 24 for inoculating the liquid metal. In the example shown in figure 8 the cavities 5, 6 each contain an inoculating material 22.
In the case of figures 8 and 9 the inoculating material 22 is in the form of a plate comprising holes 25 through which the liquid metal passes and extending over substantially all of the length and the width of the cavity 5 or 6.
The side of each plate 22 adjacent the bottom of the cavity 5 or 6 further comprises a series of recesses 26 made up of a series of parallel dihedra.
In the figure 8 example the other side of the plate 22 also comprises recesses 27. Figures 8 and 9 also show that the holes 25 in the inoculating material plate 22 have a larger cross-section than the holes 3 in the refractory material plates 2, 2a, 2b.
When the liquid metal (steel or cast iron) passes through the filter le shown in figure 8 it first comes into contact with the upper surface of the inoculating material plate 22, passes through the holes 25 in this and then fills the recesses 26 on the lower surface of the plate 22, thereafter flowing through the filter holes 3 in the plate 2.
Because the holes 3 are smaller than the holes 25 in the inoculating material plates 22 the metal fills the recesses 26 which achieves a large area of contact between the liquid metal and the inoculating material which is beneficial to the metal treatment reaction.
In this way the presence of the inoculating material 22 in the filter in combination with the filter holes 3 makes it possible to improve the metal more effectively than by means of a simple filtration operation.
In the embodiment of figures 10 and 11 the inoculating material 23 is in the form of spaced bars 28, 29 extending over substantially all the length and the width of the cavities 5 and 6 in the refractory plates 2, 2a.
In this embodiment the bars 28, 29 are disposed in two superposed and crossed layers, as shown in figure 11 in particular.
During -filtration the liquid metal laps over the surface of the bars 28, 29 and then accumulates at the bottom of the cavities 5, 6 before flowing downwardly through the holes 3.
This embodiment also achieves a large area of contact between the liquid metal and the inoculating material enabling the yield from the inoculant to be improved.
In- the figure 12 embodiment the side of the inoculating material plate 24 adjacent the bottom of the cavity 5 of the refractory plate 2 has a recess 30 delimited by a peripheral lip 31 which rests on the bottom of the cavity 5. This plate 24 has holes 32 in it through which the liquid metal passes.
As in the embodiments of figures 8 through 11 the holes 32 in the inoculating material plate 24 are larger than the holes 3 in the plate 2. Because of this the liquid metal which is poured onto the plate 24 passes through the holes 32 and then fills the recess 30 before flowing through the holes 3 in the plate 2.
By filling the recess 30 the liquid metal is in contact with a large proportion of the surface of the inoculating material 24 so that the inoculation action is more effective.
In the figure 13 example the inoculating material is in the form of a plate 2c with holes 3c the same shape as those of the refractory material plates 2, 2b and is substituted for one of the latter.
Also, as shown in figures 8, 10 and 13 at least one of the cavities of the refractory material plates 2, 2a, 2b is filled with a filter material 20, for example with refractory fibers.
The filter material 20 is preferably disposed in a cavity 7 on the side of a cavity 5 or 6 containing an inoculating material 22 or 23 which is the downstream side relative to the direction D in which the liquid metal passes through the cavity (see figures 8 and 10).
The filter material 20 is effective in its own right and further enhances the performance of the filter in accordance with the invention.
To give a non-limiting example, the inoculating material is selected from the following substances: iron alloys (Fe-Si alloy, for example), magnesium and magnesium compounds, calcium and calcium compounds, lithium compounds, strontium and barium compounds, silicon, zirconium, aluminum, rare earths, graphite and carbon.
Of course, the invention is not limited to the embodiments that have just been described and numerous modifications may be made thereto without departing from the scope of the invention. The pressed or sintered plates 14a, 14b may be replaced with solid molded plates.
In the embodiment of figures 10 and 11 the inoculating material 23 is in the form of spaced bars 28, 29 extending over substantially all the length and the width of the cavities 5 and 6 in the refractory plates 2, 2a.
In this embodiment the bars 28, 29 are disposed in two superposed and crossed layers, as shown in figure 11 in particular.
During -filtration the liquid metal laps over the surface of the bars 28, 29 and then accumulates at the bottom of the cavities 5, 6 before flowing downwardly through the holes 3.
This embodiment also achieves a large area of contact between the liquid metal and the inoculating material enabling the yield from the inoculant to be improved.
In- the figure 12 embodiment the side of the inoculating material plate 24 adjacent the bottom of the cavity 5 of the refractory plate 2 has a recess 30 delimited by a peripheral lip 31 which rests on the bottom of the cavity 5. This plate 24 has holes 32 in it through which the liquid metal passes.
As in the embodiments of figures 8 through 11 the holes 32 in the inoculating material plate 24 are larger than the holes 3 in the plate 2. Because of this the liquid metal which is poured onto the plate 24 passes through the holes 32 and then fills the recess 30 before flowing through the holes 3 in the plate 2.
By filling the recess 30 the liquid metal is in contact with a large proportion of the surface of the inoculating material 24 so that the inoculation action is more effective.
In the figure 13 example the inoculating material is in the form of a plate 2c with holes 3c the same shape as those of the refractory material plates 2, 2b and is substituted for one of the latter.
Also, as shown in figures 8, 10 and 13 at least one of the cavities of the refractory material plates 2, 2a, 2b is filled with a filter material 20, for example with refractory fibers.
The filter material 20 is preferably disposed in a cavity 7 on the side of a cavity 5 or 6 containing an inoculating material 22 or 23 which is the downstream side relative to the direction D in which the liquid metal passes through the cavity (see figures 8 and 10).
The filter material 20 is effective in its own right and further enhances the performance of the filter in accordance with the invention.
To give a non-limiting example, the inoculating material is selected from the following substances: iron alloys (Fe-Si alloy, for example), magnesium and magnesium compounds, calcium and calcium compounds, lithium compounds, strontium and barium compounds, silicon, zirconium, aluminum, rare earths, graphite and carbon.
Of course, the invention is not limited to the embodiments that have just been described and numerous modifications may be made thereto without departing from the scope of the invention. The pressed or sintered plates 14a, 14b may be replaced with solid molded plates.
Claims (28)
1. Apparatus for filtering and treating molten metal adapted to implement a process for simultaneously filtering and treating a molten metal during an operation to cast said molten metal into a mold, said apparatus comprising a series of at least two refractory mineral material filtering plates in contact with each other at their periphery and defining between them at least one cavity, said filtering plates each having a series of filtering holes through which said molten metal flows and by which said molten metal is filtered, the dimensions of the filtering holes and the number of the filtering plates being selected so as to eliminate from the molten metal solid inclusions likely to affect the quality of the cast metal, said apparatus containing within said at least one cavity an inorganic treatment material for treating said molten metal flowing through the cavity, said treating material being in the form of one solid compressed or molded or sintered treating plate positioned in said at least one cavity and extending over a major portion of the length and of the width of said at least one cavity, said treating plate having when viewed in the direction of metal flow, a shape such that one or more passage holes are arranged in said treating plate for said molten metal to pass through said passage holes and through said apparatus.
2. Apparatus according to claim 1, wherein the weight of said treating material in said at least one cavity is in the range from about 0,001% to about 1% of the weight of said molten metal.
3. Apparatus according to claim 1, wherein the dimensions of said treating plate is less than or equal to the inside dimensions of said at least one cavity adapted to receive them.
4. Apparatus according to claim 1, wherein at least the side of said treating plate adjacent the bottom of said at least one cavity comprises a series of recesses.
5. Apparatus according to claim 4, wherein said recesses comprise a series of parallel dihedra.
6. Apparatus according to claim 4, wherein the other side of said treating plate also comprises recesses.
7. Apparatus according to claim 1, wherein said passage holes in said treating plate are larger than said filtering holes in said filtering plates.
8. Apparatus according to claim 1, wherein the side of said treating plate adjacent the bottom of said at least one cavity incorporates a recess defined by a peripheral rim, which rests on the bottom of, said at least one cavity.
9. Apparatus according to claim 1, wherein said treating material is chosen from the following substances: iron alloys, magnesium and magnesium compounds, calcium and calcium compounds, lithium compounds, strontium and barium compounds, silicon, zirconium, aluminum, rare earths, graphite and carbon.
10. Apparatus according to claim 1, wherein said treating material is in the form of a treating plate having passage holes the same shape as those of said filtering plates and is substituted for one of said filtering plates.
11. Apparatus according to claim 1, wherein said filtering plates define a plurality of cavities between them, and at least one of said cavities in said filtering plates is filled with a filter material.
12. Apparatus according to claim 11, wherein said filter material is disposed in a cavity on the downstream side of a cavity containing said treating material in the direction in which the molten metal flows through the apparatus.
13. Apparatus for filtering and inoculating molten metal adapted to implement a process for simultaneously filtering and inoculating a molten metal during an operation to cast said molten metal into a mold, said apparatus comprising a series of at least two refractory mineral material filtering plates in contact with each other at their periphery and defining between them at least one cavity, said filtering plates each having a series of filtering holes through which said molten metal flows and by which said molten metal is filtered, the dimensions of the filtering holes and the number of the filtering plates being selected so as to eliminate from the molten metal solid inclusions likely to affect the quality of the cast metal, said apparatus containing within said at least one cavity an inorganic inoculating material for inoculating said molten metal flowing through the cavity said inoculating material being in the form of one solid compressed or molded or sintered inoculating plate positioned in said at least one cavity and extending over a major portion of the length and of the width of said at least one cavity, said inoculating plate having when viewed in the direction of metal flow, a shape such that one or more passage holes are arranged in said inoculating plate for said molten metal to pass through said passage holes and through said apparatus.
14. Apparatus as defined in claim 1, wherein said treating material is selected from the group consisting of desulphurizing, thermogenic, inoculating, spheroidizing, recarburizing, refining and modifying products and additive alloys.
15. Apparatus for filtering and treating molten metal adapted to implement a process for simultaneously filtering and treating a molten metal during an operation to cast said molten metal into a mold, said apparatus comprising a series of at least two refractory mineral material filtering plates in contact with each other at their periphery and defining between them at least one cavity, said filtering plates each having a series of filtering holes through which said molten metal flows and by which said molten metal is filtered, the dimensions of the filtering holes and the number of the filtering plates being selected so as to eliminate from the molten metal solid inclusions likely to affect the quality of the cast metal, said apparatus containing within said at least one cavity an inorganic treatment material for treating said molten metal flowing through the cavity, said treating material being in the form of one solid compressed . or molded or sintered treating plate positioned in said at least one cavity and extending over a major portion of the length and of the width of said at least one cavity, said treating plate having when viewed in the direction of metal flow, a shape such that one or more passage holes are arranged around said treating plate for said molten metal to pass through said passage holes and through said apparatus.
16. Apparatus according to claim 15, wherein the weight of said treating material in said at least one cavity is in the range from about 0,001% to about to of the weight of said molten metal.
17. Apparatus according to claim 15, wherein the dimensions of said treating plate is less than or equal to the inside dimensions of said at least one cavity adapted to receive them.
18. Apparatus according to claim 15, wherein at least the side of said treating plate adjacent the bottom of said at least one cavity comprises a series of recesses.
19. Apparatus according to claim 18, wherein said recesses comprise a series of parallel dihedra.
20. Apparatus according to claim 18, wherein the other side of said treating plate also comprises recesses.
21. Apparatus according to claim 15, wherein said passage holes in said treating plate are larger than said filtering holes in said filtering plates.
22. Apparatus according to claim 15, wherein the side of said treating plate adjacent the bottom of said at least one cavity incorporates a recess defined by a peripheral rim, which rests on the bottom of, said at least one cavity.
23. Apparatus according to claim 15, wherein said treating material is chosen from the following substances: iron alloys, magnesium and magnesium compounds, calcium and calcium compounds, lithium compounds, strontium and barium compounds, silicon, zirconium, aluminum, rare earths, graphite and carbon.
24. Apparatus according to claim 15, wherein said treating material is in the form of a treating plate having passage holes the same shape as those of said filtering plates and is substituted for one of said filtering plates.
25. Apparatus according to claim 15, wherein said filtering plates define a plurality of cavities between them, and at least one of said cavities in said filtering plates is filled with a filter material.
26. Apparatus according to claim 25, wherein said filter material is disposed in a cavity on the downstream side of a cavity containing said treating material in the direction in which the molten metal flows through the apparatus.
27. Apparatus for filtering and inoculating molten metal adapted to implement a process for simultaneously filtering and inoculating a molten metal during an operation to cast said molten metal into a mold, said apparatus comprising a series of at least two refractory mineral material filtering plates in contact with each other at their periphery and defining between them at least one cavity, said filtering plates each having a series of filtering holes through which said molten metal flows and by which said molten metal is filtered, the dimensions of the filtering holes and the number of the filtering plates being selected so as to eliminate from the molten metal solid inclusions likely to affect the quality of the cast metal, said apparatus containing within said at least one cavity an inorganic inoculating material for inoculating said molten metal flowing through the cavity said inoculating material being in the form of one solid compressed or molded or sintered inoculating plate positioned in said at least one cavity and extending over a major portion of the length and of the width of said at least one cavity, said inoculating plate having when viewed in the direction of metal flow, a shape such that one or more passage holes are arranged around said inoculating plate for said molten metal to pass through said passage holes and through said apparatus.
28. Apparatus as defined in claim 15, wherein said treating material is selected from the group consisting of desulphurizing, thermogenic, inoculating, spheroidizing, recarburizing, refining and modifying products and additive alloys.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| LU88124 | 1992-05-29 | ||
| LU88124A LU88124A1 (en) | 1992-05-29 | 1992-05-29 | LIQUID METAL FILTER |
| FR9213039A FR2697444B1 (en) | 1992-10-30 | 1992-10-30 | Filter for liquid metal with inoculant. |
| FR9213039 | 1992-10-30 | ||
| FR9300062 | 1993-01-06 | ||
| FR9300062A FR2691654B1 (en) | 1992-05-29 | 1993-01-06 | Process for treating molten metal in a casting operation with the interposition of a filter, and filter for implementing this process. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2097261A1 CA2097261A1 (en) | 1993-11-30 |
| CA2097261C true CA2097261C (en) | 2001-07-24 |
Family
ID=27252674
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002097261A Expired - Fee Related CA2097261C (en) | 1992-05-29 | 1993-05-28 | Process for treating molten metal during casting operation using a filter and filter for implementing the process |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0578517B1 (en) |
| JP (1) | JPH06108170A (en) |
| CA (1) | CA2097261C (en) |
| DE (1) | DE69322006T2 (en) |
| ES (1) | ES2126637T3 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2774611B1 (en) * | 1998-02-11 | 2000-04-28 | Daussan & Co | DEVICE FOR FILTERING AND TREATING MOLTEN METAL |
| FR2780322B3 (en) | 1998-06-25 | 2000-05-12 | Daussan & Co | PROCESS FOR PREPARING A CASTING MOLD |
| EP1369190A1 (en) | 2002-06-03 | 2003-12-10 | Carbon Application Technology Ltd. | Filter device for molten metal filtration |
| GB0613001D0 (en) * | 2006-06-30 | 2006-08-09 | Juma Kassim A | A filter |
| DE102018201577B4 (en) * | 2017-02-03 | 2020-02-06 | Technische Universität Bergakademie Freiberg | Process for producing a molten metal hybrid filter and ceramic molten metal hybrid filter |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3658115A (en) * | 1970-11-30 | 1972-04-25 | Gen Motors Corp | Method of inoculating nodular cast iron |
| DE2608282A1 (en) * | 1976-02-28 | 1977-09-08 | Baur Eduard Dr Ing | Adding inoculants and/or alloying agents to metal before casting - where agents are located in pouring funnel used to fill mould |
| DE3509113A1 (en) * | 1985-03-14 | 1986-09-18 | Stettner & Co, 8560 Lauf | DEVICE FOR FILTERING METAL MELT |
| FR2593077B1 (en) * | 1986-01-23 | 1990-10-19 | Desobeau Jacques | REFRACTORY MATERIAL FILTER. |
| JPS62185859A (en) * | 1986-02-10 | 1987-08-14 | Kubota Ltd | Reaction container for in-mold inoculation |
| GB8604569D0 (en) * | 1986-02-25 | 1986-04-03 | Foseco Int | Casting of molten ferrous metal |
| IT1189162B (en) * | 1986-06-11 | 1988-01-28 | Oet Metalconsult Srl | PROCESS OF DEGASSING, REFINING OR FILTRATION TREATMENT OF METALS OR ALLOYS IN THE LIQUID STATE AND RELATED DEVICE |
-
1993
- 1993-05-28 DE DE69322006T patent/DE69322006T2/en not_active Expired - Fee Related
- 1993-05-28 EP EP93401373A patent/EP0578517B1/en not_active Expired - Lifetime
- 1993-05-28 CA CA002097261A patent/CA2097261C/en not_active Expired - Fee Related
- 1993-05-28 ES ES93401373T patent/ES2126637T3/en not_active Expired - Lifetime
- 1993-05-31 JP JP5149797A patent/JPH06108170A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| ES2126637T3 (en) | 1999-04-01 |
| EP0578517B1 (en) | 1998-11-11 |
| JPH06108170A (en) | 1994-04-19 |
| DE69322006T2 (en) | 1999-06-10 |
| DE69322006D1 (en) | 1998-12-17 |
| EP0578517A1 (en) | 1994-01-12 |
| CA2097261A1 (en) | 1993-11-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |