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WO2008033307A2 - Unité de filtres en combinaison pour une coulée continue - Google Patents

Unité de filtres en combinaison pour une coulée continue Download PDF

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Publication number
WO2008033307A2
WO2008033307A2 PCT/US2007/019675 US2007019675W WO2008033307A2 WO 2008033307 A2 WO2008033307 A2 WO 2008033307A2 US 2007019675 W US2007019675 W US 2007019675W WO 2008033307 A2 WO2008033307 A2 WO 2008033307A2
Authority
WO
WIPO (PCT)
Prior art keywords
filter
molten metal
vessel
casting
tube
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.)
Ceased
Application number
PCT/US2007/019675
Other languages
English (en)
Other versions
WO2008033307A3 (fr
Inventor
David Neff
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pyrotek Inc
Original Assignee
Pyrotek Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Pyrotek Inc filed Critical Pyrotek Inc
Publication of WO2008033307A2 publication Critical patent/WO2008033307A2/fr
Publication of WO2008033307A3 publication Critical patent/WO2008033307A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D43/00—Mechanical cleaning, e.g. skimming of molten metals
    • B22D43/001—Retaining slag during pouring molten metal
    • B22D43/004—Retaining slag during pouring molten metal by using filtering means

Definitions

  • the invention relates generally to the field of molten metal casting and to the field of filtration. More particularly, the invention relates to a filtering device for molten metal, and specifically, to the combination of two different types of molten metal filters in one single vessel.
  • inclusions result from impurities in the raw materials used to form the melt, from slag, dross and oxides which form on the surface of the melt, and from small fragments of the refractory material used to form the chamber or vessel in which the molten metal melt is formed.
  • inclusions if not removed from the molten state of the metal, can result in weakened points and/or porosity in the finally solidified metal body — the end product of the casting operation.
  • Molten metal filtration is usually accomplished using filter elements formed of a porous refractory material.
  • the molten metal is directed through the filter elements such that impurities are removed.
  • Filtration can be performed by flowing molten metal through a filter box, which houses a filter assembly in such a way that the assembly may be removed and replaced as it becomes contaminated with the removed impurities.
  • a plate filter is positioned as a type of trap in the trough. Molten metal, therefore, passes through the plate as gravity flows it through the trough.
  • TTF Trough Tube Filter
  • CF Cartridge Filter
  • the normal endplates which house the filter tubes
  • the filter tubes are housed in fixed slanted refractory as shown in Figure 1. Consequently, only a single row (or at most a double row) of tubes can be easily placed and removed practicably. Therefore, with a limited number of filter tubes, this filtering system finds usage only in low flow-rate continuous casting, usually not exceeding 100 kg/min, using three or four filter tubes.
  • Figure 1 shows the filtering vessel housing these tubes. These filter units typically employ 30 kW silicon carbide electric heating elements. Such a system has advantages over the conventional CF.
  • a standard CF system normally requires shutdown, draining, and cool-down before the spent cartridge filter assembly can be removed and the vessel cleaned. Then one or more new filter arrays are installed and the full unit preheated to nearly 800 0 C for 24-30 hours before the vessel can be filled and casting restarted. By contrast, the TTF can be shut-down, drained, spent filters removed, unit cleaned, and new filter tubes installed in approximately 30 minutes after casting.
  • Vertical-mode filters have been employed for many years in low flow rate applications both in shape-casting foundry processing, and in continuous-casting processes in wrought aluminum production.
  • Figure 2 shows a simple vessel, which allows two filter positions in slots within the refractory sidewalls, an operating filter, and space for a new filter in the second slot when the first filter is spent.
  • the chemical integrity of the bonded particle filter media in this instance silicon carbide particulate with the molten aluminum resistant ceramic binder, allows such a filter to be used in sustained fashion for up to several hundred tons throughput depending on filter grade and size employed.
  • Bonded Particle Filter provides higher stability when casting magnesium-containing alloys.
  • a new filter can be installed in the second position and the spent filter can be removed from the first position.
  • the normal filter preheat temperature required before insertion is 400-600 0 F (202-312 0 C)
  • installing the filter into molten metal is possible using the molten metal itself as the secondary heat source.
  • Compressible gaskets on the edges of the filter plate provide sealing with refractory slots.
  • DVGF technology is suitable for conventional low-flow rate roll-casting applications (up to 100 kg/min flow rate) for strip-casting of either fine foil or building sheet product. A slightly larger variation can be specified for rod casting applications with flow rates up to 8 mt/hour.
  • An apparatus for filtering molten metal including a single molten metal vessel, at least one trough tube filter tube, and at least one vertical gate filter.
  • FIGURE 1 is a perspective view of a trough tube filter unit;
  • FIGURE 2 is a perspective view of a dual vertical gate filter unit;
  • FIGURE 3 is a top view of a combination filter unit.
  • the present novel apparatus would serve those customers who, for example, want to put in two continuous casting lines, and ideally produce both fine foil stock (5 micron) and garden-variety building product (much less quality-critical) on either line and in the same vessel, so they do not have to remove, exchange, or interchange the vessels from one line to the other.
  • VGF vertical gate filter
  • trough tube filter By combining a vertical gate filter (VGF) with a trough tube filter, one could employ a single vessel which would allow for either fine foil cast strip production through the TTF array, or standard strip quality production though VGF array. This permits continuous-casting operations to use a single unit to achieve the full range of product quality requirements most economically, especially with frequent alloy changes and short casting campaigns.
  • the vessel would be constructed with the angled refractory slots, as with the TTF, to accommodate the 20-grit filter tubes for casting premium products. When less critical quality production is scheduled, the tubes could be removed and a preheated vertical gate filter would be inserted into the slots provided in the refractory construction.
  • a single molten metal vessel is shown, which stores molten metal during a casting operation.
  • a single vessel also minimizes the layout space required, as well as the energy, time, and complexity associated with filter changes.
  • the molten metal vessel can include, but is not limited to, such vessels as a refractory furnace, a filter vessel, a filter box, a holding furnace or a casthouse chamber.
  • the molten metal vessel includes side walls and a bottom wall that define a chamber.
  • the vessel has an inlet for conveying molten metal to a filter well, that communicates with an upstream station of the casting operation and an outlet for conveying filtered molten metal from the filter well, which communicates with a downstream station of the casting operation.
  • An upstream station can include a melting furnace and one example of a downstream station can include a mold for casting.
  • the side walls of the vessel include recesses or slots which permit the vertical gate filter to be slid into and out of engagement with the filter well.
  • a filter such as a TTF or VGF, is placed inside the vessel to filter out any impurities from the molten metal that enters the vessel via the inlet.
  • the filter can be made from a porous ceramic material in the form of bonded silicon carbide or alumina particles that create numerous tortuous paths that provide effective filtration.
  • the filter can also be made of a ceramic foam filter, or any other known material that is capable of filtering the molten metal to remove impurities during a casting operation.
  • the exemplary embodiment of the present apparatus is a single vessel configuration, which can accommodate either at least one, but preferably, four fine 20 grit filter tubes sans endplates similar to the TTF product, for the premium product production, or slots in the refractory sidewalls to accommodate a single or dual-stage vertical filter, such as bonded particle filter available from Metaullics Systems, Co., LP., in coarser grit, 6-8 up to 10-12 grit filter grade.
  • Either filter configuration can accommodate up to 175 Ibs/min flow rate (approximately 5 tph), which fits many continuous roll-caster applications.
  • the single molten metal vessel further includes angled refractory slots in order to accommodate the 20-grit filter tubes for casting premium products.
  • the tubes will be removable in order to allow a preheated vertical gate filter to be inserted into the slots provided in the refractory construction.
  • an integrated, self-contained handling system would be incorporated into the unit so that operators can easily make the filter changeover without having to depend on an overhead crane.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Casting Support Devices, Ladles, And Melt Control Thereby (AREA)

Abstract

L'invention concerne un appareil pour filtrer un métal fondu comportant un récipient de métal fondu, au moins un tube de filtre à tube traversant, et au moins un filtre d'entrée verticale. L'invention concerne également un filtre adapté pour aller à l'intérieur du récipient d'une opération de coulée de métal fondu comportant au moins un tube de filtre à tube traversant, et au moins un filtre d'entrée verticale.
PCT/US2007/019675 2006-09-11 2007-09-11 Unité de filtres en combinaison pour une coulée continue Ceased WO2008033307A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US84366306P 2006-09-11 2006-09-11
US60/843,663 2006-09-11

Publications (2)

Publication Number Publication Date
WO2008033307A2 true WO2008033307A2 (fr) 2008-03-20
WO2008033307A3 WO2008033307A3 (fr) 2008-05-02

Family

ID=39184280

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/019675 Ceased WO2008033307A2 (fr) 2006-09-11 2007-09-11 Unité de filtres en combinaison pour une coulée continue

Country Status (1)

Country Link
WO (1) WO2008033307A2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115232984A (zh) * 2022-07-20 2022-10-25 中亿丰罗普斯金材料科技股份有限公司 再生变形铝合金铸棒夹杂物的组合过滤方法及过滤装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3129675B2 (ja) * 1997-04-16 2001-01-31 三井金属鉱業株式会社 セラミックフィルター及びその製造方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115232984A (zh) * 2022-07-20 2022-10-25 中亿丰罗普斯金材料科技股份有限公司 再生变形铝合金铸棒夹杂物的组合过滤方法及过滤装置
CN115232984B (zh) * 2022-07-20 2023-08-25 中亿丰罗普斯金材料科技股份有限公司 再生变形铝合金铸棒夹杂物的组合过滤方法及过滤装置

Also Published As

Publication number Publication date
WO2008033307A3 (fr) 2008-05-02

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