A molten metal treatment furnace (10) with metal treatment and level control includes a heating chamber (12) for containing and heating a supply of molten metal (60), a pump (22) connected to the heating chamber (12), a molten metal treatment chamber (16, 18) located at the outlet of the pump (22), and a dosing chamber (40) located downstream and in fluid communication with the molten metal treatment chamber (16, 18). A trough (44) is connected to the dosing chamber (40) for supplying the molten metal (60) to a downstream process. A molten metal level sensor (66) is located in the dosing chamber (40). The pump (22) is a variable speed pump having a pump inlet (24) connected to the heating chamber (12) and configured to pump the molten metal (60) through the furnace (10) during operation. The molten metal level sensor (66) is connected to the pump (22) for providing a pump speed control signal to the pump (22). The molten metal level sensor (66) is configured to monitor the level of the molten metal (60) in the dosing chamber (40) and maintain a preset level of the molten metal (60) in the dosing chamber (40) by controlling the speed of the pump (22) with the pump speed control signal.

Molten metal treatment furnace with level control and method

Tooling for handling molten or hot solid aluminum and its alloys wherein the tooling is made of a passivated titanium aluminide (TiAl) intermetallic compound having a thin passivating surface oxide film formed in-situ thereon by contact with an oxygen-bearing atmosphere at elevated temperature. The surface oxide film passivates and renders the tooling non-wetted by and non-reactive with molten aluminum and its alloys and non-bonded to hot solid aluminum and its alloys.

Passivated titanium aluminide tooling

Exemplary embodiments of the invention provide a molten metal containment structure including a refractory molten metal containment vessel having an external surface, and a metal casing for the vessel having an internal surface at least partially surrounding the external surface of the vessel at a distance therefrom forming a spacing between the vessel and the casing. The spacing includes an unobstructed upwardly extending gap that is vented to the exterior of the structure by upper and lower openings in the casing. A layer of insulating material is preferably positioned in the spacing between the internal surface of the casing and the external surface of the vessel, with the layer of insulating material being narrower than the spacing at least at upwardly extending sides of the casing, thereby forming the unobstructed gap. The vessel may be a metal conveying trough, a housing for a metal filter, a container for a metal degasser unit, a crucible, or the like.

Molten metal containment structure having flow through ventilation

A device is described for injecting gas into molten metal, e.g. molten aluminum, in a furnace chamber. It comprises: (a) a stirring apparatus having a reservoir chamber separate from the furnace chamber, a connector portion with an orifice connecting the interior of the furnace and the reservoir for the passage of the molten metal between them through the connector portion, vacuum/pressure generating means connected to the reservoir chamber interior for alternatively and successively producing therein a vacuum for drawing molten metal into its interior from the furnace chamber and a positive pressure for expelling the molten metal therefrom into the furnace chamber through the orifice in the form of a high velocity stirring jet, and (b) gas injector means adapted to inject gas into the high velocity stirring jet such that the gas is broken down into a large number of small bubbles which are circulated throughout the furnace chamber with the stirring jet.

Jet flow device for injecting gas into molten metal and process

The melter furnace includes a heating chamber (16), a pump chamber (18), a degassing chamber (20), and a filter chamber (22). The pump chamber 818) is located adjacent the heating chamber (16) and houses a molten metal pump (30). The degassing chamber (20) is located adjacent and in fluid communication with the pump chamber (18) and houses a degassing mechanism (36). The filter chamber (22) is located adjacent and in fluid communication with the degassing chamber (20). The filter chamber (22) includes a molten metal filter (38). The melter furnace (12) is used to supply molten metal to an externally located holder furnace (14), which then recirculates molten metal back to the melter furnace (12).

Recirculating molten metal supply system and method

A method of measuring the quenchability of a liquid coolant used to cool objects such as ingots produced by direct-chill casting. The method involves providing a sample of the liquid coolant; providing a probe for immersion in the sample, the probe having a temperature-sensing electrical device contained therein which generates an electrical response corresponding to temperature sensed; heating the probe in a gas, preferably by means of electrical resistance heating by a circuit which is electrically connected to the temperature-sensing electrical device, to a predetermined temperature measured by the electrical response of the temperature sensing device, immersing the probe into the sample and measuring the electrical response for a predetermined measurement period, and comparing the measured electrical response to a response of a reference liquid measured under equivalent conditions, to thereby determine the quenchability property of the liquid coolant. The invention also relates to apparatus for carrying out the method, as well as a method and apparatus for controlling the cooling of the object based on the measured quenchability of the coolant. In an alternative, the probe may be heated by means other than the electrical resistance heating at a rate of at least about 40 °C/second.

Method and apparatus for measuring quenchant properties of coolants

A method is described for priming an in-line molten metal filtration unit having a porous ceramic or refractory filter mounted substantially horizontally in a filter box. This filter box has an inlet for molten metal and an outlet for molten metal, the outlet being a closeable outlet in an exit well connecting to the downstream side of the filter. The method of the invention comprises the steps of adding a molten metal to the filter box sufficient to entirely cover the upstream side of the filter with a depth of molten metal and temporarily sealing the outlet in the exit well. A steadily increasing vacuum is then applied to the closed exit well at a rate between 0.1 and 10 kPa per second by withdrawing a stream of air from the exit well by means of a fan or air venturi until molten metal begins to flow through the filter. At that point the vacuum is quickly released and the molten metal outlet is opened. Once the filter has been primed in this manner, flow of metal through the filter continues while requiring only a relatively low head of molten metal on the inlet side of the filter.

Method of priming filter for molten metal

The invention provides a new stirring apparatus for stirring the liquid metal contents of a furnace, particularly the shallow furnaces used in the processing of aluminum and its alloys. The apparatus consists a reservoir separate from the furnace of relatively large horizontal cross-section and volume, into which a vaccuum draws metal from the furnace through a nozzle, the metal then being returned by gas pressure forcibly into the furnace through the nozzle in the form of a horizontally directed jet. The cycle is repeated at sufficiently close intervals to ensure that the furnace bath is quickly and effectively mixed. The nozzle directs the molten metal entering the reservoir tangentially to swirl the metal and reduce the accumulation of dross. The reservoir comprises a bottom static part including the nozzle and a readily removable top cover carrying heaters for heating the reservoir interior and the dross that deposits on the side wall to ease its removal. The cover also carries level control electrodes, an observation port, inlet ports, etc. A pressure disturbance monitor connected to the reservoir interior is used for lower level control by detecting undesired bubbling of the pressurizing gas into the metal, and can also be used to monitor the pressure reversals between vacuum and pressurization phases. The cycles of vaccuum and pressure are controlled in a manner that maximizes the quantity of metal entering the reservoir so as to obtain the maximum stirring effect.

Andre Gendron

Papers

Method and apparatus for measuring quenchant properties of coolants

Method of priming filter for molten metal

Apparatus for stirring molten metal

Fremgangsmåte og anordning for å initiere en strøm av metall gjennom et filter