Devices and apparatus for injecting gas into high temperature liquids, e.g. molten metals

Gas injection apparatus for introducing gas into a container vessel for molten metal via an opening in or adjacent the bottom of the vessel, comprising a nozzle for installation in the said opening of the vessel, the nozzle having a passage with a gas permeable closing means through which gas in use is passed to the melt, there being melt-tightly and gas-tightly fitted inside the passage an injection cartridge comprising an openended, gas-impermeable sleeve blocked adjacent each of its opposite ends by a compressible wad of fibrous refractory material and containing a filling of particulate refractory matter, the cartridge being permeable to flow of gas towards the vessel interior and impermeable to flow of molten metal therethrough, and ducting in operative, gas-tight juxtaposition with the nozzle passage and its cartridge for conveying gas thereto from a supply, the ducting including a stationary body, a movable body and means to bias the latter into gas-tight, slidable contact with the former, the bodies having orifices therein which, in a first position of the movable body are registered for passing gas to the nozzle, and in a second position thereof are out of registry for closing the ducting, the stationary body having an insert sleeve defining its orifice and the movable body having an imperforate insert positioned therein to register with the insert sleeve when the movable body is moved to the duct-closing position, the two inserts being made of highly thermally conductive materials.

A method employing a gas injection apparatus for introducing gas into a container vessel for molten metal via an opening in or adjacent the bottom of the vessel, said apparatus comprising a nozzle for installation in the said opening of the vessel, the nozzle having a passage with a gas permeable closing means through which gas in use is passed to the melt, there being melt-tightly and gas-tightly fitted inside the passage an injection cartridge comprising an open-ended, gas-impermeable sleeve blocked adjacent each of its opposite ends by a compressible wad of fibrous refractory material and containing a filling of particulate refractory matter, the cartridge being permeable to flow of gas towards the vessel interior and impermeable to flow of molten metal therethrough, and ducting in operative, gas-tight juxtaposition with the nozzle passage and its cartridge for conveying gas thereto from a supply, the ducting including a stationary body, a movable body and means to bias the latter into gas-tight, slidable contact with the former, the bodies having orifices therein which, in a first position of the movable body are registered for passing gas to the nozzle, and in a second position thereof are out of registry for closing the ducting, the stationary body having an insert sleeve defining its orifice and the movable body having an imperforate insert positioned therein to register with the insert sleeve when the movable body is moved to the duct-closing position, the two inserts being made of highly thermally conductive materials, said method comprising injecting said gas into the molten metal in the vessel while simultaneously teeming metal from the vessel via a teeming control means of the vessel.

A method employing a metal pouring apparatus, said apparatus comprising a container vessel for molten metal, an opening in or adjacent the bottom of the vessel and associated means operable to control teeming of molten metal through the opening, and means for injecting gas into molten metal in the vessel, the injecting means including a nozzle installed in a wall of the vessel in the vicinity of and separate from the said opening and the teeming control means, and ducting exteriorly of the vessel for conveying gas to a passage through the nozzle, the ducting including two abutting orificed refractory bodies, one of the refractory bodies being movable relative to the other to place the orifices out of registry thereby to close the ducting and prevent any molten metal entering the nozzle passage from escaping from the vessel via the nozzle and ducting, and inside the passage there is melt-tightly fitted an injection cartridge comprising an open-ended, gas-impermeable sleeve closed adjacent each of its opposite ends by a compressible wad of fibrous refractory material and containing a filling of particulate refractory matter, the cartridge being permeable to flow of gas towards the vessel interior and impermeable to flow of molten metal therethrough, said method comprising injecting said gas into molten metal in the vessel while simultaneously teeming metal from the vessel via the teeming control means.