J. Mulcahy Enterprises Inc.

Other

Co-steel International Limited

Inverpower Controls Ltd.

Joseph A Mulcahy

Hassan Ali Kojori

Julian Szekely

Janos Rajda

Leonid Beitelman

Dawit Tadesse

An electric arc furnace includes a container for receiving metal, an electrode spaced apart from the container, and an electrical power source coupled to the electrode and the container for generating an electrical discharge between the electrode and the container for melting the metal in the container. The arc furnace includes a flicker controller for reducing flicker induced in the power source by the electric arc furnace. The flicker controller consists of a switch electrically connected between the power source and the electrode, and a control system coupled to the switch. The switch includes a gating input for controlling a conduction interval of the switch, and the control system applies gating signals to the gating input for maintaining a magnitude of reactive current flow through the arc furnace substantially constant.

Electric arc furnace controller

An induction stirring method wherein molten metal is electromagnetically stirred during continuous casting in a mold includes control of velocity of the stirring motion at the meniscus and the region adjacent to it, either to decrease or enhance the stirring of the molten metal produced by the main electromagnetic stirrer. An A.C. magnetic stirring modifier is positioned adjacent the region of meniscus to produce electromagnetic stirring of the molten metal at the meniscus, either to oppose the rotary motion of the main electromagnetic stirrer and provide a surface free from the stirring motion or to enhance the rotary stirring motion of the main magnetic stirrer. These two alternative modes of operation permit a casting machine to be used for casting molten metals requiring widely varying operating conditions.

Method and apparatus for control of stirring in continuous casting of

Twin-roll casting of molten metal to form a continuous cast metal strand is improved by electromagnetic stirring of molten metal immediately upstream of the nip between the rolls to provide a substantially homogenized melt of substantially uniform temperature upstream of the nip.

Liquid metal stirring during casting

Liquid metals are centrifugally pumped from a static container without the necessity for employing a mechanical impeller. A powerful rotating magnetic field surrounding the static container causes the metal to be rotated vigorously and the velocity head so created is converted in a volute shaped head into vertical motion to the desired delivery point.

Pumping liquid metals

A static high intensity magnetic field is applied to electromagnetically-stirred molten metal to minimize turbulence in the molten metal. One application of the invention is to minimize meniscus distortions and/or surface disturbances produced by the electromagnetic stirring at a free surface. Another application is to improve laminar flow in the entrance to horizontal molds.

Magnetic control of molten metal systems

The continuous casting of heavy metals in a magnetic field is improved by using a magnetic field in the form of essentially uniform flux lines closely parallel to the casting surface. The instability experienced with the liquid meniscus is minimized and higher intensity fields, permitting casting of heavier metals, can be achieved.

Use of magnetic field in continuous casting

In the continuous casting of steel, surface imperfections associated with the use of an oscillating bar for removal of the cast billet from the mold are substantially eliminated by providing a pulsating high intensity magnetic field around the mold to cause flexing of the metal to detach solidified metal from the internal wall of the mold.

Continuous casting of steel

Molten steel or other electroconductive metal is treated with vacuum to remove dissolved gases therefrom. A rod of molten steel is drawn from a bath by applying vaccum to a vertical tube dipping into the molten bath. An electrical coil surrounding the tube applies an intense magnetic field to the steel rod by the passage of high frequency alternating current through the coil. The rod is compressed radially inwardly by the magnetic field exposing the whole of the external surface of the rod to vacuum. At the same time, the induced eddy currents superheat the steel rod. The large surface area of application of vacuum combined with the narrow dimension through which the gas must travel ensure rapid and efficient removal of the gases. The procedure is repeated until all the steel in the bath has been treated. Lack of contact of the steel rod with the tube surface eliminates loss of heat be convection and the superheating of the steel rod by the eddy currents ensures that the overall heat losses are minimal during processing of the molten metal bath.

Vacuum treating steels

A body of molten metal is simultaneously heated and rotated by the use of electromagnetic forces. In one embodiment, the melting of metals by induction heating is improved by using a circular spirally-wound electro-magnetic core located between a central flow channel and six peripherally-located flow channels. Three-phase electrical current is applied to the core windings to form a rotating magnetic field which intercepts the metal in the peripherally-located flow channels. The magnetic field causes heating of the metal in the peripheral channels with negligible heating in the central channel, thereby causing flow of heated metal through the peripheral channels to the bath. The magnetic field also causes rotational motion of the body of molten metal, thereby improving mixing and minimizing surface turbulence. In another embodiment, the electro-magnetic core is immersed in a body of molten metal to be surrounded thereby. Peripherally-located metal is heated and flows into the body of metal while axially-located metal is rotated.

Induction furnace

A means for electromagnetic stirring of steel in a continuous casting operation comprises at least two multi-turn conducting loons. Each turn has a group of winding segments running longitudinally along a mould side, such connected in series to another group of segments running longitudinally along the opposite mould side. Such an arrangement provides a rotating field which produces flux across the mould, transverse to the casting direction.

Growing community of inventors

Brooklin, Canada

Joseph A Mulcahy