摘要:
A device for continuously manufacturing a cast strand by continuous casting of liquid metal melt wherein the flow of the liquid metal in the non-solidified portions of the strand is controlled by means of a static or periodic low-frequency magnetic field. A mould adapted to be supplied with the melt includes copper plates (2a,2b) which form a casting mould space with a rectangular cross section, water box beams (3) which are arranged outside the copper plates to support and cool them, and a member (4) holding the mould together. Magnetic field-generating devices, i.e., magnets, are provided close to the mould to generate a static or periodic low-frequency magnetic field which acts in the path of the inflowing melt and divides the primary flow as well as checks any secondary flows arising. Each magnet comprises a front core (5), a rear core and a coil (7). The front core is a fully integral part of the water box beam and the rear core comprises a rear movable part (6b) which is movable in a direction which substantially coincides with the direction of the field.
摘要:
A method and a device for controlling the flow of the molten metal in non-solidified portions of a cast strand in connection with casting of metal. A mould (11) is supplied with at least one primary flow (20) of molten metal and at least one strand (1) is formed in the mould. At least one static or periodic low-frequency magnetic field (10) is applied to act with a maximum magnetic field strength in the mould exceeding 1000 Gauss in the path of the inflowing molten metal to brake and divide the primary flow (20) of molten metal flowing into the mould and to control any secondary flows (21, 22) arising. The static magnetic field (10) acts over essentially the whole width (W) of the cast strand (1) formed in the mould, whereby the magnetic field strength in a plane across the casting direction, on a level with the centre of the range of action of the magnetic field (10), varies within an interval of 60 to 100 per cent of its maximum value, while at the same time the field strength on a level with the upper surface/the meniscus of the molten metal amounts to at most 500 Gauss. (FIG. 1 )
摘要:
A control system for regulating the flow of liquid metal in a device for casting a metal. A detector measures a process variable. A control unit evaluates data from the detector. At least one process parameter is automatically varied in order to optimize casting conditions. The detector measures a characteristic of the meniscus at at least two points on the meniscus instantaneously throughout the casting process.
摘要:
An inductive heating unit for a magnetically permeable ladle containing molten steel has a cylindrical permeable wall for receiving the ladle and on which is wound an induction coil with an outer cylindrical permeable wall surrounding and enclosing the coil. The coil is wound from a conductor formed by a plurality of superposed flat metal strips which are insulated from each other. The outer wall is formed with a vertical channel in which a power lead for the coil is positioned.
摘要:
A channel inductor and a furnace for melting, holding or refining metal. The channel inductor has a closed-loop core, a primary winding arranged around the core and a refractory lining in which the winding and core is partly enclosed and in which an inductor channel is formed. The channel inductor also has a detector to detect metal penetration of the refractory lining.
摘要:
A method and a device for inductively stirring a molten metal. Magnetic fields are applied to act on the melt through a wall (11) which comprises a magnetic material. Said wall is saturated by a magnetic direct field such that an anisotropically directed magnetic saturation, a low relative permeability, is obtained in the saturation direction (S). A low-frequency magnetic travelling alternating field, comprising components which are located in a plane oriented parallel to said saturation direction and perpendicular to the plane of the wall, is applied superposed on the magnetic direct field, whereby the low-frequency magnetic travelling alternating field passes through said wall with small losses and little damping to apply a stirrer field which provides the desired circulation in the melt.
摘要:
Lining wear in an arc heated ladle containing a bath of melt and slag is reduced by rotating the melt in a horizontal direction to provide a concave bath surface in which the slag accumulates towards the center, thus preventing the slag attacking the ladle lining. In addition to heating the charge, the arc or arcs melt(s) the slag whereas the lining is partly protected from the radiation by the concave surface. A flow perturbing means is arranged at the ladle to attain an increased homogenization and the possibility of intensified sulfur removal.
摘要:
A furnace plant which at least one furnace vessel with side walls and a bottom and at least one heat source which by radiation and convection heats molten metal and/or solid metal present in the furnace vessel. At least one two- or multiphase electromagnetic side stirrer is arranged in or near the wall of the furnace vessel to act through the wall and apply a stirrer field to the molten metal. The side stirrer comprises at least two phase windings arranged around an iron core having a vertical extent, H, which essentially covers the region, D.sub.max, between the bottom and the upper surface of the molten metal at a maximum bath depth used in the furnace 15 vessel. The side stirrer is arranged with a pole pitch.tau. which exceeds twice the distance from the iron core to the molten metal, .tau.>2 dw.
摘要:
A device and a method for stabilising a metallic object of magnetic material. The metallic object is transported along a transportation path or plane. The plane includes a transportation direction and is parallel to the longitudinal direction of the object therein. A sensor is arranged to sense the valve of a parameter depending on the position of the object with respect to the plane. An electromagnetic actuator is arranged to apply a magnetic force to the object in respone to the sensed position. The magnetic force has a force component directed transversely to the transportation direction and transversely to the plane.
摘要:
An electrical converter equipment for providing a d.c. voltage from an alternating current source. The converter has a unique operating cycle wherein a variable control angle is effected. The operating cycle for the converter comprises a series of half periods of the alternating current source. During different periods of time, the converter operates with different control angles. The control cycles comprise n periods of the input signal, where n is an odd number not less than three. During two half periods of a cycle, the control angle is varied. During two other half periods of the cycle, the converter operates at a fixed control angle. The half periods during which the converter is controlled with a variable control angle are time equidistant.