摘要:
A method for reducing vortex formation in molten metal when bottom tapping the molten metal from a metallurgical vessel in a metal making process. The method includes the steps of tapping the molten metal via a tapping hole in the metallurgical vessel, and providing a flow of the molten metal in the metallurgical vessel while tapping via a time-varying electromagnetic field applied to the metallurgical vessel, the flow of the molten metal being such that it constantly moves vortices in the molten metal away from a tapping hole region during the tapping to thereby prevent accumulation of the vortices for vortex formation over the tapping hole. It is also presented an arrangement for carrying out the method.
摘要:
An apparatus for electromagnetic stirring of the steel melt in an electrical arc furnace includes two electromagnetic stirrer units, a current supply, and a control unit. The two stirrers are mounted on an outer bottom surface of the electrical arc furnace at opposites sides of a central position of the bottom surface, the current supply is operatively connected to the two electromagnetic stirrer units, and the control unit is operatively connected to the current supply to control the operation of the two electromagnetic stirrer units.
摘要:
An apparatus for crystallization of silicon includes a crucible for containing silicon, a heating and heat dissipating arrangement provided for melting the silicon contained in the crucible and for subsequently solidifying the molten silicon, and an electromagnetic stirring device provided for stirring the molten silicon in the crucible during the solidification of the molten silicon. A control arrangement is provided for controlling the heating and heat dissipating arrangement to solidify the molten silicon at a specified solidification rate and for controlling the electromagnetic stirring device to stir the molten silicon in response to the specified solidification rate of the molten silicon such that the ratio of a speed of the molten silicon and the specified solidification rate is above a first threshold value.
摘要:
A continuous casting device includes a mould, a nozzle, and an electromagnetic stirrer provided around the nozzle above the mould, the stirrer including a core of a magnetic material that extends circumferentially around the nozzle and a plurality of windings wound around the core. The windings are wound around a cross section of the core as seen in the circumferential direction of the core.
摘要:
A system for in-flight control of an aerial vehicle (2) including an on-board flight control system (5), a remote control station (4) and a read-only digital representation of a subset of the airspace. The flight control system (5) and the remote control station (4) each comprises the digital representation. The digital representation comprises data for an allowed airspace (3) and at least one mission airspace (11) within the allowed airspace (3). The flight control system (5) is arranged to operate the aerial vehicle (2) within the mission airspace (11) under control of the remote control station (4).
摘要:
The present invention relates to a device for continuous or semi-continuous casting of a metal material. The device comprises a first arrangement comprising a coil (7) having an extension around the casting mould (2) in an area, which is arranged to comprise molten metal material. The coil (7) is arranged to be fed with alternating current such that a varying magnetic field generated and is applied to the molten metal material in the casting mould (2). The device also comprises a second arrangement comprising at least two magnetic poles (8), which are provided at opposite sides of the casting mould (2). The poles (8) are arranged to supply a static or periodic low-frequency magnetic field to the molten metal material in the casting area. The poles (8) comprise at least a portion (11) which comprises a plurality of material layers which are electrically insulated from each other.
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 apparatus for continuous casting of metals has members (16) adapted to generate a stationary magnetic field of a variable strength over substantially the entire horizontal cross section of the mould from one long side to the other long side close to, or below, the region for supply of molten metal at a distance below the upper surface of the molten metal. There are also members (17) adapted to generate a variable magnetic field in the area of the upper surface in a region that is centrally located with respect to said cross section and close to a region for supply of molten metal. A unit (12) is adapted to control said magnetic members (16, 17) to generate, independently of each other, magnetic fields with an appearance that is dependent on the value prevailing of one or more predetermined casting parameters.
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 device for sensing the free surface level of melt in a continuous casting mold having an electromagnetic stirrer consisting of stirrer coils and magnetic poles therefor disposed around the circumference of the mold. The device is characterized in that at least one elongated radiation source extending in the direction of casting is arranged on one side of the mold, and that a detector for the radiation with a small extension in the casting direction is arranged on substantially the diametrically opposite side of the mold but at a height different from that of the radiation source. In the radiation path from the source to the detector an oblong slot is provided for the passage of the radiation through the pole of a stirrer coil.