A heating coil includes a plurality of loop portions disposed coaxially along an axis, a first lead portion and a second lead portion which electrically connect to a power source, and a connection portion which connects the plurality of loop portions, the first lead portion, and the second lead portion in series.

Systems and methods of non-contact tensioning of a metal strip during metal processing include passing the metal strip adjacent a magnetic rotor. The magnetic rotor is spaced apart from the metal strip by a first distance. The systems and methods also include tensioning the metal strip through the magnetic rotor by rotating the magnetic rotor. Rotating the magnetic rotor induces a magnetic field into the metal strip such that the metal strip is tensioned in an upstream direction or a downstream direction. In other aspects, rotating the magnetic rotor induces a magnetic field into the metal strip such that a force normal to a surface of the metal strip is applied to the metal strip.

Systems and methods of non-contact tensioning of a metal strip during metal processing include passing the metal strip adjacent a magnetic rotor. The magnetic rotor is spaced apart from the metal strip by a first distance. The systems and methods also include tensioning the metal strip through the magnetic rotor by rotating the magnetic rotor. Rotating the magnetic rotor induces a magnetic field into the metal strip such that the metal strip is tensioned in an upstream direction or a downstream direction. In other aspects, rotating the magnetic rotor induces a magnetic field into the metal strip such that a force normal to a surface of the metal strip is applied to the metal strip.

A solenoidal induction coil with dynamically variable coil geometry is provided for inductively welding or heating continuous or discontinuous workpieces passing through the solenoidal induction coil in a process line. The coil geometry can change, for example, as the outer dimension of the workpiece passing through the solenoidal induction coil changes or as non-continuous workpieces pass through the solenoidal induction coil in an induction heating or welding process line.

Induction heating facilitated coating systems and processes for pipes overcome corrosion and erosion of the pipes at extreme temperatures and pressures in applications including oil and gas downhole tubulars and pipelines as well as processing facilities. Being based on vitreous fused inorganic compounds, the present invention achieves very high corrosion resistance at remarkably modest cost. Attractive economics and immunity to chlorides and moisture permeation at extreme concentrations and temperatures also make it well suited to desalination plants and potable water piping applications. Due to its extreme temperature resistance, it also is very well suited for geothermal wells. Additionally, due to its characteristic smooth durable surface, the present invention is ideally suited for applications involving the opposite of corrosion, namely scaling problems, such as fouling in sewage systems and scale buildup in heavy oil wells.

A rotating magnet heater for metal products, such as aluminum strip, can include permanent magnet rotors arranged above and below a moving metal strip to induce moving or time varying magnetic fields through the metal strip. The changing magnetic fields can create currents (e.g., eddy currents) within the metal strip, thus heating the metal strip. A magnetic rotor set can include a pair of matched magnetic rotors on opposite sides of a metal strip that rotate at the same speed. Each magnetic rotor of a set can be positioned equidistance from the metal strip to avoid pulling the metal strip away from the passline. A downstream magnetic rotor set can be used in close proximity to an upstream magnetic rotor set to offset tension induced by the upstream magnetic rotor set.

A heating coil of a heat treatment apparatus is configured to inductively heat an elongated workpiece having a recessed lateral surface. The heating coil includes a base conductor and a projected conductor. A width of the projected conductor is narrower than a width of the base conductor. The projected conductor is arranged to project toward the recess from a position of the base conductor. The base conductor and the projected conductor are arranged to extend in a longitudinal direction of the workpiece. A heat treatment apparatus includes a cooling section and the heating coil. A heat treatment method uses the heating coil described above.

Methods and apparatus for induction heating are disclosed. An example induction heating cable assembly includes: a first group of one or more cables extending substantially in parallel; a second group of one or more cables extending substantially in parallel, the first group of cables in parallel with the second group of cables; and an insulation layer configured to insulate the first group of cables and the second group of cables from electrical contact, the insulation layer configured to group the first group of cables, to group the second group of cables, and to extend between the first group and second groups of cables, in which the first group of cables, the second group of cables, and the insulation layer are conformable to enable conformance of the induction heating cable assembly to a workpiece to be heated via the induction heating cable assembly.

A post-heating treatment device performs a post-heating treatment for a welded section of a rail, after an induction heating coil is automatically disposed at a predetermined position based on the welded section. The device includes welded section detecting unit for detecting the position of a welded section on a rail, a first coil and a second coil that form an induction heating coil, first coil moving unit for moving the first coil to a position spaced apart from the rail at a predetermined distance, second coil moving unit for moving the second coil to a position separated from the rail at a predetermined distance, where the second coil is contacted to the first coil, clamping unit for pressing against the contact portion between the first coil and the second coil, and current applying unit for applying a predetermined current to the formed induction heating coil.

A first coil 110 and a second coil 120 are faced each other across a conductor plate S so that the first coil (110) and the second coil (120) become substantially the same in position in a Y-axis direction. The conductor plate S is inductively heated by applying alternating currents at a frequency at which a depth of penetration of the current becomes equal to or less than half a plate thickness of the conductor plate S to the first coil (110) and the second coil (120) in opposite directions.