GB1463071A - Inductuion heating coils assemblies - Google Patents

Abstract

1463071 Induction furnace CHELTENHAM INDUCTION HEATING Ltd 8 March 1974 [9 March 1973] 11558/73 Heading H5H An induction heating coil 3 is wound on a rigid annular former on which flux conducting magnetic members 22 embracing the coil 3 are carried, and the assembly so formed is then brought into coaxial relationship with a reactor vessel 1, moved into a position surrounding the vessel 1 and secured thereto. The former comprises a plurality of equispaced vertical steel channels 7 secured centrally to a massive arcuate channel section beam 8 or a plurality of arcuate section beams which are joined to form a closed circle by flange plates 9 and spring loaded bolts. A pair of horizontal plates 4, 5 are secured with the aid of reinforcing gussets 6 to the top and bottom of each channel 7. A second vertical channel member 11 having a pair of threaded studs welded to its bottom end is secured to each channel member 7 by passing the studs through appropriate holes in the channel member 7 and fixing nuts thereto. A spider (not shown) temporarily holds the upper ends of the second channel members 11 in the desired radial positions. In each second channel is a transversely grooved insulating block 16 about which the coil 3 is then wound before an insulating clamping post 17 and an aluminium batten 18 are inserted in the first channel member 6 against the outer surface of the coil. After the pairs of channels 6, 11 are secured together at the tops by bolts 13 the temporary spider is removed and bolts 19 threaded in nuts welded to channels 6 are tightened to clamp the coil 3 between block 16 and post 17. If more than one layer of turns forms the coil, layers of asbestos insulate the layers. U-Shaped lamination packs 22 provided with brackets 23, 24 are then secured against one side wall of channel 7 by bolts 26 passing through radial slots 25 in brackets 23, 24 and threaded into holes in plates 4, 5. Finally thermally insulating curved panels 31 stitched to a stainless steel backing 32 are mounted on the assembly by means threaded studs 33 fixed to the mesh engaging in threaded gussets 23A, 24A of brackets 23, 24 and threaded brackets 34 are bolted to plates 4, 5. This assembly is then jacked up or drawn up around the vessel 1 and secured to a horizontal shelf 2 of the vessel 1 by suspension bolts and nuts (not shown) passing through holes 27 in plates 4. A second assembly can be suspended in a similar manner from the lower plates 5. The lamination packs 22 are now radially adjusted to leave thermally insulating air gaps between the metal wall of vessel 1. A third coil assembly 3<SP>1</SP> may be suspended from the second coil assembly and a central reinforcing disc 37 of the reactor vessel 1.