Copper sheathed twin core mineral insulated cable - has wires reduced by drawing block before passing through mineral filling tube

摘要

A hopper containing the mineral discharges into a vertical filling tube, past which the copper strip is pulled vertically and formed by rollers into a tube. The wires are pulled through a wire drawing block above the hopper, to pass through the filling tube. There may be two sets of forming rollers, below which is an argon arc welding head. Lower down the filled and welded cable are sets of drawing rollers which reduce the overall size of the cable, followed by an annealing furnace and a quenching bath. The wires are reduced in diameter by between one and 1.5% of their initial diameter, and the drawing block determines their exact position inside the tube.