Abstract: Increased heat control is obtained in the melting zone of a zone melting process utilizing an electric current passed longitudinally through the charge, to melt the charge, by constricting the melted charge in the melting zone.

Abstract: In a coke oven, a coke discharge opening communicating with the coking chamber is closed by a door which carries an angularly-shaped packing strip having an extended edge surface for engaging a door frame. The packing strip is adjustably supported by clamping plates attached to the door. The extended edge surface of the packing strip is resiliently urged at spaced locations about the periphery of the door by means of a spring-biased plunger carried by guide plates that are adjustably positioned on the door. The disclosure additionally provides stop plates at opposite sides of the door frame for engagement with adjustable bolts supported by the door for adjustably locating the door relative to the door frame.