Furnace construction for plasma arc remelting of metal

A plasma arc remelting installation for producing ingots comprising:

• a hermetically sealable chamber;
• an ingot-forming mold contained in said chamber;
• a plurality of plasma arc torch means positioned above said mold;
• an electric power supply source, said torch means connectable so as to supply plasma to melt metal;
• and means enabling a metal charge to be arranged for melting in the plasma arcs and the molten metal therefrom to be solidified in said mold to form an ingot;
• at least one of said plasma arc torch means including a plasma arc torch, a ball and socket assembly providing a sealed mounting for enabling projection of said torch from exterior to interior of said chamber so the torch nozzle is disposed within said chamber and enabling adjustment of said torch, and an adjustment control mechanism mounted on said furnace adjacent to said ball and socket assembly coacting with said torch to provide and enable infinitely variable inclination adjustment of said torch during remelting and including at least two independently operable control members to accomplish the variable inclination;
• said assembly including socket means secured to said chamber and ball means disposed for swivelling movement in said socket means;
• said torch having a cylindrical elongate body projecting through said ball means and sleeve gland means mounting said torch body within said ball means, said sleeve gland means sealing and permitting adjustable axial reciprocable movement of said torch relative to said ball means;
• said adjustment mechanism includes gimbal means operatively connected to said torch at a location exterior of said chamber;
• and said assembly includng further means enabling adjustment of said torch for movement along its axis as well as for the variable angular disposition about a selected point which is on the torch axis.

A plasma arc remelting installation for producing ingots comprising:

• a chamber;
• an ingot-forming mold contained in said chamber;
• a plurality of plasma arc torch means positioned above said mold;
• an electric power supply source, said torch means connectable so as to supply plasma to melt metal;
• and means enabling a metal charge to be arranged for melting in the plasma arcs and the molten metal therefrom to be solidified in said mold to form an ingot;
• at least one of said plasma arc torch means including a plasma arc torch, a ball and socket assembly providing a sealed mounting for enabling projection of said torch from exterior to interior of said chamber so the torch nozzle is disposed within said chamber and enabling adjustment of said torch and an adjustment control mechanism mounted on said furnace adjacent to said ball and socket assembly coacting with said torch to provide and enable infinitely variable inclination adjustment of said torch during remelting and including at least two independently operable control members to accomplish the variable inclination, said torch having a center electrode and a nozzle end structure comprising an elongate hollow body coaxially surrounding and spaced from the lower end of said electrode and a plurality of circumferentially spaced apart electrically conductive heat sink inserts mounted in the interior of said body, around and radially spaced from said electrode, each said insert having a portion radially adjacent said electrode and an end of at least one of said inserts projecting axially beyond the terminal end of said electrode.