11 FURNACES FOR MELTING, PURIFYING, REFINING AND REPROCESSING METALS; VACUUM FURNACES; ELECTRIC ARC FURNACES; INDUCTION FURNACES; ELECTRON BEAM FURNACES; ELECTROSLAG MELTING AND REMELTING FURNACES; NUCLEAR PHYSICS AND NUCLEAR ENGINEERING UNITS; CRYSTAL GROWING AND ZONE MELTING/REFINING PLANTS; UNITS FOR DRYING, FREEZE DRYING, DEGASSING, DECANTING, IMPREGNATING, MIXING, SINTERING, HOT PRESSING, ISOTHERMALLY, FORGING, CASTING, DISTILLING, HEAT TREATING, MELTING, SPUTTERING, ATOMIZING, EVAPORATING, VAPOR-DEPOSITING OR COATING OF MATERIALS UNDER VACUUM; UNITS FOR HEAT TREATING METALS IN A VACUUM; CRYOGENIC UNITS; GAS PURIFIERS AND GAS RECOVERY UNITS