Protection device for extending electrodes of vacuum consumable electrode smelting furnace and construction method

The invention discloses a protection device for extending electrodes of a vacuum consumable electrode smelting furnace and a construction method. By means of the protection device for extending the electrodes of the vacuum consumable electrode smelting furnace, external equipment can be effectively protected in the consumable electrode extending process, and by means of the construction method, the consumable electrodes can be extended when being protected by the protection device. The protection device comprises an isolation housing, wherein the isolation housing is provided with an operationopening. The isolation housing is detachably connected to the upper end of a crucible including the electrodes needing to be extended in a housing manner. The construction method comprises the stepsthat firstly, the isolation housing is connected to a connecting flange of the crucible including the electrodes needing to be extended in the housing manner; then, the consumable electrode and an auxiliary electrode are in bu