Patent ID: 8156709

Claim:
A method of constructing and thereafter installing at a direct smelting plant site a smelting unit comprising a direct smelting vessel, which method comprises the steps of: prefabricating away from a predetermined location of the plant site for the direct smelting vessel, a base module, an intermediate module, and an upper module to be brought together to form the vessel, each module comprising a cylindrical vessel wall section formed of steel plate, transporting the prefabricated modules to the predetermined location and depositing sequentially the base module, the intermediate module, and the upper module on top of one another by depositing the intermediate module onto the base module and connecting the intermediate module to an upper part of the base module, and by depositing the upper module on an upper part of the intermediate module and connecting the upper module to the upper part of the intermediate module, joining the modules together by one or more continuous horizontal circumferential welds between successive cylindrical wall sections of the modules to form a unitary direct smelting vessel, prefabricating away from said predetermined location a plurality of tower modules to be brought together to form a vessel access tower that extends about the vessel at the completion of installation, transporting the prefabricated tower modules to the predetermined location, and depositing the prefabricated tower modules sequentially on top of one another and joining them together to form the tower, wherein the base and intermediate modules of the vessel and adjacent tower modules are installed prior to the installation of the upper module of the vessel.