VHE to Supply Stub Straightening Machine to Romanian Aluminium Smelter

　　VAE has been awarded a contract to supply a stub straightening machine to the ALRO aluminium smelter in Romania.

　　Inward bending of anode stubs, generally known as "toe-in", is a well understood occurrence in all pre-bake aluminum smelters. The difference in linear expansion of the carbon anode and the steel yoke or spider of the anode rod at high temperatures in the reduction cell means that the yoke expands more than the anode, bending the stubs which are anchored in the anode block.

　　Stubs become bent inwards just above the iron thimble, changing the geometry of the yoke, and stubs can no longer be correcly located in the anode holes during subsequent rodding. Ultimately the stubs will no longer fit into the holes.

　　The machine to be supplied to ALRO will be designed for the 2x2 130mm stub diameter techonology in use at that smelter and will be delieverd in 2012.

　　VHE of Iceland has proven solutions suitable for different reduction technologies. For smaller diameter stubs, ambient temperature straightening is an economical approach. For larger stub diameters, hot straightening is often a better solution. Stubs heated to 650°C need considerably less straightening force, and the cost of an induction pre-heating unit is to a large extent off-set by savings in the heavy duty steelwork and hydraulic systems which would otherwise be needed.

　　Velaverkstaedi Hjalta Einarssonar - VHE is a major mechanical fabricator, offering a comprehensive range of design, manufacturing and site services. VHE now provides all Stimir solutions to the primary aluminium industry, with particular focus on the Rodding Plant. All aspects of design and fabrication are undertaken at VHE's own facilities, ensuring total quality control and on-time delivery.