High bath levels can result in ring erosion of anode stubs. The same effect also occurs when anode life is extended by lowering the rod further into the pot that would normally be the case. Smelters which buy their anodes from third parties have a good economic reason to extend anode life, minimising the quantity of butt to be returned or otherwise disposed.
Placing carbon collars around each stub is an accepted method to prevent ring erosion. VHE of Iceland has considerable expertise in the manufacture of automatic collar forming systems.
The VHE collar forming machine is fully automatic. The machine has a fast throughput and may be easily accommodated in existing rodding plants. The machine is able to handle card and aluminium, loaded as a coil and automatically fed, cut to length, then formed into a collar around the rod stub and securely closed.
VHE's collar filling machine accurately measures and dispenses carbon paste into the preformed collars. The filling system ensures even distribution of the carbon paste and provides a virtually dust-free operation to produce uniformly shaped and centered carbon collars.
VHE's Collar Forming Machine and Collar Filling Machine together comprise an integrated Stub Protection System facilitating maximum anode life without unwanted anode stub erosion.
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.