Stub Straightening System


ALTECH has designed and installed special Stub Straightening Systems for correcting the bending of stubs on anode rods.

Bending of the stubs in the cells due to the heating of the yoke assembly is a well-known problem in all smelters. This is called toe-in or cowboy phenomenon and causes misalignment of the stubs and anode holes. It limits the useful life of stubs and causes considerable cost, as bent stubs have to be cut off the yokes and new stubs welded on.

A rod assembly in service becomes hot in the Cell. The expansion of the horizontal section of the yoke causes the stub to bend, as the heat expansion of the carbon anode is negligible.

With ALTECH’s Stub Straightening System the bent stubs are straightened instead of replacing them. It therefore improves the useful life of the rod stubs leading to significant operational savings in the smelter. The Stub Straightening System is therefore not only economical in operation but also environmentally friendly as it uses clean electrical energy for the induction heating.
Key components
  • Hydraulic straightening press for straightening the bent stubs to a pre-set value with hydraulic cylinders
  • A lifting frame for raising the press up to the stubs with hydraulic cylinders and a flow divider
  • Hydraulic System
  • Power Inverter
  • Induction Coils in a special assembly.
  • A lifting frame for raising the coils up to the stubs with hydraulic cylinders and a flow divider
  • Cooling Water System
  • Control and Electrical System
  • Terminal boxes and position sensors


Major benefits
  • Significant operational saving in reduction of stub replacement and expensive maintenance on the stub welding machine
  • Increased service life of the stubs from 12 to 24 months.
  • Reduced need for "extra" inventory of complete rod assemblies
  • One smelter claimed that after installation of the Stub Straightening Machine they could reduce the inventory of complete rods by not replacing some 300 pcs of "worn out rods” at USD 1,200 / each or an extra saving of USD 360,000 besides the savings in reduced stub maintenance cost
  • Reduced inventory of expensive stub material
  • The stub and anode hole alignment problems are corrected ensuring uniform thickness of cast iron for rod/anode sealing.
  • Reduces the risk of “loose casts” and potroom problems
  • Environmental friendly and supports ISO 14002 standard


Payback period
  • Please contact Altech for further information. Normal paybakck period for most smelters is one to two years depending on the smelter and numbe rof rods.


 Main features
  • Fully automatic
  • Positioned off-line  or in-line in the P&F conveyor line.
  • Adjustable straightening


Various models

The Stub Straightening Machine is available for all diffrerent  yoke configurations with:

  • 1 x 2 stubs
  • 1 x 3 stubs
  • 1 x 4 stubs
  • 2 x 2 stubs
  • 2 x 3 stubs


Installations


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