BCL Ltd of Botswana is the first recipient of Tenova Pyromet’s new generation AutoFurn™ controller, proprietary automatic software providing unique features for optimizing furnace control. It was supplied and installed within three months of order placed with Tenova Pyromet, part of the Tenova Mining & Minerals Group.
The software was installed on two submerged arc furnaces at BCL’s plant in Selebi Phikwe with installation taking less than two weeks.
Tenova Pyromet was awarded the contract based on the client’s experience of a successful installation in the USA. In addition, Tenova Pyromet has a solid track record with BCL, having supplied a range of copper products and having conducted a study for the plant.
The BCL plant is old with limited field instrumentation. Challenges related to integrating the system into the existing set-up were easily overcome due to the adaptability of AutoFurn, which enables it to communicate with existing control systems. The many additional features of the new generation controller include enhanced furnace automation to provide automatic slipping, electrode baking after long slips and electrode sounding.
Tenova says the user-friendly controller can be applied to existing furnaces and those being built. By automating the process and maintaining the required furnace power and electrode resistances or currents, the controller brings consistency to the operation, allowing for rapid recovery from upsets, optimizing power input and reducing downtime. It also maximizes furnace potential by allowing it to run as close to safe limitations as possible.
One of the greatest challenges for operators of any ferroalloy furnace with Søderburg electrodes is electrode management. Tenova says AutoFurn enables operators to balance slipping rate and electrode length, while ensuring the electrode is sufficiently baked. Furnace power input is maximized by taking advantage of the fact that transformers, busbars and other electrical infrastructure are often not used to full capacity. This functionality does not run the majority of the time but gives operators the ability to increase production by briefly increasing megawatts per hour. The controller provides access to important operational information in easy to read graphical formats. The inbuilt data historian stores data at intervals as short as 1 second for the lifespan of the controller.
“Although AutoFurn has been employed successfully on furnaces for many years, our commitment to innovation means we are continually improving it to accommodate the changing requirements and challenges of ferroalloy furnace operators,” says Tenova Pyromet’s managing director Chris Oertel.