New energy-saving control system gave fresh air below ground.
LKAB is a world leading producer of processed iron ore products for steelmaking. LKAB’s ventilation fans at its Kiruna mine in Sweden was controlled by a system that has been in operation for more than 20 years. ÅF was commissioned to replace the control system for the mine’s 600 fans with a new system from ABB. The new control system allowed greater control of the ventilation, which reduced energy consumption while improving the work environment.
In order to be able to work in the Kiruna mine, at different levels right down to a depth of 1 365 metres, new air needed to be continually brought down and old air removed. Nearly 2 000 cubic metres of fresh air is pumped down into the mine every second. During winter, the air that is pumped down also needs to be heated. Patching up and repairing the old system to control ventilation was not an option. Several fans also lacked any means of control, and fans that are continually operating consume large amounts of energy, even when there is no real need for air circulation.
ÅF was appointed general contractor and replaced the entire system with a new, modern and controllable system, adapted to the specific needs of the Kiruna mine. The project was implemented successfully, thanks to cross-division cooperation within ÅF and total commitment from LKAB’s project team.
With the new system in place, the operating time for each fan could be reduced by an average of eight hours in every 24-hour period. This is achieved by the ventilation being focused on the areas where it is needed most. This in turn results in a significantly lower and more efficient use of energy. The new system also allows the quality of the air to be measured to reduce the aeration time.