The Vacon Variable Speed Drive Strikes Gold!

Ralspeed are extremely proud to supply Vacon Variable Speed Drives, a market-leading company with an unmatched product range that consistently offers the most professional results. Allowing precision control of a range of motors, variable speed drives are essential components across the spectrum of industry.

Fixed-speed electrical motors are not practical for many applications. The ability to accurately control motor speeds at each processing stage is therefore essential and variable speed drives are designed to solve the problem, offering smooth operation, precision torque and acceleration/deceleration control. This method of process control allows for the easy management of system energy and stress, leading to marked savings in cost thanks to the optimised use of energy within the system.

Vacon was founded in 1993 in Finland; the company still operates from here though also has research and production facilities on every continent, with a presence in almost 90 countries. The company was born when 13 engineers collaborated to create products that would, through their sheer quality and reliability, revolutionise the market of variable speed drives. Also creating an effective distribution plan, Vacon grew to become the leading AC-drive manufacturer in the world, a position they maintain by continuing to develop and optimise their product range.

Gold is extracted from mineral ore; trace amounts of the precious metal are present in each ton of the heavy material. Ore is mined before being emptied into the ball mill which, using heavy ball-bearings, crushes it into a powder from which the trace amounts of gold dust can be more easily extracted. Weighing over fifty tonnes when fully loaded and drive by a 250 kW motor, the ball mill requires a torque force of more than 24,000 nM in order to begin functioning, pressures which resulted in the failure of its gearbox.

Bearing specialists Hayley Group were called in to investigate the breakdown of the valuable machine. The results of this investigation showed that the current gearbox attached to the ball mill was barely adequate for the purpose and, to improve reliability, a gearbox of a higher-capacity should be installed. The estimated delivery time of this larger gearbox was, however, in excess of 8 weeks, during which time the mine would be completely out of service. Understandably, Omagh Minerals were reluctant to close for such an extended period of time and, as advised by Hayley Group, decided instead to fit a smaller gearbox with a 250 kW variable speed drive system as the highest load on the gearbox only occurred upon start-up.

Ralspeed were able to provide a bespoke variable speed drive system within a single week, allowing the mine to quickly resume operations. Mark Jones, representing Hayley Group, said, "The panel, which incorporates a high-performance Vacon variable speed drive, was delivered right on schedule. Because Ralspeed had designed specifically for the application, it was quick and easy to install and commission, which meant that we were able to get it into service without delay. This has turned out to be an effective and convenient solution, not least because of the very fast delivery and excellent support provided by Ralspeed (who have) certainly hit the gold standard for Omagh Minerals!"