Deritend’s Induction Services Division based in Walsall, West Midlands has won a 2-year contract to service and repair induction melting equipment used in the furnaces at the Royal Mint’s state-of-the art production facility based at Llantrisant in South Wales. The ability to deliver on short lead times, combined with extensive experience and a technical understanding of induction furnace technology are sited as the reasons for committing to work with Deritend.
The Royal Mint uses some of the most advanced coining machinery available, with the Melting, Rolling and Blanking Unit housed in one of the most up-to-date foundries in the world. Strips of metal are continually cast from large electric furnaces, reduced to the required thickness in a tandem rolling mill and transferred to large blanking presses. The blanks are then softened and cleaned in the Annealing and Pickling Plant before the final process in the Coining Press Room. Here the blanks are fed into coining presses where the obverse and reverse designs, as well as the milling on the edge, are stamped onto the blank simultaneously.
The Royal Mint operates 24 hours a day, 7 days a week, using four large furnaces with a combined capacity of over 20,000 tonnes a year to feed the coining process that can produce over 700 coins a minute. The speed and continuous nature of the operation means that maintenance windows are time critical. Deritend Induction Services proved itself on several occasions prior to the contract signing by delivering fast turnarounds on the repair of coils for both a Wertli induction channel furnace and a Birlec induction furnace.
Mike Moore, of Deritend Induction Services comments, the induction heating method is a non-contact process where heating takes place in a single loop (or channel) that passes around the coil and at the same time through a laminated steel core. This forms an electrical circuit when as the loop is filled with molten metal. As soon as power is applied to the coil a strong electromagnetic field is created and causes current to flow through the already molten steel and further heat it. As hot metal rises and leaves the inductor it raises the temperature of the entire molten charge.
The intense nature of the foundry process will eventually wear down the laminations and the coils, which have to be repaired or replaced. The challenge then is to have the correct materials and skills present to be able to return the furnace to a fully operational state as quickly as possible.
Like any other manufacturing operation, it is important the Royal Mint keeps its plant operational. This contract enables Deritend to plan for routine servicing, put more resources into preparing for emergency repairs and ensure a high level of service 24hrs a day, helping the Royal Mint meet production targets.
An online Portal system has also been set-up by Deritend to allow both Deritend staff and Royal Mint staff to track and monitor the maintenance cycle of critical components in the furnaces such as coils. By building up a repair history, it will be easier to predict and plan further ahead for routine maintenance and should also highlight any frequent problems that can then be investigated and pro-active counter measures employed to reduce occurrences.