Control upgrade boosts line output by 30%

Europe's leading manufacturer of high quality anodised aluminium coil employed Transicon to undertake a complete refit of an anodising line at its Milton Keynes plant.

Reliability, visibility and control are crucial to the running of any successful round-the-clock process operation.

Nowhere is this more true than at Europe's leading manufacturer of high quality anodised aluminium coil, Alanod, a company which can process up to 30,000 tonnes of aluminium a year.

No surprise then, that these should be some of the key criteria when the company selected Telford-based control specialist Transicon to undertake a complete refit of an existing anodising line at its Milton Keynes plant.

According to Alanod's Plant Manager Neil Arlett, the 15-year-old line was showing its age, with increasingly frequent breakdowns disrupting production.

"The original control system included some potentially obsolete equipment, which meant that it had become difficult to source components to keep the line running".

"In parallel, customer demand for our anodised aluminium was growing quickly, particularly from the lighting industry".

"Likewise, we were introducing a number of new finishes specifically targeted at the domestic appliance, computer, television, construction and automotive sectors".

"As a company we also recognised the benefits of striving for world-class manufacturing standards in order to not only maintain our position, but also to support our continued growth".

In response to these pressures, Arlett and his colleagues established a refurbishment project to ensure that the anodising line would continue to fulfil both the company's present and future demands.

Key criteria were quickly established by the team, including: process consistency and repeatability in order to maintain production quality; increased production capability; operational cost reduction; minimum line downtime both during the refurbishment exercise and in subsequent production; and close control of project costs and lead times.

"The line is at the heart of our operations", says Arlett.

"The refit was a major undertaking, whose success would depend on the development of an extremely close relationship with our selected control system integrator".

"Clearly, we needed a company which would 'go the extra mile' and be a true partner throughout the project".

Following a detailed evaluation of several suppliers, Alanod appointed Telford-based Transicon to undertake the work.

"The company had already developed a good understanding of our processes and had established a solid reputation with us on a number of earlier projects", continues Arlett.

"We were also impressed by their proposal to include a modem to allow remote monitoring and interrogation of the line, as well as their ability to support our group's decision to standardise on Siemens PLC equipment".

"Other factors that pointed us towards Transicon were that they could offer a complete solution, based on readily-available components, which would be backed by their in-house programming and installation team".

With downtime at a premium, Arlett and his colleagues believed that Transicon's ability to plan and control every aspect of the project was a further important consideration in the decision to award them the contract.

According to Transicon's Commissioning Engineer Andy Wood, planning and project management were seen to be central to meeting Alanod's expectations.

"The customer's user requirements document (URD) was just the starting point".

"With Alanod's stated success criteria, we needed to go 'back to basics' to design and build a state-of-the-art control system that would enable critical parameters such as electrical currents, temperatures, flow rates, pressures and reel tension to be monitored accurately in real time".

"We also built low maintenance and a degree of redundancy into the installation".

"For example, any one of the system's three HMIs can be used to run the line if need be".

"Likewise, if a PLC fails, it is simply a case of replacing the CPU and downloading the required program in order to have it instantly back in operation again".

To ensure that the line would be out of production for the shortest possible time, Transicon's focus was on locating and prewiring as much of the equipment as possible prior to the final installation phase.

"It resulted in us filling the largest wiring ladder we have ever used on a control system", notes Wood.

"In the end, we used more than 37km of cabling on the whole project".

"Early on, it was decided to house the Control Techniques Digital DC drives in their own air-conditioned room on a mezzanine floor located above the end of the line", he continues.

"Other features of the installation include: the use of Siemens PLCs with remote I/O and ac panels with Profibus DP communications, allowing the racks to be placed anywhere; Scada providing an overview of all equipment and drives, with instant identification and interrogation of faults; and the incorporation of remote support by modem".

"We were impressed by Transicon's attention to detail", notes Arlett.

"Such as the use of touch screens, rather than a proliferation of individual buttons that could be susceptible to early failure in our operating environment".

"Similarly, we were always fully consulted regarding any issues, and constantly updated on progress, right throughout the project".

"It all helped to build an exceptionally close working relationship, particularly during the long days and nights through the commissioning period in December last year".

Thanks to the planning and hard work by everyone concerned, the line was out of action for just a two-week period, being brought back into production with the new control system before Christmas.

Clearly, this fulfilled items 4 and 5 on Alanod's wish list.

But how has the new system shaped up against the customer's other success criteria?.

"Process consistency and repeatability have certainly improved significantly", reports Arlett.

"The encoder drives provide more accurate speed control than before and Scada gives us a complete overview of the line, every minute of the day".

"It also provides information and reporting on a much wider range of parameters, which simplifies fault identification and tracking".

"In short, we are now in full control of the process".

With a range of 20 different specifications finishes in three material thicknesses produced by the line each dependent on up to 50 process parameters Alanod can now simple select the required grade and thickness from a preconfigured library and be back in production on a new job virtually straight away, complete with updated process monitoring parameters.

In terms of production capability, the new control system has enabled Alanod's line speed to be raised from its original 18m/min to a current figure of 25m/min.

This is accompanied by improved process repeatability and stability representing a consistent increase in output of more than 30%.

According to Arlett, the control system is entirely capable of supporting his company's aim of a further doubling of line speed.

However, achievement of this goal is currently constrained by other factors, which are already being addressed.

The new control system's effect on operating costs have been equally impressive.

Not only has its high efficiency drives produced significant savings, but the Transicon installation has also been instrumental in dramatically improving the monitoring, use and control of Alanod's process water.

"Because we now have complete control of all elements of the process, we've been able to increase the effectiveness of our rinsing operations with more recycling and minimal use of fresh water", reports Arlett.

To illustrate his point, he produces figures showing the company's usage of around 1000m3 of water a day in 2004.

His latest report shows a daily average reduced to 644m3 per day, with a consumption ceiling of 850m3 during any 24-hour period.

"This consistent reduction in consumption represents a major saving to us, despite recent rises in water prices", he adds.

In conclusion, Arlett confirms that Transicon's performance "has ticked all the important boxes on the project".

"We have exceeded what we expected to achieve, particularly in terms of the time needed to get things done", he adds.

"That's as much about the setting of realistic goals as the excellent relationship we've established with Andy and his colleagues".

"I'd have no hesitation in using Transicon again on future projects or recommending their services to others".

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