In 2020, Fulton Hogan turned to N2P to provide new controllers for its batch mixing bitumen plant at the Parkburn Quarry in Cromwell. Servicing a large geographical area, the plant is a key part of the region’s infrastructure, making reliability and flexibility of production particularly important. Being a batch mixing rather than a continuous-run plant, they also needed a solution that would integrate easily.
The previous system was supported from offshore, leaving Fulton Hogan and customers potentially vulnerable if a fault occurred that that could not be resolved on-the-spot. Its older generation manual PLC system also required two people to manage the control panel gear, and had relatively limited ability to allow detailed changes to a mix in process.
THE SOLUTION
Fulton Hogan’s Divisional Manager – Quarries and Industries, Quinn McNab, says N2P systems are used elsewhere in New Zealand by Fulton Hogan, and it was an advantage to adopt a system with which the wider team was familiar. He said he was also encouraged by N2P’s experience with batch plants in Australia. “It wasn’t anything new to them,” Quinn says.
“They offered to do a AC303 PLC in the asphalt plant, and also a LC404 load-out PLC. I really liked the sound of this because it meant we could get far more data on the drops and tonnages.”
The new units were installed during the winter. “Although we dial things right back in winter, we still had a tight timeframe for the installation, with no wriggle room for delays,” Quinn says. “But it all went very smoothly. Peter came down here for two weeks to go through the commissioning process and sort out the usual teething issues you get with new equipment.”
THE PERFORMANCE
Quinn says the system is already proving its efficiency, greater accuracy and consistency.
“And of course, knowing we’ve got access to immediate support is invaluable. It means that if something goes wrong it’s an ‘us’ problem not a ‘you’ problem.
“The previous system was good at telling you there was an error, but not necessarily how to address it. With the N2P system, you get an alert pinpointing exactly what the issue is, and the expertise on hand to get it sorted quickly.”
Quinn says the new unit gives precise information about temperatures of the mixes and aggregate.
“That’s something I’m really excited about. It means we can perfect our recipe and build a robust quality process that starts from the quarry right through to the final asphalt product.”
The N2P system also allows the plant to capture and track additional data. “If a customer comes to us with an issue with the mix, we can now add sensors that will monitor the specific issue to confirm where the problem lies.
“At the moment we’re going through new mix designs and it’s looking like the plant is performing with great precision. We’re at a level now where we know our consistency is on target, so if there is an issue, we can rule out anything being wrong within the plant – and that’s a very good feeling.”
He says the new PLC’s precision means the plant is also reducing costly wastage. “Previously we weren’t maximising the value of aggregate because blends that weren’t quite right led to sometimes significant overflows. Our wastage has definitely dropped now that we have the ability to make detailed adjustments to a mix.”
THE RESULT
A better quality, more consistent product; access to valuable data; less wastage; help at hand when needed; and just one person managing the controls. Quinn says he would recommend N2P to others thinking about an upgrade.
“N2P are great to work with and made the process very easy. They were confident and competent with their solution and followed through on what they put forward – which was exactly what we needed.”
