EE - Forum Styles

DeltaV success on a shoe-string budget

Mike Bacidore

Volatile markets can make it difficult to plan for product lifecycles, especially when it comes to commodity resources such as potash. A rollercoaster price fluctuation can cause havoc in business plans and investment strategies.

Such was the case for potash producer Mosaic, a Fortune 500 company formed 15 years ago through a merger of IMC Global and Cargill’s crop nutrition division. It employs 15,000 people in eight countries. Despite its deep pockets and global resources, Mosaic tightened the belt of its Canadian operation in Colonsay, Saskatchewan, when the market seized and collapsed.

“Prices for potash soared in 2008 and 2009,” explained Allan Blakely, account manager at Spartan Controls, a western Canadian distributor, integrator and Emerson Impact Partner that worked with Mosaic at the height of the booming potash economy. “Expansions were greenlit, but, as they came on-line, they were hit with a plummeting market, with prices dropping from almost $900 per ton to just over $200. The appetite for capital investment was and remains very low for potash mines.”

This market fall prompted a period of capital constraints that motivated Matthew Gillespie, control systems engineer at Mosaic, to work with Blakely to devise creative strategies to improve mine operations without busting the budget. The two of them shared their story at the 2019 Emerson Global Users Exchange in Nashville, Tennessee.

The buck stops here

Mosaic was challenged with several aging and obsolete control systems, all of which are tagged with high-dollar value for replacement. Mosaic has been able to upgrade all of these projects, despite this period of capital constraints, by making smart decisions technically and financially.

Many organizations rally around chasing the buck when times are good, but, when the loonie flies south, financial decisions become more difficult. “Successful projects are built on mantras,” said Gillespie, who referenced Benjamin Franklin’s advice: “The bitterness of poor quality remains long after the sweetness of low price is forgotten.”

At Mosaic’s loadout facility in Colonsay, the control system had been installed, commissioned and forgotten in the 1990s. It included a Wonderware HMI and a complex database system for billing. The non-networked GE 90-70 PLC was programmed with LM90, which is essentially text-based ladder logic. “Downtime was caused by equipment failure and database overflow,” said Gillespie. “It’s a loadout, so it’s a high-traffic area, and there’s not a lot of time to play around with things. There was a computer in the cable space that was running a macro for the billing. The system was convoluted because it was backlogged with billing functions still running from the ’90s.”

A capital request for full replacement in 2014 was rejected because of the cost, timeline and need for management education. A similar capital request in 2015 was engineering-approved, but the project was rejected because of cost and design.

In 2016, Mosaic sat down with Spartan Controls and made a plan, which was accepted. “I designed the system for a fraction of the cost,” explained Gillespie. “Management approved it because it was so little money and not much of a risk.”

The I/O costs were out of scope. “We could wait on the I/O, which dropped the costs 75%,” said Gillespie. The Modbus TCP Virtual I/O Module (VIM) was used to interface with a GE RX3i PLC as an I/O server. Data was stored in the site historian, eliminating the need for an additional database. The I/O was not touched, but Mosaic invested heavily in the network.

“Doing nothing was not a good answer, and waiting wasn’t an option.” Mosaic’s Matthew Gillespie explained how to upgrade controls on a budget.

Thanks for letting me vent

In a second project, Mosaic and Spartan looked at the mine-ventilation system, one of the most critical pieces of equipment on-site. The mine area is surrounded by an underground lake, and a metal ring holds back 900 psi of water pressure.

The control system was installed, commissioned and forgotten in the year 2000. The facility includes a four-burner management system (BMS) with an un-networked 90-30 PLC and an un-networked HMI panel.

A 2015 capital request was accepted. The burners were modernized in 2016, but the controls were pushed due to budget. However, a control-system update was scheduled in 2018 with replacement in kind, looking at the RX3i to replace the 90-30 PLC. “But replacement-in-kind was not the right solution,” said Gillespie. “We had to find something better, but the budget was set.”

As it turned out, the right solution was to integrate with DeltaV for the same price as a PLC, explained Gillespie. A custom CHARMs cabinet was built. It utilized the existing SX controller in the mill and preserved the new workstation by using a fiberoptic keyboard, video and mouse (KVM) extender. To save money, in-house programming, also known as Gillespie, was utilized.

Ten years after

DeltaV servers were installed 10 years ago in the same rack that once housed Provox servers, explained Blakely. The protection was poor. “Brine leaked in from the roof. There was intense heat and frigid cold. But, as long as they kept running, management was OK with it,” he said.

“Five years ago, we embarked on what I like to call the ‘virtualization boxing match,’” said Blakely. “We started to investigate the age and state of the servers. Virtualization in a salty environment is a clear winner. The capital request was written but denied based on cost. We went through 10 full rounds of revisions and four years of disappointment. In 2018, we divided the project into three phases.”

Phase 1, replacing the servers, was approved and completed this month. Phase 2 includes building the thin-client network and replacing the workstations. Phase 3 will add a redundant virtual real-time operating system, VRTX, in a different geographic location.

“Spreading the project over three years doesn’t give us redundancy until the third year,” said Blakely. “We still have to be careful until this project is complete. And the project overall cost is slightly higher.”

Tuppence for control

“Doing nothing was not a good answer, and waiting wasn’t an option,” explained Gillespie, so actions were taken, and the results have been encouraging.

“The loadout has had less than one hour of downtime since commissioning,” he said. “Truck-loading efficiencies increased 180%, and billing has functioned flawlessly. Also, the process engineering group has identified several cost-saving projects.”

The mine-ventilation system was integrated into DeltaV for the same cost as a replacement-in-kind PLC system. Powerhouse operators are now able to troubleshoot the system properly, making efficiencies in natural-gas usage and carbon-monoxide production. It’s also opened up new opportunities for advanced control and integration.

The virtualization project is now in progress after five years of attempting to get funding. Mosaic will finally able to retire the old servers, not to mention benefitting from the reliability that comes with a virtualized system.

“Three projects were denied for several years until measures were taken to ensure funding,” said Gillespie. “We achieved this by splitting up projects into smaller pieces, leveraging existing infrastructure, salvaging parts, integrating our islands of control and using in-house labor for commissioning and programming.”