One case in point is the production of manganese-based fine chemicals. Not only does Erachem Comilog Inc. continue to produce electrolytic manganese dioxide in New Johnsonville, Tenn., but its plant there also remains the primary domestic producer of this active ingredient in alkaline batteries.

A leading reason for the company’s success has been the edge that advanced automation has given Erachem over its foreign competitors. The continuing trend in the miniaturization of electronics gives players in this industry little room for error. Even subtle variations in raw materials can disturb the electrical properties enough to cause trouble. So, suppliers such as Erachem must maintain ever-stricter control over their processes, a requirement that demands continual upgrades to automation.

Yet, generating this ever-higher quality at competitive costs requires the continuous process at New Johnsonville to run uninterrupted without unscheduled downtime. Tearing everything out and starting again from scratch is not an option. For this reason, Erachem has joined the ranks of manufacturers who are devising strategies for upgrading their installed automation over time in an orderly way.

Erachem chose a four-phase strategy that allows the automation to evolve based on technology from ABB Inc., in Wickliffe, Ohio. “Using the installed system as the foundation, evolution strategies deliver continuous improvements to automation and allow system owners to meet their business objectives in an incremental way,” says Mark Bitto, ABB’s global business development manager for control systems evolution. He believes that this strategy not only keeps the risk low, but that it also permits paying for each step from annual maintenance budgets.

By contrast, “rip-and-replace strategies involve a radical step-change and provide the user with a one-time improvement,” he continues. “These strategies require large capital-budget investments and, most likely, result in major disruptions and risk to production.” He thinks that the costs usually outweigh the benefits.

To avoid the chaos and expense associated with such shocks, systems integrator Industrial Concepts Inc., of Hartsville, S.C., helped Erachem to develop and implement the much tamer evolution strategy. The plan called for laying ABB’s 800xA extended automation control technology on top of the installed System Six distributed control system (DCS). Besides installing seven Internet protocol (IP) video cameras for remote monitoring, the first phase entailed putting a Profibus card in one of the control units, adding about 150 S800 input/output (I/O) modules, and attaching them to the Profibus card to replace the outdated distributed I/O.

Easy does it

So that Erachem could begin getting used to the new software, Industrial Concepts added the two main servers, an engineering workstation and an operator workplace in the second phase, as well as eight more video cameras. In Phase Three, the integrator added redundant servers, four more operator workplaces, a second Profibus card, and approximately 150 more S800 I/O modules. “They also put in an AC800M controller and an S800 I/O unit,” reports Randy Wimberly, Erachem’s information systems manager.

The fourth phase completed the plan. “Our evolution was executed with zero downtime, while providing us with the added functionality we need to be competitive,” says Wimberly. This includes tightening quality controls and managing costs.

Inergy Services solved a similar upgrade problem in a different way at its fractionation facility in Tupman, Calif., just outside Bakersfield. Like Erachem’s Johnsonville plant, this facility also was running up against the limitations of its old DCS. The difference was that its DCS would not support the forecasted growth of the facility, and limited the amount of information that the company could extract from the instrumentation and I/O devices. The maintenance and expansion of the DCS, moreover, was extremely expensive.

“The DCS at the time was built upon 4-to-20-milliamp (mA) transmitter signals, and I/O that was tied together with analog cards,” explains Phil Sanders, instrumentation and electronics supervisor at Inergy Services at the time of the upgrade. He is currently a senior automation engineer for Contra Costa Electric Inc. (CCE), in Bakersfield, a consultant that helped with the upgrade and continues to offer maintenance services. “We felt that we could get a lot more data from the I/O if we used communications protocols like Modbus and Hart (highway-addressable remote transducer).”

The chief challenge was linking the disparate instrumentation, I/O devices and communications platforms in the plant. To get the necessary infrastructure, Sanders and his colleagues selected a hybrid solution based upon Allen-Bradley ControlLogix programmable automation controllers (PACs) from Rockwell Automation Inc., Milwaukee. “It seemed to be the easiest and most cost-effective way to tie in multiple communications networks into our existing platform and to gather ...